Separation membrane element and separation device

Abstract

The present invention addresses the problem of providing a plate-and-frame type separation membrane element in which a sealing part on a supply side is not easily delaminated even when a gas is supplied. The solution to this problem is a plate-and-frame type separation membrane element having a sealing part between a supply-side flow path member and a permeation-side flow path member. The compression deformation amount of the permeation-side flow path member, when measured by JIS K 7181, is 0.40 mm or less, and the adhesive force of the sealing part, when measured by JIS K 6854 is 1.0 N or more.

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 liquid or gaseous raw fluids (see, for example, Patent Documents 1 to 3). 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 2017-000965 A JP 2017-000964 A U.S. Application No. 2019 / 0065091 A

[0004] However, when gas is supplied to a plate-and-frame separation membrane element such as those described in Patent Documents 1 to 3, the membrane may be pushed into the permeate side, causing the seal on the supply side to peel off.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a plate-and-frame type separation membrane element in which the sealing portion on the supply side is unlikely to peel off (more preferably, does not peel off) even when gas is supplied.

[0006] As a result of investigations to solve the above-mentioned problems, the inventors have found that the above-mentioned problems can be solved by a separation membrane element in which the amount of compressive deformation of the permeate-side flow path member is a certain level or less and the peel strength of the feed-side plugging portion is a certain level or more, and have thus completed the present invention.

[0007] The present invention includes the following features: <1> A plate-and-frame separation membrane element including a container and a separation membrane having a region arranged in the container in the form of a flat membrane, wherein the separation membrane has a separation functional layer that selectively separates specific fluid components contained in a feed fluid, the container houses a laminate including at least 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 separation membrane and the feed fluid flow, which is disposed between the two permeate-side channel members, the separation membrane element having feed-side plugs between the feed-side channel members and the separation membrane, wherein the compressive deformation amount of the permeate-side channel member measured according to JIS K 7181 is 0.40 mm or less, and the peel strength of the plugs measured according to JIS K 6854 is 1.0 N or more. <2> The plate-and-frame separation membrane element according to <1>, wherein the mesh number of the permeate-side channel member is 18 mesh or more, and when the permeate-side channel member has a multilayer structure having two or more layers, the mesh number of each layer is the same. <3> The plate-and-frame separation membrane element according to <1>, wherein the mesh number of the permeate-side channel member is 50 mesh or more. <4> The plate-and-frame separation membrane element according to any one of <1> to <3>, wherein the separation membrane has a thickness of 10 to 600 μm. <5> The plate-and-frame separation membrane element according to any one of <1> to <4>, wherein the feed fluid is a gas. <6> The plate-and-frame separation membrane element according to any one of <1> to <5>, wherein the specific fluid component is an acidic gas. <7> A separation device comprising the plate-and-frame separation membrane element according to any one of <1> to <6>, a first supply section and a first discharge section communicating with the feed-side channel member, and a second discharge section communicating with the permeate-side channel member.

[0008] According to one aspect of the present invention, a plate-and-frame separation membrane element can be provided in which the seal on the supply side is unlikely to peel off (more preferably, does not peel off) even when gas is supplied.

[0009] Fig. 1 is a perspective view schematically showing a separation membrane element according to one embodiment of the present invention. Fig. 2 is a perspective view showing an exploded view of a laminate included in a separation membrane element according to one embodiment of the present invention. Fig. 3 is a cross-sectional view of a laminate included in a separation membrane element according to one embodiment of the present invention. Fig. 4 is a perspective view illustrating a continuation of the manufacturing process shown in Fig. 5. Fig. 5 is a schematic view illustrating a testing device for airtightness tests performed in the examples.

[0010] [1. Separation Membrane Element] A separation membrane element according to one embodiment of the present invention (hereinafter also referred to as the present separation membrane element) is a plate-and-frame type separation membrane element including a container and a separation membrane having a region arranged in the container in the form of a flat membrane, wherein the separation membrane has a separation functional layer that selectively separates specific fluid components contained in a feed fluid, and the container houses a laminate including at least 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 separation membrane and the feed fluid flow, which is disposed between the permeate-side channel members, and the separation membrane element has feed-side plugs between the feed-side channel members and the separation membrane, and the amount of compressive deformation of the permeate-side channel member measured according to JIS K 7181 is 0.40 mm or less, and the peel strength of the plugs measured according to JIS K 6854 is 1.0 N or more.

[0011] 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.

[0012] Fig. 1 is a perspective view schematically showing a separation membrane element according to one embodiment of the present invention. Fig. 2 is a perspective view showing an exploded stack of 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.

[0013] The separation membrane element 1 includes a container 40 and a separation membrane 21 ( FIG. 2 ) having a region in which it is arranged in a flat membrane shape within the container 40. The term "separation membrane having a region in which it is arranged in a flat membrane shape within the container 40" means that the separation membrane 21 is contained within the container 40 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 40 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 40, and as will be described later, it may be contained within the container 40 in a folded state so as to form a flat membrane region. Here, the separation membrane element 1 is a plate-and-frame type separation membrane element.

[0014] The separation membrane 21 has a separation functional layer that selectively separates specific fluid components contained in the raw fluid. The separation membrane 21 may be composed of only the separation functional layer, or may have a laminated structure in which the 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.

[0015] The container 40 accommodates a laminate 10 having 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. In Fig. 1 , the height direction H of the container coincides with the stacking direction of the laminate 10. The separation membranes 21 included in the laminate 10 are stacked so as to have a region in which they are arranged in a flat membrane shape within the container 40. The permeate-side channel member 22 and the feed-side channel member 23 included in the laminate 10 are also usually stacked so as to have a region in which they are arranged in a flat membrane shape within the container 40.

[0016] The laminate 10 may have at least a portion where 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. 2 , the laminate 10 may have a membrane stack section 20 where 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. The separation membrane 21 and the supply-side channel member 23 may be bonded together with a supply-side plugging material. Furthermore, the permeate-side channel member 22 and the separation membrane 21 may be bonded together with a permeate-side plugging material. The plugging materials described below can be used as the supply-side plugging material and the permeate-side plugging material.

[0017] 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. 2 , 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.

[0018] Figure 3 is a cross-sectional view of the laminate of this separation membrane element, cut in a direction parallel to the second end 12. The laminate 10 has a supply-side plugging section 31 between a separation function layer 53 included in a separation membrane 21 and a supply-side channel member 23 (Figure 3). The separation function layer 53 forms a separation membrane together with a porous substrate 52. In the supply-side plugging section 31, the separation function layer 53 and the supply-side channel member 23 are bonded at an adhesive section 51 with a supply-side plugging material. Therefore, the peel strength of the supply-side plugging section 31 can also be expressed as the adhesive strength of the adhesive section 51. When a raw material fluid flows through the supply-side channel member, pressure is generated in the direction of the separation membrane 21 (i.e., in the direction of the block arrow shown in Figure 3).

[0019] The supply-side plug 31 also functions 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 of the separation membrane.

[0020] The laminate may, as 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. 2 ). The "positions corresponding to the stacking positions of the permeate-side flow path members 22" refers to positions occupied by the permeate-side flow path members 22, as well as 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. 2 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. 2 permeating into the permeate-side flow path members 22.

[0021] 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.

[0022] Each layer of the laminate 10 shown in FIG. 2 has an edge on its surface. In this specification, the term "edge" refers to a 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 upper surface portion 47 in FIG. 1 exists) but also on the lower surface (i.e., the direction in which the lower 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.

[0023] As shown in Fig. 2, the end of the laminate 10 that exists in the direction in which the supply gas passes is referred to as the second end 12, and the end that exists in the direction in which the permeation gas passes is referred to as the first end 11. Therefore, each layer included in the laminate 10 has two first ends 11 and two second ends 12 on at least one surface. In this specification, when the term "first end 11 of the laminate 10" is used, it means the first end 11 of all layers included in the laminate 10. The same applies to the second end 12.

[0024] 2 , the permeate-side plugging part 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 part 32 is provided at the first end 11, it is preferable that the permeate-side plugging part 32 is provided along the entire one side of the laminate 10 constituting the first end 11 in a plan view. In other words, the permeate-side plugging part 32 provided at the first end 11 is preferably provided along the first end 11 of the laminate 10. The second permeate-side plugging part 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. 2 that is located on a side opposite to the direction in which the permeate gas 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 a plan view.

[0025] 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 Figures 1 and 2, the intersection position can be provided at a corner of the laminate 10 in a plan view.

[0026] 1 , the vessel 40 may have a first supply port 43 communicating with the supply-side channel member 23 of the laminate 10 and for supplying a raw material fluid, a first discharge port 44 communicating with the supply-side channel member 23 of the laminate 10 and for discharging a non-permeating fluid, and a second discharge port 46 communicating with the permeate-side channel member 22 of the laminate 10 and for discharging a permeating fluid. The vessel 40 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] In the separation membrane element 1, the laminate 10 is disposed so that the second end 12 of the laminate 10 faces the side wall 49 of the container 40 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 the side wall 49 on which the second discharge port 46 of the container 40 is formed ( FIG. 1 ). When the supply and discharge port 45 of the container 40 is not used or does not have the supply and discharge port 45, the permeate-side plugging 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 40 has the supply and discharge port 45 and this supply and discharge port 45 is used, not forming the permeate-side plugging 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.

[0028] 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 40 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. On the other hand, the separation membrane element 1 is 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 40, through the first outlet 44 to the outside of the separation membrane element 1. 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 40, through the second outlet 46 to the outside of the separation membrane element 1. 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 40, through the supply and outlet ports to the outside of the separation membrane element 1. This allows the raw material fluid to be separated into a permeated fluid and a non-permeated fluid.

[0029] 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 40 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 40, through the second discharge port 46 to the outside of the separation membrane element 1.

[0030] When a feed fluid is supplied to the separation membrane element 1, internal pressure is generated in the feed-side space (i.e., in the direction of the block arrow in Figure 3) formed by the feed-side channel member 23 through which the feed fluid flows. Conventionally, plate-and-frame separation membrane elements have been used primarily for liquid permeation, and the problems caused by this internal pressure have not been recognized. For example, Patent Documents 1 and 2 mentioned above describe plate-and-frame separation membrane elements, but are intended for use primarily in the permeation of liquids such as wastewater or seawater. Patent Document 3 also describes gas permeation through a plate-and-frame separation membrane element, but does not consider permeation-side channel members or plugs, and only describes a low-cost plate-and-frame separation membrane element.

[0031] However, when gas permeation is performed using a plate-and-frame separation membrane element at normal pressure, the seals and the separation membrane are likely to peel off due to the influence of the internal pressure. When peeling occurs between the seals and the separation membrane, the airtightness of the seals decreases, making it difficult to perform good fluid separation. The fact that peeling occurs at the supply-side seals and the airtightness of the separation membrane element when a plate-and-frame separation membrane element is subjected to gas permeation is a new problem discovered by the present inventors. With this separation membrane element having the above configuration, gas can be permeated without peeling off the supply-side seals, even when gas is supplied.

[0032] 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."

[0033] 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.

[0034] 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.

[0035] The supply-side plugging section 31 can be formed, for example, by applying a plugging material so as to fill a space formed between two permeate-side flow path members 22 arranged on both sides of the membrane stacking section 20 outside the first end 11 of the membrane stacking section 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 stacking section 20, or the plugging material may be allowed to penetrate into the separation membrane 21 located at the first end 11 of the membrane stacking section 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.

[0036] The feed-side plugs 31 have a peel strength of 1.0 N or more, preferably 1.1 N or more, and more preferably 1.2 N or more, as measured in accordance with JIS K 6854. There is no particular upper limit to the peel strength, but it may be, for example, 4.0 N or less. When the peel strength is 1.0 N or more, peeling of the feed-side plugs 31 does not occur even when gas permeates the separation membrane element. The peel strength of the feed-side plugs 31 is measured by the method described in the examples below.

[0037] Double-sided tape, adhesives, etc. can be used as the sealing material. The resin contained in the adhesive is not particularly limited as long as it has a peel strength of 1.0 N or more. Examples 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. When using double-sided tape, the double-sided tape can be stuck onto the separation membrane, the release paper of the double-sided tape can be peeled off, and then the other separation membrane can be stuck onto the double-sided tape.

[0038] 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.

[0039] 1 and 2 , the second ends 12 of the two permeate-side channel members 22 arranged on both sides of the membrane stack 20 (outside in the longitudinal direction in the drawings) are positioned 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, it is sufficient that the first ends 11 of the two permeate-side channel members 22 are 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).

[0040] 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.

[0041] 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 such as residual exhaust gas from synthesis gas synthesized in plants that produce hydrogen or urea, natural gas, biogas, and combustion exhaust gases emitted from power plants, waste treatment plants, cement factories, etc.

[0042] In an airtightness test, this separation membrane element had a 40 GPU (1 GPU = 3.35 x 10 -10 mol・m -2 ・s -1 ・Pa -1 ) or less. If the separation membrane element achieves the above performance, it can be said to be fully suitable for practical use. The upper limit of GPU is not particularly limited, but may be, for example, 100 GPU or less at 200 kPG. The airtightness test is the test described in the Examples below.

[0043] (Method for manufacturing a separation membrane element) Figures 4 to 6 are perspective views illustrating the manufacturing process of a separation membrane element according to one embodiment of the present invention. In Figures 4 to 6, 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.

[0044] The separation membrane element 1 can be manufactured by using a container 40, 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 40 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 40 will be described.

[0045] First, a container 40 is prepared. The container 40 shown in Fig. 4(a) has a storage space for storing each component constituting the laminate 10, and is shown in a state where the top surface is open. The container 40 may have guide portions 41 for positioning the components stored in the storage space. When the storage space of the container 40 is prismatic, the guide portions 41 are preferably provided at the corners of the container 40 (Fig. 4(a)).

[0046] A first tape 25 is attached to both sides of the first end 11 of the laminate 10 of the permeate-side flow path member 22 to prevent seepage of the plugging material. In the permeate-side flow path member 22 shown in FIG. 4 , the first tapes 25 are attached to the first end 11 along two opposing sides ( FIG. 4B ). The permeate-side flow path member 22 with the first tape 25 attached is placed in a container 40 so that the sides to which the first tapes 25 are attached are parallel to the sides extending parallel to the width direction W. Thereafter, a plugging material 33a is applied along the second end 12 of the laminate 10 (the end of the permeate-side flow path member 22 to which the first tape 25 is not attached (the end extending parallel to the length direction L)) ( FIG. 4B ). The plugging material 33a may be applied outside the second end 12 of the permeate-side flow path member 22 in a plan view of the container 40, or may be applied so as to cover the end.

[0047] Next, a separation membrane 21 (hereinafter, sometimes referred to as the "first separation membrane 21a") is laminated on the permeate-side channel member 22 (see FIG. 4(c)). At this time, at the first end 11 (end extending parallel to the width direction W) of the laminate 10, the first separation membrane 21a is laminated so that the end of the permeate-side channel member 22 is located outside the end of the first separation membrane 21a in a plan view of the laminate 10 (see FIG. 4(c)). For example, the first separation membrane 21a is laminated so as not to cover the first tape 25 of the permeate-side channel member 22. At the second end 12 (end extending parallel to the length direction L) of the laminate 10, the end of the permeate-side channel member 22 may be located outside the end of the first separation membrane 21a in a plan view of the laminate 10, or may be located at the same position as the end of the first separation membrane 21a.

[0048] Thereafter, a plugging material 33b (corresponding to the supply-side plugging portion 31) is applied to the first end 11 of the laminate 10 ( FIG. 5( a)). For example, the plugging material 33b is applied so as to cover the entire end of the permeate-side flow path member 22 that is located outside the end of the first separation membrane 21a in a plan view of the laminate 10. FIG. 5( a) shows a case in which the plugging material 33b is applied onto the first tape 25 of the permeate-side flow path member 22. The plugging material 33b is applied so that both ends (both ends in the width direction W) of the applied plugging material 33b overlap both ends (both ends in the length direction L) of the plugging material 33a.

[0049] Next, second tapes 26 are attached to both sides of the second end 12 of the stack 10 of the supply-side channel member 23 to prevent seepage of the plugging material. The supply-side channel member 23 with the second tapes 26 attached is then stacked on the first separation membrane 21a in the container 40 ( FIG. 5B ). The supply-side channel member 23 is stacked on the first separation membrane 21a so that the side to which the second tape 26 is attached is parallel to the side extending parallel to the longitudinal direction L. At this time, the supply-side channel member 23 is stacked so that the first end 11 of the permeate-side channel member 22 is located outside the first end 11 of the supply-side channel member 23 at the first end 11 (the end extending parallel to the width direction W) of the stack 10 in a plan view of the stack 10 ( FIG. 5B ). In FIG. 5B , the supply-side channel member 23 is stacked so as not to overlap the plugging material 33b applied to the permeate-side channel member 22.

[0050] Thereafter, a separation membrane 21 (hereinafter, sometimes referred to as the "second separation membrane 21b") is further laminated on the supply-side channel member 23 in the container 40. At this time, the second separation membrane 21b is laminated so that, at the first end 11 (end extending parallel to the width direction W) of the stack 10, the first end 11 of the permeate-side channel member 22 is located outside the first end 11 of the second separation membrane 21b in a planar view of the stack 10 (see FIG. 5(c)). At the second end 12 (end extending parallel to the length direction L) of the stack 10, the second end 12 of the permeate-side channel member 22 may be located outside the second end 12 of the second separation membrane 21b in a planar view of the stack 10, or may be located at the same position as the second end 12 of the second separation membrane 21b. Next, a plugging material is applied to the second end 12 of the stack 10. The plugging material is preferably applied via the supply-side channel member 23 in a position overlapping the previously applied plugging material 33a. In this manner, the first separation membrane 21 a , the feed-side channel member 23 , and the second separation membrane 21 b stacked on the permeate-side channel member 22 constitute the membrane stack 20 .

[0051] Next, a permeate-side channel member 22 is further stacked on the second separation membrane 21b in the container 40. This permeate-side channel member 22 is stacked on the second separation membrane 21b at the first end 11 (end extending parallel to the width direction W) of the stack 10 so that the first end 11 of the permeate-side channel member 22 is located outside the first end 11 of the membrane stack 20 in a plan view of the stack 10. The membrane stack 20 (first separation membrane 21a, feed-side channel member 23, and second separation membrane 21b) and the permeate-side channel member 22 stacked on the membrane stack 20 constitute a membrane leaf. The process of stacking membrane leaves is repeated in the procedure described above to form the stack 10 in the container 40 ( FIG. 6(a) ).

[0052] After forming the laminate 10 in the container 40, the gap between the guide portion 41 of the container 40 and the laminate 10 is sealed with a sealing material. Next, the sealing material is applied to the second end portion 12 of the permeate-side channel member 22 included in the uppermost membrane leaf of the laminate 10, and an upper lid that will become the upper surface portion 47 of the container 40 is placed ( FIG. 6( b) ), and the sealing material is applied to the gap between the upper lid and the side wall portion 49 of the container 40. The sealing material is then dried or cured, thereby obtaining the separation membrane element 1 ( FIG. 6( b) ).

[0053] 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 a folded separation membrane is used, the fold should be located at the first end 11 of the stack 10. In the separation membrane element 1 shown in FIG. 6(b), it is preferable to locate the membrane so that it communicates with the second outlet 46 for discharging the permeated fluid from the container 40. In this case, there is no need to provide a feed-side plug at the first end 11 where the fold of the separation membrane is located.

[0054] [2. 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.

[0055] 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.

[0056] The first supply section is an inlet for supplying a raw fluid to the supply-side channel member 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 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 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, 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.

[0057] The separation membrane element 1 and each of the components constituting the separation device will be described in more detail below.

[0058] (Container) The container 40 accommodates the laminate 10. As shown in FIG. 1 , the container 40 has an upper surface 47, a lower surface 48, and a sidewall 49 connecting the upper surface 47 and the lower surface 48. The upper surface 47, the lower surface 48, and the sidewall 49 can define a storage space. The upper surface 47 and the lower surface 48 extend in a direction perpendicular to the stacking direction of the laminate 10, and the sidewall 49 extends in the stacking direction of the laminate. The shape of the container is not particularly limited, and the upper surface 47 and the lower surface 48 may be polygonal, such as rectangular, or may be circular. The sidewall 49 may be prismatic or cylindrical.

[0059] 5A, the container 40 may have guide portions 41 for positioning the components constituting the laminate 10. When the side wall portion 49 of the container 40 is prismatic, the guide portions 41 are preferably provided at the corners of the side wall portion 49.

[0060] The first supply port 43, supply and discharge port 45, first discharge port 44, and second discharge port 46 of the container 40 may all be provided on the side wall portion 49 of the container 40, or on the upper surface portion 47 or lower surface portion 48.

[0061] The components constituting the container 40 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 40 can be made of the same material or different materials.

[0062] (Separation membrane) The separation membrane 21 is not particularly limited as long as it is a known membrane that can selectively permeate a specific fluid component from the raw fluid. 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 permeates molecules by utilizing the difference in 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.

[0063] 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.

[0064] When the separation membrane has a porous membrane on only one side, in the membrane stacking section 20, it is preferable to stack the separation membrane 21 and the supply side flow path member 23 so that the separation function layer side of the separation membrane 21 faces the supply side flow path member 23.

[0065] 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.

[0066] (Separation Functional Layer) 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] (Porous membrane) 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] (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.

[0075] The amount of compressive deformation of the permeate-side flow path member, as measured according to JIS K 7181, is 0.40 mm or less, preferably 0.35 mm or less, and more preferably 0.30 mm or less. The lower limit of the amount of compressive deformation is not particularly limited, but may be, for example, 0.10 mm or more. When the amount of compressive deformation is 0.40 mm or less, peeling of the feed-side plugs 31 is unlikely to occur even when gas permeates through this separation membrane element. The amount of compressive deformation of the permeate-side flow path member is measured by the method described in the examples below.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] (First Tape, Second Tape) The first tape 25 and the second tape 26 are tapes used to prevent seepage of the sealing material. The first tape 25 and the second tape 26 can be made of a material that is impermeable to the sealing material. Examples of such materials include polypropylene, polyimide, polytetrafluoroethylene, glass fiber, and polyester. The materials forming the first tape 25 and the second tape 26 may be the same or different. The first tape and the second tape are used during the production of the separation membrane element, and may be removed or may remain when the separation membrane element is used.

[0081] 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.

[0082] Example 1 (Preparation of Separation Membrane) The separation membrane is a composite membrane, and is composed of 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, laminated in this order.

[0083] (Preparation of Separation Membrane Element) The permeate side flow path member used was a PET mesh (mesh count: 18 mesh) with a length of 119 mm and a width of 119 mm, a fiber diameter of 263 μm, and a thickness of 0.53 mm. The container used was a polycarbonate storage container with external dimensions of 150 mm in length, 150 mm in width, and 85 mm in height, with inner dimensions of 120 mm in length and 120 mm in width at the four corner guides. The separation membrane used was a length of 119 mm and a width of 119 mm. The supply flow path member used was a polypropylene diamond net (manufactured by SWM Co., Ltd.; product name No. 1716) with a width of 119 mm and a length of 96 mm.

[0084] (Fabrication of Separation Membrane Element 1) A separation membrane element 1 was fabricated by the following procedure using the method shown in Figures 4 to 6. 1 First, the permeate-side flow path member 22 was placed in a container, and then an adhesive (Denatite 2204, manufactured by Nagase ChemteX) was applied to both end portions (longitudinal L sides) of the permeate-side flow path member 22 (corresponding to 33a in Figure 4(b)). Although a first tape 25 is shown in Figure 4, this was omitted in this example. 2 The separation membrane 21a was placed with the separation functional layer surface facing upward (Figure 4(c)). Furthermore, sealing material A (double-sided tape (Y-4930), manufactured by 3M, 10 mm wide x 150 mm long) serving as supply-side sealing portions 31 was attached to both end portions (i.e., width direction W sides) of the permeate-side flow path member 22 opposite to the end portions coated with the adhesive (33a) (corresponding to 33b in Figure 5(a)), and the supply-side flow path member 23 was then installed (Figure 5b)). Although a second tape 26 is shown in Figures 5(b) and (c), its lamination was omitted in this example. 3 After the separation membrane 21b was placed with the separation functional layer surface facing downward (Figure 5(c)), adhesive was applied to both ends of the separation membrane opposite the supply-side sealing portion 33b (i.e., the longitudinal L side). Next, the permeate-side flow path member 22 was placed (Figure 6(a)). 4 The above steps 1 to 3 for stacking the permeate-side flow path member 22, separation membrane 21, and supply-side flow path member 23 were repeated until 20 membrane leaves were stacked. The four corners of the membrane leaf and the guide portion inside the container were sealed with the adhesive. 5 Adhesive was applied to both ends (i.e., the longitudinal L side) of the surface of the permeate-side flow path member 22 at the top of the membrane leaf. After the top lid of the container 40 was placed, adhesive was applied to the gap between the top lid and the container (Figure 6(b)). Thereafter, seven flanges (10.2 kg) with a diameter of 12 cm and a thickness of 15 mm were placed on the top cover and dried at room temperature for 10 hours to harden the adhesive, thereby obtaining a separation membrane element 1. The effective membrane area of ​​the obtained separation membrane element 1 was 0.2 m ２ It was.

[0085] Example 2 A separation membrane element was obtained in the same manner as in Example 1, except that two meshes were used as the permeate-side channel member.

[0086] Example 3 A separation membrane element was obtained in the same manner as in Example 1, except that the mesh of the permeate side flow path member was made of polypropylene, had a fiber diameter of 250 μm, a thickness of 0.50 mm, and had a mesh count of 25 meshes.

[0087] Example 4 A separation membrane element was obtained in the same manner as in Example 3, except that two meshes were used as the permeate-side channel member.

[0088] Example 5 A separation membrane element was obtained in the same manner as in Example 1, except that the mesh of the permeate side flow path member had a fiber diameter of 70 μm, a thickness of 0.14 mm, and a mesh count of 50 meshes.

[0089] Example 6 A separation membrane element was obtained in the same manner as in Example 5, except that two meshes were used as the permeate-side channel member.

[0090] Example 7 A separation membrane element was obtained in the same manner as in Example 1, except that the mesh of the permeate side channel member had a fiber diameter of 150 μm, a thickness of 0.30 mm, and a mesh count of 50 meshes.

[0091] Example 8 A separation membrane element was obtained in the same manner as in Example 7, except that two meshes were used as the permeate-side channel member.

[0092] Example 9 A separation membrane element was obtained in the same manner as in Example 1, except that the mesh of the permeate side flow path member had a fiber diameter of 70 μm, a thickness of 0.14 mm, and a mesh count of 80 meshes.

[0093] Example 10 A separation membrane element was obtained in the same manner as in Example 9, except that two meshes were used as the permeate-side channel member.

[0094] Example 11 A separation membrane element was obtained in the same manner as in Example 1, except that the mesh of the permeate side channel member had a fiber diameter of 70 μm, a thickness of 0.14 mm, and a mesh count of 100 meshes.

[0095] Example 12 A separation membrane element was obtained in the same manner as in Example 1, except that the mesh used in Example 5 (fiber diameter 70 μm, mesh count 50 mesh) was sandwiched between the mesh used in Example 11 (fiber diameter 70 μm, mesh count 100 mesh) to obtain a mesh (thickness 0.21 mm) as the permeate-side flow path member.

[0096] Example 13 A separation membrane element was obtained in the same manner as in Example 7, except that sealing material B (double-sided tape (Y-4920) manufactured by 3M, width 10 mm×length 150 mm) was used instead of sealing material A.

[0097] Comparative Example 1 A separation membrane element was obtained in the same manner as in Example 1, except that the mesh (thickness: 0.76 mm) obtained by sandwiching the mesh of Example 1 (fiber diameter: 263 nm, mesh number: 18) between the mesh of Example 3 (fiber diameter: 250 nm, mesh number: 25) was used as the permeate-side flow path member.

[0098] Comparative Example 2 A separation membrane element was obtained in the same manner as in Example 1, except that the mesh (thickness: 0.55 mm) obtained by sandwiching the mesh of Example 3 (fiber diameter: 250 nm, mesh number: 25) between the mesh of Example 5 (fiber diameter: 70 nm, mesh number: 50) was used as the permeate-side flow path member.

[0099] Comparative Example 3 A separation membrane element was obtained in the same manner as in Comparative Example 2, except that the sealing material B was used instead of the sealing material A.

[0100] Comparative Example 4 A separation membrane element was obtained in the same manner as in Example 7, except that sealing material C (two-component epoxy adhesive (90FL) manufactured by Henkel) was used instead of sealing material A.

[0101] [Measurement Method] (Determination of Peel Strength at Sealed Portions) The average peel force (hereinafter also referred to as peel strength) at the feed-side sealed portions of the separation membrane elements prepared in the Examples and Comparative Examples was determined by the following procedure. The procedure described below conforms to JIS K 6854-1. 1. The container lid was removed from the separation membrane element, and a laminate was removed. 2. A test specimen was obtained by cutting a 100 mm long x 25 mm wide piece from the removed laminate, including the feed-side sealed portion of the membrane leaf. 3. The average peel force [N] of the feed-side sealed portion present between the separation membrane and the feed-side flow path member of the test specimen (peel section 40 mm to 100 mm) was measured by a T-peel test. The T-peel test was performed at a temperature of 25°C using a testing machine (Shimadzu Corporation's "EZ-graph" small desktop testing machine).

[0102] (Compression Test) The compressive deformation amount of the permeate-side flow path member of the separation membrane element prepared in the Examples and Comparative Examples was determined by the following procedure. The procedure described below conforms to JIS K 7181. 1. The container lid was removed from the separation membrane element, and a laminate was taken out. 2. A test piece was obtained by cutting the permeate-side flow path member of the membrane leaf from the taken-out laminate to a length of 80 mm x 80 mm. 3. The deformation amount of the test piece is the compressive deformation amount of the permeate-side flow path member when a load of 900 N was applied at a rate of 0.1 mm / min. The compression test was carried out at a temperature of 25°C using a testing machine (Shimadzu Corporation's "EZ-graph" small tabletop testing machine).

[0103] (Airtightness Test) An airtightness test was performed on the separation membrane elements produced in the examples and comparative examples according to the following procedure. FIG. 7 is a schematic diagram illustrating a test apparatus for an airtightness test. In FIG. 7, the two ends parallel to the width direction W of the separation membrane element 1 were designated as a supply section 83 communicating with the first supply port 43 (FIG. 6(b)), and a discharge section 84 communicating with the first discharge port 44 (FIG. 6(b)). The two ends parallel to the length direction L of the separation membrane element 1 were designated as a supply section 85 communicating with the supply and discharge port 45 (FIG. 6(b)), and a discharge section 86 communicating with the second discharge port 46 (FIG. 6(b)). 1. Using the apparatus shown in FIG. 7, N 2 gas at room temperature (20° C.) was introduced into the separation membrane element. ２Gas was supplied to apply a pressure of 200 kPG (G indicates gauge pressure) to the supply part 83 of the separation membrane element. The pressure was confirmed with a pressure gauge, and the valves of the discharge parts 84 and 86 were closed. 2. The valve of the supply part 85 was closed, and the valve of the discharge part 86 was opened, and the flow rate of the permeated gas was measured with a high-accuracy 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.

[0104] Table 1 shows the test results for the separation membrane elements of the examples and comparative examples.

[0105] [Results] Table 1 shows that the separation membrane elements of Examples 1 to 13, in which the compressive deformation amount of the permeate-side flow path member was 0.40 mm or less and the peel strength of the feed-side plugging portion was 1.0 N or more, all had excellent airtightness and the feed-side plugging portion did not peel off. Furthermore, Example 13 showed that as long as the compressive deformation amount was 0.40 mm or less and the peel strength was sufficient, the plugging portion would not peel off even if the plugging material was changed.

[0106] On the other hand, in Comparative Examples 1 to 3, in which the amount of compressive deformation was greater than 0.40 mm, even if the peel strength of the supply-side sealing portion was high, the airtightness was poor and the supply-side sealing portion peeled off. Furthermore, Comparative Example 4 showed that even if the amount of compressive deformation was 0.40 mm or less, the supply-side sealing portion peeled off when the peel strength was less than 1.0 N.

[0107] 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.

[0108] 1 Separation membrane element, 10 Laminated body, 11 1st end portion, 12 2nd end portion, 20 Membrane laminate portion, 21 Separation membrane, 21a 1st separation membrane (separation membrane), 21b 2nd separation membrane (separation membrane), 22 Permeate side flow path member, 23 Supply side flow path member, 25 1st table, 26 2nd table, 31 Supply side sealing portion, 32 Permeate side sealing portion, 33a Sealing material, 33b Sealing material, 40 Container, 41 Gadget portion, 43 1st supply port, 44 1st discharge port, 45 Supply and discharge port, 46 2nd discharge port, 47 Upper portion, 48 Lower portion, 49 Sidewall portion, 51 Adhesive portion, 52 Separation functional layer, 53 Porous substrate, 81 Pressure gauge, 82 Flow meter, 83 supply section, 84 discharge section, 85 supply section, 86 discharge section.

Claims

1. A plate-and-frame type separation membrane element comprising a container and a separation membrane having an area arranged in the container in the form of a flat membrane, wherein the separation membrane has a separation functional layer that selectively separates a specific fluid component contained in a raw fluid, the container accommodates a laminate having at least two permeate side flow path members through which a permeated fluid that has permeated the separation membrane flows, and a supply side flow path member through which the separation membrane and the raw fluid flow, which is disposed between the two permeate side flow path members, the separation membrane element has a supply side plugging portion between the supply side flow path member and the separation membrane, the amount of compressive deformation of the permeate side flow path member measured in accordance with JIS K 7181 is 0.40 mm or less, and the peel strength of the plugging portion measured in accordance with JIS K 6854 is 1.0 N or more.

2. The plate-and-frame type separation membrane element according to claim 1, wherein the mesh number of the permeate side flow path member is 18 mesh or more, and when the permeate side flow path member has a multi-layer structure having two or more layers, the mesh number of each layer is the same.

3. The plate-and-frame type separation membrane element according to claim 1, wherein the mesh number of the permeate side flow path member is 50 mesh or more.

4. The plate-and-frame type separation membrane element according to any one of claims 1 to 3, wherein the separation membrane has a thickness of 10 to 600 µm.

5. The plate-and-frame type separation membrane element according to any one of claims 1 to 3, wherein the raw material fluid is a gas.

6. The plate-and-frame type separation membrane element according to any one of claims 1 to 3, wherein the specific fluid component is an acid gas.

7. A separation device comprising a plate-and-frame type separation membrane element according to any one of claims 1 to 3, 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 permeate side flow path member.

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