Gas separation membrane, method for manufacturing a gas separation membrane, and gas separation apparatus

Abstract

To provide a gas separation membrane with minimal defects such as pinholes, high gas selectivity and high gas permeability, a method for manufacturing the same, and a gas separation apparatus with excellent carbon dioxide separation performance. [Solution] A separation membrane for separating a specific gas component from a mixed gas having multiple gas components, comprising: a support layer made of a porous material having pores; a separation layer provided on one side of the support layer and having gas separation capability for separating the specific gas component; and a occlusion portion containing metal provided in a location corresponding to a defect where the separation layer is missing and the support layer is exposed.

Description

[Technical Field]

[0001] This invention relates to a gas separation membrane, a method for manufacturing a gas separation membrane, and a gas separation apparatus. [Background technology]

[0002] To achieve carbon neutrality and carbon negative emissions, technologies are being considered to capture and recover carbon dioxide emitted from thermal power plants and boiler facilities, as well as carbon dioxide from the atmosphere. One such technology is membrane separation, which uses gas separation membranes to separate carbon dioxide.

[0003] The thickness of gas separation membranes used in membrane separation methods is designed to be as thin as possible to allow more gas to pass through. However, fabricating a gas separation membrane that is completely free of defects is extremely difficult.

[0004] To address these challenges, Patent Document 1 proposes a defect repair method for a hydrogen separation membrane comprising a porous gas and a membrane formed thereon, which includes a process of immersing the surface of the membrane in a liquid containing a binder component that solidifies upon drying, and allowing the solution to flow in from the defective portion of the membrane by vacuum suction from the porous substrate side, and a process of solidifying the binder component in the flowed-in solution upon drying to seal the defective portion.

[0005] This defect repair method allows for the easy repair of defects in a membrane (a separation layer with gas separation capabilities) by sealing the porous substrate corresponding to the defect, thereby blocking the passage of gases and other substances through the defect. This allows for the repair of defects with minimal impairment of the overall function of the membrane. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2003-290636 [Overview of the project] [Problems that the invention aims to solve]

[0007] In the defect repair method described in Patent Document 1, the liquid containing the binder component needs to penetrate the porous substrate evenly. However, even if the binder component solidifies, gaps may remain. Therefore, it is not easy to make the porous substrate sufficiently airtight.

[0008] Therefore, the challenge is to realize a gas separation membrane that can be sealed and airtight even when there are defects in the separation layer, and that has a high gas selectivity ratio and high gas permeability for specific gas components. [Means for solving the problem]

[0009] The gas separation membrane according to an application example of the present invention is A separation membrane that separates a specific gas component from a mixed gas having multiple gas components by allowing permeation, A support layer composed of a porous material having pores, A separation layer provided on one side of the support layer and having gas separation capability for separating the specific gas components, A closure portion containing metal is provided corresponding to the missing portion where the separation layer is missing and the support layer is exposed, It is equipped with.

[0010] The method for producing a gas separation membrane according to an application example of the present invention is: A method for producing a gas separation membrane according to an application example of the present invention, A preparation step for preparing a multilayer film comprising the support layer made of the porous material and the separation layer in which the defect occurs, A blocking portion forming step is performed in which the blocking portion is selectively formed on the defective portion by a plating method, A drying step to obtain the gas separation membrane by drying the multilayer film on which the blockage portion is formed, It holds.

[0011] The gas separation device according to the application example of the present invention is a gas separation membrane according to the application example of the present invention, a fixing part that fixes the gas separation membrane and has an internal space formed on the support layer side of the gas separation membrane, and an exhaust part that decompresses the internal space so as to create a negative pressure in the external space on the separation layer side of the gas separation membrane. It is provided with.

Brief Description of the Drawings

[0012] [Figure 1] It is a cross-sectional view showing the gas separation membrane according to the embodiment. [Figure 2] It is a cross-sectional view showing a gas separation membrane for explaining the problem to be solved by the present invention. [Figure 3] It is a cross-sectional view showing a gas separation membrane according to a modified example in which a part of the blocking part enters the inside of the support layer. [Figure 4] It is a process diagram showing the configuration of the manufacturing method of the gas separation membrane according to the embodiment. [Figure 5] It is a schematic diagram for explaining the manufacturing method of the gas separation membrane shown in FIG. 4. [Figure 6] It is a schematic diagram for explaining the manufacturing method of the gas separation membrane shown in FIG. 4. [Figure 7] It is a schematic diagram for explaining the manufacturing method of the gas separation membrane shown in FIG. 4. [Figure 8] It is a schematic diagram for explaining the manufacturing method of the gas separation membrane shown in FIG. 4. [Figure 9] It is a schematic diagram for explaining the manufacturing method of the gas separation membrane shown in FIG. 4. [Figure 10] It is a schematic diagram for explaining the manufacturing method of the gas separation membrane shown in FIG. 4. [Figure 11] It is a schematic diagram for explaining the manufacturing method of the gas separation membrane shown in FIG. 4. [Figure 12] It is a cross-sectional view showing the schematic configuration of the gas separation device according to the embodiment. [Figure 13] It is Table 1 showing the configurations and evaluation results of the gas separation membranes of Comparative Examples 1 to 4 and the gas separation membranes of Examples 1 to 4. [Figure 14] Table 2 shows the configuration and evaluation results of the gas separation membranes of Comparative Examples 5-8 and Examples 5-8. [Modes for carrying out the invention]

[0013] The gas separation membrane, the method for manufacturing the gas separation membrane, and the gas separation apparatus of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.

[0014] 1. Overview of Gas Separation Membranes First, we will outline the configuration of the gas separation membrane according to this embodiment.

[0015] Figure 1 is a cross-sectional view showing a gas separation membrane 1 according to an embodiment. Figure 2 is a cross-sectional view showing a gas separation membrane for explaining the problems that the present invention aims to solve. In Figures 1 and 2 of this application, the X, Y, and Z axes are defined as three mutually orthogonal axes and are indicated by arrows. The base end of the arrows representing each axis is designated as "minus" and the tip end as "plus".

[0016] In the gas separation membrane 1 shown in Figure 1, the positive Z-axis side is defined as "up" and the negative Z-axis side as "down". A mixed gas G1 containing multiple gas components is supplied to the upper part of the gas separation membrane 1. In the gas separation membrane 1 shown in Figure 1, specific gas components are preferentially permeated and separated from the top to the bottom. As a result, the concentration of specific gas components is higher in the gas that has permeated through the gas separation membrane 1 (permeate gas G2) compared to the mixed gas G1. This allows for the separation and recovery of specific gas components from the mixed gas G1. In the following explanation, the area above the gas separation membrane 1 will also be referred to as "upstream," and the area below the gas separation membrane 1 will also be referred to as "downstream."

[0017] The gas separation membrane 1 shown in Figure 1 comprises a support layer 3 extending along the XY plane and a separation layer 4 provided on the upper surface 31 (one side) of the support layer 3.

[0018] The support layer 3 is composed of a porous material having pores. The separation layer 4 has gas separation capabilities that preferentially allow specific gas components to permeate and separate them.

[0019] When manufacturing the gas separation membrane 1, the separation layer 4 is formed to cover the upper surface 31 of the support layer 3. In order for the separation layer 4 to fully exhibit its gas separation capacity, it is necessary to form a separation layer 4 that completely covers the upper surface 31. However, no matter how advanced the manufacturing technology becomes, it is difficult to form a separation layer 4 that completely covers the upper surface 31, and defects such as pinholes 8 may occur. If such defects 8 are not repaired and the membrane is used as is, the gas separation capacity of the separation layer 4 cannot be fully utilized.

[0020] Figure 2 illustrates the flow of mixed gas G1 and permeate gas G2 when a gas separation membrane 9, comprising a support layer 3 and a separation layer 4 with a defect 8, is used without repair.

[0021] In the upper surface 31 of the support layer 3, the portion covered by the separation layer 4 allows permeate gas G2, which has a higher concentration of a specific gas component than the mixed gas G1, to permeate due to the gas separation ability of the separation layer 4. On the other hand, in the portion of the upper surface 31 of the support layer 3 that is not covered by the separation layer 4, i.e., the defective portion 8, the gas separation ability does not work, so the mixed gas G1 permeates directly. Therefore, unless the defective portion 8 is repaired, the concentration of the specific gas component cannot be sufficiently increased downstream of the gas separation membrane 9. In other words, the gas selectivity ratio of the specific gas component in the gas separation membrane 9 cannot be sufficiently increased.

[0022] Therefore, the gas separation membrane 1 shown in Figure 1 is equipped with a blocking section 2 that closes the defect 8. The blocking section 2 covers the defect 8, thereby hermetically sealing the defect 8. This suppresses the permeation of the mixed gas G1 through the defect 8. As a result, the concentration of a specific gas component can be sufficiently increased downstream of the gas separation membrane 1. In other words, a gas separation membrane 1 with a sufficiently high gas selectivity ratio for a specific gas component can be realized.

[0023] Furthermore, because the occlusion portion 2 contains metal, it has a high shielding rate against gas molecules even when thin. Therefore, it is possible to suppress the decrease in gas selectivity that occurs when gas molecules permeate through the occlusion portion 2. In addition, because the occlusion portion 2 is sufficiently thin, it is less likely to peel off even if there is a difference in thermal expansion coefficient between the occlusion portion 2 and the support layer 3.

[0024] With the above configuration, the blockage section 2 can repair defects 8 such as pinholes, resulting in zero or only a few unrepaired defects 8, and thus a gas separation membrane 1 with a high gas selectivity ratio and high gas permeability.

[0025] In addition to the sheet-like (flat) shape shown in Figure 1, the gas separation membrane according to the present invention may also be spiral-shaped, tubular, hollow fiber-shaped, or the like.

[0026] 1.1.Support layer The support layer 3 shown in Figure 1 is sheet-like and supports the separation layer 4. This makes it possible to realize a gas separation membrane 1 that is less prone to damage even if the separation layer 4 does not have sufficient mechanical properties.

[0027] The support layer 3 is composed of a porous material. The porous material is a sheet with numerous pores and has good gas permeability. In addition, the porous material has higher rigidity than the separation layer 4 and is responsible for ensuring the mechanical properties such as the self-supporting ability and durability of the entire gas separation membrane 1.

[0028] Examples of constituent materials for a porous body include organic materials such as synthetic polymers and natural polymers, as well as inorganic materials such as ceramics, metals, and silicon. Of these, the porous body preferably contains an inorganic material, and more preferably contains a ceramic material. Inorganic materials have high mechanical strength, which contributes to thinning the support layer 3 and improving the gas permeability of the support layer 3. Furthermore, if the separation layer 4 is made of an organic material, the chemical properties of the support layer 3 and the separation layer 4 can be made different. This makes it easier to selectively form the occlusion 2 on the defect 8. The constituent material of the porous body may also be a composite material of organic and inorganic materials.

[0029] Examples of organic materials include polyolefin resins such as polyethylene and polypropylene, fluororesins such as polytetrafluoroethylene, polyvinyl fluoride and polyvinylidene fluoride, polystyrene, cellulose, cellulose acetate, polyurethane, polyacrylonitrile, polyphenylene oxide, polysulfone, polyethersulfone, polyimide, polyaramid, and nylon.

[0030] Examples of ceramic materials include alumina, cordierite, mullite, silicon carbide, and zirconia. Examples of metallic materials include stainless steel. Examples of silicon materials include silicon single crystals and quartz glass.

[0031] Furthermore, the porous material may be a filter with an open-cell structure. A filter with an open-cell structure is also called an absolute-type filter, and it has pores that are continuous from one side to the other, which are in a front-back relationship with each other, and also independent of each other.

[0032] The average thickness of the support layer 3 is not particularly limited, but is preferably 1 μm to 3000 μm, more preferably 10 μm to 500 μm, and even more preferably 30 μm to 300 μm. This ensures that the support layer 3 has the necessary and sufficient rigidity to support the separation layer 4, and that sufficient gas permeability of the support layer 3 is ensured, thereby enabling the gas separation ability of specific gas components in the separation layer 4.

[0033] Furthermore, if the average thickness of the support layer 3 falls below the lower limit, the rigidity may become insufficient. On the other hand, if the average thickness of the support layer 3 exceeds the upper limit, the gas permeability of the support layer 3 decreases, and the gas separation capacity of the separation layer 4 may not be fully utilized.

[0034] The average thickness of the support layer 3 is the average of the thicknesses measured at 10 locations on the support layer 3. A thickness gauge can be used to measure the thickness of the support layer 3, for example.

[0035] A porous material has numerous pores, and the average inner diameter of these pores is called the "average pore diameter." The average pore diameter of the porous material is preferably 0.1 nm to 1000 nm, more preferably 0.5 nm to 500 nm, even more preferably 1 nm to 300 nm, and particularly preferably 10 nm to 100 nm. This ensures sufficient gas permeability of the porous material while preventing the separation layer 4 from escaping downstream of the support layer 3. If the average pore diameter of the porous material falls below the lower limit, the gas permeability of the porous material may decrease. On the other hand, if the average pore diameter of the porous material exceeds the upper limit, the separation layer 4 may escap downstream of the support layer 3.

[0036] The average pore size of the porous material is measured using a through-pore diameter evaluation device after removing the separation layer 4 from the gas separation membrane 1 and obtaining the support layer 3 on its own. An example of a through-pore diameter evaluation device is the palm porometer manufactured by PMI.

[0037] The porosity of the porous material is preferably between 20% and 90%, and more preferably between 30% and 80%. This allows the porous material to achieve both good gas permeability and sufficient rigidity.

[0038] The porosity of the porous material is measured using the aforementioned through-pore diameter evaluation device after removing the separation layer 4 from the gas separation membrane 1.

[0039] The gas permeability of carbon dioxide in support layer 3 is 10 × 10 -5 cm 3 (STP) / cm 2 It is preferable that the sec·cmHg (100 GPU) is 1000 GPU or more, more preferably 1000 GPU or more, even more preferably 3000 GPU or more, and particularly preferably 10000 GPU or more.

[0040] 1.2. Separation layer The separation layer 4 shown in FIG. 1 is provided on the upper surface 31 (one surface) of the support layer 3. The separation layer 4 has the gas separation ability for specific gas components.

[0041] The separation layer 4 may be composed of an inorganic material, but is preferably composed of an organic material. Thereby, depending on the composition of the organic material, the separation layer 4 corresponding to various gas components can be realized. Further, by using an organic material, the separation layer 4 having excellent covering property of the support layer 3 can be realized even with a thin layer thickness. Such a separation layer 4 contributes to the realization of the gas separation membrane 1 having a high gas selectivity ratio and a high gas permeability.

[0042] Examples of the organic material include polyolefin resins such as polyethylene and polypropylene, fluorine-containing resins such as polytetrafluoroethylene, polyvinyl fluoride, and polyvinylidene fluoride, polystyrene, cellulose, cellulose acetate, polyurethane, polyacrylonitrile, polyphenylene oxide, polysulfone, polyethersulfone, polyimide, polyaramide, organopolysiloxane, polyethylene terephthalate (PET), polyacetal (POM), polylactic acid (PLA), and the like. And the constituent material of the separation layer 4 may be a composite of two or more of these.

[0043] Among these, organopolysiloxane is preferably used as the constituent material of the separation layer 4. One molecule of organopolysiloxane contains, as basic structural units, a unit (T unit) represented by R 1 SiO 3 / 2 a unit (D unit) represented by R 2 R 3 SiO 2 / 2 and a unit (M unit) represented by R 4 R 5 R 6 SiO 1 / 2 at least. In each unit, R 1 ~R 6These are aliphatic hydrocarbons or hydrogen atoms. Organopolysiloxanes are composed of combinations of these T, D, and M units.

[0044] Specific examples of organopolysiloxanes include polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane, polysulfone / polyhydroxystyrene / polydimethylsiloxane copolymer, dimethylsiloxane / methylvinylsiloxane copolymer, dimethylsiloxane / diphenylsiloxane / methylvinylsiloxane copolymer, methyl-3,3,3-trifluoropropylsiloxane / methylvinylsiloxane copolymer, dimethylsiloxane / methylphenylsiloxane / methylvinylsiloxane copolymer, diphenylsiloxane / dimethylsiloxane copolymer with vinyl terminology, polydimethylsiloxane with vinyl terminology, polydimethylsiloxane with amino terminology, polydimethylsiloxane with phenyl terminology, polydimethylsiloxane with H terminology, and dimethylsiloxane-methylhydrosiloxane copolymer. The notation "with vinyl terminology" indicates that at least one end of the main chain contained in the organopolysiloxane is substituted with a substituent such as a vinyl group. Furthermore, these include forms that form cross-linked reaction products. In addition, the constituent material of the separation layer 4 may be a composite of one or more of these, or it may be a composite material in which organopolysiloxane is the main component by mass ratio, with other resin components used in combination.

[0045] Furthermore, organopolysiloxanes have a good affinity for carbon dioxide. Therefore, separation layer 4, which contains organopolysiloxanes, exhibits a high gas selectivity ratio for carbon dioxide.

[0046] Furthermore, if necessary, any functional groups may be introduced to the upstream surface of the separation layer 4 using a coupling agent or the like. By appropriately selecting functional groups, the affinity for specific gas components can be further increased.

[0047] The average thickness of the separation layer 4 is not particularly limited, but is preferably 1 nm to 1000 nm, more preferably 3 nm to 800 nm, even more preferably 5 nm to 500 nm, and particularly preferably 10 nm to 200 nm. This results in the separation layer 4 having good gas selectivity and gas permeability. As a result, it is possible to realize a gas separation membrane 1 that can reduce the amount of energy input required to separate specific gas components, specifically by reducing the pressure difference between the upstream and downstream sides of the gas separation membrane 1. If the average thickness of the separation layer 4 falls below the lower limit, the probability of numerous defects 8 occurring in the separation layer 4 increases, and the separation layer 4 may become more susceptible to damage. On the other hand, if the average thickness of the separation layer 4 exceeds the upper limit, the gas permeability in the separation layer 4 decreases, which may increase the amount of energy input required for separation, and the flexibility of the separation layer 4 may decrease.

[0048] Furthermore, the average thickness of the separation layer 4 is preferably 0.0050% to 1.0% of the average thickness of the support layer 3, more preferably 0.010% to 0.50%, and even more preferably 0.030% to 0.30%. This optimizes the ratio of the thicknesses of the two layers, allowing for a good balance between the mechanical properties, gas selectivity, and gas permeability of the gas separation membrane 1.

[0049] The average thickness of the separation layer 4 can be determined, for example, by magnifying the cross-section of the gas separation membrane 1 and taking the average of the thicknesses at 10 points. For magnified observation, a scanning electron microscope, transmission electron microscope, or scanning transmission electron microscope can be used. Alternatively, the thickness of the separation layer 4 may be determined by depth profiling analysis using X-ray photoelectron spectroscopy.

[0050] 1.3. Occlusion The occlusion portion 2 shown in Figure 1 contains metal and closes off the missing portion 8.

[0051] The metal contained in the occlusion portion 2 is not particularly limited and may be any metal, but examples include Ni (nickel), Co (cobalt), Cu (copper), Au (gold), Pt (platinum), Pd (palladium), Ag (silver), Cr (chromium), Zn (zinc), Sn (tin), In (indium), etc. These metals may be contained as elemental elements, or as alloys, compounds, or mixtures with other elements. Of these, the metal contained in the occlusion portion 2 is preferably Ni. Because Ni has excellent corrosion resistance and oxidation resistance, it contributes to improving the stability of the occlusion portion 2.

[0052] The metal content in the occlusion section 2 is preferably 50% by mass or more, and more preferably 70% by mass or more. This particularly enhances the gas shielding and stability in the occlusion section 2.

[0053] The metal content in the occlusion section 2 is measured, for example, after removing the occlusion section 2 from the gas separation membrane 1, using an inductively coupled plasma atomic emission spectrometer (ICP-OES).

[0054] Methods for forming the occlusion portion 2 include, for example, plating, liquid-phase film deposition using a metal particle-containing solution, and vapor-phase film deposition. Of these, plating is preferred. In other words, the occlusion portion 2 is preferably a plated film. A plated film has high coverage and the coverage area can be easily controlled. Therefore, by using a plated film, an occlusion portion 2 with particularly good gas shielding properties can be obtained.

[0055] Furthermore, if the occlusion portion 2 is a plated film, in addition to the above-mentioned metals, nonmetals such as P (phosphorus), B (boron), S (sulfur), C (carbon), N (nitrogen), and O (oxygen) may also be included. This further enhances the stability of the plated film.

[0056] The average thickness of the occlusion portion 2 is preferably 1 nm to 1000 nm, more preferably 5 nm to 500 nm, and even more preferably 10 nm to 300 nm. If the average thickness of the occlusion portion 2 is within the above range, it is possible to improve the coverage of the defect 8 by the occlusion portion 2 and the gas shielding performance while suppressing the effect of the thickened occlusion portion 2 on the adjacent separation layer 4. If the average thickness of the occlusion portion 2 falls below the lower limit, the occlusion performance of the defect 8 by the occlusion portion 2 and the gas shielding performance may decrease. On the other hand, if the average thickness of the occlusion portion 2 exceeds the upper limit, the thickened occlusion portion 2 may affect the adjacent separation layer 4.

[0057] The missing portion 8 refers to the part where the separation layer 4 is interrupted and the upper surface 31 of the support layer 3 is exposed. The closed portion 2 shown in Figure 1 is provided to cover the upper surface 31 exposed in this missing portion 8.

[0058] On the other hand, the occluding portion 2 may not only cover the upper surface 31, but a part of it may also extend into the interior of the support layer 3.

[0059] Figure 3 is a cross-sectional view showing a modified gas separation membrane in which a portion of the occlusion 2 extends into the interior of the support layer 3.

[0060] As shown in Figure 3, a portion of the occlusion 2 penetrates into the interior of the support layer 3. Specifically, since the support layer 3 contains pores, the occlusion 2 enters into these pores. This not only covers the upper surface of the pores but also fills the pores themselves. As a result, the defect 8 can be sealed more reliably.

[0061] Furthermore, the pores within the support layer 3 may extend in a specific direction or in various directions. In the latter case, the occluded portion 2 that has entered the pores may penetrate not only directly beneath the defect 8, but also spread outwards, as shown in Figure 3. In this case, the occluded portion 2 and the separation layer 4 will overlap at the boundary between the separation layer 4 and the defect 8. This makes it less likely for gaps to form at the boundary between the occluded portion 2 and the separation layer 4, thereby improving the coverage of the occluded portion 2.

[0062] The penetration depth of the occlusion portion 2, that is, the distance from the upper surface 31 of the support layer 3 to the lowest end of the occlusion portion 2, is not particularly limited as it varies depending on the thickness of the support layer 3, but is preferably 1 nm or more, more preferably 3 nm to 200 nm, and even more preferably 5 nm to 100 nm. This particularly enhances the coverage of the occlusion portion 2.

[0063] 1.4. Other Configurations The gas separation membrane 1 according to the embodiment has been described above, but any layer may be provided downstream of the support layer 3. For example, a porous plate with higher rigidity than the support layer 3 may be provided downstream of the support layer 3. The porous plate has a large number of through holes formed in it so that the pressure loss of the gas passing through it is smaller than that of the support layer 3. This allows the gas separation membrane 1 to be supported without hindering the gas selectivity of the gas separation membrane 1.

[0064] Examples of materials that can be used to construct a perforated plate include ceramic materials, metallic materials, and polymer materials. Furthermore, the perforated plate may be a composite material of these materials with other materials.

[0065] 2. Method for manufacturing gas separation membranes Next, a method for manufacturing the gas separation membrane according to the embodiment will be described. In the following description, the method for manufacturing the gas separation membrane 1 shown in Figure 1 will be used as an example.

[0066] Figure 4 is a process diagram showing the configuration of the gas separation membrane manufacturing method according to the embodiment. Figures 5 to 11 are schematic diagrams illustrating the gas separation membrane manufacturing method shown in Figure 4.

[0067] The method for manufacturing the gas separation membrane shown in Figure 4 comprises a preparation step S102, a blockage formation step S104, and a drying step S106. This manufacturing method allows for the efficient production of the gas separation membrane 1. Each step will be described below.

[0068] 2.1. Preparation process In preparation step S102, a multilayer film 10 shown in Figure 5 is prepared. This multilayer film 10 comprises a support layer 3 made of a porous material and a separation layer 4 in which defects 8 occur. Such a multilayer film 10 may be, for example, a gas separation membrane that was determined to be defective in a gas selectivity ratio test.

[0069] One method for forming the separation layer 4 on the support layer 3 is to apply the raw material liquid, then apply energy, and remove unwanted materials as needed.

[0070] The raw material liquid contains the constituent materials and solvent of the separation layer 4. This raw material liquid is applied to the upper surface 31 of the support layer 3 by various coating methods. Examples of coating methods include immersion, dropping, inkjet, dispenser, spray, screen printing, coater coating, and spin coating. The support layer 3 may be pre-treated before supplying the raw material liquid. Examples of pre-treatments include plasma treatment, ultraviolet irradiation treatment, and ozone treatment.

[0071] Next, energy is applied to the obtained coating film. Methods for applying energy include, for example, irradiation with energy rays such as infrared rays, visible light, or ultraviolet rays, irradiation with plasma, or irradiation with electron beams. As a result, the coating film hardens or solidifies, and a separation layer 4 is obtained.

[0072] 2.2. Occlusion formation process In the blockage formation step S104, the blockage 2 is selectively formed on the defective portion 8 by a plating method.

[0073] Plating methods include electroless plating and electrolytic plating. These will be explained in turn below.

[0074] 2.2.1. Electroless Plating Method Figures 6 to 10 illustrate the process of forming the occluded portion 2 using electroless plating.

[0075] In electroless plating, first, a catalyst solution 21 containing a catalyst is brought into contact with the separation layer 4 of the multilayer film 10, as shown in Figure 6. The method of contacting with the catalyst solution 21 is not particularly limited and examples include spin coating, dip coating, and spray coating.

[0076] After the catalyst solution 21 is brought into contact with the separation layer 4 and then removed, the catalyst solution 21 selectively adheres to the defect 8, as shown in Figure 7. This is because the support layer 3, which is made of a porous material, is exposed in the defect 8. In other words, the exposed surface of the porous material has a relatively higher surface roughness compared to the separation layer 4, which is thought to increase the wettability of the catalyst solution 21. Furthermore, if the porous material is made of an inorganic material, the wettability of the catalyst solution 21 is likely to be even higher. As a result, the catalyst solution 21 wets the upper surface 31 and also penetrates into the pores contained in the support layer 3.

[0077] On the other hand, when the separation layer 4 is made of an organic material, the catalyst solution 21 has higher liquid-repellent properties compared to the support layer 3. Due to this difference in wettability, the catalyst solution 21 selectively adheres to the defective areas 8.

[0078] The catalyst contained in catalyst solution 21 enhances the reducing agent function in electroless plating by oxidizing the reducing agent in electroless plating solution 23 shown in Figure 9. Examples of such catalysts include Pd-Sn complexes (palladium-tin complexes).

[0079] Furthermore, water is an example of a solvent contained in the catalyst solution 21. The proportion of water in the catalyst solution 21 is preferably 80% by mass or more, and more preferably 90% by mass or more. As a result, the properties of water become dominant in the catalyst solution 21, making it easier to control the wettability and liquid repellency associated with each constituent material of the support layer 3 and the separation layer 4.

[0080] The catalyst solution 21 may be supplied to the defective area 8 all at once. Alternatively, two or more liquids may be supplied sequentially, resulting in a catalyst solution 21 being supplied to the defective area 8 as a mixture of these liquids. For example, by sequentially bringing a solution containing Sn and a solution containing Pd into contact, a catalyst solution 21 containing both Pd and Sn may be deposited on the defective area 8.

[0081] After contact with the catalyst solution 21, the catalyst is activated. This activates the catalyst, and a catalyst layer 22 selectively attached to the defective area 8 is obtained, as shown in Figure 8. As an activation treatment, for example, if the catalyst is a Pd-Sn complex, a treatment may be performed to remove Sn and leave catalytically active Pd. A treatment solution such as an accelerator is used for such a treatment.

[0082] Next, as shown in Figure 9, the catalyst layer 22 is brought into contact with the electroless plating solution 23. This oxidizes the reducing agent in the electroless plating solution 23, and also releases metal ions M + The material is reduced. As a result, metal is deposited around the catalyst in the catalyst layer 22. Consequently, a blockage portion 2 is obtained that selectively covers the defective portion 8, as shown in Figure 10.

[0083] 2.2.2. Electroplating Method Figure 11 illustrates the process of forming the occlusion 2 using electroplating.

[0084] In the electroplating method, first, as shown in Figure 11, the multilayer film 10 is placed at the bottom of the plating tank 60. At this time, it is preferable that the lower surface of the support layer 3 is covered so that it does not come into contact with the electroplating solution 24. The anode 61 is then placed opposite the separation layer 4 of the multilayer film 10. The negative electrode of the DC power supply 62 is electrically connected to the support layer 3, and the positive electrode of the DC power supply 62 is electrically connected to the anode 61. In other words, the support layer 3 functions as the cathode in the electroplating method. For this reason, conductive materials are preferably used as the constituent material of the support layer 3. Examples of conductive materials include metal materials, conductive ceramic materials, and silicon materials to which conductivity has been imparted. If the constituent material of the support layer 3 is not conductive, a porous conductive layer may be provided between the support layer 3 and the separation layer 4 in advance.

[0085] Next, the electrolytic plating solution 24 is placed in the plating tank 60, and the multilayer film 10 and the anode 61 are immersed in the electrolytic plating solution 24. Then, a voltage is applied (energized) from the DC power supply 62 between the support layer 3 and the anode 61. As a result, metal ions M are released from the anode 61. + As it elutes, the eluted metal ions M + The metal ions M are reduced on the upper surface 31 of the support layer 3 that is exposed to the defect 8 and precipitate as metal. On the other hand, the part of the upper surface 31 of the support layer 3 other than the defect 8 is covered by the separation layer 4. Therefore, the metal ions M + The material is not reduced, and no metal is deposited. As a result, a occlusion portion 2 that selectively covers the defect portion 8 is obtained, as shown in Figure 10. Therefore, the material used for the occlusion portion 2 can be used for the constituent material of the anode 61.

[0086] Furthermore, in the electroplating method, if the support layer 3 is made of an inorganic material, the electroplating solution 24 not only wets the upper surface 31 but also penetrates into the pores contained in the support layer 3.

[0087] On the other hand, when the separation layer 4 is made of an organic material, the electroplating solution 24 has higher liquid repellency compared to the support layer 3. In other words, the electroplating solution 24 is prevented from penetrating the separation layer 4. Therefore, the deposition of metal can be suppressed in the portion of the upper surface 31 of the support layer 3 that is covered by the separation layer 4.

[0088] Furthermore, water is an example of a solvent contained in the electroplating solution 24. The proportion of water in the electroplating solution 24 is preferably 80% by mass or more, and more preferably 90% by mass or more. As a result, the properties of water become dominant in the electroplating solution 24, making it easier to control the wettability and liquid repellency associated with each constituent material of the support layer 3 and the separation layer 4.

[0089] 2.3.Drying process In the drying process S106, first, the multilayer film 10 on which the blockage portion 2 is formed is washed with a cleaning solution such as water. Then, the multilayer film 10 is subjected to a drying process. This yields the gas separation film 1 shown in Figure 1. The drying process may be natural drying or forced drying. Examples of forced drying include heating, gas blowing, and vacuum drying.

[0090] As described above, by using the plating method, the blocking portion 2 that selectively blocks the defective portion 8 can be efficiently formed. Therefore, the method for manufacturing a gas separation membrane according to this embodiment can efficiently manufacture the gas separation membrane 1.

[0091] 3. Applications of gas separation membranes The gas separation membrane 1 according to this embodiment is used for separating and recovering or purifying specific gas components from a mixed gas. Examples of specific gas components include hydrogen, helium, carbon monoxide, carbon dioxide, hydrogen sulfide, oxygen, nitrogen, ammonia, sulfur oxides, nitrogen oxides, as well as saturated hydrocarbons such as methane and ethane, unsaturated hydrocarbons such as propylene, and perfluoro hydrocarbons such as tetrafluoroethane.

[0092] Furthermore, the gas separation membrane 1 is particularly preferred in technologies for separating and recovering carbon dioxide from mixed gases such as air and industrial exhaust gases.

[0093] 4. Gas separation device Next, a gas separation apparatus according to an embodiment will be described. Figure 12 is a cross-sectional view showing the schematic configuration of the gas separation apparatus 5 according to this embodiment.

[0094] The gas separation device 5 shown in Figure 12 comprises a gas separation membrane 1, a fixed part 52, piping 53, an exhaust part 54, piping 55, and a gas concentration meter 56.

[0095] The fixing part 52 fixes the gas separation membrane 1. The fixing part 52 also has a perforated plate 51 that supports the gas separation membrane 1. The perforated plate 51 has numerous through holes. In addition, the fixing part 52 has an internal space 522 located on the support layer 3 side of the gas separation membrane 1.

[0096] The exhaust unit 54 exhausts the gas in the internal space 522 via the piping 53. This reduces the pressure in the internal space 522, creating a negative pressure relative to the external space 524 located on the separation layer 4 side of the gas separation membrane 1. As a result, certain gas components of the mixed gas G1 supplied to the external space 524 permeate the gas separation membrane 1 and are drawn into the internal space 522 as permeate gas G2. Then, with the exhaust by the exhaust unit 54, the permeate gas G2 is discharged from the internal space 522.

[0097] The gas concentration meter 56 takes in the permeate gas G2 discharged by the exhaust section 54 via the piping 55 and measures the concentration of a specific gas component in the permeate gas G2.

[0098] As mentioned above, the gas separation membrane 1 has a high gas selectivity and high gas permeability for specific gas components. Therefore, the gas separation device 5 can efficiently separate specific gas components while suppressing energy consumption.

[0099] The piping 55 and gas concentration meter 56 may be provided as needed, but may be omitted.

[0100] 5. Effects of the above embodiment The gas separation membrane 1 according to the above embodiment is a separation membrane that separates a specific gas component from a mixed gas having multiple gas components by permeation, and comprises a support layer 3, a separation layer 4, and a occlusion portion 2. The support layer 3 is made of a porous material having pores. The separation layer 4 is provided on the upper surface 31 (one surface) of the support layer 3 and has gas separation ability to separate a specific gas component. The occlusion portion 2 is provided in correspondence with a defect 8 where the separation layer 4 is missing and the support layer 3 is exposed, and contains metal.

[0101] With this configuration, since defects 8 such as pinholes are repaired by the blockage portion 2, the number of defects 8 is kept to a minimum, and a gas separation membrane 1 with a high gas selectivity ratio and high gas permeability is obtained. In addition, because the blockage portion 2 contains metal and has a high shielding rate for gas molecules even when thin, the blockage portion 2 is less likely to peel off, for example, even if there is a difference in thermal expansion coefficient between the blockage portion 2 and the support layer 3.

[0102] In the gas separation membrane 1 according to the above embodiment, it is preferable that the constituent material of the porous body includes an inorganic material.

[0103] With this configuration, the inorganic material has high mechanical strength, which contributes to thinning the support layer 3 and improving the gas permeability of the support layer 3. Furthermore, when the occluded portion 2 is formed by a plating method, the wettability of the catalyst solution 21 and electroplating solution 24 in the defective portion 8 can be further improved.

[0104] In the gas separation membrane 1 according to the above embodiment, it is preferable that the constituent material of the separation layer 4 is an organic material.

[0105] With this configuration, a separation layer 4 that can accommodate various gas components can be realized depending on the composition of the organic material. Furthermore, by using organic materials, a separation layer 4 with excellent coverage of the support layer 3 can be realized even with a thin layer thickness. Such a separation layer 4 contributes to the realization of a gas separation membrane 1 with a high gas selectivity ratio and high gas permeability.

[0106] In the gas separation membrane 1 according to the above embodiment, it is preferable that the occlusion portion 2 is a plated film.

[0107] With this configuration, the plating film has high coverage and the coverage area is easy to control, making it possible to realize a closed section 2 with particularly good gas shielding properties.

[0108] In the gas separation membrane 1 according to the above embodiment, the metal contained in the occlusion portion 2 may be Ni. With this configuration, since Ni has excellent corrosion resistance and oxidation resistance, the stability of the blocked section 2 is improved.

[0109] In the gas separation membrane 1 according to the above embodiment, a portion of the occlusion portion 2 may be inserted into the pores of the porous body.

[0110] With this configuration, it is possible not only to cover the upper surface of the pores but also to fill the pores themselves. As a result, a closure portion 2 is obtained that can more reliably close the missing portion 8.

[0111] The method for manufacturing a gas separation membrane according to the above embodiment is a method for manufacturing a gas separation membrane 1 according to the above embodiment, comprising a preparation step S102, a blockage portion formation step S104, and a drying step S106.

[0112] In preparation step S102, a multilayer film 10 is prepared, comprising a support layer 3 made of a porous material and a separation layer 4 in which defects 8 occur. In blockage formation step S104, blockages 2 are selectively formed on the defects 8 by a plating method. In drying step S106, the multilayer film 10 in which the blockages 2 have been formed is dried to obtain a gas separation film 1.

[0113] With this configuration, by using a plating method, the occluding portion 2 that selectively closes the defective portion 8 can be efficiently formed, thereby reducing the number of defective portions 8 and enabling the efficient production of a gas separation membrane 1 with a high gas selectivity ratio and high gas permeability.

[0114] In the method for manufacturing a gas separation membrane according to the above embodiment, the plating method may be an electroless plating method. In this case, the blockage formation step S104 involves contacting the defective portion 8 with a catalyst solution 21 containing a catalyst to selectively deposit the catalyst onto the defective portion 8, and then applying metal ions M to the catalyst deposited on the defective portion 8. + The process includes contacting the electroless plating solution 23 containing the material to deposit metal. With this configuration, the occluded portion 2 can be efficiently formed by electroless plating.

[0115] In the method for manufacturing a gas separation membrane according to the above embodiment, it is preferable that the separation layer 4 has higher liquid-repellent properties for the catalyst solution 21 compared to the support layer 3.

[0116] With this configuration, a difference in the wettability of the catalyst solution 21 occurs between the support layer 3 and the separation layer 4. This difference in wettability allows the catalyst solution 21 to selectively adhere to the defective area 8.

[0117] In the method for manufacturing a gas separation membrane according to the above embodiment, the plating method may be an electroplating method. In this case, it is preferable that the porous body is conductive. Furthermore, the blockage formation step S104 involves applying an electric current to the porous body and applying metal ions M to the defective portion 8. + The process includes contacting an electrolytic plating solution 24 containing the above to deposit metal. With this configuration, the occluded portion 2 can be efficiently formed by electroplating.

[0118] In the method for manufacturing a gas separation membrane according to the above embodiment, it is preferable that the separation layer 4 has higher liquid repellency for the electrolytic plating solution 24 compared to the support layer 3.

[0119] With this configuration, a difference in the wettability of the electroplating solution 24 occurs between the support layer 3 and the separation layer 4. This difference in wettability allows the electroplating solution 24 to be selectively deposited on the defective area 8.

[0120] The gas separation apparatus 5 according to the above embodiment comprises a gas separation membrane 1 according to the above embodiment, a fixing part 52, and an exhaust part 54. The fixing part 52 fixes the gas separation membrane 1. An internal space 522 is formed on the support layer 3 side of the fixing part 52 to the gas separation membrane 1. The exhaust part 54 reduces the pressure of the internal space 522 so that it becomes a negative pressure relative to the external space 524 on the separation layer 4 side of the gas separation membrane 1.

[0121] With this configuration, a gas separation device 5 can be obtained that can efficiently separate specific gas components while suppressing energy consumption.

[0122] Although the gas separation membrane, method for manufacturing the gas separation membrane, and gas separation apparatus according to the present invention have been described above based on preferred embodiments, the present invention is not limited thereto.

[0123] For example, the gas separation membrane and gas separation apparatus according to the present invention may be configured such that each part of the above embodiment is replaced with a component having a similar function, or any component may be added to the above embodiment.

[0124] Furthermore, the method for manufacturing a gas separation membrane according to the present invention may be modified by adding any desired steps to the above embodiment. [Examples]

[0125] Next, specific embodiments of the present invention will be described. 6. Fabrication and evaluation of gas separation membranes 6.1. Fabrication of gas separation membranes for Comparative Examples 1-4 First, four multilayer films were prepared, each consisting of a support layer and a separation layer. It was confirmed beforehand that the separation layer had defects. These four multilayer films were then used as the gas separation membranes for Comparative Examples 1-4.

[0126] A porous alumina material with an average thickness of 125 μm was used for the support layer. For the separation layer, a thin film of polydimethylsiloxane with an average thickness of 100 nm, formed on the upper surface of the support layer by liquid-phase deposition and plasma irradiation, was used.

[0127] 6.2. Evaluation Method of Gas Separation Membranes in Comparative Examples 1-4 Next, the gas separation membranes of Comparative Examples 1 to 4 were set in the gas separation apparatus shown in Figure 12. Then, air with a CO2 mass concentration of 400 ppm was used as the mixed gas, and the CO2 mass concentration of the permeate gas was measured. The measurement results are shown in Table 1 (Figure 13). Figure 13 is Table 1, which shows the configuration and evaluation results of the gas separation membranes of Comparative Examples 1 to 4 and the gas separation membranes of Examples 1 to 4.

[0128] 6.3. Fabrication of gas separation membranes for Examples 1-4 The gas separation membranes of Comparative Examples 1 to 4, which were evaluated as described above, were repaired using electroless plating to remove defects as follows.

[0129] First, the catalyst solution was supplied so as to come into contact with the separation layer of the gas separation membranes of Comparative Examples 1-4. A Pd-Sn complex was used as the catalyst. Subsequently, the catalyst was activated to form a catalyst layer that selectively covered the defective areas.

[0130] Next, the catalyst layer was brought into contact with an electroless plating solution for Ni plating, and a occlusion that selectively covered the defective areas was formed by electroless plating. After that, the multilayer film with the occlusion formed was washed and dried. This yielded gas separation membranes of Examples 1 to 4, in which the defective areas were repaired with occlusions. The average thickness of the occlusion was 80 nm.

[0131] 6.4. Evaluation Method of Gas Separation Membranes in Examples 1-4 Next, the gas separation membranes from Examples 1 to 4 were set in the gas separation apparatus shown in Figure 12. Then, air with a CO2 mass concentration of 400 ppm was used as the mixed gas, and the CO2 mass concentration of the permeate gas was measured. The measurement results are shown in Table 1 (Figure 13).

[0132] 6.5. Evaluation results of gas separation membranes in Comparative Examples 1-4 and Examples 1-4 As shown in Table 1, in the gas separation membranes of Comparative Examples 1 to 4, although the CO2 mass concentration of the permeate gas was slightly higher than that of the mixed gas, the increase was only slight. Furthermore, the large variation in the CO2 mass concentration of the permeate gas suggests that the repair of the defects was insufficient, and the mixed gas permeated directly.

[0133] On the other hand, in the gas separation membranes of Examples 1 to 4, it was observed that the CO2 mass concentration of the permeate gas was significantly higher than that of the mixed gas. From this, it was found that the gas separation membranes of Examples 1 to 4 had high gas selectivity and gas permeability for CO2. Furthermore, the small variation in the CO2 mass concentration of the permeate gas suggests that the damaged areas were reliably repaired.

[0134] Furthermore, when the gas separation membranes of Examples 1 to 4 were cut in the thickness direction and the cut surfaces were observed with an electron microscope, it was found that a portion of the blocked area had penetrated into the interior of the support layer.

[0135] 6.6. Fabrication of gas separation membranes for Comparative Examples 5-8 First, four multilayer films were prepared, each consisting of a support layer and a separation layer. It was confirmed beforehand that the separation layer had defects. These four multilayer films were then used as the gas separation membranes for Comparative Examples 5-8.

[0136] A porous stainless steel material with an average thickness of 300 μm was used for the support layer. For the separation layer, a thin film of polydimethylsiloxane with an average thickness of 100 nm was formed on the upper surface of the support layer by liquid-phase deposition and plasma irradiation.

[0137] 6.7. Evaluation Method of Gas Separation Membranes in Comparative Examples 5-8 Next, the gas separation membranes of Comparative Examples 5-8 were set in the gas separation apparatus shown in Figure 12. Then, air with a CO2 mass concentration of 400 ppm was used as the mixed gas, and the CO2 mass concentration of the permeate gas was measured. The measurement results are shown in Table 2 (Figure 14). Figure 14 is Table 2, which shows the configuration and evaluation results of the gas separation membranes of Comparative Examples 5-8 and Examples 5-8.

[0138] 6.8. Fabrication of gas separation membranes for Examples 5-8 For the gas separation membranes of Comparative Examples 5 to 8, which were evaluated as described above, the defective areas were repaired by electroplating as follows.

[0139] First, the gas separation membranes of Comparative Examples 5-8 were placed in a plating tank and immersed in an electroplating solution along with a Ni anode. Then, a voltage was applied between the support layer and the anode, and a occlusion that selectively covered the defective areas was formed by electroplating. After that, the multilayer film with the formed occlusion was washed and dried. This obtained the gas separation membranes of Examples 5-8 in which the defective areas were repaired with occlusion. The average thickness of the occlusion was 120 nm.

[0140] 6.9. Evaluation method for gas separation membranes in Examples 5-8 Next, the gas separation membranes from Examples 5-8 were set in the gas separation apparatus shown in Figure 12. Then, air with a CO2 mass concentration of 400 ppm was used as the mixed gas, and the CO2 mass concentration of the permeate gas was measured. The measurement results are shown in Table 2 (Figure 14).

[0141] 6.10. Evaluation results of gas separation membranes in Comparative Examples 5-8 and Examples 5-8 As shown in Table 2, in the gas separation membranes of Comparative Examples 5-8, although the CO2 mass concentration of the permeate gas was slightly higher than that of the mixed gas, the increase was only slight. Furthermore, the large variation in the CO2 mass concentration of the permeate gas suggests that the repair of the defects was insufficient, and the mixed gas was permeating directly.

[0142] On the other hand, in the gas separation membranes of Examples 5 to 8, it was observed that the CO2 mass concentration of the permeate gas was significantly higher than that of the mixed gas. From this, it was found that the gas separation membranes of Examples 5 to 8 had high gas selectivity and gas permeability for CO2. Furthermore, the small variation in the CO2 mass concentration of the permeate gas suggests that the damaged areas were reliably repaired.

[0143] Furthermore, when the gas separation membranes of Examples 5 to 8 were cut in the thickness direction and the cut surfaces were observed with an electron microscope, it was found that a portion of the blocked area had penetrated into the interior of the support layer.

[0144] As is clear from the evaluation results above, the gas separation membranes in each example were found to have minimal defects in the separation layer, and to possess high gas selectivity and high gas permeability for specific gas components. [Explanation of Symbols]

[0145] 1...Gas separation membrane, 2...Blocked section, 3...Support layer, 4...Separation layer, 5...Gas separation device, 8...Defective section, 9...Gas separation membrane, 10...Multilayer membrane, 21...Catalyst solution, 22...Catalyst layer, 23...Electroless plating solution, 24...Electrolytic plating solution, 31...Top surface, 51...Perforated plate, 52...Fixed section, 53...Piping, 54...Exhaust section, 55...Piping, 56...Gas concentration meter, 60...Plating tank, 61...Anode, 62...DC power supply, 522...Internal space, 524...External space, G1...Mixed gas, G2...Permeate gas, S102...Preparation process, S104...Blocked section formation process, S106...Drying process

Claims

1. A separation membrane that separates a specific gas component from a mixed gas having multiple gas components by allowing permeation, A support layer composed of a porous material having pores, A separation layer provided on one side of the support layer and having gas separation capability for separating the specific gas components, A closure portion containing metal is provided corresponding to the missing portion where the separation layer is missing and the support layer is exposed, A gas separation membrane characterized by comprising the following:

2. The gas separation membrane according to claim 1, wherein the constituent material of the porous body includes an inorganic material.

3. The gas separation membrane according to claim 1 or 2, wherein the constituent material of the separation layer is an organic material.

4. The gas separation membrane according to claim 1 or 2, wherein the occluded portion is a plated film.

5. The gas separation membrane according to claim 1 or 2, wherein the metal contained in the occluded portion is Ni.

6. The gas separation membrane according to claim 1 or 2, wherein a portion of the occluded portion is inserted into the pores of the porous body.

7. A method for producing a gas separation membrane according to claim 1 or 2, A preparation step for preparing a multilayer film comprising the support layer made of the porous material and the separation layer in which the defect occurs, A blocking portion forming step is performed in which the blocking portion is selectively formed on the defective portion by a plating method, A drying step to obtain the gas separation membrane by drying the multilayer film on which the blockage portion is formed, A method for producing a gas separation membrane, characterized by having [a certain characteristic].

8. The aforementioned plating method is an electroless plating method. The aforementioned blockage formation step is, A process in which a catalyst solution containing a catalyst is brought into contact with the defective portion, and the catalyst is selectively attached to the defective portion, The process involves contacting the catalyst attached to the defective portion with an electroless plating solution containing metal ions to deposit the metal, A method for producing a gas separation membrane according to claim 7, including the following:

9. The method for producing a gas separation membrane according to claim 8, wherein the separation layer has higher liquid repellency of the catalyst solution compared to the support layer.

10. The aforementioned plating method is an electrolytic plating method. The porous body has electrical conductivity, The aforementioned blockage formation step is, The process of applying an electric current to the porous body, The process involves contacting the defective area with an electroplating solution containing metal ions to deposit the metal, A method for producing a gas separation membrane according to claim 7, including the following:

11. The method for manufacturing a gas separation membrane according to claim 10, wherein the separation layer has higher liquid repellency of the electrolytic plating solution compared to the support layer.

12. A gas separation membrane according to claim 1 or 2, A fixing portion that fixes the gas separation membrane and has an internal space formed on the support layer side of the gas separation membrane, An exhaust section that reduces the internal space so that the external space on the separation layer side of the gas separation membrane becomes negatively pressurized, A gas separation apparatus characterized by comprising the following:

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