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The available worldwide energy sources are presented. The applications of energy over the next period are considered in this study. The applications and the importance of alternative energy sources is reviewed. The emphasis is put on the necessity of developing new technologies and rationalization of energy use. The data regarding heat and electric energy, along with water applications in cellulose and paper industry are also given.

Biomass torrefaction is a simple and appropriate thermo-chemical treatment/conversion process for upgrading agricultural residues to a high-quality fuel, which could be used as an alternative energy resource to replace fossil fuels. In this paper, reaction kinetics for torrefaction of pelletized agro-residues biomass under dry flue gas conditions were investigated. The two-step mechanism model was used to describe the biomass torrefaction decomposition, and with the experimental data, the kinetic parameters of this model were analyzed. The torrefaction reactions were found to occur in a narrow period of reaction time, and the kinetic parameters were affected by dry flue gas conditions. The model predictions can imitate the thermo-chemical degradation well, and the predicted torrefied solid was shown to contain not only chars but also some intermediate and unreacted fractions. This work provides further insights for understanding torrefaction kinetics of agricultural biomass pellets which are important in designing and operating industrial biomass conversion equipment and apparatus.

This study examined the use of the ZnO/TiO2/H2O2 process in suspension mode under visible light (VL) (1000 W/m2) to reduce TOC from the real petroleum wastewater in Sohar Refinery Company (SRC). The parameters such as treatment period (TP), ZnO concentration, pH, H2O2 concentration, and TiO2 concentration were tested for recognizing the optimal circumstances, which were (175 min), (0.59 g / l), (5.5), (0.85 g / l), and (0.7 g / l), respectively. The efficiency of treatment improved from 15 percent to 36.5 percent for total organic carbon (TOC) at pH 5.5 relative to the TiO2 process. The treatment period (TP) decreased up to 200%. The use of alternative energy sources and acceptable cost make this technique a special treatment approach for the real petroleum wastewater. Furthermore, the results in the optimum operational condition met with the effluent standards for wastewater.

Biodiesel has gained wide acceptance as an alternative energy source despite its high cost of production. This study investigated the possibility of lowering the cost of biodiesel production by exploring the use of readily available biological materials such as egg-shell (ES), pineapple peel (PP) and cow bone (CB) as catalysts. The effect of the refining process on the chemical properties of used vegetable oil was also examined. The refined oil was transesterified and biodiesel yield of 76%, 78% and 88.3% were obtained for ES, PP and CB catalyzed biodiesel samples, respectively. The three biodiesel samples were found to be of close physicochemical properties and good biodiesel potentials going by the ASTM and EN standards. It was also observed that the chemical properties such as the acid, free fatty acid and iodine value of the used vegetable oils greatly improved after the degumming process.

The Ship uses the MTU 16V956 TB 92 propulsion engine with a piston-type Mexican Hat combustion chamber. In general, the crown is used on machines with large torque. Besides that, the crown shape in the combustion chamber is also very influential on the formation of a mixture of fuel and air before the combustion process occurs. So it is necessary to know about the spray pattern of biodiesel fuel of enviromental things (castor, coconut, used cooking oil/MGB) in the Mexican Hat combustion chamber. In this study, using the Mexican Hat-shaped piston crown simulation method, the first step was to test the spray pattern of the three types of biodiesel (castor, coconut, used cooking oil) by simulating a tube with an injection pressure of 350 bar gauge pressure inside a barometric pressure tube. While the completion in the Mexican Hat combustion chamber with a chamber pressure of 35 bar gauge and injection pressure of 350 bar gauge was completed with the CFD program, Fluent 6.2, and the results of the three biodiesels were compared. From the CFD simulation results obtained spray patterns of the three types of biodiesel (castor, coconut, used cooking oil). At the same injection pressure and chamber pressure, used cooking biodiesel has the longest penetration length, followed by castor biodiesel and coconut biodiesel. The spray angle of coconut biodiesel is the largest, followed by castor biodiesel and used cooking oil biodiesel. SMD coconut biodiesel is the smallest, followed by castor biodiesel and used cooking oil biodiesel.

The transition to a circular economy needs the development of technologies to make efficient use of alternative energy and materials sources in order to reduce our dependency on fossil resources. Alternative resources such as renewable and residual materials can be converted to valuable products using mixed cultures of bacteria. Through a process called microbial chain elongation medium- chain carboxylates (MCC) are produced, platform chemicals with diverse applications in the energy, agri-food and chemical industries. This thesis studies the production of MCC through lactate as an important intermediate of organic waste fermentation with mixed cultures. Alternative MCC separation schemes are also explored. Food waste and lactate were successfully used as substrates to produce carboxylates with varied chemical structures and up to 8 carbon units long. Lactate-based chain elongation is envisioned as a relevant biotechnology in the upcycling of organic materials to valuable biobased products such as novel feed additives or aviation fuels.

Nowadays, Indonesia is faced with an increase in human growth, and followed by increasing electricity demand. One of the environmental friendly alternative energy that can solve this problem is microbial fuel cell, which utilizes organic matter as a substrate of bacteria in carrying out its metabolic activities to produce electricity. In this study, investigated the electrical energy produced by Microalgae Microbial Fuel Cell (MMFC) using Chlorella vulgaris and “Batik” wastewater. This study aims to assess the performance of the MMFC system based on the influence of yeast (8 g L−1 and 4 g L−1), “Batik wastewater” concentration (50 % and 100 %), and graphite electrodes (1:1 and 2:2). The MMFC system was carried out by filling anode chamber with “Batik” wastewater and the cathode with C. vulgaris. MMFC simulation was operated for 7 d. Concentration of 100 % “Batik” wastewater and 2:2 number of electrodes gave the best result in MMFC with voltage 0.115 Volt, algae absorbance 0.666. The COD decreased from 824 mg L−1 to 752 mg L−1 after the MMFC. The addition of 8 g L−1 yeast gave the optimum of bioelectricity production reached 0.322 Volt and the microalgae grew until the absorbance reached 1.031.

Anaerobic co-digestion provides a promising solution for converting inexpensive carbon from wastes to biogenic methane. We used microalgae (Nannochloropsis oculata) with cow manure and sludge to produce a better quantity and quality of biogas. To further improve the gas production, microalgae were pretreated with ultrasonication, hot water, and a combination of both. Interestingly, the results showed that the pretreatment of microalgae decreased biogas production by 5 to 30%. The no-pretreatment runs produced a maximum of 118 L of biogas. The relative content of biogenic methane was higher in the pretreated feedstock (48 to 52%) in comparison with the no-pretreatment runs (44%). The conversion of volatile suspended solids present in the feedstock to total biogenic methane production was highest in hot-water-treated runs. The carbon content in the gas produced by the pretreated microalgae peaked (38%) in the middle of the experiment (i.e., at 45 days), whereas for no-pretreatment runs, the content remained constant from the start to the middle and declined (from 36 to 34%) at the end of the experiment (i.e., at 90 days). We also report the chemical structure of microalgae with and without pretreatments.

Microalgae are photoautotrophic microorganisms capable of producing compounds with potential bioenergetic applications as an alternative energy source due to the imminent exhaustion of fossil fuels, their impact on the environment, and the constant population increase. The mass cultivation of these microorganisms requires high concentrations of nutrients, which is not profitable if analytical grade culture media are used. A viable alternative is the use of agro-industrial wastewater, due to the metabolic flexibility of these microorganisms and their ability to take advantage of the nutrients present in these substrates. For the reasons mentioned above, the effect of the cultivation in wastewater from cheese processing on the growth parameters and biomass composition of Scenedesmus sp. was evaluated, and its nutrient removal capacity determined. A high lipid concentration was obtained in the cultures with the dairy effluent (507.81 &plusmn, 19.09 mg g&minus, 1) compared to the standard culture medium, while the growth parameters remained similar to the control medium. Scenedesmus sp. achieved high percentages of nutrient assimilation of the wastewater used (88.41% and 97.07% for nitrogen and phosphorus, respectively). With the results obtained, the feasibility of cultivating microalgae in agro-industrial wastewater as an alternative culture medium that induces the accumulation of compounds with potential bioenergetic applications was verified.

The significance of the paper is confirmed by the need to replace petroleum motor fuels with fuels produced from alternative energy sources. Biofuels derived from various vegetable resources are considered as promising alternative fuels for diesel engines. These fuels offer significant advantages with respect to the renewability of their raw materials and good emission performances when burned in ICEs. The main problem of using vegetable oils as biofuels for diesel engines is their high viscosity. This problem can be resolved by using mixed biofuels with the addition of gasoline. The analysis of physico-chemical properties of petroleum diesel fuel (DF) and mixed biofuels containing petroleum DF, rapeseed oil (RO) and AI-80 automotive gasoline was conducted. Experimental studies of the D-245.12S diesel fuelled with these mixed fuels were carried out. The mixed fuels were prepared from 80% DF + 20% RO, from 75% DF + 20% RO + 5% AI-80, and from 70% DF + 20% RO + 10% AI-80. It was shown that the addition of gasoline to mixed biofuels could improve two main toxicity indicators of exhaust gases exhaust gases smoke and emissions of nitrogen oxides. The best emission performance was achieved for the mixture of 70% DF, 20% RO and 10% AI-80. When the diesel engine was switched from the mixture of 80% DF and 20% RO to the mixture of 70% DF, 20% RO and 10% AI-80, the exhaust gases smoke at maximum torque mode decreased from 17.5 to 14.5% on the Hartridge scale, i.e. by 17.1%. The specific emissions of nitrogen oxides decreased from 6.559 to 6.154 g/(kW·h), i.e. by 6.2%.

Son yıllarda alternatif enerji kaynağına duyulan ihtiyaç, fosil yakıt girdisinin azalması ve ayrıca fosil yakıtların çevreyi bozarak küresel ısınmaya neden olması ve insan sorunu olan atık yönetimi nedeniyle acil bir endişe kaynağı olmuştur. Alternatif enerji örneklerinden biri olan biyogaz, fosil yakıtlar ve biyolojik olarak parçalanabilir atık yönetimi ile ilgili bu sorunları ortadan kaldırmak için kullanılabilir. Çok eski zamanlardan beri, biyolojik olarak parçalanabilen atıklar, biyogaz gibi çevre dostu olan yakıt ürünlerinin keşfinin konusu olmuştur. Bu atıkların başında çoğunlukla hayvan gübreleri ve insanların ürettiği kentsel katı atıklar gelmektedir. Bu çalışmada sığır gübresi (SG) ve kentsel katı atıkların (KKA) farklı oranlardaki karışımlarının anaerobik sindirimi incelenmiştir. Ön işlemsiz anaerobik sindirim çalışmaları mezofilik koşullarda yürütülmüştür. SG: KKA karışım oranının 2:1 olduğu reaktörde diğer karışım oranlarına kıyasla en yüksek biyogaz üretimi (222.5 ± 15.7 mL/g katı madde) gerçekleşmiştir. Bu karışım oranına biyogaz verimini artırmak amacıyla NaOH ön işlemler 0,1, 0,5, 1 ve 2 N konsantrasyonlarda uygulanmıştır. 1N NaOH ön işlem sonucunda biyogaz üretimi ön işlemsiz reaktöre kıyasla % 47,46 oranında artmıştır. NaOH ön işlem konsantrasyonun 2N olması muhtemel hızlı çözünürlük nedeniyle 1N NaOH ön işlemli reaktöre kıyasla biyogaz üretimi azalmıştır. Çalışma sonucunda SG ve KKA’ nın anaerobik fermantasyonda iyi bir karışım olabileceği ve NaOH ön işlemler ile biyogaz veriminin başarıyla artırılabileceği anlaşılmıştır., In recent years, the need for alternative energy sources has become an urgent concern due to the decline in fossil fuel input and also the disruption of fossil fuels to cause global warming and waste management, which is a human problem. Biogas, an example of alternative energy, can be used to eliminate these problems related to fossil fuels and biodegradable waste management. Since ancient times, biodegradable waste has been the subject of the discovery of environmentally friendly fuel products such as biogas. Animal manure and urban solid wastes produced by humans are the leading ones among these wastes. In this study, anaerobic digestion of different ratios of cattle manure (CM) and municipal solid waste (MSW) was investigated. Anaerobic digestion studies untreated were carried out in mesophilic conditions. In the reactor where CM: MSW mixture ratio is 2: 1, the highest biogas production (222.5 ± 15.7 mL/g solid matter) was realized compared to other mixture ratios. NaOH pretreatments were applied to this mixing ratio with concentrations of 0.1, 0.5, 1 and 2 N in order to increase biogas yield. After NaOH 1N pretreatment, biogas production increased by 47.46% compared to the untreated reactor. As a result of the application of NaOH pretreatment with 2N value, due to possible rapid resolution, biogas production was decreased compared to 1N NaOH pretreated reactor. As a result of the study, it has been understood that CM and MSW can be a good mixture in anaerobic digestion and biogas production can be increased successfully with NaOH pretreatments.

World consumption of energy is estimated to increase by 49 % from 2007 to 2035, which means averagely 1.4 % yr–1. Many countries in the world began to develop alternative energy that can overcome the resources. Microalgae is one of the renewable energy that has excellent potential for making biodiesel because it contains much oil. Microalgae is the fastest organism in the photosynthesis, so it makes microalgae have high productivity. In this article, researchers use Chlorella sp. because these microalgae contain oil up to 28 % to 32 % from its dry weight, and on the other hand, this type of microalgae is easy to grow and easy to harvest. From the experimental results, the density characteristics of biodiesel Chlorella sp. have values from 0.84 g mL–1 to 0.848 g mL–1, and it is lower than the density of petroleum (diesel), and viscosity value from 2.5 cSt to 3.91 cSt, cetane numbers 51.17 to 53.72 also heating value 44.04 mJ kg–1 and Flashpoint 131 °C. The characteristic result shows that the Chlorella sp. microalgae biodiesel is still in SNI standard (Indonesia National Standard) so that the Chlorella sp. can be used as a substitute diesel fuel.

Solar energy has become a viable alternative energy because it is a clean type of energy that converts solar radiation into heat energy for various applications such as heating water, power generation, cooking, and food drying. The solar dryer, integrated with the heat energy storage system, uses nitrate salt as a heat storage medium which was designed and tested by drying 1000 grams of red pepper at 19.6 to 62.4°C. The average ambient temperature ranged from 19.3 to 37.4°C, and the maximum temperature of the heat storage media ranged from 87.8 to 125°C. The solar drying process was compared to open sun drying system loaded with 1000 grams of red pepper. The findings showed that the solar dryer maintained color and flavor and lowered the original moisture content from 86% to 10% for 24 hours compared to 36 hours of drying in open air. In this study, nitrate salt is shown to be the perfect heat storage medium for drying food products; it preserved heat for about 4 hours when there is no active sunlight.

Samples of bleached kraft pine cellulosic pulp, either treated with an enzyme preparation (a Thermomyces lanuginosus xylanase, an Aspergillus sp. cellulase, and a multienzyme preparation NS-22086 containing both these activities) or untreated, were refined in a laboratory PFI mill. The treatment with cellulases contained in the last two preparations significantly improved the pulp’s susceptibility to refining (the target freeness value of 30°SR was achieved in a significantly shorter time), increased water retention value (WRV) and fines contents while the weighted average fiber length was significantly reduced. These changes of pulp parameters caused deterioration of paper strength properties. The treatment with the xylanase, which partially hydrolyzed xylan, small amounts of which are associated with cellulose fibers, only slightly loosened the structure of fibers. These subtle changes positively affected the susceptibility of the pulp to refining (refining energy was significantly reduced) and improved the static strength properties of paper. Thus, the treatment of kraft pulps with xylanases may lead to substantial savings of refining energy without negative effects on paper characteristics.

An effort to obtain alternative energy is still interesting subject to be studied, especially production of biogas from agriculture waste. This paper was an overview of the latest development of biogas researches from rice husk waste by Solid State Anaerobic Digestion (SSAD). The main obstacle of biogas production from rice husk waste was the lignin content which is very difficult degraded by microbes. Various pretreatments have been conducted, either physically, chemically as well as biologically. The SSAD method was an attractive option because of the low water content of rice husk waste. The biogas yield by SSAD method gave more attractive result compared to Liquid Anaerobic Digestion (LAD) method. Various studies were still conducted in batch mode laboratory scale and also has not found optimum operating conditions. Research on a larger scale such as bench and pilot scale with continuous systems will be an increase trend in the future research.

The importance of using renewable green energies is being debated globally since harmful effects due to continuous combustion of fossil fuels have been realized. Biodiesel is one of the substitutions for fossil fuels. Production of biodiesel from microalgae is categorized under third generation biofuels which are considered to be viable alternative energy resources. This study was focused on investigating growth kinetics of freshwater microalgae, cultivated in synthetic wastewater under laboratory conditions in order to identify the species with the highest potential for the production of biodiesel. Three freshwater microalgal species were isolated from water samples collected from two reservoirs, Victoria reservoir in Central Province (7˚ 14ˊ N, 80˚ 47ˊ E) and Ulhitiya reservoir in Uva Province (7˚ 27ˊ N, 81˚ 3ˊ E) of Sri Lanka. Light intensity, aeration and temperature were varied during the cultivation of algal species in a synthetic wastewater medium. According to the results, Chlorella sp. showed the highest growth rate compared to Monoraphidium sp. and Scenedesmus sp. under all three environmental conditions provided.

One of the environmental solutions employed in order to achieve circular economy goals is methane fermentation—a technology that is beneficial both for the stabilization and reduction of organic waste and for alternative energy generation. The article presents the results of research aimed at determining the biogas and methane potential of bio-waste which has been pre-thermally disintegrated, and determining the influence of variable process parameters of disintegration on the kinetics of fermentation. A first-order kinetic model was used to describe the fermentation as well as two mathematical models: logistic and Gompertz. It has been found that process parameters such as time (0.5, 1 and 2 h) and temperature (between 55 to 175 °C) have a significant effect on the solubilization efficiency of the bio-waste. The methane fermentation of thermally disintegrated bio-waste showed that the highest biogas potential is characterized by samples treated, respectively, for 0.5 h at 155 °C and for 2 h at 175 °C. The best match for the experimental data of biogas production from disintegrated substrates was demonstrated for the Gompertz model.

In this research, bio-oil is produced from pine wood bark waste biomass through pyrolysis using Cr/ clay catalyst. This research aims to produce bio-oil from bark of pine with Cr/ clay catalyst as an alternative fuel. The effect of the ratio of catalyst Cr/ clay weight to biomass and influence of Chromium (Cr) impregnation on clay as catalyst were investigated. Then, the characterisation of physical and chemical characteristics of crude bio-oil produced were measured. For each of the pyrolysis runs, 50 g of pine bark having -100+200 mesh, the Cr/ clay catalysts having weight variations to biomass of 3%, 5%, and 7%, respectively, and then variation of Chromium (Cr) impregnation on clay of 0%, 1%, 2%, and 3%, respectively, were used. For any experimental run, 500 ml of silinap was added to the pyrolysis reactor as thermal homogenized aid. Pyrolysis process was carried out for 120 minutes at 320oC and having stirring speed 300 rpm. As a result, the greatest percentage of bio-oil yield of 65.77% was given of the run having Cr/ clay catalysts 7% and 3% of impregnated Chrome content. Characterisation measurement of bio-oil of physical properties was obtained as follows: density 0.812 g/ml, viscosity 0.902 cSt, acidity 7.626 mg.NaOH/gram, and flash point 31oC, respectively. In addition, the chemical characteristics of the bio-oil were obtained using Gas Chromatography-Mass Spectroscopy (GCMS): analysis found several chemical components as follows, such 9,12-Octadecadienoyl chloride, Cyclohexane, 1-methyl-2-penthyl, Octadecanoic acid, 2-Pentene, 24.4-trimethyl, and Cyclohexane, 3- (3,3-dimethylbutyl).

Biomass briquettes have been made as an alternative energy source from cow dung waste. Molasses and starch were used as binder material with a carbonization temperature of 400 °C for 2 hours. The work aims to produce biomass briquettes with the best heating value based on analysis of composition effect and type of binder on the briquette with calorific value. The heat test results showed that briquettes with 10% sugar cane binding content produced the highest calorific value of 3907.5 calories/gram. Sugar cane drops become the better binder than starch in biomass briquettes production.

Energy used for domestic application are expensive and beyond the reach of the rural poor. An alternative energy source is therefore a welcome development. This research work was aimed at determining the calorific values of Corn cob, Rice husk and Sawdust agricultural wastes materials. Standard method of calorific value determination involving the use of Bomb Calorimeter was adopted. From the investigation, the calorific value of Rice husk, Sawdust and Corn cob are 2938.86 Kcal/kg, 3155.30 Kcal/kg and 3227.78 KcaI/kg respectively. The agricultural materials were further subjected to briquetting and the calorific values determined to be 2092.48Kcal/kg, 2379.76Kcal/kg and 2923.36Kcal.kg for Rice husk, Sawdust and Corn cob briquettes respectively. The agricultural wastes met the minimum standard calorific value which range from 1500cal/kg – 1670Kcal/kg. The selected wastes have calorific values in the following decreasing order: Corn cob> Sawdust> Rice husk; and the corresponding briquettes is in the order: Corn cob>Sawdust >Rice husk. The selected wastes however, have lesser calorific values when briquetted. If agricultural wastes are used in place of firewood, this development will minimize deforestation which leads to desert encroachment and soil degradation.Keywords: Agricultural waste, calorifuc value, corn cob, Rice husk and saw dust

In 2015, the Worldatlas recorded 50 countries whose source of income is fossil fuel and its derivatives. Surprisingly, these countries solely depend on this source of energy up to 100% (Omar, Qatar, Kuwait and Saudi Arabia) because of technology improvement. It's so sadden that apart from its adverse effect on the economics of the countries, fossil fuels harmful effects on the universe cannot be overlooked. Meanwhile, the use of renewable energy as a replacement for fossil fuel and its derivatives are faced by the high oil price, high cost of investment for alternative energy, and unfathomed electricity prices. This research work evaluates desirability of making use of alternative source of energy sources by making use of biomass oil over the use of fossil fuel and its derivatives for electricity generation. Lucky nut is an agricultural non edible seed that was employed as raw material for biofuel production. The non-edible oil was extracted from the seeds and the oil was further converted to Lucky nut biofuel via a heterogeneous based catalyst produced from calcinated pearl spar. For modelling and optimization, design expert coupled with genetic algorithms were used to generate experimental designs so as to correlate the variable factors considered for production. The extraction of Lucky nut seed revealed the optimum production yield of 50.80% (v/v) and the oil is highly unsaturated. Energy Dispersive X-ray Fluorescence Spectrophotometer analyses and scanning electron microscope (SEM) of the calcined catalyst obtained from pearl spar showed the major component found in the pearl spar was K with relative abundance of 58.48%, which favoured the yield of Lucky nut biodiesel (91.00% (v/v)). Based on predicted values, the optimum validated Lucky nut biodiesel by RSMED and ANNED were 89.68% (v/v) and 92.87% (v/v), respectively. Produced properties of biofuel conformed to the biofuel standard. The study concluded that Lucky nut seed is a good source of oil, and its transformation to alternative fuel via a using calcined catalyst proved its fitness as a replacement for fossil fuel.

Indonesia as the world’s third-largest paddy producer generates abundant agricultural wastes. Approximately, 20% of those wastes obtained in the rice milling process are rice husks that have not been fully utilized. Rice husks contain cellulose, hemicellulose, and lignin. Therefore, it can be used as an alternative source of energy. In addition, an increase in the cattle population has increased the waste produced. Disposal of livestock manure, that has not been handled properly, has caused environmental pollution. The abundance of cow dung is an energy potential which is very beneficial for the community. Therefore, rice husk, cow dung, and bio-activator EM-4 were used as the main material in this study. The objectives of this study were to analyze the volume of biogas produced from (1) each composition of rice husk and cow dung, (2) addition of bio-activator EM-4, and (3) the amount of stirring in the digester. The ratio of rice husk and cow dung waste is 70%: 30% with a solid and water ratio of 10%: 90% and 20%:80%. The addition of EM-4 and stirring frequency is made with various composition aimed to accelerate the rate of increase in biogas, which can be used as alternative energy in society.

The crucial problem facing the world today is energy resources. Waste production of palm oil fruit bunch potentially produce as renewable energy resource. Palm oil fruit bunch contains 44% cellulose, 18% lignin and 34% hemicellulose. Organic carbon source is contained in biomass potentially produce biogas. Biogas is one of alternative energy, which is environmentally friendly and has been widely developed. This research is aimed to examine the effect of pretreatment in raw material of waste palm oil fruit bunch for the production of biogas, the effect of time, ratio C/N, and effect of microbial consortium. The variables are total solid (TS) used 10% and 18% with a 40 mesh physical pretreatment, chemical pretreatment with NaOH 8% gr / gr TS, and biology 5% g/vol with microbial consortium. Biogas production process was conducted over 2 months in room temperature, the test response quantitative results in the form of biogas volume every 2 days and also flame test. The result of this research shows that the highest daily production rate of biogas obtained from this study was 5,73 ml/gr TS and the highest biogas production accumulation generated at 58,28 ml/gr TS produced through a 40 mesh sieve of waste oil palm empty fruit bunch, immersion in NaOH, through solid state fermentation and C/N 30. From this research, it can be concluded that the optimum production of biogas formation occurs with the value of C/N 30, physical and biological pretreatment, and solid state method.

Nowadays, Energy comsumption in the world tend to depend on fossil fuels. Alternative energy is still less developed. Indonesia has potential to develop alternative energy, especially biomass. One of this biomass is dried leaf that can be done to be briquettes. Dried leaf briquettes can be as an alternative fuel may be a solution for energy crisis. Economically that briquetting of the dried leaf could be a very promising business. Briquetting of dry leaf can be done with the simplest of techniques. It’s necessary doing techno economic analysis of charcoal briquettes of dried leaf. This research was done by using two types of adhesives briquettes  namely tapioca flour and sago with a weight percentage of 30% by weight of dry leaf briquette. The result of this research is the best briquette adhesive is tapioca flour because it produces water content of 25%, ash content of 13.85%, carbon content 61.15% and calorific value is 7100.23 calories. If this compare with adhesive sago are the water content is 23.08%, ash content of 10.5%, carbon content 69.41% and calorific value is 6325.66 calories. When compared with the comparative quality of briquettes SNI no.1 / 6235/200, only the carbon content of which has not reached for both types of the adhesive. The results of the calculation of the cost of production, to produce briquettes with a capacity of 15,000 kg of briquettes per year is Rp 42,312,600.00 while the cost of production Rp 2820.00/kg and selling price that can be offered to consumers are Rp 4,300/Kg. In this economic calculation values obtained BEP (kg) is 15008.75 kg and BEP in rupiah at Rp 42,324,675.00. While its payback period is for 90 days.

Large amounts of coffee residues are generated from coffee processing plants in Ethiopia. These residues are toxic and possess serious environmental problems following the direct discharge into the nearby water bodies which cause serious environmental and health problems. This study was aimed to quantify wet coffee processing waste and estimate its bio-ethanol production. The study showed that the wastes are potential environmental problems and cause water pollution due to high organic component and acidic nature. The waste was hydrolyzed by dilute H2SO4 (0.2, 0.4, 0.6, 0.8 and 1 M) and distilled water. Total sugar content of the sample was determined titrimetrically and refractometry. Maximum value (90%) was obtained from hydrolysis by 0.4 M H2SO4. Ethanol production was monitored by gas chromatography. The optimum yield of ethanol (78%) was obtained from the sample hydrolyzed by 0.4 M H2SO4 for 1 h at hydrolysis temperature of 100 °C and after fermentation for 24 h and initial pH of 4.5. Based on the data, it was concluded that reuse of the main coffee industry wastes is of significant importance from environmental and economical view points. In conclusion, this study has proposed to utilize the wet coffee processing waste to produce bio-ethanol which provides the alternative energy source from waste biomass and solves the environmental waste disposal as well as human health problem.

The intensive search of new and cleaner energy catches interest in recent years due to huge consumption of fossil fuels coupled with the challenge of energy and environmental sustainability. Production of renewable and environmentally benign energy from locally available raw materials is coming in the frontline. In this work, conversion of the combined biomass (cotton gin trash, cow manure, and Microalgae [Nannochloropsis oculata]) through batch pyrolysis has been investigated. The effect of temperature to the production of energy fuels such as bio-oil, char, and biogas have been simulated considering the yield and energy content as responses. Result of the investigation generally revealed that the proportions of the different biomass did not significantly affect the product yield and energy recovery. Significant effect of temperature is evident in the simulation result of energy recovery whereby maximum conversion was achieved at 400°C for char (91 wt%), 600°C for syngas (22 wt%), and 551°C for bio-oil (48 wt%). Overall energy conversion efficiency of 75.5% was obtained at 589°C in which 15.6 MJ/kg of mixed biomass will be elevated to pyrolysis products.

The storage of renewable electrical energy within chemical bonds of biofuels and other chemicals is a route to decreasing petroleum usage. A critical challenge is the efficient transfer of electrons into a biological host that can covert this energy into high energy organic compounds. In this paper, we describe an approach whereby biomass is grown using energy obtained from a soluble mediator that is regenerated electrochemically. The net result is a separate-stage reverse microbial fuel cell (rMFC) that fixes CO2 into biomass using electrical energy. We selected ammonia as a low cost, abundant, safe, and soluble redox mediator that facilitated energy transfer to biomass. Nitrosomonas europaea, a chemolithoautotroph, was used as the biocatalyst due to its inherent capability to utilize ammonia as its sole energy source for growth. An electrochemical reactor was designed for the regeneration of ammonia from nitrite, and current efficiencies of 100% were achieved. Calculations indicated that overall bioproduction efficiency could approach 2.7±0.2% under optimal electrolysis conditions. The application of chemolithoautotrophy for industrial bioproduction has been largely unexplored, and results suggest that this and related rMFC platforms may enable biofuel and related biochemical production.

Massive utilization of petroleum and natural gas caused fossil fuel shortages. Consequently, a large amount of carbon dioxide and other pollutants are produced and induced environmental impact. Hydrogen is considered a clean and alternative energy source. It contains relatively high amount of energy compared with other fuels and by-product is water. In this study, the combination of ultrasonic mechanical and biological effects is utilized to increase biohydrogen production from dark fermentation bacteria. The hydrogen production is affected by many process conditions. For obtaining the optimal result, experimental design is planned using the Taguchi Method. Four controlling factors, the ultrasonic frequency, energy, exposure time, and starch concentration, are considered to calculate the highest hydrogen production by the Taguchi Method. Under the best operating conditions, the biohydrogen production efficiency of dark fermentation increases by 19.11%. Results have shown that the combination of ultrasound and biological reactors for dark fermentation hydrogen production outperforms the traditional biohydrogen production method. The ultrasonic mechanical effects in this research always own different significances on biohydrogen production.

In 2003 R. E. Smalley (Smalley 2003) made a list of the top 10 problems mankind was going to face in the next 50 years. 1. Energy 2. Water 3. Food 4. Environment 5. Poverty 6. Terrorism and War 7. Disease 8. Education 9. Democracy 10. Population With the declining amount of fossil fuels, and the increasing energy demand, it is not possible to satisfy our large energy consumption without alternative energy sources, especially sustainable ones that also take care of problem number 4, (Environment). One of the possible ways to produce a liquid sustainable energy source is to replace our large gasoline demand with fermented biomass (bioethanol). To ensure that the food availability does not decrease (problem 3), the biomass for bioethanol fermentation is only gathered from waste materials of the food production, such as the straw of cereals. The fermentation on waste products is commonly referred to as 2nd generation bioethanol. Biomass of interest for cellulosic produced ethanol includes wheat straw, rape straw and macro algae. In 2009 the production of oilseed rape in EU was 21×106 ton together with an even larger amount of rape straw (Eurostat 2010). The most commonly used rape in Europe is a winter rape with a low erucic acid and glucosinolate content (Wittkop et. al. 2009). The rape straw is composed of 32% cellulose and 22% hemicelluloses. In this chapter the focus will be on the fermentation of sugars derived from cellulose.

The production and use of biodiesel as an alternative diesel fuel in compression-ignition engines and boilers has increased significantly in the recent years. Biodiesel is considered to be an immediate alternative energy, providing a solution to help decrease the effects of harmful global green house gases, why decreasing the dependency of fossil fuels (Demirbas, 2008, Gartner and Reinhardt, 2003). Biodiesel is derived from plant oils, animal fats and recycled cooking oils (Biodiesel Handling and Use Guide, 2009). Bio-Diesel is a renewable fuel produced by a chemical reaction of alcohol and vegetable or animal oils, fats, or greases. Bio-Diesel offers a safer and cleaner alternative to petroleum Diesel. Biodiesel is renewable fuel, its is energy efficicient, it can be used as a 20% blend in most diesel equipment with no or only minor modifications, can reduce global warming gas emissions, it is nontoxic, biodegradable, and suitable for sensitive environments (Biodiesel Handling and Use Guide, 2009). Biodiesel is produced when vegetable oil or animal fat is chemically reacted with alcohol (methanol or ethanol) in the presence of catalyst such as sodium or potassium hydroxide (Van Gerpen, 2004). Glycerin is produced as a co-product. Biodiesel fuel is produced from oil feedstock such as soybean oil, corn oil, canola oil, cottonseed oil, mustard oil, palm oil, restaurant waste oils such as frying oils, animal fats such as beef tallow or lard, trap grease (from restaurant grease traps), float grease (from waste water treatment plants Van Gerpen, 2004). The oil or animal fat can be converted to methyl or ethylesters (biodiesel) directly, using a base reaction (catalyze) to accelerate the transesterification reaction. The most common method of production of biodiesel is by mixing the vegetable oil with methanol in the presence of sodium hydroxide. The reaction produces methyl esters (Biodiesel) and glycerin (by product). Biodiesel can be used in its pure form B100, which requires some modification to the engine, to prevent any decomposition of plastic parts. Because the level of special care needed is high, the National Renewable Energy Laboratory (NREL) and the U.S. Department of Energy (DOE) do not recommend the use of high-level biodiesel blends. When human exposure to diesel particulate matter (PM) is elevated, additional attention to equipment and fuel handling is needed (Biodiesel Handling and Use Guide, 2009). More commonly biodiesel is run as a blend, such as B5, B10, and B20 (Example: B20 is 20% of biodiesel blended with 80% of petroleum diesel). No modification of engine is needed if Biodiesel fuel blends are