Gas separation membrane, method of preparing the same, and module including the gas separation membrane

Abstract

A gas separation membrane, a method for manufacturing the same, and a module including the gas separation membrane are disclosed. The gas separation membrane comprises a porous polymer substrate; and a porous ceramic-polymer layer on one surface of the porous polymer substrate; and a gas separation layer on the other side of the porous polymer substrate; wherein the gas separation layer has a thickness of 0.1% to 20% relative to the thickness of the porous ceramic-polymer layer, and the porous ceramic-polymer layer has a thickness of 0.1% to 50% relative to the thickness of the porous polymer substrate, and the porous ceramic-polymer layer is an organic-inorganic composite layer comprising a polymer binder and a ceramic material having a melting point (Tm) of at least 180°C, and the polymer binder comprises at least one binder selected from a cellulose-based binder, a vinyl alcohol-based binder, and an acrylate-based binder having functional groups in the side chains, and the functional group may have at least one of -COOH, -NH2, -OH, -SO3H, -CN, the cation thereof, the anion thereof, and the salt thereof.

Description

Technology Field

[0001] The present disclosure relates to a gas separation membrane, a method for manufacturing the same, and a module comprising said gas separation membrane. Background Technology

[0002] To efficiently separate large volumes of gas, modules must be constructed to include various components in addition to the gas separation membrane. Performance at the module level is primarily determined by the effective membrane area, which is the ratio of the actual membrane area (excluding the adhesive layer) to the module area. To increase the effective membrane area, research has been conducted in various directions, such as extending the length or width of the membrane, increasing the area of ​​individual membranes, or reducing the thickness of module components.

[0003] Among these studies, research has been conducted on gas separation membranes with thin film composite (TFC) structures using porous polyolefin supports or heat-resistant porous polymer supports for carbon dioxide (CO2) / nitrogen (N2) gas separation. However, these thin film composite structures face challenges in ensuring stability under thinning, high temperature, and high pressure.

[0004] Therefore, there is still a demand for a gas separation membrane having excellent durability, excellent high-temperature dimensional stability, and excellent CO2 gas separation performance, a method for manufacturing the same, and a module including said gas separation membrane. The problem to be solved

[0005] One aspect is to provide a gas separation membrane having enhanced high-temperature dimensional stability and CO2 gas separation performance, along with enhanced durability.

[0006] Another aspect is to provide a method for manufacturing the above-mentioned gas separation membrane.

[0007] Another aspect is to provide a module including the above-mentioned gas separation membrane. means of solving the problem

[0008] Depending on one aspect,

[0009] porous polymer substrate;

[0010] A porous ceramic-polymer layer on one side of the above porous polymer substrate; and

[0011] A gas separation layer on the other side of the above porous polymer substrate; and

[0012] The gas separation layer has a thickness of 0.1% to 20% relative to the thickness of the porous ceramic-polymer layer, and

[0013] The porous ceramic-polymer layer has a thickness of 0.1% to 50% relative to the thickness of the porous polymer substrate, and

[0014] The above porous ceramic-polymer layer has a melting point (T) of at least 180 °C. m It is an organic-inorganic composite layer comprising a polymer binder having ) and a ceramic material, and

[0015] The above polymer binder comprises at least one binder selected from a cellulose-based binder having functional groups in a side chain, a vinyl alcohol-based binder, and an acrylate-based binder.

[0016] A gas separation membrane is provided having at least one of the functional groups -COOH, -NH2, -OH, -SO3H, -CN, the cation thereof, the anion thereof, and the salt thereof.

[0017] Depending on other aspects of work,

[0018] A step of providing a porous polymer substrate;

[0019] A step of forming a porous ceramic-polymer layer by applying a composition for forming a porous ceramic-polymer layer to one surface of the porous polymer substrate; and

[0020] The method comprises the step of manufacturing a gas separation membrane by applying a composition for forming a gas separation layer to another surface of the porous polymer substrate to form a gas separation layer;

[0021] The above-mentioned porous ceramic-polymer layer forming composition has a melting point (T) of at least 180 °C. mIt includes a polymer binder having ) and a ceramic material, and

[0022] The above polymer binder comprises at least one binder selected from a cellulose-based binder having functional groups in a side chain, a vinyl alcohol-based binder, and an acrylate-based binder.

[0023] The above functional group has at least one of -COOH, -NH2, -OH, -SO3H, -CN, the cations thereof, the anions thereof, and salts thereof, and

[0024] The porous ceramic-polymer layer has a thickness of 0.1% to 50% relative to the thickness of the porous polymer substrate, and

[0025] A method for manufacturing a gas separation membrane is provided, wherein the gas separation layer has a thickness of 0.1% to 20% relative to the thickness of the porous ceramic-polymer layer.

[0026] Depending on another aspect of work,

[0027] Gas inlet section into which supply gas flows in;

[0028] At least one supply channel connected to the above gas inlet;

[0029] At least one transmission channel spaced apart in a direction parallel to the supply channel;

[0030] At least one gas separation membrane disposed between the supply channel and the permeation channel;

[0031] A permeate collection unit for collecting permeate gas connected to the above-mentioned permeate channel; and

[0032] It includes a gas outlet on the opposite side of the gas inlet, through which residual gas not collected in the permeate collection part is discharged; and

[0033] The gas separation membrane is

[0034] porous polymer substrate;

[0035] A porous ceramic-polymer layer on one side of the above porous polymer substrate; and

[0036] A gas separation layer on the other side of the above porous polymer substrate; and

[0037] The gas separation layer has a thickness of 0.1% to 20% relative to the thickness of the porous ceramic-polymer layer, and

[0038] The porous ceramic-polymer layer has a thickness of 0.1% to 50% relative to the thickness of the porous polymer substrate, and

[0039] The above porous ceramic-polymer layer has a melting point (T) of at least 180 °C. m It is an organic-inorganic composite layer comprising a polymer binder having ) and a ceramic material, and

[0040] The above polymer binder comprises at least one binder selected from a cellulose-based binder having functional groups in a side chain, a vinyl alcohol-based binder, and an acrylate-based binder.

[0041] A module is provided having at least one of the functional group -COOH, -NH2, -OH, -SO3H, -CN, the cation thereof, the anion thereof, and the salt thereof. Effects of the invention

[0042] A gas separation membrane according to one aspect comprises a porous polymer substrate, a porous ceramic-polymer layer, and a gas separation layer. The thickness of the gas separation layer is 0.1% to 20% of the thickness of the porous ceramic-polymer layer, and the porous ceramic-polymer layer is 0.1% to 50% of the thickness of the porous polymer substrate. The porous ceramic-polymer layer has a melting point (T) of at least 180 °C. m It is an organic-inorganic composite layer comprising a polymer binder having ) and a ceramic material. The gas separation membrane has improved high-temperature dimensional stability and CO2 gas separation performance along with improved durability. Brief explanation of the drawing

[0043] FIG. 1 is a schematic cross-sectional diagram of a gas separation membrane according to one embodiment. FIG. 2 is a schematic cross-sectional view of a gas separation membrane according to another embodiment. Figure 3a shows an SEM image of the porous polymer substrate of Comparative Reference Example 1 (left) and an enlarged SEM image of its surface (right). Figure 3b shows an SEM image of the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1 (left) and an enlarged SEM image of the surface of the porous ceramic-polymer layer (right). Figure 3c shows an SEM image of the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 3 (left) and an enlarged SEM image of the surface of the porous ceramic-polymer layer (right). Figure 4a is an SEM image of the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1. Figure 4b is an SEM image of the entire gas separation membrane prepared in Example 1. FIG. 5 is a schematic diagram of a spiral wound typed module according to one embodiment. FIG. 6 is a schematic diagram of a plate and frame typed module according to another embodiment. FIG. 7 is a schematic diagram of a gas separation membrane system for capturing CO2 from flue gas according to one embodiment. FIG. 8 is a schematic diagram of a gas separation membrane system for capturing CO2 from flue gas according to another embodiment. FIG. 9 is a schematic diagram illustrating the evaluation of shrinkage rate (heat resistance evaluation) in the longitudinal (MD) and transverse (TD) directions for a gas separation membrane sample according to one embodiment. FIG. 10a is a photograph showing the appearance of the porous polymer substrate of Comparative Reference Example 1 (left), the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1 (middle), and the gas separation membrane prepared in Example 1 (right) before heating. FIG. 10b is a photograph showing the appearance of the porous polymer substrate of Comparative Reference Example 1 (left), the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1 (middle), and the gas separation membrane prepared in Example 1 (right) after heating at a temperature of 150°C for 1 hour. Figure 11 is a schematic diagram of the gas permeability measuring equipment used in Evaluation Example 3. Specific details for implementing the invention

[0044] The present inventive concept described below is subject to various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present inventive concept to specific embodiments and should be understood to include all modifications, equivalents, or substitutions that fall within the scope of the description of the present inventive concept.

[0045] The terms used below are for the purpose of describing specific embodiments only and are not intended to limit the creative concept. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0046] In this specification, expressions such as “at least one,” “one or more,” or “one or more” preceding components are to supplement the list of all components and do not mean that they are to supplement the individual components described above. In this specification, the term “combination” includes mixtures, alloys, reaction products, etc., unless specifically stated otherwise. In this specification, the term “include” means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. In this specification, terms such as “first,” “second,” etc., do not indicate order, quantity, or importance, but are used to distinguish one element from another. Unless otherwise indicated in this specification or clearly contradicted by the context, they should be interpreted to include both singular and plural forms. “Or” means “and / or” unless otherwise specified.

[0047] Throughout this specification, terms such as “one embodiment,” “an embodiment,” etc., mean that specific elements described in relation to an embodiment are included in at least one embodiment described herein and may or may not be present in other embodiments. Furthermore, it should be understood that the described elements may be combined in any appropriate manner in various embodiments.

[0048] Unless otherwise stated, all percentages, parts, ratios, etc. are based on weight. Also, if a quantity, concentration, or other value or parameter is given as a range, a preferred range, or a list of preferred upper and lower limits, this should be understood as specifically disclosing any range formed from any pair of any upper limit or preferred value and any lower limit or preferred value, regardless of whether the range is disclosed separately.

[0049] Where a range of numerical values ​​is mentioned in this specification, unless otherwise stated, the range is intended to include its endpoint and all integers and fractions within that range. The scope of the invention is not intended to be limited to the specific values ​​mentioned when defining the range.

[0050] Unless otherwise specified, the unit “parts by weight” refers to the weight ratio between each component, and the unit “parts by mass” refers to the value obtained by converting the weight ratio between each component into solid content.

[0051] As used herein, “about” means within an acceptable range of deviation from a specific value determined by a person skilled in the art, taking into account errors related to the measurement and the measurement of a specific amount, including the mentioned value (i.e., the limits of the measurement system). For example, “about” may mean within one or more standard deviations, or within ± 30%, 20%, 10%, or 5% of the specified value.

[0052] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art to which this disclosure pertains. Furthermore, it will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with that meaning in the relevant technology and this disclosure, and should not be interpreted as idealized or overly formal.

[0053] Exemplary embodiments are described herein with reference to cross-sectional views, which are schematic diagrams of idealized embodiments. Accordingly, the shape of the examples may vary, for example, as a result of manufacturing techniques and / or tolerances. Accordingly, the embodiments described herein should not be interpreted as being limited to the specific shape of the regions described herein and should include variations in shape that occur, for example, during the manufacturing process. For example, regions that are exemplified or described as flat may generally have rough and / or non-linear features. Also, exemplified acute angles may be rounded. Accordingly, regions exemplified in the drawings are by nature schematic, and their shapes are not intended to exemplify the exact shape of the regions or to limit the scope of the claims.

[0054] When separating CO2 from exhaust gas using a gas separation membrane, the exhaust gas may be in a high-temperature and high-pressure state. Accordingly, the gas separation membrane must possess thermal and mechanical stability when exposed to exhaust gas for extended periods.

[0055] Gas separation membranes are gas separation membrane materials possessing heat resistance and mechanical properties, and have been manufactured by coating a nonwoven fabric with poly(sulfone), poly(ethersulfone), poly(tetrafluoroethylene), or poly(acrylonitrile), followed by a phase transition to form a porous membrane and coating a polymer layer capable of selectively separating carbon dioxide.

[0056] Since the thickness of a single gas separation membrane of this type reaches several micrometers, there was a problem in that the thickness of each component constituting the module had to be reduced. However, even if the thickness of each component constituting the module is reduced, the increase in the effective membrane area, that is, the increase in the actual membrane area / module area excluding the adhesive layer, is limited.

[0057] Based on these points, the inventors of the present invention intend to describe in more detail the following gas separation membrane, a method for manufacturing the same, and a module including said gas separation membrane.

[0059] Gas separation membrane (10, 10')

[0060] FIG. 1 is a schematic cross-sectional view of a gas separation membrane (10) according to one embodiment.

[0061] According to FIG. 1, a gas separation membrane (10) according to one embodiment comprises a porous polymer substrate (1), a porous ceramic-polymer layer (2) on one side of the porous polymer substrate (1), and a gas separation layer (3) on the other side of the porous polymer substrate (1).

[0062] A gas separation membrane (10) according to one embodiment has at least a three-layer structure. The porous polymer substrate (1) comprises a polyolefin-based polymer. A polyolefin-based polymer refers to a polymer that comprises at least 50% by weight of a polyolefin, such as polyethylene, polypropylene, polyisopropylene, or polybutylene, based on 100% by weight of the total polymer composition. Polyolefin-based polymers include homopolymers, copolymers such as ethylene and propylene, graft polymers, or mixtures thereof.

[0063] The weight-average molecular weight (Mw) of the polyolefin polymer may be about 50,000 g / mol to less than about 5,000,000 g / mol. For example, the weight-average molecular weight (Mw) of the polyolefin polymer may be about 100,000 g / mol to less than about 4,500,000 g / mol. In this specification, the weight-average molecular weight (Mw) may be measured by gel permeation chromatography.

[0064] Optionally, for heat resistance or durability, the polyolefin-based polymer may use ultra-high molecular weight polyolefins, such as ultra-high molecular weight polyethylene, either alone or as copolymers. The term "ultra-high molecular weight polyolefin" means a polyolefin having a viscosity-average molecular weight (Mv) of 300,000 g / mol or more. For ease of processing, the viscosity-average molecular weight (Mv) of the ultra-high molecular weight polyolefin may be 4,000,000 g / mol or less. In this specification, the viscosity-average molecular weight (Mv) may be measured using a Ubbelohde viscometer.

[0065] The average pore size of the porous polymer substrate (1) may be 50 nm to 80 nm. For example, the average pore size of the porous polymer substrate (1) may be 50 nm to 70 nm or 50 nm to 60 nm. Since the porous polymer substrate (1) has a small pore size and a small pore distribution within the above average pore size range, a thin film substrate can be easily manufactured.

[0066] The porosity of the porous polymer substrate (1) may be about 25 volume% or more to 80 volume% or 30 volume% or more to 70 volume% based on 100 volume% of total pores. The porous polymer substrate (1) can sufficiently secure gas permeability and mechanical strength within the above porosity range.

[0067] The thickness of the porous polymer substrate (1) may be 10 μm to 40 μm. For example, the thickness of the porous polymer substrate (1) may be 10 μm to 35 μm, 10 μm to 30 μm, 10 μm to 28 μm, 10 μm to 26 μm, 10 μm to 24 μm, 10 μm to 22 μm, 10 μm to 20 μm, 10 μm to 18 μm, or 10 μm to 16 μm. The porous polymer substrate (1) has excellent mechanical strength even within the above thin film thickness range.

[0068] The porous ceramic-polymer layer (2) is located on one side of the porous polymer substrate (1).

[0069] The porous ceramic-polymer layer (2) has a melting point (T) of at least 180°C. m It may be an organic-inorganic composite layer comprising a polymer binder having ) and a ceramic material.

[0070] The porous ceramic-polymer layer (2) may be formed by connecting and fixing the ceramic material to the polymer binder. The ceramic material may exist in the form of particles distributed in the polymer binder at a uniform density.

[0071] A ceramic material according to an exemplary embodiment may be a spherical ceramic material having an average particle size of 0.1 μm to 1 μm, a plate-shaped ceramic material having an average particle size of 0.1 μm to 10 μm, or a ceramic material having a mixed structure thereof.

[0072] Examples of spherical ceramic materials may include at least one selected from alumina (Al2O3), boehmite (γ-AlO(OH)), and silica (SiO2). The spherical ceramic material has empty spaces between the numerous ceramic particles, forming micropores of less than 1 μm. The spherical ceramic material has excellent heat resistance, so it can prevent the porous ceramic-polymer layer (2) and the gas separation membrane containing it from rapidly shrinking or deforming even under high temperatures.

[0073] The average particle size of the spherical ceramic material may be 0.1 μm to 1 μm. If the average particle size of the spherical ceramic material is less than 0.1 μm, the dispersibility of the particles is reduced, making it difficult to form a uniform porous ceramic-polymer layer (2), and if the average particle size of the ceramic material is greater than 1 μm, the mechanical properties may be reduced and the gas separation performance may be reduced.

[0074] In this specification, the average particle size is "D 50 It means the value. "D 50The term "value" refers to the particle diameter value corresponding to 50% of the smallest particles when the total number of particles is set to 100%, in a distribution curve accumulated from the smallest particles to the largest particles. The average particle diameter (D) of a two-dimensional or three-dimensional ceramic material. 50 Methods for measuring ) include measuring with a particle size analyzer or measuring from TEM or SEM images. Alternatively, it can be obtained by measuring using a dynamic light-scattering measuring device, performing data analysis to count the number of particles for each particle size range, and then calculating from this.

[0075] Examples of plate-shaped ceramic materials may include at least one selected from magnesium hydroxide (Mg(OH)2), aluminum hydroxide (Al(OH)3), mica, clay, and talc.

[0076] The average particle size of the plate-shaped ceramic material may be 0.1 μm to 10 μm. If the average particle size of the plate-shaped ceramic material is less than 0.1 μm, the dispersion of the particles is reduced, making it difficult to form a uniform porous ceramic-polymer layer (2), and if the average particle size of the plate-shaped ceramic material is greater than 10 μm, the mechanical properties may be reduced and the gas separation performance may be reduced.

[0077] The polymer binder enables the spherical or / and plate-shaped ceramic material particles to be well dispersed without mutual aggregation and to adhere well to the porous polymer substrate (1).

[0078] A polymer binder according to an exemplary embodiment may comprise at least one binder selected from a cellulose-based binder, a vinyl alcohol-based binder, and an acrylate-based binder having a functional group in a side chain. The functional group may have at least one of -COOH, -NH2, -OH, -SO3H, -CN, the cation thereof, the anion thereof, and the salt thereof.

[0079] For example, polymer binders include cellulose-based binders such as hydroxypropylmethylcellulose (HPMC), hydroxyethylmethylcellulose (HEMC), hydroxyethylcellulose (HEC), and carboxymethylcellulose (CMC); vinyl alcohol-based binders such as polyvinyl alcohol (PVA); and may include acrylic binders such as polyacrylic acid (PAA), polyacrylate, polymethacrylic acid, polyacrylate, 2-hydroxyacrylate, 4-hydroxybutylacrylate, 2-hydroxyethylacrylate, 2-hydroxypropylacrylate, 2-hydroxy-3-phenoxypropylacrylate, polyurethaneacrylate, polymethacrylate, polyacrylamide, polymethacrylamide, polyacrylonitrile, polymethacrylonitrile, and polyethacrylonitrile. The polymer binder may use the above-described polymer binder alone, use a mixture of two or more types, or use two or more copolymers.

[0080] Since the functional groups of the side chains of the polymer binder are hydrophilic, they easily adsorb onto the surface of hydrophilic ceramic materials to form a binder surface adsorption layer. These binder surface adsorption layers adhere to each other to form a rigid film.

[0081] Among the acrylic binders, the weight-average molecular weight of the acrylic copolymer may be 200,000 g / mol to 700,000 g / mol, for example, 200,000 g / mol to 600,000 g / mol, or 300,000 g / mol to 700,000 g / mol. When the weight-average molecular weight of the acrylic copolymer satisfies the above range, the porous ceramic-polymer layer (2) containing the acrylic copolymer may have excellent adhesion, heat resistance, air permeability, etc.

[0082] Among the cellulose-based binders, the weight-average molecular weight of carboxymethylcellulose (CMC) may be 50,000 g / mol to 250,000 g / mol, for example, 700,000 g / mol to 250,000 g / mol, or 10,000 g / mol to 250,000 g / mol.

[0083] The vinyl alcohol-based binder may be a polyvinyl alcohol-based polymer comprising repeating units having -OH functional groups, or a polyvinyl alcohol-based polymer in which some of the -OH functional groups are modified into functional groups such as carboxyl groups, sulfonic acid groups, amino groups, silanol groups, thiol groups, etc. The weight-average molecular weight of the polyvinyl alcohol-based polymer may be 10,000 g / mol to 50,000 g / mol, and for example, 15,000 g / mol to 30,000 g / mol.

[0084] The weight-average molecular weight described in this specification may be the polystyrene-equivalent average molecular weight measured using gel permeation chromatography.

[0085] The weight ratio of the polymer binder to the ceramic material may be 1:8 to 1:45. When the weight ratio of the polymer binder to the ceramic material is within the above range, the ceramic material within the polymer binder can obtain sufficient dispersion stability, and the porous ceramic-polymer layer (2) is uniformly formed, thereby providing a gas separation membrane with improved high-temperature dimensional stability and CO2 gas separation performance.

[0086] The pore size of the porous ceramic-polymer layer (2) may be 10 nm to 999 nm. For example, the pore size of the porous ceramic-polymer layer (2) may be 10 nm to 500 nm. The porous ceramic-polymer layer (2) may have excellent CO2 gas permeability by forming micropores within the above range.

[0087] The porosity of the porous ceramic-polymer layer (2) may be about 25 volume% or more to 60 volume% or 30 volume% or more to 50 volume% based on 100 volume% of total pores. The porous ceramic-polymer layer (2) may have excellent CO2 gas permeability and improved high-temperature dimensional stability within the above porosity range.

[0088] A porous ceramic-polymer layer (2) located on one side of a porous polymer substrate (1) has a thickness of 0.1% to 50% relative to the thickness of the porous polymer substrate (1). For example, the porous ceramic-polymer layer (2) may have a thickness of 1% to 48%, 3% to 45%, 5% to 42%, 7% to 40%, 9% to 38%, 11% to 35%, 13% to 32%, or 15% to 32%. The porous ceramic-polymer layer (2) may have excellent high-temperature dimensional stability even within the above thin film thickness range.

[0089] A gas separation layer (3) is located on the other side of the porous polymer substrate (1).

[0090] The gas separation layer (3) serves to allow specific gases to pass through from exhaust gas or flue gas. The gas separation layer (3) includes a (co)polymer that preferentially allows CO2 gas to pass through.

[0091] The gas separation layer (3) comprises a polymer or copolymer having C1-C5 alkylene oxide structural units in the main chain. The weight-average molecular weight (Mw) of the polymer or copolymer may be 50,000 g / mol to 200,000 g / mol, 60,000 g / mol to 150,000 g / mol, or 700,000 g / mol to 150,000 g / mol.

[0092] For example, a polymer containing C1-C5 alkylene oxide structural units in the main chain may be a cross-linked C1-C5 alkylene oxide. The cross-linked C1-C5 alkylene oxide is a copolymer containing C1-C5 alkylene oxide repeating units and may be a polymer having double bonds or carboxyl groups, amine groups, hydroxyl groups, or cyano groups at both ends and capable of being cross-linked by heat or light after coating.

[0093] Cross-linked C1-C5 alkylene oxides have superior CO2 gas permeability.

[0094] Cross-linked C1-C5 alkylene oxides can be formed by a reaction initiated by electron beam irradiation or UV, heat, etc.

[0095] The content of the above C1-C5 alkylene oxide structural units may be 50% to 100% by weight based on 100% by weight of the total structural units of the main chain. For example, the content of the above C1-C5 alkylene oxide structural units may be 50% to 90% by weight or 50% to 80% by weight based on 100% by weight of the total structural units of the main chain.

[0096] The copolymer may comprise a block copolymer comprising C1-C5 alkylene oxide rubbery structural units and hard structural units in the main chain. The rubbery structural units may have a glass transition temperature of -80°C to -50°C. The hard structural units may have a melting point of 180°C to 200°C. For example, the hard structural units may comprise one or more selected from polyamide, polybutylene terephthalate, polybutadiene, polychloroprene, and polyurethane.

[0097] For example, the copolymer may include a block copolymer comprising C1-C5 alkylene oxide structural units and amide structural units. The alkylene oxide repeating units may have a glass transition temperature of -80 °C to -40 °C. For example, the alkylene oxide repeating units may have a glass transition temperature of -70 °C to -40 °C, or -60 °C to -40 °C.

[0098] Optionally, the gas separation layer (3) may additionally include polyacrylic acid, polyvinyl alcohol, polyethyleneimine, polyvinylamine, polyallylamine, or polyvinylpyrrolidone.

[0099] Optionally, the gas separation layer (3) may include additives such as a radical scavenger, a peroxide decomposer, a surfactant, a filler, and a crosslinking agent. The content of the additive may be 0.01% to 5% by weight based on 100% by weight of the total gas separation layer (3).

[0100] The gas separation layer (3) may have a thickness of 0.1% to 20% relative to the porous ceramic-polymer layer. For example, the gas separation layer (3) may have a thickness of 0.1% to 18%, 0.1% to 16%, 0.1% to 14%, 0.1% to 12%, or 0.1% to 10% relative to the porous ceramic-polymer layer. The gas separation layer (3) may have improved carbon dioxide (CO2) / nitrogen (N2) selectivity and improved high-temperature dimensional stability even within the thin film thickness range.

[0101] The gas separation layer (3) may be a layer that separates carbon dioxide (CO2) / nitrogen (N2) gas.

[0102] The gas separation membrane (10) has a selectivity for carbon dioxide (CO2) / nitrogen (N2) according to the following formula 1 ( ) can be 20 to 100:

[0103] [Equation 1]

[0104] = .

[0105] The shrinkage rate of the gas separation membrane (10) in the longitudinal direction (MD) and transverse direction (TD) according to the following formula 2 may both be greater than 0% and less than 5%:

[0106] [Equation 2]

[0107] Shrinkage rate (%) =

[0108] During the meal,

[0109] D0 may represent the length before heating in the MD direction or TD direction of the gas separation membrane, and

[0110] Dh can represent the length in the MD direction or TD direction after heating the above gas separation membrane at a temperature of 150 ℃ for 1 hour.

[0111] FIG. 2 is a schematic cross-sectional view of a gas separation membrane (10') according to one embodiment.

[0112] According to FIG. 2, a gas separation membrane (10') according to one embodiment comprises a porous polymer substrate (1'), a porous ceramic-polymer layer (2') and a gas separation layer (3') sequentially arranged on one side of the porous polymer substrate (1'). The specific composition, content, thickness, and characteristics of the porous polymer substrate (1'), the porous ceramic-polymer layer (2'), the gas separation layer (3'), and the gas separation membrane (10') are the same as those described above, so further explanation is omitted.

[0114] Method for manufacturing a gas separation membrane (10, 10')

[0115] A method for manufacturing a gas separation membrane (10) according to another embodiment comprises the steps of: providing a porous polymer substrate (1); forming a porous ceramic-polymer layer (2) by applying a composition for forming a porous ceramic-polymer layer to one surface of the porous polymer substrate (1); and manufacturing a gas separation membrane (10) by forming a gas separation layer (3) by applying a composition for forming a gas separation layer to the other surface of the porous polymer substrate (1); wherein the composition for forming a porous ceramic-polymer layer has a melting point (T) of at least 180°C. m The polymer binder and ceramic material having ) may be included, wherein the polymer binder comprises at least one binder selected from a cellulose-based binder, a vinyl alcohol-based binder, and an acrylate-based binder having functional groups in a side chain, and the functional group has at least one of -COOH, -NH2, -OH, -SO3H, -CN, the cation thereof, the anion thereof, and the salt thereof, and the porous ceramic-polymer layer (2) may have a thickness of 0.1% to 50% relative to the thickness of the porous polymer substrate (1), and the gas separation layer (3) may have a thickness of 0.1% to 20% relative to the thickness of the porous ceramic-polymer layer (2).

[0116] A porous polymer substrate (1) is provided. The porous polymer substrate (1) comprises a polyolefin-based polymer. Examples of polyolefin-based polymers include homopolymers of polyethylene, polypropylene, polyisopropylene, or polybutylene, copolymers thereof, graft polymers, or mixtures thereof. Optionally, the polyolefin-based polymer may comprise a mixture of a polyolefin polymer and a non-polyolefin polymer or a copolymer of an olefin and a non-olefin monomer.

[0117] The weight-average molecular weight (Mw) of the polyolefin polymer may be about 50,000 g / mol to less than about 5,000,000 g / mol.

[0118] The average pore size of the porous polymer substrate (1) may be 50 nm to 200 nm, 50 nm to 100 nm, or 50 nm to 70 nm.

[0119] The porosity of the porous polymer substrate (1) may be about 10 volume% or more to 30 volume% or 10 volume% or more to 20 volume% based on 100 volume% of total pores.

[0120] The thickness of the porous polymer substrate (1) may be 10 μm to 40 μm. For example, the thickness of the porous polymer substrate (1) may be 10 μm to 35 μm, 10 μm to 30 μm, 10 μm to 28 μm, 10 μm to 26 μm, 10 μm to 24 μm, 10 μm to 22 μm, 10 μm to 20 μm, 10 μm to 18 μm, or 10 μm to 16 μm.

[0121] Next, a composition for forming a porous ceramic-polymer layer is applied to one side of a porous polymer substrate (1) to form a porous ceramic-polymer layer (2).

[0122] A composition for forming a porous ceramic-polymer layer has a melting point (T) of at least 180 °C. mIt may be a slurry mixed with a polymer binder having ), a ceramic material, and a solvent. The composition for forming a porous ceramic-polymer layer has a melting point (T) of 180 °C. m A mixture can be prepared by mixing a polymer binder having ) and a solvent, and a slurry can be prepared by adding and dispersing a ceramic material into the mixture.

[0123] The solvent may include water, deionized water, or a water-soluble organic solvent. Examples of water-soluble organic solvents may include alcohol-based solvents such as ethanol, propanol, butanol, 1,5-pentanediol, and 1-methylamino-2,3-propanediol; lactone-based solvents such as ε-caprolactone and α-acetyl γ-butyrolactone; glycol-based solvents such as diethylene glycol, 1,3-butylene glycol, and propylene glycol; glycol ether-based solvents such as triethylene glycol dimethyl ether, tripropylene glycol dimethyl ether, and diethylene glycol monobutyl ether; and carbonate-based solvents such as propylene carbonate and ethylene carbonate. The above-described water-soluble organic solvents may be used alone or in a mixture of two or more types.

[0124] Conventional methods may be used for mixing, for example, by a mixer equipped with planetary and desper. The mixing time may be carried out for about 1 to about 20 hours. Alternatively, as a mixing method, a mixing vessel with a melting point (T) of 180 °C m A slurry may also be prepared by providing a polymer binder having ), a ceramic material, and a solvent all at once and mixing them by a stirring blade.

[0125] Optionally, a grinding process of the ceramic material may be performed before and after mixing the ceramic material in the form of a slurry. The grinding method of the ceramic material may use conventional methods, and milling methods such as ball milling or bead milling may be used, for example.

[0126] The weight ratio of the polymer binder to the ceramic material may be 1:8 to 1:45. When the weight ratio of the polymer binder to the ceramic material is within the above range, sufficient dispersion stability of the ceramic material within the polymer binder can be obtained, and a porous ceramic-polymer layer (2) is uniformly formed, thereby providing a gas separation membrane having improved high-temperature dimensional stability and CO2 gas separation performance.

[0127] The particle size, structure, and type of the ceramic material and the type of the polymer binder are the same as those described above, so further explanation is omitted.

[0128] Conventional methods can be used for the coating method, such as dip coating, spin-got coating, roll coating, Meyer bar coating, comma coating, die coating, gravure coating, screen printing, offset printing, brush coating, spray coating, or a combination of these coating methods. After coating, the porous ceramic-polymer layer (2) is formed by drying at room temperature or in an oven.

[0129] The pore size of the porous ceramic-polymer layer (2) may be 10 nm to 999 nm. For example, the pore size of the porous ceramic-polymer layer (2) may be 10 nm to 500 nm.

[0130] The porosity of the porous ceramic-polymer layer (2) may be about 10 volume% or more to 50 volume% or 15 volume% or more to 30 volume% based on 100 volume% of total pores.

[0131] A porous ceramic-polymer layer (2) located on one side of a porous polymer substrate (1) has a thickness of 0.1% to 50% relative to the thickness of the porous polymer substrate (1). For example, the porous ceramic-polymer layer (2) may have a thickness of 1% to 48%, 3% to 45%, 5% to 42%, 7% to 40%, 9% to 38%, 11% to 35%, 13% to 32%, or 15% to 32%.

[0132] Next, a composition for forming a gas separation layer is applied to the other side of the porous polymer substrate (1) to form a gas separation layer (3) and to manufacture a gas separation membrane (10, 10').

[0133] The composition for forming a gas separation layer may be a slurry mixed with a solvent and a polymer or copolymer containing C1-C5 alkylene oxide structural units in the main chain.

[0134] The solvent may include water, ion-exchanged water, or a water-soluble organic solvent. Examples of water-soluble organic solvents may include the alcohol-based, lactone-based, glycol-based, glycol ether-based, and carbonate-based solvents described above.

[0135] A mixed solvent comprising water or ion-exchanged water and a water-soluble organic solvent may be used. The weight ratio of the mixed solvent may be 7:3 to 8:2. Within the above weight ratio range, the mixed solvent may have improved carbon dioxide (CO2) / nitrogen (N2) selectivity and high-temperature dimensional stability.

[0136] The content of the above C1-C5 alkylene oxide structural units may be 50% to 100% by weight based on 100% by weight of the total structural units of the main chain. For example, the content of the above C1-C5 alkylene oxide structural units may be 50% to 90% by weight or 50% to 80% by weight based on 100% by weight of the total structural units of the main chain.

[0137] The copolymer may include a block copolymer comprising C1-C5 alkylene oxide rubbery structural units and hard structural units in the main chain. The rubbery structural units may have a glass transition temperature of -80°C to -50°C. The hard structural units may have a melting point of 180°C to 200°C. For example, the hard structural units may include one or more selected from polyamide, polybutylene terephthalate, polybutadiene, polychloroprene, and polyurethane.

[0138] Optionally, the composition for forming the gas separation layer may include a polymer such as polyacrylic acid, polyvinyl alcohol, polyethyleneimine, polyvinylamine, polyallylamine, or polyvinylpyrrolidone.

[0139] Optionally, the composition for forming the gas separation layer may additionally include additives such as radical scavengers, peroxide decomposers, surfactants, fillers, and crosslinking agents. The content of the additives may be 0.01% to 5% by weight based on 100% by weight of the total gas separation layer (3).

[0140] The mixing method, coating method, and drying of the composition for forming the gas separation layer are the same as the mixing method, coating method, and drying of the porous ceramic-polymer layer (2), so the following description is omitted.

[0141] The gas separation layer (3) may have a thickness of 0.1% to 20% relative to the porous ceramic-polymer layer (2). For example, the gas separation layer (3) may have a thickness of 0.1% to 18%, 0.1% to 16%, 0.1% to 14%, 0.1% to 12%, or 0.1% to 10% relative to the porous ceramic-polymer layer (2).

[0142] The gas separation layer (3) may be a layer that separates carbon dioxide (CO2) / nitrogen (N2) gas.

[0143] A method for manufacturing a gas separation membrane (10') according to another embodiment comprises the steps of: providing a porous polymer substrate (1'); forming a porous ceramic-polymer layer (2') by applying a composition for forming a porous ceramic-polymer layer to one side of the porous polymer substrate (1'); and manufacturing a gas separation membrane (10') by forming a gas separation layer (3') by applying a composition for forming a gas separation layer to the opposite side of the porous polymer substrate (1') of the porous ceramic-polymer layer (2').

[0144] The specific steps for providing a porous polymer substrate (1'), forming a porous ceramic-polymer layer (2'), and forming a gas separation layer (3') to manufacture a gas separation membrane (10') are described as above, so the description below is omitted.

[0146] Module including a gas separation membrane (10, 10')

[0147] A module according to another embodiment comprises: a gas inlet into which a supply gas is introduced; at least one supply channel connected to the gas inlet; at least one permeable channel spaced apart in a direction parallel to the supply channel; at least one gas separation membrane disposed between the supply channel and the permeable channel; a permeate collection unit for collecting permeate gas connected to the permeable channel; and a gas outlet unit on the opposite side of the gas inlet into which residual gas not collected in the permeate collection unit is discharged.

[0148] A module according to an exemplary implementation example may be the following module.

[0149] FIG. 5 is a schematic diagram of a spiral wound typed module (100) according to one embodiment.

[0150] According to FIG. 5, a spiral-wound module (100) according to one embodiment is a module having a structure in which a plurality of packets, each consisting of a supply channel (115) having a spacer, a gas separation membrane (112), and a permeation channel (111) having a spacer, are spirally wound around a permeate collection porous tube (113) connected to the permeation channel (111). The spacers of the supply channel (115) and the permeation channel (111) may each be in the form of a mesh. The gas separation membrane envelope (114) may be sealed with an adhesive. The exterior of the module may be wrapped with glass fiber.

[0151] The spiral-wound module (100) may have a gas inlet located at one end (left) through which a flue gas containing CO2, N2, etc. is introduced. For example, the flue gas supply gas may be introduced by applying pressure to the gas inlet. The introduced supply gas passes through the gas separation membrane (112), and a residual gas flow with diluted CO2 may exist at the opposite end. The gas separation membrane (112) may be the gas separation membrane (10, 10') described above. The gas separation membrane (112) is a membrane with strong selectivity for CO2 gas, so that CO2 gas can first penetrate into the gas separation membrane envelope (114). The permeate gas, i.e., CO2 gas, can be collected in the permeate collection tube (113) by flowing downward along the gas separation membrane envelope (114) under vacuum in a direction opposite to the supply flow. Alternatively, the permeate gas can be allowed to flow air into the holes of the permeate collection tube (113) through the permeate channel (111) in a direction opposite to the supply flow due to a pressure difference. Optionally, a pipe plug may be positioned in the middle of the permeate collection tube (113) to allow a portion of the CO2 gas to pass out without backflow. A gas outlet is located in the permeate collection tube (113) for the discharge of residual gas that is not collected.

[0152] The packing density of the spiral-wound module (100) is 200 m 2 / m 3 to 1000 m 2 / m 3 It may be. Packing density has the same meaning as effective film area / module volume. Since the spiral-wound module (100) described above has a high packing density, it can provide a module with improved performance used in flat films.

[0153] FIG. 6 is a schematic diagram of a plate and frame typed module (200) according to another embodiment.

[0154] According to FIG. 6, the plate and frame typed module (200) is a module having a structure in which two sets of membranes are stacked on one frame to form a sandwich-like shape and are positioned toward a gas inlet where a supply gas is introduced. The membrane sets are alternately stacked with a supply channel (115'), a gas separation membrane (112'), and a permeable channel (111') having a spacer. The spacer of the permeable channel (111') may be in the form of a mesh. Although not shown in the supply channel (115'), it may include a mesh-shaped spacer. At least one baffle (120') may be included between adjacent supply channels. The baffle (120') serves to improve the flow of the supply gas. For example, the baffle (120') may be in the form of a cylinder with a plurality of through holes formed on its surface. The gas separation membrane (112') may be the gas separation membrane (10, 10') described above. The gas separation membrane (112') is a membrane with strong selectivity for CO2 gas, and CO2 gas can be permeated by flowing upward under vacuum in a direction intersecting the supply flow from the gas inlet where flue gas is introduced. The CO2-concentrated gas that is not permeated is discharged to the gas outlet located on the opposite side of the gas inlet.

[0155] The packing density of the flat module (200) is 30 m 2 / m 3 to 500 m 2 / m 3 It may be. The flat plate module (200) has the lowest pressure drop.

[0157] System using a gas separation membrane (10, 10')

[0158] A system using a gas separation membrane (10, 10') according to an exemplary embodiment may be the following system.

[0159] FIG. 7 is a schematic diagram of a gas separation membrane system for capturing CO2 from flue gas according to one embodiment.

[0160] According to a gas separation membrane system for capturing CO2 from flue gas according to one embodiment of FIG. 7, flue gas containing CO2, N2, etc. is introduced into a wet scrubber (131). The flue gas introduced from the wet scrubber (131) is cooled to the operating temperature of the gas separation membrane (133). The cooled flue gas passes through a compressor (132) and is supplied into a module (133) containing a gas separation membrane. A portion of the CO2 permeate gas and concentrated CO2 gas (stream) that have passed through the module (133) containing the gas separation membrane are obtained on the permeate side. Meanwhile, the flue gas is discharged to the gas outlet as residual gas. Since the partial pressure of the CO2 gas is very low, a compressor (132) and a vacuum pump (134, 134') are used to increase the partial pressure between the supply side and the permeate side. The concentrated CO2 permeate gas is cooled through an intercooling (135) process between vacuum pumps (134, 134') and an aftercooling (136) process after the vacuum pump (134').

[0161] FIG. 8 is a schematic diagram of a gas separation membrane system for capturing CO2 from flue gas according to another embodiment.

[0162] According to a gas separation membrane system for capturing CO2 from flue gas according to another embodiment of FIG. 8, flue gas containing CO2, N2, etc. undergoes pretreatment, passes through a filter (211) for removing contaminants, and then passes through a cooler (212) to remove moisture. The flue gas from which moisture has been removed is transferred to a compressor (213). The flue gas passing through the compressor (213) is humidified and adjusted to the operating temperature of the gas separation membrane unit (216) in a humidifier (214) containing a heat exchanger (215). The CO2 permeated gas passing through the gas separation membrane unit (216) passes through a vacuum pump (217) and a condenser (218) to capture CO2 gas. The residual gas in the flue gas from the gas separation membrane unit (216) is discharged through a vent.

[0163] The gas separation membrane system for CO2 capture according to FIGS. 7 and 8 includes a cooling process and a compression process in front of a module (133) or gas separation membrane unit (216) that includes a gas separation membrane.

[0164] Therefore, a system using a gas separation membrane (10, 10') according to the implementation has improved durability and improved high-temperature dimensional stability, so the operating range of the cooling and compression processes can be expanded and CO2 capture costs can be reduced.

[0166] Examples and comparative examples of the present invention are described below. However, the following examples are merely one example of the present invention, and the present invention is not limited to the following examples.

[0168] [Example]

[0170] Comparative Reference Example 1: Porous polymer substrate

[0171] A 14.35 μm thick polyethylene porous substrate (G14AB1, manufactured by Toray, average pore size: approximately 55 nm) was prepared as a porous polymer substrate.

[0173] Reference Example 1: Porous polymer substrate / porous ceramic (Al 2 O 3 )-Polymer (CMC) layer

[0174] On one side of the polyethylene porous substrate of Comparative Reference Example 1, a carboxymethylcellulose (CMC) binder (Carboxymethylcellulose sodium salt, medium viscocity, Sigma-Aldrich) and 0.9 μm D 50 A composition (solid content: about 20%) in which alumina (Al2O3) of particle size was dissolved in ion-exchanged water at a weight ratio of 1:45 and mixed was applied with a bar coater and dried at about 80°C for 12 hours to form a porous ceramic-polymer layer (pore size: 320 nm) with a thickness of about 4.7 μm.

[0176] Reference Example 2: Porous polymer substrate / porous ceramic (Al 2 O 3 )-Polymer (Acrylic copolymer / PVA) layer

[0177] An acrylic copolymer binder was prepared as follows.

[0178] Distilled water (968 g), acrylic acid (45.00 g, 0.62 mol), ammonium persulfate (0.54 g, 2.39 mmol, 1500 ppm relative to monomer), 2-acrylamido-2-methylpropanesulfonic acid (5.00 g, 0.02 mol), and 5N sodium hydroxide aqueous solution (0.8 equivalents relative to the total amount of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid) were added to a 3 L 4-neck flask equipped with a stirrer, thermometer, and condenser. After reducing the internal pressure to 10 mmHg using a diaphragm pump and returning the internal pressure to atmospheric pressure with nitrogen, the operation was repeated 3 times, and then acrylonitrile (50.00 g, 0.94 mol) was added.

[0179] The reaction was carried out for 18 hours while controlling the temperature of the reaction solution to stabilize between 65 °C and 70 °C. After adding ammonium persulfate (0.23 g, 1.00 mmol, 630 ppm relative to the monomer), the temperature was raised to 80 °C and the reaction was carried out for another 4 hours. After cooling to room temperature, the pH of the reaction solution was adjusted to 7 to 8 using a 25% aqueous ammonia solution to prepare poly(acrylic acid-co-acrylonitrile-co-2-acrylamido-2-methylpropanesulfonic acid) sodium salt. The molar ratio of acrylic acid, acrylonitrile, and 2-acrylamido-2-methylpropanesulfonic acid was 39:59:2. Approximately 10 mL of the reaction solution (reaction product) was taken and the non-volatile component was measured, resulting in 9.0% (theoretical value: 10%).

[0180] Prepared acrylic copolymer binder, polyvinyl alcohol (PVA) binder (Poly(vinyl alcohol), Mw: 13,000-23,000, 87-89% hydrolyzed, Sigma-Aldrich) (weight ratio = 70:30) and 0.9 μm D 50 A porous ceramic-polymer layer (pore size: 300 nm) with a thickness of about 4.2 μm was formed on one side of a porous polymer substrate in the same manner as Reference Example 1, except that a composition (solid content: about 30%) in which alumina (Al2O3) of particle size was dissolved and mixed in ion-exchanged water at a weight ratio of 1:35 (solid content: about 30%) was applied with a bar coater and dried.

[0182] Reference Example 3: Porous polymer substrate / porous ceramic (Mg(OH) 2 )-Polymer (Acrylic copolymer / PVA) layer

[0183] Acrylic copolymer binder prepared in Reference Example 2, polyvinyl alcohol (PVA) binder (Poly(vinyl alcohol), Mw: 13,000-23,000, 87-89% hydrolyzed, Sigma-Aldrich) (weight ratio = 90:10) and 1.2 μm D 50A porous ceramic-polymer layer (pore size: 250 nm) with a thickness of about 4.4 μm was formed on one side of a porous polymer substrate in the same manner as Reference Example 1, except that a composition (solid content: about 30%) obtained by dissolving and mixing magnesium hydroxide (Mg(OH)2) of particle size in ion-exchanged water at a weight ratio of 1:45 (solid content: about 30%) was applied with a bar coater and dried.

[0185] Reference Example 4: Porous polymer substrate / porous ceramic (Al 2 O 3 )-Polymer (PUA / PVdF) layer

[0186] Polyurethane acrylate (PUA) binder, PVdF binder (KF9300, Kureha) ((weight ratio = 50:50), SC2152, Miwon Specialty Chemical Co. Ltd.) and 0.9 μm D 50 A porous ceramic-polymer layer (pore size: 200 nm) with a thickness of about 4.4 μm was formed on one side of a porous polymer substrate in the same manner as Reference Example 1, except that a composition (solid content: about 40%) in which alumina (Al2O3) of particle size was dissolved and mixed in an acetone / dimethylacetamide (DMAc) mixture (weight ratio = 80:20) at a weight ratio of 1:8 was applied with a bar coater and dried.

[0188] Reference Example 5: Porous polymer substrate / porous ceramic (Al 2 O 3 )-Polymer (PUA / PVdF) layer

[0189] Polyurethane acrylate (PUA) binder, PVdF binder (KF9300, Kureha) ((weight ratio = 50:50), SC2152, Miwon Specialty Chemical Co. Ltd.) and 0.9 μm D 50A porous ceramic-polymer layer (pore size: 220 nm) with a thickness of about 4.5 μm was formed on one side of a porous polymer substrate in the same manner as in Reference Example 1, except that a composition (solid content: about 25%) in which alumina (Al2O3) of particle size was dissolved and mixed in an acetone / dimethylacetamide (DMAc) mixture (weight ratio = 80:20) at a weight ratio of 1:20 was applied with a bar coater and dried.

[0191] Example 1: Gas separation membrane

[0192] A gas separation membrane was prepared by forming a gas separation layer with a thickness of about 516 nm by applying a composition (solid content: about 6%) (where a polyethylene (PEO)-polyamide (PA6) block copolymer (PEO content = about 57 wt%, Mw: 140,000 g / mol, PEBAX 1657, Arkema)) dissolved in a mixed solvent consisting of ethanol and water (weight ratio = 7:3) and mixed on the other side of a porous polymer substrate having a porous ceramic (Al2O3)-polymer (CMC) layer prepared in Reference Example 1, using a bar coater and drying at about 60°C for 12 hours.

[0194] Example 2: Gas separation membrane

[0195] A gas separation membrane was prepared in the same manner as in Example 1, except that a polyethylene (PEO)-polyamide (PA6) block copolymer (PEO content = about 57 wt%, Mw: 140,000 g / mol, PEBAX 1657, Arkema) was dissolved in a mixed solvent consisting of ethanol and water (weight ratio = 7:3) and mixed, and the resulting composition (solid content: about 6%) was coated with a bar coater and dried to form a gas separation layer about 343 nm thick.

[0197] Example 3: Gas separation membrane

[0198] A gas separation membrane was prepared in the same manner as in Example 1, except that a polyethylene (PEO)-polyamide (PA6) block copolymer (PEO content = about 57 wt%, Mw: 140,000 g / mol, PEBAX 1657, Arkema) was dissolved in a mixed solvent consisting of ethanol and water (weight ratio = 7:3) and mixed, and the resulting composition (solid content: about 3%) was coated with a bar coater and dried to form a gas separation layer about 265 nm thick.

[0200] Example 4: Gas separation membrane

[0201] A gas separation membrane was prepared in the same manner as in Example 1, except that a polyethylene (PEO)-polyamide (PA6) block copolymer (PEO content = about 57 wt%, Mw: 140,000 g / mol, PEBAX 1657, Arkema) was dissolved in a mixed solvent consisting of ethanol and water (weight ratio = 8:2) and mixed, and the resulting composition (solid content: about 3%) was coated with a bar coater and dried to form a gas separation layer about 249 nm thick.

[0203] Example 5: Gas separation membrane

[0204] A gas separation membrane was prepared in the same manner as in Example 1, except that a composition (solid content: about 3%) was prepared by dissolving a polyethylene (PEO)-polyamide (PA6) block copolymer (PEO content = about 57 wt%, Mw: 140,000 g / mol, PEBAX 1657, Arkema) in a mixed solvent consisting of ethanol and water (weight ratio = 8:2) and mixing it, and then applying and drying it with a bar coater to form a gas separation layer about 163 nm thick.

[0206] Evaluation Example 1: SEM Analysis - Substrate, Ceramic-Polymer Layer, Gas Separation Layer

[0207] SEM analysis was performed to confirm the porous polymer substrate of Comparative Reference Example 1 and the surface and thickness of each layer of the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1 and Reference Example 3. The results are shown in Figures 3a, 3b, and 3c, respectively.

[0208] The scanning electron microscope (SEM) used for SEM analysis was Hitachi SU-8030, and images were taken at magnifications of 4,000x and 50,000x, respectively.

[0209] Referring to Fig. 3a, the thickness of the porous polymer substrate of Comparative Reference Example 1 is about 15 μm, and it shows pores of about 50 nm to 60 nm in size formed on its surface.

[0210] Referring to Fig. 3b, the porous ceramic-polymer layer in the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1 has a thickness of about 4.7 μm and shows an A2O3 ceramic material with a particle size of about 0.9 μm and pores of about 320 nm formed on its surface.

[0211] Referring to Fig. 3c, the porous ceramic-polymer layer in the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 3 has a thickness of about 4.4 μm and shows an A2O3 ceramic material with a particle size of about 1.2 μm and pores of about 250 nm formed on its surface.

[0212] In addition, SEM analysis was performed to confirm the thickness of each layer of the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1 and the gas separation membrane prepared in Example 1. The results are shown in Figures 4a and 4b, respectively.

[0213] Referring to FIGS. 4a and 4b, the gas separation membrane can be seen to consist of a gas separation layer (3) with a thickness of 516 nm, a porous polymer substrate (1) with a thickness of 14.35 μm, and a porous ceramic-polymer layer (2) with a thickness of 4.047 μm.

[0215] Evaluation Example 2: Evaluation of properties of porous polymer substrate / porous ceramic-polymer layer

[0216] The physical properties of the porous polymer substrate of Comparative Reference Example 1 and all or part of the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Examples 1 to 5 were evaluated as follows.

[0218] (1) Changes in airflow

[0219] For each porous polymer substrate / porous ceramic-polymer layer, the air permeability was measured before and after the application of the porous ceramic-polymer layer, and the difference in air permeability before and after the application of the porous ceramic-polymer layer was defined as the change in air permeability. The results are shown in Table 1 below.

[0220] Air permeability was measured according to Japanese Industrial Standard 9117:1998 Gurley (JIS Gurley). The JIS Gurley value is 1 inch of 100 cc of nitrogen (N2) gas at a static pressure of 0.05 MPa. 2 It is defined as the time in seconds required to penetrate a porous polymer substrate or a porous polymer substrate / porous ceramic-polymer layer per unit area.

[0222] (2) Shrinkage rate (%) in longitudinal (MD) and transverse (TD) directions - Heat resistance evaluation

[0223] Each porous polymer substrate / porous ceramic-polymer layer with an area of ​​4 cm x 4 cm was placed in a 150 ℃ oven for 1 hour, and the lengths in the longitudinal (MD) and transverse (TD) directions of the portion indicated by the arrows in the longitudinal and transverse directions of Fig. 9 were measured before and after heating. The measured lengths were substituted into Equation 2-1 below to calculate the shrinkage rate (%) in the longitudinal (MD) and transverse (TD) directions. The results are shown in Table 1 below.

[0224] [Equation 2-1]

[0225] Shrinkage rate (%) =

[0226] During the meal,

[0227] D0 represents the length before heating in the MD direction or TD direction of the porous polymer substrate / porous ceramic-polymer layer, and

[0228] Dh represents the length in the MD direction or TD direction for the porous polymer substrate / porous ceramic-polymer layer after heating at a temperature of 150 °C for 1 hour.

[0229] In addition, photographs were taken of the porous polymer substrate of Comparative Reference Example 1 and the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1 before and after heating, after being left in a 150°C oven for 1 hour. The results are shown on the left and center of Fig. 10a and Fig. 10b, respectively.

[0230] The left photograph in Figures 10a and 10b is a photograph of the porous polymer substrate of Comparative Reference Example 1 before and after heating.

[0231] The middle photographs of Figs. 10a and 10b are photographs of the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1 and the porous polymer substrate / porous ceramic-polymer layer / gas separation layer prepared in Example 1, before and after heating.

[0233] (3) Carbon dioxide (CO2) transmittance (cm 3 / scm 2 cmHg)

[0234] The carbon dioxide (CO2) permeability of the porous polymer substrate of Comparative Reference Example 1 and the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1 was measured using a bubble flowmeter at a pressure of 0.2 bar with the equipment shown in Fig. 11. The results are shown in Table 1 below. At this time, 1 GPU = 10 -6 cm 3 STP / cm 2 It is defined as scmHg.

[0236]

[0237] Referring to Table 1, the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Examples 1 to 5 showed a change in air permeability of 10 to 20 sec before and after coating, and the MD / TD shrinkage rate before and after heating was less than 5%. The CO2 permeability of the substrate / porous ceramic-polymer layer prepared in Reference Example 1 was 0.03564 10 -6 cm 3 STP / cm 2 It was scmHg.

[0238] Referring to FIGS. 10a and 10b, the portion indicated by the longitudinal and transverse arrows for the porous polymer substrate prepared in Comparative Reference Example 1 shrank significantly before and after heating. In comparison, the portion indicated by the longitudinal and transverse arrows for the porous polymer substrate / porous ceramic-polymer layer prepared in Reference Example 1 and the porous polymer substrate / porous ceramic-polymer layer / gas separation layer prepared in Example 1 shrank almost no before and after heating.

[0240] Evaluation Example 3: Evaluation of Gas Separation Performance of Gas Separation Membrane

[0241] The gas separation performance of the gas separation membranes prepared in Examples 1 to 5 was evaluated as follows.

[0243] (1) CO2 permeability, N2 permeability, and CO2 / N2 selectivity

[0244] For each gas separation membrane, the CO2 permeability and N2 permeability were measured using a bubble flowmeter at a pressure of 0.2 bar with the equipment shown in Fig. 11. By substituting the measured CO2 permeability and N2 permeability into Equation 1 below, the selectivity ( ) was calculated. The results are shown in Table 2 below. In this case, 1 GPU = 10 -6 cm 3 / cm 2 It is defined as s cmHg.

[0245] [Equation 1]

[0246] = .

[0247] (2) Shrinkage rate in longitudinal (MD) and transverse (TD) directions - Heat resistance evaluation

[0248] Each gas separation membrane with an area of ​​4 cm x 4 cm was placed in a 150 ℃ oven for 1 hour, and the lengths in the longitudinal (MD) and transverse (TD) directions of the portion indicated by the longitudinal and transverse arrows in Fig. 9 were measured before and after heating. The measured lengths were substituted into Equation 2 below to calculate the shrinkage rate (%) in the longitudinal (MD) and transverse (TD) directions. The results are shown in Table 2 below.

[0249] [Equation 2]

[0250] Shrinkage rate (%) =

[0251] During the meal,

[0252] D0 represents the length of the gas separation membrane before heating in the MD direction or TD direction, and

[0253] Dh represents the length in the MD direction or TD direction after heating the above gas separation membrane at a temperature of 150 ℃ for 1 hour.

[0254] In addition, photographs were taken of the gas separation membrane prepared in Example 1) before and after heating, after being left in a 150°C oven for 1 hour. The results are shown on the right side of Figures 10a and 10b, respectively.

[0255]

[0256] Referring to Table 2, the selectivity of the gas separation membranes prepared in Examples 1 to 5 ) was 29.7 or higher, and the MD / TD shrinkage rate before and after heating was less than 5%.

[0257] Referring to FIG. 10a and FIG. 10b, the gas separation membrane prepared in Example 1) hardly shrank while maintaining the shape of the portion indicated by the longitudinal and transverse arrows before and after heating.

[0258] From this, it can be seen that the gas separation membrane according to one embodiment has excellent durability, excellent high-temperature dimensional stability, and CO2 gas separation performance. Explanation of the symbols

[0260] 1, 1': porous polymer substrate, 2, 2': porous ceramic-polymer layer, 3, 3': Gas separation layer, 10, 10', 112, 112': Gas separation membrane, 100: Spiral Wound typed module, 111, 111': Permeate channel with spacer, 113: Permeate collection porous tube, 114: Gas separation membrane envelope, 115; Feed channel with spacer, 115': Feed channel, 120': Baffle, 131: Wet scrubber, 132, 213: Compressor, 133: Module including a gas separation membrane, 134, 134', 217: Vacuum pump, 135: Intercooling, 136: Aftercooling, 200: Plate and Frame typed module, 211, 211': Filter, 212: Cooler, 214: Humidifier, 215: Heat exchanger, 216: Gas separation membrane unit, 218: Condenser

Claims

Claim 1 A porous polymer substrate; a porous ceramic-polymer layer on one side of the porous polymer substrate; and a gas separation layer on the other side of the porous polymer substrate; wherein the gas separation layer has a thickness of 0.1% to 20% relative to the thickness of the porous ceramic-polymer layer, the porous ceramic-polymer layer has a thickness of 0.1% to 50% relative to the thickness of the porous polymer substrate, and the porous ceramic-polymer layer has a melting point (T) of at least 180°C. m A gas separation membrane comprising an organic-inorganic composite layer including a polymer binder having ) and a ceramic material, wherein the polymer binder comprises at least one binder selected from a cellulose-based binder, a vinyl alcohol-based binder, and an acrylate-based binder having functional groups in a side chain, and the functional group has at least one of -COOH, -NH2, -OH, -SO3H, -CN, the cation thereof, the anion thereof, and the salt thereof. Claim 2 In claim 1, the porous ceramic-polymer layer is a gas separation membrane in which the ceramic material is connected and fixed by the polymer binder. Claim 3 A gas separation membrane according to claim 1, wherein the ceramic material is a spherical ceramic material having an average particle size of 0.1 μm to 1 μm, a plate-shaped ceramic material having an average particle size of 0.1 μm to 10 μm, or a ceramic material having a mixed structure thereof, wherein the spherical ceramic material comprises at least one selected from alumina (Al2O3), boehmite (γ-AlO(OH)), and silica (SiO2), and the plate-shaped ceramic material comprises at least one selected from magnesium hydroxide (Mg(OH)2), aluminum hydroxide (Al(OH)3), mica, clay, and talc. Claim 4 A gas separation membrane according to claim 1, wherein the weight ratio of the polymer binder to the ceramic material is 1:8 to 1:

45. Claim 5 A gas separation membrane according to claim 1, wherein the pore size of the porous ceramic-polymer layer is 10 nm to 999 nm and the average pore size of the porous polymer substrate is 50 nm to 80 nm. Claim 6 In claim 1, the porous polymer substrate comprises a polyolefin-based polymer and is a gas separation membrane having a thickness of 10 μm to 40 μm. Claim 7 A gas separation membrane according to claim 1, wherein the gas separation layer comprises a polymer or copolymer having a C1-C5 alkylene oxide structural unit in its main chain, the weight-average molecular weight (Mw) of the polymer or copolymer is 50,000 g / mol to 200,000 g / mol, and the content of the C1-C5 alkylene oxide structural unit is 50% to 100% by weight based on the content of 100% by weight of the total structural unit of the main chain. Claim 8 A gas separation membrane according to claim 7, wherein the copolymer comprises a block copolymer having C1-C5 alkylene oxide rubbery structural units and hard structural units in the main chain, and the rubbery structural units having a glass transition temperature of -80°C to -50°C. Claim 9 In claim 1, the gas separation layer is a layer for separating carbon dioxide (CO2) / nitrogen (N2) gas, and the selectivity of carbon dioxide (CO2) / nitrogen (N2) according to the following Equation 1 ( Gas separation membrane where ) is 20 to 100: [Equation 1] = . Claim 10 In claim 1, the gas separation membrane, wherein the shrinkage rate in the longitudinal direction (MD) and transverse direction (TD) according to the following Equation 2 of the gas separation membrane is both greater than 0% and less than 5%: [Equation 2] Shrinkage rate (%) = In the formula, D0 represents the length of the gas separation membrane in the MD direction or TD direction before heating, and Dh represents the length of the gas separation membrane in the MD direction or TD direction after heating at a temperature of 150°C for 1 hour. Claim 11 The method comprises the steps of: providing a porous polymer substrate; applying a composition for forming a porous ceramic-polymer layer to one surface of the porous polymer substrate to form a porous ceramic-polymer layer; and applying a composition for forming a gas separation layer to the other surface of the porous polymer substrate to form a gas separation layer and thereby manufacturing a gas separation membrane; wherein the composition for forming a porous ceramic-polymer layer has a melting point (T) of at least 180 °C m A method for manufacturing a gas separation membrane comprising a polymer binder having ) and a ceramic material, wherein the polymer binder comprises at least one binder selected from a cellulose-based binder, a vinyl alcohol-based binder, and an acrylate-based binder having a functional group in a side chain, and the functional group has at least one of -COOH, -NH2, -OH, -SO3H, -CN, the cation thereof, the anion thereof, and the salt thereof, and the porous ceramic-polymer layer has a thickness of 0.1% to 50% relative to the thickness of the porous polymer substrate, and the gas separation layer has a thickness of 0.1% to 20% relative to the thickness of the porous ceramic-polymer layer. Claim 12 A method for manufacturing a gas separation membrane according to claim 11, wherein the ceramic material is a spherical ceramic material having an average particle size of 0.1 μm to 1 μm, a plate-shaped ceramic material having an average particle size of 0.1 μm to 10 μm, or a ceramic material having a mixed structure thereof, wherein the spherical ceramic material comprises at least one selected from alumina (Al2O3), boehmite (γ-AlO(OH)), and silica (SiO2), and the plate-shaped ceramic material comprises at least one selected from magnesium hydroxide (Mg(OH)2), aluminum hydroxide (Al(OH)3), mica, clay, and talc. Claim 13 A method for manufacturing a gas separation membrane according to claim 11, wherein the weight ratio of the polymer binder to the ceramic material is 1:8 to 1:

45. Claim 14 A method for manufacturing a gas separation membrane according to claim 11, wherein the porous polymer substrate comprises a polyolefin-based polymer and has a thickness of 10 μm to 40 μm. Claim 15 A method for manufacturing a gas separation membrane according to claim 11, wherein the gas separation layer comprises a polymer or copolymer having a C1-C5 alkylene oxide structural unit in its main chain, the weight-average molecular weight (Mw) of the polymer or copolymer is 50,000 g / mol to 200,000 g / mol, and the content of the C1-C5 alkylene oxide structural unit is at least 50% to 100% by weight based on the content of 100% by weight of the total structural unit of the main chain. Claim 16 In claim 11, the gas separation layer is a layer that separates carbon dioxide (CO2) / nitrogen (N2) gas, and the selectivity of carbon dioxide (CO2) / nitrogen (N2) according to the following Equation 1 ( Method for manufacturing a gas separation membrane in which ) is 20 to 100: [Equation 1] = . Claim 17 In claim 11, a method for manufacturing a gas separation membrane, wherein the shrinkage rate in the longitudinal direction (MD) and transverse direction (TD) according to the following Equation 2 of the gas separation membrane is both greater than 0% and less than 5%: [Equation 2] Shrinkage rate (%) = In the formula, D0 represents the length of the gas separation membrane in the MD direction or TD direction before heating, and Dh represents the length of the gas separation membrane in the MD direction or TD direction after heating at a temperature of 150°C for 0.5 hours. Claim 18 A gas inlet for receiving a supply gas; at least one supply channel connected to the gas inlet; at least one permeable channel spaced apart in a direction parallel to the supply channel; at least one gas separation membrane disposed between the supply channel and the permeable channel; a permeate collection unit for collecting permeate gas connected to the permeable channel; and a gas outlet unit on the opposite side of the gas inlet for discharging residual gas not collected in the permeate collection unit; wherein the gas separation membrane comprises a porous polymer substrate; a porous ceramic-polymer layer on one side of the porous polymer substrate; and a gas separation layer on the other side of the porous polymer substrate; wherein the gas separation layer has a thickness of 0.1% to 20% relative to the thickness of the porous ceramic-polymer layer, the porous ceramic-polymer layer has a thickness of 0.1% to 50% relative to the thickness of the porous polymer substrate, and the porous ceramic-polymer layer has a melting point (T) of at least 180°C m A module comprising an organic-inorganic composite layer including a polymer binder having ) and a ceramic material, wherein the polymer binder comprises at least one binder selected from a cellulose-based binder, a vinyl alcohol-based binder, and an acrylate-based binder having a functional group in a side chain, and the functional group has at least one of -COOH, -NH2, -OH, -SO3H, -CN, the cation thereof, the anion thereof, and the salt thereof. Claim 19 In paragraph 18, the module comprises two or more supply channels and includes at least one baffle between adjacent supply channels. Claim 20 In claim 18, the gas introduced into the gas inlet includes carbon dioxide (CO2) and nitrogen (N2) gas, and the selectivity of carbon dioxide (CO2) / nitrogen (N2) according to the following Equation 1 ( Module:[Equation 1] where ) is 20 to 100 = .

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