| 摘要 |
The phase separation in the decanter of a process for producing acetic acid by carbonylating methanol in the presence of a catalyst under low water-high acid conditions is facilitated and expedited by forming a liquid mixture (D) which has a water content of at most 10% by weight, based on the weight of the liquid mixture, an acetic acid content of at least 10% by weight, based on the weight of the liquid mixture, and a weight ratio of methyl iodide to methyl acetate of at least 1.5:1, and partitioning the liquid mixture at a temperature of from 0 to 35° C. |
| 主权项 |
1. A process for producing acetic acid which comprises:
(a) carbonylating methanol in the presence of a catalyst in a reaction zone to obtain a reaction mixture (A) comprising acetic acid, methyl acetate, methyl iodide, the catalyst, and water; (b) separating at least a part of the reaction mixture (A) in a flash zone to obtain a liquid stream (BL) comprising the catalyst, and a vapor stream (BV) comprising acetic acid, methyl acetate, methyl iodide, and water, and withdrawing the vapor stream (BV) from the flash zone; (c) separating the vapor stream (BV) in a fractioning zone to obtain a product stream (CP) comprising acetic acid and a minor amount of water, and an overhead stream (CO) comprising acetic acid, methyl acetate, methyl iodide, and water, (d) condensing the overhead stream (CO) and forming a liquid mixture (D) which has a water content of at most 10% by weight, an acetic acid content of at least 10% by weight, and which comprises methyl iodide and methyl acetate in a weight ratio of methyl iodide to methyl acetate of at least 1.5:1, (e) partitioning the liquid mixture (D) in a partitioning zone to obtain a light, aqueous phase (DA) comprising acetic acid, and water, and a heavy, organic phase (DO) comprising methyl iodide, and methyl acetate; wherein the liquid mixture (D) is partitioned at a temperature of from 0 to 35° C. wherein the liquid mixture (D) comprises (i) from 30 to 84.9% by weight of methyl iodide, (ii) from 10 to 25% by weight of acetic acid, (iii) from 5 to 35% by weight of methyl acetate, and (iv) from 0.1 to 10% by weight of water, the weight percentages in each case being based on the total weight of the components (i) to (iv). |
