Abstract: A gas separation membrane system and a method of preparing such gas separation membrane system by providing a porous support upon which is supported a membrane layer comprising a first gas-selective material and having a membrane thickness and removing therefrom a substantial portion of the first gas-selective material from the membrane layer by the use of an ultra-fine abrasive to thereby provide the membrane layer having a reduced membrane thickness. A second gas-selective material is deposited upon the membrane layer having the reduced membrane thickness to provide an overlayer of the second gas-selective material having an overlayer thickness so as to thereby provide the gas separation membrane system having the membrane layer of the reduced membrane thickness and the overlayer of the overlayer thickness.

Abstract: A carbon dioxide permeable membrane is described. In some embodiments, the membrane includes a body having a first side and an opposite second side; a plurality of first regions formed from a molten carbonate having a temperature of about 400 degrees Celsius to about 1200 degrees Celsius, the plurality of first regions forming a portion of the body and the plurality of first regions extending from the first side of the body to the second side of the body; a plurality of second regions formed from an oxygen conductive solid oxide, the plurality of second regions combining with the plurality of first regions to form the body and the plurality of second regions extending from the first side of the body to the second side of the body; and the body is configured to allow carbon dioxide to pass from the first side to the second side.

Abstract: A leak-proof membrane element (1) for the selective separation or cleaning of gas, wherein a metal foil (membrane) (3) is deposited onto a supporting stock (substrate) (2, 20) having connection means (4, 21, 34) on the ends/edges of the substrate allowing the membrane element to be installed in a housing. A metal foil (3), having a thickness of less that 10 micrometers and being selectively permeable for specific gases, is arranged in flakes or wound with overlapping joints (8) on the outside of the substrate (2, 20), any joints being welded together by diffusion bonding so that the foil forms a continuous, leak-proof metal membrane layer. The substrate being made of a material (metal, ceram, polymer, or combinations thereof) exhibiting a very high gas flux for the gas(es) that the membrane is to let through.

Abstract: A membrane cartridge is manufactured by repeatedly folding and joining two strips of membrane to form a cross-pleated cartridge with a stack of openings or fluid passageways configured in an alternating cross-flow arrangement. The cartridge can be modified for other flow configurations including co-flow and counter-flow arrangements. Methods for manufacturing such cross-pleated membrane cartridges, as well as apparatus used in the manufacturing process are described. Cross-pleated membrane cartridges comprising water-permeable membranes can be used in a variety of applications, including in heat and water vapor exchangers. In particular they can be incorporated into energy recovery ventilators (ERVs) for exchanging heat and water vapor between air streams being directed into and out of buildings.

Abstract: An air dryer includes a housing with an air inlet, an air outlet and a liquid drain outlet; and a membrane separator having surfaces extending between a first and second ends of the membrane. A first passage in the housing is connected to the air inlet and air outlet at it respective ends and extends between the first and second ends of the membrane separator along the surfaces of the membrane separator. A second passage in the housing is connected to the drain outlet and air outlet at it respective ends and extends between the first and second ends of the membrane along a surface of the membrane separator. A valve is connected between the second passage and the drain outlet for controlling the draining of the liquid and sweep air flow through the second passage. The dryer is to be inserted in a reservoir at its inlet or outlet. A coalescing filter may be provided in the housing in series with the membrane separator and the housing would include a second drain for the coalescing filter.

Abstract: A passive humidifier membrane includes polyolefin with a plurality of pores, wherein the average pore size of the plurality of pores is 0.05 ?m to 0.4 ?m as established by a PMI Capillary Flow Porometer. The humidifier membrane is virtually airtight while providing a high transfer rate of water. Transfer of heat is also high. The humidifier membrane is particularly suitable for heat exchange and water transfer between fluids and, it is particularly useful for applications inside or outside fuel cells such as PEMFC. The membrane is also particularly useful in the application as humidifier for air or oxygen.

Abstract: The present invention discloses new types of polybenzoxazole-based mixed matrix membranes and methods for making and using these membranes. The polybenzoxazole-based mixed matrix membranes are prepared by fabricating a polyimide-based mixed matrix membrane by dispersing molecular sieve particles in a continuous aromatic polyimide matrix with pendent hydroxyl groups ortho to the heterocyclic imide nitrogen; and then converting the polyimide-based mixed matrix membrane to a polybenzoxazole-based mixed matrix membrane by heating between 200° and 600° C. under inert atmosphere or vacuum. The polybenzoxazole-based mixed matrix membranes of the present invention can be fabricated into any convenient geometry such as flat sheet (or spiral wound), tube, hollow fiber, or thin film composite.

Abstract: A membrane-based gas separation process for treating gas streams that contain methane in low concentrations. The invention involves flowing the stream to be treated across the feed side of a membrane and flowing a sweep gas stream, usually air, across the permeate side. Carbon dioxide permeates the membrane preferentially and is picked up in the sweep air stream on the permeate side; oxygen permeates in the other direction and is picked up in the methane-containing stream. The resulting residue stream is enriched in methane as well as oxygen and has an EMC value enabling it to be either flared or combusted by mixing with ordinary air.

Abstract: First, a mixture of a polytetrafluoroethylene fine powder and a liquid lubricant into a sheet-form body extending in a first direction. Next, the liquid lubricant is removed from the sheet-form body. Then, the sheet-form body is stretched by a factor of 40 to 250 in the longitudinal direction at a temperature equal to or higher than a melting point of polytetrafluoroethylene, and the stretched sheet-form body is further stretched by a factor of 3 to 40 in the width direction. Thus, a highly air-permeable porous polytetrafluoroethylene membrane is obtained.

Abstract: A feed stream, comprising hydrogen sulphide (H2S), carbon dioxide (CO2), hydrogen (H2) and, optionally, carbon monoxide (CO), is separated into at least a CO2 product stream and an H2 or H2 and CO product stream. The stream is separated using a pressure swing adsorption system, an H2S removal system and a further separation system, which systems are used in series to separate the stream. The method has particular application in the separation of a sour (i.e. sulphur containing) syngas, as for example produced from the gasification of solid or heavy liquid carbonaceous feedstock.

Abstract: Carbon dioxide and oxygen are separated from a feed gas, preferably derived from flue gas from an oxyfuel combustion process, by diffusion across at least one membrane in a membrane separation system to produce separated carbon dioxide gas comprising oxygen, which is fed to the oxyfuel combustion process to improve the performance of the process.

Abstract: This invention describes a new concept of flexible template-directed microporous partially pyrolyzed polymeric membranes which have greatly improved performance in separation of gas pairs compared to their precursor polymeric membranes. Organic hosts, such as crown ethers, cyclodextrins (CDs), calixarenes (CXs), and spherands, or polymeric additives, such as poly(ethylene glycol) (PEG) and polyvinylpyrrolidone (PVP) were used as the micropore-forming templates. Micropore-forming template/polymer blend membranes comprising organic micropore-forming templates embedded in a polymer matrix were prepared by dissolving the organic micropore-forming templates in the polymer solution followed by solution-casting and solvent evaporation or solvent exchange. Low-temperature selectively pyrolyzing micropore-forming templates in the micropore-forming template/polymer blend membranes at a nitrogen flow resulted in the formation of flexible microporous partially pyrolyzed polymeric membranes.

Abstract: The present invention relates to the selective separation of hydrogen (“H2”) hydrocarbons in streams containing both hydrogen and hydrocarbons (e.g. methane, ethylene, ethane, propylene, propane, etc.) utilizing a zeolitic imidazolate framework (“ZIF”) material. Preferably, the stream to be separated is fed to the present process in a substantially gaseous phase. In preferred embodiments, the current invention is utilized in either a pressure swing adsorption process, a temperature swing adsorption process, or a membrane separations process to separate hydrogen from hydrocarbons present in hydrogen production streams or petrochemical/petroleum refining product streams and intermediate streams.

Abstract: A membrane dryer includes a shell having an inner tube and an outer tube and a bundle of hollow fibers supported in the shell. A dryer air inlet into the hollow fibers and a sweep air outlet from the inner tube are at a first end of the shell. A dryer air outlet into the hollow fibers and a sweep air inlet from the inner tube are at a second end of the shell. The inner tube has a first set of circumferential openings into the sweep air space adjacent the first end of the shell and a second set of circumferential openings into the sweep air space adjacent the first end of the shell; and a second plug is in the inner tube between the first and second set of openings.

Abstract: Process for preparing a two layer metal palladium or palladium alloy composite membrane consisting of a porous substrate support and a palladium or palladium alloy membrane by rinsing/washing and drying the porous substrate support, treating the porous substrate support with a pore filler in order to decorate the pores of the support and the disfigurements of the substrate surface, sensitizing and activating with a palladium solution the decorated substrate support, and plating the resulting support with a palladium solution to form the two layer composite membrane, drying. The resulting composite membrane is subjected to a post-processing where the pore fillers residing in the pore-channels of the porous substrate are partly removed or reduced in volume through heating.

Abstract: An apparatus for separating at least one component from a mixture of a plurality of chemical species is provided. The apparatus comprises a membrane structure comprising a plurality of pores disposed within a matrix material to allow mass transport from a first surface of the membrane structure to a second surface of the membrane structure. The matrix material has a thermal conductivity of at least about 10 W/m/K; and a functional material disposed within at least a portion of the plurality of pores. The functional material has the property of promoting selective transport of at least one species through the membrane structure from the first surface to the second surface.

Abstract: The present invention discloses a novel method of making high performance mixed matrix membranes (MMMs) using stabilized concentrated suspensions of solvents, uniformly dispersed polymer stabilized molecular sieves, and at least two different types of polymers as the continuous blend polymer matrix. MMMs as dense films or asymmetric flat sheet or hollow fiber membranes fabricated by the method described in the current invention exhibit significantly enhanced permeation performance for separations over the polymer membranes made from the continuous blend polymer matrix. MMMs of the present invention are suitable for a wide range of gas, vapor, and liquid separations such as alcohol/water, CO2/CH4, H2/CH4, O2/N2, CO2/N2, olefin/paraffin, iso/normal paraffins, and other light gases separations.

Abstract: A method and apparatus for humidifying air in which the first side of a permselective water transport membrane is contacted with water vapor laden flue gas from a combustion process having a first water vapor partial pressure and a first temperature and at least a portion of the water vapor is condensed, producing condensed water. The condensed water is transported through the membrane to the opposite side of the membrane, which is contacted with an air stream having a second water vapor partial pressure, which second water vapor partial pressure is less than the first water vapor partial pressure, and having a second temperature, which second temperature is less than the first temperature. Upon contact with the air stream, the condensed water evaporates into the air stream, resulting in a humidified air stream.

Abstract: There is disclosed a method of manufacturing a thin and uniform ceramic filter formed with less membrane formation times and having less defects. A ceramic sol whose average pore diameter after the sol itself has been formed into a membrane is larger than that of a ceramic separation membrane and is 10 nm or less is brought into contact with the surface of a ceramic separation membrane having an average pore diameter of 0.5 to 10 nm, and the ceramic separation membrane having the ceramic sol is dried and then fired to repair a defect portion of the ceramic separation membrane.

Abstract: A carbon dioxide permeable membrane is described. In some embodiments, the membrane includes a body having a first side and an opposite second side; a plurality of first regions formed from a molten carbonate having a temperature of about 400 degrees Celsius to about 1200 degrees Celsius, the plurality of first regions forming a portion of the body and the plurality of first regions extending from the first side of the body to the second side of the body; a plurality of second regions formed from an oxygen conductive solid oxide, the plurality of second regions combining with the plurality of first regions to form the body and the plurality of second regions extending from the first side of the body to the second side of the body; and the body is configured to allow carbon dioxide to pass from the first side to the second side.

Abstract: A process and apparatus for dehumidifying a gas stream is provided. The apparatus includes a single semi-permeable osmotic membrane, at least one gas stream compartment formed in part by the osmotic membrane, and at least one osmotic fluid compartment formed in part by the osmotic membrane. The semi-permeable osmotic membrane has randomly arranged pores disposed across a thickness extending between a first side and a second side, and wherein some of the pores are small enough to permit capillary condensation within the membrane, leading to condensate travel across the thickness of the single membrane without requiring a separate capillary condenser, and which single membrane restricts transport of the osmotic fluid across the thickness of the membrane. The first side of the osmotic membrane is exposed to the gas stream compartment, and the second side of the osmotic membrane is exposed to the osmotic fluid compartment.

Abstract: A hydrogen purification system and method that utilizes a hydrogen separator with a novel composite structure. The hydrogen separator has a first porous layer of a hydrogen permeable material. The first porous layer is comprised of premanufactured nano-particles of hydrogen permeable material that have been bonded together. A solid layer of the same hydrogen permeable material is then disposed onto the first porous layer. A pressure differential is created across the structure of the composite hydrogen separator. The porous layer of hydrogen permeable material supports the solid layer and enables the solid layer to withstand large pressure differentials. Furthermore, the porous layer of the hydrogen permeable material bonds to the solid layer, thereby greatly increasing the effective surface area of the solid layer that is exposed to hydrogen gas. Accordingly, a large flow rate of hydrogen gas can be obtained in a small amount of space.

Abstract: Integrated separation and preparation process comprising a gas separation process wherein a first component is separated from a mixture of components by diffusion of the first component through a porous partition into a stream of sweeping component; and a preparation process wherein the sweeping component is used as feed. Separation unit and device for use in such a process and industrial set-up for use in such a process.

Abstract: Metal-organic framework-based molecular sieves comprising pores with a temperature-adjustable pore opening. The temperature-adjustable pore size molecular sieves comprise a plurality of metal clusters bound with a plurality of amphiphilic ligands, each ligand comprising a functionalized hydrophobic moiety and a functionalized hydrophilic moiety, and wherein the metal clusters and amphiphilic ligand hydrophilic moieties form a metal cluster layer, the metal cluster layer forming at least one hydrophilic pore. On each side of the metal cluster layer, a plurality of associated amphiphilic ligand hydrophobic moieties cooperate with the metal cluster layer to form a tri-layer and a plurality of tri-layers are held in proximity with each other to form at least one hydrophobic chamber. The hydrophobic moieties form temperature-adjustable pore size hydrophobic pores.

Abstract: A process for purification of hydrogen from a stream of synthesis gas or other reformate gases is described. The process, generally conducted at temperatures of approximately 800-1000° C., involves the use of a cell in which a mixture of reformate gas and steam are flowed on one side of a dense solid state ceramic membrane, while steam is passed on the other side. High purity hydrogen is generated on the steam side. The membrane is similar to one that has in the past been used for oxygen purification and can be single or two phase, for example La0.9Sr0.1Ga0.8Mg0.2O3+Pd.

Abstract: A system and method for separation of a gas, e.g., carbon dioxide, from a gaseous mixture using a hollow fiber membrane module. The module contains an absorbent solution that is effective in absorbing the gas for an extended period, e.g., eight hours, without regeneration or replacement. The absorbent solution is then regenerated by passing a sweep gas through the hollow fibers in the module. The separation system is particularly useful for fuel cell and battery applications.

Abstract: SAPO membranes and methods for their preparation and use are described. The SAPO membranes are prepared by contacting at least one surface of a porous membrane support with an aged synthesis gel. A layer of SAPO crystals is formed on at least one surface of the support. SAPO crystals may also form in the pores of the support. SAPO-34 membranes of the invention can have improved selectivity for certain gas mixtures, including mixtures of carbon dioxide and methane.

Abstract: Method of operating an oxygen-permeable mixed conducting membrane having an oxidant feed side and a permeate side, which method comprises controlling the differential strain between the oxidant feed side and the permeate side by varying either or both of the oxygen partial pressure and the total gas pressure on either or both of the oxidant feed side and the permeate side of the membrane while changing the temperature of the membrane from a first temperature to a second temperature.

Abstract: A method with associated equipment for feeding two gases into and out of a multi-channel monolithic structure. The two gases will normally be gases with different chemical and/or physical properties. The first gas and the second gas are fed by means of a manifold head into channels for the first and second gases, respectively. The gases are distributed in the monolith in such a way that at least one of the channel walls is a shared or joint wall for both gases. The walls that are joint walls for the two gases will then constitute a contact area between the two gases that is available for mass and/or heat exchange. This means that the gases must be fed into channels that are spread over the entire cross-sectional area of the monolith. The entire contact area or all of the monolith's channel walls are directly used for heat and/or mass transfer between the gases. This means that the channel for one gas will always have the other gas on the other side of its channel walls.

Abstract: The present invention deals with a process for treating a polyimide comprising exposing said polyimide to a compound selected from the group consisting of dendrimers, hyperbranched polymers and mixtures thereof. The polyimide may be in the form of a membrane and the membrane, after treatment according to the process of the invention, may be suitable for use in a membrane-based separation technique, for example gas separation, filtration, microfiltration, ultrafiltration, reverse osmosis or pervaporation. The membrane may for example be suitable for separation of gas and hydrocarbon mixtures including mixtures of H2/N2, H2/CO2, He/N2, CO2/CH4, and C2–C4 hydrocarbon mixtures.

Abstract: The present invention deals with a process for treating a polyimide comprising exposing said polyimide to a compound selected from the group consisting of dendrimers, hyperbranched polymers and mixtures thereof. The polyimide may be in the form of a membrane and the membrane, after treatment according to the process of the invention, may be suitable for use in a membrane-based separation technique, for example gas separation, filtration, microfiltration, ultrafiltration, reverse osmosis or pervaporation. The membrane may for example be suitable for separation of gas and hydrocarbon mixtures including mixtures of H2/N2, H2/CO2, He/N2, CO2/CH4, and C2-C4 hydrocarbon mixtures.

Abstract: Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

Abstract: The present invention relates to methods for the preparation of polyesters, poly(ester amide)s and poly(ester imide)s. The materials obtained by the methods of present invention are useful as fluid separation membranes and as high performance materials.

Abstract: There is disclosed amembrane assisted evaporation process (MAE) for economically and reliably removing water added to brine. The process comprises using low-grade waste heat and air to evaporate water from diluted salt brines when the water moves across a membrane in a liquid state.

Abstract: A process for the separation of mixture components uses a supercritical fluid that is fresh to at least one side of a nonporous membrane after which the fluid is either recycled to the opposite side of the membrane or removed from the separation process. Fluids and membranes, including modified membranes, are provided to facilitate passage of one or more components of a mixture through the membrane while retarding passage of other components of the mixture. The process is useful for the separation of mixtures with similar components including axeotropic mixtures and pharmaceutical and biological products.

Abstract: The present invention relates to laminated membranes formed by multi-layer processing techniques including alternating layers of thermoplastic urethane and a copolymer of ethylene and vinyl alcohol. The membranes are characterized in that hydrogen bonds are formed between the layers of thermoplastic urethane and the copolymer of ethylene and vinyl alcohol. The membranes are characterized in that hydrogen bonds are formed between the layers of thermoplastic urethane and the copolymer of ethylene and vinyl alcohol.

Abstract: A separation system comprising a stationary phase, a double stranded conductive polymer system contacting the stationary phase and means to place a mobile phase carrying a component to be separated from the mobile into contacting relationship with the polymer system whereby the component is captured by the polymer. The double stranded polymer is comprised of a -conjugated polymer and a polyelectrolyte.

Abstract: A ceramic membrane structure and method for separating oxygen from an oxygen containing feed at temperatures above about 600° C. The membrane is provided with a dense layer and one or more active porous layers. The dense layer contains at least a mixed conducting material and the active porous layer is formed of a mixture having an ion conducting phase capable of predominantly conducting oxygen ions and a mixed conducting phase capable of conducting both said oxygen ions and electrons. The ion conducting phase is present within the mixture in an amount greater than a percolation threshold and the mixed conducting material and phase have a greater electronic conductivity than ionic conductivity.

Abstract: In microelectronics (semiconductor) processing, pitting and voiding of aluminum and aluminum alloys by deionized (DI) water is prevented. The present method and apparatus degasifies the DI water to remove the dissolved oxygen gas. The oxygen gas concentration of the DI water is thus reduced from the saturation levels typically present to vastly less than saturation. It has been found that oxygen gas serves as the oxidizing agent in an electro-chemical reaction that includes the aluminum metal as the anode. The degasified DI water can be used at high temperatures and for long exposure times to rinse wafers without problematic aluminum etching. The present method is applicable to any semiconductor wafer fabrication or integrated circuit assembly process that uses DI water in contact with aluminum metallization.

Abstract: The invention relates to a method for transferring mass between a flow of a first fluid, preferably a gas phase such as a combustion flue gas, and flow of a second fluid, preferably a liquid phase, where the first fluid is contacted with the outer surface of porous (semi-permeable) membranes, e.g. Polytetrafluoroethylene (PTFE, Teflon®) membranes, in the form of hollow fibers having gas-containing pores and containing the second fluid with the inner surface of the membranes. Useful membranes are characterized in that they e.g. have a porosity (&egr;) of at least 0.50, a mass transfer coefficient of e.g. at least 3 cm/s, and a tortuosity factor of e.g. at the most 1.4/&egr; when the porosity &egr; is lower than 0.80 and at the most 1.3/&egr; when the porosity &egr; is 0.80 or higher. The membranes may also be arranged in hollow tubular members where the mass transfer coefficient of the membranes is at least on tenth of the mass transfer coefficient of the gas phase.

Abstract: A novel polyimide having a repeating structure unit expressed by the following general formula (1), a method for manufacturing the same, a gas separation membrane using the novel polyimide and the method for manufacturing the same. The gas separation membrane using this polyimide is excellent in gas permeable performance and separation selectivity for gas, for example, carbon dioxide, methane, etc.General Formula (1) ##STR1## where R denotes a quadrivalent organic group.

Abstract: The present invention relates to membranes useful in the separation of water from a solution containing volatile organic compounds and water. The membranes may be used in dehydrating an organic/water mixture to purify an organic when an organic is of interest or, alternatively, producing pure water from an organic/water mixture when clean water is of interest. The membranes include a hydrophilic base polymer, an optional pore-forming polymer and a surface modifying macromolecule (SMM) which imparts surface hydrophobicity to the membrane.

Abstract: A method of making an ophthalmic lens including the steps of: preparing a polymerizable composition comprising excessive oxygen content; contacting the polymerizable composition with a gas that is inert or substantially inert to the polymerizable composition, and deoxygenating or partially deoxygenating the polymerizable composition; conveying all or part of the polymerizable composition to an ophthalmic lens mold; polymerizing all or part of the polymerizable composition and obtaining a polymeric ophthalmic lens, and the lens produced by such process.

Abstract: A spiral-wound, gas-separation membrane module and a gas-separation process. The module and process provide at least partial counter-current flow between the feed and permeate gas streams without requiring a permeate sweep. The counter-current flow pattern can be achieved by appropriate placement of barriers or baffles in the feed channel. Similar modules and processes may also be used for pervaporation.

Abstract: An efficient method removes oxidants from fluids (gases and liquids, particularly air) by means of solid phase extraction or reaction. The solid phase extraction or reaction medium comprises a porous, preferably fibrous, polymeric, membrane or web in which are incorporated oxidant scavenger particulates. Typical oxidants removed in the method include ozone, oxides of nitrogen, halogen, and peroxides. The method of the invention protects organic analytes in analytical applications and removes oxidants in remediation applications by use of oxidant scavenger particles in porous membranes.

Abstract: A process for purifying water including removing cations, anions and carbon dioxide and/or ammonia from water feed stream to produce high purity water having a resistivity of greater than 1 megohm-era comprising the steps of providing a water feed stream to be purified, the stream containing cations, anions and carbon dioxide and/or ammonia; introducing the water feed stream to a high pressure side of a first reverse osmosis membrane module; passing water through the first reverse osmosis membrane to provide a first retentate having cations and anions concentrated therein and a first permeate depleted in cations and anions and containing carbon dioxide and/or ammonia; adding the first permeate to a high pressure side, of a gas permeable hydrophobic membrane module; passing carbon dioxide and/or ammonia through the gas-permeable membrane from the first permeate in the high pressure side of the gas-permeable hydrophobic membrane to provide a carbon dioxide and/or ammonia permeate on a low pressure side of the h

Abstract: The present invention concerns a polyester gas separation membrane which is obtained by the interfacial polymerization of benzenetricarbonyl trihalide or benzene tetracarbonyl tetrahalide in a water-insoluble organic solvent in one phase and a variety of polyfunctional phenols present as the di- or tri-salt in a mixture of water and phase transfer agent and a water-soluble organic solvent in the second phase. The present invention also includes the polyester membrane itself, its methods of preparation and the use of the membranes to separate gas mixtures, such as carbon dioxide and methane, helium and methane and the like.

Abstract: A high temperature ceramic membrane device for separation of fluids at high temperature, the device comprises: (a) a housing having: (i) an entrance for introducing fluids to the housing to be separated, (ii) an exit for removing fluids after being subjected to separation; (b) a plate mounted in one end of the housing, the plate having openings therein; (c) ceramic membrane comprised of porous ceramic tubes having a closed end and an open end, the tubes permeable by a fraction of the fluid to be removed from the fluid as filtrate and impermeable to a second fraction, the open end designed to remove the filtrate from the tube, the tubes mounted in the openings in the plate so that the closed end is projected into the housing and the open end is extended outside the housing for removing the filtrate; (d) a seal for sealing the plate in the housing; (e) insulation provided in the housing, the insulation means located adjacent the plate and surrounding the tubes projecting therethrough, the insulation adapted to

Abstract: Novel aromatic polyimide, polyamide and polyamide-imide gas separation membranes and the process of using such membranes to separate one or more gases from a gaseous mixture is disclosed. The polyimides, polyamides and polyamide-imides are formed from diamines of the formula ##STR1## where Ar' is ##STR2## Q is nothing or an aromatic group and Z is independently alkyl groups having 1 to 10 carbon atoms, most preferably a tertiary butyl group, n is an integer from 0 to 4, preferably 1.

Abstract: By using AVLIS or other methods capable of providing a depleted isotopic mixture, troublesome isotopes such as Gd.sup.154, Gd.sup.156 and Er.sup.166 are selectively removed from naturally occurring isotopic mixtures, while avoiding the additional costs associated with complete fractionation of the mixture. Such mixtures can be used to provide a burnable nuclear fuel absorber having a selectively depleted isotope or isotopes. In particular, the invention concerns burnable absorbers containing erbium with a depleted 166 isotope, gadolinium with a depleted 156 isotope or with depleted 154 and 156 isotopes, and methods for making such absorbers.