Separation membrane element and separation device

Abstract

Provided is a plate-and-frame type separation membrane element having excellent pressure resistance.　A plate-and-frame type separation membrane element according to the present disclosure comprises: a container; and a membrane disposed in the container. The container includes: a container body having a bottom surface part and a side wall part; and a lid joined to the container body and disposed so as to face the bottom surface part with the side wall part therebetween. The lid has a projection part protruding toward the bottom surface part along the outside of the side wall part.

Description

Separation membrane element and separation device

[0001] The present invention relates to a separation membrane element and a separation device.

[0002] Plate-and-frame separation membrane elements, which are made by stacking flat membranes, are known as separation membranes for separating specific fluid components from a liquid or gaseous raw fluid (see, for example, Patent Document 1). In recent years, the performance of separation membranes has improved, making it possible to realize thinner separation membranes. Such thin separation membranes can be used to remove carbon dioxide and other substances contained in gases such as exhaust gases. The plate-and-frame separation membrane elements can use thin separation membranes that are difficult to use with spiral-wound separation membrane elements.

[0003] JP 2017-000964 A

[0004] However, the above-mentioned conventional techniques have room for improvement in terms of pressure resistance when a fluid is supplied to a plate-and-frame type separation membrane element. One aspect of the present invention aims to realize a plate-and-frame type separation membrane element with excellent pressure resistance.

[0005] In order to solve the above problems, a plate-and-frame type separation membrane element according to one embodiment of the present invention comprises a container and a separation membrane having a region arranged in the form of a flat membrane within the container, the container including a container body having a bottom surface and a side wall, and a lid joined to the container body and arranged opposite the bottom surface across the side wall of the container body, the lid having a protrusion that protrudes toward the bottom surface of the container body along the outside of the side wall of the container body.

[0006] According to one aspect of the present invention, a plate-and-frame separation membrane element having excellent pressure resistance can be provided.

[0007] 12 is a perspective view illustrating a separation membrane element according to one embodiment of the present invention. FIG. 13 is a cross-sectional view illustrating a separation membrane element provided with a flat-plate-shaped lid. FIG. 14 is a cross-sectional view illustrating a separation membrane element provided with a flat-plate-shaped lid in a pressurized state. FIG. 15 is a cross-sectional view illustrating a separation membrane element according to one embodiment of the present invention. FIG. 16 is a cross-sectional view illustrating a separation membrane element according to one embodiment of the present invention in a pressurized state. FIG. 17 is a cross-sectional view illustrating a separation membrane element according to one embodiment of the present invention. FIG. 18 is a cross-sectional view illustrating a separation membrane element according to one embodiment of the present invention. FIG. 19 is a cross-sectional view illustrating a separation membrane element according to one embodiment of the present invention. FIG. 19 is a perspective view illustrating an exploded view of a laminate included in a separation membrane element according to one embodiment of the present invention. FIG. 19 is a cross-sectional view illustrating a laminate included in a separation membrane element according to one embodiment of the present invention. FIG. 19 is a perspective view illustrating a manufacturing process for a separation membrane element according to one embodiment of the present invention. FIG. 11 is a cross-sectional view illustrating a manufacturing process for a separation membrane element according to one embodiment of the present invention.

[0008] An embodiment of the present invention will be described below, but the present invention is not limited thereto. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more and B or less."

[0009] [1. Separation membrane element] A plate-and-frame type separation membrane element according to one embodiment of the present invention comprises a container and a separation membrane having a region arranged in the shape of a flat membrane within the container, the container including a container body having a bottom surface and a side wall, and a lid joined to the container body and positioned opposite the bottom surface across the side wall of the container body, the lid having a protrusion that protrudes along the outer side of the side wall of the container body toward the bottom surface of the container body.

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

[0011] 1 is a perspective view schematically showing a separation membrane element according to one embodiment of the present invention. In Fig. 1, L represents the length direction of the container, W represents the width direction of the container, and H represents the height direction of the container.

[0012] The separation membrane element 1 is a plate-and-frame type separation membrane element. The separation membrane element 1 includes a container 50.

[0013] As shown in Fig. 1 , the container 50 includes a container body 40 and a lid 60. The container body 40 has a bottom surface 48 and a side wall 49. The lid 60 is joined to the container body 40 and is disposed opposite the bottom surface 48 with the side wall 49 of the container body 40 in between. The side wall 49 can also be considered a member connecting the bottom surface 48 and the lid 60. The lid 60 and the bottom surface 48 extend in a direction perpendicular to the stacking direction of the laminate 10 described below, and the side wall 49 extends in the stacking direction of the laminate 10.

[0014] The side wall portion 49 has an upper end 47. The upper end 47 of the side wall portion 49 is located on the opposite side of the container body 40 from the bottom surface portion 48. An opening is formed on the opposite side of the container body 40 from the bottom surface portion 48. In a plan view, the upper end 47 of the side wall portion 49 can also be said to be a portion that surrounds the opening. The upper end 47 abuts against the lid 60. The lid 60 is positioned so as to close the opening. The lid 60, the bottom surface portion 48, and the side wall portion 49 can define a storage space.

[0015] The shape of the container 50 is not particularly limited, and the lid 60 and the bottom portion 48 may be polygonal, such as rectangular, or may be circular. The side wall portion 49 may be prismatic or cylindrical.

[0016] 12 , the container body 40 may have guide portions 41 for positioning the components constituting the stack 10. When the side wall portion 49 of the container body 40 is prismatic, the guide portions 41 are preferably provided at the corners of the side wall portion 49.

[0017] FIG. 2 is a cross-sectional view schematically illustrating a separation membrane element equipped with a flat lid. A conventional separation membrane element 201, as shown in FIG. 2, has a flat lid 260 without protrusions. In the separation membrane element 201, the vessel body 240 and the lid 260 are bonded via a sealing material such as an adhesive. FIG. 3 is a cross-sectional view schematically illustrating a state in which a separation membrane element equipped with a flat lid is pressurized. When a raw fluid is supplied to the separation membrane element 201, the vessel body 240 and the lid 260 may deform by expanding outward due to pressure from the inside. In a plate-and-frame separation membrane element 201 equipped with a flat lid 260, this can cause the sealing material between the vessel body 240 and the lid 260 to peel off, resulting in fluid leakage. It is possible to improve the pressure resistance of the separation membrane element 201 by increasing the thickness of the vessel 250 or changing the material of the vessel 250, but this is costly.

[0018] FIG. 4 is a cross-sectional view schematically illustrating a separation membrane element according to one embodiment of the present invention. FIG. 5 is a cross-sectional view schematically illustrating a separation membrane element according to one embodiment of the present invention in a pressurized state. The present inventors discovered that the pressure resistance of the separation membrane element 1 can be improved by providing the lid 60 with a protrusion 61 that protrudes toward the bottom surface 48 of the vessel body 40 along the outer side of the side wall 49 of the vessel body 40. In this case, even if the lid 60 deforms outward, the protrusion 61 can suppress or prevent the side wall 49 of the vessel body 40 from deforming outward. This prevents peeling of the sealing material between the vessel body 40 and the lid 60 (for example, both on the outer side of the side wall 49 and at the upper end 47 of the vessel body 40). Therefore, fluid leakage can be prevented.

[0019] Furthermore, according to the above-mentioned configuration, CO is removed from harmful gases such as exhaust gas. ２ These effects will also contribute to the achievement of the Sustainable Development Goals (SDGs) advocated by the United Nations, including Goal 7 "Affordable and clean energy," Goal 12 "Ensure sustainable consumption and production patterns," and Goal 13 "Take urgent action to combat climate change."

[0020] In this specification, "the protrusion protrudes toward the bottom surface of the container body along the outer side of the side wall of the container body" means that the protrusion protrudes downward parallel to the height direction H of the container. Here, when the container is placed so that the height direction of the container is parallel to the vertical direction, "downward" means vertically downward.

[0021] The shape of the lid 60 is not particularly limited as long as it has a shape that includes the protrusions 61. For example, as shown in FIGS. 1 and 4, the protrusions 61 may be provided on the peripheral edge of a flat lid 60. Alternatively, as shown in FIG. 6, the flat portion of the lid 60a may extend outward from the protrusions 61a. That is, as shown in FIG. 6, the cross section of the portion where the protrusions 61a protrude from the flat portion of the lid 60a may be T-shaped. Alternatively, as shown in FIG. 7, the lid 60b may have a shape that, when placed on the container body 40, the center of the lid 60b is lower than the peripheral edge, so that the lid 60b fits onto the container body 40 (a shape known as a hook lid in Japanese).

[0022] From the viewpoint of sealing performance, it is preferable that the protrusions 61 are present on the entire peripheral edge of the lid 60 in a plan view. In other words, it is preferable that the protrusions 61 are present so as to surround the entire side wall 49 of the container body 40. For example, if the container body 40 is rectangular in a plan view, it is preferable that the protrusions 61 are present so as to surround all four sides of the rectangle.

[0023] The lid 60 is bonded to the container body 40 via a sealing material. For example, the lid 60 is bonded to at least one of the outer side of the side wall portion 49 and the upper end 47 of the container body 40 via the sealing material.

[0024] The components constituting the container 50 can be made of resin, glass, metal, ceramic, or the like. Examples of resins include polycarbonate, acrylic resin, fluororesin, polybutylene succinate (PBS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS), polyphenylene sulfide (PPS), polyethersulfone (PES), polysulfone (PSF), polyacrylonitrile (PAN), polyphenylene oxide (PPO), polyamide (PA), polyimide (PI), polyetherimide (PEI), polyetheretherketone (PEEK), and polypropylene (PP), as well as fiber-reinforced resins obtained by mixing these resins with glass or other fibers. Examples of metals include stainless steel (SUS), aluminum, copper, and the like. The components constituting the container 50 can be made of the same material or different materials.

[0025] Double-sided tape, adhesives, etc. can be used as the sealing material. Examples of resins contained in the adhesive include epoxy resins, urethane resins, silicone resins, vinyl chloride copolymer resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinylidene chloride copolymer resins, vinyl chloride-acrylonitrile copolymer resins, butadiene-acrylonitrile copolymer resins, polyamide resins, polyvinyl butyral resins, polyester resins, cellulose derivative (nitrocellulose, etc.) resins, styrene-butadiene copolymer resins, various synthetic rubber (elastomer) resins, phenolic resins, urea resins, melamine resins, phenoxy resins, and urea-formamide resins. Among these, the sealing material is preferably an epoxy resin (resin for epoxy adhesives), and more preferably a two-component mixed epoxy adhesive. In the case of double-sided tape, a structural bonding tape in which an acrylic pressure-sensitive adhesive is applied to an acrylic foam can be used.

[0026] 1 , the vessel 50 may have a first supply port 43 communicating with a supply-side channel member 23 of the laminate 10 (described later) for supplying a raw material fluid, a first discharge port 44 communicating with the supply-side channel member 23 of the laminate 10 for discharging a non-permeating fluid, and a second discharge port 46 communicating with a permeate-side channel member 22 of the laminate 10 for discharging a permeating fluid. The vessel 50 may further have a supply and discharge port 45 communicating with the permeate-side channel member 22 of the laminate 10. The supply and discharge port 45 may be used as a second supply port for supplying a sweep fluid or as a third discharge port for discharging a permeating fluid.

[0027] The first supply port 43, supply and discharge port 45, first discharge port 44, and second discharge port 46 of the container 50 may all be provided on the side wall portion 49 of the container body 40, or on the lid 60 or bottom portion 48.

[0028] This separation membrane element has an effective membrane area of ​​0.1 m ２ It is preferable that the length is 12.0 m or more. ２ More preferably, it is 36.0 m or more. ２ It is more preferable that the effective membrane area is 500.0 m or more. ２ Preferably, it is 100.0 m or less. ２ More preferably, it is 50.0 m or less. ２ It is more preferable that the effective membrane area is within the above ranges. The effective membrane area means the membrane area that can be used for gas separation. It is preferable that the effective membrane area is within these ranges from the viewpoint that a separation device with sufficient performance can be easily manufactured using the separation membrane element.

[0029] <1-2. Separation membrane> The separation membrane element 1 includes a separation membrane 21 having a region in which it is arranged in a flat membrane shape within a container 50. "A separation membrane having a region in which it is arranged in a flat membrane shape within a container 50" means that the separation membrane 21 is contained within the container 50 so as to include a region in which it is arranged in a flat state without being wound into a roll or a cylindrical shape. The separation membrane 21 contained within the container 50 may have a folded portion as long as it has a region in which it is arranged in a flat membrane shape within the container 50, and as described below, it may be contained within the container 50 in a folded state so as to form a flat membrane region.

[0030] The separation membrane 21 is not particularly limited, and any known membrane capable of selectively allowing specific fluid components to permeate from the raw fluid can be used. The separation membrane 21 can be, for example, an ultrafiltration membrane, a nanofiltration membrane, a reverse osmosis membrane, a dialysis membrane, a forward osmosis membrane, a solution-diffusion membrane, a facilitated transport membrane, or the like. A solution-diffusion membrane is a membrane that selectively allows molecules to permeate by utilizing the differences in the solubility and diffusibility of fluid molecules. A facilitated transport membrane is a membrane that contains a substance that promotes the solubility and / or diffusibility of fluid molecules. The separation membrane 21 is preferably a solution-diffusion membrane.

[0031] The separation membrane 21 can have a porous membrane and a separation functional layer. The porous membrane of the separation membrane 21 may have one or more layers, or may have two or more layers, or may have three or more layers. The porous membrane can be provided on one or both sides of the separation functional layer. The porous membrane provided on one or both sides of the separation functional layer may have one layer, or may have two or more layers. Furthermore, the separation membrane 21 may have a support layer for reinforcement, if necessary.

[0032] The thickness of the separation membrane is preferably 10 to 600 μm, more preferably 10 μm to 550 μm, and even more preferably 10 to 510 μm. If the thickness of the separation membrane is within this range, the membrane thickness will be thin, and specific fluid components such as carbon dioxide can be sufficiently separated from the raw fluid. Furthermore, if the thickness of the separation membrane is within this range, it is difficult to use it in a spiral-type separation membrane element, but it can be used in a plate-and-frame type separation membrane element.

[0033] (Separation Functional Layer) The separation membrane 21 may have a separation functional layer that selectively separates specific fluid components contained in the raw fluid. The separation functional layer can be selected depending on the type of membrane. The separation functional layer is preferably a layer formed using a composition containing a resin. Examples of such resins include polyacrylic acid, polyamide, cellulose acetate, polysulfone, polyethersulfone, vinylidene fluoride, polyacrylonitrile, polyvinyl chloride-polyacrylonitrile copolymer, epoxy resin, polyimide, polyvinyl alcohol, polysiloxane, polyether block amide copolymer, and polyethylene oxide. The polyacrylic acid may be crosslinked polyacrylic acid, or may be uncrosslinked polyacrylic acid.

[0034] The separation functional layer may be a gel layer. The gel layer contains a hydrophilic resin such as polyacrylic acid, and may further contain an amino acid, an aminosulfonic acid, and / or an aminophosphonic acid. The gel layer may contain a surfactant for adjusting the wettability of the porous membrane. When the specific fluid component is a gas, the gel layer may further contain an alkali metal compound and / or a hydration reaction catalyst for improving the reaction rate between the specific gas component and the alkali metal compound.

[0035] The thickness of the separation functional layer is preferably 1 to 1,000 nm, more preferably 10 to 500 nm, and even more preferably 100 to 400 nm. If the thickness of the separation functional layer is within the above range, specific fluid components such as carbon dioxide can be sufficiently separated from the raw material fluid.

[0036] The separation functional layer can be produced, for example, by applying a coating liquid containing the resin and medium onto a porous membrane. Methods for applying the coating liquid onto a porous membrane include slot die coating, spin coating, bar coating, die coating, blade coating, air knife coating, gravure coating, roll coating, spray coating, dip coating, comma roll coating, kiss coating, screen printing, inkjet printing, etc.

[0037] (Porous Membrane) The separation membrane 21 may be composed of only a separation functional layer, or may have a laminated structure in which a separation functional layer and a porous membrane are laminated. The porous membrane can be provided on one or both sides of the separation functional layer and can support or protect the separation functional layer.

[0038] The porous membrane can be a support layer for supporting the separation functional layer or a protective layer for protecting the separation functional layer. The porous membrane can be in direct contact with the separation functional layer. The porous membrane preferably has porosity with high fluid permeability so as not to act as a diffusion resistance for the raw fluid supplied to the separation functional layer or a specific fluid component contained in the raw fluid.

[0039] The porous membrane is preferably made of a resin material or an inorganic material. Examples of the resin material constituting the porous membrane include polyolefin resins such as polyethylene (PE) and polypropylene (PP); fluorine-containing resins such as polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), and polyvinylidene fluoride (PVDF); polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate; polystyrene (PS), polyethersulfone (PES), polyphenylene sulfide (PPS), polysulfone (PSF), polyacrylonitrile (PAN), polyphenylene oxide (PPO), polyamide (PA), polyimide (PI), polyetherimide (PEI), polyetheretherketone (PEEK), high-molecular-weight polyester, heat-resistant polyamide, aramid, polycarbonate, and mixtures of two or more of these resin materials. Among these, from the viewpoint of water repellency and heat resistance, it is preferable to contain at least one of a polyolefin resin and a fluorine-containing resin, and it is more preferable to contain one or more of polyethylene, polypropylene, and polytetrafluoroethylene. Examples of inorganic materials constituting the porous membrane include metal, glass, ceramics, etc.

[0040] The porous membrane is not particularly limited as long as it is a porous body. The porous membrane may be a porous sheet-like body such as a porous resin film, nonwoven fabric, woven fabric, foam, mesh, or net. These porous bodies can also be used as a reinforcing support layer.

[0041] The porous membrane of the separation membrane may be, for example, one or more layers of porous resin film laminated on one side of the separation functional layer and one or more layers of nonwoven fabric laminated on the other side of the separation functional layer.

[0042] (Stack) Figure 8 is an exploded perspective view showing a stack of a separation membrane element according to one embodiment of the present invention. A container 50 houses a stack 10 including two permeate-side channel members 22 and a separation membrane 21 and a feed-side channel member 23 disposed between the two permeate-side channel members 22. A raw fluid flows through the feed-side channel member 23. A permeated fluid that has permeated the separation membrane 21 flows through the permeate-side channel member 22. In Figure 1, the height direction H of the container 50 coincides with the stacking direction of the stack 10. The separation membranes 21 included in the stack 10 are stacked so as to have a region in which they are arranged in a flat membrane shape within the container 50. The permeate-side channel member 22 and the feed-side channel member 23 included in the stack 10 are also typically stacked so as to have a region in which they are arranged in a flat membrane shape within the container 50.

[0043] The laminate 10 may have at least a portion in which a permeate-side channel member 22, a separation membrane 21, a supply-side channel member 23, and a permeate-side channel member 22 are stacked in this order. For example, as shown in Fig. 8, the laminate 10 may have a membrane stack section 20 in which a separation membrane 21, a supply-side channel member 23, and a separation membrane 21 are stacked in this order. The laminate 10 preferably has a structure in which the membrane stack section 20 is disposed between two permeate-side channel members 22. When the separation membrane has a porous membrane on only one side, in the membrane stack section 20, the separation membrane 21 and the supply-side channel member 23 are preferably stacked such that the separation functional layer side of the separation membrane 21 faces the supply-side channel member 23.

[0044] The separation membrane 21 and the supply-side channel member 23 may be bonded together with a supply-side plugging material. Alternatively, the permeate-side channel member 22 and the separation membrane 21 may be bonded together with a permeate-side plugging material. The supply-side plugging material forms the supply-side plugging section 31, and the permeate-side plugging material forms the permeate-side plugging section 32. These will be described later.

[0045] In the laminate 10, the membrane stack section 20 and the permeate-side channel member 22 stacked on the membrane stack section 20 may constitute a membrane leaf. The membrane leaf is a laminate having a layered structure in which the permeate-side channel member 22, the separation membrane 21, the feed-side channel member 23, and the separation membrane 21 are stacked in this order. The laminate 10 may include only one membrane leaf, but preferably has a structure in which multiple membrane leaves are stacked. When the laminate 10 has a structure in which multiple membrane leaves are stacked, as shown in FIG. 8 , each component and separation membrane may be repeatedly stacked on the membrane stack section 20, such that the permeate-side channel member 22, the separation membrane 21, etc. are stacked. The number of membrane leaves included in the laminate 10 is not particularly limited, but may be, for example, 2 to 100, 5 to 50, or 10 to 30. The uppermost and lowermost surfaces of the laminate 10 are preferably permeate-side channel members 22. In this case, the uppermost permeate-side channel member 22 constitutes a membrane leaf.

[0046] (Feed-Side Channel Member and Permeate-Side Channel Member) The feed-side channel member 23 and the permeate-side channel member 22 preferably have the functions of promoting turbulence (surface renewal of the membrane surface) of the feed fluid and the permeated fluid that has permeated the separation membrane 21, thereby increasing the membrane permeation rate of the permeated fluid in the feed fluid, and minimizing the pressure loss of the feed fluid supplied and the permeated fluid that has permeated the separation membrane 21. Since the feed-side channel member 23 and the permeate-side channel member 22 preferably have the functions of a spacer that forms the flow paths of the feed fluid and the permeated fluid, and the functions of generating turbulence in the feed fluid and the permeated fluid, mesh-like (net-like, mesh-like, etc.) ones are preferably used. The shape of the unit lattice of the mesh is preferably selected from, for example, a square, a rectangle, a rhombus, a parallelogram, etc. depending on the purpose, since the fluid flow path changes depending on the shape of the mesh.

[0047] The materials for the supply-side channel member 23 and the permeate-side channel member 22 are not particularly limited, but are preferably heat-resistant materials capable of withstanding the operating temperature conditions of the separation apparatus in which the separation membrane element 1 is installed. The supply-side channel member 23 and the permeate-side channel member 22 may each independently have a single-layer structure or a multilayer structure. The supply-side channel member 23 and the permeate-side channel member 22 having a multilayer structure preferably have a structure in which one or more types of mesh-like layers are stacked, and the stacked mesh-like layers may have different mesh structures. Preferably, the permeate-side channel member 22 has a single-layer structure.

[0048] In this specification, the phrase "the permeate-side channel member 22 has a single-layer structure" means that the permeate-side channel member 22 does not have multiple layers. In other words, this means that the permeate-side channel member 22 is made of a single mesh or net, and does not mean that the permeate-side channel member 22, the separation membrane 21, and the feed-side channel member 23 are not laminated in the separation membrane element 1. Furthermore, the phrase "the permeate-side channel member 22 has a multi-layer structure" means that the permeate-side channel member 22 is made of multiple meshes or nets.

[0049] In one embodiment of the present invention, the permeate-side channel member is preferably mesh-shaped. When the permeate-side channel member is mesh-shaped and has a multilayer structure having two or more layers, it is preferable that the number of meshes in each layer of the permeate-side channel member is the same. If the number of meshes in each layer is the same, deformation of the permeate-side channel member due to one layer penetrating into another layer is less likely to occur, thereby improving the compressive strength of the permeate-side channel member. When the permeate-side channel member has a single-layer structure, or when the permeate-side channel member has a multilayer structure and the number of meshes in each layer is the same, the number of meshes in the permeate-side channel member is preferably 18 meshes or more. The upper limit of the mesh number is not particularly limited, but it may be, for example, 150 meshes or less.

[0050] In another embodiment of the present invention, the permeate-side flow path member is mesh-like and has a multilayer structure having two or more layers, and the mesh count of each layer of the permeate-side flow path member may be different. In this case, the mesh count of the permeate-side flow path member is preferably 50 meshes or more. The upper limit of the mesh count is not particularly limited, but may be, for example, 150 meshes or less. When the mesh count of the permeate-side flow path member is 50 meshes or more, the mesh openings between the meshes are sufficiently small, making it difficult for one layer to penetrate into another layer, thereby preventing deformation of the permeate-side flow path member.

[0051] The laminate 10 may, if necessary, have permeate-side plugging parts 32 provided so as to include positions corresponding to the stacking positions of the permeate-side flow path members 22 in the stacking direction of the laminate 10 ( FIG. 8 ). The "positions corresponding to the stacking positions of the permeate-side flow path members 22" refer not only to the positions occupied by the permeate-side flow path members 22, but also to positions occupied by extended portions of the permeate-side flow path members 22 when the permeate-side flow path members 22 are extended in a direction along the plane of the laminate 10 (the direction in which the permeate-side plugging parts 32 in FIG. 8 exist). The permeate-side plugging parts 32 may be formed so as to include the permeated portions, with the permeate-side plugging material for forming the permeate-side plugging parts 32 shown in FIG. 8 permeating into the permeate-side flow path members 22.

[0052] Each layer of the laminate 10 shown in FIG. 8 has an edge on its surface. In this specification, the term "edge" refers to the region of the surface of each layer extending a certain distance from the outer periphery of the layer. The certain distance is not particularly limited as long as it does not impede the effectiveness of the separation membrane element, and may be, for example, 1% or less, 5% or less, or 10% or less of the distance between the opposing sides. In one embodiment, the edge region may be 0.5% or more of the distance between the opposing sides. The edge may exist not only on the upper surface of the laminate 10 (i.e., the direction in which the lid 60 in FIG. 1 exists) but also on the lower surface (i.e., the direction in which the bottom surface portion 48 in FIG. 1 exists). It is preferable that the certain distance between the upper edge and the lower edge of the same layer is the same.

[0053] The end of the supply-side channel member 23 may be provided with tape to prevent seepage of the permeate-side plugging material used to form the permeate-side plugging sections 32 described below. The tape is preferably provided on the end of the supply-side channel member 23 on the side facing the separation membrane 21, and when the separation membranes 21 are disposed on both sides of the supply-side channel member 23, the tape may be provided on both sides of the end of the supply-side channel member 23. Similarly, the end of the permeate-side channel member 22 may be provided with tape to prevent seepage of the supply-side plugging material used to form the supply-side plugging sections 31. Note that when the plugging material is double-sided tape, it is not necessary to use tape to prevent seepage.

[0054] As shown in Fig. 8, the end of the stack 10 that exists in the direction in which the raw material fluid passes is referred to as the second end 12, and the end that exists in the direction in which the permeating fluid passes is referred to as the first end 11. Therefore, each layer included in the stack 10 has two first ends 11 and two second ends 12 on at least one surface. In this specification, when "first ends 11 of the stack 10" is mentioned, it means the first ends 11 of all layers included in the stack 10. The same applies to the second ends 12.

[0055] 8 , the permeate-side plugging parts 32 may be provided at the first end 11 of the laminate 10 in addition to the second end 12. When the permeate-side plugging parts 32 are provided at the first end 11, the permeate-side plugging parts 32 are preferably provided along the entire one side of the laminate 10 constituting the first end 11 in a plan view. That is, the permeate-side plugging parts 32 provided at the first end 11 are preferably provided along the first end 11 of the laminate 10. The permeate-side plugging parts 32 provided at the first end 11 may also be provided at a position corresponding to the stacking position of the permeate-side channel member 22 in the stacking direction of the laminate 10, and may be formed so that the plugging material permeates into the permeate-side channel member 22 and includes this permeated portion. When the permeate-side plugging parts 32 are also provided at the first end part 11, the permeate-side plugging parts 32 may be provided at the two second end parts 12 and at one end part of the first end part 11 shown in FIG. 8 that is located on a side opposite to the direction in which the permeate fluid is discharged, and the permeate-side plugging parts 32 at the second end part 12 and the first end part 11 may be formed in a state in which they are connected (for example, U-shaped) in plan view.

[0056] The supply-side plugging portion 31 and the permeate-side plugging portion 32 are preferably bonded to each other at a position where the plugging portions intersect in a plan view (hereinafter, this may be referred to as an "intersection position"). In the laminate 10 shown in Figs. 1 and 8, the intersection position can be provided at a corner of the laminate 10 in a plan view.

[0057] FIG. 9 is a cross-sectional view of the laminate 10 of this separation membrane element, cut in a direction parallel to the second end 12. The separation function layer 53, together with the porous substrate 52, forms the separation membrane 21. The laminate 10 has a supply-side plugging portion 31 between the separation function layer 53 included in the separation membrane 21 and the supply-side channel member 23 (e.g., adhesive portion 51). FIG. 9 shows a state in which the supply-side plugging material forming the supply-side plugging portion 31 has permeated not only the adhesive portion 51 but also the end of the supply-side channel member 23 (hatched portion). In the supply-side plugging portion 31, the separation function layer 53 and the supply-side channel member 23 are bonded at the adhesive portion 51 by the supply-side plugging material. When a feed fluid flows through the supply-side channel member 23, pressure is generated in the direction of the separation membrane 21 (i.e., the direction of the block arrow shown in FIG. 9 ).

[0058] The supply-side plugs 31 also function to prevent mixing of the fluid flowing through the supply-side channel member 23 and the fluid flowing through the permeate-side channel member 22. The fluid flowing through the supply-side channel member 23 is, for example, a feed fluid and a non-permeated fluid that has not permeated the separation membrane 21. The fluid flowing through the permeate-side channel member 22 is, for example, a permeated fluid that has permeated the separation membrane 21, and a sweep fluid that is supplied to the permeate-side channel member 22 and discharged together with the permeated fluid. The sweep fluid is a fluid that is inactive with respect to the separation functional layer 53 of the separation membrane 21.

[0059] In the separation membrane element 1, the laminate 10 is disposed so that the second end 12 of the laminate 10 faces a side wall 49 of the container 50 on which the first supply port 43 and the first discharge port 44 are formed, and the first end 11 of the laminate 10 faces a side wall 49 of the container 50 on which the second discharge port 46 is formed ( FIG. 1 ). When the supply and discharge port 45 of the container 50 is not used or does not have the supply and discharge port 45, the permeate-side plugging part 32 is formed on the side of the first end 11 of the laminate 10 on which the supply and discharge port 45 in FIG. 1 is depicted. When the container 50 has the supply and discharge port 45 and this supply and discharge port 45 is used, not forming the permeate-side plugging part 32 at the first end 11 of the laminate 10 allows a sweep fluid to be supplied to the permeate-side channel member 22 or a permeate fluid to be discharged from the supply and discharge port 45.

[0060] The separation membrane element 1 having the above structure can separate specific fluid components as follows. First, a feed fluid is supplied from the first supply port 43 of the container 50 to the second end 12 side of the stack 10, thereby supplying the feed fluid into the supply-side channel member 23. The separation functional layer of the separation membrane 21 can selectively permeate specific fluid components contained in the feed fluid flowing through the supply-side channel member 23. As a result, the permeated fluid that has permeated the separation membrane 21 contains a higher content of the specific fluid component than the feed fluid. The separation membrane element 1 is provided with a supply-side plug 31, which prevents the feed fluid supplied to the supply-side channel member 23 and the non-permeated fluid that has not permeated the separation membrane 21 from mixing with the permeated fluid flowing through the permeate-side channel member 22. The separation membrane element 1 is also provided with a permeate-side plug 32, which prevents the permeated fluid that has permeated the separation membrane 21 and flowed through the permeate-side channel member 22 from mixing with the feed fluid and non-permeated fluid flowing through the supply-side channel member 23. The non-permeated fluid that did not permeate the separation membrane 21 flows through the supply-side channel member 23 and is discharged from the second end 12 of the stack 10, which is located on the first outlet 44 side of the container 50, to the outside of the separation membrane element 1 via the first outlet 44. The permeated fluid that permeated the separation membrane 21 flows through the permeate-side channel member 22 and is discharged from the first end 11 of the stack 10, which is located on the second outlet 46 side of the container 50, to the outside of the separation membrane element 1 via the second outlet 46. The permeated fluid flowing through the permeate-side channel member 22 may be discharged from the first end 11 of the stack 10, which is located on the supply and outlet 45 side of the container 50, to the outside of the separation membrane element 1 via the supply and outlet 45, in addition to the second outlet 46. This allows the raw material fluid to be separated into a permeated fluid and a non-permeated fluid.

[0061] When supplying a sweep fluid to the separation membrane element 1, the sweep fluid is supplied from the supply and discharge port 45 of the vessel 50 to the first end 11 side of the stack 10, thereby supplying the sweep fluid to the permeate-side channel member 22. The sweep fluid flows through the permeate-side channel member 22 and is discharged from the first end 11 side of the stack 10, which is on the second discharge port 46 side of the vessel 50, via the second discharge port 46 to the outside of the separation membrane element 1.

[0062] When the supply-side sealing portion 31 and the permeation-side sealing portion 32 are bonded to each other at the intersection of the first end portion 11 and the second end portion 12 (i.e., at the four corners of the laminate 10), the adhesion of the supply-side sealing portion 31 can be improved at the intersection, which makes it easier to further improve the airtightness of the supply-side sealing portion 31.

[0063] The supply-side plugging portion 31 and the permeate-side plugging portion 32 can be formed using a plugging material. The supply-side plugging portion 31 and the permeate-side plugging portion 32 may each independently use an adhesive or double-sided tape as the plugging material. When an adhesive is used, the plugging material may be an adhesive layer obtained by drying or curing the adhesive.

[0064] In FIG. 8 , for convenience, the layers constituting the laminate 10 are depicted as having the same size, but the edges of the layers do not need to be aligned. For example, the membrane stack 20 may be smaller than the permeate-side flow path member 22 in a plan view. The supply-side plugging section 31 can be formed, for example, by applying a plugging material so as to fill the space formed between two permeate-side flow path members 22 arranged on both sides of the membrane stack 20 outside the first end 11 of the membrane stack 20, and then drying or curing the applied plugging material. When applying the plugging material, the plugging material may be applied to the first end 11 of the membrane stack 20, or the plugging material may be allowed to penetrate the separation membrane 21 located at the first end 11 of the membrane stack 20 or the porous membrane of the separation membrane 21 and the supply-side flow path member 23, and the plugging material may be dried or cured in this state to form the supply-side plugging section 31.

[0065] As the sealing material, the same double-sided tape, adhesive, etc. as the sealing material for adhering the lid can be used. When using double-sided tape to attach two separation membranes, the double-sided tape can be attached to one of the separation membranes, the release paper of the double-sided tape can be peeled off, and the other separation membrane can then be attached.

[0066] The supply-side plugging section 31 and the permeate-side plugging section 32 may be formed of the same plugging material or different plugging materials. That is, for example, the plugging material of the supply-side plugging section 31 may be double-sided tape and the plugging material of the permeate-side plugging section 32 may be adhesive, or the plugging material of the supply-side plugging section 31 may be adhesive and the plugging material of the permeate-side plugging section 32 may be double-sided tape. Furthermore, both the plugging material of the supply-side plugging section 31 and the plugging material of the permeate-side plugging section 32 may be double-sided tape or adhesive.

[0067] 1 and 8 , the second ends 12 of the two permeate-side channel members 22 arranged on both sides of the membrane stack 20 (outside in the height H direction in the drawings) may be located outside the second end 12 of the membrane stack 20, but the laminate according to one embodiment of the present invention is not limited to this. In a plan view of the laminate 10, the first ends 11 of the two permeate-side channel members 22 may be located outside the first end 11 of the separation functional layer. For example, in a plan view of the laminate 10, the first ends 11 of the two permeate-side channel members 22 may be located outside the first end 11 of the separation membrane 21 (separation functional layer and porous membrane) and may be located at the same position as the end of the supply-side channel member 23 arranged between the two permeate-side channel members 22. Alternatively, in a plan view of the laminate 10, the first ends 11 of the two permeate-side channel members 22 may be located outside the first end 11 of the supply-side channel member 23 disposed between the two permeate-side channel members 22, and may be located at the same position as the first end 11 of the porous membrane included in the separation membrane 21. When, in a plan view of the laminate 10, the first ends 11 of the two permeate-side channel members 22 are located at the same position as the first end 11 of the porous membrane and / or the supply-side channel member 23 included in the separation membrane 21, the supply-side plug 31 may include a part of the separation membrane 21 and / or a part of the supply-side channel member 23 (e.g., the first end 11).

[0068] Alternatively, the laminate 10 may have a structure shown in FIG. 10 . FIG. 10 is a cross-sectional view of the laminate 10 cut in a direction parallel to the second end 12. In FIG. 10 , two separation membranes 21 are arranged to sandwich one supply-side channel member 23, and two permeate-side channel members 22 are arranged to sandwich the supply-side channel member 23 and the two separation membranes 21. In FIG. 10 , the first ends 11 of the two separation membranes 21 and the two permeate-side channel members 22 are located outside the first end 11 of the supply-side channel member 23. In FIG. 10 , a supply-side plugging portion 31 is provided outside the first end 11 of the supply-side channel member 23 to fill the space formed between the two separation membranes 21. For example, double-sided tape may be used as a sealing material for forming the supply-side plugging portion 31, and the two separation membranes 21 may be bonded together. In FIG. 10 , a permeate-side plugging portion 32 is provided at the first ends 11 of the two permeate-side channel members 22. For example, an adhesive may be used as the sealing material for forming the permeate-side plugs 32 , and the permeate-side plugs 32 may be formed by allowing the adhesive to penetrate into the first end 11 of the permeate-side channel member 22 .

[0069] The separation membrane element 1 can separate a specific fluid component from a feed fluid containing at least the specific fluid component. The feed fluid, the specific fluid component, the permeate fluid, the non-permeate fluid, and the sweep fluid may each independently be a gas or a liquid. The separation membrane element 1 is preferably a gas separation membrane element, and is preferably one that selectively allows the specific gas component to permeate from the feed gas.

[0070] The specific fluid component is preferably an acid gas. Examples of the acid gas include carbon dioxide (CO ２ ), hydrogen sulfide (H ２ S), sulfur oxides (SO ｘ ), and nitrogen oxides (NO ｘ) and the like. The specific gas component is preferably carbon dioxide or hydrogen sulfide, and more preferably carbon dioxide. Examples of the raw material gas include gases containing acidic gases, and specific examples include residual exhaust gases from synthesis gases synthesized in plants that produce hydrogen, urea, or the like; natural gas; biogas; and combustion exhaust gases emitted from power plants, waste treatment plants, cement factories, and the like.

[0071] In an airtightness test of this separation membrane element, when the pressure on the supply side was set to 150 kPaG, the flow rate of the fluid that does not normally permeate the separation membrane, measured at the outlet for discharging the permeating fluid, was 40 GPU (1 GPU = 3.35 × 10 －１０ mol・m －２ ・s －１ ・Pa －１ ) or less. If the separation membrane element achieves the above performance, leakage is suppressed even when pressurized, and it can be said to have sufficient pressure resistance and be suitable for practical use. The upper limit of GPU is not particularly limited, but may be, for example, 100 GPU or less at 150 kPaG. The airtightness test is the test described in the Examples below.

[0072] 11 to 13 are perspective views illustrating the manufacturing process of a separation membrane element according to one embodiment of the present invention. In Fig. 11 to 13, L represents the length direction of the container, W represents the width direction of the container, and H represents the height direction of the container.

[0073] The separation membrane element 1 can be manufactured by using a container 50, a separation membrane 21, a permeate-side channel member 22, and a feed-side channel member 23, and stacking the permeate-side channel member 22, the separation membrane 21, and the feed-side channel member 23 in the storage space of the container 50 to form a stack 10. Hereinafter, an example of a method for manufacturing a separation membrane element 1 in which a stack 10 having a rectangular shape in plan view is housed in a prismatic container 50 will be described.

[0074] First, as shown in FIG. 11 , a membrane stack 20 is fabricated using a first separation membrane 21a and a second separation membrane 21b as separation membranes 21 and a supply-side channel member 23. The supply-side channel member 23 is placed on the first separation membrane 21a. In FIG. 11 , the first end 11 of the first separation membrane 21a is located outside the first end 11 of the supply-side channel member 23. In a plan view, double-sided tape 25 (corresponding to the supply-side sealing portion 31) is laminated on the first separation membrane 21a at a portion outside the first end 11 of the supply-side channel member 23. The second separation membrane 21b is laminated on the supply-side channel member 23 and the double-sided tape 25. The first end 11 of the second separation membrane 21b is located outside the first end 11 of the supply-side channel member 23. Thus, the first separation membrane 21a and the second separation membrane 21b are bonded together at the first end 11 via the double-sided tape 25. As a result, a membrane stack 20 is obtained that includes the supply-side channel member 23 between the first separation membrane 21a and the second separation membrane 21b.

[0075] Then, as shown by reference numeral 1000 in Fig. 12 , a container body 40 is prepared. The container body 40 has a storage space for storing each component constituting the laminate 10, and is shown with its top surface open. The container body 40 may have guide portions 41 for positioning the components stored in the storage space. When the storage space of the container body 40 is prismatic, the guide portions 41 are preferably provided at the corners of the container body 40.

[0076] Next, as indicated by reference numeral 1001 in Fig. 12 , the permeate-side flow path member 22 is placed in the container body 40. A plugging material 33 (corresponding to the permeate-side plugging portion 32) is applied to the second end portion 12 (an end portion extending parallel to the longitudinal direction L of the container body 40) of the permeate-side flow path member 22. Next, as indicated by reference numeral 1002 in Fig. 12 , the membrane stacking portion 20 is stacked on the permeate-side flow path member 22. Here, the membrane stacking portion 20 is placed so that, in a plan view, the portion of the membrane stacking portion 20 to which the double-sided tape 25 is attached overlaps an end portion (the first end portion 11, an end portion extending parallel to the width direction W of the container body 40) different from the second end portion 12 to which the plugging material 33 is applied.

[0077] Furthermore, as shown by reference numeral 1003 in FIG. 13 , a permeate-side channel member 22 is placed on the membrane stacking unit 20, and a sealing material 33 is applied. The membrane stacking unit 20 (the first separation membrane 21 a, the feed-side channel member 23, and the second separation membrane 21 b) and the permeate-side channel member 22 stacked on the membrane stacking unit 20 constitute a membrane leaf. Again, as shown by reference numeral 1004 in FIG. 13 , the membrane stacking unit 20 is stacked on the permeate-side channel member 22. Thereafter, by repeating the operations of applying the sealing material 33, placing the membrane stacking unit 20, and placing the permeate-side channel member 22, a stack 10 is formed in the container body 40, as shown by reference numeral 1005 in FIG. 13 . After the stacking unit 10 is formed in the container body 40, the gap between the guide portion 41 of the container body 40 and the stacking unit 10 is sealed with a sealing material.

[0078] Next, a sealing material 33 is applied to the second end 12 of the permeate-side channel member 22 included in the uppermost membrane leaf of the stack 10 and to the upper end 47 of the side wall portion 49. Then, a lid 60 is placed on the upper surface of the vessel body 40. Thereafter, the sealing material is dried or cured to obtain the separation membrane element 1 shown in FIG.

[0079] In the manufacturing method described above, two separation membranes (first separation membrane 21a and second separation membrane 21b) are used to form the membrane stack 20. However, the membrane stack 20 may also be formed by folding one separation membrane in half and sandwiching the feed-side flow path member 23 between the folded separation membranes. When using a folded separation membrane, the fold should be located at the first end 11 of the stack 10. The fold is preferably located so as to communicate with the second outlet 46 for discharging the permeated fluid from the container 50. In this case, there is no need to provide a feed-side sealing portion at the first end 11 where the fold of the separation membrane is located.

[0080] [3. Separation Apparatus] A separation apparatus can have one or more separation membrane elements of the present invention. The arrangement and number of separation membrane elements to be provided in the separation apparatus can be selected depending on the required throughput, the recovery rate of specific fluid components, the size of the space where the separation apparatus is to be installed, etc.

[0081] The separation device can include a first supply part and a first discharge part communicating with the supply-side channel member 23 of the separation membrane element 1, and a second discharge part communicating with the permeate-side channel member 22 of the separation membrane element 1. The separation device may further include a supply / discharge part communicating with the permeate-side channel member 22 of the separation membrane element 1.

[0082] The first supply section is an inlet for supplying a raw fluid to the supply-side channel member 23 and can be connected to a first supply port 43 of the separation membrane element 1. The first discharge section is an outlet for discharging a non-permeating fluid flowing through the supply-side channel member 23 and can be connected to a first discharge port 44 of the separation membrane element 1. The second discharge section is an outlet for discharging a permeating fluid flowing through the permeate-side channel member 22 and can be connected to a second discharge port 46 of the separation membrane element 1. The supply and discharge section can be used as a second supply section, which is an inlet for supplying a sweep fluid to the permeate-side channel member 22, or as a third discharge section for discharging a permeating fluid. The supply and discharge section can be connected to a supply and discharge port 45 of the separation membrane element 1.

[0083] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0084] One embodiment of the present invention may include the following configurations. <1> A plate-and-frame separation membrane element comprising a container and a separation membrane having a flat membrane-like region within the container, the container including a container body having a bottom and a sidewall, and a lid joined to the container body and positioned opposite the bottom across the sidewall of the container body, the lid having a protrusion that protrudes toward the bottom along the outer side of the sidewall of the container body. <2> The plate-and-frame separation membrane element according to <1>, wherein the lid is bonded to at least one of the outer side and the upper end of the sidewall of the container body via a sealing material. <3> The plate-and-frame separation membrane element according to <1> or <2>, wherein the separation membrane has a separation functional layer that selectively separates a specific fluid component contained in a feed fluid. <4> The plate-and-frame separation membrane element according to <3>, wherein the feed fluid is a gas. <5> The plate-and-frame separation membrane element according to <3> or <4>, wherein the specific fluid component is an acidic gas. <6> The plate-and-frame separation membrane element according to any one of <3> to <5>, wherein the container houses a stack having two permeate-side channel members through which a permeated fluid that has permeated the separation membrane flows, and a feed-side channel member through which the raw fluid flows, disposed between the two permeate-side channel members. <7> A separation device comprising the plate-and-frame separation membrane element according to <6>, a first supply section and a first discharge section that communicate with the feed-side channel member, and a second discharge section that communicates with the permeate-side channel member.

[0085] An embodiment of the present invention will be described below.

[0086] Example 1 (Preparation of Separation Membrane) The separation membrane used was a composite membrane, and was configured by laminating a separation functional layer (Pebax (registered trademark) polyether block amide copolymer), a porous substrate (polyacrylonitrile), and a PET nonwoven fabric serving as a reinforcing support layer in this order.

[0087] (Preparation of Separation Membrane Element) A PP mesh (manufactured by Innovex Corporation; product name 50-150PPN) measuring 319 mm in length and 319 mm in width was used as the permeate-side flow path member. A polycarbonate containment vessel was used as the vessel body. The outer dimensions of the vessel body were 350 mm in length, 350 mm in width, and 85 mm in height, and the inner dimensions of the four corner guide sections were 320 mm in length and 320 mm in width. A separation membrane measuring 319 mm in length and 319 mm in width was used as the separation membrane. A PP diamond net (manufactured by SWM Corporation; product name No. 1716) measuring 319 mm in length and 296 mm in width was used as the feed-side flow path member. A two-component mixed epoxy adhesive (manufactured by Nagase ChemteX Corporation; product name Denatite 3324) was used as the sealing material for forming the permeate-side plugging section. The two-component mixed epoxy adhesive was used hereinafter when referring to the adhesive, not only for the permeation-side sealing portion, but also for other sealing portions. Double-sided tape (product name Y4930, manufactured by 3M) was used as the sealing material for forming the supply-side sealing portion.

[0088] (Fabrication of membrane stack 20) ​​Before fabricating the separation membrane element, membrane stack 20 was fabricated by the method shown in Fig. 11. Membrane stack 20 had a three-layer structure, with one separation membrane (first separation membrane 21a) and one second separation membrane 21b) used as the upper and lower layers, and one supply-side flow path member 23 used as the middle layer. The upper and lower separation membranes (first separation membrane 21a and second separation membrane 21b) were sealed with supply-side sealing unit 31.

[0089] That is, the supply-side flow path member 23 was placed on the first separation membrane 21a, and double-sided tape 25 was placed as a sealing material to form the supply-side sealing portion 31 on the outer sides of both end portions of the supply-side flow path member 23 in a plan view. However, the double-sided tape 25 was placed only on the outer sides of the end portion (first end portion 11) that would later be arranged parallel to the width direction W of the container body 40. The second separation membrane 21b was placed on the supply-side flow path member 23 and the double-sided tape 25. Here, both the first separation membrane 21a and the second separation membrane 21b were placed so that the separation functional layer was in contact with the supply-side flow path member 23.

[0090] (Fabrication of Separation Membrane Element 1) A separation membrane element 1 was fabricated by the method shown in Figs. 12 and 13 in the following procedure.

[0091] First, as indicated by reference numeral 1001 in FIG. 12 , the permeate-side flow path member 22 was placed in the container body 40, and an adhesive was applied as the sealing material 33 to both end portions (end portions extending parallel to the longitudinal direction L of the container body 40, that is, the second end portions 12) of the permeate-side flow path member 22.

[0092] Next, as indicated by reference numeral 1002 in Fig. 12 , the membrane stacking unit 20 was placed in the container body 40. Here, in a plan view, the double-sided tape 25 of the membrane stacking unit 20 was placed so as to overlap an end (an end extending parallel to the width direction W of the container body 40, i.e., the first end 11) different from the end to which the adhesive was applied to the permeate-side flow path member 22.

[0093] Furthermore, as indicated by reference numeral 1003 in Fig. 13, a permeate-side flow path member 22 was installed on the membrane stacking unit 20. Thereafter, the operations of applying adhesive (sealing material 33), installing the membrane stacking unit 20, and installing the permeate-side flow path member 22 were repeated until 30 membrane leaves were installed (reference numerals 1003, 1004, and 1005 in Fig. 13). The membrane leaves and the four corners of the guide portion inside the vessel body were sealed with adhesive.

[0094] An adhesive was applied to both end portions (end portions extending parallel to the longitudinal direction L of the vessel body, second end portions 12) of the surface of the permeate-side flow path member 22 at the uppermost stage of the membrane leaf and to the upper end 47 of the side wall portion 49 of the vessel body 40, and a lid 60 was then placed. The adhesive was then cured at room temperature for 24 hours to obtain a separation membrane element 1. The effective membrane area of ​​the obtained separation membrane element 1 was 4 m ２ It was.

[0095] In Example 1, a cover lid was used as the lid 60. The cross-sectional shape of the cover lid was as shown in Fig. 4. The protrusion 61 of the cover lid protruded toward the bottom surface 48 of the container body 40 along the outer side of the side wall 49 of the container body 40.

[0096] In Example 2, a separation membrane element was obtained by the same manufacturing method as in Example 1, except that a hook lid was used as the lid 60. The cross-sectional shape of the hook lid was as shown in Figure 7. The protrusion 61b of the hook lid protruded toward the bottom surface 48 of the container body 40 along the outside of the side wall 49 of the container body 40.

[0097] In Comparative Example 1, a separation membrane element was obtained by the same manufacturing method as in Example 1, except that a flat lid was used. The cross-sectional shape of the flat lid was as shown in Figure 2. The flat lid 260 did not have any protrusions.

[0098] [Airtightness Test] The separation membrane elements produced in the examples and comparative examples were subjected to an airtightness test according to the following procedure. Fig. 14 is a schematic diagram illustrating a test device for an airtightness test. In Fig. 14, a supply section 83 communicating with the first supply port and a discharge section 84 communicating with the first discharge port were provided at two ends extending parallel to the longitudinal direction L of the separation membrane element 1. A supply section 85 communicating with the supply and discharge port and a discharge section 86 communicating with the second discharge port were provided at two ends extending parallel to the width direction W of the separation membrane element 1. Valves were provided in the supply section 83, the discharge section 84, the supply section 85, and the discharge section 86. In addition, the supply section 83 had a valve for supplying N to the first supply port. ２ 1. Using the apparatus shown in FIG. 14, N 2 gas at room temperature (20° C.) was introduced into the separation membrane element 1. ２ Gas was supplied to apply a pressure of 150 kPaG (G indicates gauge pressure) to the supply part 83 of the separation membrane element. The pressure was confirmed with a pressure gauge 81, and the valves of the discharge parts 84 and 86 were closed. 2. The valve of the supply part 85 was closed, the valve of the discharge part 86 was opened, and the flow rate of the permeated gas was measured with a membrane flow meter 82 (high-precision precision membrane flow meter, "VP-U series" manufactured by Horiba, Ltd.), and evaluated according to the following criteria. A: N indicated by the membrane flow meter ２ The permeation rate is 40 GPU or less. B: N indicated by a membrane flow meter ２ The transmission is greater than 40 GPU.

[0099] [Results] Table 1 shows the test results for the separation membrane elements of the Examples and Comparative Examples.

[0100]

[0101] As can be seen from Table 1, the separation membrane elements of Examples 1 and 2 equipped with lids having protrusions were sufficiently airtight even when pressurized and therefore had excellent pressure resistance. On the other hand, the separation membrane element of Comparative Example 1 equipped with a lid without protrusions was inferior in pressure resistance compared to the Examples.

[0102] One aspect of the present invention is a method for producing CO from a mixed gas containing at least an acid gas and water vapor, such as a synthesis gas synthesized in a large-scale plant for producing hydrogen or urea, a combustion exhaust gas discharged from a power plant, a waste disposal site, a cement factory, or the like, or natural gas or other exhaust gas. ２ The present invention can be widely used in processes for separating acid gases such as urea, urea, and urea.

[0103] 1 Separation membrane element 10 Laminated body 11 First end 12 Second end 20 Membrane stack 21 Separation membrane 21a First separation membrane (separation membrane) 21b Second separation membrane (separation membrane) 22 Permeation side channel member 23 Supply side channel member 25 Double-sided tape 31 Supply side sealing section 32 Permeation side sealing section 33 Sealing material 40 Container body 41 Guide part 43 First supply port 44 First discharge port 45 Supply and discharge port 46 Second discharge port 47 Upper end 48 Bottom part 49 Side wall part 50 Container 51 Adhesive part 52 Porous base material 53 Separation functional layer 60 Lid 61 Projection part 81 Pressure gauge 82 Membrane flowmeter 83 Supply part 84 Discharge section 85 Supply section 86 Discharge section

Claims

1. A plate-and-frame separation membrane element comprising a container and a separation membrane having a region arranged in the container in the form of a flat membrane, wherein the container comprises a container body having a bottom surface and a side wall, and a lid joined to the container body and arranged opposite the bottom surface across the side wall of the container body, wherein the lid has a protrusion that protrudes along the outside of the side wall of the container body toward the bottom surface of the container body.

2. A plate-and-frame separation membrane element according to claim 1, wherein the lid is bonded to at least one of the outer side and the upper end of the side wall of the vessel body via a sealing material.

3. A plate-and-frame type separation membrane element according to claim 1, wherein the separation membrane has a separation functional layer that selectively separates a specific fluid component contained in the raw fluid.

4. The plate-and-frame type separation membrane element according to claim 3, wherein the raw material fluid is a gas.

5. The plate-and-frame type separation membrane element according to claim 3, wherein the specific fluid component is an acid gas.

6. A plate-and-frame separation membrane element according to any one of claims 3 to 5, wherein the container houses a stack having two permeation-side flow path members through which the permeated fluid that has permeated the separation membrane flows, and a feed-side flow path member through which the raw fluid flows, the separation membrane, and the feed-side flow path member disposed between the two permeation-side flow path members.

7. A separation device comprising the plate-and-frame separation membrane element according to claim 6, a first supply section and a first discharge section communicating with the supply-side flow path member, and a second discharge section communicating with the permeation-side flow path member.

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