Gas separation membrane module

Abstract

To provide a gas separation membrane module having low pressure loss to a high flow rate.SOLUTION: In a gas separation membrane module where a plurality of hollow fiber membranes are arranged inside in one direction in a module case,: the hollow fiber membranes are open at both ends of the module case; a space between hollow fiber membranes and a space between the hollow fiber membrane and the module case are sealed with a potting material; the inside diameter of the hollow fiber membrane is 0.6 mm or more and 6 mm or less; and the total sum of the cross-section area at the hollow part of the hollow fiber membrane vertically cut cross section of the module case to a longitudinal direction of the hollow fiber membrane is 0.04 m2 or more and 25.0 m2 or less.SELECTED DRAWING: Figure 1(A)

Description

[Technical field]

[0001] The present invention relates to a gas separation membrane module, and more particularly to a gas separation membrane module suitable for use in a humidity control unit used in an air conditioner or a heat exchanger. [Background technology]

[0002] Porous membranes are widely used in medical applications such as blood purifiers for patients with renal failure, and in water treatment applications such as water purifiers. In addition, hollow fiber membranes with pores of a size that allows gas separation exhibit superior gas separation properties among various inorganic membranes, and can be used in environments where chemical resistance and heat resistance are required. There are various gas separation targets using hollow fiber membranes, including separation of water vapor and carbon dioxide from the air, and separation of harmful components contained in exhaust gases from factories, etc.

[0003] Hollow fiber membranes that are permeable to water vapor are increasingly being used for purposes such as humidifying fuel gas to keep the electrolyte membrane built into fuel cell systems moist, and dehumidifying water in spaces such as offices and homes. Ultrafiltration membranes, microfiltration membranes, and the like are generally widely used as hollow fiber membranes, and a method has been proposed in which a polysulfone-based resin, which has excellent strength stability under humidified conditions, is used (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2020-44523 [Patent Document 2] Patent Publication No. 2011-67812 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to increase the gas separation efficiency, when a large flow rate of gas to be treated or treated is passed inside the hollow fiber membrane, the pressure loss in the module increases, which may lead to an increase in the load on the equipment for treatment and a decrease in the efficiency of the entire device. For example, the hollow fiber membrane modules described in Patent Documents 1 and 2 use high-pressure air compressed by a compressor to perform dehumidification and humidification, and when such a hollow fiber membrane module is connected to an air conditioner or blower, the pressure loss generated in the hollow fiber membrane module may exceed the maximum static pressure of the blower, and the blower may not be able to blow air. Therefore, when a conventional hollow fiber membrane module is introduced into an existing facility, it may be necessary to introduce a blower with high power consumption and a static pressure that exceeds the pressure loss in the module, which makes it difficult to actually install it in addition to an existing air conditioner. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention comprises the following configuration. The gas separation membrane module according to the present invention is characterized in that it is a gas separation membrane module containing a plurality of hollow fiber membranes arranged in one direction in a module case, the hollow fiber membranes are open at both ends of the module case, the gaps between the hollow fiber membranes and between the hollow fiber membranes and the module case are sealed with a potting material, the inner diameter of the hollow fiber membranes is 0.6 mm or more and 6 mm or less, and the sum of the cross-sectional areas of the hollow parts of the hollow fiber membranes in a cross section of the module case cut perpendicularly to the longitudinal direction of the hollow fiber membranes is 0.04 m 2 More than 25.0m 2 The following is a gas separation membrane module. Effect of the Invention

[0007] The gas separation membrane module obtained by the present invention reduces pressure loss by ensuring the cross-sectional area within the hollow fiber membrane through which the fluid passes, and by appropriately setting the inner diameter of the hollow fiber membrane, it is possible to reduce pressure loss due to sudden expansion and contraction of the fluid at the fluid inlet and outlet ports, thereby providing a gas separation membrane module with low pressure loss even at high flow rates. [Brief description of the drawings]

[0008] [Figure 1(A)] 1 is a perspective view of a gas separation membrane module according to the present invention. [Figure 1(B)] 1 is an overhead view of a gas separation membrane module according to the present invention. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a block diagram relating to the power supply of a fuel cell vehicle. [Figure 4] FIG. 2 is a schematic diagram of a total heat exchanger. [Diagram 5] FIG. 2 is a schematic diagram showing a method for measuring moisture permeability. [Figure 6] FIG. 2 is a schematic diagram showing a durability evaluation method by an intermittent air test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

[0010] A gas separation membrane module containing a plurality of hollow fiber membranes arranged in one direction in a module case, the hollow fiber membranes are open at both ends of the module case, the gaps between the hollow fiber membranes and between the hollow fiber membranes and the module case are sealed with a potting material, the inner diameter of the hollow fiber membranes is 0.6 mm or more and 6 mm or less, and the sum of the cross-sectional areas of the hollow parts of the hollow fiber membranes in a cross section (hereinafter referred to as a vertical cross section) obtained by cutting the module case perpendicular to the longitudinal direction of the hollow fiber membranes is 0.04 m 2 More than 25.0m 2 The following is a gas separation membrane module. The gas separation membrane module of the present invention allows a first fluid to flow inside a hollow fiber membrane and a second fluid to flow outside the hollow fiber membrane, with at least one of the first fluid and the second fluid being a gas, and performs gas separation between the first fluid and the second fluid via the hollow fiber membrane, thereby reducing pressure loss in high flow rate gas separation. One of the first fluid and the second fluid is a gas, and the other is a gas or a liquid. Examples of the gas include air, factory air, room air, dry air, natural gas, hydrogen gas, a mixed gas containing carbon dioxide, a mixed gas containing water vapor, and various mixed gases. Examples of the liquid include pure water, ionic liquid, and various mixed liquids, and it is preferable that the liquid is a solution in which the gas that permeates through the gas separation membrane module dissolves.

[0011] Since the pressure loss increases as the mass density of the liquid increases, it is preferable that the second fluid is a gas. For example, when the first fluid or the second fluid is a mixed gas containing water vapor and the other fluid is dry air, the gas separation membrane module allows water vapor to permeate the hollow fiber membrane due to the partial pressure difference, and can adjust the humidity of the first fluid or the second fluid. Also, for example, when the first fluid or the second fluid is outdoor air containing odors and pollutants that is taken in during ventilation, and the other fluid is indoor air that is discharged during ventilation, the gas separation membrane module can transfer the odors and pollutants to the discharged indoor air due to the partial pressure difference, thereby reducing the odors and pollutants in the outdoor air taken in during ventilation.

[0012] FIG. 1(A) is a perspective view of a gas separation membrane module 100 according to the present invention, and FIG. 1(B) is a bird's-eye view of the gas separation membrane module 100 according to the present invention. The gas separation membrane module 100 contains a plurality of hollow fiber membranes 101 in a rectangular module case 110. The ends of the hollow fiber membranes 101 and the rectangular module case 110 are fixed with a potting material 120. The material of the potting material is not particularly limited as long as it can seal the ends, and for example, polyurethane, epoxy, silicone, nylon, etc. can be appropriately selected and used. The gas separation membrane module 100 has a first fluid inlet surface 121, a first fluid outlet surface 122, a second fluid inlet surface 123, and a second fluid outlet surface 124, which are connected to a first fluid supply pipe 125, a first fluid discharge pipe 126, a second fluid discharge pipe 127, and a second fluid supply pipe 128, respectively. The first fluid flows from the first fluid inlet surface 121 through the inside of the hollow fiber membrane 101 to the first fluid outlet surface 122. Here, the first fluid inlet surface 121 and the first fluid outlet surface 122 are surfaces to which the ends of the hollow fiber membrane 101 are fixed. The cross-sectional area of ​​the hollow part of the hollow fiber membrane 101 at the first fluid inlet surface 121 and the first fluid outlet surface 122 is the flow path cross-sectional area for the flow of the first fluid in the gas separation membrane module 100. In addition, the second fluid flows from the second fluid inlet surface 123 through the outside of the hollow fiber membrane 101 in the rectangular module case 110 to the second fluid outlet surface 124. Here, the hollow fiber membranes are communicated between the second fluid inlet surface 123 and the second fluid outlet surface 124 in the rectangular module case 110. The gas separation membrane module of the present invention has a cross-sectional area of ​​the hollow fiber membranes of 0.04 m2 in a cross section of the module case cut perpendicularly to the longitudinal direction of the hollow fiber membranes. 2 More than 25.0m 2 or less. By increasing the sum of the cross-sectional areas of the hollow parts, the flow velocity relative to the flow rate of the first fluid can be reduced, and pressure loss can be suppressed. On the other hand, if the sum of the cross-sectional areas of the hollow parts is excessively large, the cross-sectional area of ​​the entire hollow fiber membrane module also becomes large, making installation difficult. In addition, if the sum of the cross-sectional areas of the hollow parts of the hollow fiber membranes in a cross section obtained by cutting the module case perpendicularly to the longitudinal direction of the hollow fiber membranes is less than 0.09 m 2 More than 4.0m 2 By setting the pressure loss in this range, it is possible to further reduce the size of the gas separation membrane module. The sum of the cross-sectional areas of the hollow parts can be measured by the following method. First, 10 random locations are selected on the surface of the fixed end of the hollow fiber membrane so that they do not overlap. Images of the 10 selected locations are taken using an image dimension measuring device. The captured images are binarized into hollow parts and other areas using image processing and measurement software (e.g., WinROOF, manufactured by Mitani Shoji Co., Ltd.), and the total cross-sectional area of ​​the hollow parts in the image is measured, and the cross-sectional area of ​​the hollow parts per area is calculated. The same measurement is performed on 10 locations, and the average value of the cross-sectional area of ​​the hollow parts per area obtained for the total of 10 locations is calculated, and the sum of the cross-sectional area of ​​the hollow parts is calculated from the product of this average value and the area of ​​the surface of the end of the hollow fiber membrane. The inner diameter of the hollow fiber membrane can be calculated by the following method. First, cut out five cross sections from each of five hollow fiber membranes. If the hollow fiber membrane is fixed to a module case, extract any five hollow fiber membranes from the gas separation membrane module and cut out five cross sections from each of them. Photograph the obtained hollow fiber membrane cross sections at a magnification that is easy to measure using an optical microscope or an image dimension measuring device (for example, a magnification of 100 times, but depending on the size of the hollow fiber membrane, a magnification of 1000 times or 10 times may be used). Measure the diameter (= inner diameter) of the inscribed circle of the hollow part using image processing and measurement software for the photographed image. Measure the inner diameter of the hollow fiber membrane for five images taken for each of the five cut cross sections in the same manner. The above series of measurements is carried out on any five hollow fiber membranes, and the average inner diameter of the resulting 25 hollow fiber membranes is calculated. In the gas separation membrane module according to the present invention, the inner diameter of the hollow fiber membrane 101 is 0.6 mm or more and 6 mm or less. By setting the inner diameter within this range, it is possible to reduce the resistance of the first fluid when the first fluid passes through the inside of the hollow fiber membrane 101, and furthermore, it is possible to maintain the durability of the hollow fiber membrane 101. Furthermore, it is preferable that the inner diameter of the hollow fiber membrane 101 is 0.6 mm or more and 3 mm or less. By setting the inner diameter within this range, it is possible to further increase the durability of the hollow fiber membrane while reducing the resistance when the first fluid passes through the hollow fiber membrane, and to reduce the size of the gas separation membrane module. The longitudinal length of the hollow fiber membrane of the gas separation membrane module according to the present invention is preferably 0.1 m or more and 5.0 m or less. By setting it in this range, it is possible to suppress pressure loss while preventing a decrease in the total amount of gas permeating through the hollow fiber membrane 101. Moreover, it is more preferable that the longitudinal length of the hollow fiber membrane is 0.2 m or more and 2.0 m or less. By setting it in this range, it is possible to further suppress pressure loss, and it becomes possible to apply the gas separation membrane module even in a lower static pressure environment. Here, the longitudinal length of the hollow fiber membrane is calculated as the average value of the lengths measured for 10 hollow fiber membranes contained in the gas separation membrane module, including the parts fixed by the potting material, cut out. The gas separation membrane module according to the present invention preferably satisfies the following relational formula [1]. 0.2 <Ad 2 / L<10 [1] expression Here, A is the sum of the cross-sectional areas of the hollow parts of the hollow fiber membranes in a cross section obtained by cutting the module case perpendicularly to the longitudinal direction of the hollow fiber membranes of the gas separation membrane module, d is the inner diameter of the hollow fiber membranes (the average value mentioned above), and L is the longitudinal length of the hollow fiber membranes (the average value mentioned above). By configuring the gas separation membrane module to satisfy this range, it is possible to reduce the size of the gas separation membrane module while more suitably reducing the resistance when the first fluid passes through the hollow fiber membrane. Moreover, it is more preferable that the gas separation membrane module according to the present invention satisfies the following relational formula [2].

[0013] 2 <Ad 2 / L<1.0 [2] Formula By configuring a gas separation membrane module so as to satisfy this range, the longitudinal length of the hollow fiber membrane relative to the total cross-sectional area of ​​the hollow portion of the hollow fiber membrane is appropriately maintained, and gas can efficiently permeate between the first fluid and the second fluid, thereby achieving both reduced pressure loss and improved moisture permeability. The membrane thickness of the hollow fiber membrane 101 in the gas separation membrane module according to the present invention is preferably 0.05 to 0.4 times, and more preferably 0.1 to 0.3 times, the inner diameter of the hollow fiber membrane 101. By setting the membrane thickness within this range, it is possible to prevent a decrease in the permeation rates of the first and second fluids through the hollow fiber membrane while maintaining the strength of the hollow fiber membrane. 1 shows a structure in which a plurality of hollow fiber membranes are housed in a rectangular module case 110, but the shape of the module case 110 according to the present invention is not limited to this, and may be, for example, a cylindrical or polygonal module structure. The hollow fiber membranes 101 do not have to be arranged in a straight line inside the module case 110. However, if the hollow fiber membranes 101 are housed in a curved shape within the gas separation membrane module, the pressure at which the first fluid is lost within the module increases, and therefore it is preferable that the hollow fiber membranes 101 are housed in a shape close to a straight line within the module. Furthermore, although the first fluid inlet surface 121 and the first fluid outlet surface 122 of the gas separation membrane module shown in FIG. 1 are flat surfaces, the shape of the module according to the present invention is not limited to this and may, for example, have a curved surface or an uneven surface. Between the hollow fiber membranes 101 of the gas separation membrane module according to the present invention, a space for the second fluid to flow may be provided, and a flow path material such as a corrugated plate, a partition plate, a mesh-like material, or a covering thread may be provided. In particular, the provision of a flow path material is preferable because it allows the first fluid and the second fluid to efficiently permeate through the hollow fiber membrane, and suppresses the vibration of the hollow fiber membrane caused by the flow of the second fluid. The material of the flow path material is not particularly limited, but it is preferable that it has mechanical properties, heat resistance against the temperature at which the gas separation membrane module is used, chemical resistance against the second fluid and the gas permeating through the hollow fiber membrane, and solvent resistance. In particular, polyethylene and polypropylene are preferable because they are unlikely to damage the surface of the hollow fiber membrane and are inexpensive. The shape of the flow path material is not limited, but a shape in which an area for the hollow fiber membrane and the second fluid to come into contact with each other is preferable. The method for operating the gas separation membrane module according to the present invention comprises supplying a fluid to the inside of a hollow fiber membrane in the gas separation membrane module, calculating the pressure loss P (Pa) calculated from the pressure difference before and after passing through the gas separation membrane module, and calculating the flow rate F (m 3 It is preferable to operate the gas separation membrane module so that the ratio (F / P) of the static pressure difference between the upstream and downstream of the gas separation membrane module and the flow rate of the fluid discharged from the gas separation membrane module is 0.1 or more. By operating under these conditions, the pressure loss generated in the gas separation membrane module is lower than the static pressure difference between the upstream and downstream of the gas separation membrane module of the supplied fluid, making it possible to suppress a decrease in the flow rate discharged from the gas separation membrane module. In order to achieve a ratio (F / P) of 0.1 or more, the pressure of the fluid is measured at the inlet and outlet faces of the fluid in the gas separation membrane module, and the pressure loss generated in the gas separation membrane module is calculated from the difference between the two pressures. The output of the device that supplies the fluid to the gas separation membrane module, such as a pump or a blower, is adjusted based on the obtained pressure loss value so that the ratio (F / P) is 0.1 or more. <Hollow fiber membrane> The material of the hollow fiber membrane is not particularly limited, but it is advisable to select a material that is easy to form a hollow fiber membrane and a gas separation functional layer. For example, when water vapor is the target, polysulfone-based polymers, polystyrene, polyurethane, polyethylene, polypropylene, polycarbonate, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyvinyl chloride, polyester, etc. are listed. Among these, it is preferable to include a polysulfone-based polymer from the viewpoint of easy formation of a hollow fiber membrane. It is preferable to have a polysulfone-based polymer as the main component and further include a hydrophilic polymer. Examples of hydrophilic polymers include polyalkylene oxide, polyvinyl alcohol, polyethylene glycol, polyvinyl pyrrolidone, etc., and among them, polyvinyl pyrrolidone is preferable because it has excellent compatibility with polysulfone-based polymers and has high hydrophilicity. As an embodiment of the method for producing a hollow fiber membrane, the following method can be mentioned. That is, when a membrane-forming stock solution in which a polysulfone-based polymer and polyvinylpyrrolidone are dissolved in a mixed solution of a good solvent for polysulfone (preferably N,N-dimethylacetamide, dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone, dioxane, etc.) and a poor solvent is discharged from a double ring die, a core liquid is flowed inside, and after running through a dry section, it is coagulated in a coagulation solution. In addition, it is preferable to use a core liquid composition based on the solvent used in the membrane-forming stock solution from the viewpoint of process suitability. As an example of the core liquid concentration, when N,N-dimethylacetamide is used, an aqueous solution with a core liquid concentration of 10 to 60 mass %, or more preferably 20 to 50 mass %, is preferably used.

[0014] The solidified hollow fiber membrane is washed with hot water at 40°C to 90°C and wound up. Next, a heat treatment is performed to fix the pore size to the desired size, and a dry hollow fiber membrane is obtained. The size of the pores shrinks by drying the wet porous membrane after the heat treatment. The polysulfone-based polymer concentration in the membrane-forming solution is preferably 20% by mass or more and 35% by mass or less, more preferably 25% by mass or more and 30% by mass or less, based on the total mass of the membrane-forming solution. If the polysulfone-based polymer concentration in the membrane-forming solution is less than 20% by mass, the porosity of the hollow fiber membrane increases, and the durability tends to decrease. Polyvinylpyrrolidone (hereinafter sometimes abbreviated as PVP) added to the membrane-forming solution has a weight-average molecular weight of about 10,000 to 1,200,000, and preferably has a molecular weight of about 40,000 to 1,200,000. PVP is preferably used at a ratio of 5 to 50 mass% per 100 mass% of polysulfone-based polymer, more preferably at a ratio of 8 to 30 mass%. If the amount is less than 5 mass% relative to the polysulfone-based polymer, it is difficult to impart hydrophilicity to the hollow fiber membrane surface, and there is a concern that the affinity with water vapor may be reduced. If the amount exceeds 50 mass%, the strength of the hollow fiber membrane may be reduced, making it difficult to form the membrane. The hollow fiber membrane thus produced has a controlled phase separation behavior near the outer surface and is formed as a microporous membrane. By controlling the pore size of this microporous membrane to a size suitable for water vapor permeation, a gas separation membrane with excellent moisture permeability can be obtained. <Manufacturing method of gas separation membrane module> The method for producing the gas separation membrane module of the present invention is not particularly limited, but an example is as follows.

[0015] First, the hollow fiber membrane is cut to a required length, the required number of hollow fiber membranes are arranged in the same direction, and both ends of the hollow fiber membranes are fixed to each other to form a hollow fiber membrane sheet. As a method for fixing the hollow fiber membranes to each other, a tape, an adhesive, heat fusion, etc. can be used. Next, a laminate of hollow fiber membranes is obtained by stacking a plurality of hollow fiber membrane sheets so that the longitudinal direction of the hollow fiber membranes is in the same direction. At this time, the laminate may be stacked so that a space is generated between the stacked hollow fiber membrane sheets, or a flow path material may be provided between the stacked hollow fiber membrane sheets. In addition, the hollow fiber membrane laminate may be obtained in a state where the hollow fiber membrane sheet has a curved surface, or a hollow fiber membrane laminate may be obtained by bundling a plurality of hollow fiber membranes without forming a hollow fiber membrane sheet. Then, the obtained laminate of hollow fiber membranes is placed in a module case. Then, both ends are temporarily capped, and a potting agent is added to both ends of the hollow fiber membrane. At this time, a method of adding a potting agent while rotating the module with a centrifuge is preferable because the potting agent is uniformly filled. After the potting agent has solidified, both ends of the hollow fiber membrane are cut so that both ends are open, thereby obtaining a gas separation membrane module. <Possible applications of gas separation membrane modules> The gas separation membrane module of the present invention can be applied to hydrogen production equipment, carbon dioxide separation and capture equipment, exhaust gas separation and capture equipment, natural gas separation equipment, deodorization equipment, humidity control equipment, dehumidifiers, humidifiers, air conditioners such as dehumidifiers and humidifiers, fuel cell systems, desiccant air conditioning systems, and total heat exchangers. <Humidity control device> A humidity control device including a gas separation membrane module according to an embodiment of the present invention will be described. This humidity control device is a device that exchanges water vapor between two fluids via a hollow fiber membrane. For example, the humidity control device is a device that supplies air containing water or water vapor to the inside of a hollow fiber membrane and supplies air to the outside of the hollow fiber membrane, so that water vapor permeates to the outside of the hollow fiber membrane and humidifies the air supplied to the outside of the hollow fiber membrane. Also, for example, the humidity control device is a device that supplies dry air or a hygroscopic liquid such as a lithium chloride aqueous solution to the inside of a hollow fiber membrane and supplies air containing water vapor to the outside of the hollow fiber membrane, so that water vapor permeates the hollow fiber membrane and dehumidifies the air outside the hollow fiber membrane. <Air conditioner> An air conditioner including a gas separation membrane module according to an embodiment of the present invention will be described. The air conditioner is a device for controlling humidity in general homes, buildings, offices, factories, etc., such as a humidifier, dehumidifier, dehumidifier and air conditioner. The air conditioner of the present invention is a device in which the humidity of the taken-in outside air is adjusted by the above-mentioned gas separation membrane module. An example of a schematic diagram of an air conditioner is shown in Figure 2. When outside air is taken into the air conditioner 20, it passes through an air filter 21, a cooling coil 22, a heating coil 23, a gas separation membrane module 24, and a blower 25 in that order, and is then supplied to the room. The cooling coil 22 and the heating coil 23 operate depending on whether the room is to be humidified or dehumidified. Humidification or dehumidification may also be performed by adding a desiccant to the hollow fiber membrane of the gas separation membrane module 24. <Fuel cell system> A fuel cell system including a gas separation membrane module according to an embodiment of the present invention will be described below. This fuel cell system is applicable to, for example, fuel cell vehicles and household fuel cells. A fuel cell system includes at least the above-mentioned gas separation membrane module and a fuel cell. An example of this fuel cell system is, without particular limitation, a system in which air humidified using a gas separation membrane module and / or hydrogen are supplied to a fuel cell while supplying power. For example, a block diagram of power supply for a fuel cell vehicle having a gas separation membrane module 31 and a fuel cell 32 is shown in FIG. 3, and the obtained power is supplied to a motor 34 and a battery 35 via a power control unit 33. In addition, the gas separation membrane module 31 is built into a metal or resin housing in order to function as a humidifier, and the required specifications can be adjusted by freely changing the number of gas separation membrane modules installed depending on the purpose of use. <Total heat exchanger> A total heat exchanger including a gas separation membrane module according to an embodiment of the present invention will be described. A total heat exchanger is a device that performs ventilation by exchanging heat and water vapor between air from inside the room and air from outside the room, and is widely used in houses, buildings, and factories as an energy saving measure. The total heat exchanger of the present invention is a device that exchanges air heat and water vapor while suppressing pressure loss between the indoor air and the outdoor air by using the above-mentioned gas separation membrane module. A schematic diagram of a total heat exchanger is shown in Figure 4. A total heat exchanger 60 is provided with an outdoor intake port 62 for drawing in outdoor air and an outdoor outlet port 64 for exhausting indoor air on the outdoor side of the above-mentioned gas separation membrane module 61, while an outdoor air supply passage 63 for supplying outdoor air into the room and an indoor air discharge passage 65 for discharging indoor air to the outside are provided on the indoor side of the gas separation membrane module 61. In addition, a blower 66 for discharging indoor air is provided between the outdoor air outlet 62 and the gas separation membrane module 61. A blower 67 for taking in outdoor air is provided between the outdoor air supply passage 63 and the gas separation membrane module 61. By using the total heat exchanger 60, the outside air exchanges water vapor and heat with the exhausted indoor air via the gas separation membrane module 61 and is supplied to the room through the outside air supply passage 63, eliminating the need to add excess latent heat and sensible heat to the outside air. EXAMPLES

[0016] The present invention will now be described more specifically with reference to examples. However, the present invention should not be construed as being limited to the following examples. The evaluation methods used in the examples are explained in the following [1] to [6].

[0017] [1] Thickness, inner diameter and cross-sectional area of ​​hollow fiber membrane The hollow fiber membrane was cut in the membrane thickness direction with a single blade and set in a microwatcher (Keyence, VH-Z100). If the cross section of the hollow fiber membrane was crushed by cutting, it was cut again until it became approximately a perfect circle. The cross section of the hollow fiber membrane was observed with a 1000x lens, the membrane thickness width of the hollow fiber membrane was specified on the monitor screen on which the cross section was projected, and the numerical value displayed on the monitor screen was read. In addition, the inner diameter of the hollow fiber membrane was displayed on the monitor screen by specifying the width of the hollow part. Five arbitrary hollow fiber membranes present in the gas separation membrane module were extracted, and the same measurement was performed, and the average value was calculated to be the membrane thickness and inner diameter of the hollow fiber membrane.

[0018] [2] Measurement of the total cross-sectional area of ​​the hollow parts in a gas separation membrane module Ten random locations were selected from the end surface where the hollow fiber membranes in the gas separation membrane module were fixed. The selected locations were set in an image dimension measuring device (KEYENCE, IM-8030), and an image was taken with a 5x lens and imported into a computer. Next, the number of pixels of the scale bar showing a known length in the image was counted on the image processing software, and the length (mm) per pixel was calculated. The size of the imported image was 45 mm wide x 25 mm long. The contrast and brightness were adjusted to make the hollows in the hollow fiber membranes easier to see by making the hollows black and the hollow fiber membranes white, and then a threshold was set to obtain a binarized image for analysis. From the binarized image, the areas between the hollow fiber membranes that had been colored black were removed by region division to obtain an image in which only the hollows between the hollow fiber membranes were black, and the number of hollows in the image and the area of ​​each hollow were analyzed. The same measurement was performed on 10 selected locations, and the average cross-sectional area of ​​the hollows per area was calculated. The area of ​​one face of the end where the hollow fiber membrane was fixed was measured, and the total cross-sectional area of ​​the hollow parts in the gas separation membrane module was calculated from the product of this and the average cross-sectional area of ​​the hollow parts per area.

[0019] [3] Measurement of the longitudinal length of the hollow fiber membrane Ten hollow fiber membranes were randomly selected from the gas separation membrane module, and their lengths were measured. The average value was calculated and used as the longitudinal length of the hollow fiber membranes.

[0020] [4] Conduction pressure loss test The pressure loss of the gas separation membrane module was measured as follows. First, pipes were connected to the two open sides of the hollow fiber membrane of the gas separation membrane module. Dry air at a temperature of 35°C was flowed from one of the connected pipes to the inside of the hollow fiber membrane, and the air was exhausted from the other pipe. Manostar gauges were connected to the two pipes to determine the pressure loss caused by the gas separation membrane module, and the evaluation was performed according to the following criteria. A (Good): Pressure loss (Pa) and dry air flow rate (m 3 / hr) ratio (F / P) is 1.0 or higher. B (OK): Pressure loss (Pa) and dry air flow rate (m 3 / hr) ratio (F / P) is 0.1 or more and less than 1.0. C (not possible): Pressure loss (Pa) and dry air flow rate (m 3 / hr) ratio (F / P) is less than 0.1.

[0021] [5] Measurement of moisture permeability The moisture permeability was measured as follows: First, the gas membrane module was connected as shown in FIG. In Fig. 6, 70 is an air flow meter, 71 is a dry air inlet, 72 is a humidity-conditioned air outlet, 73 is a gas separation membrane module, 74 is a dry air outlet, 75 is a temperature and humidity measurement point, 76 is a humidity-conditioned air inlet, and 77 is a humidification container. Humidity-conditioned air whose humidity has been adjusted at 77 is allowed to flow into 76, and dry air from 71 is allowed to flow into 73, and the permeated water vapor flows out from 74. By measuring the relative humidity and temperature at 75, the moisture permeation amount per hour flowing out from 74 was calculated. Using a gas separation membrane module, dry air at a temperature of 35°C was passed through the area inside the hollow fiber membrane, and conditioned air at a temperature of 25°C and a relative humidity of 70% was passed through the area outside the hollow fiber membrane in a single cross-flow. The moisture permeability of the gas separation membrane module per hour was measured and evaluated according to the following criteria. A (good): Water vapor transmission rate (g / hr) is 800 or more. B (Acceptable): Water vapor transmission rate (g / hr) is 420 or more and less than 800. C (unacceptable): Water vapor transmission rate (g / hr) is less than 420.

[0022] [6] Durability evaluation using intermittent air testing Durability evaluation by air intermittent test was measured as follows. First, the gas separation membrane module was connected as shown in Figure 6. Water vapor was flowed on the outside of the hollow fiber membrane of the gas separation membrane module, and the temperature of the gas separation membrane module body was maintained at 95°C or higher. One side of the inside of the hollow fiber membrane of the gas separation membrane module was sealed with a pressure sensor, and dry air was applied intermittently from the other side (ON: 200 kPa for 10 seconds, OFF: 0 kPa for 5 seconds, one cycle for 15 seconds). At this time, when the pressure sensor in the ON state became less than 150 kPa, it was determined that damage had occurred to the membrane, and the test was stopped. Durability was evaluated according to the following criteria based on the number of cycles from the start of the test to the end of the test. A (Good): The pressure sensor did not drop below 150 kPa even after 100,000 cycles. B (Acceptable): The pressure sensor did not drop below 150 kPa even after 10,000 cycles. C (Unacceptable): The pressure sensor reached 150 kPa or more after less than 10,000 cycles.

[0023] Example 1 A total of 100% by mass of 28% polysulfone (Solvay's "Udel" P-3500), 3.0% by mass of polyvinylpyrrolidone (BASF's K30), 68% by mass of N,N-dimethylacetamide, and 1% by mass of water were heated and dissolved to prepare a membrane-forming stock solution. A total of 100% by mass of a solution of 30% by mass of N,N-dimethylacetamide and 70% by mass of water was used as the core liquid.

[0024] The membrane-forming solution was sent to the spinneret section, discharged from the outer tube of the orifice-type double-tube spinneret, and the core solution was discharged from the inner tube. The discharged membrane-forming solution passed through a humidity-controlled dry zone atmosphere, then led to a coagulation bath and passed through a water washing process at 40°C. The resulting wet hollow fiber membrane was wound into a bundle. The wound bundle of hollow fiber membranes was dried in a dry heat dryer at 100°C for 24 hours to obtain a dry hollow fiber membrane. The hollow fiber membrane had an inner diameter of 0.8 mm and a membrane thickness of 0.1 mm.

[0025] The total cross-sectional area of ​​the hollow fiber membrane is 0.09m2 in three significant digits, and is contained in a rectangular stainless steel module case with internal dimensions of 0.75m in length, 0.4m in width, and 0.45m in depth. 2 To obtain a gas separation membrane module A, 180,000 hollow fiber membranes were packed, both ends of the hollow fiber membranes were fixed to the ends of a rectangular module case with potting material, and parts of the ends of the potting material were cut to open both ends of the hollow fiber membranes, thereby forming a gas separation membrane module A. Here, both ends of the hollow fiber membranes were fixed in the length direction of the rectangular module case, and the length of the hollow fiber membrane in the gas separation membrane module A was 0.4 m. The configuration and evaluation results of the gas separation membrane module A are shown in Table 1. For the obtained gas separation membrane module A, the results of the conduction pressure loss test, moisture permeation measurement, and durability evaluation by intermittent air test were all B (pass). A gas separation membrane module was obtained that was not only excellent in suppressing pressure loss, but also had excellent moisture permeation and durability.

[0026] Example 2 The total cross-sectional area of ​​the hollow fiber membrane is 0.25m in three significant digits inside a rectangular stainless steel module case with internal dimensions of 0.75m in length, 0.75m in width, and 0.68m in depth. 2 A gas separation membrane module B was obtained in the same manner as in Example 1, except that 500,000 hollow fiber membranes were packed so that the total number of hollow fiber membranes was 1.0 to 1.0 mm. The length of the hollow fiber membrane in the gas separation membrane module B was 0.6 m. The configuration and evaluation results of the gas separation membrane module B are shown in Table 1. For the obtained gas separation membrane module B, the results of the conduction pressure loss test and the moisture permeability measurement were both A (good), and the durability evaluation in the intermittent air test was B (passable). The large total cross-sectional area of ​​the hollow parts suppresses pressure loss, and the long hollow fiber membrane allows sufficient permeation of water vapor from the humidified air to the dry air, resulting in a gas separation membrane module with excellent moisture permeability.

[0027] Example 3 A hollow fiber membrane was obtained in the same manner as in Example 1, except that the spinneret was changed. The inner diameter of the obtained hollow fiber membrane was 0.65 mm, and the thickness was 0.1 mm. The total cross-sectional area of ​​the hollow part of the hollow fiber membrane was 0.06 m2 in three significant digits in a rectangular module case made of stainless steel with inner dimensions of 0.75 m in length, 0.4 m in width, and 0.5 m in depth. 2 A gas separation membrane module C was obtained in the same manner as in Example 1, except that 180,000 hollow fiber membranes were packed so that the total number of hollow fiber membranes was 180,000. The length of the hollow fiber membrane in the gas separation membrane module C was 0.4 m. The configuration and evaluation results of the gas separation membrane module C are shown in Table 1. For the obtained gas separation membrane module C, the results of both the conduction pressure loss test and the moisture permeability measurement were B (passable), and the durability evaluation in the intermittent air test was A (good). Not only was the pressure loss suppression and moisture permeability excellent, but the gas separation membrane module obtained was also particularly durable due to the reduced inner diameter of the hollow fiber membrane.

[0028] Example 4 The total cross-sectional area of ​​the hollow fiber membrane is 0.16m2 in three significant digits, and is contained in a rectangular stainless steel module case with internal dimensions of 0.9m length, 0.45m width, and 0.35m depth. 2 A gas separation membrane module D was obtained in the same manner as in Example 2, except that 483,000 hollow fiber membranes were packed so that the total number of hollow fiber membranes was 483,000. The length of the hollow fiber membrane in the gas separation membrane module D was 0.3 m. The configuration and evaluation results of the gas separation membrane module D are shown in Table 1. For the obtained gas separation membrane module D, the results of the conduction pressure loss test, the moisture permeation amount measurement, and the durability evaluation by the intermittent air test were all A (good). The total cross-sectional area of ​​the hollow portion was obtained.

[0029] Example 5 Except for changing the spinneret part, a hollow fiber membrane was obtained in the same manner as in Example 1. The obtained hollow fiber membrane had an inner diameter of 1.20 mm and a membrane thickness of 0.15 mm.

[0030] The total cross-sectional area of ​​the hollow fiber membrane is 0.16m2 in three significant digits, and is contained in a rectangular stainless steel module case with internal dimensions of 0.9m length, 0.45m width, and 0.25m depth. 2 To obtain a gas separation membrane module E, 142,000 hollow fiber membranes were packed, both ends of the hollow fiber membranes were fixed to the ends of the rectangular module case with potting material, and part of the end of the potting material was cut to open both ends of the hollow fiber membranes, thereby producing a gas separation membrane module E. Here, both ends of the hollow fiber membranes were fixed in the length direction of the rectangular module case, and the length of the hollow fiber membrane in the gas separation membrane module E was 0.2 m. The configuration and evaluation results of the gas separation membrane module E are shown in Table 1. For the obtained gas separation membrane module E, the result of the conduction pressure loss test was A (good), and the results of the moisture permeability measurement and the durability evaluation in the intermittent air test were both B (passable). Because the total cross-sectional area of ​​the hollow part is large, a gas separation membrane module that is particularly excellent at suppressing pressure loss was obtained.

[0031] Comparative Example 1 The total cross-sectional area of ​​the hollow fiber membrane is 0.02 m with three significant digits. 2 A gas separation membrane module F was obtained in the same manner as in Example 2, except that 60,000 hollow fiber membranes were packed so that the total length of the hollow fiber membranes in the gas separation membrane module F was 0.4 m. The configuration and evaluation results of the gas separation membrane module F are shown in Table 1. For the obtained gas separation membrane module F, the results of both the conduction pressure loss test and the moisture permeability measurement were C (unacceptable), and the durability evaluation in the intermittent air test was A (good). The small inner diameter of the hollow fiber membrane makes the module particularly durable, but the small total cross-sectional area of ​​the hollow portion makes the module poor in pressure loss suppression and moisture permeability.

[0032] [Table 1] [Explanation of symbols]

[0033] 20:Air conditioner 21: Air filter 22: Cooling coil 23: Heating coil 24: Gas separation membrane module 25: Blower 31: Gas separation membrane module 32: Fuel cell 33: Power control unit 34: Motor 35: Battery 60: Total heat exchanger 61: Gas separation membrane module 62: Outdoor intake port 63: Outside air supply passage 64:Outdoor air outlet 65: Indoor air release passage 66: Blower 67: Blower 70: Air flow meter 71: Dry air inlet 72: Humidity-controlled air outlet 73: Gas separation membrane module 74: Dry air outlet 75: Temperature and humidity measurement points 76: Humidity control air inlet 77: Humidification container 80: Regulator 81: Dry air inlet 82: Water vapor 83: Water vapor inlet 84: Water vapor outlet 85: Pressure gauge 86: Hollow fiber membrane 87: Gas separation membrane module 88: Solenoid valve 89: Impulse Unit 100: Gas separation membrane module 101: Hollow fiber membrane 110: Rectangular module case 120: Potting material 121: Inlet surface for first fluid 122: Outlet surface of the first fluid 123: Inlet surface for second fluid 124: outlet surface of second fluid 125: First fluid supply pipe 126: First fluid discharge pipe 127: Second fluid supply pipe 128: Second fluid outlet pipe

Claims

1. A gas separation membrane module containing a plurality of hollow fiber membranes arranged in one direction in a module case, the hollow fiber membranes are open at both ends of the module case, gaps between the hollow fiber membranes and between the hollow fiber membranes and the module case are sealed with a potting material, the inner diameter of the hollow fiber membranes is 0.6 mm or more and 6 mm or less, and the sum of the cross-sectional areas of the hollow parts of the hollow fiber membranes in a cross section obtained by cutting the module case perpendicularly to the longitudinal direction of the hollow fiber membranes is 0.04 m ２ Over 25.0m ２ A gas separation membrane module as shown below.

2. 2. The gas separation membrane module according to claim 1, wherein the hollow fiber membrane has an inner diameter of 0.6 mm or more and 3 mm or less.

3. 2. The gas separation membrane module according to claim 1, wherein the length of the hollow fiber membrane in the longitudinal direction is 0.1 m or more and 5.0 m or less.

4. The inner diameter d (mm) of the hollow fiber membrane, the length L (m) of the hollow fiber membrane in the longitudinal direction, and the sum A (m ２ 2. The gas separation membrane module according to claim 1, wherein the above-mentioned relationship satisfies the following formula [1]: 0.2<Ad ２ / L<10.0 [1] Formula

5. 2. The gas separation membrane module according to claim 1, wherein the hollow fiber membrane comprises a polysulfone-based polymer and polyvinylpyrrolidone.

6. 2. A method for operating a gas separation membrane module according to claim 1, comprising the steps of: calculating a pressure loss P (Pa) calculated from a pressure difference before and after passing through the gas separation membrane module and a flow rate F (m ３ / hr) (F / P) is 0.1 or more.

7. A humidity control device comprising the gas separation membrane module according to claim 5.

8. An air conditioner comprising the gas separation membrane module according to claim 1.

9. A total heat exchanger comprising the gas separation membrane module according to claim 1.

10. A fuel cell system comprising the gas separation membrane module according to claim 1.

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