Gas separation system

Abstract

A gas separation system (1) separates CH4from a mixed gas containing H2O, NH3, CO2, and CH4. The gas separation system (1) includes a first separation membrane (10), a second separation membrane (20) disposed on a downstream side of the first separation membrane (10), and a third separation membrane (30) disposed on a downstream side of the second separation membrane (20). The first separation membrane (10) generates a first enriched gas in which H2O is enriched and a first depleted gas in which H2O is depleted and NH3 is enriched by selectively permeating H2O. The second separation membrane (20) generates a second enriched gas in which NH3 is enriched and a second depleted gas in which NH3 is depleted by separating NH3. The third separation membrane (30) generates a third enriched gas in which CO2 is enriched and a third depleted gas in which CO2 is depleted by separating CO2.

Description

Technical Field

[0001] This invention relates to gas separation systems. Background Technology

[0002] Previously, as a method for separating specified components contained in a gas mixture, a method combining pressure variation adsorption (PSA) and membrane separation is known (e.g., Patent Document 1).

[0003] Regarding the method described in Patent Document 1, an adsorbent is used to separate the mixed gas into waste gas (H2O and NO). x After the gas is concentrated (CO2), the concentrated gas is separated into high-concentration CO2 and low-concentration CO2 by membrane separation.

[0004] In the method described in Patent Document 1, H2O and NO, which are polar gases, are reacted using the PSA method. x It is collected as waste gas (impurities) and then separated.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-236134 Summary of the Invention

[0008] However, it is desirable to combine H2O and NO, which are polar gases. x If at least one of the components is to be recovered and reused, the waste gas separated by the adsorbent needs to be further separated into H2O and NO. x That would be more complicated.

[0009] The purpose of this invention is to provide a gas separation system capable of separating polar gases and then separating non-polar gases.

[0010] The first aspect of the present invention relates to a gas separation system that separates a second non-polar gas from a mixture of a first polar gas, a second polar gas, a first non-polar gas, and a second non-polar gas. The gas separation system comprises: 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 permeates through the first polar gas to generate a first enriched gas enriched with the first polar gas and a first depleted gas depleted of the first polar gas and enriched with the second polar gas. The first separator separates the second polar gas to generate a second enriched gas enriched with the second polar gas and a second depleted gas depleted of the second polar gas. The second separator separates the first non-polar gas to generate a third enriched gas enriched with the first non-polar gas and a third depleted gas depleted of the first non-polar gas.

[0011] The gas separation system of the second aspect of the present invention is based on the first aspect described above, wherein the first separator is a second separation membrane that allows the second polar gas to selectively permeate.

[0012] The gas separation system involved in the third aspect of the present invention is based on the second aspect described above, but the composition of the second separation membrane is different from that of the first separation membrane.

[0013] The gas separation system of the fourth aspect of the present invention is based on any one of the first to third aspects described above, wherein the second separator is a third separation membrane that allows the first non-polar gas to selectively permeate.

[0014] The gas separation system of the fifth aspect of the present invention is based on the fourth aspect described above, but the composition of the third separation membrane is different from that of the first separation membrane.

[0015] The sixth aspect of the present invention relates to a gas separation system based on any of the first to fifth aspects described above, 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.

[0016] The gas separation system of the seventh aspect of the present invention is based on any one of the first to sixth aspects described above, in which at least one of the first polar gas and the second polar gas is reused.

[0017] Invention Effects

[0018] According to the present invention, a gas separation system capable of separating non-polar gases after separating polar gases can be provided. Attached Figure Description

[0019] Figure 1 This is a schematic diagram showing the configuration of the gas separation system according to the embodiment.

[0020] Figure 2 This is a schematic diagram showing the configuration of the gas separation system involved in Modification Example 1. Detailed Implementation

[0021] (Gas separation system 1)

[0022] Figure 1 This is a schematic diagram showing the configuration of gas separation system 1.

[0023] 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.

[0024] The first separation membrane 10 is an example of the "first separation membrane" according to the present invention. The second separation membrane 20 is an example of the "first separator" according to the present invention. The third separation membrane 30 is an example of the "second separator" according to the present invention.

[0025] [Methanation Reactor 5]

[0026] The methanation reactor 5 is located upstream of the first separation membrane 10. The methanation reactor 5 synthesizes CH4 (methane) from CO2 (carbon dioxide) and H2 (hydrogen), thereby generating a mixed gas.

[0027] As a source of H2, for example, the decomposition gas of NH3 is utilized. Therefore, the mixed gas generated by the methanation reactor 5 contains, in addition to CH4, undecomposed NH3, unreacted CO2, and H2O (water vapor) or N2 (nitrogen) as byproducts.

[0028] H₂O is an example of the "first polar gas" involved in this invention. The dynamic molecular diameter of H₂O is 0.265 nm. NH₃ is an example of the "second polar gas" involved in this invention. The dynamic molecular diameter of NH₃ is 0.26 nm. CO₂ is an example of the "first nonpolar gas" involved in this invention. The dynamic molecular diameter of CO₂ is 0.33 nm. CH₄ is ​​an example of the "second nonpolar gas" involved in this invention. The dynamic molecular diameter of CH₄ is ​​0.38 nm.

[0029] Thus, the mixed gas involved in this embodiment includes two polar gases (NH3 and H2O) and two non-polar gases (CO2 and CH4).

[0030] Polar gases are gases composed of polar molecules. That is, polar gases are gases whose constituent molecules have an electric dipole moment. Nonpolar gases are gases composed of nonpolar molecules. That is, nonpolar gases are gases whose constituent molecules do not have an electric dipole moment.

[0031] It should be noted that the mixed gas involved in this embodiment includes two polar gases and two non-polar gases, but is not limited to this. The mixed gas may contain at least two polar gases and at least two non-polar gases. Accordingly, the mixed gas may contain three or more polar gases, or it may contain three or more non-polar gases. The mixing ratio of each gas in the mixed gas can be appropriately set.

[0032] [First separation membrane 10]

[0033] 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. A mixed gas comprising NH3, H2O, CO2, and CH4 is supplied from the methanation reactor 5 to the first separation membrane 10. The mixed gas supplied to the first separation membrane 10 is preferably pressurized.

[0034] The first separation membrane 10 separates H2O, one of the polar gases, from the mixed gas. The first separation membrane 10 is an H2O separation membrane capable of selectively permeating H2O from the mixed gas. The first separation membrane 10 is only required to be a membrane capable of selectively permeating H2O, and its constituent material is not particularly limited. The first separation membrane 10 is preferably a membrane that preferentially adsorbs H2O compared to NH3 (e.g., a hydrophilic membrane). For example, zeolite membranes, carbon membranes, silica membranes, and synthetic resin membranes can be used as the first separation membrane 10. In particular, zeolite membranes exhibit high separation performance even under high temperature conditions, and are therefore preferred.

[0035] It should be noted that, in this specification, selective permeation means that the desired component is enriched in the permeation space of the separation membrane.

[0036] The first separation membrane 10 selectively permeates H2O contained in the mixed gas to generate a first enriched gas enriched with H2O and a first depleted gas depleted with H2O and enriched with NH3, CO2 and CH4.

[0037] The first enriched gas is discharged to the outside through the permeate side space of the first separation membrane 10. The concentration of H2O in the first enriched gas is not particularly limited; however, the first enriched gas preferably mainly contains H2O. "Mainly contains H2O" means that the highest concentration of H2O in the first enriched gas is H2O.

[0038] A first depleted gas flows out from the non-permeable side space of the first separation membrane 10 and is supplied to the second separation membrane 20. The first depleted gas contains NH3, CO2, and CH4. The first depleted gas may contain H2O.

[0039] [Second separation membrane 20]

[0040] 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. A first lean gas containing NH3, CO2 and CH4 is supplied from the first separation membrane 10 to the second separation membrane 20.

[0041] The first depleted gas supplied to the second separation membrane 20 may contain H2O; however, the concentration of H2O in the first depleted gas is lower than the concentration of H2O in the mixed gas supplied to the first separation membrane 10.

[0042] The second separation membrane 20 separates NH3, which is one of the polar gases, from the first depleted gas. The second separation membrane 20 is an NH3 separation membrane capable of selectively permeating NH3 from the first depleted gas. The material of the second separation membrane 20 is not particularly limited; it can be any membrane capable of selectively permeating NH3. Examples of materials that can be used for the second separation membrane 20 include zeolite membranes, carbon membranes, silica membranes, and synthetic resin membranes.

[0043] The composition of the second separation membrane 20 is preferably different from that of the first separation membrane 10. The second separation membrane 20 is preferably composed of a structure suitable for the separation of NH3. Different composition refers to concepts including different constituent materials and different pore sizes. For example, it is preferable that the pore size of the second separation membrane 20 is larger than the dynamic molecular diameter of NH3 and smaller than the dynamic molecular diameter of CO2. Furthermore, the second separation membrane 20 may not have water adsorption properties.

[0044] It should be noted that the second separation membrane 20 can have the same structure as the first separation membrane 10. For example, if H2O is depleted and the second separation membrane 20 allows selective permeation of NH3, the first and second separation membranes 10 and 20 can have the same structure.

[0045] The second separation membrane 20 generates a second enriched gas enriched with NH3 and a second depleted gas enriched with CO2 and CH4 by selectively permeating NH3 contained in the first depleted gas.

[0046] In this embodiment, the second enriched gas is discharged to the outside through the permeation side space of the second separation membrane 20. The concentration of NH3 in the second enriched gas is not particularly limited; however, it is preferable that the second enriched gas mainly contains NH3. "Mainly contains NH3" means that the highest concentration of NH3 in the second enriched gas is NH3. If the first depleted gas contains H2O, the second enriched gas may also contain H2O.

[0047] The second lean gas flows out from the non-permeable side space of the second separation membrane 20 and is supplied to the third separation membrane 30. The second lean gas contains CO2 and CH4. If the first lean gas contains H2O, the second lean gas may also contain H2O. The second lean gas may also contain NH3.

[0048] [Third separation membrane 30]

[0049] The third separation membrane 30 is disposed downstream of the second separation membrane 20. A second lean gas containing CO2 and CH4 is supplied from the second separation membrane 20 to the third separation membrane 30.

[0050] The concentration of H2O in the second depleted gas supplied to the third separation membrane 30 is lower than the concentration of H2O in the mixed gas supplied to the first separation membrane 10.

[0051] The concentration of NH3 in the second depleted gas supplied to the third separation membrane 30 is lower than the concentration of NH3 in the first depleted gas supplied to the second separation membrane 20.

[0052] The third separation membrane 30 separates CO2, which is a non-polar gas, from the second lean gas. The third separation membrane 30 is a CO2 separation membrane that allows selective permeation of CO2 from the second lean gas. The material of the third separation membrane 30 is not particularly limited; it can be any membrane that allows selective permeation of CO2. Examples of materials that can be used for the third separation membrane 30 include zeolite membranes, carbon membranes, silica membranes, and synthetic resin membranes.

[0053] The third separation membrane 30 is preferably composed differently from the first separation membrane 10. The third separation membrane 30 is preferably composed of a structure suitable for CO2 separation. The third separation membrane 30 may not have water adsorption properties.

[0054] The third separation membrane 30 is preferably composed differently from the second separation membrane 20. For example, the pore size of the third separation membrane 30 is preferably larger than the dynamic molecular diameter of CO2 and smaller than the dynamic molecular diameter of CH4.

[0055] The third separation membrane 30 generates a third enriched gas enriched with CO2 and a third depleted gas enriched with CH4 by selectively permeating CO2 contained in the second depleted gas.

[0056] The third enriched gas is discharged to the outside through the permeate side space of the third separation membrane 30. The concentration of CO2 in the third enriched gas is not particularly limited; however, it is preferable that the third enriched gas mainly contains CO2. "Mainly containing CO2" means that the highest concentration of CO2 in the third enriched gas is present. The third lean gas flows out through the non-permeate side space of the third separation membrane 30. The concentration of CH4 in the third lean gas is not particularly limited; however, it is preferable that the third lean gas mainly contains CH4. "Mainly containing CH4" means that the highest concentration of CH4 in the third lean gas is present.

[0057] (feature)

[0058] (1) Gas separation system 1 separates CH4 from a mixture of H2O (a first polar gas), NH3 (a second polar gas), CO2 (a first nonpolar gas), and CH4 (a second nonpolar gas). Gas separation system 1 includes: a first separation membrane 10; a second separation membrane 20 (a first separator) disposed downstream of the first separation membrane 10; and a third separation membrane 30 (a second separator) disposed downstream of the second separation membrane 20. The first separation membrane 10 selectively permeates H2O to generate a first enriched gas enriched with H2O and a first depleted gas depleted with H2O and enriched with NH3. The second separation membrane 20 separates NH3 to generate a second enriched gas enriched with NH3 and a second depleted gas depleted with NH3. The third separation membrane 30 separates CO2 to generate a third enriched gas enriched with CO2 and a third depleted gas depleted with CO2.

[0059] Thus, according to gas separation system 1, when separating CH4 from the mixed gas, H2O and NH3, which are polar gases, can be separated in advance, and CO2 and CH4, which are non-polar gases, can be separated separately. Therefore, polar gases can be separated before non-polar gases are separated, so there is no need to set up a separate production line for separating polar gases.

[0060] (2) The gas separation system 1 includes a second separation membrane 20 that selectively allows NH3 to pass through, serving as the "first separator". Therefore, compared to the case where an adsorption tower that separates NH3 by pressure variation adsorption (PSA) is used as the first separator, the gas separation system 1 can suppress pressure fluctuations in the second lean gas supplied to the third separation membrane 30. Accordingly, complex pressure control of the second lean gas is unnecessary. In addition, the energy required to pressurize the reduced pressure portion of the second lean gas can be reduced. Furthermore, compared to the case where a structure that separates NH3 by temperature variation adsorption (TSA) or absorption is used as the first separator, the gas separation system 1 does not require complex temperature control of the first lean gas. In addition, in the case of TSA or absorption, the gas temperature is sometimes lowered to perform adsorption or absorption more effectively. Therefore, the energy required to heat the first lean gas can be reduced.

[0061] (3) The structure of the second separation membrane 20 is preferably different from that of the first separation membrane 10. Accordingly, a separation membrane suitable for separating NH3 as a second polar gas can be used as the second separation membrane 20.

[0062] (4) The gas separation system 1 includes a third separation membrane 30 that selectively allows CO2 to pass through, serving as a "second separator". Therefore, compared to the case where the gas separation system 1 uses a structure that separates CO2 by PSA as the second separator, it can suppress pressure fluctuations in the third lean gas. Accordingly, there is no need for complex pressure control of the third lean gas, and the energy required to partially pressurize the third lean gas is reduced. Furthermore, compared to the case where the second separator uses a structure that separates CO2 by TSA or absorption (e.g., amine absorbent) as the second separator, there is no need for complex temperature control of the third lean gas, and the energy required to heat the third lean gas is reduced.

[0063] (5) The structure of the third separation membrane 30 is preferably different from that of the first separation membrane 10. Accordingly, a separation membrane suitable for separating CO2, which is a first non-polar gas, can be used as the third separation membrane 30.

[0064] (6) The concentration of H2O in the second lean gas (an example of "gas supplied to the second separator") is lower than the concentration of H2O in the mixed gas (an example of "gas supplied to the first separation membrane"). This means that H2O, which is a polar gas, is removed before CO2 and CH4, which are nonpolar gases contained in the second lean gas, are separated. Accordingly, the influence of polar gases in the third separation membrane 30 can be eliminated, and therefore, CH4 can be separated from the second lean gas with good precision compared to the case where CH4 is directly separated from the mixed gas.

[0065] (Modifications of the implementation method)

[0066] The above describes one embodiment of the present invention. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention.

[0067] [Variation Example 1]

[0068] In the above embodiments, H2O is cited as an example of the first polar gas, and NH3 is cited as an example of the second polar gas, but the embodiments are not limited thereto. For example, H2O, NH3, MeOH, CO, CH3OH, C2H5OH, etc., can be used as the first and second polar gases.

[0069] In the above embodiments, CO2 is cited as an example of the first nonpolar gas, and CH4 is cited as an example of the second nonpolar gas, but the embodiments are not limited thereto. For example, CO2, CH4, N2, H2, etc., can be used as the first and second nonpolar gases.

[0070] Here, representative examples of combinations of the first polar gas, the second polar gas, the first nonpolar gas, and the second nonpolar gas contained in the gas mixture are summarized in Table 1.

[0071] [Table 1]

[0072]

[0073] The combination of gases is determined by the composition of the mixed gases to be treated; however, the gas separation system of the present invention can be used particularly effectively in the following situations.

[0074] First, in the mixed gas, it is preferable to include H2O as the first polar gas and NH3 as the second polar gas. In this case, by separating H2O, which has a lower vapor pressure and is more easily condensed, before NH3, it is possible to prevent H2O from condensing in the separation membrane to form NH3 water (ammonia water), and thus, it is possible to prevent the separation membrane from being damaged by NH3 water.

[0075] Furthermore, NH3 is preferably included as the first polar gas in the gas mixture. In this case, the concentration of corrosive NH3 can be preferentially reduced, thereby suppressing the deterioration of the separation membrane and the apparatus.

[0076] Furthermore, in the mixed gas, it is preferable to include H2O as the first polar gas and MeOH as the second polar gas. In this case, the concentration of H2O in the first enriched gas can be increased, and therefore, the first enriched gas can be easily and fully utilized as an H2 source (e.g., a raw material for MeOH synthesis).

[0077] [Variation Example 2]

[0078] In the above embodiments, the mixed gas contains two polar gases and two non-polar gases, but is not limited thereto. The mixed gas may contain at least two polar gases and at least two non-polar gases.

[0079] When the mixed gas contains three or more polar gases, the gas separation system of the present invention can separate at least the first and second polar gases, and does not necessarily require the separate separation of polar gases other than the first and second polar gases. For example, polar gases other than the first and second polar gases can permeate through at least one of the first separation membrane, the first separator, and the second separator.

[0080] For example, in a gas mixture containing H2O (a first polar gas), NH3 (a second polar gas), CO2 (a first nonpolar gas), CH4 (a second nonpolar gas), and N2 (a third nonpolar gas), in Figure 1 In the gas separation system 1 shown, CO2 and N2 are separated by passing through the third separation membrane 30.

[0081] Furthermore, when the mixed gas contains H2O (first polar gas), NH3 (second polar gas), CO2 (first nonpolar gas), CH4 (second nonpolar gas), and H2 (third nonpolar gas), such as Figure 2 As shown, the gas separation system 1 may include a fourth separation membrane 40, which is disposed between the second separation membrane 20 and the third separation membrane 30.

[0082] A fourth separation membrane 40 is disposed downstream of the second separation membrane 20. The fourth separation membrane 40 is also disposed upstream of the third separation membrane 30. A second lean gas containing CO2, CH4, and H2 is supplied from the second separation membrane 20 to the fourth separation membrane 40. It should be noted that in this modified example, a portion of the H2 contained in the first lean gas supplied to the second separation membrane 20 can be separated from NH3 (the second polar gas) through the second separation membrane 20.

[0083] The fourth separation membrane 40 separates H2, which is a nonpolar gas, from the second lean gas. The fourth separation membrane 40 is an H2 separation membrane capable of selectively permeating H2 from the second lean gas. The material of the fourth separation membrane 40 is not particularly limited, as long as it is a membrane capable of selectively permeating H2. For example, zeolite membranes, carbon membranes, silica membranes, and synthetic resin membranes can be used as the fourth separation membrane 40.

[0084] The composition of the fourth separation membrane 40 is preferably different from that of the first to third separation membranes 10, 20, and 30. Specifically, since the dynamic molecular diameter of H2 is 0.289 nm, the pore size of the fourth separation membrane 40 is preferably larger than that of the first and second separation membranes 10 and 20 and smaller than that of the third separation membrane 30.

[0085] The fourth separation membrane 40 generates a fourth enriched gas enriched with H2 and a fourth depleted gas depleted with H2 by selectively permeating H2 contained in the second depleted gas.

[0086] The fourth enriched gas flows out from the permeate side space of the fourth separation membrane 40. The concentration of H2 in the fourth enriched gas is not particularly limited; however, the fourth enriched gas preferably mainly contains H2. "Mainly contains H2" means that the highest concentration of H2 in the fourth enriched gas is H2. The fourth lean gas flows out from the non-permeate side space of the fourth separation membrane 40 and is supplied to the third separation membrane 30. The concentration of H2 in the fourth enriched gas is not particularly limited; however, the fourth lean gas contains CO2 and CH4.

[0087] A fourth lean gas containing CO2 and CH4 is supplied to a third separation membrane 30. The third separation membrane 30 selectively permeates the CO2 contained in the fourth lean gas to generate a third enriched gas enriched with CO2 and a third lean gas depleted with CO2.

[0088] [Variation Example 3]

[0089] In the above embodiments, the gas separation system 1 includes a methanation reactor 5; however, it may not include a methanation reactor 5. Therefore, the mixed gas is not limited to the gas synthesized by methanation, and any gas containing at least two polar gases and at least two non-polar gases can be used.

[0090] [Variation Example 4]

[0091] In the above embodiments, the gas separation system 1 includes a second separation membrane 20 as an example of a first separator; however, the first separator is not limited to a separation membrane. The first separator can be any structure capable of separating the second polar gas. For example, a structure that separates the second polar gas using a PSA method, a TSA method, or an absorption method can be used as the first separator.

[0092] [Variation Example 5]

[0093] In the above embodiments, the gas separation system 1 includes a third separation membrane 30 as an example of a second separator; however, the second separator is not limited to a separation membrane. The second separator can be any structure capable of separating the first non-polar gas. For example, a structure that separates the first non-polar gas using a PSA method, a TSA method, or an absorption method can be used as the second separator.

[0094] [Variation Example 6]

[0095] In the above embodiments, the polar gases (H2O and NH3) contained in the mixed gas are discharged to the outside; however, at least one polar gas can be reused. For example, NH3 can be reused as a raw material for generating H2 supplied to the methanation reactor 5, or as fuel for combustion in other processes. Furthermore, in the above-described modification 1, H2, which is one of the non-polar gases, can be reused. This improves the gas utilization efficiency of the entire system.

[0096] [Variation Example 7]

[0097] In the above embodiments, after all the polar gases are separated from the gas mixture, the non-polar gases are separated. However, a portion of the non-polar gases can be separated before all the polar gases are separated from the gas mixture.

[0098] For example, a portion of the CO2 can be pre-separated by a CO2 separation membrane disposed upstream of the first separation membrane 10. Alternatively, a portion of the CO2 can be pre-separated by a CO2 separation membrane disposed between the first separation membrane 10 and the second separation membrane 20.

[0099] [Variation Example 8]

[0100] In the above embodiment, H2O is separated by the first separation membrane 10 and NH3 is separated by the second separation membrane 20. However, NH3 can be separated by the first separation membrane 10 and H2O can be separated by the second separation membrane 20.

[0101] Explanation of reference numerals in the attached figures

[0102] 1. Gas separation system

[0103] 5. Methanation reactor

[0104] 10 First separation membrane

[0105] 20 Second separation membrane

[0106] 30 Third separation membrane

[0107] 40 Fourth separation membrane

Claims

1. A gas separation system for separating a second nonpolar gas from a mixture of a first polar gas, a second polar gas, a first nonpolar gas, and a second nonpolar gas, characterized in that, The gas separation system comprises: First separation membrane; A first separator, disposed downstream of the first separation membrane; and A second separator is disposed downstream of the first separator. The first separation membrane selectively permeates the first polar gas to generate a first enriched gas in which the first polar gas is enriched, and a first depleted gas in which the first polar gas is depleted and the second polar gas is enriched. The first separator separates the second polar gas to generate a second enriched gas enriched with the second polar gas and a second depleted gas depleted of the second polar gas. The second separator generates a third enriched gas (enriched by the first nonpolar gas) and a third depleted gas (depleted by the first nonpolar gas) by separating the first nonpolar gas.

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

3. The gas separation system according to claim 2, characterized in that, The second separation membrane has a different structure than the first separation membrane.

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

5. The gas separation system according to claim 4, characterized in that, The third separation membrane has a different composition than the first separation membrane.

6. The gas separation system according to any one of claims 1 to 3, characterized in that, 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 separator membrane.

7. The gas separation system according to any one of claims 1 to 3, characterized in that, At least one of the first polar gas and the second polar gas is reused.

8. The gas separation system according to any one of claims 1 to 3, characterized in that, The first polar gas is H2O. The second polar gas is NH3.

9. The gas separation system according to any one of claims 1 to 3, characterized in that, The first polar gas is NH3.

10. The gas separation system according to any one of claims 1 to 3, characterized in that, The first polar gas is H2O. The second polar gas is MeOH.

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