Patent ID: 8598376

Claim:
A method for reducing a free fatty acid content of a crude natural oil, comprising: (a) contacting the crude natural oil with an immiscible solvent to thereby produce: an oil product phase substantially depleted in free fatty acids; and a free fatty acid rich solvent phase containing the extracted free fatty acids and further containing glycerides that have been extracted from the crude natural oil; (b) separating the oil product phase substantially depleted in free fatty acids from the free fatty acid rich solvent phase; (c) providing a selectively permeable membrane having a first surface and a second surface; and (d) processing the free fatty acid rich solvent phase with the membrane to recover the glycerides from the solvent phase by contacting the free fatty acid rich solvent phase with the first surface to thereby transfer a portion of the solvent from the first surface to the second surface, wherein the portion of the solvent that is transferred contains a portion of the free fatty acids and a portion of the glycerides, wherein the pressure at the first surface is greater than the pressure at the second surface, and wherein the membrane is a selectively permeable membrane such that the membrane rejections of the free fatty acids (RFFA) and glycerides (RGLY) are greater than 0%, and the membrane rejection (RGLY) of the glycerides is at least 5% greater than the membrane rejection (RFFA) of the free fatty acids.