PRODUCTION OF CARBOXYLIC ACID

摘要

PURPOSE:To provide the title production process intended to reduce production cost in such a way that a product by carbonylation is put to extraction treatment to obtain the objective carboxylic acid; concurrently with this, part of the catalyst used is withdrawn, diluted with water, put to extraction treatment again and recycled. CONSTITUTION:Firstly, in the presence of a catalyst selected from (A) an aqueous sulfuric acid solution, (B) the component A plus phosphoric acid, (C) the component A plus a metal oxide, and (D) the component A plus phosphoric acid plus a metal oxide, a reaction is carried out in a reactive extraction tank 1 between an olefin, carbon monoxide and water into a carbonylated product. Thence, this product is put to extraction treatment to obtain the objective carboxylic acid; concurrently with this, part of the catalyst is introduced into an extraction liquid-receiving tank 2 from which the catalyst is withdrawn and put into a washing tank 3 where it is diluted with water and extracted again. The resulting catalytic phase is then returned to the reactive extraction tank 1. That is, the catalyst recycled in the tank 3 is merged wit another batch of catalyst directly returned from the tank 2 to the tank 1 to be reused, and put to use again.