Abstract: A substantially solids-free sample of an oil having substantially the same hydrocarbon distribution as a heavy oil contained in a subterranean reservoir is prepared by vacuum-topping a field sample of the oil or oil-containing material while cold-trapping volatiles, diluting the topped oil with a volatile oil solvent, mechanically separating the solution from entrained solids, vacuum-distilling the solvent from the dissolved oil and recombining the oil and the cold-trapped volatiles.

Abstract: Used lubricating oil is rerefined utilizing hydride reducing agents. The hydride reducing agent contacts the used oil in an aqueous solution, for example. Contact with the hydride reducing agent may occur before, during or after distillation or evaporation of the used lubricating oil. The disclosed method reduces the concentration of carbonyl compounds and metals and reduces the corrosion characteristics of used lubricating oil.

Abstract: In a process for the re-refinement of used lubricating oil containing fuel fraction, an upgraded fuel fraction is provided by combining fuel fraction with demetallized lubricating oil prior to the hydrotreatment stage.

Abstract: Process oil is made by conversion from "waste" materials, particularly used oils, and most particularly used crankcase oils, by flash evaporation at about 250.degree. F. and filtration for removal of solids therefrom, to produce a product substantially free of water and low boiling point components and of contaminant solids, which has a flash point above 310.degree. F., or is blended with other products from the same process to produce a final product having a flash point above 310.degree. F., and an aromatic content above 10%, preferably above 20%, by weight. The product may be used generally in a wide variety of process oil applications but is most particularly adapted for use as a rubber process oil and such use is also part of the present invention.

Abstract: The object of the invention is a process for recycling used lubricating oils. After drying and gasoline removal, the oil is distilled and then treated with sodium or sodium hydride in a finely-divided state at elevated temperature. This is followed by a further distillation. Both distillations are at temperatures below 300.degree. C., the oil fractions of low volatility being respectively distilled in a molecular distillation apparatus at below 2 mbar.

Abstract: Used oil is rerefined by distillation and extraction with tetrahydrofurfuryl alcohol. In accordance with the process, used oil is rerefined by distillation to remove a volatile forecut followed by further distillation with recirculation provisions to obtain the desired fractions of lubricating oil products while reducing the vaporization temperature of the oil. The recycle effect tends to reduce coking and cracking while providing a greater recovery of lubricating oil products through the carrier effect of the light ends. After the desired fractions of lubricating oil have been obtained by the distillation phase of the process, tetrahydrofurfuryl alcohol is utilized in an extraction process to remove impurities remaining in the distilled oil. The tetrahydrofurfuryl alcohol-lube oil mixture is separated into a raffinate and extract stream for distilling and steam stripping the tetrahydrofurfuryl alcohol therefrom.

Abstract: Used oil is refined by distillation to remove a volatile forecut followed by further distillation with recirculation provisions to obtain the desired fractions of lubricating oil products while reducing the vaporization temperature of the oil. The recycle effect tends to reduce coking and cracking while providing a greater recovery of lubricating oil products through the carrier effect of the light ends.In one embodiment of the invention, a waste oil feedstock has water, gasoline and other similarly volatile components removed in a first stage evaporator (16). Heavier fuel, such as fuel oil is then removed in a second stage evaporator (28). A light lube oil fraction is then obtained by distillation with a third stage wiped-film evaporator (40). Finally, a heavy lube oil fraction is obtained by distillation of the bottoms from the evaporator (40) with a fourth-stage evaporator (64).

Abstract: A method for the continuous decomposition of stable carbon dispersions in waste engine oils, the decomposition being immediately followed by an oil re-refining step as, preferably, a short-path distillation. In accordance with the invention, waste oil is heated, under a pressure ranging from 1 to 100 Pa, in the form of a thin film (0.1 to 2 mm thickness) to a temperature of 200.degree.-300.degree. C., whereby liberated vapors together with entrained microdrops condense at a temperature of 20.degree.-100.degree. C. Thereupon the condensate is immediately subjected to a short-path distillation to be re-refined. The entire process is advantageously effected in a single apparatus.

Abstract: A method for reprocessing used lubricating oils is disclosed wherein the oil is dried, treated with finely dispersed sodium metal at elevated temperature, the remaining free or organically bound metal is decomposed by means of an active hydrogen containing compounds, followed by distillation of the oil for recovery.

Abstract: A process for the reprocessing of used lubricating oil wherein said oils are treated with a mixture of potassium hydroxide and sodium hydroxide.

Abstract: For refining spent motor oils in order to recover lubricating bases to be reused, the stock to be refined is first stripped of water and light hydrocarbons, then a first extraction with a solvent (preferably a lower paraffin), heating the oil stripped of the solvent, distilling it under vacuum to separate light, medium and heavy lubricating bases, heating the heavier lubricating base and then extracting it with the same solvent as aforesaid, and sending the lubricating bases, separately and individually, to a hydrofinishing stage. The recycle to solvent extraction of the heavy bases affords the advantage of important heat savings and the possibility of adopting blander working conditions in the hydrofinishing of the heavier lubricating bases.

Abstract: A simplified, essentially maintenance-free yet highly efficient distillation tower and method for waste oil rerefining is provided which allows direct vacuum distillation of additive-supplemented waste oils without chemical pretreatment thereof and yields a highly refined intermediate oil suitable for immediate use or final polishing, along with a valuable bottoms fraction usable in greases or asphalts, for example. The tower includes an upright, cylindrical chamber with a tangential waste oil inlet and cooperating internal baffle for creating a whirling oil flow pattern therewithin, along with means for maintaining the proper temperature conditions within the tower for maximizing vaporization and recovery of hydrocarbons from the waste oil while also preventing undesirable decomposition or cracking of the oil.

Abstract: Screened and drained used lubricating oil stock is predistilled in a steam stripping still for about 4 hours or more. The thus predistilled used oil then flows to an evaporator for a vacuum distillation at a temperature below the cracking temperature of the stock, about 480.degree.-650.degree. F., to effect an evaporation of the used lubricating oil and its separation from a concentrate by-product of heavy lube hydrocarbons and additives.

Abstract: A process for reclaiming used hydrocarbon oils through prepurification by means of coagulation, adsorption, filtration, distillation, and after-treatment, wherein said oils are prepurified and then dehalogenated, fractionally distilled and hydrogenated. It is preferred that for the prepurification, said coagulation and said adsorption are carried out by means of a hydroxide or hydroxide mixture, preferably aluminum and/or ferric hydroxide, in a proportion of 0.5 - 5.0% by weight, preferably 1-2% by weight, of hydroxide relative to said used oil at a reaction temperature of from 20.degree. - 200.degree. C, preferably from 50 to 150.degree. C, said hydroxide or hydroxides being produced directly in said used oil in the presence of water or being introduced into said used oil in the form of an aqueous slurry.

Abstract: A re-refining process is described by which high-quality finished lubricating oils are prepared from used waste lubricating and crankcase oils. The used oils are stripped of water and low-boiling contaminants by vacuum distillation and then dissolved in a solvent of 1-butanol, 2-propanol and methylethyl ketone, which precipitates a sludge containing most of the solid and liquid contaminants, unspent additives, and oxidation products present in the used oil. After separating the purified oil-solvent mixture from the sludge and recovering the solvent for recycling, the purified oil is preferably fractional vacuum-distilled, forming lubricating oil distillate fractions which are then decolorized and deodorized to prepare blending stocks. The blending stocks are blended to obtain a lubricating oil base of appropriate viscosity before being mixed with an appropriate additive package to form the finished lubricating oil product.

Abstract: A method for purifying and reclaiming used lubricating oils containing additives such as detergents, antioxidants, corrosion inhibitors, extreme pressure agents and the like and other solid and liquid contaminants by preferably first vacuum distilling the used oil to remove water and low-boiling contaminants, and treating the dried oil with a solvent mixture of butanol, isopropanol and methylethyl ketone which causes the separation of a layer of sludge containing contaminants, unspent additives and oxidation products. After solvent recovery, the desludged oil is then subjected to conventional lubricating oil refining steps such as distillation followed by decolorization and deodorization.

Abstract: An effective method of reclaiming or re-refining modern-day, additive-supplemented waste oils such as those derived from gasoline or diesel engine crankcases is provided which achieves substantial oil purification at relatively low cost and without creation of waste disposal problems common to conventional methods such as those involving clay and acid treatment. The method hereof includes the steps of dehydrating and fractionating the waste oil to remove water and the light ends, followed by vacuum distillation to give various grades of oil and solvent treatment with a solvent such as nitrobenzene to remove substantially all undesirable impurities from the oil. Reclaimed oil is thereafter recovered by steam stripping techniques which also allows collection and reuse of the solvent, in order to materially reduce operational costs.

Abstract: Used lubricating oil is contacted with particles of a solid adsorption resin comprising at least 0.1 cc per gram of pores of diameter in the range of 6 to 300 angstroms. The resin is preferably a porous polycondensate or cross-linked copolymer comprising pyridyl or hydroxy groups, for example a polycondensate of phenol and formaldehyde. The resin may be reactivated by rinsing with an organic solvent such as an alcohol, a ketone or a chlorinated hydrocarbon.

Abstract: Used oil is rerefined by distilling it to remove a volatile forecut followed by a fraction of lubricating viscosity; the latter is then extracted with an immiscible liquid extractant to remove impurities. As optional preliminary steps, the oil may be diluted with a volatile diluent and insoluble impurities removed therefrom, and heated with an aqueous solution of a strongly alkaline material to concentrate metallic constituents (such as metal-containing additives) in a solid sludge.