Direct air capture system and control method for the same

Abstract

To provide a direct air capture system capable of selecting an appropriate capture method in accordance with usage of carbon dioxide to be recovered.SOLUTION: A direct air capture system according to this disclosure is a direct air capture system including a plurality of direct air capture devices with different carbon dioxide capture methods; and a controller that controls the plurality of direct air capture devices. The controller acquires usage information on usage of carbon dioxide to be recovered by the direct air capture system, and selects any one of the plurality of direct air capture devices on the basis of the usage information.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a direct air recovery system and a method for controlling the same. [Background technology]

[0002] Patent Document 1 discloses a direct air capture (DAC) device that includes a reaction flow path containing a carbon dioxide adsorbent in the wall and a heat exchange flow path for flowing a heat medium for heating or cooling the reaction flow path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2013 / 106043 Summary of the Invention [Problem to be solved by the invention]

[0004] The direct air capture system disclosed in Patent Document 1 uses a chemical adsorption method in which carbon dioxide in the atmosphere is adsorbed onto an adsorbent and captured. In addition to the chemical adsorption method, other known methods for capturing carbon dioxide in direct air capture systems include chemical absorption, membrane separation, and cryogenic separation. The concentration of captured carbon dioxide varies depending on the carbon dioxide capture method, and therefore the suitable uses for the captured carbon dioxide also vary. In other words, the appropriate capture method also varies depending on the use of the captured carbon dioxide.

[0005] The present disclosure has been made in consideration of the above circumstances, and provides a direct air capture system that allows selection of an appropriate capture method depending on the use of the carbon dioxide to be captured. [Means for solving the problem]

[0006] A direct air capture system according to the present disclosure comprises: Multiple direct air capture devices with different carbon dioxide capture methods, a controller for controlling the plurality of direct air recovery devices, The controller obtaining use information regarding the use of the carbon dioxide captured by the direct air capture system; Based on the application information, one of the plurality of direct air recovery devices is selected.

[0007] The direct air capture system according to the present disclosure acquires use information relating to the use of the carbon dioxide captured by the direct air capture system, and selects one of a plurality of direct air capture devices with different carbon dioxide capture methods based on the use information. In this way, an appropriate capture method can be selected depending on the use of the carbon dioxide to be captured.

[0008] The recovery method may be any one of a chemical adsorption method in which carbon dioxide in the atmosphere is adsorbed onto a solid adsorbent and recovered; a chemical absorption method in which carbon dioxide in the atmosphere is absorbed into an absorption liquid and recovered; a membrane separation method in which carbon dioxide is recovered using a separation membrane that selectively allows carbon dioxide in the atmosphere to permeate; and a cryogenic separation method in which carbon dioxide in the atmosphere is cooled and solidified to recover the carbon dioxide.

[0009] If the use of the carbon dioxide captured by the direct air capture system is to produce synthetic fuels or chemicals by synthesizing the carbon dioxide with hydrogen, the controller may select the direct air capture device using the chemical adsorption method or the chemical absorption method as the capture method.

[0010] If the use of the carbon dioxide captured by the direct air capture system is to produce carbonate using the carbon dioxide, the controller may select the direct air capture device using the membrane separation method as the capture method.

[0011] A method for controlling a direct air recovery system according to the present disclosure includes: A control method for a direct air capture system having a plurality of direct air capture devices with different carbon dioxide capture methods, comprising: The computer obtaining use information regarding the use of the carbon dioxide captured by the direct air capture system; Based on the application information, one of the plurality of direct air recovery devices is selected.

[0012] In the control method for a direct air capture system according to the present disclosure, application information relating to the use of the carbon dioxide captured by the direct air capture system is acquired, and one of a plurality of direct air capture devices with different carbon dioxide capture methods is selected based on the application information. In this way, an appropriate capture method can be selected depending on the use of the captured carbon dioxide. [Effects of the Invention]

[0013] According to the present disclosure, a direct air capture system can be provided that allows for the selection of an appropriate capture method depending on the use of the carbon dioxide to be captured. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a block diagram showing the configuration of a direct air recovery system according to a first embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of a suction device 110. [Figure 3] FIG. 2 is a block diagram showing an example of the configuration of a membrane separation device 120. [Figure 4] 3 is a flowchart showing a control method for the direct air recovery system according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, specific embodiments of the present disclosure will be described in detail with reference to the drawings. However, the present disclosure is not limited to the following embodiments. In addition, the following description and drawings have been simplified as appropriate for clarity of explanation.

[0016] (First embodiment) <Configuration of direct air recovery system> First, the configuration of a direct air recovery system according to a first embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing the configuration of a direct air recovery system according to the first embodiment. In Fig. 1, thick arrows indicate gas flow, and thin arrows indicate signal flow. As shown in FIG. 1, the direct air recovery system according to this embodiment includes an adsorption device 110, a membrane separation device 120, a cryogenic separation device 130, and a controller 200.

[0017] The adsorption device 110 is a direct air recovery device that uses, for example, a chemical adsorption method with a solid adsorbent. As shown in FIG. 1, a first gas is supplied to the adsorption device 110 via an electromagnetic valve V1. The first gas is not limited to the atmosphere but also includes exhaust gases from factories, automobiles, etc. Gases in the first gas other than carbon dioxide (CO2) pass through a CO2 adsorption unit 111 and are discharged as they are (not shown).

[0018] 2 is a block diagram showing an example of the configuration of the adsorption apparatus 110. The adsorption apparatus 110 shown in Fig. 2 includes a CO2 adsorption unit 111, a heater 112, and a decompression pump 113. As shown in Fig. 2, in the adsorption apparatus 110, CO2 in the first gas is adsorbed onto a solid adsorbent included in the CO2 adsorption unit 111.

[0019] Thereafter, in the adsorption device 110, the CO2 adsorption unit 111 (i.e., the solid adsorbent) that has adsorbed the CO2 is heated to, for example, about 100°C by a heater 112, and the pressure is reduced by a decompression pump 113. With this configuration, CO2 gas is extracted from the adsorption device 110. For example, CO2 gas with a high concentration of about 99.9% can be obtained.

[0020] In this way, the adsorption device 110 repeats a process of passing the first gas through the CO2 adsorption unit 111 at room temperature to recover CO2, and a process of heating and depressurizing the CO2 adsorption unit 111 to extract CO2.

[0021] In the CO2 adsorption unit 111, the first gas is brought into contact with a porous carrier carrying, for example, a solid adsorbent, and the CO2 in the first gas is adsorbed by the carbon dioxide absorbent and recovered. Here, the porous carrier carrying the solid adsorbent is not particularly limited, but may be, for example, coated on a substrate having a honeycomb structure.

[0022] The solid adsorbent is not particularly limited, but is, for example, a hydrophilic polymer, more specifically, an amine-based polymer such as polyethyleneimine, primary amine, secondary amine, or secondary alkanolamine.

[0023] The heater 112 is a heating device for heating the CO2 adsorption unit 111 when CO2 is extracted from the solid adsorbent that has adsorbed CO2. The heater 112 is controlled by, for example, the controller 200 shown in FIG.

[0024] The decompression pump 113 is a decompression device for decompressing the CO2 adsorption unit 111 when CO2 is extracted from the solid adsorbent that has adsorbed CO2. The decompression pump 113 is controlled by, for example, the controller 200 shown in FIG. The decompression pump 113 is merely an example of a decompression device, and includes a vacuum pump.

[0025] The membrane separation device 120 shown in Figure 1 is a direct air recovery device that uses a membrane separation method to separate and capture CO2 using, for example, a separation membrane that selectively allows CO2 to permeate. As shown in Figure 1, a first gas is supplied to the membrane separation device 120 via an electromagnetic valve V2. The membrane separation device 120 uses a separation membrane module that selectively allows CO2 to permeate, and separates and extracts CO2 gas from the first gas. Gases other than CO2 in the first gas pass through the membrane separation device 120 and are discharged as passed gas.

[0026] Here, FIG. 3 is a block diagram showing an example of the configuration of the membrane separation device 120. As shown in FIG. As shown in Fig. 3, the membrane separation device 120 includes separation membrane modules SM1 to SM3 and suction pumps P1 to P3. The suction pumps P1 to P3 are controlled by, for example, a controller 200. In Fig. 3, arrows indicate the flow of gas.

[0027] The separation membrane modules SM1 to SM3 selectively allow CO2 to permeate through separation membranes. In the separation membrane modules SM1 to SM3, for example, a cylindrical container is filled with a large number of bundled hollow fiber separation membranes that extend to both ends.

[0028] As shown in Figure 3, a first gas is introduced into one end of the separation membrane module SM1 and passes through the interior of the separation membrane module SM1. A suction pump P1 is connected to the outer peripheral surface at the other end of the separation membrane module SM1. The suction pump P1 causes CO2 in the first gas passing through the interior of the separation membrane module SM1 to pass through the hollow fiber separation membranes and be extracted to the outside of the separation membrane module SM1. The gas extracted from the separation membrane module SM1 contains a higher concentration of CO2 than the first gas. On the other hand, the gas from which CO2 has been removed is discharged from the other end of the separation membrane module SM1 as a passing gas.

[0029] As shown in FIG. 3, the gas extracted from the separation membrane module SM1 is introduced into one end of the separation membrane module SM2. A suction pump P2 is connected to the outer peripheral surface at the other end of the separation membrane module SM2. The suction pump P2 causes CO2 in the gas passing through the interior of the separation membrane module SM2 to pass through the hollow fiber separation membranes and be extracted to the outside of the separation membrane module SM2. The gas extracted from the separation membrane module SM2 contains a higher concentration of CO2 than the gas extracted from the separation membrane module SM1. On the other hand, the gas from which CO2 has been removed is discharged from the other end of the separation membrane module SM2 as a passing gas.

[0030] As shown in FIG. 3, the gas extracted from the separation membrane module SM2 is introduced into one end of the separation membrane module SM3. A suction pump P3 is connected to the outer peripheral surface at the other end of the separation membrane module SM3. The suction pump P3 causes CO2 in the gas passing through the interior of the separation membrane module SM3 to pass through the hollow fiber separation membranes and be extracted to the outside of the separation membrane module SM3. The gas extracted from the final separation membrane module SM3 contains a higher concentration of CO2 than the gas extracted from the separation membrane module SM2. On the other hand, the gas from which CO2 has been removed is discharged from the other end of the separation membrane module SM3 as a passing gas.

[0031] In this way, a plurality of separation membrane modules SM1 to SM3 are connected in multiple stages in the membrane separation device 120. With this configuration, CO2 gas with a concentration of, for example, about 95% can be obtained. Naturally, the number of separation membrane modules connected in multiple stages is not limited to three as shown in Figure 2. The more stages of separation membrane modules connected, the higher the CO2 concentration in the output gas, and the fewer stages of separation membrane modules connected, the lower the CO2 concentration in the output gas.

[0032] The cryogenic separation device 130 shown in FIG. 1 is a direct air recovery device using a cryogenic separation method. As shown in FIG. 1, a first gas is supplied to the cryogenic separation device 130 via an electromagnetic valve V3. The cryogenic separation device 130 compresses and cools the first gas, solidifies the CO2 in the first gas, and separates and extracts the CO2 from the first gas. The cryogenic separation device 130 produces a very high-concentration CO2 gas, for example, with a concentration of 99.9% or more.

[0033] As shown in Fig. 1, the controller 200 acquires usage information regarding the usage of the captured CO2, and selects one of a plurality of direct air capture devices based on the usage information. In the example shown in Fig. 1, the direct air capture devices are an adsorption device 110, a membrane separation device 120, and a cryogenic separation device 130.

[0034] 1, the controller 200 controls the electromagnetic valves V1 to V3 for supplying the first gas based on the application information. When the adsorption device 110 is selected, the controller 200 opens the electromagnetic valve V1 and closes the electromagnetic valves V2 and V3. When the membrane separation device 120 is selected, the controller 200 opens the electromagnetic valve V2 and closes the electromagnetic valves V1 and V3. When the cryogenic separation device 130 is selected, the controller 200 opens the electromagnetic valve V3 and closes the electromagnetic valves V1 and V2.

[0035] 1, the controller 200 selects one of the adsorption device 110, the membrane separation device 120, and the cryogenic separation device 130 by opening and closing the electromagnetic valves V1 to V3, but the present invention is not limited to such a configuration. For example, the controller 200 may be configured to directly control the operation and stop of the adsorption device 110, the membrane separation device 120, and the cryogenic separation device 130. In other words, the electromagnetic valves V1 to V3 are not essential.

[0036] 1, the high-concentration CO2 gas with a concentration of about 99.9% output from the adsorption device 110 is used to synthesize the CO2 with hydrogen to produce synthetic fuels and chemical products, such as polycarbonate, methanol, ethanol, carbon black, ethylene, methane, and high-purity carbonates.

[0037] Furthermore, although not particularly limited, as shown in FIG. 1, the CO2 gas having a concentration of about 95% output from the membrane separation device 120 can be used for the production of carbonates, concrete, cement, carbon, etc. Furthermore, although not particularly limited, as shown in FIG. 1, the high-concentration CO2 gas having a concentration of 99.9% or more output from the cryogenic separation device 130 can be used, for example, to produce carbonated drinks. The above uses are input to the controller 200 as use information.

[0038] 1, the controller 200 includes a calculation unit such as a CPU (Central Processing Unit), and memories such as RAM (Random Access Memory) and ROM (Read Only Memory) that store various programs, data, etc. In other words, the controller 200 functions as a computer and executes various processes based on the various programs, etc.

[0039] As described above, the direct air capture system according to this embodiment acquires use information related to the use of the carbon dioxide captured by the direct air capture system. Then, based on the use information, one of multiple direct air capture devices with different carbon dioxide capture methods is selected. Therefore, an appropriate capture method can be selected depending on the use of the captured carbon dioxide.

[0040] The direct air capture system according to this embodiment only needs to include multiple direct air capture devices with different CO2 capture methods, and does not need to include all of the adsorption device 110, membrane separation device 120, and cryogenic separation device 130 shown in Figure 1. On the other hand, the direct air capture system according to this embodiment may further include a direct air capture device that uses another CO2 capture method not shown in FIG.

[0041] For example, the direct air recovery system according to this embodiment may include a direct air recovery device using a chemical absorption method, in which CO2 in the atmosphere is absorbed in an absorption liquid and recovered, instead of or in addition to the adsorption device 110. A direct air recovery device using a chemical absorption method can also produce CO2 gas with a high concentration, for example, of about 99.9%, and can be used for applications similar to those of the adsorption device 110.

[0042] <Control method for direct air recovery system> Next, a control method for the direct air recovery system according to the first embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing a control method for the direct air recovery system according to the first embodiment. In the description of Fig. 4, Fig. 1 will be referred to as appropriate.

[0043] First, as shown in FIG. 4, the controller 200 acquires use information relating to the use of the CO2 captured by the direct air capture system (step ST1). Then, as shown in FIG. 4, the controller 200 selects one of the plurality of direct air recovery devices based on the application information (step ST2).

[0044] In the example shown in FIG. 1, the controller 200 controls the electromagnetic valves V1 to V3 for supplying the first gas based on the application information. Specifically, if the application is, for example, synthetic fuel or chemical production, the controller 200 selects the adsorber 110. In that case, the controller 200 opens the solenoid valve V1 and closes the solenoid valves V2 and V3.

[0045] If the application is, for example, carbonate production, the controller 200 selects the membrane separation device 120. In this case, the controller 200 opens the solenoid valve V2 and closes the solenoid valves V1 and V3. If the application is, for example, the production of carbonated drinks, the controller 200 selects the cryogenic separation device 130. In this case, the solenoid valve V3 is opened and the solenoid valves V1 and V2 are closed.

[0046] In addition, if the direct air recovery system of this embodiment is equipped with a direct air recovery device using a chemical absorption method instead of or in addition to the adsorption device 110, and the application is the production of synthetic fuels or chemicals, the controller 200 can appropriately select either the adsorption device 110 or the direct air recovery device using a chemical absorption method.

[0047] As described above, the control method for a direct air capture system according to this embodiment acquires use information related to the use of carbon dioxide captured by the direct air capture system. Then, based on the use information, one of a plurality of direct air capture devices with different carbon dioxide capture methods is selected. Therefore, an appropriate capture method can be selected depending on the use of the captured carbon dioxide.

[0048] The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate within the scope of the present disclosure. This disclosure also contributes to carbon neutrality, decarbonization, and the Sustainable Development Goals (SDGs). [Explanation of symbols]

[0049] 110 Adsorption device 111 CO2 absorption unit 112 Heater 113 Pressure reducing pump 120 Membrane separation equipment 130 Cryogenic separation equipment 200 Controller P1~P3 suction pump SM1~SM3 Separation membrane modules V1~V3 solenoid valves

Claims

1. Multiple direct air capture devices with different carbon dioxide capture methods, a controller for controlling the plurality of direct air recovery devices, The controller obtaining use information regarding the use of the carbon dioxide captured by the direct air capture system; selecting one of the plurality of direct air recovery devices based on the application information; Direct air recovery system.

2. The recovery method includes: A chemical adsorption method in which atmospheric carbon dioxide is absorbed onto a solid adsorbent and then recovered. Chemical absorption method, which recovers carbon dioxide from the atmosphere by absorbing it into an absorption solution; a membrane separation method for recovering carbon dioxide using a separation membrane that selectively allows carbon dioxide in the atmosphere to permeate; or cryogenic separation, which cools and solidifies atmospheric carbon dioxide to capture it.

10. The direct air recovery system of claim 1.

3. If the carbon dioxide captured by the direct air capture system is used to produce synthetic fuels or chemicals by synthesizing the carbon dioxide with hydrogen, The controller Selecting a direct air recovery device using the chemical adsorption method or the chemical absorption method as the recovery method.

3. The direct air recovery system of claim 2.

4. If the carbon dioxide captured by the direct air capture system is used to produce carbonates, The controller Selecting a direct air recovery device using the membrane separation method as the recovery method; 3. The direct air recovery system of claim 2.

5. A control method for a direct air capture system having a plurality of direct air capture devices with different carbon dioxide capture methods, comprising: The computer obtaining use information regarding the use of the carbon dioxide captured by the direct air capture system; selecting one of the plurality of direct air recovery devices based on the application information; Control methods for direct air recovery systems.

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