Patent ID: 8252560

Claim:
A process for producing fatty acids, comprising feeding a liquid mixture comprising two liquid phases formed of an oil-phase substrate containing oils and fats and an aqueous phase substrate into a fixed-bed reaction column comprising an immobilized lipase, and allowing the two liquid phases to flow in a co-current manner wherein a hydrolysis reaction is performed when said liquid phases are in contact with said immobilized lipase in said fixed-bed reaction column; wherein the fixed-bed reaction column comprises partition plates so as to comprise a plurality of tube-shaped structures, wherein each tube-shaped structure has a cross-section which is rectangular, circular, oval, or polygonal in shape with at least a part being unclosed and the cross-section has a representative length of 100 mm or less; wherein the representative length means a length of the diagonal if the cross-section is rectangular, wherein the representative length means a length of the diameter if the cross-section is circular, wherein the representative length means a length of the diameter of a circle having the same area as projected area of the shape if the cross-section is oval or polygonal shape, and wherein the length of the part being unclosed in the cross-section is 0.1 to 10 mm.