Carbon dioxide capture system

Abstract

To suppress increase in a main controller processing load and increase in wiring effort and cost even when providing a plurality of units for recovery of carbon dioxide.SOLUTION: A main controller 1 provides to each unit roller 17A to 17C of a plurality of recovery units 10A to 10C, control guidelines which are guidelines when unit controllers 17A to 17C control operations of an electrochemical cell 12a, a flow channel on-off valve 11, a pump 13, and a flow channel selector valve 14. The unit controllers 17A to 17C are so configured as to determine control contents of the electrochemical cell 12a, the flow channel on-off valve 11, the pump 13, and the flow channel selector valve 14 on the basis of the control guidelines.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a carbon dioxide recovery system that separates and recovers carbon dioxide from the atmosphere containing carbon dioxide.

Background Art

[0002] In Patent Document 1, a gas separation system that separates carbon dioxide from a mixed gas containing carbon dioxide by an electrochemical reaction has been proposed. In this gas separation system, a mixed gas containing carbon dioxide is introduced into a housing in which an electrochemical cell is disposed. In a charging mode in which electrons are directed to the negative electrode of the electrochemical cell, the electroactive material provided at the negative electrode is reduced. Therefore, a bond between the electroactive material at the negative electrode and carbon dioxide occurs, and carbon dioxide is separated from the mixed gas. On the other hand, in a discharging mode in which an electron flow is generated in a direction opposite to the electron flow during the charging mode, the electroactive material at the negative electrode is oxidized. As a result, carbon dioxide is desorbed from the electroactive material at the negative electrode.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to increase the amount of recovered carbon dioxide, it is conceivable to increase the number of units including a housing containing the electrochemical cell as described above, and connect these plurality of units in parallel to a tank for accumulating carbon dioxide. When configured in this way, in a plurality of units, while adsorbing carbon dioxide respectively, the adsorbed carbon dioxide is desorbed in order and recovered into the tank, so that a large amount of carbon dioxide can be efficiently recovered.

[0005] However, if multiple units are used, the main controller may face an enormous processing load if it attempts to control the adsorption and desorption of carbon dioxide in all units. Furthermore, the number of connection lines between the main controller and the multiple control targets contained in each unit will also increase, potentially raising the wiring effort and cost of the connection lines.

[0006] This disclosure is made in view of the above-mentioned points, and aims to provide a carbon dioxide capture system that can suppress an increase in the processing load of the main controller and an increase in wiring effort and cost, even when multiple units are provided. [Means for solving the problem]

[0007] To achieve the above-mentioned objectives, one aspect of the carbon dioxide capture system according to this disclosure is a carbon dioxide capture system that separates and captures carbon dioxide from an atmosphere containing carbon dioxide, A carbon dioxide capture tank (3) for storing the captured carbon dioxide, A group of recovery units (10) including multiple recovery units (10A, 10B, 10C) connected in parallel to a carbon dioxide recovery tank, which separate carbon dioxide from the atmosphere and send the separated carbon dioxide to the carbon dioxide recovery tank, It includes a main controller (1) that controls the recovery unit group, Each of the multiple recovery units included in the recovery unit group is: An electrochemical cell (12a) is placed inside the enclosure and adsorbs carbon dioxide by applying an adsorption potential and desorbs the adsorbed carbon dioxide by applying a desorption potential, When the electrochemical cell adsorbs carbon dioxide, the air inlet of the housing is opened to allow air to be introduced into the housing, and when the electrochemical cell desorbs the adsorbed carbon dioxide, the air inlet of the housing is closed to isolate the inside of the housing from the air, an opening / closing mechanism (11) Discharge units (13, 14) that draw carbon dioxide released from the electrochemical cell out of the housing and send it toward the carbon dioxide recovery tank, It includes a unit controller (17) that controls the operation of the electrochemical cell, the switching unit, and the dispensing unit, The main controller controls each unit controller of the multiple recovery units. , regulation We will provide you with guidance. The control guidelines include a stop command to halt the operation of the carbon dioxide capture system, an improvement in the amount of carbon dioxide captured relative to the amount of carbon dioxide captured when the capture unit is operating, the operating time of the capture unit, a reduction in energy consumption relative to the energy consumption of the capture unit when it is operating, and the operation of the capture unit. The unit controller controls the electrochemical cell, switchgear, and discharge unit based on control guidelines. Execute It is configured to do so.

[0008] With the configuration described above, the main controller only needs to provide control guidelines to each unit controller of the multiple recovery units, which serve as guidelines for the unit controllers to control the operation of the electrochemical cell, switchgear, and discharge unit. The specific control content of the electrochemical cell, switchgear, and discharge unit is determined by the unit controller based on the control guidelines. This suppresses an increase in the processing load on the main controller. Furthermore, since there is no need to directly connect the main controller to the electrochemical cell, switchgear, and discharge unit of each recovery unit, wiring effort and costs can also be reduced.

[0009] Furthermore, as mentioned above, since the roles of the main controller and unit controllers are defined, it is easy to add more recovery units later or to build systems with different numbers of recovery units.

[0010] Another aspect of the carbon dioxide capture system described herein is a carbon dioxide capture system that separates and captures carbon dioxide from an atmosphere containing carbon dioxide, A carbon dioxide capture tank (103) for storing the captured carbon dioxide, A group of retention units (110) including multiple retention units (110A~110L) connected in parallel to a carbon dioxide capture tank, which are capable of separating and retaining carbon dioxide from the atmosphere and desorbing the retained carbon dioxide, A pump (107) that sucks up carbon dioxide detached from each of the multiple holding units and sends it toward a carbon dioxide recovery tank, It includes a main controller (101) that controls the holding unit group, Each of the multiple holding units included in the holding unit group is, An electrochemical cell, which is placed inside a housing, adsorbs carbon dioxide when an adsorption potential is applied and desorbs the adsorbed carbon dioxide when a desorption potential is applied, When the electrochemical cell adsorbs carbon dioxide, the air inlet of the housing is opened to allow air to be introduced into the housing, and when the electrochemical cell desorbs the adsorbed carbon dioxide, the air inlet of the housing is closed to isolate the inside of the housing from the air. It includes a unit controller that controls the operation of the electrochemical cell and the switching part, The main controller controls each unit controller of the multiple holding units. , regulation We will provide you with guidance. The control guidelines include a stop command to halt the operation of the carbon dioxide capture system, an improvement in the amount of carbon dioxide captured relative to the amount of carbon dioxide captured when the holding unit is operating, the operating time of the holding unit, a reduction in energy consumption relative to the energy consumption of the holding unit when it is operating, and the operation of the holding unit. The unit controller controls the electrochemical cell and switchgear based on control guidelines. Execute It is configured to do so.

[0011] In another embodiment of the carbon dioxide capture system, a common pump is provided for multiple holding units. This common pump draws in the carbon dioxide released from each of the multiple holding units and sends it to a carbon dioxide capture tank.

[0012] Thus, although there are some differences in configuration between one embodiment of a carbon dioxide capture system and another embodiment of a carbon dioxide capture system, the other embodiment of a carbon dioxide capture system can achieve the same effects and benefits as the first embodiment of a carbon dioxide capture system.

[0013] The reference numbers in parentheses above are merely examples of correspondences with specific configurations in embodiments described later, in order to facilitate understanding of this disclosure, and are not intended to limit the scope of this disclosure in any way.

[0014] Regarding the technical features described in each claim of the claims other than the features of the present disclosure described above, they will become clear from the description of the embodiments described below and the accompanying drawings.

Brief Description of the Drawings

[0015] [Figure 1] It is an overall configuration diagram showing the overall configuration of a carbon dioxide recovery system according to the first embodiment. [Figure 2] It is a functional block diagram showing the main functions respectively possessed by the main controller and the unit controller in block diagram form. [Figure 3] It is a configuration diagram showing the configuration of the recovery unit. [Figure 4] (a)-(d) are explanatory diagrams for explaining the adsorption mode, scavenging mode, desorption mode, and recovery mode included in a series of control sequences. [Figure 5] It is a flowchart showing the processing executed by the external information mediation unit of the main controller. [Figure 6] It is a flowchart showing the external information mediation process in the flowchart of FIG. 5. [Figure 7] It is a flowchart showing the target recovery rate calculation process in the flowchart of FIG. 6. [Figure 8] It is a flowchart showing the target suppression rate calculation process in the flowchart of FIG. 6. [Figure 9] It is a flowchart showing the processing executed by the control guideline setting unit of the main controller. [Figure 10] It is a time chart showing various signals transmitted and received between the main controller and the unit controller. [Figure 11] It is a flowchart showing the processing executed by the recovery mediation unit of the main controller. [Figure 12] It is a flowchart showing the processing during recovery in the flowchart of FIG. 11. [Figure 13]This figure shows an example of priority recovery, where a recovery transition permission notification is sent preferentially to the unit controller of the recovery unit with the highest expected CO2 recovery amount. [Figure 14] This figure shows an example of simultaneous retrieval, where retrieval transition permission notifications are sent simultaneously to the unit controllers of multiple retrieval units. [Figure 15] This is part of a flowchart showing the processes performed by the CO2 capture processing unit of the unit controller. [Figure 16] This is the remainder of the flowchart showing the processes performed by the CO2 recovery processing unit of the unit controller. [Figure 17] This flowchart shows the process for creating a map to generate adsorption amount change map data. [Figure 18] This is a time chart showing the operation of each part during the creation of the adsorption amount change map data. [Figure 19] (a)-(c) are explanatory diagrams illustrating an example of a procedure for estimating the maximum carbon dioxide adsorption capacity and maximum adsorption time of an electrochemical cell. [Figure 20] This figure shows an example of adsorption amount change map data. [Figure 21] This is a flowchart showing the map data update process. [Figure 22] This is an explanatory diagram illustrating the map data update process. [Figure 23] This figure shows an example of updated adsorption amount change map data. [Figure 24] This is a configuration diagram showing the configuration of the carbon dioxide capture system according to the second embodiment. [Modes for carrying out the invention]

[0016] (First Embodiment) Hereinafter, a carbon dioxide capture system according to the first embodiment of this disclosure will be described in detail with reference to the drawings. Parts that are identical or equivalent to each other across multiple drawings are denoted by the same reference numerals. The carbon dioxide capture system according to this embodiment separates and captures carbon dioxide from the atmosphere containing carbon dioxide. The air from which carbon dioxide has been removed is discharged to the outside. Figure 1 is an overall configuration diagram showing the overall configuration of the carbon dioxide capture system 100 according to this embodiment. Figure 2 is a functional block diagram showing the main functions of the main controller 1 and the unit controller 17, respectively, in block diagram form.

[0017] As shown in Figure 1, the carbon dioxide capture system 100 includes a main controller 1, a plurality of capture units 10A-10C (which may be collectively referred to as a capture unit group 10), a CO2 sensor 2, and a CO2 capture tank 3.

[0018] The main controller 1 consists of a well-known microcomputer including a CPU, ROM, and RAM, and its peripheral devices. The peripheral devices include a first transceiver unit that communicates with the renewable energy system 4, the user interface 5, and the external server 6, and a second transceiver unit that communicates with the unit controller 17 provided in each of the multiple recovery units 10A-10C.

[0019] The renewable energy system 4 includes, for example, a solar power generation panel and a storage battery. The electricity generated by the solar power generation panel is used to power the carbon dioxide capture system 100. Any surplus electricity generated by the solar power generation panel is stored in the storage battery. The electricity stored in the storage battery is provided to the carbon dioxide capture system 100 as operating power as needed, such as when the amount of electricity generated by the solar power generation panel is low. The main controller 1 of the carbon dioxide capture system 100 communicates with the controller of the renewable energy system 4 and obtains, for example, the amount of electricity that the renewable energy system 4 can supply to the carbon dioxide capture system 100 as one of the pieces of information indicating the external environment. Note that the renewable energy system 4 may generate renewable energy using sources other than sunlight, such as wind power, hydropower, or geothermal energy.

[0020] The user interface 5 receives user requests regarding the operation of the carbon dioxide capture system 100 and provides information about these user requests to the main controller 1. This allows the main controller 1 to obtain information about the user requests. The information about user requests that the user interface 5 provides to the main controller 1 includes, for example, an emergency stop request to immediately stop the carbon dioxide capture system 100, a normal stop request to stop the operation of each capture unit 10A-10C after the control for carbon dioxide capture being performed in each capture unit 10A-10C has been completed, a request to improve the amount of carbon dioxide captured, a request to reduce energy consumption, and information about the scheduled time for stopping the carbon dioxide capture system 100.

[0021] The external server 6 provides the main controller 1 with information regarding the occurrence or prediction of disasters such as earthquakes, tsunamis, and tornadoes, as well as information regarding weather or weather forecasts such as rain, snow, temperature, humidity, and typhoons. This allows the main controller 1 to acquire disaster-related information and weather-related information as information representing the external environment.

[0022] As shown in Figure 2, the main controller 1 has an external information arbitration unit 1a that arbitrates information (external information) acquired from at least one of the renewable energy system 4, the user interface 5, and the external server 6, selects external information to be used as the basis for determining control guidelines, and determines control targets based on the selected external information. The main controller 1 also has a control guideline setting unit 1b that sets control guidelines based on the control targets determined by the external information arbitration unit. The control guideline setting unit 1b sets one of the following as control guidelines to be provided to the multiple recovery units 10A-10C: for example, stop instruction, improvement of carbon dioxide recovery amount, reduction of energy consumption, normal operation, and operating time. Furthermore, the main controller 1 has a recovery arbitration unit 1c that arbitrates the transition of the multiple recovery units 10A-10C to the recovery mode when the multiple recovery units 10A-10C simultaneously request to transition to the recovery mode in which the recovered carbon dioxide is sent to the CO2 recovery tank 3.

[0023] A unit controller 17 is provided for each recovery unit 10A-10C. Like the main controller 1, the unit controller 17 is composed of a well-known microcomputer including a CPU, ROM, and RAM, and its peripheral devices. The peripheral devices include a transceiver unit that communicates with the main controller 1, a storage unit 18 having a storage medium, and so on. The storage unit 18 stores adsorption amount change map data. As shown in Figure 20, the adsorption amount change map data shows the relationship between the target carbon dioxide adsorption amount and the execution time of the adsorption mode (adsorption time). The adsorption amount change map data and its usage method will be explained in detail later.

[0024] As shown in Figure 2, the unit controller 17 has a CO2 recovery unit 17a that controls various controllable devices included in each recovery unit 10A-10C to recover carbon dioxide and further sends the recovered carbon dioxide to the CO2 recovery tank 3. Based on control guidelines provided by the main controller 1, the CO2 recovery unit 17a of the unit controller 17 determines the control contents of the controllable devices of the recovery unit 10A-10C, such as the electrochemical cell 12a, the flow path switching valve 11 as an opening / closing unit, and the pump 13 and flow path switching valve 14 as delivery units. The CO2 recovery unit 17a then controls the operation of the electrochemical cell 12a, the flow path switching valve 11, the pump 13, the flow path switching valve 14, etc., according to the determined control contents.

[0025] The above describes the general functions and roles of the main controller 1 and the unit controller 17. The specific control processing details of the main controller 1 and the unit controller 17 will be explained in detail later.

[0026] Thus, the main controller 1 of this embodiment does not directly control the various controlled devices included in each of the multiple recovery units 10A-10C, but merely provides control guidelines and permits transition to recovery mode to the unit controllers 17 provided in each of the multiple recovery units 10A-10C. Therefore, even if the number of recovery units 10A-10C increases, the increase in processing load on the main controller 1 can be suppressed. In addition, since there is no need to directly connect the main controller 1 to the controlled devices of each recovery unit 10A-10C with wiring, wiring effort and costs can be reduced. Furthermore, as described above, since the roles of the main controller 1 and the unit controllers 17 are defined, it is easy to add more recovery units 10A-10C later or to construct systems with different numbers of recovery units 10A-10C.

[0027] The multiple recovery units 10A to 10C shown in Figure 1 each separate carbon dioxide from the atmosphere and send the separated carbon dioxide toward the CO2 recovery tank 3. The configuration of the multiple recovery units 10A-10C will be described in detail later.

[0028] The CO2 recovery tank 3 stores the carbon dioxide recovered by multiple recovery units 10A-10C and discharged from these units. The CO2 sensor 2 measures the concentration and flow rate of carbon dioxide flowing through the piping at predetermined time intervals as carbon dioxide is discharged from each of the multiple recovery units 10A-10C towards the CO2 recovery tank 3. The values ​​detected by the CO2 sensor 2 are provided to the main controller 1. The main controller 1 can calculate the amount of carbon dioxide recovered from each of the recovery units 10A-10C into the CO2 recovery tank 3 from the concentration and flow rate values ​​detected by the CO2 sensor 2.

[0029] The amount of carbon dioxide recovered may also be calculated by the CO2 sensor 2. In this case, the CO2 sensor 2 outputs the amount of carbon dioxide recovered to the main controller 1. Also, the concentration of carbon dioxide flowing through the piping toward the CO2 recovery tank 3 is usually close to 100%. For this reason, the CO2 sensor 2 may be a sensor capable only of detecting the flow rate of carbon dioxide. Furthermore, the CO2 sensor 2 may output the detected value or the amount of carbon dioxide recovered to the unit controller 17 of multiple recovery units 10A-10C. Alternatively, the CO2 sensor 2 may be installed in each recovery unit 10A-10C and configured to output the detected value or the amount of carbon dioxide recovered to the corresponding unit controller 17.

[0030] Next, the configurations of the multiple recovery units 10A-10C will be described with reference to Figure 3. All of the multiple recovery units 10A-10C have the same configuration. Therefore, the configuration of recovery unit 10A will be described using recovery unit 10A as a representative example.

[0031] As shown in Figure 3, the recovery unit 10A includes a flow path switching valve 11, a recovery device 12, a pump 13, a flow path switching valve 14, a solenoid valve 15, a blower 16, and a unit controller 17.

[0032] The flow path valve 11 is controlled to open or close by the unit controller 17. When the flow path valve 11 is open, air containing carbon dioxide can be introduced into the recovery unit 12 via the flow path piping that connects the outside (atmosphere) to the inside of the recovery unit 12. On the other hand, when the flow path valve 11 is closed, the flow path piping that connects the outside to the inside of the recovery unit 12 is blocked, and the recovery unit 12 is sealed from the outside. The flow path valve 11 may be replaced by a shutter or the like that opens and closes the opening of the recovery unit 12.

[0033] The blower 16 is driven by the unit controller 17 when the flow path valve 11 is open, and sends carbon dioxide-containing air into the recovery unit 12 via flow path piping that connects the outside and the inside of the recovery unit 12. However, the blower 16 may be omitted. Alternatively, the pump 13 may perform the role of the blower 16. That is, the unit controller 17 may drive the pump 13 when the flow path valve 11 is open to draw carbon dioxide-containing air from the outside into the recovery unit 12 via the flow path piping.

[0034] The recovery unit 12 includes an electrochemical cell 12a, for example, located inside a metal casing. The electrochemical cell 12a is capable of adsorbing carbon dioxide through an electrochemical reaction, separating it from the atmosphere, and desorbing the adsorbed carbon dioxide, which is then stored in the CO2 recovery tank 3 by a pump 13. The unit controller 17 can adsorb carbon dioxide onto the electrochemical cell 12a by applying an adsorption potential to the electrochemical cell 12a. The unit controller 17 can also desorb the adsorbed carbon dioxide onto the electrochemical cell 12a by applying a desorption potential to the electrochemical cell 12a.

[0035] The recovery unit 12 has two openings. One opening is an inlet for introducing air containing carbon dioxide from the outside into the housing of the recovery unit 12. The other opening is an outlet for discharging air from which carbon dioxide has been removed, or carbon dioxide desorbed from the electrochemical cell 12a. The flow channel piping that connects the outside and the inside of the recovery unit 12 is connected to the inlet, and the flow channel piping equipped with the pump 13 is connected to the outlet. Note that "inside the recovery unit 12" is synonymous with "inside the housing".

[0036] Inside the housing of the recovery unit 12, for example, multiple electrochemical cells 12a are arranged in a stacked manner. The stacking direction of the multiple electrochemical cells 12a is perpendicular to the direction of atmospheric flow. Each individual electrochemical cell 12a is constructed in a plate shape, and its plate surface is arranged to intersect with the cell stacking direction. A predetermined gap is provided between adjacent electrochemical cells 12a. The gap provided between adjacent electrochemical cells 12a becomes a gas channel through which atmospheric air flows.

[0037] Each electrochemical cell 12a is constructed by stacking, for example, a working electrode current collector layer, a working electrode, a separator, a counter electrode, and a counter electrode current collector layer in the order described. The working electrode is the negative electrode, and the counter electrode, which is paired with the working electrode, is the positive electrode. By changing the potential difference applied between the working electrode and the counter electrode, electrons can be supplied to the working electrode to adsorb carbon dioxide onto the carbon dioxide adsorbent on the working electrode, or electrons can be released from the working electrode to desorb the adsorbed carbon dioxide.

[0038] The working electrode current collector layer consists of a porous conductive material having pores through which carbon dioxide-containing air can pass. The working electrode current collector layer only needs to have gas permeability and conductivity, and materials such as metallic materials or carbonaceous materials can be used to form the working electrode current collector layer.

[0039] The working electrode is formed from a mixture of materials including a carbon dioxide adsorbent, a conductive material, and a binder. The carbon dioxide adsorbent has the property of adsorbing carbon dioxide by accepting electrons and desorbing the adsorbed carbon dioxide by releasing electrons. For example, polyanthraquinone can be used as the carbon dioxide adsorbent. The conductive material forms a conductive path to the carbon dioxide adsorbent. For example, carbon materials such as carbon nanotubes, carbon black, and graphene can be used as the conductive material. The binder is for holding the carbon dioxide adsorbent and the conductive material. For example, a conductive resin can be used as the binder. For example, the conductive resin can be an epoxy resin containing Ag as a conductive filler, or a fluororesin such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF).

[0040] The counter electrode is formed from a mixture of materials including an electroactivating auxiliary, a conductive substance, and a binder. The conductive substance and binder of the counter electrode are the same as those of the working electrode, so their explanation is omitted. The electroactivating auxiliary of the counter electrode is composed of a material having an active substance that acts as an electron donor. The electroactivating auxiliary of the counter electrode is an auxiliary electroactive species that facilitates electron transfer with the carbon dioxide adsorbent of the working electrode. As an electroactivating auxiliary, for example, a metal complex that enables electron transfer by changing the valence of metal ions can be used. Examples of such metal complexes include cyclopentadienyl metal complexes such as ferrocene, nickerosene, and cobaltocene, or porphyrin metal complexes. These metal complexes may be polymers or monomers. The counter electrode current collector layer is formed from a conductive material such as a metal material or a carbonaceous material, similar to the working electrode current collector layer.

[0041] A separator is placed between the working electrode and the counter electrode to separate them. The separator is an insulating ion-permeable membrane that prevents physical contact between the working electrode and the counter electrode, thereby suppressing electrical short circuits, while also allowing ions to pass through. As the separator, cellulose membranes, polymers, composite materials of polymers and ceramics, etc., can be used. In addition, the electrochemical cell 12a is provided with an electrolyte that spans both the working electrode and the counter electrode. The electrolyte can be, for example, an ionic liquid. An ionic liquid is a salt of a liquid that is non-volatile at room temperature and pressure.

[0042] Pump 13 sucks in residual air from the recovery unit 12, from which carbon dioxide has been removed, and releases it to the outside (i.e., scavenging the residual air inside the recovery unit 12), and when the carbon dioxide adsorbent desorbs the carbon dioxide it has adsorbed, pump 13 sucks in the desorbed carbon dioxide from the recovery unit 12 and discharges it toward the CO2 recovery tank 3. Pump 13 is controlled by a unit controller 17. For example, when the unit controller 17 controls pump 13 to scavenge the residual air inside the recovery unit 12, it controls the flow path valve 11 to shut off the flow path piping that connects the outside and the inside of the recovery unit 12. In this way, the scavenging of residual air inside the recovery unit 12 is performed by vacuuming with pump 13. Furthermore, the subsequent discharge of carbon dioxide to the CO2 recovery tank 3 is also performed in a state closer to a vacuum than to the atmosphere.

[0043] The flow path switching valve 14 is a three-way valve that switches the flow path of the gas flowing through the piping downstream of the pump 13. The switching of the flow path of the flow path switching valve 14 is controlled by the unit controller 17. Specifically, when air containing carbon dioxide is introduced into the recovery unit 12, and when residual air in the recovery unit 12 is scavenged by the pump 13, the unit controller 17 controls the flow path switching valve 14 to connect the piping downstream of the pump 13 to the outside (atmosphere). As a result, the air from which carbon dioxide has been removed and the residual air in the recovery unit 12 are released to the outside. On the other hand, when the carbon dioxide adsorbent in the electrochemical cell 12a desorbs the carbon dioxide adsorbed by it, and the pump 13 sucks the desorbed carbon dioxide from the recovery unit 12 and discharges it, the unit controller 17 controls the flow path switching valve 14 to connect the piping downstream of the pump 13 to the CO2 recovery tank 3. As a result, the carbon dioxide recovered by the recovery unit 12 can be sent to the CO2 recovery tank 3 and stored in the CO2 recovery tank 3.

[0044] The solenoid valve 15 is installed in the flow path piping between the flow path switching valve 14 and the CO2 recovery tank 3, and is capable of switching between opening and closing the flow path piping. The solenoid valve 15 is controlled by the unit controller 17. When the unit controller 17 sends carbon dioxide from its recovery unit 10A to the CO2 recovery tank 3, it controls the solenoid valve 15 to the open state. On the other hand, when the unit controller 17 does not send carbon dioxide from its recovery unit 10A to the CO2 recovery tank 3, it controls the solenoid valve 15 to the closed state. This prevents the recovery unit 10A from affecting the sending of carbon dioxide from the other recovery units 10B and 10C to the CO2 recovery tank 3. The opening and closing function of the solenoid valve 15 may also be incorporated into the flow path switching valve 14. That is, the flow path switching valve 14 may be configured to be switchable between a state of opening to external piping, a state of opening to piping connected to the CO2 recovery tank 3, or a closed state that does not open to any piping.

[0045] Here, a series of control sequences for adsorbing carbon dioxide contained in the atmosphere onto the electrochemical cell 12a in multiple recovery units 10A-10C, desorbing the adsorbed carbon dioxide, and recovering it in the CO2 recovery tank 3 will be explained with reference to Figure 4. The series of control sequences includes an adsorption mode, a scavenging mode, a desorption mode, and a recovery mode.

[0046] In the adsorption mode, which is the first operating mode in a series of control sequences, the flow path valve 11 is opened to allow air containing carbon dioxide to be introduced into the recovery unit 12, as shown in Figure 4(a). If a blower 16 is provided, the blower 16 is driven at a predetermined constant rotational speed to ensure that a predetermined amount of air is introduced into the recovery unit 12. If the pump 13 also serves the role of the blower 16, the pump 13 is driven by a motor (not shown) at a predetermined rotational speed to draw in air and bring it into the recovery unit 12 from the outside. In this case, since the pump 13 is driven simply to draw in air from the outside, the energy required for this suction is less than that required for driving the pump for vacuuming in the scavenging mode and recovery mode described later.

[0047] In addition, in adsorption mode, an adsorption potential is applied between the working electrode and the counter electrode of the electrochemical cell 12a of the recovery unit 12, such that the carbon dioxide adsorbent at the working electrode can adsorb carbon dioxide. This adsorption potential is a predetermined constant potential. Furthermore, in adsorption mode, as shown in Figure 4(a), the flow path switching valve 14 is controlled to connect the downstream piping of the pump 13 to the outside.

[0048] Through the control of the flow control valve 11, the electrochemical cells 12a of the recovery unit 12, and the flow control valve 14, in the adsorption mode, as shown by the dotted arrows in Figure 4(a), air containing carbon dioxide passes through the flow control valve 11 and enters the recovery unit 12. The carbon dioxide contained in the air that enters the recovery unit 12 is adsorbed by multiple electrochemical cells 12a. As a result, carbon dioxide is removed from the air. The air from which carbon dioxide has been removed passes through the pump 13 and is guided by the flow control valve 14 to a flow pipe leading to the outside, and is released to the outside through that flow pipe.

[0049] In the scavenging mode, which is the second operating mode of the control sequence, the flow path switching valve 11 is closed, as shown in Figure 4(b). If a blower 16 is provided, the blower 16 is stopped. The adsorption potential applied between the working electrode and the counter electrode of the electrochemical cell 12a of the recovery unit 12 is maintained. Communication between the downstream piping of the pump 13 and the outside is also maintained via the flow path switching valve 14.

[0050] Then, in scavenging mode, the pump 13 is started. As described above, the flow path valve 11 is closed, so the recovery unit 12 is sealed upstream of the pump 13. When the pump 13 is started in this state, the residual air from which carbon dioxide has been removed, which remains inside the sealed recovery unit 12, is sucked out of the recovery unit 12 and released to the outside. This allows the residual air inside the recovery unit 12 to be scavenged.

[0051] Furthermore, since the recovery unit 12 upstream of the pump 13 is sealed, the residual air inside the recovery unit 12 is scavenged by vacuuming with the pump 13. For this reason, if the pump 13 also functions as a blower 16, the pump 13 continues to run, but its output is increased compared to the intake mode when the scavenging mode is initiated.

[0052] Through the control of the flow control valve 11, the electrochemical cell 12a of the recovery unit 12, the pump 13, and the flow control valve 14, in the scavenging mode, as shown by the dotted arrow in Figure 4(b), the residual air from which carbon dioxide has been removed in the recovery unit 12 passes through the pump 13, is guided by the flow control valve 14 to a flow pipe leading to the outside, and is released to the outside through that flow pipe.

[0053] In the desorption mode, which is the third operating mode in the series of control sequences, the flow path switching valve 11 is kept closed, as shown in Figure 4(c). The flow path switching valve 14 connects the piping downstream of the pump 13 to the piping connected to the CO2 recovery tank 3. The pump 13 is stopped. Therefore, as shown in Figure 4(c), no forced gas flow occurs from the pump 13. A desorption potential is applied between the working electrode and the counter electrode of the electrochemical cell 12a, causing electrons to be released from the working electrode, which in turn allows the carbon dioxide adsorbent on the working electrode to desorb the carbon dioxide adsorbed by it. This desorption potential is a predetermined constant potential. In this way, in the desorption mode, since the desorption potential is applied to the electrochemical cell 12a with the pump 13 stopped, the desorption of carbon dioxide from the electrochemical cell 12a can be promoted while avoiding energy consumption by the pump 13.

[0054] In the recovery mode, which is the final operating mode in the control sequence, the flow path switching valve 11 is kept closed, as shown in Figure 4(d). The pump 13 is restarted. In the recovery mode, the pump 13 is driven with a drive output equal to or greater than that of the scavenging mode, in order to draw in carbon dioxide desorbed from the adsorbent of the electrochemical cell 12a in a state closer to a vacuum than atmospheric pressure. In addition, in the recovery mode, the desorption potential is continuously applied to the electrochemical cell 12a. Furthermore, in the recovery mode, as shown in Figure 4(d), the flow path switching valve 14 is kept in a state where the piping downstream of the pump 13 is connected to the piping leading to the CO2 recovery tank 3.

[0055] Through the control of the flow path switching valve 11, the electrochemical cell 12a of the recovery unit 12, the pump 13, and the flow path switching valve 14, in recovery mode, as shown by the dotted arrow in Figure 4(d), carbon dioxide detached from the adsorbent of the electrochemical cell 12a passes through the pump 13 and is guided by the flow path switching valve 14 to a pipe leading to the CO2 recovery tank 3, where it is accumulated. At this time, the concentration and flow rate of carbon dioxide flowing through the pipe toward the CO2 recovery tank 3 are detected by the CO2 sensor 2.

[0056] Note that the solenoid valve 15 is not shown in Figures 4(a)-(d). The solenoid valve 15 is kept closed during the execution of the adsorption mode, scavenging mode, and detachment mode shown in Figures 4(a)-(c). When the detachment mode ends, the unit controller 17 sends a notification to the main controller 1 requesting a transition to the recovery mode (hereinafter also referred to as a recovery transition request notification). The main controller 1 mediates the recovery transition requests from each recovery unit 10A-10C and then sends a notification to the unit controller 17 of each recovery unit 10A-10C granting permission to transition to the recovery mode (hereinafter also referred to as a recovery transition permission notification). Even after the detachment mode ends, the unit controller 17 waits to transition to the recovery mode until it receives a recovery transition permission notification from the main controller 1. Upon receiving the recovery transition permission notification from the main controller 1, the unit controller 17 opens the solenoid valve 15 and starts the recovery mode.

[0057] Furthermore, although the desorption mode and recovery mode were separated in the example described above, it is also possible to execute the desorption mode and recovery mode simultaneously. That is, by starting the application of the desorption potential to the electrochemical cell 12a and simultaneously starting the operation of the pump 13, the desorption mode and recovery mode can be executed at the same time. In this case, when the scavenging mode is completed, the unit controller 17 should send a notification to the main controller 1 requesting permission to transition to the desorption / recovery mode. Then, when the unit controller 17 receives the notification from the main controller 1 requesting permission to transition to the desorption / recovery mode, it should start the desorption / recovery mode.

[0058] Next, we will explain each function of the main controller 1 with reference to the diagrams. The flowcharts in Figures 5 to 8 show the processes that the main controller 1 performs in order to function as the external information arbitration unit 1a. The external information arbitration unit 1a will be explained with reference to the flowcharts in Figures 5 to 8. The processes shown in the flowchart of Figure 5 are executed, for example, at predetermined time intervals.

[0059] In the first step S100, the main controller 1 determines whether or not external information has been input from the renewable energy system 4, the user interface 5, or the external server 6, or whether or not any abnormality has occurred in the carbon dioxide capture system 100. The main controller 1 monitors for abnormalities in the operation of various controlled devices within the capture units 10A-10C and for abnormalities in the normal discharge of carbon dioxide from the capture units 10A-10C, based on the values ​​detected by the CO2 sensor 2, through communication with the unit controller 17. If a positive determination is made in step S100, the main controller 1 proceeds to the process in step S130. On the other hand, if a negative determination is made in step S100, the main controller 1 proceeds to the process in step S110.

[0060] In step S110, if a target value for the amount of carbon dioxide recovered or a target value for the energy consumed for carbon dioxide recovery has been set, the main controller 1 determines whether the actual amount of carbon dioxide recovered or the energy consumed has reached the target value. The target value for the amount of carbon dioxide recovered can be set by the user as an arbitrary amount, or as an amount equivalent to the capacity of the CO2 recovery tank 3. The target value for energy consumed can be set as an amount of energy equivalent to the amount of electricity that can be used by the carbon dioxide recovery system 100 from the electricity generated by the renewable energy system 4. If, in the process of step S110, it is determined that the actual amount of carbon dioxide recovered or the energy consumed has not reached the target value, or if no target value has been set, the main controller 1 returns to the process of step S100. On the other hand, if it is determined that the actual amount of carbon dioxide recovered or the energy consumed has reached the target value, the main controller 1 proceeds to the process of step S120.

[0061] In step S120, the main controller 1 determines whether or not to continue operating the carbon dioxide capture system 100. For example, if the user is notified that the target value has been reached and the user instructs the system to continue operating, the main controller 1 may decide to continue operating the carbon dioxide capture system 100. Alternatively, if there is still capacity in the CO2 capture tank 3 or if there is available energy, the main controller 1 may decide to continue operating the carbon dioxide capture system 100. Furthermore, if worsening weather is predicted, there is a high possibility that the carbon dioxide capture system 100 cannot be operated during that period of bad weather, so the main controller 1 may decide to continue operating the carbon dioxide capture system 100 until the weather deteriorates. If the main controller 1 decides to continue operating the carbon dioxide capture system 100, it proceeds to step S130. On the other hand, if the main controller 1 decides not to continue operating the carbon dioxide capture system 100, it proceeds to step S140.

[0062] In step S130, the main controller 1 performs external information arbitration processing. External information arbitration processing will be described in detail later. In step S140, the main controller 1 stops the operation of the carbon dioxide capture system 100. Specifically, the main controller 1 instructs the unit controllers 17 of each capture unit 10A-10C to perform a normal stop as a control guideline. A normal stop means that after the control (series of control sequences) for carbon dioxide capture being performed in each capture unit 10A-10C is completed, the operation of each capture unit 10A-10C is stopped.

[0063] Next, the external information arbitration process in step S130 of the flowchart in Figure 5 will be explained in detail with reference to the flowchart in Figure 6.

[0064] First, in step S200, the main controller 1 determines whether or not it is necessary to stop the operation of the carbon dioxide capture system 100 based on acquired external information. For example, if an earthquake, tsunami, typhoon, tornado, heavy rain, or strong winds is predicted, if a user requests that the system be stopped, or if an abnormality is detected in the carbon dioxide capture system 100, the main controller 1 may determine that it is necessary to stop the operation of the carbon dioxide capture system 100. If the main controller 1 determines in step S200 that it is necessary to stop the operation of the carbon dioxide capture system 100, it proceeds to step S210. On the other hand, if the main controller 1 determines that it is not necessary to stop the operation of the carbon dioxide capture system 100, it proceeds to step S260.

[0065] In step S210, the main controller 1 determines whether the carbon dioxide capture system 100 has a high priority for stopping operation and whether it is necessary to immediately stop the operation of the carbon dioxide capture system 100. For example, the main controller 1 may determine that it is necessary to immediately stop the operation of the carbon dioxide capture system 100 if it receives external information about the occurrence of a disaster such as an earthquake or tsunami, receives an emergency system shutdown request from a user, or detects that a serious abnormality has occurred in the carbon dioxide capture system 100. If the main controller 1 determines in step S210 that it is necessary to immediately stop the operation of the carbon dioxide capture system 100, it proceeds to the process in step S220. On the other hand, if the main controller 1 determines that it is not necessary to immediately stop the operation of the carbon dioxide capture system 100, it proceeds to the process in step S230.

[0066] In step S220, emergency stop is determined as the control target. This control target is used when the control guideline setting unit 1b of the main controller 1 sets the control guideline to be provided to the unit controller 17 of each recovery unit 10A-10C.

[0067] In step S230, the main controller 1 determines whether the carbon dioxide capture system 100 has an intermediate priority for stopping operation and whether it is necessary to stop the operation of the carbon dioxide capture system 100 relatively quickly. For example, if the main controller 1 obtains external information such as an approaching typhoon or tornado or a forecast of heavy rain, or if it detects a relatively serious abnormality in the carbon dioxide capture system 100, it may determine that it is necessary to stop the operation of the carbon dioxide capture system 100, but not relatively quickly, if it obtains external information other than those mentioned above, receives a normal stop request from a user, or detects a minor abnormality in the carbon dioxide capture system 100. If the main controller 1 determines in step S230 that it is necessary to stop the operation of the carbon dioxide capture system 100 relatively quickly, it proceeds to step S240. On the other hand, if the main controller 1 determines that it is not necessary to stop the operation of the carbon dioxide capture system 100 relatively quickly, it proceeds to step S250.

[0068] In step S240, protective shutdown is determined as the control target. The difference between emergency shutdown and protective shutdown is that emergency shutdown instructs the unit controller 17 to immediately stop the operation of each recovery unit 10A-10C, regardless of the state of the carbon dioxide recovery system 100. In contrast, protective shutdown instructs the unit controller 17 to stop the operation of each recovery unit 10A-10C after, for example, closing the flow path switching valve 11, connecting the flow path switching valve 14 to the outside, and driving the solenoid valve 15 to close, in order to protect the carbon dioxide recovery system 100 itself and to retain the recovered carbon dioxide. In step S250, normal shutdown is determined as the control target. Normal shutdown instructs the unit controller 17 to stop the operation of each recovery unit 10A-10C after completing the control (series of control sequences) for carbon dioxide recovery that is currently being performed in each recovery unit 10A-10C.

[0069] In step S260, based on the amount of electricity obtained from the renewable energy system 4, the main controller 1 determines whether the amount of electricity that can be supplied from the renewable energy system 4 to the carbon dioxide capture system 100 has decreased and whether the operating power of the carbon dioxide capture system 100 is in a state of emergency. If it is determined that the operating power is in a state of emergency, the main controller 1 proceeds to the process in step S270. On the other hand, if it is determined that the operating power is not in a state of emergency, the main controller 1 proceeds to the process in step S300.

[0070] In step S270, the main controller 1 determines whether it is possible to switch the power source for the carbon dioxide capture system 100. Specifically, the main controller 1 determines whether it is possible to switch the power source for the carbon dioxide capture system 100 from the renewable energy system 4 to the commercial power supply. If there is no power outage or other issue with the commercial power supply and it is determined that it is possible to switch the power source, the main controller 1 proceeds to step S280 and switches the power source. On the other hand, if it is determined that it is not possible to switch the power source, the main controller 1 proceeds to step S290.

[0071] In step S290, the main controller 1 determines whether the operating power shortage is severe enough to require an emergency stop. If it determines that an emergency stop is necessary, the main controller 1 proceeds to step S220. On the other hand, if it determines that an emergency stop is not necessary, the main controller 1 proceeds to step S230.

[0072] In step S300, the main controller 1, based on information from the user interface 5, determines whether it has received a user request to prioritize carbon dioxide capture over energy consumption and to improve carbon dioxide capture. If it determines that it has received a user request to improve carbon dioxide capture, the main controller 1 proceeds to step S310. On the other hand, if it determines that it has not received a user request to improve carbon dioxide capture, the main controller 1 proceeds to step S320.

[0073] Step S310 executes the target recovery rate calculation process. The details of the target recovery rate calculation process are shown in the flowchart in Figure 7. The specific contents of the target recovery rate calculation process will be explained below with reference to the flowchart in Figure 7.

[0074] First, in step S400, it is determined whether or not a user request to improve the amount of carbon dioxide captured has been received. As will be described later, in the flowchart of Figure 6, the target capture rate calculation process in step S310 is also executed when it is expected that the amount of carbon dioxide captured in the future will decrease. The determination process in step S400 is performed to determine whether the target capture rate calculation process was started by a user request or by a prediction of a decrease in the amount of carbon dioxide captured in the future. If the target capture rate calculation process was started by a user request, the main controller 1 proceeds to the process in step S410. On the other hand, if the target capture rate calculation process was started by a prediction of a decrease in the amount of carbon dioxide captured in the future, the main controller 1 proceeds to the process in step S420.

[0075] In step S410, the main controller 1 determines the performance level desired by the user regarding the improvement of carbon dioxide capture. The user interface 5 is configured to accept user requests for at least two performance levels (e.g., maximum level and normal level) regarding the improvement of carbon dioxide capture. The main controller 1 can recognize the performance level desired by the user regarding the improvement of carbon dioxide capture through communication with the user interface 5. If the performance level desired by the user is the maximum level, the main controller 1 proceeds to the process in step S430. On the other hand, if the performance level desired by the user is the normal level, the main controller 1 proceeds to the process in step S440.

[0076] In step S420, the main controller 1 determines the magnitude of the impact of a predicted decrease in future carbon dioxide capture capacity if it is necessary to shut down the carbon dioxide capture system 100 due to future adverse weather conditions (rain, snow, etc.) or maintenance, based on the predicted shutdown period. Specifically, the main controller 1 determines whether the predicted shutdown period of the carbon dioxide capture system 100 is greater than or equal to a standard value. For example, if the predicted shutdown period is 3 days or more within the next week from the present, the predicted shutdown period may be determined to be greater than or equal to the standard value. Also, if the predicted shutdown period extends for 50% or more of the period from the present, whether it is a day, half a day, or a predetermined time, the predicted shutdown period may be determined to be greater than or equal to the standard value. If the predicted shutdown period is determined to be greater than or equal to the standard value, the main controller 1 proceeds to step S430. On the other hand, if the predicted shutdown period is determined to be less than the standard value, the main controller 1 proceeds to step S440.

[0077] In step S430, the main controller 1 sets a target recovery rate of 100% as the control target. A target recovery rate of 100% means instructing the unit controller 17 to control the electrochemical cell 12a, pump 13, etc., in each recovery unit 10A-10C so that the electrochemical cell 12a maximizes its carbon dioxide adsorption performance to adsorb carbon dioxide and recovers all of the adsorbed carbon dioxide. However, if the electrochemical cell 12a and pump 13 etc. are controlled so that the electrochemical cell 12a maximizes its carbon dioxide adsorption performance to adsorb carbon dioxide and recovers all of the adsorbed carbon dioxide, the energy consumed in each recovery unit 10A-10C will also increase.

[0078] In step S440, the main controller 1 determines a target recovery rate of X+α% as the control target. As mentioned above, a recovery target rate of 100% increases the amount of carbon dioxide that can be recovered, but the energy consumption in each recovery unit 10A-10C may increase even more. Therefore, as will be described later, in normal operation where there is no requirement to improve the amount of carbon dioxide recovered and no requirement to reduce energy consumption, the main controller 1 determines a target recovery rate lower than 100%, at X% (for example, 70% to 80%), taking into consideration the balance between the amount of carbon dioxide recovered and the energy consumption. In step S440, the control target is determined to be a target recovery rate of X+α%, which is slightly higher than the target recovery rate of X% in normal operation.

[0079] In the example above, two levels of target recovery rates higher than the normal operating target recovery rate of X% are set, but it is also possible to configure the system to set more levels of target recovery rates higher than the normal operating target recovery rate. Conversely, there may be only one level of target recovery rate higher than the normal operating target recovery rate.

[0080] Returning to the flowchart in Figure 6, let's continue the explanation. In step S320, the main controller 1 prioritizes reducing energy consumption over carbon dioxide capture and determines whether it has received a user request to suppress energy consumption. If it determines that it has received a user request to suppress energy consumption, the main controller 1 proceeds to step S330. On the other hand, if it determines that it has not received a user request to suppress energy consumption, the main controller 1 proceeds to step S340.

[0081] In step S330, the target suppression rate calculation process is executed. The details of the target suppression rate calculation process are shown in the flowchart in Figure 8. The specific contents of the target suppression rate calculation process will be explained below with reference to the flowchart in Figure 8.

[0082] First, in step S500, it is determined whether or not a user request to reduce energy consumption has been received. As will be described later, in the flowchart of Figure 6, the target reduction rate calculation process in step S330 is also executed if the proportion of electrochemical cells 12a with degraded carbon dioxide adsorption performance among the recovery unit group 10 increases. The determination process in step S500 is performed to determine whether the target reduction rate calculation process was started by a user request or by an increase in the proportion of electrochemical cells 12a with degraded carbon dioxide adsorption performance. If the target reduction rate calculation process was started by a user request, the main controller 1 proceeds to the process in step S510. On the other hand, if the target reduction rate calculation process was started by an increase in the proportion of electrochemical cells 12a with degraded carbon dioxide adsorption performance, the main controller 1 proceeds to the process in step S520.

[0083] In step S510, the main controller 1 determines the performance level requested by the user regarding energy consumption reduction. The user interface 5 is configured to accept user requests for at least two performance levels (e.g., maximum level and normal level) regarding energy consumption reduction. The main controller 1 can recognize the performance level requested by the user regarding energy consumption reduction through communication with the user interface 5. If the performance level requested by the user is the maximum level, the main controller 1 proceeds to the process in step S530. On the other hand, if the performance level requested by the user is the normal level, the main controller 1 proceeds to the process in step S540.

[0084] In step S520, the main controller 1 determines whether the carbon dioxide adsorption performance of the electrochemical cells 12a of each recovery unit 10A-10C has deteriorated due to aging or other factors, and whether the overall deterioration of the carbon dioxide adsorption performance of the electrochemical cells 12a has exceeded a standard value. The deterioration of the carbon dioxide adsorption performance of the electrochemical cells 12a can be calculated, for example, as the ratio of the current total amount of carbon dioxide recovered to the sum of the initial carbon dioxide recovered by all recovery units 10A-10C when each recovery unit 10A-10C is controlled according to the target recovery rate for normal operation. In other words, the deterioration of the carbon dioxide adsorption performance of the electrochemical cells 12a can be calculated based on the total amount of carbon dioxide recovered by each of the multiple recovery units 10A-10C.

[0085] Alternatively, the deterioration of the carbon dioxide adsorption performance of the electrochemical cell 12a may be determined by calculating the unit energy, which is the amount of energy required to recover a predetermined unit amount of carbon dioxide, based on the total amount of carbon dioxide recovered by the multiple recovery units 10A-10C and the total amount of energy consumed by the multiple recovery units 10A-10C, and then comparing the calculated unit energy with a predetermined reference energy. This is because as the carbon dioxide adsorption performance of the electrochemical cell 12a of each recovery unit 10A-10C deteriorates, the amount of energy required to recover a predetermined unit amount of carbon dioxide increases.

[0086] In step S520, if the main controller 1 determines that the degradation of the carbon dioxide adsorption performance of the electrochemical cell 12a is above a standard value, the main controller 1 proceeds to the process in step S530. On the other hand, if the main controller 1 determines that the expected downtime is below a standard value, the main controller 1 proceeds to the process in step S540.

[0087] In step S530, the main controller 1 determines a target reduction rate of Y% as the control target. A target reduction rate of Y% means that the amount of energy consumed when each recovery unit 10A-10C is controlled according to the target recovery rate X of normal operation will be reduced by Y%. Therefore, assuming that the amount of energy and the amount of carbon dioxide recovered are proportional, the target recovery rate can be expressed as: Target Recovery Rate = X(100-Y) / 100. On the other hand, in step S540, the main controller 1 determines a target reduction rate of Z% as the control target. A target reduction rate of Z% is smaller than a target reduction rate of Y%. That is, in step S540, the degree of energy consumption reduction is smaller compared to step S530. In this case, the target recovery rate can be expressed as: Target Recovery Rate = X(100-Z) / 100.

[0088] In the example above, the target reduction rate for energy consumption during normal operation was set in two stages, but the target reduction rate may be configured to have more stages. Conversely, the target reduction rate for energy consumption during normal operation may be set in only one stage.

[0089] Let's return to the flowchart in Figure 6 and continue the explanation. In step S340, the main controller 1 determines whether it is necessary to shut down the carbon dioxide capture system 100 due to future adverse weather conditions (rain, snow, etc.) or maintenance, and whether a decrease in future carbon dioxide capture is predicted. If it is determined that a decrease in future carbon dioxide capture is predicted, the main controller 1 proceeds to step S310. On the other hand, if it is determined that a decrease in future carbon dioxide capture is not predicted, the main controller 1 proceeds to step S350.

[0090] In step S350, the main controller 1 determines whether the carbon dioxide adsorption performance of the electrochemical cells 12a of each recovery unit 10A-10C has deteriorated due to aging or other factors. Whether the carbon dioxide adsorption performance of the electrochemical cells 12a of each recovery unit 10A-10C has deteriorated can be determined based on the ratio of the current total amount of carbon dioxide recovered to the initial total amount of carbon dioxide recovered by all recovery units 10A-10C, or the unit energy, which is the amount of energy required to recover a predetermined unit amount of carbon dioxide for the entire system. If it is determined that the carbon dioxide adsorption performance of the electrochemical cells 12a of each recovery unit 10A-10C has deteriorated, the main controller 1 proceeds to the process in step S330. On the other hand, if it is determined that the carbon dioxide adsorption performance of the electrochemical cells 12a of each recovery unit 10A-10C has not deteriorated, the main controller 1 proceeds to the process in step S360.

[0091] In step S360, the main controller 1 determines a target recovery rate of X%, which corresponds to normal operation, as the control target, since there are no user requests to improve carbon dioxide recovery or reduce energy consumption, and there are no special circumstances to stop the system, improve carbon dioxide recovery, or reduce energy consumption.

[0092] As explained above, the external information arbitration unit 1a arbitrates information (external information) obtained from the renewable energy system 4, the user interface 5, and the external server 6 according to its importance. Specifically, it first determines whether or not information that requires stopping the carbon dioxide capture system 100 has been obtained, considering such information as the most important external information. Next, it determines whether a user request prioritizing the amount of carbon dioxide captured or a user request suppressing energy consumption has been received. After that, the external environment and system status of the carbon dioxide capture system 100 are determined. In this way, the external information arbitration unit 1a selects the external information for determining the control guideline in order of priority. Then, based on the selected external information, the external information arbitration unit 1a determines the control target to be used when setting the control guideline.

[0093] Next, the processes that the main controller 1 performs in order to function as the control guideline setting unit 1b will be explained with reference to the flowchart in Figure 9. The processes shown in the flowchart in Figure 9 are performed, for example, at predetermined time intervals.

[0094] In the first step S600, the main controller 1 determines whether it is necessary to instruct the unit controllers 17A-17C of each recovery unit 10A-10C to shut down the system, based on whether the shutdown of the carbon dioxide capture system 100 has been determined as the control target in step S140 of the flowchart in Figure 5, or in steps S220, S240, or S250 of the flowchart in Figure 6. If it is determined that it is necessary to instruct the system to shut down, the main controller 1 proceeds to step S610. If it is determined that it is not necessary to instruct the system to shut down, the main controller 1 proceeds to step S620.

[0095] In step S610, the main controller 1 sets a stop command as the control guideline. However, if an emergency stop is determined as the control target in step S220 of the flowchart in Figure 6, an emergency stop command is set as the stop command. If a protective stop is determined as the control target in step S240 of the flowchart in Figure 6, a protective stop command is set as the stop command. Also, if a normal stop is determined as the control target in step S140 of the flowchart in Figure 5, or in step S250 of the flowchart in Figure 6, a normal stop command is set as the stop command.

[0096] In step S620, the main controller 1 determines whether a predetermined time has passed until the scheduled shutdown time of the carbon dioxide capture system 100. If it determines that the predetermined time has passed until the scheduled shutdown time, the main controller 1 proceeds to the process in step S630. On the other hand, if it determines that the predetermined time has not passed until the scheduled shutdown time, the main controller 1 proceeds to the process in step S640.

[0097] In step S630, the main controller 1 sets the operating time as a control guideline. Specifically, the main controller 1 sets the operating time to the time when each recovery unit 10A-10C should be able to release carbon dioxide. The time when each recovery unit 10A-10C should be able to release carbon dioxide may be the same time or different times for each recovery unit 10A-10C. If the same time is set for each recovery unit 10A-10C to be able to release carbon dioxide, the time taken to recover carbon dioxide from each recovery unit 10A-10C is taken into account and set to a time earlier than the scheduled stop time. If different times are set for each recovery unit 10A-10C to be able to release carbon dioxide, the carbon dioxide recovery from the recovery unit 10A-10C with the latest time is set to be completed by the scheduled stop time. After that, each recovery unit 10A-10C stops its operation for carbon dioxide recovery.

[0098] Alternatively, the main controller 1 may set the cycle time for each recovery unit 10A-10C, which is the time spent on the cycle from carbon dioxide adsorption to discharge, as the operating time. This is because even if the cycle time is set as the operating time, the operation of each recovery unit 10A-10C can be stopped by the scheduled stop time.

[0099] In step S640, the main controller 1 sets the target recovery rate or target suppression rate, which was set as the control target in one of steps S310, S330, or S360 of the flowchart in Figure 6, as the control guideline.

[0100] In step S650, the main controller 1 transmits the control guideline set in step S610, S630, or S640 to the unit controller 17 of each recovery unit 10A-10C. Then, as shown in Figure 10, for example, each unit controller 17A-17C of each recovery unit 10A-10C executes control (a series of control sequences) for carbon dioxide recovery according to the received control guideline. Note that in Figure 12, each unit controller 17A-17C is depicted as starting a series of control sequences after receiving a control guideline, but this is for illustrative purposes only. Each unit controller 17A-17C repeatedly executes a series of control sequences until it receives a stop command as a control guideline, regardless of whether it has received a control guideline from the main controller 1.

[0101] As shown in Figure 10, each unit controller 17A-17C sends a notification to the main controller 1 requesting a transition to the recovery mode (recovery transition request notification) when the desorption mode of a series of control sequences is completed. This recovery transition request notification includes identification information to identify each unit controller 17A-17C and the expected amount of CO2 to be recovered. Each unit controller 17A-17C can estimate the amount of carbon dioxide adsorbed onto the adsorbent of the electrochemical cell 12a by executing the adsorption mode, based on the adsorption amount change map data. Each unit controller 17A-17C can determine the expected amount of CO2 to be recovered from the carbon dioxide adsorbed amount, assuming that all the carbon dioxide adsorbed onto the adsorbent of the electrochemical cell 12a is recovered.

[0102] The main controller 1, acting as a recovery arbitration unit 1c, arbitrates the recovery transition requests from each recovery unit 10A-10C and then sends a recovery mode transition permission notification (recovery transition permission notification) back to the unit controller 17 of each recovery unit 10A-10C. The process for enabling the main controller 1 to function as a recovery arbitration unit 1c will be explained in detail later.

[0103] Each unit controller 17A-17C starts the recovery mode upon receiving a recovery transition permission notification. In other words, each unit controller 17A-17C does not immediately execute the recovery mode after the desorption mode ends, but waits to transition to the recovery mode until it receives a recovery transition permission notification from the main controller 1. When the recovery mode is started, the pump 13 is driven, and the carbon dioxide desorbed from the adsorbent of the electrochemical cell 12a is drawn in and sent toward the CO2 recovery tank 3. At that time, the concentration and flow rate of carbon dioxide flowing through the piping toward the CO2 recovery tank 3 are detected by the CO2 sensor 2.

[0104] The main controller 1 determines when carbon dioxide recovery from each recovery unit 10A-10C is complete and calculates the amount of carbon dioxide recovered, based on the carbon dioxide concentration and / or flow rate detected by the CO2 sensor 2. In other words, the main controller 1 can determine that carbon dioxide recovery is complete when the carbon dioxide concentration and / or flow rate detected by the CO2 sensor 2 falls below a threshold value used to determine the completion of carbon dioxide recovery. When the main controller 1 determines that carbon dioxide recovery is complete, it sends a recovery completion notification to the corresponding recovery unit 10A-10C, as shown in Figure 10. Furthermore, the main controller 1 can calculate the amount of carbon dioxide recovered from the concentration and flow rate detected by the CO2 sensor 2 while the recovery mode is running.

[0105] When the main controller 1 calculates the amount of carbon dioxide recovered, it feeds back the calculated amount to each unit controller 17A-17C. This allows each unit controller 17A-17C to obtain the actual amount of carbon dioxide recovered. This actual amount of carbon dioxide recovered is used by each unit controller 17A-17C to determine whether or not it is necessary to update the adsorption amount change map data.

[0106] As shown in Figure 10, each unit controller 17A-17C receives a carbon dioxide recovery amount from the main controller 1 and sends back a recovery amount receipt notification. This recovery amount receipt notification includes the amount of energy consumed in each recovery unit 10A-10C for executing a series of control sequences. Each recovery unit 10A-10C consumes energy for driving the blower 16, applying voltage to the electrochemical cell 12a, driving the pump 13, etc., while executing the series of control sequences. Each unit controller 17A-17C can calculate the energy consumption in each device from, for example, the drive current, drive voltage, and drive time.

[0107] When the main controller 1 receives a recovery amount receipt notification from each unit controller 17A-17C, it can send a recovery transition permission notification to the unit controllers 17A-17C of the other recovery units 10A-10C. Furthermore, by obtaining the amount of energy consumed from each unit controller 17A-17C, the main controller 1 can calculate, for example, the unit energy amount described above.

[0108] Here, Figure 10 shows an example where the end times of the detachment mode for each recovery unit 10A-10C are staggered, and recovery transition request notifications are sent from the unit controllers 17A-17C of each recovery unit 10A-10C at different times. In such a case, the main controller 1 should send recovery transition permission notifications in the order in which the recovery transition request notifications were received. However, in some cases, recovery transition request notifications may be sent from multiple unit controllers 17A-17C at the same time.

[0109] Therefore, the main controller 1 has a recovery arbitration unit 1c that mediates the transition of multiple recovery units 10A-10C to recovery mode when multiple recovery units 10A-10C request to transition to recovery mode at the same time. The processes that the main controller 1 performs in order to function as the recovery arbitration unit 1c will be described below with reference to the flowchart in Figure 11.

[0110] In the first step S700, the main controller 1 determines whether or not it has received a recall transition request notification. If it has received a recall transition request notification, the main controller 1 proceeds to the process in step S710. If it has not received a recall transition request notification, the main controller 1 repeats the process in step S700 and waits for the notification to be received.

[0111] In step S710, the main controller 1 saves the received retrieval transition request notification. Next, in step S720, the main controller 1 determines whether or not retrieval mode is currently being executed in any of the retrieval units 10A-10C. If it is determined that retrieval mode is being executed in any of the retrieval units 10A-10C, the main controller 1 proceeds to the process in step S730. On the other hand, if it is determined that retrieval mode is not being executed in any of the retrieval units 10A-10C, the main controller 1 proceeds to the process in step S760.

[0112] In step S730, the main controller 1 determines whether or not it has received a new recall transfer request notification. If it has received a new recall transfer request notification, the main controller 1 proceeds to step S740 and saves the new recall transfer request notification. After that, the main controller 1 proceeds to the process in step S750. On the other hand, if it has not received a new recall transfer request notification, the main controller 1 proceeds to the process in step S750.

[0113] In step S750, the main controller 1 determines whether the currently running retrieval mode has completed. If the main controller 1 determines that the retrieval mode has completed, it proceeds to the process in step S760. On the other hand, if it determines that the retrieval mode has not completed, the main controller 1 returns to the process in step S730. Therefore, when a new retrieval transition request notification is received while the retrieval mode is running, the received retrieval transition request notification can be saved without fail in step S740.

[0114] In step S760, the main controller 1 determines whether there is only one saved recall / transfer request notification. If there is only one saved recall / transfer request notification, the main controller 1 proceeds to step S770 and sends a recall / transfer permission notification to the unit controllers 17A-17C that sent the recall / transfer request notification. Furthermore, the main controller 1 clears the saved recall / transfer request notifications. After that, the main controller 1 proceeds to step S780 and executes the recall processing. The recall processing will be explained in detail later. If there are two or more saved recall / transfer request notifications, the main controller 1 proceeds to the processing in step S790.

[0115] In step S790, the main controller 1 determines whether it is permitted to perform priority recovery, sending recovery transition permission notifications in order of the expected CO2 recovery amount, regardless of the order in which the recovery transition request notifications were received. For example, if the user has requested an increase in the amount of carbon dioxide recovered, it may be determined that priority recovery is permitted. Alternatively, it may be determined that priority recovery is permitted unless the user has requested a reduction in energy consumption. Or, the determination process in step S790 may be omitted, and priority recovery may always be permitted. If the determination process in step S790 is omitted, the processes in steps S840 and S850 may also be omitted. Alternatively, the processes in steps S840 and S850 may be executed when another condition (for example, when the user has requested a reduction in energy consumption) is met. If it is determined that priority recovery is permitted, the main controller 1 proceeds to the process in step S800. On the other hand, if it is determined that priority recovery is not permitted, the main controller 1 proceeds to the process in step S840.

[0116] In step S800, the main controller 1 determines whether the expected CO2 recovery amount of the recovery unit 10A-10C with the highest expected CO2 recovery amount among the multiple recovery units 10A-10C that sent the recovery transition request notification is below a predetermined standard value. If the expected CO2 recovery amount is below the standard value, it means that the expected CO2 recovery amounts of all multiple recovery units 10A-10C that sent the recovery transition request notification, including that recovery unit 10A-10C, are all below the standard value. In this case, executing the recovery modes simultaneously to recover carbon dioxide together, rather than executing the recovery modes separately to recover carbon dioxide individually, allows more time to be allocated for the recovery unit 10A-10C with the highest expected CO2 recovery amount to execute its recovery mode. Therefore, if the main controller 1 determines that the expected CO2 recovery amount of the recovery unit 10A-10C with the highest expected CO2 recovery amount is below a predetermined standard value, the main controller 1 proceeds to step S860. On the other hand, if the main controller 1 determines that the expected CO2 recovery amount of recovery unit 10A-10C, which has the highest expected CO2 recovery amount, is greater than a predetermined standard value, the main controller 1 proceeds to the process in step S810.

[0117] Furthermore, the process in step S800 may be performed if the process in step S790 is omitted, provided that the user requests an improvement in the amount of carbon dioxide recovered.

[0118] In step S810, regardless of the order in which the capture transition request notifications were sent, the main controller 1 prioritizes sending a capture transition permission notification to the unit controller 17A-17C of the capture unit 10A-10C, which has the highest expected CO2 capture amount and is expected to release more carbon dioxide.

[0119] Figure 13 shows an example of priority recovery. In the example shown in Figure 13, the main controller 1 sends a recovery transition permission notification to the unit controller 17A, and while the recovery mode is running in the recovery unit 10A, the main controller 1 receives recovery transition request notifications from the unit controllers 17B and 17C. Each recovery transition request notification includes an estimated CO2 recovery amount, and the estimated CO2 recovery amount c(g) for the recovery unit 10C is greater than the estimated CO2 recovery amount b(g) for the recovery unit 10B. Therefore, even though the main controller 1 receives the recovery transition request notification from the unit controller 17B first, it sends a recovery transition permission notification to the unit controller 17C first after the recovery mode of the recovery unit 10A has finished. In this way, the main controller 1 prioritizes sending recovery transition permission notifications to the unit controllers 17A and 17C of the recovery units 10A and 10C, which are expected to emit more carbon dioxide.

[0120] Then, in step S820, the main controller 1 clears the retrieval transition request notification from the corresponding unit controllers 17A-17C. After that, the main controller 1 proceeds to step S830 and executes the retrieval process. The retrieval process in step S830 is the same as the retrieval process in step S780. Furthermore, in parallel with the execution of the retrieval process in step S830, the main controller 1 also executes the process in step S730. This allows the retrieval transition request notification to be saved when a new retrieval transition request notification is received while retrieval mode is being executed.

[0121] In step S840, since priority retrieval is not permitted, the main controller 1 sends a retrieval transition permission notice to the unit controllers 17A-17C that sent the retrieval transition request notice first. Then, in step S850, the main controller 1 clears the retrieval transition request notice from the corresponding unit controller 17A-17C. After that, the main controller 1 proceeds to step S830 and executes the retrieval process.

[0122] In step S860, in order to perform simultaneous retrieval, the main controller 1 sends a retrieval transition permission notification to the unit controllers 17A-17C of the multiple retrieval units 10A-10C that will be retrieved simultaneously.

[0123] Figure 14 shows an example of simultaneous recovery. In the example shown in Figure 14, the main controller 1 sends a recovery transition permission notification to the unit controller 17A, and while the recovery mode is running in the recovery unit 10A, the main controller 1 receives recovery transition request notifications from the unit controllers 17B and 17C. Each recovery transition request notification includes an estimated CO2 recovery amount, and both the estimated CO2 recovery amount b(g) for the recovery unit 10B and the estimated CO2 recovery amount c(g) for the recovery unit 10C are below the standard value. Therefore, after the recovery mode of the recovery unit 10A ends, the main controller 1 simultaneously sends a recovery transition permission notification to the unit controllers 17B and 17C. In this way, the main controller 1 simultaneously recovers carbon dioxide from the recovery units 10B and 10C.

[0124] When simultaneous recovery is performed, the main controller 1 cannot individually detect the amount of carbon dioxide recovered from multiple recovery units 10A-10C. Therefore, the main controller 1 calculates the recovery amount for each recovery unit 10A-10C by apportioning the recovery amount calculated from the value detected by the CO2 sensor 2 according to the expected CO2 recovery amount from each recovery unit 10A-10C. The calculated recovery amounts for each recovery unit 10A-10C are then fed back to their respective unit controllers 17A-17C.

[0125] For example, as shown in Figure 14, suppose that when recovery unit 10B and recovery unit 10C are targeted for simultaneous recovery, the amount of carbon dioxide recovered by this simultaneous recovery is d(g). The main controller 1 apportions this recovered amount d(g) between the assumed CO2 recovery amount b(g) of recovery unit 10B and the assumed CO2 recovery amount c(g) of recovery unit 10C. In this case, the amount of CO2 recovered by recovery unit 10B is d(b / (b+c)), and the amount of CO2 recovered by recovery unit 10C is d(c / (b+c)).

[0126] Then, in step S870, the main controller 1 clears the retrieval transition request notification from the corresponding unit controllers 17A-17C. After that, the main controller 1 proceeds to step S880 and executes the retrieval process. The retrieval process in step S880 is the same as the retrieval process in steps S780 and S830.

[0127] The main controller 1 executes the process in step S890 in parallel with the execution of the recovery process in step S880. In step S890, it is determined whether the number of saved recovery transition request notifications has become zero due to the simultaneous recovery execution. If the number of recovery transition request notifications has become zero, the main controller 1 proceeds to the process in step S700. If the number of recovery transition request notifications is not zero, the main controller 1 proceeds to the process in step S730.

[0128] Next, the recovery process in steps S780, S830, and S880 of the flowchart in Figure 11 described above will be explained with reference to the flowchart in Figure 12.

[0129] In the first step S900, the main controller 1 stores the concentration and flow rate measurements taken by the CO2 sensor 2 after sending a notification authorizing the transition to recovery. This process in step S900 is repeated until, in the next step S910, the main controller 1 determines that the CO2 sensor 2 readings have fallen below a predetermined value and that carbon dioxide recovery is complete.

[0130] In step S920, the main controller 1 calculates the amount of carbon dioxide recovered from the recovery units 10A-10C to the CO2 recovery tank 3 using the measured values ​​of the CO2 sensor 2 that have been repeatedly stored during the execution period of the recovery mode. In step S930, the main controller 1 transmits the calculated amount of recovered carbon dioxide to the corresponding unit controller 17A-17C. However, in the case of simultaneous recovery, the amount recovered by each individual recovery unit 10A-10C is calculated using the proportional calculation described above, and the calculated amount is transmitted to each unit controller 17A-17C.

[0131] In step S940, the main controller 1 determines whether or not it has received a recovery amount receipt notification from the unit controllers 17A-17C. If it has received the recovery amount receipt notification, the main controller 1 proceeds to step S950. In step S950, the main controller 1 saves the amount of energy consumed included in the recovery amount receipt notification. As a result, the main controller 1 considers the recovery mode to be complete and terminates the recovery process shown in the flowchart of Figure 12.

[0132] Next, the process for enabling each unit controller 17A-17C to function as a CO2 recovery unit 17a will be explained with reference to the flowcharts in Figures 15 and 16. Each unit controller 17A-17C controls the blower 16, flow path switching valve 11, electrochemical cell 12a, pump 13, flow path switching valve 14, and solenoid valve 15 of each recovery unit 10A-10C by executing the processes shown in the flowcharts in Figures 15 and 16, thereby enabling the recovery of carbon dioxide and the subsequent delivery of the recovered carbon dioxide to the CO2 recovery tank 3.

[0133] In the first step S1000, each unit controller 17A-17C acquires adsorption amount change map data. This adsorption amount change map data may be acquired from, for example, an external server 6, or it may be created by each unit controller 17A-17C. The adsorption amount change map data acquired from the external server 6 or created by the unit controller itself is stored in the storage unit 18. Each unit controller 17A-17C can acquire the adsorption amount change map data by reading it from the storage unit 18. Below, using unit controller 17A as a representative example, the method by which unit controller 17A creates the adsorption amount change map data will be explained with reference to the flowchart in Figure 17 and the time chart in Figure 18. Note that the adsorption amount change map data may be created by each unit controller 17A-17C, or adsorption amount change map data created by one unit controller (for example, unit controller 17A) may be reused by other unit controllers.

[0134] In step S1300, the unit controller 17A executes multiple adsorption modes with different adsorption mode execution times (adsorption times). Furthermore, it obtains the amount of carbon dioxide recovered in the multiple recovery modes executed in accordance with each adsorption mode via communication with the main controller 1. For example, Figure 18 shows an example in which three adsorption modes are executed with different adsorption mode execution times. Note that the number of times the multiple adsorption modes are executed may be two. Also, although Figure 18 shows an example in which the desorption mode and recovery mode are performed simultaneously, the desorption mode and recovery mode may be executed separately.

[0135] In Figure 18, the execution time of the first adsorption mode is relatively short, and it is set so that the amount of carbon dioxide adsorbed by the electrochemical cell 12a does not reach the upper limit of the adsorption capacity of the electrochemical cell 12a. Therefore, the amount of carbon dioxide recovered when the recovery mode corresponding to the first adsorption mode is executed is less than the upper limit of the carbon dioxide adsorption capacity of the electrochemical cell 12a.

[0136] The execution time for the second adsorption mode is relatively long, and it is set so that the amount of carbon dioxide adsorbed by the electrochemical cell 12a reaches approximately its upper limit. Therefore, the amount of carbon dioxide recovered when the recovery mode corresponding to the second adsorption mode is executed is approximately equal to the upper limit of the adsorption capacity of the electrochemical cell 12a.

[0137] The execution time for the third adsorption mode is the longest, and it is set so that the adsorption mode continues for a certain period of time even after the amount of carbon dioxide adsorbed by the electrochemical cell 12a reaches the upper limit of adsorption capacity. Therefore, the amount of carbon dioxide recovered when the recovery mode corresponding to the third adsorption mode is executed is equal to the upper limit of adsorption capacity of the electrochemical cell 12a.

[0138] In step S130 of the flowchart in Figure 17, the unit controller 17A determines whether the map creation conditions are met based on the amount of carbon dioxide recovered by the three recovery modes described above. For example, the unit controller 17A determines, as a map creation condition, that it is possible to plot the amount of carbon dioxide recovered by the three recovery modes described above on a single adsorption change map. Alternatively, the unit controller 17A may determine, as a map creation condition, that there is a maximum value of carbon dioxide recovered by the three recovery modes that is not plotted on the same straight line. When determining whether or not the points are plotted on the same straight line, tolerances may be included in the same straight line. If the unit controller 17A determines that the map creation conditions are met, it proceeds to step S1320; otherwise, it proceeds to step S1320.

[0139] In step S1320, the unit controller 17A executes multiple adsorption modes with different adsorption mode execution times (adsorption times) and obtains the amount of carbon dioxide recovered in the multiple recovery modes executed in accordance with each adsorption mode. At this time, it is desirable for the unit controller 17A to make the execution time of the third adsorption mode longer than the execution time of the previous third adsorption mode.

[0140] Then, in step S1310, the unit controller 17A determines whether the map creation conditions are met based on the amount of carbon dioxide recovered in step S1320. The unit controller 17A repeatedly executes steps S1310 and S1320 until a positive determination is made in step S1310.

[0141] Based on the amount of carbon dioxide recovered during the multiple adsorption modes and the multiple recovery modes corresponding to each adsorption mode described above, the maximum adsorption amount of the electrochemical cell 12a and the maximum adsorption time, which is the duration of the adsorption mode required to obtain that maximum adsorption amount, are estimated. Referring to Figures 19(a), (b), and (c), which show specific examples of methods for estimating the maximum adsorption amount and maximum adsorption time of the electrochemical cell 12a, the procedure for estimating the maximum adsorption amount and maximum adsorption time is described below.

[0142] In step S1330, the slope of the straight line showing the relationship between the maximum adsorption amount and the maximum adsorption time is determined in the adsorption amount change map shown in Figure 19(a). Figure 19(a) is a graph showing the amount of carbon dioxide adsorbed by the electrochemical cell 12a and the execution time of the first adsorption mode, based on the amount of carbon dioxide recovered when the recovery mode corresponding to the first adsorption mode was executed. Note that the amount of carbon dioxide adsorbed by the electrochemical cell 12a is assumed to be equal to the amount of carbon dioxide recovered. As described above, the execution time of the first adsorption mode is relatively short and is set so that the amount of carbon dioxide adsorbed by the electrochemical cell 12a does not reach the upper limit of the adsorption amount. Therefore, as shown in Figure 19(a), based on the amount of carbon dioxide adsorbed by the electrochemical cell 12a due to the execution of the first adsorption mode, an increasing slope line can be determined by assuming that the amount of carbon dioxide adsorbed increases linearly as the execution time of the adsorption mode increases.

[0143] In step S1340, the maximum carbon dioxide adsorption amount is calculated. Figure 19(b) is a graph showing the amount of carbon dioxide adsorbed by each electrochemical cell 12a, and the execution time of the second and third adsorption modes, based on the amount of carbon dioxide recovered when the recovery modes corresponding to the second and third adsorption modes are executed. As mentioned above, the execution time of the second adsorption mode is relatively long, and is set so that the amount of carbon dioxide adsorbed by the electrochemical cell 12a reaches almost the upper limit of the adsorption amount. The execution time of the third adsorption mode is the longest, and is set so that the adsorption mode is executed for a certain period of time even after the amount of carbon dioxide adsorbed by the electrochemical cell 12a reaches the upper limit of the adsorption amount. Therefore, as shown in Figure 19(b), an upper limit line for the amount of carbon dioxide adsorbed by the electrochemical cell 12a can be determined based on the amount of carbon dioxide adsorbed by the electrochemical cell 12a due to the execution of the second and third adsorption modes. The amount of carbon dioxide adsorbed corresponding to the upper limit line corresponds to the maximum amount of adsorption that the adsorbent material of the electrochemical cell 12a can adsorb.

[0144] The upper limit of the carbon dioxide adsorption capacity of the electrochemical cell 12a may be determined based on the amount of carbon dioxide adsorbed by the electrochemical cell 12a obtained through the execution of one adsorption mode and the corresponding recovery mode.

[0145] In step S1340, as shown in Figure 19(c), the maximum adsorption time, which is the adsorption mode execution time required to obtain the maximum adsorption amount of carbon dioxide, can be determined from the intersection of the increasing gradient line in Figure 19(a) and the upper limit line in Figure 19(b).

[0146] In this way, the unit controller 17A can estimate the maximum carbon dioxide adsorption amount of the electrochemical cell 12a and the maximum adsorption time, which is the execution time of the adsorption mode required to obtain that maximum adsorption amount, based on the amount of carbon dioxide recovered during multiple adsorption modes and multiple recovery modes corresponding to each adsorption mode. Then, from the estimated maximum carbon dioxide adsorption amount and maximum adsorption time, the unit controller 17A can obtain adsorption amount change map data, as shown in Figure 20, which shows the relationship between the execution time of the adsorption mode (adsorption time) and the amount of carbon dioxide adsorbed (i.e., the amount of carbon dioxide recovered) in the electrochemical cell 12a. The obtained adsorption amount change map data is stored in the storage unit 18 in step S1350.

[0147] Returning to the flowchart in Figure 15, let's continue the explanation. In step S1010, the unit controller 17A determines whether or not it has received a control pointer from the main controller 1. If it has received a control pointer, the unit controller 17A proceeds to the process in step S1040. If it has not received a control pointer, the unit controller 17A proceeds to the process in step S1020.

[0148] In step S1020, the unit controller 17A determines whether it has previously received a control pointer. If it has previously received a control pointer, the unit controller 17A proceeds to the process in step S1030. If it has not previously received a control pointer, the unit controller 17A returns to the process in step S1010.

[0149] In step S1030, the unit controller 17A calculates the execution time of the adsorption mode according to the received control guidance. The method for calculating the execution time of the adsorption mode is described in detail below.

[0150] In step S1040, the unit controller 17A determines whether the received control pointer is a stop command. If the received control pointer is a stop command, the unit controller 17A proceeds to the process in step S1050. On the other hand, if the received control pointer is not a stop command, the unit controller 17A proceeds to the process in step S1060.

[0151] In step S1050, the unit controller 17A stops the operation of the recovery unit 10A according to the commanded type of stop. That is, if the stop command is an emergency stop command, the unit controller 17A immediately stops the operation of the recovery unit 10A. If it is a protective stop command, the unit controller 17A closes the flow path on / off valve 11, connects the flow path switching valve 14 to the outside, drives the solenoid valve 15 to close, and then stops the operation of the recovery unit 10A. If the stop command is a normal stop, the unit controller 17A stops the operation of the recovery unit 10A after completing the control (series of control sequences) for carbon dioxide recovery that is being performed in the recovery unit 10A.

[0152] In step S1060, the unit controller 17A calculates the execution time of the adsorption mode according to the received control guidance. The method for calculating the execution time of the adsorption mode is described in detail below.

[0153] The adsorption mode execution time (adsorption time) can be obtained from the adsorption amount change map data shown in Figure 20, based on the control guidelines. For example, if a target recovery rate of X%, indicating normal operation, is given as the control guidelines, the unit controller 17A can refer to the adsorption amount change map data and determine the adsorption time corresponding to X% of the maximum carbon dioxide adsorption amount of the electrochemical cell 12a. Even if a target recovery rate of 100% or a target recovery rate of X+α% is given as the control guidelines, the adsorption time corresponding to each adsorption amount can be determined by referring to the adsorption amount change map data. Furthermore, if a target suppression rate is given as the control guidelines, the corresponding adsorption time can be determined from the adsorption amount change map data by converting the target suppression rate to a target recovery rate as described above. In addition, if an operating time is given as the control guidelines, the adsorption time can be determined by allocating the operating time to the adsorption mode, scavenging mode, and desorption mode, or by setting the scavenging mode to a constant time and allocating the remaining time to the adsorption mode and desorption mode.

[0154] However, the carbon dioxide adsorption performance of the electrochemical cell 12a gradually decreases with repeated use. If the adsorption amount change map data created at the beginning of use of the electrochemical cell 12a is used without regard to this degradation over time, it may result in insufficient carbon dioxide recovery commensurate with the adsorption time, or inefficient energy consumption.

[0155] Therefore, in this embodiment, as shown in the flowchart of Figure 21, if in step S1400 the unit controller 17A determines that the amount of carbon dioxide recovered has fallen below the update threshold set based on the target carbon dioxide adsorption amount, in step S1420 the unit controller 17A updates the adsorption amount change map data so that the upper limit of the carbon dioxide adsorption amount (maximum carbon dioxide adsorption amount) is reduced by, for example, an amount equivalent to the update threshold. In this case, for example, as shown in Figure 23, the unit controller 17A updates the adsorption amount change map data so that the maximum carbon dioxide adsorption amount is reduced by the update threshold. After the adsorption amount change map data is updated, the CO2 recovery unit 17a of the unit controller 17A calculates the adsorption time according to the control guideline based on the updated adsorption amount change map data. On the other hand, as shown in Figure 22, if the amount of carbon dioxide recovered is within the range from the target carbon dioxide adsorption amount to the update threshold, the unit controller 17A maintains the adsorption amount change map data as is in step S1410.

[0156] By performing this process of updating the adsorption amount change map data, the unit controller 17A can determine an appropriate adsorption time based on the adsorption amount change map data, even if the carbon dioxide adsorption performance of the electrochemical cell 12a decreases.

[0157] Returning to the flowchart in Figure 15, let's continue the explanation. In step S1030 or S1060, once the adsorption mode execution time is calculated, in step S1070, the unit controller 17A executes the adsorption mode. In this adsorption mode, the flow path valve 11 is opened to allow the introduction of air containing carbon dioxide into the recovery unit 12. If a blower 16 is provided, the blower 16 is driven at a constant rotational speed. In addition, in the adsorption mode, an adsorption potential is applied to the electrochemical cell 12a. Furthermore, in the adsorption mode, the flow path switching valve 14 is controlled to connect the piping downstream of the pump 13 to the outside.

[0158] In the following step S1080, the unit controller 17A determines whether the calculated suction mode execution time has elapsed. If it determines that the calculated suction mode execution time has elapsed, the unit controller 17A proceeds to the process in step S1090. On the other hand, if it determines that the calculated suction mode execution time has not elapsed, the unit controller 17A continues to execute the suction mode until the suction mode execution time has elapsed.

[0159] In step S1090, the unit controller 17A executes a scavenging mode. In this scavenging mode, the flow path valve 11 is closed. The adsorption potential applied to the electrochemical cell 12a is maintained. Communication between the downstream piping of the pump 13 and the outside is also maintained via the flow path switching valve 14. In scavenging mode, the pump 13 is started to drive. As a result, the residual air from which carbon dioxide has been removed, which remains in the sealed recovery unit 12, is drawn out of the recovery unit 12 and released to the outside.

[0160] In step S1100, the unit controller 17A determines whether the scavenging mode execution time has elapsed. This scavenging mode execution time is predetermined to be sufficient time to scavenge the residual air in the recovery unit 12. If it determines that the scavenging mode execution time has elapsed, the unit controller 17A proceeds to the process in step S1110. On the other hand, if it determines that the scavenging mode execution time has not elapsed, the unit controller 17A continues to execute the scavenging mode until the scavenging mode execution time has elapsed.

[0161] In step S1110, the unit controller 17A calculates the execution time of the desorption mode and then executes the desorption mode. The unit controller 17A can, for example, determine the execution time of the desorption mode in proportion to the length of the execution time of the adsorption mode. Therefore, the execution time of the desorption mode is indirectly set based on the control guidelines. In the desorption mode, the flow path switching valve 11 is kept closed. The pump 13 is stopped from driving. A desorption potential is applied to the electrochemical cell 12a. The flow path switching valve 14 is controlled to connect the piping downstream of the pump 13 to the piping connected to the CO2 recovery tank 3. However, the unit controller 17A keeps the solenoid valve 15 closed until this desorption mode is completed. As a result, the solenoid valve 15 prevents the carbon dioxide desorbed from the electrochemical cell 12a from flowing into the piping connected to the CO2 recovery tank 3.

[0162] In step S1120, the unit controller 17A determines whether the calculated deactivation mode execution time has elapsed. If it determines that the calculated deactivation mode execution time has elapsed, the unit controller 17A proceeds to the process in step S1130 of the flowchart in Figure 16. On the other hand, if it determines that the calculated deactivation mode execution time has not elapsed, the unit controller 17A continues to execute the deactivation mode until the deactivation mode execution time has elapsed.

[0163] In step S1130, the unit controller 17A calculates the expected CO2 recovery amount. The expected CO2 recovery amount is calculated as being equal to the amount of CO2 adsorbed corresponding to the execution time of the adsorption mode. Then, in step S1140, the unit controller 17A sends a recovery transition request notification to the main controller 1, which includes the expected CO2 recovery amount and its own identification information.

[0164] In step S1150, the unit controller 17A determines whether or not it has received a recall / transition permission notification from the main controller 1. If it has received the recall / transition permission notification, the unit controller 17A proceeds to the process in step S1160. If it has not received the recall / transition permission notification, the unit controller 17A waits until it receives the recall / transition permission notification.

[0165] In step S1160, the unit controller 17A executes the recovery mode. In recovery mode, the flow control valve 11 is kept closed. The pump 13 is restarted. The desorption potential continues to be applied to the electrochemical cell 12a. The flow control valve 14 connects the piping downstream of the pump 13 to the piping leading to the CO2 recovery tank 3. The solenoid valve 15 is opened. As a result, the carbon dioxide desorbed from the electrochemical cell 12a flows through the solenoid valve 15 and is recovered in the CO2 recovery tank 3.

[0166] In step S1170, the unit controller 17A determines whether or not it has received a recovery completion notification from the main controller 1. If the unit controller 17A receives a recovery completion notification, it terminates the recovery mode in step S1180. For example, in preparation for the start of the next adsorption mode, the unit controller 17A opens the flow path switching valve 11 to connect the recovery unit 12 to the outside. The unit controller 17A also stops applying the desorption potential to the electrochemical cell 12a. The unit controller 17A stops driving the pump 13. The unit controller 17A switches the flow path switching valve 14 to connect the downstream piping of the pump 13 to the outside. Furthermore, the unit controller 17A closes the solenoid valve 15.

[0167] In step S1190, the unit controller 17A determines whether or not it has received feedback on the amount of carbon dioxide recovered from the main controller 1. If it has received feedback on the amount of carbon dioxide recovered, the unit controller 17A proceeds to the process in step S1200. On the other hand, if it has not received feedback on the amount of carbon dioxide recovered, the unit controller 17A waits until it receives feedback.

[0168] In step S1200, the unit controller 17A calculates the amount of energy consumed during the execution of a series of control sequences, including driving the blower 16, applying voltage to the electrochemical cell 12a, and driving the pump 13. Then, in step S1210, the unit controller 17A sends a recovery amount receipt notification to the main controller 1. This recovery amount receipt notification includes the amount of energy consumed calculated in step S1200. After that, the unit controller 17A returns to the process of step S1010 in the flowchart of Figure 15.

[0169] (Second Embodiment) Next, a carbon dioxide capture system 200 according to the second embodiment of this disclosure will be described with reference to Figure 24. In Figure 24, the components of the carbon dioxide capture system 200 are given reference numbers in the 100s, which is for explanatory purposes to distinguish them from the components of the carbon dioxide capture system 100 of the first embodiment. Among the components of the carbon dioxide capture system 200 according to the second embodiment, components with the same last two digits in their number can be configured in the same way as the components of the carbon dioxide capture system 100 according to the first embodiment.

[0170] In the carbon dioxide capture system 200 according to the second embodiment, as shown in Figure 24, a common pump 107 is provided for a plurality of capture units 110A-110L. The pump 107 consists of two pumps 107A and 107B connected in series. The pump 107 is configured to allow for variable carbon dioxide suction force depending on whether only one of the two pumps 107A and 107B is driven or both pumps 107A and 107B are driven. Alternatively, a single pump capable of variable suction force may be provided as the pump 107.

[0171] Pump 107 is controlled by the main controller 1 to suck up carbon dioxide desorbed from each of the multiple recovery units 110A-110L and send it toward the CO2 recovery tank 103. Specifically, the main controller 1 starts driving pump 107 in response to outputting a recovery transition permission notification to at least one of the recovery units 10A-10L.

[0172] The multiple recovery units 110A-110L are equipped with pumps, similar to the pump 13 in the recovery units 10A-10C of the first embodiment. However, since these pumps only need to scavenge the inside of the recovery unit, their suction capacity can be lower than that of the pump 13 in the first embodiment. Furthermore, the pump 13 may be removed from the multiple recovery units 110A-110L, and the scavenging of the inside of the recovery unit may also be performed using the pump 107. Thus, the recovery units 110A-110L of the second embodiment mainly adsorb and retain carbon dioxide, and are therefore also called retaining units. Other components of the carbon dioxide recovery system 200 according to the second embodiment are common to the carbon dioxide recovery system 100 according to the first embodiment, so their description is omitted. Even with the configuration of the carbon dioxide recovery system 200 according to the second embodiment, the same effects and advantages as the carbon dioxide recovery system according to the first embodiment can be obtained.

[0173] Furthermore, as in the second embodiment, if a common pump 107 with variable suction force is provided for multiple holding units 110A-110L, the main controller 101, upon receiving notifications from the unit controllers of multiple holding units 110A-110L simultaneously requesting permission to transition to recovery mode, may prioritize sending notifications to the corresponding unit controllers granting permission to transition to carbon dioxide recovery mode, in order of the shortest suction distance to the pump 107. This is because the shorter the suction distance to the pump 107, the more carbon dioxide the pump 107 can draw in in a shorter time. Also, when the distance to the holding unit is relatively long, the pump 107 drives both pumps 107A and 107B to draw in the carbon dioxide released from the holding unit. On the other hand, when the distance to the holding unit is relatively short, only one of the two pumps 107A and 107B is driven to draw in the carbon dioxide released from the holding unit. Therefore, when the suction distance to the pump 107 is short, the energy consumed by the pump 107 can also be suppressed. Prioritized recovery based on suction distance may be permitted if the user requests an increase in carbon dioxide recovery.

[0174] While preferred embodiments of this disclosure have been described above, this disclosure can be implemented in various ways without being limited to the embodiments described above, and without departing from the spirit of this disclosure.

[0175] For example, the concept described in the second embodiment above, where, when the main controller 101 receives recovery transition request notifications from multiple unit controllers 110A-110L at the same time, it sends a notification to the corresponding unit controller prioritizing the transition to carbon dioxide recovery mode in order of the shortest carbon dioxide suction distance to the pump 107, can be applied to the carbon dioxide recovery system 100 according to the first embodiment. When applied to the carbon dioxide recovery system 100 according to the first embodiment, when the main controller 1 receives recovery transition request notifications from multiple unit controllers 17A-17C of multiple recovery units 10A-10C at the same time, it only needs to send a notification to the corresponding unit controller 17A-17C prioritizing the transition to carbon dioxide recovery mode in order of the shortest carbon dioxide delivery distance to the CO2 recovery tank 3. This priority recovery based on delivery distance may be permitted if the user requests an increase in the amount of carbon dioxide recovered.

[0176] In the first embodiment described above, the storage unit 18 was located inside the unit controller 17, but the storage unit 18 may be located outside the unit controller 17. Alternatively, the storage unit 18 may be located in the main controller 1.

[0177] Finally, this specification discloses several technical concepts and several combinations thereof, as listed below.

[0178] (Technical thought 1) A carbon dioxide capture system that separates and recovers carbon dioxide from the atmosphere containing carbon dioxide, A carbon dioxide capture tank (3) for storing the captured carbon dioxide, A group of recovery units (10) including a plurality of recovery units (10A~10C) connected in parallel to the carbon dioxide recovery tank, which separate carbon dioxide from the atmosphere and send the separated carbon dioxide to the carbon dioxide recovery tank, The system includes a main controller (1) that controls the aforementioned recovery unit group, The plurality of recovery units included in the group of recovery units are, An electrochemical cell (12a) is placed inside the enclosure and adsorbs carbon dioxide by applying an adsorption potential and desorbs the adsorbed carbon dioxide by applying a desorption potential, When the electrochemical cell adsorbs carbon dioxide, the air inlet of the housing is opened to allow air to be introduced into the housing, and when the electrochemical cell desorbs the adsorbed carbon dioxide, the air inlet of the housing is closed to isolate the inside of the housing from the air, the opening / closing part (11) Discharge units (13, 14) that draw carbon dioxide released from the electrochemical cell out of the housing and send it toward the carbon dioxide recovery tank, The unit controller (17) controls the operation of the electrochemical cell, the switching unit, and the dispensing unit, A carbon dioxide recovery system comprising: a main controller providing control guidelines to each of the unit controllers of a plurality of recovery units, which serve as guidelines for the unit controllers when controlling the operation of the electrochemical cell, the switching unit, and the discharge unit; and a unit controller determining the control content of the electrochemical cell, the switching unit, and the discharge unit based on the control guidelines.

[0179] (Technical thought 2) The carbon dioxide capture system according to Technical Concept 1, wherein the main controller provides the unit controller with one of the following as control guidelines: stop instruction, improvement of carbon dioxide capture amount, reduction of energy consumption, normal operation, and operating time.

[0180] (Technical Thought 3) The unit controller, as part of the control contents of the electrochemical cell, the switching unit, and the dispensing unit, determines at least the adsorption time for adsorbing carbon dioxide onto the electrochemical cell, A carbon dioxide recovery system according to technical concept 1 or 2, comprising controlling the electrochemical cell, the switching unit, and the discharge unit so that the electrochemical cell adsorbs carbon dioxide for a determined adsorption time.

[0181] (Technical Thought 4) The carbon dioxide recovery system according to technical concept 3, wherein the unit controller further determines the desorption time for desorbing carbon dioxide from the electrochemical cell, and controls the electrochemical cell, the switch, and the discharge unit so that the electrochemical cell desorbs carbon dioxide into the housing for the determined desorption time.

[0182] (Technical Thought 5) A carbon dioxide capture system according to any one of technical ideas 1 to 4, wherein the main controller provides a stop instruction to the unit controller as a control guideline based on at least one of the external environment, an abnormality in the carbon dioxide capture system, and a stop request from a user.

[0183] (Technical Thought 6) The aforementioned stop instructions include a normal stop instruction, which stops each recovery unit after terminating the ongoing carbon dioxide capture control in each recovery unit, and an emergency stop instruction, which interrupts the ongoing carbon dioxide capture control and stops each recovery unit. The carbon dioxide capture system according to technical concept 5, wherein the main controller provides the unit controller with either the normal stop instruction or the emergency stop instruction depending on the urgency of at least one of the external environment, an abnormality in the carbon dioxide capture system, and a stop request from a user.

[0184] (Technical Thought 7) The carbon dioxide capture system according to technical concept 5 or 6, wherein the external environment includes the occurrence of a disaster and the state of the energy supply for operating the carbon dioxide capture system.

[0185] (Technical Thought 8) The main controller is capable of receiving user requests regarding whether to prioritize carbon dioxide capture or to prioritize reducing the energy consumption of the carbon dioxide capture system. A carbon dioxide capture system according to any one of Technical Ideas 1 to 7, wherein the main controller, upon receiving a user request prioritizing carbon dioxide capture, provides the unit controller with control guidelines indicating an improvement in the amount of carbon dioxide captured, and upon receiving a user request prioritizing the reduction of energy consumption, provides the unit controller with control guidelines indicating a reduction in energy consumption.

[0186] (Technical Thought 9) The aforementioned main controller is capable of acquiring information related to weather forecasts. A carbon dioxide capture system according to any one of Technical Ideas 1 to 8, wherein the main controller provides the unit controller with control guidelines indicating an improvement in carbon dioxide capture amount when a future decrease in carbon dioxide capture amount is predicted based on acquired weather forecast information.

[0187] (Technical Thought 10) The main controller calculates the degree of decrease in the total amount of carbon dioxide recovered by the system as a whole, based on at least the total amount of carbon dioxide recovered by each of the multiple recovery units. The carbon dioxide capture system according to any one of technical concepts 1 to 9, wherein the main controller provides the unit controller with a control guide indicating the reduction of energy consumption when the degree of decrease in the total amount of carbon dioxide captured by the system exceeds a predetermined threshold.

[0188] (Technical Thought 11) The main controller calculates a unit energy, which is the amount of energy required to recover a predetermined unit amount of carbon dioxide, for the entire system, based on the total amount of carbon dioxide recovered by the multiple recovery units and the total amount of energy consumed by the multiple recovery units, as an indicator of the degree of decrease in the overall carbon dioxide recovery amount of the system. The carbon dioxide capture system according to technical concept 10, wherein the main controller considers that the degree of decrease in the total carbon dioxide capture amount of the system has exceeded a predetermined threshold when the calculated unit energy exceeds a predetermined reference energy.

[0189] (Technical Thought 12) The carbon dioxide capture system according to any one of Technical Ideas 1 to 11, wherein the main controller has a predetermined scheduled shutdown time for the carbon dioxide capture system, and when a predetermined amount of time has passed until the scheduled shutdown time, it provides the unit controller with the time at which the capture unit should be able to release carbon dioxide, or the cycle time to be spent in the capture unit for the cycle from carbon dioxide adsorption to release, as a control guideline for the operating time.

[0190] (Technical Thought 13) When the recovery unit becomes capable of releasing carbon dioxide, the unit controller sends a notification to the main controller requesting permission to release the carbon dioxide, and upon receiving a notification from the main controller granting permission to release the carbon dioxide, it causes the recovery unit to release carbon dioxide towards the carbon dioxide recovery tank. A carbon dioxide capture system according to any one of Technical Ideas 1 to 12, wherein, if the main controller receives notifications from multiple unit controllers requesting permission to release carbon dioxide at the same time, it sends a notification to the unit controller of the capture unit that is expected to release more carbon dioxide, prioritizing the release of carbon dioxide.

[0191] (Technical Thought 14) A carbon dioxide capture system according to technical concept 13, wherein the main controller, upon receiving a user request prioritizing carbon dioxide capture, transmits a notification to the unit controller of the capture unit that is expected to transmit more carbon dioxide, granting preferential permission to transmit carbon dioxide.

[0192] (Technical Thought 15) When the recovery unit becomes capable of releasing carbon dioxide, the unit controller sends a notification to the main controller requesting permission to release the carbon dioxide, and upon receiving a notification from the main controller granting permission to release the carbon dioxide, it causes the recovery unit to release carbon dioxide towards the carbon dioxide recovery tank. A carbon dioxide capture system according to any one of Technical Concepts 1 to 12, wherein, if the main controller receives notifications from multiple unit controllers requesting permission to release carbon dioxide at the same time, and if there are multiple capture units among them that can only release an amount of carbon dioxide less than a predetermined standard value, the main controller sends a notification to the unit controllers of the multiple capture units in question to simultaneously authorize the release of carbon dioxide, thereby causing the multiple capture units to release carbon dioxide at the same time.

[0193] (Technical Thought 16) The carbon dioxide capture system according to technical concept 15, wherein the main controller, upon receiving a user request prioritizing carbon dioxide capture, sends a notification to the unit controllers of multiple capture units that can only release an amount of carbon dioxide less than a predetermined standard value, authorizing them to release carbon dioxide simultaneously.

[0194] (Technical Thought 17) When the recovery unit becomes capable of releasing carbon dioxide, the unit controller sends a notification to the main controller requesting permission to release the carbon dioxide, and upon receiving a notification from the main controller granting permission to release the carbon dioxide, it causes the recovery unit to release carbon dioxide towards the carbon dioxide recovery tank. A carbon dioxide capture system according to any one of Technical Ideas 1 to 12, wherein, if the main controller receives notifications requesting permission to release from multiple unit controllers at the same time, it sends a notification to the unit controller of the corresponding capture unit prioritizing the release of carbon dioxide, in order of the shortest distance to the carbon dioxide release tank.

[0195] (Technical Thought 18) The carbon dioxide capture system according to technical concept 17, wherein the main controller, upon receiving a user request prioritizing carbon dioxide capture, transmits a notification to the unit controller of the corresponding carbon dioxide capture unit, in order of the shortest distance to which carbon dioxide is transmitted to the capture unit, authorizing priority transmission of carbon dioxide. [Explanation of Symbols]

[0196] 1: Main controller, 1a: External information arbitration unit, 1b: Control guideline setting unit, 1c: Recovery arbitration unit, 2: CO2 sensor, 3: CO2 recovery tank, 4: Renewable energy system, 5: User interface, 6: External server, 10: Recovery unit group, 10A-10C: Recovery unit, 11: Flow path switching valve, 12: Recovery device, 12a: Electrochemical cell, 13: Pump, 14: Flow path switching valve, 15: Solenoid valve, 16: Blower, 17A-17C: Unit controller, 18: Memory unit, 100: Carbon dioxide recovery system

Claims

1. A carbon dioxide capture system that separates and recovers carbon dioxide from the atmosphere containing carbon dioxide, A carbon dioxide capture tank (3) for storing the captured carbon dioxide, A group of recovery units (10) including a plurality of recovery units (10A to 10C) connected in parallel to the carbon dioxide recovery tank, which separate carbon dioxide from the atmosphere and send the separated carbon dioxide to the carbon dioxide recovery tank, The system includes a main controller (1) that controls the aforementioned recovery unit group, The plurality of recovery units included in the group of recovery units are, An electrochemical cell (12a) is placed inside the enclosure and adsorbs carbon dioxide by applying an adsorption potential and desorbs the adsorbed carbon dioxide by applying a desorption potential, When the electrochemical cell adsorbs carbon dioxide, the air inlet of the housing is opened to allow air to be introduced into the housing, and when the electrochemical cell desorbs the adsorbed carbon dioxide, the air inlet of the housing is closed to isolate the inside of the housing from the air, the opening / closing part (11) Discharge units (13, 14) that draw carbon dioxide released from the electrochemical cell out of the housing and send it toward the carbon dioxide recovery tank, The unit controller (17) controls the operation of the electrochemical cell, the switching unit, and the dispensing unit, The main controller provides control guidelines to each of the unit controllers of the plurality of recovery units. The control guidelines are any of the following: a stop instruction to stop the operation of the carbon dioxide capture system; an improvement in the amount of carbon dioxide captured relative to the amount of carbon dioxide captured when the capture unit is operating; the operating time of the capture unit; a reduction in energy consumption relative to the energy consumption of the capture unit when it is operating; and the operation of the capture unit. A carbon dioxide recovery system in which the unit controller controls the electrochemical cell, the switching unit, and the discharge unit based on the control guidelines.

2. The carbon dioxide recovery system according to claim 1, wherein the unit controller, when controlling the electrochemical cell, the switching unit, and the discharge unit based on the control guideline, determines at least the adsorption time for adsorbing carbon dioxide in the electrochemical cell, and controls the electrochemical cell, the switching unit, and the discharge unit so that the electrochemical cell adsorbs carbon dioxide for the determined adsorption time.

3. The carbon dioxide recovery system according to claim 2, wherein the unit controller, when controlling the electrochemical cell, the switching unit, and the discharge unit based on the control guideline, further determines the desorption time for desorbing carbon dioxide from the electrochemical cell, and controls the electrochemical cell, the switching unit, and the discharge unit so that the electrochemical cell desorbs carbon dioxide into the housing for the determined desorption time.

4. The carbon dioxide recovery system according to claim 1, wherein the main controller provides the unit controller with the stop instruction as a control guideline based on at least one of the external environment, an abnormality in the carbon dioxide recovery system, and a stop request from a user.

5. The aforementioned stop instructions include a normal stop instruction, which stops each recovery unit after terminating the ongoing carbon dioxide capture control in each recovery unit, and an emergency stop instruction, which interrupts the ongoing carbon dioxide capture control and stops each recovery unit. The carbon dioxide capture system according to claim 4, wherein the main controller provides the unit controller with either the normal stop instruction or the emergency stop instruction depending on the urgency of at least one of the external environment, an abnormality in the carbon dioxide capture system, and a stop request from a user.

6. The carbon dioxide capture system according to claim 4 or 5, wherein the external environment includes the occurrence of a disaster and the state of the energy supply for operating the carbon dioxide capture system.

7. The main controller is capable of receiving user requests regarding whether to prioritize carbon dioxide capture or to prioritize reducing the energy consumption of the carbon dioxide capture system. The carbon dioxide capture system according to claim 1, wherein the main controller, upon receiving a user request prioritizing carbon dioxide capture, provides the unit controller with the control guidelines indicating an improvement in the amount of carbon dioxide captured, and upon receiving a user request prioritizing the reduction of energy consumption, provides the unit controller with the control guidelines indicating a reduction in energy consumption.

8. The aforementioned main controller is capable of acquiring information related to weather forecasts. The carbon dioxide capture system according to claim 1, wherein the main controller provides the unit controller with control guidelines indicating an improvement in the amount of carbon dioxide captured when a decrease in the amount of carbon dioxide captured in the future is predicted based on the acquired weather forecast information.

9. The main controller calculates the degree of decrease in the total amount of carbon dioxide recovered by the system as a whole, based on at least the total amount of carbon dioxide recovered by each of the multiple recovery units. The carbon dioxide capture system according to claim 1, wherein the main controller provides the unit controller with a control guideline indicating the reduction of energy consumption when the degree of decrease in the total amount of carbon dioxide captured by the system exceeds a predetermined threshold.

10. The main controller calculates a unit energy, which is the amount of energy required to recover a predetermined unit amount of carbon dioxide, for the entire system, based on the total amount of carbon dioxide recovered by the multiple recovery units and the total amount of energy consumed by the multiple recovery units, as an indicator of the degree of decrease in the overall carbon dioxide recovery amount of the system. The carbon dioxide capture system according to claim 9, wherein the main controller considers that the degree of decrease in the total carbon dioxide capture amount of the system has exceeded a predetermined threshold when the calculated unit energy exceeds a predetermined reference energy.

11. The carbon dioxide recovery system according to claim 1, wherein the main controller has a predetermined scheduled shutdown time for the carbon dioxide recovery system, and when a predetermined amount of time has passed until the scheduled shutdown time, it provides the unit controller with, as a control guideline for the operating time, the time at which the recovery unit should be able to discharge carbon dioxide, or the cycle time to be spent in the recovery unit for the cycle from carbon dioxide adsorption to discharge.

12. When the recovery unit becomes capable of releasing carbon dioxide, the unit controller sends a notification to the main controller requesting permission to release the carbon dioxide, and upon receiving a notification from the main controller granting permission to release the carbon dioxide, it causes the recovery unit to release carbon dioxide towards the carbon dioxide recovery tank. The carbon dioxide capture system according to claim 1, wherein, if the main controller receives notifications from multiple unit controllers requesting permission to release carbon dioxide at the same time, it sends a notification to the unit controller of the capture unit that is expected to release more carbon dioxide, prioritizing the release of carbon dioxide.

13. The carbon dioxide capture system according to claim 12, wherein the main controller, upon receiving a user request prioritizing carbon dioxide capture, transmits a notification to the unit controller of the capture unit that is expected to release a larger amount of carbon dioxide, granting it priority permission to release carbon dioxide.

14. When the recovery unit becomes capable of releasing carbon dioxide, the unit controller sends a notification to the main controller requesting permission to release the carbon dioxide, and upon receiving a notification from the main controller granting permission to release the carbon dioxide, it causes the recovery unit to release carbon dioxide towards the carbon dioxide recovery tank. The carbon dioxide recovery system according to claim 1, wherein if the main controller receives notifications from multiple unit controllers requesting permission to discharge at the same time, and if there are multiple recovery units among them that can only discharge an amount of carbon dioxide less than a predetermined standard value, the main controller simultaneously sends a notification to the unit controllers of the multiple recovery units in question, allowing the multiple recovery units to discharge carbon dioxide at the same time.

15. The carbon dioxide capture system according to claim 14, wherein the main controller, upon receiving a user request prioritizing carbon dioxide capture, transmits a notification to the unit controllers of a plurality of capture units that can only transmit an amount of carbon dioxide less than a predetermined standard value, allowing them to transmit carbon dioxide simultaneously.

16. When the recovery unit becomes capable of releasing carbon dioxide, the unit controller sends a notification to the main controller requesting permission to release the carbon dioxide, and upon receiving a notification from the main controller granting permission to release the carbon dioxide, it causes the recovery unit to release carbon dioxide towards the carbon dioxide recovery tank. The carbon dioxide recovery system according to claim 1, wherein, if the main controller receives notifications from multiple unit controllers requesting permission to discharge at the same time, it preferentially transmits a notification to the unit controller of the corresponding recovery unit, in order of the shortest distance to which carbon dioxide has been discharged to the carbon dioxide recovery tank, granting permission to discharge carbon dioxide.

17. The carbon dioxide recovery system according to claim 16, wherein when the main controller receives a user request prioritizing carbon dioxide recovery, it transmits a notification to the unit controller of the corresponding recovery unit, in order of the shortest distance to the carbon dioxide recovery tank, authorizing the preferential delivery of carbon dioxide.

18. A carbon dioxide capture system that separates and recovers carbon dioxide from the atmosphere containing carbon dioxide, A carbon dioxide capture tank (103) for storing the captured carbon dioxide, A group of retention units (110) including a plurality of retention units (110A to 110L) connected in parallel to the carbon dioxide recovery tank, which are capable of separating and retaining carbon dioxide from the atmosphere and desorbing the retained carbon dioxide, A pump (107) that sucks up the carbon dioxide released from each of the plurality of holding units and sends it to the carbon dioxide recovery tank, The system includes a main controller (101) that controls the group of holding units, The plurality of holding units included in the group of holding units are, An electrochemical cell, which is placed inside a housing, adsorbs carbon dioxide when an adsorption potential is applied and desorbs the adsorbed carbon dioxide when a desorption potential is applied, When the electrochemical cell adsorbs carbon dioxide, the air inlet of the housing is opened to allow air to be introduced into the housing, and when the electrochemical cell desorbs the adsorbed carbon dioxide, the air inlet of the housing is closed to isolate the inside of the housing from the air. The unit controller controls the operation of the electrochemical cell and the switching unit, The main controller provides control guidelines to each of the unit controllers of the plurality of holding units. The control guidelines are any of the following: a stop instruction to stop the operation of the carbon dioxide capture system; an improvement in the amount of carbon dioxide captured relative to the amount of carbon dioxide captured when the holding unit is operating; the operating time of the holding unit; a reduction in energy consumption relative to the energy consumption of the holding unit when it is operating; and the operation of the holding unit. The unit controller is a carbon dioxide recovery system that controls the electrochemical cell and the switching unit based on the control guidelines.

19. The aforementioned pump is capable of varying the carbon dioxide suction force. When the holding unit becomes capable of releasing carbon dioxide, the unit controller sends a notification to the main controller requesting permission to release the carbon dioxide, and upon receiving a notification from the main controller granting permission to release the carbon dioxide, the unit controller releases the carbon dioxide from the holding unit. The carbon dioxide recovery system according to claim 18, wherein, if the main controller receives notifications from multiple unit controllers requesting permission to decompress at the same time, it sends a notification to the corresponding unit controller prioritizing permission to decompress carbon dioxide, in order of the shortest distance for carbon dioxide suction to the pump.

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