Carbon dioxide recovery device

Abstract

The problem to be solved by the present invention is to provide a carbon dioxide recovery device capable of suppressing deterioration of an adsorbent due to oxidation even if the isolation between the adsorbent and the atmosphere is released in an emergency. In order to solve the problem, a carbon dioxide recovery device (1) is provided with: a module (11) having an adsorbent (12) therein, the module (11) executing an adsorption step in which a gas containing carbon dioxide is sucked into the adsorbent (12), the adsorbent (12) adsorbs carbon dioxide, and a desorption step in which the adsorbent (12) desorbs carbon dioxide; a desorption step for desorbing carbon dioxide from the adsorbent (12) by heating the periphery of the adsorbent (12) in a reduced pressure state; a first carbon dioxide tank (66) for storing carbon dioxide recovered from the module (11) through an adsorption step and a desorption step; an antioxidant gas tank (a second carbon dioxide tank (68), an inert gas tank (69)) for storing an antioxidant gas for preventing oxidation of the adsorbent (12); and a control device (90) that, when an emergency situation is detected, supplies an antioxidant gas from the antioxidant tank to the module (11) in which the desorption step is being performed.

Description

Technical Field

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

[0002] Conventionally, a technique for recovering a specific component from the atmosphere, exhaust gas, etc. has been known. As a document describing such a technique, for example, there is Patent Document 1.

[0003] Patent Document 1 relates to an exhaust gas treatment device that removes ash from exhaust gas discharged from a waste treatment facility and adds activated carbon to the exhaust gas to remove dioxins. In Patent Document 1, it is described that an inert gas is blown into the dust containing the powder adsorbent discharged from the dust collector to suppress the oxidative heat generation of the powder adsorbent.

[0004] [Prior Art Documents]

[0005] (Patent Document)

[0006] Patent Document 1: Japanese Patent Laid-Open No. 11-226353 Summary of the Invention

[0007] [Problems to be Solved by the Invention]

[0008] However, in a carbon dioxide recovery device, a module holding an adsorbent performs an adsorption process and a desorption process to recover carbon dioxide. The adsorption process attracts and adsorbs a gas such as air containing carbon dioxide to the adsorbent, and the desorption process depressurizes and heats the adsorbent to desorb the adsorbed carbon dioxide.

[0009] If the adsorbent comes into contact with the atmosphere in a high-temperature state, it will oxidize, resulting in a decrease in adsorption performance. In the desorption process during normal operation, the valve is controlled to isolate the adsorbent from the atmosphere, but there is a concern that in the event of a power outage or a failure, the valve will open and the isolation of the adsorbent from the atmosphere will be released. In the desorption process, it is in a high-temperature state. Therefore, if the atmosphere invades the inside of the module, the adsorbent will deteriorate.

[0010] An object of the present invention is to provide a carbon dioxide recovery device that can suppress the deterioration of the adsorbent due to oxidation even when the isolation of the adsorbent from the atmosphere is released in an emergency.

[0011] [Means for Solving the Problems]

[0012] (1) The present invention relates to a carbon dioxide recovery device (for example, the carbon dioxide recovery devices 1 and 1a described hereinafter), comprising: a module (for example, the module 11 described hereinafter) having an adsorbent (for example, the adsorbent 12 described hereinafter) inside, the module performing an adsorption process and a desorption process, the adsorption process being to attract a gas containing carbon dioxide to the aforementioned adsorbent and cause the adsorbent to adsorb the aforementioned carbon dioxide, and the desorption process being to desorb the aforementioned carbon dioxide from the adsorbent by heating the periphery of the adsorbent under a reduced pressure state; a carbon dioxide tank (for example, the first carbon dioxide tank 66 described hereinafter) for storing the carbon dioxide recovered from the aforementioned module through the aforementioned adsorption process and the aforementioned desorption process; an antioxidant gas tank (for example, the second carbon dioxide tank 68 and the inert gas tank 69 described hereinafter) for storing an antioxidant gas for preventing oxidation of the aforementioned adsorbent; and a control device (for example, the control device 90 described hereinafter) that supplies the aforementioned antioxidant gas from the aforementioned antioxidant gas tank to the aforementioned module that is performing the aforementioned desorption process if an emergency is detected.

[0013] (2) In the carbon dioxide recovery device according to the above (1), the aforementioned antioxidant gas tank may be an inert gas tank for storing an inert gas as the aforementioned antioxidant gas.

[0014] (3) In the carbon dioxide recovery device according to the above (1), the aforementioned antioxidant gas tank may be a second carbon dioxide tank for storing the carbon dioxide recovered from the aforementioned module as the aforementioned antioxidant gas.

[0015] (4) In the carbon dioxide recovery device according to any one of the above (1) to (3), the aforementioned antioxidant gas tank stores the aforementioned antioxidant gas at a certain pressure or higher.

[0016] (5) In the carbon dioxide recovery device according to any one of the above (1) to (3), the aforementioned control device stops supplying the aforementioned antioxidant gas when the internal pressure of the aforementioned module where the aforementioned antioxidant gas is supplied is at a certain pressure or higher.

[0017] (Advantages of the Invention)

[0018] According to the present invention, a carbon dioxide recovery device can be provided that can suppress deterioration of the adsorbent due to oxidation even when the isolation between the adsorbent and the atmosphere is released during an emergency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram showing the configuration related to the flow of gas in the carbon dioxide recovery device according to an embodiment of the present invention.

[0020] Figure 2 It is a schematic diagram showing the configuration of the module of the carbon dioxide recovery device of the present embodiment.

[0021] Figure 3 is a flowchart showing the processing flow of the emergency control of the carbon dioxide recovery device according to the present embodiment.

[0022] Figure 4 is a schematic diagram showing the configuration related to the gas flow of the carbon dioxide recovery device according to the modified example. Detailed Embodiments

[0023] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0024] <Overall Configuration>

[0025] Figure 1 is a schematic diagram showing the configuration related to the gas flow of the carbon dioxide recovery device 1 according to an embodiment of the present invention. Figure 2 is a schematic diagram showing the configuration of the module 11 of the carbon dioxide recovery device 1 according to the present embodiment.

[0026] The carbon dioxide recovery device 1 according to the present embodiment is applied, for example, to a direct air capture (DAC) technology for recovering carbon dioxide from the atmosphere 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.

[0027] As Figure 1 and Figure 2 shown, the carbon dioxide recovery device 1 according to the present embodiment includes a module unit 10, a fan 61, a vacuum pump 62, a carbon dioxide recovery 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 ( Figure 1 not shown in Figure 1 ) and a control device 90 (

[0028] not shown in

[0029] In addition, the carbon dioxide recovery device 1 includes an adsorption pipeline 101, a vacuum pipeline 102, a carbon dioxide pipeline 103, a circulation pipeline 104, a cooperation pipeline 105, a confluence pipeline 106, and an inert gas supply pipeline 107 as gas flow paths.

[0030] The module unit 10 is constituted by arranging a plurality of modules 11 for adsorbing carbon dioxide in parallel. In the present embodiment, a total of 16 modules 11 are arranged by means of a pair of left and right module units 10.

[0031] Figure 2 It is a schematic diagram showing the configuration of the module 11 of the carbon dioxide recovery device 1 of the present embodiment. The module 11 is a carbon dioxide recovery module, and includes 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.

[0032] The adsorbent 12 is disposed inside the module 11 to adsorb carbon dioxide. The adsorbent 12 is a granular member and has the following properties: it adsorbs carbon dioxide in a low-temperature state (for example, in the range of -30°C to 50°C), and desorbs (releases) carbon dioxide in a high-temperature state (for example, in the range of 50°C to 110°C) and when the concentration of carbon dioxide in the surroundings is low. As such an adsorbent 12, for example, a solid amine carbon dioxide adsorbent formed by supporting an amine on a porous material such as silica can be cited.

[0033] The first valve 21 is a switching valve disposed at the connection portion of the carbon dioxide pipeline 103 for recovering carbon dioxide and the module 11. A carbon dioxide recovery pump 63 is disposed on the carbon dioxide pipeline 103. The second valve 22 is a switching valve disposed at the connection portion of the vacuum pipeline 102 provided with a vacuum pump 62 and the module 11. The third valve 23 is a switching valve disposed at the inlet for sucking air or the like into the inside of the module 11. The fourth valve 24 is a switching valve disposed at the connection portion of the adsorption pipeline 101 and the module 11.

[0034] The switching of the first valve 21, the second valve 22, the third valve 23, and the fourth valve 24 is all controlled by the control device 90. The first valve 21, the second valve 22, the third valve 23, and the fourth valve 24 are, for example, butterfly valves that are normally open.

[0035] 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. The measurement information of the pressure sensor 25, the carbon dioxide sensor 26, and the temperature sensor 27 is sent to the control device 90.

[0036] Return Figure 1, the adsorption pipeline 101 and the fan 61 will be described. The adsorption pipeline 101 branches and is respectively connected to each module 11. The fan 61 is arranged at the part where the branched parts of the adsorption pipeline 101 gather. The fan 61 is driven, so as to generate a gas flow from "suction" to "exhaust" to the module 11 through the adsorption pipeline 101. Thus, the atmosphere is supplied into the module 11. At the part where the gas of the adsorption pipeline 101 is discharged, a carbon dioxide concentration sensor 611, a humidity sensor 612 and a temperature sensor 613 are arranged to measure the carbon dioxide, humidity and temperature discharged from the adsorption pipeline 101. The measurement information of the carbon dioxide concentration sensor 611, the humidity sensor 612 and the temperature sensor 613 is sent to the control device 90.

[0037] The vacuum pipeline 102 branches and is respectively connected to each module 11. The vacuum pump 62 is arranged at the part where the branched parts of the vacuum pipeline 102 gather. The vacuum pump 62 is driven, so as to suck the gas inside the module 11 through the vacuum pipeline 102, making the inside of the module 11 in a vacuum state or close to a vacuum state.

[0038] The carbon dioxide pipeline 103 branches and is respectively connected to each module 11. At the part where the branched parts of the carbon dioxide pipeline 103 gather, a carbon dioxide recovery 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.

[0039] The carbon dioxide recovery pump 63 exerts an attraction force to transport the carbon dioxide flowing in the carbon dioxide pipeline 103 to the first carbon dioxide tank 66. On the upstream side of the carbon dioxide recovery pump 63 in the carbon dioxide pipeline 103, a one-way valve 631 is arranged. Thus, it becomes a structure in which the gas does not flow back from the intercooler 64 side to the module 11 side.

[0040] The intercooler 64 is an intercooler that cools the high-temperature gas containing carbon dioxide recovered from the module 11 and performs gas-liquid separation.

[0041] The water separated by the intercooler 64 into gas and liquid is recovered into the separator 65. In addition, a first valve 651 and a second valve 652 are arranged on the separator 65. The first valve 651 opens or closes the passage that connects the gas layer part of the separator 65 to the atmosphere. The second valve 652 opens or closes the path that connects the liquid phase part of the separator 65 to the atmosphere.

[0042] The first carbon dioxide tank 66 stores the carbon dioxide recovered through the carbon dioxide pipeline 103. Upstream of the first carbon dioxide tank 66 in the carbon dioxide pipeline 103, a tank valve 661 is arranged. The opening and closing of the tank valve 661 are controlled by the control device 90. In addition, various sensors such as a pressure sensor 662, a flow 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 in the carbon dioxide pipeline 103.

[0043] In addition to the carbon dioxide pipeline 103, a circulation pipeline 104 that returns the ballast to the carbon dioxide recovery pump 63 is also connected to the first carbon dioxide tank 66. A flow sensor 667 is arranged on the circulation pipeline 104. In addition, a pressure relief valve 668 that releases pressure when the pressure is above a specific value is arranged on the first carbon dioxide tank 66.

[0044] The compressor 67 is arranged between the first carbon dioxide tank 66 and the second carbon dioxide tank 68 in the carbon dioxide pipeline 103. The compressor 67 compresses the carbon dioxide stored in the first carbon dioxide tank 66 and transports it to the second carbon dioxide tank 68.

[0045] 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 pipeline 103, a cooperation pipeline 105 connected to a cooperation device and a confluence pipeline 106 that converges with the carbon dioxide pipeline 103 are also connected to the second carbon dioxide tank 68. The cooperation device is, for example, an algae cultivation device, a fuel synthesis device, an underground storage device, etc. A cooperation valve 681 is arranged on the cooperation pipeline 105, and a confluence valve 682 is arranged on the confluence pipeline 106. The opening and closing of the cooperation valve 681 and the confluence valve 682 are controlled by the control device 90.

[0046] Next, the inert gas tank 69 will be described. The inert gas tank 69 stores the inert gas N2 supplied from the 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. In addition, a pressure relief valve 693 that releases pressure when the pressure is above a specific value is arranged on the inert gas tank 69. A pressure sensor 694 is arranged inside the inert gas tank 69. The pressure information measured by the pressure sensor 694 is sent to the control device 90.

[0047] The inert gas tank 69 is connected to the carbon dioxide pipeline 103 via the inert gas supply pipeline 107. An inert gas valve 695 is arranged on the inert gas supply pipeline 107. The opening and closing of the inert gas valve 695 are controlled by the control device 90.

[0048] When the desorption process is carried out in each module 11 of the module unit 10, the heat exchange device 80 supplies thermal energy for heating the inside of the module 11 to a specific temperature. In addition, the heat exchange device 80 recovers the thermal energy that is not required during the adsorption process in each module 11. The heat exchange device 80 is composed of, for example, pipes connected to each module 11 and a heat pump. The pipes are flow paths through which the heat medium flows. The heat exchange device 80 supplies thermal energy to each module 11 or recovers the unnecessary thermal energy through the heat medium flowing through the pipes.

[0049] The control device 90 controls the operation of each part of the carbon dioxide recovery device 1. The control device 90 controls the operation such as driving or stopping the equipment used for the adsorption or desorption of carbon dioxide. The control device 90 performs the on / off control of the first valve 21, the second valve 22, the third valve 23, the fourth valve 24 provided in each module 11, or the on / off control of the separator first valve 651, the separator second valve 652, the tank valve 661, the converging valve 682, the inert gas valve 695. In addition, the control device 90 performs the drive control of the fan 61, the vacuum pump 62, the carbon dioxide recovery pump 63, the compressor 67, etc.

[0050] The control device 90 is, for example, a computer having a Central Processing Unit (CPU), a Read Only Memory (ROM), a Random Access Memory (RAM), etc. The control device 90 can be composed of one unit or multiple units.

[0051] <Recovery of Carbon Dioxide>

[0052] Next, the control for recovering carbon dioxide using the control device 90 will be described. The carbon dioxide recovery device 1 removes and recovers carbon dioxide from the air by alternately performing the adsorption process and the desorption process, compressing the desorbed carbon dioxide, and storing it in the first carbon dioxide tank 66 and the second carbon dioxide tank 68. The adsorption process is to make the adsorbent 12 in the module 11 adsorb carbon dioxide in the sucked air or other gases, and the desorption process is to desorb the carbon dioxide adsorbed by the adsorbent 12.

[0053] The adsorption process is a process in which the adsorbent 12 in the module 11 adsorbs carbon dioxide. 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 the gas containing carbon dioxide (for example, the atmosphere) is sucked through the third valve 23. The sucked gas passes through the adsorbent 12 in the module 11. At this time, the temperature inside the module 11 is normal temperature (25 °C), and the carbon dioxide in the gas is adsorbed on the adsorbent 12. Gases other than carbon dioxide, such as nitrogen or oxygen, are discharged to the outside of the carbon dioxide recovery device 1 through the fourth valve 24 and the adsorption pipeline 101.

[0054] The desorption process is a process of desorbing the carbon dioxide of 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 suck air inside the module 11 and reduce the pressure to a vacuum state or a state close to a vacuum state. At the same time, by means of the heat exchange device 80, the heat medium as a heat source flows inside the module 11 to supply heat energy, thereby heating the module 11. Thus, the adsorbent 12 is also heated to a specific temperature (for example, 90 °C) sufficient to perform the desorption process, and the carbon dioxide adsorbed on 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 recovery pump 63 is driven, and the desorbed carbon dioxide is stored in the first carbon dioxide tank 66 and the second carbon dioxide tank 68 through the carbon dioxide pipeline 103.

[0055] In the present embodiment, the control device 90 controls each module 11 so that 12 of the 16 modules 11 perform the adsorption process and 4 modules 11 perform the desorption process. Therefore, during the operation of the carbon dioxide recovery device 1, the four modules 11 performing the desorption process are in a high-temperature state.

[0056] <Emergency control>

[0057] Next, the emergency control for antioxidant protection of the adsorbent 12 in the event of a power outage or failure will be described. Refer to Figure 3 The emergency control will be described. Figure 3 It is a flowchart showing the processing flow of the emergency control of the carbon dioxide recovery device 1 of the present embodiment.

[0058] In addition, the prerequisite for emergency control is that the inside of the module 11 that is performing the desorption process during normal operation is depressurized by the vacuum pump 62 to a negative pressure, and the temperature of the adsorbent 12 is a high temperature of a certain temperature or higher by the heat exchange device 80. Further, 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 be in an open state or a closed state according to the operating conditions. The inert gas valve 695 is controlled to be in a closed state, and the internal pressure of the inert gas tank 69 is maintained at a certain pressure or higher.

[0059] In step S1, the control device 90 determines whether an operation signal indicating an emergency is received. The operation signal indicating an emergency may be a signal indicating a power outage such as a power failure, a signal indicating a failure, or a signal designating emergency control by the operator. The control device 90 continuously monitors until an operation signal indicating an emergency is received (step S1, No). When the control device 90 receives an operation signal indicating an emergency, the process proceeds to step S2 (step S1, Yes).

[0060] In step S2, each component of the carbon dioxide recovery device 1 is powered by an uninterruptible power supply device (UPS: Uninterruptible Power Supply). Thereby, the emergency control of the control system starts using the control device 90.

[0061] In step S3, the control device 90 controls all of the tank valve 661, the separator first valve 651, and the separator second valve 652 to be in a closed state. The upstream side of the first carbon dioxide tank 66 in the carbon dioxide pipeline 103 is closed.

[0062] In step S4, the control device 90 controls each valve of the module 11 that is the control object after the desorption process. In the present embodiment, the control device 90 maintains the closed state of the fourth valve 24 in the adsorption pipeline 101, and controls the second valve 22 in the vacuum pipeline 102 and the third valve 23 communicating with the atmosphere to be in a closed state.

[0063] In step S5, the control device 90 controls to start the supply of the antioxidant gas. In the present embodiment, the inert gas valve 695 in the inert gas supply pipeline 107 is controlled to be in an open state. Thereby, the inert gas tank 69 communicates with the carbon dioxide pipeline 103.

[0064] In step S6, the control device 90 controls the first valve 21 of the carbon dioxide pipeline 103 of the module 11 of the control object to an open state, thereby opening the carbon dioxide pipeline 103. Since the inside of the inert gas tank 69 is maintained at a certain pressure or higher, the inert gas N2 flows into the inside of the module 11 in a vacuum state or a state close to vacuum through the inert gas supply pipeline 107 and the carbon dioxide pipeline 103.

[0065] In step S7, the control device 90 refers to the measurement information of the pressure sensor 25 of the module 11 of the control object and determines whether the internal pressure of the module 11 is above a specific pressure. The control device 90 continuously monitors until the internal pressure of the module 11 is above a specific pressure (step S7, No). When the internal pressure of the module 11 is above a specific pressure, the control device 90 causes the process to proceed to step S8 (step S7, Yes).

[0066] In step S8, the control device 90 controls the first valve 21 of the carbon dioxide pipeline 103 of the module 11 of the control object to a closed state, thereby closing the carbon dioxide pipeline 103. Since the internal pressure of the module 11 is above a specific pressure, the air pressure difference of the atmospheric pressure is also 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 the breakage of each component of the module 11 due to pressure changes.

[0067] 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 is below a certain temperature. The control device 90 maintains the above-mentioned various controls and continuously monitors until the temperature is below a certain temperature (step S9, No). When the temperature is below a certain temperature, the control device 90 ends this process (step S9, Yes).

[0068] Refer to Figure 3, the configuration of the module 11 that supplies the inert gas N2, which will be used as the antioxidant gas, to the desorption process will be described. When a sufficient amount of carbon dioxide is stored in the second carbon dioxide tank 68, the stored carbon dioxide can also be supplied as the antioxidant gas to the module 11 of the desorption process. At this time, in step S5, the control device 90 controls the cooperation valve 681 to the closed state and controls the confluence valve 682 to the open state, so that the second carbon dioxide tank 68 communicates with the carbon dioxide pipeline 103. Then, in step S6, the control device 90 controls the first valve 21 of the carbon dioxide pipeline 103 to the open state. Since the inside of the second carbon dioxide tank 68 is maintained at a certain pressure or higher, the carbon dioxide used as the antioxidant gas flows into the inside of the module 11 in a vacuum state or a state close to a vacuum through the confluence pipeline and the carbon dioxide pipeline 103. In addition, other controls are the same as when supplying the inert gas N2, which is used as the antioxidant gas, to the module 11 of the desorption process.

[0069] In addition, the control device 90 can also be configured to switch the type of antioxidant gas according to the storage amount of N2 in the inert gas tank 69 or the storage amount of carbon dioxide in the second carbon dioxide tank 68. For example, the control device 90 can also be configured to supply the inert gas in the inert gas tank 69 as the antioxidant gas to the module 11 when the storage amount of carbon dioxide in the second carbon dioxide tank 68 is small at the beginning of operation, and supply the carbon dioxide in the second carbon dioxide tank 68 as the antioxidant gas to the module 11 if the storage amount of the inert gas in the inert gas tank 69 decreases.

[0070] As described above, the carbon dioxide recovery device 1 of the present embodiment includes: a module 11 having an adsorbent 12 inside, the module 11 performing an adsorption process and a desorption process, the adsorption process attracting a gas containing carbon dioxide to the adsorbent 12 to adsorb carbon dioxide by the adsorbent 12, and the desorption process desorbing carbon dioxide from the adsorbent 12 by heating the periphery of the adsorbent 12 under a reduced pressure state; a first carbon dioxide tank 66 storing the carbon dioxide recovered from the module 11 through the adsorption process and the desorption process; an antioxidant gas tank (the second carbon dioxide tank 68, the inert gas tank 69) storing an antioxidant gas for preventing the oxidation of the adsorbent 12; and a control device 90 that supplies the antioxidant gas from the antioxidant tank to the module 11 that is performing the desorption process if an emergency is detected.

[0071] Accordingly, in the event of an emergency such as a power outage or a failure, an antioxidant gas such as an inert gas or carbon dioxide is supplied to the module 11 that performs the desorption process. Therefore, the periphery of the adsorbent 12 inside the module 11 is filled with the antioxidant gas. Thus, even if the fourth valve 24 communicating with the atmosphere is in an open state due to a power outage or a failure, etc., the atmosphere will not enter the inside of the module 11, thereby avoiding the situation where the high-temperature adsorbent 12 comes into contact with the atmosphere and deteriorates.

[0072] In addition, in the present embodiment, the antioxidant gas tank is an inert gas tank 69 that stores an inert gas as the antioxidant gas. Accordingly, an inert gas such as N2 gas can be used to prevent the oxidation of the adsorbent 12. When the recovered carbon dioxide is used as the antioxidant gas, even if the storage amount of carbon dioxide is insufficient, the oxidation of the adsorbent 12 can be effectively prevented by using the separately prepared inert gas.

[0073] In addition, in the present embodiment, the antioxidant gas tank is the second carbon dioxide tank 68 that stores the carbon dioxide recovered from the module 11 as the antioxidant gas. Accordingly, the recovered carbon dioxide can be used, and thus a configuration for supplying the antioxidant gas in an emergency can be achieved at low cost.

[0074] In addition, in the present embodiment, the second carbon dioxide tank 68 and the inert gas tank 69 store the antioxidant gas at a certain pressure or higher pressure. Accordingly, by simply connecting the path to the module 11 in a vacuum state or a state close to a vacuum state, the antioxidant gas can be supplied using the pressure difference. A driving device such as a carbon dioxide recovery pump may not be used, and thus the power consumption in an emergency can be suppressed.

[0075] In addition, in the present embodiment, when the internal pressure of the module 11 in which the antioxidant gas is supplied is at a certain pressure or higher, the control device 90 stops the supply of the antioxidant gas (inert gas, carbon dioxide). Thus, by connecting the inside of the module 11 in a vacuum state or a state close to a vacuum state to the atmosphere, the situation where the structure of the module 11 is damaged due to the pressure difference can be avoided.

[0076] The configuration of the carbon dioxide recovery device 1 is not limited to the configuration of the above embodiment. Figure 4 It is a schematic diagram showing a configuration related to the gas flow of the carbon dioxide recovery device 1a of the modification. The carbon dioxide recovery device 1a of the modification omits the configurations such as the second carbon dioxide tank 68, the cooperation pipeline 105, the cooperation valve 681, the converging pipeline 106, and the converging valve 682 in the carbon dioxide recovery device 1 of the first embodiment. In addition, other configurations are the same as those of the above embodiment.

[0077] As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above-described embodiments or modification examples. In addition, the effects described in the above embodiments are only listed as preferred effects and are not limited to the content described in the above embodiments.

[0078] Reference numeral

[0079] 1 Carbon dioxide recovery device

[0080] 11 Module

[0081] 12 Adsorbent

[0082] 21 First valve

[0083] 22 Second valve

[0084] 23 Third valve

[0085] 24 Fourth valve

[0086] 66 First carbon dioxide tank

[0087] 68 Second carbon dioxide tank

[0088] 69 Inert gas tank

[0089] 695 Valve for inert gas

Claims

1. A carbon dioxide recovery device, comprising: a module having an adsorbent therein, the module performing an adsorption process and a desorption process, the adsorption process being to attract a gas containing carbon dioxide to the adsorbent described above and cause the adsorbent to adsorb the carbon dioxide described above, and the desorption process being to desorb the carbon dioxide from the adsorbent by heating the periphery of the adsorbent under a reduced pressure state; a carbon dioxide tank for storing the carbon dioxide recovered from the module described above through the adsorption process and the desorption process described above; an antioxidant gas tank for storing an antioxidant gas that prevents oxidation of the adsorbent described above; and a control device that, if an emergency is detected, supplies the antioxidant gas from the antioxidant gas tank to the module described above that is performing the desorption process.

2. The carbon dioxide recovery device according to claim 1, wherein the antioxidant gas tank is an inert gas tank that stores an inert gas as the antioxidant gas described above.

3. The carbon dioxide recovery device according to claim 1, wherein the antioxidant gas tank is a second carbon dioxide tank that stores the carbon dioxide recovered from the module described above as the antioxidant gas described above.

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

5. The carbon dioxide recovery device according to any one of claims 1 to 3, wherein the control device stops supplying the antioxidant gas when the internal pressure of the module that supplies the antioxidant gas is at a certain pressure or higher.

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