Disclosed is a process for the extractive recovery of an acid catalyst from an aqueous mixture of glycolic acid with an extraction solvent comprising a tertiary amine or an onium carboxylate compound, a modifier, and a diluent. The acid catalyst, which can comprise strong acids such as sulfuric acid, alkyl sulfonic acids, and fluoroalkyl sulfonic acids, can be recovered by back extraction with aqueous formaldehyde and recycled to a process for the preparation of glycolic acid by the acid-catalyzed carbonylation of formaldehyde. Also disclosed is a process for the preparation of glycolic acid by the acid-catalyzed hydrocarboxylation of formaldehyde.
本发明公开了一种从含有
乙醇酸
水溶液中提取回酸性催化剂的萃取回收工艺,所用的萃取剂包括三级胺或离子型
羧酸盐化合物、改性剂和稀释剂。酸性催化剂可以包括强酸,如
硫酸、烷基
磺酸和氟烷基
磺酸,可以通过用
甲醛水溶液进行回萃取而回收,然后回收的催化剂可以再次用于
甲醛酸催化合成
乙醇酸的工艺中。本发明还公开了一种通过酸性催化剂催化
甲醛羟基羧化合成
乙醇酸的工艺。