Table of contents

The International Conference on Biomass and Bioenergy (ICBB) 2022 was successfully held as a fully online conference by the Surfactant and Bioenergy Research Center (SBRC)-IPB University, Indonesia in collaboration with the International Society of Biomass and Bioenergy (ISBB); College of Engineering, Villanova University, USA; and Biomass Project Research Center, Hiroshima University, Japan. ICBB 2022 was sponsored by the Oil Palm Plantation Fund Management Agency of the Republic of Indonesia (BPDP Sawit). The conference was also supported by the Ministry of Energy and Mineral Resources of the Republic of Indonesia, IPB University, and Indonesian Association of Bioenergy Scientist and Technologist. ICBB 2022 with the theme of Journey of Biomass and Bioenergy Research and Development to Achieve Net Zero Emissions was the seventh international scientific conference on biomass and bioenergy hosted in Indonesia. This conference is conducted annually to raise current global advancement in biomass and bioenergy fields.

Due to consideration of the continuing limitations of holding the real conference related to COVID-19, especially in Indonesia, ICBB 2022 was held as an online conference on 1-2 August 2022 by Zoom Video Conference platform. ICBB 2022 was organized by SBRC-IPB University and hosted from IPB International Convention Center, Bogor, Indonesia. To maintain the continuity of the annual conference and the intention of scientists to disseminate and publish their research, as well as to facilitate the attendance of more international participants, the ICBB 2022 associates decided to hold a virtual conference.

ICBB 2022 main program consisted of a plenary session with five speakers and four thematic parallel sessions. ICBB 2022 successfully delivered 30 minutes-plenary lectures (20 minutes lecture, and 10 minutes discussion and Q&A sessions) of prominent scientists in biomass and bioenergy sciences from 4 different countries, i.e., Assoc. Prof. Dr. Meika Syahbana Rusli (IPB University, Indonesia), Prof. Dr. Kiyoshi Dowaki (Tokyo University of Science, Japan), Prof. Dr. Anthony Halog (The University of Queensland, Australia), Prof. Dr. Lee Keat Teong (Universiti Sains Malaysia), Prof. Dr. Eng. Muhammad Aziz (The University of Tokyo, Japan), and 59 parallel presentations (20 minutes presentation and Q&A for each presenter). ICBB 2022 thematically discussed four key topics as follows:

1. Biomass utilization and Bio-materials,

2. Bioenergy and AI/IT Technologies in Biomass/Bioenergy/Agriculture,

3. Environment, Economics, Policy, Management/Business related to Biomass or Bioenergy,

4. Bio-chemicals

The paper committee received 75 submissions and finally accepted 48 full papers of over 59 presentations which were delivered in the conference and published in this ICBB 2022 proceedings after the peer reviewing process. Authors of ICBB 2022 proceedings were from 5 countries, i.e., Indonesia, Japan, Czech Republic, Germany, and the Philippines. The representative country with the list of authors and title is as follows:

Indonesia: "Extraction of bio-pigments from the green microalgae Chlorella pyrenoidosa under different solvent ratios" (Obie Farobie, Latifah A Anis, Puji R Nurcahyani, Edy Hartulistiyoso, Delicia Y Rahman, Widya Fatriasari, Ayu L Nafisyah, Apip Amrullah, and Muhammad Aziz)

Japan: "Discussions on the heat transfer performance of the indirect pyrolysis plant using CFD modeling" (Mayu Hamazaki, Kento Torii, Miao Shan, Mitsuo Kameyama, Jericho V L Mercado, and Kiyoshi Dowaki)

Czech Republic and Germany: "Analysing maize plant height using Unmanned Aerial Vehicle (UAV) RGB based on digital surface models (DSM)" (Sri M A Letsoin, David Guth, David Herak, Ratna C Purwestri)

The Philippines: "The energy yield of the torrefied coconut shells" (R U Espina, R B Barroca, and M L S Abundo)

Furthermore, there were more than 192 participants who attended online ICBB 2022 from 11 countries (Japan, China, Czech Republic, Malaysia, Singapore, USA, UK, Germany, Philippines, Australia, and Indonesia). The differences in time zones and the quality of the participants' internet networks posed a challenge to the operation of this online conference. However, this was resolved by conducting preparatory Zoom meetings with session chairs and presenters before the conference. Therefore, the technical quality and delivery success of the conference as a whole were very good.

Acknowledgments and appreciations are conveyed to the Rector and Vice Rector of IPB University for their support to the conference, to the reviewers and editorial board members, committee members, and event partners who worked hard to make the conference and the publication of this proceedings successful. The conference committee acknowledged the support and sponsorship from the Oil Palm Plantation Fund Management Agency of the Republic of Indonesia (BPDP Sawit).

The paper committee did their best to complete manuscripts reviewing and editing by following the scientific standards in the IOP Conference Series: Earth and Environmental Science. However, there might be some shortcomings found in this proceedings. Therefore, suggestions from readers are greatly appreciated, so that the quality of the ICBB conference proceedings will be improved in the future. We hope this ICBB 2022 proceedings will improve knowledge and provide benefits to academics, scientists, industrial stakeholders, and policy makers, especially in the field of biomass and bioenergy. Thank you for your kind attention.

Bogor, February 2023

The Organizing Committee of ICBB 2022

List of Committees of the International Conference on Biomass and Bioenergy 2022 Steering Committee, Organizing Committee are available in the pdf.

Peer Review Declaration Form Guidance

On the following page you will find the declaration form.

• Please answer each question.

• You should submit the form along with the rest of your submission files.

• The deadline is the submission date written in your publishing agreement.

All conference organisers/editors are required to declare details about their peer review. We will publish the information you provide as part of your proceedings.

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

• Type of peer review: Single-blind

• Conference submission management system: EasyChair

• Number of submissions received: 75

• Number of submissions sent for review: 54

• Number of submissions accepted: 48

• Acceptance Rate (Number of Submissions Accepted / Number of Submissions Received X 100): 48 / 75 X 100 = 64

• Average number of reviews per paper: 2

• Total number of reviewers involved: 9

• Any additional info on review process:

Each reviewer received 10-18 papers (according to the acceptance and suitability of the reviewer's expertise)

The peer review process was conducted for 4 weeks (20 July to 16 August 2022)

• Contact person for queries:

Name : Dr. Eng. Obie Farobie

Affiliation: IPB University, Indonesia

Email: obiefarobie@apps.ipb.ac.id

Fat replacer is food ingredients used to mimic and replace animal fat in food products. The demand of low saturated fat in food products increase because of health concerns related to degenerative disease. Vegetable oil in a liquid state must be solidified to mimic animal fat by the emulsification process. This study aims to create and formulate fat replacer using palm olein and palm stearin as a source of unsaturated fatty acid. The formula was composed with vegetable oil concentration of 30% (K1), 35% (K2), 40% (K3), 45% (K4), and 50% (K5). A concentration of 15% fat replacers emulsion was added to make a meat analogue. Proximate analysis from all treatments showed that meat analogue has water content in the range of 53.90–57.56%, ash content of 2.87–3.10%, protein content of 9.04–15.32%, fat content of 13.22–19.13% and carbohydrate content of 2.35–2.53%. Oil concentration in fat replacer affected to the texture and sensory properties of meat analogue. The results indicate that the five treatments comply with the national quality standards for meat sausages.

Sweet sorghum is a potential plant as a raw material for bioethanol. This plant has the potential to be developed in tropical, semi-tropical and arid climates. To obtain information on elite lines as raw material for ethanol, it is necessary to characterize qualitative and quantitative traits. This study aims to obtain information about the quantitative and qualitative characters of several sweet sorghum lines that have the potential as raw materials for bioethanol. The research was carried out from August to December 2019 on the Experimental Farm of Indonesian Cereals Research Institute (ICERI), at Maros, South Sulawesi, Indonesia. The genetic materials used in this study were ten sweet sorghum lines, namely 15020B, 1115-C, 4-183ABEOTO, AB-6-1-1, EA-13-1-1, KL2, 10 (1-1), 23 (1-1), Buleleng Abang and WR2 and two varieties as check, namely Super-1 and Super-2, using a randomized block design in which genotype was the treatment factor. Qualitative data is explained by a descriptive method which refers to UPOV. Analysis of variance indicated significant differences in the quantitative and qualitative characters. Significantly different characters quantitatively were plant height, leaf length, leaf width, day to flowering, panicle length, and weight of 1000 grains. While the significant qualitative data are green leaf intensity, leaf bone color, pistil color, pistil length, dry stamen color, panicle shape, panicle density after pollination, self-pollination, husk color, husk length, grain color, seed shape, and endosperm texture. Based on morphological data, the promising elite lines as raw material for bioethanol were EA-13-1-1, KL2, WR2, Buleleng Abang, 61 (1-1) and 15020B. However, other scientific supporting data are needed to recommend superior sweet sorghum lines as raw material for bioethanol.

This research was conducted with the aim of making an alternative, nature-based biopolymer formed from the extraction of jackfruit peel pectin as a substitute for commercial polymers. The manufacture of this biopolymer is carried out by means of laboratory tests using conventional methods with a chemical extraction process on jackfruit skin. The raw material used is jackfruit skin (Artocarpus integer). Processing of jackfruit skin into pectin is carried out by several procedures such as extraction using citric acid, purification of pectin with 96% ethanol, FTIR characterization test, density test, viscosity test, shear rate test, and the effect of salinity. The FTIR test showed that pectin was formed after the extraction step, as evidenced by the structure of the pectin-forming groups which was similar to commercial pectin. The deposition of impurity particles contained in the pectin content is evidenced by the lack of optimal pectin to increase the viscosity of water. The increase in viscosity will occur as the concentration of pectin increases. Jackfruit pectin is able to survive in solutions that have high salinity, as evidenced by the higher the salinity of the solution, the thickening process continues.

Java is considered a center for the ruminant population and supplies cattle and buffalo to several parts of Indonesia. Livestock population increment needs the adequacy of feed, both quantity and quality. Potential sources of feeds are therefore needed to be inventoried to ensure the sustainability of feed adequacy. This study aimed to estimate the potential amount of feed from rice straw in Java for supporting ruminant production in the region. The method of this study was descriptive and quantitative, using secondary data. The potential amount of rice straw as cattle and buffalo feed ingredients was calculated using the yield area of rice. The yield area was converted to grain production, which led to the rice straw production as feed availability. Dry matter (DM), crude protein (CP), and total digestible nutrient (TDN) contents were used as a parameter. The percentage of the three parameters was collected from previous studies. The availability of DM, CP, and TDN from rice straws was then calculated based on the Animal Unit (AU). On the other hand, feed requirement was derived from the cattle and buffalo population. The population data were converted to AU, and then the total DM, CP, and TDN requirements were calculated based on previous studies (6.25 kg DM.AU^-1, 0.66 kg CP.AU ^-1, and 4.3 kg TDN.AU^-1). The feed availability and condition in Java province were compared and classified into three categories: surplus, sufficient, and deficit. The results showed that Banten, West Java, and Central Java provinces were sufficient to feed adequacy, whereas East Java and Yogyakarta provinces were deficient. This study suggests each province should utilize alternative feed resources in addition to rice straws to ensuring a sufficient feed supply for a ruminant.

One of the healthy lifestyles that continues to grow is consuming healthy food. The consumption of sweet bread in Indonesia continues to increase, and as a result, the cases of people with diabetes mellitus in Indonesia have also experienced a significant increase, for it is not recommended for people with diabetes mellitus to consume excessive amounts of sweet bread. A cinnamon roll is a dough roll sheet consisting of the cinnamon and sugar mixture (raisins or other sweet fruit ingredients) which are sprinkled on top of a thin layer of butter. Cinnamon Java Roll is a modified product of cinnamon roll with cinnamon and palm sugar with lower sugar content due to the ingredients in it, where there is a modification of the ingredients by adding palm sugar which has a lower glycemic index, and the addition of sliced dates as an additional sweetener and almond nuts for nutritional enrichment. One slice of bread contains 137 Cal of energy, 2.59 grams of protein, 4.93 grams of fat, and 22.36 grams of carbohydrates with a sugar content of 8.37 grams/serving (1 slice) and 75.34 grams/recipe (9 slices).

Red ginger has active chemical compounds that are beneficial for health. Besides being abundantly available, red ginger also has potential as a natural preservative. The content of active chemical compounds, antimicrobial activity, and protease enzyme support natural preservation methods in the food industry. This study aimed to determine the effect of red ginger concentration on the physical and organoleptic qualities of buffalo meat. The research method was experimental using a completely randomized design with 4 treatments and 5 replications. The treatment consisted of R0 = 0%; R1 = marinade using 20% red ginger concentration; R2 = marinade using 40% red ginger concentration; R3 = marinade using 60% red ginger concentration. The results showed that red ginger concentration had a significant effect (P<0.05) on cooking loss and colour. Red ginger concentration had a very significant effect (P<0.01) on the pH value, tenderness, and aroma but had no significant effect (P>0.05) on the water content of buffalo meat. This research concludes that marinating using red ginger biomass can improve the physical and sensory qualities of buffalo meat during storage. Red ginger biomass had the potential as a spice that can be applied sustainably to improve the buffalo meat quality.

Recently, the demand for wood pellets as solid biofuel for co-firing process in the industry has increased. However, the increase in demand is not accompanied by the availability of sawdust (SD) as a raw material. Thus, seeking alternative biomass is needed to substitute wood. One of the alternative biomasses that can be considered as raw material for bio-pellet is the solid waste from the coffee industry. Meanwhile, the coffee industry annually produces large amounts of organic waste such as spent coffee grounds (SCG) and coffee husks (CH). Both solid wastes have organic compounds contained so that they can be utilized as solid biofuel. In this research, We investigated the quality changes of wood pellets before and after the addition of coffee waste in different mass ratios (1:1, 1:3). A densification method with a pressure of 2 tons is used in the wood pellet-making process. Physicochemical characterization of wood pellets such as density, durability, compressive strength, calorific value, and proximate and composition analysis using SCG and CH are conducted. The result shows that the addition of SCG into wood pellet increased the calorific value of wood pellet from 21.03 MJ.kg^-1 to 21.71 MJ.kg^-1. The calorific value with a ratio of 50: 50 of SD: SCG produces a better calorific value than CH (20.64 MJ.kg^-1). The mechanical test of the pellet shows that the addition of SCG and CH slightly decreases the mechanical durability from 99.34% to 97.02%. Thus, increase the appearance density from ρ = 892.46 kg.m^-3 to ρ = 1119.33 kg.m^-3.

Citric acid is one of the essential organic acids in human life and rice husk has the potential to be used as a substrate because it contains about 28.6-43.3% cellulose, and its use, does not compete with human needs. This research aims to increase citric acid production by using rice husk as a substrate, with a working volume of 2000 mL. In this study, it produced citric acid using submerged fermentation and Aspergillus niger at 22.42% w/v rice husk conditions, 10% w/v sucrose, 3% v/v methanol, and 400 rpm agitation. The results showed that the citric acid pH value on day 18 of fermentation was 1.9, and the concentration of citric acid after purification was 162.667 g/L, while the concentration of citric acid before purification was 148.639 g/L. The specific growth rate of Aspergillus niger obtained was 0.0863 cells/day, and the rate of reducing sugar consumption was 0.1283 g/day. The yield of Aspergillus niger biomass produced is 1.1258 cells for each g of reducing sugar, and the yield of citric acid production is 16.8144 g for each g of cell and 18.9301 g for each g of reducing sugar.

Nowadays, the use of microalgae biomass is evolving rapidly for their various applications such as food, pharmaceutical, and cosmetics. One of the essential compounds in microalgae that have good perspectives in the market is pigment since it can be used as a natural colorant in food or cosmetics. However, the extraction of bio-pigments from the green microalgae Chlorella pyrenoidosa under different solvent ratios is still rarely reported. Therefore, this study aims to investigate the bio-pigment potential from C. pyrenoidosa extracted under different ethanol ratios. The algae-to-ethanol ratios of 1:5, 1:7.5, and 1:10 were employed in this study. Overall, C. pyrenoidosa contains total chlorophyll content much higher than carotenoids due to the fact that C. pyrenoidosa is the autotrophic microorganism that performs photosynthesis. The total chlorophyll content decreased with an increase in ethanol ratio, i.e., 134.47, 133.74, and 129.46 μg/mL at the ratio of 1:5, 1:7.5, and 1:10, respectively. In contrast, the carotenoid content slightly increased with an increase in ethanol ratio, i.e., 86.64, 87.08, 88.45 μg/mL at the ratio of 1:5, 1:7.5, and 1:10, respectively. The main chlorophyll compounds in the ethanol extract with the algae-to-ethanol molar ratio of 1:5 were identified as chlorophyll c (47.09 μg/mL), followed by chlorophyll b (38.50 μg/mL), chlorophyll a (28.67 μg/mL), and chlorophyll d (20.23 μg/mL).

Microalgae cultivation is considered fit to the concept of green economy, in which greenhouse gases (GHG's) mitigation and production of valuable substances is performed simultaneously. Carbon dioxide consumption by the algal cells reduces GHG's emission to the atmosphere, while biomass conversion to biofuel feedstock supports the concept of circular economy of microalgae cultivation process. In this study, Chlorella sp. was cultivated in a Multi Tubular Airlift Photobioreactor (MTAP) system with a total volume of about 600 L. The result of a thirteen days batch culture showed the ability of the system to fix 1.57 g CO₂ L^-1 day^-1. At the last day of experiment, 600 L MTAP showed biomass production of 0.35 g L^-1 and 18% oil from cell dry weight was observed. This research showed the ability of 600 L MTAP to absorb 942 g CO₂ and produce 37.8 g oil as biofuel feedstock. Compared to other experiments, percentage of oil in this experiment (18% from cell dry weight) was in the average range from other experiments (of about 10 – 40% from cell dry weight). However, this MTAP showed higher performance than other systems (mostly below 1 g CO₂ L^-1 day^-1) in CO₂ fixation rate.

Indonesia is the world's largest producer and consumer of palm oil. Its residents are accustomed to frying food in its food culture, hence the massive generation of used cooking oil (UCO). However, UCO has not been optimally utilized. Most is dumped into the environment, causing uncontrolled environmental pollution. The utilization of UCO as biodiesel feedstock is one solution to overcome environmental pollution while increasing its economic value. This utilization contributes to the Nationally Determined Contribution (NDC) target while simultaneously providing an additional global supply of biodiesel feedstock. The amount of UCO for biodiesel raw materials is potential to be increased further. However, the UCO collection system is extremely dependent on the existing collection system, socio-cultural and education aspects of the local community, as well as support from the local government. In Indonesia, UCO collection remains limited in a local context and is carried out partially. This study reviews several previous studies related to the potential of UCO and the environmental impact of UCO use for biodiesel. The improvement of the UCO collection management system in alignment with local socio-cultural conditions is also proposed. This paper is expected to offer a useful reference for decision-makers in updating and implementing the UCO collection method for sustainable biodiesel feedstock.

Boiler ash from palm oil mill contains high SiO2compound. The boiler ash used in this study was from PKS Cikasungka PTPN VIII, Bogor. The research objectives were to (i) optimize the conditions of silica synthesis process from boiler ash, (ii) analyze the silica content of the synthesis, (iii) and analyze the performance of silica as a moisture absorber. This research was designed using a central composite design (CCD) and the variables were optimized using the response surface method (RSM), silica was synthesis using sol-gel method and silica content was measured using XRF. The performance of silica as a moisture absorber was also studied to determine the appropriate adsorption kinetics at 32%, 64%, 75%, 85% and 97% RH conditions. The results showed that the optimum process conditions that produced the highest silica yield (41.17%) were solvent concentration of 7.39 M and extraction time 78.13 minutes. The silica gel produced is a white powder with SiO2content of 79.20%. The results showed that the water vapor adsorption kinetics at 64% RH was simulated with a first order model, while other treatments with 32%, 75%, 85% and 97% RH were simulated with a second order pseudo model. At 32% RH had a higher k value of 0.086 g/g/day than the 97% RH of 0.011 g/g/day.

The problems of degradation on oil production can be solved by chemical EOR (Enchanced Oil Recovery) methods, polymer injection is the one kind of chemical EOR methods. When the polymer fluids injected in to reservoir then it will be increase the oil sweep efficiency and fixed the mobility ratio of the injected fluids. The sample that will be tested in this experiments is biopolymer. Besides the xanthan gum that extracted by using bacterial, in side the plant contained a compound as know as paectin, it is a derived from the polysaccharide. So far the pectin was extracted and has been used in food industrial as a thickening agent and gelling agent, so in this experiments will be doing the pectin extraction and then do the analysis step that prospected as an alternative material in polymer injection method. The extraction method that used in this experiments is by using Microwave-Assisted Extraction (MAE) method from oranges peel waste. The purpose of this experiments is to knowing the pectin properness as a thickening agent as an alternative alternatife biopolymer material. The results of the FTIR test showed that there is compatibility of the function groups that formed the pection compounds.

Indigo is a natural blue dye produced from the leaves of the Indigofera plant, which is environmentally friendly and non-carcinogenic. This study aimed to determine the reduction potential value of molasses and brown sugar as reducing agents, to examine the effect of the hydrochloric acid concentrations and aeration time on the amount of indigo, and to test the fastness of rubbing against solar heat, dry, wet and acid on silk fabrics that were dyed by indigo with various fixators. To extract the indigo dye, the Indian glycosides contained in Indigofera leaves were hydrolyzed to indoxyl and glucose using hydrochloric acid. Indoxyl was then oxidized to indigo using molasses as a polysaccharide compound. The results showed that the concentration of 0.01 M hydrochloric acid produced the highest indigo content of 26.83 ppm, and the best aeration time was 4 hours to produce indigo with a concentration of 22.32 ppm. The effect of the fixator types produced different colors. The fixator of ferrous sulfate produced a dark blue-green color, limestone produced a light blue color, while alum produced a bright blue color. The fastness test showed the same result as the gray sale value of 4-5 meaning that there was a slight fading.

The use of renewable energy from wood biomass which is processed in the form of wood pellet are environmentally friendly, sustainable and also to reduce greenhouse effect and environmental pollution. The main problem in the quality of a wood pellet from Gliricidia and Calliandra is the ash content (1%) has not fulfilled the Europe quality standard requirement A1-EN14961 (ash content ≤ 0.7%) yet fulfills the A2-EN14961 quality standard. The effort to lower the ash content is by debarking and mixing with other wood variety to increase the quality of Gliricidia and Calliandra wood pellet quality in the international market. The aim of this research is to discover the effect of debarking and mixing of Gliricidia and Calliandra with pine and acacia wood toward the quality of wood pellet, especially the ash content. The result shows ash content for pine wood pellet and acacia wood pellet consecutively 0.36% and 0.71% have fulfilled the Europe quality standard EN 14961 (max. 0.7%) and have the potency to be the mixer raw material for Gliricidia (ash content 1.19%) and Calliandra (ash content 1.05%). Debarking method can lower the ash content of Gliricidia and Calliandra wood pellet consecutively 36.1% (from 1.19% to 0.76%) and 18.1% (from 1.05% to 0.86%) and almost fulfill the A1 Europe quality standard (EN 14961 max 0.7%). Wood mixing Gliricidia-Calliandra-Pine (1:1:1) ash content is 0.89% with 20.5% decreasing rate, almost fulfill the A1 Europe quality standard (EN 14961 max 0.7%). Wood mixing Gliricidia-Calliandra-Acacia (1:1:1) ash content is 1.17% with 2.7% decreasing rate. Method combination by mixing pine wood, debarking of gliricidia and calliandra have the potency to generate wood pellet with ash content suitable with the A1 Europe standard EN 14961 max 0.7% [1].

Investigation of capability of high potential pineapple (Ananas comosus) leaves powder (PLP) as reinforcing material on the starch-based foam production has not been reported. This study was aimed to characterize the physical and mechanical properties of starch foam formed from the mixture of cassava starch and PLP. The foams were made using a baking process on a thermo-pressing machine at temperature of 170°C and 180°C of the lower and upper mold temperature during 120 seconds. The starch foams were formulated with four different concentrations (0, 5, 10, and 15%) of PLP as reinforcement and tested for their characteristics of mechanical (compressibility) strength, water adsorption, morphological structure, density, color appearance, and biodegradability. Addition of PLP up to 15% improved the physical and mechanical properties of the foams.

High water content is one of the most concerning issues when implementing biodiesel as a diesel fuel blend. Vacuum heating is one of several methods to reduce the water content of biodiesel, at certain conditions, it may damage the stability of biodiesel. This study aims to understand the stability of biodiesel including water content, total acid number, and oxidation stability under vacuum heating process. The three stability parameters were tested according to ASTM D6304, ASTM D664, and EN 15751, respectively. Biodiesel with high water content was heated under a vacuum pressure of -720 mmHg. The heating temperature and time were varied to determine the effect of both variables on the stability of biodiesel. The result shows that higher heating temperature produces lower water content and higher reduction of oxidation stability. Similar effects were also observed at a longer heating time. However, either temperature or time variations gave no noticeable effect on the acid number, while oxidation stability can be maintained above 22 hours. The results of this study can be used as a recommendation in determining the limits of acceptable operating conditions in the biodiesel vacuum heating process.

The limited availability of fossil fuels and the current issue of global warming has made biodiesel an alternative The first section in your paper fuel option. Biodiesel, which is processed through the transesterification reaction in its use has been approved as a commercial fuel with a low blending ratio. However, it is possible to use it with a high ratio. Blending biodiesel and diesel fuel with a high ratio, of course, many considerations must be agreed upon regarding the quality of the product. In this study, the quality of the biodiesel-diesel blending was evaluated. Characterization of the blending fuel properties with improvement was carried out to evaluate the characteristics of the fuel blending and to indicate the maximum blending ratio that is suitable for use and does not harm the environment or its users. Diesel fuel (B0) with a cetane number of 48 and a cetane number of 51 is blended with FAME (B100) from a ratio of 10% FAME and 90% diesel (B10) to 90% biodiesel and 10% diesel (B90). Characteristics such as viscosity, density, FBT, Cleanliness, total contaminants, and CFPP were tested according to ASTM and ISO standards. The results showed an increase in the value of viscosity and density as the ratio increased but still met the ASTM D7467 standard of 0.855 mg/m³ in the B90 and the highest viscosity was 4.9 mm²/sec in the B70. The results of the FBT test, total contaminant, cleanliness, and CFPP the highest on B90 for all fuels.

This present paper is focused on the investigation of combustion characteristics of torrefied pellet biomass from agricultural waste. Four biomass pellet samples such as sugarcane bagasse, Napier grass, Palm Empty Fruit Bunches, and Cassava stem were torrefied in a designed cylinder tubular pyrolysis reactor. The reactor was set up under 30 min of residence time, and the temperature reaction was varied at 200, 250, and 300 °C in an inert atmosphere. The torrefied products were then characterized in terms of their psychochemical properties such as proximate, ultimate, calorific value, and combustion properties. The combustion properties of raw and torrefied biomass pellets during the combustion process were investigated by the thermogravimetric analyzer Exstar SII TG/DTA7300. The samples were heated at an ambient temperature up to 800 °C at a constant heating rate of airflow at 10 °C/min in airflow. The results showed that the moisture content and volatile matter of torrefied pellets decreased by 2 to 5% and 8 to 14%, subsequently. Otherwise, the fixed carbon content is up to three times higher than the raw material. The study conclusively that torrefaction can also able to enhance combustion performance in terms of ignition and burnout temperature, ignition and burnout index, and combustion rate. The results shows that, the ignition and burnout temperatures of torrefied pellets are higher than raw material. The ignition and combustion index of torrefied pellets are lower than raw material, and the torrefied pellets have a longer burning time and a higher combustion temperature.

Woody and herbaceous biomasses have been utilized as biomass energy plant feedstocks that generate electricity for years. The coconut tree, classified as woody biomass, flourishes throughout tropical regions. Every year, each tree can produce an average of 70 nuts or a maximum of 150 nuts, with each fruit consisting of 15.18% shell. The Philippines has approximately 2.2 million tons of coconut shells each year. The study aims to determine the energy yield of the coconut shells when torrefied. The coconut shells were crushed, torrefied, and analyzed elementally. Initially, the calorific value of raw coconut shells was 30.79 MJ/kg and improved to 34.37 MJ/kg after torrefying at 275°C and held for 30 minutes. The optimal mass yield was 90.10%, while the energy density was 111.64%, resulting in an energy yield of 100.59%. Torrefaction improved the calorific value of coconut shells by 11.63% and optimized the energy yield to 100.59%.

Fossil fuels still dominate future energy needs, while oil production has shown a declining trend over the past ten years. One solution to this condition is using new and renewable energy sources. In the transportation sector, one of the most common environmental problems resulting from the combustion of fossil fuels in internal combustion engines is emission. Mixing gasoline with alcohol is based on this problem. This paper calculates the composition of gasoline-ethanol-methanol with target RON 92, 95, and 98 with RON-based 89. The composition of this blend is calculated with linear molar calculation. Blending ethanol and methanol in gasoline also influences their chemical and physical properties. The characteristics, i.e., research octane number (RON) and density of gasoline-ethanol-methanol fuel blends of RON target 92, 95, and 98, are presented. The results of this calculation will be compared with the experiment. RON is one of the critical characteristics of the internal combustion engine's compression ratio and combustion quality. The obtained result revealed that the average difference from the calculation with the experiment on RON is 0.73, and the density is 0.36.

Rubber Seed-Shell is a biomass material with great potential as a bio-energy resource for future life. In preliminary research, a Rubber Seed-Shell briquette was manufactured using a laboratory briquette die. Building on the preliminary research, this study was carried out to investigate the effect of carbonization temperature on Rubber Seed-Shell briquette properties and to evaluate product properties. It was concluded that carbonization temperature does affect the properties of Rubber Seed-Shell briquettes. Results showed that moisture content ranged between 5.6 and 6.6% (db), volatile matter ranged between 26.6 and 39.3%, ash content ranged between 3.7 and 5.45% (db), fixed carbon ranged between 51.4 and 61.35 (db), and calorific value ranged from 23.1 to 26.3 MJ/kg. After being carbonized, the properties of the Rubber Seed-Shell briquette were improved. Overall, the properties of carbonized briquette observed in this work meet the briquette standard (Indonesian standard SNI 01-6235-2000) and the International standard (Japan, England, and the USA)). Thus, Carbonized Rubber Seed-Shell is proposed as a new biomass solid fuel that has the potential to be developed as a commercial briquette.

In many infrastructure of oil and gas industries, corrosion is one of the most problems that often occur, especially in pipelines. Corrosion is caused by an electrochemical reaction between material surface and corrosion fluid. This problem will affect the economy, safety, and conservation. In this case, we should give a solution such as a method or tools to minimize corrosion's effect so, it can improve safety and minimize the potential problems caused by corrosion and loss more cost. One of the ways is using organic corrosion inhibitors such as biomass agriculture waste and plant extract. A corrosion prediction model can be used to predict the corrosion rate such as NORSOK and de Waard models. Both methods are available in Olga Simulation software by Schlumberger that were used in this paper. Some of the parameters that influence corrosion were also tested: Evaluation of 1°, 2°, 3°, 4 °, and 5° of pipeline elevation to corrosion rate. Meanwhile, 31.71% of rice straw extraction (RSE) with 75% IE was used as a corrosion inhibitor compared with 30% of mono-ethylene glycol with 26% IE and 38.97% of lignin with 61% IE to determine the period of pipeline per year and to design of the pipeline. RSE that contains lignocellulose was able to give higher efficiency to decreasing corrosion. Moreover, this organic inhibitor give low cost. Therefore, this biomass would be potential as an alternative inhibitor rather than a commercial corrosion inhibitor with high cost.

This study aims to assess Near infrared (NIR) spectroscopy to predict vanillin and moisture content non-destructively. Twenty-four samples of vanilla pods (@55 grams/sample) from Sumatra and Sulawesi Island were tested. The reflectance spectra of vanilla pod were measured using a NIRFlex N-500 spectrometer at the wavelength of 1000-2500 nm. After that, the vanillin and moisture content were measured using the reference method. The reflectance spectra were transformed to absorbance spectra and several pre-treatment methods of NIR spectra were applied, and the results were calibrated with chemical data using principal component regression (PCR) and partial least square (PLS) methods. The best estimation for vanillin content using absorbance spectra with OSC pre-treatment at 3 PLS factors with the accuracy parameters of r = 0.91, SEC = 1.31%, SEP = 1.34%, CV = 45.60%, RPD = 2.30 with a consistency of 97.96%. The best prediction of vanillin content using PCR method was obtained with SNV pre-treated spectra at 6 PCR factors with the accuracy parameters of r = 0.89, SEC = 1.47%, SEP = 1.49%, CV = 43.21%, RPD = 2.09 and 101.40% consistency. The best estimation for water content using the PLS method is using the SNV pre-treatment spectra with a PLS factor of 5 with the accuracy parameters of r = 0.99, SEC = 2.11%, SEP = 2.13%, CV = 6.12%, RPD = 7.98 with consistency = 98.86%. While using the PCR method, the best estimation for moisture content was also obtained by SNV pre-treated spectra at 4 PCR factors with the accuracy values of r = 0.99, SEC = 2.33%, SEP = 2.25%, CV = 6.25%, RPD = 7.58 and consistency = 103.90%. The PLS calibration provide a better accuracy than the PCR. The NIR spectroscopy associated with the selected pre-treatments and factor numbers of PLS and PCR can be used for determination of chemical content of vanilla pods.

The operational conditions of the anaerobic bioreactor can be predicted using three parameters, such as biogas pressure, biogas mass flow rate, and methane gas content. This research will present a monitoring system for the operational conditions of an anaerobic bioreactor through the measurement of those operational parameters based on knowledge data. The knowledge-based monitoring system is equipped with an interface for connectivity with pressure sensor, mass flow rate and methane gas content sensor, so that it can monitor the condition of the bioreactor in real time. The implementation of bioreactor monitoring is applied at bioreactors in Pakal Benowo Forest, Surabaya. The trial test was carried out under three different conditions: In the morning (around 08.00 AM) indicated information on the methane gas content of 72.5% LEL, biogas pressure 7.3 kPa and mass flow rate biogas 0.3 liters per minute. The second one during the day (around 11.00 AM) indicates information on the methane gas content of 56.5% LEL, biogas pressure 1.1 kPa and biogas mass flow rate of 0.3 liters per minute. The last, in the afternoon (around 03.00 PM) indicates information on the methane gas content of 51.1% LEL, biogas pressure of 1.1 kPa and biogas mass flow rate of 0.3 liters per minute. From those results, our monitoring system is able to identify the operational conditions of the anaerobic bioreactor.

Pyrolysis is a pathway for hydrogen reproduction from sewage sludge. The critical problem in the indirect pyrolysis process is the lower heat transfer performance in the furnace. The circulation of heat media controls the heat transfer in the pyrolizer (e.g., heat carriers (HCs) in the form of alumina balls), which is essential in determining the heat transfer performance and ultimately determining the hydrogen yield. The temperature of the HCs and amount of hydrogen yield are low because the required temperature in the vessel is not satisfied. This study investigated the relationship between the operating conditions and HC temperature profile to determine the optimum conditions for sufficient HC heating. We discuss the HC performance aspects to achieve a more effective operation using low inputs. Using a computational fluid dynamics simulation, we assessed the effect of the inlet gas temperature, inlet gas flow rate, and furnace structure on the heat transfer performance. We validated our model using the test results from a demonstration plant. We observed that by increasing the hot gas inlet temperature by 51 °C, the heat loss was reduced by 2,170 MJ/h, and the thermal efficiency of the entire plant was improved by 5.46%. When the number of hot-gas inlets was split, the efficiency did not change, but the temperature dispersion of the HCs was small. This implied that tar generation, including that of liquid substances, was prevented. At the pyrolysis temperature of 600°C, the cold gas efficiency was 81.2 LHV%.

Porang is well known with its high glucomannan content. Determination of the chemical content of porang flour is commonly carried out by chemical methods in the laboratory, which are known to take a long time and expensive. This study aims to determine the chemical content of porang flour using near infrared spectroscopy (NIRS). The reflectance of porang flour was measured using an FT NIR spectrometer at a wavelength of 1000 to 2500 nm. The chemical content (water and glucomannan content) of porang flour was determined by oven and spectrophotometry as the reference method. The reflectance was transformed to absorbance and several spectral pre-treatments such as normalisation, detrending, standard normal variate (SNV), orthogonal signal correction (OSC), and multiplicative scatter correction (MSC) with various PLS and PCR factors number were applied to obtain the best chemical content prediction of porang flour with NIRS. PLS and PCR were used for calibration of NIR spectra and chemical content of porang flour. The best calibration for determining the moisture content of porang flour was obtained using NIR spectra with normalisation pre-treatment and 8 PLS factor (r=0.92; SEC=0.15%; CV=2.13%; RPD=2.68). The best calibration for determining the glucomannan content of porang flour was NIR spectra with detrending pre-treatment at PLS factor 7 (r=0.86; SEC=0.54%; CV=0.90%; RPD=1.62). A lower accuracy was obtained for predicting water and glucomannan content using PCR calibration method. For water content, the best calibration was obtained by NIR spectra with normalisation pre-treatment and 12 PCR factors (r=0.91; SEC=0.16%; CV=2.21%; RPD=2.59). For glucomannan content, the best calibration was NIR spectra using detrending pre-treatment at 9 PCR factors (r=0.81; SEC=0.62%; CV=0.94%; RPD=1.55). This study shows that NIRS can be used to determine the chemical content of porang flour.

Maize (Zea mays L.) is one of the essential agricultural products in Papua Province of Indonesia, specifically in the three largest maize producing regions, namely Nabire Regency, Biak Numfor Regency and Merauke Regency, with the number of productions of 991 tons, 764 tons, and 751 tons respectively in 2015. Unfortunately, since 2016 the secondary data on food crops productivity, including maize, has not been provided yet in the provinces statistical report, due to manual estimation methods, i.e., visual estimation. On the other side, the number of populations in this Province has a slight increase, from 2.97 million people in 2012 to 3.38 million in 2019. Further, approximately 1.20 million people are employed in the agricultural sector. Considerable population growth will intensify the demand for food stock and other utilization of food crops in this region; hence, relevant research in food crops needs to be considered. One of the dominant factors in the yield potential of maize is plant height, since it is associated with fertilizer, seed, and soil treatment and predicts yield area. Therefore, this study aims to analyse the plant height, particularly maize plant based on a digital surface model (DSM) derived from Unmanned Aerial Vehicle (UAV) Red Green Blue (RGB) images. The crop was monitored during the second and third week of January 2022 and then, processed using pix4d Mapper software to produce the DSM, Digital Terrain Model (DTM), and orthomosaic. Then, the Geographical Information System (GIS) software, and an open-source software, namely Python were used to estimate the plant height. Next, the results were assessed statistically to examine the validation, the strong correlation coefficient of the estimation to the actual height that obtained from UAV and ground-based plant height data. The findings will help to support the prior decision support on estimation of maize production in Papua Province.

Increasing bioenergy use is one of the strategies for achieving net zero emissions by 2060. Palm oil biodiesel is a type of bioenergy that has the potential to be applied to achieve this target. On the other side, there are several sources of emission along the palm oil biodiesel (POB) production chain. These potential emissions can be reduced by applying various technologies along the production chain. This study aims to develop a model for reducing emissions from palm oil biodiesel. The model developed was a combination of life cycle assessment and genetic algorithms. Two objectives are defined in this model, namely: maximizing greenhouse gas (GHG) emission reduction through technology implementation and minimizing mitigation costs in its implementation. A combination of technology implementations was represented as chromosomes generated through crossover and mutation. By running more than 1000 iterations, a combination of optimal technology implementation can be obtained with the smallest emissions and minimal mitigation costs.

Probably effective application of fly ash granules for ameliorants on sugarcane has not been meaningful reported in tropical agricultural systems and no exact results have not been established. The experiment was arranged from January 2014 up to May 2015 at IPB Bogor, Indonesia. This study aimed to determine the improvement level of additional fly ash granules as soil ameliorants on peat soil in sugar cane cultivation compared to the application of dolomite. The experiment used a complete randomized block design in sub-optimal peat soil. There were five levels of treatment at 50 kg peat soil weight at polybag as the following: without the addition of ameliorant as control (C0) at pH=4.0; Mixing with fly ash granule at pH 6.0 (C1); Mixing with fly ash granule at pH 7.0 (C2); Mixing with dolomite at pH 7.0 (D1), Mixing with dolomite at pH 6.0 (D2). The fly ash granule and dolomite application at a starting value of pH 6.0 or pH 7.0 exposed reliable impact to maintain the pH value of peat soil at least for one year during the growth of the sugarcane plant biomass until harvest. The application of fly ash granule at the starting value of pH 6.0 showed a better effect on plant growth biomass and was sufficient to ameliorate the peat soil to achieve the optimum sugar yield. More than this application rate would be luxurious, it causes no increase in sugar production.

Fuel cell (FC) systems have recently become increasingly popular in large applications, such as FC vehicles and stationary FC power systems for residences. The use of FC systems in smaller applications, such as electrically power-assisted bicycles and drones, is expected to expand. FC systems exert a low environmental impact during operation. However, in the future, the environmental impact during the manufacturing phase ought to be additionally considered. There is a concern that the sale of products may be restricted, if they fail to meet legal standards, such as the life cycle assessment (LCA) regulations in the EU countries. For instance, in TC 105 of the International Electrotechnical Commission (IEC), the technical specification of LCA methodology for a stationary FC co-generation system was issued. This study evaluates the abiotic depletion potential (ADP) in the manufacturing phase and global warming potential (GWP). As the platinum (Pt) catalyst of FC significantly impacts the environment, more than lithium and cobalt, used in conventional lithium-ion batteries, each FC application ought to be designed considering all life cycle stages, while optimizing performance product life. As a promising example, we analyzed the performance drop caused by Pt degradation during the use phase of the assisted bicycle. Moreover, the dynamic performance of the FC-assisted bikes with an FC device and the supplemental power source of a Li-ion battery were evaluated under various operating conditions.

Plant-derived reusable resources such as biomass feedstock for fuel use and upcycling food products have attracted attention for solving environmental problems. In general, food products that are inappropriately consumed include various energy production pathways through the fermentation or gasification process, which would be attractive for solving the anaerobic digestion of wasted foods to make livestock feed. In terms of comprehensive aspects, the use of upcycling food products in various ways is also significant for abating environmental burdens. For instance, products made from unutilized food through cooking, such as jams made from banana peels, have been increasingly marketed. However, while the preparation of unused food reduces food loss, the environmental impacts of their life cycle have not been well considered. To date, our research group has discussed effective consumption pathways, including recycling pathways for the edible parts of foods. For instance, a 100 g edible part of tomato has an environmental impact of 35–57 g-CO₂ emissions during the cooking stage. The environmental impact of waste would not be negligible. Therefore, the eco-burden mitigation in the entire life cycle stage is discussed based on the proposal of a practical pathway, comparing the other paths (e.g., energy use).

Hydrogen production from biomass and fuel cells is effective with respect to its small eco-burden and high energy efficiency. However, it is established that hydrogen sulfide (H₂S) in gasified biomass (bio-syngas) can reduce the efficiency of fuel cells. To maintain high efficiency, H₂S is removed by impurity adsorption. Although metal oxides are generally used as adsorbents, these can adsorb H₂S only a single time, and the large amounts used represent an eco-burden. To overcome this problem, the use of mine waste (neutralized sediment) containing highly reactive iron was examined in a previous study, with H₂S as an adsorbent to maintain a small eco-burden. It was found that its eco-burden is smaller than that of using metal oxides at 300°C. However, the authors treated the inlet H₂S concentration, which affects sulfur capture capacity, as a constant, whereas the H₂S concentration of biogas typically fluctuates dynamically between 50 and 1,200 ppmv. In addition, it is necessary to consider real situations from the perspective of a dynamic life cycle assessment. Consequently, it is necessary to determine the amounts of adsorbent used by considering changes in inlet H₂S concentration. In this study, we investigated the relationship between changes in the inlet H₂S concentration and sulfur capture capacity of neutralized sediment. The amounts used and eco-burden of neutralized sediment were calculated based on our experimental results, and on the basis of our findings, we established that the global warming potential of the proposed system at 300°0 was 70.7% smaller than that obtained using a metal oxide.

The energy demand for fuel is increasing as the vehicle population increases. Until 2035, it is projected that energy use will still be dominated by fossil energy. This needs to be addressed to diversify the use of energy which should be renewable energy (RE) to get a larger portion than at this time, RE has only utilized 5% of all fossil energy used. The higher the use of fuel, the emission of combustion gases is one of the impacts that will accompany it. So, it is necessary to look for renewable and environmentally friendly energy. Ethanol and Methanol are alcoholic chemical compounds, which contain hydrocarbons that can be used as fuel. This study looks for the fuel consumption, emissions, and performance resulting from the use of Ethanol and Methanol as a gasoline fuel mixture in the passenger car. The method used is UN-ECE R101 for fuel consumption and UN-ECE R83 for emission tests. The based and comparison fuel used is gasoline with RON 90 produced by PT. Pertamina and the mixture used is GEM. The car used is Toyota Kijang LGX. As a result, fuel consumption is still better using based fuel with a difference of 18% decreased from M1010. Meanwhile, for cleaner emissions, GEM has reduced CO and HC levels, respectively 43% in E15M5 blend, than 18% in E10M10, while NOx increased by 30% in E10M10 and E15M5 blend. The performance result is GEM better than based.

The cinnamon plant that grows a lot in Indonesia provides bioactive components with health benefits, especially as a functional food used to avoid diabetes mellitus. There is an alternative snack for people with diabetes mellitus is cinnamon rolls. The study showed the following results: the production's Break-Even Point (BEP) of 8,715 pieces, BEP of sales of IDR 139,446,148, Return on Sales of 43.96%, Return on Investment (ROI) of 462%, the NPV of IDR 624,120,256.97. Discounted Payback Period (DPBP) of 0.24-year, Profitability Index of 12.53, and Accounting Rates of Returns (ARR) of 98.9%. In conclusion, Cinnamon Java Roll is feasible for business, providing minimum product sales of 50.7%.

Indonesia commits to reducing emissions by 29% (unconditional) or 41% (conditional) in 2030, which can be achieved by encouraging the use of new and renewable energy (NRE) by 23% in 2025 while realizing national energy security. A biofuel development plan through a mandatory biodiesel program and green fuel utilization is the main priority to reduce fossil fuel consumption and achieve the energy mix target. As of January 1, 2020, through the mandatory biodiesel program, biodiesel utilization reached 30% (B30) for all diesel engine sectors, which is the highest biodiesel blending program in the world. However, the gap between government policies with emission regulation and existing vehicle technologies in this country might provide challenges in strengthening the sustainability of mandatory biodiesel programs. This study used a normative juridical method to assess the policy and enhance the regulation of the mandatory biodiesel program by obtaining library materials, theories, concepts, principles, and existing rules related to the law perspective. An appropriate and consistent energy mix policy, including its long-term strategy to increase biofuel utilization and maintain a mandatory biodiesel program, is needed to achieve a reducing emissions target. It is essential to strengthen and clarify the policy and road map. The vehicle technology and fuel quality were also crucial for enhancing emission regulation and eliminating low-quality fuels, maintaining a sustained biodiesel program, and achieving national energy security.

Biodiesel is one of the biofuels identified as a complement to conventional fuels. Socially and environmentally, biodiesel has been known to provide benefits for creating new jobs, revitalizing rural areas, and reducing global warming. However, the biodiesel industry often faces various challenges, one of which is uncertainty in decision-making. Uncertainty in the supply chain is considered as one of the greatest challenges to managing and controlling the supply chain. Other types of uncertainty are associated with events that decision-makers cannot predict or control, such as natural disasters, accidents, or artificial disasters. Supply chain complexity and global competition have increased their exposure to disruption. Therefore, reacting appropriately to disruptions is necessary for business continuity. Ultimately, resilience capabilities must be developed to help companies become more resilient than before. This paper identifies and determines the vulnerability and capability factors in the Indonesian biodiesel supply chain. The result shows several vulnerability factors, such as turbulence (price, technological failure, and pandemic), external pressures (policy and regulation), and resource limits (supply, capacity, and land availability), that may affect the resilience of the biodiesel supply chain. Meanwhile, capability factors that can be utilized to reduce these vulnerabilities are flexibility in sourcing, flexibility in order fulfilment, capacity, adaptability, visibility, and collaboration. The practical implications are also described in this paper.

Candida rugosa lipase (CRL) is an enzyme that is widely used in biopharmaceutical and biopesticide industries due to its high catalytic ability and reusability. However, conditions from industrial processes that are often outside CRL stability range may cause denaturation or destabilization of the enzyme, causing it to be not reusable, hence lowering its economic value. To increase its catalytic activity, stability, and reusability, CRL enzyme can be immobilized in a matrix. In this study, the CRL was physically adsorbed onto Celite-545. The immobilization process was done using buffer solution with the addition of acetone. The influence of initial enzyme concentration and immobilization condition (time, temperature, and pH) were optimized using OFAT method. The data were taken in terms of esterification activity, thermal stability, and protein content. The result showed good thermal stability of the immobilized biocatalysts and an increase in esterification activity at optimum conditions that supported the efficiency of Celite-545 as lipase immobilization supports.

The production system for industrial oil and gas is susceptible to corrosion, which must be controlled in order to sustain production and well direct as the production of tubing is the initial point of contact with the corrosion fluid and material agent. A chemical reaction between corrosive materials and fluids results in corrosion. Due to its mechanical characteristics, stainless steel has a wide range of uses in the building, chemical, and structural sectors. To combat corrosion issues, several chemical inhibitors are used, and numerous studies are actively working to develop organic inhibitors. Rhizome ginger is an organic component that has a high phenol antioxidant content and antioxidant compound, making it useful for corrosion issues. In this study, the effect of monoethylene glycol and ginger extract inhibitors on corrosion was reviewed. The corrosion rate was computed using an olga simulator, and the influence of the inhibitor on the rate of corrosion and the effectiveness of the inhibitors was examined.

Used cooking oil has the potential to be used as raw material for biodiesel. However, the high Free Fatty Acid (FFA) content in used cooking oil can interfere with the transesterification process. This issue will affect the quality of biodiesel yields. Therefore, FFA content in used cooking oil must be reduced through a pre-treatment process by adding activated carbon adsorbent from charcoal. In this study, the adsorption process was carried out by mixing used cooking oil and activated carbon using 20% NaOH for 3 hours. Then the degumming process was carried out by adding 0.5% v/v HCl from the volume of used cooking oil. Then add 0.5% NaOH by weight of used cooking oil and distilled water gradually, accompanied by heating to a temperature of 120 °C. In the esterification stage, the variables used are the comparison of methanol with a ratio of 1: 2, 1: 4, 1: 6, 1: 8, and 1:10. In this study, the lower acid number obtained from all variables was 2,24 mg KOH/g sample. Meanwhile, the most optimal result was the 1: 2 variables with a density of 0.8531 g/ml, and the kinematic viscosity at 40°C was 4.94 mm²/s.

Monoglycerides and glycerol are by-products contaminants, after transesterification, in biodiesel that can lead to severe operational and engine problems such as wax precipitation, filter plugging and engine deposits. Therefore, strict regulations have been made, and accurate quality control is required. In this work, levels of monoglycerides and glycerol were determined using gas chromatography (GC) equipment with flame ionization detector (FID) refers to standard methods ASTM D6584 and EN 14105. However, the monoglycerides determination still needs firmness and validation to develop standard calibration series to fit the constituent fatty acid components of the feedstock used. This paper shows three fatty acids, i.e., monoolein, monopalmitin, and monostearin, as major components in palm-based biodiesel, which would be prepared as standard calibration and determined from commercial biodiesel samples in the determination of monoglyceride levels accurately and thoroughly. The result shows that standard solutions produce a curve with high linearity; it was above 0.998 (for free glycerol, monopalmitin, monoolein, and monostearin) and its accuracy values were >95%. However, the result for eight commercial biodiesel samples in Indonesia had a range of 0.23-0.54% w/w for total monoglycerides, 0.07 to 0.14 (% w/w) for total glycerol, and < 0.01% w/w for free glycerol, which was fulfilling to the ASTM D6751 and EN 14214 specification requirements.

Biodiesel has many advantages and technical aspects of being blended in any proportion with diesel fuel to support diversification energy policy. However, biodiesel absorbs more moisture than diesel fuel since methyl esters are hygroscopic compounds, and there is a limited amount of published information about water affinity properties. Water content can affect the fuel's characteristics, reducing fuel quality if it accumulates into free, emulsion, or soluble water. This paper reports the water affinity properties of biodiesel, diesel fuel, and their blends through water saturation. It indicates a maximum water content value that the fuel can retain at a specific temperature and moisture absorption by controlled temperature and humidity. The results show that the pristine biodiesel has a water saturation range of (1366 to 1771) mg.kg^-1 in the temperature range of (288.15 to 313.15) K. Therefore, diesel fuel has a maximum water saturation of 255 mg.kg^-1 at a temperature of 313.15 K. The water saturation curve shows that biodiesel-diesel blends have a water saturation with a slope range of (12.20 to 15.11) mg.kg^-1 water per 1%-vol biodiesel in diesel fuel blend in the temperature range (288.15 to 303.15) K. During eight days of observation on eight commercial biodiesels, the moisture absorption value was 1094 mg.kg^-1 at a temperature of 298.15 K with a relative humidity of 90 %. It was also found that high moisture quickly affects the water content point in the storage period.

Cocoa Pod Husk (CPH) is the main by-product of cocoa pods (Theobroma cacao L.) with 67-76% of fruit weight. However, CPH has a negative impact if it is not utilized and disposed of directly in the environment. The main fiber content in CPH is in the form of lignin, cellulose, hemicellulose, and pectin. Cellulose content, especially α-cellulose has a high potential if it is further utilized, one of which is nanocellulose. This study aims to produce α-cellulose from cocoa husks with high purity. The first research activity carried out was the process of removing pectin and bleaching to be free from impurities such as pectin, lignin, and hemicellulose. Then the cellulose isolation process using Peracetic Acid (PAA) can shorten the α-cellulose isolation process. The variation of PAA concentration was 1:4 (mol/mol) without dilution; 1:4 (mole/mole) by dilution; and 1:1 (mole/mole). The results of this study were the highest α-cellulose content of 69.39% was obtained from a 1:4 mole ratio of PAA without dilution. However, the α-cellulose content obtained did not qualify the SNI 938-2017 standard, which was 94%. FTIR, XRD, and SEM characterization showed that α-cellulose was present in hydrolysed CPH.

Several countries have implemented the use of biodiesel as a diesel fuel blend. Indonesia currently implements the highest percentage of biodiesel, reaching 30% (B30), starting from 2020. Strict quality standards of biodiesel have been implemented worldwide, such as ASTM D6751 (USA), EN 14214 (EU), JASO M360 (Japan), and SNI 7182:2015 (Indonesia). Prior to blending with diesel, biodiesel must comply with the specification. One of the most concerning issues is the water content in biodiesel that is easily increased due to its hygroscopic nature. Currently, the handling procedure at the blending facility to maintain the immoderate water content of biodiesel is still limited. Therefore, experiments for reducing excessive water content in biodiesel were conducted using polyacrylamide-co-potassium acrylate (pAAm-co-PA) and potassium polyacrylate (PPA) hydrogels with varying contact times. The adsorption capacity of the hydrogel with the best performance was also observed. Four methods were carried out for hydrogel regeneration, i.e., drying at atmospheric pressure (A), drying at vacuum pressure (V), and a combination of solvent washing-atmospheric drying using acetone (AA) and ethanol (EA). The results indicate that the PPA hydrogel adsorps more water than the pAAm-co-PA hydrogel with the same contact time. PPA hydrogel capacity decreased to 13.4% after being used for seven adsorption cycles simultaneously. The ethanol-drying combination produces the highest water recovery in the regeneration process, reaching 39.24%.

Lipase is an enzyme commonly applied as a catalyst in the food industry, the synthesis of bioplastics, and the production of biodiesel. Candida rugosa lipase (CRL) is one of the widely used lipases due to its high selectivity and activity. However, high operating temperatures can denature enzymes, affecting enzyme activity due to structural changes. An enzyme can be immobilized on a supporting matrix to improve stability. Ethanol as an immobilization solvent may also increase the thermostability and esterification activity. This study examines the effect of ethanol solvent on the thermostability of immobilized Candida rugosa lipase. Immobilization was carried out on the Celite-545 matrix in buffer/ethanol solution. Different operating conditions such as enzyme concentrations, immobilization temperatures, immobilization time, and immobilization pH were observed. The immobilized enzyme activity was determined by esterification reaction using butyric acid and 1-butanol as substrates and isooctane as reaction medium. The results showed that immobilization increased the esterification activity by 76% at 37°C. Thermostability of immobilized enzyme was also enhanced by 29-51%, depending on the esterification temperature.

The application of biodiesel will increase in accordance with the government's mandatory program for saving fossil fuels. The challenging would come from particulate levels and water content. One of the efforts to fix the issues is by adding rhodinol from citronella oil as an additive. This research was conducted to design a vacuum distillation process which has 500L of capacity and determine the design of the fractionation distillation unit. Simulation was carried out using the Aspen HYSYS software. The result of the simulation is expected to provide an overview of the fractionation process that would comply with the standard after some data validation. The simulation was applied by vacuum pressure in 4-5 mbar and variation of reflux ratios 1,2, and 3. The best simulation obtained was reflux ratio 2 at 47.80% geraniol and 61.34% citronellol concentrations. The simulation also obtained the following results are maximum and minimum pipe diameter of 0.04 m 0.02 m, the maximum and minimum thickness of 3.7 mm 2.8 m, column height of 10.5 m, column diameter of 0.2412 m, and thickness of 3 mm, condenser length and diameter of 1.11 m and 0.2032 m, reboiler length, and diameter of 1.5 m and 0.6515 m.

The synthesis of ketones from C18:1 fatty acid using the fatty acid decarboxylation method has been carried out to increase the added value of oil palm derivative products. One of the derivative products of palm oil is Crude Palm Oil, which can be converted into fatty acids through the triglyceride hydrolysis process. Currently, palm oil fatty acids are the most potential environmentally friendly raw material in Indonesia. This research aims to synthesize ketones from palm oil fatty acids under different fatty acid types and catalyst concentrations. Ketone compounds were synthesized using a base catalyst of solid layered double hydroxide based on Mg/Al/Cu environmentally friendly because it does not produce by-products that can become pollutants. The ketone product was analyzed using the Fehling test, Tollens test, and FTIR. The results showed that the success of ketone synthesis using the fatty acid decarboxylation method into ketones through the Fehling test that red brick precipitate did not form and the Tollens test also indicated no silver mirror formation. Meanwhile, the results of the FTIR test showed the presence of ketone compounds at peak frequencies of 1697–1710 cm^-1. This study confirms that ketones produced from fatty acids have the potential to be environmentally friendly raw materials for diesel fuel, lubricants, and surfactants.

Bioethanol production technology using lignocellulosic substrates has become a focus to overcome the limited supply of fossil fuels in the current century. Simultaneous saccharification requires an understanding of suitable efficient procedures in bioconversion row material into fermented sugar. In this study, the effect of pre-treated rice straws using ionic liquid on enzymatic saccharification by isolated actinomycetes was investigated. Ionic liquid to rice straw in a ratio (IL/RS) was set up 0 to 3 (g/g), and the remaining of the ionic liquids in pre-treated biomass was examined for their effect on the hydrolytic enzyme activity of the actinomycetes. Three actinomycetes were isolated from decomposed rice straw and were purified and screened for their cellulolytic and xylanolytic activity; one strain, namely ActRS-4, was selected as an optimum isolate for further hydrolysis examination. Both cellulase and xylanase activity exhibit a peak at a ratio IL/RS of 1 (g/g), the activity was 27.72 and 66.16 U/ml, respectively. The highest yield of sugar was also achieved at this IL/RS ratio for 8 days of incubation. The pretreatment indicates that it could promote an increase in the yield of glucose and xylose by 28% and 37% respectively. This study was promising to develop a one-pot conversion of lignocellulosic biomass into bioethanol using the biological process.