Patent ID: 6712946
Filing Date: 2004-03-30
Classification: B01D

Abstract:
A method for preparing 2-keto-L-gulonic acid in a multi-compartment electrodialysis cell, which comprises the steps of:(i) introducing a first feed solution into a first feed compartment of said electrodialysis cell, said first feed solution comprising a multivalent metal salt of a gluconic acid derivative from a fermentation process; (ii) introducing a second feed solution into a second feed compartment of said electrodialysis cell, said second feed solution comprising an acid suitable for providing protons and anions that form soluble salt by-products with the multivalent metal from said multivalent metal salt of the gluconic acid derivative; (iii) transporting anions from said metal salt of the gluconic acid derivative in said first feed compartment across an anion exchange membrane and into an acid product compartment; (iv) forming the 2-keto-L-gulonic acid from the anions of said metal salt of the gluconic acid derivative in said acid product compartment by the introduction of said protons from across a cation exchange membrane in the second feed compartment, and (v) forming said soluble salt by-product by transporting multivalent cations from said multivalent metal salt of the gluconic acid derivative in the first feed compartment across a cation exchange membrane and with anions of the acid transported across an anion exchange membrane from said second feed compartment.