Thin film composite membranes having improved adhesion between layers and uses thereof - Patents.com

Abstract

In an aspect, provided herein are improved thin film composite membranes and gas separation methods using the composite membranes. The composite membranes incorporate a gutter layer from a polymeric material selected from substituted polyacetylene, addition polymerized and substituted polynorbornene, or addition polymerized and substituted polytricyclononene. The gutter layer provides improved adhesion to a gas separation layer incorporating a fluorinated ionomer. In an aspect, provided herein are thin film composite membranes having improved adhesion between the gutter layer and the fluorinated ionomer in the gas separation layer.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 220,780, filed July 12, 2021.

[0002] Government Rights This invention was made with Government support under DE-SC0021881 awarded by the Department of Energy. The Government has certain rights in this invention. [Background technology]

[0003] background Membranes can be used to separate gas mixtures produced in industrial processes such as energy production. These separations can include separation of alkenes from alkanes, such as propylene from propane in hydrocarbon refinery operations, separation of carbon dioxide from hydrocarbons such as methane (i.e., biogas), or separation of carbon dioxide from nitrogen in waste streams (i.e., flue gas) from the combustion of hydrocarbons.

[0004] Useful membranes can include composite membranes with a thin gas separation layer in contact with a high diffusion rate layer (gutter layer) for increased permeability, and a porous layer support for overall strength and durability. However, there is an unmet need for composite membranes with a gas separation layer that remains strongly attached to the gutter layer. For example, a weakly attached layer may be prone to delamination and damage by the fabrication process for making large area modules for commercial applications. A delaminated or damaged gas separation layer may have reduced performance due to lower gas separation selectivity. Summary of the Invention [Means for solving the problem]

[0005] overview In an embodiment, provided herein is a thin film composite membrane having improved adhesion between the gutter layer and the fluorinated ionomer in the gas separation layer. Such membranes can have a higher permeability compared to comparable membranes without a gutter layer. The thin film composite membrane comprises a porous layer support; a gas separation layer comprising a fluorinated ionomer; and a gutter layer comprising a polymeric material having a glass transition temperature greater than 100°C. The polymeric material is a substituted polyacetylene comprising the repeating unit structure (I), an addition polymerized and substituted polynorbornene comprising the repeating unit structure (II), or an addition polymerized and substituted polytricyclononene comprising the repeating unit structure (III), as follows: [ka] [wherein n is a number defining the degree of polymerization; R 1 contains an alkyl or aromatic group; R 2 contains an aromatic group or a silyl group; R 3 is H or contains an alkyl group, a silyl group or an alkoxy-silyl group; R 4 comprises a silyl group or an alkoxy-silyl group; R 5 is H or contains a silyl group or an alkoxy-silyl group; R 6 comprises a silyl group or an alkoxy-silyl group; R 7 is H or R 5 If H, then R 7 contains a silyl group or an alkoxy-silyl group] is selected from.

[0006] In some embodiments, the substituted polyacetylene can be poly(1-trimethylsilylpropyne), the addition polymerized and substituted polynorbornene can be poly(5-trimethylsilylnorborn-2-ene), and the addition polymerized and substituted polytricyclononene can be poly(3,3-bis(trimethylsilyl)tricyclonon-7-ene). The polymeric material can be 2800 Barr (8.04×10-13 mol m / (m 2 s Pa) and the thickness of the gutter layer can be between 0.1 μm and 1 μm. The porous layer support for the gutter layer can include polyvinylidine fluoride, expanded polytetrafluoroethylene, polyacrylonitrile, polysulfone, or polyethersulfone.

[0007] In some embodiments, the fluorinated ionomer may comprise polymerized repeat units of tetrafluoroethylene and perfluorovinyl ether monomers containing pendant sulfonic acid or sulfonate functional groups. The sulfonate functional groups may be selected from silver sulfonate, ammonium sulfonate, ammonium alkylsulfonate, lithium sulfonate or sodium sulfonate. The thickness of the gas separation layer may be between 0.02 μm and 0.5 μm.

[0008] In another aspect, provided herein is a spiral-would membrane module comprising a thin film composite membrane as described herein.

[0009] In another aspect, provided herein is a method for separating an alkene from a first gas mixture, the method comprising the steps of: providing a thin film composite membrane as described herein having silver sulfonate functional groups, a feed side and a permeate side; exposing the feed side to a flowing first gas mixture; providing a driving force across the thin film composite membrane; and producing a second gas mixture on the permeate side having a higher concentration of alkene than the concentration of alkene in the first gas mixture. In some embodiments, the first gas mixture comprises propylene and propane, and further comprises water vapor.

[0010] In another aspect, provided herein is a method for separating carbon dioxide from a first gas mixture, comprising the steps of: providing a thin film composite membrane as described herein having a feed side and a permeate side; exposing the feed side to a flowing first gas mixture; providing a driving force across the thin film composite membrane; and producing a second gas mixture on the permeate side having a higher concentration of carbon dioxide than the concentration of carbon dioxide in the first gas mixture. In some embodiments, the first gas mixture further comprises nitrogen, methane, or water vapor. Providing a driving force can include applying a vacuum to the permeate side.

[0011] This summary of the present invention introduces some of the embodiments of the present invention and is not intended to be limiting. Additional embodiments, including variations and alternative arrangements of the present invention, are further described in the detailed description of the present invention and in the examples. Certain exemplary embodiments of the present invention are described herein for the sole purpose of illustrating the present invention and should not be construed as limiting the scope of the present invention. Other embodiments of the present invention, as well as certain modifications, combinations and improvements of the described embodiments, will occur to those skilled in the art, and all such alternatives, combinations, modifications and improvements are within the scope of the present invention.

[0012] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a list of elements is not necessarily limited to only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. In addition, the use of "a" or "an" is used to describe elements and components described herein. This is done merely for convenience and for the general sense of the scope of the invention. This description should be read to include one or at least one, and the singular also includes the plural unless it is clear that it is meant otherwise. Certain additional terms are also used, some of which are further defined in the detailed description of the invention below. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Detailed Description Gas separation layers for composite membranes can be fabricated from fluorinated ionomers containing sulfonate or sulfonic acid functional groups, such as those disclosed in US Pat. No. 5,191,151 and US Pat. No. 10,639,591. A high diffusion rate layer, also known in the membrane art as a gutter layer, can provide greater overall permeability and may be located (layered) between the gas separation layer and the porous layer support for greater overall strength and durability. Composite membranes with gas separation and gutter layers derived from fluorinated ionomers are described in US Pat. No. 10,399,044 and US Patent Publication No. 2021 / 0016231. Therein, the gutter layer was prepared by solution casting a fluorinated polymer material, such as Teflon® AF2400, pre-dissolved in a fluorinated solvent onto the porous layer support. The gas separation layer was then fabricated by coating (i.e., solution casting) a fluorinated ionomer from a non-fluorinated solvent onto the gutter layer.

[0014] Fluorinated ionomers are hydrophilic and can absorb and transmit liquid water, while gutter layers such as Teflon® AF2400 are also fluorinated and hydrophobic, repelling liquid water but allowing water vapor to pass through. Both materials may be fluorinated, but such properties may be insufficient for good layer adhesion and operational life in humid environments for similar properties. A weakly adhered gas separation layer from a fluorinated ionomer with silver sulfonate functional groups can be separated from the gutter layer, such as by pulling it apart with adhesive tape, and may be prone to delamination and damage by the fabrication process into large area modules for commercial applications. A delaminated or damaged gas separation layer may have reduced performance due to lower gas separation selectivity. Thus, a thin film composite membrane with improved adhesion between the gutter layer and the fluorinated ionomer in the gas separation layer, with an overall higher permeability for the composite membrane versus a comparable composite membrane without a gutter layer, is desirable.

[0015] In contrast, provided herein is a thin film composite membrane that has surprisingly improved adhesion between the fluorinated ionomer in the gas separation layer and the gutter layer that comprises a polymeric material, and is chemically heterogeneous, non-fluorinated and hydrophobic.The gas separation layer is laminated to the gutter layer, which is laminated to the porous layer support.In some cases, the gas separation layer and the gutter layer are not separated (i.e., peeled off) using painter's masking tape, unlike the composite membrane with the gutter layer made of Teflon AF2400.Herein, the polymeric material for incorporation into the gutter layer is selected from substituted polyacetylene, addition-polymerized and substituted polynorbornene, or addition-polymerized and substituted polytricyclononene.

[0016] The substituted polyacetylene can include poly(1-trimethylsilylpropyne) (PTMSP), the addition polymerized and substituted polynorbornene can include poly(5-trimethylsilylnorborn-2-ene) (PTMSN), or the addition polymerized and substituted polytricyclononene can include poly(3,3-bis(trimethylsilyl)-tricyclonon-7-ene) (PTCNSi2g). The structures of these exemplary polymer materials are shown in (1), (2), and (3), respectively. The improved adhesion between the gas separation layer and the gutter layer allows for the processing of the thin film composite membrane into large area modules with fewer defects. In some embodiments, the thin film composite membranes are useful for the separation of alkenes from alkanes or alkenes from other gases such as nitrogen. In some embodiments, the thin film composite membranes can be used for the separation of carbon dioxide from gases such as nitrogen, alkanes, or alkenes. [ka]

[0017] Substituted polyacetylene, addition polymerized and substituted polynorbornene, or addition polymerized and substituted polytricyclononene may have high intrinsic gas permeability but low to moderate gas separation selectivity. Herein, a gutter layer incorporating a polymeric material in combination with a gas separation layer incorporating a fluorinated ionomer may have a comparable carbon dioxide gas separation selectivity over nitrogen for a thin film composite membrane compared to a composite membrane having a gas separation layer incorporating a fluorinated ionomer directly on a porous layer support. For alkene separation from alkanes, the thin film composite membrane may have at least a 50% increase in gas separation selectivity. Comparable or increased gas separation selectivity is unexpected because it may be generally understood in the membrane technology field that gas separation selectivity is not additive and that a gutter layer may increase overall permeability but at the possible cost of reduced gas separation selectivity. Unlike Teflon® AF2400, each of PTMSP, PTMSN, and PTCNSi2g is soluble in organic solvents such as toluene. This solubility avoids the use of fluorinated solvents, thereby simplifying manufacturing, avoiding much more stringent requirements for solvent recovery, and eliminating any potential emission of fluorinated solvent vapors, which can be potent greenhouse gases.

[0018] The polymeric materials are substituted in that they incorporate functional groups into their repeat unit structure. For example, PTMSP, PTMSN, or PTCNSi2g are silyl-substituted polymeric materials that contain trimethylsilyl groups in their repeat unit structure. The silyl substitution can aid in adhesion with fluorinated ionomers in the gas separation layer. PTMSP, PTMSN, and PTCNSi2g are also glassy polymeric materials with glass transition temperatures greater than 300 degrees Celsius. The glass transition temperatures greater than the predicted maximum operating temperature of 100 degrees Celsius for thin film composite membranes can help stabilize the interface between the gas separation layer and the gutter layer, helping to retain or possibly enhance gas separation selectivity compared to comparable membranes with a gas separation layer directly on a porous layer support.

[0019] Substituted polynorbornene or substituted polytricyclononene are addition polymerized. Unlike other possible polymerization techniques such as ring-opening metathesis or radical polymerization, the fused ring structures that accompany the monomer polymerization with the addition polymerized polymeric material remain intact and unrearranged. Thus, the fused ring structures are bulkier in the addition polymerization, resulting in high gas permeability. For example, the reported intrinsic permeability of PTMSN and PTCNSi2g for carbon dioxide is approximately 5,300 and 19,900 barrers, respectively. PTMSP has an initial carbon dioxide permeability of 34,000 barrers, and its synthesis can also be considered as an addition polymerization. However, PTMSP does not contain fused ring structures, and its high permeability is instead due to the high free volume from the inefficient chain packing of the rigid (versus bulky) backbone structure. PTMSN, PTCNSi2g, and PTMSP are 2800 barr (8.04 × 10 -13 mol m / (m 2 s Pa) are preferred polymeric materials.

[0020] Other substituted polyacetylenes, other addition polymerized and substituted polynorbornenes, and other addition polymerized and substituted polytricyclononenes may have a glass transition temperature of at least 100 degrees Celsius, may have an intrinsic permeability to carbon dioxide greater than 2800 barrers, and may be suitable for incorporation into a gutter layer. General structures for polymeric materials having silyl, alkoxy-silyl, or aromatic substitution in addition to alkyl groups are shown below. Substituted polyacetylenes include repeat unit structure (I), addition polymerized and substituted polynorbornenes include repeat unit structure (II), and addition polymerized and substituted polytricyclononenes include repeat unit structure (III). The polymeric materials may be homopolymers or copolymers, where n is a number defining the degree of polymerization; R 1 contains an alkyl or aromatic group; R 2contains an aromatic group or a silyl group; R 3 is H or contains an alkyl group, a silyl group or an alkoxy-silyl group; R 4 comprises a silyl group or an alkoxy-silyl group; R 5 is H or contains a silyl group or an alkoxy-silyl group; R 6 comprises a silyl group or an alkoxy-silyl group; R 7 is H or R 5 If H, then R 7 contains a silyl group or an alkoxy-silyl group. [ka] [ka]

[0021] Other substituted polyacetylenes can include certain indane-containing poly(diphenylacetylene) derivatives disclosed by Hu et al. in "Synthesis and Properties of Indan-Based Polyacetylenes That Feature the Highest Gas Permeability among All the Existing Polymers" Macromolecules 2008, 41, 8525-8532. Other addition-polymerized substituted polynorbornenes can include alkoxysilyl-substituted polynorbornenes such as those disclosed by Maroon et al. in "Addition-type alkoxysilyl-substituted polynorbornenes for post-combustion carbon dioxide separations" Journal of Membrane Science, 595, February 2020, 117532.

[0022] PTMSP is commercially available from Gelest (Morrisville, PA) and is soluble in organic solvents including toluene, cyclohexane, heptane, and chloroform. PTMSN can be synthesized by addition polymerization of 5-trimethylsilyl-2-norbornene as disclosed by Finkelshtein et al. in "Addition-Type Polynorbornenes with Si(CH3)3Side Groups: Synthesis, Gas Permeability, and Free Volume" Macromolecules 2006, 39, 7022-7029. PTMSN is soluble in organic solvents including toluene and chloroform. PTCNSi2g can be synthesized by addition polymerization of 3,3-bis(trimethylsilyl)tricyclonon-7-ene as disclosed by Gringolts et al. in Russian Patent No. 2,410,397 or by Chapala et al. in "A Novel, Highly Gas-Permeable Polymer Representing a New Class of Silicon-Containing Polynorbornenes as Efficient Membrane Materials" Macromolecules 2015, 48, 8055-8061. PTCNSi2g is soluble in organic solvents including toluene and chloroform.

[0023] The support film that then becomes the gutter layer can be prepared by coating (i.e., solution casting) a dilute solution of the polymeric material onto the surface of the porous layer support. The porous layer support can be in the form of a flat sheet, hollow fiber, or other tubular and porous structure. In a hollow fiber or other tubular and porous structure, the dilute solution of the polymeric material can be cast onto the outer surface (shell) or inner surface (lumen). A dilute solution of PTMSP, PTMSN, or PTCNSi2g can be prepared in an organic solvent at a concentration that is less than 2% or between 0.1% and 1%. Acceptable coating methods include, but are not limited to, ring casting, dip coating, spin coating, slot die coating, roll coating, Mayer rod coating, and injection coating. The organic solvent can be evaporated to form a support film of the polymeric material that then becomes the gutter layer. Residual or trace organic solvent remaining in the support film should not interfere with subsequent processing steps.

[0024] The support film, which then becomes the gutter layer, is thin and can be between 0.05 μm and 5 μm, or between 0.1 μm and 1 μm. The permeation, which is the pressure normalized flux, is typically 10 GPU×10 6 ×cm 3 (STP) / (cm 2 Permeability is reported as the Gas Permeability Units (GPU) coefficient, which has units of s / cmHg. Permeability is the permeability normalized for thickness and is typically reported in Barrers, where the Barrer permeability coefficient is p Barrer ×10 10 ×cm 3 It has units of (STP) / (cm s cmHg). In summary, the support film and porous layer substrate can have a helium or carbon dioxide permeability of at least 5000 GPU, or greater than 10,000 GPU, measured at 25° C.

[0025] The gas separation layer in the thin film composite membrane comprises a fluorinated ionomer. The fluorinated ionomer is a fluorinated copolymer having a fluorinated backbone and covalently attached pendant groups that contain ionic functional groups such as sulfonic acid, sulfonate, carboxylic acid, carbonate, phosphate, or phosphonium. Fluorinated ionomers containing sulfonic acid or sulfonate functional groups may be more preferred. Certain counterions (cations) to the sulfonate functional groups can impart high water permeability to the fluorinated ionomers. Suitable cations include alkylammonium, ammonium, silver, lithium, or sodium cations. Sulfonate functional groups with silver cations can be used for the practical separation of alkenes from alkanes. The equivalent weight of a fluorinated ionomer is the weight of a fluorinated ionomer that contains one mole of sulfonate or sulfonic acid functional groups. The equivalent weight (EW) can be less than 5000 grams per mole, less than 2000, or between 500 and 800 g / mole. Suitable fluorinated ionomers include those that contain polymerized repeat units derived from tetrafluoroethylene and perfluorovinyl ether monomers and have pendant sulfonate or sulfonic acid functionality, such as Nafion® (Chemours, Wilmington Del.) and Aquivion® (Solvay, Houston Tex.), etc. Aquivion® has a lower equivalent weight than Nafion®.

[0026] The gas separation layer may be fabricated by coating a dilute solution of the fluorinated ionomer (i.e., solution casting). The dilute solution may be prepared at a concentration that is less than 5% (w / w), less than 2%, or between 0.1% and 2%. The dilute solution may be prepared by mixing a preformed, concentrated, commercially available solution of the fluorinated ionomer with a miscible and non-fluorinated solvent. The solvent may be the same as or different from the solvent in the preformed solution, thus forming a solvent mixture. Acceptable dilute solution coating methods include ring casting, dip coating, spin coating, slot die coating, roll coating, and Mayer rod coating. The dilute solution may be coated onto the surface of the film that will become the gutter layer, which may already be on the porous layer support. The solvent or solvent mixture may be removed by evaporation, etc. The solvent or solvent mixture may be evaporated to form a "dry" gas separation layer in due course. The thickness of the gas separation layer has a significant effect on the permeability of the thin film composite membrane and therefore is as low as between 0.01 μm and 5 μm, or 0.02 μm and 0.5 μm in thickness.

[0027] The porous layer support can reinforce the thin gutter layer and the gas separation layer, helping to strengthen the composite so that the thin film composite membrane can be fabricated into complex shapes, including spiral-wound or hollow fiber membrane modules. The porous layer support can be in the form of a flat sheet, hollow fiber, or other tubular and porous structure. Suitable materials for the porous layer support include, but are not limited to, polyvinylidene fluoride, expanded polytetrafluoroethylene, polyacrylonitrile, polysulfone, and polyethersulfone. The porous layer support may also include a porous and stronger backing material, such as a nonwoven polyester or polypropylene sheet. Inorganic substrates, such as porous silica or alumina sheets or tubes, can also be suitable materials for the porous layer support. The porous layer support can have a helium or carbon dioxide permeability higher than the gutter layer, for example at least two times higher, or at least five times higher. The permeate gas can flow relatively unobstructed through the porous layer support, which has a porosity of at least 40%. The average pore size can be less than 0.1 μm or between 0.01 and 0.03 μm, corresponding to molecular weight cutoffs of approximately 50,000 and 200,000 Daltons, respectively.

[0028] The thin film composite membranes can be subjected to a heat treatment step to "anneal" them to improve their mechanical durability and long-term performance stability. The fluorinated ionomers in the gas separation layer can be annealed by heating the thin film composite membrane to near or above the glass transition temperature of the fluorinated ionomer. The exact glass transition temperature will depend on the composition of the fluorinated ionomer. In general, the annealing temperature for the fluorinated ionomers is between 50 and 200°C, and between 75 and 150°C, in some cases. The thin film composite membranes can be heated for 0.1 to 10 minutes, or for 1 to 5 minutes. The appropriate annealing temperature and time should not degrade the other components of the improved thin film composite membrane.

[0029] Fluorinated ionomers containing sulfonic acid or sulfonate functional groups other than silver sulfonate functional groups in the gas separation layer are initially inactive for the separation of alkenes from alkanes; that is, the thin film composite membranes are not significantly permselective (selectivity ≦5) and have low alkene permeability (<25 GPU). The thin film composite membranes can be activated by exchange of protons or other cations (counterions) with the silver in the gas separation layer. For example, exchange can be performed by contacting the exposed surface of the gas separation layer with water and a solution containing a soluble and ionizable silver compound, such as silver nitrate. A sufficient level of exchange can occur rapidly in a thin (≦2 μm) gas separation layer, as evidenced by the high permeability (>100 GPU) and selectivity (>25) for propylene over propane after less than one minute of contact with aqueous silver nitrate at ambient (about 23° C.) temperature.

[0030] The thin film composite membrane has improved adhesion between the fluorinated ionomer in the gas separation layer and the polymeric material in the gutter layer compared to a comparative composite membrane having a gutter layer made of Teflon® AF2400. The improved adhesion is evident from peel tests using painter's masking tape to separate the gas separation layer from the underlying gutter layer, where the fluorinated ionomer contains a sulfonate functional group, such as silver sulfonate, lithium sulfonate, or sodium sulfonate. Painter's masking tape, such as that manufactured by 3M (St. Paul, MN), is applied to the surface of a circular sample of the thin film composite membrane with one end placed near the center and the other end extending beyond the edge. The tape is then peeled away from the edge toward the center of the sample. The gas separation layer remains attached to the gutter layer incorporating the polymeric material. The gas separation layer remains attached to the tape and was peeled away in a comparative test with a comparative composite membrane having a gutter layer incorporating Teflon® AF2400. Additionally, the sulfonic acid functionality was inherently tacky and bonded strongly to painter's masking tape, not a good indicator of improved adhesion.

[0031] The thin film composite membranes may be useful for the separation of alkenes from alkanes, such as propylene from propane, or alkenes from nitrogen, when the counterion of the fluorinated ionomer is silver. In some embodiments, the thin film composite membranes may be useful for the separation of carbon dioxide from nitrogen, or carbon dioxide from alkanes, such as methane. In embodiments where the counterion is not silver, the thin film composite membranes may be useful for the separation of carbon dioxide from alkenes, such as ethene. In the separation process, the thin film composite membrane is exposed to a flowing gaseous feed mixture containing the alkene or carbon dioxide. A "driving force" is provided across the thin film composite membrane, where the partial pressure of the alkene or carbon dioxide on the feed side is higher than that on the permeate side of the thin film composite membrane. The driving force may include applying a vacuum to the permeate side, which may be preferred for the separation of carbon dioxide from nitrogen in the flue gases of fossil fuel-powered power plants due to lower energy consumption. Gas separation of the alkene or carbon dioxide from the gaseous feed mixture occurs through the membrane to produce a permeate mixture on the membrane permeate side having a higher concentration of alkene or carbon dioxide than the feed mixture. The performance of thin film composite membranes can be enhanced by having water vapor in the feed mixture and, optionally, including water vapor on the permeate side in the sweep gas, which can also serve to increase the driving force by reducing the alkene or carbon dioxide concentration.

[0032] Spiral-wound modules are highly useful for large-scale membrane separations and are an efficient means for assembling large area flat sheets of thin film composite membranes into a compact volume. Spiral-wound module design and construction are well documented in the literature. As generally described, flat sheet membranes are folded into rectangular and slightly asymmetric membrane leaves with the feed side facing outward. The membranes are bonded along three sides into a pocket shape with a plastic mesh spacer on the inside for the permeate gas flow. The partially exposed spacer in the asymmetric pocket is sealed (bonded) along its edges to a perforated core tube, and then the leaf(s) are wrapped around the core tube with an additional interleaved mesh spacer for the feed flow. The outside of the wrapped module is wrapped with adhesive tape to hold the module components in place.

[0033] The spiral-wound module may be placed in a pressure vessel for gas separation. The pressurized feed gas stream passes through the open mesh channels of the feed spacer parallel to the long axis of the spiral-wound module, and certain components permeate the thin-film composite membrane. The permeated components flow perpendicular to the long axis and the feed stream through the open mesh channels of the permeate spacer in the spiral leaf. The permeated components exit the permeate spacer and are collected in the core tube. Other spiral-wound module designs may be constructed in a similar manner that would circulate a sweep gas or fluid through the permeate side of the membrane leaf in addition to the core tube. This can be achieved by adding flow directing elements in the core tube and the permeate spacer of the pocket-shaped leaf. EXAMPLES

[0034] Example 1 Fabrication of PTMSP gutter layer or Teflon® AF2400 gutter layer on porous layer support. Poly(trimethylsilylpropyne) (PTMSP) was dissolved at 0.5% (w / w) in heptane and filtered through 1 μm glass microfiber. Teflon® AF2400 was dissolved at 0.5% (w / w) in Opteon® SF10 and filtered through 1 μm glass microfiber. The solutions were then cast separately on a 100 cm x 200 cm porous layer support comprising a polyvinylidene fluoride (PVDF) ultrafiltration membrane with a molecular weight cut-off of 100,000 Daltons on a non-woven polyester backing (Synder, Filtration, Vacaville CA) using a vertical roll coater. The solvent was allowed to evaporate under a dry nitrogen atmosphere at ambient room temperature to form a support film that would become the gutter layer. The apparent laminar thickness for the PTMSP support film was estimated gravimetrically to be 0.80 μm using the applied solution mass, concentration, porous layer support area, and PTMSP density of 0.77 g / mL. The apparent laminar thickness for the Teflon® AF2400 support film control was similarly estimated to be 0.25 μm using a Teflon® AF2400 density of 1.67 g / mL. A 47 mm diameter sample from each support film was placed separately in a stainless steel cross-flow cell. The support films were tested for helium permeability at ambient room temperature (about 24° C.) at 5 to 10 psig feed pressure and gauge permeate pressure at 200 mL / min (STP). An Agilent ADM flow meter, model G6691A, was used to measure the permeate gas flow rate. The PTMSP support film had a helium permeability of approximately 5800 GPU at pressures between 5 and 10 psig. The Teflon® AF2400 support film had a helium permeability of approximately 7900 GPU. Example 2

[0035] Gas separation layer fabrication in PTMSP gutter layer or Teflon® AF2400 gutter layer control. Aquivion® D72-25BS dispersion in water (25% w / w) (Solvay, Houston TX) with an equivalent weight of 720 g / mole was diluted to 1.5% with isopropanol and then filtered through 1 μm glass microfiber to prepare a solution of fluorinated ionomer. The solution of fluorinated ionomer was then cast separately onto the PTMSP film or Teflon® AF2400 film prepared in Example 1 using a vertical roll coater. The isopropanol and water were evaporated under nitrogen atmosphere at ambient room temperature to form a gas separation layer. The gas separation layer for each thin film composite membrane was then annealed by infrared heating at 120 to 130° C. for approximately 1 minute. The apparent thin layer thickness for the gas separation layer in the PTMSP gutter layer was estimated gravimetrically to be 0.62 μm using the applied solution mass, concentration, membrane area, and Solvay reported Aquivion® density of 2.07 g / mL. The apparent thin layer thickness for the gas separation layer in the Teflon® AF2400 gutter layer control was similarly estimated to be 0.69 μm. Example 3

[0036] Gas separation layer fabrication directly on porous layer support. The fluorinated ionomer solution as prepared in Example 2 was cast directly onto a 100 cm x 200 cm PVDF porous layer support as described in Example 1 using a vertical roll coater. The isopropanol and water were evaporated at ambient room temperature under nitrogen atmosphere to form a gas separation layer. The gas separation layer in the thin film composite membrane was then annealed by infrared heating at 120-130°C for approximately 1 minute. The apparent thin layer thickness for the gas separation layer was estimated gravimetrically to be 0.67 μm using the applied solution mass, concentration, membrane area, and Solvay reported Aquivion® density of 2.07 g / mL. Example 4

[0037] Activation of gas separation layer, thickness of thin film composite membrane from helium (He) permeability, and early life performance for mixed gas separation of propylene from propane. Circular samples (47 mm diameter) from each of the thin film composite membranes prepared in Examples 2 and 3 were activated separately by immersion in 0.15 M silver nitrate aqueous solution for 1 minute. Excess silver nitrate solution was gently blown off with dry air, and the circular samples were placed separately in a stainless steel cross-flow cell. The circular samples were first tested for helium permeability under dry conditions at ambient room temperature (about 24° C.) at 30 and 50 psig feed pressures at 200 mL / min (STP) and atmospheric pressure permeation. Permeation flow rates were measured using an Agilent ADM flow meter, model G6691A. Helium (He) permeability was less than 25 GPU, and an estimate of the thickness of the thin film composite membrane from the helium permeability was calculated using the dry permeability as disclosed by Baschetti et al. in "Gas permeation in perfluorosulfonated membranes: Influence of temperature and relative humidity" International Journal of Hydrogen Energy 38 (2013) 11973-11982, by dividing the helium permeability at 22 barr for Aquivion® (20 barr for Nafion®) in the gas separation layer by the measured helium permeability.

[0038] The samples were then tested for early life performance for separation of a 50 / 50 feed mixture of propylene and propane. The 50 / 50 feed mixture at 200 mL / min (STP) was first passed through a humidified water bubbler at ambient room temperature before entering a cross-flow cell, also at ambient room temperature. The feed pressure was maintained at 60 psig by a backflow pressure regulator at the retentate outlet. The stage cut was less than 5% and the permeate flow rate (at atmospheric pressure) was measured using a soap film flowmeter. The permeate composition was measured by gas chromatography. Table 1 summarizes the thickness and early life separation performance of the thin film composite membranes calculated from the helium permeability. At least three samples of each thin film composite membrane were tested and the average (Avg) values ​​and standard deviation (SDev) are shown. Membranes with PTMSP or Teflon® AF2400 gutter layers had an average propylene (C3H6) separation selectivity that was at least 50% higher over propane (C3H8), in addition to the expected permeability increase of at least 75% higher. [Table 1] Example 5

[0039] PTMSN or PTCNSi2g gutter layer fabrication on porous layer support: A 5% (w / w) solution of poly(5-trimethylsilylnorbornene) (PTMSN) in toluene is diluted to 0.5% with heptane and filtered through 1 μm glass microfiber. A 0.5% (w / w) solution of PTCNSi2g is prepared in heptane and filtered through 1 μm glass microfiber. The solution is then cast separately on a 100 cm x 200 cm porous layer support comprising a polyvinylidene fluoride (PVDF) ultrafiltration membrane with a molecular weight cut-off of 100,000 Daltons on a non-woven polyester backing (Synder, Filtration, Vacaville CA) using a vertical roll coater. The solvent is allowed to evaporate at ambient room temperature under a dry nitrogen atmosphere to form the gutter layer. The apparent thin layer thickness for the PTMSN and PTCNSi2g gutter layers is estimated gravimetrically to be between 0.75 μm and 0.85 μm using the applied solution mass, concentration, porous layer support area, and PTMSN or PTCNSi2g density of 0.88 g / mL and 0.85 g / mL, respectively. A 47 mm diameter circle is cut from each of the support films and placed separately in a stainless steel cross-flow cell. The support films are tested for helium permeability at ambient room temperature (about 24° C.) at 5 psig delivery pressure at 200 mL / min (STP) and gauge permeate pressure. An Agilent ADM flow meter, model G6691A, is used to measure the permeate gas flow rate. The helium permeability of the PTMSN support film is at least 7500 GPU, and the PTCNSi2g support film is at least 8300 GPU. Example 6

[0040] Gas separation layer fabrication and activation of the gas separation layer in PTMSN or PTCNSi2g gutter layer: Aquivion® D72-25BS dispersion in water (25% w / w) (Solvay, Houston TX) with an equivalent weight of 720 g / mol was diluted to 1.5% with isopropanol and then filtered through 1 μm glass microfiber to prepare a fluorinated ionomer solution. The fluorinated ionomer solution was cast separately on the PTMSN or PTCNSi2g film as prepared in Example 5 using a roll coater. The isopropanol and water were evaporated under nitrogen atmosphere at ambient room temperature to form a gas separation layer. The gas separation layer in the thin film composite membrane was then annealed by infrared heating at 120 to 130° C. for approximately 1 minute. The apparent thin layer thickness for the gas separation layer is estimated gravimetrically to be approximately 0.6 μm using the applied solution mass, concentration, PTMSN or PTCNSi2g support film area, and Solvay reported Aquivion® density of 2.07 g / mL. Circular samples of 47 mm diameter from each of the thin film composite membranes with PTMSN or PTCNSi2g gutter layers were separately activated by immersion in 0.15 M aqueous silver nitrate solution for 1 min. Excess silver nitrate solution was gently blown off with dry air. Example 7

[0041] Tape Adhesion Test. 3 / 4 inch wide painter's masking tape (manufactured by 3M) was applied to the surface of additional circular membrane samples of thin film composite membranes from Examples 4 and 6 that had been activated with silver nitrate as described therein. One end of the tape was placed near the center of the membrane circle and the other end was extended beyond the edge. The tape was then peeled away from the edge toward the center. The gas separation layer remained attached to the gutter layer for the circular membrane samples with gutter layers from PTMSP and to the respective gutter layers for the circular membrane samples with gutter layers from PTMSN and PTCNSi2g. The gas separation layer was peeled away and adhered to the tape from the thin film composite membrane of Example 4 with gutter layers from Teflon® AF2400. Example 8

[0042] Spiral-wound module fabrication and separation performance. 30 cm x 100 cm sheets of thin film composite membranes from Example 2 with gutter layers from either Teflon® AF2400 or PTMSP were activated with silver nitrate for alkene separation as outlined in Example 4. Single leaf spiral-wound modules were fabricated separately from each of the sheets as broadly outlined herein. The spiral-wound modules were fabricated with a 1500 cm 2 The spiral-wound modules were placed separately in a pressure vessel and tested with nitrogen for permeability and potential leakage. The spiral-wound modules with PTMSP gutter layers had a nitrogen permeability of less than 1 GPU. The spiral-wound modules with gutter layers from Teflon® AF2400 had a nitrogen permeability of approximately 2 GPU. The pressure vessels containing the spiral-wound modules were placed separately in an apparatus designed to test large area modules for alkene / alkane permeability and separation selectivity at near commercial operating conditions. The spiral-wound modules were tested with a humidified 60 / 40 mixture of propylene and propane at 145 psig feed pressure. The stage cut was 35% and the permeate pressure was 2 psig. The spiral-wound modules with gutter layers from Teflon® AF2400 had a propylene permeability of 50 GPU and a selectivity to propane of over 5. The spiral-wound module with the PTMSP gutter layer had a propylene permeance of 105 GPU and a selectivity over 12 for propane. Example 9

[0043] Thin film composite membrane with gas separation layer incorporating Nafion® ionomer in PTMSP gutter layer. A Nafion® D2020 dispersion (20% w / w) in n-propanol / water purchased from Ion Power (New Castle, DE) with an equivalent weight of 1000 g / mole was diluted to 1.5% with isopropanol and then filtered through 1 μm glass microfiber to prepare a fluorinated ionomer solution. A 3-inch diameter circle of the PTMSP support film from Example 1 was placed in a 3-inch diameter ring holder and covered with the fluorinated ionomer solution. The ring holder was tilted slightly and excess solution was pipetted out. The remaining wet film was quickly weighed and then dried in a horizontal position under a dry nitrogen atmosphere at ambient room temperature to form a gas separation layer. The thin film composite membrane was then heat treated in a forced air oven at 120° C. for approximately 3 minutes while still in the ring holder. The thin layer thickness for the gas separation layer was estimated gravimetrically to be 0.88 μm using the applied solution mass, concentration, PTMSP support film area, and Chemours reported Nafion® density of 1.97 g / mL. The thin film composite membrane was activated with 0.15 M silver nitrate and then placed in a stainless steel cross-flow cell for early life performance for the separation of propylene from propane as described in Example 4. The membrane thickness from helium permeation was 0.6 μm, the propylene permeation was 90 GPU, and the selectivity over propane was 49. A second thin film composite membrane was prepared in the same manner and tested for tape adhesion as outlined in Example 7. The gas separation layer could not be removed with blue painter's tape and remained attached to the gutter layer. Example 10

[0044] Carbon dioxide (CO2) permeability and mixed gas selectivity over nitrogen. Circular membrane samples (47 mm diameter) of the thin film composite membranes of Examples 2 and 3 with and without the PTMSP gutter layer, respectively, were placed separately in a stainless steel cross-flow cell and tested for CO2 permeability and selectivity over nitrogen. CO2 and nitrogen were delivered from separate gas cylinders and mass flow controllers and then mixed. The gas mixture contained 40% CO2 at 2 L / min (STP) and was passed through a humidified water bubbler at ambient room temperature before entering the cross-flow cell, also at ambient room temperature. The delivery pressure was maintained at 60 psig by a backflow pressure regulator at the retentate outlet. The stage cut was less than 2%, and the permeate flow rate at atmospheric pressure permeation was measured using an Agilent 1100 flow meter. The CO2 concentration in the permeate stream was measured using a Landtec 5000 biogas analyzer. The calculated CO permeability for the thin film composite membrane with the PTMSP gutter layer was 500 GPU and the selectivity over nitrogen was 40. The calculated CO permeability for the thin film composite membrane without the gutter layer was 220 GPU and the selectivity over nitrogen was 35. Example 11

[0045] Gas separation layer fabrication from fluorinated ionomer with silver sulfonate functional groups. Aquivion® D72-25BS dispersion in water (25% w / w) (Solvay, Houston TX) with an equivalent weight of 720 g / mole was diluted to 2.5% with isopropanol and stirred overnight with 1 equivalent of silver carbonate relative to the sulfonic acid functional groups. The mixture was then filtered through 1 μm glass microfiber to remove excess silver carbonate from the solution of fluorinated ionomer with silver sulfonate functional groups. The solution of fluorinated ionomer was then cast onto the PTMSP support film prepared as described in Example 1 using a vertical roll coater. The isopropanol and water were evaporated at ambient room temperature under nitrogen atmosphere to form a gas separation layer. The apparent thin layer thickness for the gas separation layer in the PTMSP gutter layer was estimated gravimetrically to be 1.2 μm using the applied solution mass, concentration, PTMSP gutter layer / porous layer support area, and Solvay reported Aquivion® density of 2.07 g / mL. The gas separation layer could not be removed from the gutter layer using blue painter's tape as described in Example 7. Circular membrane samples (47 mm diameter) were tested at 50° C. for early-life separation of propylene from propane as described in Example 4. The propylene permeance was 110 GPU and the selectivity over propane was 41.

Claims

【Claim 1】 A method for separating carbon dioxide from a first gas mixture, the method comprising: a) providing a thin film composite membrane having a feed side and a permeate side, the thin film composite membrane comprising: i. a porous layer support; ii. a gas separation layer comprising a fluorinated ionomer; iii. a gutter layer comprising a polymer material having a glass transition temperature higher than 100 °C and the polymer material being a substituted polyacetylene comprising a repeating unit structure (I), an addition polymerized and substituted polynorbornene comprising a repeating unit structure (II), or an addition polymerized and substituted polytricyclononene comprising a repeating unit structure (III): 【Chemical Formula 5】 [wherein n is a number defining the degree of polymerization; R １ includes an alkyl or aromatic group; R ２ includes a silyl group; R ３ is H or includes an alkyl group, a silyl group or an alkoxy-silyl group; R ４ includes a silyl group or an alkoxy-silyl group; R ５ is H or includes a silyl group or an alkoxy-silyl group; R ６ includes a silyl group or an alkoxy-silyl group; R ７ is H or, when R ５ is H, R ７ includes a silyl group or an alkoxy-silyl group] selected from the group consisting of; b) exposing the feed side to the flowing first gas mixture; c) providing a driving force across the thin film composite membrane. d) generating, on the permeate side, a second gas mixture having a higher concentration of carbon dioxide than the concentration of carbon dioxide in the first gas mixture A method comprising: **Claim 2** The method according to claim 1, wherein the first gas mixture further comprises nitrogen or an alkane. **Claim 3** The method according to claim 1, wherein the first gas mixture further comprises water vapor. **Claim 4** The method according to claim 1, wherein the step of providing a driving force comprises applying a vacuum to the permeate side. **Claim 5** The method according to claim 1, wherein the polymeric material is the substituted polyacetylene having the repeating unit structure (I). **Claim 6** The method according to claim 1, wherein the polymeric material is the addition-polymerized and substituted polynorbornene comprising the repeating unit structure (II), and the substituted polynorbornene is a silyl-substituted polynorbornene. **Claim 7** The method according to claim 5, wherein the substituted polyacetylene is poly(1-trimethylsilylpropyne). **Claim 8** The method according to claim 6, wherein the addition-polymerized and silyl-substituted polynorbornene is poly(5-trimethylsilylnorborn-2-ene). **Claim 9** The method according to claim 1, wherein the polymeric material is the addition-polymerized and silyl-substituted polytricyclononene having the repeating unit structure (III), preferably poly(3,3-bis(trimethylsilyl)tricyclonona-7-ene). **Claim 10** The method according to claim 1, wherein the fluorinated ionomer comprises a sulfonic acid or sulfonate functional group selected from silver sulfonate, ammonium sulfonate, alkyl-ammonium sulfonate, lithium sulfonate or sodium sulfonate.

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