Carbonylation process for the production of acetic acid and/or methyl acetate

1. A process for the manufacture of at least one of acetic acid and methyl acetate comprising the step of carbonylating at least one carbonylatable reactant selected from methanol, dimethyl ether and dimethyl carbonate with carbon monoxide in the presence of a zeolite of structure type MOR, wherein the zeolite has greater than 50% of its crystals in the size range 0.1 to 3 microns.

2. A process according to claim 1 wherein greater than 50% of the crystals are in the size range 0.1 to 2 microns.

3. A process according to claim 2 wherein greater than 50% of the crystals are in the size range 0.1 to 1.5 microns.

4. A process according to claim 1 wherein greater than 80% of the crystals are in the size range 0.1 to 2 microns.

5. A process according to claim 1 wherein the zeolite has an average particle size of no greater than 6 microns.

6. A process according to claim 5 wherein the average particle size is in the range 2 to 3.5 microns.

7. A process according to claim 4 and wherein the average particle size is in the range 2 to 6 microns.

8. A process according to claim 3 and wherein the average particle size is in the range 2 to 3.5 microns.

9. A process according to claim 1 wherein the zeolite is H-mordenite.

10. A process according to claim 1 wherein the zeolite is a mordenite which has been ion-exchanged or otherwise loaded with one or more metals selected from copper, silver, gold, nickel, iridium, rhodium, platinum, palladium and cobalt.

11. A process according to claim 1 wherein the zeolite has a silica:alumina molar ratio in the range 10 to 40:1.

12. A process according to claim 1 wherein the carbonylatable reactant is dimethyl ether or dimethyl carbonate and the gaseous feed to the process contains less than 2.5 wt % water.

13. A process according to claim 1 wherein the carbonylation is conducted in the presence of hydrogen.