Claims
- 1. A process for the production of an essentially pure lube oil stock from a used lubricating oil containing ash-forming and additive components which comprises:
- (a) contacting said used lubricating oil with an aqueous solution of a treating agent consisting essentially of an ammonium salt selected from the group consisting of ammonium sulfate, ammonium bisulfate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate and mixtures thereof, said treating agent being present in an amount at least sufficient to react with essentially all of the metal constituents in said used lubricating oil, wherein said contacting is carried out at a temperature in the range of from 60.degree. to 120.degree. C. and a pressure in the range of 1 atmosphere to 250 psia and wherein said agent is kept in contact with said used lubricating oil for a time sufficient to disperse said agent in said used lubricating oil and to react said agent with essentially all the ash-forming metal components of said used lubricating oil;
- (b) removing a major portion of water and light hydrocarbon components from the resulting aqueous reaction mixture from step (a) by maintaining said mixture at a temperature in the range of 110.degree. to 140.degree. C. and a pressure in the range of 5 to 25 psia for a period of time sufficient to effect removal of a major portion of water and light hydrocarbons therefrom;
- (c) separating the oil phase from the residual mixture consisting essentially of used lubricating oil and reacted treating agent resulting from step (b) by filtration;
- (d) heating the resulting filtered oil from step (c) to a temperature in the range of 200.degree. to 480.degree. C;
- (e) contacting the resulting heated oil from step (d) with at least one adsorbent selected from the group consisting of activated carbon, silica gel, clay, bauxite and alumina in a contacting zone;
- (f) hydrotreating the resulting oil from step (e) by contacting said oil with hydrogen and a hydrotreating catalyst at a temperature in the range of 200.degree. to 430.degree. C. and at a pressure in the range of 150 to 3000 psia;
- (g) stripping the resulting hydrotreated oil from step (f) in a stripping zone maintained at a temperature in the range of about 280.degree. to 395.degree. C. and at a pressure in the range of atmospheric to 50 psia; and thereafter
- (h) recovering the resulting stripped oil from said stripping zone as a product of the process.
- 2. A process according to claim 1 wherein the concentration of ammonium salt in said aqueous solution of a treating agent is in the range of 30 to 95 weight percent of that in an aqueous solution at 25.degree. C. saturated with the treating agent.
- 3. A process according to claim 1 wherein said treating agent is present in an amount such that the ratio of treating agent to used lubricating oil is in the range of 0.002 to 0.05:1.
- 4. A process according to claim 1 wherein the mixture of step (a) is maintained at the temperature of 60.degree. to 120.degree. C. for a period of time in the range of from 10 to 120 minutes and the mixture of step (b) is maintained at the temperature of 110.degree. to 140.degree. C. for a period of time in the range of from 10 to 120 minutes.
- 5. A process according to claim 1 wherein a filter aid is added to said used lubricating oil prior to filtration step (c).
- 6. A process according to claim 5 wherein said filter aid is added in an amount such that the weight ratio of filter aid is up to 0.15:1.
- 7. A process according to claim 1 wherein said residual mixture of used lubricating oil and reacted treating agent is maintained at a temperature in the range of 60.degree. to 120.degree. C. for a period of at least 10 minutes prior to further processing.
- 8. A process according to claim 1 wherein the mixture from step (b) is thereafter maintained at a temperature in the range of 140.degree. to 200.degree. C., a pressure in the range of 5 to 25 psia for a time sufficient to effect removal of essentially all remaining water and light hydrocarbons prior to filtration.
- 9. A process according to claim 1 wherein said adsorbent contains about 0.2 to about 20 weight percent of at least one metal selected from the group consisting of Group VIB and Group VIII metals, weight being based on the total weight modified adsorbent.
- 10. A process according to claim 1 wherein step (e) is omitted and the hot oil in step (d) is heated to a temperature in the range of 300.degree. to 410.degree. C. in the presence of hydrogen and an adsorbent suspended in the oil, thereafter is cooled to a temperature in the range of 60.degree. to 200.degree. C. and is then refiltered prior to hydrotreating.
- 11. A process according to claim 1 wherein said stripping step (g) is steam stripping.
- 12. A process according to claim 1 wherein said stripping step (g) is gas stripping.
Parent Case Info
This application is a continuation-in-part of Ser. No. 797,212, filed May 16, 1977, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3791965 |
Fitzsimons et al. |
Feb 1974 |
|
3879282 |
Johnson |
Apr 1975 |
|
3930988 |
Johnson |
Jan 1976 |
|
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
797212 |
May 1977 |
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