Process for production of adipic acid from 1,6-hexanediol
Processes are disclosed for the conversion of 1,6-hexanediol to adipic acid employing a chemocatalytic reaction in which 1,6-hexanediol is reacted with oxygen in the presence of particular heterogeneous catalysts including at least one of platinum or gold. The metals are preferably provided on a support selected from the group of titania, stabilized titania, zirconia, stabilized zirconia, silica or mixtures thereof, most preferably zirconia stabilized with tungsten. The reaction with oxygen is carried out at a temperature from about 100° C. to about 300° C. and at a partial pressure of oxygen from about 50 psig to about 2000 psig.
1. A process for preparing adipic acid, the process comprising reacting 1,6-hexanediol and oxygen in the presence of a catalyst comprising platinum on a support comprising zirconia or stabilized zirconia thereby producing a reaction mixture comprising adipic acid, wherein the catalyst does not include gold.
2. The process of claim 1 , wherein the surface area of the support is equal to or less than about 220 m 2 /g.
3. The process of claim 2 , wherein the surface area of the support is equal to or less than about 100 m 2 /g.
4. The process of claim 2 , wherein the average pore diameter of the support is in the range of at least about 5 nanometer to about 70 nanometer.
5. The process of claim 4 , wherein the average pore diameter of the support is at least about 10 nm.
6. The process of claim 1 , wherein the support further comprises tungsten.
7. The process of claim 6 , wherein the tungsten is present in an amount ranging from about 1 wt % to about 15 wt % of the total weight of the support.
8. The process of claim 1 , wherein the reacting the 1,6-hexanediol with oxygen in the presence of a heterogeneous catalyst is carried out at a temperature in the range of from about 100° C. to about 180° C.
9. The process of claim 8 , wherein the reacting the 1,6-hexanediol with oxygen in the presence of a heterogeneous catalyst is carried out at a temperature in the range of from about 135° C. to about 165° C.
10. The process of claim 1 , wherein the reaction is conducted under a partial pressure of oxygen in the range of from about 50 psig to about 2000 psig.
11. The process of claim 10 , wherein the reaction is conducted under a partial pressure of oxygen in the range of from about 50 psig to about 1000 psig.
12. The process of claim 11 , wherein the reaction is conducted under a partial pressure of oxygen in the range of from about 50 psig to about 750 psig.
13. The process of claim 1 , wherein the reaction is conducted in the presence of a solvent.
14. The process of claim 13 , wherein the solvent comprises a solvent selected from the group consisting of water, alcohols, esters, ethers, ketones, and mixtures thereof.
15. The process of claim 14 , wherein the solvent is water.
16. The process of claim 1 , wherein the adipic acid is produced at a yield of at least about 60%.
17. The process of claim 16 , wherein the adipic acid is produced at a yield of at least about 70%.
18. The process of claim 17 , wherein the adipic acid is produced at a yield of at least about 80%.
19. The process of claim 18 , wherein the adipic acid is produced at a yield of at least about 90%.
20. The process of claim 1 , further comprising recovering the adipic acid from the reaction mixture.
21. The process of claim 2 , wherein the reacting the 1,6-hexanediol with oxygen in the presence of a heterogeneous catalyst is carried out at a temperature in the range of from about 100° C. to about 180° C.
22. The process of claim 12 , wherein the reacting the 1,6-hexanediol with oxygen in the presence of a heterogeneous catalyst is carried out at a temperature in the range of from about 100° C. to about 180° C.