PROCESS FOR PRODUCING ACETIC ACID Russian patent published in 2016 - IPC C07C51/235 C07C51/42 C07C51/50 C07C53/08 

FIELD: chemistry.

SUBSTANCE: invention relates to a process of producing acetic acid comprising: (a) carbonylating methanol in the presence of a catalyst in a reaction zone to produce a reaction mixture comprising acetic acid, methyl acetate, methyl iodide, catalyst, and water; (b) phase separation of at least part of the reaction mixture in the evaporation zone to obtain: (i) a liquid stream containing catalyst, and (ii) the gaseous stream (BV) containing acetic acid, methyl acetate, methyl iodide and water; (c) separating the gaseous stream in a separation zone into fractions to obtain: (i) the product stream comprising acetic acid and water and (ii) the overhead stream comprising acetic acid, methyl acetate, methyl iodide and water; (d) condensing the overhead stream and form a liquid mixture which contains water of not more than 20 % by weight based on the weight of the liquid mixture and the weight ratio of acetic acid to water of at least 1:1, and the content of alkane ranges from 0.1 to 15 % by weight. based on the weight of the liquid mixture, and (e) separation of 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 alkanes, where a phase separation of a liquid mixture of followed by a step of separation the aqueous and organic phases to form an aqueous stream and the organic stream, and in some cases, recycling at least part of the organic stream to regulate the content of alkanes in the liquid mixture.

EFFECT: phase separation process in the filter-settler for the production of acetic acid by carbonylation of methanol in the presence of a catalyst under conditions of "low water concentrations - high acid concentration" is enhanced by formation of the liquid mixture (D), the water content of which not more than 20 % by weight, calculated based on the weight of the liquid mixture, and the weight ratio of acetic acid to water is at least 1:1, and by separating the liquid mixture by support alkane concentration in the mixture D from 1/10 to 15 wt%, calculated on the basis of weight D, to produce a light, aqueous phase and a heavy organic phase.

14 cl, 6 dwg, 5 ex, 6 tbl