Table of contents

11-14 December 2019 Bangkok, Thailand

Conference Website: https://www.isegt.org

SEGT 2019 Conference

The International Conference on Sustainable Energy and Green Technology 2019 was held at Millenium Hilton Bangkok, Bangkok from 11-14 December 2019. The conference was co-organized by 6 research centres across the Asian region, i.e. Centre for Energy Sciences (UM), The Joint Graduate School of Energy and Environment (KMUTT), Centre for Vehicular Technology (UTAR), Center of Excellence on Energy Technology & Environment (KMUTT), Center of Inter-Integration (NIU), Research Center of Energy Conservation (Taipei Tech) and United Nations Environment Programme (UNEP). Besides, there were others supporting institution such as National I-Lan University, University of Malaya, UTAR, King Mongkut's University of Technology Thonburi, National Cheng Kung University, Xi'an Jiatong University, Huazhong University of Science and Technology, Beijing Institute of Technology, De La Salle University, National Dong Hwa University, The University of Hong Kong, City University of Hong Kong, Universiti Teknologi Malaysia, ASHRAE Thailand Chapter and International Association for Hydrogen Energy. SEGT 2019 Conference welcomed more than 500 participants. These participants representing institutions from 35 countries over the world such as Malaysia, Thailand, Canada, Taiwan, Singapore, Philippines, Indonesia, Hong Kong, China, India, Iran, South Africa, France, Nigeria, Vietnam, Japan, Pakistan, South Korea, New Zealand, Australia, Nepal, Norway, Myanmar, UK, Bangladesh, Czech Republic, Netherlands, Turkey, Saudi Arabia, Pakistan, Sri Lanka, Spain, Namibia, US, Mexico, etc. There are 2 Plenary Speakers (Prof. Ibrahim Dincer from University of Ontario Institute of Technology and Prof. Jiri Jaromir Klemes from Brno University of Technology), 5 Keynote Speakers (Prof. Somchai Wongwises, Prof. Wei-Hsin Chen, Prof. Jo-Shu Chang, Prof. Meng Ni, and Prof. Jamal Chaouki) and 2 Invited Speakers (Mr. Wallop Lamlertpongpana and Mr. Warot Lamlertpongpana) from ASHRAE attended the conference.

The conference topics are:

• New and Renewable Energy

• Sustainable Technologies for Energy Conversion

• Environment and Climate Change

• Energy Management, Policy, Economics and Sustainability

• Energy Sciences

• Energy Storage and Power Engineering

• Sustainable Cities, Architecture and Green Buildings

• Green Design, Products and Manufacturing Processes

• Green Materials

• Waste Management and Waste Water Treatment

• Heating, Ventilation and Air Conditioning (HVAC)

• Smart Grid / Smart City / Smart Mobility

• Bioresource and Bioenergy

Editors (SEGT 2019 IOP-EES Conference Proceedings)

Chong Wen Tong

Wang Chin-Tsan

Bernard Saw Lip Huat

XianBo Xiang

Advisory Chairs, Conference Chairs, Conference Co-Chairs, International Steering Committee, Scientific Committee, Technical Committee and all this titles atr available in this pdf.

SEGT 2019 Organizer / Supporting Organizer / Sponsors

List of Co-organizers, Technically Supported, Sponsors are available in this pdf.

The SEGT 2019 had been successfully on 11-14/DEC/2019 in Bangkok, Thailand. The Opening Ceremony Video can be found at: https://lnkd.in/fVnbBwS

List of Conference photographs are available in this pdf.

All papers published in this volume of IOP Conference Series: Earth and Environmental Science have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

In this study, an overview of combustion characteristics of an agricultural diesel engine fuelled with papaya seed oil (PSO) biodiesel and diesel is presented. A naturally aspirated four-cylinder four-stroke tractor engine was used for all experiments. Various PSO blends (5%, 10%, and 20%) were tested and compared with diesel at speeds of 1400 rpm and 2400 rpm at full load condition. The combustion characteristics such as in-cylinder pressure, heat release rate, ignition delay, mass fraction burned, ignition duration and cylinder temperature were tested. The results show that PSO blends have some excellent attributes as fuel in regard to combustion characteristics. All PSO biodiesel blends have higher in-cylinder pressure; for example, PSO20 has 2.4% more than diesel. Heat release rate values of all PSO biodiesel blends were found to be lower than diesel due to the shorter ignition delay and lower calorific values of biodiesel. PSO20 biodiesel shows faster combustion than diesel by about 11.92% at 1400 rpm and 7.93% at 2400 rpm. The maximum cylinder temperature of all PSO biodiesel blends are also higher than that of diesel, such as PSO20 at 1400 rpm by 3.17% and at 2400 rpm by 3.73%.

As well known that waste plastic could be considered a very serious environmental issue because of their disposal problems may affect human life. One of the solutions to solve the plastic waste problem is to convert the plastic waste become plastic oil. This research was aimed to study the effect of gasoline-waste plastics oil (WPO) blends on (SI) engine performance at high-speed rotation. In this experiment, the engine of Honda GP 160 H-SD was selected which has specification a single-cylinder spark ignition, power is 5.5 HP and output net 3600 rpm. The composition of gasoline-waste plastic oil blends was variated of about WPO-10, WPO-20 and WPO-30. WPO-10 means that the waste plastic oil was added in gasoline oil of about 10 % vol. The SI engine performance was elucidated such as engine power, specific fuel consumption and thermal efficiency. The experimental results show that increasing speed rotation from 1500 to 3000 rpm greatly increases engine output power and specific fuel consumption. Consequently, the thermal efficiency reduced by 21.1%. It is also found, the increasing of blending ratio to WPO-30 has dropped the SI engine power approximately by 10.3 %. As results the specific fuel consumption reduced by 17.4 % while thermal efficiency can be increased by 15.5 %.

Malaysia and Indonesia are the largest palm oil producers worldwide. In palm oil production, approximately one tonne of empty fruit bunch (EFB) will be generated as waste for every one tonne of palm oil produced. Currently, these fresh EFB are still underutilised and generally disposed under open environment. The fresh EFB are more susceptible to microbial attack under natural environment when exposed even for short period and become degraded empty fruit bunch (DEFB) which have lower quality. Consequently, disposal of DEFB becomes an enormous challenge as well as its following environmental problems including soil pollution and emission of greenhouse gases such as methane. However, DEFB remain as a promising lignocellulosic biomass feedstock with huge potential for production of high value added products entailing biofuels, bio-polymer and membrane with appropriate pretreatment. Therefore, DEFB was subjected to organosolv pretreatment in this research to recover its cellulose content. DEFB was discovered to possess higher cellulose content, lignin content and lower hemicellulose content as compared to fresh EFB. Organosolv pretreatment successfully fractionated DEFB to recover the cellulose portion by removing the lignin and hemicellulose content. Pretreatment with 50 v/v% ethylene glycol in the presence of 3 v/v% NaOH removed 75.1 wt.% lignin and 81.5 wt.% hemicellulose with 90.4 wt.% cellulose recovery. Furthermore, the cellulose purity of treated DEFB was improved drastically from 55.9% to 84.5%. For pretreatment liquor, the recoverable lignin was amounted to 74.6 % at pH 2.0. This study proved that organosolv pretreated DEFB exhibited the desirable properties for subsequent processes such as hydrolysis to synthesise the biomass waste into other high value added bio-products.

The conventional kilns were used for biochar production, but it took more than 7-9 hours for processing, and its process temperature was not uniform because some of the material could be converted into biochar and used lots of heat source input resulting in low production efficiency. Then the objective of this research was to improve the biochar production by using modified biochar kiln by reducing the temperature distribution. A 50-liter kiln with a modified core was needed in this research. This core was heating source for the pyrolysis process. The heat source came from the combustion of biomass. The core pipe was core puncture diameter for releasing product gas between a process, and it was core puncture diameter in 3 sizes (i.e., 3.18 mm, 4.76 mm and 6.35 mm). Seven kilograms of corncob rice husk and longan peel were loaded in the biochar kiln using three kilograms of fuel. The physical and chemical properties of biochar were analyzed such as water content, pH, electrical conductivity (EC) using scanning electron microscope (SEM), and Energy-dispersive X-ray spectroscopy (EDX). The element and mineral compositions were also analyzed, including C, N, O, K, and P. It was found that most of the materials were converted into biochar at uniform temperature with the modified core. The temperature inside a kiln with the heat insulation the modified core was around 400-600°C better than the common core (100-700°C) and it took only 3 hours for the process. In terms of products obtained from pyrolysis condition, the average temperature positions inside the kiln were found to be 430 ± 583 °C, 271 ± 512 °C, and 189 ± 503 °C and consisted of biochar yield were found to be 45.7, 34. 3 and 31.4 wt.% for rice husk, corncob, and longan peel, respectively. Gas yields were found to be 68.6, 68.6, and 48.6 wt.% for longan peel, corncob, and rice husk, respectively Ash yields were found to be 10.0, 5.7, and 5.7 wt.%, for longan peel, corncob, and rice husk, respectively. The biochar properties from corncob rice husk and longan peel were beneficial, resulting in being useful for the soil amendment. It had suitable properties for improving the deteriorated soil structure conditions.

In northern Thailand, there are a great amount of agricultural residues generated after the harvest, most of which are burned as a means of disposal, affecting the soil for agriculture, wild animals, as well as causing air pollution. One of the solutions that may be beneficial in terms of carbon credit is to turn these agricultural residues into biochar using slow pyrolysis. Biochar is widely accepted biologically derived matter with the ability to contain carbon, large amount of nutrients, adding biodiversity in soils. The attribute of biochar is varied depending on its production process. This research aims to study biochar production conditions and possible attributes with slow pyrolysis process under 100 ml/min nitrogen condition. Two types of agricultural residues including rice husk and corn cob were used, at the process temperature of 300-700 °C. The results indicated that when the temperature was increased, the produced biochar decreased, but different amounts of carbon, electrical conductivity, amounts of inorganic minerals (N, P, K, Mg, Ca, Fe), and alkalinity increased. This enabled the produced biochar to add more carbon to the soil when used, reduce acidity or alkalinity, as well as help the soil to contain more water and other required nutrients for plants better and become a home to microbe. More air ventilation was allowed in the soil, improving its quality.

Most of the agricultural residues have low density resulting in increasing the cost of storage and transportation. With the reduced volume by the compacting process, density and other properties are increased while the storage and transportation space and cost can be reduced. The effects of screw characteristics on the briquette qualities were measured. The process condition for producing fuel briquettes with screw extruders can be used as renewable energy in the industry. Rice husk was collected and its moisture content was reduced around 8-12%. A screw used as feeding and compacting with a length of 45 centimeters and 19 degrees of screw tip angle. The mold temperatures were around 300-400 degrees Celsius. Three lengths of the screw were tested. While the briquette properties were analyzed, such as density durability, an expansion length, heating value, and moisture content of fuel briquettes after the compression process. The experimental results showed that the suitable compression condition for agricultural materials was in the range of 45.9 cm screw length and mold temperature in the range of 330 - 360 degrees Celsius. The briquettes had a durability of 98.67%, a density of 0.846 g/cm3, expansion ratio of 1.1853 %, the heat value of 3813 cal / g, moisture content after compression of 1.9% w.b. and capacity of 112.8 kg/hr. Increasing the screw length improved the performance of compression, continuous working, and briquette fuel quality. Reducing the screw length required a higher mold temperature, leading to the failure of continuous working, defective machines due to extra burden and deteriorating quality of fuel briquettes.

Lignin is the complex organic polymers contain in lignocellulosic biomass, acting as structural support of the biomass. Its presence making the biomass recalcitrance to bioprocessing. Therefore, pretreatment is essential in removing the lignin content to enhance the sugar extraction and bioethanol production from lignocellulosic biomass. In this work, pretreatment of oil palm empty fruit bunch (OPEFB) using ultrasound-assisted deep eutectic solvents (DESs) was performed. Three types of DESs, namely choline chloride-lactic acid (ChCl-LA), choline chloride-glycerol (ChCl-G) and choline chloride-urea (ChCl-U) in delignification were studied. The pretreatment was conducted with the presence of ultrasonication. The DESs recyclability were also performed in this work. ChCl-LA exhibited the best delignification properties, in which ChCl-LA pretreated OPEFB had the lowest total lignin content of 18.8%, followed by ChCl-U (19.4%) and ChCl-G (21.2%). All the three DESs were successfully recycled with slight decrement in delignification performance after two recycles. The recyclability of the DESs would improve the economic feasibility of the pretreatment process.

In recent decades up to now, researches on alternative energies have been intensified particularly those on biomethane and biohydrogen from agriculture wastes and municipal wastes. The objective of this research was to study the biogas production from anaerobic co-digestion of Thai rice noodle wastewater with rice husk and different types of animal manure (chicken manure, cow manure, and quail manure), with and without ash supplement. There were 27 experiments conducted in batch digesters at room temperature (28-30 °C) and each experiment was triplicated. Each digester contained 10 g of animal manure, 10 g of rice husk, and 200 ml total working volumes of Thai rice noodle wastewater. Five different amounts of ashes (0, 2, 4, 6, 8 and 10 g) were supplemented. The results showed that the co-digestion of Thai rice noodle wastewater with chicken manure, rice husk, and 6 g of ash supplement gave the highest methane percentage, cumulative methane production and bio-methane potential (BMP): average value of 71.5%, 1,846 mL and 311.2 mLCH4/gVSremoved respectively. This co-digestion gave the initial pH of 7.0 and it was sustained in an optimal range (pH 6.8-7.5) until the digestion stopped (45 days). Slow release of nutrients from slowly digestible substrates helped to balance the digestion steps, sustaining pH to around 7. In contrary, other sub-optimal ratios produced the final pH was lower than its initial pH, and the AD process could fail or produced less methane. In the kinetic study, it was also found that traditional Gompertz and Monod-type models for single substrate digestion could not describe the biogas evolution curve satisfactory. Two-substrate models were used instead and able to describe the experimental data very well.

Microbial fuel cells (MFCs) are expected to be the next green energy systems, which can harvest chemical energy existing in domestic waste. In this research, a two-chambered microbial fuel cell (MFC) was developed. On the anode side, an activated carbon-based electrode with biofilms of yeast cells was used as the anode. On the cathode side, potassium ferricyanide was used as catholyte, and buckypaper (BP) was used as the cathode electrode. Many researchers made BP by the chemical vapor deposition method, which is high-cost. In this research, the vacuum filtration method was used to reduce the fabrication cost of BP. The power density of the MFCs using different cathode materials was compared: (1) 2.8 µW/cm² of carbon sheet, (2) 3.2 µW/cm² of carbon sheet-coated carbon nanotubes (CNTs) and (3) 4.3 µW/cm² of two-layer BP. Based on the experimental results, the surface area of BP might be much larger than that of the carbon sheet-coated CNTs.

Microalgae is highlighted as the most feasible bioenergy feedstock because it can produce high amounts of lipids, carbohydrates, and hydrogen, which are necessary compounds for the production of various biofuels, while only requiring minimal water and land due to high photosynthetic efficiency. However, there are technical limitations that negatively influence the mass production of biofuel from algae, making it economically infeasible on a commercial scale. One of these bottlenecks exist in its cultivation. The cultivation method and system are critical in determining the amount and quality of biofuel that may be generated from the microalgae. Additionally, the peak biomass concentration, and productivities for the different compounds and nutrients within microalgae do not occur at the same time. Hence, this work proposes a planning tool for microalgae cultivation systems that incorporates species selection, and cultivation and harvesting approach selection and scheduling, while balancing the minimization of environmental impact and maximization of profit realized. The capabilities of the proposed decision support model is demonstrated through a hypothetical case study. Scenario analyses is likewise conducted to establish an understanding of system behavior and performance over time and under various conditions. The results of the computational experiments show the tools capabilities in simultaneously considering algae growth rates and compound productivities in decision making, for instance biomass species that is able to generate the most of a certain high value fuel is prioritized in cultivation and harvesting.

Biofuels derived from microalgae is an emerging technology that can supply fuel demand and alleviate greenhouse gas emissions. However, exclusively producing biofuels from microalgae remains to be commercially unsustainable because of its high investment and operating costs. A promising opportunity to address this are algal bio-refineries. Nonetheless, there is still a need to verify the environmental sustainability of this system along its entire process chain, from raw material acquisition to end-of-life. This study utilizes a life-cycle perspective approach to assess the sustainability of the algal bio-refinery and developed environmental impact prediction model using artificial intelligence, particularly adaptive neuro fuzzy inference system. Results will indicate the environmental impacts of a bio-refinery system identifying its major hotspots on different environmental impact categories. Results show that in the investigated proposed algal bio-refinery, the transesterification process had a huge contribution on the overall environmental impact having over 51.5 % of the total weight. In addition, ANFIS results showed the correlation of input parameters with respect to the environmental impact of the system. The model also indicated that there is a perfect correlation between the two parameters. The model and its accuracy should be further validated with the use of real data.

Traditional biomass remains the primary energy source in rural Zambia – providing 98% of the energy needs. Its use is unsustainable, inefficient, and leads to harmful emissions with serious health implications, and deforestation. Modern bioenergy systems offer viable energy supply alternatives - but only if sustainably developed. Among other causes, the limited provision of modern bioenergy in rural areas is attributed to an ineffective public policy for promoting these systems in Zambia. Accordingly, this study evaluates the policy in place that seeks to promote sustainable bioenergy systems for rural areas in Zambia through the analysis of related strategies. It is observed that one of the significant weaknesses of the bioenergy policy framework is its lack of consideration of the bioenergy supply chains. These are influenced by four main elements – i.e., feedstock availability, conversion technology, intermediate energy carriers, and energy service demands - that considerably differ across rural localities within districts. Thus, the bioenergy policy-making process should be considered at such subnational levels (district). A suggestion that is well-aligned with the country's decentralized governance agenda that is being implemented. Considering that there are numerous rural communities within a district and that information regarding the different elements of the bioenergy supply chain is required for the local government policy-making process, a framework to guide the generation of such information has been proposed.

The production of wood pellets has more than doubled between 2010 and 2015 to over 30 million metric tons. It is expected to grow to even more than 50 million metric tons by 2025. Thus, increasing demand for wood pellets for its energy utilization has prompted researchers to search for non-woody feedstocks. In this context, a potentially huge underutilized biomass such as garden waste can be explored as an alternative feedstock. The key factors affecting the quality of fuel pellets were evaluated during the garden waste pelletization process. Experiments were performed using a flat die pellet mill to investigate the effect of feedstock moisture content, die size, and milling size on pellet quality. Quality parameters such as pellet moisture, pellet length, bulk density, and durability were measured as per ASABE standards. Feed moisture content had a significant effect on durability and bulk density, with high quality pellets produced at the low feed moisture content (< 20%). The quality parameters of produced pellets were evaluated as per standards. It is concluded from the investigation that pellets produced at 5-10% feed moisture content using 15 mm die and fine shredded biomass satisfies the ISO standard and other norms.

Microalgae have been long considered as a potential source of biofuel. Species such as Chlorella sorokiniana can store large amounts of carbohydrates and lipids which can be used to produce biofuels. This paper demonstrates a method for developing an artificial neural network model which can predict C. sorokiniana growth in a photobioreactor. The data used for training the model came from cultivation experiments conducted at the National Cheng Kung University in Taiwan. A feedforward backpropagation ANN model with three inputs (i.e. aeration rate, biomass concentration, and nitrate concentration) and two targets (i.e. biomass concentration and nitrate concentration after 24 hours) was used for this study. Using MATLAB, multiple configurations of this ANN model were created and tested by varying the number of neurons and hidden layers and the training algorithm. Models were initially assessed in terms of their mean square error (MSE) and training performance plots. The models were then further assessed based on their simulation capabilities. After setting the initial biomass and nitrate concentration and aeration profile, the model can already predict the daily biomass and nitrate concentration of C. sorokiniana for the whole cultivation period. The final model selected has one (1) hidden layer and four (4) hidden neurons and it was trained using the Bayesian regularization backpropagation algorithm. For the final selected model, the calculated mean absolute percentage error (MAPE) for the predicted daily biomass and nitrate concentration were all below 7.59% and 3.68% respectively. Thus, the simulation results showed that the final model can accurately predict C. sorokiniana growth at varying aeration profiles. For future studies, this model can be used to determine the aeration profile that can maximize C. sorokiniana growth in a photobioreactor while minimizing aeration costs.

Cyclo-alkanes are the major constituents of hydrocarbons in market fuels such as petrol, diesel, and aviation fuels. Diesel fuels derived from bituminous sands have up to 30 % of cyclo-alkanes. Besides that, cyclo-alkanes play a vital role in soot formation as they yield aromatic compounds through dehydrogenation. Thus, it is crucial to include cyclo-alkanes in the formulation of multi-component diesel surrogate fuel models. As a consequence, better prediction in the combustion and emission simulations can be achieved. In this study, a reduced cyclo-alkane kinetic model, namely methyl-cyclohexane (MCH) is developed for diesel engine applications. Here, the detailed MCH model with 1,540 species is served as the base model. The reduced MCH model is derived by performing mechanism reduction using five-stage reduction scheme. Accordingly, a reduced MCH model with 86 species is obtained after the reduction procedures. A 94% reduction in the mechanism size has been successfully achieved. Next, the reduced MCH model is validated against the detailed model with respect to ignition delay (ID) timings in zero-dimensional (0-D) simulations. Computed results by the reduced MCH model are in close agreement with the detailed model, with maximum deviation recorded at 33%. The reduced MCH model developed is ready to be used to represent cyclo-alkanes in multi-component diesel surrogate fuel models.

Torrefaction is a process for upgrading raw biomass into an energy-dense fuel. In this study, an energy analysis was conducted to assess the energy consumption in the production of torrefied microalgal biomass. The functional unit of one kilogram torrefied biomass and a system boundary of cradle-to-gate was used. This includes the life cycle stages of cultivation, harvesting, drying, and torrefaction. To include the varying method for the upstream processes, four different scenarios of torrefied biomass production are considered. The result of the analysis revealed that across all four scenarios, the torrefaction stage had a minimal contribution of 1-20% as compared with other life cycle stages. However, even with very optimistic assumptions among all scenarios, the result of the study shows a large energy deficit on the system due to the high energy consumption involved in the cultivation method and even in the drying process. To minimize energy consumption during the cultivation stage, solar lighting was highly recommended. The use of a solar-assisted drying was also advisable to lessen the energy consumption for the drying stage.

In most European countries the use of different biodiesel fuels has been proved to be a sustainable method to reduce the pollutant emissions of the operating Diesel engines. An in-debt analysis of combustion characteristics is necessary to give a detailed perspective on the advantages of biodiesel use in compression ignition engines. Among all the essential parameters characterizing the compression ignition engine operation, the ignition delay is the most difficult to be estimated. This parameter offers the possibility to have more control over the combustion process inside the cylinder. This gives the ability to better quantify and ultimately to decrease the pollutant emission for this type of engine. An experimental study has been conducted on a tractor Diesel engine using different biofuel mixtures with 7% and 20% volumetric fractions of fatty acid methyl esters in Diesel fuel. No modifications were made to the fuel injection system in order to have a better image of the direct impact of biodiesel fuel on performance and emissions of the engine. The obtained results showed some reductions of total unburned hydrocarbons and nitrogen oxide emissions over the entire engine speed domain for both tested biodiesel fuels. The estimation of the ignition delay was experimentally carried out and correlated with the properties of the biodiesel fuel; a proper control of the combustion process by fuel reactivity ensured thus the mitigation of carbon monoxide, carbon dioxide and smoke. The link between the experimentally determined ignition delay, mainly it's reduction, and fuel reactivity is what the present work tries to analyse. A better evaluation of the ignition delay parameter, shorter when using biodiesel mixtures, should lead to better control of combustion and further lowering the exhaust pollutant emissions, without major impact on engine performance. An in-debt analysis of the combustion process starting from the injection characteristics correlated with the fuel reactivity is necessary for shortening the ignition delay and reducing carbon dioxide emissions.

The pyrolysis process is the conversion of a biomass into biofuel but the process requires a high amount of external heat in order to increase the temperature of raw material which affects the production costs and energy efficiency. The effect of heat storage to control a temperature on the shell of pyrolysis reactor for the properties and energy recovery of pyrolysis products were considered in this study. Agricultural waste drop tube pyrolysis reactor that was designed into double layer shell wall to contain ceramic bead for heat storage. The parametric test of this study as temperature (350 °C – 550 °C), and biomass type (corncob, coffee grounds and coffee husk) were investigated. This result showed that, the heating rate of the reactor when starting to the setting temperature of the comparison testing (CT) was lower than that of the heat storage testing (HT). It indicated that the energy input for the reactor in case of HT was lower than that from CT. The yield of bio-oil and bio-char of the HT were lower than that of the CT in the same pyrolytic temperature. When increasing temperature for 350 °C to 550 °C effected to decreasing the yield of bio-char while the maximum yield of bio-oil found in the temperature of 450 °C. The heating value of pyrolysis products were increased in the higher temperature. The bio-fuel products from corncob had the higher heating value (HHV) and the energy recovery higher than that from another biomass.

There are global efforts to reduce the impacts from climate change by limiting increases in temperature to 1.5 °C until 2030, and achieve carbon neutrality by 2050. Thus, it is necessary to design new neutral processes and systems that can meet the varying and growing demands of the population in terms of energy, water and food. One of the main carbon emitters and contributors to climate change is the energy industry, which primarily uses oil and natural gas as an energy source. Fortunately, alternative resources are available such as renewable energies that assemble various environmental and economic benefits. However, more work is necessitated to efficiently utilise these resources by designing, analysing, and optimising existing and new renewable energy-based processes. Therefore, this study proposes a net negative carbon emissions energy system that utilises waste biomass as a feedstock. A biomass based integrated gasification combined cycle combined with a post combustion carbon capture unit by means of chemical absorption is designed and analysed. Two different chemical solvents are used for comparison: Monoethanolamine (MEA) and potassium carbonate. The proposed integrated system is modelled and simulated in Aspen Plus software, and is analysed thermodynamically in terms of energy and exergy efficiencies. A sensitivity analysis is also conducted to assess the effect of varying operating conditions such as flowrate, and temperature of the lean solvent, and the pressure inside the stripper. At design conditions with 80% carbon capture, the system generates 419 kW of electricity and operates at -0.32 kg/kWh of CO₂ for both the potassium carbonate and MEA systems.

The rise of global urbanisation has led to massive pressures on resources such as food, water, infrastructure, and energy demand to support growing populations. It brings adverse impacts on the liveable condition and economic growth of a country if this problem remains unsolved. Smart city is a potential solution to address the challenges of urbanisation by leveraging the technological breakthrough such as internet of things (IoT), Artificial Intelligence (AI), machine learning, big data, and cloud computing to facilitate scarce resources planning and management. With numerous connected devices and vast communication networks, it poses a challenges of security threat which cannot be addressed by the conventional cybersecurity solutions. Blockchain offers a solution in securing the huge numbers of connected devices in smart city network. The application of blockchain technology is leading in the banking and financial industry. However, the uses and implementations in smart city have emerged in recent years. The combination of blockchain technology and smart city has offered a great potential for sustainable development. Thus, it is imperative to discuss the potential of these two elements in making the city safer and sustainable. This paper explores how the blockchain technology application can help in managing smart city and achieve sustainability. The findings revealed that there are five key areas of blockchain application in smart city which are smart governance, smart mobility, smart asset, smart utility and smart logistic. A framework for smart sustainable city with blockchain technology is presented as an outcome of this study. It gives a clear overview for the policy makers and regulators of how blockchain supports within smart city framework. It facilitates the transition towards smart and sustainable cities through the use of blockchain.

The penetration of underfloor air distribution systems (UFAD) in residential and commercial air conditioning has been rather slow. The most notable applications would be on data centers, where thermal stratification requirements are more demanding. The present study supports and strengthens recent work in the design and development of UFAD systems, by augmenting literature on proper vent positioning and design. In UFAD systems where thermal stratification is more pronounced, significant energy savings may be achieved through proper positioning of supply and return vents. Using a validated numerical simulation model in ANSYS CFX, four UFAD vent layouts are investigated with regards to their implications on thermal stratification and indoor air quality. Results show that not only ventilation layout, but also vent type selection can significantly affect the performance of a UFAD system. Spreading multiple, smaller supply diffusers is preferable than having large supply diffusers on the perimeter of the rooms, both from a temperature distribution and indoor air quality perspective. Notably, air flow is significantly poor in the perimeter layout, causing warmer temperature at the center of the room.

The IC engine converts the chemical energy of the fuels into the mechanic energy with the efficiency is around 35-40% depends on the type and operation condition of the engines. It means around 60-65% of the energy is wasted mostly in the form of heat (dissipated through the cooling process and exhaust gas) and friction. A thermoelectric exhaust heat recovery system can be used to harvest the waste heat which potentially could increase the efficiency of the IC engine indirectly. In this experimental study, the heat recovery system consists of a rectangular duct in which sixteen thermoelectric modules are attached to its sides (each side consist of four thermoelectric modules). The aluminium fins are mounted at the cold sides of thermoelectric modules (at the outer sides of the rectangular duct) and cooled by air supplied by computer fan coolers. To harvest the exhaust heat of the IC engine, the heat recovery system is connected to the exhaust pipe. The effect of aluminium fin arrangements, mounted on the inner surfaces of the rectangular duct of the heat recovery device, is investigated. The arrangements include mounting of the fins at the lateral sides, top and down sides, and the whole sides of the heat recovery device. Besides, the effect of the absence of the fins at the exhaust gas passage of the heat recovery device is examined. The performance of the heat recovery system is studied when the engine operates under the no-load condition at rotational speeds of 1300, 1600, 1900 and 2200 RPM. The experimental result reveals that the voltage and current generated by the thermoelectric exhaust gas recovery system increase in line with the increase of engine speed. In addition, it is found that the highest voltage and current are generated by the whole side fin arrangement, namely 12,52V and 122 mA respectively, at an engine speed of 2200 RPM. It is observed that the finless arrangement generates the lowest voltage and current among others, namely 5.36 V and 20.43 mA.

Direct evaporative cooling systems usually involve the process of spraying water, which may form the drift of water droplets. In addition, the use of circulating water can also lead to the growth of bacteria and molding on the surface of the packing material, affecting the indoor air quality. To address these issues, this paper intends to propose an evaporative cooling method incorporated with hollow fiber membranes. The selective permeation membrane technology allows the membrane module to isolate air from water, which selectively allows only water vapor to pass through, preventing the droplets from entraining bacteria into the air. A mathematical model has been developed to theoretically investigate the heat and moisture transfer between water and air in a hollow fiber membrane-based evaporative cooling module. The governing equations for the pre-cooling IEHX were established and then solved by employing the COMSOL Multiphysics platform. This study validated the model by comparing its outlet air dry bulb temperature and relative humidity against experimental data acquired from literature sources. The numerical model showed good agreement with the experimental findings with maximum discrepancy of 7.0%. The validated model was employed to investigate the influences of the inlet air velocity, inlet air dry-bulb temperature, inlet air relative humidity and geometric parameters on the cooling effect of the evaporative cooling module. Simulation results indicated that the outlet air temperature is greatly affected by the relative humidity of the inlet air under constant inlet air temperature conditions. A higher inlet air relative humidity will result in a higher outlet air dry bulb temperature. In addition, the cooling effectiveness was reduced for a higher inlet air velocity. The design of the hollow fiber membrane-based evaporative cooling module was optimized based on the simulation study.

Tube-type compact heat exchangers are one of the most commonly used heat exchangers in the industry. Compact heat exchangers are known for their large surface area to volume ratios allowing more optimal heat transfer rate. This study examines both the coefficient and the rate of convective heat transfer on the outer surface of a tube-type compact heat exchanger. The heat exchanger was configured in the sharp turns and spiral fin which is varied in pitch. The Fin pitches were 1 cm, 2 cm, 3 cm, 5 cm, and 7 cm. The length of the heat exchanger pass was 30 cm with a turn length was 8.2 cm and the total length of the heat exchanger was 6 m. Heat exchangers were made using galvanized pipes with an inside diameter (Di) 20 mm and an outside diameter (Do) of 22 mm, fins are made using aluminium with a thickness of 0.3 mm. Water was maintained at a constant temperature of 80 °C and circulated into the heat exchanger with a flow rate of 0.4 L/s. The air was blown using a fan with varying speeds of 2.4 m/s, 2.8 m/s and 3.4 m/s (the ambient air temperature was 28 °C). The results showed that the highest convection heat transfer coefficient and heat transfer rate occurred in the heat exchanger with a fin pitch of 2 cm, because the turbulence was more optimal and fewer airflow losses. In the heat exchanger with a fin pitch of 3 cm, 5 cm and 7 cm has a large gap between the fins so that turbulence is not optimal while in the heat exchanger with a fin pitch of 1 cm the gap between the fins is too small so that it inhibits the rate of airflow.

Natural gas distributed energy systems (NGDESs) have the advantages of peak load shifting and good economic benefits suitable situations, In the paper, the energy processes of NGDESs for large-scale hospitals in Xi'an are analyzed firstly, by considering the current policy of "grid-connected with no power injection" and the characteristics of prime mover, residual heat utilization equipment and energy consumption in hospital buildings. Secondly, the hourly cooling, heating and electrical loads of a hospital complex in one year are simulated by DesignBuilder software. Based on the further analysis of hourly loads in the year and its changes on typical days, the main devices of the NGDES are chosen optimally. The number of internal combustion engines is determined after comparing their economic benefits of different number of internal combustion engines. Finally, through comparing their initial investment and annual operating cost of the NGDES with that of the separating supply system, the results show that the annual average energy utilization rate of the NGDES is 80%, and its energy saving rate is 34.4% compared with that of the separating supply system.

To enable heating, ventilation and air-conditioning systems to effectively work for the next generation-built environment by reducing unnecessary energy loads while also maintaining satisfactory thermal comfort conditions, this present work introduces a demand-driven deep learning-based framework, which can be integrated with building energy management systems and provide accurate predictions of occupancy activities. The developed framework utilises a deep learning algorithm and an artificial intelligence-powered camera. Tests are performed with new data fed into the framework which enables predictions of typical activities in buildings; walking, standing sitting and napping. Building energy simulation was used with various occupancy profile schedules: two typical static office occupancy profiles, a schedule generated via the deep learning framework and an actual prediction profile. An office space within a case study building was modelled. Initial results showed that the overall occupancy heat gains were up to 30.56% lower when the deep learning generated profile was used; as compared to the static office occupancy profile. This indicated a 0.015 kW decrease in occupancy gains, which also influenced the increase in building heating loads. Analysis indicates the occupancy detection-based framework is a potential solution for the development of effective heating, ventilation and air-conditioning systems. Additionally, the requirement for the deep learning framework to work for multiple occupancy activity detection and recognition was identified.

The present work will develop a learning-based approach for a demand-driven control system which can automatically adjust the Heating, Ventilation and Air Conditioning (HVAC) setpoints and supply conditions in terms of the actual requirements of the conditioned space. Internal heat gains from typical office equipment, such as computers, printers and kettle will be the focus of this paper. Due to its irregular use during scheduled heating or cooling service periods, an opportunity is offered to reduce unnecessary energy demands of HVAC systems related to the actual use of the equipment and its heat gains, i.e. over- and under-utilization of equipment indicate whether interior spaces are required to be conditioned or not. The work will be using deep learning enabled cameras which can locally run trained algorithms to analyse and take action based on how equipment is utilised in a space. This proposed strategy automatically responds to the equipment usage for optimising energy consumption and indoor conditions. The work will compare the performance of the developed approach with a conventional approach such as the use of static heating or cooling profiles. To highlight its capabilities, the approach is applied to detect the equipment usage in a real open plan office and the output (i.e. deep learning profile) is used as input for a building energy simulation model. The initial results showed that while maintaining thermal comfort levels, up to 19% reduction of the annual energy consumption can be achieved by employing the proposed strategy in comparison to conventionally-scheduled HVAC systems, while only focusing on three types of equipment.

Commercial software and simulation tools frequently used by researchers in predicting indoor thermal condition and energy consumption of a green building can ensure high precision, however, the computational process are usually time-consuming and cannot clearly and directly give suggestions for a 'greener' design. This paper aimed to develop a novel model based on artificial neural network (ANN) to speed up the simulation and provide optimal design solutions. Training and testing data representing design scenarios of different insulation thickness, shading coefficient, ventilation rate and their corresponding Annual Energy Demand (AED) and Uncomfortable Degree Hours (UDH) value were obtained from a numerical analysis model at first. The deduced ANN model was tested and validated, showing very high accuracy as a predictor for broad range of inputs. Relationship between design parameters and outputs were analysed and presented intuitively. The ANN results directly offered suggestions of minimizing AED and UDH, the optimum solution was to reduce ventilation and increase insulation to the limit, and reduce shading coefficient form base-case 0.5 to approximately 0.2. UDH could be lessened by 4% and AED could be reduced by nearly 29% compared to the base case design in this way.

China's energy consumption of building operation is increasing year by year. The characteristic of building envelope is an important factor affecting energy consumption, including color and material. This paper based on the analysis of the relationship between the heat balance of the enclosure structure and the solar radiation, the micro effects of different color on the daily and hourly air conditioning energy consumption of the building are studied, and the energy saving mechanism is further divided Analysis. We found that: through the simulation calculation, the cooling load accounts for a large proportion in the hypermarket, and the number of days with cooling demand accounts for 361 days., the cooling energy consumption from May to October accounts for 100% of the total energy consumption. When the color of the coating applied on the building surface is from deep to shallow, with the increase of daily cooling consumption, the larger the number of points in the energy saving of air conditioning, the more significant the energy saving effect. The change of paint color mainly affects the energy saving rate of air conditioning when there is solar radiation in the supermarket. From the micro dimension, with the increase of solar radiation, the trend of absolute energy saving and relative energy saving effect of building air conditioning cooling load is the same.

For decades, forced convection boiling heat transfer has been considered as one of the most efficient type in the heat transfer mechanism. It has been widely utilized in heat transfer equipment of various industries. Meanwhile, helically-coiled heat exchanger has been commonly utilized in numerous industrial applications. Thus, there is an interest to utilize forced convection boiling heat transfer in helically-coiled heat exchanger. Boiling phenomenon inside helically-coiled tube is more complex as compared to the straight tube due to the secondary flow induced by centrifugal force. This study investigates flow boiling heat transfer performance of water-vapor inside helically-coiled tube by using computational fluid dynamic approach. A Eulerian-Eulerian two-fluid model is used to capture interphase exchange forces and heat transfer between liquid and vapor phase. Wall boiling model is adopted to take into account the boiling condition in the vicinity of the wall. The developed model is then validated against the previously published experimental data. Good agreement for the outlet vapor quality and pressure drop between numerical study and experimental measured value is achieved. The result reveals that the boiling starts at the inner wall of the tube (φ=450°) due to the presence of secondary flow induced by coil curvature. The relationship between HTC and vapor quality along the helically-coiled tube are discussed and evaluated. This study serves as a guideline for future study on forced convection boiling heat transfer in the helically-coiled tube.

Dependency on fossil fuel and associated carbon footprints have increased the urge to look for methods to increase the thermal efficiency of heating and cooling systems. Exhaust air heat recovery system is one of the promising solutions with viable potential in industrial applications such as mine ventilation and so on. Direct contact heat exchangers can be feasibly used in these applications due to their characteristic advantages such as the ability to exchange at low temperature differences. Given the numerous advantages of such systems, there is a need for thorough understanding of the complex fluid flow and heat transfer performance of these heat exchangers. While water spray is commonly used for capturing the heat from exhaust air in direct heat exchange systems, performance of such system is highly dependent on the various operating parameters such as droplet size distribution, continuous phase temperature, velocity and relative humidity, spray nozzle angle and discrete phase temperature and velocity which is required to be studied in greater depth. Computational Fluid Dynamics can play a key role to investigate the performance of these two-phase flow systems. In this paper, a three-dimensional two-phase model has been presented to study heat recovery from exhaust air by using direct spray water heat recovery systems. Also, an analytical model has been developed using a self-written MATLAB code and compared to the numerical one. The results of the study show that the analytical model can capture the CFD runs outcomes with a high degree of accuracy. Also, the conducted parametric study confirms the dominant impacts of droplet size distribution and air flow rate on the performance of the system.

The human living standard has been increasing day-by-day. Not only the building energy performance has to meet a high expectation, but the noise quality of a building has to be par with it. Sound absorption is one of the key elements in determining the quality of the acoustics performance in a room. A room with high background noise and high reverberant time will affect the comfort level of the occupants in the room. Hence, a well-designed room with acoustics treatment is required. The sound absorptive materials play an important role in reducing the overall sound pressure level in the room. Conventionally sound absorber materials are porous and resonator. With the advancement of the addictive technology, the sound insulation materials can be further improved and optimized with 3D printed structured materials. Two 3D printed structured designs have been developed in this study and were printed out by using fused deposited modelling in 3D printing technology. The two designs are micro perforated design (MPP) and porous design. The structured materials have been tested for its sound absorption ability using the sound impedance tube. The frequency range tested is between 100 Hz to 6400 Hz. In conclusion, micro perforated design (MPP) model has a very good sound absorptive behavior at the low frequency at 4000Hz and below, whereas the porous model is effective at high frequency at the 2500Hz and above. Through the study, the perforation ratio is found to be closely related to the peak sound absorption coefficient frequency. The peak frequency is reduced with the increase of the perforation ratio. The gap between the 3D printed structured materials and end wall also play the important role. The larger the gap, the lower the peak absorptive frequency.

This paper presents the design concept, and monitoring results of the Resilient Nest which was participated in the Solar Decathlon Europe 2019 competition. The Resilient Nest has been designed as a lightweight rooftop house which can be placed on top of a row house in Bangkok, Thailand to respond an increased urban density. This additional rooftop house does not only increase the living space on an existing building, but it also ensures that the existing building become more viable, comfortable and eco-friendly. A solar energy, both electrical energy from photovoltaic panel and thermal energy from solar collector which are renewable energy, can accommodate the Resilient Nest rooftop as well as the existing building. The monitored results during 10 days competition results showed that the energy balance of the Resilient Nest was net positive of 171.81 kWh which was the highest value compared to other 9 competitors. The Resilient Nest generated 277.78 kWh as the first runner-up for the Energy generation. The power consumption for the HVAC system of the Resilient Nest during 10 days was only 37.65 kWh. Comparing to the suitable air conditioned house recommended by the Government Public Relations Department of Thailand, the Resilient Nest consumed over 14 times less energy because of its high performance thermal insulation, heat recovery system and solar thermal system. The low HVAC power consumption gave high performance for indoor comfort. As a result, the Resilient Nest won a second place in Comfort conditions contest.

This study performs the comparative assessment of the initial embodied energy and life-cycle greenhouse gas (GHG) emission between Thailand's conventional reinforced concrete (RC) house and the Resilient Nest house which was designed and constructed for the Solar Decathlon Europe 2019 competition. The Resilient Nest is a prototype for the sustainable house and an alternative building in perspectives of renewable-energy, green building, energy efficient, and net-zero waste house. This house was designed and constructed by KMUTT team with an integration design of cosy house and the green economic system concept which have become a major concern nowadays for mitigating the environmental impacts due to an urban development. The environmental sustainability performance was investigated. All the materials used for convectional and the Resilient Nest houses as well as the energy used for the construction, were evaluated to illustrate the embodied energy (MJ) and GHG emission (kgCO₂eq). As per square meter of the usable space of the house, the results show that the Resilient Nest house has embodied energy of 2,302.2 MJ/m² and life-cycle greenhouse gas is about 122.22 kgCO₂eq. Whereas, the conventional house is illustrated the consequences of embodied energy of 1,400 to 3,580 MJ/m² and 300 – 4,625 kgCO₂eq per square meter. The Resilient Nest house clearly proofs the minimizing environmental impact than the conventional house. The designation of materials was considered as an important parameter. In addition, as the whole life-cycle, the higher impact from the initial phase would be minimized and compensated during the service phase. To enhance the ultimate goal of the Resilient Nest house, recommendations for further improvement of the prototype house have been discussed.

Autoclaved aerated concrete (AAC) has become more attractive in construction due to its excellent environmentally friendly in building construction. Due to its increasing applications, the AAC wastes become abundance in construction site. Apparently, recycling the concrete waste powder to a wall concrete, particularly an autoclaved aerated concrete (AAC) was not frequently practiced in construction and moreover no study has been carried out yet. AAC is relatively lightweight, having lower thermal conductivity, higher heat resistance, lower shrinkage, and faster in construction process compared to normal concrete. AAC concrete is a combination of silica sand, cement, lime, water and an expansion agent. To improve its physical and mechanical properties and to reduce its production cost, tremendous innovation which used waste materials as partial replacement of AAC materials have been done. From these innovations, the use of recycled AAC as a partial replacement for wall concrete has not been carried out yet. This paper is intended to classify the literatures on the innovations that have been done on replacement in AAC materials to enhance its physical and mechanical properties and thermal performance. The physical properties in terms of its microstructure and the mechanical properties such as density, compressive strength, water absorption are presented to classify the investigation that has been done in such innovations. Apart of that, the discussion on innovations to improve its thermal performance also presented. To conclude, up to now, there is no attempt on using the recycled AAC waste powder as a partial replacement in AAC as a wall concrete is reported.

Recently, fly ash from the coal combustion process in power generation has been used in the cement industry as an additive to cement or as partial replacing binder in cement-based structural mortars. The use of fly ash can reduce costs in cement production, including a reduction in the environmental impact. Co-firing biomass with coal is one of the existing technologies for utilizing biomass energy in the power generation system. However, this technology also influences the quantity and quality of the ash produced. The present work, therefore, aims to investigate the pozzolanic properties of ashes obtained from the co-firing ofcoal with corncob. Pozzolanic and physical properties of such ashes were investigated by varying the percentages of corncob at 20, 30 and 40 during combustion. The Pozzolanic compounds (SiO₂+ Al₂O₃+ Fe₂O₃) according to ASTM C618 were determined by using X-ray fluorescence spectroscopy (XRF). Scanning electron microscopy (SEM) was used to investigate the structure of ash samples. The results show that content of pozzolanic compounds in ashes produced from cofiring corncob with coal decreased when increasing ratio of corncob and became stable when ratio of corncob was higher than 30%. It is observed that the morphology of such ashes illustrated in the form of small spherically shaped particles which can improve rheological behavior, viscosity and flow performance. Considering the requirements for pozzolanic-cementitious material, it is found that the ashes produced in this study has lower content of pozzoolanic compounds than the standard specification for pozzolan class C.

Heating Ventilation and Air Conditioning (HVAC), including, Mechanical ventilation (MV) in the building sector accounts for around 40% of electricity consumption and a large percentage of Greenhouse Gas (GHG) emissions. Natural ventilation (NV), as an alternative method, assist in decreasing energy consumption as well as harmful emissions. Balconies, a common architectural element in high rise residential buildings, could enhance NV and reduce reliance on mechanical ventilation in cooling dominant climates. Indoor air velocity and distribution, IAV and IAD, due to NV is less predictable than MV, and the impacts of balcony geometry on IAV and IAD profile have not yet been classified. This study, focusing on single-sided ventilation apartments, seeks to determine to what extent balcony depth and door opening area impacts on the indoor environment of the attached living area. For this, 3D – steady-state Computational Fluid Dynamics (CFD) simulations were conducted using ANSYS Fluent. The simulation results were validated against measured data in a full-scale experimental study in a residential building in subtropical Brisbane, Australia. Five different openings and nine depth scenarios were modelled, with results showing variances in indoor mean air velocity and temperature. The outcomes reveal the impacts of opening and depth scales on IAD profile, as well as IAV and temperature magnitude at the attached indoor area. Although the defined scenarios could not reach a firm conclusion, the findings of simulation reject the shallowest balcony scenario (depth less than 2 m) due to weak IAD. Besides, the results show that a small opening could lead to an acceptable IAV at the attached indoor area. Results also suggest that further research on the indoor distribution of temperature and air velocity, consequently neutrality based on thermal comfort model, may provide further clarity on the effect of geometric factors on occupant comfort through NV.

Road renewable energy system has raised much attention from both industrial and academic research on how abundant solar radiation absorbed by road surfaces can be collected while reducing the impact of high surface temperature towards urban environment. Cities consume about 3% of total global land mass with road and parking lots consuming around 35 to 50% of land use footprint. These urban road networks permit the dynamic movement of human activities and physical development of the cities. Remarkably, researches have given much spaces to explore on how roads can contribute to make cities more sustainable. Therefore, ideas on road renewable energy system have surfaced to its audiences. The heat island effect has been reported to raise temperature up to 12°C in urban areas which affects building cooling energy load and simultaneously the people comfort. High discomfort can lead to high energy and cost utilisation, which further worsens the issue. This study assessed the beneficial impacts of urban road pavement solar collector towards reducing outdoor temperature by carrying out de-coupled numerical modelling of an urban canyon model integrated with the pavement solar collector in ANSYS FLUENT, validated with experimental data. Numerical results showed up to 4.67 °C air temperature reduction and up to 27.0 % surface temperature reduction after the U-RPSC application. When applying to street canyon with different heights, the concern was highlighted on the system performance in reducing potential UHI effect in deeper canyon during less windy condition and during the night-time. The study also presents the experimental work on the performance of a laboratory-scale U-RPSC system.

The Association of Southeast Asian Nations (ASEAN) is a developing region that is poised to be one of the key contributors to rising CO₂ emissions in the future. In particular, the electricity sector's emissions have risen by 2.4 times since 2000 and may increase by another 2.6 times by 2040, motivated by the burgeoning regional energy demand. If realised, this growth in CO₂ emissions could stall global climate mitigation and sustainability efforts. The electricity sector, however, has a large potential for decarbonization. To reveal the driving factors of historical trends, spatial-temporal index decomposition analyses (ST-IDA) based on the logarithmic mean Divisia index (LMDI) is applied to analyse ASEAN's aggregate carbon intensity (ACI) of electricity from 2000 to 2015. The technique combines temporal and spatial data to reveal the factors influencing regional trends and allow for comparisons across countries. The results show that in the face of rapidly rising electricity demands, many ASEAN countries have failed to maintain consistent improvements in the ACI through the adoption of renewable energy or improvement in generation mix. While some countries have switched to cleaner forms of generation such as natural gas, varying energy resource endowments, national circumstances and energy demand trends are challenges to the adoption of renewable energy. Pressures from energy demand and technological challenges also prevent some countries from sustaining overall improvements in generation efficiencies of fossil fuel plants. Improving energy planning, demand management and greater regional cooperation are key to the decarbonisation of the electricity system.

Electric power interruption is becoming a day to day phenomenon in our distribution system. For distribution system to be effective there should be less outage in the system and if fault occur these faults should be cleared as soon as possible. Sustained power interruption occurs several times a day from few minutes to hours. Interruptions may be due to failure of substation equipment or failure of distribution network elements. This paper attempts to identify different causes of interruption and problems that customers in Nepal have been facing due to frequent planned and unplanned sustained interruptions by evaluating various reliability indices and parameters of Lainchaur distribution substation and its associated feeders operated under Nepal Electricity Authority. First, reliability analysis of substation configuration only is done followed by analysis of reliability improvement measures like use of double bus bar, parallel distribution feeders and underground cables in DIgSILENT PowerFactory only considering sustained failures of equipment and feeders. Calculated reliability indices like System Average interruption Duration Index (SAIDI), System Average Interruption Frequency Index (SAIFI), Energy Not Served (ENS) are compared for different cases so that it will be easy to make choice between options to the utility to upgrade/improve the system. Considering all feeders, result shows that main cause of interruption in the distribution system is failure of distribution lines showing 104 interruptions for total duration of 107 hours per annum in the system, followed by failure of distribution transformers indicating 19 interruptions for total duration of 47 hours per annum. Simulation result in DIgSILENT shows yearly total ENS of distribution system is high due to present configuration, and can be reduced by the use of parallel feeders and underground cables respectively. It is seen that ENS due to failure of substation components only is very low and huge revenues can be saved if auto-reclosures are used or a provision of charging feeders as soon as possible is made.

The price allocation of transmission line usage for an open access system considering Integrated Nepal Power System (INPS) has been discussed in this paper using the MVA (mega volt ampere) - KM (kilometer) and MVA cost method. The price allocation has been compared for INPS (Integrated Nepal Power System) and IEEE 14 bus system. The transmission line costs in IEEE 14 bus system is based on average construction and operation cost whereas, the costs in the INPS is an actual cost of the present transmission system. The price has been first calculated for different bus with reference to slack bus and for different bilateral and multilateral transactions, using MW KM - MW cost and MVA KM - MVA cost methods. The active and apparent powers for the base case and transaction cases have been calculated using Newton Raphson Method. The prices from MVA KM - MVA cost method are higher than MW KM - MW cost method for both bilateral transaction and multi-lateral transaction indicating more reactive power support in addition to the real power loading due to transactions in the system. The result shows that MVA KM - MVA cost method requires incentives for reactive power support to the system such as INPS.

Biomass has had an essential role in the energy sector of the world due to applications in bioenergy. Stand level biomass is frequently calculated from allometric models with field measurements, which is usually time-consuming and costly. They are limited because of the consideration of spatial pattern analysis of above-ground biomass (AGB) across the landscape. Therefore, the development of reliability and low-cost methods is necessary for AGB estimations in landscape level. This study aims to develop a model for estimating AGB for Eucalyptus plantation located in the Sahacogen Green Co., Ltd., in Lampang province, Thailand using remotely sensed data. The AGB value was coupled which calculated from field measurement (tree height, H and diameter at breast height, DBH) using the allometric equation with various vegetation indices. The 55 sample plots and 5 vegetation indices derived from Thailand Earth Observation System (THEOS) were used to develop a model for estimating AGB of Eucalyptus plantation. After discussing the results of the investigation, the Transformed Normalized Difference Vegetation Index (TNDVI) showed a robust correlation with AGB compared to other indices (r = 0.833). Based on stepwise linear regression between AGB and 5 vegetation indices demonstrated TNDVI was only selected while the other indices were eliminated because their relationship was not significant. The developed model R² was 0.693, adjusted R² was 0.684 and SEE was 12.41 Mg ha⁻¹. The relationship between observed AGB and predicted AGB from the THEOS model of Eucalyptus plantation with R² of 0.742 and RMSE of 9.63 Mg ha⁻¹ indicated that remotely sensed data from THEOS can be useful for AGB estimation with high accuracy.

The objectives of this study are (i) to design and fabricate the internet-based real-time fuel consumption reporting system and (ii) to evaluate reliability of the reporting system. Real-time fuel consumption rate of the testing vehicle which was measured from fuel injector control signal by the real-time fuel consumption meter proposed in the previously research was used to be the data for reporting by the internet-based real-time fuel consumption reporting system fabricated in this study. A universal asynchronous receiver transmitter (UART) protocol which is a computer hardware device for synchronous serial communication was used to communicate and transmit data between devices and operation of the system was controlled by the Arduino Mega 2560 microcontroller. Then, the Quectel BC95-B8 module was used to transmit data for recording on virtual database through narrow band internet of thing (NB-IoT) technology which operates in the 900-MHz frequency band. The results could be concluded that (i) the average fuel consumption rate shown on the ThingsBoard application was less than the calculated fuel consumption for about 11.6% due to number and duration of disconnection of the NB-IoT module. (ii) When data is remotely observed via internet connection, it was found that the data displayed in the database has a lag time for less than 9 seconds due to latency of data transmission system. From these points, the system proposed in this study was acceptably to be installed onto truck fleet in private or small-scale carriers for real-time monitoring and internal data collecting applications. However, reliability in data communication and additional feature to reduce data losing were strongly recommended to be applied on the system before it could be extended to be used in larger scale carriers.

Computer simulations of a wide range of applications like materials processing, thermal energy storage and conversion systems, nuclear reactors, solar energy, and pollution control, etc. are of high importance in this era. In many of these applications, strong thermofluidic interactions between fluid and structures exist. Efficient and accurate numerical modelling of these interactions provide initial predictions of the process, but at times, it becomes challenging where complex shape of the structures is involved. To address this issue, often numerical methods that are proposed suffer lower computational accuracy and complex algorithms to capture interfacial predictions. In this paper, development, accuracy study and robustness of an in-house openMP parallelized Immersed Boundary-Thermal Lattice-Boltzmann (IB-TLB) solver are presented, which is capable of simulating complex boundary problems involving thermal interactions and accurately capture interfacial predictions. The solver showed excellent agreement with literature for a natural convection problem involving eccentrically placed stationary heated cylinder inside a cold square enclosure and forced convection around an iso-thermal circular cylinder. The numerical simulation of moving bodies is already quite a complex problem and the complexity increases further when we introduce heat transfer phenomena in it. Spatial order of accuracy test revealed, the IB-TLB algorithm exhibits first-order accuracy for velocity and temperature errors while pressure error retained second-order accuracy for moving boundary problems. It is also observed that the present algorithm can accurately predict local parameters like coefficient of pressure and Nusselt number with good accuracy and thus possesses promising potential to simulate complex moving boundary problems. The present solver will find its application in a wide range of areas such as heat exchangers, solar energy systems and chemical and food industries etc.

Hybrid Power System (HPS) is an energy system with combination of different regenerative energy sources like Solar, Wind, Geo-Thermal, Biomass and several others to achieve energy sustainability. This paper investigates the feasibility of grid connected and stand-alone hybrid energy system to meet electric load requirement of a community or organization, by utilizing the available resources. Potentiality of different energy sources like solar, wind, bio-gas, etc. along with currently used energy sources is studied thoroughly by taking a case study of Kathmandu University central campus, located at Dhulikhel, Nepal. Technical and economic analysis of on-grid and off-grid hybrid system is performed to get optimum model that supply continuous energy to the end user. Furthermore, the possibility of net metering with national utility has been analysed. The main objective of this study is to identify the suitable energy mixed model, that provide the sustainable energy supply to the university, and recommend the possible energy generators to be added for fulfilling the continuously increasing load demand. The load profile of several years of the University is taken into consideration for forecasting the power demand. The findings of the research show that system when adopted to hybrid system can meet up to 55% of the load by renewable resources. Maximum renewable fraction is found to be 0.603 and maximum renewable penetration of 812%.

In international management, ISO 50001 has been widely applied in organisations across the world, including Thailand. The main objective of this standard is to continuously and sustainably improve the energy performance of the organisation in order to reduce energy consumption and costs, including alleviating environmental climate change impacts. This standard stipulates the measurement of energy performance improvement using energy performance indicators (EnPIs) and the energy baseline (EnB). This study proposes a simplified model of energy performance indicators ( EnPIs), effective for ISO 50001 energy management at organisational level. Appropriate internal benchmarking is proposed for measuring three levels of energy performance, namely organisational, process, and main machine, through energy consumption, intensity, and efficiency. Multiple linear regression was selected to develop energy equations to express the relationship between energy consumption and significantly related variables such as service usage, operating hour, and CDD for business buildings, etc. The proposed EnPIs are applied to measure the energy performance of the case study of business buildings in Thailand complying with ISO 50001. This method can be effectively used to measure changes in the energy performance of the organisation as well as the processes and considered as a comparative alternative to public benchmarking, such as kWh/m². The findings of this study are considered to be beneficial for every organisation adopting the ISO 50001 system. This proposed method can be effectively used to monitor and measure the organisation's energy performance towards sustainable energy management. However, it still has certain limitations. In the case of energy consumption models that are related to non-linear related variables, it is necessary to conduct further studies to determine more appropriate EnPIs.

The transformer is a vital component of the power system. Continuous stress on the transformer due to overload, transient and faults will lead to physical damages. The isolation of the transformer causes significant revenue loss and inconvenience to the consumers at the distribution level. This invites the need to achieve a reliable power supply to the consumers and to perform maintenance activity appropriately. Optimized and predictive maintenance strategies are evolved to improve power availability for consumers. The model considers dispersive generation at the customer end, namely solar photovoltaics standalone system, diesel generation, and vehicle to load capabilities. Incipient or critical status of transformers' functional parameters are observed through the transformer terminal unit and sent to the internet of things platform. The remote processing unit acquires the information from all the distribution transformer and generates the optimized and reliability-centered maintenance schedule. In the proposed work, new reliability indices concerning the consumer dispersive generation are defined. The maximization of the reliability problem is solved using the coconut tree optimization technique. The highest reliability of power supply to the consumer and maintenance schedule are obtained. Economic facet of the estimated maintenance schedule exhibit benefit for both utility and consumer as it encapsulate time of use tariff. The heuristic dataset is used to synthesize the trained model by the machine learning algorithm and future maintenance schedule is predicted. The comparative study is made for the outcome of time-based optimized and predicted maintenance schedules against reliability.

Over last couple of decades, supercritical fluid has found enhanced applications in numerous commercial sectors, encompassing aerospace, chemical, fast reactors, fusion rectors and renewable energy. Supercritical fluid is of major interest to the thermal engineers, primarily owing to its superior heat transport characteristics around the pseudocritical temperature. Supercritical carbon dioxide has particularly been identified as the next-generation coolant in power industry, due to its low critical temperature and reasonable critical pressure. The heating, ventilation and air-conditioning sector has also seen increasing popularity of supercritical CO₂ with the phasing out of the conventional halocarbons, as it has zero ozone depletion potential and substantially smaller global warming potential. While decent volume of literature is available regarding the application of supercritical CO₂ in macrochannel, thermalhydraulics of supercritical CO₂ in minichannel lacks comprehensive investigation, and the present work attempts to fill that specific void through a computational appraisal of a heated horizontal minichannel of 2 mm inner diameter. Systematic simulations have been performed to explore the role of the wall heat flux ranging from 30–50 kW/m², operating pressure ranging from 8–9 MPa, inlet temperature ranging from 295–315 K and buoyancy parameter on the thermalhydraulic characteristics of supercritical CO₂. The Reynolds number in the present simulation ranges from 10000-17000. This article is aimed to explore the phenomena of heat transfer deterioration in horizontal minichannel subjected to uniform wall heat flux. It is observed that increase in wall heat flux leads to lower area-averaged heat transfer coefficient The results show an early heat transfer deterioration on top half surface whereas, normal heat transfer is observed on bottom half surface. Heat flux has significant effect on heat transfer deterioration and higher heat flux leads to reduction in peak value of heat transfer coefficient. At higher inlet temperature heat transfer coefficient decreases and peak of heat transfer coefficient shifted in the upstream direction. Also, peak of heat transfer coefficient vanishes for inlet temperature higher than pseudocritical temperature due to non-significant variation in thermophysical properties at higher temperature. Stratification of temperature, velocity and density is observed along the channel due to local buoyancy produced by non-linear thermophysical property variation of supercritical CO₂.

Sufficient quantity of raw materials is a critical factor for wood pellet production. The recommendations from past research on biomass have indicated that the cultivation of fast growing trees should be encouraged in wasteland. Leucaena and Acacia are the popular fast growing trees in Thailand because they are resistant to drought and can grow in low quality soil. Wood from them has a high heating value and entrepreneurs invite farmers to grow these varieties on contract farming for renewable energy. The purpose of this study is to assess the environmental and socio-economic of wood pellet production from Leucaena and Acacia. The environmental impacts were evaluated by cradle to gate life cycle assessment, covering fast growing tree cultivation (sprout preparation, plantation, cutting), transportation and wood pellet production. The ReCiPe2016 Midpoint method (version 1.02) was used to evaluate the environmental impacts of one tonne wood pellet production from Leucaena and Acacia. The indicators of socio-economic considered in this study were the profit from cultivation, economic assessment of wood pellet production (net present value, internal rate of return, payback period, discount payback period and benefit cost ratio) and opportunity of employment. The environmental results showed a better performance of wood pellets made from Leucaena are better than Acacia. The production capacity of 110 tonnes per day of wood pellet factory would return a profit when the price of raw material is less than 1,300 THB per tonne. Finally, Leucaena and Acacia cultivation increase the opportunity of employment at 0.16 and 0.10 person-year per ha, respectively. The wood pellet production increases the opportunity of employment at 0.0019 person-year per tonne. Considering the results of the environmental and socio-economic assessment, Leucaena is seen to be better than Acacia and should be supported as an alternative raw material for wood pellet production.

Wastewater treatment facilities are known to process water by removing nutrients before being discharged into different water bodies or reused. Traditional treatment of wastewater, however, leads to the emission of greenhouse gases contributing to climate change and air pollution. Thus, there is a need to identify the optimal configuration of treatment processes wastewater, coming from different sources, have to go through to satisfy the output quality requirements of various disposal or reuse options, while minimizing costs and negative impact to the environment In addition, microalgae cultivation is a treatment alternative for wastewater since it can remove metals, nutrients, and contaminants from wastewater, with the added benefit of carbon sequestration. The cultivated algae can then be converted to renewable energy. Despite the potential benefits that can be gained from integrating wastewater treatment facilities with microalgal biofuel production, no optimization study has considered this opportunity. Considering different wastewater inputs, the joint system would select the best treatment process for nutrient removal and cultivating algae, weighing the trade-offs in cultivating algae on different water mediums, the appropriate harvesting technique, and whether the water by-product should be sent back to the treatment facility for further processing, disposal, or reuse. The energy produced from the plant may either be sold or used to operate the two facilities. In this work, a novel multi-objective optimization model is developed to design economically and environmentally efficient integration of wastewater treatment facilities and microalgal biofuel production plants through water exchanges. A case study is solved to demonstrate the model's decision on three different scenarios. In the objective of minimizing the costs, the model utilized the production of biofuels since it was subtracted from the expenses. As for minimizing carbon emissions, the model decided to operate the wastewater treatment plant since there were less processes used in the model. When goal programming was used in order to satisfy both objectives, the model found a balance between the two plants which in return chose the have some exchanges present.

Production of biodiesel from renewable resources like microalgae biomass presents a potential for reduction of greenhouse gas emissions and fossil fuel energy consumption. The integration of processes from other industries have been implemented in microalgal biorefineries to increase economic sustainability by co-producing several high-value algal-based products. Agro-industrial processes have the potential to be incorporated into the biorefinery because it requires input material flows from other biorefinery process units to cultivate and sell crops for an additional source of revenue and increased carbon sequestration, while generating wastewater that may be used as a cultivation medium for algae or as a resource for other biorefinery processes. Circular bioeconomy, an extension of the circular economy ideology, has the goal of achieving economic and environmental sustainability through maximizing the dedicated recirculation of resource flows, and minimizing waste generation and end-of-life disposal. However, existing modelling studies have not explored this opportunity; previous studies have not considered that resource functionality runs out with repeated recirculation and reuse as it reaches its end of life. In this work, a novel multi-objective optimization model is developed to design and manage closed-loop algal biorefineries integrating agro-industrial processes that captures the effect of recirculation on resource material viability and end-of-life environmental impact. A case study is solved as proof of concept and to illustrate the design methodology, optimal solutions based on economic and environmental performance are analyzed. The results of the case study validate the initial hypothesis that there is a conflict between the economic and environmental objectives since the decision for biofuel production varied for each single objective. With the multi objective model, a balance between the two objectives was found. The results of the optimization model can be applied in the design of an algal biorefinery along with the decisions relating to production quantities incorporating a zero waste outlook.

Copper products are being utilized in many utilities such as electrical equipment, mechanical, architecture, and military industries. Basically the copper processing begins with the mining of copper ore which causes the environmental and social problems unless proper management systems are being exercised. This study focus on the effects of Acid Mine Drainage (AMD) of Kyisintaung mine, located near the confluence of the Yama Creek and the Chindwin River in Monywa, Sagaing region, Myanmar. To identify the effects, surface and ground water in the vicinity of the mine are sampled and analysed at the certified national laboratory. The study highlights the detailed analysis of the study programme and the results and findings have been discussed thoroughly. It has been observed that the hydrometallurgy method and zero discharging system are utilized at the mine. The results indicates that the effects of AMD around the area are insignificant because the laboratory analysis results of studied pollutants such as pH, temperature, hardness, conductivity, TDS, DO, Cu, Fe, Pb, Mg, SO₄^2-are within the acceptable range of national environmental quality guideline. Finally, it has been noticed that there are no significant effects of AMD to surface and groundwater around the mine site, no water pollution sources to the environment, no serious environmental damages caused by AMD to near-by areas, and hence the adopted EMS of the mine is considered to be an effective system.

Natural gas has been playing an important role in strengthening energy security of Thailand as over 60 percent of total natural gas consumed in the country is from the Gulf of Thailand. In the past 20 years, the average growth of natural gas demand is 5.5 percent per year. Thanks to its low carbon content, natural gas is considered as cleaner fuel comparing to other fossil-based fuels. Still, there are usages of carbon-intensive fuels such as fuel oil and coal in Thailand e.g. in the industrial sector. Most of fuel oil and coal consumed are imported from foreign countries. Replacing these fuels with natural gas may be an option for the country to promote domestic clean energy and reduce overall carbon emissions. This paper forecasts the possibility of replacing fuel oil and coal in the industrial sector with natural gas. The research starts with examining the limitations of Thai regulations, estimating the amount of natural gas required for the replacement, and forecasting future prices of all three fuels. The price projection shows an attractive option for fuel oil users as the long term price of natural gas is projected to be lower than that of fuel oil. On the contrary, the projected coal price alone will not encourage coal users to switch their fuels. Thus, strong government measures will be required to stimulate coal replacement. The result of the study will be useful for determining appropriate policies to support long-term demand for natural gas of the country.

The continuous increase in population, higher living standards and economic development resulted in the inevitable increase of waste generation, energy consumption, carbon emissions and environmental degradation. The current average operating expenditure (OPEX) of a landfill is RM148/tonne/day for disposing municipal solid waste (MSW) which is an economic burden to the government. Thus, this study investigates the feasibility of biogas production from organic MSW as a renewable source of energy via anaerobic digestion. The economic and environmental benefits including the sales of electricity and fertilizer were investigated. Organic fraction municipal solid waste (OFMSW) was collected at Sahom landfill, Kampar. Waste composition was analyzed to determine the percentage of organic waste. Approximate and ultimate analysis were conducted to characterize the organic samples and to measure the calorific value. The biogas and bio-fertilizer yield were estimated. It was found that OFMSW consists 45% of the total MSW. Conversion of OFMSW to electricity and fertilizer via anaerobic digestion (AD) resulted in 3,274,812.51 m³/day of biogas which consists of 56.62% CH₄ and 43.38% carbon dioxide. This can be resulted in 7,494.08 MWh/day of electrical energy and a daily yield of 13,013.73 tonnes of bio-fertilizer. This transforms the economic burden of solid waste management expenditures into an income generating movement.

ASEAN Power Grid (APG) is one of the six programme areas initially identified in the first ASEAN Plan of Action for Energy Cooperation (APAEC) series, APAEC 1999-2004. It is an initiative to ensure security and sustainability of energy in the region, particularly the electricity. In each series, the APG objectives, strategies and actions are revised and updated to reflect its current state and progress. It has been twenty years since the first APAEC series and a lot of APG strategies and actions have been implemented to achieve the stated objectives. It is therefore timely to review the current state of its implementation to gain insight on its progress. In this paper, the action plans are presented and their current states of implementation are reviewed with the aim to determine their progress and achievements to date. Most of the information needed for this study was obtained from the official APAEC reports, related documents and news cuttings. To the best of our knowledge, this is the first ever work that comprehensively review the progress and achievement of the APG to date. Existing reports are usually written per timeframe rather than per programme area, making it difficult to delve deeper into a specific programme area. Among others, findings from the review show that most of the implemented actions were focusing on the physical interconnections of the power grid and a lot still need to be done with regards to the trading. However, encouraging progress with regards to trading is also seen lately. Findings from this study would provide useful insight on the current state of the APG implementation, particularly when the relevant committees are currently drafting the second phase of the APAEC 2016-2025 that will cover the period from 2021 to 2025.

Some regions of the world with high solar irradiation conditions have a growing demand for electricity and freshwater that could cause supply problems in the industries and population. To reduce this risk, the use of solar energy to generate electricity and freshwater is an interesting option to consider. Electricity could be generated from concentrated solar power (CSP) plants fuelled by solar energy and natural gas, while freshwater could be produced from multi-effect distillation (MED) and reverse osmosis (RO) technologies driven by thermal energy and electricity, respectively. An exergy cost analysis of the integration of two desalination technologies (MED and RO) with a CSP plant is carried out to compare in terms of exergy cost. The symbolic exergoeconomics method is applied in the configurations analyzed. The different configurations are evaluated in a representative region with high irradiation conditions. Results show that the best configuration for producing electricity and freshwater is achieved when the stand-alone RO plant is connected to the grid where the unit exergy cost of electricity and water is 31% and 54% lower than in the stand-alone CSP plant and stand-alone MED, respectively. However, CSP-MED is the recommended configuration for the solar cogeneration scheme evaluated. Additionally, the most influential components in the cost formation of electricity are solar collectors (46.6% in CSP-MED and 44.3% in CSP-RO) while for freshwater they are solar collectors (27.6% in CSP-MED and 42.0% CSP-RO), multi-effect distillation module (15.7% in CSP-MED), and reverse osmosis module (20.5% in CSP-RO). In these components the design should be improved to reduce the unit exergy cost of electricity and freshwater.

Computer simulation plays a key role in chemical process design. Currently, there are a large number of widely accepted commercial software. For example, Aspen Plus which was used to simulate offshore petroleum production processes, but it is often too costly to purchase and maintain a valid software license. On the other hand, since open-source software is freely accessible, the simulation models developed using open-source software could be studied, reviewed, and modified by any interested parties. This would help promoting technology transfer and knowledge dissemination in both academic and industry sectors. We specifically focus on the simulation of chemical process using the modeling software to evaluate thermal and chemical behaviour of the system which uses the chemical processes related to offshore petroleum production facilities as an example to demonstrate the software capabilities of both Aspen Plus and DWSIM. This work emphasizes on the comparison of simulation results calculated by commercial software namely Aspen Plus vs. open-source software called DWSIM (An open-source sequential modular steady state simulator) [1]. The simulation was carried out under the steady-state conditions, adiabatic processes, and negligible pressure losses. Finally, simulation results from DWSIM and Aspen Plus were compared with the heat and mass flow diagram which was used as reference. It was found that the discrepancy between simulation and reported values was in general less than 5%. It has been demonstrated that free and open-source software like DWSIM could potentially perform similar tasks as commercial software.

Hydrogen combustion in the internal combustion engine (ICE) has currently taken part in the transportation industry due to its environmentally friendly and high engine thermal efficiency. Hydrogen direct injection introduction in the internal combustion engine eliminates the harmful emission from carbon and improves engine stability. The substitution from nitrogen to noble gases for the intake will solve the high auto-ignition temperature of hydrogen in compression ignition (CI) engine problem. This paper intended to study the combustion characteristics of direct injection hydrogen in oxygen-noble gas atmosphere such as argon and helium to find the suitable engine and injection parameters for the optimum engine efficiency. The simulation conducted using Converge CFD V2.4 software based on Yanmar NF19K direct injection CI engine. The simulation was done for different oxygen-noble gases such as argon, neon, and helium, while the injection timing and ambient temperature were modified to optimize the hydrogen combustion characteristics. The study found that noble gases help to increase the in-cylinder temperature and ignite the hydrogen. The study also found that early injection timing results in the highest in-cylinder pressure. Besides, increasing ambient temperature for intake decreases the in-cylinder pressure and lengthen the ignition delay. Therefore, the most suitable injection parameter for the most optimum hydrogen combustion characteristics is 380 K ambient temperature, early injection timing at -10°CA, and higher injection pressure. Helium produced higher in-cylinder peak pressure compared to argon due to its high specific heat ratio. Hence, further consideration of helium and good injection strategies should be applied for better engine thermal efficiency.

Ultra clean fuels generally used along with the conventional fuels such as Compressed Natural Gas (CNG) and hydrogen. The implementation of these alternatives can help take care to the high demand of environment friendly vehicles. These natural gas fuels when blended with diesel are expected to decrease emissions along-with reduction of the petroleum fuel consumption. Diesel mixed with hydrogen and methane in different concentrations enhances the performance and efficiency of vehicles. A numerical study were conducted to observe the impact of diesel mixed with hydrogen and methane (dual or tri-fuel) in the combustion process. Intake temperature was increased in between 303 K to 338 K. The simulation of the combustion process used ANSYS Fluent software based on a Yanmar L100AED single-cylinder engine parameter. The simulation conducted with engine speed of 1500 rpm, compression ratio (CR) = 19.3, and λ = 1.2 at different intake temperatures. The results compared the combustion process between a baseline fuel (100% diesel) and diesel-hydrogen-methane tri-fuel. The study found that the optimum intake temperature to enhance performance relies on a concentration of gaseous mixed with diesel. The highest performance and efficiency were obtained at 318 K intake temperature using tri-fuel of 60D-28H-12CH₄. From the in-cylinder pressure and temperature, results show increased in performance when the amount of hydrogen increased at the intake temperature. In conclusion, increasing the intake temperature and the use of tri-fuel in a direct ignition engine significantly improved the performance and efficiency of the engine.

Non-precious metals (NPM) such as iron and nitrogen-doped carbon (Fe-N-C) have been actively studied as alternative electrocatalysts to platinum for oxygen reduction reaction (ORR) in proton exchange membrane fuel cell (PEMFC). However, its low stability is associated to the structural morphology of the electrode made of Fe-N-C and its support that has restricted the mass transfer of fuel and product. In this work, it was attempted to assess the role of RGO derived from sengon wood as catalyst support to Fe-N-C catalyst, and study the effect of the Fe-N-C to RGO ratio, on the ORR activity and durability in acidic medium. This work revealed that Fe-N-C/RGO at the weight ratio of 2:0.2 demonstrated the highest onset potential of 0.91 V, with high limiting current density of 5.7 mA/cm², owing to the uniform active site distribution on the Fe-N-C/RGO surface compared to other samples with different weight ratio. It was indicated in this work that an improve in the kinetic activity was observed with increase operating temperature from 25 to 80 °C. An electron transfer number of 3.91 indicating a complete oxygen reduction process took place on the catalyst. The durability test showed that Fe-N-C/RGO 2:0.2 retained 89 % of its current density at 0.25 V over a duration of 16000 s, higher than that of the benchmark Pt/C. These results have collectively demonstrated a high performance sustainable noble metal-free ORR catalyst for PEMFC applications with proper tailoring the mass ratio of Fe-N-C to RGO support.

Direct carbon fuel cell (DCFC) is a promising technology for power generation. It works on the utilization of solid carbon fuel and is high in efficiency with low emissions. In this study, biochar derived from oil palm mesocarp fibre (PMF) biomass was evaluated as a fuel supply in a DCFC based on solid-oxide electrolyte. To understand the connection between the physicochemical properties and electrochemical performance of PMF biochar (carbon fuel) in DCFCs better, the PMF biomass is subjected to acid and alkali pre-treatment for structural modification. All samples are characterized by means of thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) and scanning electron microscope (SEM) tests to obtain the link between cell performance and fuel characteristics. The maximum power density of pre-treated PMF biochars reached up to 40-55% level when compared to conventional fuels. In specific, the HCl-treated PMF biochar showed the highest electrochemical reactivity in the DCFC, giving a maximum power output of 11.8 mW cm⁻² at 850 °C. It is found that after pre-treatment, the thermal stability of the biochar increases along with an increase in the surface area and pore volumes. Henceforth, these factors are believed to have a pronounced impact on the electrochemical reaction in the DCFC.

Microbial Fuel Cell (MFC) has various application potential as in generation of bioelectricity, bio-hydrogen production, waste water treatment and it is also used as biosensors. It would not be possible to headway without mentioning that MFCs have quite a many similarities with Chemical Fuel Cells (CFC). It is seen that a lot of research is carried out for CFCs as compared to MFCs. Most of the research works on MFCs include experimental approach while very few computational studies have been carried out for MFCs. So an endeavour is made to create a model which mimics the working by simulating the key physical and biochemical processes occurring. Results imply that variation of current density occurs with change in Reynolds number (Re) and kinetic rate of reaction (k) which lead to the study of effects of variation of flow rates, turbulence and the action of different bacteria in the efficiency of MFCs. The current density achieved computationally is around 512 mA/m² for Re=5 and k=10⁻³ which is in good agreement with the experimental data. Regions of higher current density are found which can be used to improvise the MFCs. Present mathematical model provides a new perspective in understanding the biomass concentration across the MFC and gives better knowledge of the mechanisms taking place. This simple computational framework provides insight into the fluid dynamics involved during continuous feeding, by overcoming the limitations and technical barriers in monitoring and examining through experiments. By implementing the findings from this model optimization of designs can be achieved leading to higher current generation, increase in efficacy and cost effective production techniques which paves the way for future work.

Fang oilfield is a small onshore reservoir in Thailand containing oil with gravity ranging from 20-40 °API and viscosity of approximately 10-120 cp. The depth of this field is from 300-1,200 meters and the sand thickness is varied from of 1 to 7 meters. For over 60 years of natural production, the field has low oil recovery. The difficulty has been attributed to the unfavorable production. Waterflooding, a secondary recovery, has been studied and the results show that the recovery can increase 4-6%. However, the production can be enhanced more with the tertiary recovery methods or enhanced oil recovery (EOR) which are recommended to increase oil production in this challenging field. However, the proper technologies have not been studied for commercial production yet. These technologies can be thermal recovery, gas injection, microbial enhanced oil recovery and chemical methods. Therefore, it will be the objective of this work to review and screen the EOR method to fit well with oil production in Fang oilfield in order to increase oil production. From this EOR screening, the main results from this study reveal that chemical injection is more appropriate for this field than other techniques because of reservoir characteristics and reservoir fluids. Based on the types of oil and composition in the oil, adding alkaline solution and surfactant can improve oil recovery because they can reduce interfacial tension of oil and to make the mobility higher. On the other hand, for other techniques, thermal recovery can increase mobility because of wax formation but it has higher cost. CO₂ injection can increase more oil production. Nevertheless, the sources of CO₂ has less supply and is expensive. Now, microbial enhanced oil recovery is on the beginning state and can provide the good potential. Consequently, based on the revision and screening method, the chemical method provide the higher commercial potential and feasibility to enhance oil production in Fang oilfield and the result of this study can be applied to design the plan of oil production operation in the oilfield in the future.

Platinum nanoparticles supported on carbon black (Pt/C) are widely used as the electrocatalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). Nevertheless, the kinetics of the ORR or rate of reaction is relatively slow. Recently, researchers theoretically report that, the bimetallic platinum-nickel supported on carbon black (Pt-Ni/C) have extremely high ORR activities. Therefore, this work aims to synthesize Pt-Ni/C nanoparticles electrocatalysts for ORR via solid-state chemistry method (gas phase synthesis), which involved impregnation of metal precursors on supported carbon and reducing them in an environment of carbon monoxide (CO) and hydrogen (H₂) gases mixture. The Pt-Ni nanoparticles were prepared with different carbon (i.e. Graphene, Vulcan XC-72R and Ketjen black). The ORR activities and durability of these electrocatalysts were examined by voltammetry technique, which consisted of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) under acidic condition. The results demonstrated that different types of carbon supporters could affect the ORR catalytic activities. Pt-Ni nanoparticles supported on ketjen black (Pt-Ni/K) had the highest ORR activities for both specific activity (SA) and mass activity (MA). Furthermore, after 4,000 voltage cycles of the accelerated durability test (ADT), the Pt-Ni/Ketjen black still showed better ORR stability than Pt-Ni/Vulcan XC-72R and Pt-Ni/Graphene, respectively.

In the proton exchange membrane (PEM) fuel cell development, the catalytic activity requires the smaller particle size, the better metal dispersion, the higher conductivity and the longer durability. With these, platinum on graphene was synthesized using the strong electrostatic adsorption (SEA) technique. The pH shifts of graphene was evaluated and the point of zero charge (PZC) was obtained at pH about 5.2. This was a mid-low PZC, where the positive charge of Pt (i.e, platinum tetraamine, [NH₃]₄Pt²⁺or PTA) was chosen as the metal precursor. The adsorption of PTA precursor on graphene was carried out at pH of 12 for one hour at room temperature. PTA on graphene was reduced in hydrogen environment, and transferred to Pt metal particle. The adsorption and reduction steps were repeat until the Pt metals percentage closed to 20%wt Pt/C (i.e, 19.3 % wt. for this work). The prepared Pt/graphene catalyst shows the smaller particle size that average particle size as 2.4 nm and highly better dispersion than the Pt/C-commercial. The Pt metal dispersion on the graphene support were inspected by transmission electron microscopy (TEM). The crystal structures and crystalline size were investigated by X-ray diffraction (XRD). Moreover, the electrochemical properties were tested using cyclic voltammetry (CV) and the accelerated durability test (ADT) was also carried out after 4000 cycles of reduction and oxidation reaction. Finally, the results were compared with the 20% wt. Pt/C-commercial catalysts. It was observed that the oxidation reduction reaction (ORR) activity in terms of mass activity (MA) and specific activity (SA) were better than Pt/C-commercial.

Nitrogen-doped reduced graphene oxide (NG) with high nitrogen level was synthesized by a facile pyrolysis. NG has been getting attention because of its high catalytic activity toward the oxygen reduction reaction (ORR) and reduce cost. The synthesis of NG used graphene oxide (GO) and urea as a N-precursor were dissolved in ethanol. Then the mixture was evaporated by ultrasonic bath for 30 min. The mixture was slurry then was transferred to tube furnace and pyrolyzed at 300°C and 800°C (NG300 and NG800) with heating rate of 2.5 °C/min in N₂ atmosphere for 30 min. The morphology and structure of nitrogen doped graphene oxide were investigated by Scanning Electron Microscopy (SEM) and X-ray photoemission spectroscopy (XPS). The XPS spectra of NG indicated that NG300 had the highest intensity of N1S peak among others. Mass of nitrogen of NG300 and NG800 were evaluated and had about 15.5%wt and 6.6%wt, respectively. Furthermore, N spectra at high-resolution was analysed and de-convoluted to three N chemical states of pyridinic-N, pyrrolic-N, and graphitic-N. The electrochemical properties of NG were determined by cyclic voltammetry (CV) and Linear sweep voltammetry (LSV). From the results shown that NG800 catalyst yielded highest electrochemical activity particularly for oxygen reduction reaction (ORR) over GO and NG300. Thus, N atoms doped into the graphene were responsible for the ORR catalytic activity resulting from doping N atoms and provided more density of active sites and conductivity. Moreover, NG can be applied as a supporting material for Non-precious metal group catalysts of fuel cell.

Metal contaminated wastewater effluent from industries has caused several environmental problems and public health due to its toxicity. Conventional heavy metal reduction processes are neither economical nor environmentally friendly. A synergy economical single chamber up-flow membrane-less microbial fuel cell (UFML-MFC) was fabricated to study the feasibility of heavy metal reduction and voltage generation. Cu (II) was used as electron acceptor to explore the mechanism of metal treatment in UFML-MFC. The performances of the UFML-MFC were investigated with 0 mg/L, 5 mg/L and 10 mg/L concentration of Cu (II) in terms of voltage output, chemical oxygen demand (COD) reduction and Cu (II) reduction efficiency and electrode spacing distance. UFML-MFC used carbon felt as anode and cathode material where anode region was filled with 0.2 cm of gravels at anode region. Overall performance deteriorated with increased initial concentration of Cu (II). Voltage generation decreased from 71 mV to 11.1 mV. COD reduction decreased from 56% to 36%. Moreover, the Cu (II) reduction efficiency was reduced from 87.56% to 36.98%. These results showed that the increased concentration of the Cu (II) could potentially reduce the microbial activities. However, UFML-MFC showed that the shorter distance of electrode spacing (anode and cathode) could enhanced the voltage output. These results showed the great ability of integrating UFML-MFC for heavy metal reduction.

Warm mix asphalt (WMA) was developed to reduce asphalt production temperatures and energy consumption. Production of toxic gas emissions can be reduced considerably. However, lowered production temperature results in the presence of trapped moisture in the aggregates that could lead to stripping and subsequently moisture susceptibility problems, and which can be mitigated by using additives. Asphalt mixtures incorporating such additive must exhibit at least similar performance to conventional hot mix asphalts (HMA) which produce at higher temperatures. This paper evaluates the engineering properties and moisture susceptibility of asphalt mixtures incorporating Organo-Silane additive for use as WMA and anti-stripping agent. WMA samples were compacted at 125 °C and 115 °C and their performance were compared with control HMA specimens. The asphalt mixtures were prepared using similar aggregate gradation and binder types. Mixture workability was quantified in terms of the Compaction Energy Index (CEI) that was measured by integrating the area under the densification curve between gyration 8 and 92% theoretical maximum density. Lower CEI implies a more workable mixture. The CEI of WMA was 76.4, which was much less than the corresponding value for HMA. Samples were also tested for Marshal stability, resilient modulus and wheel tracking (WTT) tests according to ASTM D6927, ASTM D4123 and BS EN12697-22 procedures, respectively. The control samples perform better in the stability test. The resilient modulus of WMA was only about 10% lower compared to HMA. Resistance to permanent deformation was measured from the dynamic stability (DS) or the number of wheel passes per 1 mm rut depth over the last 15 minutes in a 60-minute tracking test. The DS of HMA, WMA compacted at 125 °C and 115 °C were 3138, 3044 and 2837, respectively. From the rutting resistance standpoint, the results are not significantly different. Hence, incorporation of the additive does not adversely affect mixture rutting resistance despite the lowered production temperature.

The adsorption of wastewater from various industrial sources is important and one of the dangerous challenges the environment. This study focuses on the investigation of the efficiency of zinc ions adsorption by using activated carbon in synthetic wastewater. Activated carbon was prepared from palm kernel shells that were obtained from Songkhla province, Thailand. Activated carbon was prepared from palm kernel shells containing sodium chloride as a catalyst at the ratio 1:0, 1:1 and 1:2 (w/w), respectively. Activated carbon was calcined at 700 °C for 2 h. Next, it was washed with hot distillate water until pH = 7. After that, it was dried at 105 °C for 24 h. Iodine number was analyzed by using CHNS/O analyzer. The concentration of solution was examined by using atomic absorption spectrophotometer (AAS). The prepared activated carbon was characterized by thermogravimetric analysis (TGA), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), X-ray fluorescence spectrophotometer (XRF), X-ray diffractometry (XRD) and Fourier-transform infrared spectroscopy (FTIR). For the pure activated carbon, it was noteworthy that the major components were O (37.25%), N (30.95%) and C (26.54%), whilst a minor content was H (2.23%), C (1.73%) and Si (0.76%). This result was strongly consistent with the XRF analysis. The ratio of activated carbon to sodium chloride 1:2 (w/w) exhibited the highest iodine number (180.95±10.82 mg/g). The factors of adsorption including initial concentration (20-150 ppm) and adsorption time (2-10 h.) The result showed that the optimum conditions of adsorption containing concentration were 65 ppm and adsorption time was 10 h. The efficiency of adsorption was 69.73 %.

A solvent and non-solvent selection method for the chemical recycling through selective dissolution and precipitation of multi-component waste metallized film wrapper is studied to recover Polyethylene (PE), Polypropylene (PP), and the metal film separately. Pre-selection of solvent for dissolution and non-solvent for precipitation is based on the similarity and compatibility of polymer and solvent molecules measured in terms of solubility parameter and calculated using group contribution approach through Hoftyzer and Van Krevelen method. Toxicity, cost, and availability of the solvent are also considered on the selection. A Hansen sphere model is developed for the prediction of polymer solubility in which p-cymene, a low-cost and naturally derived solvent is chosen as solvent and acetone as non-solvent. PE was first recovered through dissolution at a given temperature, followed by precipitation. PP which remained undissolved together with the metal film was extracted through the same technique but with different dissolution temperature. FTIR spectra of the recovered polymers showed similarity compared to virgin PE and PP films. The melting point of the recovered PE and PP using p-cymene determined in the DSC curves were 107.37 °C and 164.55 °C, respectively. Furthermore, the simplicity of the process, high recovery yield obtained, and the application of p-cymene would make the recycling economical and environment-friendly.

Extensive research work has been carried out mainly focusing on the assessment and prediction of battery cell State of Health (SoH) under operating conditions, however limited contributions focus on SoH following collision impacts. This paper proposes a method for estimating the battery cell SoH from collision deformation features. Experimental tests of collision impact were designed and realized on brand new battery cells to investigate deformation features. Deformed battery cells were subject to a 3D scanning procedure to retrieve the contour data, subsequently a number of geometrical features were extracted from the 3D image instances. The battery cells damage characterization was carried out by characterizing both physical and electrical performances following the collision impact tests. An intelligent assessment was carried out by adopting a neural network-based supervised machine learning paradigm for classification of deformed battery cells into safe, latent danger and unsafe cells respectively. Training and testing results show a clear pattern between geometrical deformation features and battery cells SoH, with classification accuracy up to 96.7% demonstrating the suitability of the proposed method for an effective assessment. Within electric vehicles applications, such method can provide a basis for safety design enhancement of lithium-ion battery system via finite element simulation of collisions impacts.

The current study aims to explore geotechnical properties of expansive soil amended with in-house produced biochar. Biochar was produced in-house using slow pyrolysis (at constant temperature of 500 °C) of commonly available Prosospis Juliflora (invasive weed) in a muffle furnace. This study also motivates alternative use of Prosospis Juliflora, whose reduction can help to minimize transmission of malaria and also threat to bio-diversity. The biochar was uniformly mixed with expansive black cotton soil at 5% and 10% content. Both basic and geotechnical properties (CBR and unconfined compressive strength) was determined for modified and unmodified soil samples. Based on results, it can be concluded that the plasticity index of an expansive soil is reduced significantly with an increase in biochar content. On the other hand, change in shrinkage limit was negligible. There is an increase in unconfined compressive strength and also reduction in free swell index of expansive soil amended with biochar. This is despite the significantly lower specific gravity and higher porous structure of biochar particles. The result is contrary to application of biochar in sandy soils in literature. The possible mechanism could be due to formation of bonds between negatively charged surface functional groups of biochar and positively charged ions of an expansive soil.

Biochar amended soil (BAS) is widely studied to apply in green infrastructure, such as landfills and slopes. Presence of biochar improved soil hydraulic properties (e.g. water retention ability) in previous studies, while influence of biochar on gas permeability (k_g) under different compaction states is not clear yet. The main objective of this study is to investigate the k_g of BAS under different soil compaction conditions. The soil selected for investigation was poorly graded sand. BAS was compacted in an in-house built 1-D column set up under three different soil density (65 %, 80 % and 95% degree of compaction) were considered in mixtures with 0% and 10% biochar content. The tests were carried out in a greenhouse at Shantou University. In tests, soil column was designed and subjected to drying-wetting cycles, during which soil suction, moisture content and k_g were measured. Results showed that BAS (i.e. minimum water content 37.2% and 22.1%) had better water retention performance than bare soil (i.e. minimum water content 20.2% and 19.5%) at compaction conditions (65% and 80% degree of compaction). However, when the degree of compaction increased to 95%, bare soil and BAS shows similar water retention characteristic (i.e. minimum water content 15.7% and 15.9% respectively). The addition of biochar could decrease k_g as compared with that of the bare soil, meanwhile, in the lower suction range, k_g decreased with an increase of compaction (i.e. k_g65%>k_g80%>k_g95%).

In this work, Al-doped ZnO transparent conducting thin films were prepared by a reactive dc magnetron sputtering method on slide glass substrate using single metallic Zn:Al (2 wt.% Al) target with the oxygen flow rate 1, 3, 5, 7 and 9 sccm, respectively. From XRD patterns, the films prepared at R(O₂) of 1 sccm showed amorphous characteristics. In contrast, the films prepared at R(O₂) of 3, 5, 7 and 9 sccm showed the preferred orientation (002) plane of hexagonal structure. Surface morphology and diameter of nanocolumns of the films were observed by AFM and FESEM. From transmittance spectra, energy gap value was found to vary between 3.24 and 3.32 eV. Electrical resistivity and Hall effect measurements were performed on the films with van der Pauw configuration. The temperature-dependent conductivity was performed in the range 20-300 K. Three types of conduction mechanisms were expected. Thermally activated band conduction at the high temperature range (250-300 K), Mott variable-range hopping (Mott-VRH) at the low temperature range (100-210 K) and Efros-Shklovskii variable-range hopping (ES-VRH) at the very low temperature range (<100 K) can be found in the films prepared with different oxygen flow rate conditions. Except for the oxygen flow rate at 5 sccm, the behavior of weakly localized electrons was observed. Then, the sets of parameters explaining the properties of localized electrons in each conduction regime were determined. The results indicated that the reactive dc magnetron sputtering using a single metallic Zn:Al (2 wt.% Al) target is suitable for TCO films since it can be easily obtained at low temperatures with good physical properties.

Pb (II) is one of the toxic heavy metal ions, which is released from the industry, especially the manufacture of batteries and electronics-devices. Its release into the water effluents causes environmental problems and affects the humans' and animals' health. Adsorption is one of the conventional techniques for removal of Pb (II) in water treatment processes. The adsorbents with effective adsorption properties with their easy operation are then desired. In this study, hierarchically porous carbon monoliths with magnetic properties have been designed and successfully fabricated by incorporating sodium alginate and black liquor in ferric chloride solution. The resulting monoliths have been used to study their adsorption efficiency towards Pb (II) in aqueous solution. The interconnected macroporous structures of the materials were generated by the freeze-drying process, while the increase in microporosity was observed after pyrolysis at 700 °C (SA-BL-Fe-700). SA-BL-Fe-700 showed a magnetization of 8.79 emu/g, and high porosity, with a BET specific surface area of 945.45 m²/g and pore size distribution calculated by DFT was less than 2 nm, which is suitable to adsorb Pb (II) ions. Furthermore, the materials obtained showed a monolith feature in a cylindrical shape with strong mechanical stability, which renders them with the easy operation. The adsorption properties of SA-BL-Fe-700 monolith toward Pb (II) ions demonstrated a maximum adsorption capacity of 75.19 mg/g at pH 5 with retaining the magnetic properties. The study of adsorption behaviours illustrated that equilibrium data and kinetic study fitted with Langmuir isotherm model and pseudo-second-order model, respectively.

Laundry wastewater constitutes of detergent compounds, bleaching agent, textile color pigments and dirt. These compounds are hazardous once discharged into the water source without proper treatment due to the adverse effects on the aquatic life in the freshwater bodies. This fixed-bed column adsorption study using the natural biomass from chemically treated sugarcane bagasse is proven to be effective for the removal of constituents present in the laundry wastewater. The synthetic laundry wastewater was prepared in the laboratory from a powder type of detergent with a concentration of 50mg/L and 250mg/L to be further used in the adsorption process. The characteristics of the synthetic laundry wastewater were analyzed by the turbidity, pH, dissolved oxygen (DO) and chemical oxygen demand (COD). The fixed-bed column experiment with the treated sugarcane bagasse was conducted under different parameters such as the effect of pH, initial concentration and bed height. The best removal efficiency was observed at a bed height of 10 cm with a concentration of 50 mg/L is 65%, followed by 33% and 20% for bed heights of 4 and 2 cm respectively. As for the concentration of 250 mg/L, the best removal efficiency was at a bed height of 10 cm which was found to be 58% followed by 26% and 17% removal for a bed height of 4 cm and 2 cm respectively. The kinetics of the adsorption was investigated using the kinetic models of Thomas and Yoon-Nelson. The experimental results fitted well on the Thomas model and Yoon-Nelson which showed a high linear regression value greater than 0.9. These results prove that chemically treated sugarcane bagasse is an effective low-cost adsorbent for reducing turbidity, pH, COD and increasing the DO concentration.

This paper presents the engineering properties of ancient masonry materials and substitution materials for the preservation of Thai historical structures. The study was divided into 2 parts. For the first part, the ancient masonry materials including brick and mortar were collected from various historical sites in Bangkok and Ayutthaya provinces. The engineering properties of masonry materials were evaluated in laboratory such as compressive strength, density, chemical compositions, porosity, and water absorption. The second part was investigation to find the suitable substitution materials for historical repair mortars. Fly ash was used as a pozzolanic materials to partial replace slaked lime for making historical repair mortar. The engineering properties of historical repair mortar containing were also evaluated and compared with the ancient masonry materials obtained from the first part. The binder to sand ratio was controlled at 1:3 by weight. The slaked lime was substituted by fly ash in the ranges of 10-30% by weight. The experimental results showed that the use fly ash to a partial replace slaked lime could decrease the setting time of historical repair mortar. The compressive strength of historical repair mortars with fly ash were ranged from 1.54-2.22 MPa, depending on the level of replacement, while that of the ancient masonry materials had the compressive strength of 1.88-2.71 MPa.

Driven by the high demand for commercialization of fuel cell (FC) technology, a design of potential oxygen reduction reaction electrocatalayst based on reduced graphene oxide (rGO) and iron oxide (Fe₃O₄) nanocomposite has been described and denoted as rGO/Fe₃O_4. The nanocomposite was synthesized by means of facile one-pot process. The resultant rGO/Fe₃O₄ was physically and electrochemically characterized by using Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffractrogram (XRD), Scanning Electron Microscopy (SEM), Cyclic Voltammetry, (CV) and Electrochemical Impedance Spectroscopy (EIS). The FTIR analysis shows the formation of rGO/Fe₃O₄ from the presence of C=C, C-C and Fe-O bonds in the spectrum of the indicating the synthesis material is successfully obtained. XRD analysis also confirms the presence of rGO and Fe₃O₄ in the composite by hematite structure indexed peak of diffractogram. Scanning Electron Microscopy (SEM) image depicts the attachments Fe₃O₄ onto the surfaces of rGO. The composite was then dissolved in the solvent and drop-casted on the glassy carbon electrode (GCE) for electrochemical analysis. Cyclic Voltammetry (CV) shows increment in current responses of nearly two and half folds for rGO/Fe₃O₄/GCE compared to bare GCE. Electrochemical Impedance Spectroscopy (EIS) shows a stable electron transfers process with lower charge transfer resistance (R_ct) of the nanocomposite modified electrode which due to the synergistic effect between rGO and Fe₃O_4. The results of the analysis show the compound could be a promising candidate as an electrocatalyst for fuel cell.

Biochar has been known to be an excellent soil amendment. However, the biochar yield and its quality are both affected by the process parameter, such as temperature and heating time, and the production method from kiln type used. Therefore, the objective of this work was to characterize the thermal distribution inside the 50-liter kiln at different heating times of the biochar production. The experiments on the kiln with a dimension of 500 mm × 380 mm (height × diameter) including the fuel core with diameter of 115 mm with 5 rows of 6.35 mm drill puncture diameters were conducted. The biochar was produced from 7 kg of agricultural waste corncob. The pyrolysis temperature increased with increasing heating time and it was controlled not exceeding 600 °C by adjusting the briquette fuel quantity. The results showed that the highest temperature was found at the fuel core and decreased in radial direction outwards to the kiln wall. The heating time showed effect on the thermal distribution as well as the biochar yield. The lower thermal gradient and the higher biochar yield were obtained at the higher heating time. The biochar yield would, however, decrease after optimal heating time due to the decomposition and degradation of biochar derived from corncob during the pyrolysis process. The production cost of biochar was also determined. These findings propose agriculturists the optimal heating time along with the production cost to facilitate the biochar production.

Magnetic properties are the concentrated studies in iron oxide based magnetic nanofluid area; however very limited number studies have been conducted on the psychical properties of this nanofluid. The main objective of this study is to investigate the viscosity properties of Maghemite: MH (iron oxide) nanoparticles dispersed de-ionized water (DW) nanofluids (DW-MH) for the addition of graphene (Gr) nanoflakes. DW-MH nanofluids were prepared by two steps technique and graphene was added with the aid of sonication and stirring process. Viscosity were measured for every samples varied for the loading of graphene in DW-MH nanofluids. Every measurement was conducted in rising temperature varied within 20 - 60°C. Effect of both of loading of graphene and rising temperature on the viscosity properties of the fluid were systemically analysed. Prepared nanofluids were kept stabile about 30 days without any visible sedimentations. After the addition of graphene in the DW-MH nanofluids the viscosity of the final nanofluid samples was increased with the increasing loading of graphene nanoflakes. It was also detected that, hybrid nanofluids sample's viscosity was decreasing for the increasing temperature. This nanofluid can be the viable replacement for the heat transfer purpose in the energy harvesting and storage applications due to the good physical stability.

In recent years, the Philippine space program has launched several small-scale satellites, and lately has commissioned its own space program. Research on improving the subsystems of these satellites would be beneficial to future space programs in the Philippines. This paper will detail the process of designing, validating, fabricating, and testing a prototype Carpal Wrist Cold Gas Propulsion System (CW-CGPS). By making use of a carpal wrist's (CW) hemispherical movement capabilities, the sixteen thrusters could theoretically be replaced by four mounted on opposite ends. Optimization of the propulsion system is based on finding the nozzle design with the most adequate values for thrust, Mach number, and specific impulse while the CW design is validated when it can be calibrated to move as the program dictates. This study uses multiple programs to simulate and verify the design. The conditions of the testing environment are established by resources from international space organizations. Assembly and feasibility are assessed based on the results of the research. It was found that the final optimized system had a model torque of 0.247 N-m, more than enough to overcome the maximum combined influence of the gravity gradient torque of 2.34E-06 N-m and aerodynamic torque of 1.57E-25 N-m. The design, development, and test campaign for the thruster system is presented.

3D laser scanning technology is one of the current technologies for developing a sustainable and smart city. This technology is applied to obtain the three-dimensional information of building in digital format. To preserve the historic structure, the current structural information is required for structural assessment, monitoring, and conservation planning. The data obtained by the 3D laser scanner is normally used to generate the three-dimensional point cloud data of the building surface. The high-density point cloud data represented the dimension, shape, and size of the building in the current state can be acquired in more accurate and faster than another technique. This paper aims to present the application of 3D laser scanning technology for preservation and monitoring of heritage pagoda in Thailand. The pagoda of Wat Krachee located in Ayutthaya province of Thailand was selected as a case study. The results obtained in this study are a part of Wat Krachee conservation project, which is led by UNESCO Bangkok and the Fine Arts Department, Thailand. One of the challenges in Wat Krachee project is how to preserve the masonry pagoda with two intertwined trees growing inside and become a part of pagoda structure. The terrestrial 3D laser scanner was applied to develop the digital data documentation and 3D model of pagoda in the current state. The 3D survey work has been started since February 2018. The analysis of data obtained in February 2018, Mar 2018, July 2018, and July 2019 was carried out. The significant dimensions and deformation of pagoda are monitored. According to the results, it is found that the 3D laser scanning technology is very effective for assessment and monitoring. The 3D point cloud model obtained in this study can be used to develop the assume original model of the Wat Krachee pagoda, which is the inverted bell-shape with a square base.

The wire sawing machine is a large-scale concrete structure cutting equipment and mining quarrying machine used in the wild, in order to reduce costs and reduce energy consumption during manufacturing, transportation and use, on the premise of ensuring its performance, it is of great significance to explore its lightweight design method. This paper uses a multidisciplinary approach to construct a research method model for product lightweight design, comprehensively considering the aesthetic principles and usability principles of products, combining structural optimization theory and Kansei engineering theory, referencing three points of modeling structure, material selection and usage, through to the two aspects of physical and visual lightweight quantitative evaluation standard to determine the optimal solution for lightweight design. First, use Solidworks to build a three-dimensional model of the wire sawing machine; then, use ANSYS Workbench to perform finite element analysis on the mechanical properties of the frame to confirm it has optimization space of the frame strength; finally, through topology optimization of the frame structure and the design of the machine casing, the weight of the mainframe was reduced by 23%. The physical and visual lightweight results verifies the feasibility of the lightweight design model applied in the product design process and provides a useful reference for the sustainable development of industrial products.

The call for greener processes and eco-friendly products has been the essence of the 2030's core agenda on 17 Sustainable Development Goals. The major challenge is in bringing systems thinking and holistic worldview to the planning and strategies to develop the Economics whilst incorporating the Environment, and Socio-cultural diversity dimension as equal components. This means a total revamp of human activities such that the discussion on climate change, famine and poverty, destruction of eco-systems and habitat for wildlife, and the emerging infectious diseases, is as relevant as, if not more important than, discussing about artificial intelligence, robotics, flying and driver-less vehicles, and exploration to Mars. There is an urgent need for resource optimization, better biodiversity management and improved agro-practices for food production and distribution, affordable health care, and cleaner energy, air and water, with strict monitoring, regulation and enforcement to minimize emission, pollution and wastage. The focus of this presentation is to highlight research and development efforts towards the realization of sustainable bioenergy production, environmental remediation and conversion into biomaterials via integrated algal biorefinery and palm oil milling processes. Recent development in microalgal research with nanotechnology for biopharmaceuticals and anti-cancer products will be discussed. The image problem and the negative perception surrounding oil palm industries especially with regards to the impact on the environment, and the efforts towards a more sustainable production route will be highlighted. This hopefully could bring forth insights towards partnerships and collaboration among the industrialists, investors, economists, scientists, engineers, and social scientists to tackle the immediate and pressing problems facing the Planet and the People, whilst reaping the Profit, yesterday, today and tomorrow.

The permanent magnets based on NdFeB is well known as rare earth alloy magnets made from neodymium, iron and boron elements and has tetragonal crystalline structure Nd₂Fe₁₄B which has high coercivity, large energy product (app 50 MGOe) and curie temperature about 312 °C. In this paper will be discussed the preparation of bakelite bonded magnet NdFeB and characterization, also the purpose of this research is to make bonded magnet NdFeB using 3 % bakelite and know the extent to which can be applied in making a small electric generator. The bonded magnet NdFeB was made by mixing a magnetic powder NdFeB with a polymer as binder. The composition of the sample consisted of 97 wt. % of NdFeB powder and 3 wt.% of bakelite. The mixed raw materials were then pressed to form a disc with pressure about 40 MPa at temperature about 160 °C for 20 minutes. It was obtained a disc with size 40 x 18 x 6 mm. The disc samples were magnetized by using impulse magnetizer at 1500 Volt DC, then the samples were measured magnetic properties by using Gauss meter and Permeagraph. The measurements result show that, the bakelite bonded magnet NdFeB has Magnetic Flux = 1100 Gauss, Remanence Br = 5.20 kGauss, Coercivity Hc = 6.14 kOe and Energy product (BH) max = 4.78 MGOe. The bonded magnet NdFeB was applied to the prototype small generator with single rotor and single stator. The results of performance test of generator indicate that it is achieved output power of generator about 9.98 Watt at a maximum speed about 500 rpm.

In this study, sugarcane bagasse (SCB) as a cheap and effective biosorbent was used for copper ions (Cu(II)) removal and modification was performed on SCB with HCl chemical washing and mercerization with strong NaOH in order to improve the removal capability of Cu(II) from aqueous solution. The effects of three influencing parameters including pH, temperature and initial metal ion concentration on Cu(II) adsorption were investigated for both untreated and modified SCB samples (U-SCB, HCl-SCB and M-SCB). The maximum removal efficiency obtained in the experiments was 98.75% for HCl-SCB while M-SCB was 93.1% at pH 5 with an initial metal ion concentration of 10 mg L⁻¹. Four isotherm models including Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm were used to describe the adsorption process of Cu(II) ions for each SCB sample. Among these four isotherms, the experimental data was best fitted to Langmuir isotherm with R² above 0.95. Based on the Langmuir isotherm, the maximum monolayer adsorption capacity was 0.523, 2.006 and 0.938 for U-SCB, HCl-SCB and M-SCB. It was concluded that the modification performed on SCB with HCl was able to improve the removal efficiency of Cu(II) from 71.6% up to 98.75%.

United Nations has settled that in 2050 world population could reach 9.8 billion people so the food and protein requirements will increase, on the basis of this, the actual paper presents a proposal for a circular economy approach of the industrial production process of the edible insect Tenebrio molitor (T. molitor) as food. Edible insects are a great solution because of their source of protein, omegas and minerals they are considered as an alternative to ensure food security in a sustainable way. The process of breeding and harvesting T. molitor has been designed from the perspective of maximum use of all the resources involved, reducing waste production, minimizing greenhouse gas emissions and the use of all by-products derived from the process, with the aim to be used in agriculture, pharmacy, food and feed. Throughout the course of the T. molitor's breeding needs to be supplied by organic food and a minimal use of water obtained by fruits and vegetables; all the waste generated by it: frass and exoskeletons (chitin), can be reuse with agricultural organic fertilizer purposes (flowering) and it is a great value supply in the food, pharmaceutical and cosmetic industries, that is why the importance of recovering of the larva's exoskeleton from the process. The processes of breeding and harvesting of the T. molitor from its beetle stage to the larval stage are described in the 'know how' to obtain an edible organic product as a powder or simply as a dehydrated product.

Agriculture is getting more inclined with modern technology. Automatic dataacquisition of soil condition with the help of a sensor lessens the time and manual work in testing a soil if it is suitable for planting. However, soil characteristic changes periodically. Thus, determining the macronutrients present in the soil is always a challenge for the currently available sensors because most of them can only get and give one or two information from the soil simultaneously. This research focused on the development of a digital single probe sensor to monitor the macronutrient contents of the soil, i.e. nitrogen, N; phosphorus, P; and potassium, K. Moreover, the soil's temperature, moisture, and pH level were also monitored. In order to obtain the N-P-K content, a rod electrode or probe, which produces electrical potential in response to the reading, was utilized. The electrical conductivity of the soil provides the N-P-K values and the electrical resistivity of the soil gives the soil's pH and moisture content. A canister for storing and releasing the reagents to enhance the sensor's conductivity is installed and once the probe is injected in the soil, a button can be pressed to release the reagents to the soil. Moreover, a Wi-Fi module was installed in order for the user to monitor the data collected by the device. The calculated percentage error of the device in monitoring soil fertility is 12%.

As E-commerce and online shopping advance swiftly and vigorously, a growing number of people choose shopping on the Internet as their major way of shopping. As the online shopping is in vogue, the problem lying in the package of express has gradually drawn people's attention. As the data reveals, the number of paper boxes that China's e-commerce brought about is over 10 billion. The packages of express resulted in environment pollution and waste of resources, At present, China does not yet have an efficient and comprehensive express packaging recycling system, and the only sustainable recycling design has a small application range and the effect is not obvious. For the purpose of improving the recycling rate of packages and in response to the "sustainable development strategy", this paper, from the standpoint of consumer psychology, the real consumption situation and package recycling status quo, makes use of the Internet as the bridge to realize the design of virtual APP and recycling device, so as to form a complete recycling system of express package. This system mainly utilizes the gravity sensor, information processing system and storing and arranging device, and is backed by sophisticated techniques. The researches have shown that, the simplification of creative recycling system, the time-saving effort, high efficiency, as well as the conception of the smart classified recycling have changed the traditional way of recycling. These improvements have greatly reduced the pollution and waste that express packages caused and make the resources being used for the second time a reality.

The world is witnessing the fourth industrial revolution, as known as Industry 4.0, which integrates advanced manufacturing and operations techniques with the most recent digital and information technologies to create dynamic, interconnected, and smart manufacturing ecosystems. The underlying components of Industry 4.0 such as smart factories and technology trends also need an ever-increasing powering, and energy sustainability has strong ties to Industry 4.0. The Industry 4.0 offer numerous opportunities for energy sustainability, and the present research applies the interpretive structural modelling (ISM) not only to model the Industry 4.0 functions for energy efficiency but also sustainability. With the mentioned methodology, the research performs a systematic review of the literature to first identify the energy efficiency sustainability functions of Industry 4.0. Besides, the research further determined the opinion of a group of experts to map and analysed the interrelationships among the sustainability functions identified. The results in this research indicates that sophisticated precedence relationships exist amongst numerous energy sustainability functions of Industry 4.0. In particular, 'Matrice d'Impacts Croisés Multiplication Appliquée àun Classement' (MICMAC) analysis indicates that the digital transformation of energy sector (Energy 4.0) itself, smart grids, and process optimization are the more immediate energy sustainability impacts of Industry 4.0. This research enable Industry 4.0 players including industrialists, academicians, consumers, and even governments to understand better the opportunities that Industry 4.0 may offer for energy sustainability.

The major drawbacks of 3D printed thermoplastic using fused deposition method (FDM) are exhibit weak mechanical properties. This reduces the usability of the printed part as the functional structure for part replacement in a real-world application. Therefore, in this study a co-extrusion of a continuous fibre of twisted Kevlar using FDM is conducted to examine the improvement of mechanical strength of the 3D printed part with reinforcement of continuous fibre. The coextruded reinforced plastic (CRP) parts consisting of polylactic acid (PLA) as matrix and twisted Kevlar as core fibre. The mechanical performance of printed parts was evaluated in a tensile test under ASTM D638 standard. The results of both CRPs were compared against unreinforced PLA which. It has been demonstrated that CRPs with twisted Kevlar was able to achieve significant increment in Ultimate tensile strength (+179.7%, 104.64MPa), maximum tensile strain (+257%, 5.384%) and relative similar Young's modules (3.29GPa) compared to unreinforced PLA. As a result, this study created a unique material print which CRP with twisted Kevlar which offer high stiffness and high strength structure.

Incorporating industrial wastes and recyclable materials as additives and/or alternatives in raw materials of concrete bricks is an approach used by environmentalists to convert wastes to reusable materials. Facing bricks are aesthetic material that can be installed in the internal or external walls of houses or buildings. Spent Activated Carbon-Bleaching Earth (SACBE) is an industrial waste generated from the physical refining process of vegetable oil. SACBE is commonly disposed or buried in dedicated landfills. SACBE has no significant utilization and causes environmental hazards upon disposal. The study is designed to find the most effective and efficient mixture ratio of cement facing bricks with SACBE. The paper also investigates the physical and mechanical properties of the SACBE mixture. Three sets of mixtures with varying amount of SACBE in 800 mL, 900 mL, and 1 L of water were created. The volume of sand in the original ratio was substituted with 0% SACBE up to 30% SACBE in increments of 5%. Cement, sand, SACBE, and water were mixed accordingly to the different ratios and air dried in 7 days. Analysis of the results showed that as the percentage of SACBE increases, the density of the facing bricks decreases while the volume of water has no concrete effect on density. The water absorbed in varying amounts of water with the same percentage of SACBE decreased for most samples while the compressive strength is lower for the 900 mL across all samples. Results showed that the 30% SACBE mixture in 1 L of water is the optimum mixture of SACBE. This mixture exhibits higher compressive strength while having lowest density and minimum water absorption compared to other mixtures.

The presence of high amount of mineral compounds such as calcium (Ca²⁺) and magnesium (Mg²⁺) in water attributed to occurrence of water hardness. Hard water causes lime scale in the kettle when boiling, and forms reddish brown stains on the clothes after washing. This study was carried out to investigate peels of durian, jackfruit and passion fruit as a potential cation exchanger for water hardness removal determining by EDTA titration. A synthetic hard water of 714.05 mg CaCO₃/L was prepared to evaluate the removal efficiency of cation exchangers prepared from raw and sodium hydroxide-citric acid (NaOH-CA) modified fruit peels for 30 min, 60 min, and 90 min contact times. Results showed that raw peel of durian had the highest (p ≤ 0.05) efficiency (24%) for water hardness removal followed by jackfruit (21.87%) and passion fruit (6.5%). This was because the total cellulose content in durian peel powder and fibre was higher as compared to jackfruit peel and passion fruit peel. Hydroxyl group in the cellulose was the main group responsible in ion exchange with Ca²⁺ and Mg²⁺ for water hardness removal. For NaOH-CA modified peels, jackfruit demonstrated the highest (p ≤ 0.05) water hardness removal efficiency (62.05%) as compared to passion fruit (29.63%) and durian (10.42%) for 90 min contact time. This phenomenon can be explained by citric acid anhydride produced from esterification. Citric acid anhydride produced was combined with hydroxyl groups of cellulose and hemicellulose and formed the ester linkage and increased the number of carboxylate groups on the ion exchange surface. Result showed that water retention capacity is directly proportional to water hardness removal efficiency for modified fruit peels (R² = 0.8181). This evidence that water retention capacity of lignocellulosic material is a good indicator of cross-linking which has a direct effect on ion exchange capability. Both raw durian peel and NaOH-CA modified jackfruit peel showed great ability in water hardness removal, hence the cost of chemicals involved in modification has to be considered for a good recommendation as great potential lignocellulosic material to be used for water hardness removal.

Zirconia ceramic has been identified as one of the advanced ceramic material with great mechanical properties which is used as engineering and implant materials. However, the great potential of the ceramic is hindered by low temperature degradation (LTD) where the ceramic experiencing t-m phase transformation that weakens the properties of 3Y-TZP in the presence of moisture. Two-step sintering was found to be effective in producing fully resistance 3Y-TZY but very long holding time is required. Manganese Oxide (MnO₂) is reported as good densification aid at low sintering temperature for 3Y-TZP but the LTD issue is not fully resolved. In this study, the effects of different sintering profiles and dwell time on 3Y-TZP added with 0.5 wt.% of MnO₂ were studied in order to improve the resistance towards LTD without affecting the intrinsic properties of the ceramic. The effects of adding 0.5 wt.% of manganese oxide (MnO₂) into 3 mol% yttria stabilized tetragonal zirconia polycrystals (3Y-TZP) were studied using different sintering profiles and dwell time. The samples were sintered at 1400°C and 1250°C with varying dwell time of 1 min and 2 hours for single step sintering and a combination of 1 min and 30 min, 2 hours and 25 hours for two step sintering. The optimal sintering profile was Profile C2 where doped 3Y-TZP undergone two step sintering with dwell time of 1 minute at 1400°C and 1250°C for 30 minutes. At this optimal sintering conditions, the doped 3Y-TZP samples exhibited 98.5% relative density, with Young's Modulus of 206.66 GPa and Vicker's Hardness of 14.35 GPa.

A single-phase of perovskite-type oxide material can be prepared at a processing temperature relatively lower than 1000 °C through a sol-gel method. However, it is affected by the nature of chemical additives employed during the synthesis process. In the present work, sol-gel derived lanthanum strontium cobaltite, La_0.6Sr_0.4CoO_3-δ (LSC64) material is prepared using various non-ionic surfactants namely polyoxyethylene (10) oleyl ether (Brij-97), polyoxyethylene octyl phenyl ether (Triton-X-100) and polyoxyethylene (20) sorbitan monooleate (Tween-80). The prepared powders of the LSC material is subsequently subjected to the thermal decomposition, phase formation and microstructure analysis by a thermal gravimetric analyzer, an X-ray diffractometer and a scanning electron microscope (SEM), respectively. The as-synthesized powders are calcined at different temperatures based on the thermal gravimetric analysis results. X-ray diffractometer results reveal that all of the calcined powders consist of more than 90 % perovskite phase of LSC64 and other secondary phases such as cobalt oxide, lanthanum oxide and strontium carbonate. The Brij-97-based and Tween-80-based calcined powders have morphology of typical clump-like network structure, while the Triton-X-100-based calcined powder has morphology of flake-like network structure.

Membrane-based technology for gas separation has great potential in HVAC (Heating, Ventilating, and Air Conditioning) industry. In this research, the nanoparticle filled poly(vinyl alcohol)/poly(vinylidene fluoride) (PVA/PVDF) hollow fiber membrane was fabricated for indoor air dehumidification. The Poly(vinyl alcohol) thin film incorporated with nanoparticles was coated in the cavity of the Poly(vinylidene fluoride) substrate membranes. The enhanced performance of three types of nanoparticles [Zeolite, Titanium Dioxide (TiO₂) and Graphene Oxide (GO)] was investigated experimentally for evaluating the water vapor permeability. The effects of nanoparticle types and nanoparticle loading concentration on the permeability enhancement of the nanoparticles filled PVA/PVDF membrane were compared and analyzed. The results indicate that the nanoparticles additives of great benefit to the performance improvement of water vapor permeability. The enhancement performance of three nanoparticles is as follows: Zeolite > GO > TiO₂. The addition of 0.05 wt% Zeolite nanoparticles lead to twice enhancement on the water vapor permeance than the original PVA/PVDF membranes. The GO nanoparticle additive enhances the water vapor permeance to around 1500 GPU (gas permeation unit) with the nanoparticle concentration from 0.1 wt% to 0.2 wt%. However, the addition of TiO₂ nanoparticle has no obvious enhancement due to its large particle size. This work provides a new perspective for strengthening the air dehumidification performance of composite membrane.

The computational fluid dynamics (CFD) simulation on the effect of pillar shapes on chitosan-ZnO nanoparticles flows in pillar-based microfilter was considered using ANSYS Fluent in the laminar flow condition. Three shapes of the pillar were studied: cylindrical, cuboid, and rotated cuboid pillar. The volume of fluid (VOF) method was performed under a certain set of considerations and assumptions in order to validate the microfilter design to have the same flow patterns based on the literature. The discrete phase model (DPM) was carried out in order to simulate and analyze the chitosan-ZnO nanoparticles flow behaviour and separation efficiency performance in pillar-based microfilter. The DPM was carried out in 200, 300, and 400 streams to track the position of the nanoparticles in order to analyze the separation performance for each pillar shape. The simulation involved a different number of streams that were observed on the impact of nanoparticle Reynolds number and the total number of nanoparticles. It was observed that microfilter-C (rotated cuboid pillar) has the best separation efficiency of chitosan-ZnO nanoparticles compared to microfilter-A (cylindrical pillar) and microfilter-B (cuboid pillar) based on the particle position from the outlet of microfilter which was 2.5 mm, 0.08 mm, and 2.1 mm respectively. The shape of the pillar is a critical parameter that plays a significant role in the separation performance of nanoparticles in pillar-based microfilter.

An innovative method for utilizing synthetic calcium fluoride (CaF₂), recovered from fluoride-containing semiconductor wastewater, and waste sulfuric acid (H₂SO₄) to produce hydrofluoric acid (HF) was investigated. The research was set to study the low-temperature production of HF via the reaction of synthetic CaF₂ and waste H₂SO₄. The impact of H₂SO₄ concentration and total volume (H₂SO₄ + H₂O)/CaF₂ ratio, drying temperature of synthetic CaF₂ on HF productivity were investigated in this study. HF yield increased with increasing H₂SO₄ concentration and total volume/CaF₂ ratio under room temperature. In addition, the HF produced in the reactions involving the 105 °C-dried synthetic CaF₂ were higher than the 600 °C-dried synthetic CaF₂ ones. The study will not only find uses for this semiconductor wastes but also provide a greener alternative to the current commercial production of HF.

Biochar has been recognized as a potential media for soil amendment regarding its high surface area and retention capacity to slowly release nutrients to soils. However, the recycling of biochar after domestic water treatment towards agricultural application is still not well known. Therefore, this research studied the role of nutrient-loaded biochars produced from agricultural residues after canal water treatment as soil promoters for Gomphrena growth. Corncob, coconut husk, coconut shell and rice straw derived biochars were separately produced in a kiln (~378 °C) (namely CC, CH, CS and RS, respectively) and a pyrolysis reactor (500 °C) (namely CC-P, CH-P, CS-P and RS-P, respectively). The CH biochar was further modified with chitosan to improve its surface properties (labeled as CHC). The CH and CHC biochars after canal water treatment at lab and pilot scales are labeled as CH-column, CHC-column, CH-pilot and CHC-pilot, respectively. The loaded and unloaded biochars were further added in aquaculture sediment and loamy soil at 0.4, 0.7 and 1% mass ratio for Gomphrena growth. From the results, biochars amended in soil and sediment significantly improved seed germinations of Gomphrena, compared to control treatments. RS 0.4% amended in soil and sediment showed the highest seedling height (~2.5 cm) among all biochars, in accordance with its releases of K⁺, PO₄^3- and NO₃⁻ into solution at high concentrations. Gomphrena growth in sediment amended with CH-column 1.0% biochar was comparable to unloaded biochar, indicating that loaded biochar can provide nutrients without harming the plant. In addition, chitosan modification induced higher plant growth in sediment amended with CHC-column 1.0% than with unmodified biochar. Gomphrena germination was also improved in CH-pilot and CHC-pilot biochars amended in sediments with maximum seedling heights of 3.5 and 4.2 cm, respectively. This is likely due to the abilities of CH-pilot and CHC-pilot biochars to release N (NH₄⁺, NO₃⁻) and total P of 0.106 and 0.111 mgN/L, and 0.770 and 0.637 mgP/L, respectively. This study revealed that the nutrient-loaded biochars can be used to sustain soil fertility through gradual releases of nutrients and thus promote the recycling of agricultural residues.

Organic waste, especially fruit and vegetables is currently a major problem in the world due to serious risks to human health and the environment. On the other hand, fruit and vegetable waste contains anthocyanin (flavonoid of polyphenol) compounds that can produce antioxidant to inhibit oxidation reaction caused by free radicals such as diseases that exist in the digestive tract. it has been an important thing to make a bioproduct solution associated with the animal element's feed ingredients. The result of this study showed that an anthocyanidin from isolates fruit and vegetable was successfully identified by (i) fermentation time variations used are 0; 1; 3; 5 and 7 days resistant to acid pH 4. The compound isolation process use liquid-liquid extraction method with ethanol 96% by diluting 1:3 in the anaerobic jar (ii) Lactic Acid Bacteria (LAB) were gram positive purple colored and basil shape based on Gram staining (iii) thus, an antimicrobial activity was shown by clear zone with E15 which were 18 mm, 20 mm and 24 mm from 72 hours incubation on nutrient media Euschericia coli.

Rapid improvements in bioseparation technology, new regulatory directives, product quality constraints, and the production efficiency have necessitated the development of more advanced and powerful downstream bioprocesses for biotechnology and biopharmaceuticals industrial. This has transformed in dramatically improvements in traditional bioseparation processes as well as the development of entirely new approaches. In this paper, we highlight some of these recent advances of integration of semi-batch cultivation and extraction for maximal lipid production in Chlamydomonas sp. Tai-03. This includes extractive cultivation, extractive bioconversion aqueous two-phase system, aqueous two-phase flotation, and newly developed liquid biphasic flotation. Alcohol/salt liquid biphasic flotation (LBF) with aid of ultrasonication which have the ability of killing two birds with one stone, it not only capable in cell rupturing, it also able to recover bioproducts simultaneously and continuously. The effect of varying crude feedstock concentration, flotation time, type of salt, concentration of salt, type of alcohol, concentration of alcohol, initial volumes of salt and alcohol were investigated. Microalgal biofuels or generation three biofuels have been widely recognized as potential replacements of fossil fuels. One of the most attractive option is the partial or full replacement of diesel fuel with microalgal biodiesel. Here, Chlamydomonas sp. Tai-03 was cultured using semi-batch cultivation to enhance its lipid production. Upon lowering the culture replacement fraction to 25%, the greatest biomass and lipid productivities were obtained at 1.23 ± 0.02 g/L/d and 239.6 ± 24.8 mg/L/d. After transesterification, palmitic acid (C16:0), oleic acid (C18:1), and linoleic acid (C18:2) were the main fatty acid methyl esters (FAMEs) present. These short-chain FAMEs and high productivities of Chlamydomonas sp. Tai-03 are suitable for biodiesel output.

Hydrogen production plays an important role in hydrogen energy development. The steam reforming reaction is an efficiency way for hydrogen production via thermochemical method. But the hydrogen concentration was limited to be about 70% because of thermodynamic equilibrium. In order to avoid equilibrium limiting, the by-product CO₂ removal during reaction was a suitable solution that drives the reaction to the right. In this study, the steam reforming of methane by in-situ CO₂ sorption was investigated. The CaO material was used as CO₂ acceptor because of its high capacity, fast kinetics and generality. The reforming catalysts were prepared by simple physical mixing of the 20 wt.% Ni/Al₂O₃ catalyst and CaO sorbents. The steam reforming of methane experiments was carried out by a fixed bed reactor. The experimental results indicate that the steam reforming of methane via in-situ CO₂ sorption obviously obtained the H₂ purity above 95% higher than conventional reaction without in-situ CO₂ removal (~72% H₂). The impurities involving CO and CO₂ during reaction were suppressed below 0.5% before CO₂ sorbent saturation. In this work, the highest H₂ purity and CH₄ conversion were founded to be 98.4% and 95% at 873K under steam/carbon ratio of four conditions. The methane steam reforming with high conversion strongly depended on the CO₂ capture performance. The cause was attributed to the equilibrium limiting of reaction overcoming by in-situ CO₂ sorption. It is also found that the product components and methane conversion was insignificantly affected in the range of space velocity from 7200 to 19200 cm³/hr/g.

With the rise of carbon emission daily, a pursuit for cleaner energy such as hydrogen fuel is necessary. Obtaining a good hydrogen storage is one of the main bottleneck to achieve a working hydrogen economy. Materials including two-dimensional systems have been widely investigated for potential hydrogen storage. In this work, the effects of nitrogen on the hydrogen adsorption on planar hexagonal aluminene was studied using density functional theory. Aluminene was decorated with nitrogen at different sites: top, hollow and bridge. Results showed that nitrogen was adsorbed at the top, bridge and hollow sites at a distance of 0.00Å to 1.80 Å with binding energies of 2.71 eV, 4.88 eV, and 3.44 eV, respectively. Comparing to the pristine aluminene, there was no major difference with its electronic and magnetic properties based on the density of states of the nitrogen-doped aluminene while the nitrogen atom gained some charges from the aluminium atoms based on the charge difference. On the other hand, a hydrogen molecule was adsorbed with binding energies ranging from 13.4meV to 26.3 meV close enough to the adatom on the decorated system. Minimal broadening of energy level was found from the density of states. This work shows that aluminene with nitrogen impurity can adsorb hydrogen molecules. However, high concentration of nitrogen will lower the hydrogen capacity of aluminene.

With the rising demand for clean energy, the concept of hydrogen economy has grown more popular, and with this popularity the need for better hydrogen storage materials increases. Decorated surface materials such as planar hexagonal aluminene are being studied to determine their potential as good hydrogen storage materials. This study theoretically investigates hydrogen adsorption on aluminene decorated with calcium, where calcium is binded on the top, bridge and hollow sites of aluminene using density functional theory. Results on decoration adsorption have shown that calcium can easily bind a distance of 1.80 Å to 2.80 Å on the top, bridge and hollow sites with binding energies of 1.85 eV, 2.01 eV, and 3.32 eV, respectively. The density of states of the calcium-decorated surface show that its electronic property is generally maintained with zero magnetization. Small amount of charges were adsorbed from the aluminium atoms to the calcium atom based on the charge difference. This leads to hydrogen molecule adsorption with low adsorption energies ranging from 34.13 meV to 80.51 meV. In addition, minimal broadening of energy levels were shown by the density of states. With these results, it can be concluded that planar hexagonal aluminene with low concentration of calcium atoms may lower the hydrogen capacity of aluminene.

Hydrogen storage is one of the challenging components in hydrogen economy towards a cleaner energy. Two-dimensional materials are being explored as a potential hydrogen storage material. Adsorption of hydrogen on buckled aluminene was investigated using first principles with the incorporation of van der Waals correction via Tkatchenko-Scheffler method. Four possible adsorption sites were identified: top of the first layer, bridge, hollow, and top of the lowest layer. Critical results of energy calculations showed that hydrogen molecule can be physisorped on any sites of buckled aluminene with a binding energy of 0.77 eV without additional energy needed to store it. This physisorption is demonstrated in the density of states showing a slight broadening of energies. Hydrogen would prefer to be adsorbed as a molecule due to a dissociation barrier of 3.23 eV to recover the hydrogen. Another critical finding is that buckled aluminene has more possible hydrogen adsorption sites and higher binding energy than that of planar aluminene indicating a better candidate as a potential hydrogen storage material at a higher ambient temperature.

Latent heat storage systems consisting of phase change materials (PCMs) offer the advantage of a large thermal energy storage density as compared to sensible heat storage systems. Most recent work has focussed on organic and inorganic PCMs which have problems of subcooling and phase segregation. Metallic PCMs are a recent innovation for medium to high temperature applications due to their high thermal conductivities, high volumetric storage capacities and their low degrees of sub-cooling during the release of latent heat. For medium temperature applications like cooking of food, very limited work has been done on metallic PCMs for energy storage. Solder based PCMs have rarely been investigated for medium temperature applications thus it is necessary to carry out an experimental study on the use of a solder as PCM candidate. No work has ever been reported using the eutectic solder (Sn63/Pb37) as a PCM. Its use is justified since it is low cost and locally manufactured solder worldwide. Another recent innovation is cascaded thermal energy storage (TES), whereby two PCMs with different melting temperatures are used in a single storage tank to improve the efficiency of energy storage. No work has also appeared in recent literature involving metallic solders in cascaded systems. In a bid to investigate the suitability of the eutectic solder as a PCM for medium temperature applications, two eutectic solder (Sn63/Pb37) based systems are experimentally evaluated during discharging cycles. The first system is a single PCM system composed of a packed bed of spherically encapsulated eutectic solder capsules. The other system is a two PCM cascaded system comprising of eutectic solder spherical capsules at the top and erythritol spherical capsules at the bottom in a storage ratio of 50 %: 50 %. Discharging experiments are carried with three different discharging flow-rates to investigate the effect of the flow-rate on the thermal performance. The three discharging flow-rates used are 4 ml/s, 6 ml/s and 8 ml/s. For both storage systems, an increase in the discharging flow-rate increases the peak discharging energy and exergy rates. For both storage systems, an increase in the discharging flow-rate increases the peak discharging energy and exergy rates. The single PCM system shows higher energy and exergy rates for most of the discharging duration compared to the cascaded system. An increase in the flow-rate increases the peak energy and exergy discharging rates for the single PCM and the cascaded PCM storage systems. The single PCM system out-performed the cascaded system during the discharging tests possibly due to the lower melting temperature and lower thermal conductivity of the bottom PCM (erythritol) in the cascaded system. However, for the higher flow-rates (6 ml/s, 8 ml/s), the cascaded system shows a slightly better or comparable performance at the start and at end of discharging.

Electricity consumption in big cities has been increasing, especially in crowded areas. Although there is a large amount of energy usage in such places, people can generate the unnoticeable electrical energy from their footsteps. This paper aims to present the feasibility on development of an energy harvesting floor—called Genpath—using a rotational electromagnetic (EM) technique to generate electricity from the human's footsteps. The system in Genpath comprises two main parts: the EM generator and the power management and storage circuit. After stepping over the floor, a rack-pinion mechanism under the floor converses the linear translation from a footstep into the rotation to drive a DC-generator to generate electricity. The EM generator yields an average energy per footstep of about 199 mJ (or average power of 331 mW) and the maximal voltage of 19 V at the rated 140-Ω load resistance. This amount of energy is sufficient for low power consumption electrical devices. The efficiency of the EM generator in Genpath is 16.6% based on the power generation from the heel strike of the human's walk of 2 W per step. Among overall energy generated by the generator, 68% of generated energy is stored in the 9-V rechargeable batteries and the rest is supplied to the 4-V, LED instantaneous loads. The power management and storage circuit consisting of the diodes and DC-DC buck voltage converters was successfully designed. With 54% efficiency of the circuit, the average energy per step of 169 mJ can be stored in the rechargeable battery, and the other 4.7 mJ can be supplied to the LED loads.

The benefits of the rotor design are optimizing power generation and reducing cost of build in wind turbines. In this study, a performance comparison of horizontal axis wind turbines in terms of their rotor diameter is made using Qblade software. The airfoil selected is the National Advisory Committee for Aeronautics (NACA 0012) for all models, and the wind turbines have three blades. From simulations, the optimal rpm for each rotor diameter was calculated, and the generated power for different wind speeds.

The results found show that the operation of wind turbines consider need operated with tip speed ratios of between 4 to 7 to give optimal power output. Maximum power was produced for a blade diameter of 170 metres and the highest power coefficient found was for a diameter of 30 metres and for this case also had the highest tip speed ratio of 6.68. Overall results can suggest which diameter range is used for choosing a rotor size that is the most cost-effective.

This paper presents the experimental work on a new tube-shape electromagnetic vibration energy harvester to obtain its optimum peak-to-peak voltage output based on different stroke length, number of coil turns and optimum frequency. The harvester is fabricated using Acrylonitrile Butadiene Styrene (ABS) material. It consists of housings with three different stroke lengths, top and bottom covers, Neodymium Iron Boron (NdFeB) magnets, spring and copper coil. The tested stroke lengths are 40 mm, 45 mm and 50 mm while the number of coil turns are 10, 20 and 30. A standard energy harvesting circuit which consists of full-wave bridge rectifier and a capacitor is designed and fabricated to conduct this experiment. The importance of this circuit is to convert alternating current (AC) to direct current (DC) as well as to enable harvesting and storing processes of electrical energy. The harvester is tested on external vertical vibrations generated by shaker with frequency ranged from 5 Hz to 50 Hz with interval of 5 Hz. The raw voltage readings have been extracted from Oscilloscope and are analysed using Microsoft Excel and Octave software. From the results obtained, the optimum peak-to-peak voltage harvested is 39.41 mV at resonant frequency of 5 Hz by 50 mm stroke length and 30 coil turns device. The higher the stroke length and number of coil turns, the higher the peak-to-peak voltage can be harvested.

The transient dynamic behaviour of floating energy storage unit (FESU) is a result of coupling between three non-linear effects, which are sloshing of floodwater, wave loading, and FESU dynamics. The coupling of these effects would result in the catastrophic failure of the FESU in extreme conditions. Computational Fluid Dynamics (CFD) has shown that it holds great potential in solving the problem in the time domain, which is suitable for the transient stage. In this study, CFD simulation of damaged stability was conducted by using OpenFOAM to determine the dynamic response of FESU under the effects of floodwater and wave in transient flooding. OpenFOAM CFD simulation was conducted for the flooding of barge shaped FESU with different water inlet and air outlet sizes in still water condition followed by damaged stability in Stokes' fifth-order beam wave and head wave condition. Dynamic responses of FESU, such as roll, pitch, heave, and floodwater volume flow rates were determined using the dynamic meshing solver of OpenFOAM. Simulation results showed similarity to experimental results within the time frame of 16 seconds. Reduction in water inlet area and air outlet area decreased the flooding time and flow rate of flood water. The amplitude of vibration of roll and pitch motion increased as the flood water volume was increased due to the force of floodwater exerted on the wall. Sloshing effects also caused the model to roll and pitch in secondary vibrational motion. Due to the coupling effect of the three non-linear criteria, the inflow and outflow of floodwater changed with time, which concludes that transient effects should not be ignored in the damaged stability assessment of FESU.

A fixed anti-sloshing mechanism such as baffles which modifies the tank structure may lead to increment of the maintenance cost. This paper proposes a floating baffle, and reviews its investigation on the sloshing behaviour in a membrane-type tank model under unidirectional excitation with 30% and 50% of filling ratio. An LNG tank was numerically simulated in OpenFOAM under regular sinusoidal motion with an amplitude of 3 cm and excitation frequency set to the natural frequency at 1.1 seconds. Impulsive pressure on the tank wall was obtained, and then benchmarked with the experimental results from the pressure sensors. The simulation and experiment results showed an acceptable agreement with a root mean squared error of less than 10%. The findings are expected to become a significant reference for safer sea transportations such as conventional LNG vessels.

Geothermal energy has been widely used in the field of the building heating through the ground heat exchanger (GHE). The groundwater flow in the aquifer is one of the significant factors affecting the heat exchange process between the GHE and ground by promoting the pure conduction to the conjugated convection and conduction heat transfer. In this paper, the variations of the ground temperature field and the thermal influence radii subject to the existence of aquifers were investigated numerically. The geometrical models consisting of a coaxial heat exchanger, multiple aquifer and aquifuge layers were established to study the effect of groundwater velocities and the number of aquifer layers on the GHE system. The results reveal that the heat exchange capacity of the GHE is enhanced when the groundwater velocity increases. The increased number of aquifer layers can also enhance the heat exchange capacity with the tested groundwater velocity at 315 m/a or 31.5 m/a, but would weaken it with the velocity of 3.15 m/a. In addition, it is found that the aquifuge temperature field is affected by the aquifer layer, and the thermal influence radius of GHE is dominated by the groudwater velocity of aquifers when the velocity is larger than the critical velocity. Conversely, the thermal influence radius is governed by the thermal diffusivities of aquifuges for the groundwater velocity samller than the critical velocity.

Wind-turbine wakes significantly affect the power output of downstream wind turbines. In order to improve the calculation accuracy of wind-turbine wakes in the atmospheric boundary layer, a new improved actuator line - large-eddy simulation (AL-LES) method is proposed and verified by experiments. The traditional AL-LES method is improved in three aspects. Firstly, the atmospheric turbulence is generated by a dynamic k-equation LES with a wall shear stress model and a buoyancy effect model. Secondly, the nacelle and tower are modelled based on the static actuator line method. Finally, the distribution of blade body force is improved by using an anisotropic 3D Gaussian function. Based on the results of three wind tunnel experiments conducted by Norwegian University of Science and Technology (NTNU), China Aerodynamics Research and Development Centre (CARDC) and Von Karman Institute for Fluid Dynamics (VKI), the improved AL-LES method is validated from the aspects of wind-turbine power performance, the generation of tip vortex, and the distribution of wake velocity under typical offshore and onshore conditions. In addition, a full-scale wind turbine installed in Gansu is used for the experimental and numerical research. The main conclusion is that compared with the traditional method, the new AL-LES method improves the numerical accuracy by nearly 22%, and can more accurately simulate the interaction between atmospheric turbulence and wind-turbine wakes. The results can help the research of wind-turbine wakes and the micro-location selection of wind farm.

Photocatalysts have increasingly become important materials to utilize renewable solar energy for decomposing pollutants, producing clean water, achieving self-cleaning surface, and so on. Therefore, it is desirable to expand the applications of photocatalysts by enhancing the functionalities and allowing ample design flexibility. Here the potential of nanoparticle-based photocatalyst films with microscale surface structures was investigated in order to enhance their useful functionalities. Photocatalyst films with microscale surface structures were prepared using the suspension of titanium dioxide (TiO₂) nanoparticles. The micro-scale structural features of prepared films were evaluated using a scanning electron microscope. Also, an atomic force microscope (AFM) was used. The AFM analysis of a film consisting of nanoparticle spherical aggregates revealed a surface profile of subwavelength surface structure. Then the optical and wetting characteristics were investigated. It was found that the visible-light transmittance increased due to subwavelength surface structures and that the microstructured TiO₂ films exhibited the contact angles below 10 degrees, i.e., superhydrophilic behavior, without ultraviolet-light illumination. On the basis of the presented results, it was suggested that the microscale surface structures of photocatalyst film can be designed to achieve enhanced functionalities. It is expected to effectively utilize the energy of sunlight in many applications using functional photocatalyst films with optimized design.

Thermal energy storage has been attracting more and more attentions due mainly to its distinctive features on peak-load shifting capability for systems with renewable energy involved. To further improve the overall thermal efficiency for charging/discharging processes, heat transfer techniques to enhance phase change heat transfer are typically employed. This paper introduced a novel concept of partially-filling ratio of metal foam into PCM. The melting heat transfer can be expected to be further enhanced with partially filled metal foams. To this aim, an axisymmetric two-dimensional computational model was established. A series of numerical simulations were carried out to study the effect of filling ratio of metal foam on the melting performance of a TES tube. Good agreement was achieved through the comparison of temperatures obtained from simulation and experimental measurements. Based on the results, it can be concluded as follows: if the goal was to enhance heat transfer simultaneously to save material cost, the suggested filling ratio was 0.90; if saving material cost was the aim, the filling ratio can be further reduced to 0.85. The proposed novel TES unit with partially-filled metal foam outperformed other competing heat transfer technique.

The effect of microwave susceptor design on the heating profiles of co-pyrolysis between waste truck tyre and empty fruit bunch was studied. Carbonaceous susceptor was used to elevate the pyrolysis temperature along with increased heating rate. Different design of microwave susceptor and its effect towards the heating profiles of the studied co-pyrolysis process was examined. The aim is to determine the effect of heating rates on the pyrolytic-oil yield, calorific value and energy recovery. From the study, it was revealed that the microwave susceptor design (D1) with a horizontal-layer single-bed, located at the bottom (SB-HL-B) of the feedstocks, showed higher heating rate (83 °C min⁻¹). Higher heating rates were observed to significantly increase pyrolytic-oil (39.0 wt%) and energy yield (59.0%). Such heating rate also upgraded the pyrolytic-oil properties, producing oil with higher calorific value (42.20 MJkg⁻¹). Thus, the present study demonstrated a viable method to optimise pyrolytic-oil yield in producing diesel-like fuel through the adoption of a microwave-assisted heating method.

Ultrasonic irradiation approach has become one of the most popular methods applied in chemical processing including lignocellulosic biomass pretreatment and industrial cleansing. The phenomenon of ultrasonic cavitation can be indeed delineated via the Rayleigh-Plesset equation (RPE), which governs the transient radius of the bubble. Nonetheless, the time marching in the numerical solutions for RPE is highly unstable, which cannot be assured using von Neumann analysis. High sensitivity of RPE to time step may lead to extremely long computational time. The lack of numerical investigation into the time stepping issue of RPE has hindered in-depth simulation of ultrasonic cavitation. Therefore, the purpose of this paper is to investigate the stability criterion of time stepping for RPE in different time progression schemes, namely Euler explicit, 2^nd order Taylor's method, 4^th order Runge-Kutta, Runge-Kutta Fehlberg and Cash-Karp Runge-Kutta method. A simple modified adaptive time step method and α independence study has been introduced in this paper for fast, stable and accurate computation of RPE. Compared with the traditional constant time marching method, the new model is able to improve the computational cost significantly without affecting the time marching stability and resolution of the results. Among the investigated method, Runge-Kutta family solvers have higher computational accuracy, with the cost of higher critical α value. The model is also applied to compute the pressure and temperature hike during bubble collapse due to different sonication power. The simulation results show that the ultrasonic irradiation with higher sonication power could produce a higher energy to break the lignocellulose wall.

This paper aims to understand the influence of vortex generators (VGs) on deep dynamic stall of the NREL S809 airfoil. The fully-resolved URANS method is used to predict aerodynamic responses of the airfoil with both single-row and double-row VGs. On one hand, single-row and double-row VGs are found to attenuate the force fluctuation and postpone the extension of flow separation when the airfoil pitches up. The onset of deep dynamic stall is therefore significantly delayed with the maximum lift coefficient increased beyond 40%. This indicates that VGs are effective in controlling deep dynamic-stall behavior. On the other hand, single-row and double-row VGs are found to make a great difference in aerodynamic responses when the airfoil pitches down. Single-row VGs undermine the torsional aeroelastic stability and have the potential risk of making the airfoil flutter. Double-row VGs can accelerate the flow reattachment effectively, and quickly restore the decreased aerodynamic force near the maximum angle of attack. These findings also imply that deep dynamic stall with VGs becomes highly complicated, because VGs can be fully submerged in separation vortices. In general, double-row VGs perform better than single-row VGs to control deep dynamic stall. This study is believed to assess the VG performance in controlling highly unsteady aerodynamic loads on wind turbines.

Celagen Island is one of the outer islands in Bangka Belitung Islands Province. The population of Celagen island is 1234 people and dominated by fishermen. Currently, electricity is supplied from 1 unit of photovoltaic with capacity 80-kWp and coupled with three units of diesel power plant with capacity 100 kW. To meet the electricity needs of 1069 kWh/day, supply from diesel power plant already sufficient. But for the economics of the cost of providing primary fuel, a hybrid from photovoltaic and diesel power plants needs to be done. Hybrid power plants are one of the options to meet the electrical energy needs of geographically difficult areas to connect to the on-grid electricity network. The hybrid system with 72% of electricity from the diesel power plant and 28% of electricity from photovoltaic is very economical. The economic analysis shows that with this modeling, the cost of providing primary fuel is lower by 1228 rupiah/kWh if only using diesel power plant.

In this paper, diode clamped type three-phase five-level inverter is used for AC load interfacing in DC microgrid. Multilevel inverters generate staircase voltage waveform with a series of power semiconductor switches from several layer voltage DC sources. Therefore, the output voltage waveforms in multilevel inverters can be generated at low switching frequency with high efficiency and low distortion. In two-level inverter, various pulse width modulation (PWM) strategies with high switching frequency is required to obtain a output voltage or a current waveform with a small amount of harmonic content. In existing DC microgrid, three-phase conventional two-level Sine-PWM inverter is used and so, total harmonic distortion (THD) is high. To reduce the THD and the size of AC filter and to get the quality output, diode clamped type three-phase five-level inverter is applied in this research. Level shift multi carrier Sine-PWM method is used for the diode clamped circuit topology. The output waveforms of conventional two-level inverter and diode clamped five-level inverter are measured and compared the each output waveform qualities such as voltage THD, current THD and AC filter size. The performance of five level diode clamped inverter is illustrated by PSIM software and experimental results are carried out with prototype.

With the increasing demand for renewable energy, solar photovoltaic technology is being a topic of concern. However, due to the accumulation of dust and dirt over the panel surface, the performance of the photovoltaic system degrades to a noticeable number. To address this issue: a fully automated, cost worthy and efficient system needs to be invented. This paper presents the design and fabrication process of a prototype able to clean the panel surface. The prototype of this system comprises of a cleaning robot and a cloud interface: the cleaning robot is mobile and able to clean the entire solar array back and forth, with its separately driven cleaning rotatory brush; whereas, the cloud interface is a human-machine interface featuring the distant monitoring and control of the robot. Additionally, to notify the performance of distantly placed solar farm, a sensing unit consisting of sensors was added to this system. Furthermore, to add an automatic cleaning feature, a month-long data of totally clean and dusty panel was processed with regression analysis, and the developed regression model was programmed into the sensing unit. The sensing unit added with the regression model is named as an autonomous unit, as it predicts the suitable time for cleaning action. According to the system evaluation done on a demonstration PV module, it was found that the designed system can clean dry dust accumulated over the panel's surface. Moreover, by attaching the metal rail tracks on a long solar array, the system seems to be implementable on a large scale solar farm.

Various hybrid nanofluids have been researched in this decade. The quality of this said-to-be alternate heat transfer medium depends on two major features – long term stability and high thermal conductivity. In recent years, graphene-based nanofluid was reported to exhibit distinguished heat transfer performance compared to most materials investigated in past studies. This study aims to compare the effect of different surfactants on thermal conductivity of graphene-based nanofluid. Sodium dodecylbenzenesulfonate (SDBS) and hexadecyltrimethylammonium bromide (CTAB) were mixed separately in advance with the mixture of water and ethylene glycol. After mixing surfactants and base fluid, total 0.025 to 0.1 wt% of nanoparticles were added into the mixture and followed by ultrasonication. Mono nanofluid was produced by adding graphene nanoplatelets (GnP) only whereas a novel hybrid combination was composed of graphene nanoplatelets and titanium dioxide. Stability of each sample was inspected using zeta potential analysis and Uv-vis spectroscopy. Thermal conductivity of samples from 30 °C to 60 °C was measured using Decagon KD2 Pro. Both surfactants contributed to high zeta potential value and minimal sedimentation for all nanofluids. CTAB improved the thermal conductivity of hybrid nanofluid more compared to SDBS, with 11.72% difference at 0.1 wt% nanoparticles concentration when compared to base fluid at 60 °C. The highest enhancement (23.74%) on base fluid was spotted at 60 °C, where 0.1 wt% of GnP was mixed with CTAB. These findings could strengthen literature on suitable surfactant to be used on graphene based nanofluid since limited comparison work has been done. High thermal conductivity of the hybrid nanofluid at high temperature could be used as coolant in cooling system.

Model verification is necessary before numerical models can be applied to produce meaningful results. For solid-liquid phase change modelling involving convection, pure gallium and tin melting have been widely used as reference for verification. It was later found that contrasting observations have been reported on the flow structure of both metals in the liquid region during the phase change process. Some researchers have reported monocellular while others reported multicellular structures in past works. In this work, tin melting problem was revisited by extending the results to flow structure visualization with Line Integral Convolution (LIC) plots to confirm the flow structure for tin melting thus pure metals in general. Enthalpy-porosity formulation coupled with Finite-Volume Method (FVM) was used to solve the set of governing equations which represented the problem at Prandtl Number = 0.02, Stefan Number = 0.01 and Rayleigh Number = 2.5 x 10⁵. The location of solid-liquid interface and LIC plots at different times were presented. At initial state, the solid-liquid interface was closely similar for all grid sizes but as time progresses, finer grids provided improved solutions as expected. Reasonable fine grid size must be selected for solid-liquid phase change models to ensure complete physics of the problems are captured and eventually yield acceptable numerical results. The LIC plots confirmed that the flow structure is multicellular. Future phase change models referring to pure metal melting problem for verification should obtain similar flow structure to be considered acceptable.

The hybrid AC/DC microgrid systems have been popular and being developed as the next generation power systems because of the comprehensive combination of both AC and DC microgrid systems. Power management scheme is one of the most critical operation aspects for hybrid microgrids because the system is operating with various generation sources and loads such as renewable energy sources, energy storage systems and AC and DC loads. Therefore, in this research, control strategies and power management scheme is considered for all possible operation modes of standalone and grid-connected conditions. In the existing microgrid system in Electrical Power Engineering department in Yangon Technological University, rooftop PV plant and battery are cooperating to supply the electricity. The inverter in this system allows the unidirectional power flow from DC to AC and there is no specific power management system for grid-connected and standalone operation mode. To provide bidirectional power flow in the existing system, the configuration of converter and control strategies for power management system are developed in this research. To provide the bidirectional power flow between AC bus and DC bus, the bidirectional interlink power converter with high frequency isolation is applied. The control system including the power balancing between generation and demand, DC link voltage control and AC link voltage and frequency control is considered. By applying droop control method in the developed system, power flow balancing between AC bus and DC bus is maintained. And also, using high frequency isolation transformer in interlink converter provides fast response of the system performance and maintaining continuous power supply within each AC system and DC system during disturbance condition in one subsystem. The performance of the proposed power management system is demonstrated by using MATLAB/Simulink.

This study presents the identification of cumulative damage at the blade root of AVANTIS AB92 wind turbine blade by evaluating the simulations generated output obtained from GH Bladed software. The blade length was 45.3 m and consisted of six (6) different airfoils. The blade material was made of GRP/Epoxy with a weight of 10.2 tons. At the blade root, the bolt hole circle diameter was 2.3 m with a 1.3 m distance from hub centre to rotor shaft flange. The fatigue loads at the blade connection of AB92 were performed according to Germanischer Lloyd guideline for a 2.5 MW horizontal axis wind turbine generator with wind class IEC IIA. The simulations were performed when the turbine operates during power production with and without occurrence of fault with wind condition satisfying the normal turbulence model. Design load cases such as during start-up and normal shutdown were also carried out with wind condition similar to normal wind profile model. The fatigue load cases at the blade connection were post-processed by determining the rainflow cycle counting and damage equivalent loads using GH Bladed software. Statistical estimation models such as graphical and exponential methods were also used to predict the Weibull parameters. The total fatigue damages due to bending moments and torsion at the blade connection were evaluated using the Palmgren-Miner's rule at different expected behaviour of S-N curves. Calculation results indicate that the total fatigue damage due to torsion, flapwise and edgewise bending moments at the blade connection of AB92 when the slope parameter of S-N curve i.e., m = 3 are less than unity with values of 0.8702, 0.0354 and 0.0180, respectively.

The production of biogas from solid wastes in addition to palm oil mill effluents is necessary due to the shortage of the effluents, operation of biogas plants at low to moderate capacities, and large amount of solid wastes, particularly oil-palm empty fruit bunches (EFB). However, the biogas production from raw EFB gives low yield. This study therefore aims to investigate the effect of EFB pretreatment methods on the improvement of biogas production. The pretreatment of EFB was carried out through chemical (NaOH solutions), physical (size reduction) and biological (activated sludge and bio-scrubber effluent) processes. The experimental data was tested against corrected Gompertz model. The results showed that size reduction and pretreatments of EFB with 7% w/v NaOH, activated sludge and bio-scrubber effluent could improve biogas yield significantly and differently. The highest yield of methane was 429.9 ml/g.VS, obtained from EFB with size reduction. For the pretreatments of EFB with 7% w/v NaOH, bio-scrubber effluent and activated sludge, the methane yields were 345.5, 326.4 and 297.3 ml/g.VS, respectively. Without pretreatment, the methane yield was only 226.0 ml/g.VS. The change in cellulose and lignin compositions of EFB after pretreatment is attributed to the improvement of biogas yield. It is economically interesting that the bio-scrubber effluent from palm oil mills can be recycled to treat EFB. In the modeling study, the corrected Gompertz model could fit all data sets reasonably well.

In recent years the power system is undergoing a rapid change from the traditional power system with large-scale power plants to small-scale distributed generations such as wind energy and solar photovoltaic system. In addition, the technology related to the electric business has been developed rapidly, such as solar power development technology, energy storage, and various communication and measurement devices, etc. The development of these technologies together with the reduced cost of technologies is the main factor in the transformation of the electric business model in many countries around the world, including Thailand to the way that electricity users turn from being consumers only to be both consumers and producers of electricity or called as prosumers. Also, it drives to the new paradigm: peer-to-peer electricity trading, where consumers and prosumers can buy or sell electricity locally. However, the concept of peer to peer energy trading is at early stage in Thailand. This study points out the benefits and barriers of peer to peer energy market based on reviewed existing peer to peer energy projects worldwide. The results of study show that the major regulatory barriers that restrictive to peer to peer market in most countries are the licensed energy supplier issue, network charging and no excess generation is fed back into the national grid.

In this paper, the numerical simulation on melting of phase change material was run by using ANSYS Workbench 17.0 that included mesh generation tools and FLUENT software. Paraffin wax was selected as the PCM and three types of nanoparticles: Alumina (Al₂O₃), Copper oxide (CuO) and Zinc Oxide (ZnO) were added to form nanoparticles enhanced phase change material. This paper focus on the melting rate and energy stored of phase change material in a 100mm × 100mm square enclosure. The effect of heat source orientation and the mass fraction of nanoparticles dispersed in phase change material were also investigated. Enthalpy porosity method was applied in this numerical study. Results shown that melting rate only can improved by adding low volume fraction of nanoparticles (2% wt). The overall melting rate of phase change material heated from the vertical side is higher than that heated from below. Besides, the energy Stored during the melting of phase change material heated from vertical side is greater and faster compared with heated from bottom. Al₂O₃ was the best enhancing nanomaterial among those three nanoparticles as it shown the fastest melting rate and highest amount of energy stored (207287 J).

This paper presents accurate control parameters estimation of the hydraulic Power Take-Off (PTO) model for the wave energy conversion system to maximise energy production. In general, the performance of the hydraulic PTO system depends on the parameters setting of hydraulic PTO system components such as hydraulic motor displacement setting, pre-charge of the hydraulic accumulator, and et cetera. Conventionally, it requires to manually obtain the optimal parameters of a hydraulic PTO system by repeating the simulation process. However, this estimation method exposed to human error and would easily be resulting in a non-optimal selection of hydraulic PTO parameters for the wave energy conversion system. Therefore, an easy and accurate approach of using the GA optimisation method for determining hydraulic PTO parameters was introduced in the present study. This approach is simple and more accurate compared to the conventional optimisation method. The hydraulic PTO model was developed in SIEMENS/Amesim environment using available components in the library. The specifications of the actual hydraulic PTO system components from the manufacturer were used during the simulation set-up. The complete hydraulic PTO system was optimised using a special genetic algorithm (GA) optimisation tools in the SIEMENS/Amesim software. The simulation results showed that GA was effective to determine the optimal configuration parameters of hydraulic PTO system. From the results, the optimal configuration parameters of hydraulic PTO system were successfully reduced about 38%. Consequently, the maximum force applied to the WEC devices was reduced up to 34%. This force reduction is important since it will enable the WECS to be operated during a smaller wave condition.

EFB pellet is the high potential biomass for combustion process due to the relatively high heating value and the high availability in the Southern of Thailand. However, the containing of high unwanted minerals, especially K and Cl is the main drawback of EFB pellet which causing the ash fouling or/and slagging during the combustion. In this study, the high quality EFB pellets (low K, low Cl, high heating value) were produced by applying the water washing and torrefaction methods. For water washing treatment, the effect of water and acetic acid solution on the mineral content of EFB pellet was studied. In addition, the effect of torrefaction temperature (250, 280 and 300 °C) on the quality of EFB pellet was investigated. Results revealed that the ash content of the washed EFB decreased from 5.3 % to 3.0 % and 0.7 % by washing with tap water and acetic acid solution, respectively. Comparing with the raw EFB pellet, K and Cl in ash were significantly reduced by washing about 60 % and 88 %, respectively. Heating value of the EFB and washed EFB pellet were increased after torrefaction with the higher temperature. The water washed EFB pellet and torrefied at 300 °C gave the highest heating value about 24.3 MJ/kg. It was 33% increased HHV when comparing with raw EFB pellet.

In this study, palm kernel shells were utilized in the gasification process to produce syngas. In addition, biochar prepared from pyrolysis of the left-over mangosteen and durian peels were used in the gasification process to enhance the tar removal efficiency. The expected outcomes of this study could result in not only the generation of renewable energy from but also the waste utilization of agricultural residues. The effect of catalysts and biochar on the syngas quality improvement were particularly studied. Palm kernel shell was used as raw material. The compositions and heating values of the biomass were characterized by the proximate, ultimate, and bomb analyses, respectively. Syngas was produced from a downdraft gasifier connected with catalytic and adsorption units in sequence. The gasification process was operated with 1 kg of palm shell per batch at a fixed air flow rate of 25 L/min. The NiO/CaO (10 %wt) catalysts on ceramic supporter with various NiO contents of 2%, 4%, and 8% were synthesized by co-impregnation. Biochars were synthesized by pyrolysis process of durian and mangosteen peels at around 300 - 500 °C for 2 hrs. Morphology and compositions of the synthesized catalysts and biochar were analyzed. The results of SEM analysis showed that the NiO and CaO were deposited and well dispersed on the porous ceramic ring supporters. The presence of active NiO on the catalyst was also confirmed in FTIR result with (wavelength of 692 cm⁻¹). Biochar from durian and mangosteen peels, with BET surface area of 0.9219 - 0.9989 m²/g and adsorption pore size of 11.193 - 11.912 nm, were obtained from a pyrolysis process at 400 - 700 °C. The syngas samples were collected from the gasification unit every 15 min to 60 min. The gas chromatography was used to analyze the syngas compositions. The GC results indicated that increasing NiO contents in the catalysts tended to result in increasing CH₄ composition of the syngas for both systems with and without biochar. With tar filtration unit containing biochar, the ability of tar removal was significantly increased by 2 to 9 times comparing to the system without biochar.

In this research, heat transfer simulation is a part of the application of heat transfer from the biochar production process for the drying system. This research aimed to investigate the three-dimensional transient conditions of the simulation used to predict heat transfer of heat exchangers comparing with the experimental study. The working fluid used inside the tube was hot water with a mass flow rate of 10 LPM. The results obtained from the simulation and the experiment analysis were heat transfer from hot water to cold air through the heat exchangers. The temperatures of hot water inlet the heat exchanger were set as 50, 60, 70, and 80 °C, respectively. Air flowed through the heat exchangers was set as 1 m/s, 2 m/s, 3 m/s, 4 m/s, and 5 m/s, respectively. The coil pipe has the outsider diameter at 1.9 cm and four panels. It was set up on a box case with 100 cm of width and height and 45 cm of length. The results showed that when the water temperature increased from 50 °C to 80 °C and airflow speed through the heat exchangers of 3 m/s, the temperature difference of air through the heat exchangers increased from 3.2 °C, 4.7 °C, 5.20 °C and 6.2 °C respectively. On the other hand, when the airflow speed through the heat exchangers increased from 1 m/s to 2 m/s, 3 m/s, 4 m/s and 5 m/s respectively, the temperature difference of air through the heat exchangers decreased from 11.81 °C to 7.33 °C, 6.20 °C, 5.20 °C, and 5.05 °C respectively. The simulated heat transfer coefficient inside the region of heat exchangers was an agreement with the experimental data. The results indicated that the simulation could be attained in the system compared with the actual experimental analysis.

Cellulose is one of the sustainable raw materials and natural polymers as it can be abundantly found in biomass products. Nanocellulose consist of three categories which are bacterial nanocellulose (BNC), cellulose nanofibrils (CNF), and cellulose nanocrystalline (CNC) has the potential to be used for working fluid in heat transfer application with nanofluid characteristics. Nanofluid is defined as a fluid that has nanoparticle dispersed in it. This nanoparticle will enhance the thermophysical properties of the base fluid. Many types of nanofluid have been used widely in heat transfer applications such as Al2O3, TiO2, CuO and CNT but only a few studies had been done using green and environmentally friendly materials. Therefore, nanocellulose is one of the best candidates as one of the nanofluid's materials which has green and environmentally friendly properties. The preparation of nanofluid is very crucial because improper preparation will lead to deterioration of nanofluid and decrease the thermal performance as heat transfer working fluid. Other than that, low stability cause nanoparticle to form clusters and sediment due to its strong van der Waals interaction. Therefore, this study will focus on the preparation method of the nanocellulose for heat transfer application. Other than that, methods of stability analysis for nanocellulose also presented in this paper.

Deep buried heat exchanger has been increasingly applied into the building heat source through the utilization of geothermal energy. During the geothermal system design process, the aquifer is an important factor that affects the overall performance prediction. The flow of underground water at different positions changes the temperature distribution of the soils around the buried pipe and then influences the heat exchange at different depths. Consequently, the variation of the temperature field causes the thermal radius of the heat exchanger no longer regularly distributed, which affects the determination of the well spacing. With the aims of improving the accuracy of performance estimation, the aquifer effect is carried out by this study. The solution to the moving line source theory is used to acquire the temperature response at different positions. The overall effect of the underground water with different velocities on the performance is evaluated. The soil temperature distribution in the heat exchange zone with aquifers at different depths is studied in detail. The predicted thermal influence radius at different depths with various groundwater velocities and soil thermal properties showed that the temperature distribution around the buried heat exchanger is largely influenced by the groundwater movement. Under the simulation condition, the thermal radius increases from less than 10 m for pure conduction condition to a maximum value of 25.3 m with groundwater flow. The aquifer enhances the heat absorption of the heat exchanger, but the high flow rate also leads to a large thermal radius. The obtained thermal influence radius under different conditions can provide guidance for the design of the geothermal system.

Geothermal has become a popular renewable energy in recent decades due to its properties of non-polluting, clean and large reserves. The vertical-butted geothermal well is a new structure for geothermal utilization. Two vertical boreholes with a certain distance are connected at bottoms by directional drilling to form a U-shape circulation loop. Due to the existence of the aquifers, the movement of underground water extends the heat exchange range and affects the geothermal system performance. This paper aims to develop an analytical method to solve the soil temperature field around the vertical-butted geothermal well with different flow directions. Taking the interacted effect of the two parallel pipes on the surrounding soil into consideration, the temperature distribution in the heat exchange zone is obtained. It is found that the temperature field changes significantly when the groundwater flow exists. The movement of underground water extends the downstream thermal radii from 4.8 m to 10.7 m, 10.6 m and 11.7 m when the flow directions are 0°, 45° and 90° toward the axis of the two pipes, respectively. The upstream thermal radii reduce from 5.4 m to 1.9 m for all the cases with groundwater movement. In addition, the effect of the underground water flow direction on the temperature field around the butted wells is analyzed. The results show that when the groundwater flow direction is perpendicular to the axis of the two pipes, the temperature field is the most beneficial to the performance of the vertical-butted geothermal well.

Waste heat from the combustion process that is left unused may cause pollution problems and adversely affect health. This waste heat should be recovered. In this research, the simulation and experimental data on heat transfer characteristics of the pipe coiled inside the re-burning kiln heat exchanger were studied. The main objective of this study was to compare heat transfer coefficients obtained from the simulation using water as the working fluid with those obtained experimentally from the re-burning kiln heat exchanger for the drying system. The re-burning kiln heat exchanger was of coil-pipe-type with an outside diameter of 38 mm. The coiled pipe set up on the re-burning kiln heat exchanger was 80 cm in width and 173 cm in height. The flow rate of the cold water used as a working fluid was varied from 10 to 20 LPM, while the surface temperature of the coil pipe was varied from 200±20°C to 400±20°C, respectively. Thermal conductivity and outlet temperature of the water were also measured as a function of the internal temperature and water flow rate. The experimental results were validated against the simulation. The results showed that when the flow rate of water inlet decreased from 20 LPM to 10 LPM, the temperature of the water outlet was increased from 52.4 °C to 76.3 °C respectively. An increase in the temperature of the water outlet because of increased the re-burning kiln heat exchanger temperature and reduced the mass flow rate of supply water. The obtained simulated heat transfer coefficient in the re-burning kiln heat exchanger was in agreement with the experimental results.

The fast development of flexible electronic devices in recent years requires the development of flexible batteries. In this study, a compact and flexible battery (15 mm × 15 mm) was developed. The anode electrode of the battery was based on an anodized stainless mesh coated multiwalled carbon nanotubes (MWCNTs). The battery can be activated anytime, anywhere, by saline solution. The anodization process was applied to the anode electrode. After the heat-treatment process, the anodized stainless mesh was coated MWCNTs. The power generation characteristics of the flexible battery were investigated. Two types of anode electrodes made of stainless mesh with and without anodization were used for the experiment. The anodized stainless mesh anode generated 169 µW/cm², which is four times higher than that of the anode without anodization, 41.9 µW/cm².

The aim of this research work to analyse the performance of the proposed solar tunnel dryer and photovoltaic (PV) system to dry star fruit. Star fruit (Averrhoa carambola L.) is a native fruit in the north eastern states of India. Due to its rich nutritional composition and medicinal property, the demand for this fruit increased nationally. The proposed design consists of a tunnel type drying chamber and thermal storage unit. Paraffin wax (PCM) was used as a thermal storing material mounted in the tunnel dryer chamber to use the thermal energy at off sunshine hours. The thermal insulation coating on the outer surface of the solar drying chamber enhances the thermal performance of the tunnel dryer. The overall efficiency of this proposed design was analysed. The results indicated that drying of star fruit occurred in the falling rate period, where no constant rate period of drying rate was observed. The quality analyses data revealed that higher values of TPC (47.59 mg GAE/gram of sample) and DPPH (73.59 μ mol of TE/gram of sample) are obtained in the samples dried in solar dried as compared to open sun-dried samples. Sensory analysis (taste, aroma and flavour) carried out on slices of star fruit indicated that the solar-dried slices provided better scores compared to open sun-dried samples.

Thermal energy storage (TES) has been widely adopted to bridge the mismatch between energy supply and demand. In general, thermal energy storage is segregated as sensible TES and latent TES whereby both have their own advantages and disadvantages. This study explores the possibility of utilizing the advantages of both sensible and latent TES by embedding phase change materials as a wall of the sensible TES. To investigate the performance of the proposed TES, an experimental set-up of TES with PCM embedded in the wall is developed. Temperature distribution within TES is measured and recorded during charging and discharging process. Several key parameters are evaluated to gauge their influence on the performance of the studied TES. The results indicate that the performance of TES with embedded PCM is superior that that without PCM, indicating the potential of the proposed design for high performance thermal energy storage application.

Man-made or unnatural wind from the industrial exhaust air system is an alternative wind resource for countries with natural low-speed or intermittent wind such as Thailand. It has strong and consistent wind speed when compared to the natural wind, with velocity about 5 to 10 m/s at a distance of 5 cm from the exhaust air outlet. However, some negative impacts to the exhaust air system performance was observed when a conventional wind turbine was employed. The objective of this research is to feasibility study the practicality of a prototype shaftless small scale horizontal axis wind turbine (SSHWT) to generate electricity from the exhaust air of the industrial exhaust air system. Aerodynamic, blade and generator designs were addressed in this study to maximize energy output and minimize negative impacts to the performance of the original exhaust air system. The performance of SSHWT was tested with a selected industrial fan that is widely used in industrial sections. The results showed that the SSHWT could generate electricity with less negative effect to exhaust air system performance. However, it still needs further improvements caused by the voltage output is too low. By the concept design, this innovative wind turbine is compact, thus needs only small space for installation. This SSHWT has high market potential for low wind speed countries to take advantage of unnatural wind resources which are better in terms of efficiency and economy for sustainable energy development.

Internal combustion engines do not effectively convert energy from the chemical reaction into useful energy, notably mechanical energy. In fact, majority of the energy are converted into heat energy, and dissipated into environment which does not fully contribute to the performance of internal combustion engine. This results in lower overall efficiency of the engine. The heat released into the environment can be converted into useful electrical energy by using thermoelectric generator (TEG). TEG consists of cold side and hot side and works based on the principle of Seebeck effect. The hot side of TEG is exposed to hot surfaces of the exhaust, and the cold side is cooled with fan cooled heat sink. The function of heat sink is to increase the temperature differences across the TEG. The conversion of waste heat into electricity by TEG in an automobile can be a good case study to replace the alternator for battery charging and increase the overall efficiency of the Internal Combustion (IC) engine. In this study, eight pieces of TEG with dimensions of 40 mm x 40 mm each were attached to a square heat exchanger. This heat exchanger was connected to the exhaust pipe of the engine. The temperature recorded in the exhaust was more than 150 °C. Thermocuples were embedded on the hot side and cold side of the thermoelectric generators to evaluate the temperature differences across the TEGs. The output of the TEGs were obtained at idle and half-throttled engine conditions. An electronic load was applied to obtain the voltage, current and the power output from the TEGs system. The TEGs were tested individually, all connected in series and parallel connections. The maximum output voltage was recorded for the series connections at 5.8 V with an average hot side temperature of 48 ° C across TEGs. Maximum power output obtained when all the TEGs connected in series was at 2.3 W.

Climate change and environmental issue is a common concern for all of us. On the other hand, energy is essential for our daily life and how to get secure, affordable and environmental sustainable energy becomes global issue. Distributed generation(DG) is one of the solution to mitigate environmental impact and to integrate as a part of the smart grid. Solar photovoltaic can be used abundantly as the small multi-distributed generation system to improve system performance in many ways. According to the previous researches, it is clear that DG can make system performance better. However, choosing location and sizing is a must considerable issue for integration of DG in the distribution network. In some research, the location and size was determined only depended on the amount of loss reduction. In our research, three factors such as reliability index, voltage stability index and loss reduction are going to evaluate to figure out the location and size of the DGs. Using forward-backward sweep method in MATLAB, power loss condition is analysed. Then, loss reduction level is check by installation DG in each bus and the most effective buses or the buses at which the highest amount of loss DG can reduce are assigned as locations for DG. And then the voltage stability index (VSI) is calculated and one of the nominate buses which has highest VSI index is chosen as the designated bus for allocation. In this way, the optimal location of DG can be assigned with the consideration of losses and VSI index. In another way, the location of DG can be determined with the consideration of reliability index. From the concept of reliability, the most effective or optimal location is the bus at which the reliability is the highest. In this research, the location and size of DGs were considered based on combination of three indices such as VSI, loss and reliability index.

Sustainable Energy Development is a must consideration for energy sector. Energy Trilemma index is quite low in Myanmar as only 40% of the country is electrified At 66% of Final Energy Consumption, the residential sector was the largest energy consumer, due to the use of fuel wood for cooking. For electricity sector, load shedding problems are frequently occurred in dry season because of insufficient generation. Local peoples are also protesting Coal fired power plants and natural gas is also not available sufficiently. In this paper, the role of solar energy to enhance energy security, affordability and environmental sustainability are analyzed using energy Trilemma index as a tool. Energy Trilemma is used as a tool to determine the sustainability development of the energy sector. According to the analysis, three indices of energy trilemma can be improved by solar energy and it is a vital role for sustainable energy development in Myanmar.

Electric vehicles are a leading alternative to traditional vehicles. However, high expenditure on battery replacement due to rapid capacity loss limits their market penetration. Given that the high temperatures reached during operation greatly contribute to capacity loss, battery cooling systems are often necessary to extend battery life. In designing a cooling system, lifetime cost is a crucial consideration as both capital expenditure and battery replacement cost savings are associated with the system. To extend the prior initial study, this study investigates the influence of various factors on the economically optimal design. Similar to the initial study, the investigated case is that of a typical electric jeepney in Manila, Philippines. Existing models for the electrothermal and aging behavior of the battery, thermal behavior of the cooling system, and capital costs of the cooling system components are linked to form a system simulation. The simulation, implemented in Simulink is coupled with a genetic algorithm implementation in MATLAB to generate the optimal cooling system design. As with the initial study, air and phase change material are the cooling media considered. Given their significant expected influence on the optimal design, the following factors are investigated: drive cycle, ambient temperatures, and component capital costs. The results of this study agree with the preliminary study. The optimization results do not favor air cooling in any case investigated; none of the cases justify its high capital and operating costs. Phase change material (PCM) cooling is also unfavored in all cases, save for that using the US06 drive cycle, showing that only extreme temperature rise due to high current draw can justify investment in PCM cooling. Although previous studies have found that lowering battery temperature extends battery life, this study reveals that the capital and operating costs of battery cooling systems are still a hurdle to be overcome.

The Thai Government has supported the use of solar photovoltaic systems for green electricity production toward the self-consumption policy since 2016. A photovoltaic support program with an installed capacity target of 100 Megawatt was announced in December 2018 to promote self-consumption and compensate for any excess photovoltaic generation at 1.68 Thai Baht/kilowatt-hour. However, the target was not achieved as a result of high upfront investment costs that are one of the main barriers in household application. To make solar photovoltaic systems more accessible to a larger group of users, financial mechanisms are required. The economic feasibility of financial options (cash, solar power purchasing agreement, solar leasing, solar loan) was analyzed for photovoltaic systems under the current Thai household solar rooftop scheme. The System Advisor Model, an open source techno-economic analysis tool, was employed to simulate photovoltaic production and cash flows to calculate the economic feasibility including the levelized cost of electricity, net present value, internal rate of return and payback period. Results showed that investment in a 3-kilowatt photovoltaic system with debt fraction of 50% and 100% cash was profitable, while investment in a 3-kilowatt photovoltaic system through a solar power purchasing agreement and leasing was not economically viable.

Electrical energy demand for Southern Thailand is continuously increasing partly due to an increase in tourism. Around 3,000 MW of coal fired power plants are planned by the government, but the proposal was put on hold due to the resistance of local communities and civil society groups. Besides this, coal fired power plants are not only large CO₂ emitters, thus intensifying the on-going climate change processes, but also require lengthy environmental impact assessments, and their technology costs remain stagnant at comparable high levels. Solar and wind energy can be produced at far lower costs than coal, however, their shares on the renewable energy mix are comparable small in Thailand, but with a steady increase. A disadvantage of solar and wind energy production is that the production is not constant due to day/night and weather, respectively. These disadvantages can be compensated by adding geothermal energy, as this energy from deeper geological sources is continuously reaching the Earth's surface. This allows the continuous feed to geothermal power plants which by this can act as a backbone of a renewable energy mix. In Southern Thailand hot springs from the north to the south are the surface expressions of active geothermal systems at depth. Surface exit temperatures can reach up to 80 degree Celsius, thus considered as low enthalpy resources, which can be utilized applying state-of-the-art binary power plant technology. In the current renewable power plan of the government geothermal energy is not considered due to the low availability of this resource. However, recent research has shown that Southern Thailand holds promising quantities of geothermal resources; with further scientific investigations needed. Finally, the only current geothermal power plant in Thailand located in Fang, Northern Thailand, is situated close to a national park in a beautiful landscape and environment, thus acting as a positive example for Southern Thailand.

This article reveals the Optimization of the Renewable Energy based Hybrid Mini-grid system to energize a village Kyein Ne Taung with 645 households. The feasibility of the project is analysed in HOMER (Hybrid Optimization of Multiple Energy Resources) Pro. The site visit is carried out in July, 2019. The architecture of the proposed model comprises 160 kW PV System, 160 kW Wind System, 1320 kWh Battery Storage System, and 123 kW Converter. Regarding the current situation, the proposed Hybrid system can terminate 4500 tons per year and 2600 $ per year for Fuel wood cooking as well as 7000 litres per year and 8000 $ per year for Diesel fuel applications. By comparing with the Diesel Mini-grid to electrify the desired scenario, the proposed planning can save Diesel fuel 132,567 liters per year, Diesel fuel cost 132,567 $ per year, as well as reduce the GHG (Greenhouse Gas) emissions, including Carbon Dioxide 347,009 kg per year, Carbon Monoxide 2,187 kg per year, Unburned Hydrocarbons 95.4 kg per year, Particular Matter 13.3 kg per year, Sulfur Dioxide 850 kg per year, and Nitrogen Oxides 2,055 kg per year. Therefore, simulated results prove the available Sustainability benefits, and the reliable performance of the proposed system. This research can be useful as the reference of the affordable and modern Energy planning for other Coastal villages in Southern Myanmar.

The availability of reliable electrical energy is essential in developing countries for functioning in modern economies such as in residential, industrial and commercial developments. The sources to produce electricity can be divided into two categories: renewable sources and non-renewable sources. Renewable energies are sources of clean and inexhaustible energies which can be produced from natural resources and they produce neither greenhouse gases nor polluting emissions. There are variety of renewable energy such as wind energy, solar energy, hydro energy, biomass and biofuel energy and etc. The photovoltaic-diesel hybrid systems are systems that combine photovoltaic system and diesel generators to generate electricity. There are many types of photovoltaic-hybrid system. They are series hybrid, switch hybrid and parallel hybrid. In the series photovoltaic-hybrid system, Photovoltaic generator or diesel generator is used along with battery bank to charge. In this paper, the sizing of photovoltaic-diesel hybrid system with grid connection is calculated for the electricity consumption of an industry. The study area of this paper is located in North Okkalapa township, Yangon division, Myanmar and at latitude 16°53'06.9"N and longitude 96°09'17.8"E. The load consumption of this garment factory is firstly collected. In this paper, a photovoltaic system was designed. The number of modules, the number of inverters, and the efficient techniques of connecting them together was stated. Also the area of the designed photovoltaic system was calculated, and a suitable location for the system was chosen. The sizing calculation of the system is designed by using HELIOSCOPE software and HOMER software.

This article presents the techno-economic investigation of the Grid-connected Hybrid system by harnessing the abundant potentials of Renewables in Ayeyarwady Delta of Myanmar. The focused village in this study, Ma Yan Chaung, is geographically situated at latitude 16°35'7"N and longitude 94°54'7"E. Its annual average Solar GHI (Global Horizontal Irradiation) is 5.08 kWh per m² per day. It is included in the electrified (Grid arrived) village tract of Moke Soe Kwin and located in the Myaungmya Township. Site survey to that village was conducted in May, 2019. According to the collected data, the available Biomass is 480 tonnes per day and the estimated demand of the focused village is 2296 kWh per day with 361.7 kW peak. The thousands of different models are simulated in the powerful Microgrid tool, HOMER (Hybrid Optimization of Multiple Energy Resources) Pro (version 3.13.3). Then, the feasible Grid-connected system is proposed with 100 kW PV; 1,800 kW Biomass; 45 kW Converter; total NPC (Net Present Cost) 4,255,082 $; levelized COE (Cost of Energy) 0.01575 $ per kWh; Initial Capital 524,000 $, and Operating Cost 219,337 $. Annual Energy Sold to Grid is 15,045,299 kWh and Average Monthly Energy Sold is 1253775 kWh. The simulated results significantly demonstrate the good performance and the available benefits of the proposed system. Moreover, this system can shape the Sustainable Electrification to tackle the Climate Crisis in Ayeyarwady Delta Region of Myanmar.

One of the most feasible Renewable Energy resources of the World is wind energy. The performance of the Maximum Power Point Tracking (MPPT) control system for the operation of the Standalone Wind Power generation system is studied in this research. Sittwe, the capital of Rakhine State in Western Coastal Region, is the chosen case study area that enriches the Wind Energy resources in Myanmar with the low electrification rate. The proposed Standalone Wind Power generation system is composed of three-phase, 20kW Permanent Magnet Synchronous Generator (PMSG), DC-DC bidirectional converter, switch mode rectifier, voltage source inverter, and three-phase load. It is modelled and simulated in the MATLAB/Simulink. The simulation period is set to 15 seconds. Under Wind speed variation from 3 m/s to 13 m/s, the investigation is performed with the nexus of the speed, torque, power, DC link input, DC link output, and the parameters of the load side. In the simulation results, the power characteristics show the 20 kW standalone wind power system. It is observed that the output load voltage can be controlled by load side converter to required load voltage. In addition, the simulation results reflect the dynamic performance can be improved with the proposed MPPT control system.

This paper focuses on reconfiguration of radial distribution system incorporated with optimal allocation of Distributed Generation units (DGs). The network reconfiguration is to optimize the structure of radial feeders by changing the status of normally closed sectionalizing and normally open tie switches. The optimal allocation of DGs in distribution system has to determine the DGs location and their correspondent sizing for enhancing the system effectively. There are many investigations with both two researches either separately or incorporated simultaneously. But network reconfiguration by using Particle Swarm Optimization (PSO) incorporated with optimal allocation of DGs based on Voltage Stability Index (VSI) and analytical approach of Forward Backward Sweep (FBS) method in radial power flow is the novelty of this research. The main objective is to achieve the minimum losses and improvement of voltage profile while all distribution constraints are satisfied. In proposed algorithm, optimal allocation is determined by finding the best sizing and location of DGs based on VSI and FBS load flow, and then PSO reconfiguration finds out the optimal location of tie and sectionalizing switches simultaneously. The study of test system is carried out on Mayangone Distribution System (MDS) and the obtained results are inefficient for this research.

Optimal Reactive Power Dispatch (ORPD) is very efficient to optimize the control variables like as generator voltages, transformer tap setting and values of reactive power injection for loss reduction in power system. ORPD is the one of the complexity of optimization problems including with equality and inequality constraints of power systems. Many research papers have developed in ORPD applied to the IEEE test systems with various intelligent methods for the loss reduction. In this paper, the test system is carried out on Yangon Distribution Network (YDN) composed of different voltage level such as 230 kV, 66 kV and 33 kV, and supplied by various types of generation sources. Thus, it is very high in losses and difficult to find out the control variables of ORPD in YDN. The main objective is to reduce the both active and reactive power losses in YDN. Particle Swarm Optimization (PSO) method implemented in ORPD problem of YDN is very applicable and effective to obtain the minimum losses while all the bus voltage profile is acceptable in voltage constraints. The obtained results from ORPD using PSO algorithm could enhance YDN efficiently.

The increase in energy demand and environmental pollution issues has led to the growth of utilizing renewable energy. Wind energy has become one of the main alternatives for power generation. In order to enhance the performance of the horizontal axis wind turbine (HAWT), the application of a diffuser is one of the innovative methods. At present, research on deploying the diffuser on the vertical axis wind turbine (VAWT) remains scarce. This paper presents the experimental study on the aerodynamic characteristics of a small H-rotor VAWT integrated with a diffuser. The diffuser comprises a pair of flat plates with an inclined angle of 30° at the outlet, with the VAWT is located between the diffuser. A comparison between the turbine performance with and without the diffuser has been conducted. From the experiment, it shows that with the presence of the diffuser, the performance of the VAWT has increased significantly. The power obtained for the bare turbine and with the diffuser is 0.38 W and 0.48 W respectively which is increased by about 26.3% and occurring at 300 rpm. Moreover, with the diffuser, the incoming velocity is also increased. This is due to the presence of the diffuser which enables the flow expansion and creates a low-pressure region at the downwind; inducing a higher incoming wind flow to the VAWT and enhancing its performance. In addition, the rotational speed and a better self-start ability can be achieved with the presence of the diffuser.

Traditional power generation mix lacks renewable energy (RE) sources to cover fast depletion of fossil fuel. Malaysia is picking up on solar energy with the aim of enhancing the national power generation mix by reducing the dependency on fossil fuel and thus mitigate the greenhouse gas (GHG) emissions. However, integration of large amount of solar power may pose a challenge to power system planning and operation. This paper therefore, attempts to present an outlook on large-scale solar (LSS) in Peninsular Malaysia for scenario year 2030, with objective to serve a guideline for future power planning by adopting the optimum penetration of LSS. Firstly, total optimal potential areas (OPA) for LSS power production in Peninsular Malaysia are determined based on several important geometry factors. Next, its corresponding technical potentials include energy generation potential (EGP), installation capacity (IC) and annual carbon dioxide emission reduction (CO₂ ER) are reported. Three hypothetical studies of solar penetration: 5%, 10% and 15% are demonstrated and subsequently compare with national electricity consumption forecast 2030. Peninsular Malaysia has enormous potential for LSS power production as reflected from total OPA of 10,092 km². With only 10% of solar penetration (206,691 GWh/yr), it is sufficient to cover national energy demand, forecast to be 134,642 GWh/yr. This positive finding is very encouraging to reveal the significant potential of LSS in national energy mix. It will give a much-needed boost to the country RE sector and a robust growth is envisaged.

The global economy depend on the fossil fuel to meet the daily power demands, ranging from electricity supply to transportation. It is estimated that more than 60% of the world power generation is depending on the fossil fuel. Therefore, the search for clean energy to replace fossil fuel has become the current research trend in the world. Metal-air battery featuring high energy density is projected as one of the promising candidate for the next generation energy storage system. There are various type of metal-air batteries available in the literature such as lithium-air battery, magnesium-air battery, silicon-air battery, aluminium-air battery, zinc-air battery, etc. However, aluminium-air batteries with its low cost and high energy density of 4300 Wh/kg show a great potential for future energy storage applications. In this study, the performance of the aluminium-air battery with polypropylene separator is being investigated. The battery is filled with 1M of Potassium Hydroxide electrolyte. Anode of the battery is made of Aluminium foil and carbon fibre cloth is used as cathode of the battery. The experimental results shown that, the maximum capacity of 23 mAh can be achieved using 6.25 mA of constant current discharge. By connecting the batteries in series, it is sufficient to power on a light-emitting diodes and charging a mobile phone.

Geothermal resources are abundant in the Weihe Basin, which provides great potential for winter district heating in the Guanzhong area in western China. As a demonstration project for deep geothermal exploitation and utilization, four boreholes of over 2,000 m were drilled and paired to form two U-shaped downhole heat exchangers (DHEs) in the Xi'an Depression of the Weihe Basin. In this paper, the borehole equilibrium temperatures of these two DHEs, measured two years after the systems had been completed, are presented. The analysis of the borehole temperatures show that: (1) the thermal and hydrological regimes of the study area are stable, as indicated by the highly consistent borehole temperatures among the four boreholes, both horizontally and vertically. (2) the geothermal gradient range down to the depth of 2,000 m in this area is 3.45 ˜ 3.47°C/hm with an average of 3.46 ± 0.01°C/hm, substantially higher than the regional mean and implying a great geothermal energy exploitation potential; the high geothermal gradient anomaly can be attributed to the rather thin crust in the Weihe Basin with a relatively high mantle heat flow and hydrothermal convection systems involving fluid circulation in nearby discordogenic fault zones. (3) the Lantian-Bahe Formation has the features of stable distribution, good aquifer yield, high transmissivity, high permeability and high thermal conductivity, and hence, it is a good hosting stratum to the horizontal section of U-shaped DHEs in this area to maximize heat exchange efficiency and sustainability.

Thermal energy storage has become more and more important to improving the overall efficiency of energy systems by utilising the wasted energy. This study was aimed to develop a chemical heat storage (CHS) system using EM8block and its dehydration and hydration reactions to recover the thermal energy wasted by the exhaust gases in internal combustion (IC) engines. To experimentally investigate the performance of the CHS system in the heat storage process, a CHS system was developed and tested on a Diesel engine (D1146TI). To further investigate the CHS system in engine conditions more than that in experiments, a CFD model of the CHS system was developed using the commercial code of ANSYS FLUENT as a platform. In the 60 minutes mode, the maximum stored energy in the CHS system was 21.9 MJ which was equivalent to 4.78% of exhaust gas energy with 72.54% of the EM8block reacted at the full engine load. The stored energy and the percentage of reacted EM8block decreased with the decrease of the engine load. In the full charge mode, the simulation results showed that the time on fully charge of the CHS reduced with the increase of the engine load and that the shortest time was 67.1 minutes at full engine load. This time on full charging increased to 110.3 minutes at 50% engine load. The simulation results also showed that the maximum percentage of the exhaust gas energy stored in the CHS system was 7.14% at 70% engine load.

Existing literature focus on the prediction of states of batteries are scattered and are individually studied based on several battery aspects such as: 1) Chemical (ionic concentration measurement or diffusion coefficient evaluation), 2) Electrochemical (capacity), 3) Electrical (internal resistance), 4) Thermal (temperature), 5) Mechanical (stack/enclosure stress) and 6) In-situ/ex-situ (characterization methods to measure porosity and grain size). Unfortunately, these studies have been done by experts of different fields and are yet to be combined in a common platform to predict the states of batteries in a comprehensive way. In this paper, the aim of this research is to propose a framework so as to establish a big database (from sources of literature, by performing real-time experiments and uncertainty studies) for batteries at all operating conditions by incorporating all aforesaid aspects. Once the data base is established, a suitable artifical intelligence approach such as artificial neural network will be applied to train and build the model for state of health prediction and physical evaluation that subsequently have the prime advantage of accurately predicting the battery capacity at system level as well as cell level based on all existing design parameters (diffusion coefficient, grain size, temperature, internal resistance, etc.) from the big database. Data collection will be processed on brand new batteries by repeating cycles of charge and discharge modes under dynamic current profiles at different temperatures for accuracy. The proposed battery model can be then integrated to the battery management system in the electric vehicle without any additional integration complexity.

In next 5-10 years, there will be 5-8 million tons of spent batteries accumulated as waste. There exists methods for recovery of materials from a battery for reuse or remanufacturing purposes. The research question arises on how about the recycling of batteries stacked in the battery modules in series or parallel configurations. This paper shall propose the qualitative framework based on intelligent robots for safer and efficient disassembly of battery modules for recycling. The framework combines the battery pack's automatic removal procedure with the battery's intelligent sorting program to recycle the reusable batteries. It has higher degree of automation and higher recycling efficiency than the existing frameworks. This also includes a smart battery information collection system (machine vision based information reading), an intelligent robot based battery disassembly system and a smart battery classification system. In addition, the framework also includes AI model based programming of robot so that it can sort out the batteries in ascending order of their remaining life.

By 2025, 2 million metric tons of batteries must be recycled. Among these batteries, the spent Zinc-Manganese batteries poses a serious threat to environment due to toxic heavy metals. This metals are toxic but at same time vital for various industrial applications. This metals are generally recovered by physical-chemical process which are highly energy intensive and polluting. An eco-friendly recycling process has to be explored to tackle such issue. The bioleaching is one such eco-friendly recycling method. The objective of this work is to optimize the process parameters of bioleaching method, so as to make this process commercially viable. The optimization of this process is done through statistical based automated neural network intelligent optimization approach. The formulated models were inline with the complex behaviour of bioleaching process. The training and validation performance of the models were near to 1. The parametric, global sensitivity and interaction analysis was undertaken for understanding the relationship between different parameters and its affect on the metal yield. The optimum values of process parameters were determined for maximizing the metal yield.

In extreme cold conditions, there are negative consequences on battery life due to extremely slower rate of chemical reactions, resulting in lower charging rates. Therefore, an efficient battery thermal management system is required to ensure temperature optimization is low which may also result in charging. In best of authors understanding, there is hardly any research being carried out in this direction. In this paper, an Intelligent Optimization framework combined with computational fluid dynamics (CFD) shall be proposed to optimize the heating method accuracy so as to maintain the uniform and desired temperature across the battery for ensuring smooth and quick charging. Battery pack model shall be designed in CFD platform and the thermal analysis shall be carried for given set of conditions (such as constant heat source, air flow rate, air temperature). Based on the obtained set of analysis samples, a model shall be formulated illustrating relationship between the minimum temperature output and the inputs (air flow rate, air temperature, etc.). The minimum temperature output shall be maximized using NSGA II so as to determine the optimum set of input conditions (air flow rate, air temperature, etc.). The battery pack simulation revealed that thermal system utilizing a liquid medium is more effective than air medium. Future research directions shall be discussed in the end.

The tropical climate, wide diversity of microalgae species, long coastline, abundant sources of agriculture effluent, and active phycology research are key factors that drives Malaysia to be highly competitive in the global microalgae market. Microalgae are vital in a variety of applications such as: biofuel, health foods, agricultural feeds and chemical extractions. However, mass cultivation of microalgae is still not cost effective in Malaysia due to huge energy consumption Therefore, cultivation of microalgae that utilizes wide ocean space and wave energy for mixing has gained interest since it has considerably lower production cost. Nonetheless, the effects of ocean wave-induced sloshing in terms of its efficiency of mixing have not been fully researched. Thus, this study has been conducted to investigate the effects of sloshing hydrodynamics in microalgae cultivation by studying the interactions of sloshing hydrodynamics and mixing efficiency inside a floating photobioreactor. A membrane type photobioreactor has been used to slosh microalgae culture on its free surface. The result of mixing efficiency for suspended solid particles in liquid is the main concern. Experiments in unidirectional excitation proven that mixing rate of solid-liquid medium is dependent on the excitation amplitude, excitation frequency and filling ratio, where mixing rate is highest at 30% filling ratio with increasing excitation amplitude and excitation frequency. With deeper comprehension on the interaction effects of sloshing hydrodynamics and mixing efficiency, upscaling of novel microalgae cultivation method in industrial size can be expected.

The necessity of managing a production system with less cost and pollution in such a competitive world has enticed the attention of many researchers. This paper deals with a multi-state two-machine flow-shop scheduling problem under Time-Of-Use electricity tariffs. The main issue is to assign a set of jobs to available time slots with different energy costs to minimize the total energy consumption costs. For this purpose, a new linear programming (LP) model is proposed, and several numerical results are solved using CPLEX Studio 12.9.0 solver to evaluate the effciency of the proposed model for the problem. The obtained results demonstrate that CPLEX solver is not able to find the optimal solution for the problems as large as 20 jobs and 90 periods during the 3600 seconds time limitation.

The Three-dimensional Open Dimension Rectangular Packing Problem (3D-ODRPP) is one of the most important optimization problems arise in reducing waste and shipping cost of packing and shipping industries. The 3D-ODRPP aims at seeking the length, width and height of a rectangular box of minimal volume that can pack a given rectangular products. Most 3D-ODRPP models in the literature use too many extra binary variables and don't consider the equilibrium of product placement. This study presents an improved mathematical model for the 3D-ODRPP. The proposed model uses fewer decision variables and constraints to define product orientation. It also adopts the full base support (FBS) constraint as a product supporting condition to guarantee packaging stability and avoid infeasible arrangements. Literature instance tests show the improvement in packaging stability of the proposed method compared with existing methods. Industrial benchmark demonstrates that, by solving the 3D-ODRPP, the proposed method can reduce package volume and create economic and ecologic gains.

Machine learning algorithms using Artificial Neural Network (ANN) were developed to predict the performance of heat pump systems in retrofit residential housing. The study attempts to address the research gap in the application of machine learning algorithms to real-life field measurements as a case study. Rowhouse units with electric resistance baseboard heating were retrofitted with Ductless Air Source Heat Pumps (DASHPs). Sensors were installed to collect the energy consumption data during the baseboard and DASHP monitoring periods. Linear and quadratic regression methods following the International Performance Measurement and Verification Protocol (IPMVP) were applied to predict energy consumption based on outdoor temperature and heating degree days. These predictions were compared against results from ANN models based on Levenberg-Marquardt algorithms using the hour of the day, day of the week, outdoor temperature, wind speed and direction, relative humidity, condition and indoor temperature as inputs. Preliminary results indicate that predictions from ANN models produced higher correlation of determination than those from IPMVP regression analysis.

Graphene-based hydrogel had been formed by chemical reduction process of graphene oxide using ascorbic acid as a reducing agent in this study. Oil adsorption capacity of the hydrogels that were synthesized using different parameters, including type of graphene oxide feedstocks (powder or flake graphite), concentration of graphene oxide used (2 mg/mL or 5 mg/mL), as well as the amount of ascorbic acid added into the graphene oxide (5 grams or 8 grams), had been evaluated in this work. Fourier Transform Infrared Spectroscopy (FTIR) results showed that the oxygen-containing functional groups which were initially present in the graphene oxide could be removed or reduced to form the 3-dimensional π-π interactions hydrogel. In overall, hydrogel produced from flake graphene oxide with the use of higher concentration of graphene oxide (5 mg/mL) and the lower amount of ascorbic acid (5 g), showed the best performance in oil adsorption capacity. The hydrogel produced from these parameters showed the highest adsorption capacity of 7.90 g of oil adsorb per g of hydrogel. This study has provided useful information on the functional groups of graphene-based hydrogels in addition to their oil adsorption capability.

The recent residue solid waste management has become a significant global concern. Due to the increase of population, the economic growth and the urban expansion, the number of solid waste has heavily risen. However, there are still lack of an appropriated solid waste management. According to Tan Deaw soild waste survey report in 2019 (Regional Environmental Office 7 Saraburi, 2018), it revealed that Tan Deaw sub-district has been facing critical solid waste management issues. This area produced 9.41 metric tons per day, while the appropriated solid waste disposal management was less than 40 percent and residue waste remains around 2,000 MTs. Therefore, the objectives of this research are to develop learning community and public awareness towards the appropriated solid waste disposal management, including 3Rs principle, to develop the systemic solid waste management strategies with the engagement from all stakeholders, and to promote and support collaborative activities among local people in the community and the concerned stakeholders in the solid waste management. A systemic approach, through participatory action research between Soft Systems Methodology (SSM) (Checkland & Scholes, 1990; Checkland & Poulter, 2006) and Critical Systems Heuristic (CSH) (Ulrich, 1983), is a significant application for structuring the process of collecting perspective from all stakeholders, exploring the key problems of solid waste management, and finding out strategies to address the key problems in Tan-Deaw solid waste management afterwards. Root definitions and models were generated by stakeholders for two activity systems identified by them for attention: Activities promoting knowledge about solid waste sorting and a community waste bank. The findings explored the seven strategies to address Tan-Deaw solid waste management problems in two aspects. This research contributes to both theoretical and practical contributions. In terms of the theoretical contribution, the application of systemic approach conducts a significant knowledge surrounding solid waste management problem solving. Regarding the practical implication, the strategies will address the solid waste problems and barriers in the area with the cooperation of all concerned stakeholders.

Malaysia has initiated initiatives to use renewable energy as a resource of electricity generation since 2011 through the establishment of laws and policies related to renewable energy. The geographical location of Malaysia has led to limited of intermittent renewable energy resources and requires a more detailed study of the various factors impacting electricity generation. This paper aims to understand the impact of El Niño-Southern Oscillation (ENSO) events on the reanalysis wind and solar data. The Wavelet Transform will be used to study the relationship between the reanalysis wind and solar dataset with the Multivariate ENSO index in the Malaysia region. During Very Strong and Strong El Nino, the site experienced an increment of both wind velocity and solar irradiance and reduced during La-Nina. This ENSO impact study is essential as a reference for future wind and solar energy development planning, energy predicting, and risk valuation in Malaysia.

The ASEAN Power Grid (APG) is a flagship initiative mooted in 1997 to strengthen and promote power interconnection and trade in the ASEAN region. The ultimate aim of the APG is to ensure energy security and sustainability in the region, particularly the electricity. One way to achieve this, as demonstrated by the Nordic countries, is by having a regional electricity market, on top of the physical interconnection of the grids. Thus, taking the cue from the Nordic region, a pre-requisite to the regional electricity market is the liberalisation of the electricity supply industry (ESI) of each of the ASEAN member countries. Although there is no one-size-fits-all solution to the establishment of the regional electricity market, liberalisation of the ESIs can potentially be the path for the ASEAN countries too, with the necessary modifications and localisations in place. Furthermore, ESI liberalisation or unbundling is not entirely new to the ASEAN countries. Nine out of the ten of its member countries have implemented unbundling, although the degree of implementation varies. To date, two ASEAN countries have unbundled their ESIs fully, namely Singapore and the Philippines. However, the two countries underwent different experience in liberalising their ESIs. While it was a 'bumpy ride' for the Philippines, Singapore had a smoother and more orderly transition. As such, deliberation of their experience in liberalising their ESIs would provide good insights for the other ASEAN countries to consider in liberalising their ESIs, should it become the direction. This paper therefore presents a brief overview of the Philippines' and Singapore's experience in their transformation towards liberalised ESIs with the aim to identify the good practices, the challenges as well as the lessons learnt from these transformations. Findings from the study show the importance of the governance and legislative framework to instate reform, as well as the gradual introduction of the reform moves. This is especially necessary as the lack of homogeneity and harmonisation of the regulatory framework and ESI structure of the ASEAN countries was found to be amongst the barriers towards the full realisation of the APG.

Application of biochar to the soil has been reported as one of the mitigation technologies of CH₄ emission from rice cultivation due to its unique characteristics of high porosity and surface area. The application of small particle size of biochar is rich in surface area that may enhance the mitigation potential. Rice cultivation and soil incubation experiments were conducted to evaluate the effect of two groups of biochar particle size on CH₄ emission and production in order to show the mitigation potential. This experiment consists of three treatments including no biochar (CT), small particle size (0.5-2 mm) biochar (SB), and large particle size (2-4 mm) biochar (LB). Both biochar sizes were amended at 10 t ha⁻¹ equivalent rate and all treatments were applied chemical fertilizer at 100 kg N ha⁻¹ equivalent rate. The results demonstrated that SB and LB reduced cumulative CH₄ emission by 24.0% and 17.1% and cumulative CH₄ production by 24.6% and 15.0% as compared to CT, respectively. Our results showed that SB achieved higher mitigation potential than LB by an average of 8.47%, although it was not significant. The mitigation of both biochar sizes was supported by the significant change of soil methanogens and methanotrophs abundances. The suppression of methanogens abundance and the stimulation of methanotrophs abundance indicated in the ratio of mcrA to pmoA was significantly reduced in SB (68.0%) which higher than in LB (56.3%) as compared to CT. Both application sizes also increased soil oxidation capacity through soil Eh increase which no difference between SB and LB. In term of grain yield, SB and LB were not different and both did not show the significant change as relative to CT. The application of small size biochar in this study affected more mitigation potential of CH₄ emission as compared to larger size, therefore there is a need of further study on typical size of biochar in order to recommend the most mitigation potential of biochar application.

Timber transportation planning is among the costliest activities in forest operation. Traditionally, the goal of timber transportation planning adopted to determine feasible way to extract high timber volume from the stump site to the final destination. However, modern transportation problems are not driven by the productivity of timber itself, but also by the efficiency of forest operation. This efficiency considerations and requirements introduce a new technique in timber extraction called log fisher as a complement to common technique, cable skidder. Nevertheless, side constraints within timber transportation planning may arise when two timber extraction techniques applied, complicates to and from several problems more extensive and more complex. While cable skidders affixed only on gentle slopes, log fishers possibly applicable regardless of slope conditions. Proper evaluation required to justify decisions since the use of these two techniques in the right places will result in efficient timber transportation planning. In the present study, a new problem-solving approach using Bees Algorithm (BA) was developed. BA can provide transportation planner with a large and complex transportation planning problem solving while complying with the forest road guidelines as required by the Forestry Department of Peninsular Malaysia. Herein, timber extraction technique is considered the least-cost in the main objective function for an efficient timber transportation planning and limitation of machinery to extract timber as constraints. Preliminary results show that this problem solving is promising for timber transportation planning problems with side constraints. A description of the algorithm development and its search process presented within this study.

Marine shrimp culture is important in agricultural sector which generates income for farmers. If marine shrimp culture is not proper management, it can cause environmental impacts on coastal ecosystem and water quality. Some areas use water spraying, washing and then flushing the pond bottom after shrimp harvesting and discharge water to receiving water which high nutrient and suspended solids exceeded the effluent standard. This research studied the marine shrimp discharge filtration using different media derived from palm shell. Three different media types for wastewater filtration were palm shell biochar (B), raw palm shell (R) and palm shell mixed with palm shell biochar (volume ratio of 1:1) (M). The simulated wastewater was daily fed via the top of the filter in semi-continuous mode (8 hours/day) at the hydraulic retention time of 4 h. During the 54 days of operation, water sample was collected to analyse SS, BOD, NH₃-N, TP and FCB. At day 54^th of operation, the average suspended solids (SS) removal efficiencies of B, R and M were 84, 82 and 84%, respectively, and the average total phosphorus (TP) removal efficiencies were 33, 28 and 30%, respectively. All filters could remove ammonia on the first 30 days of operation in which the concentration met the standard requirement of <1.1 mg/L. The average influent biochemical oxygen demand (BOD) concentration of 27 mg/L can be reduced to less than 20 mg/L after 3 days of operation in all filters. In addition, all filters were able to reduce the fecal coliform bacteria (FCB) to a lower concentration. Thus, these three different media are environmentally friendly material that can be used for effluent water filtration in the small-scale shrimp farm.

Dual-phase membrane is a newly developed membrane that is capable of capturing carbon dioxide (CO₂) from flue gas at high temperature up to 823 K. To date, the researches on CO₂ capture using dual-phase membrane are performed experimentally. However, the gas separation performance of the scale-up tubular dual-phase membrane module is scarcely studied. Therefore, the potential application of the dual-phase membrane module remains as a challenge. The design of membrane module and its implementation in actual operating conditions can be analyzed beforehand by using Computational Fluid Dynamics (CFD) simulation. In this paper, the hydrodynamic profile of the gas flowing inside a tubular dual-phase membrane module was studied to investigate its potential for industrial application. CFD simulation of gas mixture consisting of CO₂ and nitrogen (N₂) that flowing through the membrane module was performed at 823 K. Among the parameters investigated are the absolute pressure, concentration of CO₂ and gas velocity within the tubular membrane module. The inlet mass flow rate was set at 0.00448 kg s⁻¹ and the total volume of the membrane module was 0.031 m³. Based on the simulation, 0.09 bar of pressure drop was observed when the feed gas stream passed across the membrane zone to the outlet zone. There was about 86 % of CO₂ recovery with the CO₂ concentration decreased from 20 mol % to 3.3 mol %. Besides, the membrane stage cut was around 0.17 with 83 % of the gas leaving the membrane module at the retentate side. The simulation results give reliable statement over the separation efficiency of CO₂ and flow pattern in membrane module. The scale-up performance of single membrane module has been predicted through the simulation based on the experimental data.

Polymeric membrane is widely adopted for water treatment due to its stability in thermal and chemical resistance, smaller footprints and relatively low cost. However, polymer membrane always suffers the poor performance due to its hydrophobic nature. In the recent years, nanomaterials were introduced into membrane matrices to increase the hydrophilicity. In this study, three different types of nanomaterial, iron oxide (Fe₃O₄), graphene oxide (GO), and iron oxide-decorated graphene oxide (Fe₃O₄/GO) were embedded in the polysulfone (PSf) mixed-matrix membranes (MMM). This study investigated the effect of three different nanomaterials on the membrane characteristics, performance, and antifouling properties. Membrane characterization, performance, and antifouling was carried out by pore size, porosity, contact angle analysis, zeta potential analysis, flux measurements and flux recovery ratio respectively. First, GO, Fe₃O₄ and Fe₃O₄/GO nanomaterials were synthesized using Hummers method, co-precipitation method, and co-precipitation method in the presence of GO. After that, membranes were fabricated using phase inversion method. In this study, Fe₃O₄/GO-PSf MMM (76.35%) and GO-PSf MMM (64.39%) showed enhanced porosity as compared to the pure PSf membrane (56.89%) due to the presence of abundance hydrophilic group in GO nanoplates. However, the Fe₃O₄-PSf MMM show slightly lower porosity (53.82%). Contact angle analysis also revealed that Fe₃O₄-PSf MMM (71.47°), GO-PSf MMM (69.17°), Fe₃O₄/GO-PSf MMM (69.97°) showed improved hydrophilicity as compared to the pure PSf membrane (78.80°). Experiment also demonstrated that all the MMMs exhibit higher negatively surface zeta potential as compared to pure PSf membrane. The membrane performances were investigated using pure water flux and congo red (CR) dye removal. Study showed that Fe₃O₄/GO-PSf MMM give the best membrane performance with the flux of 112.47 L/m². h and CR dye removal of 97%±2. Fouling analysis reveal that all MMMs exhibit high flux recovery ratio (>80%) as compare to pure PSf membrane.

Super typhoon Haiyan made landfall in the Philippines last 2013 where an estimated 1.1 million homes were damaged. There was massive roofing damage in the houses due to strong winds. With the increasing number of roof-mounted renewable energy installations, there is a clear need to review the current systems to respond to future climactic events. The current approach for building performance analysis under typhoon wind loads involves a lot of wind tunnel tests, full scale testing and finite element modelling which is heavily reliant on wind tunnel data which are costly and time consuming. Current renewable energy mounting technologies with its different installation methods, and mounting locations consequently affected by wind loads differently. Using the proposed framework, this study evaluated solar panels attached to the gabled roof of a single detached low-rise building. The stress and deformation of the structure and the panels was determined using the typhoon's Atmospheric Boundary Layer flow simulation. Building energy simulation was used to determine the appropriate site orientation to maximise solar energy generation. Results show areas of high failure rate in the panels in the 0 degree wind angle direction and in the panels closer to the edge. Maximum solar energy generation was determined at the 90 degree site orientation.

In an era of rapid change, adequate strategy formulation is crucial to an organization, not just to overcome obstacles but to thrive in the business sustainably. To survive in the dynamic environment of the energy business, strategy formulation for energy enterprise need to consider various potential factors, together with their impacts. This includes social factors, innovation and technology factors, economic factors, environmental factors, as well as government policies and directions. The strategy formulation must be based on accurate and sufficient data, which indicates a level of impact and their uncertainties that may occur in the future. This paper presents analytical sets of key challenges, drivers, and critical uncertainties, which are expected to have significant impacts on the Thailand energy business in the next 30 years. The research starts with examining the global energy situation and challenges for the Thai energy business. The sustainable development goal is defined as a key decision focus at this step. Next, the STEEP analysis is employed to evaluate the impacts of factors on the energy business ranging from social factors, technology factors, economic factors, environmental factors to political factors. Foresight workshop with stakeholders is arranged to identify critical uncertainties. The result will be beneficial to both government and private enterprises in designing appropriate energy strategies.

Particulate-based adsorbents have been actively researched for water remediation. Despite being successful, this approach raises technical concern toward the end of its' implementation whereby the adsorbents are to be separated from the treated water. Separating the adsorbents via common filtration or centrifugation can be energy-intensive. Noting this, the present study prepared magnetite macro-beads (MMB) which can be easily isolated using a magnetic collector. Here, magnetite nanoparticles were impregnated into calcium alginate bead via facile drop-wise addition. The formed MMB was found effective in dye removal and the efficiency can be optimized by manipulate the bead's size and surface morphology. In specific, MMB of size 2.0 mm outperformed the bigger counterparts. In terms of surface morphology, large quantity of magnetite nanoparticles loading (≥10 g/L) blocked major pores of the alginate surface and reduced its efficiency. More importantly, the MMB can be rapidly separated (in < 5 seconds) using a NdFeB magnet owing to cooperative magnetophoresis effect.

Poly(vinylidene fluoride) (PVDF) is commonly used to fabricate ultrafiltration (UF) membrane due to its excellent thermal stability and chemical resistance. However, it is hydrophobic and hence has higher fouling tendency due to hydrophobic interaction with foulants. In this study, the antifouling properties of PVDF UF membranes was enhanced through the addition/blending of hydrophilic polyethylene glycol (PEG) of varying molecular weight. The addition of low molecular weight (200 Da, 4000 Da) PEG enhances the membrane's pure water permeability (from 22.049 L/m² hr bar to 24.791 L/m² hr bar) which could be explained by the improved surface wettability. However, the addition of large PEG (35k Da) on other hand reduces the membrane's pure water permeability (from 20.408 L/m² hr bar to 9.181 L/m² hr bar), with increasing rejection on humic acid (82.6 % to 98.5 %). This is due to the formation of a denser membrane with narrower surface pores. The membrane synthesized from 20% (w/v) PVDF with the addition of 4 g PEG 4000 Da showed better antifouling characteristic compared to pure PVDF membrane which could be explained by the enhancement of surface hydrophilicity. Nonetheless, the PVDF/PEG composite UF membrane suffered from rejection loss due to the leaching of PEG molecules from the membrane matrix. Lastly, a regeneration test is performed by flushing the used membrane (after the filtration on humic acid) with distilled water for one-hour duration. SEM images on the membrane surface reveals that the deposited humic acid layer was completely removed and the membrane was successfully recovered to its initial state. The results signified that the addition of PEG could enhances the hydrophilicity of the membrane and hence improving the membrane's antifouling characteristic.

Concrete in general is a poor conductor of heat, but it can suffer significant damage when exposed to fire. Investigation of concrete behaviour when exposed to fire has generated interest where most of the fire cases take place in buildings and tunnels. Incorporation of fiber in concrete can improve the mechanical performance as it acts as crack arresters, resisting the development of cracks, hence making the concrete composite matrix stronger. In this study, mechanical behaviour of basalt and carbon fiber reinforced concrete for different characteristic strengths at 28 days were investigated for its performance when exposed to fire flame. Fire flame test using methane gas was developed to simulate real fire phenomena. Concrete specimens were subjected to fire flame at the temperature of 1000 °C for a period of 90 minutes. Visual observation (colour change, cracking and spalling), loss of density and residual compressive strength of the concrete specimens were performed. The results obtained were compared with reference specimens. Test results showed that tested samples experienced cracking and spalling, reduction of mass and compressive strength. All samples experienced compressive strength loss except for G20 OPC which recovers 7.8 % compressive strength. Addition of carbon fiber showed an increased in strength before exposure compared to basalt fiber. Minor damages were observed for carbon fiber in concrete after fire exposure compared to basalt fiber.

Acquisition, treatment, and final disposal of health-care waste is a vital public concern. Improper disposal has heightened this concern as it could lead to a widened risk of transmission of agents associated with blood-borne diseases. One of the ways to address these concerns is waste disposal and waste-to-energy plant. This facility is envisioned not only to manage hazardous wastes from hospitals with the least emissions of toxic substances and greenhouse gases but also to generate electricity. This study investigated the feasibility of developing waste disposal and waste-to-energy plant which involved: the selection of hospital type and location, waste composition, energy conversion, and power plant technology, and financial viability of the plant. The sampling design process identified the hospitals to be surveyed. The criteria include proximity of the hospitals, number of beds, and type of hospitals. A survey of waste generation across the specialty hospitals was then conducted and determined the type of waste, the quantity of the wastes produced, the percentage by weight, bulk density, and composition of the wastes. A selection was done to determine the energy conversion technology. The electric power plant technology was then selected knowing the characterization of the synthetic gas. The average waste generation was found to be 579 kg waste per day which has 29,062 kJ/kg calorific value. The study shows that electricity could be generated from this waste by utilizing a Pyrolyzer - Rankine Cycle power plant and is viable with a payback period of 5 years, and a Benefit-to-Cost ratio of 4. A business plan and enabling environment for the establishment of the Pyrolyzer – Rankine Cycle power plant is recommended to be studied.

Sri Lanka has shown its commitment for greenhouse gas mitigation by publishing nationally determined contributions. Key share of mitigation targets is from the energy sector, amounting to about 40 Mt CO_2e during 2020-2030. 52 mitigation options (MOs), referred to as nationally appropriate mitigation actions (NAMAs), were identified with a total mitigation potential of 75 Mt CO_2e. Globally, the commonly used methodology for prioritization of NAMAs is the marginal abatement cost (MAC) analysis. However, this approach has received criticism over the effectiveness due to its inability to consider other important aspects such as barriers, enablers and co-benefits. The present study proposes a multi-criteria assessment (MCA) methodology involving more comprehensive characteristics of MOs and use of sustainability criteria/indicators to broaden the applicability of MAC analysis. The proposed methodology involves a stage-wise evaluation in three levels. Firstly, MOs identified are pre-screened based on technology maturity and information availability as indicators for chance of success in implementation. Among 52 MOs, 38 qualified for the next assessment level. These MOs are then undergone screening, where MAC and mitigation potential are combined with a scoring system together with a prescribed benchmark value as a qualifying criterion. Accordingly, 31 MOs are qualified, which represent a total mitigation potential of 62 Mt CO_2e.Finally, at third level, indicators in relation to barriers, enablers and co-benefits are used to derive an overall score of MCA. The results of MAC and MCA analyses are used in conjunction to prioritize MOs under three appealing levels as 07 highly, 14 moderately and 10 least, with a total mitigation potentials of about 17.1, 32.4 and 12.8 Mt CO_2e, respectively. Accordingly, the 21 high and moderate appealing MOs could contribute to the NDC targets. It is concluded that MCA methodology proposed is a sound approach in prioritizing MOs.

As global climate change intensifies, extreme catastrophic weather. As a result, the vulnerability of power infrastructure gradually worsens, leading to an increased threat of power supply disruption. In order to cope with the threat of possible power supply disruption and to accommodate more residents in the event of a disaster, backup power generation and storage facilities are necessary should establish in residential and commercial areas. This study establishes a software analysis model of power demand resilience in the residential area, analyzes various power demand resilience scenarios, and discusses the operation of reasonable backup power generation and energy storage facilities, and power load management and control strategies. In the future, these software tools will be used to analyze the rational allocation and operation strategies of disaster prevention at power facilities in similar situations. This study takes the Fengshan Smart Green Community as the reference field, and extends the simulated facilities as the area of power demand resilience analysis, in an integrated residential area and a commercial area. This study has completed four case studies, including: (1) baseline scenario, (2) "use of diesel generators" scenario, (3) "expanding lithium battery capacity" scenario, and (4) "expanding lithium battery capacity and controlling lithium battery power output in the integrated residential area" scenario. The conclusions of this study include: (1) To cope with the intensified global climate change, adequate deployment of various backup power generation and storage facilities to enhance power resilience can effectively mitigate the threat of power supply disruption. (2) According to the case study results, there is sufficient solar photovoltaic in the residential area of Fengshan Smart Green Community. However, the energy storage and power supply capacity of lithium batteries are insufficient, and it is challenging to perform the backup power function. (3) To supply electricity to the power management system and the medical and shelter area adequately, this study suggests Fengshan Smart Green Community strengthens the power storage and power supply capacity of lithium batteries. (4) Solar photovoltaics are zero-carbon power; it can be a priority backup for power demand resilience. However, solar power is not available when there is insufficient sunshine. (5) The use of a diesel generator can flexibly assist the solar photovoltaic and lithium batteries to ensure the adequate power supply. (6) The use of diesel generators for power generation during a time of crisis is not pollution-free. However, their use for management in a crisis or disaster situation is in order when other power supply backups are insufficient or have failed. The critical findings include: (1) Solar photovoltaics are zero-carbon power; it can be a priority backup for power demand resilience. However, solar power is not available when there is insufficient sunshine. (2) The use of diesel generators for power generation during a time of crisis is not pollution-free. However, their use for management in a crisis or disaster situation is in order when other power supply backups are insufficient or have failed.

Diclofenac (DCF) is a type of micropollutant from pharmaceutical waste which brings adverse effect to the aquatic environment if the wastewater is not well-treated. The impregnation of biopolymer on activated carbon has recently gained increasing attention to improve the removal efficiency of micropollutant from wastewater. Magnetite rice husk activated carbon/chitosan composite (MACCS) with high adsorption capacity was developed in this study by modifying rice husk activated carbon (RHAC) with iron oxide (Fe₃O₄) nanoparticles and cross-linked with chitosan. The adsorption performance of the synthesized MACCS was compared with rice husk activated carbon (RHAC) and magnetite chitosan (MCS) for DCF removal from aqueous solution. The physical and chemical properties of the synthesized biosorbents were investigated via scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). MACCS was identified as the best performing biosorbent and its DCF removal ability was further tested in batch with different parameters. The parameters reported in this study were solution pH and the synthesis ratio of activated carbon and chitosan. The most effective adsorption of DCF with MACCS was achieved at solution pH of 2.5 and activated carbon to chitosan ratio of 1:2. In acidic condition, the perfect coating of chitosan which contained abundance of amine group attached on the RHAC with high porosity had achieved 94% removal of DCF with maximum adsorption capacity of 270 mg/g. Besides, the MACCS could easily be separated from the aqueous solution due to its magnetic property. From the results, the MACCS biosorbent showed its potential to be an excellent alternative adsorbent for the removal of micropollutant from wastewater.

Machine learning can be a game-changer for a global warming prediction. About 75% global greenhouse gas (GHG) emissions cause by energy sector and this indicate a major concern to global warming community. In this study, non-supervisory machine learning technique has been used to predict the GHG effect relate to net calorific value based on intergovernmental panel on climate change (IPCC) standard. The study focuses on the characteristic of coal that is used in power generation sector and its chemical effluent that obtained from ultimate analysis (dried basis; Carbon, Hydrogen, Oxygen, Nitrogen, Sulphur and Ash) as gas emissions is concerned. The dataset shows, coal from different origin and type produce GHG emissions range approximately between 86.95 and 108.23 k-tonne CO₂/TJ with the net calorific value of 19.77 to 27.17 MJ/kg-coal. While, for ultimate analysis, the percentage of Carbon, Hydrogen, Oxygen, Nitrogen, Sulphur and Ash are in the range of [65.05 – 73.3], [1.46 – 5.49], [1.2 – 19.06], [0.3 – 1.20] and [4.82 – 15.96] respectively. In this study, principal component analysis is used to screen the training dataset and feed forward structure from artificial neural networks are used which allows the trained model to determine the GHG emission factor based on the given input data. The network relative errors of year 2017 dataset were used to adjust the weight value and as a result, the networks give r-square of 0.91678, which subsequently the trained networks are simulated for GHG emissions prediction for year 2018 at accuracy of r-square 0.82191. Furthermore, the study also shows, they are significant effect from coal characteristic towards GHS emissions and study proposed an optimal solution to simultaneously maximise power generation (in net calorific value per consumption weight) and reducing GHG value (k-tonne CO₂/TJ) of coal plant.

Indonesia has an abundance of geothermal energy potential (29 GWe) and becomes the second-largest geothermal power plant installed capacity after the United States. Geothermal is the most reliable renewable energy due to its highest capacity factor. It works as the base load in the electric grid. Unfortunately, the installed geothermal power plant was only approximately 6.3 % in 2018. Although the Government of Indonesia (GoI) has already given and supported in terms of financial incentives, regulation, technical assistance, it could not boost geothermal development significantly. Recent geothermal based electricity generation cost is rising, especially for the greenfield, caused by rising exploration cost could lead to geothermal development unfavorable, especially for affordability policy in Indonesia energy. All the incentives could not yet accelerate geothermal development significantly due to the risk and cost of geothermal exploration. Facing the fact that exploration cost tends to rise over time, G20 collaboration should be able to reduce the risk and cost associated with geothermal exploration with effective incentives. This paper aims to provide solutions and recommendations regarding exploration cost reduction through geothermal technology research and development with an emphasis on cost and risk reduction among G20 collaboration. The proposed incentives are then constructed for Indonesia's requirement to meet geothermal conditions and requirements from the trilemma energy aspect, especially for geothermal technology to reduce exploration cost and risk. The proposed incentives also deal with human resource development for improvement in learning rates to have better technology adoption and acquisition by using SWOT and Policy Gap Analysis.