| 摘要 |
For the preparation of acetic acid and acetic anhydride, methanol and methyl acetate are reacted under anhydrous conditions with carbon monoxide in the presence of a carbonyl complex of group VIII noble metals, methyl iodide, and catalyst systems containing alkali metal or quaternary organophosphonium or organoammonium acetate or iodide. The hot carbonylation mixture is depressurised, the evaporated components are added to a first distillation zone, and the remaining catalyst solution is fed back to the reaction zone. In the first distillation zone, the volatile carbonylation products are fractionally distilled; the low-boiling components methyl iodide and methyl acetate pass back into the reaction zone, and a mixture of acetic acid and acetic anhydride is obtained as a bottom product which is separated into the pure components in a second and third distillation zone. |
