Process for separation of crude naphthalene dicarboxylic acid using reverse osmosis
申请人:Mossi & Ghisolfi Overseas, S.A.
公开号:US20020123646A1
公开(公告)日:2002-09-05
Disclosed is a process for purifying 2,6-naphthalene dicarboxylic acid produced by disproportionation and more efficiently recycling byproduct dipotassium salts which includes the steps of:
a) Contacting an aqueous solution containing the disalt of 2,6-NDA(2,6-K2NDA) with carbon dioxide to form as a precipitate the monopotassium salt of 2,6-NDA (KHNDA) and an aqueous solution containing 2,3-KHNDA, K2NDA, and potassium bicarbonate;
b) Disproportionating said monopotassium salt (KHNDA) to form 2,6-NDA and an aqueous solution containing K2NDA, and potassium bicarbonate;
c) Separating said 2,6-NDA and concentrating said aqueous solution containing K2NDA and potassium bicarbonate by reverse osmosis.
本发明公开了一种用于纯化通过歧化反应生产的 2,6-萘二羧酸并更有效地回收副产物二钾盐的工艺,该工艺包括以下步骤
a) 将含有 2,6-萘二甲酸二盐(2,6-K2NDA)的水溶液与二氧化碳接触,形成 2,6-NDA 的单钾盐(KHNDA)沉淀和含有 2,3-KHNDA、K2NDA 和碳酸氢钾的水溶液;
b) 将所述单钾盐 (KHNDA) 进行歧化,形成 2,6-NDA 和含有 K2NDA 和碳酸氢钾的水溶液;
c) 通过反渗透分离所述 2,6-NDA 和浓缩所述含有 K2NDA 和碳酸氢钾的水溶液。