Carbonylation process for the production of methyl acetate
A process for the production of methyl acetate by carbonylating at a temperature of 250 to 350° C., in the presence of a zeolite catalyst, a feed comprising dimethyl ether, a gas comprising carbon monoxide and hydrogen at a molar ratio of hydrogen to carbon monoxide of at least 1, methyl acetate and one or more compounds containing a hydroxyl functional group.
1. A process for the carbonylation of dimethyl ether with carbon monoxide in the presence of a catalyst comprising a templated zeolite to produce a reaction product comprising methyl acetate wherein
the process is carried out at a temperature of from 250 to 350° C.,
the feed to the process comprises
dimethyl ether,
carbon monoxide,
hydrogen,
methyl acetate, and
one or more hydroxyl compound(s) selected from water, a C 1 -C 4 aliphatic alcohol, and a C 1 -C 4 aliphatic carboxylic acid;
the molar ratio of hydrogen to carbon monoxide in the feed is at least 1, and
the molar ratio of methyl acetate to the one or more hydroxyl compound(s) is in the range 500:1 to 0.5:1.
2. The process according to claim 1 wherein the feed comprises the hydroxyl compound(s) in a total amount of up to 1 mol % based on a total gaseous feed to the process including the hydroxyl compound(s), dimethyl ether, carbon monoxide, hydrogen, and methyl acetate.
3. The process according to claim 1 wherein the feed comprises the hydroxyl compound(s) in a total amount of 0.01 to 0.5 mol % based on a total gaseous feed to the process including the hydroxyl compound(s), dimethyl ether, carbon monoxide, hydrogen, and methyl acetate.
4. The process according to claim 1 , wherein the feed comprises methyl acetate and the hydroxyl compound(s) at a molar ratio of methyl acetate to hydroxyl compound(s) in the range 300:1 to 1:1.
5. The process according to claim 1 , wherein the hydroxyl compound is water.
6. The process according to claim 1 wherein the hydroxyl compound is a C 1 -C 4 aliphatic alcohol.
7. The process according to claim 1 wherein the hydroxyl compound is a C 1 -C 4 aliphatic carboxylic acid.
8. The process according to claim 1 wherein the hydroxyl compound is selected from one or more of water, acetic acid and methanol.
9. The process according to claim 1 , wherein the feed comprises hydrogen and carbon monoxide at a molar ratio of hydrogen to carbon monoxide in the range 1.5 to 4:1.
10. The process according to claim 1 , wherein the feed comprises methyl acetate in an amount up to 5 mol % based on a total gaseous feed to the process including the hydroxyl compound(s), dimethyl ether, carbon monoxide, hydrogen, and methyl acetate.
11. The process according to claim 1 , wherein the catalyst is a zeolite having at least one channel which is defined by an 8-membered ring.
12. The process according to claim 11 wherein the zeolite has a framework type selected from the group consisting of MOR, FER, OFF, CHA, GME, MFS, EON and ETR.
13. The process according to claim 12 wherein the zeolite has the framework type MOR and is mordenite.
14. The process according to claim 1 , wherein the process is carried out at a temperature of from 275 to 325° C.
15. The process according to claim 1 , wherein methyl acetate product is hydrolysed to acetic acid.
16. A method of maintaining or reducing the deactivation rate of a catalyst in a process for the carbonylation of dimethyl ether with carbon monoxide in the presence of a catalyst comprising a templated zeolite to produce a reaction product comprising methyl acetate in which method,
the process is carried out at a temperature of from 250 to 350° C.,
the feed to the process comprises dimethyl ether, carbon monoxide, hydrogen, methyl acetate, and one or more hydroxyl compound(s) selected from water, a C 1 -C 4 aliphatic alcohol, and a C 1 -C 4 aliphatic carboxylic acid,
the molar ratio of hydrogen to carbon monoxide in the feed is at least 1, and
the molar ratio of methyl acetate to the one or more hydroxyl compound(s) is in the range 500:1 to 0.5:1.
17. The process according to claim 1 , wherein the feed to the process includes one or more gaseous recycles, and the feed comprises methyl acetate in an amount up to 5 mol % based on a total gaseous feed, including gaseous recycles, to the process including the hydroxyl compound(s), dimethyl ether, carbon monoxide, hydrogen, and methyl acetate.
18. The process according to claim 1 , wherein the feed comprises methyl acetate and the hydroxyl compound(s) at a molar ratio of methyl acetate to hydroxyl compound(s) in the range 100:1 to 4:1.
19. The process according to claim 1 , wherein the feed comprises
methyl acetate, present in an amount of from 0.5 to 5.0 mol %; and
one or more hydroxyl compounds selected from water, acetic acid, and methanol, present in a combined amount of from 0.03 to 0.5 mol %.
20. The process according to claim 1 , wherein
methyl acetate is present in the feed in an amount of less than 2 mol %;
one or more of water, acetic acid and methanol are present in the feed in a combined amount of from 0.03 to 0.2 mol %;
hydrogen and carbon monoxide are present in the feed in a molar ratio in the range 1.5:1 to 4:1; and
the process is carried out at a temperature of from 275 to 325° C.