Rhodium/inorganic iodide catalyst system for methanol carbonylation process with improved impurity profile

摘要

The method of the present invention provides an improvement upon prior art methanol carbonylation methods which substantially reduces the production of carbonyl impurities.The production of carbonyl impurities, particularly acetaldehyde, crotonaldehyde, and 2-ethyl crotonaldehyde, in methanol carbonylation reactions has been found to decrease by maintaining less than about 4.5 wt % methyl iodide in the reaction medium during the course of the reaction.