CO2 recovery device and CO2 recovery method

Abstract

To provide a CO2 recovery device and a CO2 recovery method that can recover CO2 with a simple equipment configuration. [Solution] An apparatus for recovering CO2 from a target gas containing CO2 and having a temperature of 100°C or higher using a temperature swing method, comprising: a cooling means for cooling the target gas to a temperature of 5°C or higher but lower than 100°C; an adsorption tower containing an adsorbent for adsorbing CO2 in the cooled target gas; a target gas inlet pipe for introducing the cooled target gas into the adsorption tower; and a CO2 outlet pipe for extracting CO2 adsorbed in the adsorption tower, wherein the target gas inlet pipe is connected to the top of the adsorption tower, and the CO2 outlet pipe is connected to the bottom of the adsorption tower.

Description

[Technical Field]

[0001] The present disclosure relates to a CO2 capture device and a CO2 capture method. [Background technology]

[0002] In order to reduce emissions of carbon dioxide (CO2), a greenhouse gas, various studies are being conducted on technologies to capture CO2 from exhaust gases with relatively low CO2 concentrations, such as combustion exhaust gases emitted from power plants and steel mills, particularly from the perspective of energy conservation.

[0003] For example, Patent Document 1 (JP 2023-114890 A) discloses that by improving zeolite, a CO2 adsorbent, the temperature range for adsorption and desorption when recovering CO2 using temperature swing adsorption can be narrowed, thereby achieving energy savings.

[0004] Patent Document 2 (JP Patent Publication No. 2013-542058) discloses that a liquid amine absorbent is used as a CO2 adsorbent to absorb CO2 in the range of 70 to 90°C and desorb it at 100°C or higher, thereby achieving energy savings.

[0005] Patent Document 3 (JP 2023-108268 A) discloses that unused waste heat contained in combustion exhaust gas is utilized to generate steam, which is then used as a heat source for the CO2 desorption process, thereby achieving energy savings.

[0006] Patent Document 4 (JP 2021-159816 A) discloses that when recovering CO2 using the temperature swing adsorption method, energy savings are achieved by setting the temperature during adsorption to below 5°C in each process. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2023-114890 [Patent Document 2] Special Publication No. 2013-542058 [Patent Document 3] Japanese Patent Application Publication No. 2023-108268 [Patent Document 4] Patent Publication No. 2021-159816 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the technology described in Patent Document 1 employs zeolite, which has high hygroscopicity, and moisture adsorption inhibits CO2 adsorption. Combustion exhaust gas often contains water vapor, and using zeolite as an adsorbent poses the problem of actually requiring a dehumidifying mechanism or the like prior to the adsorption of the adsorbent. While one method of enabling moisture desorption without using a dehumidifying mechanism or the like involves heating the zeolite to around 300°C, this results in problems such as a decrease in the amount of CO2 adsorbed due to moisture adsorption and a need to improve the heat resistance of the equipment.

[0009] The technology described in Patent Document 2 uses a non-aqueous amine absorbent, and requires that CO2 absorption and desorption be carried out in separate towers, which results in the problem of complex equipment.

[0010] In the technology described in Patent Document 3, the gas flows from bottom to top during CO2 adsorption, and when treating a large amount of gas, the adsorbent packed in the adsorption tower may float, causing the adsorbent to wear out. Therefore, in order to increase the amount of gas treated, the adsorption tower must be made larger, which results in a problem of an increased size of the device.

[0011] The technology described in Patent Document 4 has the problem that it can only be implemented in places where there is cold energy, since the gas temperature during adsorption is below freezing. In addition, since the off-gas after adsorption is used as heating gas, it is difficult to achieve high purity of the product CO2.

[0012] An object of the present disclosure is to provide a CO2 capture device and a CO2 capture method that are capable of capturing CO2 with a simple equipment configuration. [Means for solving the problem]

[0013] [1] An apparatus for recovering CO2 from a target gas containing CO2 and having a temperature of 100°C or higher by a temperature swing method, A cooling means for cooling the target gas to a temperature of 5°C or higher but lower than 100°C; an adsorption tower including an adsorbent for adsorbing CO2 in the cooled target gas; a target gas introduction pipe for introducing the cooled target gas into the adsorption tower; a CO2 outlet pipe for outletting the CO2 adsorbed in the adsorption tower, the target gas introduction pipe is connected to the top of the adsorption tower, A CO2 recovery device, wherein the CO2 outlet pipe is connected to the bottom of the adsorption tower.

[0014] [2] The CO2 recovery device according to [1], wherein the cooling means is a main heat exchanger.

[0015] [3] A CO2 recovery device according to [2], further comprising a control device for controlling the flow rate of the thermal control fluid when the target gas is cooled by heat exchange between the target gas and the thermal control fluid.

[0016] [4] The CO2 recovery device according to any one of [1] to [3], wherein the target gas is a combustion exhaust gas.

[0017] [5] A method for recovering CO2 from a target gas containing CO2 and having a temperature of 100°C or higher by a temperature swing method, a cooling step of cooling the target gas to 5°C or higher but lower than 100°C; an adsorption step of adsorbing CO2 in the target gas after the cooling step using an adsorption tower filled with an adsorbent; a desorption step of desorbing CO2 by heating the adsorbent after the adsorption step, In the adsorption step, the cooled target gas is introduced from the top of the adsorption tower, A CO2 recovery method, wherein in the desorption step, the desorbed CO2 is discharged from the bottom of the adsorption tower.

[0018] [6] The CO2 recovery method according to [5], wherein the cooling step is carried out by heat exchange between the target gas and a thermal control fluid.

[0019] [7] The CO2 recovery method according to [6], wherein heat exchange between the target gas and the thermal control fluid is carried out by controlling the flow rate of the thermal control fluid.

[0020] [8] The CO2 recovery method according to any one of [5] to [7], wherein in the desorption step, the adsorbent is heated by introducing a heated gas from the top of the adsorption tower.

[0021] [9] The CO2 recovery method according to [8], wherein the heated gas is at least one selected from the group consisting of the target gas, recovered CO2 heated by heat exchange with the target gas, and steam.

[0022]

[10] The CO2 recovery method according to any one of [5] to [9], wherein the target gas is a combustion exhaust gas. [Effects of the Invention]

[0023] According to the present disclosure, it is possible to provide a CO2 capture device and a CO2 capture method that are capable of capturing CO2 with a simple equipment configuration. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a CO2 recovery device according to this embodiment. [Figure 2] FIG. 2 is a schematic diagram showing another example of the configuration of the CO2 recovery device according to this embodiment. [Figure 3] FIG. 3 is a schematic diagram showing another example of the configuration of the CO2 recovery apparatus in the present embodiment.

[0025] Hereinafter, embodiments of the present disclosure will be described. However, the following description does not limit the scope of the claims.

[0026] In the recovery of CO2, there are techniques for adsorbing and recovering CO2 with a physical adsorbent, techniques for absorbing and recovering CO2 with a chemical absorbent, and the like. Generally, adsorption and absorption are different concepts, but in the present embodiment, the term "adsorption" shall include both concepts.

[0027] <CO2 recovery apparatus> Referring to FIGS. 1 to 3, the CO2 recovery apparatus 30 in the present embodiment is an apparatus for recovering CO2 from a target gas containing CO2 and having a temperature of 100°C or higher by the temperature swing method. The CO2 recovery apparatus 30 includes a cooling means 1 for cooling the target gas to 5°C or higher and lower than 100°C, an adsorption tower 10 (10a, 10b) containing an adsorbent for adsorbing CO2 in the cooled target gas, a target gas introduction pipe 3 for introducing the cooled target gas into the adsorption tower 10, and a CO2 discharge pipe 11 for discharging the CO2 adsorbed on the adsorption tower 10. The target gas introduction pipe 3 is connected to the top of the adsorption tower 10. The CO2 discharge pipe 11 is connected to the bottom of the adsorption tower 10. Hereinafter, the CO2 recovery apparatus 30 in the present embodiment will be described.

[0028] (Target gas) In the present embodiment, the "target gas" is a gas containing CO2 and having a temperature of higher than 100°C. The target gas is, for example, exhaust gas that would be directly discharged into the atmosphere and emit CO2 into the atmosphere if it were not the target of CO2 recovery in the present embodiment. Examples of such exhaust gas include combustion exhaust gas discharged from a thermal power plant, a boiler, or the like.

[0029] The temperature of the target gas is 100°C or higher, preferably 105°C or higher and 300°C or lower, and more preferably 120°C or higher and 300°C or lower.

[0030] The concentration of CO2 contained in the target gas is preferably 1% by volume or more and 20% by volume or less, and more preferably 5% by volume or more and 20% by volume or less.

[0031] (cooling means) The cooling means 1 cools the target gas to a temperature of 5° C. or higher and lower than 100° C. As a result, CO2 in the target gas is adsorbed in an adsorption tower, which will be described later.

[0032] As described above, the target gas in this embodiment has a temperature of 100°C or higher. Generally, in gas separation using an adsorbent, it is preferable to lower the gas temperature during adsorption in order to increase the gas adsorption capacity of the adsorbent. On the other hand, in order to desorb the gas adsorbed by the adsorbent, the adsorbent must be heated. If the temperature difference ΔT between adsorption and desorption becomes large, more energy is required. From this perspective, the target gas is preferably cooled by the cooling means 1 to a temperature of 20°C or higher to 100°C or lower, more preferably to a temperature of 20°C or higher to 60°C or lower, and even more preferably to a temperature of 40°C or higher to 60°C or lower.

[0033] The cooling means 1 is not particularly limited as long as it has the ability to cool the target gas to the above-mentioned temperature, and conventionally known cooling means can be used. Examples of the cooling means 1 include a heat exchanger. Examples of the heat exchanger include a plate heat exchanger and a shell-and-tube heat exchanger.

[0034] When the cooling means 1 is the main heat exchanger 1a, the temperature of the target gas may be cooled to 5°C or more and less than 100°C by heat exchange between the target gas and a heat control fluid. There are no particular limitations on the heat control fluid as long as it is a fluid that can cool the target gas, and examples include water and air. The heat control fluid is introduced into the main heat exchanger 1a via a heat control fluid inlet pipe 4.

[0035] (Adsorption tower) The adsorption tower 10 adsorbs CO2 in the cooled target gas. The adsorption tower 10 includes an adsorbent for adsorbing CO2.

[0036] The CO2 recovery system 30 preferably includes a plurality of adsorption towers 10 (two adsorption towers 10a and 10b in FIG. 3). However, the number of adsorption towers is not limited to this and may be, for example, one, or three or more.

[0037] For example, in each of the two adsorption towers 10a and 10b, adsorption of CO2 onto the adsorbent and desorption of CO2 from the adsorbent (regeneration of the adsorbent) are alternately and repeatedly performed. Then, while the adsorption process is being performed in the adsorption tower 10a, the desorption process is performed in the adsorption tower 10b, and conversely, while the desorption process is being performed in the adsorption tower 10a, the adsorption process is performed in the adsorption tower 10b. This allows continuous recovery of CO2 from the target gas as a whole.

[0038] The adsorbent is not particularly limited as long as it is capable of adsorbing and desorbing CO2 contained in the target gas. Examples of adsorbents include activated carbon, activated metal oxides (activated alumina, activated silica, etc.), alkali metal-containing inorganic solids, solid amines (solids in which amines are supported on a porous support), ion exchange resins, porous resins, metal organic frameworks (MOFs), and covalent organic frameworks (COFs). It is preferable that the adsorbent have a large adsorption capacity of CO2 per unit volume.

[0039] The alkali metal-containing inorganic solid is a porous inorganic solid containing an alkali metal. Examples of the alkali metal contained in the alkali metal-containing inorganic solid include Na and Li, and Na is preferred.

[0040] The alkali metal-containing inorganic solid is preferably an alkali metal ferrite (oxide containing an alkali metal and iron). Examples of alkali metal ferrite include NaFeO2 (sodium ferrite) and LiFeO2 (lithium ferrite).

[0041] The adsorbent preferably has low hygroscopicity, and more preferably is a material that does not substantially adsorb moisture, or a material from which moisture is easily desorbed by heating to about 100°C. This is because moisture adsorption inhibits CO2 adsorption. For example, zeolite and the like can adsorb CO2, but are highly hygroscopic, so it is preferable to use an adsorbent other than these. In particular, zeolite and the like, which require high temperatures to desorb moisture, are not suitable as adsorbents for use in this embodiment.

[0042] By using an adsorbent that is less susceptible to moisture (low hygroscopicity), there is no need to install a dehumidification mechanism upstream of the adsorption tower, which reduces the number of parts that make up the device and also reduces the energy consumption associated with dehumidification.

[0043] The shape of the adsorbent is not particularly limited, but examples thereof include granular and honeycomb shapes.

[0044] (Target gas introduction piping) The target gas introduction pipe 3 introduces the cooled target gas into the adsorption tower 10. The target gas introduction pipe 3 is connected to the top of the adsorption tower 10.

[0045] Conventionally, gas flow into an adsorption tower has generally been from bottom to top (upflow) during gas adsorption and from top to bottom (downflow) during gas desorption. However, if the gas flow during adsorption is upflow, the adsorbent packed in the adsorption tower may float when treating a large amount of gas, potentially resulting in wear of the adsorbent. Therefore, in order to increase the gas treatment volume, the adsorption tower diameter must be increased, resulting in a problem of increased equipment size. Therefore, in this embodiment, the target gas inlet pipe 3 is connected to the top of the adsorption tower 10, and the target gas flows downflow. This is expected to overcome the above-mentioned problems while maintaining the same tower size as conventional adsorption towers.

[0046] (CO2 derivation piping) The CO2 outlet pipe 11 is connected to the bottom of the adsorption tower 10. As described above, in this embodiment, the target gas flows down. Therefore, the CO2 outlet pipe 11 is connected to the bottom of the adsorption tower 10.

[0047] (Control device) When the cooling means 1 is a main heat exchanger 1a and the target gas is cooled by heat exchange between the target gas and a thermal control fluid, the CO2 recovery device 30 may be provided with a control device 5 for controlling the flow rate of the thermal control fluid.

[0048] In this embodiment, the target gas is preferably cooled to a predetermined temperature by the main heat exchanger 1a and introduced into the adsorption tower 10 while maintaining that temperature. However, the cooled target gas may experience temperature fluctuations while flowing through the target gas inlet pipe 3 due to external factors such as the outside air temperature. As a result, if the temperature of the target gas falls outside the predetermined temperature range, CO2 adsorption may not be performed efficiently. Therefore, by providing the CO2 capture device 30 with the control device 5, the temperature of the target gas introduced into the adsorption tower 10 can be controlled, enabling stable CO2 adsorption in the adsorption tower 10. Furthermore, providing the CO2 capture device 30 with the control device 5 allows the adsorption tower 10 to be designed with an appropriate amount of adsorbent, which is preferable from the perspective of cost savings.

[0049] When the CO2 recovery device 30 is equipped with the control device 5, the CO2 recovery device 30 may also be equipped with a flow rate control valve 6 and a thermometer 7. The flow rate control valve 6 is installed in the thermal control fluid inlet pipe 4. The thermometer 7 is installed in the target gas inlet pipe 3. The temperature measured by the thermometer 7 is fed back to the control device 5. When the control device 5 detects a temperature abnormality, the flow rate of the thermal control fluid is controlled by the flow rate control valve 6, and heat exchange between the target gas and the thermal control fluid is properly performed.

[0050] (Secondary heat exchanger) The CO2 recovery device 30 may include a secondary heat exchanger 13. The secondary heat exchanger 13 exchanges heat between the target gas and CO2 recovered from the target gas (hereinafter, the recovered CO2 will also be referred to as "recovered CO2"). For example, the recovered CO2 is introduced into a separation device (condenser 15 and gas-liquid separator 16) and then introduced into the secondary heat exchanger 13 by a blower 17, where heat exchange occurs. The recovered CO2 heated by heat exchange with the target gas (hereinafter, the "heated recovered CO2" will also be simply referred to as "heated recovered CO2") is introduced via a CO2 inlet pipe 12 from the top of the adsorption tower 10 after CO2 adsorption. As a result, the heat of the recovered CO2 after heat exchange causes desorption of CO2 from the adsorbent. Note that the secondary heat exchanger 13 may exchange heat between the target gas and water to generate steam, which may then be introduced from the top of the adsorption tower 10 after CO2 adsorption. Steam has a higher specific heat capacity than captured CO2, and it is expected that the amount of fluid to be circulated will be reduced.

[0051] (others) The CO2 capture system 30 may include a blower 2 and a gas-liquid separator 8. The blower 2 supplies the target gas cooled by the cooling means 1 to the adsorption tower 10. The gas-liquid separator 8 separates moisture contained in the target gas that condenses due to a drop in temperature. Note that it is sufficient for the blower 2 for introducing the target gas into the adsorption tower to be able to increase the pressure equivalent to the pressure loss in the piping and other components within the CO2 capture system 30, and therefore the energy consumption of the blower 2 can be kept to a necessary minimum.

[0052] The CO2 capture device 30 may include a flow path branching from the target gas inlet pipe and leading to an exhaust port, and a flow control valve 9 (or a throttling mechanism such as an orifice) installed in the flow path. The amount of target gas that can be processed to capture CO2 in the adsorption tower 10 is limited. Here, the amount of target gas supplied to the adsorption tower 10 may exceed the processing capacity of the adsorption tower 10. In such cases, by increasing the opening of the flow control valve 9, the portion of the target gas supplied to the adsorption tower 10 that exceeds the processing capacity of the adsorption tower 10 can be exhausted.

[0053] According to the properties of the target gas, a pretreatment device may be installed in the target gas introduction pipe 3 to remove trace impurities contained in the target gas. In this case, the pretreatment device may be installed between the cooling means 1 and the blower 2, or may be installed between the blower 2 and the adsorption tower 10.

[0054] <CO2 Recovery Method> The CO2 recovery method in this embodiment is a method for recovering CO2 from a target gas containing CO2 and having a temperature of 100°C or higher by the temperature swing method. The CO2 recovery method includes a cooling step of cooling the target gas to 5°C or higher and less than 100°C, an adsorption step of adsorbing CO2 in the target gas after the cooling step using an adsorption tower filled with an adsorbent, and a desorption step of desorbing CO2 by heating the adsorbent after the adsorption step. In the adsorption step, the cooled target gas is introduced from the top of the adsorption tower. In the desorption step, the desorbed CO2 is导出 from the bottom of the adsorption tower. Hereinafter, the CO2 recovery method in this embodiment will be described. Note that descriptions overlapping with those described in the above <CO2 Recovery Device> are omitted.

[0055] (Cooling Step) The cooling step is a step of cooling the target gas to 5°C or higher and less than 100°C.

[0056] (Adsorption Step) The adsorption step is a step of adsorbing CO2 in the target gas after the cooling step using an adsorption tower filled with an adsorbent. In the adsorption step, the cooled target gas is introduced from the top of the adsorption tower.

[0057] (Desorption Step) The desorption step is a step of desorbing CO2 by heating the adsorbent after the adsorption step. In other words, the desorption step is a step of making the adsorbent filled in the adsorption tower reusable. In the desorption step, the desorbed CO2 is导出 from the bottom of the adsorption tower.

[0058] Examples of methods for heating the adsorbent include introducing a heated gas into the top of the adsorption tower and directly heating the adsorbent. From the viewpoint of simplifying the equipment configuration, it is preferable to introduce a heated gas into the top of the adsorption tower. Examples of the heated gas include the target gas, heated recovered CO2, and steam. Furthermore, from the viewpoint of the purity of the recovered CO2, it is more preferable to introduce heated recovered CO2 into the top of the adsorption tower.

[0059] Here, the temperature of the adsorbent after heating is usually equal to or higher than the temperature at which CO2 begins to desorb from the adsorbent. The temperature of the adsorbent after heating varies depending on the type of adsorbent, but is, for example, 60°C or higher and 200°C or lower. However, as mentioned above, if the temperature difference ΔT between adsorption and desorption becomes large, more energy is required. From this perspective, it is preferable that the temperature of the adsorbent after heating be 60°C or higher and 100°C or lower.

[0060] The above steps and the operation of the CO2 recovery device 30 will be further described below with reference to Fig. 3. As shown in Fig. 3, in the following description, in the absorption step, the target gas is cooled by heat exchange with a thermal control fluid. In addition, in the desorption step, the adsorbent is heated by the heated recovered CO2 through heat exchange with the target gas.

[0061] (Step 1) In step 1, the adsorption step is performed in the adsorption tower 10a, and the desorption step is performed in the adsorption tower 10b. In this case, the valves 20a, 21b, 22b, and 23a are opened, and the valves 20b, 21a, 22a, and 23b are closed.

[0062] The target gas cooled in the main heat exchanger 1a is introduced into the adsorption tower 10a by the blower 2 through the target gas inlet pipe 3. In the adsorption tower 10a, CO2 in the target gas is adsorbed, and the unadsorbed gas is exhausted.

[0063] Meanwhile, a portion of the recovered CO2 is introduced into the auxiliary heat exchanger 13 via the CO2 introduction pipe 12 by the blower 17. The recovered CO2 heated in the auxiliary heat exchanger 13 is introduced into the adsorption tower 10b. This causes CO2 to be desorbed from the adsorbent.

[0064] Here, target gases such as combustion exhaust gas contain CO2, but many of their components are other than CO2, such as nitrogen and water vapor. After the adsorption process, the voids inside the adsorption tower are filled with gas containing many of these components other than CO2. Therefore, in the desorption process, immediately after introducing (purging) the heated recovered CO2 into the adsorption tower as described above, gas containing many components other than CO2 (gas with a low CO2 concentration) is discharged from the adsorption tower. By venting this gas with a low CO2 concentration, gas with a high CO2 concentration (recovered CO2) can be obtained. This enables efficient processing, for example, when chemically converting CO2 gas into CH4, CO, etc., or when producing liquefied carbon dioxide or dry ice from CO2 gas.

[0065] That is, among the recovered CO2, gas with a low CO2 concentration that is discharged at the beginning of the desorption process is exhausted through a branched pipe by switching the three-way valve 14. Thereafter, by switching the three-way valve 14, the recovered CO2 is recovered by a separation device (condenser 15 and gas-liquid separator 16) and is used to heat the adsorbent or is discharged to the outside of the system as product CO2. This makes it possible to prevent the gas with a low CO2 concentration from mixing with the recovered CO2.

[0066] (Step 2) In step 2, the desorption step is performed in the adsorption tower 10a, and the adsorption step is performed in the adsorption tower 10b. In this case, the valves 20b, 21a, 22a, and 23b are opened, and the valves 20a, 21b, 22b, and 23a are closed.

[0067] The target gas cooled in the main heat exchanger 1a is introduced into the adsorption tower 10b by the blower 2 through the target gas inlet pipe 3. In the adsorption tower 10b, CO2 in the target gas is adsorbed, and the unadsorbed gas is exhausted.

[0068] Meanwhile, a portion of the recovered CO2 is introduced into the auxiliary heat exchanger 13 via the CO2 introduction pipe 12 by the blower 17. The heated and recovered CO2 in the auxiliary heat exchanger 13 is introduced into the adsorption tower 10a. This causes CO2 to be desorbed from the adsorbent.

[0069] In this way, the adsorption step and the desorption step are repeated in each of the adsorption towers 10a and 10b, and as a whole, CO2 recovery from the target gas can be carried out continuously. [Example]

[0070] The following examples are provided to illustrate, but not to limit, the scope of the claims.

[0071] (No. 1-3) When CO2 is captured from a target gas using the CO2 capture device shown in Figure 3, the CO2 concentration in the captured gas was calculated.

[0072] The target gas was 85% by volume of N2, 5% by volume of O2, 10% by volume of CO2, and saturated water at 100°C. The adsorbent was coconut shell activated carbon (granulated, 6.5-10 mesh sieve). In the desorption process, the heated gas was heated and recovered CO2.

[0073] As a result, it was found that the gas recovered in the separation step (gas-liquid separation in the gas-liquid separator 16) contains 99% by volume of CO2, 1% by volume of N2, and a saturated amount of moisture.

[0074] No. 1 is an example of a conventional method. In No. 1, if the flow velocity is 0.2 m / sec, it is thought that operation is possible when the tower diameter is 500 A.

[0075] On the other hand, in No. 2, when the tower diameter is 300A, the target gas is introduced into the adsorption tower at a flow velocity of 0.42 m / sec, which is faster than No. 1, but by adopting a downflow, it is possible to avoid floating and wearing of the adsorbent. Also, when the target gas fluid temperature is high as in No. 3, the flow velocity is 0.46 m / sec, which is faster than No. 2, but by adopting a downflow like No. 2, it is possible to avoid floating and wearing of the adsorbent. The calculation results are shown in Table 1 below.

[0076] [Table 1]

[0077] The CO2 capture device and CO2 capture method disclosed herein can capture CO2 from target gases containing CO2, thereby reducing CO2 emissions. This can reduce greenhouse gas emissions and contribute to some of the Sustainable Development Goals (SDGs).

[0078] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0079] 1 Cooling means, 1a Main heat exchanger, 2 Blower, 3 Target gas introduction piping, 4 Heat control fluid introduction piping, 5 Control device, 6 Flow control valve, 7 Thermometer, 8 Gas-liquid separator, 9 Flow control valve, 10, 10a, 10b Adsorption tower, 11 CO2 extraction piping, 12 CO2 introduction piping, 13 Auxiliary heat exchanger, 14 Three-way valve, 15 Condenser, 16 Gas-liquid separator, 17 Blower, 20a, 20b, 21a, 21b, 22a, 22b, 23a, 23b Valves, 30 CO2 recovery device.

Claims

1. By the temperature swing method, CO ２ from a target gas containing CO and having a temperature of 100°C or higher ２ 1. An apparatus for recovering a cooling means for cooling the target gas to a temperature of 5°C or higher but lower than 100°C; CO in the cooled target gas ２ an adsorption tower containing an adsorbent for adsorbing the a target gas introduction pipe for introducing the cooled target gas into the adsorption tower; CO adsorbed in the adsorption tower ２ CO for deriving ２ and an outlet pipe, the target gas introduction pipe is connected to the top of the adsorption tower, The CO ２ The outlet pipe is connected to the bottom of the adsorption tower. ２ Recovery device.

2. 2. The CO 2 system of claim 1, wherein the cooling means is a main heat exchanger. ２ Recovery device.

3. When the target gas is cooled by heat exchange between the target gas and a thermal control fluid, ２ 3. The CO recovery system of claim 2, further comprising a controller for controlling the flow rate of the thermal conditioning fluid. ２ Recovery device.

4. 4. The CO 2 analyzer according to claim 1, wherein the target gas is a combustion exhaust gas. ２ Recovery device.

5. By the temperature swing method, CO ２ from a target gas containing CO and having a temperature of 100°C or higher ２ 1. A method for recovering a cooling step of cooling the target gas to 5°C or higher but lower than 100°C; The CO in the target gas after the cooling step ２ an adsorption step of adsorbing the above-mentioned mixture using an adsorption tower filled with an adsorbent; By heating the adsorbent after the adsorption step, CO ２ and a desorption step of desorbing In the adsorption step, the cooled target gas is introduced from the top of the adsorption tower, In the desorption step, the CO desorbed from the bottom of the adsorption tower ２ is derived, CO ２ Recovery method.

6. 6. The CO 2 gas according to claim 5, wherein the cooling step is performed by heat exchange between the target gas and a thermal control fluid. ２ Recovery method.

7. The CO 2 gas according to claim 6, wherein the heat exchange between the target gas and the thermal regulating fluid is performed by controlling the flow rate of the thermal regulating fluid. ２ Recovery method.

8. 8. The CO 2 adsorption method according to claim 5, wherein in the desorption step, the adsorbent is heated by introducing a heating gas from the top of the adsorption tower. ２ Recovery method.

9. The heating gas may be the target gas, recovered CO 2 heated by heat exchange with the target gas, or ２ and steam. ２ Recovery method.

10. 8. The CO 2 analyzer according to claim 5, wherein the target gas is a combustion exhaust gas. ２ Recovery method.

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