Patent ID: 11873463
Assignee: REGEN III CORP.
Field: Basic materials chemistry (Chemistry)
Classification: CPC C | IPC C

Claim 17:
18. A method comprising:
contacting a feedstock comprising purified used oil with an extraction solvent to perform continuous liquid-liquid solvent extraction, to produce an extract stream comprising the extraction solvent and an extract dissolved in the extraction solvent, wherein the feedstock and the extraction solvent are agitated by a variable speed agitator during the solvent extraction at a selected agitation speed;
separating the extract from the extraction solvent; and
subjecting the extract to a continuous flow liquid phase hydrogenation treatment to produce an oil product having a viscosity index of at least 80, wherein the liquid phase hydrogenation treatment comprises:
adding a diluent to the extract to increase solubility of hydrogen in the extract, thus forming a liquid mixture comprising the diluent and the extract;
adding hydrogen to the liquid mixture to dissolve the hydrogen in the liquid mixture; and
heating the liquid mixture with dissolved hydrogen in the presence of a hydrogenation catalyst to saturate unsaturates in the liquid mixture, and removing sulfur and aromatics from the liquid mixture, thus forming the oil product,
wherein the extract comprises phosphorus, and silicon, and the continuous flow liquid phase hydrogenation treatment comprises removing phosphorus and silicon from the liquid mixture before exposing the liquid mixture to the hydrogenation catalyst.