Claims
- 1. A process for making a lubricant oil of low pour point and improved oxidation stability, employing a hydrocarbon feedstock which boils in the lube range, containing aromatic compounds, sulfur-containing compounds and nitrogen-containing compounds, the method comprising the following steps:(a) passing the hydrocarbon feedstock to a solvent extraction zone for the improvement of viscosity index, wherein a solvent is used to extract a portion of the aromatic compounds contained in the hydrocarbon feedstock, thereby forming an extraction zone raffinate; (b) passing the extraction zone raffinate to a catalytic dewaxing zone wherein hydrogen is contacted with extraction zone raffinate at catalytic dewaxing conditions at a dewaxing temperature between 500° F. and 700° F. in the presence of a first catalyst composition comprising an intermediate pore size zeolite, and which does not contain a metal hydrogen component, in the hydrogen or decationized form, to form a catalytically dewaxed product, the dewaxing being carried out in a dewaxing cycle in which the dewaxing temperature is progressively increased to maintain a substantially constant product target pour point; (c) passing the catalytically dewaxed product to a hydrotreating zone wherein the catalytically dewaxed product is hydrotreated under hydrotreating conditions, at hydrotreating temperatures in the range from about 400° to 600° F. in the presence of a second catalyst compositions comprising a Group VIII metal hydrogenation component selected from the group consisting of Co, Ni, Pd, and Pt and a non-acidic material which is amorphous or crystalline oxide, which is selected from the group consisting of alumina, silica, and silica-alumina; and (d) at the end of the dewaxing cycle, reactivating the catalyst by contact with hydrogen at elevated temperature, after which the catalyst is subjected to a dewaxing cycle which is of a duration at least equal to that of the previous dewaxing cycle.
- 2. A process according to claim 1 which in the intermediate pore size zeolite of step (b) is ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23 or ZSM-35.
- 3. A process according to claim 2 which is carried out at a hydrogen pressure of 300 to 500 psig, a temperature of 570° F. to 670° F. and a space velocity of 0.5 to 2.0 LHSV.
- 4. A process according to claim 2 in which the aging rate of the catalyst is less than 2° F. per day at dewaxing temperatures above 650° F.
- 5. A process according to claim 1 in which aging rate of the dewaxing catalyst, as represented by the dewaxing temperature needed to maintain the product target pour point, is less than 5° F. per day.
- 6. A process according to claim 1 in which the dewaxing cycle is carried out over a temperature range of 550° to 670° F.
- 7. A process according to claim 1 which is carried out at a hydrogen pressure of 200 to 1000 psig, a temperature of 570° F. to 670° F. and a space velocity of 0.5 to 2.0 LHSV.
- 8. A process according to claim 1 in which the aging rate of the catalyst is less than 4° F. per day.
- 9. A process according to claim 1 in which the aging rate of the catalyst is less than 1° F. per day at dewaxing temperatures above 650° F.
- 10. A process according to claim 1 in which the aging rate of the catalyst is less than 4° F. per day during the subsequent dewaxing cycle.
- 11. A process according to claim 1 in which the aging rate of the catalyst during the subsequent dewaxing cycle is less than 2° F. per day at dewaxing temperatures above 650° F.
- 12. A process according to claim 1 in which the aging rate of the catalyst is less than 1° F. per day at dewaxing temperatures above 650° F.
- 13. A process according to claim 1 in which the feedstock comprises a neutral stock having a viscosity of about 100 SUS (20 cSt) to 750 SUS (160 cSt) at 40° C. obtained by subjecting a vacuum distillate to solvent extraction to remove aromatics.
- 14. A process according to claim 1 in which the feed comprises a bright stock having a viscosity of about 100 SUS (21 cSt) to 300 SUS (61 cSt) at 100° C. and produced by subjecting a vacuum resid to propane deasphalting followed by solvent extraction to remove aromatics.
- 15. A process according to claim 1 wherein said lubricant oil product is a light to heavy neutral stock having a viscosity of about 100 to 800 SUS at 40° C., an organic sulfur content of at least 0.2 wt. %, and an aliphatic sulfur content of at least 0.15 wt. %.
- 16. A process according to claim 1 wherein said lubricant oil product has an organic sulfur content of at least 0.10 wt. %.
- 17. A process according to claim 1 wherein said lubricant oil product is a light to heavy neutral stock having a viscosity of about 100 to 800 SUS at 40° C., an organic sulfur content of at least 0.2 wt. %, and an aliphatic sulfur content of at least 0.15 wt. %, or a bright stock having a viscosity of 100 to 300 SUS at 100° C., an organic sulfur content of at least 1.00 wt. %, and an aliphatic sulfur content of at least 0.35 wt. %.
- 18. A process according to claim 1 which in the first catalyst composition contains no metal hydrogenation component.
Parent Case Info
This application is a continuation of Ser. No. 07/997,617 filed Dec. 12, 1992, now abandoned, which is a continuation of application Ser. No. 07/728,752, filed on Jul. 8, 1991, now abandoned, which is a continuation of application Ser. No. 07/544,088, filed on Jun. 27, 1990, now abandoned, which is a continuation of Ser. No. 07/359,605, now abandoned filed Jun. 1, 1989.
US Referenced Citations (22)
Foreign Referenced Citations (1)
Number |
Date |
Country |
1116642 |
Jan 1982 |
CA |
Continuations (4)
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Number |
Date |
Country |
Parent |
07/997617 |
Dec 1992 |
US |
Child |
08/291320 |
|
US |
Parent |
07/728752 |
Jul 1991 |
US |
Child |
07/997617 |
|
US |
Parent |
07/544088 |
Jun 1990 |
US |
Child |
07/728752 |
|
US |
Parent |
07/359605 |
Jun 1989 |
US |
Child |
07/544088 |
|
US |