Abstract: A process for separating a feed gas stream containing elemental oxygen and nitrogen to produce a purified nitrogen gas stream by removing oxygen from the feed gas stream using an ion transport membrane to produce a retentate gas stream and a permeate gas stream, wherein the feed gas stream or the retentate gas stream is purified to remove impurities either before or after the separation step to produce the purified nitrogen gas stream.

Abstract: A process for producing a pressurized oxygen stream by compressing and heating a feed gas stream containing elemental oxygen, and separating the heated feed gas stream using an ion transport module into an oxygen-depleted gas stream on the retentate side and an oxygen-containing gas stream on a permeate side. The permeate side of the ion transport membrane is purged using a gas stream containing steam to produce a pressurized gas stream containing oxygen and steam, and the gas stream is separated into the pressurized oxygen stream saturated with water vapor and a residual water stream.

Abstract: Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least one glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Abstract: The present invention utilizes a membrane cartridge that removes water vapor or fluid from air that passes through the cartridge. The longer the air remains within the cartridge, the more fluid is removed from the air. Consequently, as the air becomes "drier", the dew point temperature of the air also falls. The present invention permits decreases in the flow rate and system pressure while providing dehumidified air with the desired dew point temperature. These decreases in pressure and flow rate result from increased elevation or system wear. The decrease in system pressure and flow rate increases the residence time of the air in the membrane cartridge. As a result, the dew point temperature of the dehumidified air remains stable because increased residence time increases the amount of fluid removed from the air, which tends to reduce the dew point temperature of the dehumidified air.

Abstract: A process for recovering SF.sub.6 from a gas is provided. The process includes the step of contacting a gas stream comprising SF.sub.6 and at least one of N.sub.2, O.sub.2, CO.sub.2, and H.sub.2 O with a membrane in at least one membrane separation unit at conditions effective to obtain a retentate stream rich in SF.sub.6 and a permeate stream rich in at least one of N.sub.2, O.sub.2, CO.sub.2, and H.sub.2 O.

Abstract: A process for removing oxygen from a feed gas stream to produce an oxygen-depleted retentate gas stream by supplying the feed gas stream to a bulk oxygen separation system for removing oxygen to produce an oxygen-depleted crude product gas stream and a first oxygen-containing permeate effluent stream, and supplying the oxygen-depleted crude product gas stream to a separator having a primary ion transport membrane to produce a second permeate effluent stream and the oxygen-depleted retentate gas stream. A reactive purge gas is added to react with a portion of the oxygen permeating through the primary ion transport membrane and purge the permeate side of the primary ion transport membrane, and/or a recycle gas stream comprising at least a portion of one gas stream produced during the process is added to at least one other of the gas streams.

Abstract: Membrane-based vapor permeation system for selective removal of a vapor from a fluid feed stream, wherein a countercurrent sweep stream is used that has a particular partial pressure of the vapor to be removed.

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: A contaminant reduction system is shown for a disk drive assembly having a closed interior and slider disk components located therein which would be adversely affected by condensed volatiles generated within the assembly. A Peltier element is located within the closed interior of the disk drive assembly so as to condense volatiles present within the interior at a desired condensation point within the closed interior. A getter material, such as a microporous sintered alumina, is located within the closed interior of the disk drive assembly at the condensation point for permanently trapping and maintaining condensed volatiles which are condensed by the Peltier element.

Abstract: This invention comprises an improved process for generating Nitrogen from air in which a vacuum is placed on the permeate side of a gas separation membrane, usually of the polysulfone type, resulting in highly enhanced flow rates and nitrogen purity sufficient for oil and gas pipeline repair use and for use in grain silos.

Abstract: The invention produces essentially pure nitrogen from air by an intermittent, automatic, and unattended process. Air is filtered, compressed and enters a nitrogen module containing a permeable membrane that selectively separates nitrogen from the air and discharges oxygen and other gases. Automated temperature and pressure controls allow the permeable membrane to separate air components. A discharge hose allows use of the nitrogen product for a variety of intermittent applications including vending for inflation of tires, filling portable nitrogen vessels, and use in manufacturing processes.

Abstract: The present invention utilizes a membrane cartridge that removes water vapor or fluid from air that passes through the cartridge. The longer the air remains within the cartridge, the more fluid is removed from the air. Consequently, as the air becomes "drier", the dew point temperature of the air also falls. The present invention permits decreases in the flow rate and system pressure while providing dehumidified air with the desired dew point temperature. These decreases in pressure and flow rate result from increased elevation or system wear. The decrease in system pressure and flow rate increases the residence time of the air in the membrane cartridge. As a result, the dew point temperature of the dehumidified air remains stable because increased residence time increases the amount of fluid removed from the air, which tends to reduce the dew point temperature of the dehumidified air.

Abstract: A process for the dehydration of a vaporous mixture. The basic process involves directing a predominantly condensable water vapor-containing vaporous mixture against the feed side of a membrane while maintaining the feed near saturation without condensing it, directing a condensable vapor sweep stream past the permeate side of the membrane in a countercurrent flow, thereby transporting water vapor in the vaporous mixture from the feed side to the permeate side of the membrane to form a noncondensed combined permeate side mixture of condensable vapor and transported water vapor.

Abstract: This invention relates to a method of and apparatus for separating component gases in a gas mixture employing a glassy polymer membrane at temperatures of 5.degree. C. or less so as to achieve superior separation of gas components.

Abstract: An ionomer for an ion complex membrane useful for the separation of water-organic solvent by osmosis or low pressure osmosis as well as by pervaporation and a method for producing ion complex membrane therefrom are disclosed. The ionomer for producing ion complex membrane can be prepared by heat polymerization of an alkyl compound having pyridyl groups such as 1,3-di(4-pyridyl) propane at both terminal ends with a dihaloalkane compound such as dibromooctane and dichloroheptane having two halogen atoms at both terminal ends or with one or two halogen atoms affixed to intermediate carbon atoms in a polar solvent such as acrylonitrile. An ion complex membrane can be produced by preparing a membrane of a polycation or polyanion in a solution casting method and dipping the membrane in a solution of polycation or polyanion for 24 hours to give an ion complex membrane. This ion complex membrane may be a single membrane or composite membrane. Composite membrane includes a plain membrane and a hollow fiber membrane.

Abstract: The present invention relates to a process for the dehydration of a gas, particularly of a gas where the gas values should all be substantially recovered as dehydrated gas. The process uses membrane dryers and provides a sweep gas for each of the dryers. The sweep gas is substantially recovered and used again as a sweep gas. The process is economical and can process large quantities of gas.

Abstract: An improved system for producing dry, high pressure air uses a semipermeable membrane dehydrator to remove water vapor from compressed air between two stages of compression in a multistage air compressor.

Abstract: A dehumidifying method which comprises contacting a gas containing water vapor to one side of a vapor permselective membrane, while contacting a dry gas to the other side of the membrane, to let the water vapor selectively permeate through the membrane, wherein the membrane is made of an ion exchange membrane having ion exchange groups, of which counter ions are partly or entirely substituted by metal ions.

Abstract: A capillary membrane gas dehydrator. A gaseous stream having water vapor therein flows into the tube side of the capillaries. Water vapor permeates through the fibers to the shell side. A portion of the dehydrated stream is used as a purge stream for the shell side of the dehydrator. A pressure valve meter combination is used in the bypass stream to ensure that the pressure of the purge stream is maintained at a constant level independent of any variation in the pressure of the feed stream. This ensures that if there is an increase in pressure in the feed stream there is no increase in the purge rate and no corresponding increase in purge losses.

Abstract: Essentially pure nitrogen gas is produced from air and stored by an intermittent, automatic, and unattended process that is compact and self contained. Air is first filtered, compressed and enters a nitrogen module containing a permeable membrane that selectively separates nitrogen from the air and discharges oxygen and other gases. The nitrogen gas then flows into a vessel for storage. The apparatus is enclosed in a housing where automated temperature and pressure controls allows the permeable membrane to separate air components. A discharge hose allows use of the nitrogen product for a variety of intermittent applications including vending for inflation of tires, filling portable nitrogen vessels, and use in other processes needing intermittent and automatic manufacture of nitrogen gas.

Abstract: A method and apparatus for producing liquid nitrogen from air comprising a gaseous mixture of about 78% by volume of nitrogen, about 21% by volume of oxygen, less than 1.0% by volume of argon, and small amounts of carbon dioxide, water vapour, and other trace elements and compounds comprise an extractor that extracts portions of the oxygen, carbon dioxide, and water vapour so as to produce a nitrogen-rich gaseous mixture comprising about 90% to about 99% by volume of nitrogen, about 10% to about 1% by volume of oxygen, and no more than trace amounts of carbon dioxide, water vapour, and other elements and compounds. A nitrogen recycle compressor compresses the nitrogen-rich gaseous mixture to a specified pressure.

Abstract: A method for removing condensable organics from a fluid is disclosed. A fluid contaminated with condensable organics is provided. A poly (alkyl sulfone) permeable membrane having a selectivity.gtoreq.20 is provided. The fluid is passed along a surface of the membrane. The organics permeate through the membrane. The permeated organics are recycled.

Abstract: An electrically powered dehumidifier is provided which has no moving mechanical parts. The dehumidifier employs convection of a deliquescent solution around a fluid circuit having vapor permeable windows. The apparatus is driven by a solid state electronic heat pump, such as a Peltier effect solid-state heat pump, for example.

Abstract: Process and apparatus for the separation of at least one gas from an entering gaseous mixture (1), of the type in which a membrane separation is conducted with at least two successive membrane separators in the following manner: the entering mixture is passed through a first membrane separator (2) operating at a first operating temperature and all or a portion of the residual mixture (5) from this first membrane separator is passed through a second membrane separator (3) operating at a second operating temperature. A mixture enriched in the gas is obtained from the permeate outlet (6, 4) of each of these two separators. Two separators are used whose selectivities for the gas are different. These may be membranes of different type, or membranes of the same type, if the first operating temperature is different from the second operating temperature.

Abstract: The present invention provides a method and apparatus for the dehydration of gases utilizing hollow fiber membranes. The invention provides an internal sweep of the permeate side of the membranes utilizing an aperture in the tubesheet at the product end of the module thereby sweeping the permeate side of the membrane with product gas.

Abstract: The invention relates to a process for the separation of a gaseous hydride or a mixture of gaseous hydrides from a gaseous medium containing at least one gas from the group consisting of H.sub.2, Ar, He, according to which the gaseous medium is passed on to a membrane module so that the concentration of the hydride or of the mixture of hydrides obtained at the outlet of the module is higher than their initial concentration in the gaseous medium.

Abstract: A dehumidifying device for use in a ventilator for reducing the relative humidity of the expired air of a patient has a plurality of tubes, permeable to moisture, arrayed in a bundle and encircled by a loosely wound spiral harness between a first connection section and a second connection section in the dehumidifying device. When gas expired by the patient reaches the dehumidifying device, the water vapor therein diffuses into the tubes, and the relative humidity of expired gas is decreased.

Abstract: Improved membranes and improved membrane processes for treating gas streams containing hydrogen sulfide, carbon dioxide, water vapor and methane, particularly natural gas streams. The processes rely on the availability of two membrane types, one of which has a hydrogen sulfide/methane selectivity of at least about 40 when measured with multicomponent gas mixtures at high pressure. Based on the different permeation properties of the two membrane types, optimized separation processes can be designed.

Abstract: Improved processes for treating gas streams containing hydrogen sulfide, carbon dioxide, water vapor and methane, particularly natural gas streams. The processes rely on the availability of two membrane types, one of which has a hydrogen sulfide/methane selectivity of at least about 40 when measured with multicomponent gas mixtures at high pressure. Based on the different permeation properties of the two membrane types, optimized separation processes can be designed. The membrane separation is combined with non-membrane treatment of the residue and/or permeate streams.

Abstract: Improved membranes and improved membrane processes for treating gas streams containing hydrogen sulfide and methane, plus water vapor, carbon dioxide or both. The processes rely on the availability of two membrane types, one of which has a high hydrogen sulfide/methane selectivity and a high water vapor/methane selectivity, when measured with multicomponent gas mixtures at high pressures. Based on the different permeation properties of the two membrane types, optimized separation processes can be designed. In favorable cases, the processes can simultaneously dehydrate the gas stream and remove the hydrogen sulfide to very low levels.

Abstract: An organic emissions elimination apparatus, and process for same, for substantially eliminating the emission of potentially harmful organic constituents, such as benzene, toluene and xylene ("BTX") into the ambient environment during dehydration of water bearing gas. The apparatus includes a first chamber which incorporates a membrane for use in association with a water absorbing material (such as triethylene glycol) which is operably displaceable and retained within the membrane fibers. Although the water vapors from the gas will permeate the membrane (and become absorbed by the triethylene glycol), the BTX will not be able to permeate the membrane. Accordingly, the BTX and the dehydrated gas will be discharged from the first chamber toward a point of use by conventional dehydrated gas using equipment.

Abstract: A composite or asymmetric membrane for separating and concentrating a particular component from a mixture of gases. The asymmetric membrane is of a fluorine-containing aromatic polyimide resin of the 6FDA type. The composite membrane has a thin film of an elastomeric polymer formed on a supporting film of a fluorine-containing aromatic polyimide resin of the 6FDA type.

Abstract: The present invention relates to processes and apparatuses for starting up and shutting down membrane gas separation systems comprising at least one gas separation membrane module and at least one membrane dryer module.

Abstract: The present invention relates to fluid separation composite membranes prepared from sulfonated aromatic polymers in lithium salt form with sulfonic acid groups attached to aromatic rings that are incorporated into the main polymeric backbone.

Abstract: A process and system for pressurizing a vessel for integrity testing with gas comprising helium, recovering the gas comprising helium, and purifying the gas comprising helium for reuse. The process for purifying the gas stream comprising helium comprises drying the gas stream; separating the dried gas stream in a membrane separator stage into a helium-enriched permeate product stream and a helium-depleted raffinate stream; recovering helium in the raffinate stream in a membrane stripper stage thereby producing a purge stream; and purging water from the dryer with the purge stream.

Abstract: Acid gases are separated from a gas stream by bringing the gas stream into contact with a multilayer composite membrane comprising a nonselective polymeric support layer and an active separating layer comprising a polyelectrolyte polymer which contains cationic groups which are electrostatically associated with anions for which the pK.sub.a of the conjugate acid is greater than 3.

Abstract: A process for inerting an interior of a container, the process comprising:(a) introducing an inert fluid rich stream into the interior of the container, the concentration of inert fluid in the inert fluid rich stream inert fluid being greater than the inert fluid concentration in the interior of the container;(b) increasing the concentration of inert fluid in the inert fluid rich stream during its introduction into the interior of the container; and(c) withdrawing or purging a waste gas stream containing at least one impurity and inert fluid from the interior of the container.

Abstract: Valuable process gas is dried to a low water content, for example a dew point of less than -20.degree. F., using membrane separation in which compression of the permeate gases and condensation and separation of liquid water from the permeate stream is combined with a total recycle of uncondensable permeate gases so that no process gas is lost as a result of the drying operation. Feed gas is combined with the recycled gas either prior to compressing, cooling and separating the liquid water from the process gas or subsequent to these steps, depending upon the pressure of the available feed stream to be dried. Membrane separation efficiency is improved by sweeping the downstream surfaces of the membrane with dried product gas. All of the sweep gas is recaptured with the permeate gases and returned to the separation unit, thereby enabling 100%, recovery of the fresh feed gas from the drying operation. Only liquid water and dissolved gases are purged from the system.

Abstract: This invention pertains to an improved process for the removal of moisture from a moisture laden gas stream such as air utilizing a membrane dryer unit. The membrane dryer unit is equipped such that it incorporates a selective surface flow adsorbent membrane consisting essentially of an inorganic membrane material selected from the group consisting of alumina and silica gel membranes wherein the membrane has a thickness of approximately 0.5 to 50 microns with a mean pore size of less than about 15 A and preferably within about 4 to 10 A. In the cryogenic separation of air, an air stream contaminated with moisture and carbon dioxide is passed through the membrane dryer unit in countercurrent flow to a dry purge gas, wherein the water is selectively removed from the air stream. The partially dried air stream then is conveyed to an adsorption system operated under thermal swing or pressure swing conditions wherein the residual water and carbon dioxide are removed.

Abstract: A process for removing and recovering a condensable vapor from a gas stream by a membrane contactor is disclosed wherein a gas stream containing a condensable vapor is circulated on one side of hollow fiber membranes while cool extraction fluid is circulated on the other side under a total pressure differential, thereby condensing the condensable vapor in the gas stream, the condensed vapor permeating the membrane and becoming entrained in the cool extraction fluid.

Abstract: Aromatic polyimide membranes have superior flux at low temperature for carbon dioxide and other condensable gases. Superior flux is achieved without reduction in selectivity or other valuable properties of prior art membranes.