Abstract: A method and apparatus for improving the separation of a distillation system comprising a main distillation zone and at least one sidestream separation zone is described. The method comprises returning vapor separated in the sidestream separation zone to the main distillation zone at a location at least two trays and/or at least one theoretical stage above the liquid draw-off from the main distillation zone to the sidestream separation zone.

Abstract: Flux solvents and/or pitch neomesophase anti-solvents used in the generation of carbon fiber precursors from pitch are separated from mixtures of such solvent and uncoverted carbon fiber precursors by contacting said mixtures with asymmetric hydrophobic membranes under conditions of reverse osmosis. The membranes used in this separation are asymmetric polyimide membranes and asymmetric polyvinylidene fluoride membranes. Separation conditions include a contacting pressure sufficient to overcome the osmotic pressure of the solvent. The pressure is typically about 300 to 1000 psi. Contacting temperature is about 0.degree. to 100.degree. C., preferably about 20.degree. to 80.degree. C. The membrane of choice is an asymmetric polyimide membrane.

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 process for increasing the production of Bright Stock oil in a lube oil process scheme. Aromatic extract oil, after being separated from the extraction solvent, is recycled back to the deasphalter unit and combined with a vacuum residuum in 10-20 LV %, based on the total deasphalter feed, prior to deasphalting. After deasphalting and aromatics extraction the absolute yield of raffinate is increased.

Abstract: In fabricating membrane elements, and especially spiral wound membrane elements, for the separation of extraction solvents, especially N-methyl-2-pyrrolidone (NMP) from extracted oil fractions (e.g., extract of raffinate), adhesive systems consisting of specific silicone elastomers in combination with specific primers have been identified which are useful in forming the bonds necessary to produce an element, as for example, in forming the edge-seal bonds of the membrane that is used to effect the separation, in bonding the membrane leaves to the metal or plastic components of the element, and in forming a protective outer-wrap for the element.

Abstract: In the production of alkylaromatics by the alkylation of aromatic hydrocarbons with alkylating agents such as olefins typically in the presence of a catalyst, the unconverted aromatic hydrocarbon remaining after completion of the alkylation process is separated from the alkylaromatic product and the terminal alkylaromatic isomers are separated from the mixture of alkylaromatic isomers produced in the alkylation process by the selective permeation of the aromatic hydrocarbon and the terminal isomers through a permselective membrane, preferably an asymmetric membrane producing a permeate rich in the terminal isomers and a retentate which is lean (i.e., depleated) in the terminal isomers. Permeation is under reverse osmosis conditions, that is, under a pressure sufficient to at least overcome the osmotic pressure of the aromatic hydrocarbon present in the mixture made up of the aromatic hydrocarbon, the olefin and the mixed isomer alkylaromatic product.

Abstract: Aromatic molecules are alkylated using a silica-alumina catalyst derived from zeolite. The silica-alumina catalyst is a partially collapsed zeolite, i.e., a material of reduced crystallinity. The alkylation process which employs this material of reduced crystallinity is characterized by a high level of selectivity for the production of monoalkylated product.

Abstract: The instant invention is directed to shear thickening fluids which comprise a water-swellable material (clay), present in a sufficient concentration so as to be capable of forming a stiff paste upon interaction with the water used, and water wherein the clay and water are kept separated by an intervening hydrocarbon-surfactant composition. The intervening oil phase prevents the interaction between the water and the clay phases and results in a stable, nonreacting, pumpable composite until such time as the oil envelope is ruptured by application of a sufficiently high shear force. Upon such rupture, the materials interact rapidly forming a semi-rigid stiff paste.Various well-control problems, such as oil and gas with blowouts, can be controlled by use of the above-described composite. The composite is pumped down the well pipe.

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: Asymmetric polyimide reverse osmosis membranes of high flux and selectivity for organic liquid separations are described. These membranes are prepared from undegraded polyimide by dissolving from 14-30 wt. % of the undegraded polymer in a dual solvent system comprising a polymer pro-solvent/anti-solvent wherein the pro-solvent is DMF and the anti-solvent is dioxane, wherein the ratio of anti-solvent/pro-solvent ranges from about 10:1 or more-1:1, preferably about 8:1-1.5:1, most preferably about 7:1-3:1; the polymer-solvent mixture is spread into a thin film of the desired thickness and permitted to evaporate for a time just sufficient to permit formation of an asymmetric dense active layer, i.e., within the range 2-120 seconds, preferably 2-60 seconds, most preferably 2-20 seconds before being immersed in a gelation bath.The membranes may be fabricated in the form of sheets, tubes, hollow fibers, etc.

Abstract: The present invention is directed to a process for producing high quality aromatic solvents in the middle distillate range containing 95.sup.+ % aromatics by contacting the liquid feed with a perm selective membrane under pressure thereby selectively permeating the aromatic components as the high quality solvents. This separation can be performed by contacting the feed stream in combination with a low boiling light polar aromatics extraction solvent (such as acetonitrile) with the membrane. The middle distillate feed has a molecular weight range of about 120 to 250 g/mole and an aromatic content of 75 to 90 volume percent aromatics and preferably 80 to 90 volume percent aromatics. The membranes which can be employed to effect this separation are selected from the group of regenerated cellulose, cellulose acetate and polyimide membranes, preferably the polyimide membranes.

Abstract: It has been discovered that the pour point and wax content of waxy hydrocarbon oils, either natural or derived from synthetic sources such as tar sands, shale oil, etc., preferably natural waxy petroleum oils, most preferably waxy lube, transformer, specialty oils and waxy fuels such as kerosene or jet fuel, can be effectively reduced under standard catalytic dewaxing conditions using an aluminosilicate catalyst with very low crystallinity (VLC), as measured by x-ray diffraction. These VLC materials are derived from crystalline aluminosilicate zeolites which will not themselves reduce the pour point and wax content of waxy oils by the thermal decomposition of said zeolites following their exchange with cations which yield hydroxyl groups during the thermal decomposition step.

Abstract: Used oils, especially used lubricating oils which are normally considered waste and are discarded or burned, are reclaimed for reuse by a re-refining procedure involving the steps of:(a) heat soaking the used oil;(b) distilling the heat soaked oil;(c) passing the distillate through a guard bed of activated material;(d) hydrotreating the guard bed treated distillate under standard hydrotreating conditions.If the used oil to be re-refined contains a quantity of water and/or fuel fraction which the practioner considers sufficiently large to be detrimental, the used oil may be subjected to a dewatering/defueling step prior to being heat soaked.

Abstract: Selective extraction solvents such as NMP, phenol or furfural employed for the extraction of specialty oils, i.e. lubricating, transformer and insulating oils, to remove undesirable aromatic components therefrom, is itself recovered from the extract stream and/or raffinate streams by preferential ultrafiltration through selective membranes of regenerated cellulose. The extract stream, because of its higher solvent content, is the preferred stream for solvent recovery treatment by the reverse osmosis membrane permeation technique. Solvent recovery employing membrane permeation exhibits the advantage of not being energy intensive as is distillation or stripping. The solvent is recovered at a high enough flux rate and at a high enough level of purity to be introduced back into the solvent extraction process optionally at some point in the process wherein the composition of the recovered solvent approximately matches the composition of the solvent present in the process at the point of introduction.

Abstract: An improved process for dewaxing waxy hydrocarbon oils, wherein said waxy oil is introduced at a temperature above its cloud point into a direct chilling zone divided into a plurality of stages, passing said waxy oil from stage-to-stage of said chilling zone, introducing a cold dewaxing solvent into at least a portion of said stages, maintaining a high degree of agitation in at least a portion of the stages containing solvent and waxy oil, thereby effecting substantially instantaneous mixing thereof while cooling said solvent-waxy oil mixture, preferably at a rate of from about 1.degree. to 8.degree. F./min.

Abstract: Novel catalyst compositions are provided comprising a silica/alumina carrier having a silica content less than about 40% by weight and at least one noble metal component of Group VIII of the Periodic Table and wherein the catalyst contains (1) pores having a diameter of smaller than 600 .ANG. occupying at least 90% of the total pore volume and (2) pores having a diameter of 150 to 600 .ANG. occupying at least about 40% of the total volume of the pores having a diameter of smaller than 600 .ANG.. This catalyst is particularly useful in the production of jet fuels and white oils.

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: Corrosion of the process equipment in solvent extraction units utilizing N methyl-2-pyrrolidone as the selective extraction solvent is significantly reduced by means of a sacrificial metal contacting zone or bed containing a metal or metal alloy with a higher electro chemical potential than the metals used in the extraction unit vessels and lines. Preferred sacrificial metals are magnesium, zinc, calcium, barium, and strontium, most preferably magnesium, as metal strips, shavings, ribbons, sponge, filings, chips, blocks, bricks, etc.

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