对氯苯甲酸在氯苯甲酸体系中的分离

Separation of p-chlorobenzoic Acid from Chlorobenzoic Acids System

难分离的混合邻、对氯甲苯经氧化可制得混合邻、对氯苯甲酸。根据两种酸在水中溶解度和离解常数的差异,采用碱性萃取剂离解萃取结晶分离对氯苯甲酸,制得高纯度的对氯苯甲酸产品。本文考察了萃取剂浓度、用量、反应温度、分散用水量等因素对对氯苯甲酸离解萃取过程的影响,得到了最佳的分离工艺条件。

Chlorobenzoic acids can be synthesized by oxidation of mixed chlorotoluene which was difficult to separate. The separation of p-chlorobenzoic acid was studied by dissociation extractive crystallization in order to obtain high purity products according to their differences in solubilities and dissociation constants in water. In this study, base and acid were used for extraction, and the amount and concentration of extraction, temperature and the amount of water as scatter were investigated during the process of the dissociation extractive ofp-chlorobenzoic acid from chlorobenzoic acid system, the optimal parameters were gotten.