Gas separation system

Abstract

A gas separation system (1) separates CH4 from a mixed gas containing H2O, NH3, CO2, and CH4. The gas separation system (1) comprises: a first separation membrane (10); a second separation membrane (20) disposed downstream of the first separation membrane (10); and a third separation membrane (30) disposed downstream of the second separation membrane (20). The first separation membrane (10) selectively transmits H2O, thereby generating a first enriched gas in which H2O is enriched and a first deficient gas in which H2O is reduced and NH3 is enriched. The second separation membrane (20) separates NH3, thereby generating a second enriched gas in which NH3 is enriched and a second deficient gas in which NH3 is reduced. The third separation membrane (30) separates CO2, thereby generating a third enriched gas in which CO2 is enriched and a third deficient gas in which CO2 is reduced.

Description

Gas Separation Systems

[0001] The present invention relates to a gas separation system.

[0002] BACKGROUND ART Conventionally, a method for separating a predetermined component contained in a mixed gas has been known in which pressure swing adsorption (PSA) is combined with membrane separation (see, for example, Patent Document 1).

[0003] The method described in Patent Document 1 uses an adsorbent to convert the mixed gas into an exhaust gas (H ２ O and NO ｘ ) and concentrated gas (CO ２ ) and then the concentrated gas is separated by membrane separation to obtain high-concentration CO ２ and low concentration CO ２ It is separated into two.

[0004] In the method described in Patent Document 1, a polar gas, H ２ O and NO ｘ are separated together as exhaust gas (impurities).

[0005] JP 2012-236134 A

[0006] By the way, the polar gas H ２ O and NO ｘ If you want to recover and reuse at least one of the two, you can use an adsorbent to separate the exhaust gas and ２ O and NO ｘ This requires further separation, which is cumbersome.

[0007] SUMMARY OF THE INVENTION An object of the present invention is to provide a gas separation system that can separate non-polar gases after individually separating polar gases.

[0008] A gas separation system according to a first aspect of the present invention is a gas separation system for separating a second nonpolar gas from a mixed gas containing a first polar gas, a second polar gas, a first nonpolar gas, and a second nonpolar gas. The gas separation system includes a first separation membrane, a first separator disposed downstream of the first separation membrane, and a second separator disposed downstream of the first separator. The first separation membrane selectively allows the first polar gas to permeate, thereby producing a first enriched gas enriched in the first polar gas and a first depleted gas depleted in the first polar gas and the second polar gas. The first separator separates the second polar gas, thereby producing a second enriched gas enriched in the second polar gas and a second depleted gas depleted in the second polar gas. The second separator separates the first nonpolar gas, thereby producing a third enriched gas enriched in the first nonpolar gas and a third depleted gas depleted in the first nonpolar gas.

[0009] A gas separation system according to a second aspect of the present invention is related to the first aspect, wherein the first separator is a second separation membrane that selectively allows a second polarity gas to permeate.

[0010] A gas separation system according to a third aspect of the present invention is related to the second aspect, and the configuration of the second separation membrane is different from the configuration of the first separation membrane.

[0011] A gas separation system according to a fourth aspect of the present invention relates to any one of the first to third aspects, wherein the second separator is a third separation membrane that selectively allows the first non-polar gas to permeate.

[0012] A gas separation system according to a fifth aspect of the present invention relates to the fourth aspect, and the configuration of the third separation membrane is different from the configuration of the first separation membrane.

[0013] A gas separation system according to a sixth aspect of the present invention relates to any one of the first to fifth aspects, wherein the concentration of the first polar gas in the gas supplied to the second separator is lower than the concentration of the first polar gas in the gas supplied to the first separation membrane.

[0014] A gas separation system according to a seventh aspect of the present invention relates to any one of the first to sixth aspects, in which at least one of the first polar gas and the second polar gas is reused.

[0015] According to the present invention, it is possible to provide a gas separation system capable of separating non-polar gases after individually separating polar gases.

[0016] Schematic diagram showing the configuration of a gas separation system according to an embodiment. Schematic diagram showing the configuration of a gas separation system according to Modification 1.

[0017] (Gas Separation System 1) FIG. 1 is a schematic diagram showing the configuration of a gas separation system 1. As shown in FIG.

[0018] The gas separation system 1 includes a methanation reactor 5 , a first separation membrane 10 , a second separation membrane 20 , and a third separation membrane 30 .

[0019] The first separation membrane 10 is an example of a "first separation membrane" according to the present invention. The second separation membrane 20 is an example of a "first separator" according to the present invention. The third separation membrane 30 is an example of a "second separator" according to the present invention.

[0020] [Methanation Reactor 5] The methanation reactor 5 is disposed upstream of the first separation membrane 10. The methanation reactor 5 is ２ (carbon dioxide) and H ２ (hydrogen) to CH ４ (methane) to produce a mixed gas.

[0021] H ２ The source may be, for example, NH ３ Therefore, the mixed gas generated by the methanation reactor 5 is CH ４ In addition, undecomposed NH ３ , unreacted CO ２ , and the by-product H ２ O (water vapor) and N ２ (nitrogen).

[0022] H ２ O is an example of the "first polar gas" according to the present invention. ２ The kinetic diameter of NH is 0.265 nm. ３ is an example of the "second polarity gas" according to the present invention. ３ The kinetic diameter of CO is 0.26 nm. ２ is an example of the "first non-polar gas" according to the present invention.２ The kinetic diameter of CH is 0.33 nm. ４ is an example of the "second non-polar gas" according to the present invention. ４ The kinetic molecular diameter of is 0.38 nm.

[0023] As described above, the mixed gas according to this embodiment contains two types of polar gases (NH ３ and H ２ O) and two non-polar gases (CO ２ and CH ４ ) and

[0024] A polar gas is a gas composed of polar molecules. In other words, a polar gas is a gas in which the molecules that make up the gas have an electric dipole moment. A nonpolar gas is a gas composed of nonpolar molecules. In other words, a nonpolar gas is a gas in which the molecules that make up the gas do not have an electric dipole moment.

[0025] The mixed gas according to this embodiment contains two polar gases and two non-polar gases, but is not limited to this. It is sufficient for the mixed gas to contain at least two polar gases and at least two non-polar gases. Therefore, the mixed gas may contain three or more polar gases, or may contain three or more non-polar gases. The mixing ratio of each gas in the mixed gas can be set as appropriate.

[0026] [First Separation Membrane 10] The first separation membrane 10 is disposed downstream of the methanation reactor 5. The first separation membrane 10 is disposed upstream of the second separation membrane 20. The first separation membrane 10 receives NH ３ , H ２ O, CO ２ and CH ４ The mixed gas supplied to the first separation membrane 10 is preferably pressurized.

[0027] The first separation membrane 10 separates H, one of the polar gases, from the mixed gas. ２ The first separation membrane 10 separates H from the mixed gas. ２ H that can selectively permeate O ２ The first separation membrane 10 is a H ２The material of the first separation membrane 10 is not particularly limited as long as it is a membrane that can selectively permeate O. ２ O to NH ３ It is preferable that the first separation membrane 10 be a membrane (e.g., a hydrophilic membrane) that can adsorb the hydroxybenzoate preferentially over the hydroxybenzoate. As the first separation membrane 10, for example, a zeolite membrane, a carbon membrane, a silica membrane, a synthetic resin membrane, or the like can be used. In particular, a zeolite membrane is preferable because it can exhibit high separation performance even under high temperature conditions.

[0028] In this specification, selective permeation means that the desired component is enriched in the permeate side space of the separation membrane.

[0029] The first separation membrane 10 is a membrane that separates H contained in the mixed gas. ２ By selectively allowing O to pass through, ２ a first enriched gas enriched in O; and H ２ As O becomes depleted, NH ３ , CO ２ and CH ４ and a first depleted gas enriched with .

[0030] The first enriched gas is discharged to the outside from the permeate side space of the first separation membrane 10. ２ The concentration of O is not particularly limited, but the first enriched gas is mainly H ２ It is preferable that it contains O. Mainly H ２ The term "containing O" means that the maximum concentration component in the first enriched gas is H ２ It means that it is O.

[0031] The first lean gas flows out from the non-permeation side space of the first separation membrane 10 and is supplied to the second separation membrane 20. The first lean gas is NH ３ , CO ２ and CH ４ The first depleted gas contains H ２ O may be included.

[0032] [Second Separation Membrane 20] The second separation membrane 20 is disposed downstream of the first separation membrane 10. The second separation membrane 20 is disposed upstream of the third separation membrane 30. The second separation membrane 20 is configured to receive NH ３ , CO ２ and CH４ A first depleted gas is supplied, the first gas comprising:

[0033] The first depleted gas supplied to the second separation membrane 20 contains H ２ Although O may be contained, H in the first depleted gas ２ The concentration of O is determined by the H ２ The concentration is lower than that of O.

[0034] The second separation membrane 20 separates the first lean gas from the polar gas, NH ３ The second separation membrane 20 separates NH from the first depleted gas. ３ selectively permeable NH ３ The second separation membrane 20 is a separation membrane. ３ The material of the second separation membrane 20 is not particularly limited as long as it is a membrane that can selectively permeate the above. As the second separation membrane 20, for example, a zeolite membrane, a carbon membrane, a silica membrane, a synthetic resin membrane, or the like can be used.

[0035] The configuration of the second separation membrane 20 is preferably different from the configuration of the first separation membrane 10. The second separation membrane 20 is ３ The different configurations include different constituent materials and different pore sizes. For example, the pore size of the second separation membrane 20 is ３ and CO ２ The kinetic molecular diameter of the second separation membrane 20 is preferably smaller than the kinetic molecular diameter of the second separation membrane 20. In addition, the second separation membrane 20 does not need to have water adsorption properties.

[0036] The configuration of the second separation membrane 20 may be the same as the configuration of the first separation membrane 10. For example, ２ As O is depleted, the second separation membrane 20 becomes NH ３ In the case where the first and second separation membranes 10 and 20 can selectively permeate the first and second separation membranes 10 and 20, the first and second separation membranes 10 and 20 can have the same structure.

[0037] The second separation membrane 20 is formed by separating NH contained in the first depleted gas. ３ By selectively permeating ３ a second enriched gas enriched in NH ３ is depleted and CO ２ and CH４ and a second depleted gas enriched with .

[0038] In this embodiment, the second enriched gas is discharged to the outside from the permeate side space of the second separation membrane 20. ３ The concentration of the second enrichment gas is not particularly limited, but the second enrichment gas is mainly NH ３ It is preferable that the compound contains mainly NH ３ The term "containing" means that the maximum concentration component in the second enriched gas is NH ３ This means that the first depleted gas is H ２ If O is contained, the second enrichment gas is H ２ It may contain O.

[0039] The second lean gas flows out from the non-permeation side space of the second separation membrane 20 and is supplied to the third separation membrane 30. The second lean gas is CO ２ and CH ４ The first depleted gas contains H ２ If O is contained, the second depleted gas is H ２ The second depleted gas may contain NH. ３ may be included.

[0040] [Third Separation Membrane 30] The third separation membrane 30 is disposed downstream of the second separation membrane 20. The third separation membrane 30 is provided with a ２ and CH ４ A second depleted gas is provided, the second gas comprising:

[0041] H in the second depleted gas supplied to the third separation membrane 30 ２ The concentration of O is determined by the H ２ The concentration is lower than that of O.

[0042] NH in the second depleted gas supplied to the third separation membrane 30 ３ The concentration of NH in the first depleted gas supplied to the second separation membrane 20 is ３ Lower than the concentration of

[0043] The third separation membrane 30 separates CO, which is one of the non-polar gases, from the second depleted gas. ２ The third separation membrane 30 separates CO from the second depleted gas. ２selectively permeable to CO ２ The third separation membrane 30 is a CO ２ The material of the third separation membrane 30 is not particularly limited as long as it is a membrane that can selectively permeate the above. The third separation membrane 30 can be made of, for example, a zeolite membrane, a carbon membrane, a silica membrane, a synthetic resin membrane, or the like.

[0044] The configuration of the third separation membrane 30 is preferably different from the configuration of the first separation membrane 10. The third separation membrane 30 is ２ The third separation membrane 30 does not need to have water adsorption properties.

[0045] The configuration of the third separation membrane 30 is preferably different from the configuration of the second separation membrane 20. For example, the pore diameter of the third separation membrane 30 is ２ and CH ４ It is preferable that the kinetic diameter is smaller than that of the molecular weight of the polymer.

[0046] The third separation membrane 30 separates the CO contained in the second depleted gas. ２ By selectively permeating ２ a third enriched gas enriched in CO; ２ is impoverished and CH ４ and a third depleted gas enriched with .

[0047] The third enriched gas is discharged to the outside from the permeate side space of the third separation membrane 30. ２ The concentration of the third enriched gas is not particularly limited, but the third enriched gas is mainly CO ２ It is preferable that the mixture contains mainly CO. ２ The term "containing" means that the maximum concentration component in the third enriched gas is CO ２ The third depleted gas flows out from the non-permeation side space of the third separation membrane 30. ４ The concentration of the third impoverished gas is not particularly limited, but the third impoverished gas is mainly CH ４ It is preferable that the compound contains mainly CH ４ The term "contains" means that the maximum concentration component in the third depleted gas is CH ４ This means that

[0048] (Features) (1) The gas separation system 1 is ２ O (first polar gas), NH ３ (second polar gas), CO ２ (first non-polar gas) and CH ４ (second non-polar gas) to CH ４ The gas separation system 1 includes a first separation membrane 10 (first separation membrane), a second separation membrane 20 (first separator) disposed downstream of the first separation membrane 10, and a third separation membrane 30 (second separator) disposed downstream of the second separation membrane 20. The first separation membrane 10 separates H ２ By selectively allowing O to pass through, ２ a first enriched gas enriched in O; and H ２ As O becomes depleted, NH ３ The second separation membrane 20 generates a first depleted gas enriched with NH ３ By separating NH ３ a second enriched gas enriched in NH ３ The third separation membrane 30 generates a second depleted gas in which CO ２ By separating CO ２ a third enriched gas enriched in CO; ２ and a third depleted gas in which the first gas is depleted.

[0049] In this way, according to the gas separation system 1, CH ４ In separating the polar gas H ２ O and NH ３ After separating them, the non-polar gas CO ２ and CH ４ Therefore, there is no need to set up a separate production line for separating polar gases, since polar gases can be separated individually before non-polar gases are separated.

[0050] (2) The gas separation system 1 is ３ Therefore, the gas separation system 1 is provided with a second separation membrane 20 that selectively permeates NH by pressure swing adsorption (PSA). ３Compared to the case where an adsorption tower for separating NH is provided as the first separator, the occurrence of pressure fluctuations in the second lean gas supplied to the third separation membrane 30 can be suppressed. Therefore, there is no need to perform complicated control of the pressure of the second lean gas. Also, the energy required to increase the pressure of the second lean gas by the amount of pressure drop can be reduced. Furthermore, when the gas separation system 1 separates NH by temperature swing adsorption (TSA) or absorption, ３ In comparison with the case where a structure for separating the first depleted gas is provided as the first separator, there is no need for complicated temperature control of the first depleted gas. Furthermore, in the case of the TSA method or the absorption method, the gas temperature may be lowered to more effectively perform adsorption or absorption. Therefore, it is possible to reduce the energy required to heat the first depleted gas.

[0051] (3) The second separation membrane 20 preferably has a different structure from the first separation membrane 10. This allows the second polar gas, NH ３ A separation membrane suitable for separating the above can be used as the second separation membrane 20.

[0052] (4) The gas separation system 1 is ２ Therefore, the gas separation system 1 is provided with a third separation membrane 30 as a "second separator" that selectively permeates CO ２ In comparison with the case where a structure for separating CO is provided as the second separator, the occurrence of pressure fluctuations in the third depleted gas can be suppressed. Therefore, there is no need to perform complicated control of the pressure of the third depleted gas, and the energy required to increase the pressure of the third depleted gas by the amount of the pressure drop can be reduced. Furthermore, the CO is removed by the TSA method or the absorption method (for example, an amine absorption liquid). ２ In comparison with the case where a structure for separating the third depleted gas is provided as the second separator, there is no need to perform complicated temperature control of the third depleted gas, and the energy required to heat the third depleted gas can be reduced.

[0053] (5) The configuration of the third separation membrane 30 is preferably different from the configuration of the first separation membrane 10. This allows the first non-polar gas, CO ２ A separation membrane suitable for separating the above can be used as the third separation membrane 30.

[0054] (6) H in the second depleted gas (an example of the "gas supplied to the second separator"). ２ The concentration of O is determined by the H concentration in the mixed gas (an example of the "gas supplied to the first separation membrane"). ２ This is because the concentration of CO, a non-polar gas contained in the second depleted gas, is lower than that of O. ２ and CH ４ Before separating the polar gas H ２ This means that the influence of polar gases on the third separation membrane 30 can be eliminated, and therefore CH ４ Compared to the case of directly separating CH ４ can be separated with high accuracy.

[0055] (Modifications of the embodiment) Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention.

[0056] [Modification 1] In the above embodiment, H is used as an example of the first polar gas. ２ O is used as an example of the second polarity gas, and NH ３ However, the first and second polar gases are not limited to these. ２ O, N.H. ３ , MeOH, CO, CH ３ OH, C ２ H ５ OH and the like can be used.

[0057] In the above embodiment, CO is used as an example of the first nonpolar gas. ２ and CH as an example of the second non-polar gas. ４ However, the first and second non-polar gases are not limited to these. ２ , C.H. ４ , N ２ , H ２ etc. can be used.

[0058] Table 1 shows typical examples of combinations of the first polar gas, second polar gas, first non-polar gas, and second non-polar gas contained in the mixed gas.

[0059]

[0060] The combination of gases is determined depending on the composition of the mixed gas to be treated, but the gas separation system according to the present invention can be particularly effectively used in the following cases.

[0061] First, the mixed gas contains H as the first polar gas. ２ O and NH as the second polar gas ３ In this case, H ２ O to NH ３ By separating the hydrogen atoms first, the separation membrane ２ O condenses to form NH ３ Since the generation of water (ammonia water) is suppressed, the separation membrane can ３ It can prevent damage caused by water.

[0062] The mixed gas contains NH 3 as the first polar gas. ３ In this case, it is also preferable to include NH ３ Since the concentration of can be preferentially reduced, deterioration of the separation membrane and the device can be suppressed.

[0063] The mixed gas contains H as the first polar gas. ２ It is also preferable that the first enriched gas contains O and that the second polar gas contains MeOH. In this case, H ２ Since the concentration of O can be increased, the first enrichment gas is H ２ This makes it easier to utilize as a source of methyl methyl ether (e.g., a raw material for synthesizing MeOH).

[0064] [Modification 2] In the above embodiment, the mixed gas contains two types of polar gases and two types of non-polar gases, but this is not limiting. The mixed gas may contain at least two types of polar gases and at least two types of non-polar gases.

[0065] When a mixed gas contains three or more polar gases, the gas separation system according to the present invention does not need to separate polar gases other than the first and second polar gases individually, as long as it can separate at least the first and second polar gases. For example, polar gases other than the first and second polar gases may permeate at least one of the first separation membrane, the first separator, and the second separator.

[0066] For example, if the mixed gas is H ２ O (first polar gas), NH ３ (second polar gas), CO ２ (first non-polar gas), CH ４ (second non-polar gas) and N ２ (third non-polar gas), in the gas separation system 1 shown in FIG. ２ and N ２ are separated together by the third separation membrane 30.

[0067] In addition, the mixed gas is H ２ O (first polar gas), NH ３ (second polar gas), CO ２ (first non-polar gas), CH ４ (second non-polar gas) and H ２ When the gas separation system 1 includes a third non-polar gas, the gas separation system 1 may include a fourth separation membrane 40 disposed between the second separation membrane 20 and the third separation membrane 30, as shown in FIG. 2.

[0068] The fourth separation membrane 40 is disposed downstream of the second separation membrane 20. The fourth separation membrane 40 is disposed upstream of the third separation membrane 30. The fourth separation membrane 40 receives the CO ２ , C.H. ４ and H ２ In this modification, the second depleted gas containing H contained in the first depleted gas supplied to the second separation membrane 20 is supplied. ２ A part of the NH ３ (second polarity gas) may be separated.

[0069] The fourth separation membrane 40 separates H, which is one of the non-polar gases, from the second depleted gas. ２ The fourth separation membrane 40 separates H from the second depleted gas. ２selectively permeable H ２ The fourth separation membrane 40 is a H ２ The material of the fourth separation membrane 40 is not particularly limited as long as it is a membrane that can selectively permeate the above. For example, a zeolite membrane, a carbon membrane, a silica membrane, a synthetic resin membrane, or the like can be used as the fourth separation membrane 40.

[0070] The configuration of the fourth separation membrane 40 is preferably different from the configurations of the first to third separation membranes 10, 20, and 30. Specifically, H ２ Since the kinetic molecular diameter of the fourth separation membrane 40 is 0.289 nm, it is preferable that the pore diameter of the fourth separation membrane 40 be larger than the pore diameters of the first and second separation membranes 10 and 20 and smaller than the pore diameter of the third separation membrane 30 .

[0071] The fourth separation membrane 40 separates H contained in the second depleted gas. ２ By selectively transmitting H ２ a fourth enriched gas enriched in H; ２ and a fourth depleted gas.

[0072] The fourth enriched gas flows out from the permeate side space of the fourth separation membrane 40. ２ The concentration of the fourth enrichment gas is not particularly limited, but the fourth enrichment gas is mainly H ２ It is preferable that the compound contains mainly H. ２ The term "containing" means that the maximum concentration component in the fourth enriched gas is H ２ The fourth depleted gas flows out from the non-permeation side space of the fourth separation membrane 40 and is supplied to the third separation membrane 30. H in the fourth enriched gas ２ The concentration of the fourth depleted gas is not particularly limited, but the fourth depleted gas is CO ２ and CH ４ Contains:

[0073] The third separation membrane 30 contains CO ２ and CH ４ The third separation membrane 30 separates the fourth depleted gas containing CO ２ By selectively permeating ２ a third enriched gas enriched in CO; ２ and a third depleted gas in which the first gas is depleted.

[0074] [Modification 3] In the above embodiment, the gas separation system 1 is provided with the methanation reactor 5, but it is not necessary to provide the methanation reactor 5. Therefore, the mixed gas is not limited to a gas synthesized by methanation, and any gas containing at least two types of polar gases and at least two types of non-polar gases can be used.

[0075] [Variation 4] In the above embodiment, the gas separation system 1 includes the second separation membrane 20 as an example of the first separator, but the first separator is not limited to a separation membrane. The first separator may be any structure capable of separating the second polarity gas. For example, a structure that separates the second polarity gas by a PSA method, a TSA method, or an absorption method may be used as the first separator.

[0076] [Variation 5] In the above embodiment, the gas separation system 1 includes the third separation membrane 30 as an example of the second separator, but the second separator is not limited to a separation membrane. The second separator may be any structure capable of separating the first nonpolar gas. For example, a structure that separates the first nonpolar gas by a PSA method, a TSA method, or an absorption method may be used as the second separator.

[0077] [Modification 6] In the above embodiment, the polar gas (H ２ O and NH ３ ) is discharged to the outside, but at least one polar gas may be reused. For example, NH ３ In the case of reusing H supplied to the methanation reactor 5, ２ In the first modification, the H gas, which is one of the non-polar gases, is reused as a raw material for generating a source of H2O, or as a fuel to be burned in another process. ２ This can improve the gas utilization efficiency of the entire system.

[0078] [Variation 7] In the above embodiment, the non-polar gas is separated after all polar gases have been separated from the mixed gas, but some non-polar gases may be separated before all polar gases have been separated from the mixed gas.

[0079] For example, a CO ２ CO ２ Alternatively, a part of the CO 2 may be separated in advance. ２ CO ２ A part of the above may be separated in advance.

[0080] [Modification 8] In the above embodiment, the first separation membrane 10 ２ O is separated, and NH is separated by the second separation membrane 20. ３ However, the first separation membrane 10 ３ and H ２ O may be separated.

[0081] REFERENCE SIGNS LIST 1 gas separation system 5 methanation reactor 10 first separation membrane 20 second separation membrane 30 third separation membrane 40 fourth separation membrane

Claims

1. A gas separation system for separating a second non-polar gas from a mixed gas containing a first polar gas, a second polar gas, a first non-polar gas, and a second non-polar gas, comprising: a first separation membrane; a first separator arranged downstream of the first separation membrane; and a second separator arranged downstream of the first separator, wherein the first separation membrane selectively allows the first polar gas to permeate, thereby producing a first enriched gas enriched in the first polar gas and a first depleted gas depleted in the first polar gas and enriched in the second polar gas; the first separator separates the second polar gas, thereby producing a second enriched gas enriched in the second polar gas and a second depleted gas depleted in the second polar gas; and the second separator separates the first non-polar gas, thereby producing a third enriched gas enriched in the first non-polar gas and a third depleted gas depleted in the first non-polar gas.

2. The gas separation system according to claim 1, wherein the first separator is a second separation membrane that selectively allows the second polar gas to permeate.

3. The gas separation system according to claim 2, wherein the second separation membrane has a different configuration from the first separation membrane.

4. A gas separation system according to any one of claims 1 to 3, wherein the second separator is a third separation membrane that selectively allows the first non-polar gas to permeate.

5. The gas separation system according to claim 4, wherein the third separation membrane has a different configuration from the first separation membrane.

6. A gas separation system according to any one of claims 1 to 3, wherein the concentration of the first polar gas in the gas supplied to the second separator is lower than the concentration of the first polar gas in the gas supplied to the first separation membrane.

7. A gas separation system according to any one of claims 1 to 3, wherein at least one of the first polar gas and the second polar gas is recycled.

8. The first polar gas is H ２ O, and the second polar gas is NH ３ The gas separation system according to any one of claims 1 to 3, wherein 9. The first polar gas is NH ３ The gas separation system according to any one of claims 1 to 3, wherein 10. The first polar gas is H ２ 4. The gas separation system according to claim 1, wherein the second polar gas is O and the second polar gas is MeOH.

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