Abstract: The invention relates to a method of separating one or more components from a multi-component gas stream comprising at least one non-acid gas component and at least one acid gas component. A multi-component gas stream at a pressure above 1,200 psia (82.8 bar) and a temperature above 120° F. (48.9° C.) with the concentration of at least one acid gas component in the gas stream being at least 20 mole percent is passed to a membrane system that selectively separates at least one acid gas component from the multi-component gas stream as a permeate stream. The permeate stream has a pressure at least 20% of the pressure of the feed pressure.

Abstract: A process for treating natural gas or other methane-rich gas to remove excess nitrogen. The invention relies on two-stage membrane separation, using methane-selective membranes for the first stage and nitrogen-selective membranes for the second stage. The process enables the nitrogen content of the gas to be substantially reduced, without requiring the membranes to be operated at very low temperatures.

Abstract: In a method of utilizing a methane-containing biogas by feeding the methane-containing biogas to a gas engine of a gas engine/generator assembly generating electricity, the steps of passing the biogas through a membrane separating installation to divide the biogas into a first gas stream having a higher methane content than the biogas fed thereto and a second gas stream enriched in CO2, feeding the first gas stream to the gas engine as fuel, and returning the second gas stream to the source of the biogas.

Abstract: A process for separating a gas from a gas mixture containing an organic compound gas or vapor by a hybrid separation combining adsorption with membrane gas separation, using membranes selective for the gas over the organic compound. The membranes use a selective layer made from a polymer having repeating units of a fluorinated cyclic structure of an at least 5-member ring, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment.

Abstract: A process for treating a gas mixture containing at least an organic compound gas or vapor and a second gas, such as natural gas, refinery off-gas or air. The process uses two sequential membrane separation steps, one using membrane selective for the organic compound over the second gas, the other selective for the second gas over the organic vapor. The second-gas-selective membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons. The membrane steps can be combined in either order.

Abstract: A process and a plant for removing the gaseous fluorocompounds or fluorosulphur compounds, such as CF4, C2F6, and SF6, present in a stream of xenon and/or krypton, by permeation via one or more membranes, such as polymer membranes. The xenon and/or krypton thus produced may then be further purified or separated by cryogenic distillation. Prior to the permeation step, the other impurities, particularly the hydrocarbons, may be removed by oxidative catalysis and subsequent adsorption of the carbon dioxides and of the water produced. The xenon, the krypton and the xenon/krypton mixtures free of gaseous fluorocompounds or fluorosulphur compounds and purified by such process can be used as plasma propulsion gas, especially for satellites, or as inter-pane insulation gas for a sealed unit, particularly for double-glazing windows.

Abstract: The invention relates to a process for the treatment of a gas stream obtained from the production of polyolefins and containing unreacted compounds. According to the process, uncondensed compounds are removed from the gas stream and, when so desired, these compounds are directed to further treatment. According to the invention, the uncondensed compounds are separated from the gas stream by membrane separation. Thus the separation of gases is facilitated, since by coupling the membrane system in conjunction with distillation columns the distillation can be carried out at a substantially higher top temperature. By using the membrane system it is possible effectively to remove the lightest gases, which would otherwise accumulate in the process.

Abstract: Separation of ethylene from ethane is achieved by feeding a mixture of the C2 hydrocarbons in contact with a CTS-1 crystalline titanium silicate molecular sieve which has a controlled pore size to selectively adsorb ethylene and size exclude ethane. The feed stream can also contain acetylene which can be selectively adsorbed from both ethane and ethylene by further controlling the pore size of the CTS-1 molecular sieve. Propane/propylene separation is also disclosed.

Abstract: Composite membranes capable of separating p-xylene from mixtures including p-xylene and m-xylene, and processes for purifying p-xylene using the membranes, are disclosed. The membranes are polymer membranes with a thickness of between about 10 and 1000 microns that include non-interconnected zeolite particles less than 5 microns. In one embodiment, a relatively thin polymer layer (0.5-3 microns) that includes zeolite particles is adjacent to a relatively thick polymer layer which may or may not include zeolite particles, where the thickness of the two layers is between about 10 and 1000 microns. The preferred ratio of zeolite/polymer is about 0.2 by weight. A preferred method for preparing the composite is by dispersing the zeolite in a polymer solution, casting a film of the polymer solution, and evaporating the solvent to form a polymeric film. The polymer permits passage of p-xylene and m-xylene in the vapor state, such that p-xylene diffuses at the same or a faster rate through the polymer.

Abstract: The invention relates to a process for separating off ethylene from a gas mixture comprising more than 8% by volume of carbon dioxide or oxygen, by gas permeation.

Abstract: Process for the removal of nitrogen contained in natural gas wherein are performed the steps of: a) absorbing the hydrocarbon component of natural gas by means of virgin naphtha in an absorption device, discharging the non-absorbed nitrogen; b) stripping the hydrocarbon component absorbed by the virgin naphtha; c) recycling the virgin naphtha recovered in the stripping, to step (a); d) feeding the natural gas thus treated to a distribution network.

Abstract: A process for treating a gas stream containing an organic component and a second gas. The process uses at least two compression stages, followed by membrane separation, with recirculation of the membrane permeate streams to different points in the compression train. The process provides particular benefits for separations characterized by modest membrane selectivity and a high concentration of the organic component in the remaining gas the compression steps.

Abstract: A process for treating natural gas or other methane-rich gas to remove excess nitrogen. The invention relies on membrane separation using methane-selective membranes, but does not require the membranes to be operated at very low temperatures. We have found that, by using a two-step membrane system design, and controlling the operating pressures for the membrane steps within certain ranges, the capital and operating costs of the process can be kept within economically acceptable limits.

Abstract: A novel process for the regeneration of PTMSP membranes is disclosed. The regeneration process includes washing a fouled PTMSP membrane with a solution containing at least about 50% butanol in water for a time sufficient to increase the flux and/or selectivity of the membrane. This regeneration process with a butanol containing solution significantly improves both the flux and selectivity of the PTMSP membrane and can regenerate the flux of the PTMSP membrane to the level of a previously unused membrane.

Abstract: An apparatus and process for separating perfluorocarbon compounds from a gas mixture passes an incoming stream of a gas into a cold trap, the gas stream including a plurality of perfluorocarbon compounds. The gas mixture is cooled within the cold trap to a temperature below −100° C. to produce a condensate that is enriched in at least one perfluorocarbon compound and a non-condensed stream from which the condensate was separated. The condensate is withdrawn from the cold trap. The condensate may be withdrawn by warming the cold trap to vaporize the condensate and thereafter flowing the vaporized condensate into a storage vessel. The non-condensed stream may be vented to the atmosphere, re-circulated into the cold trap or flowed through subsequent separation processes to extract additional perfluorocarbon compounds.

Abstract: A process for separating a gas from a gas mixture containing the gas and a C3+ hydrocarbon vapor, using gas-separation membranes selective for the gas over the C3+ hydrocarbon vapor. The membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons.

Abstract: An improved process and process train for catalytic reforming of hydrocarbons. In its most simple form, the invention includes four unit operations or steps: the reforming itself usually carried out in a series of reactors; one or more steps to separate the reformate liquid product from overhead gases, predominantly C1-C6 hydrocarbons and hydrogen; one or more treatment steps to recover hydrogen from the overhead gases, and one or more treatment steps, including a membrane gas separation step, for the waste gas from the hydrogen recovery step. The process provides improved recovery of hydrogen and LPG, and reduces the amount of gas sent to the fuel line.

Abstract: The present invention relates to a solid state facilitated transport separation membrane prepared by using a polymer electrolyte, wherein the facilitated transport separation membrane has good stability and improved permeance and selectivity of alkene-series hydrocarbons.

Abstract: An improved membrane pervaporation and vapor permeation system is disclosed in which the vacuum is produced by a fluid passing through a Venturi-type nozzle. The fluid is chosen from solvents that have an affinity for the permeate molecules. It is applicable over of process feed rates, can be used with either organic or aqueous systems and conserves energy relative to existing technology.

Abstract: The present invention is a method of separating a first compound having a macromolecular structure from a mixture. The first solvent is a fluid that is a gas at standard temperature and pressure and is at a density greater than a critical density of the fluid. A macromolecular structure containing a first compound is dissolved therein as a mixture. The mixture is contacted onto a selective barrier and the first solvent passed through the selective barrier thereby retaining the first compound, followed by recovering the first compound. By using a fluid that is a gas at standard temperature and pressure at a density greater than its critical density, separation without depressurization is fast and efficient.

Abstract: A process for separating and/or recovering gases from gas and/or gas vapor mixtures includes a membrane separating device to which a gas and/or gas vapor mixture is supplied, the latter being separated in the membrane separating device into a permeate, which is enriched with gas, and a retentate, which is depleted of gas. A first membrane separating device and a downstream second membrane separating device are provided, to which is supplied (at its inlet end) the retentate from the first membrane separating device, the first membrane separating device having a membrane which is selective for higher hydrocarbons in the gas and/or gas vapor mixture to be separated and in that the second membrane separating device has a membrane which is selected for gases of small molecular diameter.

Abstract: Provided is a membrane separation method for separating a first component (106) from a second component (108) in a fluid mixture (102). The method is particularly useful for separating a more highly unsaturated organic compound from a less highly unsaturated organic compound of a saturated organic compound, as well as making other separations. A membrane is used that includes first chemical groups, that are ionic and associated with ion exchange sites in the membrane, a second chemical group that modify the electronic environment of the ion exchange sites to enhance facilitated transport through the membrane. An example membrane is a silver (I)-form Nafion™-poly(pyrrole) composite membrane. Also provided are a membrane (112), and apparatus (110) for use with the method.

Abstract: A process for separating at least one of CF4 and C2F6 from a gas. The process includes the steps of: (a) contacting a gas mixture comprising (i) at least one of CF4 and C2F6, (ii) at least one of NF3, CHF3, and N2, and (iii) SF6 with a membrane at conditions effective to obtain a retentate stream rich in SF6 and at least one of CF4 and C2F6, and a permeate stream rich in at least one of NF3, CHF3, and N2; and (b) contacting the retentate stream with an adsorbent at conditions effective to adsorb SF6 and produce a product stream rich in at least one of CF4 and C2F6.

Abstract: A vapor recovery and pressure management system for a vehicle refueling facility includes two rotary vane pumps and a hydrocarbon-stripping membrane between the pumps. One pump draws vapor from a storage tank as well as from refueling nozzles, while the other pump draws vapor from the membrane and discharges the vapor back into the tank. A controller controls both pumps to maintain a slight vacuum in the tank, thereby preventing leakage of hydrocarbons from the tank to the atmosphere. Clean air from the membrane is exhausted, preferably through a charcoal canister, and a hydrocarbon sensor monitors for the presence of undesirable hydrocarbons in the clean air exhaust. One or more liquid drop outs are provided for separating liquid from the hydrocarbon vapor and returning the liquid to the tank along with the vapor, preferably before the liquid is sent to the membrane, to thereby increase efficient fuel recovery and to protect the membrane from undesirable contact with liquid.

Abstract: A vaporizable solute transfer system for transferring a vaporizable solute from a gas feed mixture to an absorbent liquid comprises an absorption module, a porous membrane which divides the absorption module into a gas-feed chamber and an absorbent chamber, a regeneration module, and a nonporous material which divides the regeneration module into an absorbent chamber and a vacuum atmosphere chamber. The absorption module has gas feed mixture inlet and outlet ports which communicate with the gas feed chamber, and absorbent liquid inlet and outlet ports which communicate with the absorbent chamber. The regeneration module has a liquid absorbent inlet and outlet port which communicate with the liquid absorbent chamber, and a vacuum outlet port which communicates with the vacuum chamber.

Abstract: A method for generating electric power, such as at, or close to, natural gas fields. The method includes conditioning natural gas containing C.sub.3+ hydrocarbons and/or acid gas by means of a membrane separation step. This step creates a leaner, sweeter, drier gas, which is then used as combustion fuel to run a turbine, which is in turn used for power generation.

Abstract: A treatment process for a hydrogen-containing off-gas stream from a refinery, petrochemical plant or the like. The process includes three separation steps: condensation, membrane separation and hydrocarbon fraction separation. The membrane separation step is characterized in that it is carried out under conditions at which the membrane exhibits a selectivity in favor of methane over hydrogen of at least about 2.5.

Abstract: Pervaporation membranes are used for removing volatile organic compounds from wastewaters. These pervaporation membranes are prepared by dispersing at least one hydrophobic adsorbent such as activated carbon uniformly into a polymer matrix.

Abstract: A method and apparatus is disclosed for separating a vapor-gas mixture formed above a liquid in a tank and which mixture is exhausted from the tank through an exhaust line in order to relieve overpressure in the tank. The mixture is passed from the tank through a membrane unit having a separating membrane and underpressure is generated at least intermittently, on a permeate side of the membrane unit, by a pump. This produces on the permeate side of the membrane permeate enriched with vapor and on the retentate side of the membrane retentate deleted in vapor. The permeate is returned to the tank and the retentate is exhausted to the atmosphere via the exhaust line.

Abstract: A process for conditioning natural gas containing C.sub.3+ hydrocarbons and/or acid gas, so that it can be used as combustion fuel to run gas-powered equipment, including compressors, in the gas field or the gas processing plant. Compared with prior art processes, the invention creates lesser quantities of low-pressure gas per unit volume of fuel gas produced. Optionally, the process can also produce an NGL product.

Abstract: The present invention relates to an improved method and apparatus for separating one or more condensable compounds from a mixture of two or more gases of differing volatilities by capillary fractionation in a membrane-type apparatus, and a method of forming porous structures therefor. More particularly, the invention includes methods of forming and using an apparatus consisting, at least in part, of a porous structure having capillary-type passages extending between a plurality of small openings on the first side and larger openings on a second side of the structure, the passages being adapted to permit a condensed liquid to flow therethrough substantially by capillary forces, whereby vapors from the mixture are condensed, at least in part, and substantially in and adjacent to the openings on the first side, and are caused to flow in a condensed liquid state, substantially in the absence of vapor, from the openings on the first side to the openings on the second side.

Abstract: Volatile organic compounds (VOCS) can be removed from surfactant solutions using pervaporation with hydrophobic pervaporation membranes. This process can be used to remove volatile non-laqueous phase liquids from surfactant-based soil washing and soil flushing solutions for recovery of the volatile compounds and reuse of the surfactant. The process of the present invention can also be used to separate VOCs from industrial process streams containing surfactants for in-process recycling and reclamation of the VOCs and/or surfactants. In addition, the process of the present invention can be used to separate VOCs from industrial waste streams containing surfactants for waste volume reduction or for recovery/recycle of the VOCs and/or surfactant.

Abstract: A method for generating electric power from natural gas or the like that has a low Btu value and a high nitrogen content. The method involves a membrane separation step to remove a portion of the nitrogen from the gas. The upgraded gas is used as fuel for a turbine or other driver, which provides mechanical power to drive an electric power generator.

Abstract: A pervaporation process for selectively removing a component from a multicomponent aqueous solution which is practiced with an assembly comprising a feed chamber for holding and introducting the multicomponent aqueous solution to be treated therein, the feed chamber having a pressure, an exit chamber having a pressure, and located adjacent to the feed chamber and downstream thereof; at least one membrane composite located between the feed chamber and the exit chamber and adapted for fluid registry therewith, the membrane composite comprised of a porous membrane having a first and second surface, and a nonporous membrane permanently disposed on the second surface of the porous membrane, and having a permeability selective to the component, the membrane composite aligned such that the nonporous membrane is connected to the feed chamber; and a vacuum pump connected to the exit chamber for evacuating the component from the chamber.

Abstract: A treatment process for a hydrogen-containing off-gas stream from a refinery, petrochemical plant or the like. The process includes three separation steps: condensation, membrane separation and hydrocarbon fraction separation. The membrane separation step is characterized in that it is carried out using a polymeric separation membrane that is selective in favor of hydrocarbons, including methane, over hydrogen, so that the hydrogen-enriched stream is delivered at high pressure.

Abstract: Compositions useful in separating molecules or catalytic conversions comprise a substrate, a zeolite or zeolite-like layer, a selectivity enhancing coating in contact with the zeolite layer and optionally a permeable intermediate layer in contact with the substrate the zeolite layer being in contact either with the substrate or the optional intermediate layer.

Abstract: A process train for treating a gas stream containing methane, nitrogen, and at least one of water vapor, acid gas, C.sub.3+ hydrocarbons and aromatic hydrocarbons, the gas stream typically, but not necessarily, being natural gas. The treatment train includes separation of methane from nitrogen by means of membranes that preferentially permeate methane and reject nitrogen. Preferred processes include both a dehydration step and an NGL removal step to treat the gas before it passes to the methane/nitrogen membrane separation step. The process train can also include additional steps, such as an acid gas removal step, or a cryogenic methane/nitrogen separation step.

Abstract: The present invention provides a method for treating volatile hazardous air pollutant (VHAP) and volatile organic compound (VOC) waste products from gas streams. The system disclosed herein employs microporous hydrophobic membranes to remove VHAPs/VOCs from a gas stream into an oleophilic stripping fluid. The stripping fluid is directed into a separate biomembrane reactor wherein the VHAPs/VOCs are transferred across a second microporous hydrophobic membrane into an aqueous nutrient medium, where the extracted VHAPs/VOCs are degraded by microorganisms residing on the surface of the membrane. VHAPs/VOCs are degraded to carbon dioxide, water, and cell debris. The disclosed system uncouples biotreatment from waste generation, such that operation of the biotreatment unit can be continuous and optimized independently of plant work schedules or fluctuations in pollutant concentrations entering the system.

Abstract: The present invention is an improvement in a separation process. When molecular sieve membranes are used in a separation process transport flux decays over time. It has been discovered that the presence of hydrogen in the feed stream, permeate stream, or feed stream when present, either alone or in combination, causes a reduction in flux decay.

Abstract: In one aspect, a method for selectively removing at least one target component from a multicomponent feed fluid using a removal system, the system including a feed chamber having an inlet and an outlet, a permeate chamber, and a membrane for separating the feed and permeate chambers. The membrane is selective for the at least one target component.

Abstract: A membrane separation process for treating a gas stream containing methane and nitrogen, for example, natural gas. The separation process works by preferentially permeating methane and rejecting nitrogen. We have found that the process is able to meet natural gas pipeline specifications for nitrogen, with acceptably small methane loss, so long as the membrane can exhibit a methane/nitrogen selectivity of about 4, 5 or more. This selectivity can be achieved with some rubbery and super-glassy membranes at low temperatures. The process can also be used for separating ethylene from nitrogen.

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: An apparatus reduces the pressure in a fuel tank ullage including a first conduit for connection to the fuel tank ullage, a vapor extractor, a pressure sensor to detect the pressure in the fuel tank ullage, a separation module having an inlet connected to the first conduit, a separation membrane, a permeate outlet separated from the inlet by the separation membrane, and a retentate outlet, a second conduit connected to the permeate outlet for connection to the fuel tank, a vapor pump associated with the second conduit for creating a low pressure in the separation module near the permeate outlet as to induce selected vapors to pass through the separation membrane, a vent associated with the retentate outlet to vent retentate to atmosphere, a hydrocarbon detector to detect hydrocarbon concentrations in the vent, and a controller to receive inputs from the pressure sensor and the hydrocarbon detector and output control signals to the vapor extractor and the vapor pump to pull vapor from the ullage when the press

Abstract: This invention relates to a method of an apparatus and method for separating component gases in a gas mixture employing a glassy polymer membrane at temperatures at or slightly above the freezing point of any liquid present so as to achieve superior separator of gas components. The composition of certain monomers and polymers are claimed.

Abstract: The invention is a process for treating a gas stream from ethylene or propylene production, or any other stream containing low molecular weight olefin gases and other hydrocarbons, to separate hydrogen and methane from the C.sub.2+ hydrocarbons. 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: 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: A membrane hybrid process for treating organic-containing gas streams to remove or recover the organic. The process combines absorbent scrubbing, gas stripping, condensation, and membrane separation, and is particularly useful in treating high-volume, low-organic-concentration streams. The process may be operated such that the only products are a clean air stream suitable for venting to the atmosphere, and a small-volume, condensed liquid organic stream suitable to reuse or disposal.

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: 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.