Patent ID: 8304566

Claim:
A process of production of a biodiesel product comprising a fatty acid ethyl ester product, the process comprising the steps of: a) processing at least one raw material source comprising an average of at least 0.5% by weight of free fatty acids in total oil; b) extracting the free fatty acids and other reactive lipids from the raw material source and reacting the free fatty acids and other reactive lipids with ethanol using an acid catalyst and a base catalyst to form the fatty acid ethyl ester product, comprising the substeps of: i) feeding the raw material source using a screw against a countercurrent liquid flow comprising the ethanol and the acid catalyst to react with the free fatty acids and other reactive lipids; and ii) recycling at least a portion of the countercurrent liquid flow through the screw after flash dehydrating and passing the portion of the countercurrent liquid flow through a cavitation reactor; c) transesterifying any unreacted lipids with ethanol using a base catalyst; and d) separating the fatty acid ethyl ester product from a glycerin byproduct.