Development and evaluation of biodiesel fuel and by-products from jatropha oil

Biodiesel is an environmentally friend renewable diesel fuel alternative. Jatropha seeds can be a feedstock to produce a valuable amount of oil to be converted to biodiesel using transesterification reaction. Jatropha plant has been successfully grown in southern Egypt using primary treated municipal wastewater for its irrigation. Abench scale production of biodiesel from Jatropha oil (using methyl alcohol and sodium hydroxide as catalyst) was developed with methyl esters yield of 98 %. Biodiesel was produced on a pilot scale based on the bench scale experiment results with almost the same methyl esters yield of 98 %. The produced biodiesel was evaluated as a fuel and compared with petroleum diesel according to its physical and chemical parameters such as viscosity, flash point, pour point, cloud point, carbon residue, acid value and calorific value. The experimental techniques and product evaluation results show that such properties of the produced biodiesel are near to that of petroleum diesel. A mass balance representing the transesterification process is presented in this study. Glycerol of 85 % purity was produced and evaluated as a valuable byproduct of the process. Free fatty acids and sodium phosphate salts which have industrial interesting are also produced and evaluated.     

Modification of thermal and oxidative properties of biodiesel produced from vegetable oils

Trans esterification of three vegetable oils, sunflower oil, linseed oil and mixed oils as; sunflower-soyabean and olein were carried out using methanol, and potasium hydroxide as catalyst. The methyl esters of the corresponding oils were separated from the crude glycerol and characterized by physical-chemical methods to evaluate their thermal properties. This methods are determination of densities, cloud points, pour points, flash points, kinematic viscosities, hydrogen/carbon ratios, sulfur contents, ash contents and triglycerides. The physico-chemical characteristic of biodiesel treated with ozone showed improvement of pour point and flash point indicating higher degree of safety for fuel. Methyl esters mixed with their corresponding ozonated oil were subjected to comparison and evaluation for their thermal properties by the thermo gravimetric analysis differential thermal analysis from which the calculated heat of enthalpy and comparison with the heat of conventional diesel. The results showed that the oxygen content of biodiesel samples treated with ozone increased weight % and resulted in more extensive chemical reaction, promoted combustion characteristics and less carbon residue was produced. Gas chromatography appeared more suitable to address the problem of determining/verifying biodiesel methyl ester and showed that methyl ester content was impurity free. Ultra violet-detection was used for rapid quantization of triglycerols. From the analyses performed biodiesel treated with ozone modified the thermal and oxidative stability shown by the high combustion efficiency indicated by the high heat of enthalpy and reducing the emission of particulate matter.     

Production optimization and quality assessment of biodiesel from waste vegetable oil

Biodiesel production is worthy of continued study and optimization of production procedures because of its environmentally beneficial attributes and its renewable nature. In Egypt, millions L. of oil used for frying foods are discarded each year into sewage systems. Thus, it adds to the cost of treating effluent or pollutes waterways. This study is intended to consider aspects related to the feasibility of the production of biodiesel from waste/recycled oils in an attempt to help reduce the cost of biodiesel and reduce waste and pollution coming from waste oils. The variables affecting the yield and characteristics of the biodiesel produced from used frying oil were studied, the achieved results were analyzed and a set of recommendations was proposed. From the obtained results, the best yield percentage was obtained using a methanol/oil molar ratio of 6:1, potassium hydroxide as catalyst (1%) and 65 °C temperature for one hour. The yield percentage obtained from waste vegetable oil was comparable to that obtained from neat vegetable oil which reached 96.15% under optimum conditions. From the results it was clear that the produced biodiesel fuel, whether from neat vegetable oil or waste vegetable oil, was within the recommended standards of biodiesel fuel.     

Different techniques for the production of biodiesel from waste vegetable oil

The production of biodiesel from waste vegetable oil offers a triple-facet solution: economic, environmental and waste management. The new process technologies developed during the last years made it possible to produce biodiesel from recycled frying oils comparable in quality to that of virgin vegetable oil biodiesel with an added attractive advantage of being lower in price. Thus, biodiesel produced from recycled frying oils has the same possibilities to be utilized. While transesterification is well-established and becoming increasingly important, there remains considerable inefficiencies in existing transesterification processes. There is an imperative need to improve the existing biodiesel production methods from both economic and environmental viewpoints and to investigate alternative and innovative production processes. This study highlights the main changes occurring in the oil during frying in order to identify the characteristics of oil after frying and the anticipated effects of the products formed in the frying process on biodiesel quality and attempts to review the different techniques used in the production of biodiesel from recycled oils, stressing the advantages and limitations of each technique and the optimization conditions for each process. The emerging technologies which can be utilized in this field are also investigated. The quality of biodiesel produced from waste vegetable oil in previous studies is also reviewed and the performance of engines fueled with this biodiesel and the characteristics of the exhaust emissions resulting from it are highlighted. The overarching goal is to stimulate further activities in the field.     

Performance and environmental impact of a turbojet engine fueled by blends of biodiesels

Depletion of conventional fuels, concerns about environmental pollution and the tightening of exhaust emission legislations are the main reasons for increasing research on alternative fuels produced from agricultural feedstock. In this study, biodiesel fuels produced from cotton and corn vegetable oils are investigated as renewable fuels for a gas turbine engine for aviation. The biodiesel fuels are defined as cotton methyl ester (CTME) and corn methyl ester. The performance characteristics and exhaust emissions of the gas turbine engine are investigated when the engine fueled with three blends of 10%(B10), 20%(B20) and 50%(B50) of biodiesel/JetA-1 by volume. The biodiesel fuels were produced using transesterification process and characterized according to ASTM biodiesel specifications. Chemical and physical properties show a real potential of using biodiesel blends as an alternative for JetA-1. The measured engine performance parameters and exhaust emissions are compared with that of pure JetA-1 over a range of throttle setting. The gas turbine engine used in this study is equipped with pressure, flow, temperature, thrust and speed sensors that connected to data acquisition system and control unit in addition to exhaust gas analyzer. The experimental results show that biodiesel fuels can be used up to blend of 50% with JetA-1 in gas turbine engines with slight enhancement in engine performance and significant improvements in exhaust emissions. The engine static thrust is increased with 2% for B50 at lower and medium engine speeds and decreased with 11% at high engine speed compared to conventional JetA-1 fuel. The thrust-specific fuel consumption for biodiesel blends is lower than that for regular JetA-1 fuel. The gas turbine engine efficiency is increased for biodiesel blends by 14% compared to JetA-1, and this is reported for CTME B50. For oxygen concentration in exhaust gases emissions, the higher the biodiesel blend, the higher the O₂ concentration in the exhaust compared with JetA-1 fuel. The O₂ level increased by 6% for biodiesel blend of B50 compared to JetA-1 fuel. The emissions of CO and HC emissions decreased by 5 and 37%, respectively, compared with conventional JetA-1. Additionally, the biodiesel blends achieve a higher CO₂ and NO_x emissions with 11 and 27%, respectively, compared to JetA-1. The sulfur dioxide SO₂ decreased by 75% compared to the regular JetA-1 fuel.     

A review of the synthesis and characterisation of pillared clays and related porous materials for cracking of vegetable oils to produce biofuels

This paper presents an overview of the modification of clay minerals by propping apart the clay layers with an inorganic complex. This expanded material is converted into a permanent two-dimensional structure, known as pillared clay or shortly PILC, by thermal treatment. The resulting material exhibits a two-dimensional porous structure with acidic properties comparable to that of zeolites. Synthetic as well as natural smectites serve as precursors for the synthesis of Al, Zr, Ti, Fe, Cr, Ga, V, Si and other pillared clays as well as mixed Fe/Al, Ga/Al, Si/Al, Zr/Al and other mixed metal pillared clays. Biofuels form an interesting renewable energy source, where these porous, catalytically active materials can play an important role in the conversion of vegetable oils, such as canola oil, into biodiesel. Transesterification of vegetable oil is currently the method of choice for conversion to biofuel. The second part of this review focuses on the catalysts and cracking reaction conditions used for the production of biofuel. A distinction has been made in three different vegetable oils as starting materials: canola oil, palm oil and sunflower oil.     

Optimum reaction time, performance and exhaust emissions of biodiesel produced by microwave irradiation

While transesterification is well established, there remain considerable inefficiencies in existing transesterification processes. In this study an alternative energy stimulant, “microwave irradiation” was used for the production of the alternative energy source, biodiesel. The optimum parametric conditions obtained from the conventional technique were applied using microwave irradiation in order to compare both systems. The results showed that application of radio frequency microwave energy offers a fast, easy route to this valuable biofuel with advantages of enhancing the reaction rate and improving the separation process. The methodology allows for the use of high free fatty acid content feedstock, including used cooking oil; hence it helps to reduce the cost of production which constitutes a major hurdle towards widespread commercialization of biodiesel. The study also showed that the optimum reaction time for microwave-enhanced biodiesel production should be highly respected. Exceeding the optimum reaction time will lead to deterioration of both biodiesel yield and purity. This paper also reported the performance and exhaust emissions from a diesel engine when fuelled with a petroleum diesel fuel and two different biodiesel fuels; one obtained by the conventional technique and the other by microwave irradiation. It was concluded that microwave-enhanced biodiesel is not, at least, inferior to that produced by the conventional technique.     

脂肪酸酯分子结构对酯基钻井液性能的影响

脂肪酸酯的分子结构对酯基钻井液的性能具有重要的影响。在分析脂肪酸酯分子中酯基基团数、饱和度、分子构型、分子量大小以及分子间作用力的基础上,选取了6种饱和脂肪酸酯作为研究介质,测试了在不同温度条件下介质的粘度与密度,分析了影响介质粘度与密度的机理,得出了在低温下介质的粘度大小主要取决于脂肪酸酯中脂肪醇分子链的长度。介质密度的高低主要取决于脂肪酸酯的分子量,与脂肪酸酯中酯基的位置、α氢的活泼性以及分子间作用力大小无关。     

Performance analysis of Diesel engines fueled by biodiesel blends via thermodynamic simulation of an air-standard Diesel cycle

Because of environmental problems, it becomes necessary to develop alternative fuels that give engine performance at par with diesel. Among the alternative fuels, biodiesel and its blends hold good promises as an eco-friendly and the most promising alternative fuel for Diesel engine. The properties of biodiesel and its blends are found similar to that of diesel. Many researchers have experimentally evaluated the performance characteristics of conventional Diesel engines fueled by biodiesel and its blends. However, experiments require enormous effort, money and time. Hence, via finite-time thermodynamics simulation, an air-standard Diesel cycle model with heat transfer loss and variable specific heats of working fluid is analyzed to predict the performance of Diesel engine. The effect of compression ratio, cut-off ratio and fuel type on output work and thermal efficiency is investigated through the model. The fuels considered for the analysis are conventional diesel, rapeseed oil biodiesel and its blend (20 % biodiesel and 80 % diesel by volume). Numerical simulations showed that the output work and thermal efficiency of the engine decrease with increase of cut-off ratio for all fuels. Also, the model predicts similar performance with diesel and biodiesel blend which means that the biodiesel blend (20 % biodiesel and 80 % diesel by volume) could be a good alternative and eco-friendly fuel for conventional Diesel engines without any need to modify the engine.     

Changes in physicochemical properties of biodiesel after degradation and remediation

Biodiesel is the main substitute for petrodiesel being constituted by several alkyl esters including unsaturated compounds. It can undergo partial oxidation when stored for long periods and transported over long distances. The aims of this study were to analyze the impact of the oxidation process on the physicochemical properties of biodiesel and its remediation through distillation and esterification. Due to its high susceptibility to oxidation, sunflower biodiesel was used as a model. Specific mass, cloud point, cold filter plugging point, oxidation stability and iodine value were the properties analyzed. The results revealed that the treatments affected each sample differently, and in some cases the product after remediation had properties close to or even better than the initial biodiesel. The results reported here indicate that although biodiesel undergoes degradation during storage and transport, this does not mean the affected fuel cannot be marketed. Some important properties can be recovered with simple treatment.     

盐湖相低熟油脂肪酸的组成与分布特征

对泌阳凹陷碱性盐湖相、舞阳凹陷盐湖相、襄城凹陷膏盐湖相、南阳凹陷淡水湖相低熟油脂肪酸组成和分布特征进行了分析与研究。结果表明这些不同盐湖相的低熟原油的脂肪酸为丰度不同的饱和正构酸、不饱和正构酸、少量异构酸、类异戊二烯酸及脂肪酸乙酯系列化合物。脂肪酸的组成和分布反映了原始有机质的来源。     

The effect of opium poppy oil diesel fuel mixture on engine performance and emissions

Recently, decreasing of fossil fuel reserves and their negative effect on environment have increased the interest in alternative energy sources. One of the alternative energy sources is vegetable oils. In this study, blends of 50 % opium poppy oil — 50 % diesel fuel mixture are tested as alternative fuel on a single cylinder, 4-stroke, air cooled, pre-combustion chamber diesel engine at different speeds and its effects on engine performance and emissions are investigated. When compared to the diesel fuel as average, engine torque and power decrease at 4 % and 5.73 %, respectively. Specific fuel consumption increases by using of 50% opium poppy oil — 50 % diesel fuel mixture. When compared to the diesel fuel as average, carbon monoxide and nitrogen oxides emissions of 50 % opium poppy oil — 50 % diesel fuel mixture decrease to 15.5 % and 5.9 %, respectively. Diesel fuel-opium poppy oil mixture has been found notably successful and environment friendly as an alternative fuel for diesel engines.     

Biodiesel production using solid metal oxide catalysts

Biodiesel production is worthy of continued study and optimization of production procedures due to its environmentally beneficial attributes and its renewable nature. Heterogeneous transesterification is considered to be a green process. The process requires neither catalyst recovery nor aqueous treatment steps and very high yields of methyl esters can be obtained, close to the theoretical value. However, heterogeneously catalyzed transesterification generally requires more severe operating conditions, and the performance of heterogeneous catalysts is generally lower than that of the commonly used homogeneous catalysts. Heterogeneous catalysis for biodiesel production has been extensively investigated in the last few years. Many metal oxides have been studied for the transesterification process of oils; these include alkali earth metal oxides, transition metal oxides, mixed metal oxides and supported metal oxides. The use of solid metal oxides as catalysts in oil transesterification is well established, accordingly, researchers’ attempts are now focused on how to attain the highest catalyst activity. Catalyst activity is a function of its specific surface area, base strength and base site concentration. High specific surface area, strong base strength and high concentration of base sites are characteristics of an active transesterification catalyst. This review provides a brief overview of the different metal oxides frequently used in the process of transesterification of oils for the production of biodiesel with special reference to the various methods of catalyst preparation and catalyst characterization. Reaction conditions and catalyst leaching analysis are also highlighted. Finally, concluding remarks regarding catalyst selection and catalyst preparation steps are provided.     

Impact of a Jet A-1/HEFA blend on the performance and emission characteristics of a miniature turbojet engine

It is forecast that in the future, alternative fuels derived from non-petroleum sources will become the basic propellant for turbine aircraft engines. Currently, five types of aviation turbine fuel containing synthesized hydrocarbons are certified and accepted, and allow adding a maximum of 50% of synthetic component to conventional fuel. The experimental performance and the emission characteristics of a turbojet engine were investigated in this paper. The studies were conducted with the use of a miniature turbojet engine, which is the main component of a laboratory test rig. The test rig is an interesting solution for engine research, due to the fact that studies concerning full-scale aircraft engines are very complex and expensive. The literature of the subject contains many papers using small-scale turbojet engines for testing alternative fuels. However, most of them concern components of fuels, e.g. biodiesel, butanol, which do not have direct application in aviation. Two different fuel samples, a conventional Jet A-1 fuel and a blend of 48% synthesized paraffinic kerosene from hydroprocessed esters and fatty acids process with Jet A-1 were tested. This process is one of the routes of producing alternative fuel for aviation, approved by ASTM standard. The test rig studies were performed according to a specific profile of engine test, which models different modes of a turbojet engine’s operation. The obtained results are compared in relation to the results for neat Jet A-1 fuel and then discussed.     

Biodiesel synthesis from non-edible oils by transesterification using the activated carbon as heterogeneous catalyst

The need for renewable environmentally friendly energy resources is growing every day. Biodiesel is one of the most promising alternatives to the conventional non-renewable energy resources. Heterogeneous catalysts proved a high efficiency in the transesterification of oils to produce biodiesel. In this research, activated carbon was tested as a heterogeneous catalyst in the transesterification of two non-edible oils (waste cooking oil and Jatropha oil) with methanol to produce biodiesel. Activated carbon was characterized using X-ray diffraction, scanning electron microscope and Fourier transformed infrared. The effect of different operating parameters, namely operation time (30, 60, 120 and 180 min), alcohol-to-oil molar ratio (4:1, 6:1, 8:1 and 10:1), catalyst loading [0.5, 1, 2, 3 and 5% (w/w)] and rotational speed (100, 200, 300 and 400 rpm), was investigated. Results showed that increasing the operational time, the alcohol-to-oil molar ratio and the catalyst loading increases the conversion to biodiesel but only to some extent; increasing the stirring rate was found to be beneficial to the process. The optimum conditions were found to be 2 h of heating, 6:1 alcohol-to-oil ratio, 1 wt% catalyst loading and 400 rpm stirring. Under optimum conditions, the conversion to biodiesel reached 93.95 and 93.27% for the waste cooking oil and the Jatropha oil, respectively. The properties of the obtained biodiesel (density, viscosity, flash point, pour point and cloud point) were measured giving promising results.     

Gaseous emission comparison of a compression–ignition engine fueled with different biodiesels

In this study, it was performed a comparison of the performance and emissions of two methyl ester fuels: one obtained from animal fat and the other from crude canola oil, in a compression-ignition engine against diesel fuel. The experimental results compared with diesel fuel showed that significant reductions could be obtained by biodiesel derived from animal fat in carbon monoxide and oxides of nitrogen emissions. Carbon dioxide emissions showed a trend of decreasing with the biodiesel fuels. An increase in brake specific fuel consumption was observed for different biodiesel fuels when compared with diesel fuel. It was concluded that animal tallow methyl ester performed better than canola oil methyl ester, whereas slightly higher brake torque is observed with canola oil methyl ester.     

Biodiesel production from three mixes of oils with high free fatty content: quality evaluation and variable analysis

Due to the excessive use of fossil fuels around the world, more environmentally friendly alternatives have been studied. Technologies for the production of ethanol, biogas and biodiesel are focusing on the importance of improving costs and efficiency. Biodiesel can be used in automotive internal combustion, is biodegradable and has no presence of metals, however, it lacks competitiveness versus petrodiesel mainly by the high cost of the pure oils used for its production. The aim of this study was to obtain biodiesel from oil samples with high content of free fatty acids (>1 %) obtained from three fast food restaurants using their molecular weight and acidity index values in order to neutralize the free fatty acids in a one-step reaction and perform a screening for optimal conditions for transesterification. The experimental design consisted of two reaction times (60 and 90 min); four methanol–oil molar ratios—6:1, 10:1, 15:1 and 20:1; and two catalysts (NaOH and KOH) at three concentrations 0.5, 1 and 1.5 % with a constant temperature of 60 °C and 500 rpm. The optimum conditions for the different waste cooking oil feedstocks were established reaching a final yield up to 85.53 % of biodiesel, concluding that there is viability of production through the use of this raw material and free fatty acids neutralization technique, obtaining a biofuel that meets international quality standards.     

松粉热解脂肪酸生物标志物的特征及其地球化学意义

现代松粉的温－压热模拟实验中，产出的轻质烃和氯仿抽提物芳烃馏份的GC－MS分析均检出大量偶数碳优势明显的脂肪酸类分子生物标志物，轻烃主要为C16，C18烷酸及其甲，乙酯，芳烃组分相对比较复杂，包括饱和脂肪酸（酯），不饱和脂肪酸（酯）和脂肪酸内酯，前者碳数分布为C15－，C30，C16，C18碳酸（酯）相对丰度占绝对优势为特征，后者碳数分布为C20-C30,以C26，C28和C30脂肪酸内酯为主，在250℃以下样品中检测出相对丰度较高的不饱和C18碳酸（酯），脂肪酸酯化合物在极低的温度条件下便可排出，并分别在200－300℃和300－400℃之间形成两次产出高峰；花粉内质体中的游离态脂肪酸及不饱和脂肪酸形成低温阶段的第一次高峰；花粉壁脂质结构中的脂肪酸及饱和脂肪酸在较高温度阶段形成第二次高峰，原样及低温样品以脂肪酸酯为主，250℃及其以上温度条件下因水解产生较多的脂肪酸，随温率继续升高，脂肪酸酯易发生脱羰反应而生成链烷烃。400℃以后因强烈降解脂肪酸酯含量大大降低，这与350－450℃之间奇数碳优势正构烷烃在轻质烃和饱和烃中的大量产出相吻合，研究表明，植物花粉是沉积有机质中饱和及不饱和C16，C18脂肪酸酯的重要母源之一。     

柴达木盆地西部原油极性化合物特征及其地球化学意义

柴达木盆地西部原油主要形成于高盐强还原环境和有机质低成熟演化阶段。这种特殊成油环境，为研究原油中极性生物标志物示踪作用提供了有利条件。对6个原油胶质馏分硅醚衍生物进行了GC—MS分析，从中检出丰富的脂肪酸、烷基醇、脂肪酸甘油—酯、酰胺和甾烯醇化合物，并且脂肪酸甘油—酯为首次从原油中检出。研究认为，这些生物标志化合物主要来自母源。它们的分布特征为链状化合物以短链组分为主，甾醇主要为C27甾烯醇，指示成油母质主要为菌藻类；高丰度脂肪酸甘油—酯的存在，提出生物油脂是这些原油的重要成油母质。原油中存在不饱和链状化合物及其高的CPI值和甾烯醇都说明原油具有低的成熟度。通过原油极性和烷烃化合物的对比研究，认为成油物质及其低演化产物的可溶有机质胶质组分，对原油的形成可能起了重要的作用。     

Stereochemical studies of acyclic isoprenoid compounds—II The role of chlorophyll in the derivation of isoprenoid-type acids in a lacustrine sediment

The stereochemistries of a series (I)–(IX) of isprenoid-type acids in the lacustrine Green River Shale (Eocene) have been examined. The absolute configurations of five of the acids present in the free-fatty acid fraction have been determined by high resolution gas Chromatographic analysis of the methyl and (?)-menthyl esters and are compatible with an origin from the phytyl moiety of chlorophyll. The results for two other isoprenoid-type acids, 5,9,13-trimethyltetradecanoic acid (IV) and 6,10,14-trimethylpentadecanoic acid (VI), do not at present preclude a chlorophyll derivation. The 4,8,12,16-tetramethylheptadecanoic (VIII) and 5,9,13,17-tetramethyloctadecanoic (IX) acids each comprise two or more stereoisomers. The stereoisomeric composition of the 2,6,10,14-tetramethylpentadecanoic acid (VI) indicates that it is unlikely that 2,6,10,14-tetramethylpentadecane, pristane, is an intermediate in the geochemical pathways presumed to lead from phytol to this acid.