Claims
- 1. In a Fischer-Tropsch process wherein a synthesis gas is catalytically converted into a Fischer-Tropsch reaction product mixture comprising paraffins and oxygenates and wherein the oxygenates include primary and internal alcohols, the process improvement comprising:
(a1) passing all or part of the Fischer-Tropsch reaction product mixture over at least one bed packed with an alumina catalyst to dehydrate substantially all of the alcohols to their corresponding olefins.
- 2. The process improvement of claim 1 further comprising the step of: (a0) vaporizing all or part of the Fischer-Tropsch reaction product mixture before step (a1).
- 3. The process improvement of claim 1 further comprising the steps of:
(b) condensing a dehydrated product; (c) separating aqueous and organic phases of the dehydrated product.
- 4. The process improvement of claim 1 further comprising the step of hydroisomerizing all or part of the organic phase.
- 5. The process improvement of claim 1 wherein the reaction temperature of dehydration in step (a1) is between about 400° and about 800° F.
- 6. The process improvement of claim 1 wherein the alumina is a high surface area alumina.
- 7. The process improvement of claim 6 wherein the alumina is selected from the group of gamma-alumina and theta-alumina.
- 8. The process improvement of claim 1 wherein the alumina is passivated alumina.
- 9. The process improvement of claim 1 wherein the reaction temperature of dehydration in step (a1) is between about 500° and about 700° F.
- 10. The process improvement of claim 1 wherein the reaction temperature of dehydration in step (a1) is between about 550° and about 675° F.
- 11. The process improvement of claim 1 wherein the alumina catalyst is activated alumina.
- 12. The process improvement of claim 1 wherein the LHSV of the packed bed is between about 0.1 hr−1 and about 10.0 hr−1.
- 13. The process improvement of claim 1 wherein the LHSV of the packed bed is between about 0.12 hr−1 and about 2.0 hr−1.
- 14. The process improvement of claim 1 wherein step (a1) is operated at a pressure of from about 0 psia to about 200 psig.
- 15. The process improvement of claim 3 wherein the Fischer Tropsch reaction product mixture comprises from about 0 wt % to about 95 wt % olefins.
- 16. The process improvement of claim 3 wherein the Fischer Tropsch reaction product mixture comprises from about 0.5 to about 40 wt % oxygenates.
- 17. The process improvement of claim 16 wherein at least 90 wt % of the oxygenates are primary and internal alcohols.
- 18. An integrated Fischer Tropsch process comprising the steps of:
(a) producing a synthetic crude by Fischer-Tropsch reaction of synthesis gas; (b) fractionating the synthetic crude at least into a light Fischer Tropsch liquid, and a heavy Fischer Tropsch liquid; and (c) reacting at least a part of the light Fischer Tropsch liquid over an alumina catalyst to dehydrate alcohols in the light Fischer Tropsch liquid to corresponding alpha- and internal-olefins and forming a dehydrated product.
- 19. The process of claim 18 further comprising the step of:
(d) fractionating the dehydrated product into at least a naphtha, nominally 30-300° F., fraction, and at least one middle distillate fraction, nominally 250-600° F.
- 20. The process of claim 18 further comprising the step of:
(e) hydroisomerizing all or part of the middle distillate.
- 21. The process of claim 18 further comprising the step of:
(f) hydroprocessing all or part of the heavy Fischer Tropsch liquid.
- 22. The process improvement of claim 1 wherein the synthesis gas is prepared from a gas comprising methane.
- 23. The process improvement of claim 22 wherein the synthesis gas is produced by autothermal reformation.
- 24. The process improvement of claim 23 wherein the autothermal reformation feedstock comprises 10% to 60% N2.
- 25. The process improvement of claim 22 wherein the gas is natural gas.
- 26. The process improvement of claim 22 wherein the gas is coal gas.
- 27. The process improvement of claim 1 wherein at least 95 wt % of alcohols present in the Fischer Tropsch reaction product are converted to olefins in step (a1).
- 28. The process improvement of claim 1 wherein the dehydrated product from step (a1) contains substantially no alcohols.
- 29. The process improvement of claim 1 wherein the dehydrated product from step (a1) contains substantially no oxygenates.
- 30. The process of claim 18 wherein at least 95 wt % of alcohols present in the light Fischer Tropsch liquid are converted to olefins in step (c).
- 31. The process of claim 18 wherein the dehydrated product from step (c) contains substantially no alcohols.
- 32. The process of claim 18 wherein the dehydrated product from step (c) contains substantially no oxygenates.
- 33. The process of claim 18 wherein the synthesis gas is prepared from a gas comprising methane.
- 34. The process of claim 33 wherein the synthesis gas is produced by autothermal reformation.
- 35. The process of claim 34 wherein the autothermal reformation syngas product comprises 10% to 60% N2.
- 36. The process of claim 1 wherein step (a1) is conducted over a moving bed of alumina catalyst and further comprising continuous catalyst regeneration.
- 37. The process of claim 36 wherein the moving bed is selected from the group of ebullating beds, slurry bed and a fluidized bed.
- 38. The process of claim 1 wherein the catalyst is selected from the group of silica-alumina, silico-alumino phosphate, and mole sieves.
- 39. The process of claim 38 wherein the mole sieve is a zeolite.
- 40. The process of claim 18 wherein step (c) is conducted over a moving bed of alumina catalyst and further comprising continuous catalyst regeneration.
- 41. The process of claim 40 wherein the moving bed is selected from the group of ebullating beds, slurry bed and a fluidized bed.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application Serial No. 60/449,560, filed on Feb. 24, 2003.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60449560 |
Feb 2003 |
US |