The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 08, 2005
Filed:
Dec. 21, 2001
Steven Thomas Perri, Kingsport, TN (US);
Michael Roy Cushman, Punta Gorda, FL (US);
Jeffery Earl Grant Powell, Blountville, TN (US);
Brendan William Boyd, Johnson City, TN (US);
Bhaskar Krishna Arumugam, Kingsport, TN (US);
Nick Allen Collins, Fall Branch, TN (US);
Steven Thomas Perri, Kingsport, TN (US);
Michael Roy Cushman, Punta Gorda, FL (US);
Jeffery Earl Grant Powell, Blountville, TN (US);
Brendan William Boyd, Johnson City, TN (US);
Bhaskar Krishna Arumugam, Kingsport, TN (US);
Nick Allen Collins, Fall Branch, TN (US);
Eastman Chemical Company, Kingsport, TN (US);
Abstract
The present invention comprises the use of sulfite additives to reduce discoloration of L-ascorbic acid produced from acid or aqueous solutions of 2-keto-L-gulonic acid. In one aspect, the present invention comprises a continuous process for producing L-ascorbic acid from an aqueous solution of 2-keto-L-gulonic acid. The use of sulfite additives reduces product stream color and improves product recovery by binding to high molecular weight reaction by-products. In a continuous process, the reaction stream is separated from residual sulfite and sulfite-bound by-products to produce a product stream enriched in aqueous ascorbic acid for recovery, and an enriched 2-keto-L-gulonic acid stream which is recycled to the reactor. The in situ use of sulfite additives during the reaction increases the overall yield of L-ascorbic acid, with no loss in selectivity of the synthesis.