Showing papers on "Transesterification published in 2010"
TL;DR: In this article, the main factors affecting the yield of biodiesel, i.e. alcohol quantity, reaction time, reaction temperature and catalyst concentration, are discussed, as well as new new processes for biodiesel production.
2,207 citations
TL;DR: It was found that using heterogeneous acid catalyst and enzyme are the best option to produce biodiesel from oil with high FFA as compared to the current commercial homogeneous base-catalyzed process, which still suffers from serious mass transfer limitation problems and therefore is not favorable for industrial application.
1,132 citations
TL;DR: The conversion of vegetable oils into biodiesel is an effective way to overcome all the problems associated with the vegetable oils, such as high fuel viscosity, high ignition delay and longer combustion duration and hence low particulate emissions as discussed by the authors.
782 citations
TL;DR: The current status of biodiesel production with immobilized lipase is reviewed, including various lipases, immobilization methods, various feedstocks, lipase inactivation caused by short chain alcohols and large scale industrialization.
618 citations
TL;DR: This paper is meant to review the latest development in the field of lipase catalyzed transesterification of biologically derived oil to produce biodiesel.
Abstract: Recently, with the global shortage of fossil fuels, excessive increase in the price of crude oil and increased environmental concerns have resulted in the rapid growth in biodiesel production. The central reaction in the biodiesel production is the transesterification reaction which could be catalyzed either chemically or enzymatically. Enzymatic transesterification has certain advantages over the chemical catalysis of transesterification, as it is less energy intensive, allows easy recovery of glycerol and the transesterification of glycerides with high free fatty acid contents. Limitations of the enzyme catalyzed reactions include high cost of enzyme, low yield, high reaction time and the amount of water and organic solvents in the reaction mixture. Researchers have been trying to overcome these limitations in the enzyme catalyzed transesterification reaction. This paper is meant to review the latest development in the field of lipase catalyzed transesterification of biologically derived oil to produce biodiesel.
463 citations
TL;DR: In this paper, the effect of important reaction variables on the production of biodiesel from non-edible microalgae lipids, using the acid-catalysed in situ transesterification process was described.
424 citations
TL;DR: A carbon-based solid acid catalyst was used to simultaneously catalyze esterification and transesterification to synthesis biodiesel when a waste vegetable oil with large amounts of free fatty acids (FFAs) was used as feedstock as discussed by the authors.
404 citations
TL;DR: The solid oxide catalysts derived from waste shells of egg, golden apple snail, and meretrix venus were employed to produce biodiesel from transesterification of palm olein oil and showed high biodiesel production activity over 90% fatty acid methyl ester (FAME) in 2h.
367 citations
TL;DR: In this paper, the authors showed that balanced bifunctional acid-base catalysts where the Lewis acid activates the carbonyl of the urea and the conjugated basic site activates the hydroxyl group of the glycerol were the most active and selective catalysts.
358 citations
TL;DR: In this paper, a promising catalyst based on a biomass pyrolysis byproduct, biochar, has been developed for the production of biodiesel two carbon-based solid acid catalysts were prepared by sulfonating pyrolyses char with concentrated or fuming sulfuric acids.
Abstract: A promising catalyst based on a biomass pyrolysis by-product, biochar, has been developed for the production of biodiesel Two carbon-based solid acid catalysts were prepared by sulfonating pyrolysis char with concentrated or fuming sulfuric acids Prepared catalysts were studied for their ability to catalyze transesterification of vegetable oils and esterification of free fatty acids The catalyst sulfonated with the concentrated sulfuric acid demonstrated considerable conversion in free fatty acid esterification, while indicating limited transesterification activity Using the stronger sulfonating reagent, fuming sulfuric acid, resulted in much higher transesterification activity Further investigation of the latter catalyst was conducted to determine the effect of sulfonation time (5 and 15 h) and surface area on the transesterification reaction The surface area of the biochar was increased by chemical treatment using 10 M potassium hydroxide through porosity development The resulting four catalysts were compared for their catalytic activity Results showed the catalyst with the highest surface area and acid density to have the highest catalytic activity for the production of biodiesel from canola oil in the presence of methanol as the reagent Furthermore, the catalyst with the higher surface area indicated higher transesterification activity among the catalyst with similar acid densities The effects of alcohol to oil (A:O) molar ratio, reaction time and catalyst loading on the esterification reaction catalyzed by the sulfonated biochar were also investigated Free fatty acid (FFA) conversion increased with increasing A:O molar ratio, reaction time and catalyst loading The catalyst has a tremendous potential to be used in a process converting a high FFA feedstock to biodiesel
341 citations
TL;DR: The results indicate that sweet sorghum juice could effectively enhance algal lipid production, and its application may reduce the cost of algae-based biodiesel.
TL;DR: In an effort to process wet algal biomass directly, eliminate organic solvent use during lipid extraction, and recover nutrients for reuse, a catalyst-free, two-step technique for algal biodiesel production is developed.
Abstract: In an effort to process wet algal biomass directly, eliminate organic solvent use during lipid extraction, and recover nutrients (e.g., N, P, and glycerol) for reuse, we developed a catalyst-free, two-step technique for algal biodiesel production. In the first step, wet algal biomass (ca. 80% moisture) reacts in subcritical water to hydrolyze intracellular lipids, conglomerate cells into an easily filterable solid that retains the lipids, and produce a sterile, nutrient-rich aqueous phase. In the second step, the wet fatty acid-rich solids undergo supercritical in situ transesterification (SC-IST/E) with ethanol to produce biodiesel in the form of fatty acid ethyl esters (FAEEs). Chlorella vulgaris grown sequentially under photo- and heterotrophic conditions served as the lipid-rich feedstock (53.3% lipids as FAEE). The feedstock and process solids were characterized for lipid components using highly automated microscale extraction and derivatization procedures and high-temperature gas chromatography. Hyd...
TL;DR: In this paper, a quaternary ammonium salt-glycerine-based ionic liquid is proposed as a solvent for extracting glycerine from the transesterification biodiesel product.
TL;DR: Amorphous carbon bearing sulfonic acid groups, a new type of solid Bronsted acid catalyst, was investigated for potential application to environmentally benign biodiesel production and cellulose saccharification as discussed by the authors.
Abstract: Amorphous carbon bearing sulfonic acid groups, a new type of solid Bronsted acid catalyst, was investigated for potential application to environmentally benign biodiesel production and cellulose saccharification. The carbon material exhibits much higher catalytic performance for the esterification of higher fatty acids, transesterification of triglycerides and the hydrolysis of cellulose than conventional solid acid catalysts.
TL;DR: In this article, the ultrasonic assisted transesterification of palm oil in the presence of alkaline earth metal oxide catalysts (CaO, SrO and BaO) was investigated.
TL;DR: A comprehensive review of the literature on the subject of biodiesel production was carried out in this paper, where the most popular microbes used for their lipases have been filamentous fungi and recombinant bacteria.
Abstract: Problem Statement: The research on the production of biodiesel has increased significantly in recent years because of the need for an alternative fuel which endows with biodegradability, low toxicity and renewability. Plant oils, animal fats, microalgal oils and waste products such as animal rendering, fish processing waste and cooking oils have been employed as feedstocks for biodiesel production. In order to design an economically and environmentally sustainable biodiesel production process, a proper understanding of the factors affecting the process and their relative importance is necessary. Approach: A comprehensive review of the literature on the subject of biodiesel production was carried out. Traditionally biodiesel has been produced using either acid or base catalysts. The multi-step purification of end products, wastewater treatment and energy demand of the conventional process has lead to search for alternative option for production of biodiesel. The use the enzyme lipase as a biocatalyst for the transesterification reaction step in biodiesel production has been extensively investigated. Lipase is produced by all living organisms and can be used intracellularly or extracellularly. Conclusion: To date, the most popular microbes used for their lipases have been filamentous fungi and recombinant bacteria. A summary of lipases used in transesterification and their optimum operating conditions is provided. In addition to the choice of lipase employed, factors which make the transesterification process feasible and ready for commercialization are: enzyme modification, the selection of feedstock and alcohol, use of common solvents, pretreatment of the lipase, alcohol to oil molar ratio, water activity/content and reaction temperature. Optimization of these parameters is necessary in order to reduce the cost of biodiesel production. Use of no/low cost waste materials as feedstocks will have double environmental benefits by reducing the environmental pollution potential of the wastes and producing an environmentally friendly fuel.
TL;DR: The enzyme has been the first lipase whose structure was reported and its interfacial activation is very well known, making this enzyme a good template for modeling studies, and seems to be advantageous when compared to other lipases mainly in esterificaton reactions in anhydrous media.
Abstract: The lipase from Rhizomucor miehei (RML), formerly Mucor miehei, is a commercially available enzyme in both soluble and immobilized forms with very high activity and good stability under diverse experimental conditions (anhydrous organic solvents, supercritical fluids, etc.). The uses of the enzyme were initially oriented towards food industry, that way the enzyme has found a broad application in this area. This review intends to show the enzyme features and some of the most relevant aspects of the use of this interesting enzyme in oils and fats modification. The enzyme has been the first lipase whose structure was reported and its interfacial activation is very well known, making this enzyme a good template for modeling studies. Finally, the main uses of the enzyme in fatty acids, oils and fats modification will be revised (hydrolysis of glycerides, transesterification, esterification, acidolysis and interesterification). This lipase seems to be advantageous when compared to other lipases mainly in esterificaton reactions in anhydrous media, while other lipases can be preferred in transesterification reactions.
TL;DR: DT proved a convenient and more accurate method than the extraction techniques for quantifying total fatty acid content in microalgae and was more effective than each individually when the sample contained water.
Abstract: Assays for total lipid content in microalgae are usually based on the Folch or the Bligh and Dyer methods of solvent extraction followed by quantification either gravimetrically or by chromatography. Direct transesterification (DT) is a method of converting saponifiable lipids in situ directly to fatty acid methyl esters which can be quantified by gas chromatography (GC). This eliminates the extraction step and results in a rapid, one-step procedure applicable to small samples. This study compared the effectiveness of DT in quantifying the total fatty acid content in three species of microalgae to extraction using the Folch, the Bligh and Dyer and the Smedes and Askland methods, followed by transesterification and GC. The use of two catalysts in sequence, as well as the effect of reaction water content on the efficiency of DT were investigated. The Folch method was the most effective of the extraction methods tested, but comparison with DT illustrated that all extraction methods were incomplete. Higher levels of fatty acid in the cells were obtained with DT in comparison with the extraction-transesterification methods. A combination of acidic and basic transesterification catalysts was more effective than each individually when the sample contained water. The two-catalyst reaction was insensitive to water up to 10% of total reaction volume. DT proved a convenient and more accurate method than the extraction techniques for quantifying total fatty acid content in microalgae.
TL;DR: The present work illustrates the use of sonochemical reactors for the synthesis of biodiesel from waste cooking oil using low frequency ultrasonic reactor (20 kHz) and the efficacy of using ultrasound has been compared with the conventional stirring approach.
TL;DR: An efficient microwave-assisted transesterification (MAT) technique was developed to prepare biodiesel from yellow horn oil with a heteropolyacid catalyst and the product properties of yellow horn biodiesel are found to be in agreement with EN 14214 standard.
TL;DR: In this article, a KF/CaO nanocatalyst was prepared by using impregnation method and used to convert Chinese tallow seed oil to biodiesel, and the effects of different preparation conditions on biodiesel yield were investigated and the structure of the catalyst was characterized.
TL;DR: In this paper, a commercial bench stirred tank (BST) was used to synthesize biodiesel from refined sunflower oil using calcium oxide as a heterogeneous catalyst, with constant parameters of temperature, pressure, and reaction time (1.5-5.5h).
TL;DR: In this paper, the authors used Response Surface Methodology (RSM) in combination with Central Composite Design (CCD) to optimize the operating parameters of ICP-MS for transesterification of palm oil using CaO/Al 2 O 3 solid base catalyst.
TL;DR: In this article, a quadratic polynomial equation was obtained for biodiesel conversion by multiple regression analysis and verification experiments confirmed the validity of the predicted model and provided a practical method to biodiesel production from raw feedstocks with high FFA with high reaction rate, less corrosion, less toxicity, and less environmental problems.
TL;DR: In this article, a two-step acid-esterification and base-transesterification process was further used for biodiesel production from Jatropha oil, and stable and clear yellowish biodiesel was obtained with 964% yield after reaction for 05 h.
TL;DR: In this article, castor methyl ester (CME) was prepared by transesterification using potassium hydroxide (KOH) as catalyst and was used in four stroke, single cylinder variable compression ratio type diesel engine.
TL;DR: In this article, the performance of SBA-15-modified mesostructured materials was investigated for biodiesel production from crude palm oil containing high percentage of free fatty acids over conventional ion-exchange sulfonic resins (Amberlyst-36 and SAC-13) in the simultaneous esterification and transesterification of triglycerides with methanol.
TL;DR: The basic property of the catalyst showed that the fatty acid methyl ester (FAME) yield was related to their basicity, and the model of the solid-state reaction on the surface of La( 2)O(3)/ZrO(2) catalyst was proposed.
TL;DR: The transesterification of palm oil with dimethyl carbonate for preparing biodiesel has been studied in solvent-free system at the catalysis of potassium hydroxide (KOH) as heterogeneous catalyst and a plausible reaction mechanism for the catalytic process with DMC as acyl acceptor was proposed.
TL;DR: Waste lipids such as waste frying oils, waste fats, and soapstock has been proposed as low-cost alternative feedstocks for FAME production, characterized by their elevated acid value due to the high level of free fatty acid (FFA) content.
Abstract: As biodiesel (fatty acid methyl ester (FAME)) is mainly produced from edible vegetable oils, crop soils are used for its production, increasing deforestation and producing a fuel more expensive than diesel. The use of waste lipids such as waste frying oils, waste fats, and soapstock has been proposed as low-cost alternative feedstocks. Non-edible oils such as jatropha, pongamia, and rubber seed oil are also economically attractive. In addition, microalgae, bacteria, yeast, and fungi with 20% or higher lipid content are oleaginous microorganisms known as single cell oil and have been proposed as feedstocks for FAME production. Alternative feedstocks are characterized by their elevated acid value due to the high level of free fatty acid (FFA) content, causing undesirable saponification reactions when an alkaline catalyst is used in the transesterification reaction. The production of soap consumes the conventional catalyst, diminishing FAME production yield and simultaneously preventing the effective separation of the produced FAME from the glycerin phase. These problems could be solved using biological catalysts, such as lipases or whole-cell catalysts, avoiding soap production as the FFAs are esterified to FAME. In addition, by-product glycerol can be easily recovered, and the purification of FAME is simplified using biological catalysts.