US4154670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of rerefining oil by dilution, clarification and extraction
Assignee: Lubrizol Corp
•
Filing: 1977-01-10
•
Granted: 1979-05-15
•
Expires: 1997-01-10
Abstract
Abstract Used oil is rerefined by diluting it with a non-polar diluent, removing insoluble impurities from the resulting solution, extracting said solution with an immiscible liquid extractant to remove further impurities, and finally removing extractant and diluent from the oil.
Inventors
- 👤 John W. Forsberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:49
CPC Classifications
C; C10; C10M; C10M175/00; C10M175/005; C10G; C10G2400/00; C10G2400/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
92 words
A method of recovering oil of lubricating viscosity from used oil which comprises the steps of: (A) Diluting said used oil with a substantially nonpolar diluent in which said used oil is substantially soluble, and removing insoluble impurities from the solution of said oil in said diluent; (B) Extracting impurities from the solution of step A with an organic liquid extractant which is substantially free from inorganic acids and bases and substantially inert to and immiscible with said solution; and (C) Removing said extractant and diluent from the product of step B.
Claim 2
Independent Claim
92 words
A method of recovering oil of lubricating viscosity from used oil which comprises the steps of: (A) Diluting said used oil with a substantially nonpolar diluent in which said used oil is substantially soluble, and removing insoluble impurities from the solution of said oil in said diluent; (B) Extracting impurities from the solution of step A with an organic liquid extractant which is substantially free from inorganic acids and bases and substantially inert to and immiscible with said solution; and (C) Removing said extractant and diluent from the product of step B.
Claim 3
Dependent Claim
16 words
A method according to claim 1 wherein the diluent in step A is an aliphatic hydrocarbon.
Claim 4
Dependent Claim
16 words
A method according to claim 2 wherein the diluent in step A is hexane or naphtha.
Claim 5
Dependent Claim
16 words
A method according to claim 1 wherein insoluble impurities are removed in step A by centrifugation.
Claim 6
Dependent Claim
74 words
A method according to claim 4 wherein the extractant of step B is at least one material selected from the group consisting of: Ethanol Diacetone alcohol Ethylene glycol mono-(lower alkyl) ethers Diethylene glycol Diethylene glycol mono-(lower alkyl) ethers o-Chlorophenol Furfural Acetone Formic acid 4-Butyrolactone Lower alkyl esters of lower mono- and dicarboxylic acids Dimethylformamide 2-Pyrrolidone and N-(lower alkyl)-2-pyrrolidones Epichlorohydrin Dioxane Morpholine, lower alkyl and amino-(lower alkyl)morpholines Benzonitrile Di-(lower alkyl) sulfoxides Di-(lower alkyl) (lower alkyl)phosphonates.
Claim 7
Dependent Claim
44 words
A method according to claim 5 wherein the extractant of step B has a boiling point at one atmosphere pressure in the range 120°-225° C. and a specific gravity, measured at 20° C. in comparison with water at 4° C., in the range 0.90-1.05.
Claim 8
Dependent Claim
20 words
A method according to claim 6 wherein the extractant of step B is ethylene glycol monomethyl ether, dimethylformamide or N-methyl-2-pyrrolidone.
Claim 9
Dependent Claim
17 words
A method according to claim 7 wherein the diluent is removed in step C by vacuum stripping.
Claim 10
Dependent Claim
16 words
A method according to claim 8 wherein the diluent in step A is an aliphatic hydrocarbon.
Claim 11
Dependent Claim
16 words
A method according to claim 9 wherein the diluent in step A is hexane or naphtha.
Claim 12
Dependent Claim
16 words
A method according to claim 1 wherein insoluble impurities are removed in step A by filtration.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-14 | 1982-11-13 | 1983-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-14 | 1986-11-13 | 1987-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-14 | 1990-11-13 | 1991-05-15 | $7700.00 | Window Closed / Lapsed |