Gas separation system and gas separation method using the same

Abstract

The objective is to provide a means to suppress the deterioration of the gas separation performance of a gas separation membrane in a gas separation system that uses a gas separation membrane containing a glassy polymer. [Solution] A gas separation system comprising: a first gas separation membrane unit having a first gas separation membrane, a first gas supply port and a first non-permeable gas outlet disposed on one side of the first gas separation membrane, and a first permeable gas outlet disposed on the other side of the first gas separation membrane; and a first gas pumping means connected to the first permeable gas outlet for permeating gas from one side to the other side of the first gas separation membrane, wherein the first gas separation membrane includes a first support layer and a first separation function layer disposed on the first support layer, the first separation function layer includes a glassy polymer, and the gas pumping means for permeating gas from one side to the other side of the first gas separation membrane is not provided on one side of the first gas separation membrane.

Description

Technical Field

[0001] The present invention relates to a gas separation system and a gas separation method using the same.

Background Art

[0002] In recent years, as part of greenhouse gas reduction, development of technologies for separating and recovering CO2 from exhaust gases emitted from the atmosphere, thermal power plants, etc. has been underway. For example, in Non-Patent Document 1, as a new technology for so-called DAC (direct air capture) that directly recovers CO2 from air, a multi-stage membrane separation process using a gas separation membrane has been proposed. In the multi-stage membrane separation process, a plurality of units having a gas separation membrane including a siloxane nanomembrane classified as a rubbery polymer are connected in series, and the process is driven by a vacuum pump installed on the downstream side of each unit and a blower installed on the upstream side of the first unit.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, according to the study by the present inventors, it has been found that when a gas separation membrane containing a glassy polymer is applied to the multi-stage membrane separation process, the gas separation performance of the gas separation membrane may deteriorate.

[0005] Therefore, the object of the present invention is to provide a means that can suppress the deterioration of the gas separation performance of a gas separation membrane in a gas separation system using a gas separation membrane containing a glassy polymer. [Means for solving the problem]

[0006] The inventors of the present invention conducted intensive studies in view of the above problems. In the process, they discovered that the above problems could be solved by providing a gas pumping means for permeating gas through a gas separation membrane containing a glassy polymer only downstream of the gas separation membrane relative to the gas flow, in a gas separation system using such a membrane, and thus completed the present invention.

[0007] In other words, a gas separation system according to one embodiment of the present invention comprises a first gas separation membrane unit having a first gas separation membrane, a first gas supply port and a first non-permeable gas outlet disposed on one side of the first gas separation membrane, and a first permeable gas outlet disposed on the other side of the first gas separation membrane, and a first gas pumping means connected to the first permeable gas outlet for permeating gas from one side to the other side of the first gas separation membrane. The first gas separation membrane includes a first support layer and a first separation function layer disposed on the first support layer. The first separation function layer includes a glassy polymer. Furthermore, in this gas separation system, one side of the first gas separation membrane does not have a gas pumping means for permeating gas from one side to the other side of the first gas separation membrane. [Effects of the Invention]

[0008] According to the present invention, in a gas separation system using a gas separation membrane containing a glassy polymer, it is possible to suppress the deterioration of the gas separation performance of the gas separation membrane. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view showing an example of the configuration of a gas separation system according to one embodiment of the present invention. [Figure 2]This is a cross-sectional view showing an example of the configuration of the first gas separation membrane 11 shown in Figure 1. [Figure 3] A cross-sectional view showing an example of the configuration of a gas separation system according to another embodiment of the present invention. [Figure 4] A cross-sectional view showing an example of the configuration of a gas separation system according to another embodiment of the present invention. [Modes for carrying out the invention]

[0010] A gas separation system according to one embodiment of the present invention comprises a first gas separation membrane unit having a first gas separation membrane, a first gas supply port and a first non-permeable gas outlet disposed on one side of the first gas separation membrane, and a first permeable gas outlet disposed on the other side of the first gas separation membrane, and a first gas pumping means connected to the first permeable gas outlet for permeating gas from one side to the other side of the first gas separation membrane. The first gas separation membrane includes a first support layer and a first separation function layer disposed on the first support layer. The first separation function layer contains a glassy polymer. Furthermore, in this gas separation system, one side of the first gas separation membrane does not have a gas pumping means for permeating gas from one side to the other side of the first gas separation membrane. According to this embodiment of the gas separation system, in a gas separation system using a gas separation membrane containing a glassy polymer, it is possible to suppress a decrease in the gas separation performance of the gas separation membrane.

[0011] In this gas separation system, the gas pumping means for permeating gas from one side of the first gas separation membrane to the other side is located only on the other side of the first gas separation membrane (the downstream side of the gas flow). With this configuration, unnecessary kinetic energy is not imparted to the gas present on one side of the first gas separation membrane, and when the gas comes into contact with the glassy polymer contained in the first separation functional layer of the first gas separation membrane, the gas dissolves more easily into the glassy polymer. This improves the gas permeability of the first gas separation membrane and further improves the gas separation selectivity of the first gas separation membrane. As a result, the gas separation performance of the gas separation system is improved.

[0012] The embodiments of the present invention will be described below with reference to the attached drawings, but the technical scope of the present invention is not limited to the following forms. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant explanations are omitted. Also, the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios. In this specification, "X~Y" indicating a range means "X or more and Y or less". Unless otherwise specified, operations and measurements of physical properties, etc., are performed under room temperature (20~25℃) / relative humidity 40~50% conditions.

[0013] <Gas Separation System> Figure 1 is a cross-sectional view showing an example of the configuration of a gas separation system 1 according to one embodiment of the present invention. The gas separation system 1 includes a first gas separation membrane unit 10 and a first gas pumping means 15. The internal space of the first gas separation membrane unit 10 is divided into two parts, a first part 10a and a second part 10b, by a first gas separation membrane 11. One surface 11a of the first gas separation membrane 11 faces the first part 10a, and the other surface 11b of the first gas separation membrane 11 faces the second part 10b. The first gas separation membrane unit 10 has a first gas supply port 12 and a first impermeable gas outlet 13 on the first part 10a side. The first gas supply port 12 is an opening for taking in a raw material gas (e.g., air) containing the gas to be separated (e.g., CO2) into the first gas separation membrane unit 10. The first non-permeable gas outlet 13 is an opening for discharging gas that does not permeate the first gas separation membrane 11 to the outside of the first gas separation membrane unit 10. The first gas separation membrane unit 10 has a first permeable gas outlet 14 on the second portion 10b side. The first permeable gas outlet 14 is an opening for discharging permeable gas that has permeated the first separation membrane 11 to the outside of the first gas separation membrane unit 10. The first permeable gas outlet 14 is connected to the first gas pumping means 15. The first gas pumping means 15 lowers the pressure in the second portion 10b. As a result, the pressure in the first portion 10a becomes relatively high and the pressure in the second portion 10b becomes relatively low through the first separation membrane 11. This pressure difference causes gas to permeate from one side of the first gas separation membrane to the other side.

[0014] [First gas separation membrane unit 10] The first gas separation membrane unit 10 includes a first gas separation membrane 11, a first gas supply port 12, a first non-permeable gas outlet 13, and a first permeable gas outlet 14. The size, shape, material, etc., of the first gas separation membrane unit 10 itself are not particularly limited, as long as the first gas separation membrane 11 can partition the first part 10a and the second part 10b.

[0015] (First gas separation membrane 11) Figure 2 is a cross-sectional view showing an example of the configuration of the first gas separation membrane 11 shown in Figure 1. The first gas separation membrane 11 is composed of three layers: a first support layer 111, a first intermediate layer 112 covering one main surface of the first support layer 111, and a first separation function layer 113 covering the surface of the first intermediate layer 112 opposite to the surface facing the first support layer 111. In the first gas separation membrane 11 shown in Figure 2, the first separation function layer 113 is located on the outermost surface (constituting the outermost layer). The first support layer 111 has a plurality of pores 111a that communicate from one surface 11a to the other surface 11b of the first gas separation membrane 11. With this configuration, gas that reaches one surface 11a of the first gas separation membrane 11 dissolves in the first separation functional layer 113, diffuses through the interior of the first separation functional layer 113, reaches the interface between the first separation functional layer 113 and the first intermediate layer 112, and desorbs from the first separation functional layer 113. Subsequently, the gas permeates through the first intermediate layer 112, passes through the pores 111a of the first support layer 111, and flows out from the other surface 11b of the first gas separation membrane 11 to the second portion 10b. The solubility and diffusivity of gas in the first separation functional layer differ depending on the type of gas. These differences are utilized to achieve the gas separation performance of the first gas separation membrane 11.

[0016] The material constituting the first support layer 111 may be either an organic material or an inorganic material, but an organic material is preferred. Examples of the organic material include various resin materials such as polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). These can be used alone or in combination of two or more. When combining two or more kinds of various resin materials, it may be a mixture made into a uniform material, or it may have a structure with two or more layers with the same kind of resin material as one layer. Preferred materials constituting the first support layer 111 include PTFE and PP.

[0017] From the viewpoints of imparting mechanical strength and high gas permeability, the thickness of the first support layer 111 is preferably 1 μm or more and 3000 μm or less, more preferably 5 μm or more and 500 μm or less, and even more preferably 5 μm or more and 150 μm or less. The thickness of the first support layer 111 can be measured and calculated as follows. First, at an arbitrary position of the first gas separation membrane 11, the first gas separation membrane 11 is cut along the thickness direction. Next, the obtained cut surface is observed by SEM, TEM, etc., and the distance from one surface to the other surface of the first support layer 111 is measured at four locations. Then, the average value of the distances at those four locations is calculated and taken as the thickness of the first support layer 111.

[0018] In the first support layer 111, as long as the first support layer 111 has sufficient gas permeability, its average pore diameter and porosity are not particularly limited. The average pore diameter (diameter) of the first support layer 111 may be, for example, 0.01 μm or more, 0.02 μm or more, 0.03 μm or more, or 0.05 μm or more, and may also be 0.5 μm or less, 0.3 μm or less, or 0.1 μm or less. That is, the average pore diameter of the first support layer 111 is, for example, 0.01 to 0.3 μm, and more preferably 0.02 to 0.1 μm. Further, the porosity of the first support layer 111 is preferably 40% or more and 80% or less. The average pore diameter of the first support layer 111 can be measured and calculated in the following manner. Depending on whether the pores of the first support layer 111 are slit-shaped or through-holes, the surface or cross-section of the first support layer 111 is observed by SEM, TEM, etc., respectively, and among the distances between any two points on the contour line of the pores (observation surface) of the first support layer 111, the maximum distance is measured. Then, the average value of the pores observed in several to dozens of fields of view is calculated and taken as the average pore diameter. Also, the porosity of the first support layer 111 can be measured using a general immersion method.

[0019] The first intermediate layer 112 is disposed between the first support layer 111 and the first separation functional layer 113. Note that the "intermediate layer" is also referred to as the "gutter layer". The first intermediate layer 112 has a function of suppressing the excessive penetration of the composition when applying the composition for forming the first separation functional layer 113 onto the first support layer 111. Therefore, by providing the first intermediate layer 112, the first separation functional layer 113 can be favorably formed on the first support layer 111. Further, the first intermediate layer 112 has a function of suppressing the leakage of gas (raw material gas) from the defect even when a defect occurs in the first separation functional layer 113.

[0020] The material constituting the first intermediate layer 112 is not particularly limited, and a resin having gas permeability can be appropriately employed. Examples of such resins include silicone resins, amorphous fluororesins, and the like. The first intermediate layer 112 may have a single-layer structure or a multi-layer structure.

[0021] The first intermediate layer 112 is an optional layer in the first gas separation membrane 11 according to this embodiment. Therefore, the first gas separation membrane 11 does not have to have the first intermediate layer 112, in which case the first separation function layer 113 may be directly provided on the surface of the first support layer 111.

[0022] The first separation functional layer 113 is a layer in the first gas separation membrane 11 that is directly involved in gas separation. Since the first separation functional layer 113 is responsible for gas dissolution and desorption, it is preferable that it is located on the outermost surface (constituting the outermost layer) on one surface 11a and the other surface 11b of the first gas separation membrane 11 so that it can directly contact the gas. However, if sufficient gas dissolution and desorption can be achieved, another layer with high gas permeability (for example, a protective layer) may be provided on the first separation functional layer 113.

[0023] In the first gas separation membrane 11 according to this embodiment, the first separation functional layer 113 contains a glassy polymer. The glassy polymer is an amorphous solid in a thermodynamically non-equilibrium metastable state, in which the movement of polymer chains is very slow, and all parts exhibit a glassy state in which only thermal vibration occurs at their positions. The glassy polymer is not particularly limited, and conventionally known materials can be suitably used. Examples of such materials include organic polymer materials such as polymers of intrinsic microporosity (PIM), polytrimethylsilylpropyne (PTMSP), polyimide, and silicone. These can be used individually or in combination of two or more. Among these, it is preferable to use polyimides such as aromatic polyimide and fluorine-containing polyimide, and intrinsic microporous polymers such as PIM-1 and PIM-7, with PIM-1 being more preferable. PIM-1 has, for example, a constituent unit represented by the following formula (I).

[0024] [ka]

[0025] In equation (I) above, R 1 R is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. 2 R is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cyano group. 3 R is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cyano group. Multiple R in the same structural unit. 1 , R 2 and R 3 These may be the same or different.

[0026] As shown in formula (I), PIM-1 is a polymer that has a rigid ladder-like structure and a bent skeleton, and can form micropores within its layers. Therefore, the first separation functional layer 113 containing PIM-1 has excellent gas permeability.

[0027] The glassy polymer described above may have the property of being highly permeable to CO2 and / or O2 compared to N2. Therefore, the glassy polymer can selectively permeate CO2 from a mixed gas containing CO2 and N2. Furthermore, the glassy polymer can selectively permeate O2 from a mixed gas containing O2 and N2. In other words, the first gas separation membrane 11 may be a CO2 separation membrane that selectively permeates CO2 from a mixed gas (raw material gas) containing CO2 and N2. Alternatively, the first gas separation membrane 11 may be an O2 separation membrane that selectively permeates O2 from a mixed gas (raw material gas) containing O2 and N2. Here, the mixed gas containing CO2 and N2 and the mixed gas containing O2 and N2 may be air. By using such a configuration, separation of CO2 and / or O2 becomes possible.

[0028] The first separation functional layer 113 may further contain inorganic particles in addition to the glassy polymer. Examples of materials constituting the inorganic particles include ceramic materials such as silica and zeolites. In the case of silica particles, examples include (1) fumed silica nanoparticles synthesized by a gas-phase method (dry method) in which silicon-containing raw materials such as silicon tetrachloride are burned in an oxygen and hydrogen flame to hydrolyze them, and (2) colloidal silica nanoparticles synthesized by a liquid-phase method (wet method), such as the water glass method in which sodium is removed by ion exchange of sodium silicate and then heated and aged, or the alkoxide hydrolysis method in which alkoxides such as tetraethoxysilane are hydrolyzed and polycondensed in an alcohol solvent.

[0029] From the viewpoint of forming a first separation functional layer 113 with superior gas permeability and gas selectivity by forming fine pores between the inorganic particles and between the inorganic particles and the glassy polymer, the average particle diameter (D50) of the inorganic particles is preferably 1 nm to 20 nm, more preferably 1 nm to 10 nm, and even more preferably 1 nm to 5 nm. The particle diameter of the inorganic particles can be measured and calculated in the following manner. First, the first gas separation membrane 11 is cut along the thickness direction at an arbitrary position on the first gas separation membrane 11. Next, the obtained cut surface is observed with an optical microscope, scanning electron microscope (SEM), or transmission electron microscope (TEM), and if necessary, further observed with energy-dispersive X-ray analysis (EDS) or X-ray photoelectron spectroscopy (XPS), and the maximum distance between any two points on the contour line for four particles is measured. Then, the average value of the maximum distance of the four particles is calculated and used as the average particle diameter of the particles.

[0030] From the viewpoint of forming a first separation functional layer 113 with excellent gas permeability and gas selectivity by forming fine pores between inorganic particles having sterically hindrance-inducing modifying groups and a glassy polymer, it is preferable that the inorganic particles have modifying groups on their surface. Such inorganic particles having modifying groups can be obtained, for example, by surface-modifying inorganic particles with a silane coupling agent.

[0031] From the viewpoint of improving gas permeability and gas selectivity, the first separation functional layer 113 preferably contains a glassy polymer and the inorganic particles described above. From the viewpoint of improving gas permeability and gas selectivity, the inorganic particle content in the first separation functional layer 113 is preferably 10% by mass or more and 80% by mass or less, and more preferably 20% by mass or more and 60% by mass or less. The inorganic particle content in the first separation functional layer 113 can be measured and calculated in the following manner. First, a fixed amount (1g) of the first separation functional layer 113 is taken and its mass is measured. Next, the glassy polymer is removed from the first separation functional layer 113 by combustion or the like, and the mass of the residual inorganic particles is measured. Then, the ratio of the mass of the inorganic particles to the mass of the first separation functional layer 113 is calculated to determine the inorganic particle content in the first separation functional layer 113.

[0032] From the viewpoint of improving gas permeability, the thickness of the first separation functional layer 113 is preferably 500 nm or less, and more preferably 400 nm or less. Furthermore, from the viewpoint of the mechanical strength of the first separation functional layer 113, the thickness of the first separation functional layer 113 is preferably 5 nm or more, and more preferably 10 nm or more. In one embodiment, the thickness of the first separation functional layer 113 is preferably 5 nm or more and 500 nm or less, and more preferably 10 nm or more and 400 nm or less. The thickness of the first separation functional layer 113 can be measured and calculated in the following manner. The cross-section of the first gas separation membrane 11 when it is cut in the thickness direction is observed with an optical microscope, SEM or TEM, etc., and the thickness is measured at four locations. Then, the average value of the thicknesses at these four locations is calculated and taken as the thickness of the first separation functional layer 113.

[0033] (First gas supply port 12) The first gas supply port 12 is an opening provided for taking in raw material gas into the first gas separation membrane unit 10. The first gas supply port 12 only needs to be provided at least one location on the first portion 10a side of the first gas separation membrane unit 10, and there are no particular restrictions on its number, location, size, etc. When the raw material gas supply source and the first gas separation membrane unit are far apart, the raw material gas supply source and the first gas supply port 12 may be connected by a gas supply line.

[0034] (First impermeable gas outlet 13) The first impermeable gas outlet 13 is an opening provided to discharge from the first gas separation membrane unit 10 gas that has not permeated the first gas separation membrane 11 (impermeable gas) from the first gas separation membrane unit 10. The first impermeable gas outlet 13 only needs to be provided at least one location on the first portion 10a side of the first gas separation membrane unit 10, and there are no particular restrictions on its number, position, size, etc. In addition, an impermeable gas discharge means (e.g., a vacuum pump) may be arranged outside the first gas separation membrane unit 10 to facilitate the discharge of impermeable gas from the first gas separation membrane unit 10. The impermeable gas discharge means may be connected to the first impermeable gas outlet 13 via a gas supply line.

[0035] (First permeable gas outlet 14) The first permeate gas outlet 14 is an opening provided to discharge the gas that has permeated through the first gas separation membrane 11 (permeate gas) from the first gas separation membrane unit 10. The first permeate gas outlet 14 only needs to be provided at least one location on the second portion 10b side of the first gas separation membrane unit 10, and there are no particular restrictions on its number, position, size, etc. The first permeate gas outlet 14 is connected to the first gas pumping means 15, which will be described later.

[0036] [First gas pumping means 15] The first gas supply means 15 is connected to the first permeate gas outlet 14. The first gas supply means 15 reduces the air pressure in the second portion 10b of the first gas separation membrane unit 10, thereby allowing gas to permeate from one surface 11a to the other surface 11b of the first gas separation membrane 11. The first gas supply means 15 is not particularly limited as long as it can reduce the air pressure in the second portion 10b, but examples include vacuum pumps (water-sealed vacuum pumps, liquid-sealed vacuum pumps, oil-sealed rotary vacuum pumps, dry vacuum pumps), compressors, blowers, etc. The first gas supply means 15 is used such that the air pressure decreases upstream of the first gas supply means 15 and increases downstream of it.

[0037] Figure 3 is a cross-sectional view showing an example of the configuration of a gas separation system according to another embodiment of the present invention. In order to avoid repetition of explanations, detailed descriptions of configurations similar to those of the gas separation system 1 described in the above embodiment will be omitted below.

[0038] In the gas separation system 1A shown in Figure 3, a second gas separation membrane unit 20 is further located downstream of the first gas separation membrane unit 10 and the first gas pumping means 15. The second gas separation membrane unit 20 has a second gas separation membrane 21, a second gas supply port 22 and a second impermeable gas outlet 23 located on one side 21a of the second gas separation membrane 21, and a second permeable gas outlet 24 located on the other side 21b of the second gas separation membrane 21. The first gas pumping means 15 is connected to the second gas supply port 22. As mentioned above, the first gas pumping means 15 is used such that the air pressure decreases upstream of the first gas pumping means 15 and increases downstream of the first gas pumping means 15. Here, the second gas separation membrane unit 20, the second gas separation membrane 21, the second gas supply port 22, the second impermeable gas outlet 23, and the second permeable gas outlet 24 have the same configuration as the first gas separation membrane unit 10, the first gas separation membrane 11, the first gas supply port 12, the first impermeable gas outlet 13, and the first permeable gas outlet 14, respectively. With this configuration, the permeable gas that has permeated through the first gas separation membrane 11 will further permeate through the second gas separation membrane 21. This makes it possible to increase the purity of the gas to be separated (e.g., CO2). Furthermore, as shown in the gas separation system 1A in Figure 3, it is also possible to further increase the purity of the gas to be separated (e.g., CO2) by providing a second gas pumping means 25 and a third gas separation membrane unit 30 downstream of the second gas separation membrane unit 20 and increasing the number of separations by the gas separation membrane. The number of gas pumping means and gas separation membrane units can be appropriately set by those skilled in the art depending on the type and purity of the gas to be separated.

[0039] Figure 4 is a cross-sectional view showing an example of the configuration of a gas separation system according to another embodiment of the present invention. The gas separation system 1B shown in Figure 4 further includes a first gas cooling means 16 between the first gas pumping means 15 and the second gas supply port 22 for lowering the temperature of the gas pumped by the first gas pumping means 15. The gas that has passed through the first gas pumping means 15 may reach a state of elevated temperature because it is pressurized by the first gas pumping means 15. The glassy polymer contained in the second gas separation membrane 21 has the property that the solubility of the gas decreases as the gas temperature rises. Therefore, by lowering the gas temperature with the first gas cooling means 16, the deterioration of the gas separation performance of the second gas separation membrane 21 is suppressed, and further purification of the target gas (e.g., CO2) becomes possible. The first gas cooling means 16 is not particularly limited, and conventionally known heat exchangers can be appropriately adopted. Furthermore, if a second gas pumping means 25 and a third gas separation membrane unit 30 are further provided downstream of the second gas separation membrane unit 20, as in the gas separation system 1A shown in Figure 3, it is preferable to provide a second gas cooling means 26 similar to the first gas cooling means 16 between the second gas pumping means 25 and the third gas supply port 32. The gas temperature after passing through the first gas cooling means 16 is not particularly limited, but is, for example, 40°C or less, preferably 30°C or less, more preferably 25°C or less, even more preferably 20°C or less, and particularly preferably 0°C or more and 20°C or less.

[0040] <Gas separation method> According to the present invention, a gas separation method using the above-described gas separation system is also provided. This gas separation method comprises supplying a raw material gas to the first gas supply port.

[0041] The raw material gas is a mixed gas containing the gas to be separated and other gases. The raw material gas is not particularly limited, but may be a mixed gas containing CO2 and N2, or a mixed gas containing O2 and N2. More specifically, the raw material gas may be air, or exhaust gas emitted from an internal combustion engine.

[0042] When supplying the above-mentioned raw material gas to the above-mentioned first gas supply port, the temperature of the raw material gas is preferably low from the viewpoint of improving the gas separation performance of the gas separation membrane. Specifically, the temperature is, for example, 40°C or lower, preferably 30°C or lower, more preferably 25°C or lower, even more preferably 20°C or lower, and particularly preferably 0°C or higher and 20°C or lower.

[0043] Furthermore, the following embodiments are also included in the scope of the present invention: a gas separation system according to claim 1 having the features of claim 2; a gas separation system according to claim 2 having the features of claim 3; a gas separation system according to any one of claims 1 to 3 having the features of claim 4; a gas separation system according to any one of claims 1 to 3 having the features of claim 5; a gas separation system according to claim 4 or 5 having the features of claim 6; a gas separation method using a gas separation system according to any one of claims 1 to 6 having the features of claim 7; and a gas separation method according to claim 7 having the features of claim 8. [Explanation of symbols]

[0044] 1, 1A, 1B Gas Separation System 10. First gas separation membrane unit, 10a Part 1, 10b second part, 11. First gas separation membrane, 11a, 11b, 21a, 21b sides, 12. First gas supply port, 13. First impermeable gas outlet, 14. First permeable gas outlet, 15 First gas pumping means, 16 First gas cooling means, 20 Second gas separation membrane unit, 21 Second gas separation membrane, 22 Second gas supply port, 23 Second impermeable gas outlet, 24 Second permeable gas outlet, 25 Second gas pumping means, 26 Second gas cooling means, 30 Third gas separation membrane unit, 32 Third gas supply port, 111 1st support layer, 111a Pores, 112 First Meso-Marginal Layer, 113 First separation functional layer.

Claims

1. First gas separation membrane, A first gas supply port and a first non-permeable gas outlet are located on one side of the first gas separation membrane, and A first permeate gas outlet is located on the other side of the first gas separation membrane. A first gas separation membrane unit having, A first gas pumping means connected to the first permeate gas outlet for permeating gas from one side to the other side of the first gas separation membrane, It has, The first gas separation membrane includes a first support layer and a first separation functional layer disposed on the first support layer. The first separation functional layer contains a glassy polymer, A gas separation system wherein one side of the first gas separation membrane does not have a gas pumping means for permeating gas from one side of the first gas separation membrane to the other side.

2. Second gas separation membrane, A second gas supply port and a second non-permeable gas outlet are located on one side of the second gas separation membrane, and A second permeate gas outlet is located on the other side of the second gas separation membrane. It further comprises a second gas separation membrane unit having, The gas separation system according to claim 1, wherein the first gas pumping means and the second gas supply port are connected to each other.

3. The gas separation system according to claim 2, further comprising a first gas cooling means between the first gas pumping means and the second gas supply port for lowering the temperature of the gas pumped by the first gas pumping means.

4. The first gas separation membrane is CO ２ and N ２ CO from a mixed gas containing ２ CO selectively permeates ２ The gas separation system according to claim 1, wherein the separation membrane is a separation membrane.

5. The first gas separation membrane is O ２ and N ２ From a mixed gas containing O ２ Selectively transparent O ２ The gas separation system according to claim 1, wherein the separation membrane is a separation membrane.

6. The gas separation system according to claim 4 or 5, wherein the mixed gas is air.

7. A gas separation method using the gas separation system described in claim 1, A gas separation method comprising supplying a raw material gas to the first gas supply port.

8. The gas separation method according to claim 7, wherein the temperature of the raw material gas when it is supplied to the first gas supply port is 25°C or lower.

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