# US 4,392,944 A · Alkali recycle process for recovery of heavy oils and bitumens > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,392,944 A - Document ID: US4392944A - Status: Granted - Kind: A - Application number: 06/157,935 - Filed: 1980-06-09 - Granted: 1983-07-12 - Earliest claimed: 1979-06-08 - Assignees: The Research Council of Alberta - Inventors: Michael A. Kessick - Web page: https://patentgrep.com/patent/US4392944A ## CPC - C10G 1/047: {Hot water or cold water extraction processes} - B01D 17/047: {with separation aids} - C10G: CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION (cracking to hydrogen or synthesis gas C01B; cracking or pyrolysis of hydrocarbon gases to individual hydrocarbons or mixtures thereof of definite or specified constitution C07C; cracking to cokes C10B); RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract Heavy oils, including oil sands, are recovered from mined or in-situ formation by a novel procedure which involves an initial emulsification of the oil with aqueous alkali, usually sodium hydroxide solution, at a pH above about 11. After separation of any residual solid phase, such as sand, the resulting oil-in-water emulsion is inverted by the use of slaked lime to form a water-in-oil emulsion and thereby regenerating part of the sodium hydroxide solution. The water-in-oil emulsion is dewatered to recover the oil phase while the aqueous phase is recycled to the initial emulsification, after removal of clay particles when oil sands are treated. ## Claims ### Claim 1 A process for the recovery of oil, which comprises: contacting a crude oil having an API gravity value of less than 25.degree. C. and containing groups capable of forming surfactants with water containing at least sufficient sodium hydroxide to provide a pH of the water of at least about 11 so as to form an oil-in-water emulsion having a concentration of about 10 to about 60 wt. % of the crude oil, contacting said oil-in-water emulsion with slaked lime in an amount of about 0.02 to about 1 wt. % of the oil in said oil-in-water emulsion and sufficient to invert said oil-in-water emulsion to form a water-in-oil emulsion, dewatering the water-in-oil emulsion to recover said oil therefrom, and recovering an aqueous sodium medium containing at least a major proportion of said sodium hydroxide from said emulsion inversion and dewatering steps. ### Claim 2 (depends on 1) The process of claim 1 wherein said pH is at least about 12. ### Claim 3 (depends on 1) The process of claim 1 wherein said sodium hydroxide is used in an amount of about 0.05 to about 1.5 wt. % based on the weight of said crude oil and said sodium hydroxide solution is of a concentration of up to about 0.5 wt. % NaOH. ### Claim 4 (depends on 3) The process of claim 3 wherein said sodium hydroxide solution has a concentration of about 0.1 to about 0.2 wt. % NaOH. ### Claim 5 (depends on 1, 3) The process of claim 1 or 3 wherein said water is deaerated water. ### Claim 6 (depends on 1) The process of claim 1 wherein said contact is effected at a temperature of about 60.degree. to about 80.degree. C. ### Claim 7 (depends on 1) The process of claim 1 wherein said slaked lime is used in an amount of about 0.05 to about 0.5 wt. % of the oil in the oil-in-water emulsion. ### Claim 8 (depends on 1) The process of claim 1 wherein said dewatering of said water-in-oil emulsion is effected by dissolving the oil in a water-immiscible solvent therefor, separating the resulting solvent-oil solution from the aqueous phase, and recovering the oil from the solvent-oil solution. ### Claim 9 (depends on 1, 8) The process of claim 1 or 8 wherein aqueous medium is recycled to the crude oil contacting step. ### Claim 10 (depends on 1) The process of claim 1 wherein said emulsion inversion and water-in-oil emulsion dewatering are effected by mixing with said oil-in-water emulsion sufficient water-immiscible solvent for said oil to dissolve the same, sufficient slaked lime to invert said oil-in-water emulsion to form a water-in-oil emulsion and sufficient water-soluble high molecular weight partially hydrolyzed polyacrylamide to cause separation of the resulting mixture into a solvent-oil solution phase, an aqueous phase and a mineral solids phase. ### Claim 11 (depends on 10) The process of claim 10 wherein said aqueous phase is recycled to the crude oil contacting step.