Gas treatment system

Abstract

To provide a gas treatment system that is simplified in a configuration for cleaning while securing a cleaning function of a separation membrane module.SOLUTION: A gas treatment system includes a plurality of gas separation systems. Each gas separation system includes: a separation membrane module having a separation membrane through which CO2 from combustion exhaust gas selectively permeates, an inflow port of the combustion exhaust gas, a first outflow port through which permeate gas flows out, a second outflow port through which non-permeate gas flows out; a first flow passage connected to the inflow port; a first switching section on the first flow passage, a second flow passage branched from the first flow passage, a third flow passage connected to the second outflow port; a second switching section on the third flow passage; a fourth flow passage branched from the third flow passage; and a fifth flow passage that connects the third flow passages of the plurality of gas separation systems. When the separation membrane module of a first gas separation system is cleaned, the second and third flow passages of the first gas separation system are opened; the first and third flow passages of a second gas separation system are opened; and non-permeate gas in the second gas separation system flows from the fifth flow passage to the third flow passage and the separation membrane module in the first gas separation system.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to gas processing systems. [Background technology]

[0002] A gas processing system is known in which a gas containing CO2 is supplied to a separation membrane module and CO2 is separated from the supply gas. In addition, a gas separation system is disclosed in Patent Document 1, for example, in which impurities adhering to a separation membrane module as a result of the supply gas passing through the separation membrane module are removed and the separation membrane module is cleaned.

[0003] The gas separation system disclosed in Patent Document 1 has two gas separation systems, each equipped with a separation membrane module. The permeate gas separated by the separation membrane of one gas separation system is supplied to the other gas separation system, and impurities adhering to the separation membrane in the other gas separation system are removed by entraining them in the permeate gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-48276 Summary of the Invention [Problem to be solved by the invention]

[0005] The gas separation system disclosed in Patent Document 1 uses a low-pressure permeate gas that has permeated one separation membrane to remove impurities adhering to the other separation membranes. Therefore, there is room for improvement in the cleaning function of the separation membrane module. In addition, there is a need for a simplified configuration for cleaning the separation membrane module.

[0006] The present disclosure provides a gas treatment system having a simplified configuration for cleaning a separation membrane module while ensuring the cleaning function of the separation membrane module. [Means for solving the problem]

[0007] In a first aspect, a gas processing system includes a plurality of gas separation systems, each of the plurality of gas separation systems including a separation membrane that selectively permeates CO2 and separates CO2 from combustion exhaust gas, an inlet into which the combustion exhaust gas flows, a first outlet through which a first permeable gas of the combustion exhaust gas that has flowed in from the inlet and permeated the separation membrane flows out, and a second outlet through which a non-permeable gas of the combustion exhaust gas that does not permeate the separation membrane flows out; a first flow path connected to the inlet, a first switching unit provided in the first flow path, a second flow path branching from the first flow path via the first switching unit, a third flow path connected to the second outlet, a second switching unit provided in the third flow path, and a second non-permeable gas of the combustion exhaust gas that branches off from the third flow path via the second switching unit. and a fourth flow path, and the gas processing system further comprises a fifth flow path connected to the third flow path and connecting the plurality of gas separation systems together, and when cleaning the separation membrane module of at least one gas separation system among the plurality of gas separation systems, in the first gas separation system, the second flow path is opened by the first switching unit and the third flow path is opened by the second switching unit, and in at least a second gas separation system, the first flow path is opened by the first switching unit and the third flow path is opened by the second switching unit, so that the non-permeate gas from at least a second gas separation system flows via the fifth flow path to the third flow path and the separation membrane module of the first gas separation system.

[0008] In a second aspect, a separation membrane module includes: a separation membrane that selectively permeates CO2 and separates CO2 from combustion exhaust gas; an inlet through which the combustion exhaust gas flows; a first outlet through which permeate gas of the combustion exhaust gas that has permeated the separation membrane flows out; and a second outlet through which non-permeate gas of the combustion exhaust gas that does not permeate the separation membrane flows out; a first flow path connected to the inlet; a fifth switching unit provided in the first flow path; a twelfth flow path branching from the first flow path via the fifth switching unit; a thirteenth flow path connected to the second outlet and communicating with the atmospheric environment; and a fourth pressure reducing means connected to the 12th flow path; and when the separation membrane module is cleaned, the twelfth flow path is opened by the fifth switching unit, and atmospheric air is introduced into the separation membrane module via the thirteenth flow path. [Effects of the Invention]

[0009] According to the technique of the present disclosure, it is possible to provide a gas processing system that has a simplified configuration for cleaning a separation membrane module while ensuring the cleaning function of the separation membrane module. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing an example of the overall configuration of a gas processing system according to a first embodiment. [Figure 2] 1 is a schematic cross-sectional view showing an example of the configuration of a separation membrane module of a gas processing system according to a first embodiment. [Figure 3] 2 is a block diagram showing an example of the configuration of a control unit of the gas processing system according to the first embodiment. FIG. [Figure 4] FIG. 2 is a diagram for explaining the CO2 separation operation of the separation membrane module in the gas processing system according to the first embodiment. [Figure 5] FIG. 3 is a view for explaining the cleaning operation of the separation membrane module in the gas processing system according to the first embodiment. [Figure 6] FIG. 2 is a schematic diagram showing an example of the overall configuration of a gas processing system according to a modified example of the first embodiment. [Figure 7]FIG. 10 is a diagram for explaining the CO2 separation operation of the auxiliary separation membrane module in the gas processing system according to the modified example of the first embodiment. [Figure 8] FIG. 10 is a view for explaining the cleaning operation of the auxiliary separation membrane module in the gas processing system according to a modified example of the first embodiment. [Figure 9] FIG. 10 is a schematic diagram showing an example of the overall configuration of a gas processing system according to a second embodiment. [Figure 10] FIG. 10 is a diagram for explaining the CO2 separation operation of the separation membrane module in the gas processing system according to the second embodiment. [Figure 11] FIG. 10 is a view for explaining the cleaning operation of the separation membrane module in the gas processing system according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, examples of gas processing systems according to embodiments will be described with reference to the drawings. Here, the term "connection" as used herein is not limited to a direct connection between one component A and another component B, but also includes a connection between component A and component B via one or more other components.

[0012] [First embodiment] <Overall structure> 1 to 3, a configuration example of a gas processing system 1 according to a first embodiment is shown. FIG. 1 is a schematic diagram showing an example of the overall configuration of the gas processing system 1 according to the first embodiment. FIG. 2 is a schematic cross-sectional view showing an example of the configuration of a separation membrane module of the gas processing system 1 according to the first embodiment. FIG. 3 is a block diagram showing an example of the configuration of a control unit of the gas processing system 1 according to the first embodiment.

[0013] The gas processing system 1 processes combustion exhaust gas containing CO2. For example, the gas processing system 1 processes combustion exhaust gas discharged from an engine 100E equipped on a ship. However, the combustion exhaust gas processed by the gas processing system 1 is not limited to that discharged from the engine 100E equipped on a ship. For example, the gas processing system 1 may process combustion exhaust gas containing CO2 discharged from combustion equipment that burns fossil fuels, such as a boiler in a coal-fired power plant. The engine 100E equipped on a ship is an example of a "combustion exhaust gas supply source."

[0014] The combustion exhaust gas contains impurities such as soot and dust. The impurities derived from the combustion exhaust gas clog part or all of the separation membrane 110, which will be described separately with reference to FIG. 2. When the impurities derived from the combustion exhaust gas adhere to the separation membrane 110 and clog the separation membrane 110, the CO2 permeation function of the separation membrane 110 is reduced. Here, the term "clogging" in this specification is not limited to the case where the flow of gas into and out of the separation membrane 110 is blocked by impurities adhered to the separation membrane 110, but also includes the case where the CO2 permeation function of the separation membrane 110 is reduced but the flow of gas into and out of the separation membrane 110 remains. Note that the term "clogging of a separation membrane module" including the separation membrane 110 may be used to refer to the clogging of the separation membrane 110. Note that the impurities are not limited to soot and dust.

[0015] The gas processing system 1 includes a plurality of gas separation systems and a flow path (a fifth flow path, which will be described separately) connecting the plurality of gas separation systems. Each of the plurality of gas separation systems includes a separation membrane module, a flow path (a plurality of flow paths, such as a first flow path, a second flow path, a third flow path, and a fourth flow path, which will be described separately), and a switching unit (a plurality of switching units, such as a first switching unit and a second switching unit, which will be described separately). The gas processing system 1 may also include other components such as a measuring unit that measures at least one of the pressure, flow rate, and concentration of the gas flowing through the flow path, a compressor 51, a control unit 60, etc. The gas processing system 1 may also include a storage tank for collecting CO2 separated by the separation membrane module.

[0016] In the example shown in FIG. 1 , examples of separation membrane modules included in each of the multiple gas separation systems include a first separation membrane module 11, a second separation membrane module 12, and a third separation membrane module 13. However, the number of separation membrane modules included in the gas processing system 1 is not limited to three. At least two separation membrane modules may be provided in the gas processing system 1. The first separation membrane module may be the first separation membrane module 11. However, the first separation membrane module is not limited to the first separation membrane module 11. A gas separation system having a first separation membrane module may be referred to as the "first gas separation system." The second separation membrane module may be the second separation membrane module 12. However, the second separation membrane module is not limited to the second separation membrane module 12. A gas separation system having a second separation membrane module may be referred to as the "second gas separation system." The third separation membrane module may be the third separation membrane module 13. However, the third separation membrane module is not limited to the third separation membrane module 13. A gas separation system having a third separation membrane module may be referred to as a “third gas separation system.” When the first separation membrane module 11 to the third separation membrane module 13 are described without distinction, the respective separation membrane modules are collectively referred to as “separation membrane module 10.”

[0017] The gas processing system 1 also includes multiple auxiliary gas separation systems. In the example shown in FIG. 1, the gas processing system 1 includes two auxiliary gas separation systems, but the number of auxiliary gas separation systems is not limited. Each of the multiple auxiliary gas separation systems includes an auxiliary separation membrane module, a flow path (multiple flow paths such as the seventh flow path, the ninth flow path, and the tenth flow path, which will be described separately), and a switching unit (multiple switching units such as the fourth switching unit, which will be described separately). The gas separation system and the auxiliary gas separation system are connected via a flow path (the sixth flow path, which will be described separately) extending from a separation membrane module 10 included in the gas separation system. Examples of auxiliary separation membrane modules included in the auxiliary gas separation system include a fourth separation membrane module 14 and a fifth separation membrane module 15. When the fourth separation membrane module 14 and the fifth separation membrane module 15 are described without distinction, these separation membrane modules will be collectively referred to as the "auxiliary separation membrane module 10S."

[0018] The gas processing system 1 will be described in detail below. Note that, in the following description, each flow path corresponds to a gas path including at least one pipe. Furthermore, although the switching unit will be described as a three-way valve, the switching unit is not limited to the three-way valve. Other examples of the switching unit include a flow path switching valve other than a three-way valve and a flow path switching mechanism including multiple two-way valves provided in each flow path to be switched. The number of three-way valves provided in the gas processing system 1 is not limited. Each three-way valve may include a processing unit that operates the valve element in response to a control signal output from the control unit 60. Furthermore, although the measuring unit will be described as a pressure sensor, the measuring unit is not limited to a pressure sensor. Other examples of the measuring unit include a flow rate sensor that measures the flow rate of gas and a concentration sensor that measures the concentration of gas. The number of measuring units, such as pressure sensors, provided in the gas processing system 1 is not limited. All of the multiple measuring units provided in the gas processing system 1 may be the same type of measuring unit that measures the same physical quantity of gas (e.g., pressure, flow rate, concentration), or a combination of different types of measuring units that measure different physical quantities.

[0019] <Separation membrane module 10 and auxiliary separation membrane module 10S> The configurations of the separation membrane module 10 and the auxiliary separation membrane module 10S will be described. As shown in Fig. 2, the separation membrane module 10 includes a separation membrane 110 and a container 120. The separation membrane 110 is housed in the container 120. The auxiliary separation membrane module 10S also includes a separation membrane 110 and a container 120.

[0020] The separation membrane 110 is, for example, a polymer membrane that selectively allows CO2 to permeate. In the example shown in FIG. 2, the separation membrane 110 is, for example, a hollow fiber membrane bundle formed by bundling several hundred to several hundred thousand hollow fiber membranes. Here, the "inner space 110A" of the separation membrane 110 corresponds to the hollow space formed inside each hollow fiber membrane. Furthermore, the "outer space 110B" of the separation membrane 110 corresponds to the space outside the outermost hollow fiber membrane among the hollow fiber membranes that make up the hollow fiber membrane bundle. However, the separation membrane 110 is not limited to a hollow fiber membrane bundle. Other examples of the separation membrane 110 include a stack of flat membranes and a spiral-shaped membrane made by winding flat membranes.

[0021] The combustion exhaust gas supplied to the separation membrane module 10 is introduced into the inner space 110A from an opening on one side of the hollow fiber membrane bundle. At this time, CO2 in the combustion exhaust gas permeates through the hollow fiber membranes. That is, CO2 in the combustion exhaust gas permeates the separation membrane 110 and reaches the space 110B outside the separation membrane 110. The gas that permeates the separation membrane 110 is called the "permeated gas."

[0022] In contrast, other components in the combustion exhaust gas are introduced into the inner space 110A through an opening on one side of the hollow fiber membrane bundle and then discharged from an opening on the other side of the hollow fiber membrane bundle. That is, the other components in the combustion exhaust gas do not permeate into the outer space 110B of the separation membrane 110, but pass through the inner space 110A of the separation membrane 110. The gas that does not permeate into the outer space 110B of the separation membrane 110 and passes through the inner space 110A is called a "non-permeated gas." Note that the non-permeated gas may contain CO2 that did not permeate the separation membrane 110.

[0023] Examples of materials that can be used to form the separation membrane 110 include polymer materials such as polyimide, polyetherimide, polyamide, polyamideimide, polysulfone, polycarbonate, silicone resin, and cellulose-based polymers, and ceramic materials such as zeolite. The separation membrane 110 may also be a membrane containing an ionic liquid. However, the materials that can be used to form the separation membrane 110 are not limited to these.

[0024] The container 120 includes an inlet 121, a first outlet 122, and a second outlet 123. The inlet 121 is an opening through which the combustion exhaust gas to be supplied to the separation membrane module 10 flows into the container 120. The combustion exhaust gas that flows in from the inlet 121 is introduced into the space 110A inside the separation membrane 110. The first outlet 122 is an opening through which the permeated gas that has permeated from the space 110A inside the separation membrane 110 to the space 110B outside flows out. The second outlet 123 is an opening through which the non-permeated gas that has passed through the space 110A inside the separation membrane 110 flows out.

[0025] The permeate gas flowing out from the first outlet 122 of the separation membrane module 10 may be referred to as the "permeate gas from the separation membrane module 10" or the "permeate gas from the gas separation system." The non-permeate gas flowing out from the second outlet 123 of the separation membrane module 10 may be referred to as the "non-permeate gas from the separation membrane module 10" or the "non-permeate gas from the gas separation system." The permeate gas from the separation membrane module 10 flows into the inlet 121 of the auxiliary separation membrane module 10S. The permeate gas flowing out from the first outlet 122 of the auxiliary separation membrane module 10S may be referred to as the "permeate gas from the auxiliary separation membrane module 10S" or the "permeate gas from the auxiliary gas separation system." The non-permeate gas flowing out from the second outlet 123 of the auxiliary separation membrane module 10S may be referred to as the "non-permeate gas from the auxiliary separation membrane module 10S" or the "non-permeate gas from the auxiliary gas separation system."

[0026] <Example of flow path> Next, specific examples of the flow paths will be described. The gas separation system having the first separation membrane module 11 further includes pipes 22a, 22b, 22c, 22d, 22e, 22f, 22g, 26a, and 27a. Pipe 27a is also a pipe shared with the gas separation system having the second separation membrane module 12 and the third separation membrane module 13. Pipes 22a and 22b are an example of a "first flow path." Pipe 22c is an example of a "second flow path." Pipes 22d and 22e are an example of a "third flow path." Pipe 22f is an example of a "fourth flow path." Pipes 22g, 26a, and 27a are an example of a "sixth flow path."

[0027] The gas separation system having the second separation membrane module 12 further includes pipes 23a, 23b, 23c, 23d, 23e, 23f, 23g, 26b, 26c, and 27a. Pipe 26b is a pipe shared with the gas separation system having the third separation membrane module 13. Pipes 23a and 23b are an example of a "first flow path." Pipe 23c is an example of a "second flow path." Pipes 23d and 23e are an example of a "third flow path." Pipe 23f is an example of a "fourth flow path." Pipes 23g, 26b, 26c, and 27a are an example of a "sixth flow path."

[0028] The gas separation system having the third separation membrane module 13 further includes pipe 24a, pipe 24b, pipe 24c, pipe 24d, pipe 24e, pipe 24f, pipe 24g, pipe 26b, and pipe 27a. Pipe 24a and pipe 24b are an example of a "first flow path." Pipe 24c is an example of a "second flow path." Pipe 24d and pipe 24e are an example of a "third flow path." Pipe 24f is an example of a "fourth flow path." Pipe 24g, pipe 26b, and pipe 27a are an example of a "sixth flow path."

[0029] In the first embodiment, the pipes 22c, 23c, and 24c, which correspond to the second flow paths of the respective gas separation systems, are connected to the atmosphere. The gases that have passed through the pipes 22c, 23c, and 24c are discharged to the outside.

[0030] The gas processing system 1 is provided with a fifth flow path that connects multiple gas separation systems. Examples of the fifth flow path include pipe 25a and pipe 25b. One end of pipe 25a is connected to pipe 22e, which is an example of a third flow path. The other end of pipe 25a is connected to pipe 24e, which is an example of a third flow path. One end of pipe 25b is connected to the other end of pipe 25a. That is, one end of pipe 25b is connected to pipe 24e. The other end of pipe 25b is connected to pipe 23e, which is an example of a third flow path.

[0031] Next, the auxiliary gas separation system having the fourth separation membrane module 14 has pipes 28a, 28d, 28e, 28f, and 28g. Pipe 28a is an example of a "seventh flow path." Pipes 28d and 28e are examples of a "ninth flow path." Pipe 28f is an example of a "tenth flow path." Pipe 28g is connected to the first outlet 122 of the fourth separation membrane module 14. Pipe 28g may also be connected to a storage tank that collects the second permeate gas. The gas that flows through pipe 28g is discharged to the outside. The permeate gas from the fourth separation membrane module 14 is an example of a "second permeate gas."

[0032] The auxiliary gas separation system having the fifth separation membrane module 15 has pipes 29a, 29d, 29e, 29f, and 29g. Pipe 29a is an example of a "seventh flow path." Pipes 29d and 29e are examples of a "ninth flow path." Pipe 29f is an example of a "tenth flow path." Pipe 29g is connected to the first outlet 122 of the fifth separation membrane module 15. Pipe 29g may also be connected to a storage tank that collects the second permeate gas. The gas that flows through pipe 29g is discharged to the outside. The permeate gas from the fifth separation membrane module 15 is an example of a "second permeate gas."

[0033] <Specific Examples of Connection Configuration of Separation Membrane Module 10 and Switching Unit> As shown in Fig. 1, each of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13 is connected to, for example, a ship engine 100E. Combustion exhaust gas discharged from the ship engine 100E is supplied to each of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13. By supplying the combustion exhaust gas to at least two of the separation membrane modules 10 in multiple systems, even if the separation membrane of a separation membrane module 10 in one system becomes clogged, CO2 can be separated from the combustion exhaust gas through the separation membrane modules 10 in the other systems. As a result, the CO2 capture efficiency can be improved.

[0034] First, the connection configuration between the ship engine 100E and the first separation membrane module 11 will be described. The first separation membrane module 11 is connected to the ship engine 100E via pipes 21, 22a, and 22b. An equal pipe 21D may be interposed between pipes 21 and 22a. The combustion exhaust gas discharged from the ship engine 100E flows through these pipes and reaches the first separation membrane module 11. Pipe 22b is connected to the inlet 121 of the first separation membrane module 11.

[0035] Three-way valve 31a is disposed between pipe 22a and pipe 22b. That is, three-way valve 31a is provided in a first flow path including pipe 22a and pipe 22b. Three-way valve 31a is an example of a "first switching unit." Three-way valve 31a includes a first port 31a1, a second port 31a2, a third port 31a3, and a valve element that switches each port between open and closed.

[0036] A first port 31a1 of the three-way valve 31a is connected to the pipe 22a. A second port 31a2 is connected to the pipe 22b. A third port 31a3 is connected to the pipe 22c. For example, a filter that adsorbs impurities may be provided in the pipe 22c. A second flow path corresponding to the pipe 22c branches off from the first flow path including the pipes 22a and 22b via the three-way valve 31a.

[0037] When the valve element of the three-way valve 31a is operated and the first port 31a1 and the second port 31a2 are opened, the pipes 22a and 22b are connected to each other and the pipe 22c is closed. This opens the first flow path including the pipes 22a and 22b. On the other hand, when the valve element of the three-way valve 31a is operated and the second port 31a2 and the third port 31a3 are opened, the pipes 22a and 22b are not connected to each other and the pipes 22b and 22c are connected to each other. This opens the second flow path including the pipe 22c.

[0038] Next, the connection configuration between the ship engine 100E and the second separation membrane module 12 will be described. The second separation membrane module 12 is connected to the ship engine 100E via pipe 21, pipe 23a, and pipe 23b. An equal pipe 21D may be interposed between pipe 21 and pipe 23a. The combustion exhaust gas discharged from the ship engine 100E flows through these pipes and reaches the second separation membrane module 12. Pipe 23b is connected to the inlet 121 of the second separation membrane module 12.

[0039] A three-way valve 31b may be disposed between the pipe 23a and the pipe 23b. That is, the three-way valve 31b is provided in a first flow path including the pipe 23a and the pipe 23b. The three-way valve 31b is an example of a "first switching unit." The three-way valve 31b includes a first port 31b1, a second port 31b2, a third port 31b3, and a valve element that switches each port between open and closed. The first port 31b1 of the three-way valve 31b is connected to the pipe 23a. The second port 31b2 is connected to the pipe 23b. The third port 31b3 is connected to the pipe 23c. For example, a filter that adsorbs impurities may be provided in the pipe 23c.

[0040] When the valve element of the three-way valve 31b is operated and the first port 31b1 and the second port 31b2 are opened, the pipes 23a and 23b are connected to each other and the pipe 23c is closed. This opens the first flow path including the pipes 23a and 23b. On the other hand, when the valve element of the three-way valve 31b is operated and the second port 31b2 and the third port 31b3 are opened, the pipes 23a and 23b are not connected to each other and the pipes 23b and 23c are connected to each other. This opens the second flow path including the pipe 23c.

[0041] Next, the connection configuration between the ship engine 100E and the third separation membrane module 13 will be described. The third separation membrane module 13 is connected to the ship engine 100E via pipes 21, 24a, and 24b. An equal pipe 21D may be interposed between pipes 21 and 24a. The combustion exhaust gas discharged from the ship engine 100E flows through these pipes and reaches the third separation membrane module 13. Of the flow path including pipes 24a and 24b, pipe 24b is connected to the inlet 121 of the third separation membrane module 13.

[0042] A three-way valve 31c may be disposed between the pipe 24a and the pipe 24b. That is, the three-way valve 31c is provided in a first flow path including the pipe 24a and the pipe 24b. The three-way valve 31c includes a first port 31c1, a second port 31c2, a third port 31c3, and a valve element that switches between opening and closing each port. The three-way valve 31c is an example of a "first switching unit." The first port 31c1 of the three-way valve 31c is connected to the pipe 24a. The second port 31c2 is connected to the pipe 24b. The third port 31c3 is connected to the pipe 24c. For example, a filter that adsorbs impurities may be provided in the pipe 24c.

[0043] When the valve element of the three-way valve 31c is operated and the first port 31c1 and the second port 31c2 are opened, the pipes 24a and 24b are connected to each other and the pipe 24c is closed. This opens the first flow path including the pipes 24a and 24b. On the other hand, when the valve element of the three-way valve 31c is operated and the second port 31c2 and the third port 31c3 are opened, the pipes 24a and 24b are not connected to each other and the pipes 24b and 24c are connected to each other. This opens the second flow path including the pipe 24c.

[0044] Next, the connection configuration between the first separation membrane module 11 and the second separation membrane module 12 will be described. The first separation membrane module 11 and the second separation membrane module 12 are connected to each other via pipes 22d, 22e, 25a, 25b, 23e, and 23d. That is, the third flow path (pipes 22d and 22e) connected to the first separation membrane module 11 and the third flow path (pipes 23d and 23e) connected to the second separation membrane module 12 are connected via a fifth flow path including pipes 25a and 25b. The fifth flow path connects the third flow paths connected to the multiple separation membrane modules 10. The fifth flow path between the third flow path (pipes 22d and 22e) connected to the first separation membrane module 11 and the third flow path (pipes 24d and 24e) connected to the third separation membrane module 13 corresponds to pipe 25a. In addition, the fifth flow path between the third flow path (pipes 23d and 23e) connected to the second separation membrane module 12 and the third flow path (pipes 24d and 24e) connected to the third separation membrane module 13 corresponds to pipe 25b.

[0045] The pipe 22d is connected to the second outlet 123 of the first separation membrane module 11. A three-way valve 31d is disposed between the pipe 22d and the pipe 22e. That is, the three-way valve 31d is provided in a third flow path including the pipe 22d and the pipe 22e. A filter may be provided in the pipe 22e. The three-way valve 31d is an example of a "second switching unit."

[0046] The three-way valve 31d includes a first port 31d1, a second port 31d2, a third port 31d3, and a valve element that switches between opening and closing each port. The first port 31d1 of the three-way valve 31d is connected to a pipe 22d. The second port 31d2 is connected to a pipe 22e. The third port 31d3 is connected to a pipe 22f. The non-permeated gas from the first separation membrane module 11 flows through the pipes 22d and 22f and is discharged to the outside. A filter may be provided in the pipe 22f.

[0047] When the valve element of the three-way valve 31d is operated and the first port 31d1 and the second port 31d2 are opened, the pipes 22d and 22e are connected to each other and the pipes 22d and 22f are not connected to each other. This opens the third flow path including the pipes 22d and 22e. On the other hand, when the valve element of the three-way valve 31d is operated and the first port 31d1 and the third port 31d3 are opened, the pipes 22d and 22f are connected to each other and the pipes 22d and 22e are not connected to each other. This opens the fourth flow path including the pipe 22f.

[0048] The pipe 23d is connected to the second outlet 123 of the second separation membrane module 12. A three-way valve 31e is disposed between the pipe 23d and the pipe 23e. That is, the three-way valve 31e is provided in a third flow path including the pipe 23d and the pipe 23e. The three-way valve 31e is an example of a "second switching unit." The three-way valve 31e includes a first port 31e1, a second port 31e2, a third port 31e3, and a valve element that switches each port between open and closed. The first port 31e1 of the three-way valve 31e is connected to the pipe 23d. The second port 31e2 is connected to the pipe 23e. The third port 31e3 is connected to the pipe 23f. A filter may be provided in the pipe 23f.

[0049] When the valve element of the three-way valve 31e is operated to open the first port 31e1 and the second port 31e2, pipe 23d communicates with pipe 23e, but pipe 23d does not communicate with pipe 23f. This opens the third flow path including pipe 23d and pipe 23e. On the other hand, when the valve element of the three-way valve 31e is operated to open the first port 31e1 and the third port 31e3, pipe 23d does not communicate with pipe 23e, but pipe 23d communicates with pipe 23f. This opens the fourth flow path including pipe 23f. When pipe 23d communicates with pipe 23e, non-permeate gas from the second separation membrane module 12 passes through pipe 25b and pipe 25a and flows toward the three-way valve 31d. When pipe 23d communicates with pipe 23f, non-permeate gas from the second separation membrane module 12 is discharged to the outside.

[0050] Next, we will explain the connection configuration between the first separation membrane module 11 and the third separation membrane module 13. The first separation membrane module 11 and the third separation membrane module 13 are connected to each other via pipes 22d, 22e, 25a, 24e, and 24d.

[0051] A three-way valve 31f is disposed between the pipe 24d and the pipe 24e. That is, the three-way valve 31f is provided in a third flow path including the pipe 24d and the pipe 24e. The three-way valve 31f is an example of a "second switching unit." The three-way valve 31f includes a first port 31f1, a second port 31f2, a third port 31f3, and a valve element that switches between opening and closing each port. The first port 31f1 of the three-way valve 31f is connected to the pipe 24d. The second port 31f2 is connected to the pipe 24e. The third port 31f3 is connected to the pipe 24f. A filter may be provided in the pipe 24f.

[0052] When the valve element of the three-way valve 31f is operated to open the first port 31f1 and the second port 31f2, pipe 24d communicates with pipe 24e, but pipe 24d does not communicate with pipe 24f. This opens the third flow path including pipe 24d and pipe 24e. On the other hand, when the valve element of the three-way valve 31f is operated to open the first port 31f1 and the third port 31f3, pipe 24d communicates with pipe 24f, but pipe 24d does not communicate with pipe 24e. This opens the fourth flow path including pipe 24f. When the flow path including pipe 24d and pipe 24e is open, non-permeate gas from the third separation membrane module 13 passes through pipe 25a and flows toward the three-way valve 31d. When the flow path including pipe 24d and pipe 24f is open, non-permeate gas from the third separation membrane module 13 is discharged to the outside.

[0053] <Connection configuration and switching section of auxiliary separation membrane module 10S> Next, the connection configuration and switching unit of the auxiliary separation membrane module 10S will be described. The fourth separation membrane module 14 and the fifth separation membrane module 15 are each connected to at least one of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13. The permeate gases from the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13 are supplied to the fourth separation membrane module 14 and the fifth separation membrane module 15, respectively.

[0054] First, we will explain the connection configuration between the first separation membrane module 11 and the fourth separation membrane module 14. The first separation membrane module 11 and the fourth separation membrane module 14 are connected via a pipe 22g, a pipe 26a, a pipe 27a, and a pipe 28a.

[0055] A three-way valve 31g is disposed between the pipe 27a and the pipe 28a. The three-way valve 31g includes a first port 31g1, a second port 31g2, a third port 31g3, and a valve element that switches between opening and closing each port.

[0056] A first port 31g1 of the three-way valve 31g is connected to a pipe 28a, a second port 31g2 is connected to a pipe 29a (described separately), and a third port 31g3 is connected to a pipe 27a.

[0057] When the valve element of the three-way valve 31g is operated and the first port 31g1 and the third port 31g3 are opened, the pipes 27a and 28a are connected to each other and the pipe 29a is closed. This opens the flow path including the pipes 27a and 28a. On the other hand, when the valve element of the three-way valve 31g is operated and the second port 31g2 and the third port 31g3 are opened, the pipes 27a and 28a are not connected to each other and the pipes 27a and 29a are connected to each other. This opens the flow path including the pipes 27a and 29a.

[0058] Next, we will explain the connection configuration between the second separation membrane module 12 and the fourth separation membrane module 14. The second separation membrane module 12 and the fourth separation membrane module 14 are connected via a pipe 23g, a pipe 26c, a pipe 27a, and a pipe 28a.

[0059] Next, we will explain the connection configuration between the third separation membrane module 13 and the fourth separation membrane module 14. The third separation membrane module 13 and the fourth separation membrane module 14 are connected via a pipe 24g, a pipe 26b, a pipe 27a, and a pipe 28a.

[0060] Next, we will explain the connection configuration between the first separation membrane module 11 and the fifth separation membrane module 15. The first separation membrane module 11 and the fifth separation membrane module 15 are connected via a pipe 22g, a pipe 26a, a pipe 27a, and a pipe 29a.

[0061] Next, we will explain the connection configuration between the second separation membrane module 12 and the fifth separation membrane module 15. The second separation membrane module 12 and the fifth separation membrane module 15 are connected via a pipe 23g, a pipe 26c, a pipe 27a, and a pipe 29a.

[0062] Next, we will explain the connection configuration between the third separation membrane module 13 and the fifth separation membrane module 15. The third separation membrane module 13 and the fifth separation membrane module 15 are connected via a pipe 24g, a pipe 26b, a pipe 27a, and a pipe 29a.

[0063] Next, the connection configuration between the fourth separation membrane module 14 and the fifth separation membrane module 15 will be described. The fourth separation membrane module 14 and the fifth separation membrane module 15 are connected to each other via pipes 28d, 28e, 25c, 29e, and 29d. That is, the ninth flow path (pipes 28d and 28e) connected to the fourth separation membrane module 14 and the ninth flow path (pipes 29d and 29e) connected to the fifth separation membrane module 15 are connected via an eleventh flow path corresponding to pipe 25c.

[0064] The pipe 28d is connected to the second outlet 123 of the fourth separation membrane module 14. A three-way valve 31h is disposed between the pipe 28d and the pipe 28e. That is, the three-way valve 31h is provided in the ninth flow path including the pipe 28d and the pipe 28e. A filter may be provided in the pipe 28e. The three-way valve 31h is an example of a "fourth switching unit."

[0065] The three-way valve 31h includes a first port 31h1, a second port 31h2, a third port 31h3, and a valve element that switches between opening and closing each port. The first port 31h1 of the three-way valve 31h is connected to a pipe 28d. The second port 31h2 is connected to a pipe 28e. The third port 31h3 is connected to a pipe 28f. The non-permeated gas from the fourth separation membrane module 14 flows through the pipes 28d and 28f and is discharged to the outside. A filter may be provided in the pipe 28f.

[0066] When the valve element of the three-way valve 31h is operated and the first port 31h1 and the second port 31h2 are opened, the pipes 28d and 28e are connected to each other and the pipes 28d and 28f are not connected to each other. This opens the ninth flow path including the pipes 28d and 28e. On the other hand, when the valve element of the three-way valve 31h is operated and the first port 31h1 and the third port 31h3 are opened, the pipes 28d and 28f are connected to each other and the pipes 28d and 28e are not connected to each other. This opens the tenth flow path including the pipe 28f.

[0067] The pipe 29d is connected to the second outlet 123 of the fifth separation membrane module 15. A three-way valve 31i is disposed between the pipe 29d and the pipe 29e. That is, the three-way valve 31i is provided in a ninth flow path including the pipe 29d and the pipe 29e. The three-way valve 31i is an example of a "fourth switching unit." The three-way valve 31i includes a first port 31i1, a second port 31i2, a third port 31i3, and a valve element that switches each port between open and closed. The first port 31i1 of the three-way valve 31i is connected to the pipe 29d. The second port 31i2 is connected to the pipe 29e. The third port 31i3 is connected to the pipe 29f. A filter may be provided in the pipe 29f.

[0068] When the valve element of the three-way valve 31i is operated to open the first port 31i1 and the second port 31i2, pipe 29d and pipe 29e are connected, but pipe 29d and pipe 29f are not connected. This opens the ninth flow path including pipe 29d and pipe 29e. On the other hand, when the valve element of the three-way valve 31i is operated to open the first port 31i1 and the third port 31i3, pipe 29d and pipe 29e are not connected, but pipe 29d and pipe 29f are connected. This opens the tenth flow path including pipe 29f. When pipe 29d and pipe 29e are connected, non-permeate gas from the fifth separation membrane module 15 passes through pipe 25c and flows toward the three-way valve 31h. When pipe 29d and pipe 29f are connected, non-permeate gas from the fifth separation membrane module 15 is discharged to the outside.

[0069] <Measurement section> Next, an example of the measurement unit will be described. As shown in Fig. 1, the gas processing system 1 may include, for example, a measurement unit 41a that measures the pressure of the combustion exhaust gas supplied to the first separation membrane module 11, a measurement unit 41b that measures the pressure of the permeate gas from the first separation membrane module 11, and a measurement unit 41c that measures the pressure of the non-permeate gas from the first separation membrane module 11. A measurement unit that measures the pressure of the combustion gas supplied to another separation membrane module 10, a measurement unit that measures the pressure of the permeate gas from another separation membrane module 10, and a measurement unit that measures the pressure of the non-permeate gas from another separation membrane module 10 may also be provided separately.

[0070] The measuring unit 41a is provided, for example, on the pipe 22b. The measuring unit 41b is provided, for example, on the pipe 22g. The measuring unit 41c is provided, for example, on the pipe 22d. The measuring units 41a, 41b, and 41c output measurement signals indicating the measured pressure values ​​(measurement values) to the control unit 60.

[0071] The measuring unit 41a may be a flow sensor that measures the flow rate of the combustion exhaust gas supplied to the first separation membrane module 11, or a concentration sensor that measures the concentration of CO2 in the combustion exhaust gas supplied to the first separation membrane module 11. The measuring unit 41b may be a flow sensor that measures the flow rate of the permeate gas from the first separation membrane module 11, or a concentration sensor that measures the concentration of CO2 in the permeate gas from the first separation membrane module 11. The measuring unit 41c may be a flow sensor that measures the flow rate of the non-permeate gas from the first separation membrane module 11, or a concentration sensor that measures the concentration of CO2 in the non-permeate gas from the first separation membrane module 11.

[0072] <Compressor> The compressor 51 compresses the gas flowing into the inlet 121 of the separation membrane module 10. In the example shown in FIG. 1, two compressors 51a and 51b are provided. The compressor 51a is provided, for example, in the pipe 21. The compressor 51a compresses the combustion exhaust gas discharged from the engine 100E of the ship. The high-pressure combustion exhaust gas compressed by the compressor 51a is supplied to the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13, respectively. However, the position of the compressor 51a is not limited as long as it is located upstream of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13 and closer to the engine 100E of the ship.

[0073] The compressor 51b is provided on the pipe 27a. The compressor 51b compresses the permeated gas from the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13. The high-pressure gas compressed by the compressor 51b is supplied to the fourth separation membrane module 14 and the fifth separation membrane module 15, respectively.

[0074] <Control unit> Next, the control unit 60 will be described. As shown in Fig. 3, the control unit 60 is an information processing device including, for example, an arithmetic processing unit 61, a storage unit 62, and a communication unit 63. The arithmetic processing unit 61, the storage unit 62, and the communication unit 63 are connected to each other via a bus 68.

[0075] The control unit 60 is communicatively connected to each of the measurement units 41a, 41b, and 41c, and also communicatively connected to each of the three-way valves 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h, and 31i.

[0076] The arithmetic processing unit 61 is a processor that controls and processes various operations in the control unit 60. A CPU (Central Processing Unit) is an example of the arithmetic processing unit 61. The arithmetic processing unit 61 may also be configured with other electronic circuits that perform the same functions as a processor such as a CPU.

[0077] The storage unit 62 stores programs executed by the arithmetic processing unit 61 and various data required for executing the programs. An example of the storage unit 62 is a non-volatile storage medium such as a ROM (Read Only Memory).

[0078] The communication unit 63 is, for example, a communication interface that includes components such as a communication circuit and an antenna for communicating with each of the measuring units 41a, 41b, and 41c and the three-way valves 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h, and 31i.

[0079] Next, various functions of the arithmetic processing unit 61 will be described. The arithmetic processing unit 61 functions as each means such as an acquisition means 611 and a detection means 612. The arithmetic processing unit 61 executes a program stored in the storage unit 62 to cause the control unit 60 to function as each of these means. The program may be provided by being stored in a computer-readable storage medium, or may be provided via a communication network such as the Internet.

[0080] The acquiring means 611 receives measurement signals from each of the measuring units 41a, 41b, and 41c via the communication unit 63. As a result, the acquiring means 611 acquires various types of information, such as information on the pressure of the combustion exhaust gas supplied to the first separation membrane module 11, the pressure of the permeate gas from the first separation membrane module 11, and the pressure of the non-permeate gas from the first separation membrane module 11.

[0081] The detection means 612 detects blockage of the first separation membrane module 11 based on the information acquired by the acquisition means 611. For example, the detection means 612 detects that the first separation membrane module 11 is blocked when the pressure of the combustion exhaust gas supplied to the first separation membrane module 11 exceeds a predetermined threshold, or when the pressure of the permeate gas from the first separation membrane module 11 or the pressure of the non-permeate gas from the first separation membrane module 11 falls below a predetermined threshold.

[0082] Furthermore, if the measuring units 41a, 41b, 41c are flow sensors, they may detect blockage of the first separation membrane module 11 when the flow rate of the combustion exhaust gas supplied to the first separation membrane module 11, the flow rate of the permeate gas from the first separation membrane module 11, and the flow rate of the non-permeate gas from the first separation membrane module 11 are below predetermined thresholds. The control unit 60 may detect blockage of other separation membrane modules 10 using a similar method.

[0083] When the detection means 612 detects clogging of the first separation membrane module 11, it outputs a control signal to a predetermined one of the three-way valves 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h, and 31i. When the control signal from the detection means 612 is output to the predetermined three-way valve, a cleaning operation of the first separation membrane module 11 is performed.

[0084] <Separation membrane module cleaning operation> Next, the cleaning operation of the separation membrane module 10 performed by the gas processing system 1 will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a diagram for explaining the CO2 separation operation of the separation membrane module 10. Fig. 5 is a diagram for explaining the cleaning operation of the separation membrane module 10.

[0085] As a premise, the CO2 separation operation of the first separation membrane module will be described with reference to FIG. 4. Hereinafter, the CO2 separation operation of the first separation membrane module 11 will be described as the first separation membrane module, but the other separation membrane modules 10 may also perform similar CO2 separation operations. As shown in FIG. 4, the three-way valve 31a connects the pipe 22a to the pipe 22b and closes the pipe 22c. This allows the combustion exhaust gas discharged from the ship engine 100E to be supplied to the first separation membrane module 11. At this time, the three-way valve 31b may connect the pipe 23a to the pipe 23b or may close it. In other words, the combustion exhaust gas discharged from the ship engine 100E may or may not be supplied to the second separation membrane module 12. Furthermore, the three-way valve 31c may connect the pipe 24a to the pipe 24b or may close it. That is, the combustion exhaust gas discharged from the engine 100E of the ship may or may not be supplied to the third separation membrane module 13.

[0086] The three-way valve 31d connects the pipes 22d and 22f, but does not connect the pipes 22d and 22e. The non-permeate gas from the first separation membrane module 11 flows through the pipes 22d and 22f and is discharged to the outside. In contrast, the permeate gas from the first separation membrane module 11 flows through the pipes 22g, 26a, 27a, and 28a to flow to the fourth separation membrane module 14. The permeate gas from the first separation membrane module 11 may also flow through the pipes 22g, 26a, 27a, and 29a to head toward the fifth separation membrane module 15.

[0087] When combustion exhaust gas is supplied to the second separation membrane module 12, the three-way valve 31e connects pipes 23d and 23f and does not connect pipes 23d and 23e. Non-permeate gas from the second separation membrane module 12 flows through pipes 23d and 23f and is discharged to the outside. In contrast, permeate gas from the second separation membrane module 12 flows through pipes 23g, 26c, 26b, 27a, and 28a to flow to the fourth separation membrane module 14. Note that the permeate gas from the second separation membrane module 12 may also flow through pipes 23g, 26c, 26b, 27a, and 29a to head toward the fifth separation membrane module 15.

[0088] When combustion exhaust gas is supplied to the third separation membrane module 13, the three-way valve 31f connects pipe 24d to pipe 24f and does not connect pipe 24d to pipe 24e. The non-permeate gas from the third separation membrane module 13 flows through pipe 24d and pipe 24f and is discharged to the outside. In contrast, the permeate gas from the third separation membrane module 13 flows through pipe 24g, pipe 26b, pipe 27a, and pipe 28a to flow to the fourth separation membrane module 14. The permeate gas from the third separation membrane module 13 may also flow through pipe 24g, pipe 26b, pipe 27a, and pipe 29a to head toward the fifth separation membrane module 15.

[0089] The CO2 separation operation of the fourth separation membrane module 14 will now be described. As shown in Fig. 4, the three-way valve 31g connects the pipe 27a and the pipe 28a and closes the pipe 29a. This allows the permeated gas from at least one of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13 to be supplied to the fourth separation membrane module 14.

[0090] The three-way valve 31h connects the pipes 28d and 28f, but does not connect the pipes 28d and 28e. The non-permeate gas from the fourth separation membrane module 14 flows through the pipes 28d and 28f and is discharged to the outside. The permeate gas from the fourth separation membrane module 14 flows through the pipe 28g to, for example, a storage tank.

[0091] The CO2 separation operation of the fifth separation membrane module 15 may be similar to the CO2 separation operation of the fourth separation membrane module. For example, the three-way valve 31g connects the pipe 27a and the pipe 29a and closes the pipe 28a. This allows the fifth separation membrane module 15 to be supplied with permeated gas from at least one of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13.

[0092] The three-way valve 31i connects the pipe 29d to the pipe 29f and does not connect the pipe 29d to the pipe 29e. The non-permeate gas from the fifth separation membrane module 15 flows through the pipe 29d and the pipe 29f and is discharged to the outside. The permeate gas from the fifth separation membrane module 15 flows through the pipe 29g to, for example, a storage tank.

[0093] Next, the cleaning operation of the first separation membrane module will be described with reference to Figure 5. Below, the cleaning operation of the first separation membrane module 11 will be described as the first separation membrane module, but similar cleaning operations may be performed on other separation membrane modules 10. Furthermore, the second separation membrane module 12 is used as the second separation membrane module that supplies non-permeate gas for cleaning the first separation membrane module, but the second separation membrane module may be another separation membrane module. Furthermore, the third separation membrane module is referred to as the third separation membrane module 13, but the third separation membrane module may be another separation membrane module 10.

[0094] First, the detection means 612 of the control unit 60 detects clogging of the first separation membrane module 11 based on the measurement values ​​acquired from each of the measurement units 41a, 41b, and 41c.

[0095] Subsequently, the detection means 612 outputs a control signal to each of the three-way valves 31a, 31d, and 31e. Furthermore, when the combustion exhaust gas is not supplied to the second separation membrane module 12, the detection means 612 outputs a control signal to the three-way valve 31b.

[0096] The three-way valve 31a closes the communication between the pipe 22a and the pipe 22b and connects the pipe 22b and the pipe 22c in response to a control signal from the detection means 612. This stops the supply of combustion exhaust gas to the first separation membrane module 11.

[0097] The three-way valve 31b connects the pipe 23a and the pipe 23b in response to a control signal from the detection means 612. As a result, the combustion exhaust gas is supplied to the second separation membrane module 12.

[0098] In response to a control signal from the detection means 612, the three-way valve 31d closes the communication between the pipes 22d and 22f and connects the pipes 22d and 22e. In addition, in response to a control signal from the detection means 612, the three-way valve 31e closes the communication between the pipes 23d and 23f and connects the pipes 23d and 23e. This allows communication between the pipes 22d, 22e, 25a, 25b, 23e, and 23d. That is, when cleaning the separation membrane module 10 in the first gas separation system, in the first gas separation system, the first switch (e.g., three-way valve 31a) opens the second flow path (e.g., pipe 22c) and the second switch (e.g., three-way valve 31d) opens the third flow path (e.g., pipes 22d and 22e). In the second gas separation system having the second separation membrane module 12, the first flow path (e.g., pipes 23a and 23b) is opened by the first switching unit (e.g., three-way valve 31b), and the third flow path (e.g., pipes 23d and 23e) is opened by the second switching unit (e.g., three-way valve 31e). As a result, the non-permeated gas from the second separation membrane module 12 flows through the fifth flow path (e.g., pipes 25a and 25b) to the third flow path (e.g., pipes 22d and 22e) and the first separation membrane module 11.

[0099] By the operation of the three-way valves 31b, 31d, and 31e, the non-permeate gas from the second separation membrane module 12 can be supplied toward the second outlet 123 of the first separation membrane module 11. That is, the non-permeate gas from the second separation membrane module 12 can be caused to flow into the space 110A inside the separation membrane 110 in the first separation membrane module 11. This allows the first separation membrane module 11 to be washed with the non-permeate gas from the second separation membrane module 12. In other words, the first separation membrane module can be washed with the non-permeate gas from the second separation membrane module.

[0100] The non-permeate gas from the second separation membrane module 12 has a higher pressure than the permeate gas from the second separation membrane module 12. This allows the first separation membrane module 11 to be washed using the relatively high-pressure non-permeate gas from the second separation membrane module 12. As a result, the washing function of the first separation membrane module 11 can be ensured. In addition, there is no need to separately provide a dedicated member for washing the first separation membrane module 11. Furthermore, by appropriately combining the piping for flowing the non-permeate gas from the first separation membrane module 11 and the piping for flowing the non-permeate gas from the second separation membrane module 12, the non-permeate gas from the second separation membrane module 12 can be supplied to the first separation membrane module 11 during washing. As a result, the configuration for washing the first separation membrane module 11 can be simplified.

[0101] Furthermore, the pressure of the combustion exhaust gas supplied to the second separation membrane module 12 is increased by the compressor 51a. That is, the non-permeate gas from the second separation membrane module 12 flows to the first separation membrane module 11 in an increased pressure state. This allows gas at a relatively high pressure to flow into the space 110A inside the separation membrane 110 in the first separation membrane module 11. As a result, the cleaning function of the first separation membrane module 11 can be improved. Note that even when the second separation membrane module is a separation membrane module 10 other than the second separation membrane module 12, the pressure of the non-permeate gas from the separation membrane module 10 corresponding to the second separation membrane module may be increased by the compressor 51a.

[0102] Furthermore, during the cleaning operation of the first separation membrane module 11, even if the permeate gas from the first separation membrane module 11 is not supplied to the fourth separation membrane module 14 and the fifth separation membrane module 15, the permeate gas from the second separation membrane module 12 is supplied to the fourth separation membrane module 14 and the fifth separation membrane module 15. This makes it possible to continue supplying gas to the downstream fourth separation membrane module 14 and the fifth separation membrane module 15 even when the cleaning operation of the first separation membrane module 11 is performed. As a result, the CO2 concentration can be increased.

[0103] The detection means 612 may further output a control signal to the three-way valve 31f. Furthermore, when the combustion exhaust gas is not supplied to the third separation membrane module 13, the detection means 612 may output a control signal to the three-way valve 31c.

[0104] The three-way valve 31c connects the pipe 24a and the pipe 24b in response to a control signal from the detection means 612. As a result, the combustion exhaust gas is supplied to the third separation membrane module 13.

[0105] In response to a control signal from the detection means 612, the three-way valve 31f closes the communication between the pipes 24d and 24f and connects the pipes 24d and 24e. This allows the pipes 22a, 22e, 25a, 24e, and 24d to communicate with each other. As a result, the non-permeate gas from the third separation membrane module 13 can be supplied toward the second outlet 123 of the first separation membrane module 11. That is, in addition to the non-permeate gas from the second separation membrane module 12, the non-permeate gas from the third separation membrane module 13 can also flow into the space 110A inside the separation membrane 110 in the first separation membrane module 11. As a result, the cleaning function of the first separation membrane module 11 can be further improved.

[0106] Next, the cleaning operation of the auxiliary separation membrane module 10S will be described. Hereinafter, an example in which the fifth separation membrane module 15 is cleaned with the non-permeate gas from the fourth separation membrane module 14 will be described, but this is not limiting. That is, the fourth separation membrane module 14 may be cleaned with the non-permeate gas from the fifth separation membrane module 15. Although not shown, the fifth separation membrane module 15 is assumed to be provided with measurement units similar to the measurement units 41a, 41b, and 41c. The measurement units provided in the fifth separation membrane module 15 output measurement signals related to the pressures of, for example, pipes 29a, 29g, and 29d to the control unit 60. Similarly, when cleaning the fourth separation membrane module 14, the fourth separation membrane module 14 is assumed to be provided with measurement units similar to the measurement units 41a, 41b, and 41c. The measurement units provided in the fourth separation membrane module 14 output measurement signals related to the pressures of, for example, pipes 28a, 28g, and 28d to the control unit 60.

[0107] The detection means 612 of the control unit 60 detects the blockage of the fifth separation membrane module 15 based on the measurement value acquired from the measurement unit. Then, the detection means 612 outputs a control signal to each of the three-way valves 31g, 31h, and 31i.

[0108] The three-way valve 31g does not connect the pipe 27a to the pipe 29a, but connects the pipe 27a to the pipe 28a, in response to a control signal from the detection means 612. This allows, for example, the permeated gas from the first separation membrane module 11 to flow to the fourth separation membrane module 14.

[0109] The three-way valve 31h connects the pipe 28d to the pipe 28e in response to a control signal from the detection means 612. The three-way valve 31i connects the pipe 29d to the pipe 29e in response to a control signal from the detection means 612. This connects the pipes 28d, 28e, 25c, 29e, and 29d. As a result, the non-permeate gas from the fourth separation membrane module 14 can be supplied toward the second outlet 123 of the fifth separation membrane module 15. That is, the non-permeate gas from the fourth separation membrane module 14 can flow into the space 110A inside the separation membrane 110 in the fifth separation membrane module 15. This allows the fifth separation membrane module 15 to be cleaned with the non-permeate gas from the fourth separation membrane module 14. The non-permeate gas that is supplied from the fourth separation membrane module 14 and passes through the fifth separation membrane module 15 may be discharged to the outside through a pipe provided in the fifth separation membrane module 15, for example.

[0110] In the cleaning operation of the separation membrane module 10 and the auxiliary separation membrane module 10S, the operation of each three-way valve was controlled by the control unit 60, but the operation of the three-way valve may also be performed manually. Furthermore, in the cleaning operation of the auxiliary separation membrane module 10S, the operation of the three-way valve may also be performed manually.

[0111] [Variations] Next, modified examples of the gas processing system 1 according to the first embodiment will be described with reference to Figures 6 to 8. Note that in the modified examples, components similar to those in the first embodiment will be denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0112] Referring to FIG. 6, a configuration example of a gas processing system 1 according to a modified example will be described. The gas processing system 1 according to the modified example may include a vacuum pump 51c, a vacuum pump 52, and a vacuum pump 53. The vacuum pump 51c is an example of a "second pressure reduction means." The vacuum pump 52 is an example of a "first pressure reduction means." The vacuum pump 53 is an example of a "third pressure reduction means." The vacuum pump 51c is provided on the pipe 27a. The vacuum pump 51c sucks permeate gas from the first outlet 122 of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13, and flows the sucked permeate gas to the fourth separation membrane module 14 and the fifth separation membrane module 15. As will be described separately, the vacuum pump 52 is provided so as to be able to suck non-permeate gas discharged from the inlet 121 of the cleaned separation membrane module 10 after the separation membrane module 10 has been cleaned. The vacuum pump 52 is connected to the second flow path of each gas separation system. The vacuum pump 53 is provided so as to be able to suck the permeate gas from the fourth separation membrane module 14 and the permeate gas from the fifth separation membrane module. The vacuum pump 53 is connected to the first outlet 122 of the fourth separation membrane module 14 and the first outlet 122 of the fifth separation membrane module 15 via pipes HS1 and HS2. A blower 51a-2 may be provided instead of the compressor 51a provided in the pipe 21 in the first embodiment. The combustion exhaust gas from the engine 100E blown by the blower 51a-2 increases its flow rate and flows to the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13.

[0113] In addition, in the modified example, the configuration of the flow path and the configuration of the switching unit provided in the auxiliary gas separation system are different. The auxiliary gas separation system of the modified example further includes an eighth flow path, which will be described separately, and a third switching unit, which will be described separately.

[0114] In the auxiliary gas separation system having the fourth separation membrane module 14, the pipe 28g is connected to the pipe HS1. The pipe HS1 is connected to a vacuum pump 53. The permeated gas from the fourth separation membrane module 14 flows to the vacuum pump 53 side via the pipe 28g.

[0115] In this modification, the auxiliary gas separation system having the fourth separation membrane module 14 has pipes 28a-1 and 28a-2 as a seventh flow path. The auxiliary gas separation system having the fourth separation membrane module 14 also has a three-way valve 31k between pipes 28a-1 and 28a-2. That is, the three-way valve 31k is provided in the seventh flow path of the auxiliary gas separation system. The three-way valve 31k is an example of a "third switching unit." The three-way valve 31k has a first port 31k1, a second port 31k2, a third port 31k3, and a valve body that switches each port between open and closed.

[0116] The first port 31k1 of the three-way valve 31k is connected to the pipe 28a-1. The second port 31k2 is connected to the pipe 28a-2. The third port 31k3 is connected to the pipe 28c. The pipe 28c is an example of an "eighth flow path." The eighth flow path corresponding to the pipe 28c branches off from the seventh flow path, which includes the pipes 28a-1 and 28a-2, via the three-way valve 31k.

[0117] When the valve element of the three-way valve 31k is operated and the first port 31k1 and the second port 31k2 are opened, the pipes 28a-1 and 28a-2 are connected to each other and the pipe 28c is closed. This opens the seventh flow path including the pipes 28a-1 and 28a-2. On the other hand, when the valve element of the three-way valve 31k is operated and the second port 31k2 and the third port 31k3 are opened, the pipes 28a-1 and 28a-2 are not connected to each other and the pipes 28a-2 and 28c are connected to each other. This opens the eighth flow path including the pipe 28c.

[0118] In this modification, the first separation membrane module 11 and the fourth separation membrane module 14 are connected via a pipe 22g, a pipe 26a, a pipe 27a, a pipe 28a-1, and a pipe 28a-2.

[0119] The second separation membrane module 12 and the fourth separation membrane module 14 are connected via a pipe 23g, a pipe 26b, a pipe 26c, a pipe 27a, a pipe 28a-1, and a pipe 28a-2.

[0120] The third separation membrane module 13 and the fourth separation membrane module 14 are connected via a pipe 24g, a pipe 26b, a pipe 27a, a pipe 28a-1, and a pipe 28a-2.

[0121] In the auxiliary gas separation system having the fifth separation membrane module 15, the pipe 29g is connected to the pipe HS2. The pipe HS2 is connected to a vacuum pump 53. The permeated gas from the fifth separation membrane module 15 flows to the vacuum pump 53 side via the pipe 29g.

[0122] The auxiliary gas separation system having the fifth separation membrane module 15 has pipes 29a-1 and 29a-2 as a seventh flow path. The auxiliary gas separation system having the fifth separation membrane module 15 also has a three-way valve 31j between pipes 29a-1 and 29a-2. That is, the three-way valve 31j is provided in the seventh flow path of the auxiliary gas separation system. The three-way valve 31j is an example of a "third switching unit." The three-way valve 31j has a first port 31j1, a second port 31j2, a third port 31j3, and a valve body that switches each port between open and closed.

[0123] The first port 31j1 of the three-way valve 31j is connected to the pipe 29a-1. The second port 31j2 is connected to the pipe 29a-2. The third port 31j3 is connected to the pipe 29c. The pipe 29c is an example of an "eighth flow path." The eighth flow path corresponding to the pipe 29c branches off from the seventh flow path, which includes the pipes 29a-1 and 29a-2, via the three-way valve 31j.

[0124] When the valve element of the three-way valve 31j is operated and the first port 31j1 and the second port 31j2 are opened, the pipes 29a-1 and 29a-2 are connected to each other and the pipe 29c is closed. This opens the seventh flow path including the pipes 29a-1 and 29a-2. On the other hand, when the valve element of the three-way valve 31j is operated and the second port 31j2 and the third port 31j3 are opened, the pipes 29a-1 and 29a-2 are not connected to each other and the pipes 29a-2 and 29c are connected to each other. This opens the eighth flow path including the pipe 29c.

[0125] In this modification, the first separation membrane module 11 and the fifth separation membrane module 15 are connected via a pipe 22g, a pipe 26a, a pipe 27a, a pipe 29a-1, and a pipe 29a-2.

[0126] The second separation membrane module 12 and the fifth separation membrane module 15 are connected via a pipe 23g, a pipe 26b, a pipe 26c, a pipe 27a, a pipe 29a-1, and a pipe 29a-2.

[0127] The third separation membrane module 13 and the fifth separation membrane module 15 are connected via a pipe 24g, a pipe 26b, a pipe 27a, a pipe 29a-1, and a pipe 29a-2.

[0128] Next, the CO2 separation operation of the fourth separation membrane module 14 will be described with reference to Fig. 7. As shown in Fig. 7, the three-way valve 31k connects the pipes 28a-1 and 28a-2 and closes the pipe 28c. This allows the permeate gas from at least one of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13 to be supplied to the fourth separation membrane module 14. At this time, the three-way valve 31j may connect the pipes 29a-1 and 29a-2 or may close them.

[0129] The three-way valve 31h connects the pipes 28d and 28f, but does not connect the pipes 28d and 28e. The non-permeate gas from the fourth separation membrane module 14 flows through the pipes 28d and 28f and is discharged to the outside. In contrast, the permeate gas from the fourth separation membrane module 14 flows through the pipes 28g and HS1 toward the vacuum pump 53. The vacuum pump 53 may be connected to, for example, a storage tank for the permeate gas. The permeate gas that has passed through the vacuum pump 53 may flow into the storage tank.

[0130] The CO2 separation operation of the fifth separation membrane module 15 will be described. As shown in Fig. 7, the three-way valve 31j connects the pipes 29a-1 and 29a-2 and closes the pipe 29c. This allows the fifth separation membrane module 15 to be supplied with permeated gas from at least one of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13. At this time, the three-way valve 31k may connect the pipes 28a-1 and 28a-2 or may close them.

[0131] The three-way valve 31i connects the pipes 29d and 29f, but does not connect the pipes 29d and 29e. The non-permeate gas from the fifth separation membrane module 15 flows through the pipes 29d and 29f and is discharged to the outside. In contrast, the permeate gas from the fifth separation membrane module 15 flows through the pipes 29g and HS2 toward the vacuum pump 53. The permeate gas that has passed through the vacuum pump 53 may flow into a storage tank.

[0132] Next, the cleaning operation of the auxiliary separation membrane module 10S will be described with reference to FIG. 8. Hereinafter, an example in which the fourth separation membrane module 14 is cleaned with the non-permeate gas from the fifth separation membrane module 15 will be described, but the present invention is not limited to this. That is, the fifth separation membrane module 15 may be cleaned with the non-permeate gas from the fourth separation membrane module 14. Although not shown, the fifth separation membrane module 15 is assumed to be provided with a measuring unit similar to the measuring units 41a, 41b, and 41c. The measuring unit provided in the fifth separation membrane module 15 outputs measurement signals related to the pressures of, for example, pipes 29a-2, 29g, and 29d to the control unit 60. Similarly, when the fourth separation membrane module 14 is cleaned, the fourth separation membrane module 14 is assumed to be provided with a measuring unit similar to the measuring units 41a, 41b, and 41c. The measurement unit provided in the fourth separation membrane module 14 outputs to the control unit 60, for example, measurement signals relating to the pressures of the pipes 28a-2, 28g, and 28d.

[0133] The detection means 612 of the control unit 60 detects the blockage of the fourth separation membrane module 14 based on the measurement value acquired from the measurement unit. Then, the detection means 612 outputs a control signal to each of the three-way valves 31h, 31i, 31j, and 31k.

[0134] The three-way valve 31j does not connect the pipe 29a-1 to the pipe 29c, but connects the pipe 29a-1 to the pipe 29a-2, in response to a control signal from the detection means 612. This allows, for example, the permeated gas from the first separation membrane module 11 to flow to the fifth separation membrane module 15.

[0135] The three-way valve 31i connects the pipe 29d to the pipe 29e in response to a control signal from the detection means 612. The three-way valve 31h connects the pipe 28d to the pipe 28e in response to a control signal from the detection means 612. This connects the pipes 28d, 28e, 25c, 29e, and 29d. The three-way valve 31k connects the pipe 28a-2 to the pipe 28c in response to a control signal from the detection means 612. As a result, the non-permeate gas from the fifth separation membrane module 15 can be supplied toward the second outlet 123 of the fourth separation membrane module 14. This allows the non-permeate gas from the fifth separation membrane module 15 to flow into the space 110A inside the separation membrane 110 in the fourth separation membrane module 14. This allows the fourth separation membrane module 14 to be cleaned with the non-permeate gas from the fifth separation membrane module 15. Furthermore, the non-permeate gas that has passed through the fourth separation membrane module 14 flows toward the vacuum pump 52 via the pipe 28a-2, the pipe 28c, the pipe HL3, the pipe HL4, and the pipe HL2.

[0136] That is, when at least the first auxiliary separation membrane module (e.g., the fourth separation membrane module 14) of the auxiliary gas separation system is washed, in the first auxiliary gas separation system, the third switching unit (e.g., the three-way valve 31k) opens the eighth flow path (e.g., the pipe 28c), and the fourth switching unit (e.g., the three-way valve 31h) opens the ninth flow path (e.g., the pipes 28d and 28e). Also, in the second auxiliary gas separation system having the fifth separation membrane module 15, for example, the third switching unit (e.g., the three-way valve 31j) opens the seventh flow path (e.g., the pipes 29a-1 and 29a-2), and the fourth switching unit (e.g., the three-way valve 31i) opens the ninth flow path (e.g., the pipes 29d and 29e). As a result, for example, non-permeable gas from the second auxiliary gas separation system having the fifth separation membrane module 15 flows via the eleventh flow path (e.g., pipe 25c) to the ninth flow path (e.g., pipes 28d and 28e) and the fourth separation membrane module 14.

[0137] [Second embodiment] <Overall structure> Referring to FIG. 9, an example configuration of a gas processing system 1A according to the second embodiment is shown. FIG. 9 is a schematic diagram showing an example of the overall configuration of a gas processing system 1A according to the second embodiment. In the second embodiment, components similar to those in the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted where appropriate. In the second embodiment, the configuration of the flow path (a thirteenth flow path, which will be described separately) connected to the second outlet 123 of the separation membrane module 10 in each gas separation system is different from that in the first embodiment.

[0138] 9 shows three separation membrane modules 10, namely, a first separation membrane module 11, a second separation membrane module 12, and a third separation membrane module 13, but the number of separation membrane modules 10 is not limited to three. Also, while FIG. 9 shows two auxiliary separation membrane modules 10S, namely, a fourth separation membrane module 14 and a fifth separation membrane module 15, the number of auxiliary separation membrane modules 10S is not limited to this.

[0139] 9, the first separation membrane module 11 is connected to the ship engine 100E via a flow path including a pipe 21 and pipes 22a and 22b. The combustion exhaust gas discharged from the ship engine 100E flows through these pipes and reaches the first separation membrane module 11. The flow path including the pipes 22a and 22b is an example of a "first flow path."

[0140] The gas separation system having the first separation membrane module 11 further includes a pipe 22m branching from a flow path including the pipes 22a and 22b. The pipe 22m is an example of a "twelfth flow path." The three-way valve 31a is disposed between the pipes 22a and 22b, and the third port 31a3 is connected to the pipe 22m. The three-way valve 31a is an example of a "fifth switching unit." The pipe 22m is connected to a vacuum pump 55 via pipes EL1 and EL. The vacuum pump 55 sucks gas flowing through the pipe 22m. The vacuum pump 55 also discharges the sucked gas, for example, to the outside. A filter may be provided in the pipe 22m. The vacuum pump 55 is an example of a "fourth pressure reducing means."

[0141] When the valve element of the three-way valve 31a is operated and the first port 31a1 and the second port 31a2 are opened, the pipes 22a and 22b are connected to each other and the pipe 22m is closed. This opens the first flow path including the pipes 22a and 22b. On the other hand, when the valve element of the three-way valve 31a is operated and the second port 31a2 and the third port 31a3 are opened, the pipes 22a and 22b are not connected to each other and the pipes 22b and 22m are connected to each other. This opens the twelfth flow path including the pipe 22m.

[0142] A pipe 22h is connected to the second outlet 123 of the first separation membrane module 11. The pipe 22h also communicates with the atmospheric environment. The pipe 22h is an example of a "thirteenth flow path." The thirteenth flow path, including the pipe 22h, is always open.

[0143] The second separation membrane module 12 is connected to the ship engine 100E via pipe 21, pipe 23a, and pipe 23b. The combustion exhaust gas discharged from the ship engine 100E flows through these pipes and reaches the second separation membrane module 12. The flow path including pipe 23a and pipe 23b is an example of a "first flow path."

[0144] The gas separation system having the second separation membrane module 12 further includes a pipe 23m branching from a flow path including the pipes 23a and 23b. The pipe 23m is an example of a "twelfth flow path." A three-way valve 31m may be disposed between the pipes 23a and 23b. The three-way valve 31m is an example of a "fifth switching unit." The three-way valve 31m includes a first port 31m1, a second port 31m2, a third port 31m3, and a valve element that switches each port between open and closed. The first port 31m1 of the three-way valve 31m is connected to the pipe 23a. The second port 31m2 is connected to the pipe 23b. The third port 31m3 is connected to the pipe 23m. The pipe 23m is connected to a vacuum pump 55 via a pipe EL. A filter may be provided in the pipe 23m.

[0145] When the valve element of the three-way valve 31m is operated and the first port 31m1 and the second port 31m2 are opened, the pipes 23a and 23b are connected to each other and the pipe 23m is closed. This opens the first flow path including the pipes 23a and 23b. On the other hand, when the valve element of the three-way valve 31m is operated and the second port 31m2 and the third port 31m3 are opened, the pipes 23a and 23b are not connected to each other and the pipes 23b and 23m are connected to each other. This opens the twelfth flow path including the pipe 23m.

[0146] A pipe 23h is connected to the second outlet 123 of the second separation membrane module 12. The pipe 23h communicates with the atmospheric environment. The pipe 23h is an example of a "thirteenth flow path."

[0147] The third separation membrane module 13 is connected to the ship engine 100E via a pipe 21, a pipe 24a, and a pipe 24b. The combustion exhaust gas discharged from the ship engine 100E flows through these pipes and reaches the third separation membrane module 13. The flow path including the pipe 24a and the pipe 24b is an example of a "first flow path."

[0148] The gas separation system having the third separation membrane module 13 further includes a pipe 24m branching from a flow path including the pipes 24a and 24b. The pipe 24m is an example of a "twelfth flow path." A three-way valve 31n may be disposed between the pipes 24a and 24b. The three-way valve 31n is an example of a "fifth switching unit." The three-way valve 31n includes a first port 31n1, a second port 31n2, a third port 31n3, and a valve element that switches each port between open and closed. The first port 31n1 of the three-way valve 31n is connected to the pipe 24a. The second port 31n2 is connected to the pipe 24b. The third port 31n3 is connected to the pipe 24m. The pipe 24m is connected to a vacuum pump 55 via the pipes EL1 and EL. A filter may be provided in the pipe 24m.

[0149] When the valve element of the three-way valve 31n is operated and the first port 31n1 and the second port 31n2 are opened, the pipes 24a and 24b are connected to each other and the pipes 24b and 24m are not connected to each other. This opens the first flow path including the pipes 24a and 24b. On the other hand, when the valve element of the three-way valve 31n is operated and the second port 31n2 and the third port 31n3 are opened, the pipes 24a and 24b are not connected to each other and the pipes 24b and 24m are connected to each other. This opens the twelfth flow path including the pipe 24m.

[0150] A pipe 24h is connected to the second outlet 123 of the third separation membrane module 13. The pipe 24h communicates with the atmospheric environment. The pipe 24h is an example of a "thirteenth flow path."

[0151] The fourth separation membrane module 14 is connected to the first separation membrane module 11 via pipe 22g, pipe 26a, pipe 27a, pipe 28a-1, and pipe 28a-2. The fourth separation membrane module 14 is connected to the second separation membrane module 12 via pipe 23g, pipe 26c, pipe 26b, pipe 27a, pipe 28a-1, and pipe 28a-2. The fourth separation membrane module 14 is connected to the third separation membrane module 13 via pipe 24g, pipe 26b, pipe 27a, pipe 28a-1, and pipe 28a-2.

[0152] A three-way valve 31p may be disposed between the pipes 28a-1 and 28a-2. The three-way valve 31p includes a first port 31p1, a second port 31p2, a third port 31p3, and a valve element that switches between opening and closing each port. The first port 31p1 of the three-way valve 31p is connected to the pipe 28a-1. The second port 31p2 is connected to the pipe 28a-2. The third port 31p3 is connected to the pipe 28m. The pipe 28m is connected to the vacuum pump 55 via the pipes EL2 and EL. A filter may be provided in the pipe 28m.

[0153] When the valve element of the three-way valve 31p is operated and the first port 31p1 and the second port 31p2 are opened, the pipes 28a-1 and 28a-2 are connected to each other and the pipes 28a-2 and 28m are not connected to each other. This opens the flow path including the pipes 28a-1 and 28a-2. On the other hand, when the valve element of the three-way valve 31p is operated and the second port 31p2 and the third port 31p3 are opened, the pipes 28a-1 and 28a-2 are not connected to each other and the pipes 28a-2 and 28m are connected to each other. This opens the flow path including the pipe 28m.

[0154] A pipe 28h is connected to the second outlet 123 of the fourth separation membrane module 14. The pipe 28h is in communication with the atmospheric environment. A pipe 28g is connected to the first outlet 122 of the fourth separation membrane module 14. The pipe 28g is connected to a vacuum pump 57c via a pipe 27b.

[0155] The fifth separation membrane module 15 is connected to the first separation membrane module 11 via pipe 22g, pipe 26a, pipe 27a, pipe 29a-1, and pipe 29a-2. The fifth separation membrane module 15 is connected to the second separation membrane module 12 via pipe 23g, pipe 26c, pipe 26b, pipe 27a, pipe 29a-1, and pipe 29a-2. The fifth separation membrane module 15 is connected to the third separation membrane module 13 via pipe 24g, pipe 26b, pipe 27a, pipe 29a-1, and pipe 29a-2.

[0156] A three-way valve 31q may be disposed between the pipes 29a-1 and 29a-2. The three-way valve 31q includes a first port 31q1, a second port 31q2, a third port 31q3, and a valve element that switches between opening and closing each port. The first port 31q1 of the three-way valve 31q is connected to the pipe 29a-1. The second port 31q2 is connected to the pipe 29a-2. The third port 31q3 is connected to the pipe 29m. The pipe 29m is connected to the vacuum pump 55 via the pipes EL2 and EL. A filter may be provided in the pipe 29m.

[0157] When the valve element of the three-way valve 31q is operated and the first port 31q1 and the second port 31q2 are opened, the pipes 29a-1 and 29a-2 are connected to each other and the pipes 29a-2 and 29m are not connected to each other. This opens the flow path including the pipes 29a-1 and 29a-2. On the other hand, when the valve element of the three-way valve 31q is operated and the second port 31q2 and the third port 31q3 are opened, the pipes 29a-1 and 29a-2 are not connected to each other and the pipes 29a-2 and 29m are connected to each other. This opens the flow path including the pipe 29m.

[0158] A pipe 29h is connected to the second outlet 123 of the fifth separation membrane module 15. The pipe 29h is in communication with the atmospheric environment. A pipe 29g is connected to the first outlet 122 of the fifth separation membrane module 15. The pipe 29g is connected to a vacuum pump 57c via a pipe 26d.

[0159] 9, the gas processing system 1A may include a blower 57a such as a blower, and vacuum pumps 57b and 57c. For example, the blower 57a increases the flow rate of the combustion exhaust gas discharged from the ship engine 100E and flowing through the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13. The blower 57a is provided, for example, in the piping 21. However, the location of the blower 57a is not limited as long as it is located upstream of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13 and closer to the ship engine 100E.

[0160] The vacuum pump 57b is preferably disposed in a position where it can suck the permeate gas from the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13. For example, the vacuum pump 57b is preferably provided on the downstream side of the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13, such as the pipe 27a. By using the vacuum pump 57b to suck the permeate gas from the first separation membrane module 11, the second separation membrane module 12, and the third separation membrane module 13, the flow rate of the gas supplied to the fourth separation membrane module 14 and the fifth separation membrane module 15 can be increased.

[0161] The vacuum pump 57c is preferably disposed in a position where it can suck the permeated gas from the fourth separation membrane module 14 and the fifth separation membrane module 15. For example, the vacuum pump 57c is preferably provided downstream of the fourth separation membrane module 14 and the fifth separation membrane module 15, such as on the pipe 27b.

[0162] <Separation membrane module cleaning operation> Next, the cleaning operation of the separation membrane module 10 performed by the gas processing system 1A will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a diagram for explaining the CO2 separation operation of the separation membrane module 10. Fig. 11 is a diagram for explaining the cleaning operation of the separation membrane module 10.

[0163] The cleaning operation of the separation membrane module 10 will be described using the first separation membrane module 11 as an example. However, similar cleaning operations may also be performed for other separation membrane modules 10. As a premise, the CO2 separation operation of the first separation membrane module 11 and the flows of permeate gas and non-permeate gas generated by the CO2 separation operation will be described with reference to Figure 10. However, similar CO2 separation operations may also be performed for other separation membrane modules 10.

[0164] 10, the three-way valve 31a connects the pipe 22a and the pipe 22b and closes the pipe 22m, thereby supplying the first separation membrane module 11 with the combustion exhaust gas discharged from the engine 100E of the ship.

[0165] The first separation membrane module 11 separates the combustion exhaust gas into permeate gas and non-permeate gas. The permeate gas flows out of the first outlet 122 of the first separation membrane module 11 and flows through pipes 22g, 26a, 27a, 28a-1, and 28a-2 to the fourth separation membrane module 14. Alternatively, the permeate gas from the first separation membrane module 11 may flow out of the first outlet 122 of the first separation membrane module 11 and flows through pipes 22g, 26a, 27a, 29a-1, and 29a-2 to the fifth separation membrane module 15. In contrast, the non-permeate gas flows out of the second outlet 123 of the first separation membrane module 11 and flows through pipe 22h. The non-permeate gas from the first separation membrane module 11 is discharged into the atmospheric environment.

[0166] The CO2 separation operation in the separation membrane modules 10 other than the first separation membrane module 11 and the flow of permeate gas and non-permeate gas generated by the CO2 separation operation are similar to those of the first separation membrane module 11. Note that the permeate gas from the fourth separation membrane module 14 and the permeate gas from the fifth separation membrane module 15 may flow into a storage tank for recovering CO2.

[0167] Next, the cleaning operation of the first separation membrane module 11 will be described with reference to Fig. 11. First, the detection means 612 of the control unit 60 detects clogging of the first separation membrane module 11 based on the measurement values ​​acquired from each of the measurement units 41a, 41b, and 41c.

[0168] Subsequently, the detection means 612 outputs a control signal to the three-way valve 31a. In response to the control signal from the detection means 612, the three-way valve 31a closes the communication between the pipe 22a and the pipe 22b and opens the communication between the pipe 22b and the pipe 22m. This stops the supply of combustion exhaust gas to the first separation membrane module 11.

[0169] Furthermore, the pipe 22b and the pipe 22m communicate with each other, so that the pipe 22h, the space 110A inside the separation membrane 110 in the first separation membrane module 11, the pipe 22b, and the pipe 22m communicate with each other.

[0170] Pipe 22m is connected to a vacuum pump 55. Pipe 22h is connected to the atmosphere. That is, the pressure on the pipe 22m side is lower than the pressure on the pipe 22h side. Therefore, the atmosphere introduced from the flow path including pipe 22h passes through the space 110A inside the separation membrane 110 in the first separation membrane module 11, and flows into the flow path including pipes 22b and 22m. This allows the first separation membrane module 11 to be cleaned.

[0171] By connecting a vacuum pump 55 to the inlet 121 of the first separation membrane module 11 and connecting a pipe 22h connected to the second outlet 123 of the first separation membrane module 11 to the atmosphere, it is possible to allow the atmosphere to flow from the second outlet 123 of the first separation membrane module 11 to the inlet 121. This simplifies the configuration for cleaning the first separation membrane module 11 while ensuring the cleaning function of the first separation membrane module 11.

[0172] The same applies to the cleaning operation of the separation membrane modules 10 other than the first separation membrane module 11. In the cleaning operation of the separation membrane module 10, the operation of the three-way valve is controlled by the control unit 60, but the operation of the three-way valve may also be performed manually.

[0173] Although the embodiments have been described above, they are presented as examples and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims. [Explanation of symbols]

[0174] 1,1A Gas Treatment System 10 Separation membrane module 11 First separation membrane module 12 Second separation membrane module 13 Third separation membrane module 10S Auxiliary Separation Membrane Module 14 Fourth separation membrane module 15 5th separation membrane module 21,22a,22b,22c,22d,22e,22f,22g,22m,22h,23a,23b,23c,23d,23e,23f,23g,23m,23h,24a,24b,24c,24d,24e,24f,24g, 24m,24h,25a,25b,25c,26a,26b,26c,26d,27a,28a-1,28a-2,28d,28e,28f,28g,28h,29a-1,29a-2,29d,29e,29f,29g,29h plumbing 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h, 31i, 31j, 31k, 31m, 31n, 31p, 31q three-way valve 41a, 41b, 41c Measuring section 51 (51a, 51b) Compressor 57a blower 51c, 52, 53, 55, 57b, 57c Vacuum pump 60 Control Unit 110 Separation membrane 121 Inlet 122 1st outlet 123 Second Outlet

Claims

1. 1. A gas processing system comprising a plurality of gas separation systems, Each of the plurality of gas separation systems comprises: CO ２ and CO ２ a separation membrane module including: a separation membrane for separating carbon dioxide and carbon monoxide; an inlet into which the combustion exhaust gas flows; a first outlet through which a first permeate gas that has permeated the separation membrane out of the combustion exhaust gas that has flowed in from the inlet flows out; and a second outlet through which a non-permeate gas that has not permeated the separation membrane out of the combustion exhaust gas flows out; a first flow path connected to the inlet; a first switching unit provided in the first flow path; a second flow path branched from the first flow path via the first switching unit; a third flow path connected to the second outlet; a second switching unit provided in the third flow path; a fourth flow path branched from the third flow path via the second switching portion; and The gas processing system further includes a fifth flow path connected to the third flow path and connecting the plurality of gas separation systems together, When cleaning the separation membrane module included in at least one gas separation system among the plurality of gas separation systems, In the first gas separation system, the second flow path is opened by the first switching unit, and the third flow path is opened by the second switching unit; In at least a second gas separation system, the first flow path is opened by the first switching unit, and the third flow path is opened by the second switching unit, the non-permeate gas from at least a second gas separation system flows through the fifth flow path to the third flow path and the separation membrane module of the first gas separation system; Gas treatment system.

2. When cleaning the separation membrane module of at least the first gas separation system, in a third gas separation system, the first flow path is opened by the first switching unit and the third flow path is opened by the second switching unit, the non-permeate gas from the third gas separation system flows through the fifth flow path to the third flow path and the separation membrane module of the first gas separation system; The gas processing system of claim 1 .

3. The second gas separation system further includes at least a compressor that compresses the combustion exhaust gas that flows into the inlet of the separation membrane module. The gas processing system according to claim 1 or claim 2.

4. Further, the gas separation system further includes at least a first pressure reducing means connected to the second flow path of the first gas separation system. The gas processing system according to claim 1 or claim 2.

5. The system further includes at least a second pressure reducing means connected to a first outlet of the separation membrane module of the first gas separation system. The gas processing system according to claim 1 or claim 2.

6. a plurality of auxiliary gas separation systems; a sixth flow path connected to a first outlet of the separation membrane module included in the gas separation system; Furthermore, Each of the plurality of auxiliary gas separation systems comprises: CO ２ and selectively permeates CO from the first permeable gas. ２ an auxiliary separation membrane module including: a separation membrane for separating the first permeable gas; an inlet through which the first permeable gas flows; a first outlet through which a second permeable gas that has permeated the separation membrane among the first permeable gases that has flowed in from the inlet flows out; and a second outlet through which a non-permeable gas that has not permeated the separation membrane among the first permeable gases flows out; a seventh flow path connected between the sixth flow path and the inlet of the auxiliary separation membrane module; a third switching unit provided in the seventh flow path; an eighth flow path branching from the seventh flow path via the third switching unit; a ninth flow path connected to the second outlet of the auxiliary separation membrane module; a fourth switching unit provided in the ninth flow path; a tenth flow path branching from the ninth flow path via the fourth switching unit; and The gas processing system further includes an eleventh flow path connected to the ninth flow path and connecting the plurality of auxiliary gas separation systems together, When cleaning the auxiliary separation membrane module of at least one auxiliary gas separation system among the plurality of auxiliary gas separation systems, In the first auxiliary gas separation system, the eighth flow path is opened by the third switching unit, and the ninth flow path is opened by the fourth switching unit; and In at least a second auxiliary gas separation system, the seventh flow path is opened by the third switching unit and the ninth flow path is opened by the fourth switching unit; The non-permeate gas from at least a second auxiliary gas separation system flows through the eleventh flow path to the ninth flow path and the auxiliary separation membrane module of the first auxiliary gas separation system. The gas processing system according to claim 1 or claim 2.

7. a third pressure reducing means connected to the first outlet of the auxiliary separation membrane module; The gas processing system of claim 6 .

8. CO ２ and CO ２ a separation membrane module including an inlet through which the combustion exhaust gas flows, a first outlet through which permeate gas of the combustion exhaust gas that has permeated the separation membrane flows out, and a second outlet through which non-permeate gas of the combustion exhaust gas that does not permeate the separation membrane flows out; a first flow path connected to the inlet; a fifth switching unit provided in the first flow path; a twelfth flow path branching from the first flow path via the fifth switching unit; a thirteenth flow path connected to the second outlet and communicating with the atmospheric environment; a fourth pressure reducing means connected to the twelfth flow path; Equipped with When cleaning the separation membrane module, the twelfth flow path is opened by the fifth switching unit, and air is introduced into the separation membrane module via the thirteenth flow path. Gas treatment system.

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