Claims
- 1. A process for producing a lubricant of improved oxidative stability and additive solubility characteristics, which method comprises:
- (i) solvent dewaxing a hydrocarbon fraction to produce a separated wax,
- (ii) hydroisomerizing the wax to form a fraction of lower pour point
- (iii) dewaxing the fraction of lower pour point to form a dewaxed lube fraction
- (iv) subjecting the dewaxed lube fraction to solvent extraction using a solvent selective for aromatics to remove selectively a portion of the aromatics in the dewaxed lube fraction and form a solvent-extracted lubricant fraction containing from 5 to 20 wt. percent aromatics.
- 2. A process according to claim 1 in which the separated wax is subjected to de-oiling before being hydroisomerized.
- 3. A process according to claim 1 in which the separated wax is hydroisomerized by contact with zeolite beta.
- 4. A process according to claim 1 in which the fraction of lower pour point is catalytically dewaxed to form the dewaxed lube fraction.
- 5. A process according to claim 4 in which the fraction of lower pour point is catalytically dewaxed in the presence of a dewaxing catalyst comprising ZSM-5.
- 6. A process according to claim 4 in which the fraction of lower pour point is catalytically dewaxed in the presence of a dewaxing catalyst comprising ZSM-23.
- 7. A process according to claim 1 in which the solvent extraction is carried out using phenol, furfural or N-methyl-pyrrolidone as the solvent.
- 8. A process according to claim 1 in which the solvent extraction is carried out using furfural as the solvent.
- 9. A process according to claim 1 in which not more than 50 wt. percent of aromatic components are removed from the dewaxed lube fraction during the solvent extraction.
- 10. A process according to claim 1 in which the solvent extracted lubricant contains 10 to 20 wt. percent aromatics.
Parent Case Info
This application is a continuation of Ser. No. 07/078,486 filed 07/27/87, now abandoned, which is a Continuation-in-part of Ser. No. 07/044,187, filed 04/30/87, now abandoned, and also is a continuation-in-part of Ser. No. 06/793,937, filed 11/01/85, now abandoned.
US Referenced Citations (17)
Related Publications (1)
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Number |
Date |
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793937 |
Nov 1985 |
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Continuations (1)
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Number |
Date |
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Parent |
78486 |
Jul 1987 |
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Continuation in Parts (1)
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Number |
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44187 |
Apr 1987 |
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