ARS | Publication request: In situ Transesterification: Process Modifications to Improve Efficiency; and Use of the Spent Meal in an Aquaculture Diet

Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2007
Publication Date: May 1, 2007
Citation: Haas, M.J., Barrows, F., Mcaloon, A.J., Scott, K.M. 2007. In situ Transesterification: Process Modifications to Improve Efficiency; and Use of the Spent Meal in an Aquaculture Diet [abstract]. Annual Meeting and Expo of the American Oil Chemists' Society. p. 94.

Technical Abstract: We have previously shown that it is possible to directly transesterify the triglyceride fatty acids of the lipids of soybean, corn germ, canola, distillers dried grains with solubles, and meat & bone meal. Near quantitative 'in situ' transesterification occurs during incubation of the feedstock with alcohol containing alkaline catalyst at temperatures of 23 - 65ºC and ambient pressure. The resulting ester preparation from soybeans meets ASTM specifications for biodiesel. However, a 200 - 300 fold molar excess of alcohol over triglyceride is required for successful reaction. The energy required to recover the excess unreacted alcohol after the reaction, by distillation and condensation, renders the entire process economically noncompetitive with conventional biodiesel production from isolated oil. Using soybeans, and batch-mode reaction conditions, the impact of different methods of feedstock pretreatment on the optimal alcohol requirement for high level transesterification was examined. A simple pretreatment method was identified that resulted in a nearly 60% reduction in the amount of required alcohol. Details of this finding will be discussed. Also presented briefly will be the results of an investigation of the suitability of soy meal previously treated by in situ transesterification as a dietary component of trout meal.