CO2 separation element and CO2 separation system

Abstract

To provide a CO2 separation element capable of reducing pressure loss. [Solution] The CO2 separation element 20 comprises a CO2 separation membrane 22 provided between an internal air passage 116 and an external air passage 117, and a plurality of spacing members 11 provided on one surface of the CO2 separation membrane 22. The CO2 separation membrane 22 comprises a CO2 separation layer 60 that selectively permeates CO2, a first porous layer 61a and a second porous layer 61b provided on the front and back surfaces of the CO2 separation layer 60, and a sealing material 64 that suppresses the inflow and outflow of air through the porous layers. The CO2 separation membrane 22 and the spacing members 11 are stacked alternately, and the first porous layer 61a supports the CO2 separation layer 60.

Description

Technical Field

[0001] The present invention relates to a CO2 separation element and a CO2 separation system.

Background Art

[0002] In recent years, the development of technologies for selectively separating carbon dioxide (CO2) in mixed gases or the atmosphere has been progressing. These are used for recovering CO2 in exhaust gases or reducing the concentration of CO2 in the air in a closed target space, etc.

[0003] For example, a CO2 separation system for reducing the concentration of CO2 in the air in a closed target space is known (Patent Document 1). The CO2 separation system has a module (CO2 separation element) that preferentially separates CO2. When air in the target space is supplied to the CO2 separation system, the CO2 contained in the air is preferentially separated and released in the module, so that the air with reduced CO2 remains. The CO2 separation system can reduce the concentration of CO2 in the target space by returning this remaining air to the target space.

[0004] Also, conventionally, a hollow fiber type has been known as a CO2 separation element (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In conventional hollow fiber type CO2 separation elements, the amount of air that can flow through the CO2 separation element is relatively small due to reasons such as high pressure loss in the air passage, resulting in a small amount of CO2 separation per unit area of ​​the CO2 separation element.

[0007] On the other hand, stacked CO2 separation elements have lower pressure loss in the airflow path compared to other methods, allowing them to be used with relatively high airflow rates. In other words, stacked CO2 separation elements have a high CO2 separation rate per unit area.

[0008] However, in stacked CO2 separation elements, there is a concern that the CO2 separation layers, which are stacked with predetermined gaps (air passages) between them, may flex, potentially blocking the air passages. In other words, there is a concern that pressure loss may increase.

[0009] The present invention aims to solve the above-mentioned conventional problems and to provide a device that can reduce pressure loss by providing a configuration in which the air passage is less likely to be blocked. [Means for solving the problem]

[0010] To achieve this objective, the CO2 separation element of the present invention comprises a CO2 separation membrane provided between a first air passage and a second air passage, and a plurality of spacing members provided on one surface of the CO2 separation membrane. The CO2 separation membrane also comprises a CO2 separation layer that selectively permeates CO2, and a porous layer that supports the CO2 separation layer. This achieves the intended objective. [Effects of the Invention]

[0011] According to the present invention, a CO2 separation element capable of reducing pressure loss can be provided. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 shows an overview of the CO2 separation system. [Figure 2] Figure 2 shows an overview of the CO2 separation element shown in Figure 1. [Figure 3] Figure 3 shows the configuration of the CO2 separation element in Figure 1. [Figure 4] Figures 4(a) and 4(b) show the effect of the sealing material in the CO2 separation element shown in Figure 1. [Figure 5] Figure 5 is a schematic diagram of the CO2 separation element according to Embodiment 2. [Figure 6] Figure 6 is a schematic diagram of the CO2 separation element according to Embodiment 3. [Modes for carrying out the invention]

[0013] Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. The embodiments described below are all preferred specific examples of the present invention. Therefore, the numerical values, shapes, materials, and components shown in the following embodiments, as well as the arrangement and connection configurations of the components, are examples only and are not intended to limit the present invention. Accordingly, among the components in the following embodiments, those not described in the independent claim representing the highest-level concept of the present invention will be described as optional components. Furthermore, in each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations are omitted or simplified.

[0014] (Embodiment 1) First, the schematic configuration of the CO2 separation system 1 equipped with a CO2 separation element 20 according to Embodiment 1 of the present invention will be described with reference to Figure 1. Figure 1 is a schematic diagram showing an example of the installation of the CO2 separation system 1. The CO2 separation system 1 is installed indoors in a building such as a house, and is a system that separates a target gas (for example, carbon dioxide (CO2) etc.) from the air 39a in a target space 2 indoors and releases it outdoors.

[0015] The CO2 separation system 1 includes a housing 10, a CO2 separation element 20, an internal air passage 16, an external air passage 17, an internal fan 31, an internal filter 37, an external fan 41, an external filter 47, a control unit 5, and a CO2 detection unit 8.

[0016] The housing 10 is a substantially box-shaped member that forms the outer shell of the CO2 separation system 1. The internal air duct 16 and the external air duct 17 are independently formed in such a way as to divide the internal space formed inside this housing 10. Also, an internal air inlet 33, an air supply port 35, an external air inlet 43, and an exhaust port 45 are arranged on the outer periphery of the housing 10.

[0017] The internal air duct 16 is a duct formed inside the housing 10. In the internal air duct 16, the air 39a in the target space 2, which is the object to be removed of CO2 indoors, is introduced and circulated, and the air 39b with a reduced CO2 concentration is refluxed to the target space 2 by the separation function of the CO2 separation element 20 from the air 39a. In the following description, the air 39a and the air 39b are collectively referred to as "internal air".

[0018] The internal air inlet 33 is a suction port that sucks the air 39a in the target space 2 as internal air into the internal air duct 16 of the CO2 separation system 1. The internal air introduction duct 52 and the internal air duct 16 are communicatively connected via the internal air inlet 33.

[0019] The indoor suction port 51 is an opening provided in the indoor target space 2, and sucks the air 39a in the target space 2 as RA (Return Air).

[0020] The internal air introduction duct 52 is a duct that guides the air 39a in the target space 2 sucked from the indoor suction port 51 to the internal air inlet 33. One end of the internal air introduction duct 52 is connected to the indoor suction port 51, and the air 39a in the target space 2 flows into the internal air introduction duct 52 as RA. The other end of the internal air introduction duct 52 is connected to the internal air inlet 33, and causes the RA to flow into the internal air duct 16. That is, the internal air introduction duct 52 introduces and circulates the air 39a in the target space 2 indoors as internal air into the internal air duct 16.

[0021] The air supply port 35 is a discharge port that discharges the air 39b, which is the internal air with a reduced CO2 concentration by the CO2 separation element 20, from the CO2 separation system 1. In other words, the internal air duct 16 and the internal air blow duct 54 are communicatively connected via the air supply port 35.

[0022] The indoor air outlet 53 is an opening provided in the indoor target space 2, and supplies air 39b with reduced CO2 concentration to the target space 2 as SA (Supply Air).

[0023] The internal air discharge duct 54 is a duct that guides the air 39b discharged from the CO2 separation system 1 to the indoor air outlet 53. One end of the internal air discharge duct 54 is connected to the air supply port 35, and the air 39b, whose CO2 concentration has been reduced by the CO2 separation element 20, flows into the internal air discharge duct 54. The other end of the internal air discharge duct 54 is connected to the indoor air outlet 53, and the air 39b inside the internal air discharge duct 54 is supplied to the target space 2 as SA. In other words, the internal air discharge duct 54 recirculates the air 39b back into the target space 2.

[0024] The outside air passage 17 is an air passage through which outdoor air 49a is introduced and circulated, and which releases air 49b with increased CO2 concentration to the outside due to the CO2 separation function of the CO2 separation element 20. In the following explanation, air 49a and air 49b will be collectively referred to as "outside air".

[0025] The outside air inlet 43 is an intake port that draws in outdoor air 49a as outside air into the outside air passage 17 of the CO2 separation system 1. The outside air passage 17 and the outside air intake duct 56 are connected via the outside air inlet 43.

[0026] The outdoor intake port 55 is an opening in the exterior wall of the building, and draws in outdoor air 49a as OA (Outside Air) into the outdoor air intake duct 56.

[0027] The outside air intake duct 56 is a duct that guides the air 49a drawn in from the outdoor intake port 55 to the outside air port 43. One end of the outside air intake duct 56 is connected to the outdoor intake port 55, and the air 49a from outside flows into the outside air intake duct 56 as outside air (OA). The other end of the outside air intake duct 56 is connected to the outside air port 43, and the OA flows into the outside air passage 17. In other words, the outside air intake duct 56 introduces the outdoor air 49a as outside air into the outside air passage 17 and circulates it.

[0028] The exhaust port 45 is a discharge port from the CO2 separation system 1 that releases outside air 49b, whose CO2 concentration has increased due to the CO2 being absorbed from the inside air by the CO2 separation element 20. The outside air passage 17 and the outside air discharge duct 58 are connected in communication via the exhaust port 45.

[0029] The outdoor outlet 57 is an opening in the exterior wall of the building, and it discharges the air 49b with increased CO2 concentration to the outside as EA (Exhaust Air).

[0030] The outside air discharge duct 58 is a duct that guides the air 49b discharged from the CO2 separation system 1 to the outdoor outlet 57. One end of the outside air discharge duct 58 is connected to the exhaust port 45, and the air 49b, whose CO2 concentration has increased due to the CO2 separation element 20, flows into the outside air discharge duct 58. The other end of the outside air discharge duct 58 is connected to the outdoor outlet 57, and the outside air discharge duct 5 The air 49b inside 8 is discharged outdoors as EA. In other words, the outdoor air discharge duct 58 releases the air 49b outdoors.

[0031] Furthermore, the internal air intake duct 52 and the internal air discharge duct 54 may be grouped together with the internal air passage 16 as an "internal air passage," and the external air intake duct 56 and the external air discharge duct 58 may be grouped together with the external air passage 17 as an "external air passage."

[0032] The CO2 separation element 20 is installed inside the housing 10, spanning both the internal air passage 16 and the external air passage 17. It separates CO2 from the air 39a flowing through the internal air passage 16 and releases the separated CO2 into the air 49a flowing through the external air passage 17. Details of the CO2 separation element 20 will be described later.

[0033] The internal fan 31 is installed in the internal air passage 16, for example, downstream of the CO2 separation element 20, and is a blower that blows internal air in the internal air passage 16 by drawing in internal air from the target space 2 through the internal air port 33 and discharging it back into the target space 2 through the air supply port 35.

[0034] By driving the internal fan 31, the internal air drawn in from the target space 2 through the internal air inlet 33 is blown to the CO2 separation element 20 via the internal air filter 37, and then discharged back into the target space 2 through the air intake 35.

[0035] Furthermore, the internal fan 31 may be installed upstream of the CO2 separation element 20, or it may be installed downstream of the internal filter 37 and upstream of the CO2 separation element 20.

[0036] The internal air filter 37 is a filter that removes dust and dirt from the internal air flowing into the housing 10 and supplies the purified air 39a to the CO2 separation element 20. For example, a HEPA (High Efficiency Particulate Air) filter may be used for the internal air filter 37.

[0037] The outside air fan 41 is attached to the outside air passage 17 and is a fan that blows outside air in the outside air passage 17 by drawing in outside air from outdoors through the outside air port 43 and discharging it outdoors through the exhaust port 45.

[0038] By driving the outside air fan 41, outside air drawn in from outside through the outside air inlet 43 is blown to the CO2 separation element 20 via the outside air filter 47, and then discharged to the outside via the exhaust port 45.

[0039] The outside air fan 41 is installed, for example, upstream of the CO2 separation element 20, preferably downstream of the outside air filter 47 and upstream of the CO2 separation element 20. With this arrangement, the outside air can be heated by the heat generated by the operation of the outside air fan 41, and when the outside air is colder than the inside air, the heat loss due to heat exchange between the outside air and the inside air is reduced. However, the outside air fan 41 may also be installed downstream of the CO2 separation element 20.

[0040] The outside air filter 47 is a filter that removes dust and dirt from the outside air that flows into the housing 10 and supplies the purified air 49a to the CO2 separation element 20. For example, a HEPA filter may be used.

[0041] The CO2 detection unit 8 is attached to the indoor air intake duct 52 and detects the CO2 concentration in the air 39a flowing through the indoor air intake duct 52. The air 39a flowing through the indoor air intake duct 52 is air taken in from the target space 2. Therefore, the CO2 concentration detected by the CO2 detection unit 8 corresponds to the CO2 concentration in the target space 2.

[0042] Information regarding the CO2 concentration in the target space 2 detected by the CO2 detection unit 8 is transmitted to the control unit 5. Alternatively, the CO2 detection unit 8 may be directly attached to the target space 2 to detect the CO2 concentration within the target space 2 and transmit the detected CO2 concentration to the control unit 5.

[0043] The control unit 5 controls the internal fan 31 and the external fan 41. Specifically, based on the CO2 concentration in the target space 2 detected by the CO2 detection unit 8, the control unit 5 determines the CO2 separation efficiency of the CO2 separation element 20 to reduce the CO2 concentration of the air in the target space 2 that has that CO2 concentration. The control unit 5 determines the airflow rate of the internal fan 31 (internal airflow rate) and the airflow rate of the external fan 41 (external airflow rate) to achieve the determined CO2 separation efficiency. Then, the control unit 5 controls the internal fan 31 to achieve the determined internal airflow rate and the external fan 41 to achieve the determined external airflow rate.

[0044] Next, an overview of CO2 separation by the CO2 separation element 20 will be explained. Figures 2(a) and 2(b) show an overview of the CO2 separation element 20. Figure 2(a) is a cross-sectional view showing a simplified configuration of the CO2 separation element 20. In Figure 2(a), an internal air passage 116 through which internal air (white arrow in Figure 2(a)) flows from left to right, and an external air passage 117 through which external air (black arrow in Figure 2(a)) flows from left to right are arranged in a vertically overlapping configuration. A CO2 separation membrane 22 is also placed between the internal air passage 116 and the external air passage 117. The internal air introduced into the internal air passage 116 contains a mixture of carbon dioxide 18 (CO2) and nitrogen 19 (N2). Actual air also contains oxygen (O2), etc., but these are omitted here for clarity of explanation.

[0045] As the internal air flows through the element's internal air passage 116 along the CO2 separation membrane 22, the CO2 separation membrane 22 selectively allows carbon dioxide 18 in the internal air to pass through, and the carbon dioxide 18 is discharged into the outside air through the element's external air passage 117. As a result, the concentration of carbon dioxide 18 in the internal air decreases, while the concentration of carbon dioxide 18 in the outside air increases.

[0046] The element internal air passage 116 is part of the internal air passage 16. More specifically, the element internal air passage 116 is an air passage within the internal air passage 16 that guides internal air into the CO2 separation element 20. The element internal air passage 116 is also called the "first air passage".

[0047] The element outside air passage 117 is part of the outside air passage 17. More specifically, the element outside air passage 117 is an air passage within the CO2 separation element 20 that guides outside air, which is part of the outside air passage 17. The element outside air passage 117 is also called the "second air passage".

[0048] Figure 2(b) shows the configuration of the CO2 separation element 20 for more efficient separation of carbon dioxide 18 than Figure 2(a). The CO2 separation element 20 includes the first internal air passage 116a to the third internal air passage 116c, collectively referred to as the element internal air passage 116 (first air passage), the first external air passage 117a to the third external air passage 117c, collectively referred to as the element external air passage 117 (second air passage), and the first CO2 separation membrane 22a to the fifth CO2 separation membrane 22e, collectively referred to as the CO2 separation membrane 22. The number of element internal air passages 116 and element external air passages 117 is not limited to "3". From top to bottom, the first external air passage 117a, the first internal air passage 116a, the second external air passage 117b, the second internal air passage 116b, the third external air passage 117c, and the third internal air passage 116c are arranged in that order. Furthermore, a first CO2 separation membrane 22a is placed between the first outside air passage 117a and the first inside air passage 116a, a second CO2 separation membrane 22b is placed between the first inside air passage 116a and the second outside air passage 117b, and a third CO2 separation membrane 22c is placed between the second outside air passage 117b and the second inside air passage 116b. A fourth CO2 separation membrane 22d is placed between the second inside air passage 116b and the third outside air passage 117c, and a fifth CO2 separation membrane 22d is placed between the third outside air passage 117c and the third inside air passage 116c. A CO2 separation membrane 22e is positioned. Similar to Figure 2(a), carbon dioxide 18 in the internal air duct 116 is selectively permeated through the CO2 separation membrane 22 and discharged into the outside air in the external air duct 117.

[0049] Figure 3 shows the configuration of the CO2 separation element 20. Figure 3 is a perspective view showing the laminated structure 6 used as the CO2 separation element 20 mounted in the CO2 separation system 1. In the following description, the stacking direction of the laminated structure 6 will be described as the vertical up-down direction, but this does not necessarily indicate the direction when the laminated structure 6 is mounted in the CO2 separation system 1.

[0050] The laminated structure 6 is formed by alternately stacking rectangular CO2 separation membranes 22 and rod-shaped spacing members 11 in the vertical direction. In other words, the laminated structure 6 is a structure composed of alternating layers of internal air passages 116 and external air passages 117 that intersect with the internal air passages 116. More precisely, the laminated structure 6 is a single structure combining the CO2 separation membrane 22 and the spacing members 11, with the spacing members 11 stacked orthogonally so that they are alternating in each layer. That is, the internal air passages 116 and external air passages 117 are formed to be orthogonal to each other when viewed in a plan view in the stacking direction.

[0051] With this configuration, as shown in Figure 2(b), an element internal air passage 116 through which internal air passes and an element external air passage 117 through which external air passes are alternately formed, and internal and external air flow alternately orthogonally through each air passage. In other words, internal and external air flow alternately orthogonally in the stacking direction of the CO2 separation membrane 22, so that the CO2 separation element 20 can selectively permeate CO2 from the internal air side to the external air side.

[0052] The CO2 separation membrane 22 has a roughly rectangular shape when viewed in a plan view in the stacking direction. The CO2 separation membrane 22 is a sheet-like member designed to allow CO2 to pass from the inner air to the outside air when the inner air and outside air flow across the CO2 separation membrane 22. Spacing members 11 are provided above and below the CO2 separation membrane 22. In addition, a sealing material 64 is provided on the side surface of the CO2 separation membrane 22, but the details of the sealing material 64 will be described later.

[0053] The CO2 separation membrane 22 uses the CO2 partial pressure difference as a driving force for CO2 permeation, allowing CO2 to pass from high-concentration CO2 gas to low-concentration CO2 gas. Therefore, the relative amounts of CO2 in the treated gas and the sweep gas are treated gas > sweep gas. In this embodiment, "internal air" corresponds to "treated gas," and "external air" corresponds to "sweep gas."

[0054] The spacing member 11 is a rod-shaped member that maintains the airflow shape of the internal air passage 116 and the external air passage 117 of the element. In other words, the spacing member 11 forms the first air passage and the second air passage. The spacing member 11 extends in a direction perpendicular to the stacking direction, that is, in a direction along the plane of the CO2 separation membrane 22. The height dimension of the spacing member 11 becomes the height dimension of the internal air passage 116 or the external air passage 117 of the element. The smaller the height dimension of the spacing member 11, the smaller the volume of the stacked structure 6, but the pressure loss in the internal air passage 116 and the external air passage 117 of the element increases, so the height dimension of the spacing member 11 is preferably about 1 mm. In addition, the internal air passage 116 and the external air passage 117 of the element become straight air passages with low pressure loss because the spacing member 11 has a straight shape. Multiple spacing members 11 are arranged side by side with a predetermined spacing D1 in a direction perpendicular to the stacking direction, that is, along the surface of the CO2 separation membrane 22. The predetermined spacing D1 is wider than the width D2 of the spacing members 11 in the same direction. By providing multiple spacing members 11 with a predetermined spacing D1, the CO2 separation membrane 22 is supported and deformation of the CO2 separation membrane 22 is suppressed. More precisely, in this embodiment, the easily flexible CO2 separation layer 60 is supported by the first porous layer 61a, which will be described later, and further, the first porous layer 61a is supported by the spacing members 11, thereby suppressing the flexing of the CO2 separation layer 60.

[0055] This configuration makes it possible to suppress the deflection of the CO2 separation membrane 22 and the blocking of the air passage. In other words, it is possible to reduce pressure loss. A more detailed explanation of the spacing member 11 will be given later, along with a detailed explanation of the sealing material 64.

[0056] Figures 4(a) and 4(b) more schematically illustrate the structure of the laminated structure 6 and the airflow in order to clearly demonstrate the effect of the sealing material 64. Figure 4(a) shows the structure without the sealing material 64, and Figure 4(b) shows the structure with the sealing material 64. Figures 4(a) and 4(b) illustrate the three axes (x, y, and z axes). In the following explanation, the direction indicated by the arrows on each x, y, and z axis may be referred to as the "positive direction," and the direction opposite to the direction indicated by the arrow may be referred to as the "negative direction."

[0057] The CO2 separation membrane 22 comprises a CO2 separation layer 60 having a CO2 separation function, a first porous layer 61a supporting the CO2 separation layer 60, and a second porous layer 61b protecting the CO2 separation layer 60. A first spacing member 62a is provided on one side of the CO2 separation membrane 22, and a second spacing member 62b is provided on the remaining side.

[0058] Multiple first spacing members 62a are provided at predetermined intervals in the x-axis direction of Figures 4(a) and 4(b). In other words, the first spacing members 62a form an element internal air passage 116 by allowing internal air to circulate through the predetermined intervals. The first spacing members 62a have a rectangular shape when viewed in plan in the y-axis direction, but they may also have a semicircular shape, for example.

[0059] Multiple second spacing members 62b are provided at predetermined intervals in the y-axis direction of Figures 4(a) and 4(b). In other words, the second spacing members 62b form an element outside air passage 117 by allowing outside air to circulate through the predetermined intervals. The second spacing members 62b have a rectangular shape when viewed in plan along the x-axis direction, but they may also have a semicircular shape, for example.

[0060] The CO2 separation layer 60 is a layer made of a material that has the ability to selectively permeate CO2, for example, a dried CO2 separation solution, but the type of solution is not limited. In other words, the CO2 separation layer 60 is a membrane that can selectively separate CO2 by a facilitated transport method or a molecular sieve method.

[0061] The first porous layer 61a is provided below the CO2 separation layer 60 (on the negative z-axis side) for the purpose of supporting the CO2 separation layer 60, and is a layer formed of a porous material that allows for air permeability. In other words, the first porous layer 61a is formed on the back surface of the CO2 separation layer 60. For example, if the CO2 separation layer 60 is a dried CO2 separation solution, the pore size of the first porous layer 61a is determined to be such that the applied CO2 separation solution does not permeate while maintaining air permeability, allowing the CO2 separation layer 60 to be formed. The first porous layer 61a is, for example, a porous resin material such as polytetrafluoroethylene (PTFE) or a nonwoven fabric. The thickness of the first porous layer 61a in the lamination direction is greater than the thickness of the CO2 separation layer 60.

[0062] This configuration makes it possible to more reliably support the CO2 separation layer 60 with the first porous layer 61a and suppress deformation of the CO2 separation layer 60.

[0063] The second porous layer 61b is provided on top of the CO2 separation layer 60 (on the positive z-axis side) for the purpose of protecting the surface of the CO2 separation layer 60, and is a layer formed of a porous material with permeability. In other words, the second porous layer 61b is formed on the surface of the CO2 separation layer 60. For example, if the CO2 separation layer 60 is a dried CO2 separation solution, the pore size of the second porous layer 61b is determined to be such that the CO2 separation solution does not permeate while maintaining permeability, allowing the CO2 separation layer 60 to be formed. The second porous layer 61b is made of, for example, polytetrafluoroethylene (P These are porous resin materials such as TFE or nonwoven fabrics. The first porous layer 61a and the second porous layer 61b are collectively referred to as the "porous layer".

[0064] The sealing material 64 is provided on all four sides (side surfaces) of the CO2 separation membrane 22. More specifically, the sealing material 64 completely seals the side surfaces 101, 102, 103, and 104 of the CO2 separation membrane 22 without any gaps. The sealing material 64 seals at least the first porous layer 61a and the second porous layer 61b of each side surface.

[0065] The side surface 101 is one side of the laminated structure 6. More specifically, the side surface 101 is one of the side surfaces of the laminated structure 6 located on the side in the positive x-axis direction (yz plane). The side surface 101 is also the surface from which air 49 is blown.

[0066] The side surface 102 is one side of the laminated structure 6. More specifically, the side surface 102 is one of the side surfaces of the laminated structure 6 located on the negative y-axis side (xz plane). The side surface 102 is also the surface into which air 39 is drawn.

[0067] The side surface 103 is one side of the laminated structure 6. More specifically, the side surface 103 is one of the side surfaces of the laminated structure 6 located on the negative x-axis side (yz plane). The side surface 103 is also the surface into which air 49 is drawn.

[0068] The side surface 104 is one side of the laminated structure 6. More specifically, the side surface 104 is one of the side surfaces of the laminated structure 6 located on the side in the positive y-axis direction (xz plane). The side surface 104 is also the surface from which air 39 is blown.

[0069] In the following explanation, when referring to side surfaces 101-104 without making any particular distinction, the term "side surface" will be used.

[0070] Figure 4(a) shows the airflow when the sealing material 64 is not provided. When the sealing material 64 is not provided, a portion of the air 49 (indicated by the dashed arrows branching from the air 49) entering the element's external air passage 117 from the inlet (side surface 103) of the laminated structure 6 (CO2 separation element 20) passes through the first porous layer 61a or the second porous layer 61b and enters the element's internal air passage 116, where it mixes with the air 39.

[0071] Similarly, some of the air 39 entering the internal air passage 116 of the element (indicated by the dashed arrows branching off from the air 39) passes through the first porous layer 61a or the second porous layer 61b and enters the external air passage 117 of the element, where it mixes with the air 49.

[0072] In this way, when air 39 and air 49 are mixed, if outside air is used as the sweep gas, heat exchange occurs between the inside air and the outside air, resulting in thermal loss.

[0073] Therefore, in this embodiment, by providing the sealing material 64 without any gaps on the side surfaces of the first porous layer 61a and the second porous layer 61b, as shown in Figure 4(b), it is possible to suppress the unintentional passage of air 39 or air 49 through the first porous layer 61a or the second porous layer 61b, thereby preventing the mixing of internal and external air.

[0074] The sealing material 64 is an airtight adhesive, such as a silicone-based adhesive, which is applied in advance to each side surface of the CO2 separation membrane 22. Then, the CO2 separation membrane 22 and the spacing member 11 are alternately stacked to produce the laminated structure 6.

[0075] Furthermore, as the sealing material 64, UV (Ultraviolet) curing resin, thermosetting resin Resin can also be used. In this case, the CO2 separation membrane 22 and the spacing member 11 are alternately stacked, and then the entire side surface is immersed in resin and sealed by post-treatment such as UV irradiation or heating. Since no resin remains at the openings of the internal air passage 116 and the external air passage 117 of the element, the air passages can be formed without any problems.

[0076] Furthermore, a plate-shaped member with an opening only in the air passage portion can also be used as the sealing material 64. Specifically, the sealing material 64 may be a plate-shaped member having the same outer shape as the side surface of the laminated structure 6. More specifically, the sealing material 64 may have an opening in the region of the plate-shaped member that overlaps with the internal air passage 116 (external air passage 117) of the element when the plate-shaped member is attached to the side surface of the laminated structure 6.

[0077] Furthermore, when integrally molding the spacing member 11 and the CO2 separation membrane 22, a method can also be considered in which the sealing material 64 is integrally molded by covering the side surface of the CO2 separation membrane 22 with resin (for example, film insert molding).

[0078] Furthermore, the sealing material 64 may cover not only the side surfaces of the first porous layer 61a and the second porous layer 61b, but also the side surfaces of the CO2 separation layer 60.

[0079] Furthermore, the first porous layer 61a and the second porous layer 61b may be of the same shape or may be of different shapes. (Embodiment 2) Next, Embodiment 2 of the present invention will be described with reference to Figure 5. Figure 5 is a schematic diagram showing the configuration of the CO2 separation element 20a according to Embodiment 2. The difference is that in Embodiment 1, the CO2 separation element 20 is rectangular, whereas in Embodiment 2, the CO2 separation element 20a is hexagonal.

[0080] The CO2 separation element 20a has a hexagonal shape when viewed in a plan view in the stacking direction and is composed of a CO2 separation membrane 22k, a first spacing member 62c, and a second spacing member 62d. In this embodiment, the CO2 separation element 20a is formed by repeatedly stacking the CO2 separation membrane 22k, the first spacing member 62c, the CO2 separation membrane 22k, and the second spacing member 62d in order from bottom to top in the stacking direction (in the positive direction of the z axis).

[0081] The CO2 separation membrane 22k has a hexagonal shape when viewed in a plan view in the stacking direction. The CO2 separation membrane 22k is provided between the first spacing member 62c and the second spacing member 62d in the stacking direction. The CO2 separation membrane 22k comprises a CO2 separation layer 60a, a first porous layer 61c, a second porous layer 61d, and a sealing material 64a.

[0082] The CO2 separation layer 60a is a layer made of a material that has the ability to selectively permeate CO2. Specifically, the CO2 separation layer 60a is a membrane that selectively separates CO2 by means of, for example, an facilitated transport method or a molecular sieve method.

[0083] The first porous layer 61c is provided below the CO2 separation layer 60a (on the negative z-axis side) for the purpose of supporting the CO2 separation layer 60a, and is a layer made of a porous material that allows for airflow. The air 39c flowing through the internal air passage 216 of the element is guided to the CO2 separation layer 60a via the first porous layer 61c.

[0084] The second porous layer 61d is provided above the CO2 separation layer 60a (on the positive z-axis side) for the purpose of protecting the CO2 separation layer 60a, and is a layer made of a porous material that allows for airflow. The air 49c flowing through the element's outside air passage 217 is guided to the CO2 separation layer 60a via the second porous layer 61d.

[0085] The sealing material 64a prevents the air 39c in the internal air passage 216 of the element and the air 49c in the external air passage 217 of the element from unintentionally flowing out through the first porous layer 61c or the second porous layer 61d. In other words, it is provided to prevent the mixing of air 39a and air 49a. The sealing material 64a completely covers the side surfaces of the first porous layer 61c and the second porous layer 61d without any gaps. More specifically, the sealing material 64a completely covers the side surfaces of the hexagonal first porous layer 61c and the second porous layer 61d without any gaps. The sealing material 64a may also cover the side surfaces of the CO2 separation layer 60a.

[0086] Multiple first spacing members 62c are provided along one surface (xy plane) of the CO2 separation membrane 22k at predetermined intervals. In this embodiment, two first spacing members 62c are provided on the same CO2 separation membrane 22a at intervals, and the internal air passage 216 of the element is formed in the interval. The first spacing members 62c are provided from end 201, which is one end of the CO2 separation membrane 22k, to end 202, which is the other end of the CO2 separation membrane 22k. In this embodiment, the first spacing members 62c have a substantially S-shape when viewed in plan in the stacking direction, but the shape of the first spacing members 62c is not limited to this. For example, the first spacing members 62c may have a straight shape connecting end 201 and end 202. When the first spacing members 62c have a straight shape, the air 39c can move in a straight line within the internal air passage 216 of the element, thus reducing pressure loss.

[0087] Multiple second spacing members 62d are provided along one surface (xy plane) of the CO2 separation membrane 22k at predetermined intervals. In this embodiment, two second spacing members 62d are provided on the same CO2 separation membrane 22k at intervals, and the element outside air passage 217 is formed in the interval. The second spacing members 62d are provided from end 301, which is one end of the CO2 separation membrane 22k, to end 302, which is the other end of the CO2 separation membrane 22k. In this embodiment, the second spacing members 62d have a substantially S-shape when viewed in plan in the stacking direction, but the shape of the second spacing members 62d is not limited to this. For example, the second spacing members 62d may be a straight line connecting end 301 and end 302. When the second spacing members 62d are straight, the air 49c can move in a straight line within the element outside air passage 217, thus reducing pressure loss.

[0088] Furthermore, in this embodiment, the airflow directions of air 39c and air 49c are opposing flows, facing each other. Because air 39c and air 49c flow in opposite directions across the CO2 separation membrane 22k, the CO2 partial pressure difference across the entire membrane becomes more uniform compared to a direct alternating current, and the number of localized areas with small CO2 partial pressure differences decreases, thereby activating the separation of CO2 at the CO2 separation membrane 22k. As a result, it becomes possible to separate CO2 more efficiently. (Embodiment 3) Next, Embodiment 3 will be described with reference to Figure 6. Embodiment 3 differs from Embodiment 1 in that the sealing material 64 covers only a portion of the side surfaces of the laminated structure 6 (first porous layer 61a and second porous layer 61b). Figure 6 is a schematic diagram of the CO2 separation element 20b in Embodiment 3.

[0089] The sealing material 64 includes a first sealing material 64c and a second sealing material 64d.

[0090] The first sealant 64c seals two sides of the first porous layer 61c. More specifically, the first sealant 64c seals the side circumferential surface 102 and the side circumferential surface 104 of the first porous layer 61a. In other words, the first sealant 64c is formed on the surface (xz surface) along the direction of airflow of the air 49. To put it another way, the first sealant 64c is provided on two opposing sides of the side circumferential surface of the first porous layer 61a.

[0091] With this configuration, the inflow and outflow of air through the side surfaces 102 and 104 of the first porous layer 61a is suppressed, while the side surfaces 101 and 103 of the first porous layer 61a can be used as part of the intake or outlet of the laminated structure 6. In other words, the intake or outlet can be made wider than in the configuration of Embodiment 1, so pressure loss can be reduced even further.

[0092] The second sealant 64d seals two sides of the second porous layer 61b. More specifically, the second sealant 64d seals the side circumferential surface 101 and the side circumferential surface 103 of the second porous layer 61b. In other words, the second sealant 64d is formed on the surface (yz plane) that is in line with the airflow direction of the air 39. To put it another way, the second sealant 64d is provided on two opposing sides of the side circumferential surface of the second porous layer 61b.

[0093] In other words, the CO2 separation element 20b in this embodiment has a rectangular shape when viewed in plan in the stacking direction and comprises a CO2 separation layer 60 that selectively separates CO2, a first porous layer 61a that supports the CO2 separation layer 60, and a second porous layer 61b that protects the CO2 separation layer 60. Furthermore, the first porous layer 61a is provided with a first sealing material 64c on two opposing side surfaces of the first porous layer 61a to suppress the inflow and outflow of air. In addition, the second porous layer 61b is provided with a second sealing material 64d on two opposing side surfaces of the second porous layer 61b to suppress the inflow and outflow of air. To put it another way, the first porous layer 61a and the second porous layer 61b facing the internal air passage 116 of the element are provided with sealing material 64 on two side surfaces (side surface 101 and side surface 103) that are approximately parallel to the airflow direction of the internal air passage 116 of the element. Furthermore, the first porous layer 61a and the second porous layer 61b, which face the element's external air passage 117, are provided with sealing material 64 on two circumferential surfaces (circumferential surface 102 and circumferential surface 104) that are approximately parallel to the airflow direction of the element's external air passage 117.

[0094] With this configuration, the inflow and outflow of air through the side surfaces 101 and 103 of the second porous layer 61b is suppressed, while the side surfaces 102 and 104 of the second porous layer 61b can be used as part of the intake or outlet of the laminated structure 6. In other words, the intake or outlet can be made wider than in the configuration of Embodiment 1, so pressure loss can be reduced even further. [Explanation of Symbols]

[0095] 1 Separation System 2. Target space 5. Control Unit 6. Laminated Structure 10 cabinets 11 Spacing member 16 Internal air channel 17 Outside air channel 18 Carbon dioxide 19 Nitrogen 20, 20a, 20b Separation elements 22, 22k separation membrane 31 Internal fan 33 Indoor vent 35 Air supply port 37 Interior air filter 39, 39a, 39b, 39c air 41 Outdoor fan 43. Outdoor air vent 45 Exhaust vent 47. Outdoor air filter 49, 49a, 49b, 49c Air 51 Indoor intake 52 Interior air intake duct 53 Indoor air outlet 54 Interior air outlet duct 55 Outdoor intake port 56. Outdoor air intake duct 57 Outdoor outlet 58. Outdoor air outlet duct 60, 60a Separation layer 61a, 61c First porous layer 61b, 61d Second porous layer 62a, 62c First spacing holding member 62b, 62d Second spacing retaining member 64, 64a Sealing material 64c First sealing material 64d Second sealing material 116, 216 element internal air passage 117, 217 element outside air passage

Claims

1. CO installed between the first air passage and the second air passage ２ Separation membrane and The aforementioned CO ２ The separation membrane comprises a plurality of spacing-maintaining members provided on one surface of the membrane, The aforementioned CO ２ The separation membrane is CO ２ CO selectively transmits ２ Separation layer and The aforementioned CO ２ A porous layer supporting a separation layer, CO ２ Separation element.

2. The aforementioned CO ２ The separation membrane is The CO ２ separation layer, and The aforementioned CO ２ A first porous layer is provided on the back surface of the separation layer, The aforementioned CO ２ A second porous layer provided on the surface of the separation layer, CO as described in claim 1 ２ Separation element.

3. The aforementioned CO ２ The CO2 according to claim 1, formed by alternately stacking the separation membrane and the spacing member. ２ Separation element.

4. The aforementioned spacing member is The first spacing member that forms the first air passage, The second spacing member that forms the second air passage is included, The first spacing member is By arranging them side by side at predetermined intervals in a direction perpendicular to the stacking direction, the first air passage is formed in the interval. The second spacing member is By arranging them side by side at predetermined intervals in a direction perpendicular to the stacking direction, the second air passage is formed in the interval. The first airflow path and the second airflow path are, In a plan view looking in the direction of stacking, the lines are straight and intersecting. CO as described in claim 2 ２ Separation element.

5. CO in the stacking direction ２ The thickness of the separation layer is thinner than that of the porous layer, as described in claim 2. ２ Separation element.

6. The side surface of the porous layer is provided with a sealing material, The aforementioned sealing material is The CO2 according to claim 1, which suppresses the inflow and outflow of air into the porous layer. ２ Separation element.

7. The aforementioned sealing material is The CO2 described in claim 6, which seals the side surface of the porous layer without any gaps. ２ Separation element.

8. The first sealing material includes a first sealing material and a second sealing material. The first sealing material is, Of the side surfaces of the first porous layer, two sides are provided parallel to the airflow direction of the air passage that the first porous layer faces. The aforementioned second sealing material is Of the side surfaces of the second porous layer, two sides parallel to the airflow direction of the air passage that the second porous layer faces are provided: CO as described in claim 6 ２ Separation element.

9. CO as described in claim 1 ２ Separation Qualitative Qualitative ２ Separation system.

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