Carbon dioxide recovery device

Abstract

To provide a carbon dioxide recovery device which can suppress deterioration of an adsorption material caused by oxidation, even if cut-off of an adsorption material from atmosphere is cancelled in emergency.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 12 in a decompressed state, and thereby desorbing the carbon dioxide from the adsorption material 12; a first carbon dioxide tank 66 for storing the carbon dioxide recovered from the module 11 through the adsorption step and the desorption step; an antioxidation gas tank (second carbon dioxide tank 68 and inert gas tank 69) for storing antioxidation gas for preventing oxidation of the adsorption material 12; and a control device 90 for supplying antioxidation gas from the antioxidation tank to the module 11 during execution of the desorption step, when having detected that it is emergency.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a carbon dioxide capture device. [Background technology]

[0002] Conventionally, there are known techniques for recovering predetermined components from the atmosphere, exhaust gas, etc. Patent Document 1, for example, describes this type of technique.

[0003] Patent Document 1 relates to an exhaust gas treatment facility that removes ash from exhaust gas emitted from a waste treatment facility and removes dioxins by adding activated carbon to the exhaust gas. Patent Document 1 describes a method in which an inert gas is blown into collected dust ash containing a powder adsorbent discharged from a dust collector to suppress heat generation due to oxidation of the powder adsorbent. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-226353 Summary of the Invention [Problem to be solved by the invention]

[0005] In a carbon dioxide capture device, carbon dioxide is captured by carrying out an adsorption process in which a module holding an adsorbent sucks in gases such as air containing carbon dioxide and adsorbs them into the adsorbent, and a desorption process in which the adsorbent is depressurized and heated to desorb the adsorbed carbon dioxide.

[0006] When the adsorbent is exposed to the atmosphere at high temperatures, it oxidizes and its adsorption performance deteriorates. During the desorption process in normal operation, the valve is controlled to isolate the adsorbent from the atmosphere, but in the event of a power outage or malfunction, the valve may open, releasing the adsorbent's isolation from the atmosphere. During the desorption process, the module is in a high-temperature state, so if the atmosphere enters the interior of the module, the adsorbent will deteriorate.

[0007] An object of the present invention is to provide a carbon dioxide capture device that can suppress deterioration of the adsorbent due to oxidation even if the adsorbent is released from the atmosphere in an emergency. [Means for solving the problem]

[0008] (1) The present invention provides a carbon dioxide capture device (e.g., carbon dioxide capture devices 1 and 1a described later) that includes an adsorbent (e.g., adsorbent 12 described later) and a module (e.g., module 11 described later) that performs an adsorption process in which a gas containing carbon dioxide is drawn into the adsorbent to adsorb the carbon dioxide, and a desorption process in which the adsorbent is heated under reduced pressure to desorb the carbon dioxide from the adsorbent; a carbon dioxide tank (e.g., first carbon dioxide tank 66 described later) that stores the carbon dioxide recovered from the module through the adsorption process and the desorption process; an antioxidant gas tank (e.g., second carbon dioxide tank 68 and inert gas tank 69 described later) that stores an antioxidant gas that prevents oxidation of the adsorbent; and a control device (e.g., control device 90 described later) that supplies the antioxidant gas from the antioxidant gas tank to the module performing the desorption process when an emergency is detected.

[0009] (2) In the carbon dioxide recovery device described in (1) above, the antioxidant gas tank may be an inert gas tank that stores an inert gas as the antioxidant gas.

[0010] (3) In the carbon dioxide recovery device described in (1) above, the antioxidant gas tank may be a second carbon dioxide tank that stores the carbon dioxide recovered from the module as the antioxidant gas.

[0011] (4) In the carbon dioxide recovery system according to any one of (1) to (3) above, the antioxidant gas tank stores the antioxidant gas at a pressure equal to or higher than a certain pressure.

[0012] (5) In the carbon dioxide recovery device described in any one of (1) to (3) above, the control device stops the supply of the antioxidant gas when the internal pressure of the module that supplies the antioxidant gas reaches a certain level or higher. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a carbon dioxide capture device that can suppress deterioration of the adsorbent due to oxidation even if the adsorbent is released from the isolation of the adsorbent from the atmosphere in an emergency. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic diagram showing a configuration relating to gas flow in a carbon dioxide capture device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing the configuration of a module of the carbon dioxide capture device of the present embodiment. [Figure 3] 4 is a flowchart showing the flow of processing for emergency control of the carbon dioxide capture device of the present embodiment. [Figure 4] FIG. 10 is a schematic diagram showing a configuration relating to gas flow in a modified carbon dioxide capture device. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] <Overall structure> Fig. 1 is a schematic diagram showing the configuration related to gas flow in a carbon dioxide capture device 1 according to one embodiment of the present invention. Fig. 2 is a schematic diagram showing the configuration of a module 11 of the carbon dioxide capture device 1 of this embodiment.

[0017] The carbon dioxide capture device 1 of this embodiment is applied to, for example, direct air capture (DAC) technology that captures carbon dioxide from the atmosphere in order to reduce the carbon dioxide concentration in the atmosphere. The carbon dioxide captured by the carbon dioxide capture device 1 is stored underground or reused as fuel or material.

[0018] As shown in Figures 1 and 2, the carbon dioxide capture device 1 of this embodiment includes a module unit 10, a fan 61, a vacuum pump 62, a carbon dioxide capture pump 63, an intercooler 64, a separator 65, a first carbon dioxide tank 66, a compressor 67, a second carbon dioxide tank 68, an inert gas tank 69, a heat exchange device 80 (not shown in Figure 1), and a control device 90 (not shown in Figure 1).

[0019] The carbon dioxide recovery device 1 also includes an adsorption line 101, a vacuum line 102, a carbon dioxide line 103, a circulation line 104, a connection line 105, a junction line 106, and an inert gas supply line 107 as gas flow paths.

[0020] In the following description, the flow of gas from "intake" to "exhaust" and the flow of gas from the module 11 to the first carbon dioxide tank 66 and the second carbon dioxide tank 68 are referred to as flow from upstream to downstream.

[0021] The module unit 10 is configured by arranging a plurality of modules 11 in parallel that adsorb carbon dioxide. In this embodiment, a total of 16 modules 11 are arranged by a pair of left and right module units 10.

[0022] 2 is a schematic diagram showing the configuration of a module 11 of the carbon dioxide capture device 1 of this embodiment. The module 11 is a carbon dioxide capture module including an adsorbent 12, a first valve 21, a second valve 22, a third valve 23, a fourth valve 24, a pressure sensor 25, a carbon dioxide sensor 26, and a temperature sensor 27.

[0023] The adsorbent 12 is disposed inside the module 11 to adsorb carbon dioxide. The adsorbent 12 is a particulate material that has the property of adsorbing carbon dioxide at low temperatures (for example, in the range of -30°C to 50°C) and desorbing (releasing) carbon dioxide at high temperatures (for example, in the range of 50°C to 110°C) when the ambient carbon dioxide concentration is low. Examples of such adsorbent 12 include solid amine carbon dioxide adsorbents formed by supporting amines on porous materials such as silica.

[0024] The first valve 21 is an on-off valve arranged at the connection between the module 11 and a carbon dioxide line 103 that captures carbon dioxide. A carbon dioxide capture pump 63 is arranged in the carbon dioxide line 103. The second valve 22 is an on-off valve arranged at the connection between the module 11 and a vacuum line 102 in which a vacuum pump 62 is arranged. The third valve 23 is an on-off valve arranged at the inlet that takes in air and the like into the module 11. The fourth valve 24 is an on-off valve arranged at the connection between the adsorption line 101 and the module 11.

[0025] 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 a control device 90. The first valve 21, the second valve 22, the third valve 23, and the fourth valve 24 are each configured by, for example, a normally open butterfly valve.

[0026] The pressure sensor 25 measures the internal pressure of the module 11. The carbon dioxide sensor 26 measures the carbon dioxide concentration inside the module 11. The temperature sensor 27 measures the temperature of the adsorbent 12. Measurement information from the pressure sensor 25, the carbon dioxide sensor 26, and the temperature sensor 27 is sent to the control device 90.

[0027] Returning to FIG. 1 , the adsorption line 101 and the fan 61 will be described. The adsorption line 101 branches off and is connected to each of the modules 11. The fan 61 is located where the branched portions of the adsorption line 101 converge. When driven, the fan 61 generates a gas flow from "intake" to "exhaust" through the adsorption line 101 to the module 11. This supplies atmospheric air into the module 11. A carbon dioxide concentration sensor 611, a humidity sensor 612, and a temperature sensor 613 are located in the gas exhaust portion of the adsorption line 101, and measure the carbon dioxide, humidity, and temperature exhausted from the adsorption line 101. Measurement information from the carbon dioxide concentration sensor 611, the humidity sensor 612, and the temperature sensor 613 is sent to the control device 90.

[0028] The vacuum line 102 is branched and connected to each of the modules 11. The vacuum pump 62 is disposed at the point where the branched portions of the vacuum line 102 converge. When the vacuum pump 62 is driven, it sucks gas from inside the module 11 through the vacuum line 102, bringing the inside of the module 11 into a vacuum state or close to a vacuum state.

[0029] The carbon dioxide line 103 branches off and is connected to each of the modules 11. At the point where the branched portions of the carbon dioxide line 103 converge, a carbon dioxide capture pump 63, an intercooler 64, a separator 65, a first carbon dioxide tank 66, a compressor 67, and a second carbon dioxide tank 68 are arranged.

[0030] The carbon dioxide capture pump 63 applies suction force to send the carbon dioxide flowing through the carbon dioxide line 103 to the first carbon dioxide tank 66. A one-way valve 631 is arranged upstream of the carbon dioxide capture pump 63 in the carbon dioxide line 103. This prevents gas from flowing back from the intercooler 64 side to the module 11 side.

[0031] The intercooler 64 is an intermediate cooling device that cools the high-temperature gas containing carbon dioxide recovered from the module 11 and separates it into gas and liquid.

[0032] The water separated into gas and liquid in intercooler 64 is collected in separator 65. Separator 65 is also provided with a first valve 651 and a second valve 652, and first valve 651 opens and closes a passage that connects the gas phase of separator 65 with the atmosphere. Second valve 652 opens and closes a passage that connects the liquid phase of separator 65 with the atmosphere.

[0033] The first carbon dioxide tank 66 stores the carbon dioxide recovered through the carbon dioxide line 103. A tank valve 661 is arranged upstream of the first carbon dioxide tank 66 on the carbon dioxide line 103. The tank valve 661 is controlled to open and close by the control device 90. In addition, various sensors such as a pressure sensor 662, a flow rate sensor 663, a humidity sensor 664, a temperature sensor 665, and a carbon dioxide concentration sensor 666 are arranged between the tank valve 661 and the first carbon dioxide tank 66 on the carbon dioxide line 103.

[0034] In addition to the carbon dioxide line 103, a circulation line 104 that returns ballast to the carbon dioxide capture pump 63 is connected to the first carbon dioxide tank 66. A flow rate sensor 667 is disposed in the circulation line 104. Also, the first carbon dioxide tank 66 is provided with a pressure release valve 668 that releases pressure when the pressure reaches or exceeds a predetermined pressure.

[0035] The compressor 67 is disposed between the first carbon dioxide tank 66 and the second carbon dioxide tank 68 in the carbon dioxide line 103. The compressor 67 compresses the carbon dioxide stored in the first carbon dioxide tank 66 and sends it to the second carbon dioxide tank 68.

[0036] The second carbon dioxide tank 68 stores the carbon dioxide compressed by the compressor 67 at a certain pressure or higher (for example, 980 kPa). In addition to the carbon dioxide line 103, the second carbon dioxide tank 68 is connected to a connection line 105 that is connected to a connection device, and to a confluence line 106 that confluences with the carbon dioxide line 103. The connection device is, for example, an algae cultivation device, a fuel synthesis device, an underground storage device, etc. A connection valve 681 is arranged in the connection line 105, and a confluence valve 682 is arranged in the confluence line 106. The opening and closing of the connection valve 681 and the confluence valve 682 is controlled by the control device 90.

[0037] Next, the inert gas tank 69 will be described. The inert gas tank 69 stores N2 as an inert gas supplied from an N2 gas cylinder 691 at a certain pressure or higher (for example, 980 kPa). A gas cylinder valve 692 is arranged between the inert gas tank 69 and the N2 gas cylinder 691. Also, the inert gas tank 69 is arranged with a pressure release valve 693 that releases the pressure when the pressure reaches a predetermined pressure or higher. A pressure sensor 694 is arranged inside the inert gas tank 69. Pressure information measured by the pressure sensor 694 is sent to the control device 90.

[0038] The inert gas tank 69 is connected to the carbon dioxide line 103 via an inert gas supply line 107. An inert gas valve 695 is disposed on the inert gas supply line 107. The inert gas valve 695 is controlled to open and close by the control device 90.

[0039] The heat exchanger 80 supplies thermal energy to heat the interior of each module 11 of the module unit 10 to a predetermined temperature when the module 11 performs the desorption process. The heat exchanger 80 also recovers unnecessary thermal energy when the module 11 performs the adsorption process. The heat exchanger 80 is composed of, for example, piping connected to each module 11 and a heat pump. The piping is a flow path through which a heat medium flows. The heat exchanger 80 supplies thermal energy to each module 11 and recovers unnecessary thermal energy using the heat medium passing through the piping.

[0040] The control device 90 controls the operation of each part of the carbon dioxide capture device 1. The control device 90 controls the operation of devices used for adsorption and desorption of carbon dioxide, such as driving and stopping. The control device 90 controls the opening and closing of the first valve 21, second valve 22, third valve 23, and fourth valve 24 provided in each module 11, as well as the opening and closing of the separator first valve 651, separator second valve 652, tank valve 661, confluence valve 682, and inert gas valve 695. The control device 90 also controls the driving of the fan 61, vacuum pump 62, carbon dioxide capture pump 63, compressor 67, etc.

[0041] The control device 90 is, for example, a computer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The control device 90 may be configured as one device or as multiple devices.

[0042] <Carbon dioxide capture> Next, we will explain the control for capturing carbon dioxide by the control device 90. The carbon dioxide capture device 1 alternately performs an adsorption process in which the adsorbent 12 in the module 11 adsorbs carbon dioxide in gases such as the air that has been taken in, and a desorption process in which the carbon dioxide adsorbed by the adsorbent 12 is desorbed, and compresses the desorbed carbon dioxide and stores it in the first carbon dioxide tank 66 and the second carbon dioxide tank 68, thereby removing and capturing carbon dioxide from the air.

[0043] The adsorption process is a process in which carbon dioxide is adsorbed by the adsorbent 12 in the module 11. In the adsorption process, the first valve 21, the third valve 23, and the fourth valve 24 of the module 11 are opened, and the second valve 22 is closed. The fan 61 is driven to generate a gas flow from upstream to downstream, and a gas containing carbon dioxide (e.g., the atmosphere) is drawn in through the third valve 23. The drawn in gas passes through the adsorbent 12 in the module 11. At this time, the temperature inside the module 11 is room temperature (25°C), and the carbon dioxide in the gas is adsorbed by 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.

[0044] 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 is operated to draw air into the interior of the module 11 and reduce the pressure to create a vacuum or near-vacuum state. At the same time, the heat exchanger 80 causes a heat medium, which serves as a heat source, to flow through the module 11 to supply thermal energy and heat the module 11. As a result, the adsorbent 12 is also heated to a predetermined temperature (e.g., 90°C) sufficient for the desorption process, and the carbon dioxide adsorbed in the adsorbent 12 is desorbed. 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 capture pump 63 is driven. The carbon dioxide desorbed through the carbon dioxide line 103 is stored in the first carbon dioxide tank 66 and the second carbon dioxide tank 68.

[0045] In this embodiment, the control device 90 controls each of the 16 modules 11 so that 12 of the 16 modules 11 perform the adsorption process and four of the 16 modules 11 perform the desorption process. Therefore, while the carbon dioxide capture device 1 is in operation, the four modules 11 performing the desorption process are in a high temperature state.

[0046] <Emergency Control> Next, emergency control for preventing oxidation of the adsorbent 12 in an emergency such as a power outage or a malfunction will be described. The emergency control will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the flow of processing for emergency control in the carbon dioxide recovery device 1 of this embodiment.

[0047] As a premise for emergency control, it is assumed that the inside of the module 11 during the desorption step in normal operation is under negative pressure due to the reduced pressure of the vacuum pump 62, and that the temperature of the adsorbent 12 is kept at a certain high temperature or higher by the heat exchanger 80. Furthermore, during normal operation, the first valve 21, the tank valve 661, the separator first valve 651, and the separator second valve 652 are controlled to an open or closed state depending on the operating conditions. It is assumed that the inert gas valve 695 is controlled to a closed state, and the internal pressure of the inert gas tank 69 is maintained at a certain level or higher.

[0048] In step S1, the control device 90 determines whether or not it has received an operation signal indicating an emergency. The operation signal indicating an emergency may be a signal indicating a power outage such as a power loss, a signal indicating a malfunction, or a signal specifying emergency control by an operator. The control device 90 continues monitoring until it receives an operation signal indicating an emergency (step S1; No). When the control device 90 receives an operation signal indicating an emergency, it proceeds to step S2 (step S1; Yes).

[0049] In step S2, an uninterruptible power supply (UPS) supplies power to each component of the carbon dioxide capture device 1. This causes the control device 90 to start emergency control of the control system.

[0050] In step S3, the control device 90 controls to close all of the tank valve 661, the separator first valve 651, and the separator second valve 652. The upstream side of the first carbon dioxide tank 66 in the carbon dioxide line 103 is closed.

[0051] In step S4, the control device 90 controls each valve of the module 11 that is the control target and that is performing the desorption process. In this embodiment, the control device 90 maintains the fourth valve 24 of the adsorption line 101 in a closed state, and controls the second valve 22 of the vacuum line 102 and the third valve 23 that communicates with the atmosphere to be in a closed state.

[0052] In step S5, the control device 90 performs control to start the supply of antioxidant gas. In this embodiment, the control device 90 controls the inert gas valve 695 of the inert gas supply line 107 to be in an open state. This allows the inert gas tank 69 and the carbon dioxide line 103 to communicate with each other.

[0053] In step S6, the control device 90 controls the first valve 21 of the carbon dioxide line 103 of the module 11 to be controlled to an open state, thereby opening the carbon dioxide line 103. Since the inside of the inert gas tank 69 is maintained at a certain pressure or higher, N2 as an inert gas flows into the inside of the module 11, which is in a vacuum state or a near-vacuum state, through the inert gas supply line 107 and the carbon dioxide line 103.

[0054] In step S7, the control device 90 refers to the measurement information of the pressure sensor 25 of the module 11 to be controlled and determines whether the internal pressure of the module 11 has reached a predetermined level or higher. The control device 90 continues monitoring until the internal pressure of the module 11 reaches a predetermined level or higher (step S7; No). When the internal pressure of the module 11 reaches a predetermined level or higher, the control device 90 proceeds to step S8 (step S7; Yes).

[0055] In step S8, the control device 90 controls the first valve 21 of the carbon dioxide line 103 of the module 11 to be controlled to a closed state, thereby closing the carbon dioxide line 103. Because the internal pressure of the module 11 is equal to or greater than a predetermined level, the pressure difference with the atmospheric pressure also becomes small. Even if the fourth valve 24 is opened and the inside of the module 11 is exposed to the atmosphere, it is possible to avoid a situation in which the components of the module 11 are damaged by a pressure change.

[0056] In step S9, the control device 90 refers to the measurement information of the temperature sensor 27 of the module 11 and determines whether the temperature of the adsorbent 12 of the module 11 has fallen below a certain temperature. The control device 90 continues monitoring while maintaining the above-mentioned controls until the temperature falls below the certain temperature (step S9; No). When the temperature falls below the certain temperature, the control device 90 ends this flow (step S9; Yes).

[0057] 3, a configuration has been described in which N2 inert gas is supplied as an antioxidant gas to the desorption module 11. However, if a sufficient amount of carbon dioxide is stored in the second carbon dioxide tank 68, the stored carbon dioxide may be supplied as an antioxidant gas to the desorption module 11. In this case, in step S5, the control device 90 controls the link valve 681 to a closed state and the confluence valve 682 to an open state, thereby connecting the second carbon dioxide tank 68 with the carbon dioxide line 103. Then, in step S6, the control device 90 controls the first valve 21 of the carbon dioxide line 103 to an open state. Because the interior of the second carbon dioxide tank 68 is maintained at a certain pressure or higher, carbon dioxide as an antioxidant gas flows into the interior of the module 11, which is in a vacuum or near-vacuum state, through the confluence line and the carbon dioxide line 103. Note that other control procedures are the same as those in the case of supplying N2 inert gas as an antioxidant gas to the desorption module 11.

[0058] Furthermore, the control device 90 may be configured to switch the type of antioxidant gas depending on the amount of N stored in the inert gas tank 69 and the amount of carbon dioxide stored in the second carbon dioxide tank 68. For example, when the amount of carbon dioxide stored in the second carbon dioxide tank 68 is small at the start of operation, the control device 90 may be configured to supply the inert gas in the inert gas tank 69 to the module 11 as the antioxidant gas, and when the amount of inert gas stored in the inert gas tank 69 becomes low, the control device 90 may be configured to supply the carbon dioxide in the second carbon dioxide tank 68 to the module 11 as the antioxidant gas.

[0059] As described above, the carbon dioxide recovery device 1 of this embodiment has an adsorbent 12 inside, and includes a module 11 that performs an adsorption process in which gas containing carbon dioxide is drawn into the adsorbent 12 to adsorb the carbon dioxide, and a desorption process in which carbon dioxide is desorbed from the adsorbent 12 by heating the adsorbent 12 under reduced pressure; a first carbon dioxide tank 66 that stores the carbon dioxide recovered from the module 11 through the adsorption process and desorption process; an antioxidant gas tank (second carbon dioxide tank 68, inert gas tank 69) that stores antioxidant gas that prevents oxidation of the adsorbent 12; and a control device 90 that, when an emergency is detected, supplies antioxidant gas from the antioxidant tank to the module 11 that is performing the desorption process.

[0060] As a result, in the event of an emergency such as a power outage or malfunction, an antioxidant gas such as an inert gas or carbon dioxide is supplied to the module 11 that executes the desorption step, and the antioxidant gas fills the area around the adsorbent 12 inside the module 11. Therefore, even if the fourth valve 24 that connects to the atmosphere is opened due to a power outage or malfunction, the atmosphere will not enter the inside of the module 11, and it is possible to avoid a situation in which the adsorbent 12 at a high temperature comes into contact with the atmosphere and deteriorates.

[0061] In this embodiment, the antioxidant gas tank is an inert gas tank 69 that stores an inert gas as the antioxidant gas. This allows the inert gas, such as N2 gas, to prevent oxidation of the adsorbent 12. When using recovered carbon dioxide as the antioxidant gas, even if the amount of carbon dioxide stored is insufficient, the separately prepared inert gas can reliably prevent oxidation of the adsorbent 12.

[0062] In this embodiment, the antioxidant gas tank is a second carbon dioxide tank 68 that stores the carbon dioxide recovered from the module 11 as antioxidant gas. This allows the recovered carbon dioxide to be used, making it possible to realize a configuration that supplies antioxidant gas in an emergency at low cost.

[0063] In this embodiment, the second carbon dioxide tank 68 and the inert gas tank 69 store antioxidant gas at a pressure equal to or higher than a certain level. This allows antioxidant gas to be supplied by pressure difference simply by connecting a path to the module 11, which is in a vacuum state or a near-vacuum state. Since there is no need to use a driving device such as a carbon dioxide capture pump, power consumption in an emergency can be reduced.

[0064] In this embodiment, the control device 90 stops the supply of antioxidant gas (inert gas, carbon dioxide) when the internal pressure of the module 11 that supplies the antioxidant gas reaches a certain level or higher. This prevents the interior of the module 11 from communicating with the atmosphere in a vacuum or near-vacuum state, thereby preventing damage to the structure of the module 11 due to a pressure difference.

[0065] The configuration of the carbon dioxide capture apparatus 1 is not limited to that of the above embodiment. Fig. 4 is a schematic diagram showing the configuration related to the gas flow of a modified carbon dioxide capture apparatus 1a. The modified carbon dioxide capture apparatus 1a is obtained by omitting the second carbon dioxide tank 68, the connection line 105, the connection valve 681, the merging line 106, the merging valve 682, and other components from the carbon dioxide capture apparatus 1 of the first embodiment. The other configurations are the same as those of the above embodiment.

[0066] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and modifications. Furthermore, the effects described in the above embodiments are merely preferred effects, and the present invention is not limited to those described in the above embodiments. [Explanation of symbols]

[0067] 1. Carbon dioxide capture device 11 Modules 12 Adsorbent 21 First valve 22 Second valve 23 Third valve 24 4th valve 66 Carbon Dioxide Tank No. 1 68 Second Carbon Dioxide Tank 69 Inert Gas Tank 695 Inert Gas Valve

Claims

1. a module having an adsorbent therein, which performs an adsorption step of drawing a gas containing carbon dioxide into the adsorbent to adsorb the carbon dioxide, and a desorption step of heating the adsorbent under a reduced pressure around the adsorbent to desorb the carbon dioxide from the adsorbent; a carbon dioxide tank that stores the carbon dioxide recovered from the module after the adsorption step and the desorption step; an antioxidant gas tank for storing an antioxidant gas that prevents oxidation of the adsorbent; a control device that, upon detecting an emergency, supplies the antioxidant gas from the antioxidant gas tank to the module that is performing the desorption process; A carbon dioxide capture device comprising:

2. The antioxidant gas tank is an inert gas tank that stores an inert gas as the antioxidant gas. The carbon dioxide capture device according to claim 1 .

3. the antioxidant gas tank is a second carbon dioxide tank that stores the carbon dioxide recovered from the module as the antioxidant gas; The carbon dioxide capture device according to claim 1 .

4. The antioxidant gas tank stores the antioxidant gas at a pressure equal to or higher than a certain pressure. The carbon dioxide recovery device according to any one of claims 1 to 3.

5. the control device stops the supply of the antioxidant gas when the internal pressure of the module that supplies the antioxidant gas reaches a certain level or higher. The carbon dioxide recovery device according to any one of claims 1 to 3.

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