Carbon dioxide capture system and carbon dioxide capture method
The carbon dioxide capture system addresses the inefficiency of atmospheric capture by utilizing indoor exhaust air with higher concentrations, achieving efficient carbon dioxide recovery through a solid adsorbent in the exhaust passage, thereby improving capture efficiency and energy savings.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- IHI CORP
- Filing Date
- 2024-10-23
- Publication Date
- 2026-05-11
AI Technical Summary
Existing carbon dioxide capture systems face challenges in efficiently capturing carbon dioxide from the low concentration in the atmosphere, requiring large volumes of air processing to achieve significant recovery.
A carbon dioxide capture system that utilizes an exhaust channel to capture carbon dioxide from indoor air within buildings, utilizing a carbon dioxide recovery unit with a solid adsorbent in the exhaust passage to concentrate carbon dioxide, which has a higher concentration due to human activity and combustion processes.
Enables more efficient capture of carbon dioxide by leveraging higher indoor concentrations, reducing the amount of air to be processed and potentially reusing conditioned air, thus enhancing capture efficiency and reducing energy consumption.
Smart Images
Figure 2026075917000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a carbon dioxide recovery system and a carbon dioxide recovery method.
Background Art
[0002] Carbon dioxide is regarded as a cause of global warming, and efforts to suppress the increase in carbon dioxide concentration are spreading worldwide. As one method of reducing the carbon dioxide concentration in the atmosphere, a technique called direct air capture (DAC) has been proposed. DAC is a technique for directly capturing carbon dioxide in the air and has attracted attention as a measure to reduce carbon dioxide emissions into the atmosphere.
[0003] Patent Document 1 discloses a DAC system including a first DAC device that recovers carbon dioxide from the atmosphere and a second DAC device that is installed such that an intake port is located on the exhaust port side of the first DAC device and recovers carbon dioxide from the atmosphere.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] By the way, the carbon dioxide concentration in the atmosphere is very low at 400 ppm, and in order to recover carbon dioxide from the atmosphere, a large amount of air must be brought into contact with a carbon dioxide capture material. For example, in order to recover 1 ton / day of carbon dioxide by DAC, it is sufficient to process the exhaust gas of a coal-fired power plant at 180 Nm 3 / hour, but it is necessary to process 56,000 Nm 3 / hour of the air in the atmosphere.
[0006] Therefore, the purpose of this disclosure is to provide a carbon dioxide capture system and a carbon dioxide capture method that can capture carbon dioxide more easily than capturing carbon dioxide from the air in the atmosphere. [Means for solving the problem]
[0007] The carbon dioxide recovery system according to this disclosure comprises an exhaust channel for exhausting indoor air to the outside, and a carbon dioxide recovery unit located within the exhaust channel for capturing carbon dioxide in the air exhausted from the room.
[0008] The carbon dioxide recovery unit may include a solid adsorbent that adsorbs carbon dioxide from the air.
[0009] The carbon dioxide capture system includes an intake passage that supplies air to the room, and at least some of the air in the room may be circulated through the intake passage and the exhaust passage.
[0010] A fan may be provided in at least one of the intake passage and the exhaust passage.
[0011] The concentration of carbon dioxide passing through the intake port of the exhaust passage may be higher than the concentration of carbon dioxide in the air passing through the intake passage.
[0012] The concentration of carbon dioxide passing through the intake port of the intake passage may exceed 400 ppm.
[0013] The carbon dioxide recovery method relating to this disclosure includes a step of capturing carbon dioxide in the air exhausted from a room in an exhaust channel that exhausts indoor air to the outside. [Effects of the Invention]
[0014] This disclosure provides a carbon dioxide capture system and a carbon dioxide capture method that can capture carbon dioxide more easily than capturing carbon dioxide from the air in the atmosphere. [Brief explanation of the drawing]
[0015] [Figure 1] This is a schematic diagram showing a carbon dioxide capture system according to one embodiment. [Figure 2] This is a schematic diagram illustrating an example of desorption of carbon dioxide from a carbon dioxide capture unit. [Modes for carrying out the invention]
[0016] Several exemplary embodiments will be described below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios.
[0017] Figure 1 is a schematic diagram showing a carbon dioxide recovery system 1 according to one embodiment. As shown in Figure 1, the carbon dioxide recovery system 1 comprises an intake passage 10, an exhaust passage 20, and a carbon dioxide recovery unit 30. This embodiment shows an example in which the carbon dioxide recovery unit 30 is applied to the exhaust passage 20 of building B.
[0018] In this embodiment, building B has a plurality of rooms R. Building B includes an intake passage 10 and an exhaust passage 20, and each room R is connected to the intake passage 10 and the exhaust passage 20. Building B also has an air conditioning room ACR that houses an air conditioning system AC, and the air is conditioned using a central control system. At least a portion of the air in each room R circulates through the intake passage 10 and the exhaust passage 20.
[0019] Room R is a partitioned space within Building B, where people and animals such as pets are active. Combustion equipment such as gas fan heaters, oil fan heaters, cooking burners, and water heaters may be placed in Room R. Carbon dioxide is produced in Room R by animal respiration and the operation of combustion equipment. Therefore, the carbon dioxide concentration in the air inside Room R may be higher than that of the air outside Room R.
[0020] The intake air passage 10 supplies air into the room R. In this embodiment, an intake fan F1 for supplying air into the room R is provided in the intake air passage 10. The intake air passage 10 has a first intake port 11, a plurality of air outlets 12, and a second intake port 13. The first intake port 11 is arranged in the atmosphere outside the building B, and the air in the atmosphere is supplied into the intake air passage 10 through the first intake port 11. The intake air passage 10 is branched, and the plurality of air outlets 12 are provided at the tips of the branched intake air passages 10. The plurality of air outlets 12 are arranged in each room R, and the air in the atmosphere inhaled from the first intake port 11 is supplied to each room R from the air outlet 12. The second intake port 13 is arranged in the air conditioning room ACR, and the air in the air conditioning room ACR inhaled from the second intake port 13 is supplied to each room R from the air outlet 12 through the intake air passage 10.
[0021] The exhaust air passage 20 exhausts the air in the room R to the outside of the room R. In this embodiment, an exhaust fan F2 for exhausting the air in the room R to the outside of the room R is provided in the exhaust air passage 20. Specifically, the exhaust air passage 20 exhausts the air in the room R to the outside of the building B. The exhaust air passage 20 has a plurality of intake ports 21 and an exhaust port 22. The plurality of intake ports 21 are arranged in each room R, and the air in the room R taken in from each intake port 21 is supplied into the exhaust air passage 20 through the intake port 21. The exhaust port 22 is arranged in the air conditioning room ACR, and the air in each room R taken in from each intake port 21 is exhausted into the air conditioning room ACR. Also, the exhaust air passage 20 may exhaust the air in the room R to the outside of the building B through an exhaust port not shown.
[0022] The air conditioning equipment AC is equipment for conditioning the air in the room R in order to create a comfortable environment in the room R. The air conditioning equipment AC may include at least one of a temperature regulator and a humidity regulator. The temperature regulator can adjust the temperature in the room R. The humidity regulator can adjust the humidity in the room R. The temperature regulator may include at least one of a heater and a cooler. The humidity regulator may include at least one of a humidifier and a dehumidifier.
[0023] The carbon dioxide recovery unit 30 is provided in the exhaust flow path 20. And the carbon dioxide recovery unit 30 collects carbon dioxide in the air exhausted from the room R. In the room R, carbon dioxide is generated by people breathing. Also, in the room R, for example, combustion equipment such as a gas fan heater, an oil fan heater, a cooking burner, and a water heater operates to generate carbon dioxide. Therefore, the carbon dioxide concentration in the air in the room R may be higher than the carbon dioxide concentration in the atmosphere.
[0024] Therefore, in the carbon dioxide recovery system 1 according to the present embodiment, the carbon dioxide recovery unit 30 is provided in the exhaust flow path 20. And by collecting the carbon dioxide in the air exhausted from the exhaust flow path 20 with the carbon dioxide recovery unit 30, carbon dioxide can be recovered more easily than recovering carbon dioxide from the air in the atmosphere. Also, since the exhaust flow path 20 is configured to exhaust the air in the room R to the outside of the room R, carbon dioxide can be easily collected by providing the carbon dioxide recovery unit 30 in the exhaust flow path 20.
[0025] The concentration of carbon dioxide passing through the intake port 21 of the exhaust flow path 20 may be higher than the concentration of carbon dioxide in the air passing through the intake flow path 10. With such a configuration, by collecting the carbon dioxide in the air passing through the exhaust flow path 20, carbon dioxide can be recovered more efficiently than collecting the carbon dioxide in the air passing through the exhaust flow path 20.
[0026] The concentration of carbon dioxide passing through the first intake port 11 of the intake flow path 10 may be more than 400 ppm and 5000 ppm or less. When the concentration of carbon dioxide exceeds 400 ppm, the carbon dioxide in the air passing through the exhaust flow path 20 can be recovered more efficiently. Also, when the concentration of carbon dioxide is 5000 ppm or less, it is preferable from the viewpoint of indoor occupational health. The carbon dioxide concentration may be 450 ppm or more, or 500 ppm or more. Also, the carbon dioxide concentration may be 4000 ppm or less, 3000 ppm or less, 2000 ppm or less, 1000 ppm or less, or 800 ppm or less.
[0027] The carbon dioxide recovery unit 30 may contain a collection material. The collection material may be a liquid, a solid, or a combination thereof. The collection material may contain at least one of an adsorbent and an absorbent. The adsorbent can adsorb carbon dioxide from the air and desorb the adsorbed carbon dioxide to produce a carbon dioxide concentrated gas with a higher carbon dioxide concentration than air. Similarly, the absorbent can absorb carbon dioxide from the air and release the absorbed carbon dioxide to produce a carbon dioxide concentrated gas with a higher carbon dioxide concentration than air.
[0028] From the viewpoint of facilitating the design of placement within the exhaust flow path 20, it is preferable that the carbon dioxide recovery unit 30 includes a solid adsorbent. The solid adsorbent is not particularly limited as long as it adsorbs carbon dioxide, but may be a physical adsorbent, a chemical adsorbent, a reactive absorbent, or a combination thereof. The solid adsorbent may include, for example, a porous body, alkali metals, alkaline earth metals, or a combination thereof. These adsorbents can efficiently adsorb carbon dioxide.
[0029] The carbon dioxide recovery unit 30 may include an adsorption layer containing a solid adsorbent. The adsorption layer may be placed within the exhaust flow path 20 and arranged so that the air passing through the exhaust flow path 20 comes into contact with the solid adsorbent. At least a portion of the air passing through the exhaust flow path 20 should pass through the adsorption layer containing the solid adsorbent. That is, some or all of the air passing through the exhaust flow path 20 should pass through the adsorption layer containing the solid adsorbent.
[0030] Furthermore, as described above, if carbon dioxide is adsorbed in the carbon dioxide recovery unit 30, for example, the carbon dioxide can be concentrated by desorbing the adsorbed carbon dioxide. Carbon dioxide adsorption can be performed at room temperature and atmospheric pressure. Desorption of carbon dioxide can be performed by heating and reducing the pressure of the carbon dioxide collection material in the carbon dioxide recovery unit 30 that has adsorbed carbon dioxide.
[0031] For example, as shown in Figure 2, the carbon dioxide recovery system 1 may include a carbon dioxide discharge channel 31 connected to the carbon dioxide recovery unit 30, through which the concentrated carbon dioxide gas containing the desorbed carbon dioxide passes. As shown in Figure 2, the carbon dioxide discharge channel 31 may be equipped with a vacuum pump 32, a tank 33, and a compressor 34 in this order. The vacuum pump 32 reduces the pressure inside the carbon dioxide recovery unit 30 to desorb the carbon dioxide adsorbed by the carbon dioxide collecting material. The tank 33 stores the concentrated carbon dioxide gas containing the carbon dioxide desorbed from the carbon dioxide collecting material. The compressor 34 supplies the carbon dioxide stored in the tank 33 to a supply destination (not shown). Although Figure 2 describes an example in which carbon dioxide is desorbed by reducing the pressure of the carbon dioxide collecting material, carbon dioxide may also be desorbed by heating the carbon dioxide collecting material instead of, or in addition to, reducing the pressure of the carbon dioxide collecting material.
[0032] In the carbon dioxide capture system 1 according to this embodiment, if a sufficient amount of carbon dioxide is expected to be adsorbed during the daytime when human activity is high, carbon dioxide may be adsorbed in the carbon dioxide capture unit 30 during the daytime and desorbed at night when human activity is low. On the other hand, if a sufficient amount of carbon dioxide cannot be expected to be adsorbed during the daytime alone, for example, two capture materials may be arranged in parallel, and while one capture material is adsorbing carbon dioxide, the other capture material may be desorbing carbon dioxide.
[0033] In this embodiment, an example of air conditioning using a central control system has been described, but it is sufficient that the carbon dioxide recovery unit 30 is located within the exhaust flow path 20. Therefore, building B does not need to have an air conditioning room ACR, and the air in room R may be conditioned using an individual air conditioning system.
[0034] Furthermore, in this embodiment, an example has been described in which an intake fan F1 is provided in the intake passage 10 and an exhaust fan F2 is provided in the exhaust passage 20. However, if air from outside the room R is supplied into the room R via the intake passage 10, an intake fan F1 does not need to be provided in the intake passage 10. Also, if air from inside the room R is exhausted to the outside of the room R via the exhaust passage 20, an exhaust fan F2 does not need to be provided in the exhaust passage 20. For example, a fan F may be provided in either the intake passage 10 or the exhaust passage 20.
[0035] Furthermore, the aforementioned building B may be, for example, a residence, commercial facility, office, hospital, welfare facility, train station, or airport. Also, the carbon dioxide capture system 1 according to this embodiment is not limited to building B, but may be applied to the exhaust flow path 20 of a vehicle such as a train, passenger car, ship, or airplane.
[0036] As described above, the carbon dioxide recovery system 1 according to this embodiment includes an exhaust channel 20 that exhausts the air inside the room R to the outside of the room R, and a carbon dioxide recovery unit 30 that is located inside the exhaust channel 20 and collects carbon dioxide from the air exhausted from inside the room R.
[0037] Furthermore, the carbon dioxide recovery method according to this embodiment includes a step of capturing carbon dioxide in the air exhausted from room R within an exhaust channel 20 that exhausts the air inside room R to the outside of room R.
[0038] In room R, carbon dioxide is easily generated by human respiration and the operation of combustion equipment. Therefore, the air from room R that is exhausted through the exhaust channel 20 may have a relatively high concentration of carbon dioxide. For this reason, carbon dioxide can be efficiently captured by the carbon dioxide recovery unit 30 located in the exhaust channel 20. Thus, according to the carbon dioxide recovery system of this embodiment, carbon dioxide can be recovered more easily than by recovering carbon dioxide from the air in the atmosphere.
[0039] The carbon dioxide recovery unit 30 may include a solid adsorbent that adsorbs carbon dioxide from the air. This configuration makes it easier to design the placement of the carbon dioxide recovery unit 30 within the exhaust flow path 20.
[0040] The carbon dioxide recovery system 1 may include an intake passage 10 that supplies air into the room R. At least some of the air in the room R may circulate through the intake passage 10 and the exhaust passage 20. With this configuration, the air in the room R can be circulated through the intake passage 10 and the exhaust passage 20. Therefore, the air conditioned by the air conditioning system AC can be reused, and the energy consumption of the air conditioning system AC can be reduced.
[0041] A fan F may be provided in at least one of the intake passage 10 and the exhaust passage 20. This configuration allows for efficient circulation of air within the room R. The fan F may include at least one of an intake fan F1 and an exhaust fan F2.
[0042] The concentration of carbon dioxide passing through the intake port 21 of the exhaust passage 20 may be higher than the concentration of carbon dioxide in the air passing through the intake passage 10. This configuration allows for a higher carbon dioxide collection effect in the carbon dioxide recovery unit 30.
[0043] The concentration of carbon dioxide passing through the first intake port 11 of the intake passage 10 may exceed 400 ppm. With this configuration, carbon dioxide in the air passing through the exhaust passage 20 can be recovered more efficiently.
[0044] Although several embodiments have been described, it is possible to modify or transform the embodiments based on the above disclosure. All components of the above embodiments, and all features described in the claims, may be taken individually and combined, provided that they do not conflict with each other.
[0045] This disclosure can contribute, for example, to United Nations Sustainable Development Goal (SDG) 13, "Take urgent action to combat climate change and its impacts." [Explanation of symbols]
[0046] 1. Carbon dioxide capture system 10 Intake passage 11. First air intake port (air intake port) 20 Exhaust passage 21 Air intake 30 Carbon Dioxide Capture Section F Fan Room R
Claims
1. An exhaust passage that exhausts indoor air to the outside, A carbon dioxide recovery unit is located within the exhaust passage and collects carbon dioxide from the air exhausted from the room. A carbon dioxide capture system equipped with this feature.
2. The carbon dioxide recovery system according to claim 1, wherein the carbon dioxide recovery unit includes a solid adsorbent that adsorbs carbon dioxide from the air.
3. The carbon dioxide recovery system includes an intake passage for supplying air into the room. The carbon dioxide recovery system according to claim 1 or 2, wherein at least a portion of the air in the room is circulated through the intake passage and the exhaust passage.
4. The carbon dioxide recovery system according to claim 3, wherein a fan is provided in at least one of the intake passage and the exhaust passage.
5. The carbon dioxide recovery system according to claim 3, wherein the concentration of carbon dioxide passing through the intake port of the exhaust passage is higher than the concentration of carbon dioxide in the air passing through the intake passage.
6. The carbon dioxide recovery system according to claim 3, wherein the concentration of carbon dioxide passing through the intake port of the intake passage is greater than 400 ppm.
7. A method for recovering carbon dioxide, comprising the step of capturing carbon dioxide in the air exhausted from a room in an exhaust channel that exhausts indoor air to the outside.