US20180361310A1 - Method and system for purification of natural gas using membranes - Google Patents

Method and system for purification of natural gas using membranes Download PDF

Info

Publication number
US20180361310A1
US20180361310A1 US16/109,123 US201816109123A US2018361310A1 US 20180361310 A1 US20180361310 A1 US 20180361310A1 US 201816109123 A US201816109123 A US 201816109123A US 2018361310 A1 US2018361310 A1 US 2018361310A1
Authority
US
United States
Prior art keywords
gas
separation membrane
membranes
gas separation
membrane stage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US16/109,123
Inventor
Sandeep K. Karode
Yong Ding
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Air Liquide Advanced Technologies US LLC
Original Assignee
Air Liquide Advanced Technologies US LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US14/984,615 external-priority patent/US20170157555A1/en
Application filed by Air Liquide Advanced Technologies US LLC filed Critical Air Liquide Advanced Technologies US LLC
Priority to US16/109,123 priority Critical patent/US20180361310A1/en
Publication of US20180361310A1 publication Critical patent/US20180361310A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • B01D53/225—Multiple stage diffusion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • B01D53/225—Multiple stage diffusion
    • B01D53/226—Multiple stage diffusion in serial connexion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • B01D53/225—Multiple stage diffusion
    • B01D53/227—Multiple stage diffusion in parallel connexion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • B01D53/228—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion characterised by specific membranes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • B01D53/229—Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption)
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/26—Drying gases or vapours
    • B01D53/261—Drying gases or vapours by adsorption
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/26—Drying gases or vapours
    • B01D53/268—Drying gases or vapours by diffusion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/72—Organic compounds not provided for in groups B01D53/48 - B01D53/70, e.g. hydrocarbons
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/08—Hollow fibre membranes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/52—Polyethers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/52—Polyethers
    • B01D71/522—Aromatic polyethers
    • B01D71/5222—Polyetherketone, polyetheretherketone, or polyaryletherketone
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/56—Polyamides, e.g. polyester-amides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/76—Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74
    • B01D71/80—Block polymers
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
    • C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
    • C10L3/10—Working-up natural gas or synthetic natural gas
    • C10L3/101—Removal of contaminants
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
    • C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
    • C10L3/10—Working-up natural gas or synthetic natural gas
    • C10L3/101—Removal of contaminants
    • C10L3/102—Removal of contaminants of acid contaminants
    • C10L3/104—Carbon dioxide
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
    • C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
    • C10L3/10—Working-up natural gas or synthetic natural gas
    • C10L3/101—Removal of contaminants
    • C10L3/106—Removal of contaminants of water
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • B01D2053/221—Devices
    • B01D2053/223—Devices with hollow tubes
    • B01D2053/224—Devices with hollow tubes with hollow fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2256/00—Main component in the product gas stream after treatment
    • B01D2256/24—Hydrocarbons
    • B01D2256/245—Methane
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/50—Carbon oxides
    • B01D2257/504—Carbon dioxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/80—Water
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2311/00—Details relating to membrane separation process operations and control
    • B01D2311/14—Pressure control
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2325/00—Details relating to properties of membranes
    • B01D2325/20—Specific permeability or cut-off range
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L2290/00—Fuel preparation or upgrading, processes or apparatus therefore, comprising specific process steps or apparatus units
    • C10L2290/08—Drying or removing water
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L2290/00—Fuel preparation or upgrading, processes or apparatus therefore, comprising specific process steps or apparatus units
    • C10L2290/54—Specific separation steps for separating fractions, components or impurities during preparation or upgrading of a fuel
    • C10L2290/542—Adsorption of impurities during preparation or upgrading of a fuel
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L2290/00—Fuel preparation or upgrading, processes or apparatus therefore, comprising specific process steps or apparatus units
    • C10L2290/54—Specific separation steps for separating fractions, components or impurities during preparation or upgrading of a fuel
    • C10L2290/548—Membrane- or permeation-treatment for separating fractions, components or impurities during preparation or upgrading of a fuel
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
    • Y02C20/00—Capture or disposal of greenhouse gases
    • Y02C20/40—Capture or disposal of greenhouse gases of CO2

Definitions

  • the present invention relates to the purification of natural gas using gas separation membranes.
  • Water, carbon dioxide, hydrogen sulfide and heavy hydrocarbons are common contaminants for natural gas. During the gas conditioning process, these contaminants are removed so that the natural gas can be used onsite or transported to the pipeline. Depending upon whether emissions of the reject gas from such a gas conditioning process are subject to governmental regulation, the reject stream from the gas conditioning process may be flared. The reject stream may instead be re-injected deep underground, thus producing near zero air emissions.
  • the conditioned gas has to meet certain natural gas pipeline specifications, such as a carbon dioxide concentration below 2% (vol/vol), a C 3+ hydrocarbon dewpoint of no more than ⁇ 4 OF ( ⁇ 20° C.), and an H 2 S concentration of less than 2 ppm.
  • the water concentration should be below 7 lb per million std ft 3 per day (11.2 kg per million std m 3 per day) and sometimes as much as below 5 lb per million std ft 3 per day (8.0 kg per million std m 3 per day).
  • the C 3+ hydrocarbon content of the conditioned gas should be limited so that the BTU/caloric content of the conditioned gas is about 950-1050 Btu (240-265 kcal).
  • the reject stream In the event that the reject stream is re-injected deep underground, it has to be dry in to avoid corrosion of the injection line and the formation of hydrocarbon hydrates.
  • the water content for the reinjected stream has to be below 50 ppm (vol/vol) and sometimes as low as 1 ppm (vol/vol).
  • gas separation membranes are normally utilized for carbon dioxide removal due to their relatively small foot print and light weight and their relatively high energy efficiency.
  • Gas separation membranes can generate conditioned gas with a suitable moisture content.
  • the reject gas is at a relatively lower pressure and it is of course enriched with water.
  • the conventional solution is to first dehydrate the unconditioned feed gas with a molecular sieve and then treat the dehydrated gas with a gas separation membrane purification step.
  • This type of hybrid process can indeed meet the specifications for both the conditioned gas and gas to be re-injected.
  • the relatively high footprint, volume, and mass of the molecular sieve dehydration process are a concern for many natural gas conditioning applications, especially for off shore applications where the footprint, volume, and capacity to withstand massive equipment are at a premium.
  • glassy polymers such as polyimide, polysulfone, polybenzimidazole, etc.
  • selectivity and permeance of the membranes prepared from those materials often quickly decrease once they are used for natural gas conditioning in the presence of C 3+ hydrocarbons. This loss of membrane performance is caused by condensation of the C 3+ hydrocarbons on the membrane surface.
  • the conventional solution for this problem is to use a system including a molecular sieve and carbon trap for removing the C 3+ hydrocarbons upstream of CO2 removal.
  • these pretreatment systems can effectively remove heavy hydrocarbons from the natural gas stream, the cost of the pretreatment sometime can be prohibitive. Indeed, the cost of the pretreatment system can be as high as 50% of the total system cost (pretreatment plus membrane).
  • a method for purification of natural gas including methane, CO2, and C 3+ hydrocarbons comprises the following steps.
  • a feed gas consisting of the natural gas is fed to a first gas separation membrane stage comprising one or more membranes in series or parallel having a selective layer that is selective for C 3+ hydrocarbons over methane.
  • a first permeate stream is withdrawing from the membrane(s) of the first stage that is enriched in C 3+ hydrocarbons in comparison to the feed gas.
  • a first retentate stream is withdrawn from the membrane(s) of the first stage that is deficient in C 3+ hydrocarbons in comparison to the feed gas.
  • the first retentate stream is fed to a second gas separation membrane stage comprising one or more membranes in series or parallel having a selective layer that is selective for CO 2 over methane.
  • a second permeate stream is withdrawn from the membrane(s) of the second stage that is enriched in CO 2 in comparison to the feed gas.
  • a second retentate stream is withdrawn from the membrane(s) of the second stage that is deficient in CO 2 in comparison to the feed gas.
  • a system for purification of natural gas including methane, CO2, and C 3+ hydrocarbons comprising: a source of natural gas; a first gas separation membrane stage comprising one or more membranes in series or parallel fluidly communicating with said source, each membrane of the first gas separation membrane stage having a selective layer that is selective for C 3+ hydrocarbons over methane; and a second gas separation membrane stage comprising one or more membranes fluidly in series or parallel communicating with a retentate outlet(s) of the membranes of the first gas separation membrane stage so as to receive retentate from the first gas separation membrane stage as a feed gas in the second gas separation membrane stage, each membrane of the second gas separation membrane stage having a selective layer that is selective for CO 2 over methane.
  • the method and/or system may include one or more of the following aspects:
  • each Z is the molecular segment of formula (5)
  • 20% of the diamine-derived units are the diamine-derived moiety of either formula (A) or formula (B) and 80% of the diamine-derived units are the diamine-derived moiety of formula (C), where when the diamine-derived moiety of formula (A) is the case, only one of X 1 , X 2 , X 3 , and X 4 is a methyl group and the others are hydrogen, and where when the diamine-derived moiety of formula (B) is the case, only one of X 5 , X 6 , X 7 , and X 8 is a methyl group and the others are hydrogen:
  • the FIGURE is a schematic of the method and system of the invention.
  • Natural gas may be conditioned with gas separation membranes so as to meet desired levels of C3+ hydrocarbons, CO 2 , and optionally H 2 S.
  • the unconditioned gas may optionally be pre-treated with a molecular sieve (or equivalent dehydration technique) upstream of the gas separation membranes in order to dry the unconditioned gas prior to membrane separation.
  • the conditioning process includes feeding the feed gas (i.e., the unconditioned natural gas which has optionally been dehydrated with a molecular sieve or equivalent dehydration technique) to a first gas separation membrane stage.
  • a feed gas of natural gas or conditioned (i.e., dehydrated) natural gas is fed as feed gas stream 1 to one or gas separation membranes of the first gas separation membrane stage 3 in series or parallel.
  • a first stage permeate stream 5 is withdrawn from a permeate side of the first gas separation membrane stage 3 and a first stage retentate stream 7 is withdrawn from the feed gas side of the first gas separation membrane stage 3 .
  • the membranes of the first gas separation membrane stage 3 include a selective layer that is selective for C 3+ hydrocarbons over methane.
  • the first retentate stream 7 is fed to a second gas separation membrane stage 9 containing one or more gas separation membranes in series or in parallel.
  • the membranes of the second gas separation membrane stage 9 include a selective layer that is selective for CO 2 over methane.
  • a second stage permeate stream 11 is withdrawn from a permeate side of the second gas separation membrane stage 9 and a second stage retentate stream 13 is withdrawn from the feed gas side of the second gas separation membrane stage 9 .
  • first and/or second stage permeate streams 5 , 11 may be re-injected deep underground (or in the case of subsea natural gas extraction, deep under the seabed).
  • such a stream may first be dehydrated by any suitable technique for gas dehydration to reach a moisture content of no more than 50 ppm (vol/vol) and as low as 1 ppm (vol/vol).
  • the first and/or second stage permeate stream 5 , 11 may be combusted as a flare gas with or without additional separate flare gases associated with other gases collected in the natural gas extraction and conditioning processes.
  • the separation layer of each of, or at least one of, the gas separation membranes the first gas separation membrane stage 3 may be made of a copolymer or block polymer of tetramethylene oxide, and/or propylene oxide, or ethylene oxide. These types of polymers exhibit modest productivity (i.e., permeance) for methane and preferential permeation of C 3+ hydrocarbons. Due to the modest methane productivity of these polymers in comparison with silicone based polymers, membranes with low methane productivity for methane can be conveniently achieved.
  • the membrane(s) of the first gas separation stage membrane 3 Through selection of a separation layer with modest methane productivity and preferential permeation of C 3+ hydrocarbons, for the membrane(s) of the first gas separation stage membrane 3 , only a relatively low pressure drop across the first gas separation membrane stage 3 (i.e., the difference in pressure between the feed gas 1 and the retentate gas 7 ) may be realized. As a result, there is no need for recompression of the first retentate 7 before it is fed to the gas separation membrane(s) of the second gas separation membrane stage 9 . Typically, the pressure drop between the feed gas 1 and the retentate gas 7 is less than 50 psi (3.45 bar).
  • the pressure drop may be less than 30 psi (2.07 bar) or even less than 20 psi (1.38 bar).
  • the membrane productivity for methane should be below 68 GPU (22.4 mol/m 2 ⁇ sec ⁇ Pa). Often, it is below 34 GPU or even below 20 GPU.
  • Copolymers or block polymers of tetramethylene oxide, and/or propylene oxide, or ethylene oxide may be conveniently synthesized, such as the polyester ether disclosed in U.S. Pat. No. 6,860,920, the polyester ethers of which are incorporated by reference.
  • PE may be one or more of the following structures:
  • copolymers or block polymers of tetramethylene oxide, and/or propylene oxide, or ethylene oxide may be conveniently synthesized, such as polyimide ether disclosed in U.S. Pat. No. 5,776,990, the polyimide ethers of which are incorporated by reference.
  • copolymers can be further obtained by copolymerization of acrylated monomers containing oligomeric propylene oxide, ethyelene oxide, or tetramethyelene oxide.
  • Commercially available copolymers include poly(ether-b-amide) multiblock copolymers available from Arkema under the trade name of PEBAX, and poly(butylene terephthalate) ethylene oxide copolymer available under the trade name of Polyactive.
  • the PEBAX polymers from Arkema include PEBAX 7233, PEBAX 7033, PEBAX 6333, PEBAX 2533, PEBAX 3533, PEBAX 1205, PEBAX 3000, PEBAX 1657, or PEBAX 1074.
  • PEBAX 1657 exhibits a methane permeability of 5.12 Barrer. H. Rabiee, et al., J. Membrane Sci. vol. 476, pp. 286-302 (2015).
  • PDMS exhibits a methane permeability of 800 Barrer. Stern, et al., J. Appl. Polym. Sci., Vol. 38, 2131(1989).
  • the PEBAX polymers have the following general chemical structure:
  • PA is an aliphatic polyamide “hard” block (nylon 6 [PA6] or nylon 12 [PA12], and PE denotes a polyether “soft” block, either poly(ethylene oxide) [PEO] or poly(tetramethylene oxide) [PTMEO].
  • PolyActive multiblock copolymers have the following general chemical structure:
  • the gas separation membrane(s) of the first gas separation membrane stage 3 may have any configuration known in the field of gas separation, typically they are formed as a flat film or as a plurality of hollow fibers.
  • the separation layer is supported by a support layer where the separation layer performs the desired separation while the support layer provides mechanical strength.
  • the separation layer is configured as a sheath surrounding a core made of the support layer.
  • the support layer may be any porous substrate known in the field of gas separation membranes and includes but is not limited to, polyimides, polysulfones, and polyether ether ketones.
  • Typical hollow fiber membrane supports are PEEK porous substrate fibers commercially available from Air Liquide Advanced Separations, a unit of Air Liquide Advanced Technologies, US.
  • the gas separation membrane(s) of the first gas separation membrane stage 3 includes membranes commercially available from Medal under the trade name PEEK-SEP.
  • the separation layer of the membrane(s) of the second gas separation membrane stage 9 may be made of any polymer or copolymer known in the field of gas separation membranes that is selective for CO 2 over methane.
  • the separation layer of the membranes of the second gas separation membrane stage 9 is made of cellulose acetate, a polysulfone, or a polyimide.
  • the polyimide essentially consists of repeating units of dianhydride-derived units of formula (I) and diamine-derived units.
  • Each R is a molecular segment independently selected from the group consisting of formula (1), formula (2), formula (3), and formula (4):
  • Each Z is a molecular segment independently selected from the group consisting of formula (5), formula (6), formula (7), formula (8), and formula (9).
  • Each diamine-derived unit is a diamine-derived moiety independently selected from the group consisting of formula (A), formula (B), formula (C), formula (D), formula (E), formula (F), formula (G), and formula (H):
  • Each X, X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , and X 8 is independently selected from the group consisting of hydrogen, an aromatic group, and a straight or branched C 1 to C 6 alkyl group.
  • Each R a is a straight or branched C 1 to C 6 alkyl group having either a terminal hydroxyl group, a terminal carboxylic acid group, or a terminal carbon to carbon double bond.
  • Each Z′ is a molecular segment selected from the group consisting of formula (a), formula (b), formula (c), and formula (d):
  • Each Z′′ is a moiety selected from the group consisting of formula (U) and formula (V):
  • Each X 9 is selected from the group consisting of hydrogen, a straight or branched alkyl group having 1 to 6 carbon atoms, and a straight or branched pefluoroalkyl group having 1 to 6 carbon atoms.
  • R is the molecular segment of formula (3)
  • Z is the molecular segment of formula (5)
  • 20% of the diamine-derived units are the diamine-derived moiety of either formula (A) or formula (B)
  • 80% of the diamine-derived units is the diamine-derived moiety of formula (C).
  • the diamine-derived moiety of formula (A) is the case, only one of X 1 , X 2 , X 3 , and X 4 is a methyl group and the others are hydrogen.
  • the diamine-derived moiety of formula (B) is the case, only one of X 5 , X 6 , X 7 , and X 8 is a methyl group and the others are hydrogen.
  • P84® polyimide This particular polymide is sold by Evonik Fibres GmbH under the trademark P84® (hereinafter the P84® polyimide).
  • P84 has a CO 2 solubility at 35° C. and 10 bar pressure of >0.07 [cm 3 (STP)/cm 3 (polymer)-cmHg] and a glass transition temperature of 316° C.
  • the gas separation membrane(s) of the second gas separation membrane stage 9 may have any configuration known in the field of gas separation, typically they are formed as a flat film or as a plurality of hollow fibers.
  • the separation layer of each of, or at least one of, the gas separation membranes of the second gas separation membrane stage 9 is supported by a support layer where the separation layer performs the desired separation while the support layer provides mechanical strength.
  • the separation layer is configured as a sheath surrounding a core made of the support layer.
  • the support layer may be any porous substrate known in the field of gas separation membranes. Suitable membranes for the second gas separation membrane stage are commercially available from Air Liquide Advanced Separations, a unit of Air Liquide Advanced Technologies, US.
  • a computer simulation was performed in order to demonstrate the process of the invention.
  • a feed gas with the following gas composition was fed into a composite membrane including a PEBAX separation layer and a PEEK support layer with methane permeance of 15 GPU at 1000 psia and 30 C.
  • the membrane cartridge exhibits a pressure drop of only 37 psi.
  • a computer simulation was also attempted for the purpose of demonstrating a process that is not of the invention.
  • a silicone based membrane with methane permeance of 120 GPU is used.
  • the same feed condition as in the Example was used for the calculation.
  • the pressure drop is so significant that the calculation did not converge.
  • “Comprising” in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing i.e. anything else may be additionally included and remain within the scope of “comprising.” “Comprising” is defined herein as necessarily encompassing the more limited transitional terms “consisting essentially of” and “consisting of”; “comprising” may therefore be replaced by “consisting essentially of” or “consisting of” and remain within the expressly defined scope of “comprising”.
  • Providing in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.
  • Optional or optionally means that the subsequently described event or circumstances may or may not occur.
  • the description includes instances where the event or circumstance occurs and instances where it does not occur.
  • Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.

Abstract

Natural gas may be purified by removing C3+ hydrocarbons and CO2 in respective first and second gas separation membrane stages to yield conditioned gas lower in C3+ hydrocarbons and CO2 in comparison to the un-conditioned natural gas.

Description

    CROSS-REFERENCE TO RELATED APPLICATIONS
  • This application is a Continuation of U.S. patent application Ser. No. 15/367,477, filed Dec. 2, 2016, which is a Continuation-In-Part of U.S. Non-Provisional patent application Ser. No. 14/984,615, filed Dec. 30, 2015 which claims the benefit of priority under 35 U.S.C. § 119 (e) to U.S. Provisional Patent Application No. 62/262,652, filed Dec. 3, 2015, the entire contents of each of which are incorporated herein by reference.
    • BACKGROUND Field of the Invention
  • The present invention relates to the purification of natural gas using gas separation membranes.
    • Related Art
  • Water, carbon dioxide, hydrogen sulfide and heavy hydrocarbons are common contaminants for natural gas. During the gas conditioning process, these contaminants are removed so that the natural gas can be used onsite or transported to the pipeline. Depending upon whether emissions of the reject gas from such a gas conditioning process are subject to governmental regulation, the reject stream from the gas conditioning process may be flared. The reject stream may instead be re-injected deep underground, thus producing near zero air emissions.
  • The conditioned gas has to meet certain natural gas pipeline specifications, such as a carbon dioxide concentration below 2% (vol/vol), a C3+ hydrocarbon dewpoint of no more than −4 OF (−20° C.), and an H2S concentration of less than 2 ppm. The water concentration should be below 7 lb per million std ft3 per day (11.2 kg per million std m3 per day) and sometimes as much as below 5 lb per million std ft3 per day (8.0 kg per million std m3 per day). Additionally, the C3+ hydrocarbon content of the conditioned gas should be limited so that the BTU/caloric content of the conditioned gas is about 950-1050 Btu (240-265 kcal).
  • In the event that the reject stream is re-injected deep underground, it has to be dry in to avoid corrosion of the injection line and the formation of hydrocarbon hydrates. The water content for the reinjected stream has to be below 50 ppm (vol/vol) and sometimes as low as 1 ppm (vol/vol).
  • In the natural gas conditioning process, gas separation membranes are normally utilized for carbon dioxide removal due to their relatively small foot print and light weight and their relatively high energy efficiency. Gas separation membranes can generate conditioned gas with a suitable moisture content. However, the reject gas is at a relatively lower pressure and it is of course enriched with water. The conventional solution is to first dehydrate the unconditioned feed gas with a molecular sieve and then treat the dehydrated gas with a gas separation membrane purification step. This type of hybrid process can indeed meet the specifications for both the conditioned gas and gas to be re-injected. However, the relatively high footprint, volume, and mass of the molecular sieve dehydration process are a concern for many natural gas conditioning applications, especially for off shore applications where the footprint, volume, and capacity to withstand massive equipment are at a premium.
  • It is well documented that glassy polymers, such as polyimide, polysulfone, polybenzimidazole, etc., exhibit exceptional high intrinsic CO2/methane selectivity. However, the selectivity and permeance of the membranes prepared from those materials often quickly decrease once they are used for natural gas conditioning in the presence of C3+ hydrocarbons. This loss of membrane performance is caused by condensation of the C3+ hydrocarbons on the membrane surface. The conventional solution for this problem is to use a system including a molecular sieve and carbon trap for removing the C3+ hydrocarbons upstream of CO2 removal. Although these pretreatment systems can effectively remove heavy hydrocarbons from the natural gas stream, the cost of the pretreatment sometime can be prohibitive. Indeed, the cost of the pretreatment system can be as high as 50% of the total system cost (pretreatment plus membrane).
    • SUMMARY
  • There is disclosed a method for purification of natural gas including methane, CO2, and C3+ hydrocarbons. The method comprises the following steps. A feed gas consisting of the natural gas is fed to a first gas separation membrane stage comprising one or more membranes in series or parallel having a selective layer that is selective for C3+ hydrocarbons over methane. A first permeate stream is withdrawing from the membrane(s) of the first stage that is enriched in C3+ hydrocarbons in comparison to the feed gas. A first retentate stream is withdrawn from the membrane(s) of the first stage that is deficient in C3+ hydrocarbons in comparison to the feed gas. The first retentate stream is fed to a second gas separation membrane stage comprising one or more membranes in series or parallel having a selective layer that is selective for CO2 over methane. A second permeate stream is withdrawn from the membrane(s) of the second stage that is enriched in CO2 in comparison to the feed gas. A second retentate stream is withdrawn from the membrane(s) of the second stage that is deficient in CO2 in comparison to the feed gas.
  • There is also disclosed a system for purification of natural gas including methane, CO2, and C3+ hydrocarbons, comprising: a source of natural gas; a first gas separation membrane stage comprising one or more membranes in series or parallel fluidly communicating with said source, each membrane of the first gas separation membrane stage having a selective layer that is selective for C3+ hydrocarbons over methane; and a second gas separation membrane stage comprising one or more membranes fluidly in series or parallel communicating with a retentate outlet(s) of the membranes of the first gas separation membrane stage so as to receive retentate from the first gas separation membrane stage as a feed gas in the second gas separation membrane stage, each membrane of the second gas separation membrane stage having a selective layer that is selective for CO2 over methane.
  • The method and/or system may include one or more of the following aspects:
      • water is removed from the feed gas prior to feeding the feed gas to the first gas separation membrane stage.
      • said water removal comprises feeding the feed gas to a molecular sieve adapted and configured to remove water from fluids.
      • said water removal comprises feeding the feed gas to a dehydration gas separation membrane.
      • the first and/or the second permeate streams is combusted as a flare gas.
      • the feed gas is obtained from natural gas extracted from a subterranean or subsea geological formation and said step further comprises injecting the first and/or second stage permeate streams into the geological formation.
      • the first and/or second permeate streams are dehydrated prior to injection into the geological formation such that a water content in the first and/or second permeate stream injected into the geological formation is no more than 50 ppm (vol/vol).
      • each of the one or membranes of the first gas separation membrane stage have a separation layer made of a copolymer or block polymer of tetramethylene oxide, and/or propylene oxide, or ethylene oxide.
      • a pressure drop between a pressure of the feed gas and a pressure of the retentate gas is less than 50 psi (3.45 bar).
      • a pressure drop between a pressure of the feed gas and a pressure of the retentate gas is less than 30 psi (2.07 bar).
      • a pressure drop between a pressure of the feed gas and a pressure of the retentate gas is less than less than 20 psi (1.38 bar).
      • the one or more membranes of the first gas separation membrane stage have a methane permeance of less than 68 gas permeation units (22.4 mol/m2·sec·Pa).
      • the one or more membranes of the first gas separation membrane stage have a methane permeance of less than 34 GPU.
      • the one or more membranes of the first gas separation membrane stage have a methane permeance of less than 20 GPU.
      • the one or membranes of the first gas separation membrane stage have a separation layer made of a copolymer or block polymer of the formula:
  • Figure US20180361310A1-20181220-C00001
      • where PA is an aliphatic polyamide having 6 or 12 carbon atoms and PE is either poly(ethylene oxide) poly(tetramethylene oxide).
      • the one or membranes of the first gas separation membrane stage have a separation layer made of repeating units of the following monomers:
  • Figure US20180361310A1-20181220-C00002
      • the separation layer of the membranes of the second gas separation membrane stage is a polymer or copolymer selected from cellulose acetate, polysulfones, and polyimides.
      • the separation layer of the membranes of the second gas separation membrane stage is a polyimide essentially consisting of repeating units of dianhydride-derived units of formula (I) and diamine-derived units
  • Figure US20180361310A1-20181220-C00003
      • where each R is the molecular segment of formula (3)
  • Figure US20180361310A1-20181220-C00004
  • each Z is the molecular segment of formula (5),
  • Figure US20180361310A1-20181220-C00005
  • 20% of the diamine-derived units are the diamine-derived moiety of either formula (A) or formula (B) and 80% of the diamine-derived units are the diamine-derived moiety of formula (C), where when the diamine-derived moiety of formula (A) is the case, only one of X1, X2, X3, and X4 is a methyl group and the others are hydrogen, and where when the diamine-derived moiety of formula (B) is the case, only one of X5, X6, X7, and X8 is a methyl group and the others are hydrogen:
  • Figure US20180361310A1-20181220-C00006
      • each of the one or more membranes of the first gas separation membrane stage are formed as flat films or as a plurality of hollow fibers.
      • each of the one or more membranes of the first gas separation membrane stage has a separation layer that is supported by a support layer.
      • each of the support layers is made of a polyimide, polysulfone, or polyether ether ketone.
      • each of the support layers is porous and is made of polyether ether ketone.
      • each of the membranes of the second gas separation membrane stage is made of cellulose acetate, a polysulfone, or a polyimide.
    BRIEF DESCRIPTION OF THE DRAWINGS
  • The FIGURE is a schematic of the method and system of the invention.
    •  DESCRIPTION OF PREFERRED EMBODIMENTS
  • Natural gas may be conditioned with gas separation membranes so as to meet desired levels of C3+ hydrocarbons, CO2, and optionally H2S. The unconditioned gas may optionally be pre-treated with a molecular sieve (or equivalent dehydration technique) upstream of the gas separation membranes in order to dry the unconditioned gas prior to membrane separation. The conditioning process includes feeding the feed gas (i.e., the unconditioned natural gas which has optionally been dehydrated with a molecular sieve or equivalent dehydration technique) to a first gas separation membrane stage.
  • A feed gas of natural gas or conditioned (i.e., dehydrated) natural gas is fed as feed gas stream 1 to one or gas separation membranes of the first gas separation membrane stage 3 in series or parallel. A first stage permeate stream 5 is withdrawn from a permeate side of the first gas separation membrane stage 3 and a first stage retentate stream 7 is withdrawn from the feed gas side of the first gas separation membrane stage 3. The membranes of the first gas separation membrane stage 3 include a selective layer that is selective for C3+ hydrocarbons over methane. By “selective for C3+ hydrocarbons over methane”, we mean that, as a whole, the C3+ hydrocarbons become enriched in the permeate stream 5 in comparison to the feed gas 1 and the C3+ hydrocarbons dewpoint of the retentate is lowered. Those skilled in the art of gas separation membrane technology will recognize that the C3+ hydrocarbons dewpoint is the temperature at which cooling of the retentate 7 will cause condensation of C3+ hydrocarbons.
  • The first retentate stream 7 is fed to a second gas separation membrane stage 9 containing one or more gas separation membranes in series or in parallel. The membranes of the second gas separation membrane stage 9 include a selective layer that is selective for CO2 over methane. A second stage permeate stream 11 is withdrawn from a permeate side of the second gas separation membrane stage 9 and a second stage retentate stream 13 is withdrawn from the feed gas side of the second gas separation membrane stage 9.
  • If flaring of the first and/or second stage permeate streams 5, 11 is prohibited due to environmental regulations or if it is economical or otherwise desirable to not flare such streams, it may be re-injected deep underground (or in the case of subsea natural gas extraction, deep under the seabed). In the event that the first and/or second stage permeate stream 5, 11 contains too high of a moisture content to allow re-injection as is, such a stream may first be dehydrated by any suitable technique for gas dehydration to reach a moisture content of no more than 50 ppm (vol/vol) and as low as 1 ppm (vol/vol).
  • If flaring is otherwise allowable and desired instead of re-injection, the first and/or second stage permeate stream 5, 11 may be combusted as a flare gas with or without additional separate flare gases associated with other gases collected in the natural gas extraction and conditioning processes.
  • The separation layer of each of, or at least one of, the gas separation membranes the first gas separation membrane stage 3 may be made of a copolymer or block polymer of tetramethylene oxide, and/or propylene oxide, or ethylene oxide. These types of polymers exhibit modest productivity (i.e., permeance) for methane and preferential permeation of C3+ hydrocarbons. Due to the modest methane productivity of these polymers in comparison with silicone based polymers, membranes with low methane productivity for methane can be conveniently achieved. Through selection of a separation layer with modest methane productivity and preferential permeation of C3+ hydrocarbons, for the membrane(s) of the first gas separation stage membrane 3, only a relatively low pressure drop across the first gas separation membrane stage 3 (i.e., the difference in pressure between the feed gas 1 and the retentate gas 7) may be realized. As a result, there is no need for recompression of the first retentate 7 before it is fed to the gas separation membrane(s) of the second gas separation membrane stage 9. Typically, the pressure drop between the feed gas 1 and the retentate gas 7 is less than 50 psi (3.45 bar). The pressure drop may be less than 30 psi (2.07 bar) or even less than 20 psi (1.38 bar). Typically, the membrane productivity for methane should be below 68 GPU (22.4 mol/m2·sec·Pa). Often, it is below 34 GPU or even below 20 GPU.
  • Copolymers or block polymers of tetramethylene oxide, and/or propylene oxide, or ethylene oxide may be conveniently synthesized, such as the polyester ether disclosed in U.S. Pat. No. 6,860,920, the polyester ethers of which are incorporated by reference.
  • Figure US20180361310A1-20181220-C00007
  • where PE may be one or more of the following structures:
  • Figure US20180361310A1-20181220-C00008
  • Other copolymers or block polymers of tetramethylene oxide, and/or propylene oxide, or ethylene oxide may be conveniently synthesized, such as polyimide ether disclosed in U.S. Pat. No. 5,776,990, the polyimide ethers of which are incorporated by reference.
  • The copolymers can be further obtained by copolymerization of acrylated monomers containing oligomeric propylene oxide, ethyelene oxide, or tetramethyelene oxide. Commercially available copolymers include poly(ether-b-amide) multiblock copolymers available from Arkema under the trade name of PEBAX, and poly(butylene terephthalate) ethylene oxide copolymer available under the trade name of Polyactive.
  • Typically, the PEBAX polymers from Arkema include PEBAX 7233, PEBAX 7033, PEBAX 6333, PEBAX 2533, PEBAX 3533, PEBAX 1205, PEBAX 3000, PEBAX 1657, or PEBAX 1074. PEBAX 1657 exhibits a methane permeability of 5.12 Barrer. H. Rabiee, et al., J. Membrane Sci. vol. 476, pp. 286-302 (2015). In contrast, PDMS exhibits a methane permeability of 800 Barrer. Stern, et al., J. Appl. Polym. Sci., Vol. 38, 2131(1989). The PEBAX polymers have the following general chemical structure:
  • Figure US20180361310A1-20181220-C00009
  • Where PA is an aliphatic polyamide “hard” block (nylon 6 [PA6] or nylon 12 [PA12], and PE denotes a polyether “soft” block, either poly(ethylene oxide) [PEO] or poly(tetramethylene oxide) [PTMEO].
  • Commercial available PolyActive multiblock copolymers have the following general chemical structure:
  • Figure US20180361310A1-20181220-C00010
  • While the gas separation membrane(s) of the first gas separation membrane stage 3 may have any configuration known in the field of gas separation, typically they are formed as a flat film or as a plurality of hollow fibers. In one embodiment, the separation layer is supported by a support layer where the separation layer performs the desired separation while the support layer provides mechanical strength. In the context of hollow fibers, the separation layer is configured as a sheath surrounding a core made of the support layer. Regardless of the configuration of the membrane, the support layer may be any porous substrate known in the field of gas separation membranes and includes but is not limited to, polyimides, polysulfones, and polyether ether ketones. Typical hollow fiber membrane supports are PEEK porous substrate fibers commercially available from Air Liquide Advanced Separations, a unit of Air Liquide Advanced Technologies, US.
  • Typically, the gas separation membrane(s) of the first gas separation membrane stage 3 includes membranes commercially available from Medal under the trade name PEEK-SEP.
  • The separation layer of the membrane(s) of the second gas separation membrane stage 9 may be made of any polymer or copolymer known in the field of gas separation membranes that is selective for CO2 over methane. Typically, the separation layer of the membranes of the second gas separation membrane stage 9 is made of cellulose acetate, a polysulfone, or a polyimide. Typically, the polyimide essentially consists of repeating units of dianhydride-derived units of formula (I) and diamine-derived units.
  • Figure US20180361310A1-20181220-C00011
  • Each R is a molecular segment independently selected from the group consisting of formula (1), formula (2), formula (3), and formula (4):
  • Figure US20180361310A1-20181220-C00012
  • Each Z is a molecular segment independently selected from the group consisting of formula (5), formula (6), formula (7), formula (8), and formula (9).
  • Figure US20180361310A1-20181220-C00013
  • Each diamine-derived unit is a diamine-derived moiety independently selected from the group consisting of formula (A), formula (B), formula (C), formula (D), formula (E), formula (F), formula (G), and formula (H):
  • Figure US20180361310A1-20181220-C00014
  • Each X, X1, X2, X3, X4, X5, X6, X7, and X8 is independently selected from the group consisting of hydrogen, an aromatic group, and a straight or branched C1 to C6 alkyl group. Each Ra is a straight or branched C1 to C6 alkyl group having either a terminal hydroxyl group, a terminal carboxylic acid group, or a terminal carbon to carbon double bond. Each Z′ is a molecular segment selected from the group consisting of formula (a), formula (b), formula (c), and formula (d):
  • Figure US20180361310A1-20181220-C00015
  • Each Z″ is a moiety selected from the group consisting of formula (U) and formula (V):
  • Figure US20180361310A1-20181220-C00016
  • Each X9 is selected from the group consisting of hydrogen, a straight or branched alkyl group having 1 to 6 carbon atoms, and a straight or branched pefluoroalkyl group having 1 to 6 carbon atoms.
  • In one particular embodiment of the polyimide, R is the molecular segment of formula (3), Z is the molecular segment of formula (5), 20% of the diamine-derived units are the diamine-derived moiety of either formula (A) or formula (B) and 80% of the diamine-derived units is the diamine-derived moiety of formula (C). When the diamine-derived moiety of formula (A) is the case, only one of X1, X2, X3, and X4 is a methyl group and the others are hydrogen. When the diamine-derived moiety of formula (B) is the case, only one of X5, X6, X7, and X8 is a methyl group and the others are hydrogen. This particular polymide is sold by Evonik Fibres GmbH under the trademark P84® (hereinafter the P84® polyimide). P84 has a CO2 solubility at 35° C. and 10 bar pressure of >0.07 [cm3(STP)/cm3(polymer)-cmHg] and a glass transition temperature of 316° C.
  • Figure US20180361310A1-20181220-C00017
  • While the gas separation membrane(s) of the second gas separation membrane stage 9 may have any configuration known in the field of gas separation, typically they are formed as a flat film or as a plurality of hollow fibers. In one embodiment, the separation layer of each of, or at least one of, the gas separation membranes of the second gas separation membrane stage 9 is supported by a support layer where the separation layer performs the desired separation while the support layer provides mechanical strength. In the context of hollow fibers, the separation layer is configured as a sheath surrounding a core made of the support layer. Regardless of the configuration of the membrane, the support layer may be any porous substrate known in the field of gas separation membranes. Suitable membranes for the second gas separation membrane stage are commercially available from Air Liquide Advanced Separations, a unit of Air Liquide Advanced Technologies, US.
    • PROPHETIC EXAMPLES Example
  • A computer simulation was performed in order to demonstrate the process of the invention. In the simulation, a feed gas with the following gas composition was fed into a composite membrane including a PEBAX separation layer and a PEEK support layer with methane permeance of 15 GPU at 1000 psia and 30 C. The membrane cartridge exhibits a pressure drop of only 37 psi.
  • FEED RAFF PERM
    F,MMSCFD(60F) 1.257 1 0.2567
    PRESS, psia 1000 963.88 26.3
    CONCENTRATIONS, mol %
    WATER 0.1991 0.0043 0.9582
    CARBON_DIOXIDE 44.9649 37.0415 75.8347
    NITROGEN 0.4978 0.6132 0.0486
    ETHANE 5.5858 5.9936 3.9967
    PROPANE 3.6243 3.7977 2.9486
    N-BUTANE 1.613 1.4971 2.0646
    N-PENTANE 0.4978 0.3258 1.1681
    N-HEXANE 0.2091 0.1007 0.6313
    METHANE 42.8082 50.6262 12.3492
    • Comparative Example 2
  • A computer simulation was also attempted for the purpose of demonstrating a process that is not of the invention. A silicone based membrane with methane permeance of 120 GPU is used. The same feed condition as in the Example was used for the calculation. The pressure drop is so significant that the calculation did not converge.
  • While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.
  • The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.
  • “Comprising” in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing i.e. anything else may be additionally included and remain within the scope of “comprising.” “Comprising” is defined herein as necessarily encompassing the more limited transitional terms “consisting essentially of” and “consisting of”; “comprising” may therefore be replaced by “consisting essentially of” or “consisting of” and remain within the expressly defined scope of “comprising”.
  • “Providing” in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.
  • Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.
  • Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.
  • All references identified herein are each hereby incorporated by reference into this application in their entireties, as well as for the specific information for which each is cited.

Claims (39)

What is claimed is:
1. A method for purification of natural gas including methane, CO2, and C3+ hydrocarbons, comprising the steps of:
feeding a feed gas consisting of the natural gas to a first gas separation membrane stage comprising one or more membranes in series or parallel having a selective layer that is selective for C3+ hydrocarbons over methane;
withdrawing a first permeate stream from the membrane(s) of the first stage that is enriched in C3+ hydrocarbons in comparison to the feed gas;
withdrawing a first retentate stream from the membrane(s) of the first stage that is deficient in C3+ hydrocarbons in comparison to the feed gas;
feeding the first retentate stream to a second gas separation membrane stage comprising one or more membranes in series or parallel having a selective layer that is selective for CO2 over methane;
withdrawing a second permeate stream from the membrane(s) of the second stage that is enriched in CO2 in comparison to the feed gas; and
withdrawing a first retentate stream from the membrane(s) of the first stage that is deficient in CO2 in comparison to the feed gas.
2. The method of claim 1, further comprising removing water from the feed gas prior to feeding the feed gas to the first gas separation membrane stage.
3. The method of claim 2, wherein said step of removing water comprises feeding the feed gas to a molecular sieve adapted and configured to remove water from fluids.
4. The method of claim 2, wherein said step of removing water comprises feeding the feed gas to a dehydration gas separation membrane.
5. The method of claim 1, further comprising the step of combusting the first and/or the second permeate streams as a flare gas.
6. The method of claim 1, wherein the feed gas is obtained from natural gas extracted from a subterranean or subsea geological formation and said step further comprises injecting the first and/or second stage permeate streams into the geological formation.
7. The method of claim 6, further comprising dehydrating the first and/or second permeate streams prior to injection into the geological formation such that a water content in the first and/or second permeate stream injected into the geological formation is no more than 50 ppm (vol/vol).
8. The method of claim 1, wherein the one or membranes of the first gas separation membrane stage have a separation layer made of a copolymer or block polymer of tetramethylene oxide, and/or propylene oxide, or ethylene oxide.
9. The method of claim 8, wherein a pressure drop between a pressure of the feed gas and a pressure of the retentate gas is less than 50 psi (3.45 bar).
10. The method of claim 8, wherein a pressure drop between a pressure of the feed gas and a pressure of the retentate gas is less than 30 psi (2.07 bar).
11. The method of claim 8, wherein a pressure drop between a pressure of the feed gas and a pressure of the retentate gas is less than less than 20 psi (1.38 bar).
12. The method of claim 8, wherein the one or more membranes of the first gas separation membrane stage have a methane permeance of less than 68 gas permeation units (22.4 mol/m2·sec·Pa).
13. The method of claim 8, wherein the one or more membranes of the first gas separation membrane stage have a methane permeance of less than 34 GPU.
14. The method of claim 8, wherein the one or more membranes of the first gas separation membrane stage have a methane permeance of less than 20 GPU.
15. The method of 8, wherein the one or membranes of the first gas separation membrane stage have a separation layer made of a copolymer or block polymer of the formula:
Figure US20180361310A1-20181220-C00018
where PA is an aliphatic polyamide having 6 or 12 carbon atoms and PE is either poly(ethylene oxide) poly(tetramethylene oxide).
16. The method of claim 8, wherein one or membranes of the first gas separation membrane stage have a separation layer made of repeating units of the following monomers:
Figure US20180361310A1-20181220-C00019
17. The method of claim 8, wherein the one or more membranes of the first gas separation membrane stage are formed as flat films or as a plurality of hollow fibers.
18. The method of claim 8, wherein each of the one or more membranes of the first gas separation membrane stage has a separation layer that is supported by a support layer.
19. The method of claim 18, wherein each of the support layers is made of a polyimide, polysulfone, or polyether ether ketone.
20. The method of claim 19, wherein each of the support layers is porous and is made of polyether ether ketone.
21. The method of claim 1, wherein each of the membranes of the second gas separation membrane stage is made of cellulose acetate, a polysulfone, or a polyimide.
22. A system for purification of natural gas including methane, CO2, and C3+ hydrocarbons, comprising:
a source of natural gas;
a first gas separation membrane stage comprising one or more membranes fluidly in series or parallel communicating with said source, each membrane of the first gas separation membrane stage having a selective layer that is selective for C3+ hydrocarbons over methane; and
a second gas separation membrane stage comprising one or more membranes in series or parallel fluidly communicating with a retentate outlet(s) of the membranes of the first gas separation membrane stage so as to receive retentate from the first gas separation membrane stage as a feed gas in the second gas separation membrane stage, each membrane of the second gas separation membrane stage having a selective layer that is selective for CO2 over methane.
23. The system of claim 22, further comprising a water removal apparatus adapted and configured to remove water from the feed gas prior to feeding the feed gas to the first gas separation membrane stage.
24. The system of claim 23, wherein said water removal apparatus is a molecular sieve adapted and configured to remove water from fluids.
25. The system of claim 23, wherein said water removal apparatus is a dehydration gas separation membrane.
26. The system of claim 22, wherein each of the one or membranes of the first gas separation membrane stage has a separation layer made of a copolymer or block polymer of tetramethylene oxide, and/or propylene oxide, or ethylene oxide.
27. The system of claim 26, wherein each of the one or membranes of the first gas separation membrane stage exhibits a pressure drop between a pressure of the feed gas and a pressure of the retentate gas is less than 50 psi (3.45 bar).
28. The system of claim 26, wherein each of the one or membranes of the first gas separation membrane stage exhibits a pressure drop between a pressure of the feed gas and a pressure of the retentate gas is less than 30 psi (2.07 bar).
29. The system of claim 26, wherein each of the one or membranes of the first gas separation membrane stage exhibits a pressure drop between a pressure of the feed gas and a pressure of the retentate gas is less than less than 20 psi (1.38 bar).
30. The system of claim 26, wherein each of the one or membranes of the first gas separation membrane stage exhibits a methane permeance of less than 68 gas permeation units (22.4 mol/m2·sec·Pa).
31. The system of claim 26, wherein each of the one or membranes of the first gas separation membrane stage exhibits a methane permeance of less than 34 GPU.
32. The system of claim 26, wherein each of the one or membranes of the first gas separation membrane stage exhibits a methane permeance of less than 20 GPU.
33. The system of claim 26, wherein the one or membranes of the first gas separation membrane stage have a separation layer made of a copolymer or block polymer of the formula:
Figure US20180361310A1-20181220-C00020
where PA is an aliphatic polyamide having 6 or 12 carbon atoms and PE is either poly(ethylene oxide) poly(tetramethylene oxide).
34. The system of claim 26, wherein one or membranes of the first gas separation membrane stage have a separation layer made of repeating units of the following monomers:
Figure US20180361310A1-20181220-C00021
35. The system of claim 26, wherein the one or more membranes of the first gas separation membrane stage are formed as flat films or as a plurality of hollow fibers.
36. The system of claim 26, wherein each of the one or more membranes of the first gas separation membrane stage has a separation layer that is supported by a support layer.
37. The system of claim 36, wherein each of the support layers is made of a polyimide, polysulfone, or polyether ether ketone.
38. The system of claim 37, wherein each of the support layers is porous and is made of polyether ether ketone.
39. The system of claim 22, wherein each of the membranes of the second gas separation membrane stage is made of cellulose acetate, a polysulfone, or a polyimide.
US16/109,123 2015-12-03 2018-08-22 Method and system for purification of natural gas using membranes Abandoned US20180361310A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US16/109,123 US20180361310A1 (en) 2015-12-03 2018-08-22 Method and system for purification of natural gas using membranes

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US201562262652P 2015-12-03 2015-12-03
US14/984,615 US20170157555A1 (en) 2015-12-03 2015-12-30 Method and system for purification of natural gas using membranes
US15/367,477 US10143961B2 (en) 2015-12-03 2016-12-02 Method and system for purification of natural gas using membranes
US16/109,123 US20180361310A1 (en) 2015-12-03 2018-08-22 Method and system for purification of natural gas using membranes

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US15/367,477 Continuation US10143961B2 (en) 2015-12-03 2016-12-02 Method and system for purification of natural gas using membranes

Publications (1)

Publication Number Publication Date
US20180361310A1 true US20180361310A1 (en) 2018-12-20

Family

ID=58799506

Family Applications (2)

Application Number Title Priority Date Filing Date
US15/367,477 Active US10143961B2 (en) 2015-12-03 2016-12-02 Method and system for purification of natural gas using membranes
US16/109,123 Abandoned US20180361310A1 (en) 2015-12-03 2018-08-22 Method and system for purification of natural gas using membranes

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US15/367,477 Active US10143961B2 (en) 2015-12-03 2016-12-02 Method and system for purification of natural gas using membranes

Country Status (1)

Country Link
US (2) US10143961B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110425414A (en) * 2019-07-05 2019-11-08 芜湖中燃城市燃气发展有限公司 CNG gas station is dehydrated compressibility
WO2020132262A1 (en) * 2018-12-22 2020-06-25 Advanced Liquide Advanced Technologies U.S. LLC A method of separating a gas mixture comprising first and second gases using a gas separation membrane module having a plurality of hollow fiber membrane elements
US11318412B2 (en) 2018-12-22 2022-05-03 Air Liquide Advanced Technologies U.S. Llc Gas separation membrane module with membrane elements arranged in series

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017096149A1 (en) * 2015-12-03 2017-06-08 Air Liquide Advanced Technologies, U.S. LLC Method and system for purification of natural gas using membranes
US10143961B2 (en) * 2015-12-03 2018-12-04 Air Liquide Advanced Technologies U.S. Llc Method and system for purification of natural gas using membranes
FR3067261B1 (en) * 2017-06-09 2020-06-26 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude METHOD FOR THE PURIFICATION OF NATURAL GAS USING MEMBRANES.
US10589215B2 (en) 2017-09-21 2020-03-17 Air Liquide Advanced Technologies U.S. Llc Production of biomethane using multiple types of membrane
US10919002B2 (en) 2018-08-28 2021-02-16 Saudi Arabian Oil Company Fluorinated polytriazole membrane materials for gas separation technology
US11155760B2 (en) * 2019-04-30 2021-10-26 Honeywell International Inc. Process for natural gas production
US11926758B2 (en) 2020-07-17 2024-03-12 Saudi Arabian Oil Company Polytriazole coating materials for metal substrates
US11814473B2 (en) 2020-07-17 2023-11-14 Saudi Arabian Oil Company Polytriazole copolymer compositions
CN113769580A (en) * 2021-11-12 2021-12-10 山东颐工材料科技股份有限公司 Tail gas treatment device for producing high rubber powder ASA
US11635049B1 (en) * 2021-12-20 2023-04-25 Mann+Hummel Gmbh Air induction system including air duct having cylindrical wall with opening extending radially therethrough and feature for minimizing airflow disturbances caused by presence of opening

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4963165A (en) * 1987-04-27 1990-10-16 Membrane Technology & Research, Inc. Composite membrane, method of preparation and use
US5401300A (en) * 1993-10-25 1995-03-28 Membrane Technology And Research, Inc. Sour gas treatment process including dehydration of the gas stream
US6053965A (en) * 1998-10-14 2000-04-25 Membrane Technology And Research, Inc. Fuel gas conditioning process
US6648944B1 (en) * 2003-01-28 2003-11-18 Membrane Technology And Research, Inc. Carbon dioxide removal process
US20120000355A1 (en) * 2010-06-30 2012-01-05 Uop Llc Flexible System To Remove Carbon Dioxide From A Feed Natural Gas
US20120085232A1 (en) * 2010-05-06 2012-04-12 Sethna Rustam H Methods for removing contaminants from natural gas
US20120223014A1 (en) * 2009-06-10 2012-09-06 Evonik Membrane Extraction Technology Limited Polymide membrane
US20130111949A1 (en) * 2008-05-20 2013-05-09 Lummus Technology Inc. Carbon Dioxide Purification
US10143961B2 (en) * 2015-12-03 2018-12-04 Air Liquide Advanced Technologies U.S. Llc Method and system for purification of natural gas using membranes

Family Cites Families (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4529411A (en) 1982-03-12 1985-07-16 Standard Oil Company CO2 Removal from high CO2 content hydrocarbon containing streams
US4466946A (en) 1982-03-12 1984-08-21 Standard Oil Company (Indiana) CO2 Removal from high CO2 content hydrocarbon containing streams
JP2531906B2 (en) 1991-09-13 1996-09-04 インターナショナル・ビジネス・マシーンズ・コーポレイション Foam polymer
US5482539A (en) 1993-09-22 1996-01-09 Enerfex, Inc. Multiple stage semi-permeable membrane process and apparatus for gas separation
US5557030A (en) 1995-03-23 1996-09-17 Uop Process for rejecting heavy hydrocarbons from light hydrocarbons gases
US5688307A (en) 1996-02-29 1997-11-18 Membrane Technology And Research, Inc. Separation of low-boiling gases using super-glassy membranes
US5964923A (en) 1996-02-29 1999-10-12 Membrane Technology And Research, Inc. Natural gas treatment train
EP0908219B1 (en) 1997-10-09 1999-12-08 Gkss-Forschungszentrum Geesthacht Gmbh Multi-stage process for the separation/recovery of gases
FI108448B (en) 1998-03-04 2002-01-31 Borealis Tech Oy A method for treating a gas stream of unreacted compounds from the manufacture of polyolefins
US6368382B1 (en) 2000-07-27 2002-04-09 Uop Llc Epoxysilicone coated membranes
US6860920B2 (en) 2002-03-28 2005-03-01 L'air Liquide-Societe Anoyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes George Claude Block polyester-ether gas separation membranes
US7442233B2 (en) 2005-07-06 2008-10-28 Basf Catalysts Llc Integrated heavy hydrocarbon removal, amine treating and dehydration
WO2009087156A1 (en) 2008-01-08 2009-07-16 Shell Internationale Research Maatschappij B.V. Multi - stage membrane separation process
US8083834B2 (en) 2008-05-07 2011-12-27 Uop Llc High permeability membrane operated at elevated temperature for upgrading natural gas
US8192524B2 (en) 2009-01-29 2012-06-05 Chevron U.S.A. Inc. Process for upgrading natural gas with improved management of CO2
US8839875B2 (en) 2009-12-28 2014-09-23 Ben M. Enis Method and apparatus for sequestering CO2 gas and releasing natural gas from coal and gas shale formations
CN103269766A (en) * 2010-11-18 2013-08-28 “盖瑞斯”股份有限公司 Membrane gas separation plant and method for operating same
US8575414B2 (en) 2010-12-17 2013-11-05 Uop Llc Membrane system for natural gas upgrading
CN103269767A (en) 2010-12-20 2013-08-28 陶氏环球技术有限责任公司 Crosslinked silane-modified molecularly self-assembling material
US8659001B2 (en) 2011-09-01 2014-02-25 Sandisk 3D Llc Defect gradient to boost nonvolatile memory performance
US9302227B2 (en) 2011-09-02 2016-04-05 Membrane Technology And Research, Inc. Membrane separation assembly for fuel gas conditioning
GB201117950D0 (en) 2011-10-18 2011-11-30 Imp Innovations Ltd Membranes for separation
EP2844368B1 (en) 2012-05-01 2019-08-07 Dow Global Technologies LLC Use of a hollow fiber carbon molecular sieve membrane
WO2015123257A1 (en) 2014-02-11 2015-08-20 Tech 3 Solutions, Inc. Apparatus for flare gas processing and use
US10427094B2 (en) * 2015-07-16 2019-10-01 Cameron Solutions, Inc. Process design for acid gas removal

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4963165A (en) * 1987-04-27 1990-10-16 Membrane Technology & Research, Inc. Composite membrane, method of preparation and use
US5401300A (en) * 1993-10-25 1995-03-28 Membrane Technology And Research, Inc. Sour gas treatment process including dehydration of the gas stream
US6053965A (en) * 1998-10-14 2000-04-25 Membrane Technology And Research, Inc. Fuel gas conditioning process
US6648944B1 (en) * 2003-01-28 2003-11-18 Membrane Technology And Research, Inc. Carbon dioxide removal process
US20130111949A1 (en) * 2008-05-20 2013-05-09 Lummus Technology Inc. Carbon Dioxide Purification
US20120223014A1 (en) * 2009-06-10 2012-09-06 Evonik Membrane Extraction Technology Limited Polymide membrane
US20120085232A1 (en) * 2010-05-06 2012-04-12 Sethna Rustam H Methods for removing contaminants from natural gas
US20120000355A1 (en) * 2010-06-30 2012-01-05 Uop Llc Flexible System To Remove Carbon Dioxide From A Feed Natural Gas
US10143961B2 (en) * 2015-12-03 2018-12-04 Air Liquide Advanced Technologies U.S. Llc Method and system for purification of natural gas using membranes

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020132262A1 (en) * 2018-12-22 2020-06-25 Advanced Liquide Advanced Technologies U.S. LLC A method of separating a gas mixture comprising first and second gases using a gas separation membrane module having a plurality of hollow fiber membrane elements
US11318412B2 (en) 2018-12-22 2022-05-03 Air Liquide Advanced Technologies U.S. Llc Gas separation membrane module with membrane elements arranged in series
CN110425414A (en) * 2019-07-05 2019-11-08 芜湖中燃城市燃气发展有限公司 CNG gas station is dehydrated compressibility

Also Published As

Publication number Publication date
US20170157556A1 (en) 2017-06-08
US10143961B2 (en) 2018-12-04

Similar Documents

Publication Publication Date Title
US20180361310A1 (en) Method and system for purification of natural gas using membranes
US10874979B2 (en) Method and system for purification of natural gas using membranes
US20170157555A1 (en) Method and system for purification of natural gas using membranes
US20200179868A1 (en) Production of biomethane using multiple types of membrane
US8192524B2 (en) Process for upgrading natural gas with improved management of CO2
US9034175B2 (en) Method for reducing the mercury content of natural gas condensate and natural gas processing plant
US9045582B2 (en) Cross-linked rubbery polyurethane-ether membranes for separations
US10780392B2 (en) Multi-stage membrane for N2 rejection
JP2019520198A5 (en)
CN104001408A (en) Helium recovery from natural gas
CN111348630A (en) Recovery of helium from natural gas
Kargari et al. Application of membrane gas separation processes in petroleum industry
US10363518B2 (en) Systems and methods to debottleneck an integrated oil and gas processing plant with sour gas injection
US9751053B2 (en) Asymmetric integrally-skinned flat sheet membranes for H2 purification and natural gas upgrading
EP3197853A1 (en) Asymmetric integrally-skinned flat sheet membranes for h2 purification and natural gas upgrading
BR112018011294B1 (en) METHOD FOR PURIFYING NATURAL GAS USING MEMBRANES
US11866667B2 (en) Membrane process for natural gas liquids recovery and hydrocarbon dew point control
EP2433702A1 (en) Process for separating kinetic hydrate polymer inhibitors
US9162208B2 (en) Process and system for producing synthetic crude oil from offshore produced fluids containing high CO2 content
BR112018011305B1 (en) METHOD FOR PURIFICATION OF NATURAL GAS USING MEMBRANES
US20240093108A1 (en) System and method for recovery of fuel gas from crude oil purification

Legal Events

Date Code Title Description
STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION