| 摘要 |
The present invention relates to a process for producing carboxylic acid anhydrides by the carbonylation reaction of a carboxylic acid ester, derived from an alcohol and a carboxylic acid, with carbon monoxide containing a small amount of hydrogen in a liquid reaction medium in the presence of a Group VIII B catalyst to produce a carboxylic acid anhydride. The liquid reaction medium comprises the Group VIII B catalyst, an organic halide, the carboxylic acid ester, an alkali metal salt, the carboxylic acid anhydride, the carboxylic acid, N-acetylimidazole as a protecting agent, and ethylidene diacetate (EDA) as an organic promoter. By making use of the protecting agent of N-acetylimidazole, metal ions in the reactor can be prevented from reacting with EDA so as to reduce the formation of hardly-soluble tars during the reaction. Also, the EDA organic promoter is kept at a certain content in the system to promote the overall carbonylation reaction rate. |
