Base stock lube oil manufacturing process

• US 5,993,644 A
• Filed: 06/26/1997
• Issued: 11/30/1999
• Est. Priority Date: 07/16/1996
• Status: Expired due to Term

• Current Assignee: Chevron USA Incorporated (Chevron Corp.)
• Original Assignee: Chevron USA Incorporated (Chevron Corp.)
• Inventors: Ziemer, James N., Winslow, Phil, Xiao, Jirong
• Primary Examiner(s): MYERS, HELANE ELEANORA
• Application Number:
  US08/883,001
• Time in Patent Office: 887 Days
• Field of Search: 208/97, 208/89, 208/28, 208/259, 208/57, 208/58, 208/118, 208/61
• US Class Current: 208/89
• CPC Class Codes: C10G 2400/10 Lubricating oil
• CPC Class Codes: C10G 65/043 at least one step being a change in the structural skeleton

Abstract

A process is provided for preparing high quality Group II and Group III lubricating base oils from a sulfur containing feedstock using mild hydrotreating followed by isomerization/dewaxing followed by hydrogenation over a sulfur resistant hydrogenation catalyst.

Claims

1. A process for producing a lubricating oil base stock comprising:

a) contacting a petroleum feedstock which has a normal boiling point in the range of about 600°

F. (316°

C.) to about 1250°

F. (677°

C.) in a hydrotreating reaction zone with a hydrotreating catalyst at a hydrogen partial pressure of less than about 1600 psia (11 MPa) and a temperature between about 500°

F. (260°

C.) and about 800°

F. (427°

C.) to produce a hydrotreated oil having a viscosity index which is at least about 5 greater than the viscosity index of the petroleum feedstock and a viscosity measured at 100°

C. of at least about 2 cSt;

b) contacting the hydrotreated oil at hydrodewaxing conditions in a dewaxing reaction zone with an intermediate pore size molecular sieve catalyst to produce a dewaxed oil having a pour point lower than the pour point of the hydrotreated oil; and

c) contacting the dewaxed oil at hydrogenation conditions in a hydrofinishing reaction zone with a hydrogenation catalyst comprising a platinum/palladium alloy to produce a lubricating oil base stock, wherein the platinum/palladium molar ratio of the platinum/palladium alloy is between about 2.5;

1 and about 1;

2.

2. The process according to claim 1 wherein the platinum/palladium molar ratio of the platinum/palladium alloy is between about 2.0:

1 and about 1;

1.5.

3. The process according to claim 1 wherein the hydrogen partial pressure in the hydrotreating reaction zone is less than about 1250 psia (8.6 MPa).

4. The process according to claim 3 wherein the hydrogen partial pressure in the hydrotreating reaction zone is less than about 1100 psia (7.6 MPa).

5. The process according to claim 1 wherein the temperature in the hydrotreating reaction zone is in the range of about 600°

F. (316°

C.) to about 700°

F. (371°

C.).

6. The process according to claim 1 wherein the intermediate pore size molecular sieve catalyst comprises a zeolite selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-21, ZSM-23, ZSM-35, ZSM-38 and SSZ-32.

7. The process according to claim 6 wherein the intermediate pore size molecular sieve catalyst comprises SSZ-32.

8. The process according to claim 1 wherein the intermediate pore size molecular sieve catalyst comprises a molecular sieve selected from the group consisting of SAPO-11, SAPO-5, SAPO-31, SAPO-41.

9. The process according to claim 8 wherein the intermediate pore size molecular sieve catalyst comprises SAPO-11.

10. The process according to claim 1 wherein the petroleum feedstock has a normal boiling point in the range of about 800°

F. (427°

C.) to about 1250°

F. (677°

C.).

11. The process according to claim 1 wherein the hydrotreated oil has a viscosity index of greater than about 70.

12. The process according to claim 11 wherein the hydrotreated oil has a viscosity index of greater than about 90.

13. The process according to claim 12 wherein the hydrotreated oil has a viscosity index of greater than about 115.

14. The process according to claim 1 wherein the petroleum feedstock is a raffinate derived from a solvent extraction process.

15. The process according to claim 1 wherein the petroleum feedstock is derived from a VGO.

16. The process according to claim 1 wherein the petroleum feedstock is derived from a waxy feedstock comprising greater than about 50% by weight wax.

17. The process according to claim 1 wherein the lubricating oil base stock has a saturates content of greater than 90%, a sulfur content of less than or equal to 0.03% and a viscosity index of between 80 and 120.

18. The process according to claim 1 wherein the lubricating oil base stock has a saturates content of greater than 90%, a sulfur content of less than or equal to 0.03% and a viscosity index of greater than 120.

19. The process according to claim 1 to produce the hydrotreated oil having a viscosity index of at least VI_H, wherein ##EQU4## Δ

C is the conversion during the step of hydrotreating; and

VI_O is the viscosity index of the petroleum feedstock.

20. The process according to claim 19 wherein:

##EQU5##

21. The process according to claim 1 wherein the hydrotreating conditions are selected to maintain a volumetric cracking conversion during hydrotreating of less than about 20% by volume.

22. The process according to claim 1 wherein the hydrotreating conditions are selected to maintain a volumetric cracking conversion during hydrotreating of less than about 10% by volume.

23. The process according to claim 1 wherein the hydrotreated oil contains less than 50 ppm sulfur.

24. A process for producing a lubricating oil base stock comprising:

a) contacting a petroleum feedstock which has a normal boiling point in the range of about 600°

F. (316°

C.) to about 1250°

F. (677°

C.) in a hydrotreating reaction zone with a hydrotreating catalyst at a hydrogen partial pressure of less than about 1250 psia (8.6 MPa) to produce a hydrotreated oil having a viscosity index of at least VI_H, wherein ##EQU6## Δ

C is the conversion during the step of hydrotreating; and

VI_O is the viscosity index of the petroleum feedstock;

b) contacting the hydrotreated oil at hydrodewaxing conditions in a dewaxing reaction zone with an intermediate pore size molecular sieve catalyst to produce a dewaxed oil having a pour point lower than the pour point of the hydrotreated oil; and

c) contacting the dewaxed oil at hydrogenation conditions in a hydrofinishing reaction zone with a hydrogenation catalyst comprising a noble metal hydrogenation component on an alumina base to produce a lubricating oil base stock.

25. The process according to claim 24 wherein the hydrogenation catalyst comprises a platinum/palladium alloy hydrogenation component, wherein the platinum/palladium molar ratio of the platinum/palladium alloy is between about 2.5:

1 and about 1;

2.

26. The process according to claim 24 wherein the intermediate pore size molecular sieve catalyst comprises SSZ-32.

27. The process according to claim 24 wherein the intermediate pore size molecular sieve catalyst comprises SAPO-11.

28. The process according to claim 24 wherein the petroleum feedstock has a normal boiling point in the range of about 800°

F. (474°

C.) to about 1250°

F. (677°

C.).

29. The process according to claim 24 wherein the hydrogen partial pressure in the hydrotreating reaction zone is less than about 1100 psia (7.6 MPa).

30. A process for producing a lubricating oil base stock comprising:

a) contacting a petroleum feedstock which has a normal boiling point in the range of about 600°

F. (316°

C.) to about 1250°

F. (677°

C.) in a hydrotreating reaction zone with a hydrotreating catalyst at temperature in the range of about 600°

F. (316°

C.) to about 700°

F. (371°

C.) to produce a hydrotreated oil having a viscosity measured at 100°

C. of at least about 2 cSt and a viscosity index of at least VI_H, wherein ##EQU7## Δ

C is the conversion during the step of hydrotreating; and

VI_O is the viscosity index of the petroleum feedstock;

b) contacting the hydrotreated oil at hydrodewaxing conditions in a dewaxing reaction zone with an intermediate pore size molecular sieve catalyst to produce a dewaxed oil having a pour point lower than the pour point of the hydrotreated oil; and

c) contacting the dewaxed oil at hydrogenation conditions in a hydrofinishing reaction zone with a hydrogenation catalyst comprising a platinum/palladium alloy to produce a lubricating oil base stock, wherein the platinum/palladium molar ratio of the platinum/palladium alloy is between about 2.5;

1 and about 1;

2.

31. The process according to claim 30 wherein the platinum/palladium molar ratio of the platinum/palladium alloy is between about 2.0:

1 and about 1;

1.5.

32. The process according to claim 31 wherein:

##EQU8##

33. The process according to claim 32 wherein the lubricating oil base stock has a saturates content of greater than 90%, a sulfur content of less than or equal to 0.03% and a viscosity index of between 80 and 120.

34. The process according to claim 30 wherein the lubricating oil base stock has a saturates content of greater than 90%, a sulfur content of less than or equal to 0.03% and a viscosity index of between 80 and 120.

35. The process according to claim 34 wherein the intermediate pore size molecular sieve catalyst comprises SSZ-32.

36. The process according to claim 34 wherein the intermediate pore size molecular sieve catalyst comprises SAPO-11.

37. The process according to claim 30 wherein the petroleum feedstock comprises greater than about 50% by weight of wax, and wherein the lubricating oil base stock has a saturates content of greater than 90%, a sulfur content of less than or equal to 0.03% and a viscosity index of greater than 120.

38. The process according to claim 37 wherein the intermediate pore size molecular sieve catalyst comprises SSZ-32.

39. The process according to claim 37 wherein the intermediate pore size molecular sieve catalyst comprises SAPO-11.

40. A process for producing a lubricating oil base stock comprising upgrading a petroleum feedstock to produce a lube oil feedstock having a viscosity index higher than that of the petroleum feedstock;

and reacting the lube oil feedstock at hydrotreating conditions selected to maintain a volumetric cracking conversion during hydrotreating of less than 20%, and a sulfur content of the hydrotreated oil of less than 50 ppm, wherein the change in viscosity index of the lube oil feedstock during hydrotreating, (VI_H -VI_O ) is such that (VI_H -VI_O)/Δ

C is greater than 1.0, wherein VI_H is the viscosity index of the hydrotreated oil, VI_O is the viscosity index of the lube oil feedstock to the hydrotreater, and Δ

C is the volumetric cracking conversion in the hydrotreater.

41. The process according to claim 40 wherein the volumetric cracking conversion during hydrotreating is maintained at less than 10%.

42. The process according to claim 41 wherein the volumetric cracking conversion during hydrotreating is maintained at less than 5%.

43. The process according to claim 41 wherein the sulfur content of the hydrotreated oil is less than 20 ppm.

44. The process according to claim 43 wherein the sulfur content of the hydrotreated oil is less than 10 ppm.