Vapor phase carbonylation of dimethyl ether and methyl acetate with nickel-active carbon catalysts

Abstract

Vapor phase carbonylation of dimethyl ether and methyl acetate on nickel-active carbon catalysts was studied under pressurized conditions in the presence of methyl iodide as a promoter. Methyl acetate was synthesized from dimethyl ether and carbon monoxide with a selectivity of 80 to 90% at 250° C and 11 atm. A small amount of acetic anhydride was obtained at higher pressure which was essential for the acetic anhydride formation from methyl acetate. By-products such as acetic acid, methane and carbon dioxide were formed in both reactions. In particular, fairly large amount of acetic acid was formed in spite of the reaction under water free condition to bring about the decrease in the selectivity to acetic anhydride.