Preparation of acetic anhydride

Abstract

Abstract PURPOSE:To obtain acetic anhydride, combining the preparation processes of acetic acid and acetic anhydride, without causing the problem of azeotropic boiling, by reacting methanol and methyl acetate with CO to obtain acetic acid and acetic anhydride, esterifying the acetic acid with methanol to obtain methyl acetate, and recycling the ester as a raw material. CONSTITUTION:Acetic anhydride is prepared from methanol and CO using a recycling combined preparation process comprising (i) the step for the preparation of acetic acid and acetic anhydride by the carbonylation of methanol and methyl acetate in the carbonylation reaction zone, (ii) the step for the preparation of methyl acetate by the esterification reaction of methanol with acetic acid obtained by the step (i) in the esterification reaction zone, and (iii) the step for introducing methanol and methyl acetate into the carbonylation reaction zone. Although methanol and methyl acetate together form an azeotropic mixture in the esterification reaction zone, it is not necessary to purify methyl acetate to the level purer than the azeotropic composition. The reaction product of methyl acetate with water can be used as methanol and methyl acetate used as the starting materials.

Inventors

• 👤 Takashige Nawata
• 👤 縄田　孝成
• 👤 Yasuhiko Kijima
• 👤 喜嶋　安彦
• 👤 Kenji Ishii
• 👤 賢治 石井
• 👤 Takeshi Miyauchi
• 👤 宮内　雄
• 👤 Kaoru Tsuyuki
• 👤 薫 露木

Bibliographic Details