Comparison of Membrane Extraction with Traditional Extraction Methods for Biodiesel Production
01 May 2006-Journal of the American Oil Chemists' Society (John Wiley & Sons, Ltd)-Vol. 83, Iss: 5, pp 457-460
TL;DR: In this paper, three traditional methods for the refining step in biodiesel production were compared: washing with distilled water, washing with acid (HCl), and dissolving and extracting in a solvent (hexane or petroleum ether).
Abstract: Three traditional methods for the refining step in biodiesel production were compared: (i) washing with distilled water; (ii) washing with acid (HCl); and (3) dissolving and extracting in a solvent (hexane or petroleum ether) and then washing with distilled water. Biodiesel with a high purity (97.5%) could be obtained by all three methods, but serious emulsification occurred during the refining processes, which led to high refining losses. A novel refining method was developed by using hollow fiber membrane extraction, and polysulfone was selected as the most suitable membrane. This process effectively avoided emulsification during refining and decreased the refining loss. The purity of the biodiesel obtained was about 99%; and other properties, such as density, kinematic viscosity, water content, and acid value, conformed to the standards.
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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.
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TL;DR: In this paper, the authors reviewed the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.
Abstract: The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Petroleum based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain region of the world. Therefore, those countries not having these resources are facing a foreign exchange crisis, mainly due to the import of crude petroleum oil. Hence it is necessary to look for alternative fuels, which can be produced from materials available within the country. Although vegetative oils can be fuel for diesel engines, but their high viscosities, low volatilities and poor cold flow properties have led to the investigation of its various derivatives. Among the different possible sources, fatty acid methyl esters, known as Biodiesel fuel derived from triglycerides (vegetable oil and animal fates) by transesterification with methanol, present the promising alternative substitute to diesel fuels and have received the most attention now a day. The main advantages of using Biodiesel are its renewability, better quality exhaust gas emission, its biodegradability and the organic carbon present in it is photosynthetic in origin. It does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the green house effect. This paper reviews the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.
1,250 citations
TL;DR: In this paper, the effect of novel processes such as membrane reactor, reactive distillation column, reactive absorption, ultrasonic and microwave irradiation significantly influenced the final conversion, yield and in particular, the quality of product.
630 citations
TL;DR: In this article, both conventional and most recent membrane technologies used in refining biodiesel have been critically reviewed, and the effects of catalysts, free fatty acids, water content and oil to methanol ratios on the purity and quality of biodiesel are also examined.
424 citations
TL;DR: In this article, a review is presented about generation, transesterification, factors affecting transesterion, catalysts (homogeneous and heterogeneous) and physico-chemical characterization of biodiesel by chromatographic and spectroscopic techniques.
Abstract: Biofuel has got tremendous attraction for the last decade as an alternative source of energy. Bioethanol and biodiesel are two main products of first generation biofuel. Biodiesel is chemically fatty acid methyl esters prepared from various edible and non-edible oils. It has been used as a substitute to mineral diesel during the last decade. This review is about generation, transesterification, factors affecting transesterification, catalysts (homogeneous and heterogeneous) and physico-chemical characterization of biodiesel by chromatographic and spectroscopic techniques. The alkaline homogeneous catalysts (NaOH or KOH) have been used on commercial scale for production of biodiesel because these are cheap and reaction occurs in less time. The heterogeneous catalysts such as metal oxides, e.g., CaO, MgO, SrO, ZnO, La2O3, Mg–Al hydrolalcite have been used for transesterification of vegetable oil due to their easy separation and reuse but these catalysts take more time for completion of reaction. The yield of biodiesel may be affected by alcohol/oil ratio, concentration of catalyst, time required for reaction, temperature free fatty acid moisture. The prepared biodiesel has been characterized by chromatographic techniques like gas chromatography, gas chromatography–mass spectroscopy, high performance liquid chromatography and spectroscopic techniques like nuclear magnetic resonance and infrared spectroscopy.
208 citations
References
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TL;DR: In this article, the transesterification reaction is aected by molar ratio of glycerides to alcohol, catalysts, reaction temperature, reaction time and free fatty acids and water content of oils or fats.
4,902 citations
TL;DR: In this paper, the authors showed that the conversion to methyl, ethyl and butyl esters from cottonseed, peanut, soybean and sunflower oils can be done in 1 hr with an alkaline catalyst.
Abstract: Transesterification reaction variables that affect yield and purity of the product esters from cottonseed, peanut, soybean and sunflower oils include molar ratio of alcohol to vegetable oil, type of catalyst (alkaline vs acidic), temperature and degree of refinement of the vegetable oil. With alkaline catalysts (either sodium hydroxide or methoxide), temperatures of 60 C or higher, molar ratios of at least 6 to 1 and with fully refined oils, conversion to methyl, ethyl and butyl esters was essentially complete in 1 hr. At moderate temperatures (32 C), vegetable oils were 99% transesterified in ca. 4 hr with an alkaline catalyst. Transesterification by acid catalysis was much slower than by alkali catalysis. Although the crude oils could be transesterified, ester yields were reduced because of gums and extraneous material present in the crude oils.
1,990 citations
"Comparison of Membrane Extraction w..." refers methods in this paper
...ABSTRACT: Three traditional methods for the refining step in biodiesel production were compared: (i) washing with distilled water; (ii) washing with acid (HCl); and ( 3 ) dissolving and extracting in a solvent (hexane or petroleum ether) and then washing with distilled water....
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...JAOCS, Vol. 83, no. 5 (2006) FIG. 1. Experimental device for transesterification: (1) constant temperature bath; (2) condenser; ( 3 ) glass tank reactor; (4) magnetic stirrer; (5) reaction mixture; and (6) rotor....
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TL;DR: Although all the transesterification reactions were quite rapid and the biodiesel layers achieved nearly 100% methyl ester concentrations, the reactions using sodium hydroxide turned out the fastest.
1,225 citations
Additional excerpts
...JAOCS, Vol. 83, no. 5 (2006) FIG. 1. Experimental device for transesterification: (1) constant temperature bath; ( 2 ) condenser; (3) glass tank reactor; (4) magnetic stirrer; (5) reaction mixture; and (6) rotor....
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TL;DR: In this article, the effects of the type of alcohol, 1-butanol or methanol (MeOH), molar ratio of alcohol to SBO, type and amount of catalyst, and reaction temperature on rate constants and kinetic order were examined.
Abstract: Transesterification of soybean oil (SBO) and other triglycerides with alcohols, in the presence of a catalyst, yields fatty esters and glycerol. Di- and monoglycerides are intermediates. Reactions are consecutive and reversible. Rate constants have been determined for each reaction with a computerized kinetic program. The effects of the type of alcohol, 1-butanol or methanol (MeOH); molar ratio of alcohol to SBO; type and amount of catalyst; and reaction temperature on rate constants and kinetic order were examined. Forward reactions appear to be pseudo-first order or second order depending upon conditions used. Reverse reactions appear to be second order. At a molar ratio of MeOH/SBO of 6:1, a shunt reaction was observed. Energy of activation was determined for all forward and reverse reactions under a variety of experimental conditions from plots of log k vs 1/T. Values ranged from 8–20 kcal/mol.
1,215 citations
Additional excerpts
...JAOCS, Vol. 83, no. 5 (2006) FIG. 1. Experimental device for transesterification: (1) constant temperature bath; (2) condenser; (3) glass tank reactor; (4) magnetic stirrer; ( 5 ) reaction mixture; and (6) rotor....
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TL;DR: A general review of hollow fiber membrane contactors, including operating principles, relevant mathematics, and applications, is provided in this paper, where a number of membrane module geometries are possible, hollow fiber modules have received the most attention.
1,207 citations