PROCESS FOR MAKING ACETIC ANHYDRIDE

摘要

PROCESS FOR MAKING ACETIC ANHYDRIDE The disclosure relates to a process for making acetic anhydride wherein methyl acetate and/or dimethylether (is) are reacted with carbon monoxide under practically anhydrous conditions at temperatures of 390 to 540 K, under pressures of 1 to 300 bars in the presence of a catalyst system comprised of noble metals belonging to group VIII of the Periodic System of the elements or their compounds, iodine and/or its compounds and a tertiary or quaternary organic nitrogen, phosphorus, arsenic or antimony compound. More particularly, use is made of a catalyst system containing vanadium or niobium or their compounds as additional constituents, the catalyst system being used in combination with reaction gas containing carbon monoxide and 5 to 30 volume % hydrogen.