Patent ID: 8198476

Claim:
A process for the production of acetic acid by carbonylating methanol and/or a reactive derivative thereof selected from methyl acetate, methyl iodide, dimethyl ether and mixtures thereof, with carbon monoxide in the presence of a catalyst in a liquid reaction composition comprising methyl iodide and a concentration of water in the range 0.1 to 30% by weight and wherein the catalyst comprises a complex of a metal with a pincer ligand of general formula (I) wherein Z is carbon and L 1 and L 2 are each a co-ordinating group containing a P donar atom or a N-donor atom; each R 3 is independently selected from hydrogen or a C 1 -C 6 alkyl group and M is selected from Rh and Ir, or general formula (II) wherein Z is carbon and L 3 and L 4 are each a co-ordinating group containing a P donar atom or a N-donor atom and M is selected from Rh and Ir.