Carbon dioxide recovery device and carbon dioxide recovery method

Abstract

Provided are a carbon dioxide recovery device and a carbon dioxide recovery method with which it is possible to improve CO2 recovery efficiency with respect to energy consumption. This carbon dioxide recovery device is provided with: an adsorbent that adsorbs CO2 and H2O; a reaction vessel in which an adsorbent is disposed; an H2O value detection means for detecting an H2O value, which is a value associated with the amount of H2O adsorbed on the adsorbent; and a flow rate adjustment means for adjusting the flow rate of the gas flowing into the reaction vessel on the basis of the H2O value detected by the H2O value detection means.

Description

Technical Field

[0001] The present disclosure relates to a carbon dioxide recovery device and a carbon dioxide recovery method for recovering carbon dioxide. Background Art

[0002] There is known a carbon dioxide recovery device including: an adsorbent that adsorbs CO2 and H2O, a reaction vessel in which the adsorbent is disposed, and an H2O concentration adjuster that adjusts the H2O concentration in a gas and causes the adjusted gas to flow into the reaction vessel (for example, refer to Patent Document 1).

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-034307 Summary of the Invention

[0004] In the above carbon dioxide recovery device, the H2O concentration adjuster is used to adjust the H2O concentration of the gas. Therefore, energy is required for the operation of the H2O concentration adjuster, and there is a possibility that the CO2 recovery efficiency deteriorates with respect to the energy consumption.

[0005] The present disclosure is an invention completed to solve such problems, and its main object is to provide a carbon dioxide recovery device and a carbon dioxide recovery method capable of improving the CO2 recovery efficiency with respect to the energy consumption.

[0006] One aspect of the present disclosure for achieving the above object is a carbon dioxide recovery device including: an adsorbent that adsorbs CO2 and H2O; a reaction vessel in which the adsorbent is disposed; an H2O value detection unit that detects an H2O value as a value associated with the amount of H2O adsorbed on the adsorbent; and a flow rate adjustment unit that adjusts the flow rate of the gas flowing into the reaction vessel based on the H2O value detected by the H2O value detection unit.

[0007] In this one aspect, it may be configured such that the flow rate adjustment unit increases the flow rate of the gas flowing into the reaction vessel when the H2O value detected by the H2O value detection unit is greater than a predetermined value.

[0008] In this one aspect, it may be configured such that the flow rate adjustment unit decreases the flow rate of the gas flowing into the reaction vessel when the H2O value detected by the H2O value detection unit is less than a predetermined value.

[0009] In one mode, it can also be set that the flow rate adjusting unit is switched between a low flow rate mode in which the flow rate of the gas flowing into the reaction vessel is relatively decreased and a high flow rate mode in which the flow rate of the gas flowing into the reaction vessel is relatively increased.

[0010] When the H2O value detected by the H2O value detection unit is greater than a predetermined value, the flow rate adjusting unit extends the time of the high flow rate mode, and when the H2O value detected by the H2O value detection unit is less than the predetermined value, the flow rate adjusting unit shortens the time of the high flow rate mode.

[0011] In one mode, it can also be set that the adsorbent contains amine.

[0012] In one mode, it can also be set that the adsorbent contains polyethyleneimine (PEI), the H2O value is the molar ratio of the H2O adsorption amount of the adsorbent when the humidification amount of the adsorbent is 0 to the CO2 adsorption amount of the adsorbent, and the predetermined value is 2.

[0013] In one mode, it can also be set that the adsorbent contains polyethyleneimine (PEI), and the adsorbent has a honeycomb structure supported on a honeycomb body.

[0014] One mode of the present disclosure for achieving the above object is a carbon dioxide recovery method, the carbon dioxide recovery method including: a step of detecting an H2O value which is a value associated with the amount of H2O adsorbed on an adsorbent disposed in a reaction vessel and adsorbing CO2 and H2O; a step of adjusting the flow rate of the gas flowing into the reaction vessel based on the detected H2O value.

[0015] One mode of the present disclosure for achieving the above object is a carbon dioxide recovery method, the carbon dioxide recovery method including: a low flow rate step of setting the flow rate of the gas flowing into a reaction vessel provided with an adsorbent for adsorbing CO2 and H2O to a predetermined low flow rate; a high flow rate step of setting the flow rate of the gas flowing into the reaction vessel to a high flow rate larger than the predetermined low flow rate after the low flow rate step.

[0016] According to the present disclosure, a carbon dioxide recovery device and a carbon dioxide recovery method capable of improving the CO2 recovery efficiency relative to energy consumption can be provided.

[0017] The above content and other objects, features, and advantages of the present disclosure will be more fully understood from the following detailed description and the accompanying drawings given by way of illustration only. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A block diagram of the same structure showing the outline of the carbon dioxide recovery apparatus according to the present embodiment.

[0019] Figure 2 A graph showing an example of the relationship between the cumulative CO2 adsorption amount achieved by the amine of the adsorbent material and the predetermined times t1 and t2.

[0020] Figure 3 A graph for explaining the energy consumption of the air supply device when the air supply device is switched from the low flow rate mode to the high flow rate mode.

[0021] Figure 4 A graph showing an example of the relationship between the H2O value and the H2O adsorption amount of the amine of the adsorbent material.

[0022] Figure 5 A graph showing an example of the relationship between the wind speed and the CO2 adsorption amount and the H2O adsorption amount. Detailed Embodiments

[0023] Embodiment 1

[0024] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. Figure 1 A block diagram of the system structure showing the outline of the carbon dioxide recovery apparatus according to the present embodiment. The carbon dioxide recovery apparatus 1 according to the present embodiment is, for example, an apparatus for recovering carbon dioxide from the atmosphere by the DAC (Direct Air Capture) method.

[0025] The carbon dioxide recovery apparatus 1 according to the present embodiment includes an adsorbent material 2, a reaction vessel 3, an H2O value detection unit 4, a flow rate adjustment unit 5, and a control unit 6.

[0026] The adsorbent material 2 is configured to adsorb CO2 (carbon dioxide) and H2O (water) from the surrounding gas. The adsorbent material 2 includes, for example, an amine such as PEI (polyethyleneimine) (N-(2-aminoethyl)-3-aminopropyl-methyldimethoxysilane (N-(2-aminoethyl) 3-aminopropylmethyldimethoxysilane), H2N(CH2)2NH(CH2)3SiCH3(OCH3)2: AEAPDMS). The amine of the adsorbent material 2 can also be configured as a fiber filter formed by impregnating nanofibers (Fibrillatedcellulose suspension), for example.

[0027] In addition, the structure of the above-mentioned adsorption material 2 is an example and is not limited thereto. For example, methods of forming the adsorption material 2 into a powder, granular, or pellet form, or methods of loading it on a honeycomb body can be cited. These shapes can also be determined based on necessary reaction rates, pressure losses, and the purity of CO2 in the removed gas, etc.

[0028] The adsorption material 2 is disposed at a predetermined position within the reaction vessel 3. The reaction vessel 3 is, for example, a sealed box-shaped container. An inflow pipe for allowing external air to flow into the interior and an outflow pipe for allowing the gas inside to flow out to the outside can be respectively connected to the reaction vessel 3. In addition, the external air is not limited to the atmosphere obtained by the above-mentioned DAC method, and can also be, for example, the gas discharged from factories, power plants, devices, etc.

[0029] The H2O value detection unit 4 is a specific example of the H2O value detection unit. The H2O value detection unit 4 detects the H2O value, which is a value associated with the amount of H2O adsorbed on the adsorption material 2 within the reaction vessel 3.

[0030] The H2O value is, for example, the adsorption amount or concentration of H2O adsorbed on the adsorption material 2. For example, the H2O value detection unit 4 respectively detects the amount of H2O in the gas flowing into the reaction vessel 3 from the inflow pipe and the amount of H2O in the gas flowing out of the reaction vessel 3 to the outside, which are detected by sensors or the like. Then, the H2O value detection unit 4 calculates the adsorption amount of H2O adsorbed on the adsorption material 2 based on the difference between the two detected amounts of H2O.

[0031] The flow rate adjustment unit 5 is a specific example of the flow rate adjustment unit. The flow rate adjustment unit 5 adjusts the flow rate of the gas flowing into the reaction vessel 3 from the inflow pipe based on the H2O value detected by the H2O value detection unit 4.

[0032] The flow rate adjustment unit 5 is composed of, for example, a gas supply device 51, an inflow valve 52, and an outflow valve 53. The gas supply device 51 allows gas to flow into the reaction vessel 3 via the inflow pipe. The inflow valve 52 is provided on the inflow pipe and can adjust the inflow amount of the gas flowing into the reaction vessel 3. The outflow valve 53 is provided on the outflow pipe and can adjust the outflow amount of the gas flowing out of the reaction vessel 3 to the outside.

[0033] The air supply device 51 of the flow rate adjustment unit 5 increases or decreases the flow rate of the gas flowing into the reaction vessel 3 from the inflow pipe by increasing or decreasing the wind speed (output) formed by the fan, for example, according to the control signal from the control unit 6. The air supply device 51 may also have a low flow rate mode in which the flow rate of the gas flowing into the reaction vessel 3 is relatively reduced, and a high flow rate mode in which the flow rate of the gas is relatively increased. By switching to the low flow rate mode or the high flow rate mode, the air supply device 51 can adjust the flow rate of the gas flowing into the reaction vessel 3.

[0034] In addition, the flow rate adjustment unit 5 may also adjust the flow rate of the gas flowing into the reaction vessel 3 by adjusting at least one of the inflow valve 52 and the outflow valve 53. In addition, the air supply device 51 may be provided on the outflow pipe and adjust the flow rate of the gas flowing out of the reaction vessel 3 to adjust the flow rate of the gas flowing into the reaction vessel 3.

[0035] The control unit 6 performs control such as the above-mentioned mode switching of the flow rate adjustment unit 5 and the opening and closing of the inflow valve and the outflow valve based on the H2O value detected by the H2O value detection unit 4. In addition, the control unit 6 and the flow rate adjustment unit 5 may be integrally formed.

[0036] The control unit 6 has, for example, the hardware structure of a general computer, and the hardware structure of the computer includes a processor 61 such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), an internal memory 62 such as a RAM (Random Access Memory) or a ROM (Read Only Memory), a storage device 63 such as an HDD (Hard Disk Drive) or an SDD (Solid State Drive), an input / output I / F 64 for connecting to peripheral devices such as a display, and a communication I / F 65 for communicating with devices outside the device.

[0037] Here, the characteristics of the amine of the adsorption material 2 will be described. Under dry conditions, the structure in which one molecule of CO2 is adsorbed on two molecules of amine (AEAPMDS2) becomes a stable structure. On the other hand, in the presence of H2O, the structure in which one molecule of CO2 is adsorbed on one molecule of amine (AEAPMDS1) becomes a stable structure. Therefore, the amine of the adsorption material 2 has the characteristics of adsorbing H2O or increasing the adsorption amount of CO2 in an environment with a large amount of surrounding H2O.

[0038] In addition, regarding the above characteristics, they are disclosed in detail in a non-patent document (Cost and Evaluation of the Direct Air Capture (DAC) Method of Carbon Dioxide (Vol. 2) - Adsorption and Separation Process, Low Carbon Society Strategy Center, National Research and Development Agency for Science and Technology Promotion, LCS-FY2020-PP-06), and thus this is set as content that can be appropriately cited.

[0039] Moreover, when the flow rate of the gas flowing into the reaction vessel 3 is small, compared with the case where the flow rate of the gas flowing into the reaction vessel 3 is large, the amine of the adsorbent material 2 has the characteristic that it will adsorb more H2O.

[0040] Considering the above characteristics of the amine of the adsorbent material 2, in the carbon dioxide recovery method according to the present embodiment, the flow rate adjustment unit 5 adjusts the flow rate of the gas flowing into the reaction vessel 3 based on the H2O value detected by the H2O value detection unit 4.

[0041] According to the carbon dioxide recovery method according to the present embodiment, for example, under the condition of not using special H2O concentration adjustment equipment, etc., by only adjusting the flow rate of the gas flowing into the reaction vessel 3 according to the H2O value of the adsorbent material 2, it is possible to effectively adsorb CO2 in the gas on the adsorbent material 2 and recover it. Therefore, it is possible to improve the CO2 recovery efficiency with respect to energy consumption.

[0042] For example, the flow rate adjustment unit 5 first reduces the flow rate of the gas flowing into the reaction vessel 3 at a predetermined time t1, so that the amine of the adsorbent material 2 adsorbs relatively more H2O. Thus, due to the large amount of H2O adsorbed on the amine of the adsorbent material 2, the CO2 adsorption capacity of the amine of the adsorbent material 2 is temporarily increased.

[0043] Subsequently, the flow rate adjustment unit 5 increases the flow rate of the gas flowing into the reaction vessel 3 at a predetermined time t2, so as to supply relatively more CO2 to the amine of the adsorbent material 2. Thus, it is possible to effectively adsorb the large amount of CO2 supplied by the amine of the adsorbent material 2 with increased CO2 adsorption capacity.

[0044] Therefore, it is possible to effectively adsorb more CO2 by the amine of the adsorbent material 2 while operating the flow rate adjustment unit 5 without waste to suppress its energy consumption. That is, it is possible to improve the CO2 recovery efficiency with respect to energy consumption.

[0045] In addition, although in the present embodiment, the adsorbent material 2 has a structure containing amine, it is not limited thereto, and it may also be a structure containing zeolite or activated carbon, etc., having the same characteristics as the above amine.

[0046] Next, an example of the method for determining the above-mentioned predetermined times t1 and t2 will be described. Figure 2 A graph showing an example of the relationship between the cumulative CO2 adsorption amount achieved by the amine of the adsorption material and the predetermined times t1 and t2.

[0047] In Figure 2 the dashed line represents the CO2 adsorption amount achieved by the amine of the adsorption material 2 when outside air flows into the reaction vessel 3 at a low wind speed v1 in the low flow rate mode. The dash-dotted line represents the CO2 adsorption amount achieved by the amine of the adsorption material 2 when outside air flows into the reaction vessel 3 at a high wind speed v2 in the high flow rate mode. The solid line represents the CO2 adsorption amount achieved by the amine of the adsorption material 2 when outside air flows into the reaction vessel 3 by switching from the low wind speed v1 in the low flow rate mode to the high wind speed v2 in the high flow rate mode as described later.

[0048] The air supply device 51 of the flow rate adjustment unit 5 causes air at a low wind speed v1 to flow from the inflow pipe into the reaction vessel 3 at the predetermined time t1 and in the low flow rate mode. Subsequently, the air supply device 51 causes air at a high wind speed v2 to flow from the inflow pipe into the reaction vessel 3 at the predetermined time t2 and in the high flow rate mode.

[0049] First, based on the measured humidity of the air, the H2O adsorption amount H1 and the CO2 adsorption amount C1 achieved by the amine of the adsorption material 2 when only the gas at this humidity flows into the reaction vessel 3 at a low wind speed v1 only at the predetermined time t1 are calculated.

[0050] After the amine of the adsorption material 2 has adsorbed H2O only by the above-mentioned H2O adsorption amount H1, the CO2 adsorption amount C2 achieved by the amine of the adsorption material 2 when only the gas flows into the reaction vessel 3 at a high wind speed v2 only at the predetermined time t2 is calculated. The predetermined times t1 and t2 are determined in such a way that the total CO2 adsorption amount C1 + C2 in the total CO2 adsorption process time T = t1 + t2 becomes the maximum or a certain amount or more. In addition, not only the predetermined times t1 and t2 change, but also the low wind speed v1 in the low flow rate mode and the high wind speed v2 in the high flow rate mode can be changed respectively.

[0051] In addition, the total energy consumption W1 + W2 of the air supply device 51 can be calculated based on the energy consumption W1 of the air supply device 51 in the low flow rate mode at the predetermined time t1 and the energy consumption W2 of the air supply device 51 in the high flow rate mode at the predetermined time t2. Moreover, the predetermined times t1 and t2 can be determined in such a way that the value of the total energy consumption W1 + W2 with respect to the total CO2 adsorption amount C1 + C2 becomes below the target value.

[0052] Figure 3 FIG. for explaining the energy consumption of the air supply device 51 when the air supply device 51 is switched from the low flow rate mode to the high flow rate mode as described above.

[0053] In Figure 3 , the dashed line indicates the energy consumption of the air supply device 51 at the low air velocity v1 in the low flow rate mode. The single-dot chain line indicates the energy consumption of the air supply device 51 at the high air velocity v2 in the high flow rate mode. The solid line indicates the energy consumption of the air supply device 51 when switching from the low air velocity v1 in the low flow rate mode to the high air velocity v2 in the high flow rate mode. In addition, in Figure 3 , for example, it is set that v1 = 1.2 [m / s], v2 = 3.3 [m / s], t1 = 2 [m], and t2 = 3 [m].

[0054] As Figure 3 shown, when switching from the low air velocity v1 in the low flow rate mode to the high air velocity v2 in the high flow rate mode, it can be confirmed that the energy consumption can be reduced by approximately 30% relative to the energy consumption of the air supply device 51 at the high air velocity v2 in the high flow rate mode.

[0055] Thus, in the present embodiment, in view of the CO2 adsorption ability corresponding to the H2O adsorption amount of the amine of the adsorption material 2, the inflow amount of the gas into the reaction vessel 3 achieved by the air supply device 51 can be adjusted without waste. Thereby, while suppressing the energy consumption of the air supply device 51, the amine of the adsorption material 2 can effectively adsorb more CO2. That is, the CO2 recovery efficiency relative to the energy consumption can be improved.

[0056] In addition, as described above, any method can be used for removing CO2 from the adsorption material 2 after the adsorption material 2 has adsorbed CO2. For example, a temperature-swing adsorption method of raising the temperature of the adsorption material 2 to remove CO2 is envisioned.

[0057] Although the H2O adsorption amount of the adsorption material 2 basically continues to increase as the gas flows into the reaction vessel 3, during the above-mentioned removal, the H2O adsorption amount is reset by heating. Therefore, in order for the adsorption material 2 to adsorb CO2, it is necessary to make the adsorption material 2 adsorb H2O again as described above. In addition, as a situation where the H2O adsorption amount decreases, for example, a situation where the humidity of the atmosphere changes from a high state to a low state and a gas that has been rapidly dried flows into the reaction vessel 3 is also envisioned.

[0058] The carbon dioxide recovery device 1 according to the above-described embodiment first allows air to flow into the reaction vessel 3 at a low wind speed in the low flow rate mode, and then allows air to flow into the reaction vessel 3 at a high wind speed in the high flow rate mode.

[0059] On the other hand, in the case of a DAC with a long cycle (one cycle is one day), the humidity of the air may change during this period. For example, it is conceivable that the humidity of the air is low in the morning and high at night. In this case, the carbon dioxide recovery device 1 may also allow air to flow into the reaction vessel 3 at a high wind speed in the high flow rate mode and then allow air to flow into the reaction vessel 3 at a low wind speed in the low flow rate mode.

[0060] Embodiment 2

[0061] In the present embodiment, it may also be configured such that when the H2O value detected by the H2O value detection unit 4 is greater than a predetermined value, the flow rate of the gas flowing into the reaction vessel 3 is increased.

[0062] As described above, when the H2O value of the amine in the adsorbent material 2 is greater than a predetermined value, that is, in a state where the CO2 adsorption ability of the amine is high, the amount of CO2 flowing into the reaction vessel 3 is increased. Thereby, the amine in the adsorbent material 2 can efficiently adsorb CO2.

[0063] On the other hand, it may also be configured such that when the H2O value detected by the H2O value detection unit 4 is less than a predetermined value, the flow rate of the gas flowing into the reaction vessel 3 is decreased.

[0064] As described above, when the H2O value of the amine in the adsorbent material 2 is less than a predetermined value, that is, in a state where the CO2 adsorption ability of the amine is low, the amount of CO2 flowing into the reaction vessel 3 is decreased. Thereby, by decreasing the flow rate of the gas flowing into the reaction vessel 3, the H2O adsorption amount of the amine in the adsorbent material 2 can be increased, and further, the CO2 adsorption ability of the amine can be increased by the increased H2O.

[0065] Here, an example of a method for setting the above-mentioned predetermined value will be described. Figure 4 is a diagram showing an example of the relationship between the H2O value and the CO2 adsorption amount of the amine in the adsorbent material. In addition, in Figure 4 , the H2O value is, for example, the molar ratio of the H2O adsorption amount when the humidification amount of the adsorbent material 2 is 0 to the CO2 adsorption amount of the adsorbent material 2. In addition, the adsorbent material 2 contains PEI (polyethyleneimine). As Figure 4 shown, since the CO2 adsorption amount of the adsorbent material 2 significantly increases when the H2O value generally exceeds 2, the predetermined value may also be set to approximately 2.

[0066] In addition, it can also be set that when the H2O value detected by the H2O value detection unit 4 is greater than a predetermined value, the flow rate adjustment unit 5 extends the predetermined time t2 of the high flow rate mode. Thereby, when in a state where the H2O value (H2O adsorption amount) is large and the CO2 adsorption ability of the amine of the adsorbent material 2 is high, by extending the predetermined time t2 of the high flow rate mode in which the amount of CO2 flowing into the reaction vessel 3 becomes larger, the adsorbent material 2 can adsorb CO2 with good energy efficiency.

[0067] On the other hand, it can also be set that when the H2O value detected by the H2O value detection unit 4 is less than a predetermined value, the flow rate adjustment unit 5 shortens the predetermined time t2 of the high flow rate mode. Thereby, when the H2O value (H2O adsorption amount) is small and the CO2 adsorption ability of the amine of the adsorbent material 2 is low, by shortening the time of the high flow rate mode in which the amount of CO2 flowing into the reaction vessel 3 becomes larger, it is possible to increase the H2O adsorption amount of the amine of the adsorbent material 2 and increase the CO2 adsorption ability while suppressing energy consumption.

[0068] Embodiment 3

[0069] In this embodiment, it can also be set that the adsorbent material 2 contains PEI (polyethyleneimine), and the adsorbent material has a honeycomb structure supported on a honeycomb body.

[0070] With this structure, as Figure 5 shown, the CO2 adsorption amount is increased at a wind speed of 1.83 times (3.3 / 1.8) compared to the normal wind speed (1.8). In addition, the H2O adsorption amount is increased at a wind speed of 0.56 times (1.0 / 1.8) compared to the normal wind speed (1.8).

[0071] Although some embodiments of the present disclosure have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope or gist of the invention and are included in the invention described in the claims and its equivalents.

[0072] It is clearly understood from the disclosure described in this way that the disclosed embodiments can be changed in various ways. Obviously, such changes should not be regarded as departing from the spirit and scope of the present invention, and for those skilled in the art, all such changes should be included in the appended claims.

Claims

1. A carbon dioxide recovery device, comprising: Adsorbent material, which adsorbs CO2 and H2O; a reaction container, in which the adsorption material is arranged; an H2O value detection unit that detects an H2O value that is a value associated with an amount of H2O adsorbed on the adsorption material; A flow rate adjustment unit adjusts the flow rate of the gas flowing into the reaction container based on the H 2 O value detected by the H 2 O value detection unit.

2. The carbon dioxide recovery device according to claim 1, wherein: The flow rate adjustment unit increases a flow rate of the gas flowing into the reaction container when the H 2 O value detected by the H 2 O value detection unit is greater than a predetermined value.

3. The carbon dioxide recovery device according to claim 1, wherein: The flow rate adjustment unit reduces a flow rate of the gas flowing into the reaction container when the H 2 O value detected by the H 2 O value detection unit is lower than a predetermined value.

4. The carbon dioxide recovery device according to claim 1, wherein: The flow rate adjustment unit is switched between a low flow rate mode for relatively reducing the flow rate of the gas flowing into the reaction container and a high flow rate mode for relatively increasing the flow rate of the gas flowing into the reaction container. The flow rate regulating unit extends the time of the high flow rate mode when the H2O value detected by the H2O value detecting unit is greater than a predetermined value, and shortens the time of the high flow rate mode when the H2O value detected by the H2O value detecting unit is less than a predetermined value.

5. The carbon dioxide recovery device according to claim 1, wherein: The adsorbent material contains an amine.

6. The carbon dioxide recovery device according to claim 2, wherein: The adsorbent material comprises polyethyleneimine, The H2O value is a molar ratio of the H2O adsorption amount of the adsorbent material to the CO2 adsorption amount of the adsorbent material when the humidification amount of the adsorbent material is 0, The predetermined value is 2.

7. The carbon dioxide recovery device according to claim 1, wherein: The adsorbent material includes polyethyleneimine, and the adsorbent material forms a honeycomb structure supported on a honeycomb body.

8. A method for recovering carbon dioxide, comprising: a step of detecting an H2O value which is a value associated with an amount of H2O adsorbed on an adsorbent material disposed in a reaction container and adsorbing CO2 and H2O; A step of adjusting the flow rate of the gas flowing into the reaction container based on the detected H2O value.

9. A method for recovering carbon dioxide, comprising: A low flow rate step of setting the flow rate of the gas flowing into the reaction container in which the adsorbent material for adsorbing CO2 and H2O is arranged to a predetermined low flow rate; The high flow rate step is a step of setting the flow rate of the gas flowing into the reaction container to a high flow rate that is larger than the predetermined low flow rate after the low flow rate step.

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