Claims
- 1. A process for upgrading a wax-containing feedstock to produce a lubricating oil basestock suitable for use as an automobile engine oil and a petroleum wax by selectively hydroconverting a raffinate produced from solvent refining a lubricating oil feedstock which comprises:
- (a) conducting the lubricating oil feedstock and the wax-containing feedstock, said feedstock being a distillate fraction, to a solvent extraction zone and under-extracting the feedstock to form an under-extracted raffinate whereby the yield of raffinate is maximized;
- (b) stripping the under-extracted raffinate of solvent to produce an under-extracted raffinate feed having a dewaxed oil viscosity index from about 85 to about 105 and a final boiling point of no greater than about 650.degree. C.;
- (c) passing the raffinate feed to a first hydroconversion zone and processing the raffinate feed in the presence of a non-acidic catalyst having an acidity value less than about 0.5, said acidity being determined by the ability of the catalyst to convert 2-methylpent-2-ene to 3-methylepent-2-ene and 4-methylpent-2-ene and is expressed as the mole ratio of 3-methylpent-2-ene to 4-methylpent-2-ene at a temperature of from 340 to 420.degree. C., a hydrogen partial pressure of from 600 to 2000 psig, space velocity of 0.2 to 3.0 LHSV and a hydrogen to feed ratio of from 500 to 5000 Scf/B to produce a first hydroconverted raffinate;
- (d) passing the first hydroconverted raffinate to a second reaction zone and conducting cold hydrofinishing of the first hydroconverted raffinate in the presence of a hydrofinishing catalyst which is at least one Group VIB and Group VIII metal oxide or metal sulfide on a refractory metal oxide support at a temperature of from 200 to 320.degree. C., a hydrogen partial pressure of from 600 to 2000 psig, a space velocity of from 1 to 5 LHSV and hydrogen to feed ratio of from 500 to 5000 Scf/B to produce a second hydroconverted raffinate;
- (e) passing the second hydroconverted raffinate to a separation zone to remove products having a boiling less than about 250.degree. C.; and
- (f) passing the second hydroconverted raffinate to a dewaxing zone to produce a wax and a dewaxed basestock having a viscosity index of at least 105 provided that the basestock has a dewaxed oil viscosity index increase of at least 10 greater than the dewaxed oil viscosity index of the raffinate feed, a NOACK volatility improvement over raffinate feedstock of at least about 3 wt. % at the same viscosity in the range of viscosity from 3.5 to 6.5 cSt viscosity at 100.degree. C., and a residual aromatics content of at least about 5 vol. % provided that the basestock has low toxicity and passes the IP346 or FDA(c) tests notwithstanding the residual aromatics content, and
- (g) isolating the wax from step (f) as a co-product.
- 2. The process of claim 1 wherein the raffinate feed has a final boiling point no greater than about 560.degree. C.
- 3. The process of claim 1 wherein the temperature in the first hydroconversion zone is from 360 to 390.degree. C.
- 4. The process of claim 1 wherein the non-acidic catalyst is cobalt/molybdenum, nickel/molybdenum or nickel/tungsten on an alumina support.
- 5. The process of claim 1 wherein the cold hydrofinishing is conducted at a temperature of from 230 to 300.degree. C.
- 6. The process of claim 1, wherein the separation zone comprises a vacuum stripper.
- 7. The process of claim 1 wherein the dewaxed basestock has a VI of at least 107.
- 8. The process of claim 1 wherein the dewaxed basestock has a NOACK volatility improvement over raffinate feedstock of at least about 5 wt. %, in the range of 3.5 to 6.5 cSt viscosity at 100.degree. C.
- 9. The process of claim 1 wherein the second hydroconverted raffinate is dewaxed by solvent dilution followed by cooling to crystallize wax molecules.
- 10. The process of claim 4 wherein the catalyst is nickel/molybdenum on an alumina support provided that the alumina support has not been promoted with a halogen.
- 11. The process of claim 1 wherein the non-acidic catalyst has an acidity value less than about 0.5.
- 12. A process for upgrading a wax-containing feedstock to produce a lubricating oil basestock suitable for use as an automobile engine oil and a petroleum wax by selectively hydroconverting a raffinate produced from solvent refining a lubricating oil feedstock which comprises:
- (a) conducting the lubricating oil feedstock, said feedstock being a distillate fraction, to a solvent extraction zone and under-extracting the feedstock to form an under-extracted raffinate whereby the yield of raffinate is maximized;
- (b) stripping the under-extracted raffinate of solvent to produce an under-extracted raffinate feed having a dewaxed oil viscosity index from about 85 to about 105 and a final boiling point of no greater than about 650.degree. C.;
- (c) combining the raffinate feed with the wax-containing feedstock to produce a combined raffinate feed,
- (d) passing the combined raffinate feed to a first hydroconversion zone and processing the combined raffinate feed in the presence of a non-acidic catalyst having an acidity value less than about 0.5, said acidity being determined by the ability of the catalyst to convert 2-methylpent-2-ene to 3-methylpent-2-ene and 4-methylpent-2-ene and is expressed as the mole ratio of 3-methylpent-2-ene to 4-methylpent-2-ene at a temperature of from 340 to 420.degree. C., a hydrogen partial pressure of from 800 to 2000 psig, space velocity of 0.2 to 3.0 LHSV and a hydrogen to feed ratio of from 500 to 5000 Scf/B to produce a first hydroconverted raffinate; and
- (e) passing the first hydroconverted raffinate to a second reaction zone and conducting cold hydrofinishing of the first hydroconverted raffinate in the presence of a hydrofinishing catalyst which is at least one Group VIB and Group VIII metal oxide or metal sulfide on a refractory metal oxide support at a temperature of from 200 to 320.degree. C., a hydrogen partial pressure of from 600 to 2000 psig, a space velocity of from 1 to 5 LHSV and hydrogen to feed ratio of from 500 to 5000 Scf/B to produce a second hydroconverted raffinate,
- (f) passing the second hydroconverted raffinate to a separation zone to remove products having a boiling less than about 250.degree. C.; and
- (g) passing the second hydroconverted raffinate to a dewaxing zone to produce a wax and a dewaxed basestock having a viscosity index of at least 105 provided that the basestock has a dewaxed oil viscosity index increase of at least 10 greater than the dewaxed oil viscosity index of the raffinate feed, a NOACK volatility improvement over raffinate feedstock of at least about 3 wt. % at the same viscosity in the range of viscosity from 3.5 to 6.5 cSt viscosity at 100.degree. C., and a residual aromatics content of at least about 5 vol. % provided that the basestock has low toxicity and passes the IP346 or FDA(c) tests notwithstanding the residual aromatics content, and
- (h) isolating the wax from step (g) as a co-product.
- 13. The process of claim 12 wherein the raffinate feed has a final boiling point no greater than about 500.degree. C.
- 14. The process of claim 12 wherein the temperature in the first hydroconversion zone is from 360 to 390.degree. C.
- 15. The process of claim 12 wherein the non-acidic catalyst is cobalt/molybdenum, nickel/molybdenum or nickel/tungsten on an alumina support.
- 16. The process of claim 12 wherein the cold hydrofinishing is conducted at a temperature of from 230 to 300.degree. C.
- 17. The process of claim 12 wherein the second hydroconverted raffinate has residual aromatics content of at least about 5 vol. % provided that the raffinate has low toxicity and passes the IP346 or FDA(c) tests notwithstanding the residual aromatics content.
- 18. The process of claim 12 wherein the non-acidic catalyst has an acidity value less than about 0.5.
- 19. The process of claim 12 wherein the second hydroconverted raffinate is dewaxed by solvent dilution followed by cooling to crystallize wax molecules.
Parent Case Info
This application is a continuation-in-part of U.S. Ser. No. 08/678,382 filed Jun. 28, 1996.
US Referenced Citations (8)
Continuation in Parts (1)
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Number |
Date |
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Parent |
678382 |
Jun 1996 |
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