Proposed is a process of producing a high-quality lube base oil using a refined oil fraction obtained from waste lubricant as a feedstock. The process includes purifying waste lubricant to obtain a refined oil fraction, pretreating the refined oil fraction, and blending the pretreated refined oil fraction with unconverted oil (UCO), before or after vacuum distillation and catalytic dewaxing of the unconverted oil, or between the vacuum distillation and the catalytic dewaxing of the unconverted oil.

In an embodiment is provided a process to re-refine used oil that includes introducing a used oil and a solvent to a separation unit under separation conditions selected to produce a purified oil product, the separation unit comprising a porous membrane, a semiporous membrane, or both; and separating the used oil to obtain an effluent comprising a purified oil product. In another embodiment is provided an apparatus for re-refining used oil that includes a separation unit comprising a porous or semiporous membrane; a used oil feed coupled to an inlet of the separation unit; and an inlet of a diffusate collection unit coupled to an outlet of the separation unit. In another embodiment is provided a composition generated from a membrane separation process that includes a base oil, the composition having a soot content of about 0.05% or less.

The present disclosure provides a method of producing a lubricant composition comprising the steps of hydrolyzing a starting material to provide a hydrolyzed product mixture, reacting the hydrolyzed product mixture under conditions capable of producing a condensation product mixture, contacting the condensation product mixture with a cyclic compound to provide a coupled product mixture, and hydrogenating the coupled product mixture to provide the lubricant composition. In addition, other methods and compositions thereof are also provided.

A method for re-refining used oils comprises contacting feedstock comprising purified used oil with 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. The feedstock and the extraction solvent are agitated by a variable speed agitator during the solvent extraction at a selected agitation speed. The extract is separated from the extraction solvent and subjected to a continuous flow liquid phase hydrogenation treatment to produce an oil product. A system for performing the method includes a purification unit for purifying the used oil; an extraction column for extracting the extract from the feedstock; and a continuous flow liquid phase hydrogenation unit. The extraction column comprises an agitator configured to agitate the feedstock and the extraction solvent flowing through the extraction column at a variable agitation speed.

The present invention relates to a pre-hydrotreatment and purification method for waste lubricating oil, the method comprising the following steps: mechanical impurities are removed from waste lubricating oil, and then the oil is subjected to flash distillation to separate free water and a portion of light hydrocarbons; a bottom product of the flash distillation column is mixed with hydrogen and a self-sulfurizing oil-soluble transition metal catalyst, and then enters a slurry bed reactor for pre-hydrotreatment; a gas product obtained by performing separation on a reaction effluent is subjected to adsorption purification and then enters a hydrogen recycle compressor for cyclic use; a liquid product obtained by performing separation on a reaction effluent is subjected to hydrocyclone separation and solvent washing to remove solid residue, and finally a purified lubricating oil component is obtained. The method of the present invention has such advantages as simple processing procedures, a high non-ideal component conversion rate, a high oil liquid yield, and good quality. In addition, the oil-soluble catalyst features simple dispersion, no need for vulcanization, a small catalyst adding amount, high low-temperature hydrogenation activity, and is capable of effectively preventing the coking that could occur during a process of preheating the waste lubricating oil, markedly extending the operational lifespan of a waste lubricating oil hydrogen treatment device.

A method for re-refining used oils comprises contacting feedstock comprising purified used oil with 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. The feedstock and the extraction solvent are agitated by a variable speed agitator during the solvent extraction at a selected agitation speed. The extract is separated from the extraction solvent and subjected to a continuous flow liquid phase hydrogenation treatment to produce an oil product. A system for performing the method includes a purification unit for purifying the used oil; an extraction column for extracting the extract from the feedstock; and a continuous flow liquid phase hydrogenation unit. The extraction column comprises an agitator configured to agitate the feedstock and the extraction solvent flowing through the extraction column at a variable agitation speed.

A method for re-refining used oils comprises contacting feedstock comprising purified used oil with 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. The feedstock and the extraction solvent are agitated by a variable speed agitator during the solvent extraction at a selected agitation speed. The extract is separated from the extraction solvent and subjected to a continuous flow liquid phase hydrogenation treatment to produce an oil product. A system for performing the method includes a purification unit for purifying the used oil; an extraction column for extracting the extract from the feedstock; and a continuous flow liquid phase hydrogenation unit. The extraction column comprises an agitator configured to agitate the feedstock and the extraction solvent flowing through the extraction column at a variable agitation speed.

A system for producing an American Petroleum Institute Standards Group III Base Stock from vacuum gas oil, by injecting hydrogen, heating, saturating the mixture through hydrogen reactors connected in series with a liquid hourly space velocity (LHSV).sup.1 of from 0.5 to 2.5, forming a saturated heated base oil, and coproduct. The system fractionates the saturated heated base oil to while simultaneously refluxing a cooled fuel oil fraction forming an American Petroleum Institute Standards Group III Base Stock with less than 0.03% sulfur, with greater than 90% saturates and a viscosity index greater than 120 as defined by ASTM D-2270, a viscosity from 2 to 10 centistokes as defined by ASTM D-445 a boiling range from 600 degrees F. to 1050 degrees F., and a cold crank viscosity (CCS) between 1200 and 5000 centipoise at 25 degrees C. and as defined by ASTM D-5293.

A system for producing an American Petroleum Institute Standards Group III Base Stock from vacuum gas oil, by injecting hydrogen, heating, saturating the mixture through hydrogen reactors connected in series with a liquid hourly space velocity (LHSV).sup.1 of from 0.5 to 2.5, forming a saturated heated base oil, and coproduct. The system fractionates the saturated heated base oil to while simultaneously refluxing a cooled fuel oil fraction forming an American Petroleum Institute Standards Group III Base Stock with less than 0.03% sulfur, with greater than 90% saturates and a viscosity index greater than 120 as defined by ASTM D-2270, a viscosity from 2 to 10 centistokes as defined by ASTM D-445 a boiling range from 600 degrees F. to 1050 degrees F., and a cold crank viscosity (CCS) between 1200 and 5000 centipoise at 25 degrees C. and as defined by ASTM D-5293.

A method for producing an American Petroleum Institute Standards Group III Base Stock from vacuum gas oil, by injecting hydrogen, heating, saturating the mixture through hydrogen reactors connected in series with a liquid hourly space velocity (LHSV).sup.1 from 0.5 to 2.5, forming a saturated heated base oil, and coproduct. The method fractionates the saturated heated base oil while simultaneously refluxing a cooled light oil fraction forming an American Petroleum Institute Standards Group III Base Stock with less than 0.03% sulfur, with greater than 90% saturates and a viscosity index greater than 120 as defined by ASTM D-2270, a viscosity from 2 to 10 centistokes as defined by ASTM D-445 a boiling point range from 600 degrees F. to 1050 degrees F. as defined by ASTM D-86, and a cold crank viscosity (CCS) between 1200 and 5000 centipoise at minus 25 degrees C. and as defined by ASTM D-5293.