Patent ID: 7671233

Claim:
A process for preparing a carboxylic acid, comprising the steps of: reacting an alcohol or its derivative with carbon monoxide in a liquid reaction solution to carry out a carbonylation reaction to form the carboxylic acid, wherein the liquid reaction solution comprises a rhodium catalyst, water, organohalide, carboxylic ester, hydrohalic acid, a catalyst promoter and the carboxylic acid, and wherein the catalyst promoter has a structure represented by formula (I): MnYz (I) wherein, M is selected from the group consisting of group IIIA-IVA metals, group IB-VIIIB metals and lanthanides; Y is selected from the group consisting of simple or complex anions of hydroxide, carbonate, oxalate, acetate, nitrate, oxygen-containing halic acid, sulfate, phosphate, halogen atom and oxygen atom; and n and z are integers for balancing charges; and a dissolved concentration of the rhodium catalyst in the liquid reaction solution ranges from 200 to 5000 ppm.