| abstract |
A process for producing acetic anhydride alone or both of acetic anhydride and acetic acid by the reaction of methyl acetate and/or dimethyl ether and, as optional component(s), water and/or methanol with carbon monoxide alone or both of carbon monoxide and hydrogen in the presence of a rhodium compound and methyl iodide as the principal catalysts, wherein trace impurities causative of tar generation is removed by separating the same through distillation in the evaporator and/or in the subsequent refining step, thus reducing the generation of the tar which otherwise turns into a contaminant. |