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The production of simple alkyl FA esters by direct alkali-catalyzed in situ transesterification of the acylglycerols (AG) in soybeans was examined. Initial experiments demonstrated that the lipid in commercially produced soy flakes was readily transesterified during agitation at 60°C in sealed containers of alcoholic NaOH. Methyl, ethyl, and isopropyl alcohols readily participated in the reaction, suggesting that the phenomenon is a general one. Statistical experimental design methods and response surface regression analysis were used to optimize reaction conditions, using methanol as alcohol. At 60°C, the highest yields of methyl ester with minimal contamination by FFA and AG were predicted at a molar ratio of methanol/AG/NaOH of 226:1:1.6 with an approximately 8-h incubation. An increase in the amount of methanol, coupled with a reduced alkali concentration, also gave high ester yields with low FFA and AG contamination. The reaction also proceeded well at 23°C (room temperature), giving higher predicted ester yields than at 60°C. At room temperature, maximal esterification was predicted at a molar ratio of 543:1:2.0 for methanol/AG/NaOH, again in 8 h. Of the lipid in soy flakes, 95% was removed under such conditions. The amount of FAME recovered after in situ transesterification corresponded to 84% of this solubilized lipid. Given the 95% removal of lipid from the soy flakes and an 84% efficiency of conversion of this solubilized lipid to FAME, one calculates an overall transesterification efficiency of 80%. The FAME fraction contained only 0.72% (mass basis) FFA and no AG. Of the glycerol released by transesterification, 93% was located in the alcoholic ester phase and 7% was on the post-transesterification flakes.Paper no. J10571 in JAOCS 81, 83-89 (January 2004).KEY WORDS: Biodiesel, fats and oils utilization, fatty acid ester, in situ transesterification, transesterification.The simple alkyl esters of FA have numerous established uses in the food, textile, cosmetic, rubber and metal processing, and synthetic lubricant industries. FAME are the predominant esters consumed, with a year 2000 global consumption of 1 million metric tons (MMT) (1). In addition, FAME are the favored starting material for the production of fatty amides, more complex esters, ester sulfonates, and fatty alcohols. Fatty alcohols alone were consumed at a world rate of 6.2 MMT in 2000 (1). Production and consumption of the methyl esters of FA are rapidly increasing due to their growing use as biodiesel, a renewable replacement for petroleum-based diesel engine fuel.Contemporary industrial technology for the synthesis of fatty acyl esters of vegetable oils involves isolation of oilseed acylglycerides by extrusion or solvent extraction, degumming and refining of the oil, and its alkali-catalyzed transesterification. Hexane extraction is the main technology for oil recovery in the United States. Extraction plants achieve high levels of solvent recovery, with a typical soybean processing plant losing less than 1.25 L of solvent per metric to...

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ABSTRACT. The first comprehensive life-cycle assessment (LCA)

FAME of lard, beef tallow, and chicken fat were prepared by base-catalyzed transesterification for use as biodiesel fuels. Selected fuel properties of the neat fat-derived methyl esters (B100) were determined and found to meet ASTM specifications. The cold-flow properties, lubricity, and oxidative stability of the B100 fat-derived fuels also were measured. In general, the cold-flow properties of the fat-based fuels were less desirable than those of soy-based biodiesel, but the lubricity and oxidative stability of the fat-based biodiesels were comparable to or better than soy-based biodiesel. Nitrogen oxide (NO x ) emission tests also were conducted with the animal fat-derived esters and compared with soybean oil biodiesel as 20 vol% blends (B20) in petroleum diesel. The data indicated that the three animal fat-based B20 fuels had lower NO x emission levels (3.2-6.2%) than did the soy-based B20 fuel.Paper no. J11054 in JAOCS 82, 585-591 (August 2005).