Novel process and catalyst system for improving dewaxing catalyst stability and lubricant oil yield.

• US 20110079540A1
• Filed: 10/06/2009
• Published: 04/07/2011
• Est. Priority Date: 10/06/2009
• Status: Active Grant

• Current Assignee: Chevron USA Incorporated (Chevron Corp.)
• Original Assignee: Chevron USA Incorporated (Chevron Corp.)
• Inventors: Krishna, Kamala R., Ziemer, James N., Biscardi, Joseph A., Rainis, Andrew, Harris, Thomas V.
• Granted Patent: US 8,431,014 B2
• Time in Patent Office: Days
• US Class Current: 208/58
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 21/12 Silica and alumina
• CPC Class Codes: B01J 23/40 of the platinum group metals
• CPC Class Codes: B01J 23/44 Palladium
• CPC Class Codes: B01J 23/58 with alkali- or alkaline earth metals
• CPC Class Codes: B01J 29/04 having base-exchange properties, e.g. crystalline zeolites B01J29/005 takes precedence
• CPC Class Codes: B01J 29/06 Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
• CPC Class Codes: B01J 29/62 Noble metals
• CPC Class Codes: B01J 29/74 Noble metals
• CPC Class Codes: B01J 35/0006 Catalysts containing parts with different compositions
• CPC Class Codes: B01J 35/1019 100-500 m2/g
• CPC Class Codes: B01J 35/1042 0.5-1.0 ml/g
• CPC Class Codes: B01J 35/19 Catalysts containing parts with different compositions
• CPC Class Codes: B01J 35/615 100-500 m2/g
• CPC Class Codes: B01J 35/635 0.5-1.0 ml/g
• CPC Class Codes: B01J 37/0018 Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)
• CPC Class Codes: B01J 37/0201 Impregnation
• CPC Class Codes: C10G 2400/10 Lubricating oil

Abstract

The invention provides for a process for dewaxing a waxy hydrocarbon feedstock to form a lubricant oil. The invention is also directed to a catalyst system comprising a hydrotreating catalyst upstream of a dewaxing catalyst, used in the dewaxing of a waxy hydrocarbon feedstock to form a lubricant oil. In particular, the invention is directed to a process and catalyst system designed to maintain yield of lubricant oil product. Specifically, the yield of lubricant oil does not decrease more than 2%, at a target pour point, over a dewaxing temperature range. The hydrotreating catalyst helps prevent aging of the dewaxing catalyst and maintains lubricant oil product yield at a target pour point over a wide temperature range. The hydrotreating catalyst comprises platinum, palladium, or combinations thereof on a low acidity inorganic oxide support where acidity is measured by a decalin conversion of less than 10% at 700° F.

Claims

1. A process for catalytically dewaxing a waxy hydrocarbon feedstock to yield a lubricant oil comprising the steps of:

a) contacting a waxy hydrocarbon feedstock in a first reaction zone, under hydrotreating conditions in which the aromatics content of the feedstock is reduced, with a hydrotreating catalyst wherein the hydrotreating catalyst comprises a Group VIII metal supported on an inorganic oxide support, and wherein the hydrotreating catalyst exhibits a decalin conversion of less than 10% at 700°

F., to form a first effluent and;

b) contacting at least a portion of the first effluent in a second reaction zone with a dewaxing catalyst under dewaxing conditions to yield a lubricant oil, wherein the lubricant oil has a pour point lower than the pour point of the first effluent,

and wherein the yield of lubricant oil does not decrease more than 2%, at a target pour point, over a dewaxing temperature range.

2. The process of claim 1, wherein the aromatic content of the feedstock is reduced by at least 20%.

3. The process of claim 1, wherein the aromatic content of the feedstocks is reduced at least 30%.

4. The process of claim 1, wherein the dewaxing temperature range is from 450°

F. to 750°

F.

5. The process of claim 4, wherein the dewaxing temperature range is from 600°

F. to 675°

F.

6. The process of claim 1, wherein the dewaxing conditions and the hydrotreating conditions are the same.

7. The process of claim 1, wherein the target pour point is in the range from −

10°

C. to −

45°

C.

8. The process of claim 1, wherein the hydrotreating catalyst and the dewaxing catalyst are in the same reactor.

9. The process of claim 1, wherein the hydrotreating catalyst and the dewaxing catalyst are in a ratio of about 1:

20 to about 1;

2.

10. The process of claim 9, wherein the hydrotreating catalyst and the dewaxing catalyst are in a ratio of about 1:

20 to about 1;

10.

11. The process of claim 1, wherein the feedstock comprises less than about 10 ppm nitrogen.

12. The process of claim 1, wherein the feedstock comprises less than about 2 ppm nitrogen.

13. The process of claim 1, wherein the inorganic oxide comprises amorphous material.

14. The process of claim 13, wherein the inorganic oxide is selected from the group consisting of silica, alumina, titania, magnesia, zirconia, and combinations thereof.

15. The process of claim 1, wherein the inorganic oxide comprises crystalline material.

16. The process of claim 15, wherein the inorganic oxide is selected from the group consisting of silico-aluminophosphates, zeolites, metalloaluminophosphates, and combinations thereof.

17. The process of claim 1, wherein the Group VIII metal is platinum, palladium, or combinations thereof.

18. The process of claim 1, further comprising the step of contacting at least a portion of the lubricant oil with a hydrofinishing catalyst in a third reaction zone.

19. A layered catalyst system comprising:

a) a hydrotreating catalyst comprising a Group VIII metal supported on an inorganic oxide support wherein the hydrotreating catalyst exhibits a decalin conversion of less than 10% at 700°

F. and;

b) a dewaxing catalyst comprising a Group VIII metal and an acidic component selected from the group consisting of zeolites, zeolite analogs, nonzeolitic molecular sieves, acidic clays, or combinations thereof;

wherein the hydrotreating catalyst and the dewaxing catalyst are in a ratio of about 1;

20 to about 1;

2.

20. The layered catalyst system of claim 19, wherein the Group VIII metal of the hydrotreating catalyst is platinum, palladium, or combinations thereof.

21. The layered catalyst system of claim 19, wherein the Group VIII metal of the dewaxing catalyst is platinum, palladium, or combinations thereof.

22. The layered catalyst system of claim 19, wherein the inorganic oxide is selected from the group consisting of silica, alumina, titania, magnesia, zirconia, silicoaluminophosphates, zeolites, metalloaluminophosphates, and combinations thereof.