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US 5,514,272 AGranted
Process for re-refining used oil
OwnerBenjamin S. Santosinventor
Life of this patent
Estimating the term…
Abstract
A process for significantly decreasing the acid sludge settling time in waste oil recovery processes comprising the steps of heating used oil to a high temperature above 700 degrees Fahrenheit, cooling the heated oil, adding an oxidizing agent to the oil, allowing the acid sludge to settle within a period of approximately 24 to 72 hours, separating the acid-sludge-free oil from the acid sludge which settles out of solution as a result of addition of the oxidizing agent, and adding a polishing agent and separating the re-refined oil from the spent polishing agent. The process produces a high quality re-refined oil rapidly and economically.
Claims20
A process for re-refining used oil comprising the steps of:
- (1) providing used oil having impurities including carbonaceous materials, metals and other oxidizable components and dispersant additives,
- (2) heating the oil for whatever interval is necessary to reach a temperature equal to or greater than about 745 degrees Fahrenheit and less than or equal to 1000 degrees Fahrenheit and holding said temperature for an interval effective to negate the ability of any dispersant additives to keep said impurities in solution,
- (3) cooling the oil to approximately 70-120 degrees Fahrenheit,
- (4) adding a sufficient amount of oxidizing agent of a type adequate to oxidize at least said carbonaceous materials, metals and other oxidizable components to create acid sludge in solution and of a concentration adequate to cause substantially complete settling of acid sludge from said oil being processed within an interval of less than approximately three days such that the resulting mixture is 20-30% by volume acid sludge with the remainder being acid-sludge-free oil,
- (5) waiting until substantially all settling of acid sludge occurs, and then separating the acid sludge which has settled out of the mixture of the used oil and the oxidizing agent from the remaining components of the mixture to create a volume of substantially acid-sludge-free oil;
- and
- (6) adding a polishing agent adequate at least to substantially neutralize remaining acidity and remove at least some of the remaining particles which color the oil so as to obtain a quantity of re-refined oil which constitutes a yield of approximately 70-80% by volume of the quantity of used oil remaining after the heating of step (2) above.
4 more elements
A process for re-refining used oil comprising the steps of:
- (1) providing used oil having impurities including carbonaceous materials, metals and other oxidizable components and dispersant additives,
- (2) heating the oil for whatever interval is necessary to reach a temperature equal to or greater than about 745 degrees Fahrenheit and less than or equal to 1000 degrees Fahrenheit and holding said temperature for an interval effective to negate the ability of any dispersant additives to keep said impurities in solution,
- (3) cooling the oil to approximately 70-120 degrees Fahrenheit,
- (4) adding a sufficient amount of oxidizing agent of a type adequate to oxidize at least said carbonaceous materials, metals and other oxidizable components to create acid sludge in solution and of a concentration adequate to cause substantially complete settling of acid sludge from said oil being processed within an interval of less than approximately three days such that the resulting mixture is 20-30% by volume acid sludge with the remainder being acid-sludge-free oil,
- (5) waiting until substantially all settling of acid sludge occurs, and then separating the acid sludge which has settled out of the mixture of the used oil and the oxidizing agent from the remaining components of the mixture to create a volume of substantially acid-sludge-free oil;
- and
- (6) adding a polishing agent adequate at least to substantially neutralize remaining acidity and remove at least some of the remaining particles which color the oil so as to obtain a quantity of re-refined oil which constitutes a yield of approximately 70-80% by volume of the quantity of used oil remaining after the heating of step (2) above, and
- wherein the step of adding an oxidizing agent comprises the step of adding sulfuric acid having a concentration adequately high and having a volume sufficient to cause complete sedimentation of acid sludge within about 72 hours or less.
5 more elements
An improved process for re-refining used oil, comprising:
- providing used oil having impurities therein;
- heating the used oil to a temperature above about 745 degrees Fahrenheit and usually less than or equal to approximately 850 degrees Fahrenheit;
- cooling the oil to a temperature in the range from 70-120 degrees Fahrenheit;
- adding an oxidizing agent of a type adequate to oxidize at least carbonaceous materials, metals and other oxidizable components in the used oil so as to cause oxidation of impurities and create acid sludge in solution with the concentration and volume of said oxidizing agent being sufficient to cause settling of substantially all said acid sludge within less than approximately 2 days;
- waiting for a period of less than or equal to approximately one to two days for the acid sludge created by addition of said oxidizing agent to settle to the bottom of the vessel containing the used oil being re-refined;
- separating oil which is free of acid sludge from said acid sludge to create a quantity of acid-sludge-free oil;
- adding a polishing agent to said acid-sludge-free oil, said polishing agent being adequate at least to substantially neutralize remaining acidity in said acid-sludge-free oil and to substantially remove the remaining particles which color the oil.
4 more elements
Dependencies are inferred from the claim text.