Methanol carbonylation process with rhodium catalyst and a lanthanide metal co-catalyst

摘要

A carbonylation process for making acetic acid using a metallic co-catalyst composition, effective as a rhodium stabilizer and/or rate promoter, at molar ratios of metal/rhodium of about 0.5 to 40. The process includes reacting methanol with carbon monoxide in the presence of a rhodium-based catalytic metal complex with about 1 to 20 weight percent methyl iodide, less than about 8 weight % water and about 0.5 to about 30 weight percent methyl acetate. The crude acetic acid is flashed and further purified. This process is stable in the absence of a lithium iodide cocatalyst, or in low concentrations of lithium iodide, with an STY greater than 10 mol/L/hr.