Catalyst and process for the production of acetic acid and dimethyl ether
View Patent ↗Process for the co-production of acetic acid and dimethyl ether products from a mixture of methanol and methyl acetate by contacting the mixture at a temperature from 200 to 260° C., with a catalyst composition containing a zeolite possessing a 2-dimensional channel system. The catalyst system contains at least one channel having a 10-membered ring and a silica:alumina molar ratio of at least 22:1.
1. A process for the co-production of acetic acid and dimethyl ether from a mixture of methanol and methyl acetate which process comprises contacting in a reaction zone methanol feedstock and methyl acetate feedstock with a catalyst composition at a temperature from 200 to 260° C. to produce acetic acid and dimethyl ether, and wherein said catalyst composition comprises a zeolite which has a 2-dimensional channel system comprising at least one channel having a 10-membered ring and a silica:alumina molar ratio of at least 22:1.
2. A process according to claim 1 wherein the zeolite further comprises at least one channel having an 8-membered ring.
3. A process according to claim 2 wherein the zeolite has a framework structure selected from the group consisting of FER, HEU, MFS, DAC, STI, NES, MWW and TER.
4. A process according to claim 3 wherein the zeolite has the framework structure FER.
5. A process according to claim 4 wherein the zeolite of framework structure FER is ferrierite.
6. A process according to claim 1 wherein the zeolite is in the hydrogen form.
7. A process according to claim 1 wherein the zeolite has a SAR in the range 30 to 60.
8. A process according to claim 1 wherein the process is carried out at a temperature in the range 220 to 250° C.
9. A process according to claim 1 wherein at least one of the methanol and methyl acetate feedstocks comprises acetone.
10. A process according to claim 9 wherein the acetone is present in at least one of the methanol and methyl acetate feedstocks in a total amount of from >0 to 5 mol % based on the total feed (including any recycles).
11. A process according to claim 1 wherein at least one of the methanol and methyl acetate feedstocks comprises acetone, and the methanol and methyl acetate feedstocks are contacted at a temperature in the range 210 to 250° C. with a zeolite which is a ferrierite in the hydrogen form and which ferrierite has a SAR in the range 22 to 90.
12. A process according to claim 11 wherein acetone is present in at least one of the methanol and methyl acetate feedstocks in a total amount of from >0 to 5 mol % based on the total feed (including any recycles) to the reaction zone.
13. A process according to claim 1 wherein the catalyst composition comprises at least one inorganic oxide binder.
14. A process according to claim 13 wherein the binder is an alumina.
15. A process according to claim 13 wherein the catalyst composition is in the form of an extrudate.
16. A process according to claim 1 wherein the methanol and methyl acetate are in a molar ratio in the range 1:0.1 to 1:40.
17. A process according to claim 1 wherein water is introduced into the reaction zone.
18. A process according to claim 17 wherein water is introduced in an amount in the range 3 to 40 mol % based on the total feed to the reaction zone (including any recycles).
19. A process according to claim 1 wherein the process is operated in the vapour phase.