Patent ID: 6610863
Filing Date: 2003-08-26
Classification: C07D,Y02P

Abstract:
A continuous process for manufacturing L-ascorbic acid comprising the steps of:(a) heating in a reactor an aqueous solution comprising 2-keto-L-gulonic acid, diacetone-2-keto-L-gulonic acid, or an ester of 2-keto-L-gulonic acid to form L-ascorbic acid at a conversion of less than 100 percent; (b) continuously removing from the reactor a post-reaction solution comprising unreacted 2-keto-L-gulonic acid compound and L-ascorbic acid; (c) continuously separating L-ascorbic acid from unreacted 2-keto-L-gulonic acid compound in the post-reaction solution to form an L-ascorbic acid rich solution and a solution rich in unreacted 2-keto-L-gulonic acid compound; and (d) continuously recycling the solution rich in 2-keto-L-gulonic compound of step (c) back to the reactor.