PURPOSE:To obtain high-quality fatty acids effectively for energy saving and pollution policy, by treating alkali oil cake with lipase to give decomposed oil cake, adding an acid to the cake to liberate fatty acids and heat-treating them with an emulsion breaking agent. CONSTITUTION:1pt.vol. alkali oil cake of fat and oil purification process of rice bran oil, beaf tallow, etc., is blended with <=1pt.vol. aqueous solution having 5-100 units lipase based on 1g alkali oil cake. Then, >=95% of the mixture is decomposed at 30-50 deg.C for <= several hours. Then, an acid is added to the decomposed oil cake, which is adjusted to <=3pH. The whole soap and acidic soap in the decomposed oil cake are converted into liberated fatty acids. Then, 0.01-10wt% based on the decomposed oil cake of an emulsion breaking agent (e.g., is solution of higher alcohol sulfate in acetone) is added to the decomposed oil cake, the blend is heated at 40-100 deg.C and centrifuged. A solvent is removed from a separated oil layer, and the fatty acids are further purified by distillation, to give high-quality fatty acids.
