Disclosed herein is a system comprising: a) a separator tank comprising a first inlet, a second inlet, a first outlet, and a second outlet, b) a heat exchanger, and c) a holding tank comprising a third inlet and a third outlet, wherein the separator tank is in fluid communication with the holding tank via a first connector and via a second connector, wherein the first connector is connected to the first outlet of the separator tank and to the third inlet of the holding tank, wherein the second connector is connected to the first inlet of the separator tank and to the third outlet of the holding tank, and wherein the first connector and the second connector are in communication with the heat exchanger.

Ionic liquids of the general formula C.sup.+A.sup.− where C.sup.+ represents an organic cation, specifically, but not limited to the imidazolium, pyridinium, isoquinolinium, ammonium types, which have aliphatic and aromatic substituents, while A.sup.− represents a carboxylate, aromatic and aliphatic anion. The ionic liquids are synthesized under conventional heating or microwave irradiation This invention is also related to the application of ionic liquids to remove sulfur compounds of naphthas through a liquid-liquid extraction and the recovery and reuse of ionic liquids by the application of heat, reduced pressure and washing with solvents.

Ionic liquids of the general formula C.sup.+A.sup.− where C.sup.+ represents an organic cation, specifically, but not limited to the imidazolium, pyridinium, isoquinolinium, ammonium types, which have aliphatic and aromatic substituents, while A.sup.− represents a carboxylate, aromatic and aliphatic anion. The ionic liquids are synthesized under conventional heating or microwave irradiation This invention is also related to the application of ionic liquids to remove sulfur compounds of naphthas through a liquid-liquid extraction and the recovery and reuse of ionic liquids by the application of heat, reduced pressure and washing with solvents.

Disclosed is a method of removing calcium from a hydrocarbon fraction using an extraction agent including 2-oxopropanal or derivatives thereof, the method including (S1) adding a hydrocarbon fraction with an extraction agent including 2-oxopropanal or derivatives thereof to give a mixture, (S2) converting an oil-soluble calcium compound into a water-soluble calcium compound by reacting the hydrocarbon fraction with the 2-oxopropanal or derivatives thereof, and (S3) removing the water-soluble calcium compound.

Treatment of hydrocarbon streams, and in one non-limiting embodiment refinery distillates, with high pH aqueous reducing agents, such as borohydride, results in reduction of the sulfur compounds such as disulfides, mercaptans and thioethers that are present to give easily removed sulfides. The treatment converts the original sulfur compounds into hydrogen sulfide or low molecular weight mercaptans that can be extracted from the distillate with caustic solutions, hydrogen sulfide or mercaptan scavengers, solid absorbents such as clay or activated carbon or liquid absorbents such as amine-aldehyde condensates and/or aqueous aldehydes.

A method for recovering base oil from waste lubricating oil by separating base oil range constituents from a waste lubricating oil mixture, thereafter separating higher quality base oil constituents and lower quality base oil constituents from the base oil recovered from the waste lubricating oil mixture and thereafter treating the lower quality base oil constituents to produce marketable base oil. The total base oil produced from a waste lubricating oil mixture by this process is greater than the quantity producible by previous processes using only base oil separation from the waste lubricating oil mixture or processes which use only treatment of the base oil recovered from the waste lubricating oil mixture to produce the product base oil.

A method for recovering base oil from waste lubricating oil by separating base oil range constituents from a waste lubricating oil mixture, thereafter separating higher quality base oil constituents and lower quality base oil constituents from the base oil recovered from the waste lubricating oil mixture and thereafter treating the lower quality base oil constituents to produce marketable base oil. The total base oil produced from a waste lubricating oil mixture by this process is greater than the quantity producible by previous processes using only base oil separation from the waste lubricating oil mixture or processes which use only treatment of the base oil recovered from the waste lubricating oil mixture to produce the product base oil.

Techniques for separating a fuel on-board a vehicle include mixing an input fuel stream and a fluid solvent; separating the mixture into a first liquid fuel stream and a second liquid fuel stream, the first liquid fuel stream including a first portion of the input fuel stream defined by a first auto-ignition characteristic value and the fluid solvent, the second liquid fuel stream including a second portion of the input fuel stream defined by a second auto-ignition characteristic value that is different than the first auto-ignition characteristic value; separating the first liquid fuel stream into the fluid solvent and the first portion of the input fuel stream; directing the first portion of the input fuel stream to a first fuel tank on the vehicle; and directing the second portion of the input fuel stream to a second fuel tank on the vehicle.

The invention relates to a class of novel surfactants that have utility in the recovery and/or extraction of oil.

Described herein are methods and systems for performing liquid-liquid extraction in bulk tankage. According to certain embodiments, the liquid-liquid extraction can occur in a bulk tank via a circulation loop, in which a solvent mixture is injected with the hydrocarbon ahead of mix valves on the circulation loop. According to other embodiments, a misting system is installed in the vapor or head space of bulk tankage. The misting system distributes small micro-drops of a solvent mixture so as to cause a uniform lay down over the entire top surface area of hydrocarbon. The solvent mixture migrates from the top surface of the hydrocarbon to the bottom of the bulk tank, reacting during migration to cause liquid-liquid extraction.