Abstract: A process for feed oil refining for production of lubricating oil, by using an equipment for lubricating oil production including a fulfural refining unit, a hydrotreating unit and a ketone dewaxing unit, all connected in series. In this process, operations associated with the switch of feed oil are conducted by carrying out the first to seventh step groups successively. Each step group is initiated when a given time has passed since the start of the previous step group, or when the value of a particular measurement item has reached a target value, or when the value of a particular measurement item has shown a change. First, in the first step group, the amount of feed oil supplied to each unit, etc. is adjusted and, in the second step group, the feed oil to the furfural refining unit is switched.

Abstract: A method for providing a continuous injection of a substantially constant amount of a desired treatment chemical into a flowing process stream is described. This method insures that the concentration of the desired treatment chemical is maintained at a relatively constant and effective concentration throughout the flowing process stream. The means for providing the relatively continuous injection of the treatment chemical is preferably a pump that provides a continuous injection at a relatively constant flow rate of the treatment chemical into a flowing process stream.Providing a uniform concentration of a treatment chemical in a flowing process stream maximizes the benefit of the treatment chemical. Conventional methods for injecting treatment chemicals provide intermittent injection of the treatment chemical such that sections of the flowing process stream have no concentration of the treatment chemical. This reduces the benefit of the treatment chemical and may prevent it from providing any benefit at all.

Abstract: A charge containing dewaxed oil/dewaxing solvent may be treated to effect separation of components by a thermally cross-linked hydrocarbon-derived elastomer membrane, typified by polybutadiene.

Abstract: The present invention is an automatic filter cleaning system which includes a solvent dewaxing filter which removes wax from a wax mix slurry and provides a filtrate. Status control apparatus is connected to the filter for affecting the operational status of the filter. Drain apparatus responsive to a control signal controls draining of the filter. Cleaning apparatus is also connected to the filter. A control network connected to the status apparatus, the draining apparatus and the cleaning apparatus controls those apparatus in a manner so as to allow selective changing of the status of the filter from an operational state to a down state to automatically drain the filter and clean the filter while the filter is in the down state.

Abstract: There are disclosed processes for separating waxes of different melting points from a room temperature amorphous or liquid hydrocarbon mixture in an energy conservative manner by selectively causing precipitation of crystallized waxes. The processes involve the use of a selected co-solvent totally miscible with light and intermediate hydrocarbons from a group consisting of acetone, ketene, propanone, 2-propanone, methanol, ethanol, isopropanol, N-propanol, acetic acid, formic acid, and propionic acid or combinations thereof as a precipitating agent. Hydrocarbon mixtures, especially those with elevated pour points are first diluted by solvents such as toluene and/or methylethyl ketone which must be free of any significant quantity of the aforesaid co-solvents. The diluted hydrocarbon mixture at above 50 degrees F.

Abstract: An improved solvent dewaxing process in which a method and apparatus for continuous hot wash of a dewaxing filter is disclosed. A hot wash solvent is continuously sprayed below the doctor blade followed by a cold solvent spray below the hot solvent spray. Additionally, a solvent management process for changing the proportions of the solvent in response to different viscosity feedstocks thereby increasing filtration efficiency is also disclosed.

Abstract: This invention relates to a process of dewaxing a hydrocarbon oil involving the steps of separating and precipitating the wax component of the hydrocarbon oil. This process is facilitated by incorporating into the oil a linear polymer of carbon monoxide with one or more olefins comprising .alpha.-olefins with at least 10 carbon atoms per molecule (C.sub.10+ .alpha.-olefins) wherein in this polymer monomer units of carbon monoxide and olefins are present in a substantially alternating arrangement. Optionally, the process may also involve the use of a polymer of one or more olefinically unsaturated compound comprising of alkyl acrylates or alkyl methacrylates with at least 8 carbon atoms in the alkyl group (C.sub.8+ alkyl esters). The process may be practiced using the single-stage or multi-stage dilution method.

Abstract: Hydrocarbon lubricants having a high viscosity index (V.I.) and low pour point are produced by hydroisomerizing a waxy lube feed such as slack wax or a waxy gas oil over zeolite beta after which aromatic components are removed by extraction, e.g. with furfural. The raffinate is then dewaxed, preferably by solvent dewaxing to target pour point with a final hydrofinishing step. The hydroisomerization coupled with the aromatics extraction and dewaxing increases the range of crudes that can be processed into high V.I. lubes while maintaining equivalent product qualities. Hydrogen consumption in the process is relatively low.

Abstract: A method for the solvent dewaxing of wax-containing petroleum products with at least one solvent suitable for dewaxing and a polymeric dewaxing aid comprising polyacrylates, by mixing the products to be dewaxed with the solvent and the polymeric dewaxing aid, chilling the mixture so obtained, and separating the precipitated wax, the dewaxing aid used being a mixture of(I) a polymer of esters of acrylic acid with C.sub.10 -C.sub.40 alkanols and(II) a polymer of esters of methacrylic acid with alkanols comprising more than 10 weight percent of branched alkanols,the weight ratio between components (I) and (II) ranging from 1:20 to 20:1.

Abstract: Mixtures of light and heavy waxes are fractionated by permeation through a porous membrane at temperatures just above the cloud point of the mixture with the heavier, higher melting point waxes being the component of the mixture which selectively permeates through the porous membrane.

Abstract: Slack waxes and synthetic wax are isomerized and processed into high viscosity index and very low pour point lube base stock oils and blending stocks by the process comprising the steps of hydrotreating the wax, if necessary, to remove heteroatom and polynuclear aromatic compounds and/or deoiling the wax, if necessary, to an oil content between about 5-20% oil, isomerizing the wax over a Group VI-Group VIII on halogenated refractory metal oxide support catalyst, said isomerization being conducted to a level of conversion such that .about.40% and less unconverted wax remains in the 330.degree. C..sup.+, preferably the 370.degree. C..sup.+ fraction sent to the dewaxer. The total isomerate from the isomerization unit is fractionated into a lube oil fraction boiling at 330.degree. C..sup.+, preferably 370.degree.p9 C..sup.+. This oil fraction is solvent dewaxed preferably using MEK/MIBK at 20/80 ratio and unconverted wax is recycled to the isomerization unit.

Abstract: An improvement has been discovered in a process for solvent dewaxing a hydrocarbon lubricating oil stock. Solvent dewaxed oils are steam stripped and then vacuum dehydrated at 2.5 psia at the steam stripping temperature of 350.degree. F. to 450.degree. F. Nitrogen or natural gas having a dew point of -100.degree. F. or lower is contacted with the oil at 0.5 to 1 SCF/bbl. A solvent free lubricating oil is produced which is water haze free in cold storage.

Abstract: Dewaxed oil containing dewaxing solvent from solvent dewaxing is treated by contact with a separating membrane to yield a retentate containing increased content of dewaxed oil and decreased content of dewaxing solvent and a permeate which contains increased content of dewaxing solvent and decreased content of dewaxing oil--the membrane including a polyimine layer which has been cross-linked with polyisocyanate or poly(carbonyl chloride).

Abstract: Copolymers of dialkyl fumarate and vinyl acetate having Specific Viscosities of at least 2.5 at 2% polymer concentration in xylene at 40.degree. C., and wherein at least 50 wt. % of said alkyl groups are C.sub.20 to C.sub.24, are useful as dewaxing aids, particularly in propane dewaxing.

Abstract: A process for obtaining a very high quality lube base stock is disclosed which comprises:(a) introducing an aromatic and nitrogen-and sulfur-containing feedstock selected from the group consisting of a dewaxed oil obtained from refining distillate fraction and having a 60-700 SUS at 100.degree. F. and a dewaxed oil obtained from refining vacuum resid and having a 2300-2700 SUS at 100.degree. F., and hydrogen, into a single stage hydrotreating reactor; and,(b) subjecting the feedstock to hydrotreating in said reactor in the presence of a sulfided cobalt/molybdenum hydrotreating catalyst at an average reactor temperature of from about 550.degree. to about 700.degree. F. at a hydrogen partial pressure of from about 1500 to about 3000 psia at the reactor outlet, an LHSV of from about 0.1 to about 1.

Abstract: Dewaxed oils can have their low temperature performance improved by the removal of residual wax by adsorption of said residual wax onto a hydrophobic molecular sieve. The wax-laden hydrophobic molecular sieve is regenerated by use of dewaxing solvents, such as ketones.The dewaxed oils, which have residual wax removed by the present invention, are oils which have been dewaxed by means of solvent dewaxing procedures or by catalytic dewaxing processes. These oils, produced by the combination of conventional-adsorptive trim dewaxing, exhibit superior formulated oils low temperature performance as compared to formulated oils made from oils dewaxed to the same pour point solely by conventional dewaxing by either solvent or catalytic processes practiced under severe conditions (deep dewaxing).

Abstract: Lubricants of improved characteristics are produced by carrying out a solvent extraction to remove aromatic components after solvent or catalytic dewaxing. Aromatic extraction solvents such as phenol, furfural or N-methyl pyrrolidone may be used. The process is particularly useful with wax-derived lubricants produced by the hydroisomerization of a petroleum wax which has then been dewaxed.

Abstract: In a lube oil dewaxing plant in which waxy lube oil is firstly conditioned to promote wax crystallization, such as by adding an oil solvent and chilling the resulting admixture, and then filtered in at least one rotary drum filter (213), the filter includes at least one spray header (92') including a plurality of charge injectors (300) which inject charge by field emission into a field which is sprayed from orifices (246) in the underside of the header onto the filter drum (20). The injected charge has the effect of enhancing separation of haze from the lube oil in the rotary drum filter (213). The charge carrier fluid may for example be solvent-diluted waxy oil or oil solvent liquid alone.

Abstract: Solvent dewaxing of waxy hydrocarbon oils using scraped surface chillers is improved by injecting cold solvent into the scraped surface chillers at multiple points to augment the indirect chilling occurring in said scraped surface chillers. In utilizing this multi-point cold solvent injecting process it is important to control the .DELTA.T occurring at each injection point within each chiller bank across the entire chiller train.The .DELTA.T at each injection point attributable only to cold solvent injection must be equal if one is to secure the benefit of the present invention which is an improved liquids/solids ratio without deterioration of the feed filter rate.Preferably, to avoid any possible deterioration of filter rate and/or liquids solids, the cold solvent injection should be completed prior to the slurry in the scraped surface chiller train experiences any shock chilling.

Abstract: A control system controls a lubricating oil dewaxing apparatus. The temperature of waxy oil flowing through the apparatus is controlled. A sequential plurality of temperature sensing means senses the temperature of the waxy oil. A Comparing Means determines an isothermal heat transfer zone corresponding to latent heat transfer wax crystallization. Temperature upstream of the isothermal zone is controlled to a selected chilling rate. Temperature downstream of the isothermal zone is controlled to a selected filtering temperature. The control system effects the growth of wax crystals of a uniform and moderate size for optimum filtering rate and oil content.

Abstract: I disclose a single stage, multilayered catalyst system capable of hydrodehazing and hydrofinishing a solvent dewaxed lube oil base stock. In the first layer, I catalytically dewax the solvent dewaxed stock. In the second layer, I hydrofinish the catalytically dewaxed stock. My invention also relates to a process for hydrodewaxing and hydrofinishing a solvent dewaxed lube oil base stock.

Abstract: For removing haze from dewaxed hydrocarbon oil mixture boiling in the lubricating oil range which is hazy, the hazy oil mixture is filtered in the filtration stage (201) of a dewaxing plant which is concurrently filtering undewaxed hydrocarbon oil mixture boiling in the lubricating oil range. Prior to filtering, the hazy dewaxed oil mixture is subjected to pretreatment (in pretreatment stage 204) such as to promote removal of haze from the dewaxed oil mixture during filtering. This pretreatment is carried out independently of the undewaxed oil mixture and can involve dilution/chilling with an oil solvent (e.g. liquid propane) and/or introduction of free excess electric charge, for example by charge injection. As an alternative to the pretreatment, the temperature conditions under which filtration takes place may be low enough to promote wax crystallization.

Abstract: This invention relates to an electrical insulating oil consisting essentially of a oil having a boiling point of not less than 150.degree. C., a viscosity of 2 to 500 centistokes (at 40.degree. C.), a pour point of not more than -35.degree. C., a sulfur content of from more than 5 ppm to not more than 1,000 ppm, an aromatic hydrocarbon content (%C.sub.A) of more than 5% and a cloud point of less than -25.degree. C.

Abstract: This invention relates to an electrical insulating oil consisting essentially of a oil having a boiling point of not less than 150.degree. C., a viscosity of 2 to 500 centistokes (at 40.degree. C.), a pour point of not more than -35.degree. C., a sulfur content of from more than 5 ppm to not more than 1,000 ppm and an aromatic hydrocarbon content (% C.sub.A) of more than 5%.

Abstract: Solvent dewaxing of waxy hydrocarbon oils is improved by using a poly (n-C.sub.24) alkyl methacrylate polymer dewaxing aid in combination with lower melting point weight poly (C.sub.8 -C.sub.20) alkyl methacrylate polymer dewaxing aids. The solvent dewaxing processes improved using this combination dewaxing aid are the incremental and total predilution solvent type processes employing either surface chilled indirect heat exchanger means or direct chilling using cold solvent.The solvent dewaxing processes are those employing normally liquid dewaxing solvents, as exemplified by C.sub.3 -C.sub.6 ketones, such as methyl ethyl ketone, methyl isobutyl ketone and mixtures thereof, mixtures of ketones with aromatic such as MEK/toluene, halogenated C.sub.2 -C.sub.4 hydrocarbons such as tetrachloraethane, trichloro ethylene, etc.

Abstract: The filtration performance of a slurry containing crystallized wax, dewaxed oil and dewaxing solvent is improved by use of an agitator means which possesses a characteristic dimension which when divided by the average wax crystal diameter yields a dimensionless number of about 1,500 or less, preferably about 1,000 or less, more preferably about 500 or less, most preferably about 250 or less. Use of an agitator means which possesses a characteristic dimension yielding a dimensionless number in the range recited above causes a reduction in the size of the vortex generated as the agitator means passes through the slurry during chilling. As a consequence, more intimate contacting of the wax particles during chilling is promoted.The needed characteristic dimension of the agitator may be obtained in any number of equally acceptable ways. Single large agitator blades can be replaced by more numerous smaller blades; large blades can be perforated, notched, etc.

Abstract: Wax crystals of improved morphology are produced by employing a dewaxing aid in an agitated solvent dewaxing environment, preferably an agitated indirect chilling solvent dewaxing environment, such as an agitated chiller, such as a scraped surface chiller which has been modified so that the scraper is not in contact with the internal wall of the chiller wherein a high degree of agitation is maintained by rotating the paddles to achieve a paddle tip speed of 25 to 400 ft./min. and the gap between the agitator tip and the inner wall of the vessel is about 0.5 to 40% of the internal diameter of the chiller. Agitation in agitated indirect chiller appratus has been shown to produce significantly improved feed filter rates and liquids/solids ratios when employed in conjunction with dewaxing aids in solvent dewaxing processes.

Abstract: It has been discovered that cellulose acetate membranes, fabricated using nonaqueous solvent systems, can be used for the separation of polar solvents, especially ketone dewaxing solvents from dewaxed oil. The cellulose acetate membranes so prepared are of a reduced acetyl content and exhibit very good resistance to ketone solvents. The specific fabrication procedure avoids exposing the cellulose acetate to even transient mixtures of ketone and alcohol or ketone and water. Although the cellulose acetate polymer is insoluble in pure water, alcohol, or ketone it is soluble in mixtures of ketone-alcohol and ketone-water.The resulting membrane is an effective means for separating ketone dewaxing solvent from dewaxed oil.

Abstract: Multi-step synergistic process for converting waxy-containing hydrocarbon feedstocks to lube oil stocks having targeted pour points is disclosed. The waxy feed is first catalytically partially dewaxed with the catalyst having the structure of ZSM-5, and then the partially dewaxed oil is subjected to solvent dewaxing to reach a targeted pour point. Pretreating the crude prior to catalytic dewaxing process such as by deasphalting and aromatic removal is also disclosed. In an alternative process, the waxy-containing hydrocarbon feed is subjected to the steps of solvent dewaxing, catalytic dewaxing, and solvent dewaxing.

Abstract: Copolymers of dialkyl fumarate and vinyl acetate having Specific Viscosities of at least 2.5 at 2% polymer concentration in xylene at 40.degree. C., and wherein at least 50 wt. % of said alkyl groups are C.sub.20 to C.sub.24, are useful as dewaxing aids, particularly in propane dewaxing.

Abstract: This invention discloses an economic series flow dewaxing scheme having a first solvent dewaxing step followed by a catalytic dewaxing step. The use of methylisopropyl ketone as a key component in the solvent dewaxing step produces a solvent dewaxed effluent with an intermediate pour point which may be readily catalytically dewaxed to a pour point suitable for lubricant applications. The catalytic dewaxing unit can also be used to recover lost oil yield from the soft wax product of the solvent dewaxing zone (sometimes referred to as footsoil) and thereby sustain, if not increase, overall lubricating oil yield.

Abstract: A process for producing high quality, high molecular weight microcrystalline wax from a hydrocracked, undewaxed bright stock, comprising hydrodenitrification, mild hydrofinishing, and solvent dewaxing.

Abstract: A solvent dewaxing process is described comprising mixing a waxy hydrocarbon oil, preferably a waxy petroleum oil, most preferably a waxy lube or specialties oil, with dewaxing solvent and a dewaxing aid comprising (A) a dialkylfumarate-vinyl laurate copolymer and (B) a wax-naphthalene condensation copolymer, a dialkyl fumarate-vinyl acetate copolymer or an ethylene vinyl acetate copolymer and chilling the mixture to yield a slurry comprising solid particles of precipitated wax and a solution of dewaxed oil and solvent and separating said solid wax from dewaxed oil solution.

Abstract: A solvent dewaxing process for dewaxing waxy lubricating oil with a dewaxing solvent and a dewaxing aid which comprises using as the dewaxing aid a styrene dialkyl maleate copolymer wherein the side chain groups contain from C.sub.16 -C.sub.24.sup.+ carbon atoms. These polymers are further characterized as having a molecular weight within the range of 10,000-150,000.

Abstract: Process for the extractive production of valuable, natural waxes from fossil and/or freshly grown vegetable and/or animal starting material by extraction of the starting material in an extraction stage with a physiologically unobjectionable gas at supercritical pressure and temperature conditions, separation of the extract-containing gas in a separator part by pressure reduction and/or temperature change, periodical or continuous withdrawal of the extract and return of the separated gas to the extraction stage.

Abstract: It has been discovered that cellulose acetate membranes, fabricated using nonaqueous solvent systems, can be used for the separation of polar solvents, especially ketone dewaxing solvents from dewaxed oil. The cellulose acetate membranes so prepared are of a reduced acetyl content and exhibit very good resistance to ketone solvents. The specific fabrication procedure avoids exposing the cellulose acetate to even transient mixtures of ketone and alcohol or ketone and water. Although the cellulose acetate polymer is insoluble in pure water, alcohol, or ketone it is soluble in mixtures of ketone-alcohol and ketone-water.The resulting membrane is an effective means for separating ketone dewaxing solvent from dewaxed oil.

Abstract: Refined waxes and dewaxed lubricating oil basestocks are simultaneously produced in a reversed deoiling-dewaxing process employing conventional dewaxing solvents and existing process equipment. Improved yields, lower solvent useage, and higher throughputs are achieved using dewaxing aids in the final stage. Waxy hydrocarbon oils are solvent dewaxed to a temperature which produces a low oil content refined high melting point hard wax product which is recovered, e.g. by filtration. The hard wax product can be deoiled. The filtrate from the initial dewaxing operation is then injected with dewaxing aid and further chilled in secondary chiller means such as scraped surface chillers to a lower temperature to produce more deeply dewaxed oil and a low melting point soft wax product which are separated e.g. by filtration. The low melting point wax is desolvated and the dewaxing aid may be recovered for example by passing the wax through a membrane or by distillation.

Abstract: An improved process for the solvent dewaxing of petroleum oil stocks. Wax-containing oil is chilled in an elongated chilling zone by introducing cold dewaxing solvent into said zone, at a plurality of points along same, said chilling zone containing or having associated with it a plurality of static means for mixing the solvent and wax-containing oil under conditions of plug flow radial mixing, thereby avoiding shock chilling without the need for the intense agitation and/or dynamic agitators normally required for such processes.

Abstract: A method is described for the production of regenerated cellulose membranes which method comprises the steps of:(a) dissolving a cellulose material to form a solution;(b) casting the cellulose solution into a film;(c) coagulating the cellulose solution film using an alkali alcoholic solution;(d) washing the coagulated cellulose film in an alcohol;(e) regenerating the cellulose film using acidic alcohol solution;(f) washing the regenerated cellulose membrane using an alcohol.The regenerated cellulose thus formed may be dried, if desired, preferably without a softener.The regenerated cellulose thus produced, when prepared in the form of a film or membrane, possesses higher flux and superior selectivity for organic liquid separation than regenerated cellulose membranes prepared employing aqueous solutions in steps b through e above and is most advantageously employed for the recovery of polar dewaxing solvents (e.g. ketones and mixed ketone/aromatic solvents) from dewaxed oil.

Abstract: A hydrocarbon dewaxing process comprising the steps of:(a) chilling the waxy hydrocarbon feed to be dewaxed in the absence of solvent to crystallize a portion of the hard wax;(b) introducing the hydrocarbon feed to be dewaxed into a centrifuge;(c) centrifuging the solvent free hydrocarbon feed thereby generating two streams, stream (I) comprising a major portion of oil with a minor portion of entrained wax, stream (II) comprising a major portion of wax with a minor portion of entrained oil;(d) adding a dewaxing solvent to stream (II) generating a slurry A;(e) feeding slurry A to a centrifuge thereby separating slurry A into an oil-solvent stream (III) and a wax-solvent stream (IV);(f) passing the oil-solvent stream (III) to a membrane separation unit wherein the stream is separated into a recycle solvent stream and an oil-solvent stream of reduced solvent content (stream V);(g) passing oil-solvent stream (V) to an oil recovery unit wherein the stream is separated into a recycle solvent stream and an oil strea

Abstract: An improved method for separating a slack wax into a wax fraction and a lube oil fraction is disclosed. The method comprises passing the slack wax into a first mixing zone and subsequently into a second mixing zone. Solvent selectively miscible with the lube oil fraction is added to the zones. The temperature of the solvent added to the second mixing zone is substantially higher than the temperature of the solvent added to the first mixing zone. This process produces a wax fraction having a relatively low lube oil content.

Abstract: This invention relates to solvent dewaxing processes for dewaxing waxy hydrocarbon oil distillates employing a dewaxing aid which dewaxing aid is a mixture of (a) a poly-dialkylfumarate/vinyl acetate copolymer and (b) a wax-naphthalene condensation product. Component (a) has pendent alkyl side chain groups of from 16 to 30 carbon atoms in length (excluding branching) with an average pendent side chain carbon length of predominantly (>50%) C.sub.22. Component (a) has a number average molecular weight of from about 1,000 to 100,000 preferably greater than about 5,000. Component (b) has a number average molecular weight of at least about 1,000. The combination (a) and (b) may be employed in a weight ratio (A)/(B) within the range from about 1/10 to 20/1 preferably about 1/3 to 6/1 most preferably about 3/1 and at an aid dose level ranging from about 0.005 to 2.0 wt. % preferably 0.01 to 0.2 wt. % active ingredient.

Abstract: It has been discovered that (a) poly di alkyl fumarate/vinyl acetate copolymers in combination with (B) poly alkyl (meth-) acrylate polymers are effective dewaxing aids for the solvent dewaxing of bright stocks. The poly di alkyl fumarate/vinyl acetate copolymer component of the combination dewaxing aid used in the process of the present invention has a number average molecular weight of about 1000 to 100,000 and possesses alkyl side chain moieties of from C.sub.16 -C.sub.24.sup.+ in length (excluding branching) with a pendent side chain length of predominantly (>50%) C.sub.20. The polyalkyl (meth-) acrylate is the polymeric ester of aliphatic alcohols having groups 10 to 20 carbons in length, excluding branching (pendent side chain length predominantly (>50%) C.sub.14 and lower) and acrylic or (meth-) acrylic acid (preferably methacrylic acid) and possesses a number average molecular weight of at least 5,000.

Abstract: This invention relates to solvent dewaxing processes, for dewaxing waxy hydrocarbon oils using a dewaxing aid, which dewaxing aid comprises a mixture of (A) polyalkyl arcylate having alkyl group side chain length of from 10-26 carbons (excluding branching) and (B) an n-alkyl methacrylate polymer having alkyl group side chain length of from 10-20 carbons (excluding branching). Component (A) typically has a number average molecular weight of from 3,000 to 500,000 while component (B) typically has a number average molecular weight of from 5,000 to 200,000. The combination (A) plus (B) may be employed in a weight ratio within the range from about 1/100 to 100/1, preferably about 1/6 to 2/1 and at an aid does level ranging from about 0.01 wt % to 1 wt %, preferably 0.02 to 0.2 wt % active ingredient.

Abstract: A dewaxing process for reducing the pour point of waxy oils in which the oil is cooled by direct contact with a liquid autorefrigerant such as propane. The wax which separates upon cooling is removed by flotation assisted by the bubbles of vaporized autorefrigerant which rise through the oil to form a frothy slurry of wax which can be decanted and the wax recovered from it. A dewaxing solvent such as methyl ethyl ketone may be used to assist separation of the wax.

Abstract: A process is disclosed for the solvent dewaxing of wax containing hydrocarbon oils, preferably waxy petroleum oils most preferably waxy lubricating or transformer oils. The process employs methyl tertiary butyl ether as the dewaxing solvent, either alone or in combination with other dewaxing solvents such as ketones, halogenated hydrocarbon anti-solvents, and mixtures thereof. The use of methyl tertiary butyl ether as a dewaxing solvent, or in combination with conventional dewaxing anti-solvents permits lower volumes of solvent to be employed in the dewaxing process while simultaneously producing an oil of lower wax content and lower dewaxed oil pour point at the same filter temperature as that commonly employed using conventional dewaxing solvents. Dewaxed oil yields for equivalent pour point are 3 to 4% higher with the MTBE system.

Abstract: An improved process for dewaxing waxy hydrocarbon oils, wherein said waxy oil is cooled in an indirect chilling zone to a temperature greater than the wax separation temperature whereby wax is precipitated to form a wax-oil-solvent slurry, cooling the slurry to the wax separation temperature in an indirect chilling zone thereby precipitating a further portion of wax from said waxy oil and separating said precipitated wax from the wax-oil-solvent slurry in solid-liquid separation means, the improvement comprising using as the indirect chilling zone an indirect heat exchanger means operated at a high level of agitation. Expressed in terms of Impeller Reynolds Number the agitation is on the order of about 1,000 to 1,000,000.Alternatively, the direct chilling zone is totally replaced by the high agitation indirect heat exchanger means.

Abstract: This invention relates to processes for solvent dewaxing bright stock waxy raffinate oil employing a dewaxing aid which dewaxing aid is a mixture of (a) poly di alkyl fumarate/vinyl acetate copolymers and (b) a wax-naphthalene condensate. The dewaxing aid mixture is a mixture of (a) poly di alkyl fumarate/vinyl acetate copolymer having a number average molecular weight of about 1,000 to 100,000, preferably 5,000 or greater, possessing alkyl side chain moieties of from C.sub.16 -C.sub.24+ in length (excluding branching) with an average pendent side chain length of predominantly (>50%) C.sub.20 and (b) a wax-naphthalene condensation product having a number average molecular weight of about 1,000 and greater. The combination (a) plus (b) may be employed in a weight ratio within the range from about 45/55 to 1/100, preferably about 1/3, and at an aid dose level ranging from about 0.005 to 2.0 wt %, preferably 0.01 to 0.2 wt % active ingredient.

Abstract: An improved dewaxing aid for solvent dewaxing process comprising a mixture of (A) an .alpha.-olefin polymer having an average molecular weight of from about 10,000 to 1,000,000 and a wide molecular weight distribution exceeding the range of from about 10,000 to 1,000,000 but falling within the range of from about 2,000 to 3,000,000 wherein the .alpha.-olefin polymer is a homopolymer made up of a C.sub.10 to C.sub.25 alpha-olefin monomer or is a copolymer made up of a monomer mixture comprising more than 50 wt. % of at least 2 C.sub.10 to C.sub.25 alpha-olefin monomers and a melt index greater than 1.8 g/10 min. and (B) an olefin vinyl acetate copolymer having a vinyl acetate content of from about 15 to 40 wt. % and an average molecular weight of from about 50,000 to 1,000,000 and a melt index greater than 2 g/10 min. The .alpha.

Abstract: Recovery of solvent from hydrocarbon oil extract fractions comprising solvent and oil is effected in at least three sequential flash vaporization stages wherein the pressure of the second vaporization stage is at the highest pressure level and the pressure of the third vaporization stage is at a pressure level intermediate the pressure level of the first and second vaporization stages.