Abstract: A system and a method include a wand assembly including a sanitizing head having an ultraviolet (UV) lamp configured to emit UV light to sanitize a surface of a component. The wand assembly further includes a first monitored member. The system also includes a second monitored member. A verification control unit is in communication with the first monitored member and the second monitored member. The verification control unit is configured to detect a speed of the wand assembly based on a comparison of the first monitored member in relation to the second monitored member.

Abstract: An improved method and apparatus for removing acid gases and other impurities from raw biogas streams, such as biogas from landfills or biogas from controlled anaerobic digestion, is disclosed. The method provides efficient generation of high-purity renewable natural gas from raw biogas. The biogas is treated in a multi-stage membrane system integrated with compression equipment. The membrane separation units are arranged into interconnected high-pressure and low-pressure gas recycling loops powered by high-pressure and low-pressure compressors. The combined system provides for the generation of efficient contaminant removal from raw biogas to generate high-purity methane products with reduced compression energy consumption.

Abstract: A single compressor is used to separately compress permeate from cascaded first and second gas separation membrane-based separation units and residue from a fourth gas separation membrane-based separation unit in order to avoid too high a CO2 partial pressure in the compressed permeate. After the permeates from the first and second stages are compressed, the compressed stream is fed to a third gas separation membrane-based separation unit.

Abstract: A system and method for generating renewable natural gas from raw biogas streams, such as biogas from landfills or biogas from controlled anaerobic digestion of biomass, provides for the efficient removal of acid gases and other impurities, including oxygen and nitrogen from biogas. The biogas is treated in a multi-stage membrane gas separation system integrated with a pressure swing adsorption system to generate pipeline-specification renewable natural gas. The combined system provides for efficient acid gas removal while simultaneously limiting oxygen carryover into the product stream.

Abstract: An air separation module includes a canister extending between a first end and an opposite second end, a separator fixed within the canister to separate a compressed air flow into an oxygen-enriched air flow fraction and an oxygen-depleted air flow fraction, and a one-piece cap. The one-piece cap is connected to the first end of the canister and has a filter module mount portion on a side of the one-piece cap opposite the separator to support a filter module with the air separation module. Nitrogen generation systems and methods of making air separation modules are also described.

Abstract: An air separation module includes a cylindrical canister and a separator. The cylindrical canister has a longitudinal axis, an inlet, an oxygen-depleted air outlet, and a drain portion with an oxygen-enriched air outlet. The separator is arranged within the cylindrical canister to separate a compressed air flow into an oxygen-depleted air flow fraction and an oxygen-enriched air flow fraction, the oxygen-depleted air flow fraction provided to the oxygen-depleted air outlet and the oxygen-enriched air flow fraction to the drain portion of the canister. The drain portion extends tangentially from the cylindrical canister to issue the oxygen-enriched air flow fraction with entrained condensate from the oxygen-enriched air outlet with a tangential flow component. Nitrogen generation systems and methods of removing condensate from air separation modules are also described.

Abstract: The present invention relates to a method for the purification of alkanes, especially methane, wherein an alkane comprising impurities, especially methane, is reacted with an active compound, optionally in the presence of sulfur trioxide, whereby the impurities are removed. The present invention furthermore relates to the use of the active compound and sulfur trioxide in the purification of alkanes, especially methane.

Abstract: A carbon molecular sieve (CMS) membrane having improved separation characteristics for separating olefins from their corresponding paraffins is comprised of carbon with at most trace amounts of sulfur and a transition metal, wherein the transition metal is one or more of a group 4-10 and 12 transition metal. The CMS membrane may be made by pyrolyzing a precursor polymer devoid of sulfur in which the precursor polymer has had a transition metal incorporated into it. The pyrolyzing for the precursor having the transition metal incorporated into it is performed in a nonoxidizing atmosphere and at a heating rate and temperature such that the metal has a valence greater than zero (i.e., not metal bonded) to a valence desirably closer to its maximum valence.

Abstract: A method of separation of predetermined gas from the mixture of gases or an atmosphere, wherein said method of separation of predetermined gas from a mixture of gases or an atmosphere comprises passing a mixture of gases or an atmosphere through the reinforced mass selective fluid bandpass filter (8). The reinforced mass selective fluid bandpass filter comprises the mass selective fluid bandpass filter element (9) permanently affixed to the sintered metal load bearing structure (14). The mass selective fluid bandpass filter element consists of quartz glass, of either natural or manmade origin. This method provides removing predetermined gas from the group consisting of: 1H2, 1H2H, 2H2, 1H3H, 2H3H, 3H2, 1H2O, 1H2HO, 2H2O, 1H3HO, 2H3HO, 3H2O, O2, O3, 12CO2, 13CO2, 14CO2, 4 CO, N2, NO, NO2, NOx, SiO2, FeO, Fe2O3, SiF4, HF, NH3, SO2, SO3, H2SO4, H2S, 35Cl2, 37Cl2, F2, Al2O3, CaO, MnO, P2O5, phenols, volatile organic compounds, and peroxyacyl nitrates.

Abstract: A method for separating a raw feed gas stream using a plurality of membrane separation stages includes separating a pressurized feed gas stream into a first nonpermeate stream and a first permeate stream, compressing the first permeate stream to form a compressed first permeate stream, separating the compressed first permeate stream into a second nonpermeate stream and a second permeate stream, separating the second permeate stream into a third nonpermeate stream and a third permeate stream, combining the third nonpermeate stream with a raw feed gas stream to form a combined feed stream, compressing the combined feed stream to form a compressed combined feed stream, and combining the second nonpermeate stream with the compressed combined feed stream to form the pressurized feed gas stream.

Abstract: A fuel cell first and second electrode catalyst layers and a polymer electrolyte membrane (PEM) situated therebetween. A graphene-based material coated onto a first and/or second surface of the first and/or second electrode catalyst layers. The graphene-based material has a number of defects including a number of quad-vacancy (QV) defects formed by a vacancy of four adjacent carbon atoms in the graphene-based material. The number of QV defects are configured to mitigate dissolution of the first and/or second catalyst materials through the first and/or second surface of the first and/or second electrode catalyst layers.

Abstract: Reverse osmosis (RO) separation of organic solvent mixtures where solvent molecular weights <100 Da is challenging especially for powerful solvents that swell most uncrosslinked polymers. To avoid polymer swelling by solvents, a particular perfluoropolymer, perfluoro-2,2-dimethyl-1,3-dioxole copolymerized with tetrafluoroethylene, (PDD-TFE), designated CMS-7, was studied. This amorphous glassy extremely hydrophobic copolymer has a very high free volume (FV) fraction. The maximum radial dimension of FV regions is less than ˜0.65 nm allowing only single solvent molecule permeation. Further, interactions between polarity, dimensions and shapes of solvent molecules with those of polymer FV elements can lead to extraordinarily selective permeation. Permeation behaviors of other solvent mixtures, toluene-n-heptane, NMP-tetrahydrofuran, methanol-water, ethanol-water as well as individual phases of the immiscible mixture of NMP and the nonpolar solvent n-heptane were also studied.

Abstract: Nitrogen is removed from biogas using a three-stage separation system based on gas separation membranes. The first stage separates a biomethane feed stream into a first permeate gas stream and a first retentate gas stream. The second stage separates the first permeate stream into a biomethane product gas and a first low quality biomethane gas stream. The third stage separates the first retentate into a second low quality biomethane gas stream and a waste gas. A biogas feed stream is pretreated to remove amounts of water, VOCs, and CO2 to yield a methane-enriched biogas stream. The methane-enriched biogas stream is compressed together with the first and second low quality biomethane gas streams to form the biomethane feed stream.

Abstract: Sheets of graphene-based material comprising single layer graphene and suitable for formation of a plurality of perforations in the single layer graphene are provided. In an aspect, the sheets of graphene-based material are formed by chemical vapor deposition followed by one or more conditioning steps. In a further aspect, the sheets of graphene-based material include non-graphenic carbon-based material and may be characterized the amount, mobility and/or volatility of the non-graphenic carbon-based material.

Abstract: Composite membranes comprised of at least two layers, one of the layers being a silver ionomer and a second layer which is a fluorinated polymer with certain permeability properties, are especially useful for the separation of alkanes from alkenes, Particularly useful is a three-layer composite membrane in which a porous layer is laminated to the second layer.

Abstract: This invention relates to a device for separating carbon dioxide that includes a self-recycling loop, and to a method of separating carbon dioxide, which serve to effectively separate carbon dioxide from a combustion gas using a separation membrane provided with the self-recycling loop. This invention adopts a self-recycling loop in which the residue gas passing through a specific separation membrane is introduced into another separation membrane and in which a permeate gas passing through the specific separation membrane is introduced back into the specific separation membrane. Accordingly, the concentration of carbon dioxide in the feed gas of the specific separation membrane is increased, which increases the concentration of the permeate gas to thus improve the separation performance of the separation membrane, thereby separating high-purity carbon dioxide.

Abstract: The invention relates to gas separation, particularly to a process for separating CO2 from a CO2 containing gas stream with varying CO2 concentration using a membrane-based separation system. The process for separating CO2 comprises: (i) feeding the CO2 containing gas stream into a membrane-based separation system comprising one or more membrane stages in-line, each membrane stage producing a CO2-depleted retentate stream and a rich CO2 permeate stream, and (ii) recycling a part of the CO2-rich permeate stream from at least one membrane stage as a recycled stream, into a preceding feed stream of one or more membrane stages in the membrane-based separation system to adjust the CO2 concentration of the feed stream. The process could stabilize the CO2 concentration in the feed steam by recirculation of a fraction of the high purity CO2 permeate to the feed of the membrane system, which would result in a lower incremental auxiliary load than other options such as compression of the entire gas stream.

Abstract: Disclosed herein is a process for separating components of a gas mixture using gas-separation copolymer membranes. These membranes use a selective layer made from copolymers of perfluorodioxolane monomers. The resulting membranes have superior selectivity performance for gas pairs of interest while maintaining fast gas permeance compared to membranes prepared using conventional perfluoropolymers, such as Teflon® AF, Hyflon® AD, and Cytop®.

Abstract: Compositions of and methods for separating components of a natural gas stream are disclosed. In one embodiment, the method includes receiving an inlet stream comprising natural gas, the inlet stream having an inlet pressure, and the inlet stream further comprising methane, helium, and an impurity. The method includes allowing the inlet stream to contact a block co-polyimide membrane, the block co-polyimide membrane exhibiting both higher permeability for and higher selectivity for the helium and the impurity than for the methane at the inlet pressure of the inlet stream and separating the methane from the helium and the impurity to create a retentate stream, the retentate stream comprising an increased concentration of methane relative to the inlet stream. The method also includes creating a permeate stream comprising the helium and the impurity at an increased concentration of helium and impurity relative to a concentration of helium and impurity in the inlet stream.

Abstract: A gas separation membrane having a gas separating layer containing a polybenzoxazole resin, in which the polybenzoxazole exhibits a solubility of 1% by mass or more to any one solvent selected from tetrahydrofuran, chloroform, methyl ethyl ketone, and N-methylpyrrolidone, at a temperature of 30° C., a gas separation module utilizing the gas separation membrane, a gas separation apparatus, and a gas separation method.

Abstract: Disclosed are treated mixed matrix polymeric membranes comprising a plurality of metal-organic frameworks (MOFs) and a polymeric matrix, wherein the plurality of MOFs are attached to the polymeric matrix through covalent or hydrogen bonds or Van der Waals interaction. The membranes can be treated with plasma, electromagnetic radiation, or thermal energy or any combination thereof.

Abstract: Disclosed are polymeric blend membranes, and methods for their use, that include a blend of at least a first polymer and a second polymer, wherein the first and second polymers are each selected from a polymer of intrinsic microporosity (PIM), a polyetherimide (PEI) polymer, a polyimide (PI) polymer, or a polyetherimide-siloxane (PEI-Si) polymer, and wherein the polymeric membranes have been both ultraviolet (UV)-treated and thermally-treated.

Abstract: A method of determining an optimal geometry for monoliths useful for capturing CO2 is described. Monoliths having the determined desired geometry are also described.

Abstract: The object of the invention is porous membranes (M) comprising organopolysiloxane/polyurea/polyurethane/polyamide/polyoxalyl diamine copolymers of the general formula (1), where R, X, Y, D, E, F, B, B?, m, n, a, b, c and d have the meanings indicated in claim 1, with the proviso that at least 10% of the RH groups present in structural elements E, F and bound to nitrogen indicate hydrogen, and a method for the production of the membranes (M) and use thereof for separating material mixtures.

Abstract: A filtration and selective fluidic recovery device comprises a housing having an inlet and an outlet. The housing has an opening extending from the inlet to the outlet and an internal support structure maintained in the opening. At least one planar filtration media is carried by the internal support structure where the media separates feedwater received at the inlet into at least a permeate and a concentrate that separately exit at the outlet.

Abstract: Disclosed herein is a process for separating components of a gas mixture using gas-separation copolymer membranes. These membranes use a selective layer made from copolymers of perfluorodioxolane monomers. The resulting membranes have superior selectivity performance for gas pairs of interest while maintaining fast gas permeance compared to membranes prepared using conventional perfluoropolymers, such as Teflon® AF, Hyflon® AD, and Cytop®.

Abstract: Disclosed herein are membranes comprising a substrate, a support layer, and a selective layer. In some embodiments the membrane may further comprise a permeable layer. Methods of forming membranes are also disclosed comprising forming a support layer on a substrate, removing adsorbed species from the support layer, preparing a solution containing inorganic materials of a selective layer, contacting the support layer with the solution, drying the membrane, and exposing the membrane to rapid thermal processing. Also disclosed are methods of fluid purification comprising providing a membrane having a feed side and a permeable side, passing a fluid mixture across the feed side of the membrane, providing a driving force for transmembrane permeation, removing from the permeate side a permeate stream enriched in a purified fluid, and withdrawing from the feed side a fluid that is depleted in a purified fluid.

Abstract: This invention relates to the field of processes for membrane separation and applies in particular to the purification of C2 or C3 olefins. This process makes it possible more particularly to separate propylene from a mixture that contains other C3 hydrocarbons such as propane. The membranes that are used in the process according to this invention are vitreous polymer-based membranes whose pattern contains a bis-phenyl-9,9-fluorene group.

Abstract: A method for filtration of harmful gas effluents from a nuclear power plant including the steps of providing a gas effluent from a nuclear power plant, the effluent including a mixture of gases; filtering the harmful, notably radioactive elements from the gas effluent by membrane separation through at least one membrane, the membrane separation being achieved by sifting, sorption and/or diffusion; storing the filtered harmful elements in storage reservoirs, and discharging the processed gas effluent to the atmosphere.

Abstract: A water-proof air-permeable filter (1) includes: a resin film (2) having formed therein a plurality of through pores (21); and a treated layer (3) having hydrophobicity and oil repellency, and formed on at least one of both surfaces in the thickness direction of the resin film (2) such that the treated layer (3) has openings (31) at positions corresponding to the through pores (21). The through pores (21) each have a predetermined size larger than or equal to 0.01 ?m and smaller than or equal to 10 ?m, and are uniformly distributed such that a density of the through pores falls within specific limits included in a range from 10 to 1×108 pores/mm2.

Abstract: A system and method for passive capture of ammonia in an ammonia-containing liquid effluent. The invention allows for the passage of ammonia through microporous hydrophobic gas-permeable membranes and its capture in a circulated stripping solution with concomitant production of a concentrated non-volatile ammonium salt.

Abstract: The invention relates to a specific apparatus, more particularly a chain of gas separation membrane modules, for separation of gas mixtures into two fractions each of elevated purity.

Abstract: Biogas is converted to a vehicle fuel equivalent to compressed natural gas high in methane in a simple, low cost process involving steps of refrigeration, non-regenerative activated carbon purification and carbon dioxide removal using low-pressure membrane technology.

Abstract: This invention relates to self-cross-linkable and self-cross-linked aromatic polyimide polymers, their membranes and methods for making and using these polymers and membranes. The self-cross-linkable aromatic polyimide polymer described in the present invention comprises both hydroxyl functional groups and carboxylic acid functional groups. The self-cross-linked aromatic polyimide was formed via heating the self-cross-linkable aromatic polyimide polymer at ?300° C. The self-cross-linked aromatic polyimide membranes exhibit high selectivity in separation of mixtures of gases and liquids.

Abstract: A method of making a polybenzoxazole (PBO) membrane from a self-cross-linked aromatic polyimide polymer membrane is provided. These membranes are useful in the separation of gas mixtures and liquid mixtures. The PBO membrane is made by fabricating a self-cross-linkable aromatic polyimide polymer membrane comprising both hydroxyl functional groups and carboxylic acid functional groups; cross-linking the polymer to form a self-cross-linked aromatic polyimide polymer membrane by heating the membrane at 250° to 300° C. under an inert atmosphere; and thermal heating the self-cross-linked aromatic polyimide polymer membrane at a temperature from about 350° to 500° C. under an inert atmosphere to convert the self-cross-linked aromatic polyimide polymer membrane into a PBO membrane. A membrane coating step may be added by coating the selective layer surface of the PBO membrane with a thin layer of high permeability material.

Abstract: Technologies are generally described for perforated graphene monolayers and membranes containing perforated graphene monolayers. An example membrane may include a graphene monolayer having a plurality of discrete pores that may be chemically perforated into the graphene monolayer. The discrete pores may be of substantially uniform pore size. The pore size may be characterized by one or more carbon vacancy defects in the graphene monolayer. The graphene monolayer may have substantially uniform pore sizes throughout. In some examples, the membrane may include a permeable substrate that contacts the graphene monolayer and which may support the graphene monolayer. Such perforated graphene monolayers, and membranes comprising such perforated graphene monolayers may exhibit improved properties compared to conventional polymeric membranes for gas separations, e.g., greater selectivity, greater gas permeation rates, or the like.

Abstract: The present disclosure refers to a method and an apparatus for cryogen-free concentration of a hyperpolarized noble gas in a continuously flowing stream of gas. The method comprises the following steps: providing a mixture of gases containing hyperpolarized noble gas and at least one process gas; passing the prepared gas mixture as a continuously flowing stream of gas through a gas separation device with a semipermeable membrane in order to separate the gases; and concentrating the hyperpolarized noble gas in the gas separation device, in which at least part of the at least one process gas or the hyperpolarized noble gas is separated from the continuously flowing stream of gas by means of the semipermeable membrane. It also provides for the use of a continuous stream of gas with concentrated hyperpolarized noble gas for magnetic resonance spectroscopy or magnetic resonance tomography.

Abstract: A gas separation method includes contacting a membrane filter with gas feed, permeating the gas from the gas feed through the membrane, and producing filtered gas from the filter. The filtered gas is produced from the filter as a result of the membrane removing any hydrocarbons containing six or more carbon atoms to produce a total of 0.001 ppm w/w or less. A gas separation method includes feeding gas into a filter containing a hollow fiber membrane that exhibits the property of resisting degradation due to exposure to hydrocarbons containing six or more carbon atoms. The filter exhibits a pressure drop across the membrane of less than 5 psi. The method includes feeding the filtered gas into a gas separation module that exhibits a susceptibility to degradation from exposure to hydrocarbons containing six or more carbon atoms.

Abstract: The present invention generally relates to high permeability, UV cross-linkable copolyimide polymers and membranes for gas, vapor, and liquid separations, as well as methods for making and using these membranes. The invention provides a process for separating at least one gas from a mixture of gases using the high permeability copolyimide membrane or the UV cross-linked copolyimide membrane, the process comprising: (a) providing a high permeability copolyimide membrane or a UV cross-linked copolyimide membrane which is permeable to said at least one gas; (b) contacting the mixture on one side of the high permeability copolyimide membrane or the UV cross-linked copolyimide membrane to cause said at least one gas to permeate the membrane; and (c) removing from the opposite side of the membrane a permeate gas composition comprising a portion of said at least one gas which permeated said membrane.

Abstract: An aircraft fuel tank flammability reduction method includes contacting a membrane filter with air feed, permeating oxygen and nitrogen from the air feed through the membrane, and producing filtered air from the filter. The filtered air is produced from the filter as a result of the membrane removing any hydrocarbons containing six or more carbon atoms to produce a total of 0.001 ppm w/w or less. An air separation method includes feeding air into a filter containing a hollow fiber membrane that exhibits the property of resisting degradation due to exposure to hydrocarbons containing six or more carbon atoms. The filter exhibits a pressure drop across the membrane of less than 5 psi. The method includes feeding the filtered air into an air separation module containing a hollow fiber membrane that exhibits a susceptibility to degradation from exposure to hydrocarbons containing six or more carbon atoms.

Abstract: The present invention discloses high performance cross-linked polyimide asymmetric flat sheet membranes and a process of using such membranes. The cross-linked polyimide asymmetric flat sheet membranes have shown CO2 permeance higher than 80 GPU and CO2/CH4 selectivity higher than 20 at 50° C. under 6996 kPa of a feed gas with 10% CO2 and 90% CH4 for CO2/CH4 separation.

Abstract: Disclosed herein is a process for separating components of a gas mixture using gas-separation copolymer membranes. These membranes use a selective layer made from copolymers of perfluorodioxolane monomers. The resulting membranes have superior selectivity performance for gas pairs of interest while maintaining fast gas permeance compared to membranes prepared using conventional perfluoropolymers, such as Teflon® AF, Hyflon® AD, and Cytop®.

Abstract: The present invention discloses a new type of high selectivity UV-cross-linked tetrazole group functionalized polymer nanosieve (TZPIM) membranes, their preparation, as well as their use for gas and liquid separations. The UV-cross-linked TZPIM membrane showed more than 50% improvement in CO2/CH4 selectivity and more than 30% improvement in CO2/N2 selectivity compared to the uncross-linked TZPIM membrane for CO2/CH4 and CO2/N2 separations, respectively.

Abstract: A gas separation method includes flowing a gas feed along a feed flow path within a housing directionally from a product end to a feed end of a gas separation membrane. After the feed flow path, the gas feed flows along a membrane flow path defined by the membrane from the feed end to the product end. The feed flow path is counter to the membrane flow path. Heat may be exchanged between the feed flow path and the membrane flow path and increase separation efficiency. Also, heat exchanged may compensate for some temperature drop in the membrane due to enthalpy of gas separation. A gas separation module includes a feed flow path within a housing extending directionally from a product end to a feed end of a membrane. The feed flow path is counter to a membrane flow path defined by the membrane.

Abstract: A vapor particle separator including a temperature controlled chamber for desorbing vapors from the particulates of an exhaust gas and a separation chamber including a micro porous membrane. The micro porous membrane provides an interface between at least one particle passageway and at least one vapor passageway through the separation chamber. The particle passageway extends from an entrance to the separation chamber to a particle exit from the separation chamber. The vapor passageway extends from the micro-porous membrane to a vapor exit from the separation chamber that is separate from the particle exit from the separation chamber.

Abstract: In an embodiment there is provided a fluid separation assembly. The assembly has a hollow fiber bundle with a plurality of hollow fiber membranes. The assembly further has a first tubesheet and a second tubesheet encapsulating respective ends of the hollow fiber bundle, wherein one of the tubesheets has a plurality of radial through openings formed in the tubesheet. The assembly further has a housing surrounding the hollow fiber bundle and the first and second tubesheets, the housing having a feed inlet port, a permeate outlet port, and a non-permeate outlet port. The feed gas, permeate gas, or non-permeate gas are introduced into or removed from the hollow fiber membranes via the plurality of radial through openings formed in the tubesheet, such that the radial through openings of the tubesheet intersect each or substantially each of the hollow fiber membranes.

Abstract: Provided is a gas separation membrane having superior gas permeability, separation selectivity and mechanical properties. A gas separation membrane to separate at least one acid gas from a mix gas, comprising in this order: a first layer that is porous; a second layer that is a separation-active layer containing a compound having a molecular weight of 150,000 or less and capable of interacting with the acid gas; and a third layer having high gas permeability.

Abstract: The present invention generally relates to gas separation membranes and, in particular, to high selectivity fluorinated ethylene-propylene polymer-comprising polymeric blend membranes for gas separations. The polymeric blend membrane comprises a fluorinated ethylene-propylene polymer and a second polymer different from the fluorinated ethylene-propylene polymer. The fluorinated ethylene-propylene polymers in the current invention are copolymers comprising 10 to 99 mol % 2,3,3,3-tetrafluoropropene-based structural units and 1 to 90 mol % vinylidene fluoride-based structural units. The second polymer different from the fluorinated ethylene-propylene polymer is selected from a low cost, easily processable glassy polymer.

Abstract: Disclosed herein is a method for preparing a crosslinked hollow fiber membrane. The method involves spinning a one phase solution comprising a monoesterified polyimide polymer, acetone as a volatile solvent, a spinning solvent, a spinning non-solvent, and optionally an organic and/or inorganic additive, wherein the volatile solvent is present in an amount of greater than 25 wt. % to about 50 wt. %, based on the total weight of the solution.

Abstract: The present invention relates to an asymmetric hollow fiber membrane for gas separation made of a soluble aromatic polyimide, wherein an orientation index is 1.3 or less, a separation coefficient ?(P?O2/P?N2) as a permeation rate ratio of oxygen gas/nitrogen gas at 40° C. is 5.3 or more, and a tensile fracture elongation is 15% or more.