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United States Department of Agriculture

Agricultural Research Service

Title: The General Applicability of the Direct Transesterification of Lipid-Bearing Materials for Biodiesel Production

Authors
item Haas, Michael
item McAloon, Andrew
item Foglia, Thomas
item Marmer, William

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2006
Publication Date: February 5, 2006
Citation: Haas, M.J., Mcaloon, A.J., Foglia, T.A., Marmer, W.N. 2006. The general applicability of the direct transesterification of lipid-bearing materials for biodiesel production. National Biodiesel Conference & Expo. p. 37.

Technical Abstract: In contemporary biodiesel production it is typical to employ a feedstock that is an isolated lipid, such as vegetable oil, animal fat, or waste grease. This necessitates the prior isolation of the lipids from raw material feedstocks, which adds cost and processing technology to biodiesel production. We have demonstrated that incubation of flaked soybeans directly in alkaline methanol achieves high efficiency transesterification, eliminating the need for prior isolation of the lipid (Haas et al., J. Am. Oil Chem. Soc., 81(1):83-89, 2004). However, economic analysis indicated that the process costs were not competitive with those for producing biodiesel from isolated oil. We have now determined that the removal of water from the soy flakes greatly reduces the alcohol requirement of the reaction. Following optimization of the reaction employing dried feedstock, an economic analysis indicated a 68% reduction in process costs relative to the use of full-moisture flakes. Following a simple wash to remove a small amount of contaminating free fatty acids, fatty acid esters produced by this method met ASTM specifications. The applicability of this 'in situ' transesterification process for simple fatty acid alkyl ester production from other feedstocks has also been investigated. The approach appears to be generally applicable. Optimal conditions for virtually quantitative transesterification of the lipids in distillers dried grains with solubles and in meat & bone meal are presented, as are conditions for high level transesterification of canola. Production of fatty acid alkyl esters from such feedstocks by in situ transesterification could greatly expand biodiesel production without increasing the use of edible-grade fats and oils.

Last Modified: 11/22/2014