FIELD: chemistry.
SUBSTANCE: disclosed is a method for removing acetaldehyde from a mixture of methyl acetate, dimethyl ether and acetaldehyde, comprising: (i) loading a mixture of methyl acetate, acetaldehyde and dimethyl ether into a distillation column; (ii) distilling the mixture to generate an overhead stream depleted in acetaldehyde as compared to the feed mixture, a base stream depleted in acetaldehyde as compared to the feed mixture and a sidedraw stream enriched in acetaldehyde as compared to the feed mixture; (iii) withdrawing from the column the sidedraw stream enriched in acetaldehyde at a point above the feed point of the feed mixture to the column; and wherein the feed mixture to the distillation column is derived from one or more processes for carbonylating dimethyl ether with carbon monoxide in the presence of a zeolite carbonylation catalyst. Also disclosed is a method for combined production of acetic acid and dimethyl ether.
EFFECT: ensuring the content of acetaldehyde and methyl formate, acceptable for subsequent use in the methods of combined production of acetic acid and dimethyl ether from raw material containing methyl formate and methanol.
19 cl, 4 dwg, 7 tbl, 5 ex
