Carbonylation process
View Patent ↗Process for the production of methyl acetate by carbonylating dimethyl ether with carbon monoxide in the presence of hydrogen and a zeolite catalyst. The process is carried out with a molar ratio of hydrogen to carbon monoxide of at least 1 and the catalyst has been calcined at a temperature of from about 375° C. to about 475° C.
1. A process for the production of methyl acetate which comprises carbonylating dimethyl ether with carbon monoxide in the presence of hydrogen and a zeolite catalyst wherein the process is carried out with a molar ratio of hydrogen to carbon monoxide of at least 1 and the catalyst has been calcined at a temperature of from about 375° C. to about 475° C.
2. A process for improving the performance of a zeolite catalyst in the production of methyl acetate by the carbonylation of dimethyl ether with carbon monoxide in the presence of hydrogen wherein the process is carried out with a molar ratio of hydrogen to carbon monoxide of at least 1 and the catalyst has been calcined at a temperature of from about 375° C. to about 475° C.
3. A process according to claim 1 wherein the process is initially conducted with a carbon monoxide to hydrogen molar ratio of at least 1 and thereafter carried out with an hydrogen to carbon monoxide molar ratio of at least 1.
4. A process according to claim 3 wherein the process is initially conducted with a carbon monoxide to hydrogen molar ratio in the range 1 to 4:1 and thereafter carried out with an hydrogen to carbon monoxide molar ratio in the range 1 to 2:1.
5. A process according to claim 1 wherein the catalyst is calcined at a temperature of from about 400° C. to about 475° C.
6. A process according to claim 5 wherein the catalyst is calcined at a temperature of from about 400° C. to about 450° C.
7. A process according to claim 1 wherein the catalyst is calcined in an inert atmosphere or in an oxidising atmosphere.
8. A process according to claim 7 wherein the oxidising atmosphere is air.
9. A process according to claim 1 wherein the catalyst is calcined for a duration of from about 10 minutes to about 10 hours.
10. A process according to claim 9 wherein the catalyst is calcined for a duration of from about 1 hour to about 3 hours.
11. A process according to claim 1 wherein the molar ratio of hydrogen to carbon monoxide is in the range 1 to 10:1.
12. A process according to claim 11 wherein the molar ratio of hydrogen to carbon monoxide is 1 to 2:1.
13. A process according to claim 1 wherein the zeolite contains at least one channel or pocket which is defined by an 8-member ring and the 8-member ring channel or pocket is interconnected with at least one channel defined by a ring with 10 or 12 members.
14. A process according to claim 13 wherein the zeolite is selected from zeolites of framework type MOR, FER, OFF, CHA, GME and MFS.
15. A process according to claim 13 wherein the zeolite is selected from mordenite, ferrierite and offretite.
16. A process according to claim 15 wherein the zeolite is a mordenite in a hydrogen-exchanged or an ammonium-exchanged form.
17. A process according to claim 1 wherein the zeolite is combined with a binder.
18. A process according to claim 17 wherein the binder is a refractory inorganic oxide binder.
19. A process according to claim 18 wherein the refractory inorganic oxide binder is selected from aluminas, silica-aluminas or silicas.
20. A process according to claim 17 wherein the binder is present in an amount of 10% to 30% by weight.
21. A process according to claim 17 wherein the zeolite combined with the binder is in the form of an extrudate.
22. A process according to claim 1 wherein the process is carried out at a concentration of water of less than 1 mol % based on the total gaseous feed to the process.
23. A process according to claim 1 wherein synthesis gas is used as the source of carbon monoxide and hydrogen.
24. A process according to claim 1 wherein the process is carried out at a temperature in the range 200° C. to 350° C.
25. A process according to claim 24 wherein the process is carried out at a temperature in the range 280° C. to 320° C.
26. A process according to claim 1 wherein the process is carried out at a total pressure of from 10 to 100 barg.
27. A process according to claim 1 wherein methyl acetate is introduced into the process in an amount of from 0.05 mol % to 5 mol % based on the total feed to the process.
28. A process according to claim 1 wherein the process is carried out as a vapour phase process.
29. A process according to claim 1 wherein methyl acetate is recovered from the process and some or all of the recovered methyl acetate is converted to acetic acid.