Abstract: A mixture that contains benzene, other aromatic hydrocarbons and paraffinic hydrocarbons and/or naphthenic hydrocarbons that have 5 to 10 carbon atoms undergoes distillation in a first column, producing a distillate and a residue; a phase is drawn off laterally from the first distillation column, preferably at a point on the column where the benzene content is essentially at maximum where the toluene content is low; the phase that is drawn off is sent toward a first permeation stage, which produces a permeate that is enriched with benzene and a retentate; at least a portion of said retentate is recycled toward said first distillation column; the benzene-enriched permeate from stage (3) is sent to a second distillation column, from which the purified benzene comes out at the bottom and a distillate vapor comes out at the top; the distillate vapor is condensed, and the condensed distillate is sent at least in part to a second permeation stage; in said second permeation stage, a permeate that is also enriched in

Abstract: The present invention is directed toward a new zeolite membrane which exhibits a columnar cross-sectional morphology and preferred crystallographic orientation comprising a porous substrate having coated thereon a mesoporous growth enhancing layer and a layer of columnar zeolite crystals on said mesoporous growth enhancing layer, and wherein said mesoporous growth enhancing layer comprises nanocrystalline or colloidal sized zeolites, nanocrystalline or colloidal zeolite and metal oxide, or nanocrystalline or colloidal zeolite and colloidal metal, or nanocrystalline or colloidal zeolite, colloidal metal and metal oxide, and wherein said mesoporous growth enhancing layer has interstices of about 20 to about 2000 .ANG., and wherein said columnar zeolite layer is a polycrystalline layer wherein 99.9% of said columnar zeolite crystals have at least one point between adjacent crystals that is .ltoreq.20 .ANG..

Abstract: A process disclosed for the separation, purification and recovery of an unsaturated hydrocarbon from its mixture with at least one other material using a facilitated transport liquid membrane system.

Abstract: Applicant has discovered a new zeolite membrane and a process for preparing the same. The membrane is unique in that the zeolite crystals making up the membrane pack in a manner such that the membrane is essentially continuous with no large scale voids even when the membrane is <10 .mu.m thick. Thus, the present invention is directed toward a zeolite membrane wherein said membrane is comprised of a porous substrate and a layer of zeolite crystals wherein said layer of zeolite crystals is a polycrystalline layer with at least 99% of said zeolite crystals having at least one point between adjacent crystals that is .ltoreq.20 .ANG. and wherein at least 90% of said crystals have widths of from about 2 to about 50 microns and wherein at least 75% of said crystals have a thickness of within 20% of the average crystal thickness and wherein said membrane has at most 1 V % voids in said zeolite layer.

Abstract: A large pore (500.degree.-2000.degree. A) ceramic membrane is used to separate asphaltenes from heavy crude oil. Permeate is recycled to the feed for an initial period, during which the pores are deliberately fouled to reduce pore size. This reduction eventually levels off, at which point recycling is terminated and ultrafiltration is continued thereafter at good flux rates with effective asphaltenes removal.

Abstract: An improved, membrane-based method of treating gas evolved during natural gas liquids (NGL) stabilization, to separate the very light hydrocarbon gases, methane in particular, from the heavier hydrocarbons. The membrane acts as a demethanizer and establishes a vapor/liquid equilibrium during phase separation that is different than would otherwise obtain. This can increase NGL production and reduce the weight of C.sub.3+ hydrocarbons in the off-gas from the stabilizing phase separators.

Abstract: An improved, membrane-based method of treating gas evolved during gas/oil separation, to separate the very light hydrocarbon gases, methane in particular, from the heavier hydrocarbons. The membrane acts as a demethanizer and establishes a vapor/liquid equilibrium during phase separation that is different than would otherwise obtain. This can increase oil production and reduce the weight of C.sub.4+ hydrocarbons lost in the associated gas.

Abstract: A process for treating a purge vent stream from a polymer manufacturing operation, the vent stream containing a polymer, such as ethylene or propylene, and a purge gas, such as nitrogen. The invention involves three separation steps: condensation, flash evaporation and membrane separation. The steps are integrated together in such a way as to provide a good separation between the components, and to avoid creation of secondary streams that need additional treatment.

Abstract: A homogeneous membrane or an asymmetric membrane which is made of polyimide resin containing fluorine as a main component and has high separation and permeation properties, is used in a method of separating unsaturated hydrocarbon from a mixture of unsaturated and saturated hydrocarbon. The method includes the steps of contacting the mixture onto the membrane made of the polyimide resin having a repeating unit shown in the following formula as a main component, selectively permeating unsaturated hydrocarbon through the membrane, and separating unsaturated hydrocarbon from the mixture. The membrane satisfies the condition of a solubility coefficient ratio between unsaturated and saturated hydrocarbon.gtoreq.1.2 at 25.degree. C. and more than 50 Torr when the absorption of hydrocarbon to the polyimide resin is in equilibrium.

Abstract: A hydrocarbon stream is cracked to produce a hot gaseous stream which is compressed and cooled to condense almost all of the hydrocarbons contained in the stream. A noncondensed stream remaining after the condensation step, comprised predominantly of hydrogen and C.sub.1 to C.sub.3 hydrocarbons, is subjected to pressure swing adsorption or temperature swing adsorption at an adsorption temperature of about 0.degree. to about 250.degree. C. in a bed of adsorbent which selectively adsorbs ethene and propene, thereby adsorbing substantially all of the ethene and propene from the gas stream. The ethene and/or propene is recovered upon bed regeneration. Higher alkenes are separated from alkanes by various methods.

Abstract: A membrane and process for separating unsaturated hydrocarbons from fluid mixtures. The membrane and process differ from previously known membranes and processes, in that the feed and permeate streams can both be dry, the membrane need not be water or solvent swollen, and the membrane is characterized by a selectivity for an unsaturated hydrocarbon over a saturated hydrocarbon having the same number of carbon atoms of at least about 20, and a pressure-normalized flux of said unsaturated hydrocarbon of at least about 5.times.10.sup.-6 cm.sup.3 (STP)/cm.sup.2 .multidot.s.multidot.cmHg, said flux and selectivity being measured with a gas mixture containing said unsaturated and saturated hydrocarbons, and in a substantially dry environment.

Abstract: A process for purification of a substantially non-aqueous, viscous, contaminated organic liquid, in particular tri-ethylene glycol, comprising heating the contaminated organic liquid to a temperature in the range of about 70.degree. C. to about 100.degree. C. and passing the contaminated organic liquid through a reverse osmosis membrane at a pressure in the range of about 400 psig to 650 psig. As a result of passing through the reverse osmosis membrane, a purified organic liquid is formed on one side of the membrane and a retentate with contaminants removed from the contaminated organic liquid is formed on the other side of the reverse osmosis membrane.

Abstract: This invention relates to a method for effectively separating an unsaturated hydrocarbon from a feedstock containing at least two similar unsaturated hydrocarbons comprising passing the feedstock over one side of an ionopore membrane charged with a facilitator having an affinity for each of the at least two similar unsaturated hydrocarbons and recovering from a second side of the membrane permeate containing predominantly one of the at least two similar unsaturated hydrocarbons, the similar unsaturated hydrocarbons being selected from the group consisting essentially of aromatic, alkene, and diene hydrocarbons.This invention further relates to a method for achieving liquid phase separation of at least two competing components from a feedstock containing the components such that the separation factor for the competing components is at least about 4 times the separation factor calculated when permeating single components using the same membrane and under the same conditions.

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: Derivatized molybdenum-sulfide dimers of the general formula [(C.sub.5 R.sub.5 Mo).sub.2 (.mu.-S).sub.4-x (.mu.-SR).sub.x ].sup.n are utilized in the solid state, incorporated in permselective membranes and in aqueous solution as chemical specific complexing agents in various separation processes.

Abstract: A feed stream comprising a mixture of at least two separable components is separated into a permeate rich in one or more components and a retentate lean in those same components by a process comprising dissolving the feed in a supercritical solvent under supercritical conditions to produce a solution and contacting the solution with a dense, non-porous perstraction membrane having a first and a second surface, said contacting being along a first surface, wherein a portion of the feed dissolves into the first surface of the membrane, migrates through the perstraction membrane under a concentration gradient and emerges from the membrane at the second surface, as a permeate, the permeate being removed from the second surface by use of a sweep fluid comprising a supercritical solvent at supercritical conditions which may be the same as or different from the supercritical solvent in which the feed is dissolved.

Abstract: Derivatized molybdenum-sulfide dimers of the general formula [(C.sub.5 R.sub.5 Mo).sub.2 (.mu.-S).sub.4-x (.mu.-SR).sub.x ].sup.n are utilized in the solid state, incorporated in permselective membranes and in aqueous solution as chemical specific complexing agents in various separation processes.

Abstract: A process for purifying crude dicyclopentadiene which comprises the steps of: cracking the crude dicyclopentadiene to form a monomeric-containing effluent which comprises at least one monomer selected from the group consisting of: C.sub.4 acyclic dienes, C.sub.5 acyclic dienes, cyclopentadiene and methylcyclopentadiene; separating the monomeric-containing effluent into a cyclopentadiene-enriched stream and a cyclopentadiene-poor stream; dimerizing the cyclopentadiene-enriched stream to form a dimerizer effluent; contacting a membrane separator under pervaporation conditions with the dimerizer effluent wherein the C.sub.4 acyclic dienes, C.sub.5 acyclic dienes and cyclopentadiene permeate through the membrane separator and wherein a dicyclopentadiene product having a purity of at least about 98% is retained as retentate.

Abstract: The present invention includes the use of crosslinked fluorinated polyolefin membranes membranes for the separation of aromatics from saturates, wherein aromatics can contain sulfur and nitrogen.

Abstract: Derivatized molybdenum-sulfide dimers of the general formula [(C.sub.5 R.sub.5 Mo).sub.2 (.mu.-S).sub.4-x (.mu.-SR).sub.x ].sup.n are utilized in the solid state, incorporated in permselective membranes and in aqueous solution as chemical specific complexing agents in various separation processes.

Abstract: A process for solvent dewaxing a waxy oil feed to obtain petroleum oil lubricating stock comprising the steps of contacting a warm waxy oil feed by indirect heat exchange first with cold filtrate, then with refrigerant to crystallize and precipitate the wax in the oil feed to form an oil/solvent/wax mixture. The oil/solvent/wax mixture is diluted with cold solvent to adjust the viscosity of the mixture and the mixture is fed to a filter which filters and removes the wax from the cold oil/solvent/wax mixture. A cold wax cake is recovered and a cold oil/solvent filtrate stream is recovered. The cold oil/solvent filtrate stream is fed, at the filtration temperature, to a selective permeable membrane. The membrane selectively separates the cold filtrate into a cold solvent permeate stream and a cold filtrate stream which contains the dewaxed oil and the remaining solvent. The cold solvent permeate stream at the filtration temperature is recycled to the filter feed stream.

Abstract: A process for solvent dewaxing a waxy oil feed to produce a lubricating oil by contacting a warm waxy oil feed in counter-current with a cold oil/solvent filtrate stream through a selectively permeable membrane to transfer cold solvent through the membrane to the feed and simultaneously cool the feed, dilute it with solvent and separate solvent from the cold oil/solvent filtrate stream. The cooled, diluted feed stream is then further cooled to precipitate the wax to form an oil/solvent/wax mixture which is further diluted with cold solvent and filtered to remove wax. The cold oil/solvent filtrate stream is cycled to the selectively permeable membrane for the counter-current contact with the warm waxy oil feed and, after removal of a portion of the solvent over the membrane, is sent to an oil/solvent separation operation in which the solvent is removed from the dewaxed oil.

Abstract: A method of treating sour liquefied petroleum gas comprising removing hydrogen sulfide from the sour liquefied petroleum gas by:(a) contacting the liquefied petroleum gas in an extraction column with a liquid and regenerable absorbent to obtain purified liquefied petroleum gas;(b) supplying the purified liquefied petroleum gas to a membrane unit comprising a membrane selected from a permselective membrane and a porous hydrophobic membrane, a permeate outlet and a retentate outlet; and(c) removing from the permeate outlet of the membrane unit treated liquefied petroleum gas and from the retentate outlet of the membrane unit contaminated liquefied petroleum gas.

Abstract: A process for separating a mixture of aluminum alkyl and alpha-olefin, said process comprising contacting a silica modified inorganic membrane filter with said mixture and recovering, as the permeate, an alpha-olefin fraction which contains a lower concentration of aluminum alkyl than in said mixture, as the retentate, an aluminum alkyl fraction which contains a higher concentration of aluminum alkyl than in said mixture.

Abstract: A process for separating a mixture of aluminum alkyl and alpha-olefin comprises contacting, under an elevated pressure of at least about 300 psig, an organic solvent stable, polyphenylene oxide-derived membrane with said mixture and recovering as the permeate an alpha-olefin fraction which contains a lower concentration of aluminum alkyl than in the starting mixture.

Abstract: Dewaxed oil containing dewaxing solvent from solvent dewaxing is treated by contact with a separating elastomer 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 dewaxed oil--the membrane including a barrier layer of an adduct of maleic acid anhydride and a poly(aliphatic terpene) which has been thermally cross-linked.

Abstract: The present invention is a process for the recovery of normal alcohols, especially C.sub.1 -C.sub.20 n-alcohols, preferably n-C.sub.4 -C.sub.14 alcohols, most preferably n-C.sub.6 -C.sub.11 alcohols from n-paraffins by means of pervaporation through a membrane. The alcohols/paraffin feed mixture may be that produced in the Fischer-Tropsch synthesis process wherein mixtures of CO and H.sub.2 are reacted to produce paraffin waxes and a minor but still valuable amount of alcohols.

Abstract: A process for separating C.sub.2 -C.sub.4 alkenes from C.sub.1 -C.sub.6 alkanes comprises the presence of water vapor in the alkene/alkane feed and the use of an Ag.sup.+ -exchanged sulfonated copolymer of tetrafluoroethylene and perfluorovinyl ether having been prepared by one of several specific ion-exchange methods.

Abstract: The present invention describes a method for the synthesis of unsaturated aliphatic polyesters, their crosslinking by thermal treatment and the use of the corresponding crosslinked membranes to separate aromatics from saturates.

Abstract: The present invention describes a method for the synthesis of saturated aliphatic polyesters by reaction of saturated or aromatic diacid chlorides with oligomeric aliphatic polyester diols, a method to thermally crosslink membranes prepared from the above saturated aliphatic polyesters, and the use of the crosslinked membranes to separate aromatics from saturates.

Abstract: The present invention describes a method for separating mixtures of aromatics and non-aromatics into aromatic-enriched and non-aromatic-enriched streams by contacting the mixture with one side of a polysulfone membrane and selectively permeating the aromatic components through the membrane.

Abstract: A process for the fractionation of a gaseous mixture containing hydrogen, light aliphatic hydrocarbons and light aromatic hydrocarbons wherein following compression of the mixture and separation of one or more light fractions, a gas is contacted with light aliphatic hydrocarbons and then hydrogen is separated by permeation. A series of distillation steps makes it possible to isolate the aliphatic hydrocarbons and the aromatic hydrocarbons subsequent to the separations.

Abstract: Charge containing dewaxed oil and dewaxing solvent (typically methyl ethyl ketone and toluene) is treated to separate dewaxing solvent by use of a separating membrane barrier of a polyurea.

Abstract: Process for reducing the metal content of a hydrocarbon feed mixture by reverse osmosis, comprising contacting the feed mixture substantially boiling in the range between about 100.degree. and about 350.degree. C. and containing at most about 1000 parts per billion by weight (ppbw) of metal(s) with a metal-selective membrane to give a hydrocarbon permeate stream having a metal content which is less.

Abstract: Water is separated from an MEK toluene dewaxing solvent by pervaporation through a poly(vinyl pyridine) membrane which has been cross-linked with 1,4-dibromobutane mounted on a polyacrylonitrile support layer.

Abstract: Raffinate yield from solvent extraction is improved when the extract phase recovered from the solvent extraction process is subjected to a membrane separation step wherein a saturates/1-ring aromatics rich retentate is produced and a 2+ ring aromatics rich permeate are produced and the saturates/1-ring aromatic rich retentate phase is recycled to the solvent extraction process.

Abstract: Naphthenic hydrocarbons are separated from aliphatic rich hydrocarbon feeds comprising mixtures of naphthenes with paraffinic hydrocarbons by a membrane extraction process whereby the hydrocarbon feed is contacted with one face of a porous, non-selective partition barrier membrane while simultaneously contacting the other side of said membrane with a polar solvent such as ethylenediamine. The naphthenic hydrocarbon preferentially migrates through the porous membrane partition barrier in response to the polar solvent present on the permeate side of the barrier.

Abstract: Non-normal, branched paraffins (isoparaffins) are separated from hydrocarbon feeds comprising mixtures of isoparaffins and normal paraffins by the procedure involving the steps of contacting the hydrocarbon feed with one face of a non-selective, microporous partition barrier membrane while simultaneously contacting the opposite face of said membrane, preferably in countercurrent flow, with a polar solvent. The isoparaffins in the feed selectively permeate across the porous partition barrier membrane in response to the polar solvent to the solvent side of the membrane whereby a permeate enriched in isoparaffins and a retentate of decreased isoparaffin content as compared to the feed are obtained.

Abstract: Olefins are selectively separated from hydrocarbon feeds containing mixtures of olefins and paraffins by contacting said hydrocarbon feed mixture with one side of a micro-porous, non-selective partition barrier membrane while simultaneously passing, preferably in countercurrent flow, along the opposite side of said membrane a polar solvent. The olefin preferentially passes through said micro-porous non selective partition barrier in response to the polar solvent yielding a permeate enriched in olefin and a retentate enriched in paraffin as compared to the original feed stream.

Abstract: Traditionally, volatile organic compounds are monitored using the purge and trap technique required by the U.S. Environmental Protection Agency. However, this technique operates in two phases, liquid and gas, requiring gravity to effect the separation of the two phases. The present invention, which can be automated, incorporates a microporous hydrophobic bladder to permit zero gravity monitoring of volatile organic compounds in an aqueous solution.

Abstract: The yield, raffinate product quality, and throughput of the selective solvent extraction of hydrocarbon feeds is improved by subjecting the hydrocarbon feeds from which aromatic hydrocarbons are to be selectively solvent extracted to a membrane separation process which selectively permeates aromatics through the membranes to produce a permeate rich in aromatics and a retentate rich in saturates and 1-ring aromatics and subjecting this retentate to the selective solvent extraction process.

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: A new membrane for the separation of aromatic hydrocarbons from mixtures of said aromatic hydrocarbons and non-aromatic hydrocarbons has been prepared comprising a highly aromatic polyurethane membrane. These highly aromatic polyurea/urethane membranes are symmetric, dense film membranes made from the corresponding polyurea/urethane copolymers by standard membrane casting techniques. The polyurea/urethane copolymers are produced by reacting dihydroxy or polyhydroxy compounds, such as polyethers or polyesters having molecular weights in the range of about 500 to 5000 with aliphatic, alkylaromatic or aromatic diisocyanates or polyisocyanates and low molecular weight chain extenders, such as diamines, polyamines or amino alcohols.

Abstract: A membrane is provided for separating aliphatically unsaturated hydrocarbons from hydrocarbon mixtures, the membrane comprising a hydrophilic polymer which contains metals capable of complexing with aliphatically unsaturated hydrocarbons and a hydrophilic salt of a Group I metal.

Abstract: The subject invention relates to a process for the selective separation of at least one component of a gaseous feedstream comprising passing the feedstream containing the component through a separation unit, the separation unit containing a porous membrane having a feed side and a permeate side, and a pore size of from about 10 Angstroms to about 200 Angstroms, and having disposed in the pores of the porous membrane a facilitator liquid comprising a carrier dissolved in a suitable solvent, including:a) dissolving the component in the facilitator liquid on the feed side of the porous membrane at the feed gas/membrane interface;b) forming a component-carrier complex;c) diffusing the complex to the permeate side of the porous membrane; andd) releasing the component from the carrier.

Abstract: A new membrane for the separation of aromatic hydrocarbons from mixtures of said aromatic hydrocarbons and non-aromatic hydrocarbons has been prepared comprising a highly aromatic polyurea/urethane membrane. These highly aromatic polyurea/urethane membranes are symmetric, dense film membranes made from the corresponding polyurea/urethane copolymers by standard membrane casting techniques. The polyurea/urethane copolymers are produced by reacting dihydroxy or polyhydroxy compounds, such as polyethers or polyesters having molecular weights in the range of about 500 to 5000 with aliphatic, alkylaromatic or aromatic diisocyanates or polyisocyanates and low molecular weight chain extenders, such as diamines, polyamines or amino alcohols.

Abstract: The present invention describes a method for separating mixtures of aromatics and non-aromatics by permeation through a sulfonated polysulfone membrane which is selective for aromatics.

Abstract: This invention relates to a process for drying liquid hydrocarbons using cellulosic membranes.

Abstract: The present invention is a method for separating aromatics from saturates using a non-porous polycarbonate membrane. In a preferred embodiment, the polycarbonate membrane may be crosslinked.

Abstract: A membrane is provided for separating aliphatically unsaturated hydrocarbons from hydrocarbon mixtures, the membrane comprising a hydrophilic polymer which contains metals capable of complexing with aliphatically unsaturated hydrocarbons.