PURPOSE: In preparing acetic anhydride by cabonylating methyl acetate as a raw material with carbon monoxide, to improve yield and selectivity, by using a supported nickel catalyst, carrying out reaction in the presence of an iodine compound in a gaseous phase at ≥ specific pressure.
CONSTITUTION: Methyl acetate and carbon monoxide are subjected to gaseous phase carbonylation reaction in the presence of a catalyst obtained by supporting nickel on a carrier such as active carbon, etc. and an iodine compound as a reaction promotor at ≥15kg/cm2G total pressure to give acetic anhydride. Nickel chloride, nickel, etc. is preferable as nickel to be supported on the carrier of the catalyst, and its amount supported is preferably 0.5W10wt%. An amount of the iodine compound used is especially preferably 0.075W0.25 (iodine in iodine compound)/(iodine and methyl acetate in iodine compound). The reaction temperature is especially preferably 200W280°C.
FUJIMOTO KAORU
SHIKADA TSUTOMU
MITSUBISHI CHEM IND
TOYO ENGINEERING CORP