Catalytic performance in processes for preparing acetic acid
AssigneeBP Chemicals Limited
InventorsBerian John Daniel, John Glenn Sunley, Russell Alan Taylor, Gareth Gerald Armitage
Life of this patent
Estimating the term…
Abstract
In processes for the hydrolysis of a methyl acetate with at least one of water and methanol in the presence of at least one Brønsted acid catalyst to produce acetic acid the performance of the catalyst is improved by using a methyl acetate feed in which the total amount of acetaldehyde and 1,1 dimethoxyethane impurities is maintained at 100 ppm wt or less calculated as mass equivalents of acetaldehyde.
Claims18
A process for the dehydration-hydrolysis of methyl acetate and methanol to co-produce acetic acid and dimethyl ether which process is integrated with a carbonylation process for the production of methyl acetate which integrated process comprises the steps:
- a) carbonylating dimethyl ether with a carbon monoxide-containing gas in the presence of a zeolite carbonylation catalyst to produce a carbonylation reaction product and recovering methyl acetate therefrom;
- b) pre-treating at least a portion of the methyl acetate recovered in step (a) to reduce the amount of acetaldehyde and 1,1 dimethoxyethane impurities therein;
- c) converting methanol and methyl acetate by dehydration-hydrolysis in the presence of at least one Brønsted acid catalyst to co-produce acetic acid and dimethyl ether;
- in which dehydration-hydrolysis process the performance of the at least one Brønsted acid catalyst is improved by using as a methyl acetate feed methyl acetate pre-treated in step (b) in which the total amount of acetaldehyde and 1,1 dimethoxyethane impurities is maintained at 100 ppm wt or less calculated as mass equivalents of acetaldehyde,
- wherein each of the at least one Brønsted acid catalysts is a zeolite or a heteropolyacid.
Dependencies are inferred from the claim text.