Patent ID: 7342129

Claim:
A process for the production of acetic acid comprising carbonylating methanol and/or a reactive derivative thereof with carbon monoxide in a carbonylation reaction zone containing a liquid reaction composition comprising an iridium carbonylation catalyst, methyl iodide co-catalyst, a finite concentration of water, acetic acid, methyl acetate, at least one promoter selected from the group consisting of ruthenium, osmium and rhenium and a stabilizing compound selected from the group consisting of alkali metal iodides, alkaline earth metal iodides, metal complexes capable of generating I − , salts capable of generating I − , and mixtures of two or more thereof wherein the molar ratio of promoter to iridium is greater than 2:1, and the molar ratio of stabilizing compound to iridium is in the range greater than 0:1 to 5:1, except that when the stabilizing compound is a lithium compound the molar ratio of promoter to iridium is greater than 5:1 and the molar ratio of the lithium stabilizing compound to iridium is 0.05:1 to 5:1, such that loss of the catalyst and/or the promoter from the liquid reaction composition and/or subsequent process streams is reduced.