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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
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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 16:42
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.

References Cited (Backward Citations)

US1281354A Cited
US2605272A Cited
US2726986A Cited
JPS4715025U Cited
FR2203871A1 Cited
US3819508A Cited
US3835035A Cited
US3919076A Cited
US4001109A Cited
US3985642A Cited
US4021333A Cited
US4028226A Cited

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

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