Gas separation device

Abstract

To provide a gas separation device which can maintain a high concentration of a predetermined gas component on a surface of a gas separation membrane and inhibit deterioration of separation efficiency.SOLUTION: A gas separation device includes: a first separation membrane unit having a first gas separation membrane configured to separate a predetermined gas component contained in a mixed gas supplied to a first front surface by causing the predetermined gas component to permeate through a first rear surface opposite to the first front surface, and a first gas flow path section through which the predetermined gas component separated flows; a gas introduction unit that is arranged via a gap from the first front surface and that has a gas introduction section that introduces the mixed gas toward the first gas separation membrane; and a gas exhaust unit that is arranged via a gap from the first front surface and that has a gas exhaust section that exhausts the mixed gas introduced from the gas introduction unit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas separation device. [Background technology]

[0002] To achieve carbon neutral or carbon negative, technologies are being considered for capturing and capturing carbon dioxide emitted from thermal power plants, boiler facilities, etc., and carbon dioxide in the atmosphere. One known technology for this purpose is the membrane separation method, which separates carbon dioxide using a gas separation membrane.

[0003] For example, Patent Document 1 discloses a gas separation method for selectively permeating a specific gas (A) from a mixed gas using a gas separation membrane. This gas separation method includes supplying the mixed gas to one side of a gas separation membrane, in which the membrane thickness of the gas separation membrane is 1 μm or less, the concentration of the gas (A) in the mixed gas is 10,000 mass ppm or less, and the selective permeation of the gas (A) by the gas separation membrane is performed under conditions where the pressure difference across both sides of the gas separation membrane is 1 atmosphere or less.

[0004] According to this gas separation method, the gas (A) can be separated satisfactorily even under mild conditions such as a pressure difference of 1 atmosphere or less across the two sides of the gas separation membrane. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-033590 A Summary of the Invention [Problem to be solved by the invention]

[0006] In membrane separation, the challenge is to increase the separation efficiency of a specific gas component. In order to increase the separation efficiency of a gas separation membrane, it is necessary to maintain a high concentration of the specific gas component on the upstream side of the gas separation membrane. However, when the specific gas component permeates the gas separation membrane, the concentration on the upstream side decreases accordingly, resulting in a decrease in separation efficiency.

[0007] Therefore, there is a demand for a gas separation device that is less likely to lose concentration even when a specific gas component permeates a gas separation membrane, and that can suppress a decrease in separation efficiency. [Means for solving the problem]

[0008] A gas separation device according to an application example of the present invention includes: a first separation membrane unit including a first gas separation membrane that separates a predetermined gas component contained in a mixed gas supplied to a first surface by transmitting the predetermined gas component to a first back surface opposite to the first surface, and a first gas flow path portion through which the separated predetermined gas component flows; a gas introduction unit disposed across a gap from the first surface and having a gas introduction portion for introducing the mixed gas toward the first gas separation membrane; a gas exhaust unit disposed at a gap from the first surface and having a gas exhaust portion for exhausting the mixed gas introduced from the gas introduction unit; Equipped with. [Brief description of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a configuration of a gas separation device according to a first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the gas separation device shown in FIG. [Diagram 3] 4 is a graph showing the relationship between the gas permeability of carbon dioxide through a first gas separation membrane and the concentration of carbon dioxide at a first surface of the first gas separation membrane. [Figure 4] FIG. 4 is a cross-sectional view showing the configuration of a gas separation device according to a second embodiment. [Diagram 5] FIG. 5 is a perspective view of the gas separation device shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a gas separation device of the present invention will be described in detail based on an embodiment shown in the accompanying drawings. 1. First embodiment First, the gas separation device according to the first embodiment will be described.

[0011] Fig. 1 is a cross-sectional view showing the configuration of a gas separation device 1 according to a first embodiment. Fig. 2 is an exploded perspective view of the gas separation device 1 shown in Fig. 1. Note that in Fig. 2, part of the configuration shown in Fig. 1 is omitted.

[0012] In each figure of the present application, the X-axis, Y-axis, and Z-axis are set as three mutually orthogonal axes. Each axis is represented by an arrow, with the tip of the arrow being "plus" and the base of the arrow being "minus". In the following description, for example, "X-axis direction" includes both the plus and minus directions of the X-axis. The same applies to the Y-axis and Z-axis directions. In the following description, the plus side of the Z-axis is also referred to as "upper" and the minus side of the Z-axis is also referred to as "lower". However, the Z-axis does not need to be parallel to the vertical axis, and may cross the vertical axis.

[0013] 1.1. Overview 1 includes a first separation membrane unit 21, a second separation membrane unit 22, a gas introduction unit 5, a gas exhaust unit 6, and an exhaust pump 7. The first separation membrane unit 21 has a first gas separation membrane 31, and the second separation membrane unit 22 has a second gas separation membrane 32. The gas introduction unit 5 introduces a mixed gas G1 toward a first surface 311 of the first gas separation membrane 31 and a second surface 321 of the second gas separation membrane 32, and the gas exhaust unit 6 exhausts the mixed gas G1 introduced toward the first surface 311 and the second surface 321.

[0014] In such a gas separation device 1, after the mixed gas G1 is introduced from the gas introduction unit 5 toward the first surface 311 and the second surface 321, the mixed gas G1 can be quickly discharged by the gas discharge unit 6. In the vicinity of the first surface 311 and the second surface 321, separation of carbon dioxide CO2 progresses immediately after the introduction of the mixed gas G1, so that the concentration of carbon dioxide CO2 decreases over time, which is a problem in that the separation efficiency decreases. The gas discharge unit 6 quickly discharges the mixed gas G1 with a reduced concentration of carbon dioxide CO2 in this way, thereby suppressing the mixed gas G1 with a reduced concentration of carbon dioxide CO2 from remaining in the vicinity of the first surface 311 and the second surface 321. As a result, the concentration of carbon dioxide CO2 on the first surface 311 and the second surface 321 can be maintained high, and the decrease in separation efficiency in the first gas separation membrane 31 and the second gas separation membrane 32 can be suppressed.

[0015] The mixed gas G1 contains carbon dioxide CO2, which is a gas component to be separated, and other gas components (non-target components). The mixed gas G1 is not particularly limited, but may be, for example, the atmosphere, exhaust gas discharged from facilities such as factories, etc. The gas component to be separated is not limited to carbon dioxide CO2, but may be other gas components. The non-target components vary depending on the mixed gas G1, but when the mixed gas G1 is the atmosphere, they are nitrogen, oxygen, etc.

[0016] 1.2.Separation membrane unit In the gas separation device 1 shown in Fig. 1, a first separation membrane unit 21 and a second separation membrane unit 22 are arranged side by side and spaced apart from each other in the Z-axis direction. By providing the gas separation device 1 with a plurality of separation membrane units, it is possible to realize a gas separation device 1 with particularly high separation efficiency of carbon dioxide CO2. The number of separation membrane units provided in the gas separation device 1 may be one, or three or more.

[0017] The first separation membrane unit 21 has two first gas separation membranes 31, 31 and a first gas flow path section 41. The first gas separation membrane 31 separates carbon dioxide CO2 from the mixed gas G1 by allowing it to permeate. The first gas flow path section 41 has an internal space S1. The internal space S1 is exhausted by an exhaust pump 7. As a result, the first gas flow path section 41 exhausts and recovers gas containing carbon dioxide CO2 that has permeated and been separated into the internal space S1 (gas having a higher concentration of carbon dioxide CO2 than the mixed gas G1).

[0018] The second separation membrane unit 22 has two second gas separation membranes 32, 32 and a second gas flow path section 42. The second gas separation membrane 32 separates carbon dioxide CO2 from the mixed gas G1 by allowing it to permeate. The second gas flow path section 42 has an internal space S2. The internal space S2 is also exhausted by the exhaust pump 7. As a result, the second gas flow path section 42 exhausts and recovers gas containing carbon dioxide CO2 that has permeated and been separated into the internal space S2 (gas having a higher concentration of carbon dioxide CO2 than the mixed gas G1).

[0019] 1.2.1. Gas separation membranes The first gas separation membrane 31 has a first front surface 311 and a first back surface 312 which are opposite sides to each other. The second gas separation membrane 32 has a second front surface 321 and a second back surface 322 which are opposite sides to each other. The first gas separation membrane 31 and the second gas separation membrane 32 may have the same configuration as each other or different configurations. The following description will be given using the first gas separation membrane 31 as a representative, but the following description also applies to the second gas separation membrane 32.

[0020] The first gas separation membrane 31 selectively allows carbon dioxide CO2 contained in the mixed gas G1 supplied to the first front surface 311 side to permeate to the first back surface 312 side, preferentially over other gas components. Therefore, the first gas separation membrane 31 has a property that the gas permeability of carbon dioxide CO2 is greater than the gas permeability of non-target components (the property that the gas selectivity ratio of carbon dioxide CO2 is high). Hereinafter, the ratio of the gas permeability of carbon dioxide to the gas permeability of nitrogen will be simply referred to as the "gas selectivity ratio".

[0021] The gas selectivity ratio of the first gas separation membrane 31 is preferably 3 or more, and more preferably 10 or more and 1000 or less. When the gas selectivity ratio is within the above range, the first gas separation membrane 31 can efficiently separate and recover carbon dioxide CO2 in the mixed gas G1.

[0022] The nitrogen gas permeability of the first gas separation membrane 31 and the carbon dioxide gas permeability of the first gas separation membrane 31 are each measured in accordance with the gas permeability test method (Part 1: differential pressure method) specified in JIS K 7126-1:2006. A gas permeability measuring device is used for the measurement. An example of the gas permeability measuring device is GTR-11A / 31A manufactured by GTR Tech Co., Ltd. In this device, the gas that has permeated the first gas separation membrane 31 is introduced into a gas chromatograph, and the gas permeability of each component is measured.

[0023] In the first gas separation membrane 31, the gas permeability of carbon dioxide is preferably 1000 GPU or more, more preferably 5000 GPU or more and 100,000 GPU or less, and even more preferably 10,000 GPU or more and 50,000 GPU or less. This makes it possible to reduce the amount of energy input required for separation, specifically, to realize a first gas separation membrane 31 that can reduce the pressure difference between the first front surface 311 side and the first back surface 312 side. If the gas permeability of carbon dioxide of the first gas separation membrane 31 falls below the lower limit, a lot of energy is required to separate carbon dioxide, and there is a risk that the economic efficiency of the operation of the gas separation device 1 will decrease. On the other hand, if the gas permeability of carbon dioxide of the first gas separation membrane 31 exceeds the upper limit, there is a risk that the cost of manufacturing the first gas separation membrane 31 will increase. Note that 1 GPU is 3.35×10 -10 mol m -2 ·s -1 ·Pa -1 It is.

[0024] 3 is a graph showing the relationship between the gas permeability of carbon dioxide through the first gas separation membrane 31 and the concentration of carbon dioxide on the first surface 311 of the first gas separation membrane 31. The graph shown in FIG. 3 plots the concentration of carbon dioxide on the first surface 311 one second after the mixed gas G1 is supplied, when the flow rate of the mixed gas G1 with a carbon dioxide concentration of 400 ppm supplied onto the first surface 311 is zero. In this case, since the flow rate is zero, it is assumed that carbon dioxide spreads in the mixed gas G1 only by the effect of diffusion. In addition, the gas selectivity of the first gas separation membrane 31 is assumed to be infinite.

[0025] 3, when the carbon dioxide gas permeability of the first gas separation membrane 31 becomes 1000 GPU or more, the carbon dioxide concentration drops sharply. For this reason, when the gas permeability is 1000 GPU or more, the carbon dioxide concentration at the first surface 311 becomes particularly important in increasing the carbon dioxide separation efficiency in the first gas separation membrane 31.

[0026] The thickness of the first gas separation membrane 31 is not particularly limited, but is preferably 1 nm to 1000 μm, more preferably 5 nm to 100 μm, and even more preferably 10 nm to 10 μm.

[0027] The average thickness of the first gas separation membrane 31 is the average value of thicknesses measured at 10 points on the first gas separation membrane 31. The thickness of the first gas separation membrane 31 can be measured using, for example, a thickness gauge.

[0028] Although the size of the first gas separation membrane 31 is not particularly limited, the maximum length is preferably 5 cm to 2 m, and more preferably 10 cm to 1 m. This provides a first gas separation membrane 31 that has mechanical strength sufficient to withstand pressure differences and can ensure a sufficient gas permeability.

[0029] The first gas separation membrane 31 may be a single layer or a composite layer formed by laminating multiple layers. The first gas separation membrane 31 may also be supported by a porous layer that is porous. In particular, when the thickness of the first gas separation membrane 31 is 100 μm or less, it is preferable to laminate the first gas separation membrane 31 and a porous layer to improve the overall strength.

[0030] Examples of the constituent material of the first gas separation membrane 31 include a polymer material, a ceramic material, a metal material, etc. Furthermore, the constituent material of the first gas separation membrane 31 may be a composite material of these materials or a composite material of these materials and another material.

[0031] Examples of polymeric materials include polyolefin resins such as polyethylene and polypropylene, fluorine-containing resins such as polytetrafluoroethylene, polyvinyl fluoride and polyvinylidene fluoride, organopolysiloxane (silicone resin), polystyrene, cellulose, cellulose acetate, polyurethane, polyacrylonitrile, polyphenylene oxide, polysulfone, polyethersulfone, polyimide, polyaramid, nylon, and the like.

[0032] Examples of the ceramic material include alumina, cordierite, mullite, silicon carbide, zirconia, etc. Examples of the metal material include stainless steel, etc.

[0033] 1.2.2.Gas flow path The first gas flow path section 41 has a wall 411 that defines an internal space S1 through which the separated gas containing carbon dioxide CO2 flows, and an exhaust port 412 provided in the wall 411. The second gas flow path section 42 has a wall 421 that defines an internal space S2 through which the separated gas containing carbon dioxide CO2 flows, and an exhaust port 422 provided in the wall 421. The first gas flow path section 41 and the second gas flow path section 42 may have the same configuration or different configurations. The following description will be given using the first gas flow path section 41 as a representative example, but the following description also applies to the second gas flow path section 42.

[0034] The wall body 411 is a box body having a flat shape extending along the XY plane, with a hollow interior, and having a substantially rectangular parallelepiped shape. The wall body 411 defines the above-mentioned internal space S1. In addition, a part of each of the two faces intersecting with the Z axis is opened, and the first gas separation membrane 31 is arranged so as to close the opening. Therefore, as shown in FIG. 1, two first gas separation membranes 31, 31 arranged vertically are arranged on the wall body 411. That is, the two first gas separation membranes 31, 31 are arranged so that the first back surfaces 312 face each other. This enables separation of carbon dioxide CO2 on both the upper surface side and the lower surface side of the first separation membrane unit 21. The number of first gas separation membranes 31 provided on one wall body 411 is not particularly limited, and may be one or three or more. Furthermore, in this embodiment, the first gas separation membrane 31 is arranged so as to intersect with the Z-axis, but a first gas separation membrane 31 arranged so as to intersect with the X-axis may be added.

[0035] The exhaust port 412 is tubular and communicates with the internal space S1. As shown in FIG. 1, an exhaust pump 7 is connected to the exhaust port 412. The exhaust pump 7 is operated to exhaust the internal space S1 through the exhaust port 412. The pressure in the internal space S1 when the exhaust pump 7 is operating may be less than atmospheric pressure, and is preferably 10 kPa or less, and more preferably 1 kPa or less. This ensures a sufficient pressure difference between the first surface 311 side and the first back surface 312 side of the first gas separation membrane 31, and can sufficiently increase the separation efficiency of carbon dioxide CO2. The lower limit of the pressure in the internal space S1 is not particularly limited, but is preferably 0.001 Pa or more, and more preferably 0.1 Pa or more, in consideration of the introduction cost and running cost of the exhaust pump 7, the deformation resistance of the first gas separation membrane 31, and the like. In addition, taking these points into consideration, the air pressure difference between the internal space S1 and the outside is preferably set to 0.001 Pa or more and 10 kPa or less, and more preferably 0.1 Pa or more and 1 kPa or less.

[0036] Examples of materials constituting the wall 411 and the exhaust port 412 include resin materials, metal materials, ceramic materials, etc. Also, composite materials containing these materials may be used.

[0037] The wall 411 and the first gas separation membrane 31 are bonded together so as not to impair airtightness. The bonding method is not particularly limited, but examples thereof include bonding with an adhesive, bonding by sandwiching, bonding by fusion, etc.

[0038] The height h of the wall 411 in the Z-axis direction is not particularly limited, but is preferably 5 mm to 30 cm, and more preferably 1 cm to 10 cm. This makes it possible to prevent the gas separation device 1 from becoming large.

[0039] The maximum length of the wall 411 along the XY plane is not particularly limited, but is preferably 5 cm to 2 m, and more preferably 10 cm to 1 m. This makes it possible to arrange a sufficiently large first gas separation membrane 31, and realizes a first separation membrane unit 21 that can ensure a sufficient gas permeation rate.

[0040] 1.3.Gas introduction unit The gas introduction unit 5 has a first mixed gas channel section 51, a first opening 52 (gas introduction section), and a gas introduction pump 55.

[0041] The first mixed gas channel section 51 is disposed adjacent to the first separation membrane unit 21 and the second separation membrane unit 22 in the Z-axis direction. Specifically, the gas introduction units 5 are disposed below the first separation membrane unit 21, above the second separation membrane unit 22, and between the first separation membrane unit 21 and the second separation membrane unit 22.

[0042] As shown in FIG. 2, the first mixed gas flow passage section 51 has a rectangular column shape extending in the X-axis direction and is hollow inside. The first mixed gas flow passage section 51 is connected to a gas introduction pump 55 via a pipe. The mixed gas G1 delivered from the gas introduction pump 55 is filled inside the first mixed gas flow passage section 51. In addition, in the first mixed gas flow passage section 51, a part of the surface facing the first surface 311 of the first gas separation membrane 31 and the second surface 321 of the second gas separation membrane 32 is opened. This is the first opening 52, and the mixed gas G1 supplied to the first mixed gas flow passage section 51 is introduced from the first opening 52 toward the first surface 311 and the second surface 321. In FIG. 1, the flow of the mixed gas G1 is indicated by a dashed arrow.

[0043] The gas introduction unit 5 preferably has a plurality of first openings 52. This allows the mixed gas G1 to be introduced evenly over a wide range, making it easier to increase the separation efficiency.

[0044] In the first mixed gas flow path section 51 configured as described above, the mixed gas G1 is introduced through the first openings 52 that are sufficiently narrower than the cross-sectional area (cross-sectional area in a plane perpendicular to the X-axis direction) of the first mixed gas flow path section 51. For this reason, when multiple first openings 52 are arranged in the first mixed gas flow path section 51, it is easier to suppress variations in the flow rate of the mixed gas G1 introduced from each of the first openings 52.

[0045] The inner diameter of the first opening 52 is not particularly limited, but from the viewpoint of optimizing the flow rate and flow rate of the introduced mixed gas G1, it is preferably 0.1 mm or more and 100 mm or less, and more preferably 1 mm or more and 10 mm or less.

[0046] The first opening 52 may be an opening provided in the first mixed gas flow path section 51 as described above, but may have another shape. For example, it may be a tube extending from the opening.

[0047] In addition, the gas introduction unit 5, which is arranged between the first separation membrane unit 21 and the second separation membrane unit 22, has a first opening 52 arranged on both the surface facing the first surface 311 and the surface facing the second surface 321.

[0048] The gas introduction pump 55 delivers the mixed gas G1 toward the first mixed gas channel section 51. The type of the gas introduction pump 55 is not particularly limited.

[0049] The gas introduction unit 5 is disposed with a gap between the first surface 311 of the first gas separation membrane 31. The distance d5 between the gas introduction unit 5 and the first surface 311 of the first gas separation membrane 31 in the Z-axis direction is not particularly limited, but is preferably more than 0 mm and not more than 30 mm, more preferably 0.5 mm or more and not more than 10 mm, and even more preferably 1 mm or more and not more than 5 mm. This allows the mixed gas G1 introduced toward the first surface 311 to spread to some extent along the first surface 311, and can be prevented from spreading too much. If the distance d5 is below the lower limit, the distance d5 is too small, and the flow of the introduced mixed gas G1 may be impaired. In this case, the introduced mixed gas G1 may be difficult to discharge by the gas exhaust unit 6 described later. On the other hand, if the distance d5 exceeds the upper limit, the distance d5 is too large, and the introduced mixed gas G1 may be discharged by the gas exhaust unit 6 before reaching the first surface 311. In this case, the carbon dioxide concentration on first surface 311 decreases, and there is a risk of the separation efficiency decreasing.

[0050] The above explanation about the distance d5 also applies to the distance between the gas introducing unit 5 and the second surface 321 of the second gas separation membrane 32.

[0051] Examples of materials that can be used to form the first mixed gas flow path section 51 include resin materials, metal materials, and ceramic materials. Also, the first mixed gas flow path section 51 may be made of a composite material that contains these materials.

[0052] 1.4.Gas exhaust unit The gas exhaust unit 6 has a second mixed gas channel section 61 , a second opening 62 (gas exhaust section), and a gas exhaust pump 65 .

[0053] The second mixed gas channel section 61 is disposed adjacent to the first separation membrane unit 21 and the second separation membrane unit 22 in the Z-axis direction. Specifically, the gas exhaust units 6 are disposed below the first separation membrane unit 21, above the second separation membrane unit 22, and between the first separation membrane unit 21 and the second separation membrane unit 22.

[0054] As shown in FIG. 2, the second mixed gas channel section 61 has a rectangular column shape extending in the X-axis direction and is hollow inside. In addition, in the second mixed gas channel section 61, a part of the surface facing the first surface 311 of the first gas separation membrane 31 and the second surface 321 of the second gas separation membrane 32 is opened. This is the second opening 62, and the mixed gas G1 introduced into the first surface 311 and the second surface 321 is taken into the second mixed gas channel section 61 through the second opening 62. The second mixed gas channel section 61 is connected to a gas exhaust pump 65 through a pipe. The mixed gas G1' taken into the second mixed gas channel section 61 is exhausted by the gas exhaust pump 65 through a pipe.

[0055] The gas discharge unit 6 preferably has a plurality of second openings 62. This makes it possible to discharge the mixed gas G1' over a wide range, which makes it easier to increase the separation efficiency.

[0056] In the second mixed gas flow path section 61 configured as described above, the cross-sectional area (cross-sectional area in a plane perpendicular to the X-axis direction) of the second mixed gas flow path section 61 is sufficiently large compared to the area of ​​the second openings 62, so that the mixed gas G1' can be discharged smoothly through each second opening 62.

[0057] The gas exhaust unit 6 is disposed with a gap between it and the first surface 311 of the first gas separation membrane 31. By disposing both the gas introduction unit 5 and the gas exhaust unit 6, the mixed gas G1 can be introduced and the mixed gas G1' can be discharged quickly. This makes it possible to maintain a high concentration of carbon dioxide CO2 on the first surface 311 and the second surface 321, and to suppress a decrease in the separation efficiency in the first gas separation membrane 31 and the second gas separation membrane 32.

[0058] The inner diameter of the second opening 62 is not particularly limited, but is preferably 0.1 mm or more and 100 mm or less, more preferably 1 mm or more and 10 mm or less, from the viewpoint of optimizing the flow rate and flow rate of the discharged mixed gas G1'. Also, the inner diameter of the second opening 62 is preferably larger than the inner diameter of the first opening 52. This allows for smoother exhaust.

[0059] The second opening 62 may be an opening provided in the second mixed gas flow path section 61 as described above, but may also have another shape. For example, it may be a tube extending from the opening.

[0060] The gas exhaust pump 65 exhausts the mixed gas G1' taken into the second mixed gas channel section 61. The type of the gas exhaust pump 65 is not particularly limited.

[0061] The gas exhaust unit 6 is disposed with a gap therebetween from the first surface 311 of the first gas separation membrane 31. The distance d6 between the gas exhaust unit 6 and the first surface 311 of the first gas separation membrane 31 in the Z-axis direction is not particularly limited, but is preferably more than 0 mm and not more than 30 mm, more preferably 0.5 mm or more and 10 mm or less, and even more preferably 1 mm or more and 5 mm or less. This allows the mixed gas G1 introduced toward the first surface 311 to spread to some extent along the first surface 311, and can be prevented from spreading too much. If the distance d6 falls below the lower limit, the distance d6 is too small, and the flow of the introduced mixed gas G1 may be impaired. In this case, it may be difficult to discharge the introduced mixed gas G1 by the gas exhaust unit 6. On the other hand, if the distance d6 exceeds the upper limit value, the distance d6 is too large, and the introduced mixed gas G1 may be exhausted by the gas exhaust unit 6 before reaching the first surface 311, resulting in a decrease in separation efficiency.

[0062] The above description of the distance d6 also applies to the distance between the gas exhaust unit 6 and the second surface 321 of the second gas separation membrane 32.

[0063] The distances d5 and d6 may be the same or different. In the latter case, the distance d6 is set to be greater than the distance d5. In this case, when the mixed gas G1 introduced from the gas introduction unit 5 is discharged by the gas discharge unit 6, a space can be secured around the second opening 62, so that the discharge efficiency can be improved.

[0064] The gas separation device 1 shown in FIG. 1 and FIG. 2 includes a plurality of gas introduction units 5 and a plurality of gas discharge units 6. These are alternately arranged along the Y-axis direction (the direction parallel to the first surface 311). As a result, the gas introduction units 5 and the gas discharge units 6 are adjacent to each other, so that the first openings 52 (gas introduction section) and the second openings 62 (gas discharge section) are also alternately arranged along the Y-axis direction. As a result, the gas exchange efficiency (introduction efficiency and discharge efficiency) of the mixed gas G1 can be particularly improved. As a result, the decrease in the separation efficiency in the first gas separation membrane 31 and the second gas separation membrane 32 can be particularly suppressed. It is not necessary that all the gas introduction units 5 and the gas discharge units 6 are alternately arranged, and it is sufficient that at least some of them are alternately arranged.

[0065] The number of gas introduction units 5 included in the gas separation device 1 is not particularly limited, but is preferably multiple. This results in multiple first openings 52 (gas introduction parts), making it possible to introduce the mixed gas G1 evenly over a wide range, making it easier to improve separation efficiency. As a result, it is possible to particularly suppress a decrease in separation efficiency in the first gas separation membrane 31 and the second gas separation membrane 32.

[0066] The shortest distance between the center of the first opening 52 and the center of the second opening 62 in the XY plane is set according to the size of the gas separation device 1, the flow rate of the mixed gas G1, the inner diameters of the first opening 52 and the second opening 62, and is not particularly limited, but is preferably 1 mm or more and 300 mm or less, more preferably 5 mm or more and 200 mm or less, and even more preferably 15 mm or more and 100 mm or less. This allows the mixed gas G1 to be introduced evenly, so that the separation performance of the first gas separation membrane 31 and the second gas separation membrane 32 can be fully exerted.

[0067] Examples of materials that can be used to form the second mixed gas flow path section 61 include resin materials, metal materials, and ceramic materials. Also, the second mixed gas flow path section 61 may be made of a composite material that contains these materials.

[0068] 1.5.Exhaust Pump Examples of the exhaust pump 7 include dry pumps such as screw pumps and scroll pumps, oil rotary pumps, and turbo molecular pumps. Of these, dry pumps are preferably used, and screw pumps are more preferably used. These pumps are useful as the exhaust pump 7 because they do not use oils or liquids, so there is no risk of contaminating the internal spaces S1 and S2, and they consume low power.

[0069] 2. Second embodiment Next, a gas separation device according to a second embodiment will be described.

[0070] Fig. 4 is a cross-sectional view showing the configuration of the gas separation device 1 according to the second embodiment. Fig. 5 is a perspective view of the gas separation device 1 shown in Fig. 4. Note that Fig. 4 omits illustration of configurations that overlap with those of the first embodiment. Also, Fig. 5 omits illustration of a part of the configuration shown in Fig. 4.

[0071] The second embodiment will be described below, but in the following description, the differences from the first embodiment will be mainly described, and a description of similar points will be omitted.

[0072] The second embodiment is similar to the first embodiment, except that the configurations of the gas introduction unit 5 and the gas exhaust unit 6 are different.

[0073] The gas introduction unit 5 shown in FIGS. 4 and 5 has a first mixed gas flow path section 51, a first opening 52, and an introduction pipe 53.

[0074] The first mixed gas flow passage section 51 shown in FIG. 4 and FIG. 5 is a box body having a flat shape extending along the XY plane and a hollow inside, and having a substantially rectangular parallelepiped shape. The introduction pipe 53 is arranged so that the base end is connected to the first mixed gas flow passage section 51 in accordance with the first opening 52, and the tip end is located near the first surface 311 of the first gas separation membrane 31 and near the second surface 321 of the second gas separation membrane 32. The distance between the introduction pipe 53 and the first surface 311 and the second surface 321 is the same as the distance d5 described above. By providing such an introduction pipe 53, the mixed gas G1 can be introduced to a position close to the first gas separation membrane 31 and the second gas separation membrane 32. As a result, it is easy to maintain the concentration of carbon dioxide at the first surface 311 and the second surface 321 high.

[0075] The gas discharge unit 6 shown in FIGS. 4 and 5 has a second mixed gas flow path portion 61, a second opening portion 62, and a discharge pipe 63.

[0076] The second mixed gas flow passage section 61 shown in FIG. 4 and FIG. 5 is a box body having a flat shape extending along the XY plane and a hollow inside, and having a substantially rectangular parallelepiped shape. The exhaust pipe 63 is arranged so that the base end is connected to the second mixed gas flow passage section 61 in accordance with the second opening 62, and the tip end is located near the first surface 311 of the first gas separation membrane 31 and near the second surface 321 of the second gas separation membrane 32. The distance between the exhaust pipe 63 and the first surface 311 and the second surface 321 is the same as the distance d6 described above. By providing such an exhaust pipe 63, the mixed gas G1 introduced into the first surface 311 and the second surface 321 can be efficiently exhausted. As a result, it is easy to maintain the concentration of carbon dioxide at the first surface 311 and the second surface 321 high.

[0077] 5, the inlet pipes 53 and the exhaust pipes 63 are alternately arranged along the X-axis direction and the Y-axis direction (parallel to the first surface 311). This allows the inlet pipes 53 and the exhaust pipes 63 to be sufficiently close to each other, and the distribution of the two pipes becomes more uniform. As a result, the gas exchange efficiency of the mixed gas G1 at the first surface 311 and the second surface 321 can be particularly improved. The arrangement of the inlet pipes 53 and the exhaust pipes 63 is not limited to this. In the second embodiment as described above, the same effects as in the first embodiment can be obtained.

[0078] 3. Advantages of the above embodiment As described above, the gas separation device 1 according to the embodiment includes the first separation membrane unit 21, the gas introduction unit 5, and the gas exhaust unit 6. The first separation membrane unit 21 has a first gas separation membrane 31 and a first gas flow path section 41. The first gas separation membrane 31 separates carbon dioxide CO2 (a predetermined gas component) contained in the mixed gas G1 supplied to the first surface 311 by passing it through the first back surface 312 opposite to the first surface 311. The separated carbon dioxide CO2 flows through the first gas flow path section 41. The gas introduction unit 5 has a first opening 52 (gas introduction section). The first opening 52 is disposed from the first surface 311 via a gap, and introduces the mixed gas G1 toward the first gas separation membrane 31. The gas exhaust unit 6 has a second opening 62 (gas exhaust section). The second opening 62 is disposed from the first surface 311 via a gap, and exhausts the mixed gas G1 introduced from the gas introduction unit 5.

[0079] With this configuration, even if the concentration of carbon dioxide CO2 on the first surface 311 decreases due to the action of the first gas separation membrane 31, the mixed gas G1 containing such a low concentration of carbon dioxide CO2 can be quickly discharged and new mixed gas G1 can be quickly introduced. As a result, a gas separation device 1 can be obtained in which the concentration of carbon dioxide CO2 on the first surface 311 is less likely to decrease and a decrease in separation efficiency is suppressed.

[0080] In the gas separation device 1 according to the embodiment, the gas introduction unit 5 has a plurality of first openings 52 (gas introduction parts), and the gas discharge unit 6 has a plurality of second openings 62 (gas discharge parts).

[0081] According to such a configuration, the mixed gas G1 can be introduced evenly over a wide area, and the mixed gas G1 can be discharged over a wide area, which makes it easier to improve separation efficiency.

[0082] In addition, in the gas separation device 1 according to the embodiment, the first openings 52 (gas inlet section) and the second openings 62 (gas outlet section) are arranged alternately along the Y-axis direction (a direction parallel to the first surface 311).

[0083] With this configuration, the gas exchange efficiency (introduction efficiency and exhaust efficiency) of the mixed gas G1 can be particularly improved. As a result, a decrease in the separation efficiency in the first gas separation membrane 31 and the second gas separation membrane 32 can be particularly suppressed.

[0084] Moreover, the gas separation device 1 according to the embodiment includes a plurality of gas introduction units 5 and a plurality of gas exhaust units 6. The gas introduction units 5 and the gas exhaust units 6 are alternately arranged along the Y-axis direction (a direction parallel to the first surface 311).

[0085] With this configuration, the gas exchange efficiency (introduction efficiency and exhaust efficiency) of the mixed gas G1 can be particularly improved. As a result, a decrease in the separation efficiency in the first gas separation membrane 31 and the second gas separation membrane 32 can be particularly suppressed.

[0086] Moreover, in the gas separation device 1 according to the embodiment, the gas introduction unit 5 has a first mixed gas flow path section 51 through which the mixed gas G1 flows, and a first opening 52 as a gas introduction section that opens into the first mixed gas flow path section 51.

[0087] According to this configuration, the mixed gas G1 is introduced through the first openings 52 which are sufficiently narrower than the cross-sectional area (cross-sectional area in a plane perpendicular to the X-axis direction) of the first mixed gas flow path section 51. Therefore, even if multiple first openings 52 are arranged in the first mixed gas flow path section 51, it is easier to suppress variations in the flow rate of the mixed gas G1 introduced through each first opening 52.

[0088] Moreover, in the gas separation device 1 according to the embodiment, the gas introduction unit 5 further includes an introduction pipe 53 extending from the first opening 52 .

[0089] With this configuration, the mixed gas G1 can be guided to a position close to the first gas separation membrane 31. As a result, the concentration of carbon dioxide on the first surface 311 can be maintained high.

[0090] In addition, in the gas separation device 1 of the above embodiment, the gas exhaust unit 6 has a second mixed gas flow path section 61 through which the mixed gas G1 supplied from the gas introduction unit 5 flows, and a second opening 62 as a gas exhaust section that opens into the second mixed gas flow path section 61.

[0091] According to this configuration, the cross-sectional area (cross-sectional area in a plane perpendicular to the X-axis direction) of the second mixed gas flow path section 61 is sufficiently larger than the area of ​​the second openings 62, so that the mixed gas G1 can be discharged smoothly through each second opening 62.

[0092] Moreover, in the gas separation device 1 according to the embodiment, the gas discharge unit 6 further includes a discharge pipe 63 extending from the second opening 62 .

[0093] According to such a configuration, it is possible to efficiently exhaust mixed gas G1 introduced into first surface 311. As a result, the concentration of carbon dioxide at first surface 311 can be maintained high.

[0094] The gas permeability of the first gas separation membrane 31 to carbon dioxide is preferably 5,000 GPU or more and 100,000 GPU or less.

[0095] With such a configuration, it is possible to realize first gas separation membrane 31 that can reduce the amount of energy input required for separation, specifically, that can reduce the pressure difference between first front surface 311 side and first back surface 312 side.

[0096] Moreover, the gas separation device 1 according to the embodiment further includes a second separation membrane unit 22. The second separation membrane unit 22 has a second gas separation membrane 32 and a second gas flow path section 42. The second gas separation membrane 32 separates carbon dioxide (predetermined gas component) contained in the mixed gas G1 supplied to the second surface 321 by allowing it to permeate to a second back surface 322 opposite to the second surface 321. The separated carbon dioxide flows through the second gas flow path section 42. Furthermore, the second separation membrane unit 22 is disposed on the opposite side to the first separation membrane unit 21 with the gas introduction unit 5 and the gas exhaust unit 6 interposed therebetween.

[0097] With such a configuration, it is possible to realize a gas separation device 1 that has a particularly high carbon dioxide separation efficiency.

[0098] Although the gas separation device according to the present invention has been described above based on the illustrated embodiment, the present invention is not limited to this.

[0099] For example, the gas separation device of the present invention may be one in which each part of the above-mentioned embodiment is replaced with any component having a similar function, or one in which any component is added to the above-mentioned embodiment. [Explanation of symbols]

[0100] Reference Signs List 1...gas separation device, 5...gas introduction unit, 6...gas exhaust unit, 7...exhaust pump, 21...first separation membrane unit, 22...second separation membrane unit, 31...first gas separation membrane, 32...second gas separation membrane, 41...first gas flow path section, 42...second gas flow path section, 51...first mixed gas flow path section, 52...first opening, 53...inlet pipe, 55...gas introduction pump, 61...second mixed gas flow path section, 62...second opening, 63...exhaust pipe, 65...gas exhaust pump, 311...first surface, 312...first back surface, 321...second surface, 322...second back surface, 411...wall, 412...exhaust port, 421...wall, 422...exhaust port, CO2...carbon dioxide, G1...mixed gas, G1'...mixed gas, S1...internal space, S2...internal space, d5...distance, d6...distance, h...height

Claims

1. a first separation membrane unit including a first gas separation membrane that separates a predetermined gas component contained in a mixed gas supplied to a first surface by transmitting the predetermined gas component to a first back surface opposite to the first surface, and a first gas flow path portion through which the separated predetermined gas component flows; a gas introduction unit disposed across a gap from the first surface and having a gas introduction portion for introducing the mixed gas toward the first gas separation membrane; a gas exhaust unit disposed at a gap from the first surface and having a gas exhaust portion for exhausting the mixed gas introduced from the gas introduction unit; A gas separation device comprising:

2. The gas introduction unit has a plurality of the gas introduction parts, The gas separation device according to claim 1 , wherein the gas discharge unit has a plurality of the gas discharge sections.

3. The gas separation device according to claim 2 , wherein the gas inlet portions and the gas outlet portions are alternately arranged along a direction parallel to the first surface.

4. The gas supply system includes a plurality of the gas introduction units and a plurality of the gas exhaust units, The gas separation device according to claim 1 or 2, wherein the gas introduction units and the gas discharge units are alternately arranged along a direction parallel to the first surface.

5. 3. The gas separation device according to claim 1 or 2, wherein the gas introduction unit has a first mixed gas flow path section through which the mixed gas flows, and a first opening section as the gas introduction section that opens into the first mixed gas flow path section.

6. The gas separation device according to claim 5 , wherein the gas introduction unit further comprises an introduction pipe extending from the first opening.

7. The gas separation device according to claim 1 or 2, wherein the gas exhaust unit has a second mixed gas flow path section through which the mixed gas supplied from the gas introduction unit flows, and a second opening as the gas exhaust section that opens into the second mixed gas flow path section.

8. The gas separation device according to claim 7 , wherein the gas discharge unit further comprises a discharge pipe extending from the second opening.

9. 3. The gas separation device according to claim 1 or 2, wherein the first gas separation membrane has a gas permeability to carbon dioxide of 5,000 GPU or more and 100,000 GPU or less.

10. The gas separator further includes a second separation membrane unit having a second gas separation membrane that separates the predetermined gas component contained in the mixed gas supplied to the second surface by allowing the predetermined gas component to permeate through a second back surface opposite to the second surface, and a second gas flow path portion through which the separated predetermined gas component flows, 3. The gas separation device according to claim 1, wherein the second separation membrane unit is disposed on an opposite side to the first separation membrane unit with the gas introduction unit and the gas exhaust unit interposed therebetween.

Images