Claims
- 1. A process for producing a high Viscosity Index (VI) lubricant having a VI of at least 125 from a waxy hydrocarbon feed having a wax content of at least 40%, which comprises catalytically dewaxing waxy paraffins present in the feed primarily by isomerization, in the presence of hydrogen and in the presence of a low acidity large pore zeolite isomerization catalyst having a ratio of SiO.sub.2 /Al.sub.2 O.sub.3, as synthesized, of at least 50:1, the isomerization catalyst having an alpha value of not more than 20 in addition to a noble metal hydrogenation component wherein the catalyst is prepared in the absence of boron.
- 2. The process of claim 1 wherein the large-pore zeolite possesses at least one pore channel of 12-membered oxygen rings.
- 3. The process of claim 1, wherein the large pore zeolite is zeolite beta.
- 4. The process of claim 1, wherein the ratio of SiO.sub.2 /Al.sub.2 O.sub.3 is at least 200:1.
- 5. The process of claim 4, wherein the ratio of SiO/Al.sub.2 O.sub.3 is at least 600:1.
- 6. The process of claim 1, in which the noble metal of the isomerization catalyst is Pt or Pd.
- 7. The process of claim 1, in which the noble metal content of the catalyst is in the range from about 0.1 to 2 wt %.
- 8. The process of claim 1 in which the feed comprises a waxy hydrocarbon feed having a wax content of at least 50 wt % and an aromatic content of least than 25 wt %.
- 9. The process of claim 1 wherein the feedstock is selected from the group consisting of a slack wax, deoiled wax, wax from Fischer-Tropsch process, petrolatum, vacuum gas oil, or a raffinate from solvent extraction of a vacuum distillate.
- 10. The process of claim 1, in which the process is carried out in the presence of hydrogen.
- 11. The process of claim 10, in which the wax conversion is from 40 to 90 wt. % of the wax contained in the feed.
- 12. The process of claim 9, in which the wax conversion is from 50 to 80 wt % based on the feed.
- 13. The process of claim 1, wherein the effluent has a pour point which ranges from about 30 to about 100.degree. F.
- 14. The process of claim 1, wherein conditions include a hydrogen partial pressure ranging from 600 to 3000 psig and a temperature from 550 to 800.degree. F.
- 15. The process of claim 1, wherein the preferred range of VI is from 130 to 150.
- 16. The process of claim 1 in which the effluent is subjected to further dewaxing to achieve target pour point, with a yield loss during dewaxing of not more than 15 wt %.
- 17. The process of claim 16, in which dewaxing is accomplished by either solvent or catalytic means.
- 18. The process of claim 1, in which the effluent is hydrotreated by contacting it with a catalyst comprising a metal hydrogenation component on an amorphous, porous support material at a pressure in the range from about 500 to about 3000 psig, a reaction temperature in the range from about 500.degree. F. to about 800.degree. F., a space velocity which is in a range from about 0.1 to about 10 LESV, and a once-through hydrogen circulation rate which extends from about 1000 SCF/B to about 10,000 SCF/B, in order to improve the thermal and oxidative stability of the lubricant.
- 19. A process for producing a high Viscosity Index (VI) lubricant having a VI of at least 125, the process comprising the following steps:
- (a) solvent dewaxing a raffinate or hydrocracked stream to produce a waxy hydrocarbon feed having a wax content of at least 40 wt %;
- (b) catalytically dewaxing the waxy effluent of step (a) primarily by isomerization, in the presence of hydrogen and in the presence of a low acidity large pore zeolite isomerization catalyst having a ratio of SiO.sub.2 /Al.sub.2 O.sub.3, as synthesized, of at least 50:1, an alpha value of not more than 20 and further comprising a noble metal hydrogenation component wherein the catalyst is prepared in the absence of boron.
- 20. The process of claim 19 wherein the large-pore zeolite possesses at least one pore channel of 12-membered oxygen rings.
- 21. The process of claim 19, wherein the large pore zeolite is zeolite beta.
- 22. The process of claim 19, wherein the ratio of SiO.sub.2 /Al.sub.2 O.sub.3 is at least 200:1.
- 23. The process of claim 19, wherein the ratio of SiO.sub.2 /Al.sub.2 O.sub.3 is at least 600:1.
- 24. The process of claim 19 wherein the feedstock is selected from the group consisting of a slack wax, deoiled wax, wax from Fischer-Tropsch process, petrolatum, vacuum gas oil, and a raffinate from solvent extraction of a vacuum distillate.
- 25. The process of claim 19 wherein conditions include a hydrogen partial pressure ranging from 600 to 3000 psig and a temperature from 550 to 800.degree. F.
- 26. The process of claim 19, wherein the preferred range of VI is from 130 to 150.
- 27. The process of claim 19 in which the effluent of step (b) is subjected to further dewaxing to achieve target pour point, with a loss during dewaxing of not more than 15 wt %.
- 28. The process of claim 19, in which the effluent of step (b) is hydrotreated by contacting it with a catalyst comprising a metal hydrogenation component on an amorphous porous support material at a pressure in the range from about 500 to about 3000 psig, a reaction temperature in the range from about 500.degree. F. to about 800.degree. F., a space velocity which is in a range from about 0.1 to about 10 LHSV, and a once-through hydrogen circulation rate which extends from about 1000 SCF/B to about 10,000 SCF/B, in order to improve the thermal and oxidative stability of the lubricant.
- 29. A process for producing a high Viscosity Index (VI) lubricant having a VI of a least 125, the process comprising the following steps:
- (a) solvent dewaxing a raffinate or hydrocracked steam to produce a waxy hydrocarbon feed having a wax content of at least 40 wt. %;
- (b) hydrocracking of the waxy effluent of step (a) in order to reduce its nitrogen content as well as to remove napthenic and aromatic components, thereby improving VI, the hydrocracking process comprising contacting the feed with a catalyst composed of a metal hydrogenation component on an acidic support;
- (c) catalytically dewaxing waxy paraffins present in effluent of step (b) primarily by isomerization, in the presence of hydrogen and in the presence of a low acidity large pore zeolite isomerization catalyst having a ratio of SiO.sub.2 /Al.sub.2 O.sub.3, as synthesized, of at least 50:1, an alpha value of not more than 20 and further comprising a noble metal hydrogenation component wherein the catalyst is prepared in the absence of boron.
- 30. The process of claim 29 wherein the large-pore zeolite possesses at least one pore channel of 12-membered oxygen rings.
- 31. The process of claim 29, wherein the large pore zeolite is zeolite beta.
- 32. The process of claim 29, wherein the ratio of SiO.sub.2 /Al.sub.2 O.sub.3 is at least 200:1.
- 33. The process of claim 31, wherein the ratio of SiO.sub.2 /A.sub.2 0.sub.3 is at least 600:1.
- 34. The process of claim 29 wherein the feedstock is selected from the group consisting of a slack wax, deoiled wax, wax from Fischer-Tropsch process, petrolatum, vacuum gas oil, and a raffinate from solvent extraction of a vacuum distillate.
- 35. The process of claim 29 wherein conditions include a hydrogen partial pressure ranging from 600 to 3000 psig and a temperature from 550 to 800.degree. F.
- 36. The process of claim 29, wherein the preferred range of VI is from 130 to 150.
- 37. The process of claim 29 in which the effluent of step (b) is subjected to further dewaxing to achieve target pour point, with a loss during dewaxing of not more than 15 wt %.
- 38. The process of claim 29, in which the effluent of step (c) is hydrotreated by contacting it with a catalyst comprising a metal hydrogenation component on an amorphous porous support material at a pressure in the range from about 500 to about 3000 psig, a reaction temperature in the range from about 500.degree. F. to about 800.degree. F., a space velocity which is in a range from about 0.1 to about 10 LHSV, and a once-through hydrogen circulation rate which extends from about 1000 SCF/B to about 10,000 SCF/B, in order to improve the thermal and oxidative stability of the lubricant.
- 39. A process for producing a high Viscosity Index (VI) lubricant having a VI of at least 120 from a waxy hydrocarbon feed having a wax content of at least 30 wt %, the process employing two catalysts operating synergistically, and comprising the following steps:
- (a) hydrocracking of the feed in order to reduce its nitrogen content as well as to remove naphthenic and aromatic components, thereby improving VI, the hydrocracking process comprising contacting the feed with a catalyst composed of a metal hydrogenation component on an acidic support;
- (b) catalytically dewaxing waxy paraffins present in the effluent of step (b) primarily by isomerization, in the presence of hydrogen and in the presence of a low acidity large pore zeolite isomerization catalyst having a ratio of SiO.sub.2 /Al.sub.2 O.sub.3, as synthesized, of at least 50:1, an alpha value of not greater than 20 and further comprising a noble metal hydrogenation component wherein the catalyst is prepared in the absence of boron.
- (c) subjecting the effluent of the initial catalytic dewaxing step to a second catalytic dewaxing step in which the effluent is contacted with a constrained intermediate pore crystalline material, which contains a metal hydrogenation dehydrogenation component.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to co-pending application Ser. No. 08/017,949 (continuation of Ser. No. 07/548,702) entitled Production of High Viscosity Index Lubricants, which describes a two-step process for producing high Viscosity Index lubricants by hydrocracking and hydroisomerization of petroleum wax feeds using a low acidity zeolite beta hydroisomerization catalyst. Ser. No. 08/017,955, also entitled Production of High Viscosity Index Lubricants, describes a wax hydroisomerization process using zeolite catalysts of controlled low acidity at high pressures. The instant application is a continuation-in-part of Ser. No. 08/017,955. The instant application is also a continuation-in-part of Ser. No. 08/017,949. Ser. No. 08/017,955 is incorporated by reference in the instant application. Corresponding European Patent No. 464,547A1, (a patent which specifies the use of low acidity zeolite beta for wax isomerization) is also incorporated by reference. The instant application is related to co-pending application Ser. No. 08/303,091 in which two dewaxing catalysts operate synergistically to produce a lubricant of high Viscosity Index. It is also related to Ser. No. 08/329,914, which is concerned with isomerizing petroleum waxes using large pore zeolites of small crystallite size.
US Referenced Citations (6)