Rhodium/inorganic iodide catalyst system for methanol carbonylation process withimproved 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 a partial pressure of hydrogen between about 0.1 and 4 psia at reaction total pressure of from about 15 to about 40 atmospheres total reaction pressure.