Abstract: Systems and methods are provided for performing solvent dewaxing using a dewaxing solvent that is not fully miscible with the feed being dewaxed. It has been unexpectedly discovered that by operating with a ketone solvent mixture that is beyond the miscibility limit by a small amount, the rate of solvent dewaxing can be substantially increased. Additionally, the difference between the filtration temperature during solvent dewaxing and the pour point of the resulting dewaxed product is unexpectedly reduced. The dewaxing solvent beyond the miscibility limit can correspond to, for example, a solvent mixture where the weight percent of methyl ethyl ketone is beyond the miscibility limit by 0.1 vol % to 5.0 vol %.

Abstract: The present invention relates to a process for preparing a residual base oil from a hydrocarbon feed which is derived from a Fischer-Tropsch process, the process comprises the steps of: (a) providing a hydrocarbon feed which is derived from a Fischer-Tropsch process; (b) subjecting the hydrocarbon feed of step (a) to a hydrocracking/hydroisomerisation step to obtain an at least partially isomerised product; (c) separating at least part of the at least partially isomerised product as obtained in step (b) into one or more lower boiling fractions and a hydrowax residue fraction; (d) catalytic dewaxing of the hydrowax residue fraction of step (c) to obtain a highly isomerised product; (e) separating the highly isomerised product of step (d) into one or more light fractions and a isomerised residual fraction; (f) mixing of the isomerised residual fraction of step (e) with a diluent to obtain a diluted isomerised residual fraction; (g) cooling the diluted isomerised residual fraction of step (f) to a temperature be

Abstract: A drive system for driving a fan in a wet cooling tower, wherein the fan has a fan hub and fan blades attached to the fan hub. The drive system has a high-torque, low speed permanent magnet motor having a motor casing, a stator and a rotatable shaft, wherein the rotatable shaft is configured for connection to the fan hub. The drive system includes a variable frequency drive device to generate electrical signals that effect rotation of the rotatable shaft of the motor in order to rotate the fan.

Abstract: A method of recovering an extraction aid from distillers corn oil, by directing stillage containing distillers oil and an extraction aid to a centrifugal separator, recovering a light phase from the centrifugal separator, the light phase containing at least a portion of the distillers oil and at least a portion of the extraction aid, cooling the light phase and causing a precipitate to form, and recovering a precipitate from the cooled light phase containing at least a portion of the extraction aid. A method of recovering distillers oil.

Abstract: Subject-matter of the invention are processes for preparing fatty acid vinyl ester copolymers by radically initiated polymerization of a) one or more vinyl esters of carboxylic acids having 16 to 22 carbon atoms and b) one or more vinyl esters of carboxylic acids having 2 to 15 carbon atoms, with one or more vinyl esters a) and one or more vinyl esters b) being metered in during the polymerization, characterized in that during the polymerization either the metering rate of vinyl ester a) or the metering rate of vinyl ester b) is reduced and the metering rate of the other of the two vinyl esters, a) or b), is increased.

Abstract: Methods are provided for producing lubricant base oils from petrolatum. After solvent dewaxing of a brightstock raffinate to form a brightstock base oil, petrolatum is generated as a side product. The petrolatum can be hydroprocessed to form base oils in high yield. The base oils formed from hydroprocessing of petrolatum have an unexpected pour point relationship. For a typical lubricant oil feedstock, the pour point of the base oils generated from the feedstock increases with the viscosity of the base oil. By contrast, lubricant base oils formed from hydroprocessing of petrolatum have a relatively flat pour point relationship, and some of the higher viscosity base oils unexpectedly have lower pour points than lower viscosity base oils generated from the same petrolatum feed. The base oils from petrolatum are also unusual in yielding both high viscosity and high viscosity index and can be generated while maintaining a high yield.

Abstract: The disclosure provides (i) a lubricating oil composition including a base oil (A) with a kinematic viscosity at 100° C. of 8.2-12.6 mm2/s and a saturated hydrocarbon content of 90% by mass or more, a metallic detergent (B) and a zinc dithiophosphate (C), wherein a content of the metallic detergent (B) is 2.5 mmol or more as a soap content concentration per 100 g of the composition, a phosphorous content is 200-1000 mass ppm, and a base number is 7.5 mg KOH/g or more, and (ii) a lubricating oil composition including the base oil (A), the metallic detergent (B), the zinc dithiophosphate (C) and an amine-based antioxidant (E), wherein a content of the amine-based antioxidant (E) is 0.3% by mass or more in terms of total content of the composition, a base number is 6.5 mg KOH/g or more, and a phosphorous content is 200-1000 mass ppm.

Abstract: The disclosed embodiments relate to systems and methods for heating a slurry to increase a solids concentration of the slurry while maintaining the viscosity of the slurry below a threshold viscosity. For example, in one embodiment, a system includes a fuel slurry preparation system having a slurry tank configured to hold a fuel slurry, the fuel slurry having a solid fuel and a liquid. The fuel slurry preparation system also includes a heat source and a controller configured to control the heat source to heat the fuel slurry to decrease a viscosity of the slurry below a threshold viscosity.

Abstract: The present invention relates to a method for preparing lubricating base oils by using vacuum distilled deasphalted oil, and more specifically, to a method for preparing various kinds of lubricating base oils by distilling a distillate obtained from a solvent deasphalting (SDA) process under reduced pressure to obtain heavy deasphalted oil (H-DAO) and light deasphalted (Lt-DAO) and then treating the H-DAO and the Lt-DAO by catalytic reactions, respectively. According to the present invention, it is possible to obtain heavy lubricating base oil (150BS) of a high viscosity grade which can not be obtained by a known catalytic reaction and a lubricating base oil of group III by hydrogenation, in a high yield, and thus economical efficiency is excellent.

Abstract: A process for production of a lubricating base oil whereby a lubricating base oil is obtained by a first step in which a stock oil containing normal paraffins of C20 or more is subjected to isomerization reaction so that the content of the normal paraffins of C20 or more is 6-20 wt % based on the total weight of hydrocarbons of C20 or more in the obtained reaction product, a second step in which a lube-oil fraction containing hydrocarbons of C20 or more is separated from the reaction product of the first step, and a third step in which the lube-oil fraction obtained in the second step is separated into a dewaxed oil and a wax by a solvent dewaxing treatment.

Abstract: The determination of wax crystal particle size and population is used to monitor the performance of wax crystallizers used in lubricant oil processing using solvent dewaxing. The wax crystal particle size is monitored using online measurements. The information obtained from on-line monitoring is then used to control crystallization in the dewaxing equipment in order to optimize performance of the dewaxing units.

Abstract: A process to prepare a heat transfer oil, comprising: a. dewaxing a substantially paraffinic wax feed by hydroisomerization dewaxing using a shape selective intermediate pore size molecular sieve under hydroisomerization conditions including a defined hydrogen to feed ratio, whereby a lubricating base oil is produced, b. selecting one or more fractions of the lubricating base oil having: i. a low pour point, ii. greater than 10 weight percent and less than 70 weight percent total molecules with cycloparaffinic functionality, wherein the one or more fractions have at least 31.2 wt % 1-unsaturations by FIMS, and iii. a ratio of weight percent molecules with monocycloparaffinic functionality to weight percent molecules with multicycloparaffinic functionality greater than 15; and c. blending the one or more fractions of the lubricating base oil with less than 0.2 wt % antifoam agent to prepare the heat transfer oil of a defined ISO viscosity grade.

Abstract: The invention relates to a process for preparing lube oil basestocks from lube oil boiling range feeds. More particularly, the present invention is directed toward a process wherein a wax containing feed is solvent dewaxed to produce at least a partially dewaxed lube oil boiling range stream, which is hydrodewaxed to produce a first lube basestock. The first lube basestock is added to an independently selected second lube basestock and additives to make a lubricating oil.

Abstract: The present invention discloses a process for the preparation of syngas from two sources with different hydrogen: carbon ratios, the first source having a low hydrogen:carbon ratio including any one or a combination of coal, brown coal, peat, bitumen and tar sands, and the second source having a high hydrogen:carbon ratio including any one or a combination of natural gas, associated gas and coal bed methane. The sources are converted to syngas and then combined to provide syngas with an optimum hydrogen:carbon monoxide ratio for use in a Fischer-Tropsch process.

Abstract: The invention provides a lubricating base oil with a saturated component content of 90% by mass or greater, a proportion of cyclic saturated components of no greater than 40% by mass of the saturated components, a viscosity index of 110 or greater, an aniline point of 106 or greater and an ?-methylene proportion of 14-20% of the total constituent carbons, as well as a lubricating oil composition comprising the lubricating base oil.

Abstract: The invention relates to copolymers which are suitable for producing additives for solvent deparaffination of paraffin-containing mineral oil distillates and which consist of radically polymerized monomers of formulas A and B, wherein the radicals have the meaning cited in the description. The invention also relates to the use of said copolymers for the production of dewaxing additives.

Abstract: Process to prepare a base oil having a viscosity index of between 80 and 140 starting from a distillate or a de-asphalted oil by (a) contacting the feedstock in the presence of hydrogen with a sulphided hydrodesulphurization catalyst comprising nickel and tungsten on an acid amorphous silica-alumina carrier and (b) performing a pour point reducing step on the effluent of step (a) to obtain the base oil.

Abstract: A process for producing lube basestocks involving solvent dewaxing a waxy feed to produce at least a partially dewaxed lube oil boiling range stream and then hydrodewaxing the partially dewaxed lube oil boiling range stream to produce a lube basestock.

Abstract: The invention relates to a method for analyzing a lubricating oil for low temperature properties. The method utilizes 2-dimensional gas chromatography (2D GC) to determine the amounts of paraffins and isoparaffins in the oil. In particular, the method analyzes for a particular isoparaffin fraction which is correlated to low temperature performance. The compositional information thus obtained is correlated with formulated oil Mini Rotary Viscometer (MRV) properties.

Abstract: The invention relates to a hydrocracking process for hydrocracking petroleum and chemical feedstocks using bulk Group VIII/VIB catalysts. Preferred catalysts include those comprised of Ni—Mo—W.

Abstract: A method and apparatus are disclosed for recovering pure naphthalene from hot crude coke oven gas. The hot crude coke oven gas is directly cooled by means of sprinkling water directly thereon, and the naphthalene is recovered by subsequent filtering out of tar and other impurities, followed by cooling to obtain crystalline pure naphthalene. More specifically, after direct cooling of the hot crude coke oven gas, the gas is then guided through an electrofilter to be subsequently cooled in such a manner that the naphthalene contained in the crude coke oven gas is separated from the gaseous phase and is obtained in the form of pure naphthalene crystals without any required additional treatment.

Abstract: An integrated process for preparing a lubricating oil base stock includes an isomerization step followed by a solvent dewaxing step. A waxy feed is isomerized to an intermediate pore point, which is at least 6° C. above a target pour point, over a select molecular sieve having specified pore properties. The isomerized oil is then solvent dewaxed to a very low pour point. This process produces a dewaxed lubricating oil base stock which has an exceptionally high viscosity index.

Abstract: This invention relates to processes of producing lubricant base oils comprising paraffinic hydrocarbon components that have optimized branching. The lubricant base oils comprising paraffinic hydrocarbon components with optimized branching have low amounts of branching with the branching concentrated toward the center of the lubricant base oil molecules. The lubricant base oils comprising paraffinic hydrocarbon components with optimized branching have low pour points and extremely high viscosity indexes. The invention further relates to processes of producing commercial lubricants comprising the lubricant base oils comprising paraffinic hydrocarbon components with optimized branching from waxy feeds.

Abstract: A method of refining a petroleum product to remove aromatics and to separate paraffinic oils and waxes is provided. The method involves the utilization of phase equilibria wherein crystallized or solidified waxes, normally present in the petroleum product, are used to remove oils from a liquid solvent phase containing dissolved aromatics present in the unrefined petroleum product. The wax containing the oils is separated from the aromatic-containing solvent and is further processed to separate the waxes and oils. For petroleum products containing little, if any, wax, additional wax may be added and recycled back for further use in removing oils from the petroleum product. The method has particular application in preparing lubricating oils having a high viscosity index, where the presence of aromatics and wax can be detrimental.

Abstract: A laser beam reflected by wax crystals is used in determining the wax crystallization temperature of a hot dewaxing solvent upstream of solvent chillers. This is automatically achieved by an on-line method from a remote control point, in which a slipstream of solvent is passed through an attached solvent loop into a sample chamber in the loop, without being exposed to ambient conditions. As the sample is cooled, the beam reflections are detected and indicate the wax to crystallization temperature. Corrective measures can then be taken to prevent fouling of the chillers, if need be.

Abstract: Lube base stocks and lube stock compositions, as well as a process for preparing lube base stocks and lube stock compositions, are disclosed. The lube oils preferably have a viscosity index above about 115. The process involves obtaining feedstocks that have a 95% point below 1150° F. and feedstocks that have 95% point above 1150° F. The feedstocks that have a 95% point below 1150° F. are catalytically dewaxed, and the feedstocks that have 95% point above 1150° F. are solvent dewaxed. The resulting products can optionally be blended, and the base stocks can be combined with various additives to form lube oil compositions. Hydrotreatment can optionally be performed on the lube base stocks to remove olefins, oxygenates and other impurities. In one embodiment, one or more of the fractions are obtained from Fischer-Tropsch synthesis.

Abstract: An integrated process for preparing a lubricating oil base stock includes an isomerization step followed by a solvent dewaxing step. A waxy feed is isomerized to an intermediate pore point, which is at least 6° C. above a target pour point, over a select molecular sieve having specified pore properties. The isomerized oil is then solvent dewaxed to a very low pour point. This process produces a dewaxed lubricating oil base stock which has an exceptionally high viscosity index.

Abstract: A process for treating organic compounds includes providing a composition which includes a substantially mesoporous structure of silica containing at least 97% by volume of pores having a pore size ranging from about 15 Å to about 30 Å and having a micropore volume of at least about 0.01 cc/g, wherein the mesoporous structure has incorporated therewith at least about 0.02% by weight of at least one catalytically and/or chemically active heteroatom selected from the group consisting of Al, Ti, V, Cr, Zn, Fe, Sn, Mo, Ga, Ni, Co, In, Zr, Mn, Cu, Mg, Pd, Pt and W, and the catalyst has an X-ray diffraction pattern with one peak at 0.3° to about 3.5° at 2&thgr;.

Abstract: Hydroconversion process of petroleum and chemical feedstocks using bulk Group VIII/Group VIB catalysts. Preferred catalysts include those comprised of Ni—Mo—W.

Abstract: A process for producing a high VI/low volatility lubricating oil basestock and a lubricating oil basestock prepared by said process. The process comprises subjecting the raffinate from a solvent extraction step to a two step, single stage hydroconversion process wherein the first step involves severe hydroconversion of the raffinate followed by a cold hydrofinishing step.

Abstract: A laser beam reflected by wax crystals is used in determining the wax crystallization temperature of a hot dewaxing solvent upstream of solvent chillers. This is automatically achieved by an on-line method from a remote control point, in which a slipstream of solvent is passed through an attached solvent loop into a sample chamber in the loop, without being exposed to ambient conditions. As the sample is cooled, the beam reflections are detected and indicate the wax to crystallization temperature. Corrective measures can then be taken to prevent fouling of the chillers, if need be.

Abstract: A process for increasing the hydrogenation activity, particularly the carbon monoxide hydrogenation activity, of a catalyst or catalyst precursor comprised of a particulate solids support component and a catalytic metal, or metals component, preferably cobalt; cobalt alone or cobalt and an additional metal, or metals added to promote or modify the reaction produced by the cobalt. Treatment of the catalyst, or catalyst precursor is conducted at low temperature ranging from ambient to about 275° C. sufficient to form on the surface of a catalyst precursor, e.g., a cobalt catalyst precursor, a cobalt metal hydroxide, low valence cobalt metal oxide, or mixture of cobalt metal hydroxide and low valence cobalt metal oxide. Sometimes also metallic metal, e.g., cobalt, is also formed, and dispersed on the surface of the support.

Abstract: A method of refining a petroleum product to remove aromatics and to separate paraffinic oils and waxes is provided. The method involves the utilization of phase equilibria wherein crystallized or solidified waxes, normally present in the petroleum product, are used to remove oils from a liquid solvent phase containing dissolved aromatics present in the unrefined petroleum product. The wax containing the oils is separated from the aromatic-containing solvent and is further processed to separate the waxes and oils. For petroleum products containing little, if any, wax, additional wax may be added and recycled back for further use in removing oils from the petroleum product. The method has particular application in preparing lubricating oils having a high viscosity index, where the presence of aromatics and wax can be detrimental.

Abstract: A process for producing a lubricating oil basestock having at least 90 wt. % saturates and a VI of at least 105 by selectively hydroconverting a raffinate from a solvent extraction zone in a two step hydroconversion zone followed by a hydrofinishing zone, and a lubricating oil basestock produced by said process.

Abstract: A method of refining a petroleum product to remove aromatics and to separate paraffinic oils and waxes is provided. The method involves the utilization of phase equilibria wherein crystallized or solidified waxes, normally present in the petroleum product, are used to remove oils from a liquid solvent phase containing dissolved aromatics present in the unrefined petroleum product. The wax containing the oils is separated from the aromatic-containing solvent and is further processed to separate the waxes and oils. For petroleum products containing little, if any, wax, additional wax may be added and recycled back for further use in removing oils from the petroleum product. The method has particular application in preparing lubricating oils having a high viscosity index, where the presence of aromatics and wax can be detrimental.

Abstract: A method for producing a process oil is provided in which an aromatic extract oil is added to a paraffinic rich feed to provide a blended feed. The blended feed is then hydrotreated in a first hydrotreating stage to convert at least a portion of sulfur and nitrogen in the feed to hydrogen sulfide and ammonia. After stripping, the feed is subjected to a second hydrotreating stage to provide a process oil.

Abstract: A process for dewaxing including the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, essentially free of a selected cosolvent, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent with the amount of wax precipitation being controlled by the quantity and temperature of cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, "environmentally compatible" solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants.

Abstract: A process for catalytically dehazing lubricating base oils is disclosed, which comprises contacting the lubricating base oil in the presence of hydrogen with a catalyst comprising naturally occurring and/or synthetic ferrierite which ferrierite has been modified to reduce the mole percentage of alumina and a low acidity refractory oxide binder material which is essentially free of alumina.

Abstract: A process for significantly decreasing processing time, reducing capital costs, increasing yield, improving quality, and improving the safety of refining petroleum residues and sludges generated by the oil producers, refineries and re-refiners comprising the steps of heating under vacuum the petroleum residues and sludges with steam or inert gas injection or both until a temperature ranging from between 680.degree. F. to 1000.degree. F. is attained and holding the mixture at this temperature for a short residence time of from less than an hour to abut 6 hours while vacuum and sparging are being carried out to generate asphalt. Volatile products are condensed to produce fuel, waxy oil and can be further processed to produce refined fuel, wax and dewaxed oil.

Abstract: A process for dewaxing including the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, essentially free of a selected cosolvent, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent with the amount of wax precipitation being controlled by the quantity and temperature of cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, "environmentally compatible" solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants.

Abstract: The wax-containing hydrocarbon feedstocks are pre-treated by contacting them with a homogeneous solution containing 1-5 vol. % of an acid diluted in an alcohol/water mixture (preferably containing 60-90 vol. % alcohol). The pre-treated feedstock is then contacted, in the presence of hydrogen, with at least two catalysts in sequence and with no intermediate separation, comprising at least one hydrodewaxing catalyst and one hydrocracking catalyst, to recover high-grade middle distillates.

Abstract: A semicontinuous process for solvent dewaxing a waxy petroleum oil feed stream including the steps of: diluting of the waxy oil feed stream with solvent; feeding cold oil/solvent/wax mixture to a filter to remove the wax and obtain an oil/solvent filtrate stream; contacting the oil/solvent filtrate stream with a selective semipermeable membrane to selectively transfer solvent through the membrane to obtain a solvent-rich permeate; and periodically directing a warm stream of recovered solvent onto the membrane surface to wash the membrane and remove impurities therefrom.

Abstract: A method and apparatus for changing the solvent composition in a solvent recovery system of a dewaxing apparatus, depending on the type of stock oil, by introducing a part of dry solvent into a wet solvent tank to thereby increase or decrease a concentration of MEK in the wet solvent used as a primary solvent for initially mixing with the stock oil.

Abstract: A process for dewaxing including the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, essentially free of a selected cosolvent, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent with the amount of wax precipitation being controlled by the quantity and temperature of cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, "environmentally compatible" solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants.

Abstract: An apparatus for changing the solvent composition in a solvent recovery system of a dewaxing apparatus, depending on the type of stock oil, by introducing a part of dry solvent into a wet solvent tank to thereby increase or decrease a concentration of MEK in the wet solvent used as a primary solvent for initially mixing with the stock oil.

Abstract: The invention decloses a method for dewaxing a hydrocarbon oil which comprises adding an oil-soluble poly C.sub.18 -C.sub.22 alkylmethacrylate having a molecular weight of from about 10,000 to about 2,000,000 daltons to a hydrocarbon oil containing wax; cooling the oil to allow wax crystals to form, separating the wax crystals from the oil and recovering a dewaxed oil.

Abstract: A process for solvent dewaxing petroleum feedstock to separate crystallized wax from lubricant oil by filtration of a wax/oil/solvent mixture. The feedstock is sequentially cooled and mixed with cold polar solvent to form a wax crystal phase and oil-solvent phase, and-the oil-solvent filtrate stream is contacted with solvent permeable selective membrane at low temperature to recover an internal circulating permeate solvent stream and an oil-rich retentate stream containing dewaxed oil product and residual solvent. Improved operation is achieved by splitting the internal circulating solvent stream into a multiple cold solvent recycle streams and injecting a plurality of the cold solvent recycle streams into the waxy petroleum feedstock during sequential cooling and mixing. By initially injecting a cold recycle solvent stream in to the waxy petroleum feedstock at a small temperature differential near the wax crystallization temperature, shock cooling and excess small wax crystal formation is avoided.

Abstract: A process for dewaxing including the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, essentially free of a selected cosolvent, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent with the amount of wax precipitation being controlled by the quantity and temperature of cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, "environmentally compatible" solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants.

Abstract: A method of dehydrating a solvent originating from a hydrocarbon dewaxing operation, wherein a moist composite organic solvent, for example a moist MEK/toluene mixture is dehydrated in a first distillation zone, the resulting first distillate is contacted with water to form two phases one of which, rich in organic solvent, is returned as a reflux to the first distillation zone whereas the other phase rich in water is distilled in a second distillation zone, and the head product and one portion of the bottom product of the second distillation zone are returned to the zone of contact between the first distillate and water, the invention being applicable to the dewaxing of lubricating oils.

Abstract: The incremental solvent dilution chilling of 600N waxy oils in a staged agitated chilling tower using cold solvent injection is improved in terms of feed filter rate with respect to a 600N waxy oil having a final boiling point of >600.degree. C. and a mean boiling point of about 500.degree. C. when the solvent dewaxing process is practiced under conditions of cold solvent injection such that there is an equal chilling rate/stage profile as compared to an equal temperature drop/stage profile in the chilling tower and with respect to a 600N waxy oil having a final boiling point of 600.degree. C. and a mean boiling point of about 500.degree. C. when the solvent dewaxing process is practiced under conditions of cold solvent injection such that there is an equal temperature drop/stage profile as compared to an equal chilling rate/stage profile in the chilling tower.