Carbon dioxide recovery device

Abstract

To provide a carbon dioxide recovery technique with excellent energy efficiency.SOLUTION: A carbon dioxide recovery device includes a first adsorbent capable of adsorbing moisture contained in gas introduced into a processing tank, or desorbing the adsorbed moisture, and a second adsorbent disposed on the downstream side of the first adsorbent and capable of adsorbing carbon dioxide contained in the gas, or desorbing the adsorbed carbon dioxide. The second adsorbent desorbs the carbon dioxide using the moisture desorbed from the first adsorbent.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a method and apparatus for removing water and carbon dioxide from a gas mixture using pressure swing adsorption. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2007-529297 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology of Patent Document 1 uses pressure swing adsorption (PSA) to adsorb and desorb water and carbon dioxide, which requires the use of exhaust gas discharged under high pressure or the setting of conditions such as adjusting the treated gas to a predetermined pressure, which may limit the locations where high-pressure exhaust gas can be treated. Furthermore, increasing the pressure of the treated gas requires a compressor and other large-scale associated equipment, which may increase the energy consumption required for using the device. Furthermore, in the water adsorption / desorption process, the water desorbed to regenerate the adsorbent is discharged directly outside the system, resulting in a loss of energy for water desorption.

[0005] In view of the above-mentioned problems, the disclosed technology aims to provide a carbon dioxide capture technology with excellent energy efficiency. One aspect of the present invention provides a technology that contributes to the improvement and development of a sustainable environment. [Means for solving the problem]

[0006] A carbon dioxide recovery apparatus according to one aspect of the present invention includes: a first adsorbent capable of adsorbing moisture contained in a gas introduced into a treatment tank or desorbing the adsorbed moisture; a second adsorbent disposed downstream of the first adsorbent and capable of adsorbing carbon dioxide contained in the gas or desorbing the adsorbed carbon dioxide; The second adsorbent desorbs the carbon dioxide using the moisture desorbed from the first adsorbent. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a carbon dioxide recovery technology that is excellent in energy efficiency. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a carbon dioxide capture device according to an embodiment. [Figure 2] FIG. 1 is a diagram showing an example of the configuration of a carbon dioxide capture device according to an embodiment. [Figure 3] FIG. 4 is a diagram illustrating the operation of the carbon dioxide capture device during adsorption treatment. [Figure 4] FIG. 4 is a diagram illustrating the operation of the carbon dioxide capture device during desorption processing. [Figure 5] FIG. 2 is a control block diagram of the carbon dioxide capture device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.

[0010] [Device Overview] 1 is a diagram showing an example of the configuration of a carbon dioxide capture device according to an embodiment. The carbon dioxide capture device has, as its components, a treatment tank 10 that forms the housing of the device, a cooling unit 20, and a heating unit 30. The treatment tank 10 is a member that defines an internal space separated from an external space, and the treatment tank 10 is a member that surrounds the internal space.

[0011] (Configuration of treatment tank 10) The treatment tank 10 is provided inside with a moisture adsorbent MT1 that adsorbs moisture and a carbon dioxide adsorbent MT2 (CO2 adsorbent) that adsorbs carbon dioxide. The treatment tank 10 is configured so that the pre-treatment introduced gas 110 flows from the upstream side to the downstream side. The gas treated in the treatment tank 10 is referred to as gas 120. In this embodiment, the lower side of the treatment tank 10 is referred to as the upstream side, and the upper side of the treatment tank 10 is referred to as the downstream side. The moisture adsorbent MT1 is provided on the upstream side of the treatment tank 10, and the carbon dioxide adsorbent MT2 is provided downstream of the moisture adsorbent MT1.

[0012] The moisture adsorbent MT1 is a material capable of adsorbing moisture from gas. The moisture adsorbent MT1 has the property that it easily adsorbs moisture contained in gas when cooled and easily desorbs the adsorbed moisture when heated. Examples of materials that can be used as moisture adsorbents include silica gel, zeolite, metal organic frameworks (MOFs), covalent organic frameworks (COFs), and activated carbon, and any one or more of these may be included. The moisture adsorbent MT1 may also have the property of desorbing the adsorbed moisture by applying external conditions such as microwaves or ultrasound while the moisture adsorbed by the moisture adsorbent MT1 is in a moisture-adsorbed state. The mist-like moisture desorbed by microwaves or ultrasound can also be brought into contact with the downstream carbon dioxide adsorbent MT2 to promote the desorption of carbon dioxide.

[0013] The carbon dioxide capture device may include an auxiliary device that applies microwaves or ultrasound to the moisture adsorbent MT1 as an external condition. For example, the auxiliary device may be attached to the surface of the moisture adsorbent MT1 to apply microwaves or ultrasound to the moisture adsorbent MT1. By applying microwaves or ultrasound to the moisture adsorbent MT1, moisture can be dispersed in a mist form from the moisture adsorbent MT1. Contact between the dispersed moisture in a mist form and the carbon dioxide adsorbent MT2 can promote desorption of carbon dioxide.

[0014] The carbon dioxide adsorbent MT2 is a material capable of adsorbing and desorbing carbon dioxide. The carbon dioxide adsorbent MT2 has the property of easily adsorbing carbon dioxide contained in a gas when the gas is dehumidified, and easily desorbing the adsorbed carbon dioxide when the gas is humidified to a predetermined humidity (e.g., relative humidity of 20% or more). For example, the carbon dioxide adsorbent MT2 can be made of an amine-based material, a polymer material, an inorganic material, or the like, and it is sufficient that the carbon dioxide adsorbent MT2 contains at least one of these materials. The carbon dioxide adsorbent MT2 may have the property of desorbing carbon dioxide by coming into contact with moisture dispersed (desorbed) in a mist form from the moisture adsorbent MT1.

[0015] The moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 are supported without being in direct contact with each other. The moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 may be supported inside the treatment tank 10 in either a solid or liquid state. When used in a solid state, the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 may be supported inside the treatment tank 10 by being enclosed in a single column (container) composed of members SP1, SP2, and SP3. When used in a liquid state, the moisture adsorbent MT1 or the carbon dioxide adsorbent MT2 may be supported inside the treatment tank 10 by being housed in different columns (containers) composed of members SP1, SP2, and SP3.

[0016] Furthermore, the moisture adsorbent MT1 or the carbon dioxide adsorbent MT2 may be supported by members SP1, SP2, and SP3 inside the treatment tank 10 while being supported on a substrate. The substrate can be, for example, a porous body made of metal with continuous pores (porous metal body). A porous metal body is a solid substance or structure containing a large number of pores, and pores refer to the gaps present inside a material. The pores inside the porous metal body are distributed in three dimensions and interconnected. Therefore, the porous metal body is breathable despite being a metal substance. Alternatively, a membrane filter, granular silica, or the like can be used as the substrate. The substrate may include at least one of a porous body, a membrane filter, and granular silica.

[0017] The lower side of the moisture adsorbent MT1 is supported by a member SP1, and the upper side of the moisture adsorbent MT1 is supported by a member SP3. The lower side of the carbon dioxide adsorbent MT2 is supported by a member SP3, and the upper side of the carbon dioxide adsorbent MT2 is supported by a member SP2.

[0018] The member SP3 is a member provided between the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2, and the member SP3 supports the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 while keeping them apart so that they do not come into direct contact with each other. Here, the members SP1, SP2, and SP3 may be made of a metal material. In the following description, when the members are collectively referred to, they may be simply referred to as SP. When the member SP is heated or cooled, the moisture adsorbent MT1 or the carbon dioxide adsorbent MT2 is heated or cooled by thermal conduction.

[0019] The treatment tank 10 is configured so that a pre-treatment gas 101 is introduced (input) into the upstream side, and a gas 120 treated in the treatment tank 10 is released (output) from the downstream side. The pre-treatment gas 101 passes through a filter 81 and a check valve 82 and is introduced into the interior (upstream side) of the treatment tank 10. Dust contained in the pre-treatment gas 101 is removed by passing the pre-treatment gas 101 through the filter 81. In FIG. 1, the pre-treatment gas 101 introduced into the treatment tank 10 is shown as a pre-treatment introduced gas 110. The members SP1, SP2, and SP3 may have openings formed therein to allow the pre-treatment introduced gas 110 to flow therethrough. Furthermore, when the moisture adsorbent MT1 or the carbon dioxide adsorbent MT2 is supported by a substrate, the pre-treatment introduced gas 110 can be allowed to flow downstream by utilizing the openings in the member SP and the breathability of the substrate.

[0020] The pre-treatment introduced gas 110 is configured to pass through the component SP1, moisture adsorbent MT1, component SP3, carbon dioxide adsorbent MT2, and component SP2 by utilizing the openings formed in the components SP1, SP2, and SP3 or the breathability of the substrate. As the gas passes through these components (SP1, MT1, SP3, MT2, and SP2), carbon dioxide adsorption and desorption processes are alternately performed. In FIG. 1, the gas that has passed through the components (SP1, MT1, SP3, MT2, and SP2) is shown as post-treatment gas 120. The gas 120 is released to the outside of the treatment tank 10 via the ventilation pipe 41.

[0021] The first concentration sensor 80 is a sensor that detects the concentration of carbon dioxide contained in the untreated gas 101 before it is introduced into the treatment tank 10, and the second concentration sensor 90 is a sensor that detects the concentration of carbon dioxide contained in the treated gas 120 that has been treated inside the treatment tank 10. The difference between the detection results by the first concentration sensor 80 and the second concentration sensor 90 can be used as an index that indicates the amount of carbon dioxide adsorbed by the carbon dioxide adsorbent MT2 inside the treatment tank 10. The detection results by the first concentration sensor 80 and the second concentration sensor 90 are input to the control device 140 (FIG. 5).

[0022] The first temperature sensor 85 (FIG. 5) is a sensor that detects the temperature of the carbon dioxide adsorbent MT2, and the second temperature sensor 95 (FIG. 5) is a sensor that detects the temperature of the moisture adsorbent MT1. The detection results by the first temperature sensor 85 and the second temperature sensor 95 are input to the control device 140 (FIG. 5).

[0023] The maintenance and inspection units 11 and 12 are provided on the outer wall of the treatment tank 10. The maintenance and inspection units 11 and 12 may be configured as doors that can be opened and closed. The maintenance and inspection units 11 and 12 may also be provided with transparent windows that allow the interior of the treatment tank 10 to be viewed. For example, while the apparatus is in operation, the maintenance and inspection units 11 and 12 can be closed, allowing the user to view the interior of the treatment tank 10 through the windows. Furthermore, with the maintenance and inspection units 11 and 12 open, the user can perform maintenance work such as inspecting, cleaning, and replacing parts inside the treatment tank 10. As shown in FIG. 1, multiple maintenance and inspection units 11 and 12 may be provided so that maintenance work and viewing of the interior can be performed from different directions.

[0024] (Configuration of cooling unit 20 and heating unit 30) The cooling unit 20 can cool the members SP1 and SP2 to a predetermined temperature by supplying a cooling medium (cooling water) to the members SP1 and SP2. For example, the cooling unit 20 may use, for example, cold water from a heat exchanger or a chiller, or waste cold heat supplied from the outside, to supply the members SP1 and SP2 with cooling water cooled to a predetermined temperature. Note that the type of cooling source in the cooling unit 20 is an example, and other cooling sources may also be used.

[0025] Cooling unit 20 is connected to member SP1 via water pipe 21 and to member SP2 via water pipe 23. Water pipe 32 is connected between water pipe 21 and water pipe 23. Water pipes 21 and 23 are provided with flow path switching units 24 and 25 that can switch the flow of water in the connected water pipes. Flow path switching units 24 and 25 can switch the connected water pipes depending on the supply of cooling water by cooling unit 20 or the supply of heated water by heating unit 30.

[0026] The heating unit 30 is capable of heating the members SP1 and SP2 to a predetermined temperature by supplying a heating medium (heated water) to the members SP1 and SP2. The heating unit 30 can heat the heated water to a predetermined temperature using, for example, an electric heater, energy based on received sunlight, hot water from a heat pump, or waste heat supplied from the outside, and supply the heated water to the members SP1 and SP2. Note that the types of heat sources are merely examples, and other heat sources may also be used.

[0027] Heating unit 30 is connected to member SP1 via water pipe 33 and to member SP2 via water pipe 31. Water pipe 22 is connected between water pipe 31 and water pipe 33. Water pipe 31 and water pipe 33 are provided with flow path switching units 34 and 35 that can switch the flow of water in the connected water pipes. Flow path switching units 34 and 35 can switch the connected water pipes in response to the supply of cooling water by cooling unit 20 or the supply of heated water by heating unit 30.

[0028] Focusing on the operation of flow path switching units 24, 25, 34, and 35, when cooling members SP1 and SP2, flow path switching units 24 and 25 should operate to disconnect water pipe 32 from water pipes 21 and 23 at both ends. Also, flow path switching units 34 and 35 should operate to connect water pipe 22 to water pipes 21 and 23. That is, one end of water pipe 22 should be connected to water pipe 21 via a portion of water pipe 33 and member SP1, and the other end of water pipe 22 should be connected to water pipe 23 via a portion of water pipe 31 and member SP2.

[0029] When heating members SP1 and SP2, flow path switching units 34 and 35 operate to disconnect water pipe 22 from water pipes 31 and 33 at both ends. Flow path switching units 24 and 25 also operate to connect water pipe 32 to water pipes 31 and 33. That is, one end of water pipe 32 communicates with a portion of water pipe 23 and water pipe 31 via member SP2, and the other end of water pipe 32 communicates with a portion of water pipe 21 and water pipe 33 via member SP1.

[0030] When cooling the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 by cooling the members SP1 and SP2, the cooling water delivered from the cooling unit 20 is pumped by the pump P1 and input to the member SP1 via the water pipe 21. The cooling water input from the water pipe 21 flows through a flow path formed inside the member SP1 and cools the member SP1. The cold energy of the member SP1 is transferred to the moisture adsorbent MT1 by thermal conduction, and the moisture adsorbent MT1 is cooled to a predetermined temperature.

[0031] The cooling water output from the member SP1 is input to the water pipe 22 via a part of the water pipe 33 by the operation of the flow path switching unit 34. The cooling water flowing through the water pipe 22 is input to the member SP2 via a part of the water pipe 31 by the operation of the flow path switching unit 35. The cooling water input to the member SP2 flows through a flow path formed inside the member SP2 and cools the member SP2. The cold heat of the member SP2 is transferred to the carbon dioxide adsorbent MT2 by thermal conduction, thereby cooling the carbon dioxide adsorbent MT2 to a predetermined temperature. Here, the cooling temperatures when cooling the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 can be controlled by adjusting the temperature of the cooling water.

[0032] The cooling water output from member SP2 is returned to cooling section 20. By circulating the cooling water through the water pipes (21, part of 33, 22, part of 31, 23) as described above to cool members SP1 and SP2, it is possible to cool the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2. In the following description, the water pipes (21, part of 33, 22, part of 31, 23) are also referred to as "cooling water pipes."

[0033] When the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 are heated by heating the members SP1 and SP2, heated water delivered from the heating unit 30 is pumped by the pump P2 and input to the member SP2 via the water pipe 31. The heated water input from the water pipe 31 flows through a flow path formed inside the member SP2 and heats the member SP2. The heat of the member SP2 is transferred to the carbon dioxide adsorbent MT2 by thermal conduction, and the carbon dioxide adsorbent MT2 is heated to a predetermined temperature.

[0034] The heated water output from the member SP2 is input to the water pipe 32 via a part of the water pipe 23 by the flow path switching unit 24. The heated water flowing through the water pipe 32 is input to the member SP1 via a part of the water pipe 21 by the flow path switching unit 25. The heated water input to the member SP1 flows through a flow path formed inside the member SP1 and heats the member SP1. The heat of the member SP1 is transferred to the moisture adsorbent MT1 by thermal conduction, heating the moisture adsorbent MT1 to a predetermined temperature. Here, the heating temperature when heating the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 can be controlled by adjusting the temperature of the heated water.

[0035] The heated water output from member SP1 is returned to heating unit 30. The heated water circulates through the water pipes (31, part of 23, 32, part of 21, 33) as described above to heat members SP1 and SP2, thereby heating the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2. In the following description, the water pipes (31, part of 23, 32, part of 21, 33) are also referred to as "heating water pipes."

[0036] (Exhaust system configuration) The fan 40 is connected to the ventilation pipe 41 via the ventilation pipe 45 and the valve 50. When the valve 60 is closed and the valve 50 is opened, the ventilation pipe 45 and the ventilation pipe 41 are in communication with each other. When the valve 50 is opened and the fan 40 is operated, the fan 40 creates a negative pressure inside the treatment tank 10 and can function as a power source to draw the pre-treatment gas into the treatment tank 10. The ventilation pipe 45 is a ventilation pipe for guiding carbon dioxide having a lower concentration than the pre-treatment gas to the fan 40. When the adsorption treatment is performed, the gas 120 (treated gas) in the treatment tank 10 is exhausted to the outside through the ventilation pipe 41 and the ventilation pipe 45 (first exhaust route) by the operation of the fan 40. Gas 102 represents the dehumidified gas containing a low concentration of carbon dioxide exhausted by the fan 40. The control device 140 (FIG. 5) can adjust the amount of gas 110 introduced before treatment or the amount of gas 120 (gas after treatment) sucked from the treatment tank 10 by controlling the output of the fan 40.

[0037] Condenser section 70 (condenser) is connected to ventilation pipe 41 via ventilation pipe 42, valve 60, and ventilation pipe 43. Pump P3 also connects condenser section 70 via ventilation pipe 44. When valve 50 is closed and valve 60 is opened, ventilation pipes 42, 43, 44 and ventilation pipe 41 are connected to each other. Pump P3 is a pump that creates negative pressure inside treatment tank 10. With valve 50 closed and valve 60 open, pump P3 sucks in gas 120 (treated gas) from inside treatment tank 10 and discharges the sucked gas 104.

[0038] The condenser 70 cools the treated gas 120 obtained by the desorption process to remove moisture. The condenser 70 removes moisture 103 contained in the gas 120 (high humidity and with a higher concentration of carbon dioxide than the gas before treatment) sucked in by the pump P3, and outputs high-concentration carbon dioxide from which the moisture 103 has been removed from the gas 120. The condenser 70 can cool the treated gas 120 using air cooling or waste cold energy from a carbon dioxide recovery device. The moisture 103 removed by the condenser 70 can be reused, for example, as cooling water in the cooling unit 20 or heating water in the heating unit 30.

[0039] The pump P3 discharges the high-concentration carbon dioxide output from the condenser 70 as gas 104. The control device 140 (FIG. 5) can adjust the amount of the introduced gas 110 before treatment or the amount of gas 120 (treated gas) sucked from the treatment tank 10 by controlling the output of the pump P3.

[0040] The ventilation pipes 41-44 (second exhaust route) are ventilation pipes that exhaust carbon dioxide at a higher concentration than the ventilation pipes 41, 45 (first exhaust route), and when performing desorption processing, the gas 120 in the processing tank 10 is exhausted to the outside via the ventilation pipes 41-44 (second exhaust route). Gas 104 represents the high-concentration carbon dioxide pumped out by the pump P3.

[0041] In this embodiment, the ventilation pipes 41, 45, and fan 40 function as a first exhaust route for exhausting low-concentration carbon dioxide when performing the adsorption process, and the ventilation pipes 41 to 44, the condenser 70, and the pump P3 function as a second exhaust route for exhausting high-concentration carbon dioxide when performing the desorption process.

[0042] In the apparatus configuration of FIG. 1, a configuration using pump P3 and fan 40 has been described as an exhaust mechanism. However, as shown in FIG. 2, for example, either pump P3 or fan 40 may be used. The example of FIG. 2 illustrates a configuration example using fan 40. When performing an adsorption process, valve 50 may be opened, valve 60 may be closed, and fan 40 may be operated to suck gas 120 (processed gas) from within treatment tank 10 and discharge gas 102 (dehumidified low-concentration carbon dioxide). When performing a desorption process, valve 50 may be closed, valve 60 may be opened, and fan 40 may be operated to suck gas 120 (processed gas) from within treatment tank 10 and discharge gas 104 (high-concentration carbon dioxide).

[0043] [Control device] 5 is a control block diagram of a carbon dioxide capture device according to an embodiment. The control device 140 includes a processing unit 141 (processor), an interface unit 142, and a storage unit 143. The processing unit 141 is a general-purpose integrated circuit for executing operations by the carbon dioxide capture device, and may be configured by, for example, a central processing unit (CPU). The processing unit 141 is able to execute various processes by reading and executing programs stored in the storage unit 143. The storage unit 143 stores control information corresponding to the adsorption process or desorption process, and the processing unit 141 may execute the process corresponding to the adsorption process or desorption process based on the control information.

[0044] The interface unit 142 is an interface for various sensor groups 150 and device groups 160 included in the carbon dioxide capture device, and the processing unit 141 (processor) can control the device group 160 based on information obtained from the sensor group 150 via the interface unit 142.

[0045] Here, the sensor group 150 includes, for example, a first concentration sensor 80, a second concentration sensor 90, a first temperature sensor 85, and a second temperature sensor 95. The device group 160 includes first to third pumps P1 to P3, a cooling unit 20, a heating unit 30, flow path switching units 24, 25, 34, and 35, a fan 40, valves 50 and 60, and a condensing unit 70. The control device 140 can switch between an adsorption process for adsorbing carbon dioxide and a desorption process for desorbing the adsorbed carbon dioxide based on the detection results of the first concentration sensor 80 and the second concentration sensor 90.

[0046] (Explanation of adsorption treatment) 3 is a diagram illustrating the operation of the carbon dioxide capture device during the adsorption process. When the adsorption process starts, the cooling unit 20 starts operating and cooling water circulates through the cooling water pipes (21, part of 33, 22, part of 31, 23). By cooling the members SP1 and SP2, the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 are cooled.

[0047] The temperatures of the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 are detected by a first temperature sensor 85 and a second temperature sensor 95. When the temperatures of the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 are cooled to a predetermined temperature (e.g., the outside air temperature), the untreated gas 101 is introduced into the treatment tank 10.

[0048] The untreated gas 110 introduced into the treatment tank 10 flows from the upstream side to the downstream side. As the gas passes through the member SP1, the moisture adsorbent MT1, the member SP3, the carbon dioxide adsorbent MT2, and the member SP2, the moisture adsorbent MT1 adsorbs the moisture contained in the untreated gas 101, and the dehumidified gas is supplied to the carbon dioxide adsorbent MT2 on the downstream side.

[0049] The carbon dioxide adsorbent MT2 is cooled and comes into contact with the dehumidified gas. In this state, the carbon dioxide adsorbent MT2 adsorbs carbon dioxide from the dehumidified gas. As a result, the gas 120 (processed gas) in the treatment tank 10 becomes a dehumidified low-concentration carbon dioxide state. The valve 50 of the exhaust mechanism is opened, and the valve 60 is closed. In this state, the gas 120 (dehumidified low-concentration carbon dioxide) is exhausted (102) to the outside of the treatment tank 10 through the ventilation pipes 41, 45 (first exhaust route).

[0050] The detection result of the concentration of carbon dioxide contained in the untreated gas 101 detected by the first concentration sensor 80 does not change during the progress of the adsorption process, but the detection result of the concentration of carbon dioxide contained in the treated gas 120 detected by the second concentration sensor 90 may change during the progress of the adsorption process.

[0051] For example, when an adsorption process is performed after the desorption process is completed, in the early stages of the adsorption process, the second concentration sensor 90 may detect a concentration lower than the detection result of the first concentration sensor 80. As the adsorption process progresses, the detection result of the second concentration sensor 90 tends to gradually approach the detection result of the first concentration sensor 80.

[0052] When the difference in the carbon dioxide concentrations detected by the first concentration sensor 80 and the second concentration sensor 90 becomes equal to or less than a certain value, the control device 140 (FIG. 5) determines that the adsorption process has ended and transitions from the adsorption process to the desorption process.

[0053] (Description of desorption process) 4 is a diagram illustrating the operation of the carbon dioxide capture device during the desorption process. When the desorption process starts, the heating unit 30 operates, and heated water circulates through the heating water pipes (31, part of 23, 32, part of 21, 33), heating the members SP2 and SP1, thereby heating the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2.

[0054] The temperatures of the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 are detected by a first temperature sensor 85 and a second temperature sensor 95. When the temperatures of the moisture adsorbent MT1 and the carbon dioxide adsorbent MT2 are heated to a predetermined temperature (above the ambient temperature, for example, preferably 60°C, up to 100°C), moisture is desorbed from the moisture adsorbent MT1.

[0055] When moisture is desorbed from the moisture adsorbent MT1, the humidity in the treatment tank 10 increases, and the humidity of the gas surrounding the carbon dioxide adsorbent MT2 also increases. The carbon dioxide adsorbent MT2 is heated and comes into contact with the humidified gas. In this state, carbon dioxide begins to desorb from the carbon dioxide adsorbent MT2. Due to the desorption of carbon dioxide, the gas 120 (the gas after treatment) in the treatment tank 10 becomes highly humid and has a high concentration of desorbed carbon dioxide.

[0056] The valve 50 of the exhaust mechanism is closed and the valve 60 is opened. In this state, the processed gas 120 (high humidity and high concentration carbon dioxide) is sucked by the pump P3 and flows through the ventilation pipes 41 to 44 (second exhaust route).

[0057] As the treated gas 120 flows through the ventilation pipes 41-44 (second exhaust route), the moisture 103 from the high-humidity, high-concentration carbon dioxide is condensed and removed by the condenser 70. By removing the moisture 103 by the condenser 70, it becomes possible to further increase the concentration of the high-concentration carbon dioxide (104). By sucking the gas 120 from the treatment tank 10 with the pump P3, it becomes easier to desorb the carbon dioxide, and it becomes possible to promote the desorption process more rapidly. In addition, the moisture 103 removed by the condenser 70 can be reused as cooling water in the cooling unit 20 or heating water in the heating unit 30.

[0058] The concentration of carbon dioxide contained in the treated gas 120, detected by the second concentration sensor 90, increases as the desorption of carbon dioxide progresses, but after desorption is complete, the carbon dioxide concentration gradually decreases. When the detection result of the second concentration sensor 90 becomes equal to or lower than a predetermined concentration, the control device 140 (FIG. 5) determines that the desorption process is complete and transitions from the desorption process to the adsorption process. The carbon dioxide capture device of this embodiment can capture high concentrations of carbon dioxide from the untreated gas by alternately performing the adsorption process and the desorption process.

[0059] The carbon dioxide capture device disclosed in this embodiment captures carbon dioxide contained in gas using the humidity swing method. In a low humidity state where moisture is adsorbed from the gas by the moisture adsorbent MT1, the carbon dioxide adsorbent MT2 adsorbs carbon dioxide. In a high humidity state where moisture is desorbed from the moisture adsorbent MT1, the carbon dioxide adsorbent MT2 desorbs carbon dioxide.

[0060] Here, the amount of moisture desorbed from the moisture adsorbent MT1 can be controlled based on the temperature change of the moisture adsorbent MT1. Also, the change in humidity inside the treatment tank 10 can be controlled based on the amount of moisture. Also, the amount of carbon dioxide desorbed from the carbon dioxide adsorbent MT2 can be controlled based on the change in humidity.

[0061] The humidity swing method can use common pumps and fans, and does not require the large-scale equipment required in pressure swing adsorption (PSA), such as equipment for using exhaust gas discharged under high pressure conditions or compressors.As a result, the humidity swing method can reduce the energy consumption required for operating the equipment compared to pressure swing adsorption.

[0062] Furthermore, the moisture 103 removed by the condenser 70 may be reused as cooling water in the cooling unit 20 or as heating water in the heating unit 30. By reusing the removed moisture 103, the problem of energy loss during water desorption in the pressure swing adsorption method according to the conventional technology can be resolved, and water resources can be used effectively.

[0063] As described above, the technology disclosed in the embodiments can provide a carbon dioxide capture technology with excellent energy efficiency.

[0064] [Other embodiments] Furthermore, a program for realizing one or more functions described in each embodiment can be supplied to the control device via a network or a storage medium, and one or more processors in the computer of the system or control device can read and execute the program. The present invention can also be realized in such an embodiment.

[0065] The present invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0066] 10: Treatment tank, 20: Cooling unit, 30: Heating unit, MT1: Moisture adsorbent, MT2: Carbon dioxide adsorbent (CO2 adsorbent)

Claims

1. a first adsorbent capable of adsorbing moisture contained in a gas introduced into the treatment tank or desorbing the adsorbed moisture; a second adsorbent disposed downstream of the first adsorbent and capable of adsorbing carbon dioxide contained in the gas or desorbing the adsorbed carbon dioxide; The second adsorbent is a carbon dioxide recovery device that desorbs the carbon dioxide using the moisture desorbed from the first adsorbent.

2. 2. The carbon dioxide recovery apparatus according to claim 1, wherein the first adsorbent includes at least one of silica gel, zeolite, metal-organic framework (MOF), covalent organic framework (COF), and activated carbon.

3. 3. The carbon dioxide recovery device according to claim 2, wherein the first adsorbent has a property of adsorbing the moisture contained in the gas when the temperature is lowered by cooling, and desorbing the adsorbed moisture when the temperature is raised by heating.

4. The carbon dioxide recovery device according to claim 2 , wherein the first adsorbent has a property of desorbing the adsorbed moisture by applying an external condition of microwaves or ultrasound to the first adsorbent while the first adsorbent has adsorbed the moisture.

5. The carbon dioxide recovery device according to claim 1 , wherein the second adsorbent contains at least one of an amine-based material, a polymer material, and an inorganic material.

6. 6. The carbon dioxide recovery device according to claim 5, wherein the second adsorbent has a property of adsorbing the carbon dioxide contained in the gas when the gas is in a dehumidified state, and desorbing the adsorbed carbon dioxide when the gas is in a humidified state to a predetermined humidity.

7. The carbon dioxide recovery device according to claim 5 , wherein the second adsorbent has a property of desorbing the carbon dioxide by the water dispersed in the form of mist from the first adsorbent.

8. The carbon dioxide recovery apparatus according to claim 2 or 5, wherein the first adsorbent or the second adsorbent is supported inside the treatment tank in a solid state or a liquid state, respectively.

9. the first adsorbent or the second adsorbent is supported inside the treatment tank in a state where it is supported on a substrate; 6. The carbon dioxide recovery device according to claim 2 or 5, wherein the substrate includes at least one of a porous body, a membrane filter, and granular silica.

10. The carbon dioxide recovery device according to claim 1 , wherein the first adsorbent and the second adsorbent are supported inside the treatment tank without being in direct contact with each other.

11. a first concentration sensor for detecting the concentration of carbon dioxide contained in the untreated gas before being introduced into the treatment tank; The carbon dioxide recovery device according to claim 1 , further comprising: a second concentration sensor that detects the concentration of carbon dioxide contained in the gas treated inside the treatment tank.

12. The carbon dioxide recovery device according to claim 11, further comprising a control device that switches between an adsorption process for adsorbing the carbon dioxide and a desorption process for desorbing the adsorbed carbon dioxide based on the detection results of the first concentration sensor and the detection results of the second concentration sensor.

13. The carbon dioxide recovery device according to claim 12, further comprising a condenser that cools the gas obtained by the desorption process to remove moisture.

14. The carbon dioxide recovery apparatus according to claim 13, wherein the condenser cools the treated gas by air cooling or by utilizing waste cold energy in the carbon dioxide recovery apparatus.

15. 5. The carbon dioxide capture system of claim 4, further comprising an auxiliary device that applies the external conditions to the first adsorbent that promote desorption of the moisture.

16. the amount of moisture desorbed from the first adsorbent is controlled based on a temperature change of the first adsorbent; The change in humidity inside the treatment tank is controlled based on the amount of moisture; The carbon dioxide capture device according to claim 1 , wherein the amount of carbon dioxide desorbed from the second adsorbent is controlled based on the change in humidity.

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