Table of contents

Preface: The 1st International Symposium of Indonesian Chemical Engineering (ISIChem) 2018

Hakun Wirawasista Aparamarta¹, Yi-Hsu Ju², Fusheng Li³, Soorathep Kheawhom⁴, Kusdianto¹, Widiyastuti¹, Himsar Ambarita⁵, Siti Nurkhamidah¹, Raden Darmawan¹

*Editor of ISIChem 2018

¹ Chemical Engineering Department, Institut Teknologi Sepuluh Nopember (ITS) Surabaya, Indonesia

² Chemical Engineering Department, National Taiwan University of Science and Technology (NTUST), Taiwan

³ Chemical Engineering Department, Gifu University, Japan

⁴ Chemical Engineering Department, Chulalongkorn University, Thailand

⁵ Mechanical Engineering Department, University of Sumatera Utara (USU), Indonesia

This proceedings volume contains selected articles from the "1^st International Symposium of Indonesian Chemical Engineering (ISIChem) 2018" held in Kryad Bumi Minang Hotel, West Sumatra, Indonesia from October 4-6, 2018, that has been peer reviewed.

Despite the fact that this is only our first international symposium of Indonesian Chemical Engineers, and the sixth for the national one, we are so honored to announce that this year we have abundance of enthusiastic participants from five different countries participating in the conference. In the October 4-6, 2018, 250 research papers have been presented in the ISIChem, covering eleven research areas, such as: Biochemical Engineering, Catalyst and Reaction Engineering, Waste Water Treatment Technology, Renewable Energy Technology, Nano Materials and Nanotechnologies, System Engineering Process, Thermodynamics and Supercritical Technology, Separation and Purification Technology, Food and Pharmaceutical Technology, Chemical Engineering Management, and Chemical Engineering Education. We are also delighted to announce that the selected papers will be published in IOP Conference Series: Materials Science and Engineering.

All papers published in this volume of IOP Conference Series: Materials Science and Engineering 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.

Fertilizer is a material that can provide nutrients for plants. Organic fertilizers are fertilizers composed of living creatures that are processed through decomposition by decomposers, such as weathering the remains of plants, animals, and humans. The purpose of this research is to see the effect of fermentation time and influence of EM4 composition on nutrient quality in solid organic fertilizer. The results obtained based on the length of time of fermentation and Volume Efective Microorganism 4 EM4 then obtained the best results at 60 ml EM4 volume and 16^th days fermentation time with 0.90% nitrogen content, 0.93% phosphorus, and potassium levels of 1.48%. The longer and more EM4 volume the more nutrients it gets.

In this study, solid-state fermentation was carried out to produce single cell protein by local Aspergillus niger. Rice straw pulp produced from the pretreatment by liquid hot water at temperature 121 °C for 60 minutes of cooking time was used as carbon source. The effects of nitrogen sources, initial medium pH, C/N ratios of substrates and fermentation time on SCP production were evaluated in these experiments. The single cell protein was measured as crude protein content in the fermentation product by the Kjeldahl analysis method. The maximum crude protein of 18.9 % (w/w) contained in the fermentation product occurred at the fermentation condition with C/N ratio 30:1, the initial medium pH 4, temperature 30 °C, moisture content 75 % and relative humidity 95 %.

This study has successfully investigated the effect of microorganisms, enzymes, and surfactants mixture to produce a reducing sugar from Coffee pulp waste. The experiment consisted of microbial pretreatment to reduce lignin content followed by comparing the hydrolysis by enzymes and microorganism using a surfactant and without surfactant to get a higher yield of reducing sugar. Pretreatment was conducted by mixture of Bacillus subtilis (BS) with Trichoderma reesei (TR) in the ratio of 2:1 (v/v) and Aspergillus niger (AN) with TR in the ratio of 1:1 (v/v). BS-TR mixture increased the cellulose content to 10.939 % and decreased the lignin and pectin content to 71.261 % and 55.046 %, respectively. Whereas, AN:TR mixture increased the cellulose content to 12.572 % and decreased the lignin and pectin content to 69.941 % and 52.294 %, respectively. Afterward, the result of enzymatic hydrolysis with 3 g of Tween 80 and biological hydrolysis showed increasing of reducing sugar yield of 0.5831 and 0.0341 %, respectively. Further investigation was described as the crystallinity index and the fructose, glucose, and sucrose contents. The addition of both PEG 4000 and Tween 80 as a surfactant in the enzymatic hydrolysis process could significantly increase the concentration of reducing sugar.

Industrial interest of glutathione, as a pure substance or accumulated in yeast, has been prominent as a result of various applications of glutathione in food and pharmaceutical industries. Glutathione production by fermentation process is easier and more economical compare to production by chemical and enzymatic reaction. This study aims to evaluate environmental condition to the fermentation process producing glutathione in three different strategies. In the following work, stress conditions and cysteine addition coupled with fed-batch fermentation of Saccharomyces cerevisiae ITBCC R58 for glutathione accumulation have been investigated. Stress conditions applied on this study included temperature shift from 30 to 50°C and 27°C, pH shift from 5 to 1.2 and 8.8, and osmotic stress by addition NaCl to the solution. Another strategy was to add cysteine as one of glutathione precursors into the fermentation medium. Later, the oxidative state of glutathione harvested was also checked. Osmotic stress showed the best result amongst stress variations applied on this work, however combined cysteine addition with fed-batch fermentation stood out as the best strategy in this study. In all experiments, oxidized-state glutathione was identified, indicating the need of a specific method development to harvest glutathione in reduced state.

Molasses is the final liquid from the process of crystallization of sucrose in a sugar factory. In general this liquid is only disposed to the surrounding environment or used as a fertilizer mixture. However, this fluid still contains glucose that can be fermented into lactic acid. Lactic acid is a water-soluble compound commonly used in food, pharmaceutical and chemical industries. Through the polymerization process, lactic acid changes into polylactic acid (PLA) which is a biodegradable plastic. In general, PLA is made from corn. If PLA can be synthesized from molasses, it can reduce the use of corn as a raw material for making PLA and reduce waste in the sugar industry. This study aims to determine the optimal conditions of lactic acid fermentation by using sugarcane drops from Tulung Agung as a source of glucose and its purification so that it can obtain high levels of lactic acid. The results showed that fermentation with Lactobacillus plantarum could produce more lactic acid with faster fermentation time than the fermentation using Lactobacillus delbrucckii with a concentration of lactic acid 19.68 g/L.

The attractive biobased platform chemicals, 5-Hydroxymethylfurfural (HMF) and Levulinic Acid (LA), are commonly produced by the conversion of monomeric sugars. Nevertheless, a polymeric sugar such as inulin shows promising. This work reports the study on the thermal catalytic decomposition of inulin to HMF and LA. This work also investigated the effect of furfural during the process. The decomposition reactions were conducted in a batch reactor in a temperature (153-187)°C, an inulin loading (0.03- 0.12) g mL⁻¹ and reaction times (18 -74 minutes) using a central composite experimental design. Furthermore, to study the effect of fructose and glucose on furfural, some additional experiments were also performed in the batch system. The decomposition process gained 35 wt% yield of HMF and 13 wt % yield of LA. The HMF and the LA model were statistically formulated and showed a good fit to the experimental data. The fructose particularly plays a role in furfural disappearance during the process.

Biodiesel produced from waste cooking oil (WCO) with initial free fatty acids (FFA) of 6.67 % through one-stage reaction (transesterification) and two-stage reaction (esterification followed by transesterification) had been studied. The esterification process was catalyzed by solid catalyst of synthesized sulfated alumina and transesterification reaction was catalyzed by NaOH. The objective of this research is to determine the optimum condition of biodiesel production from WCO using sulfated alumina catalysts by esterification reaction and to compare biodiesel yield using homogeneous catalysts of sulfuric acid with a heterogeneous catalyst of sulfated alumina. The results showed that the optimum conditions for esterification reactions using sulfated alumina catalyst is at the volume ratio of methanol/oil of 1.5, the amount catalyst of 1 wt %/v of oil at 1 hour reaction time. With the optimum condition, the maximum conversions of free fatty acid using a sulfuric acid and sulfated alumina catalyst were 90.4 % and 89.97 % respectively. The yield of biodiesel from waste cooking oil by two-stage transesterification process is 86.67 % and one-stage transesterification is 66.67 %.

One of the ester product of glycerol and acetic acid is triacetin which has wide industrial aplication. In this study the esterification of glycerol with acetic acid over Lewatite catalyst to produce triacetin, were carried out. Lewatite is one of ion exchange resin, the use of ion exchange resins as catalyst will not produce waste, not corrosive, high thermal stability and has good selectivity. The esterification reaction of glycerol with acetic acid were performed in a three-neck flask with stirrer (175 rpm) at temperature (90 °C, 100 °C and 110 °C) and atmosphere pressure. A 9.66 % selectivity of triacetin with conversion (77.4 %) was achieved at 100 °C within 90 minutes of reaction time. This research aimed to report experimental data and kinetic modeling of glycerol esterification with acetic acid to evaluate and compare model performance and capability. A kinetic model was developed using a first order pseudo-homogeneous model according to the experimental data. The surface reaction of acetic acid with glycerol was assumed to be rate-controlling. The effect of temperature to rate of reaction constants can be expressed as follows: ${k}_{r}=8.138\,x\,{10}^{11}\,\exp (-\frac{57,176.47}{RT})({1}\!\left/ \!{s}\right.)$

The 2-ethyl-hexanol was much-needed in the plasticizer industry as a precursor for the synthesis of bis diesters (2-ethyl hexyl) phthalate (DEHP). This compound can be synthesized by oxo reaction, where one of the steps isa consecutive hydrogenation of the 2-ethyl-2-hexenal to 2-ethyl-hexanol. This reaction required metal-based catalyst. This research aimed to develop the formula and procedure of catalyst synthesized and get a kinetics of the reaction. The catalyst was synthesized with a nickel content of 50%-w. The support consists of γ-alumina and SiO₂(cab-osil) in variations of 0%-w up to 100 %-w of cab-o-sil towards support. The activity of synthesized catalysts were tested at 120°C and 30 bars in the fixed bed reactor. The results showed that the best performing catalyst was NiO50-Cab50 with 98.29% 2-ethyl-2-hexenal conversion and selectivity to 2-ethyl-hexanol 87.41 %. By varying the reaction temperature of 100-120°C in the best catalyst, it is found that the consecutive reaction was the first order with the activation energy of 2-ethyl-2-hexenal hydrogenation to 2-ethyl-hexanal was 33.66 kJ/mol and hydrogenation 2-ethyl-hexanal to 2-ethyl-hexanol was 58.39 kJ/mol. This showed that the hydrogenation of C = C bonds was easier than the C = O bond.

Several mathematical models have been developed to illustrate the drying process of crops, and one of them is thin-layer modelling. However, there are still limited information about mathematical modelling in paddy drying. In this paper, thin layer modelling of paddy drying curve on drying using fluidized bed dryer is presented. The drying paddy was done with drying temperature variations of 50, 60, 70, 80, and 90 °C. The initial paddy moisture content is 33 % dry basis. The drying process was done for 1,5 hours. Paddy moisture was measured every 10 minutes using grain moisture meter. The thin layer models used are Newton, Page, Modified Page, Henderson and Pabis, Logarithmic, Two-term, and Wang and Singh models. Model fittings were done using MATLAB 2015 software by sum square error minimization. Experimental results showed that Modified Page model gave the best results, evidenced by the highest average R² value of 0.9949 and lowest average RMSE (Root Mean Square Error) value of 0.0631, followed by Page model and Henderson and Pabis model. The plotting of MR (Moisture Ratio) and time at five drying temperatures showed that effective diffusivity (Deff) value ranged from 1.0334 x 10⁻⁸ m²/s to 2.1983 x 10⁻⁸ m²/s and the value increases as drying temperature increases. The plotting results of ln D_eff and 1/T (absolute temperature) showed that the value of diffusivity factor (D_o) is 8.5293 x 10⁻⁶ m²/s and activation energy (Ea) is 18.11 kJ/mol.

The oil from Tengkawang fruit (Shorea stenoptera) has been processed by indigenous people in West Kalimantan as cooking oil and margarine. This research examined the degumming process, neutralization and bleaching of Tengkawang oil to reduce the high acid and peroxide numbers resulted from traditional processes. The oil produced at each stage of the refining process were tested for their physicochemical properties by calculating the acid, iodine and peroxide numbers. Respectively, the values of acid number (mg NaOH/100 g sample), iodine number (g I₂/100 g sample), and peroxide number (mg equivalent O₂/kg sample) for initial Tengkawang fat were 10.14; 32.49 and 10.98; for Tengkawang fat after degumming were 10.25; 28.81 and 10.88); for Tengkawang fat after neutralization were 6.09; 30.52 and 5.57; and for Tengkawang fat after bleaching were 6.14; 31.39 and 5.55. The acid number of Tengkawang oil after neutralization process with variation of volume 5, 7.5 and 10 % were 7.83; 6.14 and 3.12 mg NaOH/100 g sample, respectively. The refining process increased the quality of physicochemical properties of Tengkawang oil to fall into industrial grade.

There are several advantages of using the human pulmonary pathways for drug delivery. These include large absorption area, more rapid onset of therapeutic effect, reduced dose of bioactive delivery and lower side effects of therapy. Inhalable products should meet several criteria, in particular shape, surface roughness and particle size (approximately 1-5 µm, or 2-3 µm as optimum) to reach the deep region of human lungs (alveolus).

In an attempt to produce such powders, supercritical fluid (SCF) technology has been proposed as an alternative to high energy consumptive yet popular mechanical methods such as milling. In this article, application of SCF technology for inhalable products manufacturing is briefly overviewed. Discussion focuses on the process development and formulation strategies to obtain improved product properties of specifically designed for pulmonary administration.

The edible coating film was prepared using native sago starch and modified sago starch with acetylation. The effects of acetic anhydride (7.5%, 15%, 30%, and 45% w/w) on swelling properties of wheat starch granules, amylose content, lipids content, protein content, a degree of substitution, percent acetylation, and gelatinization temperature were investigated. Modified sago starch and native starch were characterized by Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). As a result, modified sago starch containing 45% w/w acetic anhydride have a degree of substitution 0.12 with acetylation 45%. All modified starch granules exhibited higher amylose content compared to native starch. Higher amylose contents inhibit the extensive granule swelling power, so swelling power decreased while increased amylose content. Edible coating film used were starch concentration 5.0% w/w, and glycerol content 1.0% v/v. Edible coating film made from native and modified sago starch have been studied to hydrophobicity, Fourier transforms infrared (FTIR), water vapor absorption, and scanning electron microscopy (SEM).

Aloe Chinensis Baker is an aloe species that is frequently utilized in Asia, including Indonesia. Aloe vera contains various compounds in its leaves, such as vitamins, enzymes, and amino acids. The largest component of Aloe vera leaves is water. Vacuum evaporation is considered to be a potential method in the process to reduce the water content while maintaining the integrity of the nutrients. The objective of this research is to reduce the water content in pureed Aloe vera gel to obtain extracts. Evaporation using a rotary vacuum evaporator is conducted at an pressure of 110 mBar and temperature of 40 °C, and a varied time of 30, 60, 90, and 120 minutes. Analyses of amino acid contents are performed with HPLC. The results show that at 120 minutes, the preserved amino acid contents include: L-Isoleucine 29.3 ppm, L-Proline 10.8 ppm, L-Arginine 9.0 ppm, L-Asparagine 243 ppm, L-Threonine 56.9 ppm, L-Leucine 30.9 ppm, L-Methionine 38.4 ppm, L-Histidine 15.4 ppm, Aspartic Acid 24.4 ppm, L-Lysine 108.9 ppm, L-Cysteine 131.0 ppm, L-Alanine 40.2 ppm, and Glycine 230.7 ppm. The resulting Aloe vera extract show the following characteristics, density of 0.99 g/ml and pH of 6.5. Yield of 120 minutes evaporation is 40 %.

An edible coating is one method that could be utilized in preserving and coating on fruits. The utilization of gadung (Dioscorea hispida Dennst) starch as a raw material in edible coating making can be used as an alternative renewable raw material due to of high starch content and its potential still not been utilized optimally. This study has been evaluated the influences of hydrocolloids and plasticizers contents of the mixture to produce proper tensile strength and elongation of the coating produced. The quality and characterization of edible coating have been evaluated using weight loss test, thickness test, elongation test, tensile strength test and oxygen permeability test. The gadung starch edible coating was shown to be effective in tomato fruit preserved until 21 days. Mechanical properties of edible coating were obtained the tensile strength ranging from 5.76 to 7.03 kgf.mm-2, elongation ranging from 13.57 - 38.56%, thickness ranging from 0.01 - 0.05 mm and optimum oxygen permeability of 3.739 g.m-2.h-1 by adding of the CMC of 1% and glycerol of 10%.

Cane refining activities which produce red-cane sugar has traditionally been the primary source of income in Lawang villagers of Agam district since hundred years ago. Three main weaknesses found in the process traditionally conducted are lower evaporation rate caused in longer time production and need more fuel, lower product quality caused in lower price, and flue gas pollution. Heat transfer mechanisms involved as long as evaporation takes place in traditional cooking process of juice, namely conduction, convection, and radiation, are not well evaluated yet. Meanwhile, falling film evaporation is not found and gummy cakes formed and accumulated in the surface of basket made of woven bamboo placed in the juice pot. The influence of evaporator like device made of a series of diameters of aluminium circular plates to evaporation process has been studied in traditional cane refining in Lawang village. The device was introduced to the juice pot which significantly faster evaporation process, namely reached about 45% faster then what usually run by villagers. The influences of introduction of lids of aluminium plates as well as any variation in circular plates to faster evaporation process had also been studied. It showed that the numbers of circular plates in a series and introduction of lid of aluminium plate contributed dominantly to faster evaporation process till about 56.67% faster, while the incline of circular plates in a range of 0 to 20 degree and the existence of some holes in the inner plates for circulation of juice cooking are not significantly shorten the time needed for evaporation process. It was also found in this study that falling film evaporation occurred in the evaporator like device introduced that contributed to faster evaporation process. The special channel added at the outsider of circular plate could play a role to accumulate gummy cakes formed.

The breastfeeding dairy cows often go through metabolic disturbances and low milk production due to the use of stored body fat and minerals to assist milk production. Those problems can be solved by feeding feed supplement to the dairy lactating cows. Calcium soap is a well-known lactating dairy cattle feed supplement, which gives energy in the form of protected fat so it can increase milk productivity of dairy cattle. This research studied the use of PFAD (Palm Fatty Acid Distillate) as the free fatty acids source and calcium oxide as a calcium source to produce calcium soap using modified fusion method with water as the reaction catalyst. This study evaluated the initial mixing temperature of PFAD as the parameter affecting the conversion of PFAD, which was determined by the product acid value. The result showed that, at the same mole ratio of calcium source to PFAD, the lower initial mixing temperature gave higher reaction conversion of PFAD. The recommended initial temperature for mixing was found to be 60 °C, which gave the acid value of the product in the range of 2.96 - 3.14 mg KOH/g sample for mole ratio of CaO/PFAD 1 - 1.15.

Averrhoa bilimbi leaf extract is used as herbal medicine for various disorders treatment by communities. The causes of coronary disease such as cholesterols and triglycerides are widely established by Averrhoa bilimbi leaf extracts due to the presence of bioactive compounds such as glycoside, tannins, flavonoids and phenolic compounds. This study extracted Averrhoa bilimbi leaf using Soxhlet apparatus and 500 mL ethanol 96 % as a solvent extraction. Ethanol was used as solvent due to the solubility of bioactive compounds, non-toxic and biodegradable. The leaves were collected, chopped and dried at 60 °C until reached a constant weight. The moisture content of leaf was obtained 48.67 % at 24 hours of drying. The objective was to examined extraction time effect on the yield of leaf ethanol extracts. Extraction was carried out at constant temperature 70 °C and the time was varied at 60, 120, 240, 360 and 480 minutes. The highest yield and total flavanoid obtained for 13.77 % 13132.52 mg/L at 240 minutes. The yield of extraction was reduced at 360 minutes due to the optimum extraction time had been reached. In spite of that, this work indicate that the longer of extraction time, the more bioactive compound was extracted.

Soy milk is a traditional beverage widely consumed in Asian countries, one of which is Indonesian. Soy milk has a balanced nutrient combination which is more or less similar to cow milk, excluding its vitamins (vitamins A and B2) and minerals (K, P, and Na). Behind its limitation, soy milk is free of cholesterol, lactose, gluten, and rich of phytochemical compounds. Soy milk has been consumed as an alternative to milk for people with lactose-intolerant problem, and for vegetarian as well. Therefore, a fortified soy milk using water extract of drumstick tree (Moringa oleifera) leaves was developed. A water extract of pandan leaves (Pandanus amaryllifolius) was also added to minimize the strong aroma of leaves/sepat from the M. oleifera extract and to appeal the appetite. Hedonic ranking test as an organoleptic testing method was conducted to identify consumer preferences. The test revealed the soy milk with low addition of leaves M. oleifera extract (0.26 g/L) is correspondents' more preferable options than higher concentration of extract, i.e. 0.50 and 0.74 g/L. Minerals contents of Ca and Fe were increased to 9% and 32%, respectively, with the addition of 0.26 g/L of the extract. Unfortunately, no vitamins B and C were detected in all variables of added extract concentrations to soy milk.

One of the components in rice bran is oil, which is mainly used for cooking. Because of its high uses, there is also an increase in the supply of the defatted rice bran. Currently, it is used generally as a supplement for livestock feed. Thus, there is a need to diversify their applications to increase protein content in other food sources. The objective of this study is to extract rice bran oil with ultrasonic method, characterize defatted rice bran, and as a supplement in cassava flour biscuits. The method of this research is the stabilization of rice bran by roasting for 10 minutes, extractions of rice bran with n-hexane solvent: 1:4; 1:5, 1:6; 1:7; 1:8, 10-minute ultrasonic technique to remove the oil content, and protein analyses of defatted rice bran. Defatted rice bran is used as supplement for cassava flour biscuits. Simple organoleptic tests were conducted based on respondents' preference. Results showed that there was a significant correlation between rice bran: solvent ratios and protein contents in defatted rice bran. The highest protein content was found at 18.31% in rice bran: solvent ratio 1: 5. The most preferred by respondents in its application for cassava flour biscuits was 13.6%.

A Moringa Oleifera leaves are rich of phenolic compounds that have the ability to serve as antioxidants. Phenolic compounds as an antioxidant can stabilize free radicals with complementing the electron deficiency of free radicals. Conventional method (maceration) can extract phenolic compounds from Moringa Oleifera leaves. However, this method is known as time consuming, inefficient and using solvent that is non-environmentally friendly. In this study, the extraction of phenolic compounds from Moringa Oleifera leaves was enhanced using a subcritical water-ethanol mixture. Fresh and dried Moringa Oleifera leaves were extracted using ethanol solution with different ratio and ratio of dried leaves and ethanol solution at 200 °C for 15 min. The highest amount of phenolic compounds of 87.11 ± 0.81 mg GAE/g of dried leaves with flavonoid contents of 75.79 ± 0.73 mg/g of dried leaves, antioxidant activity of 88.75 ± 0.93 mg vitamin C/L and yield of extracts of 32.73 % ± 0.08 were obtained under following operation conditions: ratio of dried leaves 0.13:20 (g/mL) and ethanol solution 96 %. The utilization of ethanol solution as a solvent on the subcritical condition was able to enhance the amount of total phenolic compounds, flavonoid content, antioxidant activity and yield of extract.

Innovation of liquid hand soap continues to be done, among others, using natural local raw materials. This research used strong reduced water (SRW), an alkali produced from a water ionizer machine (with enhancer Sodium Chloride solution), which is eco-friendly and comfortable on the skin. The study also used fresh coconut oil (FCO), was produced by drying process and zero waste. The objective of this research was to determine the effect of utilization of SRW and FCO in the making process of liquid hand soap, which gave good viscosity. Fresh coconut oil (FCO) was reacted with SRW (pH 11.5) for 30 minutes at room temperature (30 °C), then mixed with sodium lauryl sulfate, sodium sulfate, other additives such as dyes, fragrances, electrolyzed oxydized water (EOW, pH 2.5), Ethylenediaminetetraacetic acid (EDTA) and distilled water. EOW was produced from the ionizer machine too. After saponification process was completed (about 24 hours), the viscosity and density of the liquid soap was measured. The better composition of FCO-SRW yielding good viscosity of liquid soap was 30 to 50 ml based on 500 ml distilled water production. The viscosities of this product were 982.55 to 1,782.25 centipoises, density of 1.0049-1.1175 g/ml, and pH 7. The using of reaction product of fresh coconut oil (FCO) and strong reduced water (SRW) can increase the viscosity of liquid hand soap.

Microwave energy can be used for oil palm fruit bunch sterilization. It penetrates onto the core of oil palm fruit bunches and generates heat inside out. This sterilization aims to inactivate lipase that influences palm oil quality. This study evaluates effect of dielectric properties power developed per unit volume and interior temperature distribution on heating rate during heating process. The experiment carried out at various combinations of microwave power and the oil palm bunches portion in microwave oven. This study observed that distribution of interior temperature in a single oil palm fruit was influenced by power density and fruit's diameter. Greater power density provides high microwave energy per kg sample to attain greater temperature of microwave heating and vice versa. Distribution of interior temperature in the fruit with the thickness (r) of 6 mm and above indicated non-uniformity heating. Furthermore, interior temperature of fruitlet with r = 4.5 mm indicated distribution of temperature from endocarp to exocarp, meanwhile simulation temperature on smaller fruit diameter (r = 3 mm) indicated thermal runway effect after 5 min heating duration.

Based on Indonesia National Standards (SNI), Indonesian local-salt is currently unavailable to produce high-quality salt. This study was aimed to investigate the purification process of local salt that has been carried out by local salt farmers in Sumenep, Madura Island, Indonesia and to determine the highest level of NaCl content from local salt using a washing method to make iodized salt. Purification process involves washing technique using a nearly saturated brine. The research was conducted in various particle-size (10-20 mesh and 20-35 mesh), salt/brine ratio (1:20, 1:40, 1:60), duration (10, 30, 60 minutes) and stirring speed (100, 200, 300 rpm). The highest NaCl content of 94.45 % was obtained at the washing process using the salt of 20-35 mesh at 1:60 ratio with washing time of 30 minutes at a speed of 100 rpm. The result of the process shows a decrease of Calcium and Magnesium levels by 95.56 %. In iodization process, the determination of the highest NaCl concentration was carried out using washing brine method and spray mixing injection was also done to develop a stable salt formulation. The optimum stability of KIO₃ in salt was observed as a function of time.

In this study, polyurethane foam (PUF) was used as a matrix to immobilize M. miehei lipase through a modified substance coating consisting of lecithin, gelatine, polyethylene glycol (PEG), MgCl₂, known as co-immobilized. Co-immobilized lipase application was carried out on bio-flavor manufacturing through hydrolysis and esterification reactions. Fatty acid was gained from hydrolysis of glyceride coconut oil (CNO) containing main components of C8 to C16. Furthermore, esterification of fatty acids and citronellol from citronella oil was employed. The remaining triglycerides (TAGs) in hydrolysis were analysed using LC-MS/MS. While bio-flavor was analysed using GC-FID. Maximum bio-flavor production was obtained at 40 °C and fatty acids lauric acid/citronellol mole ratio of 1:5. The remaining activity of free lipase, immobilized lipase on PUF, and immobilized lipase on co-coated PUF at 50 °C for 50 min was 0 %, 34 %, and 54 %, respectively. Immobilized lipase on co-coated PUF was able to reuse up to 5 cycles. The maximum conversion of bio-flavor was attained using lipase on modified co-immobilized. The use of co-immobilized lipase of the non-commercial source used in this study could be a promising method for a zero-waste bio-flavor production in a mild and solvent-free process to support low-cost and green technology.

The electrochemical method in two chambers with the bipolar membrane has been used to produce the nickel – hydroxyapatite particle. Hydroxyapatite is used as the supported catalyst for nickel catalyst. In this work, in-situ electrochemical synthesis in two chambers with bipolar membrane has been used in the formation of nickel-hydroxyapatite. A simple electrolysis cell from acrylic was used. The anode and the cathode were set parallel with a distance of 3 cm and immersed in the solution at a depth of 2 cm. The anode and the cathode were connected to a DC power supply. The particle was produced in the electrolysis cell. In the anode chamber, the pH solution decreases for the time of electrolysis while in the cathode chamber the pH solution increases. The nickel – hydroxyapatite particle is formed in the cathode chamber. There is no particle in the anode chamber. At the lower current density, the first formed is brushite. At the higher current density, brushite converts to HA. The higher current density the greater the chances of HA formation. The increase in the initial concentration of NiCl₂ accelerates the increase of the pH of the electrolysis solution.

Corrosion is one of major problems in refinery industry which leading to mechanical failure of equipments. Corrosion mechanism and rate depend on the corrosive substance, temperature, and material of equipment. Refinery feedstock commonly is a blending of different oils contains different corrosive substance. One of corrosive substance, Sulfur Content and TAN, can cause thinning of material surface at high temperature. This research aims to study the effect of sulfur content and TAN on corrosion mechanism and rate of equipment and piping in small scale refinery. Corrosion mechanism and rate for several refinery feedstocks, containing various sulfur content and TAN, were determined using API-581RP. Mass and energy balance for small scale refinery consists of distillation unit, sulfur removal unit, and platformer unit was done based on process simulator. Materials concerned in this research were carbon steel, alloy steel, and stainless steel. The result showed most of the mechanism in distillation column was thinning high temperature sulfidic/naphthenic corrosion while in sulfur removal and platformer were thinning high temperature H₂S/H₂ corrosion. The change of sulfur and acid content caused change corrosion rate in non-linear way. These results can be used as prediction for future corrosion assessment based on sulfur and TAN composition.

Scaffold, a template resemble an extracellular matrix, contributes a necessary part in tissue engineering to accommodate the growth of cells. In the development of scaffold made from organic materials such as chitosan and gelatin, researchers have done various ways to modify its properties and one of them is by incorporate it with inorganic materials. This research explored the potential of silica derived from geothermal power plant waste as a biocomposite material for scaffold. Biocomposites with two-dimensional (2-D) film form were prepared by simple drying process at room temperature and ambient pressure, while three-dimensional (3-D) scaffold form were fabricated by freeze-drying. The obtained biocomposites were characterized by Fourier Transform Infra-Red (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). In addition, swelling and degradation tests were also performed on the films and scaffolds. The results showed that there are interactions between each component in chitosan/gelatin/geothermal silica biocomposites and the addition of geothermal silica decreases the swelling and degradation rates of the biocomposites. These results indicate that geothermal silica has a high potential to be used as an additive for controlling the physical properties of chitosan/gelatin scaffolds.

The utilization of the palm oil waste, such as Palm Oil Mill Effluent (POME), is desirable to reduce environmental problems and increase its value as a source of biomass. POME can be processed to make Carbon Nanotube (CNT), a cylindrical carbon allotrope composed of graphene sheets. CNT, since its nanosized and high electrical conductivity, is well-suited to be used as electrodes in energy storage device such as battery. This study focuses on CNT synthesis from POME by pyrolysis process at 900°C using ferrocene as a catalyst in flowing nitrogen atmosphere. The synthesis of CNT consists of preparation of raw material (POME), synthesis of resin oil, pyrolysis, and characterization of CNT. The result shows that this process yields 0.28 g CNT (from 15 g POME, using 30 weight-% Ferrocene) whose diameter varies between 26-171 nm, the surface area is 404.62 m²g⁻¹. From the XRD analysis, a C (002) is detected at 2θ of 29.098° with intensity of 3.173 Å, slightly under perfect graphite intensity (3.354 Å). It can be concluded that CNT can be produced from POME using pyrolysis process; an affordable yet applicable way on industrial scale to produce a good quality of CNT.

Carbon fibres are important materials due to their excellent properties. Carbon fibres were formed by blending Poly(vinyl alcohol) (PVA) and a high conductivity material of Acetylene black (AB). Electrospinning technique was used to fabricate PVA and AB solutions in demineralized water. Electrospinning is an efficient technique for the formation of polymer nanofibers. The effects of solution concentration and AB contents on morphological appearance and diameter of those as-spun fibres were investigated by scanning electron microscopy (SEM). Iodine treatment on the fabricated PVA/AB composite was successfully achieved in order to build up the carbonization process and retained their original fibrous structure. The mass of iodinated nanofibers at 80 °C for 24 h increased about 130 %. The mechanism of iodine uptake by electrospun PVA/AB fibres have been obtained by thermal behaviour and its morphological characteristics. It was found that iodine treatment played an important role in changing the morphological structure during the carbonization process. With the iodine treatment of PVA/AB precursor fibres successfully converted into thin carbon fibres and SEM analysis confirmed that the diameter of fibres was about 290 nm. The resulted pure fibres and iodine treatments show guarantee for production carbon fibres.

Palm oil waste is an abundant biomass resource in Indonesia that is not well utilized as a raw material for producing high value-added materials. One product that is possible to be manufactured from oil palm biomass is activated nano carbon. Characteristics of high porosity and good conductivity will lead the activated nano carbon suitable as an electrode of supercapacitor material. Preparation of activated nano carbon is conducted by two main steps namely carbonization and activation. In this research, carbonization is done by hydrothermal process while activation is done by physico-chemical activation. This study focused on manufacturing activated nano carbon from empty fruit bunches of oil palm with hydrothermal carbonization for supercapacitor applications. The activation of mesopore area of the carbon has been taken place by using ZnCl₂ and CaCl₂ as a chemical activating agent during the hydrothermal process. The activated nano carbon produced from empty fruit bunches has a surface area of 41-1571 m²/g and a pore size of 2.0–6.8 nm. In this study activated nano carbon is used as a working electrode in symmetric hybrid supercapacitor.

Graphene is a 2D hexagonal lattice structure of sp² carbon atoms which has been acknowledged for its superior electrical, mechanical, and thermal properties. Production of graphene in large scale and low cost are attracting topic in recent years. Previous study shows that production of graphene from biomass via pyrolysis has low yield of graphene. In this study, we produced graphene sheets from oil palm empty fruit bunch via two-stages pyrolysis to increase the yield. The produced graphene sheets were characterized by scanning electron microscopy, transmission electron microscopy, Raman scattering, and X-ray diffraction. Surface properties (i.e. effective surface areas, pore volumes, and pore size distributions) were studied by nitrogen adsorption–desorption measurements. Effect of the first stage temperature of pyrolysis on the yield, structure, and properties of graphene has been investigated. Our result indicated that two-stages pyrolysis could increase the yield of graphene up to 70%. Graphene sheets shows favorable features of nanosheet frameworks (4–10 atomic layers) and high surface area (870 m² g⁻¹).

Corrosion is one of rising problem in the use of biodiesel. Improper storage of biodiesel may cause corrosion to occur faster and give a worse damage effect. Biodiesel is commonly stored longer in B100 (neat biodiesel). In this work, the corrosion characteristics of three different material of tanks for B100 and the blends (B20) are examined. Those metallic materials used are Stainless Steel 304 (SS), Carbon Steel (CS), and Galvanic Steel (GS). The fuel has been monitored every 45 days in 135 days. The corrosion occurrence related to some changes in the physical properties of the fuel stored. It is also identified through the change in tanks' thickness, weight, and the morphology of metal tank surfaces. The result shows a great change in biodiesel physical properties occurred in GS tank, where the BXX acid value increased by 25.39% and the water content changed to 43.18%. While, biodiesel which stored in SS tank performed best with minor change in base and wall thickness with the change of under 1% and the weight change was only 0.02%. In a certain of time, the morphological examination shows CS as the recommended material for biodiesel storage due to uniform corrosion performance.

Zeolite A has been successfully synthesized from coal fly ash by using fusion followed by hydrothermal method. This paper describes the characterization of zeolite A. The effects of hydrothermal time, Si/Al molar ratio, and alkalinity in the converting coal fly ash to zeolite A were also investigated. The coal fly ash was obtained from a local power plant at East Java, Indonesia and contained major oxides such as SiO₂ (18.60 wt%), Al₂O₃ (7.18 wt%), Fe₂O₃ (40.20 wt%), CaO (25.20 wt%). The fusion hydrothermal method consists of the following steps: pre-treatment, fusion of coal fly ash with sodium hydroxide, aging, and hydrothermal process. The synthesized material was characterized by using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR), and specific surface area analytical method. The results show that the products contain zeolite A as the major phase, while the highest specific surface area of zeolite A is 37.121 m²/g. It implies that zeolite A as a higher value added product can be obtained from a solid waste/by-product of power plant, which has wide range applications, including for ion exchange and heavy metal adsorbent from waste water.

Natural rubber-based products are widely used in everyday life. There are three types of upstream processed natural rubber, that are crumb rubber, conventional rubber, and concentrated latex. Latex is easily damaged by clotting and contains 35-40% w/w of water so that the packaging volume is relatively large and inefficient in transportation. Latex also contains ammonia as an anti-clotting agent so the packaging must be special to prevent unpleasant odour. This study aims to create a pilot plant of the spray drying latex from simulation results then test the performance, evaluate the performance test results, as well as making improvements to the production of rubber powder. The steps of this research are data collection for spray dryer design, design verification, construction of spray dryer, spray dryer appliance testing, and characterization of rubber powder produced. The heating system used in the spray dryer is LPG gas-fired furnace. Testing is done by varying the spray dryer drying air temperature of 120°C, 150°C, and 180°C, the water content of the feed latex 70% and 80% w/w, as well as non-stick material such as talc powder and MgO. Rubber powder characterized by water content with digital tools moisture meter and analysed spectra with Fourier Transform Infrared Spectroscopy (FTIR). The results showed the optimum operating conditions for the production of natural rubber powder is drying air temperature of 150°C and the water content of the feed latex 80% w/w. Natural rubber powder produced contains 10 to 13% w/w water but still sticky so that the powder grains stick to each other. The FTIR spectrum analysis of natural rubber powder products show similarity with bonding group of polyisoprene natural rubber compound. Natural rubber powder product can also be used as a substitute for crumb rubber.

In the present work, polypropylene (PP) and nanoclay in the form of masterbatch were melt compounded using a co-rotating twin screw extruder to fabricate polypropylene (PP)/clay nanocomposites. PP/clay nanocomposites samples with four different nanoclay loadings (i.e. 0, 5, 10, and 15 wt%) were prepared. Additionally, to study the effect of reprocessing on the properties of the nanocomposites, the melt compounding process was carried twice/recycle (i.e. 1^st cycle and 2^nd cycle). The surface morphological of the nanocomposites and their melt rheological behavior were investigated using a Scanning Electron Microscopy (SEM) and an oscillatory rheometer, respectively. The SEM micrographs showed that the nanoclay was well distributed in the polypropylene matrix for both 1^st and 2^nd cycles. While, the dispersion state of the nanoclay (either intercalated or exfoliated) could not be observed due to the limitation of the apparatus. Additionally, the melt rheological analysis results showed that the complex viscosity, |µ*| of all nanocomposites samples (for both 1^st and 2^nd cycles) were higher than the neat PP and the |µ*| also increased with the increase of nanoclay loadings. However, the 2^nd cycle showed a slightly higher improvement of |µ*| compared to the 1^st cycle, and the improvement of |µ*| was more prominent at lower angular frequencies (e.g. 0.1, 1, 10 rad/s) than at higher ones (e.g. 100, 500 rad/s).

The adsorption ability of poly(DMAAPS) grafted onto ethylene vinyl acetate (EVA) porous support prepared using various polymerization times was investigated at a variety of temperatures and permeated sample volumes. The permeability coefficient through Poly(DMAAPS) was also investigated. The poly(DMAAPS) was successfully grafted onto a EVA porous support through graft polymerization in water containing DMAAPS monomer with polymerization time of 4, 6 days, and 7 days. The permeability coefficient of Poly(DMAAPS) onto a EVA porous support decreased with increasing the temperature. Additionally, the adsorption amount of cation increased as permeated volume increased.

In this work, high density polyethylene (HDPE)/poly(vinyl alcohol) (PVA) fiber composites have been fabricated via melt compounding by employing a twin-screw extruder. The resulted composites samples of four different PVA fiber loadings (i.e. 0, 5, 10, and 20 wt%) were then characterized using an oscillatory rheometer to investigate the effect of PVA loadings on their melt rheological behavior (e.g. storage modulus, loss modulus, complex viscosity). Additionally, the surface morphology of cryo-fractured surface of the composites were also investigated by using a scanning electron microscopy (SEM). The SEM micrographs showed that PVA fibers were perfectly embedded and well blended in HDPE matrix. Additionally, the melt rheological analysis results showed that the complex viscosity of all nanocomposites samples (i.e. PVAC-5, PVAC-10, and PVAC-20) were higher than that of neat PP (i.e. PVAC-0) and increased with the increase of nanoclay concentrations. Moreover, to further study the relationship between the PVA fiber loadings and complex viscosity of the composites, a well-known Carreau-Yasuda equation was employed to model the complex viscosity data from the rheological test. It was found that the equation fitted well the rheological test data.

Porous hydroxyapatite have been attracting considerable attention for bone surgery. Relatively low mechanical strength of porous hydroxyapatite hampers its application for permanent bone implant. The aim of this work was to study the effect of chitosan concentration and time of coating on the physical, chemical and mechanical properties of porous hydroxyapatite/chitosan composites prepared using dip coating technique. Firstly, chitosan powder was dissolved into acetic acid with a concentration of 0.50 %, 0.75 % and 1.00 % (w/v). Subsequently the porous hydroxyapatite bodies were coated with chitosan using dip-coating method at dip time during 30, 45, 60 min. The composites bodies were dried in room temperature for 24 h. The hydroxyapatite/chitosan bodies with compressive strength in the range of 1.52 - 4.05 MPa, porosity of 75 – 78 %, pore size of 22.8 - 26.61 μm, and density of 0.71 - 0.78 g/cm3 were obtained. The increase of chitosan concentration from 0.50 % to 0.75 % can decrease the porosity from 78 % to 76 % and pore size from 28.25 μm become 22.88 μm. The compressive strength of the composites increased with the coating time.

Natural silica sources such as from biomass ashes provide an alternative cheap silica precursor for synthesizing advanced materials. Mostly, the silica content in the biomass is in the form of amorphous structure which is suitable to be used directly into the material formation. Bagasse fly ash (BFA) contains carbon and silica in a significant amount. The silica content can be recovered by a simple NaOH fusion method followed by water dilution to produce sodium silicate solution. Then, the obtained solution can be used for various material preparations such as zeolites and mesoporous silica materials. It was observed that the alkaline dissolution method is not only extracting silica but also other content such as Alumina and trace metals. Two different type of mesoporous silica, MCM-41 and SBA-15, have been synthesized by incorporating suitable template and sol-gel hydrothermal method using extracted silica source. The synthesized materials were characterized using TEM and XRD to confirm the morphology and crystal structure. Gas adsorption experiment of n-hexane has been done to examine the adsorption behaviour of the two prepared mesoporous silica. The results suggest that low cost natural silica sources can be an alternative for advanced material preparation.

The need for clean water continues to increase. Therefore, it is necessary to find an alternative for the get of clean water. One way is desalination process using membrane. Cellulose Acetate/Polyethylene Glycol (CA / PEG) membrane is one type of membrane that can be used for desalination process. Several studies on the manufacture of CA / PEG membranes have been performed, but have not yet produced a good performance membrane. Therefore in this research was synthesize CA/PEG/mixing solvent membrane using Acetone – THF/Acetone – DMF as the solvents at ratio 100-0, 90-10, 70-30, 50-50 (%volume) each and PEG as the additive vary PEG 200 and 400. CA/PEG/mixing solvent membrane characteristics are tested. The results showed that the hydrophilicity of mixing solvent method using Acetone-DMF (50:50) increase water content up to 375.86% and Acetone-THF (50:50)'s water content increase up to 177.10% with additive PEG 200, and for PEG 400 as additive showed that the hydrophilicity of mixing solvent method using Acetone-DMF (50:50) increase water content up to 503,86% and Acetone-THF (50:50)'s water content decrease from 173,28 % till 119,23%, as THF content increase.

The construction of Gresik LNG receiving terminal is aimed to fulfil the 109 MMSCFD (0.87 MTPA) gas requirement for combined-cycle power plant (PLTGU) Jawa-3 which is integrated with LNG Gresik Terminal. There are several potential LNG plants in Indonesia and abroad that can be the source of gas for Gresik LNG Terminal. Each of these LNG plants has varying gas price and distance to Gresik. The modelling of the LNG logistics system for Gresik LNG Terminal was built to illustrate the LNG supply chain from the LNG plants to Gresik LNG Terminal and several supply scenarios will be proposed. The built model is linear and optimized by using linear programming. Linear programming involves the determination of objective functions, decision variables and constraints. The optimization of the logistics system aims to obtain the cheapest gas supply cost for Gresik LNG receiving terminal. The result shows that the cheapest gas supply cost is obtained through direct supply scenario with gas source from domestic and abroad with combination of delivery from Bontang equal to 0.34 MTPA (40 %) with 12 shipments, Tangguh equal to 0.26 MTPA (30 %) with 9 shipments, and Bintulu Malaysia equal to 0.26 MTPA (30 %) with 9 shipments.

Java, the centre of industry in Indonesia, needs fuel gas supplies to maintain production continuity. The addition of gas infrastructures in the form of Liquefied Natural Gas (LNG) receiving terminals can be an alternative to secure gas supplies. Such a terminal is planned to be built in Gresik, East Java. This paper aims to examine the most appropriate technology for LNG receiving terminals to be built in East Java by considering both technical and economic aspects. In this research, LNG receiving technology was selected based on the terminal location and selection of the regasification technology using the method Analytic Hierarchy Process. Moreover, economic and sensitivity analyses were also performed. Research findings suggest the land-based LNG receiving terminal with regasification technology in the form of shell and tube vaporizers as the most suitable LNG receiving terminal in Gresik, East Java. Land-based LNG receiving terminal establishment in Gresik, East Java is feasible as regasification costs 0.468 USD/MMBTU, the Net Present Value (NPV) amounts to 31943500 USD, the Internal Rate of Return (IRR) reaches 19.25%, the Benefit-Cost (BC) Ratio equals 1.23, and the Payback Period (PBP) is 3.4 years. The throughput required by the power plant generates the greatest sensitivity to IRR.

Gresik LNG receiving terminal will be built to meet the needs of combined-cycle power plant (PLTGU) with natural gas regasification rate of 60.95 MMSCFD. In conventional regasification process using open rack vaporizer (ORV), the potential of LNG cold exergy will be wasted to seawater which is used as a heat source from the environment. The commercially proven scheme of the regasification process with the utilization of LNG cold exergy to generate electrical energy such as Direct Expansion, Rankine Cycle and combined Direct Expansion+Rankine Cycle is simulated with Unisim computer software. The purpose of this study is to assess technically and economically three scheme mention above. The results show that the combined scheme has the ability to produce the largest electricity surplus of 39.80 kWh per ton LNG regasified with potential revenue from electrical energy sales of USD 1,140,935 per year. The energy and exergy analysis shows that this scheme also has highest thermal efficiency of 14.48% and highest exergy efficiency of 60.71%. However, based on the results of economic analysis found that Direct Expansion scheme has the highest NPV among the three schemes with a value of USD 695,032.

This research used manihot esculenta crantz of 8-10 months old, eucalyptus and acacia mangium wood of 5-year-old. The active alkali (AA) charge variations of 16% to 20% with 1% intervals. The sample position of composition of manihot esculenta crantz wood was 0-22 cm above ground level. The density of manihot esculenta crantz, eucalyptus and acacia mangium were 480 g/cm³, 483 g/cm³ and 499 g/cm³, respectively. Base on FTIR analysis, have the same dominant functional groups. The average total yield manihot esculenta crantz were lower than eucalyptus or acacia mangium of 12.422% and 24.92% respectively and screen yield manihot esculenta crantz were lower than eucalyptus or acacia mangium of 13.678% and 26.85% respectively. Each AA charge increase of 1% in manihot esculenta crantz, eucalyptus and acacia mangium can decrease the total yield by 0.635%, 0.803% and 1.14%, the screen yield decreased by 0.543%, 0.563% and 2.196% respectively. The mean of KaNo difference of manihot esculenta crantz higher than eucalyptus or acacia mangium of 7.038 and 5.236 respectively. Each 1% increase in AA charge may decrease the average KaNo of manihot esculenta crantz, eucalyptus and acacia mangium were 7.693%, 3.778% and 6.628% also decreased viscosity by 3.70%, 2.99% and 0.974% respectively.

The importance of the rule and the demand of glucose trigger the seeking of the alternative materials to produce glucose. One of the alternatives used is the utilization of biomass such as the rice husk to produce glucose. Rice husk is the agricultural residue whose availability is very abundant. In this research, rice husk contained cellulose (42.2 %), hemicellulose (17.04 %), and lignin (20.46 %). First step to produce the glucose from rice husk was pretreatment stages (Soaking in Aqueous Ammonia pretreatment and Acid pretreatment). Furthermore it was followed by the acid hydrolysis step by using dilute H₂SO₄ solution. The concentration of H₂SO₄ used in this work was 1, 2, and 3 N with the various hydrolysis times of 30, 60, 90, 120, and 150 min. The result showed that increasing of hydrolysis time slightly increased glucose concentration. The highest glucose concentration was about 21.51% at H₂SO₄ concentration of 2 N and the hydrolysis time of 150 min. CFD modeling (ANSYS Fluent 16) was performed to investigate the hydrodynamic phenomena during hydrolysis. The hydrodynamic analysis showed that the best mixing occurred at H₂SO₄ concentration of 2 N for 150 min. It is a good agreement with the experimental finding.

The amount of plastic waste is growing over years due to the vast applications of plastics in many sectors. Of the various processes that can be used to convert solid waste into fuels, the pyrolysis process has been identified as having significant potential. Pyrolysis thermally degrading long chain polymer molecules into smaller, less complex molecules, through heat and pressure with little or in absence of oxygen. In this study, a 125 dm³ pyrolysis reactor was designed and its performance was evaluated. The feedstock for the reactor was 1 kg polypropylene type of plastic waste and conducted at temperature of 250 °C, 300 °C, 350 °C and 400 °C, each process was carried out at 30 minutes and 60 minutes of operating time. The results showed that at a temperature of 400 °C, for a period of 60 minutes, a maximum yield of 88.86% liquid fuel was achieved. Obtained pyrolysis liquid fuel is comparable with the commercial fuel set by Indonesian Ministry of Energy and Mineral Resources. Furthermore, the viscosity and calorific value of liquid fuel produced are close to those of kerosene, meanwhile the density is close to the density of gasoline.

Safe clean water, especially for consumption purposes, is needed by the humans. Various regulations on water safety standards have been developed and implemented by each country, including Indonesia Regulation of the Minister of Health Number 492/MENKES/PER/IV/2010 concerning Water Quality Requirements; SNI 01-3553 2006 on Drinking Water in Packaging and Government Regulation of the Republic of Indonesia Number 82/2001 on the Management of Water Quality and Control of Water Pollution. Some parameters of physics, chemistry, biology and radioactivity are the benchmarks of water security. Raw water treatment for clean water and drinking water has been done using oxidation and electromagnetic methods. Both of these methods have been tested in local water company (PDAM) at Bangka Barat which has problems with high organic content, the amount of heavy metal content Fe and Mn that exceeds the threshold above normal and high acidity level. Test results after processing show physical and chemical parameters that meet the criteria of water quality and drinking water requirements in accordance with regulations set by the government. Other important things besides meeting the health requirements are also the quality assurance of the measuring instrument used to test the physical and chemical parameters. This measurement traceable to International System of Units through Research Centre of Metrology-Indonesian Institute of Science.

Nonconventional column/rectifier configuration is the new alternate design for the sequence multicomponent separation of three or more products. It can accomplish an efficient energy. There are two columns, the first is the rectifier and the second is the main, the vapor sidestream is taken out from the location under the feed tray of the main column then fed to the rectifier column and the liquid that from the bottom of the rectifier column is turned back to the main column. In order to completely understand the dynamic behavior of complex process of this configuration, process dynamic and control of it has to be studied intensively. The implementation of it is demethanizer and deethanizer column. The configuration has been simulated for dynamic by using Aspen Hysys v10.0. The results show that the graph of rejecting disturbance from all controllers of the main column need more attention especially for inventory control i.e. level controller for reflux drum, sump level reboiler and pressure controller for condenser. The overshoot for level controller of reflux drum of main column is 10% from set points. The better algorithm of tuning is required. The results of this studied could provide guidance for composition controller of this configuration.

Used lube oil is a dangerous waste that must be treated before disposed on the environment. Used lube oil treatment process consists of several stages, one of them is the separation of heavy fraction. Some equipment system can be used to complete this process, and thin film evaporator (TFE) is chosen for this research. The goal of this research is to understand the effect of temperature and rotor rotation on the heat transfer that happens in the distillation process using thin film evaporator. Simulation using Aspen Plus is used and is validated by manual calculation using Matlab. Temperature is varied between 250 – 330 °C and rotor rotation are varied between 0 – 60 rotations per minute (RPM) in a vacuum pressure of 2.53 kPa. From this research, the relation between operating temperature and rotor rotation in thin film evaporator to the vapor fraction produced is directly proportional. The optimum operating condition in this research was found at a temperature of 310 °C with the agitator rotational speed of 30 RPM.

Gas conditioning tower (GCT) is a vital equipment in cement industries. The main principle in this equipment is evaporative cooling, i.e. reducing the temperature of the hot flue gas by evaporation of cooling water. Thus, the water consumption is large enough to be able to cool the hot gas from about 400 °C to 150 °C or less. In this case study, the water consumption reduction of a GCT is evaluated before and after modification. The modification of the GCT system includes the change in operating condition and tower mechanical construction which are installation of flow deflector in the inlet pipe, the addition of two perforated plates, the reduction of the nozzle sprayers and the addition of tower length. Meanwhile, the dust removal replacement from Electrostatic Precipitator (EP) to Bag Filter (BF) system allows higher outlet gas temperature of the GCT which could reduce the water and power consumption significantly. The modification effect of the GCT system is analyzed in terms of water demand and energy savings using 100 days real plant data from PT Indocement Tunggal Prakarsa, Indonesia (ITP). It is shown that the modification can reduce the total water consumption by about 20 % and the specific power consumption by about 0.5 kWh/ton of Raw Mill product. The general equation for cooling water demand calculation based on heat balance has been modified as well for better real data approach incorporating air spray flow into the equation.

Evaluation of Chemical Oxygen Demand (COD) removal by a dielectric barrier discharge (DBD) system to produce biogas from palm oil mill effluent (POME) was investigated in a batch experiment. The residence time was set at 1 hour. The batch experiments were observed with voltage variation at 10, 15, 20 and 25 kV. It was found that the COD removal was measured at 22.47% to 44.94% with the applied voltage was set at 10-25 kV, respectively. The results also shown that the maximum yields of hydrogen and methane by the system were 7.94 and 1.78 mL/mL of POME, respectively that were obtained at an applied voltage of 25 kV.

Biobutanol is a type of alcohol that can be produced from biomass lignocellulose and used as renewable fuel. One of lignocellulose sources as raw material of making biobutanol is bagasse. Bagasse as agriculture waste was useless and did not have a potential benefit for farmers, but in this research it used as raw material because of the high cellulose contained. In this research for producing biobutanol, bagasse pre-treated by using ammonia with various concentrations (0 %, 1 %, 3 %, 5 %, 7%) and hydrolysis with 2 % sulphuric acid for 2 hours and 120 °C. Then the process continued with fermentation. In this step 10 mL Clostridium acetobutylicum bacteria was used and fermentation times were varied (2, 4 and 6 days). The aims of this research were analysed the content of cellulose, hemicellulose, lignin before and after pre-treatment processes and also biobutanol content after fermentation process. The results of this research showed that using 7 % ammonia was the highest lignocellulose content which had 69.68 % of cellulose, 14.39 % of hemicellulose and 9.15 % of lignin. The highest biobutanol content was 0.85 % that produced by using 5 % ammonia in the pre-treatment process and fermented for 6 days.

Indonesian government launched an energy source substitution from fossil fuel into renewable energy such as biodiesel oil. It is known that microalgae could store high lipid content making it useful for biodiesel production. This research studied the cell growth and lipid content profile of Nannochloropsis oculata at various exposure periods of flue gas and illumination. The experiments were done in indoor bioreactor outfitted by a light source and flue gas absorber. Five liters of medium BG-11 was circulated through bioreactor and absorber while the exposure periods of light and flue gas were varied intermittently and/or continuously. N. oculata reached the highest cell density of 27.3 mg/L when it was treated at continuous illumination with the absence of flue gas exposure. The highest lipid content of 36.88% was achieved at the cell density of 14.11 mg/L in continuous illumination and 10 minutes per day of flue gas exposure. The CO₂ enrichment through flue gas exprosure showed an environmental stress toward microalgae growth and drove the lipid content as well as the periodical illumination.

The production of hydrocarbon biofuel from coconut oil can substitute for fossil fuels to reduce the environmental issues. Hydrocracking is an effective method that can convert vegetable oil into biofuel using catalyst. In this experiment, nickel-iron was combined with HZSM-5 catalyst to produce biofuel. Hydrocracking of coconut oil was carried out in a batch reactor over Ni-Fe/HZSM-5 catalyst at a temperature of 350 and 400 °C for 2 h. Liquid hydrocarbon biofuel product was analyzed by gas chromatography-mass spectrometry (GC-MS). Based on GC-MS analysis, processing at the temperature of 350 °C produced sample containing 72.56% carboxylic acids. When the temperature increased to 400 °C, the carboxylic acids decreased rapidly from 72.56% to 24.83%. Analysis results suggested that increase of temperature promoted to the increase of desirable content, hydrocarbon compounds. At the same like, it also suppressed formation of undesirable compounds: acids, ketones, phenols, alcohols, and esters. Overall, synthesized catalyst in this study improved production of n-paraffin compounds such as (tridecane (n-C₁₃), tetradecane (n-C₁₄) and pentadecane (n-C₁₅)) as high 71.85%.

Wild taro tubers (Colocasia esculenta (L.) Schott Var. Antiquorum) contain 70-80% (wt%) of starch, thus serve as potential feedstock for glucose production, providing raw materials for bioethanol production. The tubers used in this study was collected from Padang city, Indonesia. The aim of this research was to find the optimum of bioethanol yield through variation of acid catalyst (HCl, H₂SO₄ and HClO₄), acid concentration (0,00 N; 0,05 N; 0,10 N; 0,15 N; 0,20 N), enzyme (α-amylase, glucoamylase), enzyme volume (0.308 ml; 0.74 ml), hydrolysis time (1 hour, 2 hours, 4 hours), and fermentation time (48 hours,72 hours, 96 hours, 122 hours, 144 hours).At varied acid catalyst usage, the highest glucose content (27.54%) was obtained by using HClO₄ acid with a concentration of 0.10 N and the lowest glucose level of 16.64% was obtained from the usage of H₂SO₄ acid with a concentration of 0.10 N in the hydrolysis process with temperature of 120°C for 45 minutes. The highest bioethanol content as 19.10% was obtained at the time of fermentation of 96 hours with the usage of Sacharomyces cerevisiae enzyme.The highest glucose content of 20.35% was obtained by using glucoamylase enzyme of 0.308 ml.

Light naphtha is not reliable used as automotive fuel because of its low octane number (RON) and high vapor pressure. To utilize light naphtha as fuel, blending process may be used to obtain usable gasoline fuel. Diethyl carbonate (DEC) can be used as blending agent with light naphtha because its high octane number and low vapor pressure. Therefore in this work, the vapor pressure and octane number (RON) of DEC–light naphtha blends were measured to study the effect of DEC in light naphtha blending. The vapor pressure measurements show that vapor pressure of DEC–light naphtha blends decreased while the DEC fraction increased. The pseudo binary analysis approachment was used to correlate the vapor pressure experimental data and predict the vapor pressure of light naphtha + DEC blends. The Wilson and nonrandom two-liquid (NRTL) model are giving good correlation and prediction result with average absolute deviation (AAD) less than 1.3% meanwhile the Hildebrand & Scatchard model give quietly poor result with AAD value of 4.4%. The RON measurements show that the RON values of the blends increased while the DEC fraction increased. The DEC is successfully used as blending agent into light naphtha with 30% v/v optimum fraction.

Diethyl ether (DEE) is an important chemical in practical application. This substances actually very interesting to be object of study because its can be substitute the fuel oil such gasoline from the fossil. Its mean that DEE is one of alternative sources of energy. In this study the production of DEE was based on ethanol dehydration over a granule Cr-Co/γ-Al₂O₃ catalyst. The reaction was conducted in a fixed bed reactor at range temperature of 100 to 200º C and atmospheric pressure. Un nitrogen gas is fed in reactor to push the ethanol vapor. Sampling the product of reaction is taken after the condition is steady state. The catalyst was analyzed by the BET and XRD method and the result indicated that the prepared catalyst has surface area of 162,840 m²/g with pore diameter of 0,3178 cc/g. The ethanol conversion under the variable condition attaints of 93.122% of and DEE yield is 0.34%.

The production of biogas by anaerobic digestion (AD) from fruit waste and then converting biogas to electricity is an innovative approach in the development of renewable energy. To study the sustainability of the process, it important to analysis the environ-socio-economic benefits of the technology. In this study, the life cycle sustainability assessment (LCSA) were carried out in a fruit waste biogas plant system, which located in the Gemah Ripah Central Fruit Market in Indonesia. The AD system was designed for 4000 kg/day feed and supplies 148.5 kWh/day electricity. The results of assessment of environmental, economic and social aspects are 5.00 (very good), 3.00 (moderate), and 4.00 (good). This study indicates that biogas plant from fruit waste has a significant advantage for environment, economic, and society. Overall, the sustainability of BPG is in the category of very good (grade I) with a value 4.11 from maximum value of 5.

The increase of Liquid Petroleum Gas (LPG) import in Indonesia made the government promote Dimethyl Ether (DME) as partial substitution of LPG as written in the General Planning of National Energy (RUEN) 2017. DME can be produced from biomass which abundantly exists in Indonesia. Such biomass is especially oil palm empty fruit bunches (EFB) that consist of 49.07% C, 6.48% H, 0.70% N, 38.29% O, and 5.36% Ash. Techno-economic analysis of this bio-DME production plant was conducted based on literature data. The direct synthesis of DME was applied in this study, instead of using methanol as an intermediate product. Result calculated from mass and energy balance simulation was 4.1 EFB/DME. Thus, 1,090 ton per day of DME can be produced from EFB with a collecting radius of 100 km in Riau Province. Assuming 20 years plant operation with DME selling price of IDR 145,000/12-kg-LPG-equivalent and EFB price of 300 IDR/kg, economic evaluation showed that this business was economically feasible with 10.08% IRR generated. The CAPEX of this plant was 990.4 million USD and the OPEX was IDR 7,143 IDR/kg-LPG-equivalent. DME production from EFB will give the positive economics and environmental effects. Therefore, support and synergy from government, industries, and academics are needed to realize this business.

Empty fruit bunch (EFB) is not yet utilized as a solid fuel for boiler due to their physical characteristics such as very bulky, high moisture and potassium contents. The hydrothermal treatment (HT) has been conducted in our research to overcome those problems. HT experiments were conducted in a 2 L digester, with 100 grams of EFB. The liquid to solid ratio was 5:1 mL/g. HT were conducted at temperature of 120, 150, 180, 200, and 220°C, and holding time of 60 minutes. The results indicated that the properties on solid products could be improved using HT, particularly its higher heating value (HHV) of 20.1 MJ/kg (obtained from HT at 180°C) compared to feedstock of 19.68 MJ/kg and commercial pellet of EFB of 13.03 MJ/kg. Pellets made of solid product from HT at 150°C and pelletized at 200 bar were considered to meet the characteristic of commercial pellets.

Indonesia is one of the largest palm oil producers in the world. Palm oil has a wide range of derivative products that have higher values than in the upstream oil palm products. Indonesia still exports mostly crude palm oil rather than its derivatives. The objective of this research is to obtain the best strategy of developing downstream palm oil industry by considering the total price and greenhouse gas emission. Economic objective function is the total selling price of all products and environmental objective measured by the total greenhouse gas emissions. Multi-objective optimization is based on State-Task Network superstructure with fixed variable of product selling price, emission factor, conversion factor, national demand and global demand of the products. Multi-objective optimization is carried out using GAMS with Cplex 12.6.3 solver. The total selling price obtained amounted to 51.67 billion USD and total GHG emissions generated were 88.05 million tons CO₂e. The selected production pathway is the production of 54 palm oil derivatives products to meet domestic needs and 21 of them can be exported (1 FFB derivative product, 4 CPO derivative products, 1 POME derivative product, 4 EFB derivative products, 2 PKS derivative products, and 9 Palm Kernel derivative products).

Direct synthesis of DME catalyst was prepared using the co-precipitation method. The catalyst contained CuO/ZnO/Al₂O₃ about 40/27/33 (%-wt). Two types of catalyst were prepared, i.e. CZMA0 (Mg 0%-wt) and CZMA20 (Mg 20%-wt). Both of catalysts were activated using reducing gas (5% H₂ and N₂). The activity test was conducted by syngas model which contained (%-mole) 65% H₂, 28% CO and 7% N₂. The reaction was carried out in a fixed bed reactor at 5 bar, and temperature of 240, 250 and 260°C. Synthesis shown CZMA20 catalyst gave the highest catalytic activity with 73% of CO conversion and 66% of H₂ conversion (5 bar and 260°C). Direct synthesis of DME was also carried out using a dual-catalyst, i.e. catalyst for methanol synthesis (M151, the commercial catalyst of methanol synthesis) and methanol dehydration (γ-Al₂O₃-ITB). The activity of dual catalyst shown 93% of CO conversion and 91% of H₂ conversion. This activity was more stable than two other catalysts (CZMA0 and CZMA20).

In the last decade, biodiesel has been considered as one of attractive biofuels in function of replacing fossil-based diesel fuel and concerning on reduction of greenhouse gas release. For biodiesel production, the use of heterogeneous catalyst is a challenge to minimize problems related to the use of homogeneous catalyst. One of potential heterogeneous catalyst is activated carbon-based catalyst. This study investigated the effect of activating agents (hydrochloric acid and sulfuric acid), its concentration (0.5, 1.0, 1.5 and 2.0 N) and activation time (1.5, 3.0, 4.5 and 6.0 h) on iodine number of activated biochar (from coconut shell and Randu wood). The results showed that the highest iodine number (749.14 mg/g) was obtained from coconut shell biochar activated by sulfuric acid at concentration of 2 N and activation time of 6 h. Moreover, BET analysis of the best activated biochar resulted 30.88 m²/gcat of surface area, 3.26 x 10⁻² cm³/g of total pore volume and 2.11 nm of average pore radius. The performance test of this potassium-impregnated activated biochar in batch transesterification reaction (palm oil-methanol) presented 29.44 % of biodiesel conversion.

Hydrolysis of EFB's fiber was carried out using sulfuric acid in two series reactors each operates under microwave irradiation. First reactor operates at various microwave power level (medium, medium high and high), irradiation time (5, 7.5 and 10 minutes) and acid concentration (0.5, 1 and 1.5%) while the second reactor operates at constant time using similar combination of power and acid concentration. This study placed reactor A next to the waveguide, while the reactor B on the opposite position. Microwave energy emmited from magnetron into cavity through the waveguide. This study evaluated effect of wave distance source on temperature and glucose yield in both reactors. Effect of microwave power, irradiation time and acid concentration and their relationship with glucose and temperature were investigated. Overall, increment of time and power increased yield of glucose at first hydrolysis using sulfuric acid of 0.5%. Glucose yielded from reactor A usually higher as compared to reactor B. Increment acid concentration reduced the yield except the one with high power irradiation. This study observed that second stage hydrolysis had no significant contribution to add the yield.

Indonesia's lignite coal and sawdust production are 131,05 and 11,82 million tonnes, respectively, which are potential to become raw material of hybrid coal through co-pyrolysis. Hybrid coal utilization will reduce non-neutral CO₂ emission, a part of CO₂ emission released from combustion of biomass. The aim of this study is to determine the effects on biomass composition and co-pyrolysis retention time on reduction of non-neutral CO₂ emission from combustion of hybrid coal in power plant. Co-pyrolysis was conducted in a vertical tubular furnace under an inert condition in atmospheric pressure and temperature 300° C. Biomass composition and co-pyrolysis retention time was varied from 20 to 40 %-mass and from 30 to 90 minutes, respectively. Hybrid coal was characterized with proximate, ultimate and calorific value analysis. The result of analysis was used as an input on simulation to determine reduction of non-neutral CO₂ emission on hybrid coal combustion in power plant. An increase in co-pyrolysis retention time (CRT) from 30 to 90 minutes increases the CO₂ emission from 13.25 to 13.30 %-vol. While increase in biomass composition from 20 to 40 %-mass reduce CO₂ emission from 13.18 to 12.81 %-vol. Non-neutral CO₂ emission reduction rises from 24.22 to 26.86 % along with the increased of biomass composition from 20 to 40 %-mass. Average of non-neutral CO₂ emission reduction is about 26.30 % in all variation. CO₂ emission of hybrid coal as fuel for power plant increased along with the increased of co-pyrolysis retention time (CRT), which was about 780-830 kg CO₂/MWh. The highest CO₂ emission was achieved from co-pyrolysis product hybrid coal utilization with 30 %-mass of biomass composition.

Co-gasification process of coal and biomass is believed to be one of the promising way to produce hydrogen. The mixing of coal and biomass can solve the problems that usually happened during gasification of pure coal or pure biomass. Furthermore, the presence of synergistic effect between coal and biomass may increase the hydrogen production due to Alkali and Alkaline Earth Metal (AAEM) content in the biomass. However, the synergistic effect may be hindered by the presence of silica in the coal. The present study focuses on the reduction of silica content of coal by acid leaching. Based on the result, it is found that the use of hydrofluoric acid may significantly reduce the silica content shown by the reduction of ash content in the coal. Furthermore, acid leaching process also causes the increase of surface area of the coal which may increase the possibility of AAEM attachment to the surface and thus the gas production may increase as well.

A non-catalytic in-situ transesterification of biodiesel production from rice bran using subcritical water-methanol mixture was found to be unaffected by initial moisture and free fatty acids (FFA) contents. The method has been known as environmentally friendly conversion since no catalyst was used. Acid catalyst has an important role in in-situ transesterification due to their ability to accelerate the oil extraction from the bran and the reaction rate. In this study, CO₂ as pressurizing gas was added into subcritical water methanol mixture to increased yield and content of biodiesel. Effect of different operation pressure (P = 40-100 bar) at subcritical water methanol mixture (T = 200°C) and reaction time of 180 min on the yield and content of biodiesel were investigated. Rice bran with initial FFA content of 40.42 % has been subjected into hydrothermal reactor together with water methanol mixture to produce rice bran oil (RBO)-based biodiesel. The more CO₂ as pressurizing gas was added into the hydrothermal reactor, the more yield and content of biodiesel were obtained. The highest yield and content of biodiesel of 98.00±1.41% and 83.93%, respectively, were produced under P = 100 bar.

The direct and double decomposition process of palm stearin oil were evaluated for the production of basic soaps as a decarboxylation feedstock to drop-in fuel produce. The metals proposed for the saponification reaction was magnesium which has a high-basicity and is a low-cost metal. The Fourier transform infrared spectroscopy profile of the Mg(OH)–stearin basic soaps obtained by both direct and double decomposition processes showed hydrocarbon groups such as alkanes and alkene, without the oxygenate groups. The basic soap products generated by the double decomposition process showed better basicity level which was determined based on the IR spectrum intensity, especially of the -OH group. The type of saponification process used in the resulted basic soaps can provide a different effect on the generated basic soaps characteristic.

East Nusa Tenggara (NTT) is a province with low electrification ratio (78.3%) and high number of underdeveloped villages (74.8%), despite its abundant renewable energy resources potential. The objective of this study is to obtain technically-economically feasible village model with integrated renewable energy system for developing productive zone, Prukades-postharvest cocoa processing, in Wewaria, NTT. The methodology used is techno-economic analysis, in which technical analysis include optimization for hybrid power generation system (HPGS), done by using HOMER Pro. Several financing schemes are proposed to evaluate the economic feasibility. Environmental comparative analysis of mitigated GHG emission is also evaluated. It is found that the HPGS consists of 95 kW photovoltaic, 78 kW wind turbine, and 200 kW diesel generator, equipped with battery storage, and the Prukades system has annual capacity of 250 tons of wet cocoa beans/year with 32.9% yield. Prukades system is economically feasible with all proposed schemes, and potential to increase annual income of cocoa farmers. On the other hand, HPGS is only economically feasible with FS-5 scheme with 100% grant as financial intervention. The economic attractiveness of both systems is relatively higher by using integrated scenario, both owned by the same business entity, resulting in 3 other schemes to be feasible.

Utilizing fossil fuel is always has a deficiency in the environmental aspect. The processing of fossil fuel produce high carbon dioxide (CO₂) emissions. It is required an effort to utilize CO₂ emissions into feed of a high-economic value product of such as diethyl carbonate (DEC). The objective of this study was to develop the process of DEC synthesis from CO₂ using ethanol and ethylene oxide as reactant and potassium iodide – based catalyst. The catalyst used in the experiment were binary catalyst potassium iodide (KI) – cerium oxide (CeO₂) and KI – sodium ethoxide (EtoNa). The experiment conducted in cylindrical reactor equipped with stirrer and heating jacket. Reactant and catalyst were added into reactor and setting operation condition at initial pressure of 35 bar and temperature of 170 °C within 3 hours. The ratio of ethylene oxide to ethanol was investigated as well. Subsequently, the products of this synthesis were analyzed qualitatively and quantitatively to determine the reaction products and DEC yield. From the experiment, DEC was successfully obtained and the highest DEC yield was found to be 7.1 % by using KI-EtoNa as catalyst at mole ratio of ethylene oxide to ethanol of 1:15 within 3 hours of reaction time.

Biodiesel has become a promising renewable energy resource in recent years due mainly to the fluctuating global oil prices. Calophyllum inophyllum L seed has fairly high oil content of about 40-73 % by weight, thus, making it a great potential as raw material for producing biodiesel. This paper aims to study the effect of the microwave irradiation for biodiesel production from Calophyllum inophyllum L oil when solid CaCO₃ catalysts made from waste eggshells and synthetic were employed. Furthermore, the effects of operating conditions, including reaction time, microwave power, and amount of catalyst loading were also investigated. The initial step to produce Calophyllum inophyllum L biodiesel was degumming process, followed by the esterification and trans-esterification, respectively. The catalysts used are CaCO₃ synthetic and eggshell. The results of production biodiesel from Calophyllum inophyllum L oil give the highest yield of 65.36 % when performed with the microwave power of 300 Watt, 1 % eggshell catalyst and the reaction time of 10 minutes. Therefore, Calophyllum inophyllum L shown as potential biodiesel feedstock.

Microalgae has a highly potential to be biodiesel fuel due to its high lipid content. The research used Nannochloropsis oculata microalgae refer to high lipid content (approximately 68%). The objectives of this research are to study edible oil extraction process from Nannochloropsis oculata, to study the effect of microwave on biodiesel yield using KOH catalyst, time reaction as well as catalyst percentage. The trans-esterification process was carried out on microwave with lipid molar-methanol comparison of 1:10, microwave power, reaction time and catalyst composition were also varied. It was found that the addition of co-solvent (addition n-hexane) seems to give the best result in terms of yield, i.e. 54.19%, which was obtained at a 600-watt microwave power, reaction time of 40 min, and 2.5% catalyst concentration. The fatty acid consists of several major constituents, such as palmitic acid 84.81%, oleic acid 12.41% stearic acid 1.87% and linoleat 0.88%. It can be concluded from the study that the in-situ trans-esterification process is such an efficient method due to the short reaction time, less energy consumption and relatively efficient owing to the combined extraction and trans-esterification steps.

The objective of the present work is to extract natural dye substances from Ketapang leaf. This leaf contains tannin substance that can be used as natural dye for textile materials. This natural dye is one of potential alternatives to the synthetic dyes because it is environmentally friendly and also Ketapang leaf is abundantly available, especially in Indonesia country. The brief detail of Ketapang leaf extraction process can be explained as follow: Ketapang leaf was soaked/immersed in distilled water for several periods (i.e. 4, 6, and 8 days) by using maceration method. From the experimental results, the optimal immersion time was reached at 6 days. The tannin content in the extract was also determined by using UV-Vis spectrophotometer. To test the performance of this natural dye, textile material made of 100% cotton was immersed in tannin solution for 60 min, squeezed, and the color was raised with three different fixer solutions, i.e. alum (Al₂(SO₄)₃, kapur tohor (CaO), and tunjung (FeSO₄) 50 g/L for 60 min. The fabrics were then tested for color fastness using detergent washing method and rubbing method (with crockmeter test). The test results showed that the fabric with alum as the fixer exhibited the optimum result for fastness test.

The Liquid smoke can be use for food preservation, be obtained from pyrolysis of materials containing cellulose, hemicellulose, and lignin. The form of liquid smoke that has the ability to preserve,for their phenolic compounds,acids and carbonyl. The purpose of this research is to know the quality of liquid smoke from process of charcoal the biomass obtained from rotary pyrolysis carbonisator as fish preservative, the effect of liquid smoke on the chemical and organoleptic properties of fish, and the resilience of fish after being given smoke liquid. The metode of experiments with skin biomass of durian, coconut shell, and palm shell. Biomass is dried, then is burned in rotary carbonisator pyrolysis. The results ofthe process are namely liquid, tar and charcoal smoke. Next, Liquid smoke is precipitated and then it is distilled twice, namely ordinary distillation and vacuum distillation. Results combustion produces liquid smoke with a yield of 19% on the skin of durian, 23.6% on coconut shell, and 20.8% on palm shells. Organoleptic test results on the fish with the addition of liquid smoke from the skin of durian with a concentration of 5 % is most preferred by the panellists in terms of color, aroma, flavor, and texture.

This work demonstrates the comparison techniques between conventional and rapid thermal processing (CTP Vs RTP). It is to fabricate the interlayer-free P123 carbonised template silica membranes. The aim of this work is to understand the performance of fabricated membranes for water desalination. The silica sols pH 6 were prepared from a two acid-base catalyzed sol gel method by applying tetraethyl orthosilicate (TEOS) as the precursor. Triblock copolymer of Pluronic P123 was used as the templating agent and mixed homogenously with silica sols. The mixtures were calcined in two method called CTP and RTP. CTP is a slow calcination and takes 4 hours with 1 °C min-1 for dwelling time. On the other hand, RTP is rapid technique calcined in air (1 h without dwelling time). CTP confirms higher surface area (50 % higher), porosity (34 % higher) and thinner (60 %) than RTP. RTP technique is supposed to save time, energy and cost during membranes fabrication.

Sweetening process for natural gas with high content of sour gas (≥ 40% mol of CO₂ & H₂S) is difficult to be profitable. A lot of gas fields in Indonesia has high content of sour gas. New improved cryogenic distillation process of natural gas applying the concept of CO₂ freezing in the middle of the column is promising. To study the feasibility of this technology, comparison with other two methods (Absorption and Membrane process) in technical and economic aspects were elaborated. Process simulation of improved cryogenic distillation steady-state model was developed using Aspen HYSYS. CAPEX of all methods were estimated using Aspen Process Economic Analyzer. Compared to the other methods, this improved cryogenic distillation process showed tendency to have lower CAPEX and OPEX, but have some uncovered operational problems.

γ-oryzanol is unique to rice bran oil (RBO) and it is known to be a potent hypocholesterolemic agent. Separation and isolation of γ-oryzanol from crude RBO is difficult due to complexity of components in crude RBO. Converting acylglycerides and FFA in RBO into FAME will concentrate bioactive compounds in the residue after FAME was removed from the RBO-based biodiesel. In this study, wet-extraction of bioactive compound from rice bran, γ-oryzanol, has been carried out using subcritical water-methanol mixture. The effects of extraction temperature, extraction time, water-methanol volume ratio and pressurizing gas type on the content and recovery of γ-oryzanol in crude RBO-based biodiesel have been investigated. It was found that the content and recovery of γ-oryzanol in RBO-based biodiesel increased with higher extraction temperature, longer extraction time and lower water concentration. The content of γ-oryzanol in RBO-based biodiesel was higher under N₂ atmosphere since CO₂ can acidify the solvent leading to hydrolysis of γ-oryzanol. The maximum γ-oryzanol content in RBO-based biodiesel was 2.16 % (corresponding to 2750 mg γ-oryzanol/kg rice bran) obtained after extraction for 7 h at 200 °C and 40 bar with water concentration of 50 % (v/v) under N₂ atmosphere.

In recent years, membrane separation techniques gain an increasing interest to be applied in many industrial separation processes, such as the separation of produced water in petroleum industry and the treatment of used oil and used cooking oil. Used oil and used cooking oil consist of suspended solids in addition to emulsion. Both ultrafiltration and microfiltration have been used to separate oil from water. The challenges of oil-in-water emulsion separation include the possibility of big oil drops deforming through the slot or pore of membrane thus reduce the oil rejection. In addition, concentration polarisation and fouling phenomena are considered as negative attributes for membrane performances. This research applied flat sheet microfiltration membranes to treat used oil and used cooking oil. The performances of membranes in terms of flux reductions were evaluated and analysed using filtration model. Experimental results showed the decline of permeate flux with time indicating the formation of polarisation layer on the surface of the membrane. In addition, complete blocking and deep bed filtration explained the flux behavior of used oil and used cooking oil filtration, respectively.

Hollow Fiber Membrane Contactor (HFMC) technology has been widely developed as an alternative technology to separate CO₂ gas. HFMC technology combines gas absorption process with absorbent and membrane technology. Membrane contactor technology has advantages than conventional technology such as larger gas-liquid contact area, smaller equipment, modularity, and gas-liquid flow rates adjusted independently. In this research, the CO₂ absorption experiments was conducted for absorption process at 30°C temperature and various gas flow rate from 200 - 600 mL/min, feed gas of CO₂ 20%vol. flowed into shell side and the absorbents flowed in tube side of membrane contactor. Piperazine (PZ) and monosodium glutamate (MSG) as activators with 1%w/w concentration, added into methyldiethanolamine (MDEA) 30% w/w solution to form aqueous solutions of activated MDEA. The membrane material used in this experiment was hydrophobic polypropylene membrane. The effect of liquid flow rate and various activators used to get CO₂ absorption flux and CO₂ removal in HFMC. The results showed that the best of CO₂ absorption process using activated alkanolamine was MDEA-PZ, where the highest flux value was 5.5x10⁻⁴ mole/m².s and CO₂ removal reached 96.9% at a gas flow rate of 600mL/min.

The effect of alkaline hydrogen peroxide (AHP) treatment on reducing lignin content in coffee pulp waste (CPW) was investigated to increase the digestibility and accessibility of cellulose during production of valuable products by enzymatic and biological process. Hydrogen peroxide (H₂O₂) at various concentrations (2.5, 5, and 7.5% (w/w of substrate)) was mixed into 10% (w/v) of CPW-NaOH solution at 35 °C for 24 h with pH 11.5. The concentration of lignocellulosic content was investigated. The characteristic of crystallinity index, functional groups, and surface morphology of CPW at before and after the treatment have been observed using XRD, FTIR, and SEM analysis, respectively. The results showed that the highest lignin removal was achieved at the addition of 7.5% H₂O₂ which decreased from 16.85% to 8.5%. The concentration of cellulose and hemicellulose in CPW increased from 53% to 64% and 11% to 24%, respectively. The crystallinity index of AHP-treated CPW has increased from 30.83% to 42.08%. A surface morphological destruction on the CPW was getting worse as along with the increase of H₂O₂ concentration. This would be useful to increase the porosity of biomass to give cellulose accessibility by enzyme for further processes.

One alternative to reduce the effect of water pollution from the textile industry is to replace the use of synthetic dye with the natural one. Henna leaves are one of the natural dye sources which has lawsone, a unique substance that produces orange colour. Some commonly used conventional extractions are soxhletation and maceration. One extraction method that is tried to be developed in this study is the Ultrasound-assisted Extraction. The effects of feed ratio to solvent, time, temperature and solvent types were investigated and discussed in this study. The highest yield from the extraction of Henna leaves was found to be 17.96% which was achieved at pH 1 with the extraction time of 10 minutes, feed/solvent ratio of 0.02, and aquadest solvent. Based on the both qualitative and quantitative analysis of the extracted colour, the ultrasound assisted method was found to be more effective and efficient than the soxhletation method.

A sieve tray is a type of tray that is widely used in separation in industry. While sieve tray without down comer, frequently called dual flow sieve tray is commonly used to increase the effective area, so it can increase tray capacity. Dual-flow sieve tray operations can be classified into two categories, it is froth and transition based on gas/vapour velocity, so that there are parts of holes that are only flown by gas/vapour and at the same time there are parts of holes that are only flushed with liquid. Performance characteristics studied include clear-liquid height, dry and wet pressure drop, efficiency, and entrainment. The study aims to compare performance characteristic of sieve tray with and without down comer. The sieve tray without down comers showed almost 50% higher capacity compared to the sieve tray with down comers. However, sieve tray without down comers has 40% lower pressure drop compared to that with down comers. The results can ensure that the trays performance prediction for 298 mm diameter with open area in the range of 77-80%, 5 mm diameter holes, 12.5 mm hole spacing and 35 cm tray spacing satisfying and optimistic can be utilized in the distillation process.

Common problem in natural gas purification is Hydrate Formation. Hydrate is a solid – ice – like crystals in which gas molecules are trapped in the structure of solid water and causing problems especially clogging in the pipe line. Hydrate Formation usually happens at Dew Point Control Unit (DPCU) where the temperature is lowered to separate natural gas with heavy fraction by using Joule – Thomson effect. This paper aims to predict the Hydrate Formation Temperature at certain pressure by using some of HFT calculation methods. Kartz, Towler, Bahadori, and New Correlation are used to predict the Hydrate Formation Temperature with the pressure range of 700 – 2200 kPa. The obtained temperatures forming the gas at pressure of 700 kPa using Kartz, Towler, New Correlation, and Bahadori Calculation respectively are 274.26 K, 274.92 K, 275.02 K, and 275.2 K with Dew T at pressure of 700 kPa is 279.06 K, that means the Dew Point temperature is higher than the HFT, while at pressure 2200 kPa the temperature of Hydrate Formation respectively are 283.15 K, 283.46 K, 283.54 K, and 283.7 K with Dew T at pressure of 2200 kPa is 299.75 K, that means the Dew Point temperature is higher than the HFT.

Cassava is an abundant natural resource in Indonesia and mostly used as food. Starch, as the main component of cassava, can be converted to many of its derivative product such as glucose, fructose, and other reducing sugar. Conventionally, reducing sugar is produced from starch by acid and enzyme hydrolysis. A hydrothermal process is sophisticated biomass processing method which makes it possible to hydrolyze the starch by water only. However, the reducing sugar productivity of the hydrothermal process still not as high as the conventional process. By ultrasound pre-treatment, a hydrothermal process can be intensified, so that increase its productivity. This study set out to find the effect ultrasound pre-treatment to intensify production of reducing sugar from the hydrothermal process of cassava starch. The experiment was conducted by treating cassava starch suspension using ultrasonic irradiation with various operation time (0-120 minutes) and under a temperature of 40°C. For combination process, the starch suspension is processed under 15 minutes ultrasonic irradiation at 40°C, then continued to the hydrothermal process at 100°C and 100 bar using carbon dioxide as the pressurizing gas. The research found that the combination process can produce 0.693 mg/mL of reducing sugar

The experimental liquid–liquid equilibrium data of the system β–caryophyllene(1) + 1-propanol(2) + water(3) at temperatures 303.15, 313.15, and 323.15 K are presented. The mixtures of β–caryophyllene + 1-propanol + water were stirred for 4 hours and settled for at least 20 hours at constant temperature. The samples taken from both phases were analyzed by a gas chromatography (GC). The experimental equilibrium data were correlated by NRTL and UNIQUAC models. The compatibility of the models is based on the value of root mean square deviation (RMSD). The liquid-liquid phase diagram of the system shows type I phase behavior, where two binary subsystems are miscible and only one binary subsystem is partially miscible. The temperature effect of this system on immiscible zone is very small. Based on the experiment and the calculation results, the ternary equilibrium data have been successfully represented using both the NRTL and the UNIQUAC models.

In this study, Mangrove (Rhizophora mucronata) fruit waste which was generated from water-based extraction of natural dyes from this fruit was used as raw material in activated carbon preparation. Carbonization of chopped Mangrove fruit waste was conducted in a batch pyrolyzer for slow pyrolysis at temperature range of 300°C to 335°C and atmospheric pressure. The produced carbon was then soaked with potassium hydroxide (KOH) solution for 24 hours before activation process in an electrical furnace at 400°C for an hour. Effect of KOH concentration on physical characteristics of activated carbon was investigated in terms of moisture content, ash content, surface area, pore diameter, iodine number, and surface morphology. It was observed that the surface area and pore diameter increased with increasing the KOH concentration. Soaking the carbon in 2.5 M KOH provided the highest surface area and pore diameter of activated carbon, which were 1,920.6 m²/g and 5.52 µm, respectively. Also, the iodine number of 1,540.13 mg/g was obtained in correspond to the adsorption capacity.

Adsorption is one of the potential ways to removal of methylene blue in aqueous solution. The adsorbent used in the adsorption process is the activated carbon of betel nuts that produced from regeneration. The purpose of this study was to determine the effect of regeneration method to capacity and isotherm adsorption. The research occurs in a batch with three various regeneration conditions that is chemical, physical, and chemical-physical. In chemical, activated carbon is regenerated with HCl with various concentrations of 5 N, 6 N, and 7N. In physical, activated carbon is regenerated by heating it at temperatures of 160°C, 175°C, and 190°C. In chemical-physical regeneration, the condition is combination of the two. The concentration of methylene blue was analyzed using ultraviolet-visible spectrophotometer (UV-visible). The result showed the best regeneration conditions occur in chemical-physical regeneration with HCl concentration of 7 N, temperature of 190°C, and contact time of 25 minutes with an adsorption capacity on the surface is 3.57 mg/g and efficiency of 98.98%. Adsorption isotherm of removal methylene blue onto regenerated of betel nuts activated carbon follows the Langmuir model with regression value 1 (R² = 1).

Chromium (Cr) and manganese (Mn) are heavy metals which have high oxidation potential and cause mutagenesis and carcinogenic to living organisms. Microbial Fuel Cell (MFC) appears as one of the applications in the processing of Cr and Mn metals. MFC is bioreactor which converts chemical energy of organic compounds into electrical energy through the catalytic reaction of microorganisms in anaerobic conditions. The aim of this research are to find out the role of Shewanella oneidensis MR-1 bacteria on manufacture electrical energy by utilizing organic wastes, and to find out the concentration of Shewanella oneidensis MR-1 on the most influential anode side for the reduction of metallic Cr, Mn, and its mixed metal on the cathode side by using a MFC. The research method used molasses with bacteria concentration of 10%; 12.5%; 15% (v/v) on the anode side, while on the cathode side was used Cr(VI), Mn(VII) solutions, and mixtures of Cr and Mn solutions with the ratio of 1:0; 0:1; 1:1 (w/w). 15% bacteria concentration on mixture of metal solution resulted the highest electricity production, which was 46.33 (mW/m²), and the best reduction of Cr⁶⁺ to Cr³⁺ 82.15%, while for the reduction of Mn⁷⁺ to Mn² was 61.17%.

To increase sidewalks in Indonesia there are several things that must be considered, such as aggregate quality, implementation methods and asphalt quality. The amount of waste plastic waste in Indonesia at this time and in the years to come, can be reprocessed, one of them is by using it as an additive in the technique of making asphalt concrete. It is expected that a complex problem related to the amount of plastic waste piles can be turned into an opportunity to build the acceleration and quality of concrete asphalt roads in Indonesia. The method used for this research is the wet process, which is the direct method of mixing plastic material into asphalt which is heated at temperature according to Tait's parameters, then added aggregate. The optimum asphalt used in this study was 5.7%. The variables used are 5%, 7%, and 9% of the plastic for substitution at the optimum level of asphalt used. Plastic variable added 100% high density polyethylene (HDPE) plastic, 100% polypropylene (PP), HDPE: PP and mixture (50:50), then Marshall Test. The best results were obtained by adding 9% plastic mixture variable with HDPE: PP ratio (1:1) resulting in an increase of 179% MQ then normal asphalt.

The performance of calcium compound in leaching mechanisms has been known through the addition of high calcium compound material. The addition of those materials was proven that the additives could simultaneously inhibit the leaching of several trace elements such as arsenic, selenium, boron and fluorine. This study will be focused on the role of calcium compound onto fluorine leaching concentration. Fluorine is one of trace elements consisting in most of coals that has effect in environmental pollution. The application of mixture additives in leaching process was given a promising effect in inhibit the leaching of fluorine until less the environmental limit (0.8 mg/L). This researched will present the information about calcium compound related with fluorine leaching mechanism after the addition of mixture additives (Ca(OH)2, PS ash 8, and BF cement) into 14 different coal fly ashes (FA A, B, C, B, E, F, G, H, I, J, K, L, M, and N). This information will be important in the coal fly ash utilization to minimize the effect of fluorine leaching concentration into the environment.

Paper sludge (PS) ash is a waste material collected from the paper industry, which containing calcium compound. In the previous research, several paper sludge ashes have been tried into coal fly ashes in order to suppress the leaching of trace elements such as As, Se, and B into the environment. The result showed that paper sludge ashes has potential effect in inhibit the leaching of these trace elements because of the calcium contains in the paper sludge ashes. Therefore, this research provide information about the amount of calcium in paper sludge ash as suppressing material. Nine kinds of paper sludge ashes tested into coal fly ash C (FA C) in order to know the ability of each paper sludge ash in suppressing the leaching of trace elements. Inductively coupled plasma (ICP-AES) used to determine the leaching concentration of As, Se, and B. Then, the kind of calcium in paper sludge ashes were analysed by X-ray diffraction (XRD). Thermal gravimetric analysis (TG) used to determinate Ca(OH)₂ and CaCO₃. The percentage of CaO in paper sludge ashes analysed by combination ethylene glycol, ICP-AES and TG. This research found the kind of PS which most influential for controlling leached out of trace elements.

Nanoparticles represent a specific type of organic or inorganic matter with at least one dimension less than 100 nm and possess unique physical and chemical properties. The presence of nanoparticles in drinking water may pose a direct human health threat or an indirect risk through ingestion. Thus, the removal of nanoparticles from drinking water is needed. This research was carried out to study the distribution of nanoparticles in water treated with a combined filtration-inductively coupled plasma system by continuous processing. The flow rate was set at 100 and 200 mL/minute. The results showed that after 180 minutes of treatment, the amount and volume of nanoparticles in the treated water produced were different from those contained in raw water. The nanoparticles were within the diameter ranges from 2.70 to 6.50 nm and 0.62 to 712 nm for flow rate at 100 and 150 mL/minute, respectively. The particles within these diameter ranges belong to the group of proteins, small molecules and atoms. The measured zeta potential of the treated water had also decreased, indicating that the stability of the nanoparticles was reduced and removal by the combined filtration-inductively coupled plasma system had occurred. Further research is required to find the optimum flow rate and determine the exact components of the groups of nanoparticles.

This work was conducted to study the adsorption behaviour of bio adsorbent of alkali modified jackfruit wood sawdust and to investigate its possibility as adsorbent to remove heavy metals from wastewaters. The effects of sodium hydroxide concentration on the bio adsorbent adsorption capacity were investigated. The bio adsorbent prepared through chemical modification with solution of 2% sodium hydroxide showed the highest adsorption capacity with the value 3.32 mg/g at initial Pb(II) concentration 18.69 mg/L and percent removal Pb(II) ions was 88.86%. This study proved that adsorption process of Pb(II) ions onto bio adsorbent was perfectly illustrated by second order kinetic equation and adsorption isotherm of bio adsorbent was well represent by Freundlich isotherm model.

One of the environmental characteristics of chemical industries is producing wastewater effluent that containing heavy metals, which are hazardous to the aquatic life and the human health. The purpose of this research is to evaluate the use of zeolite A as a sorbent for the heavy metal ions removal from wastewater. Zeolite A was synthesized from coal fly ash by fusion-hydrothermal method by the authors contains cation exchange capacity of 5.05 meq/g. This study used a series of artificial wastewater containing one and mixed heavy metal ions (Cu (II) and Zn (II)). The result showed that wastewater containing one heavy metal ion was almost fully adsorbed, for instance percentage sorption of Cu (II) and Zn (II) ions were 95.61 % and 92.15 %. On the other hand, for binary system, the percentage sorption slightly decreased becoming 91.51 % with the increase the amount of Zn (II) ion in solution. Based on kinetic data, sorption of Cu (II) and Zn (II) ions is controlled by pseudo-second order. In addition, adsorption isotherm follows Langmuir model. From this study, it is confirmed that zeolite A has a good possibility to be used as sorbent of heavy metal ions removal in wastewater.

Preparation and evaluation of activated carbon from the palm kernel shell (PKS), an abundant agricultural residue, by physical and chemical activation were carried out. The activation treatment of adsorbent with and without chemicals modification was evaluated. The physical activation using nitrogen gas and chemical treatment using 10 wt.% of sodium hydroxide and nitrogen gas as the activating agent. This study evaluated the activation temperature and nitrogen gas rate. The results showed that activated carbon treated with NaOH followed by heating under nitrogen gas had the highest iodine number of 1062.8 mg/g and methylene-blue number of 247.2 mg/g (heating at 750 °C, nitrogen gas flow rate of 100 mL/min). The equilibrium data obtained at various initial concentration reasonably fit well with the Langmuir adsorption isotherm. The adsorption of Cu(II) ions fit with the Langmuir isotherm pattern with adsorption capacity (Xm) of 8.9445 mg/g and kf value of 0.16802 L/mg for activated carbon without NaOH treatment. The adsorption capacity of activated carbon with NaOH and heating at 750 °C under nitrogen gas was obtained 12.0773 mg/g and kf value of 0.15076 L/mg. Those results suggested the prepared adsorbent could be considered as a promising candidate for Cu(II) ions for wastewater treatment.

Biogas is one of the potential sources of energy to cope with the limitations of fossil energy. On the other hand, liquid waste of tofu industry, water hyacinth, and cow manure are poorly managed that can potentially pollute the environment. The type of those wastes was potential source for biogas production through anaerobic digestion due to high content of protein and nutrient. This study aims to determine the effect of addition of liquid waste of tofu industry (WT) and water hyacinth (WH) to cow manure (CM) on the biogas production. The amount of water hyacinth and cow manure were varied at 0-4 kg, while the liquid waste of tofu industry was fixed to 8 kg. The anaerobic digestion was conducted in biodigester container equipped with thermometer and biogas shelter. The biogas production was then analyzed using Gas chromatography–mass spectrometry (GC-MS). The optimum biogas was achieved at raw material ratio of 4:2:2 (WT:WH:CM) for 21 d. At this condition, 60 ppm of CH₄ and 10,744 ppm of CO₂ were obtained. Thus, the utilization of liquid waste of tofu industry, water hyacinth and cow manure as raw material of biogas production can minimize the environment problem and supply energy.

Electrocoagulation is electrochemical water and wastewater treatment technology that is the easiest technology using an electrochemical cell supplied by DC power to the electrodes. The application of the electrocoagulation process was purposed to treat oily bilge water. The results indicated that the oil removal efficiency was achieved approximately 99.62% at an initial oil concentration of 60 g/l in batch processes. The current density of 62.5 mA/cm² applied the process produced oil removal efficiency of 99.95%.In a continuous mode with the initial water only present in the reactor, the oil removal efficiency was achieved approximately 100% with a hydraulic residence time (HRT-1) of 6 h for 60 min of operations. However, the initial oil/water emulsion at a concentration of 63.89 g/l present in the reactor, the oil removal efficiency was approximately 73.33% with HRT-1 of 6 h for 90 h of operations.

Excessive use of inorganic fertilizers can aggravate soil conditions. The development of organic fertilizer is urgently required. The fertilizers are used to supply organic materials to improve the physical, chemical, and biological properties of the soil. Meanwhile, many potential waste from coconut porridge household industry in Ponorogo Distric of Indonesia have not been utilized properly yet. The aim of this research are to improve the quality of liquid organic fertilizers by using various microorganisms with addition of liquid materials such as coconut water waste, water of immersed coconut fiber and molasses; and to observe the growth of chilies, tomatoes, and eggplants which were treated using the organic fertilizer. Liquid organic fertilizer was made by mixing the liquid materials using various microorganisms, such as Aspergillus niger, Pseudomonas putida, Bacillus muchilaginosis, Azotobacter chrococum and bioactivator EM4. The liquid fertilizer was carried out with a mixed batch reactor equipped of aeration 4 L/min for 10 days. From this research was conducted observations on the development of height and fruit on the assesed plants using the produced fertilizer.