Carbon dioxide capture system and carbon dioxide capture method

Abstract

To provide a carbon dioxide recovery system enabled to simplify a system configuration.SOLUTION: A carbon dioxide recovery system comprises a taking-in unit, an electrolysis unit, a power supply unit and a recovery unit. The taking-in unit takes in a gas by use of flow of the gas in an arrangement environment, and in the electrolysis unit, an adsorbate can adsorb and emit carbon dioxide by electrical response corresponding to electric potential. The power supply unit causes the adsorbate to adsorb carbon dioxide contained in the inflow gas in the electrolysis unit by adjusting electric potential. The recovery unit recovers carbon dioxide emitted from the adsorbate after being adsorbed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a carbon dioxide recovery system and a carbon dioxide recovery method.

Background Art

[0002] A carbon dioxide recovery system that separates carbon dioxide from a gas and recovers the separated carbon dioxide is used. In such a carbon dioxide recovery system, a gas is introduced into an adsorption unit provided with an adsorbent capable of adsorbing and releasing carbon dioxide, and carbon dioxide contained in the introduced gas is adsorbed by the adsorbent, thereby separating carbon dioxide from the gas. Then, after discharging the residual gas in which carbon dioxide is adsorbed by the adsorbent from the adsorption unit, the carbon dioxide adsorbed by the adsorbent is released from the adsorbent, and the carbon dioxide released from the adsorbent is recovered.

[0003] In the carbon dioxide recovery system as described above, a fan, a compressor, etc. are required to efficiently introduce the gas into the system, and the space occupied by the fan, compressor, etc. in the entire system becomes large, and the piping also becomes complicated. For this reason, it is required to simplify the configuration of the carbon dioxide recovery system, such as making it possible to introduce the gas into the adsorption unit provided with the adsorbent without providing a fan or the like, or making it possible to release the adsorbed carbon dioxide from the adsorbent without heating the adsorbent.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem that this invention aims to solve is to provide a carbon dioxide capture system and a carbon dioxide capture method that can simplify the system configuration. [Means for solving the problem]

[0006] The carbon dioxide recovery system of the embodiment includes an intake unit, an electrolysis unit, a power supply unit, and a recovery unit. wind vane, control unit, flow rate adjustment unit, first thermometer and second thermometer It is equipped with an intake port formed in the intake unit, and the intake unit is , take Gas is drawn in through an intake port. The electrolysis unit is equipped with an adsorbent that can adsorb and release carbon dioxide in response to an electrical potential, and the gas drawn in through the intake port of the intake unit flows into the electrolysis unit. The power supply unit adjusts the potential so that the carbon dioxide contained in the gas flowing in through the intake port is adsorbed onto the adsorbent in the electrolysis unit, and the carbon dioxide adsorbed onto the adsorbent is released from the adsorbent. The recovery unit recovers the carbon dioxide that has been adsorbed onto the adsorbent and released from the adsorbent. The wind vane measures the direction of gas flow in the environment where the intake unit is located. Based on the wind vane's measurement, the control unit controls the position of the intake unit and adjusts the opening direction of the intake port so that the gas flows towards the intake port in the environment where the intake unit is located. The flow rate adjustment unit is located between the intake port and the electrolysis unit and adjusts the flow rate of gas flowing downstream. The first thermometer measures the temperature of the gas taken in from the intake port, located between the intake port and the flow rate adjustment unit. The second thermometer measures the temperature of the gas flowing downstream from the flow rate adjustment unit, located between the flow rate adjustment unit and the electrolysis unit. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram showing a carbon dioxide capture system according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram showing one example of an electrolysis unit in the carbon dioxide recovery system according to the first embodiment. [Figure 3] Figure 3 is a schematic diagram showing a magnified portion of the adsorption layer of the working electrode in the electrolytic cell shown in Figure 2. [Figure 4] Figure 4 shows an example of an MOF included in the adsorption member of an electrolytic cell in the first embodiment. [Figure 5] Figure 5 shows an example of COF contained in the adsorption member of the electrolytic cell in the first embodiment. [Figure 6]Figure 6 is a schematic diagram showing an example of a state in which carbon dioxide is adsorbed onto the adsorption member of the electrolytic cell of any one electrolytic unit in the carbon dioxide recovery system according to the first embodiment. [Figure 7] Figure 7 is a schematic diagram showing a different example from Figure 6 in the carbon dioxide recovery system according to the first embodiment, where carbon dioxide is adsorbed onto the adsorption member of the electrolytic cell of any one electrolytic unit. [Figure 8] Figure 8 is a schematic diagram showing an example of a state in the carbon dioxide recovery system according to the first embodiment in which excess gas is discharged from any one electrolytic unit after the state in Figure 6 or Figure 7. [Figure 9] Figure 9 is a schematic diagram showing an example of a state in the carbon dioxide recovery system according to the first embodiment, where, after the state shown in Figure 8, carbon dioxide adsorbed by any one electrolytic unit is released from the adsorption material of the electrolytic cell. [Figure 10] Figure 10 is a schematic diagram showing an example of a state in the carbon dioxide recovery system according to the first embodiment, where, after the state shown in Figure 9, carbon dioxide released by the adsorption member is discharged from any one electrolysis unit. [Figure 11] Figure 11 is a schematic diagram showing the state in the carbon dioxide recovery system according to the first embodiment, where, after the state in Figure 10, any one electrolysis unit is returned to atmospheric pressure. [Figure 12] Figure 12 is a schematic diagram showing a carbon dioxide capture system according to a modified example of the first embodiment. [Figure 13] Figure 13 is a schematic diagram showing an example of a carbon dioxide recovery system according to a modified version of Figure 12, in which excess gas is discharged from any one electrolytic unit after the state shown in Figure 6. [Figure 14] Figure 14 is a schematic diagram showing an example of a carbon dioxide recovery system according to a modified example of Figure 12, in which, after the state shown in Figure 9, carbon dioxide released by the adsorption member is discharged from any one electrolysis unit. [Figure 15]FIG. 15 is a schematic view showing an example of a state in which any one of the electrolysis units is returned to atmospheric pressure after the state of FIG. 14 in the carbon dioxide recovery system according to the modification of FIG. 12. [Figure 16] FIG. 16 is a schematic view showing the carbon dioxide recovery system according to the second embodiment. [Figure 17] FIG. 17 is a schematic view showing an example of a state in which carbon dioxide is adsorbed to the adsorption member of the electrolytic cell in the most upstream electrolysis unit in the carbon dioxide recovery system according to the second embodiment. [Figure 18] FIG. 18 is a schematic view showing an example of a state in which excess gas is discharged from the most upstream electrolysis unit after the state of FIG. 17 in the carbon dioxide recovery system according to the second embodiment. [Figure 19] FIG. 19 is a schematic view showing an example of a state in which the carbon dioxide adsorbed by the most upstream electrolysis unit is released from the adsorption member of the electrolytic cell after the state of FIG. 18 in the carbon dioxide recovery system according to the second embodiment. [Figure 20] FIG. 20 is a schematic view showing an example of a state in which carbon dioxide flows from the most upstream electrolysis unit to the second most upstream electrolysis unit after the state of FIG. 19 in the carbon dioxide recovery system according to the second embodiment, and the carbon dioxide flowing into the second most upstream electrolysis unit is adsorbed to the adsorption member of the electrolytic cell. [Figure 21] FIG. 21 is a schematic view showing an example of a state in which excess gas is discharged from the second most upstream electrolysis unit after the state of FIG. 20 in the carbon dioxide recovery system according to the second embodiment. [Figure 22] FIG. 22 is a schematic view showing any one of the electrolysis units provided in the carbon dioxide recovery system according to the third embodiment. [Figure 23] FIG. 23 is a view showing an example of a compound having redox activity contained in the electrolyte of the electrolytic cell in the third embodiment. [Figure 24]Figure 24 is a schematic diagram showing the state in which carbon dioxide is adsorbed onto the adsorbent substance contained in the electrolyte of the electrolytic cell in any one electrolytic unit in the carbon dioxide recovery system according to the third embodiment. [Figure 25] Figure 25 is a schematic diagram showing a state in which carbon dioxide adsorbed from the adsorbent contained in the electrolyte of the electrolytic cell is released in any one electrolytic unit in a carbon dioxide recovery system according to the third embodiment. [Figure 26] Figure 26 is a schematic diagram showing a carbon dioxide capture system according to the fourth embodiment. [Figure 27] Figure 27 is a schematic diagram showing any one electrolysis unit provided in the carbon dioxide recovery system according to the fourth embodiment. [Modes for carrying out the invention]

[0008] The embodiments will be described below with reference to the drawings.

[0009] In this embodiment, a carbon dioxide capture system is provided. In the carbon dioxide capture system described below, an intake unit is placed in an environment where gas flow (environmental wind) already exists to take in gas. Here, the environment where gas flow already exists is not limited to the above, but examples include the upper parts of mountainous areas, the open sea including coastlines, canyons, dams, high places such as skyscrapers, gaps between buildings, subway stations, exhaust vents connected to the ground, gas inlets to underground, elevator cylinders, tunnels, exhaust vents and gas inlets of large indoor facilities, the surrounding environment of wind power plants, exhaust vents of factories and plants, etc. Examples of environmental wind include wind that is generated naturally due to pressure differences, wind that is generated due to temperature differences, wind that is generated when an object or gas passes through a tubular or narrowed area, and wind that is generated due to the pressure difference between indoors and outdoors. In the carbon dioxide capture system, the gas flow in the environment where the intake unit is placed is used to introduce gas into an electrolytic unit which acts as an adsorption unit. Then, by performing the processing described later using the electrolytic unit, carbon dioxide is separated from the incoming gas and the separated carbon dioxide is recovered.

[0010] (First Embodiment) First, as an example of an embodiment, the first embodiment will be described. Figure 1 shows a carbon dioxide capture system 1 according to the first embodiment. As shown in Figure 1, the carbon dioxide capture system 1 includes an intake unit 2. The intake unit 2 has a defined depth direction (direction indicated by arrow X). The intake unit 2 is placed in an environment where gas flow occurs (an environment where gas flow already exists), that is, an environment where ambient wind is generated. The intake unit 2 includes an exterior member 3, and a flow path 5 is formed inside the exterior member 3 of the intake unit 2. The flow path 5 is formed along the depth direction of the intake unit 2. In addition, an intake port 6 is formed in the intake unit 2, and the flow path 5 opens at the intake port 6 to the outside of the intake unit 2, that is, to the environment in which the intake unit 2 is placed. The intake unit 2 takes in gas (outside air) from the intake port 6 by utilizing the gas flow (ambient wind) in the environment in which it is placed.

[0011] The gas taken in from the intake port 6 flows into the flow path 5. In the flow path, including the flow path 5, the side approaching the intake port 6 is the upstream side, and the side moving away from the intake port 6 is the downstream side. In the flow path 5, the gas taken in from the intake port 6 flows from the upstream side to the downstream side. In addition, in an example such as Figure 1, a section 7 is formed in the flow path 5 of the intake unit 2, where the cross-sectional area of ​​the flow path 5 decreases from the upstream side to the downstream side. In the section 7, the cross-sectional area of ​​the flow path 5 decreases from the opening area at the intake port 6 as it moves away from the intake port 6.

[0012] In this embodiment, the carbon dioxide recovery system 1 includes an electrolytic unit, and in an example such as Figure 1, it includes n electrolytic units E1 to En (where n is an integer of 2 or more). The electrolytic units E1 to En are arranged downstream of the intake unit 2 in the flow path through which the taken-in gas flows. The electrolytic units E1 to En are also arranged in parallel with each other in the flow path through which the taken-in gas flows. In this embodiment, each of the electrolytic units E1 to En is provided with one electrolytic cell 10. Gas taken in from the intake port 6 of the intake unit 2 can flow into each of the electrolytic units E1 to En.

[0013] The carbon dioxide capture system 1 includes a control unit (controller) 8. The control unit 8 controls the entire carbon dioxide capture system 1. The control unit 8 includes a processor or integrated circuit and a storage medium such as memory. The processor or integrated circuit includes any of the following: CPU (Central Processing Unit), ASIC (Application Specific Integrated Circuit), microcontroller, FPGA (Field Programmable Gate Array), and DSP (Digital Signal processor). The control unit 8 may have only one processor or may have multiple processors. The control unit 8 performs the processing described later by the processor. Alternatively, the processing of the control unit 8 described later may be performed by a virtual processor in a cloud environment instead of a processor.

[0014] In the flow path through which the gas taken in from the intake port 6 flows, an airflow meter 11 is placed between the intake port 6 and each of the electrolytic units E1 to En. The airflow meter 11 measures the flow rate (airflow) of the gas taken in at the intake port 6. In addition, in the flow path through which the taken-in gas flows, a flow rate adjustment valve (airflow adjustment valve) 12 is placed as a flow rate adjustment unit between the airflow meter 11 and each of the electrolytic units E1 to En. The flow rate adjustment valve 12 is placed downstream of the intake port 6 and upstream of the electrolytic units E1 to En, and is positioned between the intake port 6 and each of the electrolytic units E1 to En. The flow rate adjustment valve 12 adjusts the flow rate of the gas that flows downstream through the flow rate adjustment valve 12. There may be one flow rate adjustment valve 12 for each of the electrolytic units E1 to En, or one flow rate adjustment valve 12 may be provided for multiple electrolytic units E1 to En. Therefore, a single flow control valve 12 may be used to adjust the flow rates of multiple gases in the electrolytic units E1 to En.

[0015] The control unit 8 acquires the measurement result from the airflow meter 11 regarding the flow rate of the gas taken in at the intake port 6. Based on the measurement result from the airflow meter 11, the control unit 8 controls the operation of the flow rate adjustment valve 12, controlling the flow rate of the gas flowing downstream through the flow rate adjustment valve 12 so that it does not exceed the standard flow rate. If the flow rate of the gas taken in at the intake port 6 exceeds the standard flow rate, the control unit 8 controls the operation of the flow rate adjustment valve 12 so that only the standard flow rate of the taken-in gas flows downstream through the flow rate adjustment valve 12. At this time, the remaining portion of the taken-in gas that does not flow downstream through the flow rate adjustment valve 12 is discharged into the atmosphere through the flow rate adjustment valve 12. Since the flow rate of the gas flowing downstream through the flow rate adjustment valve 12 is adjusted so that it does not exceed the standard flow rate, the amount of gas flowing into each of the electrolytic units E1 to En is adjusted so that it does not exceed the appropriate range. This effectively prevents damage to the electrolytic units E1 to En.

[0016] The carbon dioxide capture system 1 includes an anemometer 13 and a motor 15, which is a driving element. The anemometer 13 measures the direction of gas flow (the direction of ambient wind flow) in the environment where the intake unit 2 is located. By driving the motor 15, the intake unit 2 rotates or performs other actions, changing its orientation. As the orientation of the intake unit 2 changes, the opening direction of the intake port 6 changes. Note that if the orientation of the intake unit 2 changes in accordance with the wind direction, it is not necessarily required to provide a driving element such as the motor 15.

[0017] The control unit 8 acquires measurement results from the wind vane 13 regarding the direction of gas flow in the environment in which the intake unit 2 is located. Based on the measurement results from the wind vane 13, the control unit 8 controls the drive of the motor 15 and controls the attitude of the intake unit 2. As a result, the control unit 8 adjusts the opening direction of the intake port 6 based on the measurement results from the wind vane 13. In one example, the attitude of the intake unit 2 is adjusted so that in the environment in which the intake unit 2 is located, gas flows toward the intake port 6 from a direction perpendicular or nearly perpendicular to the opening surface of the intake port 6, and the opening direction of the intake port 6 is adjusted accordingly.

[0018] Furthermore, it is preferable that the opening direction of the intake port 6 forms a downward angle with respect to the horizontal plane. In this case, the opening direction of the intake port 6 is inclined vertically downward with respect to the horizontal plane. In the state shown in Figure 1, the opening direction of the intake port 6 forms a downward angle with respect to the horizontal plane, and the direction indicated by arrow A1 is the opening direction of the intake port 6. In the example shown in Figure 1, the filter 16 is attached to the exterior member 3 of the intake unit 2. The filter 16 is attached to the exterior member 3 in a manner that covers the intake port 6 from the outside. The horizontal plane is a hypothetical plane perpendicular to the vertical direction (direction of gravity).

[0019] In the example shown in Figure 1, the carbon dioxide capture system 1 includes a water level gauge 17, a shutter 18 which is an opening / closing member, and a motor 19 which is a driving member. The water level gauge 17 measures the water level in the environment where the intake unit 2 is located. The shutter 18 switches between an open state and a closed state of the intake port 6. In the carbon dioxide capture system 1, the operating state of the shutter 18 is switched by driving the motor 19, and the open / closed state of the intake port 6 by the shutter 18 is switched. By closing the intake port 6 with the shutter 18, it is prevented that water or other substances will flow into the flow path 5 from outside the intake unit 2 through the intake port 6. In the carbon dioxide capture system 1, as in the example shown in Figure 1, multiple driving members such as motors 15 and 19 may be provided. Also, for example, one motor (driving member) may operate both the intake unit 2 and the shutter 18, or one driving member may operate multiple operating parts.

[0020] The control unit 8 acquires the measurement results from the water level gauge 17 regarding the water level in the environment where the intake unit 2 is located. Based on the measurement results from the water level gauge 17, the control unit 8 controls the drive of the motor 19 and controls the operation of the shutter 18. As a result, the control unit 8 adjusts the opening and closing state of the intake port 6 by the shutter 18 based on the measurement results from the water level gauge 17. If the water level in the environment where the intake unit 2 is located does not exceed the reference level, the control unit 8 opens the intake port 6. Then, based on the water level in the environment where the intake unit 2 is located exceeding the reference level, the control unit 8 closes the intake port 6 with the shutter 18. The reference level of the water level may be set in advance, or information may be acquired as needed from the cloud or network.

[0021] Furthermore, in this embodiment, the gas taken in between the intake port 6 and each of the electrolytic units E1 to En is not heated or cooled. That is, in the flow path, there is no mechanism for heating the taken-in gas or a mechanism for cooling the taken-in gas between the intake port 6 and each of the electrolytic units E1 to En. Therefore, the intake unit 2 allows the gas taken in from the intake port 6 to flow into one of the electrolytic units E1 to En without heating or cooling it. In one example, the intake unit 2 allows the gas taken in from the intake port 6 to flow into one of the electrolytic units E1 to En at a temperature within the range of -10°C or higher and 50°C or lower.

[0022] The carbon dioxide recovery system 1 is equipped with thermometers 21 and 22. Thermometer (first thermometer) 21 measures the temperature of the gas taken in from the intake port 6 between the intake port 6 and the flow rate control valve 12. Thermometer (second thermometer) 22 measures the temperature of the gas flowing downstream from the flow rate control valve 12 between the flow rate control valve 12 and each of the electrolysis units E1 to En. The control unit 8 acquires the measurement results of the gas temperature from thermometers 21 and 22, respectively.

[0023] In one example, the control unit 8 controls the operation of the flow rate adjustment valve 12 based on the measurement results from thermometers 21 and 22. In this embodiment, as described above, the gas taken in between the intake port 6 and each of the electrolysis units E1 to En is not heated or cooled. Therefore, when the carbon dioxide recovery system 1 is operating normally, the temperature measured by thermometer 21 is the same as, or almost the same as, the temperature measured by thermometer 22. Therefore, if the absolute value of the difference between the temperatures measured by thermometers 21 and 22 exceeds a reference value, the control unit 8 controls the operation of the flow rate adjustment valve 12 to prevent the taken-in gas from flowing downstream from the flow rate adjustment valve 12. In this case, for example, all of the taken-in gas is discharged into the atmosphere from the flow rate adjustment valve 12. In another example, a specified range is set for the temperatures measured by thermometers 21 and 22. If either of the temperatures measured by thermometers 21 and 22 falls outside the specified range, the control unit 8 activates the shutter 18 by driving the motor 19, and the shutter 18 closes the intake port 6. This prevents gas outside the specified temperature range from flowing into the electrolytic units E1 to En from the intake port 6, effectively preventing freezing and deterioration of the electrolytic units E1 to En. The specified temperature range is, for example, the aforementioned range of -10°C or higher and 50°C or lower.

[0024] Furthermore, in the carbon dioxide recovery system 1, the same number of pressure gauges 23, inlet switching valves 25, and discharge switching valves 26 are provided as there are electrolysis units E1 to En. In the example shown in Figure 1, n of each of the pressure gauges 23, inlet switching valves 25, and discharge switching valves 26 are provided. One of each of the pressure gauges 23, inlet switching valves 25, and discharge switching valves 26 is provided for each of the electrolysis units E1 to En. Each of the pressure gauges 23 measures the corresponding pressure of one of the electrolysis units E1 to En. The control unit 8 acquires the measurement result from the corresponding pressure gauge 23 for each of the electrolysis units E1 to En.

[0025] Each of the inflow switching valves 25 can be switched between an open state and a closed state. When each of the inflow switching valves 25 is in the open state, gas flows from the flow rate adjustment valve 12, i.e., from the upstream side, into the corresponding one of the electrolytic units E1 to En. On the other hand, when each of the inflow switching valves 25 is in the closed state, the flow of gas from the upstream side into the corresponding one of the electrolytic units E1 to En is blocked. The control unit 8 switches each of the inflow switching valves 25 between the open state and the closed state by controlling the operation of each of the inflow switching valves 25.

[0026] Each of the discharge switching valves 26 can be switched to an open state, a closed state, and a released state. When each of the discharge switching valves 26 is in the open state, it discharges gas downstream from the corresponding electrolytic unit E1 to En. On the other hand, when each of the discharge switching valves 26 is in the closed state, it shuts off the discharge of gas from the corresponding electrolytic unit E1 to En. When each of the discharge switching valves 26 is in the released state, it discharges gas into the atmosphere from the corresponding electrolytic unit E1 to En. However, when each of the discharge switching valves 26 is in the released state, no gas is discharged downstream from the corresponding electrolytic unit E1 to En. The control unit 8 switches each of the discharge switching valves 26 to the open state, closed state, and released state by controlling the operation of each of the discharge switching valves 26.

[0027] The carbon dioxide recovery system 1 includes a recovery unit 30 for recovering carbon dioxide. In the gas flow path, the recovery unit 30 is positioned downstream of the electrolysis units E1 to En. Each of the electrolysis units E1 to En can discharge gas to the recovery unit 30 when one of the corresponding discharge switching valves 26 is opened. The recovery unit 30 includes a compressor 31, a switching valve 32, and a recovery tank 33. In the gas flow path, the compressor 31 is positioned upstream of the recovery tank 33, and the switching valve 32 is positioned between the compressor 31 and the recovery tank 33.

[0028] When the compressor 31 is operated, gases such as carbon dioxide are compressed, and the compressed gas is pumped. The control unit 8 controls the operating state of the compressor 31 and switches the compressor 31 on and off. The switching valve 32 can be switched between an open state, a closed state, and a released state. When the switching valve 32 is in the open state, gas flows from the compressor 31 into the recovery tank 33. On the other hand, when the switching valve 32 is in the closed state, the flow of gas from the compressor 31 to the recovery tank 33 is blocked. Also, when the switching valve 32 is in the released state, gas is discharged from the compressor 31 into the atmosphere. However, when the switching valve 32 is in the released state, no gas is discharged from the compressor 31 to the recovery tank 33. The control unit 8 switches the switching valve 32 between the open state, the closed state, and the released state by controlling the operation of the switching valve 32.

[0029] When the switching valve 32 is open, compressed carbon dioxide is discharged from the compressor 31 into the recovery tank 33, and the carbon dioxide is stored there. This is how carbon dioxide is recovered. In the example shown in Figure 1, the carbon dioxide recovered in the recovery unit 30 is stored in the recovery tank 33, but this is not the only example. In one example, the carbon dioxide recovered in the recovery unit 30 is supplied to a device or system that uses carbon dioxide.

[0030] Furthermore, the carbon dioxide capture system 1 includes a power supply unit 40 such as a potentiostat. The power supply unit 40 is electrically connected to each of the electrolytic cells 10 of the electrolytic units E1 to En. The power supply unit 40 can apply voltage to each of the electrolytic cells 10 of the electrolytic units E1 to En. The control unit 8 controls the voltage application state to each of the electrolytic cells 10 of the electrolytic units E1 to En by controlling the drive of the power supply unit 40. In Figure 1, the electrical connection between the power supply unit 40 and each of the electrolytic cells 10 of the electrolytic units E1 to En is shown by a dashed line.

[0031] Figure 2 shows an example of electrolytic unit Ek, which is any one of the electrolytic units E1 to En. In addition to the configuration of electrolytic unit Ek, Figure 2 also shows the electrical connection structure of electrolytic unit Ek to the power supply unit 40. Note that k is any natural number between 1 and n. Furthermore, the other electrolytic units (E1 to En other than Ek) have the same configuration as electrolytic unit Ek and are electrically connected to the power supply unit 40 in the same way as electrolytic unit Ek.

[0032] In the example shown in Figure 2, an electrolytic cell 10 is placed in the space that becomes the processing chamber 41 in the electrolytic unit Ek. ​​In the electrolytic unit Ek, gas flows into the processing chamber 41 from the upstream side, and the gas is discharged from the processing chamber 41 to the downstream side or to the atmosphere. In the electrolytic unit Ek, the pressure in the processing chamber 41 is measured as the pressure of the electrolytic unit Ek by a corresponding pressure gauge 23. In the example shown in Figure 2, the electrolytic cell 10 of the electrolytic unit Ek is equipped with a working electrode 42 and a counter electrode 43. The electrolytic cell 10 is not provided with a reference electrode, and the electrolytic cell 10 is composed of two types of electrodes: the working electrode 42 and the counter electrode 43. In one example, multiple power supply units 40 may be provided, and different electrolytic units may be supplied with voltage to each of the multiple power supply units 40.

[0033] In the example shown in Figure 2, an electrolytic cell 10 is formed by stacking two working electrodes 42 on one counter electrode 43. In the electrolytic cell 10, one of the two working electrodes 42 is stacked on the counter electrode 43 from one side in the stacking direction, and the other of the two working electrodes 42 is stacked on the counter electrode 43 from the other side in the stacking direction. In the electrolytic cell 10, a sheet-like separator 45 is placed between each working electrode 42 and the counter electrode 43. The separator 45 has electrical insulating properties and electrically insulates each working electrode 42 from the counter electrode 43. Each working electrode 42 is equipped with a current collector 46 and an adsorption layer 47 formed on the surface of the current collector 46. In the example shown in Figure 2, the adsorption layer 47 is formed on the surface of each current collector 46 of the working electrode 42 that faces away from the side where the counter electrode 43 is located.

[0034] The power supply unit 40 is electrically connected to the current collector 46 and the counter electrode 43 of the working electrode 42, respectively. The power supply unit 40 applies a voltage to the electrolytic cell 10, generating a voltage (potential difference) between the working electrode 42 and the counter electrode 43, thereby adding potential to the working electrode 42. The counter electrode 43 is formed from a conductive material, such as a carbon material, a conductive polymer, or platinum. The separator 45 may be formed from an organic or inorganic material, as long as it is made from an electrically insulating material. Examples of materials for forming the separator 45 include porous polyethylene, polypropylene, polyester, polyacrylonitrile, polyethylene terephthalate, polyvinylidene fluoride, polyimide, aramid, cellulose, ceramics, carbon, and insulated metals. The separator 45 may be formed from only one of the aforementioned materials, or from a combination of several of the aforementioned materials.

[0035] The current collector 46 of the working electrode 42 is formed from a conductive material, for example, from either a carbonaceous material or a metal. When the current collector 46 is formed from a carbonaceous material, one of the following can be used as the current collector 46: glassy carbon, graphite sheet, carbon felt, carbon cloth, carbon mesh, carbon paper, and carbon sheet with a gas diffusion layer. When the current collector 46 is formed from a metal, one of the following can be used as the current collector 46: copper plate, copper sheet, copper mesh, aluminum plate, aluminum sheet, aluminum mesh, nickel plate, nickel sheet, and nickel mesh. Note that the carbonaceous material and metal forming the current collector 46 are not limited to the above-mentioned configurations. It is preferable that the current collector 46 is a porous body with many holes, such as carbon cloth, carbon mesh, and metal mesh. This increases the surface area of ​​the current collector 46, and increases the contact area between the adsorption layer 47 formed on the surface of the current collector 46 and the current collector 46. By increasing the contact area between the current collector 46 and the adsorption layer 47, it becomes easier for electric charge to move from the current collector 46 to the adsorption layer 47.

[0036] Figure 3 shows a magnified view of a portion of the adsorption layer 47 of the working electrode 42 in the electrolytic cell 10 of Figure 2. As shown in Figure 3, the adsorption layer 47 includes conductive members 48 and adsorbent members 49. In the adsorption layer 47, a large number of conductive members 48 and a large number of adsorbent members 49 are mixed together. In forming the adsorption layer 47, a paste is prepared by adding the conductive members 48 and adsorbent members 49 to a solvent and then mixing the solvent. At this time, a binder may be added to the solvent in addition to the conductive members 48 and adsorbent members 49. The prepared paste is then coated onto the surface of the current collector 46, and the adsorption layer 47 is formed by drying the coated paste.

[0037] Each of the conductive members 48 is formed from, for example, a conductive carbonaceous material. In this case, each of the conductive members 48 is formed from one of the following: carbon nanotubes, graphite, graphene, carbon nanofibers, and Ketjenblack. Furthermore, each of the conductive members 48 is preferably formed in a linear or planar shape from the viewpoint of improving the probability of contact with the current collector 46 and the adsorption member 49. In this case, each of the conductive members 48 is formed in one of the following shapes: rod, tube, fiber, sheet, or flake. The conductive members 48 may be formed from one type of material, or from a mixture of multiple types of materials.

[0038] Each of the adsorbent members 49 contains a compound having redox activity. Each of the adsorbent members 49 is formed from a porous material, and each of the adsorbent members 49 has numerous pores with a diameter of 5 nm or less. In this embodiment, each of the adsorbent members 49 contains at least one of a metal-organic framework (MOF) and a covalent-organic framework (COF). In each of the adsorbent members 49, one or more crosslinked portions are formed in the MOF and / or COF, and the MOF and / or COF contain molecules of the aforementioned compound having redox activity as crosslinked portions. The compound having redox activity includes at least one selected from the group consisting of carbonyl compounds, pyridyl compounds and imide compounds. The carbonyl compounds having redox activity include benzoquinone, naphthoquinone, anthraquinone, and phenanthrenequinone, and the pyridyl compounds having redox activity include phenanthroline, pyridine, phenazine, pyrimidine, and methyl viologen. Furthermore, imide compounds with redox activity include benzodipyrrole, phthalimide, phthaldiimide, naphthalenimide, and naphthalenediimide. Examples of derivatives of methyl viologen (also known as 1,1'-dimethyl-4,4'-bipyridinium dichloride) include viologens such as 1,1'-dibenzyl-4,4'-bipyridinium dichloride (also known as benzyl viologen), 1,1'-diphenyl-4,4'-bipyridinium dichloride, 1,1'-bis(2,4-dinitrophenyl)-4,4'-bipyridinium dichloride, 1,1'-di-n-octyl-4,4'-bipyridinium dibromide, and 1,1'-diheptyl-4,4'-bipyridinium dibromide.

[0039] When each of the adsorbent members 49 contains an MOF, the MOF contains multiple clusters as a metal complex, and in the MOF, the multiple clusters are cross-linked by a cross-linking ligand, which is the cross-linking portion. In the MOF, each of the multiple clusters that become a metal complex contains one or more of zirconium, copper, and manganese as the central metal. Furthermore, the MOF contains a molecule of one of the aforementioned compounds having redox activity as a cross-linking ligand. Examples of MOFs contained in the adsorbent member 49 include MOFs having a UiO (Universitet i Oslo) structure.

[0040] Figure 4 shows an example of an MOF contained in the adsorption member 49. In the example in Figure 4, 2,6-Zr-AQ-MOF is shown as a type of MOF having a UiO structure. As shown in Figure 4, the 2,6-Zr-AQ-MOF contains six clusters with zirconium as the central metal. Furthermore, in the 2,6-Zr-AQ-MOF, each of the 12 bridging ligands contains an anthraquinone molecule, a type of carbonyl compound. Note that in Figure 4, each of the six white circles represents a Zr6O4(OH)4 cluster with zirconium as the central metal, and of the 12 bridging ligands, only one anthraquinone molecule is shown, with the remaining 11 omitted.

[0041] Furthermore, 2,6-Zr-AQ-MOF is just one example of an MOF that can be included in the adsorption member 49, and other MOFs besides 2,6-Zr-AQ-MOF can also be included in the adsorption member 49 as appropriate. For example, 1,4-Zr-AQ-MOF and others can be included in the adsorption member 49 as MOFs having a UiO structure. In addition, MOFs other than those having a UiO structure, such as MOFs having a Cu(2,7-AQDC) structure, MOFs having a Mn(2,7-AQDC) structure, MOFs having an IRMOF structure, and MOFs having analog structures of IRMOF-9 can also be included in the adsorption member 49.

[0042] When each of the adsorbent members 49 contains COF, the COF is composed of numerous organic molecules covalently bonded together. In the COF, a two-dimensional or three-dimensional structure is formed by the covalent bonding of numerous organic molecules. Furthermore, in the COF, the organic molecules are cross-linked by cross-linking portions. The COF contains one of the aforementioned compounds having redox activity as a cross-linking portion. In one example, the adsorbent member 49 contains COF that forms a three-dimensional structure through π-π stacking. Examples of COFs that can be formed in a three-dimensional structure by π-π stacking and included in the adsorbent member 49 include TpPa-COF, PA-COF, 4KT-Tp COF, 2KT-Tp COF, 1KT-Tp COF, DAAQ-TFP-COF, PI-COF-1, PI-COF-2, PI-COF-3, CS-COF, CTF-1, CTF-2, TAPB-PDA-COF, N3-COF, COF-42, and derivatives thereof.

[0043] Figure 5 shows an example of COF contained in the adsorbent member 49. In the example in Figure 5, DAAQ-TFP-COF is shown as a type of COF that forms a three-dimensional structure by π-π stacking. As shown in Figure 5, DAAQ-TFP-COF contains anthraquinone molecules, a type of carbonyl compound, as each of the crosslinking portions that crosslink the organic molecules. Note that DAAQ-TFP-COF is just one example of COF that can be contained in the adsorbent member 49, and as mentioned above, other COFs may also be included in the adsorbent member 49 as appropriate.

[0044] Furthermore, the electrolytic cell 10 contains an electrolyte, which is held in the working electrode 42, counter electrode 43, and separator 45, etc. The electrolyte may contain either an ionic salt or an ionic conductive polymer. Examples of ionic salts that may be included in the electrolyte include alkali metal salts, alkaline earth metal salts, transition metal salts, amphoteric metal salts, ammonium salts, imidazolium salts, pyridinium salts, and phosphonium salts. The ionic salt may exist as a solid or as a liquid. When the ionic salt is included as a liquid in the electrolyte, the electrolyte is held in the electrolytic cell 10 as an ionic liquid. Examples of ionic conductive polymers that may be included in the electrolyte include polyethylene oxide (PEO), polypropyl oxide (PPO), polyacrylonitrile (PAN), polyvinyl chloride (PVC), and ionic liquid polymers.

[0045] In one example, as shown in Figure 2, the power supply unit 40 is grounded to ground (GND). The power supply unit 40 applies potential to the working electrode 42 and counter electrode 43 in each electrolytic cell 10 of the electrolytic units E1 to En, using ground as a reference. In another example, the power supply unit 40 is electrically connected to a conductive part that serves as a reference potential, located outside the electrolytic units E1 to En. In this case, the power supply unit 40 applies potential to the working electrode 42 and counter electrode 43 in each electrolytic cell 10 of the electrolytic units E1 to En, using the reference potential as a reference. The power supply unit 40 applies a predetermined potential higher than ground or the reference potential to the counter electrode 43 by applying a voltage to the electrolytic cell 10 in each of the electrolytic units E1 to En.

[0046] Furthermore, in each of the electrolytic units E1 to En, a voltage is applied to the electrolytic cell 10, thereby adding a potential to the working electrode 42 that is lower than a predetermined potential of the counter electrode 43. The power supply unit 40 applies a voltage to the electrolytic cell 10 in each of the electrolytic units E1 to En such that the potential of the working electrode 42 is either a first potential or a second potential higher than the first potential. Here, both the first potential and the second potential are lower than a predetermined potential of the counter electrode 43. In one example, as the aforementioned conductive part that serves as a reference potential, an Ag / Ag is provided outside the electrolytic units E1 to En. + Electrodes are set. Then, under the condition that the second potential is higher than the first potential, the first potential is -1.8V vs Ag / Ag + The above and 0.5V vs Ag / Ag + The potential will be one of the following ranges, and the second potential is -1.0VvsAg / Ag + The above and +1.5V vs Ag / Ag + The potential will be one of the following ranges.

[0047] In each of the electrolytic units E1 to En, a first potential is applied to the working electrode 42 by applying a voltage to the electrolytic cell 10, causing the aforementioned redox-active compound contained in the adsorption material 49 of the working electrode 42 to enter a reduced state. That is, in each of the adsorption materials 49, molecules of the redox-active compound are included as crosslinking portions in the MOF and / or COF, and these molecules of the redox-active compound enter a reduced state. Due to the reduction of the compound by the electrical response corresponding to the potential of the working electrode 42, each of the adsorption materials 49 adsorbs carbon dioxide. Here, the first potential is also called the "reduction potential".

[0048] Furthermore, in each of the electrolytic units E1 to En, the application of voltage to the electrolytic cell 10 adds a second potential higher than the first potential to the working electrode 42, causing the aforementioned compounds contained in the adsorption material 49 of the working electrode 42 to enter an oxidized state. Due to the oxidized state of the molecules of the compounds having redox activity in response to the electrical response corresponding to the potential of the working electrode 42, each of the adsorption material 49 releases the adsorbed carbon dioxide. Here, the second potential is also called the "oxidation potential". As described above, in each of the electrolytic cells 10 of the electrolytic units E1 to En, the adsorption material 49 of the working electrode 42 becomes capable of adsorbing and releasing carbon dioxide in response to the electrical response corresponding to the potential of the working electrode 42. Therefore, in this embodiment, the adsorption material 49 functions as an adsorbent capable of adsorbing and releasing carbon dioxide.

[0049] Next, we will explain the process of recovering carbon dioxide using the carbon dioxide recovery system 1. In the following explanation, we will describe the case where carbon dioxide is recovered using electrolytic unit Ek, which is any one of the electrolytic units E1 to En. Note that when using an electrolytic unit other than electrolytic unit Ek (other than Ek from E1 to En), carbon dioxide is recovered in the same manner as when using electrolytic unit Ek. ​​Also, in Figures 6 to 11 referenced in the following explanation, gas flows where only arrows are shown, and the gas flow is blocked where arrows are superimposed with cross marks.

[0050] Figure 6 shows an example of a state in which carbon dioxide is adsorbed onto the adsorption member 49 of the electrolytic cell 10 of any one electrolytic unit Ek. ​​In the state shown in Figure 6, the inlet switching valve 25 corresponding to the electrolytic unit Ek is in the open state. As a result, the gas taken in from the intake port 6 flows into the electrolytic unit Ek through the corresponding inlet switching valve 25. Also in the state shown in Figure 6, a voltage is applied to the electrolytic cell 10 of the electrolytic unit Ek by the power supply unit 40, and a first potential (reduction potential) is added to the working electrode 42 of the electrolytic unit Ek. ​​As a result, the aforementioned compound contained in the adsorption member (adsorbent substance) 49 of the working electrode 42 is reduced. As a result, in the electrolytic unit Ek, the carbon dioxide contained in the incoming gas is adsorbed onto the adsorption member 49 of the electrolytic cell 10, and carbon dioxide is separated from the incoming gas. Also in the state shown in Figure 6, the discharge switching valve 26 corresponding to the electrolytic unit Ek is in the released state. As a result, the remaining gas from which carbon dioxide has been separated by adsorption onto the adsorption member 49 is discharged into the atmosphere through the discharge switching valve 26. In this case, the remaining gas is not discharged to the recovery unit 30.

[0051] Figure 7 shows a different example from Figure 6, where carbon dioxide is adsorbed onto the adsorption member 49 of the electrolytic cell 10 of any one electrolytic unit Ek. ​​In the state of Figure 7, as in the state of Figure 6, the inlet switching valve 25 corresponding to the electrolytic unit Ek is in the open state, and the first potential is applied to the working electrode 42 of the electrolytic cell 10 of the electrolytic unit Ek. ​​However, in the state of Figure 7, the discharge switching valve 26 corresponding to the electrolytic unit Ek is in the open state. Therefore, the residual gas from which carbon dioxide has been separated by adsorption onto the adsorption member 49 is discharged to the recovery unit 30. Also, in the state of Figure 7, the compressor 31 is operated in the recovery unit 30, and the switching valve 32 is in the released state. Therefore, the residual gas that has flowed into the compressor 31 is discharged to the atmosphere from the switching valve 32 by pressure pumping by the compressor 31. Note that in Figure 7, the recovery unit 30 is omitted, and the compressor 31 and switching valve 32 that constitute the recovery unit 30 are shown.

[0052] In carbon dioxide recovery, once carbon dioxide has been adsorbed onto the adsorption member 49 for a certain period of time in the state shown in Figure 6 or Figure 7, excess gases other than carbon dioxide are discharged from the electrolytic unit Ek. ​​Figure 8 shows an example of a state in which excess gas is discharged from any one electrolytic unit Ek after the state shown in Figure 6 or Figure 7. In the state shown in Figure 8, the inflow switching valve 25 corresponding to the electrolytic unit Ek is closed. Therefore, the taken-in gases do not flow into the electrolytic unit Ek. ​​Also, in the state shown in Figure 8, no voltage is applied to the electrolytic cell 10 of the electrolytic unit Ek. ​​However, since no second potential is applied to the electrolytic cell 10, the compounds contained in the adsorption member 49 of the electrolytic cell 10 do not become oxidized. Therefore, the carbon dioxide adsorbed onto the adsorption member 49 in the state shown in Figure 6 or Figure 7 is maintained in the state adsorbed onto the adsorption member 49.

[0053] Furthermore, in the state shown in Figure 8, the discharge switching valve 26 corresponding to the electrolytic unit Ek is in the open state. Then, the compressor 31 is operated in the recovery unit 30, and the switching valve 32 is released. As a result, the excess gas remaining in the processing chamber 41 of the electrolytic unit Ek is discharged from the electrolytic unit Ek to the recovery unit 30 through the corresponding discharge switching valve 26 by the compressor 31. The excess gas discharged to the recovery unit 30 is then discharged into the atmosphere through the switching valve 32 by the compressor 31. In addition, in the carbon dioxide recovery system 1, in parallel with the adsorption of carbon dioxide onto the adsorption member 49 in the electrolytic unit Ek as described above, the adsorbed carbon dioxide may be released from the adsorption member 49 in any of the electrolytic units other than the electrolytic unit Ek (E1 to En, excluding Ek) as described later.

[0054] When excess gas remaining in the electrolytic unit Ek is discharged in the state shown in Figure 8, the electrolytic unit Ek releases the carbon dioxide adsorbed by the adsorption member 49 of the electrolytic cell 10. Figure 9 shows an example of a state after the state shown in Figure 8, where carbon dioxide adsorbed by any one of the electrolytic units Ek is released from the adsorption member 49 of the electrolytic cell 10. In the state shown in Figure 9, the inflow switching valve 25 corresponding to the electrolytic unit Ek is closed, and the intake gas does not flow into the electrolytic unit Ek.

[0055] Furthermore, in the state shown in Figure 9, the power supply unit 40 applies a voltage to the electrolytic cell 10 of the electrolytic unit Ek, adding a second potential (oxidation potential) to the working electrode 42 of the electrolytic unit Ek. ​​As a result, the aforementioned compound contained in the adsorption material (adsorbent substance) 49 of the working electrode 42 becomes oxidized. Consequently, the carbon dioxide adsorbed by the adsorption material 49 in the state shown in Figure 6 or Figure 7 is released from the adsorption material 49 in the electrolytic unit Ek. ​​Also, in the state shown in Figure 9, the discharge switching valve 26 corresponding to the electrolytic unit Ek is closed, and the carbon dioxide released from the adsorption material 49 is not discharged from the electrolytic unit Ek. ​​Therefore, the carbon dioxide released from the adsorption material 49 accumulates in the processing chamber 41 of the electrolytic unit Ek.

[0056] In the state shown in Figure 9, once carbon dioxide is released from the adsorption member 49 for a certain period of time, the carbon dioxide released from the adsorption member 49 is discharged from the electrolytic unit Ek. ​​In one example, the release of carbon dioxide from the adsorption member 49 in the state shown in Figure 9 takes place over a period of several seconds to 5 hours. Specifically, the release of carbon dioxide from the adsorption member 49 takes place over a period of 10 seconds to 5 hours. Figure 10 shows an example of a state in which the carbon dioxide released by the adsorption member 49 is discharged from any one electrolytic unit Ek after the state shown in Figure 9. In the state shown in Figure 10, the inflow switching valve 25 corresponding to the electrolytic unit Ek is closed, and the taken-in gas does not flow into the electrolytic unit Ek. ​​In addition, a second potential (oxidation potential) is added to the working electrode 42 of the electrolytic unit Ek by the power supply unit 40, and the carbon dioxide released from the adsorption member 49 in the state shown in Figure 9 is not adsorbed by the adsorption member 49.

[0057] Furthermore, in the state shown in Figure 10, the discharge switching valve 26 corresponding to the electrolysis unit Ek is in the open state. Then, the compressor 31 is operated in the recovery unit 30, and the switching valve 32 is opened. As a result, the carbon dioxide released from the adsorption material 49 in the electrolysis unit Ek is pumped by the compressor 31 and discharged from the electrolysis unit Ek through the corresponding discharge switching valve 26 to the recovery unit 30. The carbon dioxide discharged to the recovery unit 30 is then pumped by the compressor 31 and flows into the recovery tank 33. As a result, the carbon dioxide is stored in the recovery tank 33 and recovered.

[0058] In the state shown in Figure 10, once carbon dioxide recovery is complete, the pressure in the electrolytic unit Ek is returned to atmospheric pressure. Figure 11 shows the state after the state shown in Figure 10, where any one electrolytic unit Ek is returned to atmospheric pressure. In the state shown in Figure 11, the inlet switching valve 25 corresponding to the electrolytic unit Ek is open, and the taken-in gas flows into the electrolytic unit Ek. ​​Then, no voltage is applied to the electrolytic cell 10 of the electrolytic unit Ek. ​​Also, in the state shown in Figure 11, the discharge switching valve 26 corresponding to the electrolytic unit Ek is closed, and no gas is discharged from the electrolytic unit Ek. ​​Therefore, in the state shown in Figure 11, the pressure in the electrolytic unit Ek rises from the state where the electrolytic unit Ek was depressurized due to the discharge of carbon dioxide from the electrolytic unit Ek to the recovery unit 30, and the electrolytic unit Ek returns to atmospheric pressure. Note that in the state shown in Figure 11, the operation of the compressor 31 is stopped, and the switching valve 32 is closed.

[0059] When the electrolysis unit Ek is returned to atmospheric pressure in the state shown in Figure 11, the carbon dioxide recovery system 1 returns to the state shown in Figure 6 or Figure 7. Then, in the state shown in Figure 6 or Figure 7, carbon dioxide is adsorbed onto the adsorption material 49 of the electrolysis cell 10 using the electrolysis unit Ek, as described above. Then, the process described above is repeated using the electrolysis unit Ek.

[0060] In the carbon dioxide recovery system 1 of this embodiment, the intake unit 2 utilizes the gas flow in the environment in which it is installed to take in gas from the intake port 6 and direct the taken-in gas into the electrolytic units E1 to En. Therefore, gas can be introduced into each of the electrolytic units E1 to En, which act as adsorption units, without the need for fans or the like. In addition, in each of the electrolytic units E1 to En, the potential of the working electrode 42 is adjusted by the power supply unit 40, thereby adsorbing the carbon dioxide contained in the gas flowing in from the intake port 6 onto the adsorption material, which is the adsorption member 49, and releasing the carbon dioxide adsorbed onto the adsorption material 49. Therefore, in each of the electrolytic units E1 to En, the adsorbed carbon dioxide can be released from the adsorption material 49 without heating the adsorption material 49. Since there are no fans to introduce gas into the electrolytic units E1 to En, and no mechanism to heat the adsorption material 49, the configuration of the carbon dioxide recovery system 1 is simplified.

[0061] Furthermore, in the carbon dioxide capture system 1, the gas taken in from the intake port 6 flows into each of the electrolytic units E1 to En without being heated or cooled. Therefore, there is no need to provide a mechanism for adjusting the temperature of the taken-in gas between the intake port 6 and the electrolytic units E1 to En, which act as adsorption units. This further simplifies the configuration of the carbon dioxide capture system 1. This simplification of the configuration of the carbon dioxide capture system 1 makes it possible to miniaturize the carbon dioxide capture system 1. In addition, the simplification of the configuration of the carbon dioxide capture system 1 increases the flexibility of its installation location.

[0062] Furthermore, in the carbon dioxide recovery system 1, the control unit 8 controls the operation of the flow rate adjustment valve 12, which is the flow rate adjustment unit, based on the measurement results from the airflow meter 11, and controls the flow rate of gas moving downstream through the flow rate adjustment valve 12 so as not to exceed the standard flow rate. In this way, it is effectively prevented that a large amount of gas will flow into each of the electrolytic units E1 to En by one or more flow rate adjustment valves 12. As a result, in each of the electrolytic units E1 to En, by applying a first potential to the working electrode 42, the carbon dioxide contained in the incoming gas is appropriately adsorbed by the adsorption member 49.

[0063] Furthermore, in the carbon dioxide capture system 1, the control unit 8 controls the orientation of the intake unit 2 based on the measurement results from the wind vane 13 and adjusts the opening direction of the intake port 6. As a result, gas is taken in more appropriately from the intake port 6 by utilizing the gas flow in the environment in which the intake unit 2 is positioned. In addition, a cross-sectional area reduction section 7 is formed in the flow path 5 of the intake unit 2, and in the cross-sectional area reduction section 7, the cross-sectional area of ​​the flow path 5 decreases from the opening area at the intake port 6 as it moves away from the intake port 6. As a result, the flow velocity of the gas taken in from the intake port 6 increases as it passes through the cross-sectional area reduction section, and the taken-in gas can reach each of the electrolysis units E1 to En appropriately.

[0064] Furthermore, in the carbon dioxide recovery system 1, the opening direction of the intake port 6 is at a downward angle with respect to the horizontal plane. This effectively prevents liquid droplets from rain, etc., from flowing from the intake port 6 through the flow path 5 into the electrolysis units E1~En. In addition, the control unit 8 controls the operation of the shutter 18, which is an opening and closing member, based on the measurement results from the water level gauge 17, and closes the intake port 6 with the shutter 18 when the water level measured by the water level gauge 17 exceeds the reference level. This further effectively prevents liquids such as water from flowing from the intake port 6 through the flow path 5 into the electrolysis units E1~En. Furthermore, in the carbon dioxide recovery system 1, a filter 16 is attached to the intake unit 2 in a manner that covers the intake port 6. This effectively prevents dust, etc., from flowing from the intake port 6 into the flow path 5.

[0065] (Modified version of the first embodiment) Figure 12 shows a modified carbon dioxide recovery system 1 according to the first embodiment. In the modified embodiment shown in Figure 12, the configuration of the recovery unit 30 differs from that of the first embodiment, etc. As shown in Figure 12, in this modified embodiment as well, the recovery unit 30 includes a compressor 31 and a recovery tank 33. However, a switching valve 32 is not provided between the compressor 31 and the recovery tank 33. The recovery unit 30 also includes a vacuum pump 35 and a switching valve 36. The switching valve 36 is positioned upstream of the compressor 31 in the gas flow path. In the recovery unit 30, the gas flow path is branched at the switching valve 36 into a path that goes through the compressor 31 to the recovery tank 33 and a path that goes through the vacuum pump 35. By operating the vacuum pump 35, a gas flow is generated that goes from the switching valve 36 through the vacuum pump 35 to the atmosphere. The control unit 8 controls the operating state of the vacuum pump 35 and switches between operating and stopping the vacuum pump 35.

[0066] In this modified example, the switching valve 36 can be switched between an open state, a closed state, and a released state. When the switching valve 36 is in the open state, gas can flow into the recovery tank 33 through the compressor 31. On the other hand, when the switching valve 36 is in the closed state, the flow of gas to the compressor 31 and the vacuum pump 35 is blocked. Furthermore, when the switching valve 36 is in the released state, gas can be discharged to the atmosphere through the vacuum pump 35. However, when the switching valve 36 is in the released state, no gas is discharged to the compressor 31 or the recovery tank 33. The control unit 8 switches the switching valve 36 between the open state, the closed state, and the released state by controlling the operation of the switching valve 36.

[0067] The process of capturing carbon dioxide is described below. In Figures 13 to 15, which are referenced in the following description, gas flows where only arrows are shown, and the gas flow is blocked where arrows are superimposed with cross marks. In this modified example, in carbon dioxide capture, the carbon dioxide capture system 1 is set to the state shown in Figure 6 above. As a result, in the electrolytic unit Ek, the carbon dioxide contained in the incoming gas is adsorbed onto the adsorption member 49 of the electrolytic cell 10, and carbon dioxide is separated from the incoming gas. Then, in this modified example, after the adsorption of carbon dioxide onto the adsorption member 49 in the state shown in Figure 6 for a certain period of time, the carbon dioxide capture system 1 is set to the state shown in Figure 13 instead of the state shown in Figure 8, and excess gas other than carbon dioxide is discharged from the electrolytic unit Ek. ​​Figure 13 shows an example of a state in which excess gas is discharged from any one electrolytic unit Ek after the state shown in Figure 6.

[0068] In the state shown in Figure 13, similar to the state shown in Figure 8, the inlet switching valve 25 corresponding to the electrolytic unit Ek is closed, and no voltage is applied to the electrolytic cell 10 of the electrolytic unit Ek. ​​The discharge switching valve 26 corresponding to the electrolytic unit Ek is open. However, in the state shown in Figure 13, the vacuum pump 35 is operated in the recovery unit 30, and the switching valve 36 is released. Therefore, any excess gas remaining in the processing chamber 41 of the electrolytic unit Ek is discharged from the electrolytic unit Ek through the corresponding discharge switching valve 26 to the recovery unit 30 by suction from the vacuum pump 35. The excess gas discharged to the recovery unit 30 is then discharged to the atmosphere through the switching valve 36 and the vacuum pump 35 by suction from the vacuum pump 35. Note that the processing chamber 41 of the electrolytic unit Ek is omitted in Figure 13.

[0069] When the excess gas remaining in the electrolytic unit Ek is discharged in the state shown in Figure 13, the carbon dioxide recovery system 1 is returned to the state shown in Figure 9, for example. As a result, the adsorbent member 49 in the electrolytic unit Ek releases the adsorbed carbon dioxide, and the carbon dioxide released from the adsorbent member 49 accumulates in the processing chamber 41. In this modified example, after the carbon dioxide is released from the adsorbent member 49 for a certain period of time in the state shown in Figure 9, the carbon dioxide recovery system 1 is returned to the state shown in Figure 14 instead of the state shown in Figure 10, and the carbon dioxide released from the adsorbent member 49 is discharged from the electrolytic unit Ek. ​​Figure 14 shows an example of a state in which the carbon dioxide released by the adsorbent member 49 is discharged from any one of the electrolytic units Ek after the state shown in Figure 9.

[0070] In the state shown in Figure 14, similar to the state shown in Figure 10, the inlet switching valve 25 corresponding to the electrolytic unit Ek is closed, and the power supply unit 40 adds a second potential (oxidation potential) to the working electrode 42. The discharge switching valve 26 corresponding to the electrolytic unit Ek is opened, and the compressor 31 in the recovery unit 30 is operated. Also in the state shown in Figure 14, the switching valve 36 is open. Therefore, the carbon dioxide released from the adsorption material 49 in the electrolytic unit Ek is pumped by the compressor 31 and discharged from the electrolytic unit Ek through the corresponding discharge switching valve 26 and switching valve 36 to the compressor 31 in the recovery unit 30. The carbon dioxide discharged to the compressor 31 is then pumped by the compressor 31 into the recovery tank 33. As a result, carbon dioxide is stored in the recovery tank 33 and recovered. Note that in the state shown in Figure 14, the operation of the vacuum pump 35 is stopped, and carbon dioxide is not discharged into the atmosphere through the vacuum pump 35.

[0071] When carbon dioxide recovery is complete in the state shown in Figure 14, the pressure in the electrolysis unit Ek is returned to atmospheric pressure. Figure 15 shows an example of a state after the state shown in Figure 14, where any one electrolysis unit Ek is returned to atmospheric pressure. In the state shown in Figure 15, similar to the state shown in Figure 11, the inlet switching valve 25 corresponding to the electrolysis unit Ek is in the open state, and no voltage is applied to the electrolysis cell 10 of the electrolysis unit Ek. ​​The discharge switching valve 26 corresponding to the electrolysis unit Ek is in the closed state. Therefore, in the state shown in Figure 15, similar to the state shown in Figure 11, the electrolysis unit Ek returns to atmospheric pressure. In addition, in the state shown in Figure 15, the operation of the compressor 31 and vacuum pump 35 in the recovery unit 30 is stopped, and the switching valve 36 is in the closed state.

[0072] When the electrolysis unit Ek is returned to atmospheric pressure in the state shown in Figure 15, the carbon dioxide recovery system 1 is returned to the state shown in Figure 6. Then, in the state shown in Figure 6, carbon dioxide is adsorbed onto the adsorption member 49 of the electrolysis cell 10 using the electrolysis unit Ek, as described above. Then, the process described above is repeated using the electrolysis unit Ek. ​​This modified example also produces the same operation and effects as the first embodiment, etc. Therefore, the configuration of the carbon dioxide recovery system 1 is simplified in this modified example as well.

[0073] (Second embodiment) Next, a second embodiment will be described as a modification of the first embodiment. Figure 16 shows a carbon dioxide recovery system 1 according to the second embodiment. As shown in Figure 16, in this embodiment, n electrolytic units E1 to En are arranged in series with respect to each other in the flow path through which the taken-in gas flows. In the flow path, they are arranged in the order E1, E2, ..., En from the upstream side. In this embodiment as well, one pressure gauge 23 is provided for each of the electrolytic units E1 to En. In addition, in this embodiment, the same number of inlet switching valves Va, discharge switching valves Vb, and release valves Vc are provided as the number of electrolytic units E1 to En. One inlet switching valve Va, one discharge switching valve Vb, and one release valve Vc are provided for each of the electrolytic units E1 to En.

[0074] Here, as mentioned above, let k be any natural number between 1 and n. Then, let Vak, Vbk, and Vck be the ones in the inlet switching valve Va, outlet switching valve Vb, and release valve Vc that correspond to the electrolytic unit Ek. ​​Regardless of whether the electrolytic unit Ek is one of the electrolytic units E1 to En, the configuration and operation of the electrolytic unit Ek, inlet switching valve Vak, outlet switching valve Vbk, and release valve Vck are as follows. Also, let j be any natural number between 1 and n-1. Then, let Vaj, Vbj, and Vcj be the ones in the inlet switching valve Va, outlet switching valve Vb, and release valve Vc that correspond to the electrolytic unit Ej. Regardless of whether the electrolytic unit Ej is one of the electrolytic units E1 to En-1, the configuration and operation of the electrolytic unit Ej, inlet switching valve Vaj, outlet switching valve Vbj, and release valve Vcj are as follows.

[0075] In this embodiment, the gas flow path of the inflow switching valve Vaj is branched into a flow path toward the electrolytic unit Ej and a flow path toward the inflow switching valve Vaj+1. The inflow switching valve Vaj can be switched between an open state, a closed state, and a bypass state. When the inflow switching valve Vaj is in the open state, the intake gas flows into the electrolytic unit Ej. On the other hand, when the inflow switching valve Vaj is in the closed state, the inflow of intake gas into the electrolytic unit Ej is blocked. At this time, the flow of gas from the inflow switching valve Vaj to the inflow switching valve Vaj+1 is also blocked. Furthermore, when the inflow switching valve Vaj is in the bypass state, gas flows toward the inflow switching valve Vaj+1. At this time, no gas flows into the electrolytic unit Ej.

[0076] Furthermore, the inflow switching valve Van can be switched between an open state and a closed state. When the inflow switching valve Van is open, the intake gas flows into the electrolytic unit En. Conversely, when the inflow switching valve Van is closed, the inflow of intake gas into the electrolytic unit En is blocked. When the inflow switching valves Va1 to Vaj-1 are in a bypass state and the inflow switching valve Vaj is in an open state, the gas taken in from the intake port 6 flows into the electrolytic unit Ej without passing through the electrolytic units E1 to Ej-1. Also, when the inflow switching valves Va1 to Van-1 are in a bypass state and the inflow switching valve Van is in an open state, the gas taken in from the intake port 6 flows into the electrolytic unit En without passing through the electrolytic units E1 to En-1. The control unit 8 controls the operation of each of the inflow switching valves Va1 to Van.

[0077] In the carbon dioxide recovery system 1 of this embodiment, a vacuum pump 50 is provided. At the discharge switching valve Vbj, the gas flow path is branched into a flow path toward the electrolysis unit Ej+1 and a flow path toward the vacuum pump 50 via the release valve Vcj. The discharge switching valve Vbj can be switched between an open state, a closed state, and a discharge state. When the discharge switching valve Vbj is in the open state, gas flows from the electrolysis unit Ej to the electrolysis unit Ej+1. On the other hand, when the discharge switching valve Vbj is in the closed state, the flow of gas to the electrolysis unit Ej+1 is blocked. At this time, the flow of gas from the discharge switching valve Vbj to the release valve Vcj is also blocked. Furthermore, when the discharge switching valve Vbj is in the discharge state, gas is discharged toward the release valve Vcj. At this time, no gas flows into the electrolysis unit Ej+1.

[0078] Furthermore, the discharge switching valve Vbn branches the gas flow path into a path leading to the recovery unit 30 and a path leading to the vacuum pump 50 via the release valve Vcn. The discharge switching valve Vbn can be switched between an open state, a closed state, and a discharge state. When the discharge switching valve Vbn is in the open state, gas can be discharged from the electrolysis unit En to the recovery unit 30. On the other hand, when the discharge switching valve Vbn is in the closed state, the discharge of gas from the electrolysis unit En to the recovery unit 30 is blocked. At this time, the gas flow from the discharge switching valve Vbn to the release valve Vcn is also blocked. Also, when the discharge switching valve Vbn is in the discharge state, gas is discharged toward the release valve Vcn. At this time, no gas flows into the recovery unit 30. The control unit 8 controls the operation of each of the discharge switching valves Vb1 to Vbn.

[0079] In this embodiment, the recovery unit 30 consists of a compressor 31 and a recovery tank 33, and no switching valves or the like are provided. Carbon dioxide discharged from the electrolysis unit En to the recovery unit 30 is pumped under pressure by the compressor 31 and recovered into the recovery tank 33. In addition, by operating the vacuum pump 50 in the carbon dioxide recovery system 1, a gas flow is generated from each of the release valves Vc1 to Vcn through the vacuum pump 50 toward the atmosphere. The control unit 8 controls the operating state of the vacuum pump 50 and switches between operating and stopping the vacuum pump 50.

[0080] The release valve Vck can be switched between a non-released state and a released state. When the release valve Vck is in the non-released state, it connects the discharge switching valve Vbk and the vacuum pump 50. This allows gas to flow from the discharge switching valve Vbk to the vacuum pump 50 through the release valve Vck. When the release valve Vck is in the released state, it allows the gas that has flowed in from the discharge switching valve Vbk to be discharged into the atmosphere. In this case, no gas flows from the release valve Vck to the vacuum pump 50. The control unit 8 controls the operation of each of the release valves Vc1 to Vcn.

[0081] The process for recovering carbon dioxide will be described below. In Figures 17 to 21, which will be referenced in the following description, gas flows where only arrows are shown, and the gas flow is blocked where arrows are superimposed with cross marks. In this embodiment, during carbon dioxide recovery, carbon dioxide is adsorbed onto the adsorption member 49 of the electrolytic cell 10 in the electrolytic unit Ej, and then the adsorbed carbon dioxide is released from the adsorption member 49 in the electrolytic unit Ej. The carbon dioxide released from the adsorption member 49 is then discharged from the electrolytic unit Ej to the electrolytic unit Ej+1, where the carbon dioxide discharged from the electrolytic unit Ej is adsorbed onto the adsorption member 49 of the electrolytic cell 10 in the electrolytic unit Ej+1. Furthermore, in the downstream electrolytic unit En, when the adsorbed carbon dioxide is released from the adsorption member 49 of the electrolytic cell 10, the carbon dioxide released from the adsorption member 49 is discharged to the recovery unit 30. The carbon dioxide is then recovered in the recovery tank 33 of the recovery unit 30.

[0082] Figure 17 shows an example of the state in which carbon dioxide is adsorbed onto the adsorption material 49 of the electrolytic cell 10 at the upstream electrolytic unit E1. In the state shown in Figure 17, the inflow switching valve Va1 is open, and the inflow switching valves Va2 to Van are closed. Therefore, the gas taken in from the intake port 6 flows only into the electrolytic unit E1 and not into the electrolytic units E2 to En. Also, in the state shown in Figure 17, the power supply unit 40 applies a first potential (reduction potential) to the working electrode 42 of the electrolytic unit E1. Therefore, in the electrolytic unit E1, the carbon dioxide contained in the incoming gas is adsorbed onto the adsorption material 49 of the electrolytic cell 10, and carbon dioxide is separated from the incoming gas. In the state shown in Figure 17, the discharge switching valve Vb1 is in the discharge state, and the discharge switching valves Vb2 to Vbn are closed. Then, the release valve Vc1 is in the release state. Therefore, the residual gas after carbon dioxide has been separated in electrolysis unit E1 is discharged into the atmosphere through release valve Vc1 and does not flow into electrolysis unit E2.

[0083] Figure 18 shows an example of a state in which excess gas is discharged from the upstream electrolytic unit E1 after the state in Figure 17. In this embodiment, in the state in Figure 17, carbon dioxide is adsorbed onto the adsorption member 49 of the electrolytic cell 10 of the electrolytic unit E1 for a certain period of time, and then in the state in Figure 18, excess gas is discharged from the electrolytic unit E1. In the state in Figure 18, the inflow switching valve Va1 is in the closed state. Therefore, the taken-in gas does not flow into the electrolytic unit E1. Also, no voltage is applied to the electrolytic cell 10 of the electrolytic unit E1, and the carbon dioxide adsorbed in the state in Figure 17 is maintained in the state adsorbed onto the adsorption member 49. In the state in Figure 18, the discharge switching valve Vb1 is in the discharge state, and the release valve Vc1 is in the non-release state. Then, the vacuum pump 50 is operated. Therefore, the excess gas remaining in the electrolytic unit E1 is discharged to the vacuum pump 50 through the discharge switching valve Vb1 and the release valve Vc1. Then, the excess gas discharged to the vacuum pump 50 is discharged from the vacuum pump 50 into the atmosphere.

[0084] Figure 19 shows an example of a state in which carbon dioxide adsorbed in the upstream electrolytic unit E1 is released from the adsorption member 49 of the electrolytic cell 10 after the state in Figure 18. In this embodiment, after excess gas is discharged from the electrolytic unit E1 in the state in Figure 18, carbon dioxide is released from the adsorption member 49 in the electrolytic unit E1 in the state in Figure 19. In the state in Figure 19, the inflow switching valve Va1 is closed, so no gas flows into the electrolytic unit E1. Also, a second potential (oxidation potential) is added to the working electrode 42 of the electrolytic unit E1 by the power supply unit 4, so the carbon dioxide adsorbed in the electrolytic unit E1 is released from the adsorption member 49. In the state in Figure 19, the discharge switching valve Vb1 is closed. Therefore, the carbon dioxide released from the adsorption member 49 is not discharged from the electrolytic unit E1 and remains in the electrolytic unit E1.

[0085] Figure 20 shows an example of the state after the state in Figure 19, where carbon dioxide is introduced from the upstreamest electrolytic unit E1 to the second upstream electrolytic unit E2, and the carbon dioxide introduced in the second upstream electrolytic unit E2 is adsorbed by the adsorption member 49 of the electrolytic cell 10. In this embodiment, after releasing carbon dioxide from the adsorption member 49 of electrolytic unit E1 for a certain period of time in the state in Figure 19, carbon dioxide is introduced from electrolytic unit E1 to electrolytic unit E2 in the state in Figure 20. In the state in Figure 20, the inflow switching valve Va1 is open and the discharge switching valve Vb1 is open. As a result, a gas flow is formed from the intake port 6 through electrolytic unit E1 to electrolytic unit E2, and the gas taken in from the intake port 6 is used as a sweep gas to introduce carbon dioxide from electrolytic unit E1 to electrolytic unit E2. At this time, the flow rate of the sweep gas flowing into electrolytic units E1 and E2 is adjusted by the flow rate adjustment valve 12 so that it does not exceed an appropriate range. In the state shown in Figure 20, since the inflow switching valve Va2 is closed, gas does not flow into the electrolytic unit E2 without passing through the electrolytic unit E1.

[0086] Furthermore, in the state shown in Figure 20, a second potential is applied to the working electrode 42 of the electrolytic cell 10 in electrolytic unit E1, and a first potential is applied to the working electrode 42 of the electrolytic cell 10 in electrolytic unit E2. As a result, carbon dioxide contained in the incoming gas is adsorbed onto the adsorption member 49 of the electrolytic cell 10 in electrolytic unit E2. This separates carbon dioxide from the gas flowing into electrolytic unit E2. In the state shown in Figure 20, the discharge switching valve Vb2 is in the discharge state, and the release valve Vc2 is in the release state. As a result, the remaining gas from which carbon dioxide has been separated in electrolytic unit E2 is discharged into the atmosphere through the release valve Vc2 and does not flow into electrolytic unit E3.

[0087] Figure 21 shows an example of a state in which excess gas is discharged from the second upstream electrolytic unit E2 after the state in Figure 20. In this embodiment, in the state in Figure 20, carbon dioxide is adsorbed onto the adsorption member 49 of the electrolytic cell 10 of electrolytic unit E2 for a certain period of time, and then in the state in Figure 21, excess gas is discharged from electrolytic unit E2. In the state in Figure 21, the inlet switching valve Va2 is in the closed state and the discharge switching valve Vb1 is in the discharge state. Therefore, gas does not flow from the intake port 6 to electrolytic unit E2, nor does gas flow from electrolytic unit E1 to electrolytic unit E2. Also, no voltage is applied to the electrolytic cell 10 of electrolytic unit E2, and the carbon dioxide adsorbed in the state in Figure 20 is maintained in the state adsorbed onto the adsorption member 49. In the state in Figure 21, the discharge switching valve Vb2 is in the discharge state and the release valve Vc2 is in the non-release state. Then, the vacuum pump 50 is operated. Therefore, any excess gas remaining in the electrolytic unit E2 is discharged to the vacuum pump 50 through the discharge switching valve Vb2 and the release valve Vc2. The excess gas discharged to the vacuum pump 50 is then discharged from the vacuum pump 50 into the atmosphere.

[0088] Furthermore, in the state shown in Figure 21, the inflow switching valve Va1 is open, and gas flows into the electrolytic unit E1 from the intake port 6. Then, in the electrolytic unit E1, a reduction potential (first potential) is applied to the working electrode 42 of the electrolytic cell 10, and carbon dioxide contained in the inflowing gas is adsorbed by the adsorption member 49 of the electrolytic cell 10. In the state shown in Figure 21, as described above, the discharge switching valve Vb1 is in the discharge state. Then, the release valve Vc1 is in the release state. For this reason, the remaining gas from which carbon dioxide has been separated in the electrolytic unit E1 is discharged into the atmosphere through the release valve Vc1 and does not flow into the electrolytic unit E2.

[0089] In the state shown in Figure 21, when excess gas is discharged from the electrolytic unit E2, carbon dioxide is released from the adsorption member 49 in the electrolytic unit E2. At this time, carbon dioxide is released from the adsorption member 49 in the electrolytic unit E2 in the same manner as the release of carbon dioxide from the adsorption member 49 in the electrolytic unit E1. Then, carbon dioxide is introduced from the electrolytic unit E2 to the electrolytic unit E3, and the carbon dioxide introduced into the electrolytic unit E3 is adsorbed onto the adsorption member 49 of the electrolytic cell 10. At this time, carbon dioxide is introduced from the electrolytic unit E2 to the electrolytic unit E3 in the same manner as the flow of carbon dioxide from the electrolytic unit E1 to the electrolytic unit E2. However, when carbon dioxide flows from the electrolytic unit E2 to the electrolytic unit E3, the inflow switching valve Va1 is set to the bypass state, the inflow switching valve Va2 is set to the open state, and the discharge switching valve Vb2 is set to the open state. This creates a gas flow from the intake port 6 through the electrolytic unit E2 to the electrolytic unit E3, and the gas taken in from the intake port 6 is used as a sweep gas to bring carbon dioxide from the electrolytic unit E2 to the electrolytic unit E3. The sweep gas that brings carbon dioxide from the electrolytic unit E2 to the electrolytic unit E3 does not pass through the electrolytic unit E1.

[0090] As a result of the processing described above, in this embodiment, carbon dioxide adsorbed onto the adsorption member 49 and released from the adsorption member 49 in electrolytic unit E1 is adsorbed onto the adsorption member 49 and released from the adsorption member 49 in the electrolytic cell 10 in the order of electrolytic units E2, ..., En. Then, in electrolytic unit En, the carbon dioxide released from the adsorption member 49 is discharged to the recovery unit 30, where the carbon dioxide is recovered. Furthermore, in this embodiment, the configuration is the same as in the first embodiment, except that the electrolytic units E1 to En are arranged in series with respect to each other. For this reason, this embodiment also produces the same functions and effects as in the first embodiment, etc. Accordingly, in this embodiment as well, the configuration of the carbon dioxide recovery system 1 is simplified.

[0091] (Third embodiment) Next, a third embodiment will be described as a modification of the first embodiment. Figure 22 shows an arbitrary electrolytic unit Ek provided in the carbon dioxide recovery system 1 according to the third embodiment. In this embodiment, the configurations of the electrolytic units E1 to En differ from those of the previously described embodiments, and the configuration of the electrolytic cell 10 also differs. In the following description, the electrolytic unit Ek will be mainly described, but the other electrolytic units (E1 to En other than Ek) will have similar configurations to the electrolytic unit Ek. ​​Also, in the example shown in Figure 22, as in the first embodiment, one inlet switching valve 25 and one discharge switching valve 26 are provided corresponding to the electrolytic unit Ek.

[0092] As shown in Figure 22, in this embodiment, the electrolytic cell 10 of the electrolytic unit Ek includes a working electrode 42 and a counter electrode 43, similar to the embodiments described above. The counter electrode 43 is formed from the same material as in the embodiments described above. In this embodiment, the working electrode 42 consists only of a current collector 46, and no adsorption layer 47 is formed on the working electrode 42. The current collector 46 of the working electrode 42 is formed in the same manner as in the embodiments described above. In addition, in this embodiment, the electrolytic cell 10 is provided with a separator (partition wall) 58 instead of a separator 45. The separator 58 has electrical insulating properties and is formed from, for example, the same material as the separator 45. The electrolytic cell 10 is equipped with a reference electrode 57, and the power supply unit 40 applies a potential to the working electrode 42 and the counter electrode 43 based on the potential of the reference electrode 57 (reference potential), and applies a voltage to the electrolytic cell 10. The reference electrode 57 is, for example, Ag / Ag + These are electrodes. Note that the electrolytic cell 10 does not necessarily need to have a reference electrode 57. In this case, the power supply unit 40 applies a potential to the working electrode 42 and the counter electrode 43 based on the ground (GND) or the potential of a conductive part provided outside the electrolytic units E1 to En (reference potential).

[0093] In this embodiment, the electrolytic cell 10 contains an electrolyte solution 51 as the electrolyte. In the electrolyte solution, either the aforementioned ionic salt or ionic conductive polymer is dissolved in an organic solvent or aqueous solution. In the electrolytic cell 10, the working electrode 42, counter electrode 43, and reference electrode 57 are each immersed in the electrolyte solution 51. In this embodiment, in the electrolytic cell 10 of the electrolytic unit Ek, gas flows into the electrolyte solution 51 through the corresponding inflow switching valve 25. In the electrolytic cell 10, a headspace 52 that is not filled with electrolyte solution 51 is formed. In the electrolytic unit Ek, gas is discharged from the headspace 52 of the electrolytic cell 10 through the corresponding discharge switching valve 26. In the electrolytic unit Ek, the pressure in the headspace 52 is measured by a pressure gauge 23.

[0094] In the electrolytic cell 10 of this embodiment, a separator 58 is placed between the working electrode 42 and the counter electrode 43, and the electrolyte 51 is separated by the separator 58 into a portion on the working electrode 42 side and a portion on the counter electrode 43 side. If a reference electrode 57 is provided, the reference electrode 57 is immersed in the electrolyte 51 on the portion on the working electrode 42 side.

[0095] In this embodiment, the aforementioned compounds having redox activity are dissolved and dispersed in the electrolyte 51. For this reason, the electrolyte 51 may contain the aforementioned compounds having redox activity. In the electrolyte 51, the compounds having redox activity are dispersed and dissolved in either molecular or ionic form. The compounds having redox activity include at least one selected from the group consisting of carbonyl compounds, pyridyl compounds, and imide compounds, as in the embodiments described above. In this embodiment, the compounds contained in the electrolyte 51 function as adsorbents capable of adsorbing and releasing carbon dioxide. Figure 23 shows an example of a compound having redox activity contained in the electrolyte in the electrolytic cell 10. In the example in Figure 23, an anthraquinone molecule is shown as the molecule of the compound having redox activity.

[0096] In this embodiment, in each of the electrolytic units E1 to En, a first potential (reduction potential) is added to the working electrode 42 by applying a voltage to the electrolytic cell 10, causing the adsorbent compound to enter a reduced state near the working electrode 42 in the electrolyte 51. Then, as the compound enters a reduced state due to an electrical response corresponding to the potential of the working electrode 42, the adsorbent compound adsorbs carbon dioxide near the working electrode in the electrolyte 51. Furthermore, in each of the electrolytic units E1 to En, a second potential (oxidation potential) is added to the working electrode 42 by applying a voltage to the electrolytic cell 10, causing the adsorbent compound to enter an oxidized state near the working electrode 42 in the electrolyte 51. Then, as the compound enters an oxidized state due to an electrical response corresponding to the potential of the working electrode 42, the adsorbent compound becomes capable of releasing carbon dioxide near the working electrode in the electrolyte 51.

[0097] Figure 24 shows a state in which carbon dioxide is adsorbed by an adsorbent substance (a compound with redox activity) contained in the electrolyte 51 of the electrolytic cell 10 in any one electrolytic unit Ek. ​​In the state shown in Figure 24, the gas taken in at the intake port 6 flows into the electrolyte 51 of the electrolytic cell 10 in the electrolytic unit Ek through the corresponding inflow switching valve 25. Also, a first potential is applied to the working electrode 42. As a result, carbon dioxide contained in the incoming gas is adsorbed by the adsorbent substance contained in the electrolyte 51 near the working electrode 42 of the electrolyte 51. For example, carbon dioxide is adsorbed by the adsorbent substance contained in the electrolyte 51 on the working electrode 42 side relative to the separator 58. The remaining gas from which carbon dioxide has been separated is then discharged from the electrolyte 51 into the headspace 52. In the state shown in Figure 24, the corresponding discharge switching valve 26 is in the released state. As a result, the remaining gas from which carbon dioxide has been separated is discharged into the atmosphere from the headspace 52 through the corresponding discharge switching valve 26.

[0098] In the state shown in Figure 24, after adsorption of carbon dioxide onto the adsorbent material (a compound having redox activity) for a certain period of time, the excess gas remaining in the headspace 52, etc., is discharged from the electrolytic unit Ek, similar to the embodiments described above. At this time, the excess gas is discharged from the electrolytic unit Ek using a vacuum pump or the compressor 31 of the recovery unit 30, similar to the embodiments described above. After the excess gas is discharged from the electrolytic unit Ek, the carbon dioxide adsorbed on the adsorbent material is released from the adsorbent material in the electrolytic unit Ek.

[0099] Figure 25 shows a state in which any one electrolytic unit Ek is releasing carbon dioxide adsorbed from adsorbent material (compounds with oxidation-reduction activity) contained in the electrolyte 51 of the electrolytic cell 10. In the state shown in Figure 25, the corresponding inlet switching valve 25 and the corresponding outlet switching valve 26 are both closed. Therefore, no gas flows into the electrolytic unit Ek, and no gas is discharged from the electrolytic unit Ek. ​​In addition, a second potential is applied to the working electrode 42. As a result, the adsorbent material contained in the electrolyte 51 releases adsorbed carbon dioxide in the vicinity of the working electrode 42 of the electrolyte 51. For example, the adsorbent material contained in the electrolyte 51 releases carbon dioxide in the portion of the separator 58 on the working electrode 42 side. The carbon dioxide released from the adsorbent material is discharged from the electrolyte 51 into the headspace 52. Then, carbon dioxide is accumulated in the headspace 52.

[0100] In the state shown in Figure 25, after releasing carbon dioxide from the adsorbent (a compound with redox activity) for a certain period of time, the carbon dioxide released from the adsorbent is discharged to the recovery unit 30 through the discharge switching valve 26, similar to the embodiments described above. At this time, the discharge switching valve 26 corresponding to the electrolytic unit Ek is opened. Then, the carbon dioxide is recovered in the recovery unit 30. In one example, instead of discharging to the recovery unit 30, the carbon dioxide may be introduced into the electrolytic unit Ek+1 one step downstream, similar to the second embodiment. The discharge of carbon dioxide from the electrolytic unit Ek to the recovery unit 30, and the introduction of carbon dioxide from the electrolytic unit Ek to the electrolytic unit Ek+1 are carried out in the same manner as in any of the embodiments described above.

[0101] In this embodiment, in carbon dioxide recovery, the introduction of gas to each of the electrolytic units E1 to En and the discharge of gas from each of the electrolytic units E1 to En are controlled in the same manner as in any of the embodiments described above. Then, carbon dioxide is recovered in the recovery unit 30 in the same manner as in any of the embodiments described above. Furthermore, in this embodiment, the configuration is the same as in the first embodiment, except for the configuration of the electrolytic cells 10 in each of the electrolytic units E1 to En. Therefore, this embodiment also produces the same functions and effects as the first embodiment, etc. Accordingly, the configuration of the carbon dioxide recovery system 1 is simplified in this embodiment as well.

[0102] (Fourth embodiment) Next, a fourth embodiment will be described as a modification of the third embodiment. Figure 26 shows a carbon dioxide recovery system 1 according to the fourth embodiment. As shown in Figure 26, in this embodiment, each of the electrolytic units E1 to En is equipped with two electrolytic cells 10A and 10B. Each of the electrolytic cells 10A and 10B has the same configuration as the electrolytic cell 10 in the third embodiment. In this embodiment as well, each of the electrolytic units E1 to En is provided with one inlet switching valve 25 and one discharge switching valve 26. However, in this embodiment, the discharge switching valve 26 can only be switched to the open state and the closed state, and cannot be switched to the release state. In this embodiment, the recovery unit 30 is composed of a compressor 31 and a recovery tank 33. The recovery unit 30 may also be equipped with a vacuum pump similar to the vacuum pump 35 and a switching valve similar to the switching valve 36. In this case, by operating the vacuum pump, excess gas other than carbon dioxide is discharged from the electrolytic unit Ek to the atmosphere in the same manner as in the example shown in Figure 12, etc.

[0103] Figure 27 shows an arbitrary electrolytic unit Ek provided in the carbon dioxide recovery system 1. In the following description, electrolytic unit Ek will be mainly described, but the other electrolytic units (E1 to En, excluding Ek) have similar configurations. As shown in Figure 27, in electrolytic unit Ek, gas taken in from the intake port 6 flows into the electrolyte 51 of the electrolytic cell (first electrolytic cell) 10A through the corresponding inflow switching valve 25. Also in electrolytic unit Ek, gas is discharged from the headspace 52 of the electrolytic cell (second electrolytic cell) 10B to the recovery unit 30 through the corresponding discharge switching valve 26. Furthermore, in this embodiment, in electrolytic unit Ek, the relay channels 55 and 56 connect the electrolytic cells 10A and 10B, respectively. In the relay channel 55, electrolyte flows from electrolytic cell 10A to electrolytic cell 10B, and in electrolytic cell 10B, electrolyte flows from electrolytic cell 10B to electrolytic cell 10A. The relay channel 55 connects the part of the electrolyte 51 of electrolytic cell 10A on the side of the working electrode 42 to the part of the electrolyte 51 of electrolytic cell 10B on the side of the working electrode 42. The relay channel 56 connects the part of the electrolyte 51 of electrolytic cell 10A on the side of the counter electrode 43 to the part of the electrolyte 51 of electrolytic cell 10B on the side of the counter electrode 43.

[0104] Furthermore, in this embodiment, when carbon dioxide is being recovered using the electrolytic unit Ek, a first potential (reduction potential) is constantly applied to the working electrode 42 of the electrolytic cell 10A, and a second potential (oxidation potential) is constantly applied to the working electrode 42 of the electrolytic cell 10B. Also, when carbon dioxide is being recovered using the electrolytic unit Ek, the corresponding inlet switching valve 25 and the corresponding discharge switching valve 26 are opened. Then, the gas taken in from the intake port 6 is introduced into the electrolyte 51 of the electrolytic cell (first electrolytic cell) 10A using the electrolytic unit Ek. ​​In the electrolytic cell 10A, since the first potential (reduction potential) is applied to the working electrode 42, the adsorbent compound in the vicinity of the working electrode 42 in the electrolyte 51 is reduced. Then, due to the electrical response corresponding to the potential of the working electrode 42 of the electrolytic cell 10A, the compound enters a reduced state, and the adsorbent compound adsorbs carbon dioxide in the vicinity of the working electrode 42 in the electrolyte 51 of the electrolytic cell 10A. For example, carbon dioxide is adsorbed by the adsorbent contained in the electrolyte 51 of the electrolytic cell 10A at the part of the separator 58 that is on the working electrode 42 side.

[0105] The adsorbent material that has adsorbed carbon dioxide then flows from electrolytic cell 10A to electrolytic cell 10B together with the electrolyte 51 through the relay channel 55. In electrolytic cell (second electrolytic cell) 10B, a second potential (oxidation potential) is added to the working electrode 42, so that the compound, which is the adsorbent material, becomes oxidized near the working electrode 42 in the electrolyte 51. Then, due to the electrical response corresponding to the potential of the working electrode 42 of electrolytic cell 10B, the compound becomes oxidized, and the adsorbent material releases the adsorbed carbon dioxide near the working electrode 42 in the electrolyte 51 of electrolytic cell 10B. For example, at the part on the working electrode 42 side relative to the separator 58, the adsorbent material contained in the electrolyte 51 of electrolytic cell 10B releases carbon dioxide. The carbon dioxide released from the adsorbent material is discharged from the electrolyte 51 into the headspace 52 in electrolytic cell 10B. Then, carbon dioxide is discharged from the headspace 52 of the electrolytic cell 10B through the corresponding discharge switching valve 26 to the recovery unit 30, where it is recovered. Here, the recovery unit 30 is omitted in Figure 27. In one example, instead of discharging to the recovery unit 30, the carbon dioxide may be flowed into the electrolytic unit Ek+1 one step downstream, similar to the second embodiment.

[0106] In this embodiment, the configuration is similar to that of the third embodiment, except that each of the electrolytic units E1 to En is provided with two electrolytic cells 10A and 10B. Therefore, this embodiment also produces the same functions and effects as the third embodiment, etc. Consequently, the configuration of the carbon dioxide recovery system 1 is simplified in this embodiment as well.

[0107] In at least one of the embodiments described above, the intake unit utilizes the gas flow in the environment in which it is installed to take in gas from the intake port and allow the taken-in gas to flow into the electrolysis unit. The electrolysis unit then adjusts the potential using a power supply unit to adsorb carbon dioxide contained in the gas flowing in from the intake port onto an adsorbent material, and releases the carbon dioxide adsorbed onto the adsorbent material from the adsorbent material. This makes it possible to provide a carbon dioxide recovery system and carbon dioxide recovery method that can simplify the system configuration.

[0108] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

[0109] The following are additional notes. (Additional note 1) An intake unit is formed in an environment in which an intake port is located and takes in the gas from the intake port, An electrolytic unit comprising an adsorbent material capable of adsorbing and releasing carbon dioxide through an electrical response corresponding to an electric potential, into which the gas taken in from the intake port of the intake unit flows, A power supply unit that adjusts the potential to adsorb carbon dioxide contained in the gas flowing in from the intake port onto the adsorbent material in the electrolytic unit, and releases the carbon dioxide adsorbed onto the adsorbent material from the adsorbent material, A recovery unit for recovering the carbon dioxide released from the adsorbent after it has been adsorbed onto the adsorbent, A carbon dioxide capture system equipped with the following features. (Additional note 2) An air flow meter for measuring the flow rate of the gas taken in at the intake port of the intake unit, A flow rate adjustment unit is positioned between the intake port and the electrolysis unit to adjust the flow rate of the gas directed downstream, Based on the measurement results from the airflow meter, a control unit controls the operation of the flow rate adjustment unit and controls the flow rate of the gas that passes through the flow rate adjustment unit and heads downstream so as not to exceed a standard flow rate. A carbon dioxide capture system as specified in Appendix 1, further comprising the features of Appendix 1. (Additional note 3) An anemometer for measuring the direction of gas flow in the environment in which the intake unit is located, A control unit controls the orientation of the intake unit and adjusts the opening direction of the intake port based on the measurement results from the wind vane, A carbon dioxide capture system according to Appendix 1 or 2, further comprising the above. (Additional note 4) The intake unit further includes a flow path through which the gas flows from the intake port toward the electrolysis unit, The flow path of the intake unit is formed in which a portion of the cross-sectional area decreases from the opening area at the intake port as it moves away from the intake port. A carbon dioxide capture system as specified in any one of the appendices 1 through 3. (Additional note 5) The carbon dioxide capture system according to any one of the appendices 1 to 4, wherein the intake unit is positioned such that the opening direction of the intake port forms a downward angle with respect to the horizontal plane. (Additional note 6) A water level gauge for measuring the water level in the environment in which the intake unit is located, An opening / closing member that switches between a state in which the intake port of the intake unit is open and a state in which the intake port is closed, A control unit controls the operation of the opening / closing member based on the measurement results from the water level gauge, and closes the intake port with the opening / closing member based on the water level measured by the water level gauge exceeding a reference level, A carbon dioxide capture system further comprising any one of the appendices 1 to 5. (Additional note 7) A carbon dioxide recovery system according to any one of the appendices 1 to 6, further comprising a filter attached to the intake unit in a manner that covers the intake port. (Additional note 8) The intake unit is a carbon dioxide recovery system according to any one of the appendices 1 to 7, which allows the gas taken in from the intake port to flow into the electrolysis unit without heating or cooling. (Additional note 9) The intake unit is a carbon dioxide recovery system according to Appendix 8, which causes the gas taken in from the intake port to flow into the electrolysis unit at a temperature within the range of -10°C or higher and 50°C or lower. (Additional note 10) A flow rate adjustment unit is positioned between the intake port and the electrolysis unit to adjust the flow rate of the gas directed downstream, Between the intake port and the flow rate adjustment unit, a first thermometer is provided to measure the temperature of the gas taken in from the intake port. Between the flow rate adjustment unit and the electrolysis unit, a second thermometer is provided to measure the temperature of the gas flowing downstream from the flow rate adjustment unit. A carbon dioxide capture system further comprising any one of the appendices 1 to 9. (Additional note 11) A carbon dioxide recovery system according to any one of Appendix 1 to Appendix 10, wherein the adsorbent material of the electrolytic unit contains a compound having redox activity. (Additional note 12) The carbon dioxide recovery system of the electrolytic unit, wherein the adsorbent material adsorbs carbon dioxide when the compound enters a reduced state due to an electrical response corresponding to the potential, and releases carbon dioxide when the compound enters an oxidized state due to an electrical response corresponding to the potential. (Additional note 13) The adsorbent material of the electrolytic unit further comprises at least one of a metal-organic structure and a covalent organic structure. The metal-organic structure and / or the covalent organic structure include, as a crosslinking portion, molecules of the compound having redox activity. Carbon dioxide capture system as specified in Appendix 11 or 12. (Additional note 14) The electrolytic unit comprises an electrolyte solution, The compound having redox activity is contained in the electrolyte. Carbon dioxide capture system as specified in Appendix 11 or 12. (Additional note 15) A carbon dioxide recovery system according to any one of appendices 11 to 14, wherein the compound having redox activity comprises at least one selected from the group consisting of carbonyl compounds, pyridyl compounds, and imide compounds. (Additional note 16) The electrolytic unit comprises an working electrode, The working electrode of the electrolytic unit comprises a current collector and an adsorption layer formed on the surface of the current collector. The adsorption layer contains the adsorbent material, A carbon dioxide capture system as specified in any one of the appendices 1-13 or 15. (Additional note 17) The electrolytic unit comprises an electrolyte solution, The adsorbent is contained in the electrolyte. A carbon dioxide capture system as described in any one of the appendices 1-12, 14, or 15. (Additional note 18) The electrolytic unit comprises an working electrode, The working electrode of the electrolytic unit is equipped with a current collector, The main power body includes a porous body, A carbon dioxide capture system as specified in any one of the appendices 1 through 17. (Additional note 19) The gas is taken in through the intake port of the intake unit by utilizing the gas flow in the environment in which the intake unit is located. The gas taken in from the intake port of the intake unit is introduced into an electrolytic unit in which the adsorbent material can adsorb and release carbon dioxide through an electrical response corresponding to the potential, By adjusting the potential, the electrolytic unit causes carbon dioxide contained in the gas flowing in from the intake port to be adsorbed onto the adsorbent material, and the carbon dioxide adsorbed onto the adsorbent material to be released from the adsorbent material. To recover the carbon dioxide released from the adsorbent after it has been adsorbed onto the adsorbent, A carbon dioxide capture method comprising the following features. [Explanation of Symbols]

[0110] 1...Carbon dioxide capture system, 2...Intake unit, 5...Flow path, 6...Intake port, 7...Cross-sectional area reduction section, 8...Control unit, 10...Electrolytic cell, 11...Air flow meter, 12...Flow rate adjustment valve, 13...Wind direction meter, 16...Filter, 17...Water level meter, 18...Shutter, 21,22...Thermometer, 25...Inlet switching valve, 26...Discharge switching valve, 30...Recovery unit, 40...Power supply unit, 42...Working electrode, 49...Adsorption material (adsorbent substance), 51...Electrolyte, E1~En...Electrolytic unit, Va1~Van...Inlet switching valve, Vb1~Vbn...Discharge switching valve.

Claims

1. An intake port is formed, and an intake unit takes in gas from the intake port, An electrolytic unit comprising an adsorbent material capable of adsorbing and releasing carbon dioxide through an electrical response corresponding to an electric potential, into which the gas taken in from the intake port of the intake unit flows, A power supply unit that adjusts the potential to adsorb carbon dioxide contained in the gas flowing in from the intake port onto the adsorbent material in the electrolytic unit, and releases the carbon dioxide adsorbed onto the adsorbent material from the adsorbent material, A recovery unit for recovering the carbon dioxide released from the adsorbent after it has been adsorbed onto the adsorbent, An anemometer for measuring the direction of gas flow in the environment in which the intake unit is located, Based on the measurement results from the wind vane, a control unit controls the position of the intake unit and adjusts the opening direction of the intake port so that the gas is directed towards the intake port in the environment where the intake unit is located. A flow rate adjustment unit is positioned between the intake port and the electrolysis unit to adjust the flow rate of the gas directed downstream, Between the intake port and the flow rate adjustment unit, a first thermometer is provided to measure the temperature of the gas taken in from the intake port. Between the flow rate adjustment unit and the electrolysis unit, a second thermometer is provided to measure the temperature of the gas flowing downstream from the flow rate adjustment unit. A carbon dioxide capture system equipped with the following features.

2. The intake unit further comprises an air flow meter for measuring the flow rate of the gas taken in at the intake port, The control unit controls the operation of the flow rate adjustment unit based on the measurement results from the airflow meter, and controls the flow rate of the gas flowing downstream through the flow rate adjustment unit so as not to exceed the standard flow rate. A carbon dioxide capture system according to claim 1.

3. The intake unit further includes a flow path through which the gas flows from the intake port toward the electrolysis unit, The flow path of the intake unit is formed in which a portion of the cross-sectional area decreases from the opening area at the intake port as it moves away from the intake port. A carbon dioxide capture system according to claim 1.

4. The carbon dioxide recovery system according to claim 1, wherein the intake unit is arranged such that the opening direction of the intake port forms a downward angle with respect to the horizontal plane.

5. A water level gauge for measuring the water level in the environment in which the intake unit is located, An opening / closing member that switches between a state in which the intake port of the intake unit is open and a state in which the intake port is closed, Furthermore, it is equipped with, The control unit controls the operation of the opening / closing member based on the measurement results from the water level gauge, and closes the intake port with the opening / closing member based on the water level measured by the water level gauge exceeding the reference level. A carbon dioxide capture system according to claim 1.

6. The carbon dioxide recovery system according to claim 1, further comprising a filter attached to the intake unit in a manner that covers the intake port.

7. The carbon dioxide recovery system according to claim 1, wherein the intake unit allows the gas taken in from the intake port to flow into the electrolysis unit without heating or cooling.

8. The carbon dioxide recovery system according to claim 7, wherein the intake unit causes the gas taken in from the intake port to flow into the electrolysis unit at a temperature within the range of -10°C or higher and 50°C or lower.

9. The carbon dioxide recovery system according to claim 1, wherein the adsorbent material of the electrolytic unit contains a compound having redox activity.

10. The carbon dioxide recovery system according to claim 9, wherein the adsorbent material of the electrolytic unit adsorbs carbon dioxide when the compound enters a reduced state due to an electrical response corresponding to the potential, and releases carbon dioxide when the compound enters an oxidized state due to an electrical response corresponding to the potential.

11. The adsorbent material of the electrolytic unit further comprises at least one of a metal-organic structure and a covalent organic structure. The metal-organic structure and / or the covalent organic structure includes, as a crosslinking portion, a molecule of the compound having redox activity. A carbon dioxide capture system according to claim 9.

12. The electrolytic unit comprises an electrolyte solution, The compound having redox activity is contained in the electrolyte. A carbon dioxide capture system according to claim 9.

13. The carbon dioxide recovery system according to claim 9, wherein the compound having redox activity includes at least one selected from the group consisting of carbonyl compounds, pyridyl compounds, and imide compounds.

14. The electrolytic unit comprises an working electrode, The working electrode of the electrolytic unit comprises a current collector and an adsorption layer formed on the surface of the current collector. The adsorption layer contains the adsorbent material, A carbon dioxide capture system according to claim 1.

15. The electrolytic unit comprises an electrolyte solution, The adsorbent is contained in the electrolyte. A carbon dioxide capture system according to claim 1.

16. The electrolytic unit comprises an working electrode, The working electrode of the electrolytic unit is equipped with a current collector, The current collector includes a porous body, A carbon dioxide capture system according to claim 1.

17. In the environment in which the intake unit is located, the direction of gas flow is measured by an anemometer, Based on the measurement results from the wind vane, the position of the intake unit is controlled and the opening direction of the intake port is adjusted so that the gas is directed towards the intake port of the intake unit in the environment in which the intake unit is located, thereby drawing in the gas from the intake port of the intake unit. The gas taken in from the intake port of the intake unit is introduced into an electrolytic unit in which the adsorbent material can adsorb and release carbon dioxide through an electrical response corresponding to the potential, By adjusting the potential, the electrolytic unit causes carbon dioxide contained in the gas flowing in from the intake port to be adsorbed onto the adsorbent material, and the carbon dioxide adsorbed onto the adsorbent material to be released from the adsorbent material. To recover the carbon dioxide released from the adsorbent after it has been adsorbed onto the adsorbent, The flow rate adjustment unit, positioned between the intake port and the electrolysis unit, adjusts the flow rate of the gas directed downstream. Between the intake port and the flow rate adjustment unit, the temperature of the gas taken in from the intake port is measured by a first thermometer. Between the flow rate adjustment unit and the electrolysis unit, the temperature of the gas flowing downstream from the flow rate adjustment unit is measured by a second thermometer. A carbon dioxide capture method comprising the following features.

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