Patent ID: 9090554
Filing Date: 2015-07-28
Classification: C07C

Abstract:
1. A process for producing acetic acid comprising the steps of: (a) carbonylating methanol in the presence of a catalyst in a reaction zone to obtain a reaction mixture comprising acetic acid, methyl acetate, methyl iodide, the catalyst, and water; (b) separating at least a part of the reaction mixture in a flash zone to obtain: (i) a liquid stream comprising the catalyst, and (ii) a vapor stream comprising acetic acid, methyl acetate, methyl iodide, and water; (c) separating the vapor stream in a fractioning zone to obtain: (i) a product stream comprising acetic acid and water; and, (ii) an overhead stream comprising acetic acid, methyl acetate, methyl iodide, and water; (d) condensing the overhead stream and forming a liquid mixture which has a water content of at most 20% by weight, based on the weight of the liquid mixture, a weight ratio of acetic acid to water of at least 1:1, and an alkane content from 0.1 to 15%, based on the weight of the liquid mixture, and (e) partitioning the liquid mixture to form an aqueous phase and an organic phase, wherein the aqueous phase comprises acetic acid and water; and the organic phase comprises methyl iodide, methyl acetate and the alkane content wherein the step of partitioning the liquid mixture is followed by the step of separating the aqueous phase and the organic phase thereby producing an aqueous stream and an organic stream, and recycling at least a portion of the organic stream to provide the alkanes content of the liquid mixture.