Lipid rich compositions, production of lipid rich compositions, production of fatty acid alkyl esters from heterogeneous lipid mixtures

The present invention relates to a method for producing fatty acid alkyl esters, involving esterifying a material containing free fatty acids (FFA) with an alcohol and an inorganic acid catalyst to form a product containing fatty acid alkyl esters, wherein (i) the material contains at least about 40% FFA and is produced by reacting a feedstock with steam and sulfuric acid at a pH of about 1-about 2 or (ii) the material contains at least about 80% FFA and is produced by reacting a feedstock with steam and alkali at a pH of about 11-about 13 and further reacting the feedstock with steam and sulfuric acid at a pH of about 1-about 2. The feedstock may be selected from the oils or soapstocks of soy, coconut, corn, cotton, flax, palm, rapeseed/canola, safflower, sunflower; animal fats; waste greases; and mixtures thereof; or other fully or partially hydrolyzed preparations of such feedstocks. The present invention also relates to a method for producing a lipid rich composition containing at least about 80% FFA, the method involving reacting a feedstock with steam and alkali at a pH of about 11-about 13 and further reacting the feedstock with steam and sulfuric acid at a pH of about 1-about 2. The feedstock may be selected from soy, coconut, corn, cotton, flax, palm, rapeseed/canola, safflower, sunflower, animal fats, waste greases, and mixtures thereof. The feedstock may be selected from the oils or soapstocks of soy, coconut, corn, cotton, flax, palm, rapeseed/canola, safflower, sunflower; animal fats; waste greases; and mixtures thereof; or other fully or partially hydrolyzed preparations of such feedstocks. Furthermore, the present invention concerns a lipid rich composition containing at least about 80% FFA.