JP7790915B2 - Carbon dioxide separation and capture device, carbon dioxide separation and capture system, and carbon dioxide separation and capture method - Google Patents

Description

The present invention relates to a carbon dioxide separation and capture device, a carbon dioxide separation and capture system, and a carbon dioxide separation and capture method.

The Building Environmental Sanitation Management Standards stipulate that the carbon dioxide content in rooms equipped with air conditioning must be 1,000 ppm (volume basis; the same applies hereinafter in this specification) or less. As such, there is a demand for technology to remove carbon dioxide from the air inside buildings equipped with air conditioning.

For example, Patent Document 1 proposes a system that absorbs pollutants such as carbon dioxide from indoor air in an enclosed space and regenerates the absorbent material by heating it. The invention in Patent Document 1 aims to reduce energy consumption for delivering warm purge gas used in the regeneration process.

JP 2015-528743 A

By the way, carbon dioxide can be used to produce valuable materials if it is recovered using an appropriate method. However, the technology in Patent Document 1 leaves room for improvement in the carbon dioxide absorption rate (adsorption efficiency). In addition, the technology in Patent Document 1 does not take into consideration the reuse of the absorbed carbon dioxide.

The present invention therefore aims to develop a carbon dioxide separation and capture device, a carbon dioxide separation and capture method, and a carbon dioxide separation and capture system that can more efficiently adsorb carbon dioxide and reuse the adsorbed carbon dioxide.

In order to solve the above problems, the present invention has the following aspects.
[1] A cooling device and an adsorption/desorption unit having an adsorbent capable of adsorbing and desorbing carbon dioxide,
The adsorption/detachment unit is provided so as to be freely attached and detached,
The carbon dioxide separation and capture device supplies cooled air generated by the cooler to the adsorption and desorption section.
[2] The carbon dioxide separation and capture device according to [1], wherein the cooling device is a heat pump.
[3] The carbon dioxide separation and capture device according to [1] or [2], further comprising a carbon dioxide concentration measuring device on the secondary side of the adsorption and desorption section.

[4] A carbon dioxide separation and capture system comprising the carbon dioxide separation and capture device described in any one of [1] to [3] and a carbon dioxide desorption device that desorbs the carbon dioxide adsorbed by the adsorbent from the removed adsorption and desorption unit.

[5] a cooling step of cooling the air containing carbon dioxide to obtain cooled air;
an adsorption step of bringing the cooled air into contact with an adsorption/desorption section having an adsorbent, thereby causing the adsorbent to adsorb part or all of the carbon dioxide, thereby obtaining purified air;
a desorption step of removing the adsorption/desorption unit and desorbing carbon dioxide from the adsorbent to which carbon dioxide has been adsorbed;
a recovery step of recovering the carbon dioxide desorbed in the desorption step.
[6] The carbon dioxide separation and capture method according to [5], further comprising a moisture reduction operation for reducing moisture contained in the carbon dioxide-containing air in the cooling step.
[7] The carbon dioxide separation and capture method according to [5] or [6], wherein the desorption step is carried out when the difference between the carbon dioxide concentration of the clean air and the carbon dioxide concentration of the air containing the carbon dioxide becomes 10% or less.

The carbon dioxide separation and capture device, carbon dioxide separation and capture system, and carbon dioxide separation and capture method of the present invention enable more efficient adsorption of carbon dioxide and the reuse of the adsorbed carbon dioxide.

1 is a schematic diagram showing a carbon dioxide separation and capture apparatus according to one embodiment of the present invention. 1 is a schematic diagram showing a carbon dioxide separation and capture system according to one embodiment of the present invention.

<Carbon dioxide separation and capture equipment>
The carbon dioxide capture and separation device of the present invention is an apparatus to be installed in an indoor enclosed space.
The carbon dioxide separation and capture device of the present invention includes a cooling machine and an adsorption/desorption section capable of adsorbing and desorbing carbon dioxide.
A carbon dioxide separation and capture apparatus according to one embodiment of the present invention will be described in detail below with reference to FIG.

As shown in FIG. 1, the carbon dioxide capture and separation device 1 of this embodiment includes a housing 10 , a cooler 20 , an adsorption/desorption unit 30 , fans 40 a and 40 b , and a carbon dioxide concentration measuring device 50 .
The arrows in the figure indicate the direction of movement of a fluid such as air.

The housing 10 has air inlets 12a and 12b, air outlets 14a and 14b, a partition wall 16, and a drain port 18. The housing 10 is divided into an evaporation chamber 11 and a condensation chamber 13 by the partition wall 16. In this embodiment, the evaporation chamber 11 is located vertically below the condensation chamber 13.
The evaporation chamber 11 has an air inlet 12a and an air outlet 14a.
The condensation chamber 13 has an air inlet 12b and an air outlet 14b.
The chiller 20 includes an evaporator 21 , a condenser 22 , a compressor 24 , and an expansion valve 26 .
In this embodiment, the cooling device 20 is a heat pump. The evaporator 21 is located inside the evaporation chamber 11. The condenser 22 is located inside the condensation chamber 13. The evaporator 21 and the compressor 24 are connected by a pipe L1. The compressor 24 and the condenser 22 are connected by a pipe L2. An expansion valve 26 is provided between the evaporator 21 and the condenser 22. The expansion valve 26 is installed in the partition wall 16.
The drain outlet 18 is formed below the evaporator 21 (vertically downward).
In this embodiment, the adsorption/desorption unit 30 is installed inside the evaporation chamber 11 and is located on the secondary side of the evaporator 21 of the cooling device 20 .
The blower 40 a is installed inside the evaporation chamber 11 and is located on the primary side of the evaporator 21 of the cooler 20 .
The blower 40 b is installed inside the condensing chamber 13 and is located on the primary side of the condenser 22 of the cooling machine 20 .
The carbon dioxide concentration measuring device 50 is provided on the secondary side of the evaporator 21. In this embodiment, the carbon dioxide concentration measuring device 50 is located outside the housing 10 and provided at the air outlet 14a.

The housing 10 is a container of the carbon dioxide capture and separation device 1 .
The housing 10 may be, for example, a rectangular parallelepiped container made of metal or resin.
The size of the housing 10 is not particularly limited, but may be, for example, a container having a width of 300 to 3000 mm, a depth of 150 to 1500 mm, and a height of 300 to 3000 mm.

The air inlet 12 a may be any suitable opening as long as it can introduce indoor air (indoor air A<b>1 ) into the housing 10 .
The air inlet 12a may be, for example, a plurality of air vents.
Air inlet 12b is similar to air inlet 12a.

The air outlet 14 a may be configured to discharge clean air (clean air A<b>2 ) from which part or all of the carbon dioxide has been adsorbed by the adsorbent of the adsorption/desorption unit 30 to the outside of the housing 10 .
The air outlet 14a may be a vent hole similar to the air inlet 12a.
The air outlet 14b may be any suitable device as long as it can discharge warm air A3, which is indoor air A1 introduced from the air inlet 12b and heated by contact with the condenser 22, to the outside of the housing 10.
The air outlet 14b may be a vent hole similar to the air inlet 12a.

The partition wall 16 may be any wall capable of dividing the interior of the housing 10 into two regions.
The partition wall 16 preferably has excellent heat insulating properties, since this can further increase the thermal efficiency of the cooler 20 .
The partition wall 16 may be, for example, a flat plate made of a resin having heat insulating properties.

The drain outlet 18 may be any outlet capable of discharging condensed water adhering to the evaporator 21 to the outside of the housing 10 .
The drain port 18 may be, for example, a drain pipe made of metal or resin.

Examples of the evaporator 21 include fins.

Examples of the condenser 22 include fins.

The pipe L<b>1 may be any pipe that can supply the refrigerant that has passed through the evaporator 21 to the compressor 24 .
The pipe L1 may be, for example, a pipe made of metal or resin.
Examples of refrigerants include hydrocarbons (HC), fluorinated hydrocarbons (HFC), and carbon dioxide (CO ₂ ).

The pipe L2 may be any pipe that can supply the refrigerant compressed by the compressor 24 to the condenser 22.
The pipe L2 may be, for example, a pipe made of metal or resin.

The compressor 24 may be any device capable of compressing the refrigerant flowing through the inside of the cooling device 20 .
As the compressor 24, a known compressor or the like can be used.

The expansion valve 26 may be any valve capable of releasing the pressure of the refrigerant that has flowed through the inside of the condenser 22 .
As the expansion valve 26, a known valve, on-off valve, etc. can be used.

In this embodiment, the cooling device 20 is a heat pump, so the indoor air A1 can be cooled efficiently with little power (energy). Therefore, the carbon dioxide separation and capture device 1 is energy-saving and has excellent energy efficiency.
As the cooling device 20, a Peltier element or the like can be used in addition to a heat pump. However, a heat pump is preferable as the cooling device 20 because it can cool the indoor air A1 more efficiently.

The adsorption/desorption unit 30 may be any unit that can adsorb and desorb carbon dioxide.
As used herein, "adsorption" refers to the adsorption of a liquid or gas onto the surface of another solid or liquid. "Desorption" refers to the separation of an adsorbed substance from the adsorption interface. "Desorption" is also called "desorption.""Adsorption-desorption" refers to both adsorption and desorption.
The adsorption/desorption unit 30 may be, for example, a container filled with an adsorbent capable of adsorbing carbon dioxide.
The container filled with the adsorbent may be in the form of a box or a bag.

The container filled with the adsorbent has breathability, and examples of such a container include nonwoven fabric and fine mesh.
The opening size of the container filled with the adsorbent is, for example, preferably 0.34 nm to 1.4 mm, more preferably 1 nm to 1.0 mm, even more preferably 100 nm to 0.5 mm, and particularly preferably 1 μm to 0.1 mm. When the opening size of the container filled with the adsorbent is equal to or greater than the above-mentioned lower limit, carbon dioxide molecules (molecular diameter 0.34 nm) can pass through. When the opening size of the container filled with the adsorbent is equal to or less than the above-mentioned upper limit, leakage of the adsorbent can be suppressed.

The adsorbent is not particularly limited as long as it has the ability to adsorb carbon dioxide.
Examples of adsorbents include zeolite, silica gel, activated carbon, nitride-impregnated solids, metal-organic frameworks (MOFs), alumina, activated alumina, etc. Examples of nitride-impregnated solids include solid absorbents carrying amines such as triethanolamine and monoethanolamine, and amine-based weakly basic anion exchange resins. Zeolite, silica gel, activated carbon, nitride-impregnated solids, MOFs, and activated alumina are preferred as adsorbents because they have superior carbon dioxide adsorption capabilities.

The adsorption/desorption unit 30 is provided so as to be detachable from the housing 10. Because the adsorption/desorption unit 30 is provided so as to be detachable from the housing 10, it can be easily removed from the housing 10. By heating or depressurizing the adsorption/desorption unit 30 that has been removed from the housing 10, the carbon dioxide adsorbed by the adsorbent can be desorbed. The desorbed carbon dioxide can be stored in a cylinder or the like and effectively reused as a carbon source (carbon recycling).

The blower 40a is only required to be able to supply the indoor air A1 to the evaporator 21. In addition, the blower 40a is only required to be able to supply the cooled air that has been cooled by contact with the evaporator 21 to the adsorption/desorption unit 30.
Examples of the blower 40a include a fan or a blower that sends gas by the rotational movement of an impeller.
The blower 40b only needs to be able to supply the indoor air A1 to the condenser 22. In addition, the blower 40b only needs to be able to exhaust the warm air A3 that has been heated by contact with the condenser 22 to the outside of the housing 10.
The blower 40b may be a fan or a blower similar to the blower 40a.

The carbon dioxide concentration measuring device 50 only needs to be able to measure the carbon dioxide concentration in the clean air A2.
As the carbon dioxide concentration measuring device 50, a known carbon dioxide concentration meter, CO ₂ sensor, etc. can be used.
The carbon dioxide concentration measuring device 50 may be provided on the secondary side of the adsorption/desorption unit 30 and may be provided inside the housing 10 .

<Carbon dioxide separation and capture system>
The carbon dioxide separation and capture system of the present invention is a system comprising the carbon dioxide separation and capture apparatus of the present invention and a carbon dioxide desorption apparatus that desorbs carbon dioxide adsorbed by the adsorbent of the adsorption and desorption section removed from the carbon dioxide separation and capture apparatus.
The carbon dioxide separation and capture system of the present invention will be described with reference to the drawings.

As shown in FIG. 2 , the carbon dioxide separation and capture system 100 includes a carbon dioxide separation and capture device 1 installed on the floor in an indoor space 2 , a carbon dioxide desorption device 3 , and a capture vessel 4 .
The carbon dioxide desorption device 3 is located outside the indoor space 2. The carbon dioxide desorption device 3 and the recovery container 4 are connected by a pipe L3.

Indoor space 2 is a space where people are active indoors, such as an office. Indoor space 2 can be any space where people are active indoors, such as an office, a detached house, an apartment building, a hospital, a school, a gymnasium, a library, or a commercial facility, and is not particularly limited. Indoor space 2 can also be a moving space, such as a vehicle, a ship, or an aircraft.

The carbon dioxide desorption device 3 is a device that desorbs carbon dioxide from the adsorbent of the adsorption/desorption section 30 removed from the carbon dioxide separation and capture device 1 .
The carbon dioxide desorption device 3 may be, for example, a device having an enclosed space for accommodating the adsorption/desorption section 30, and both or either one of a heating means and a decompression means.
The enclosed space is not particularly limited as long as the carbon dioxide desorbed from the adsorbent does not leak. Examples of such an enclosed space include spaces enclosed by concrete, metal, glass, resin, wood, or a combination of these.

The heating means is not particularly limited, and may be, for example, a heater, a boiler, or the like, as long as it can heat the adsorption/desorption unit 30 .
The pressure reducing means is not particularly limited, and may be, for example, a vacuum pump, a suction pump, or the like, as long as it can reduce the internal pressure of the adsorption/desorption unit 30 .

Examples of the carbon dioxide desorption device 3 include a heater with a space sealed with metal, a glass container connected to a vacuum pump, etc.

The collection container 4 is not particularly limited as long as it is a container that can collect the desorbed carbon dioxide. Examples of the collection container 4 include containers such as cylinders and tanks.

Pipe L3 may be, for example, a pipe made of metal or resin. Pipe L3 may be provided with an on-off valve or the like.

<Carbon dioxide separation and capture method>
The carbon dioxide separation and capture method of the present invention includes a cooling step, an adsorption step, a desorption step, and a capture step.
The carbon dioxide separation and capture method of this embodiment will be described using a carbon dioxide separation and capture device 1 and a carbon dioxide separation and capture system 100 as an example.
Each step will be described in detail below with reference to FIGS.

<Cooling process>
The cooling step is a step of cooling carbon dioxide-containing air (indoor air A1) to obtain cooled air. The adsorbent of this embodiment can increase its carbon dioxide adsorption efficiency the lower the temperature (for example, 15°C or lower) the environment. Therefore, by including the cooling step, the carbon dioxide separation and capture method of this embodiment can further increase the carbon dioxide adsorption efficiency of the adsorbent in the subsequent adsorption step.

In the cooling process, first, the chiller 20 is started. First, the expansion valve 26 is closed, and the compressor 24 is started to compress the refrigerant and supply it to the pipe L1. The compressed refrigerant is supplied to the condenser 22. Next, the expansion valve 26 is opened. The refrigerant pressure is released, and the cooled refrigerant is supplied to the evaporator 21. The refrigerant that has flowed through the evaporator 21 is supplied to the compressor 24, and after the expansion valve 26 is closed, it is compressed again. In this way, the refrigerant flows through the inside of the chiller 20 in the order of the compressor 24, pipe L2, condenser 22, expansion valve 26, evaporator 21, and pipe L1.
Next, the fans 40a and 40b are started. The indoor air A1 is introduced into the evaporation chamber 11 through the air inlet 12a. The indoor air A1 is introduced into the condensation chamber 13 through the air inlet 12b.

In the cooling process, the blower 40a introduces indoor air A1 into the evaporation chamber 11, and the introduced indoor air A1 is brought into contact with the evaporator 21 of the cooling device 20. The indoor air A1 that has come into contact with the evaporator 21 is cooled to become cooled air, which is then supplied to the secondary side of the evaporator 21.
The temperature of the evaporator 21 in the cooling step is, for example, preferably 15° C. or lower, more preferably −20 to 15° C., and even more preferably −10 to 10° C. If the temperature of the evaporator 21 in the cooling step is equal to or higher than the above-mentioned lower limit, the load for cooling the evaporator 21 of the cooling device 20 can be reduced. If the temperature of the evaporator 21 in the cooling step is equal to or lower than the above-mentioned upper limit, the carbon dioxide adsorption efficiency of the adsorbent in the adsorption step can be further increased.

In the cooling process, it is preferable to reduce the moisture content of the indoor air A1 (moisture reduction operation). For example, by adjusting the temperature of the evaporator 21 to 10°C or below, the moisture contained in the indoor air A1 that comes into contact with the evaporator 21 adheres to the surface of the evaporator 21 as condensed water. The condensed water that adheres to the surface of the evaporator 21 is discharged to the outside of the carbon dioxide separation and capture device 1 through the drain outlet 18. As a result, some or all of the moisture contained in the indoor air A1 is removed, and cooled air with reduced moisture content is obtained (moisture reduction operation). The moisture contained in the indoor air A1 hinders the adsorbent from adsorbing carbon dioxide. Therefore, by reducing the moisture content of the indoor air A1, the adsorbent's carbon dioxide adsorption efficiency in the adsorption process can be further improved.

Indoor air A1 introduced into the condensing chamber 13 through the air inlet 12b is heated upon contact with the condenser 22 and is discharged to the outside of the housing 10 through the air outlet 14b as warm air A3. In this way, the heat generated by compressing the refrigerant is discharged to the outside of the carbon dioxide separation and capture device 1 as warm air A3.

<Adsorption process>
The adsorption step is a step in which the cooled air is brought into contact with the adsorption/desorption section to cause the adsorbent to adsorb part or all of the carbon dioxide, thereby obtaining purified air.

In the adsorption process, the cooled air obtained in the cooling process is supplied to the adsorption/desorption unit 30. The cooled air supplied to the adsorption/desorption unit 30 comes into contact with the adsorbent material within the adsorption/desorption unit 30, and some or all of the carbon dioxide contained in the cooled air is adsorbed by the adsorbent material.

The carbon dioxide concentration in the cooled air is equal to the carbon dioxide concentration in the indoor air A1.
The carbon dioxide concentration in the indoor air A1 is, for example, preferably 100 to 2,000 ppm, more preferably 200 to 1,500 ppm, and even more preferably 300 to 1,000 ppm. When the carbon dioxide concentration in the indoor air A1 is equal to or higher than the lower limit, more carbon dioxide can be adsorbed by the adsorbent, and more carbon dioxide can be desorbed in the desorption process. When the carbon dioxide concentration in the indoor air A1 is equal to or lower than the upper limit, the adsorption capacity of the adsorbent is less likely to deteriorate. In addition, when the carbon dioxide concentration in the indoor air A1 is equal to or lower than the upper limit, cleaner purified air A2 can be discharged from the housing 10.
The carbon dioxide concentration in the indoor air A1 can be measured by a carbon dioxide concentration meter (not shown) installed in the indoor space 2. Alternatively, the carbon dioxide concentration in the indoor air A1 on the air inlet 12a side of the carbon dioxide separation and capture device 1 may be measured by a carbon dioxide concentration meter (not shown) provided on the primary side of the evaporator 21. In this case, the carbon dioxide concentration meter may be provided, for example, outside the housing 10 at the air inlet 12a.

The clean air A2 in which part or all of the carbon dioxide has been adsorbed by the adsorbent has a carbon dioxide concentration lower than that of the cooled air.
The carbon dioxide concentration in the cleaned air A2 is, for example, preferably 1,000 ppm or less, more preferably 800 ppm or less, and even more preferably 500 ppm or less. When the carbon dioxide concentration in the cleaned air A2 is equal to or less than the above upper limit, the carbon dioxide concentration can be made to satisfy the building environmental sanitation management standards, and cleaner cleaned air A2 can be supplied indoors. The lower limit of the carbon dioxide concentration in the cleaned air A2 is not particularly limited, but is substantially 10 ppm.
The carbon dioxide concentration in the clean air A2 can be measured by a carbon dioxide concentration measuring device 50.

When some or all of the moisture contained in the indoor air A1 is removed during the cooling process, the humidity of the resulting purified air A2 is lower than the humidity of the indoor air A1. In other words, in this case, the cooler 20 functions as a dehumidifier. When the cooler 20 functions as a dehumidifier, the indoor air is sufficiently dehumidified, creating a more comfortable indoor environment.

<Desorption process>
The desorption step is a step in which the adsorption/desorption unit is removed from the carbon dioxide separation/capture apparatus, and carbon dioxide is desorbed from the adsorbent to which the carbon dioxide has been adsorbed.
The method for desorbing carbon dioxide from the adsorbent is not particularly limited, and examples thereof include a method of heating the adsorption/desorption unit 30 and a method of reducing the internal pressure of the adsorption/desorption unit 30 .

In the desorption step, first, the adsorption/desorption unit 30 is removed from the housing 10. The removed adsorption/desorption unit 30 is housed inside the carbon dioxide desorption device 3.
In the case of the method of heating the adsorption/desorption section 30, the carbon dioxide adsorbed to the adsorbent is desorbed according to the principle of temperature swing adsorption (TSA).
The heating temperature in the desorption step is, for example, preferably 60 to 200°C, more preferably 100 to 180°C. When the heating temperature in the desorption step is equal to or higher than the lower limit, a larger amount of carbon dioxide can be desorbed. When the heating temperature in the desorption step is equal to or lower than the upper limit, deterioration of the adsorbent can be suppressed. In addition, when the heating temperature in the desorption step is equal to or lower than the upper limit, energy can be saved.

In the case of the method of reducing the internal pressure of the adsorption/desorption unit 30, the carbon dioxide adsorbed to the adsorbent is desorbed according to the principle of pressure swing adsorption (PSA).
In the method of reducing the internal pressure of the adsorption/desorption unit 30, the adsorption/desorption unit 30 is placed in the sealed space of the carbon dioxide desorption device 3, and the pressure in the sealed space is reduced. The method of reducing the pressure in the sealed space is not particularly limited, and examples thereof include a method of suction using a vacuum pump or the like.
In this case, the pressure in the sealed space is, for example, preferably 10 ⁻⁵ to 100,000 Pa, and more preferably 10 ⁻² to 100 Pa. When the pressure in the sealed space is equal to or higher than the above lower limit, the energy required for decompression can be saved. When the pressure in the sealed space is equal to or lower than the above upper limit, more carbon dioxide can be desorbed.

During the desorption process, a method of heating the adsorption/desorption unit 30 and a method of reducing the internal pressure of the adsorption/desorption unit 30 may be used in combination. By using both heating and reducing the pressure, more carbon dioxide can be desorbed, thereby further increasing the efficiency of carbon dioxide desorption.

<Recovery process>
The recovery step is a step of recovering the carbon dioxide desorbed in the desorption step. The method for recovering carbon dioxide is not particularly limited, and examples include a method of collecting and recovering carbon dioxide in a recovery container 4, and a method of reducing the internal pressure of the recovery container 4 to negative pressure and sucking the carbon dioxide to recover it. The carbon dioxide desorbed by the carbon dioxide desorption device 3 is recovered in the recovery container 4 and can be reused as a carbon source (carbon recycling). Examples of carbon sources include hydrocarbons such as methane and ethylene. In addition, the recovered carbon dioxide may be used for plant cultivation or as a raw material for carbonated drinks, etc.

In this way, the recovery step can recover carbon dioxide with a higher concentration.
The concentration of the recovered carbon dioxide may be, for example, 1,000 ppm or more, preferably 1,000 to 750,000 ppm, 1,000 to 500,000 ppm, 1,000 to 250,000 ppm, or 1,000 to 100,000 ppm, more preferably 1,000 to 10,000 ppm, even more preferably 2,000 to 10,000 ppm, and particularly preferably 2,000 to 5,000 ppm. When the concentration of the recovered carbon dioxide is equal to or higher than the above lower limit, more carbon dioxide can be effectively utilized. When the concentration of the recovered carbon dioxide is equal to or lower than the above upper limit, management becomes easier.
The concentration of recovered carbon dioxide can be adjusted by the type and amount of adsorbent, the heating temperature in the desorption step, the internal pressure of the adsorption/desorption section 30 in the desorption step, the time in the desorption step, and a combination of these.

In the carbon dioxide separation and capture method of this embodiment, it is preferable to measure the carbon dioxide concentration of the clean air A2 and compare it with the carbon dioxide concentration of the indoor air A1.
Generally, when an adsorbent adsorbs carbon dioxide, the adsorption capacity of the adsorbent decreases. Breakthrough of the adsorbent can be confirmed by measuring the carbon dioxide concentration in the clean air A2 and comparing it with the carbon dioxide concentration in the indoor air A1.
For example, it can be determined that the adsorbent has broken through when the difference in carbon dioxide concentration between the indoor air A1 and the purified air A2 on the air inlet 12a side of the carbon dioxide separation and capture device 1 is 10% or less. The difference (%) between the carbon dioxide concentration of the indoor air A1 and the carbon dioxide concentration of the purified air A2 can be calculated using the following formula (1).
Difference (%) = (carbon dioxide concentration (ppm) of indoor air A1 - carbon dioxide concentration (ppm) of clean air A2) / carbon dioxide concentration (ppm) of indoor air A1 × 100 (1)
For example, if the carbon dioxide concentration of the indoor air A1 on the air inlet 12a side of the carbon dioxide separation and capture device 1 is 400 ppm and the carbon dioxide concentration of the purified air A2 is 360 ppm, the difference (%) is calculated from equation (1) as (400-360)/400×100=10%.

The breakthrough adsorbent can be regenerated by desorbing the carbon dioxide adsorbed by the adsorbent. That is, the breakthrough adsorbent is regenerated by performing a desorption process. Therefore, when the difference between the carbon dioxide concentration of the indoor air A1 and the carbon dioxide concentration of the purified air A2 becomes 10% or less, the adsorption/desorption unit 30 is removed and replaced with an adsorption/desorption unit filled with new adsorbent. The breakthrough adsorbent can be regenerated by performing a desorption process on the adsorbent in the removed adsorption/desorption unit 30. The difference between the carbon dioxide concentration of the indoor air A1 and the carbon dioxide concentration of the purified air A2 when performing the desorption process is, for example, preferably 10% or less, more preferably 20% or less, and even more preferably 30% or less. In this way, the adsorbent can be efficiently regenerated by performing the desorption process in accordance with the timing of the adsorbent breakthrough.
The regenerated adsorbent can be reused by returning it to the adsorption/desorption section 30 again.

If the carbon dioxide concentration of the clean air A2 is not measured, the replacement timing of the adsorption/desorption unit 30 may be determined based on the operating time of the carbon dioxide separation and capture device 1, without waiting for breakthrough of the adsorbent.

As described above, according to the carbon dioxide separation and capture system of this embodiment, cooled air generated by the cooler is supplied to the adsorption and desorption section, so that carbon dioxide can be more efficiently adsorbed into the adsorbent.
According to the carbon dioxide separation and capture device of this embodiment, the adsorption and desorption unit is provided so that it can be attached and removed, and therefore the removed adsorption and desorption unit can be easily stored in the carbon dioxide desorption device. Carbon dioxide can be easily captured by desorbing the carbon dioxide adsorbed by the adsorbent of the adsorption and desorption unit stored in the carbon dioxide desorption device. By capturing the carbon dioxide, it can be reused.
According to the carbon dioxide capture and separation system of this embodiment, indoor air can be circulated and utilized, eliminating the need to rely on outside air to supply air to indoor spaces. This reduces the outside air load, which is said to account for 40% of the air conditioning load.
The carbon dioxide capture system of this embodiment can reduce the air conditioning load, thereby reducing the energy required for air conditioning and reducing the cost of air conditioning. This reduces the workload of the power plant that generates the energy required for air conditioning, leading to a reduction in carbon dioxide emissions from the power plant.
According to the carbon dioxide separation and capture device of this embodiment, carbon dioxide can be directly captured from indoor air, and if it is widely used, it will lead to a reduction in carbon dioxide emissions worldwide.
The carbon dioxide capture and separation system of this embodiment can be applied to existing buildings without any construction work.
The carbon dioxide adsorbed and captured by the carbon dioxide capture apparatus, carbon dioxide capture method, or carbon dioxide capture system of this embodiment can be stably supplied in the amount necessary for industrial use. Therefore, the captured carbon dioxide is suitable as a material for synthesizing C1 compounds such as carbon monoxide, methane, methanol, and formic acid, C2 compounds such as ethane, ethylene, and ethanol, or olefinic compounds such as propylene and butene, through chemical engineering processes such as artificial photosynthesis.
Thus, the technology of the present invention is beneficial to the global environment.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to such specific embodiment, and various modifications are possible within the scope of the gist of the present invention as set forth in the claims.

In the above-described embodiment, the carbon dioxide capture and separation device 1 is installed on the floor in the indoor space 2, but the present invention is not limited to this.
For example, the carbon dioxide capture and separation device may be installed on the ceiling or wall of an enclosed space such as a room. However, since no construction work is required inside the enclosed space, it is preferable that the carbon dioxide capture and separation device be installed as a floor-standing device inside the enclosed space.
In the above embodiment, a container filled with an adsorbent or the like is exemplified as the adsorption/desorption unit 30, but the adsorption/desorption unit may be a porous body carrying an adsorbent or the like.
In the above-described embodiment, there is one adsorption/desorption unit 30, but the number of adsorption/desorption units may be two or more.
In the above-described embodiment, the carbon dioxide capture and separation device 1 includes a housing 10, but the carbon dioxide capture and separation device does not have to include a housing. However, for convenience in portability, it is preferable that the carbon dioxide capture and separation device include a housing.
In the above embodiment, the housing 10 has a rectangular parallelepiped shape, but the housing may also have a cylindrical or elliptical cylindrical shape.
In the above-described embodiment, the housing 10 has the partition wall 16, but it is not necessary to provide a partition wall inside the housing. However, it is preferable to provide a partition wall inside the housing because this can suppress the transfer of heat between the evaporator and the condenser and further improve the cooling efficiency of the indoor air.
In the above-described embodiment, the housing 10 has the air inlet 12b and the air outlet 14b, but the housing does not have to have the air inlet 12b and the air outlet 14b. However, it is preferable that the housing has the air inlet 12b and the air outlet 14b, because this allows the heat inside the housing to be discharged as warm air A3 and the indoor air cooling efficiency to be further improved.
Since the purified air can be made even cleaner, the carbon dioxide separation and capture device may have a filter or the like that can remove dust and the like in the air before and after the air inlet.
In the above-described embodiment, the carbon dioxide separation and capture apparatus 1 has the carbon dioxide concentration measuring device 50, but the carbon dioxide separation and capture apparatus does not have to have a carbon dioxide concentration measuring device. However, it is preferable that the carbon dioxide separation and capture apparatus have a carbon dioxide concentration measuring device, as this allows for more reliable detection of breakthrough of the adsorbent in the adsorption and desorption section.
In the above-described embodiment, the carbon dioxide separation and capture apparatus 1 has the carbon dioxide concentration measuring device 50, but the carbon dioxide separation and capture apparatus may also have a carbon dioxide concentration measuring device on the air inlet side. By having a carbon dioxide concentration measuring device on the air inlet side, breakthrough of the adsorbent in the adsorption and desorption section can be detected more accurately and reliably.
In the above-described embodiment, one carbon dioxide capture and separation apparatus is installed in one indoor space, but the number of carbon dioxide capture and separation apparatuses may be two or more in one indoor space.

1...Carbon dioxide capture device, 2...Indoor space, 3...Carbon dioxide desorption device, 4...Capture container, 10...Housing, 11...Evaporation chamber, 12a, 12b...Air inlet, 13...Condensation chamber, 14a, 14b...Air outlet, 16...Bulkhead, 18...Drain outlet, 20...Cooler, 21...Evaporator, 22...Condenser, 24...Compressor, 26...Expansion valve, 30...Adsorption/desorption unit, 40a, 40b...Blower, 50...Carbon dioxide concentration meter, 100...Carbon dioxide capture system, L1, L2, L3...Piping

Claims (6)

a cooling machine and an adsorption/desorption unit having an adsorbent capable of adsorbing and desorbing carbon dioxide;
The adsorption/detachment unit is provided so as to be freely attached and detached,
supplying cooled air generated by the cooler to the adsorption/desorption section;
the cooling device and the adsorption/desorption unit are housed in a single housing,
The housing is divided into an evaporation chamber and a condensation chamber by a partition wall,
the cooling device is a heat pump having an evaporator and a condenser,
the evaporator is located within the evaporation chamber, and the condenser is located within the condensation chamber;
The carbon dioxide separation and capture apparatus, wherein the adsorption and desorption unit is installed inside the evaporation chamber and is located on the secondary side of the evaporator of the cooling machine. The carbon dioxide separation and capture system of claim 1, further comprising a carbon dioxide concentration measuring device on the secondary side of the adsorption and desorption unit. A carbon dioxide separation and capture system comprising the carbon dioxide separation and capture apparatus according to claim 1 or 2, and a carbon dioxide desorption apparatus that desorbs the carbon dioxide adsorbed by the adsorbent from the removed adsorption and desorption unit. A carbon dioxide separation and capture method performed using the carbon dioxide separation and capture apparatus according to claim 1 or 2,
a cooling step of cooling the air containing carbon dioxide to obtain cooled air;
an adsorption step of bringing the cooled air into contact with an adsorption/desorption section having an adsorbent, thereby causing the adsorbent to adsorb part or all of the carbon dioxide, thereby obtaining purified air;
a desorption step of removing the adsorption/desorption unit and desorbing carbon dioxide from the adsorbent to which carbon dioxide has been adsorbed;
a recovery step of recovering the carbon dioxide desorbed in the desorption step,
The carbon dioxide separation and capture method, wherein the cooling step and the adsorption step are performed within the single casing. The carbon dioxide separation and capture method according to claim 4, further comprising a moisture reduction operation in which the moisture contained in the carbon dioxide-containing air is reduced during the cooling process. The carbon dioxide separation and capture method according to claim 4 or 5, wherein the desorption step is carried out when the difference between the carbon dioxide concentration of the clean air and the carbon dioxide concentration of the air containing the carbon dioxide becomes 10% or less.