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Biodiesel
Terms modified by Biodiesel Selected AbstractsBiodiesel fuel production via transesterification of oils using lipase biocatalystGCB BIOENERGY, Issue 2 2009MAN XIAO Abstract Biodiesel has gained widespread importance in recent years as an alternative, renewable liquid transportation fuel. It is derived from natural triglycerides in the presence of an alcohol and an alkali catalyst via a transesterification reaction. To date, transesterification based on the use of chemical catalysts has been predominant for biodiesel production at the industrial scale due to its high conversion efficiency at reasonable cost. Recently, biocatalytic transesterification has received considerable attention due to its favorable conversion rate and relatively simple downstream processing demands for the recovery of by-products and purification of biodiesel. Biocatalysis of the transesterification reaction using commercially purified lipase represents a major cost constraint. However, more cost-effective techniques based on the immobilization of both extracellular and intracellular lipases on support materials facilitate the reusability of the catalyst. Other variables, including the presence of alcohol, glycerol and the activity of water can profoundly affect lipase activity and stability during the reaction. This review evaluates the current status for lipase biocatalyst-mediated production of biodiesel, and identifies the key parameters affecting lipase activity and stability. Pioneer studies on reactor-based lipase conversion of triglycerides are presented. [source] Lipase-mediated methanolysis of soybean oils for biodiesel productionJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 1 2008Xin Chen Abstract BACKGROUND: Biodiesel is increasingly perceived as an important component of solutions to the important current issues of fossil fuel shortages and environmental pollution. Biocatalysis of soybean oils using soluble lipase offers an alternative approach to lipase-catalyzed biodiesel production using immobilized enzyme or whole-cell catalysis. The central composite design (CCD) of response surface methodology (RSM) was used here to evaluate the effects of enzyme concentration, temperature, molar ratio of methanol to oil and stirring rate on the yield of fatty methyl ester. RESULTS: Lipase NS81006 from a genetically modified Aspergillus oryzae was utilized as the catalyst for the transesterification of soybean oil for biodiesel production. The experimental data showed that enzyme concentration, molar ratio of methanol to oil and stirring rate had the most significant impact on the yield of fatty methyl ester; a quadratic polynomial equation was obtained for methyl ester yield by multiple regression analysis. The predicted biodiesel yield was 0.928 (w/w) under the optimal conditions and the subsequent verification experiments with biodiesel yield of 0.936 ± 0.014 (w/w) confirmed the validity of the predicted model. CONCLUSION: RSM and CCD were suitable techniques to optimize the transesterification of soybean oil for biodiesel production by soluble lipase NS81006. The related lipase NS81006 reuse stability, chemical or genetic modification, and transesterification mechanism should be taken into consideration. Copyright © 2007 Society of Chemical Industry [source] Biodiesel production by direct methanolysis of oleaginous microbial biomassJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2007Bo Liu Abstract Biodiesel is a renewable fuel conventionally prepared by transesterification of pre-extracted vegetable oils and animal fats of all resources with methanol, catalyzed by strong acids or bases. This paper reports on a novel biodiesel production method that features acid-promoted direct methanolysis of cellular biomass of oleaginous yeasts and filamentous fungi. The process was optimized for tuning operation parameters, such as methanol dosage, catalyst concentration, reaction temperature and time. Up to 98% yield was reached with reaction conditions of 70 °C, under ambient pressure for 20 h and a dried biomass to methanol ratio 1:20 (w/v) catalyzed by either 0.2 mol L,1 H2SO4 or 0.4 mol L,1 HCl. Cetane numbers for these products were estimated to range from 56 to 59. This integrated method is thus effective and technically attractive, as dried microbial biomass as feedstocks omits otherwise tedious and time-consuming oil extraction processes. Copyright © 2007 Society of Chemical Industry [source] Lipase-catalyzed production of biodiesel from rice bran oilJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2005Chao-Chin Lai Abstract Biodiesel has attracted considerable attention as an alternative fuel during the past decades. The main hurdle to the commercialization of biodiesel is the cost of the raw material. Use of an inexpensive raw material such as rice bran oil is an attractive option to lower the cost of biodiesel. Two commercially available immobilized lipases, Novozym 435 and IM 60, were employed as catalyst for the reaction of rice bran oil and methanol. Novozym 435 was found to be more effective in catalyzing the methanolysis of rice bran oil. Methanolysis of refined rice bran oil and fatty acids (derived from rice bran oil) catalyzed by Novozym 435 (5% based on oil weight) can reach a conversion of over 98% in 6 h and 1 h, respectively. Methanolysis of rice bran oil with a free fatty acid content higher than 18% resulted in lower conversions (<68%). A two-step lipase-catalyzed methanolysis of rice bran oil was developed for the efficient conversion of both free fatty acid and acylglycerides into fatty acid methyl ester. More than 98% conversion can be obtained in 4,6 h depending on the relative proportion of free fatty acid and acylglycerides in the rice bran oil. Inactivation of lipase by phospholipids and other minor components was observed during the methanolysis of crude rice bran oil. Simultaneous dewaxing/degumming proved to be efficient in removing phospholipids and other minor components that inhibit lipase activity from crude rice bran oil. Copyright © 2005 Society of Chemical Industry [source] Titelbild: Verbrennungschemie der Biokraftstoffe: von Ethanol bis Biodiesel (Angew. Chem.ANGEWANDTE CHEMIE, Issue 21 201021/2010) Biodiesel ein Gemisch von Estern, wird aus Raps produziert; weitere potenzielle Biokraftstoffe sind Alkohole und Ether. Wie K. Kohse-Höinghaus et,al. im Aufsatz auf S.,3652,ff. schildern, besteht bei Kraftstoffmolekülen ein signifikanter Einfluss der Struktur auf die Verbrennungschemie. Die komplexen chemischen Reaktionswege der Brennstoffzersetzung und -oxidation können durch Massenspektrometrie und Lasertechniken direkt analysiert werden. [source] Verbrennungschemie der Biokraftstoffe: von Ethanol bis BiodieselANGEWANDTE CHEMIE, Issue 21 2010Katharina Kohse-Höinghaus Prof. Abstract Biokraftstoffe wie Bioethanol, Biobutanol und Biodiesel erfahren zunehmendes Interesse als Alternativen zu Brennstoffen auf Erdölbasis, denn sie versprechen als regenerierbare Energieträger eine langfristige und nachhaltige Perspektive mit vorteilhafter Klimabilanz. Gegenwärtige Diskussionen befassen sich mit der Produktion dieser Brennstoffe, ihrer Kompatibilität mit vorhandenen Motoren und Versorgungsstrukturen sowie der Konkurrenz zwischen der Herstellung von Biokraftstoffen und Nahrungsmitteln. Die Verbrennungschemie der Biokraftstoffe hat dagegen bisher nur wenig Aufmerksamkeit erfahren. In diesem Aufsatz beschreiben wir wesentliche Aspekte der chemischen Reaktionswege bei der Verbrennung prototypischer Vertreter potenzieller Biokraftstoffe wie Alkohole, Ether und Ester. Im Vordergrund stehen dabei die Zersetzungs- und Oxidationsmechanismen sowie mögliche unerwünschte Emissionen. Neue experimentelle Methoden und Modellstudien erlauben detaillierte Einblicke in die hochkomplexen Netzwerke chemischer Reaktionen bei der Verbrennung von Biokraftstoffen. Die Chemie dieser Prozesse zu verstehen ist eine wichtige Voraussetzung für die verantwortungsbewusste Auswahl alternativer Kraftstoffe der nächsten Generation. [source] Research and Development Trends in BiodieselASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5-6 2004V. Rudolph Biodiesel, a derivative from plant oils or animal fats, has gained widespread acceptance in recent years as a sustainable alternative fuel to petroleum diesel due to its environmental benefits and renewability. Although there are several different ways in which biodiesel can be used or formulated as a fuel such as direct blending, microemulsions and thermal cracking, the most widespread remains the alkyl esters of fatty acids obtained through transesterification of the oils or fats. In transesterification, triglycerides which are the main chemical in oils or fats are converted into esters through reaction with simple alcohols. The physical and chemical properties of the esters thus obtained are very similar to those of the petroleum diesel. This paper reviews the current technologies available for the transesterifications of vegetable oils and animal fats and identifies that the biggest factor deterring a greater market uptake of biodiesel is its cost. It concludes that, in addition to government policy framework, e.g. to reduce the pump price of biodiesel through fuel tax exemption, further technological development presents significant scope for improvement. At present, there are no suitable and developed transesterification technologies that can handle cheap, low-quality feedstocks including waste animal fats and spent cooking oils. These feedstocks contain high percentages of water and free fatty acids which are extremely detrimental to the yield and reaction rates of the transesterification processes. This paper also suggests some future research and development directions and requirements for more competitive biodiesel production. [source] Production of biodiesel: possibilities and challengesBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 1 2007Sulaiman Al-Zuhair Abstract Biodiesel, defined as monoalkyl fatty acid ester (preferentially methyl and ethyl esters), represents a promising alternative fuel for use in compression-ignition (diesel) engines. Biodiesel fuel comes from renewable sources as it is plant- not petroleum-derived and as such it is biodegradable and less toxic. In addition, relative to conventional diesel, its combustion products have reduced levels of particulates, carbon oxides, sulphur oxides and, under some conditions, nitrogen oxides. Enzymatic production of biodiesel has been proposed to overcome the drawbacks of the conventional chemically catalyzed processes. The main obstacle facing full exploitation of the enzyme, lipase, potential is its cost. Therefore, reuse of lipase is essential from the economic point of view, which can be achieved by using the lipase in immobilized form. In addition, immobilized lipase displays improved stability and activity. Common immobilization techniques include attachment to solid supports and entrapment within the matrix of a polymer. This article presents a comparison between conventional processes and enzymatic processes and different possible feedstocks for biodiesel production. In addition, possible ways to overcome the problems facing the use of lipase are described. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd [source] Energielösungen für die Zukunft?CHEMIE IN UNSERER ZEIT (CHIUZ), Issue 2 2007Weiße Biotechnologie Abstract Angesichts hoher Ölpreise und der sich abzeichnenden globalen Klimaveränderungen erscheinen biotechnisch hergestellte Energieträger als vielversprechende Zukunftsoption. Mit seinen Jahresproduktionsmengen von 2 Mio t Biodiesel, 560.000 t Bioethanol und seinen 2.700 Biogasanlagen befindet sich Deutschland in Sachen Bioenergie in der vorderen Hälfte der Industrienationen. Vorgestellt werden die Möglichkeiten, die die weiße Biotechnologie zur Herstellung von Energieträgern bietet. In view of the high price of oil and the emerging global climate changes, biotechnologically produced energy sources appear to be a promising option for the future. Of the industrial nations, Germany with annual production figures of 2 m tons of biodiesel, 560,000 tons of bioethanol and some 2,700 biogas plants is in the upper half of the bioenergy rankings. Here, the potential of industrial biotechnology for energy production is presented in detail. [source] Biodiesel , Hoch siedendes Absorbens für die GasreinigungCHEMIE-INGENIEUR-TECHNIK (CIT), Issue 3 2004K. Bay Dipl.-Ing. Abstract No abstracts. [source] Einfluss des Stofftransportes auf die Herstellung von BiodieselCHEMIE-INGENIEUR-TECHNIK (CIT), Issue 1-2 2004J. Lifka Dr. Abstract No abstracts. [source] Supercritical fluid extraction of lipids from the heterotrophic microalga Crypthecodinium cohniiENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 2 2010Ricardo Miguel Couto Abstract Microalgae biomass can be a feasible source of ,-3 fatty acids due to its stable and reliable composition. In the present study, the Crypthecodinium cohnii growth and docosahexaenoic acid (DHA, 22:6,3) production in a 100,L glucose-fed batch fermentation was evaluated. The lipid compounds were extracted by supercritical carbon dioxide (SC-CO2) from C. cohnii CCMP 316 biomas, was and their fatty acid composition was analysed. Supercritical fluid extraction runs were performed at temperatures of 313 and 323,K and pressures of 20.0, 25.0 and 30.0,MPa. The optimum extraction conditions were found to be 30.0,MPa and 323,K. Under those conditions, almost 50% of the total oil contained in the raw material was extracted after 3,h and the DHA composition attained 72%,w/w of total fatty acids. The high DHA percentage of total fatty acids obtained by SC-CO2 suggested that this extraction method may be suitable for the production of C. cohnii value added products directed towards pharmaceutical purposes. Furthermore, the fatty acid composition of the remaining lipid fraction from the residual biomass with lower content in polyunsaturated fatty acids could be adequate for further uses as feedstock for biodiesel, contributing to the economy of the overall process suggesting an integrated biorefinery approach. [source] Quantification of free and esterified steryl glucosides in vegetable oils and biodieselEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2009Florence Lacoste Dr. Abstract Steryl glucosides (SG) are minor components that dramatically modify the low temperature performance of fatty acid methyl esters (FAME) used as biodiesel. SG are naturally present in vegetable oils but they may also be the result of the transesterification of esterified steryl glucosides (ESG). These are present in vegetable oils at a level of a few hundred milligrams per kilogram, depending on the nature of the feedstock. We developed an analytical method to quantify SG and ESG in vegetable oils and in FAME. The purification of SG and ESG was performed by liquid chromatography on silica gel, and the analysis of the trimethylsilyl derivatives was achieved by gas chromatography and flame ionization detection. The filterability of biodiesel is affected when the SG content is higher than 20,mg/kg. Therefore, the sensitivity of this new method is adapted for this purpose since the quantification limit is 10,mg/kg of SG and ESG. The recoveries are acceptable, between 75% and 90% depending on the species and content, and the reproducibility relative standard deviation, evaluated at 10%, is comparable to other studies. [source] A method for the determination of polyunsaturated fatty acid methyl esters in biodiesel: Results of an interlaboratory studyEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2009Sigurd Schober Abstract A gas chromatographic method for the determination of fatty acid methyl esters with four or more double bonds in biodiesel was developed and tested. The method is based on gas chromatographic separation on a wax capillary column using methyl tricosanoate as internal standard. The performance of the method was proved with the participation of 11,European laboratories by a Round Robin test on six different biodiesel samples containing different amounts of polyunsaturated fatty acid methyl esters. The results showed that the precision is sufficient around the EN,14214 limit of 1,% (m/m). At lower concentrations the variation is too high. The scope of the application can be given between as 0.6 and 1.5%. [source] Simplification of separation of the reaction mixture after transesterification of vegetable oilEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 4 2008Martin Hájek Abstract A heterogeneous reaction mixture is formed by transesterification of vegetable oils. The reaction mixture contains mainly methyl esters of higher fatty acids and glycerol. From this mixture, biodiesel is gained by spontaneous sedimentation in the gravitational field. The sedimentation can be considerably accelerated by controlled addition of water. It was found that addition of small amounts of water to the crude reaction mixture significantly affected the mixture, and substantial changes in the speed of the separation took place. Considerable differences in the composition and quality of the ester and glycerol phases occurred. The optical properties (transmittance and refractive indices) of the heterogeneous reaction mixture are changed after addition of water; this change can be observed spectrophotometrically. This method is applicable to all types of vegetable oils including waste frying oils. [source] The effect of polymers and surfactants on the pour point of palm oil methyl estersEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 4 2007Cheah Han Sern Abstract The objective of this research was to find some additives suitable to reduce the pour point (PP) of palm oil methyl esters. The PP properties of palm oil methyl esters (biodiesel) were evaluated with commercially available polymeric and surfactant compounds with various polarities, molecular sizes and structures. The compounds under study were poly(ethylene glycol), poly(methyl methacrylate), poly(ethylene-co-vinyl acetate), poly(styrene-co-maleic anhydride), poly(ethylene glycol) distearate, poly-(octadecyl methacrylate), poly(1-decene), poly(maleic anhydride- alt -1-octadecene), caprylic acid sodium salt, N -lauroylsarcosine sodium salt, polyoxyethylene(2) cetyl ether and polyoxyethylene(10) cetyl ether. Seven out of the twelve polymeric compounds tested were miscible in palm oil methyl esters due to similar polarities of the solute and biodiesel. The blends of the resultant seven polymeric compounds in palm oil methyl esters were evaluated respectively for their effect on the PP property. Poly-(maleic anhydride- alt -1-octadecene) was able to improve the PP of palm oil methyl esters from 12 to 6,°C when 2,wt-% was added. The cloud point was reduced from 12.9 to 8.1,°C, and the cold filter plugging point was reduced from 12 to 7,°C, whilst the flash point value remained unchanged at 156,°C when 2,wt-% of poly(maleic anhydride- alt -1-octadecene) was added to the palm oil methyl esters. [source] Tocotrienols and cancer: Beyond antioxidant activityEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 4 2007Kalanithi Nesaretnam Abstract The edible oil industry has emerged as an important provider of raw material for the extraction of vitamin,E. Vegetable oils, especially the seed oils, are rich sources of tocopherols. However, in palm oil, vitamin,E occurs as a complex mixture of tocopherols and tocotrienols. Various tocotrienol isomers of vitamin,E in palm oil have been reported to possess interesting biological and physiological properties not generally evident with tocopherol-rich vitamin,E preparations. They include potential blood cholesterol-lowering and cardioprotective effects, more efficient antioxidant activity in biological systems, and possible anti-cancer and neuroprotective effects. With the emergence of palm oil as the largest edible oil in world markets, technology is now available to extract tocotrienol-rich palm vitamin,E. Initiatives in Malaysia to manufacture biodiesel will further generate large amounts of micronutrients, especially tocotrienols, to be available to the nutraceutical and functional food industry. [source] Cold flow properties of fuel mixtures containing biodiesel derived from animal fatty wasteEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 9 2006Kiril Kazancev Abstract The aims of the present study were to evaluate the cold temperature behavior of methyl esters of vegetable and animal origin and of their mixtures with fossil diesel fuel, as well as to investigate the effectiveness of different depressants. Various blends of rapeseed oil methyl esters, linseed oil methyl esters, pork lard methyl esters and fossil diesel fuel were prepared, and both cloud point and cold filter plugging point (CFPP) were analyzed. It was found that mixtures with CFPP values of ,5,°C and lower may contain up to 25% of pork lard methyl esters; whereas the ratio of summer fossil diesel fuel and rapeseed oil methyl esters may vary over a wide range, i.e. such mixtures can be used in a diesel engine in the summer. In the transitory periods it is possible to use up to 20% animal and vegetable ester blends (3,:,7) with winter fossil diesel, whereas only up to 5% of esters can be added to the fuel used in winter. In order to improve the cold properties of rapeseed oil, pork lard and linseed oil methyl ester mixtures, various additives were tested. Depressant Viscoplex 10,35 with an optimal dose of 5000,mg/kg was found to be the most effective. [source] Mutations towards enantioselectivity adversely affect secretion of Pseudomonas aeruginosa lipaseFEMS MICROBIOLOGY LETTERS, Issue 1 2008Sascha Hausmann Abstract Lipases are important biocatalysts used as detergent additives to manufacture biodiesel, and in particular, for the production of enantiopure compounds such as alcohols, amines and carboxylic acids. Extensive efforts were conducted trying to optimize lipase properties and lipase LipA of Pseudomonas aeruginosa comprises the best-studied example in terms of optimizing enantioselectivity by application of numerous directed evolution methods. Its enantioselectivity in the asymmetric hydrolysis of the model substrate 2-methyldecanoic acid p -nitrophenyl ester was increased from E=1.1 for the wild-type enzyme to E=51 for the best (S)-enantioselective variant which carried six amino acid exchanges. We have observed that overexpression of this variant in the homologous host resulted in only marginal yields of enzyme in the bacterial culture supernatant, suggesting that the enantioselective LipA variant was secreted with only low efficiency. Hence, we have analysed the secretion of this lipase variant and compared it to variants carrying either the respective single mutations or some combinations. We report here the identification of two amino acid substitutions located on the protein surface, which significantly impair lipase secretion. [source] Variability and divergence in Pongamia pinnata (L.) Pierre germplasm , a candidate tree for biodieselGCB BIOENERGY, Issue 6 2009N. SUNIL Abstract Three explorations were undertaken in South East Coastal zone of India covering parts of Andhra Pradesh (AP) and Orissa states to collect Pongamia pinnata (L.) Pierre germplasm during March,June 2007. A total of 123 accessions were collected and seed data recorded were analyzed for morphometric traits viz., seed length, seed width, seed thickness, 100-seed weight and oil content. Variation in the collected germplasm was analyzed using anova, simple measures of variation and D2 statistics. Significant genetic variability between seed traits and oil content and association among the seed traits was recorded. Phenotypic variance was higher than genotypic variance for all the characters indicating dominant role of environment. High heritability (broad sense) for 100-seed weight (97.6%) and oil content (86.7%) indicated the reliability of these characters as selection criteria for plus trees. Genetic gain was maximum for 100-seed weight (62.6%) followed by oil content (30.5%). D2 analysis grouped the accessions into 12 clusters. Cluster XII and cluster IX were the most diverse based on the intercluster distance. Based on the observed diversity, Chittoor, Srikakulam and Adilabad districts of AP are most suitable for collecting diverse germplasm lines and also for in situ conservation. [source] Biodiesel fuel production via transesterification of oils using lipase biocatalystGCB BIOENERGY, Issue 2 2009MAN XIAO Abstract Biodiesel has gained widespread importance in recent years as an alternative, renewable liquid transportation fuel. It is derived from natural triglycerides in the presence of an alcohol and an alkali catalyst via a transesterification reaction. To date, transesterification based on the use of chemical catalysts has been predominant for biodiesel production at the industrial scale due to its high conversion efficiency at reasonable cost. Recently, biocatalytic transesterification has received considerable attention due to its favorable conversion rate and relatively simple downstream processing demands for the recovery of by-products and purification of biodiesel. Biocatalysis of the transesterification reaction using commercially purified lipase represents a major cost constraint. However, more cost-effective techniques based on the immobilization of both extracellular and intracellular lipases on support materials facilitate the reusability of the catalyst. Other variables, including the presence of alcohol, glycerol and the activity of water can profoundly affect lipase activity and stability during the reaction. This review evaluates the current status for lipase biocatalyst-mediated production of biodiesel, and identifies the key parameters affecting lipase activity and stability. Pioneer studies on reactor-based lipase conversion of triglycerides are presented. [source] Lipase-catalyzed ethanolysis of soybean oil in a solvent-free system using central composite design and response surface methodologyJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2008Rafael Costa Rodrigues Abstract BACKGROUND: In this work we describe the synthesis of ethyl esters, commonly known as biodiesel, using refined soybean oil and ethanol in a solvent-free system catalyzed by lipase from Thermomyces lanuginosus. Central composite design and response surface methodology (RSM) were employed to optimize the biodiesel synthesis parameters, which were: reaction time, temperature, substrate molar ratio, enzyme content, and added water, measured as percentage of yield conversion. RESULTS: The optimal conditions obtained were: temperature, 31.5 °C; reaction time, 7 h; substrate molar ratio, 7.5:1 ethanol:soybean oil; enzyme content, 15% (g enzyme g,1 oil); added water, 4% (g water g,1 oil). The experimental yield conversion obtained under these conditions was 96%, which is very close to the maximum predicted value of 94.4%. The reaction time-course at the optimal values indicated that 5 h was necessary to obtain high yield conversions. CONCLUSION: A high yield conversion was obtained under the optimized conditions, with relative low enzyme content and short time. Comparison of predicted and experimental values showed good correspondence, implying that the empirical model derived from RSM can be used to adequately describe the relationship between the reaction parameters and the response (yield conversion) in lipase-catalyzed biodiesel synthesis. Copyright © 2008 Society of Chemical Industry [source] Lipase-catalyzed production of biodiesel from rice bran oilJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2005Chao-Chin Lai Abstract Biodiesel has attracted considerable attention as an alternative fuel during the past decades. The main hurdle to the commercialization of biodiesel is the cost of the raw material. Use of an inexpensive raw material such as rice bran oil is an attractive option to lower the cost of biodiesel. Two commercially available immobilized lipases, Novozym 435 and IM 60, were employed as catalyst for the reaction of rice bran oil and methanol. Novozym 435 was found to be more effective in catalyzing the methanolysis of rice bran oil. Methanolysis of refined rice bran oil and fatty acids (derived from rice bran oil) catalyzed by Novozym 435 (5% based on oil weight) can reach a conversion of over 98% in 6 h and 1 h, respectively. Methanolysis of rice bran oil with a free fatty acid content higher than 18% resulted in lower conversions (<68%). A two-step lipase-catalyzed methanolysis of rice bran oil was developed for the efficient conversion of both free fatty acid and acylglycerides into fatty acid methyl ester. More than 98% conversion can be obtained in 4,6 h depending on the relative proportion of free fatty acid and acylglycerides in the rice bran oil. Inactivation of lipase by phospholipids and other minor components was observed during the methanolysis of crude rice bran oil. Simultaneous dewaxing/degumming proved to be efficient in removing phospholipids and other minor components that inhibit lipase activity from crude rice bran oil. Copyright © 2005 Society of Chemical Industry [source] Toward greener separations of rare earths: Bifunctional ionic liquid extractants in biodieselAICHE JOURNAL, Issue 9 2010Yinghui Liu Abstract Ionic liquids (ILs) containing quaternary phosphonium cations and phosphonic acid anions were explored as novel extractants for rare earths (RE) separation. They were considered to be bifunctional ionic liquid extractants (bif-ILEs), since both cations and anions of ILs were involved in the extraction. Trihexyl(tetradecyl)phosphonium bis 2,4,4-trimethylpentylphosphinate (Cyphos IL 104), as a bif-ILE, together with propylene carbonate (PC), dimethyl carbonate (DMC), and soybean oil methyl ester (SBME, biodiesel) as diluents was employed in the extraction of RE(III) from aqueous solutions. Acidified Cyphos IL 104 (HNO3 -Cyphos IL 104) exhibited high solubility in three diluents, and higher extraction efficiency than bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) because of the coextraction of RE(III) by quaternary phosphonium cation and phosphonic acid anion in organic phase. Additionally, this coextraction mechanism could eliminate the loss of IL. The physical properties and miscibility test results indicated that SBME was an excellent solvent for RE(III) extraction. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source] Walnut Staminate Flowers Can Be Explored as a Supplementary Plant Oil SourceJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 4 2006Husen Jia Abstract Fossil fuel is currently the major energy source driving global socio-economy, but its stock is being heavily depleted due to increasing anthropogenic activities worldwide. There are also concerns regarding the burning of fossil fuels, which contributes to global climate warming and air pollution. As such, the development of biodiesel as a non-toxic, biodegradable, and renewable alternative energy source using oil crops such as soybean and rapeseed has quickly emerged in the West countries. However, the production of oil crops in China is far from sufficient to meet the demands of the country's population of 1.3 billion, and increasing oil crop production is inhibited by a severe shortage of agricultural land, which currently averages 0.2 acre per person and, as such, is less than half the world average. The current national policy in China regarding land use is more towards revering cultivated lands in ravins and hills to forestry, which presents an ideal opportunity to further develop plantations of walnut (Juglans regia L.) trees, a plant that is tolerant to drought and infertile soils and has a high oil content. Study in this paper shows that one ament of walnut staminate flowers produces about 0.168 g dry pollen, and the dry pollen contained 49.67% oil. Based on this discovery, oil yield obtained from staminate flowers is estimated to reach 6.95% of that from walnut nuts. Thus walnut staminate flower is suggested to explore as supplementary plant oil source, and has a great opportunity to utilize as a biodiesel feedstock. (Managing editor: Wei Wang) [source] Transesterification for biodiesel production catalyzed by combined lipases: Optimization and kineticsAICHE JOURNAL, Issue 6 2010Yun Liu Abstract Preparation of biodiesel from waste cooking oil catalyzed by combined lipases in tert -butanol medium was investigated. Several crucial parameters affecting biodiesel yield were optimized by response surface methodology, such as dosage of combined lipases of Novozym 435 and Lipozyme TLIM, weight ratio of Novozym 435 to Lipozyme TLIM, amount of tert -butanol, reaction temperature, and molar ratio of oil to methanol. Under the optimized conditions, the highest biodiesel yield was up to 83.5% The proposed model on biodiesel yield had a satisfactory coefficient of R2 (= 94.02%), and was experimentally verified. The combined lipases exhibited high-operational stability. After 30 cycles (300 h) successively, the activity of combined lipases maintained 85% of its original activity. A reaction kinetic model was proposed to describe the system and deduced to be a pseudo-first-order reaction, and the calculated activation energy was 51.71 kJ/mol. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Kinetics of interaction of palm ethyl biodiesel with three different polymer materialsJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 12 2008Giselle Lutz Abstract Diesel diffuses into neoprene matrices 10% faster than palm ethyl biodiesel at 20°C. In contrast, the palm biodiesel soaks highly plasticized PVC five times faster than diesel. Phthalate plasticizer leaks from the PVC matrix 14 times faster when biodiesel is the absorbed liquid, relative to petrodiesel. This biodiesel penetrates polybutadiene-styrene resins at rates that depend on the ratio of phenyl to CHCH units in the resins. Copyright © 2008 John Wiley & Sons, Ltd. [source] Characterization of biodiesel and biodiesel blends using comprehensive two-dimensional gas chromatographyJOURNAL OF SEPARATION SCIENCE, JSS, Issue 14 2008Warawut Tiyapongpattana Abstract In this work the development of a comprehensive 2-D GC flame ionization detection (GC×GC FID) method for biodiesel fuels is reported. This method is used for the analysis of fatty acid methyl esters (FAMEs) in both biodiesel (B100) and biodiesel blend (B5) samples. The separation of FAME was based on component boiling point in the first dimension and polarity in the second dimension by using a BPX5/BP20 column set to provide a measure of ,orthogonality' in the 2-D space. Here the columns are coupled with a cryogenic modulator operating in a novel temperature programmed mode (TM) whereby the cryotrap is progressively incremented in temperature as the oven temperature is increased. The final method employs eight cryotrap temperature settings. The developed GC×GC method is able to successfully characterize and identify both B100 and B5 FAME components, which are produced from a variety of vegetable oils, animal fats and waste cooking oils, with high precision. The method is capable of analysing FAME with carbon numbers C4,C24, and is particularly suitable to characterize various types of biodiesel, making it possible to differentiate the origin and type of FAME used in the biodiesel samples. [source] Evaluation of ball and disc wear scar data in the HFRR lubricity testLUBRICATION SCIENCE, Issue 1 2008Gerhard Knothe Abstract The high-frequency reciprocating rig (HFRR) lubricity tester has become a widespread method for determining the lubricity of diesel fuels. The test is a ball-on-disc method, in which a steel ball scrapes over a steel disc immersed in the liquid to be tested. According to standards, the wear scar generated on the ball, in the form of the average of the x - and y -axes, is used for evaluating the lubricity of the sample. Generally, the smaller the wear scar, the greater the lubricity of the sample. However, a wear scar is also generated on the disc. The size of the wear scar on the disc also depends on the lubricity of the sample. In this work, the wear scar data of the balls and discs of 230 samples related to the testing of biodiesel and related compounds with petrodiesel were evaluated. Data comparisons for all wear scar combinations correlated well by linear regression. Although correlations are slightly better when using only ball wear scar data (r2 > 0.99), other wear scar data, including those generated on the disc, appear just as useable (r2 , 0.97,0.99) for evaluating lubricity by the HFRR test. The wear scars on the disc have the advantage of being more easily measurable and recognisable under the microscope, especially if the wear scars are small. Limits for all wear scar values corresponding to current limits for average ball wear scar data in standards are presented. Published in 2007 by John Wiley & Sons, Ltd. [source] Preparation and evaluation of vegetable oil derived biodiesel esters as lubricity additivesLUBRICATION SCIENCE, Issue 2 2001X. Lang Abstract Various vegetable-oil derived esters using methyl, ethyl, butyl, and 2-propyl alcohols were prepared and tested as diesel fuel lubricity additives in a roller-on-cylinder lubricity evaluator. At1% additive treat rate, the canola methyl and 2-propyl esters, the best-performing esters, increased the lubricity number of a reference fuel by 60%. Statistical analyses indicated strong effects of fatty acids and alcohols on the wear, friction, and lubricity number of the fuel. While no single fatty acid was identifiably responsible for the wear reduction, certain non-linoleic compounds correlated with the wear data in a semi-log relationship. The low-temperature behaviour of the biodiesel was studied using differential scanning calorimetry. The major transitional peak temperature of the biodiesel esters changed with the melting points of their primary fatty acids, and decreased with the lengthening and branching of the tail alkyl groups. [source] | |||||||||||||||||||||||||||||||