Process for carbonylation of alkyl ethers

Abstract

A product comprising a lower alkyl ester of a lower aliphatic carboxylic acid is produced by a process comprising reacting a lower alkyl ether with carbon monoxide in the presence of a catalyst comprising mordenite and / or ferrierite, under substantially anhydrous conditions. More specifically, methyl acetate is selectively produced by reaction of dimethyl ether with carbon monoxide in the presence of a catalyst comprising mordenite or ferrierite, under substantially anhydrous conditions.

Description

BACKGROUND OF THE INVENTION [0001] This invention relates to an improved process for the production of methyl acetate from dimethyl ether, and more generally to the production of alkyl esters of aliphatic carboxylic acids, by the carbonylation of alkyl ethers. In another aspect this invention relates to the production of lower aliphatic carboxylic acids by first producing an alkyl ester from a lower alkyl ether, followed by hydrolysis of the ester to the acid. An example of this is the production of acetic acid by carbonylation of dimethyl ether, to form methyl acetate, followed by hydrolysis of the ester to produce acetic acid. [0002] The most widely used industrial process for production of acetic acid is the carbonylation of methanol, which is described generally in British patents 1,185,453 and 1,277,242 and U.S. Pat. No. 3,689,533, for instance. In that type of process, methanol is reacted with carbon monoxide or a carbon monoxide-containing gas in the presence of a rhodium- or...

AI Technical Summary

Benefits of technology

The invention is a process for making a product called methyl acetate by reacting a compound called dimethyl ether with carbon monoxide in the presence of a special catalyst made of mordenite and / or ferrierite. This reaction is done without any water present. The technical effect of this process is the ability to produce a specific chemical compound in a controlled and efficient way.

Problems solved by technology

Though widely used, nonetheless these processes require the use of expensive corrosion-resistant alloys due to the presence of iodide and result in -production of low levels of iodine-containing byproducts that are difficult to remove from the acetic acid by conventional distillation.

Some non-halide based catalyst systems have been investigated for this reaction, but none have been commercialized, primarily due to issues with catalyst lifetime and selectivity.

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