公开(公告)号：EP1351949A1

公开(公告)日：2003-10-15

申请号：EP01991443.1

申请日：2001-12-21

申请人： EASTMAN CHEMICAL COMPANY

发明人： ARUMUGAM, Bhaskar ,  COLLINS, Nick ,  MACIAS, Transtio ,  PERRI, Steven ,  POWELL, Jeffery ,  SINK, Chester ,  CUSHMAN, Michael

IPC分类号： C07D307/62

CPC分类号： C07D307/62 ,  Y02P20/582

摘要： The present invention provides methods and an apparatus for the manufacture of an L-ascorbic acid product in high yield by direct conversion of an aqueous solution containing 2-keto-L-gulonic acid by contact with an acid catalyst or under thermal self-catalyzed conditions at a conversion level that maximizes the formation of L-ascorbic acid and minimizes decomposition of the L-ascorbic acid thus formed. The separation process for L-ascorbic acid and KLG is operated in such a way that an efficient separation process allows the majority of the KLG to be recycled for further conversion. The product stream from the separation process is then subjected to a recovery step to obtain crystalline L-ascorbic acid product.

公开(公告)号：EP1368329B1

公开(公告)日：2005-08-31

申请号：EP01992278.0

申请日：2001-12-21

申请人： EASTMAN CHEMICAL COMPANY

发明人： ARUMUGAM, Bhaskar ,  COLLINS, Nick ,  BOYD, Brendan ,  PERRI, Steven ,  POWELL, Jeffery ,  CUSHMAN, Michael

IPC分类号： C07D307/62

CPC分类号： C07D307/62 ,  Y02P20/582

摘要： 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.

公开(公告)号：EP1351949B1

公开(公告)日：2005-05-18

申请号：EP01991443.1

申请日：2001-12-21

申请人： EASTMAN CHEMICAL COMPANY

发明人： ARUMUGAM, Bhaskar ,  COLLINS, Nick ,  MACIAS, Transtio ,  PERRI, Steven Thomas ,  POWELL, Jeffery ,  SINK, Chester ,  CUSHMAN, Michael

IPC分类号： C07D307/62

CPC分类号： C07D307/62 ,  Y02P20/582

公开(公告)号：EP1368329A1

公开(公告)日：2003-12-10

申请号：EP01992278.0

申请日：2001-12-21

申请人： EASTMAN CHEMICAL COMPANY

发明人： ARUMUGAM, Bhaskar ,  COLLINS, Nick ,  BOYD, Brendan ,  PERRI, Steven ,  POWELL, Jeffery ,  CUSHMAN, Michael

IPC分类号： C07D307/62

CPC分类号： C07D307/62 ,  Y02P20/582

摘要： 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.