Carbon dioxide recovery device

Abstract

To provide a carbon dioxide recovery device which can use adsorption heat, and has high energy efficiency enough to suppress energy required for rise of a temperature of an adsorption material in a desorption step.SOLUTION: A carbon dioxide recovery device 1 includes: a module 11 which has an adsorption material 12 therein, and executes an adsorption step of sucking gas containing carbon dioxide, and making the adsorption material 12 adsorb the carbon dioxide, and a desorption step of heating the periphery of the adsorption material in a decompressed state, and thereby desorbing the carbon dioxide from the adsorption material 12; and a cooling water tank 82 for storing a cooling medium for cooling the module 11, wherein in the adsorption step, when a difference between the temperature of the adsorption material 12 and the temperature of a cooling medium in the cooling water tank 82 is equal to or more than a first threshold, the adsorption step flows the cooling medium to the module 11, and recovers the heat.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a carbon dioxide recovery device.

Background Art

[0002] Conventionally, a technique for recovering carbon dioxide from a gas containing carbon dioxide such as the atmosphere has been known. For example, Patent Document 1 describes this kind of technique. Patent Document 1 describes a method of separating gaseous carbon dioxide from a gas mixture by cyclic adsorption / desorption using an adsorbent that adsorbs gaseous carbon dioxide.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the desorption step of desorbing carbon dioxide adsorbed on the adsorbent from the adsorbent, it is necessary to heat the adsorbent to a high temperature. To raise the temperature of the adsorbent from room temperature to a desorbable temperature, a large amount of thermal energy is required from the outside. On the other hand, in the adsorption step of adsorbing carbon dioxide to the adsorbent, adsorption heat is generated in the adsorbent, but this adsorption heat has not been utilized. There is room for improvement in the prior art in terms of improving the energy efficiency required for heating the adsorbent.

[0005] An object of the present invention is to provide a highly energy-efficient carbon dioxide recovery device that can utilize adsorption heat and suppress the energy required for heating the adsorbent in the desorption step.

Means for Solving the Problems

[0006] The present disclosure solves the above problems by the following means. For ease of understanding, reference numerals corresponding to embodiments of the present disclosure are used for the description, but the present disclosure is not limited thereto.

[0007] A first disclosure includes a module (11) having an adsorbent (12) inside, an adsorption step of sucking a gas containing carbon dioxide into the adsorbent (12) to adsorb the carbon dioxide, and desorbing the carbon dioxide from the adsorbent (12) by heating the adsorbent (12) in a state where the periphery thereof is depressurized, and a tank (82) for storing a cooling medium for cooling the module (11). In the adsorption step, when the difference between the temperature of the adsorbent (12) and the temperature of the cooling medium in the tank (82) is equal to or greater than a first threshold value, the cooling medium is caused to flow through the module (11) for heat recovery. This is a carbon dioxide recovery device (1).

[0008] A second disclosure is the carbon dioxide recovery device (1) according to the first disclosure, wherein when the difference between the inlet temperature at the position where the cooling medium enters the module (11) and the outlet temperature at the position where the cooling medium exits the module (11) becomes smaller than a second threshold value, the flow of the cooling medium through the module (11) is stopped. This is a carbon dioxide recovery device (1).

[0009] A third disclosure is the carbon dioxide recovery device (1) according to the first disclosure or the second disclosure, wherein when the difference between the temperature of the adsorbent (12) and the temperature of the cooling medium in the tank (82) becomes smaller than a third threshold value, the flow of the cooling medium through the module (11) is stopped. This is a carbon dioxide recovery device (1).

Advantages of the Invention

[0010] According to the present disclosure, it is possible to provide a highly energy-efficient carbon dioxide recovery device that can suppress the energy required for raising the temperature of the adsorbent in the desorption step by making use of the heat of adsorption.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0013] <Overall Configuration> FIG. 1 is a schematic diagram showing the configuration of the liquid flow of the carbon dioxide recovery device 1 according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the configuration of the gas flow of the module 11 of the carbon dioxide recovery device 1 of the present embodiment. Note that the illustration of the configuration of the gas flow of the carbon dioxide recovery device 1 in FIG. 1 is omitted.

[0014] The carbon dioxide recovery device 1 of the present embodiment is applied to, for example, direct air capture (DAC) technology for recovering carbon dioxide in the atmosphere in order to reduce the carbon dioxide concentration in the atmosphere. The carbon dioxide recovered by the carbon dioxide recovery device 1 is stored underground or reused as fuel or material.

[0015] As shown in FIGS. 1 and 2, the carbon dioxide recovery apparatus 1 of the present embodiment includes a module unit 10, a fan 61, a vacuum pump 62, a carbon dioxide recovery pump 63, a heat exchanger 80, and a control device 90.

[0016] The module unit 10 is configured by arranging a plurality of modules 11 that adsorb carbon dioxide in parallel. In the present embodiment, a total of 16 modules 11 are arranged by a pair of left and right module units 10.

[0017] As shown in FIG. 2, the module 11 is a carbon dioxide recovery module including an adsorbent 12, a first valve 21, a second valve 22, a third valve 23, a fourth valve 24, and an adsorbent temperature sensor 27.

[0018] The adsorbent 12 is disposed inside the module 11 to adsorb carbon dioxide. The adsorbent 12 is a particulate member and has a property of adsorbing carbon dioxide in a low temperature state (for example, in the range of -30°C to 50°C) and desorbing (releasing) carbon dioxide in a high temperature state (for example, in the range of 50°C to 110°C) and a low concentration of ambient carbon dioxide. Examples of such an adsorbent 12 include a solid amine carbon dioxide adsorbent formed by supporting an amine on a porous material such as silica.

[0019] The first valve 21 is an on-off valve disposed at the connection portion between the carbon dioxide line 103 for recovering carbon dioxide and the module 11. A carbon dioxide recovery pump 63 is disposed in the carbon dioxide line 103. The second valve 22 is an on-off valve disposed at the connection portion between the vacuum line 102 where the vacuum pump 62 is disposed and the module 11. The third valve 23 is an on-off valve disposed at the inlet for taking in air or the like into the module 11. The fourth valve 24 is an on-off valve disposed at the connection portion between the adsorption line 101 and the module 11. A fan 61 is disposed in the adsorption line 101.

[0020] The first valve 21, the second valve 22, the third valve 23, and the fourth valve 24 are all controlled to open and close by the control device 90. The first valve 21, the second valve 22, the third valve 23, and the fourth valve 24 are each constituted by, for example, a normally open butterfly valve. The adsorbent temperature sensor 27 measures the temperature of the adsorbent 12. The measurement information of the adsorbent temperature sensor 27 is transmitted to the control device 90.

[0021] The adsorption line 101 is branched and connected to each of the modules 11. The fan 61 is disposed at a portion where the branched portions of the adsorption line 101 converge. When the fan 61 is driven, a gas flow from "intake" to "exhaust" is generated in the module 11 through the adsorption line 101. Thereby, the atmosphere is supplied into the module 11.

[0022] The vacuum line 102 is branched and connected to each of the modules 11. The vacuum pump 62 is disposed at a portion where the branched portions of the vacuum line 102 converge. When the vacuum pump 62 is driven, the gas inside the module 11 is sucked through the vacuum line 102, and the inside of the module 11 is brought into a vacuum state or close to a vacuum state.

[0023] The carbon dioxide line 103 is branched and connected to each of the modules 11. A carbon dioxide recovery pump 63 is disposed at a portion where the branched portions of the carbon dioxide line 103 converge. The carbon dioxide recovery pump 63 applies an attractive force to the carbon dioxide flowing through the carbon dioxide line 103 and stores the recovered carbon dioxide in a tank (not shown) for storing carbon dioxide.

[0024] Returning to FIG. 1, the heat exchange device 80 will be described. The heat exchange device 80 supplies thermal energy for heating the inside of the module 11 to a predetermined temperature when each module 11 of the module unit 10 performs a desorption process. Further, the heat exchange device 80 recovers unnecessary thermal energy when each module 11 performs an adsorption process.

[0025] The heat exchanger 80 of this embodiment includes a heat exchanger 81, a cold water tank 82, a cold water line 111, a hot water tank 83, a hot water line 112, and a three-way valve 30.

[0026] The heat exchanger 81 performs heat exchange between the heat medium flowing through the cold water line 111 and the heat medium flowing through the hot water line 112. The heat exchanger 81 is, for example, a heat pump. The heat medium is, for example, a liquid such as water. Due to the heat transfer occurring in the heat exchanger 81, the heat medium flowing through the cold water line 111 is cooled, and the heat medium flowing through the hot water line 112 is heated.

[0027] The cold water tank 82 stores the heat medium flowing through the cold water line 111. The heat medium flowing through the cold water line 111 is stored in the cold water tank 82 and then sent to the heat exchanger 81. Also, the heat medium cooled by the heat exchanger 81 is returned to the cold water tank 82 and then sent to each module 11 through the cold water line 111. A water pump 821 for heat exchanger circulation is arranged between the cold water tank 82 and the heat exchanger 81 in the cold water line 111. By driving the water pump 821 for heat exchanger circulation, the heat medium flowing through the cold water line 111 circulates between the cold water tank 82 and the heat exchanger 81.

[0028] The cold water line 111 is branched and connected to the upstream side and the downstream side of each module 11, connecting the cold water tank 82 and each module 11. Also, a first water pump 822 for cold water circulation and a second water pump 823 for cold water circulation are arranged between the cold water tank 82 and each module 11 in the cold water line 111. Further, a circulation line 824 that returns from the downstream side to the upstream side of the second water pump 823 for cold water circulation is arranged in the cold water line 111. A circulation valve 825 is arranged in this circulation line 824.

[0029] The hot water tank 83 stores the heat medium flowing through the hot water line 112. After being stored in the hot water tank 83, the heat medium flowing through the hot water line 112 is sent to the heat exchanger 81. Also, the heat medium heated by the heat exchanger 81 is returned to the hot water tank 83 and then sent to each module 11 through the hot water line 112. A water pump 831 for heat exchanger circulation is arranged between the hot water tank 83 and the heat exchanger 81 in the hot water line 112. By driving the water pump 831 for heat exchanger circulation, the heat medium flowing through the hot water line 112 circulates between the hot water tank 83 and the heat exchanger 81.

[0030] The hot water line 112 is branched and connected to the upstream side and the downstream side of each module 11, connecting the hot water tank 83 and each module 11. Also, between the hot water tank 83 and each module 11 in the hot water line 112, a first water pump 832 for hot water circulation and a second water pump 833 for hot water circulation are arranged. Further, in the hot water line 112, a circulation line 834 that returns from the downstream side to the upstream side of the second water pump 833 for hot water circulation is arranged. A circulation valve 835 is arranged in this circulation line 834.

[0031] The three-way valve 30 is connected to the cold water line 111, the hot water line 112, and the module 11. The three-way valve 30 is arranged on each of the upstream side and the downstream side of the module 11. The three-way valve 30 is configured to be switchable between a cold water connection state connecting the cold water line 111 and the module 11, a hot water connection state connecting the hot water line 112 and the module 11, and a cutoff state cutting off the connection between the cold water line 111, the hot water line 112, and the module 11.

[0032] The flow path switching of the three-way valve 30 is controlled by the control device 90. The heat medium is introduced into the module 11 through the three-way valve 30 arranged on the upstream side, and the heat medium is returned to the heat exchanger 81 side through the three-way valve 30 arranged on the downstream side.

[0033] Next, the control device 90 will be described. The control device 90 controls the operations of each part of the carbon dioxide recovery device 1. The control device 90 controls operations such as driving and stopping of devices used for adsorption and desorption of carbon dioxide. The control device 90 performs opening and closing control of the first valve 21, the second valve 22, the third valve 23, and the fourth valve 24 provided in each module 11. Further, the control device 90 performs drive control of the fan 61, the vacuum pump 62, the carbon dioxide recovery pump 63, the water pump 821 for heat exchanger circulation, the first water pump 822 for cold water circulation, the second water pump 823 for cold water circulation, the water pump 831 for heat exchanger circulation, the first water pump 832 for warm water circulation, the second water pump 833 for warm water circulation, etc., and opening and closing control of the circulation valve 825 and the circulation valve 835.

[0034] The control device 90 is a computer having, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The control device 90 may be composed of one unit or may be composed of a plurality of units.

[0035] <Recovery of Carbon Dioxide> Next, the control for recovering carbon dioxide by the control device 90 will be described. The carbon dioxide recovery device 1 alternately performs an adsorption step of adsorbing carbon dioxide in a gas such as inhaled air to the adsorbent 12 in the module 11 and a desorption step of desorbing the carbon dioxide adsorbed to the adsorbent 12, and compresses the desorbed carbon dioxide and stores it in a tank (not shown), thereby removing and recovering carbon dioxide from the air. In the present embodiment, the adsorption step and the desorption step are performed with the time of the adsorption step: the time of the desorption step = 3:1.

[0036] The adsorption process is a process of adsorbing carbon dioxide onto the adsorbent 12 in the module 11. In the adsorption process, the third valve 23 and the fourth valve 24 of the module 11 are opened, and the first valve 21 and the second valve 22 are closed. The fan 61 is driven to generate a gas flow from upstream to downstream, and the gas containing carbon dioxide (e.g., air) is inhaled through the third valve 23. The inhaled gas passes through the adsorbent 12 in the module 11. At this time, the inside of the module 11 is at room temperature (25 °C), and the carbon dioxide in the gas is adsorbed onto the adsorbent 12. Gases other than carbon dioxide, such as nitrogen and oxygen, are exhausted to the outside of the carbon dioxide recovery device 1 through the fourth valve 24 and the adsorption line 101. In addition, in this embodiment, in this adsorption process, when specific conditions are satisfied, an adsorption heat recovery operation is performed. The adsorption heat recovery operation will be described later.

[0037] The desorption process is a process of desorbing carbon dioxide from the adsorbent 12 in the module 11. In the desorption process, the first valve 21, the third valve 23, and the fourth valve 24 of the module 11 are closed, and the second valve 22 is opened. The vacuum pump 62 operates to inhale the inside of the module 11 and reduce the pressure to a vacuum state or approach a vacuum state. At the same time, the heat medium serving as a heat source flows through the inside of the module 11 by the heat exchanger 80 to supply heat energy, and the temperature of the adsorbent 12 in the module 11 is raised.

[0038] By controlling the temperature rise of the adsorbent 12, the adsorbent 12 is also heated to a predetermined temperature (e.g., 80 °C) sufficient for the desorption process, and the carbon dioxide adsorbed on the adsorbent 12 is desorbed. Next, the second valve 22, the third valve 23, and the fourth valve 24 are closed, the first valve 21 is opened, and the carbon dioxide recovery pump 63 is driven, and the desorbed carbon dioxide is stored in a tank (not shown) through the carbon dioxide line 103. In this embodiment, among the 16 modules 11, 12 execute the adsorption process, and the remaining 4 perform the desorption process, and each process is controlled accordingly.

[0039] <Adsorption Heat Recovery Operation (Control)> In the adsorption process, when carbon dioxide is adsorbed by the adsorbent 12, adsorption heat is generated. This adsorption heat has not been utilized in conventional carbon dioxide recovery devices. However, if this adsorption heat can be used to raise the temperature of the adsorbent 12 for the desorption process, the energy required to raise the temperature of the adsorbent 12 can be suppressed. Therefore, in the carbon dioxide recovery device 1 of the present embodiment, an operation for recovering adsorption heat is performed. The operation for recovering this adsorption heat will be described below.

[0040] FIG. 3 is a schematic diagram showing a heat supply path during non-adsorption heat recovery in the adsorption process. FIG. 4 is a schematic diagram showing a heat supply path during adsorption heat recovery in the adsorption process. FIG. 5 is a graph for explaining the heat transfer of the module 11 including both non-adsorption heat recovery and adsorption heat recovery in the adsorption process. In FIGS. 3 to 5, illustration of the remaining modules 11 is omitted.

[0041] First, the structure for supplying the heat medium to the module 11 will be described. As shown in FIGS. 3 and 4, the module 11 includes an inlet-side flow path 33 connected to an inlet through which the heat medium flows in, and an outlet-side flow path 34 connected to an outlet through which the heat medium flows out. A three-way valve 30 is disposed at the upstream end of the inlet-side flow path 33, and a three-way valve 30 is also disposed at the downstream end of the outlet-side flow path 34.

[0042] An inlet temperature sensor 35 is provided in the inlet-side flow path 33. The inlet temperature sensor 35 measures the temperature of the heat medium flowing into the module 11 (hereinafter also referred to as the inlet temperature), and the measurement information is transmitted to the control device 90. An outlet temperature sensor 36 is provided in the outlet-side flow path 34. The outlet temperature sensor 36 measures the temperature of the heat medium flowing out of the module 11 (hereinafter also referred to as the outlet temperature), and the measurement information is transmitted to the control device 90. In addition, the carbon dioxide recovery device 1 of the present embodiment further includes a hot water tank temperature sensor 37 and a cold water tank temperature sensor 38. The hot water tank temperature sensor 37 measures the temperature of the hot water tank 83, and the measurement information is transmitted to the control device 90. The cold water tank temperature sensor 38 measures the temperature of the cold water tank 82, and the measurement information is transmitted to the control device 90.

[0043] The operation during adsorption heat non-recovery in the adsorption process will be described. The state during adsorption heat non-recovery in the adsorption process is shown in FIG. 3. In the state during adsorption heat non-recovery in the adsorption process, since it has already been cooled to a predetermined temperature (for example, 20°C) by the cold water line 111 in the previous stage, the control device 90 controls the inlet three-way valve 30a and the outlet three-way valve 30b to cut off the module 11 from both the cold water line 111 and the hot water line 112. In this state, carbon dioxide adsorption is performed from the atmosphere introduced by driving the fan 61 and the like.

[0044] As shown in FIG. 5, when the adsorption process starts, adsorption heat is generated, so the temperature of the adsorbent 12 in the module 11 gradually rises. When the temperature difference ΔT1 between the temperature of the cold water tank 82 obtained from the cold water tank temperature sensor 38 and the temperature of the adsorbent 12 obtained from the adsorbent temperature sensor 27 becomes equal to or higher than a predetermined value (first threshold value), the control device 90 controls the inlet three-way valve 30a to connect the cold water line 111 and the inlet-side flow path 33, and controls the outlet three-way valve 30b to connect the outlet-side flow path 34 and the cold water line 111, and starts adsorption heat recovery (the state in FIG. 4). Here, the first threshold value can be set as appropriate, but for example, it can be set to 5°C. Note that even during this adsorption heat recovery, the fan 61 continues to be driven, and carbon dioxide adsorption continues.

[0045] When the adsorption heat recovery starts, when the heat medium (cooling water) passes through the module 11, it recovers the adsorption heat and is heated, and the heated cooling water returns to the cooling water tank 82. This heated cooling water undergoes heat exchange in the heat exchanger 81, and the recovered adsorption heat is used for heating the warm water. In the initial stage of the adsorption heat recovery, the temperature difference (module inlet and outlet water temperature difference ΔT2) between the inlet temperature measured by the inlet temperature sensor 35 and the outlet temperature measured by the outlet temperature sensor 36 is large, but as the heat recovery progresses, this module inlet and outlet water temperature difference gradually becomes smaller. When this module inlet and outlet water temperature difference ΔT2 becomes equal to or less than a predetermined value (second threshold value), the control device 90 controls the inlet three-way valve 30a and the outlet three-way valve 30b to cut off the module 11 from both the cooling water line 111 and the warm water line 112 (the state in FIG. 3). Here, the second threshold value can be set as appropriate, for example, it can be set to 5°C. Then, when a predetermined time has elapsed since the start of adsorption, the adsorption process is terminated.

[0046] Next, with reference to FIG. 6, the switching timing of the start and end of the adsorption heat recovery will be described. FIG. 6 is a flowchart showing an example of the operation flow of the adsorption heat recovery by the carbon dioxide recovery device of the present embodiment.

[0047] When the adsorption process starts, in step S10, the control device 90 determines whether a certain time has elapsed since the start of the adsorption process. If a certain time has elapsed since the start of the adsorption process, the control device 90 ends the processing of the adsorption process (step S10: Yes). If a certain time has not elapsed since the start of the adsorption process, the control device 90 proceeds with the processing of the adsorption process to step S20 (step S10: No).

[0048] In step S20, the control device 90 applies outside air to the adsorbent 12 to adsorb carbon dioxide. In the adsorption process of this step S20, as shown in FIG. 5, the temperature of the adsorbent 12 gradually rises due to the adsorption heat.

[0049] In step S30, the control device 90 determines whether heat recovery adsorption is in progress. If heat recovery is in progress, the control device 90 advances the processing of the adsorption step to step S90 (step S30: Yes). If heat recovery is not in progress, the control device 90 advances the processing of the adsorption step to step S40 (step S30: No).

[0050] In step S40, the control device 90 determines whether the temperature difference ΔT1 between the temperature of the cold water tank 82 obtained from the cold water tank temperature sensor 38 and the temperature of the adsorbent 12 obtained from the adsorbent temperature sensor 27 is equal to or greater than a predetermined value (first threshold value). If ΔT1 is equal to or greater than the predetermined value (first threshold value), the control device 90 advances the processing of the adsorption step to step S50 (step S40: Yes). If ΔT1 is not equal to or greater than the predetermined value (first threshold value), the control device 90 advances the processing of the adsorption step to step S70 (step S40: No).

[0051] In step S50, the control device 90 makes a decision to perform adsorption heat recovery. In step S60, the control device 90 controls the inlet three-way valve 30a to connect the cold water line 111 and the inlet side flow path 33, and controls the outlet three-way valve 30b to connect the outlet side flow path 34 and the cold water line 111 to form a flow of cold water for adsorption heat recovery.

[0052] In step S70, the control device 90 makes a decision not to perform adsorption heat recovery. In step S80, the control device 90 controls the inlet three-way valve 30a and the outlet three-way valve 30b to both be in a fully closed state, and shuts off the module 11 from both the cold water line 111 and the hot water line 112.

[0053] In step S90, the control device 90 determines whether the temperature difference (module inlet and outlet water temperature difference ΔT2) between the inlet temperature measured by the inlet temperature sensor 35 and the outlet temperature measured by the outlet temperature sensor 36 is equal to or greater than a predetermined value (second threshold value). When ΔT2 is equal to or greater than the predetermined value (second threshold value), the control device 90 advances the processing of the adsorption step to step S50 (step S90: Yes). When ΔT2 is not equal to or greater than the predetermined value (second threshold value), the control device 90 advances the processing of the adsorption step to step S100 (step S90: No).

[0054] In step S100, the control device 90 determines to end the adsorption heat recovery and advances the processing of the adsorption step to step S80.

[0055] In the above-exemplified operation flow, in step S90, the control device 90 has been described as determining whether to end the adsorption heat recovery by determining whether the module inlet and outlet water temperature difference ΔT2 is equal to or greater than the second threshold value. Not limited to such an operation, for example, when the difference between the temperature of the adsorbent 12 and the temperature of the cooling medium in the cold water tank 82 becomes smaller than the third threshold value, the adsorption heat recovery may be ended (stopping the flow of the cooling medium to the module).

[0056] As described above, in the carbon dioxide recovery device 1 of the present embodiment, in the adsorption step, when the difference between the temperature of the adsorbent 12 and the temperature of the cooling medium in the cold water tank 82 is equal to or greater than the first threshold value, the cooling medium is flowed through the module 11 to perform heat recovery, so that the adsorption heat that has not been conventionally utilized can be effectively utilized, and the amount of heat required for heat exchange in the heat exchanger 81 can be supplemented. Therefore, it is possible to provide a highly energy-efficient carbon dioxide recovery device 1 that can suppress the energy required for raising the temperature of the adsorbent 12 in the desorption step.

[0057] Further, when the difference between the inlet temperature at the position where the cooling medium enters the module 11 and the outlet temperature at the position where the cooling medium exits the module 11 becomes smaller than the second threshold value, the carbon dioxide recovery device 1 stops flowing the cooling medium through the module 11. Thereby, the module cooling performance of the entire carbon dioxide recovery device can be maintained.

[0058] Also, the carbon dioxide recovery device 1 may be configured to stop flowing the cooling medium through the module 11 when the difference between the temperature of the adsorbent 12 and the temperature of the cooling medium in the cold water tank 82 becomes smaller than the third threshold value. Thereby, the module cooling performance of the entire carbon dioxide recovery device can be maintained.

[0059] As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above-described embodiments and modifications. Also, the effects described in the above embodiments are merely a list of preferable effects and are not limited to those described in the above embodiments.

Explanation of Reference Numerals

[0060] 1 Carbon dioxide recovery device 11 Module 12 Adsorbent 30 Three-way valve 61 Fan 62 Vacuum pump 63 Carbon dioxide recovery pump 80 Heat exchanger 81 Heat exchanger 82 Cold water tank 83 Hot water tank

Claims

1. A module that has an adsorbent inside, performs an adsorption step of sucking a gas containing carbon dioxide into the adsorbent to adsorb the carbon dioxide, and a desorption step of desorbing the carbon dioxide from the adsorbent by heating the adsorbent in a state where the periphery of the adsorbent is depressurized; A tank that stores a cooling medium for cooling the module; Comprising; In the adsorption step, when the difference between the temperature of the adsorbent and the temperature of the cooling medium in the tank is equal to or higher than a first threshold value, the cooling medium is caused to flow into the module to perform heat recovery. A carbon dioxide recovery device.

2. In the carbon dioxide recovery device according to Claim 1, When the difference between the inlet temperature at the position where the cooling medium enters the module and the outlet temperature at the position where the cooling medium exits the module becomes smaller than a second threshold value, the flow of the cooling medium into the module is stopped. A carbon dioxide recovery device.

3. In the carbon dioxide recovery device according to Claim 1 or Claim 2, When the difference between the temperature of the adsorbent and the temperature of the cooling medium in the tank becomes smaller than a third threshold value, the flow of the cooling medium into the module is stopped. A carbon dioxide recovery device.

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