JP2022075298A - Air conditioning system, building air-conditioning system and carbon dioxide recovery method - Google Patents

Abstract

To provide an air conditioning system which recovers carbon dioxide, and can effectively utilize the recovered carbon dioxide.SOLUTION: An air conditioning system 1 has a carbon dioxide increase part 40 in which a concentration of carbon dioxide increases, an adsorption/desorption part 50, and a recover part 60. The adsorption/desorption part 50 has an adsorbent with carbon dioxide adsorption capacity. According to this system, processing object air containing carbon dioxide is supplied to the adsorption/desorption part 50 from the carbon dioxide increase part 40 and the processing object air is brought into contact with the adsorbent, whereby a part or all of carbon dioxide is adsorbed to the adsorbent from the processing object air to produce processed air, the processed air is discharged from the adsorption/desorption part 50, carbon dioxide adsorbed to the adsorbent is desorbed, the desorbed carbon dioxide is discharged from the adsorption/desorption part 50, and is supplied to the recovery part 60.SELECTED DRAWING: Figure 1

Description

The present invention relates to an air conditioning system, a building air conditioning system and a carbon dioxide recovery method.

The building environmental hygiene management standard stipulates that the carbon dioxide content should be 1000 ppm (volume standard; hereinafter the same in this specification) or less in the living room where air conditioning equipment is installed. There is. As described above, in the interior of a building provided with an air conditioning facility, a technique for removing carbon dioxide from the indoor air is desired.

For example, Patent Document 1 is divided into a treatment zone in which the air to be treated containing carbon dioxide is absorbed by an amine-supporting solid absorber and a regeneration zone in which the carbon dioxide absorbed by the absorber is desorbed into the regeneration air. An air conditioning system having a rotor and configured such that the enthalpy difference between the air to be processed supplied to the processing zone and the air for regeneration supplied to the regeneration zone is within a specific range has been proposed. According to the invention of Patent Document 1, carbon dioxide in the indoor air is removed to improve the air quality.

JP-A-2017-75715

By the way, carbon dioxide can be used for the production of valuable resources by recovering it by an appropriate method. However, in the technique of Patent Document 1, the removed carbon dioxide is discharged to the outside, and recovery of carbon dioxide is not considered.

Therefore, an object of the present invention is an air conditioning system, a building air conditioning system, and a carbon dioxide recovery method that can recover carbon dioxide and effectively utilize the recovered carbon dioxide in an air conditioning system in a building.

In order to solve the above problems, the present invention has the following aspects.
[1] It has a carbon dioxide increasing part, an adsorption / desorption part, and a recovery part in which the concentration of carbon dioxide increases.
The suction / desorption portion has an adsorbent having a carbon dioxide adsorbing ability, and has an adsorbent.
By supplying the treatment target air containing carbon dioxide from the carbon dioxide increasing portion to the suction / desorption portion and bringing the treatment target air into contact with the adsorbent, a part or all of the carbon dioxide from the treatment target air. Is adsorbed on the adsorbent to obtain treated air, and the treated air is discharged from the suction / desorption portion.
An air conditioning system that desorbs carbon dioxide adsorbed on the adsorbent, discharges the desorbed carbon dioxide from the suction / desorption section, and supplies the desorbed carbon dioxide to the recovery section.
[2] An air supply unit that supplies outside air to the carbon dioxide increase unit,
It has a mixing section for mixing the outside air and the treated air, and has.
The air conditioning system according to [1], wherein the mixing portion is located after the suction / desorption portion.
[3] The suction / desorption portion has two or more suction / desorption cylinders filled with the adsorbent.
Two or more of the suction / desorption cylinders are arranged in parallel, and air volume regulators are provided before and after the suction / desorption cylinders.
The carbon dioxide is adsorbed by any of the suction / desorption cylinders, and the carbon dioxide is desorbed by any other suction / desorption cylinder.
The air conditioning according to [1] or [2], wherein the adsorption of carbon dioxide and the desorption of carbon dioxide are alternately switched between the arbitrary suction / desorption cylinder and any other suction / desorption cylinder. system.
[4] The air conditioning system according to any one of [1] to [3], wherein the suction / desorption portion desorbs the carbon dioxide adsorbed on the adsorbent by reducing the internal pressure.
[5] A building air conditioning system provided with a plurality of air conditioning systems according to any one of [1] to [4] on different floors.

[6] Adsorption step of adsorbing a part or all of the carbon dioxide to the adsorbent by bringing the air to be treated containing carbon dioxide discharged from the carbon dioxide increase part where the concentration of carbon dioxide increases into contact with the adsorbent. When,
A desorption step of desorbing the carbon dioxide adsorbed on the adsorbent by the adsorbent on which the carbon dioxide is adsorbed by a pressure difference and / or a temperature difference.
A carbon dioxide recovery method comprising a recovery step for recovering the desorbed carbon dioxide.

According to the air conditioning system, the building air conditioning system, and the carbon dioxide recovery method of the present invention, carbon dioxide can be recovered and the recovered carbon dioxide can be effectively used in the air conditioning system in a building.

It is a schematic diagram which shows the air conditioning system which concerns on one Embodiment of this invention. It is a schematic diagram which shows the building air-conditioning system which concerns on one Embodiment of this invention.

≪Air conditioning system≫
The air conditioning system of the present invention has a carbon dioxide increasing part in which the concentration of carbon dioxide increases, an adsorption / desorption part having an adsorbent, an air discharging part, a carbon dioxide discharging part, and a recovery part.
Hereinafter, the air conditioning system according to the embodiment of the present invention will be described in detail with reference to FIG.

As shown in FIG. 1, the air conditioning system 1 of the present embodiment includes an air supply unit 10, a mixing unit 20, an air conditioning unit 30, a carbon dioxide increasing unit 40, an absorption / desorption unit 50, and a recovery unit 60. And have.
The air supply unit 10 and the mixing unit 20 are connected by a pipe L1. The mixing unit 20 and the air conditioning unit 30 are connected by a pipe L2. The air conditioning section 30 and the carbon dioxide increasing section 40 are connected by a pipe L3. A pipe L4 is connected to the carbon dioxide increasing portion 40. The pipe L4 is connected to the suction / detachment portion 50 by a branch 101. A blower A2 is provided in the pipe L4. The suction / detachment portion 50 is connected to the pipe L11 by a branch 102. The pipe L11 is connected to the pipe L13 by a branch 104. The suction / detachment portion 50 is connected to the pipe L12 by a branch 103. The pipe L12 is connected to the pipe L14 by a branch 105. The pipe L13 is connected to the mixing unit 20. The pipe L14 is connected to the recovery unit 60.
The arrows in the figure indicate the moving direction of a fluid such as air.

<Air supply unit>
The air supply unit 10 supplies outside air to the carbon dioxide increase unit 40. The air supply unit 10 of the present embodiment has an outside air intake port 12, a pipe L0, and a damper D1. The outside air intake port 12 and the damper D1 are connected by a pipe L0. The damper D1 is connected to the mixing unit 20 via the pipe L1. The pipes L0 and L1 may be provided with, for example, a blower that gives energy to the gas by the rotational movement of the impeller.

Examples of the outside air intake port 12 include a louver having a rain return or the like that can introduce outside air and prevent rainwater from entering.
Examples of the damper D1 include an air volume regulator that can adjust the flow rate by opening and closing a valve, a fireproof damper having a fire spread prevention function for use in the opening of a portion facing the outer wall, and the like.
Examples of the pipe L0 include a duct made of metal or resin. Examples of the pipe L1 include a duct or the like similar to the pipe L0.

<Mixing part>
The mixing unit 20 mixes the outside air with the treated air.
Examples of the mixing unit 20 include a metal or resin chamber and the like.
Examples of the pipe L2 include a duct or the like similar to the pipe L0.

<Air conditioning department>
The air conditioning unit 30 purifies the mixed fluid of the outside air and the treated air, adjusts the temperature, and then supplies the mixed fluid to the carbon dioxide increasing unit 40.
The air conditioning unit 30 has a filter 32 and a blower A1.
Examples of the air conditioning unit 30 include a device such as an air handling unit (AHU).
Examples of the filter 32 include a filter capable of removing dust and the like in the atmosphere.
Examples of the blower A1 include a blower that gives energy to a gas by the rotational motion of an impeller.

<Carbon dioxide increase part>
Examples of the carbon dioxide increasing unit 40 include a living room in which a person is active indoors such as an office. In the carbon dioxide increasing unit 40, the concentration of carbon dioxide increases as a person breathes. In addition, the carbon dioxide increasing unit 40 includes, for example, a room equipped with a combustion type heater, a firing device, and the like.
In the present specification, the carbon dioxide increasing unit 40 means a space in which the concentration of carbon dioxide can increase as compared with the atmosphere or the like, and does not necessarily mean a space in which the concentration of carbon dioxide continues to increase. It is assumed that the carbon dioxide increasing unit 40 also includes the moment when the carbon dioxide concentration decreases.
The carbon dioxide increasing unit 40 has air supply ports 41 and 42 and an exhaust port 43. A pipe L3 is connected to the air supply port 41 and the air supply port 42. A pipe L4 is connected to the exhaust port 43.
Examples of the air supply ports 41 and 42 include air control ports made of metal or resin.
Examples of the exhaust port 43 include an air control port made of metal or resin.
Examples of the pipe L4 include a metal or resin return air duct and the like.

<Suction / desorption part>
The suction / desorption unit 50 has two suction / desorption cylinders 51 and 52, pipes L5 and L6, air discharge parts L7 and L8, dampers D3 to D6, and carbon dioxide discharge parts L9 and L10. The pipe L5, the air discharge unit L7, and the carbon dioxide discharge unit L9 are connected to the suction / detachment cylinder 51. The pipe L6, the air discharge unit L8, and the carbon dioxide discharge unit L10 are connected to the suction / desorption cylinder 52. The air discharge unit L7 and the air discharge unit L8 are connected by a branch 102. That is, the suction / desorption cylinder 51 and the suction / desorption cylinder 52 are arranged in parallel. By arranging the suction / desorption cylinder 51 and the suction / desorption cylinder 52 in parallel, carbon dioxide can be adsorbed on one side and carbon dioxide can be desorbed on the other side.
As used herein, "adsorption" means that a liquid or gas is attracted to the surface of another solid or liquid. "Desorption" means that the adsorbed substance separates from the adsorption interface. Also called detachment. "Suction / desorption" means adsorption and / or desorption.
The pipe L5 is provided with a damper D3. The pipe L6 is provided with a damper D4. A damper D5 is provided in the air discharge portion L7. A damper D6 is provided in the air discharge portion L8. That is, dampers are provided before and after the suction / detachment cylinders 51 and 52.
The pipe L5 and the pipe L6 are connected by a branch 101. The air discharge unit L7 and the air discharge unit L8 are connected by a branch 102.
A valve B1 is provided in the carbon dioxide emission unit L9. A valve B2 is provided in the carbon dioxide emission unit L10.
The dampers D3 to D6 and the valves B1 and B2 are connected to the control unit C1.
The suction / desorption cylinders 51 and 52 are filled with an adsorbent having a carbon dioxide adsorbing ability.
The suction / desorption cylinders 51 and 52 are cylindrical members capable of supporting the adsorbent. Examples of the suction / detachment cylinders 51 and 52 include a cylindrical member made of metal or resin, a cylindrical member obtained by corrugating a nonflammable sheet such as ceramic fiber paper or glass fiber paper, and the like. The adsorbent is not particularly limited and may have a carbon dioxide adsorbing ability.
Examples of the adsorbent include solid absorbers carrying amines such as zeolite, silica gel, activated carbon, triethanolamine, and monoethanolamine, and amine-based weakly basic anion exchange resins. As the adsorbent, zeolite, silica gel and activated carbon are preferable, and zeolite and silica gel are more preferable.

Examples of the dampers D3, D4, D5, and D6 include an air volume controller whose opening and closing can be controlled by the control unit C1.
Examples of the valves B1 and B2 include solenoid valves whose opening and closing can be controlled by the control unit C1.
Examples of the control unit C1 include a computer capable of adjusting the opening and closing of dampers D3, D4, D5, D6, valves B1 and B2. By adjusting the opening and closing of the dampers D3, D4, D5, D6, valves B1 and B2 with the control unit C1, the adsorption of carbon dioxide and the desorption of carbon dioxide are alternated between the suction / desorption cylinder 51 and the suction / desorption cylinder 52. It can be controlled so that it can be switched to.

Examples of the pipe L5 include ducts and the like similar to the pipe L0.
Examples of the pipe L6 include a duct or the like similar to the pipe L0.

The air discharge units L7 and L8 discharge the treated air in which a part or all of carbon dioxide is adsorbed by the adsorbent from the air to be treated. Examples of the air discharge portions L7 and L8 include ducts made of metal or resin. A blower, a suction pump, or the like may be provided in the air discharge portions L7 and L8.
The air discharge portions L7 and L8 of the present embodiment are connected to the pipe L11 by a branch 102. The pipe L11 is provided with a damper D7. The pipe L11 is connected to the pipe L13 by a branch 104. The pipe L13 is provided with a damper D8.
Examples of the pipe L11 include a duct or the like similar to the pipe L0.
Examples of the pipe L13 include a duct or the like similar to the pipe L0.
Examples of the damper D7 include an air volume regulator that can adjust the flow rate by opening and closing a valve.
Examples of the damper D8 include an air volume regulator similar to the damper D7.
The pipe L11 may be provided with a fireproof damper or the like other than the damper D7.
The pipe L13 may be provided with a fireproof damper or the like other than the damper D8.

The carbon dioxide discharging units L9 and L10 discharge carbon dioxide desorbed from the adsorbent. Examples of the carbon dioxide emitting portions L9 and L10 include pipes made of metal or resin. A blower, a suction pump, or the like may be provided in the carbon dioxide emission units L9 and L10.
The carbon dioxide emission units L9 and L10 of the present embodiment are connected to the pipe L12 by a branch 103. The pipe L12 is connected to the pipe L14 by a branch 105. A pump P1 is provided in the pipe L14.
Examples of the pipe L12 include a duct or the like similar to the pipe L0.
Examples of the pipe L14 include a duct or the like similar to the pipe L0.
Examples of the pump P1 include a vacuum pump and a suction pump.

<Recovery department>
One end of the pipe L14 is connected to the recovery unit 60. The other end of the pipe L14 is connected to, for example, a carbon dioxide emission portion of another air conditioning system (not shown).
Carbon dioxide desorbed from the adsorbent is supplied to the recovery unit 60.
Examples of the recovery unit 60 include a container such as a tank capable of storing carbon dioxide.

≪Carbon dioxide recovery method (air conditioning method) ≫
The carbon dioxide recovery method of the present invention includes an adsorption step, a desorption step, and a recovery step.
The carbon dioxide recovery method of the present invention will be described by taking as an example an air conditioning method using the air conditioning system 1.
Each step will be described in detail below with reference to FIG.

<Adsorption process>
The adsorption step is a step of adsorbing a part or all of carbon dioxide to the adsorbent by bringing the air to be treated containing carbon dioxide discharged from the carbon dioxide increase unit 40 into contact with the adsorbent.
In the suction / detachment unit 50, the opening / closing of the dampers D3, D4, D5, D6, valves B1 and B2 is adjusted by the control unit C1.

In the adsorption step, first, the damper D3 is opened and the damper D4 is closed. The damper D5 is opened and the valve B1 is closed. The blower A2 is operated to suck the air to be processed, and the air to be processed is supplied to the suction / desorption cylinder 51 via the pipe L4.
The air to be treated in this embodiment is the air discharged from the carbon dioxide increasing unit 40. The carbon dioxide increasing unit 40 contains post-active air whose carbon dioxide concentration has been increased by human activity. Examples of the air to be treated include post-combustion air generated by combustion, as well as post-combustion air.

The concentration of carbon dioxide in the air to be treated is, for example, preferably 100 to 5000 ppm, more preferably 200 to 4000 ppm, further preferably 300 to 3000 ppm, further preferably 400 to 2000 ppm, particularly preferably 500 to 1500 ppm, and 600 to 1000 ppm. Most preferred. When the concentration of carbon dioxide in the air to be treated is equal to or higher than the above lower limit, more carbon dioxide can be adsorbed on the adsorbent, and more carbon dioxide can be desorbed in the desorption step. When the concentration of carbon dioxide in the air to be treated is not more than the above upper limit value, the adsorbing ability of the adsorbent is unlikely to be deteriorated. In addition, when the concentration of carbon dioxide in the air to be treated is not more than the above upper limit value, cleaner treated air can be discharged from the air discharge unit L7.

Part or all of the carbon dioxide in the air to be treated that has come into contact with the adsorbent is adsorbed by the adsorbent in the adsorption / desorption cylinder 51 (adsorption step). The result is treated air with a reduced carbon dioxide concentration.

The treated air flows from the air discharge portion L7 to the pipe L11 via the damper D5.
The carbon dioxide concentration in the treated air is lower than the carbon dioxide concentration in the treated air. The carbon dioxide concentration in the treated air is, for example, preferably 1000 ppm or less, more preferably 800 ppm or less, still more preferably 500 ppm or less. When the carbon dioxide concentration in the treated air is not more than the above upper limit value, the carbon dioxide concentration can be set to satisfy the building environmental hygiene management standard, and cleaner treated air can be supplied to the carbon dioxide increasing unit 40. The lower limit of the carbon dioxide concentration in the treated air is not particularly limited, but is substantially 10 ppm, and may be 0 ppm.

The temperature inside the suction / desorption cylinder 51 in the adsorption step is, for example, preferably 0 to 60 ° C, more preferably 0 to 40 ° C, still more preferably 5 to 35 ° C, and particularly preferably 10 to 30 ° C. When the temperature inside the suction / desorption cylinder 51 is equal to or higher than the above lower limit value, the treated air having a comfortable temperature can be supplied to the carbon dioxide increasing unit 40. When the temperature inside the suction / desorption cylinder 51 is not more than the above upper limit value, the adsorption ability of the adsorbent can be further enhanced. The temperature inside the suction / desorption cylinder 51 can be adjusted by introducing a cooling device or the like (not shown) inside the suction / desorption cylinder 51.

The pressure inside the suction / desorption cylinder 51 in the suction step is not particularly limited, but is, for example, normal pressure.
As used herein, the term "normal pressure" refers to a pressure when neither depressurization nor pressurization is performed, and is, for example, 0.1 MPa.

Next, the damper D3 is closed and the damper D4 is opened. The damper D6 is opened and the valve B2 is closed. The blower A2 is operated to suck the air to be processed, and the air to be processed is supplied to the suction / desorption cylinder 52 via the pipe L4. The air to be treated is the same as the air to be treated supplied to the suction / desorption cylinder 51.
Part or all of the carbon dioxide in the air to be treated that has come into contact with the adsorbent is adsorbed by the adsorbent in the adsorption / desorption cylinder 52 (adsorption step). The result is treated air with a reduced carbon dioxide concentration.
The treated air flows from the air discharge portion L8 to the pipe L11 via the damper D6.
The carbon dioxide concentration in the treated air is the same as that of the treated air that has passed from the air discharge portion L7 to the pipe L11 via the air discharge portion L7 via the suction / desorption cylinder 51.

The temperature inside the suction / desorption cylinder 52 in the adsorption step is the same as the temperature inside the suction / desorption cylinder 51. The temperature inside the suction / desorption cylinder 52 in the adsorption step may be the same as or different from the temperature inside the suction / desorption cylinder 51.
The pressure inside the suction / desorption cylinder 52 in the suction step is the same as the pressure inside the suction / desorption cylinder 51. The pressure inside the suction / desorption cylinder 52 in the suction step may be the same as or different from the pressure inside the suction / desorption cylinder 51.

<Detachment process>
The damper D5 is closed and the valve B1 is opened while the carbon dioxide is adsorbed by the suction / desorption cylinder 52. The pump P1 is operated to reduce the pressure inside the suction / detachment cylinder 51. When the pressure inside the suction / desorption cylinder 51 is reduced, the carbon dioxide adsorbed on the adsorbent in the suction / desorption cylinder 51 is desorbed due to the pressure difference (desorption step). The desorbed carbon dioxide is supplied from the carbon dioxide discharging unit L9 to the pipe L12 via the branch 103.

The pressure inside the suction / desorption cylinder 51 in the desorption step is preferably lower than the normal pressure. The pressure inside the suction / desorption cylinder 51 in the desorption step is, for example, preferably 100 kPa or less, more preferably 100 Pa or less, still more preferably 0.1 Pa or less. When the pressure inside the suction / desorption cylinder 51 in the desorption step is not more than the above upper limit value, more carbon dioxide can be desorbed more easily.
The lower limit of the pressure inside the suction / desorption cylinder 51 in the desorption step is preferably as low as possible, and theoretically it is an absolute vacuum (0 Pa), but it is substantially an ultra-high vacuum ( ^10-5 Pa or less).
The principle of desorbing carbon dioxide using the pressure difference in the desorption step is also referred to as pressure swing adsorption (PSA).
The principle of desorbing carbon dioxide by reducing the pressure inside the suction / desorption cylinder 51 in the desorption step to 100 kPa or less is also referred to as vacuum swing adsorption (VSA).

In the suction / desorption cylinder 51, carbon dioxide adsorbed on the adsorbent may be desorbed by lowering the partial pressure of carbon dioxide.
In this case, the partial pressure of carbon dioxide is, for example, preferably 40 Pa or less, more preferably 20 Pa or less, and even more preferably 10 Pa or less. When the partial pressure of carbon dioxide is not more than the above upper limit value, more carbon dioxide can be desorbed more easily. The lower limit of the partial pressure of carbon dioxide is not particularly limited, and examples thereof include 0.1 Pa.
The partial pressure of carbon dioxide is determined by measuring the concentration of carbon dioxide inside the suction / desorption cylinder 51.
Examples of the method of reducing the partial pressure of carbon dioxide include a method of reducing the pressure inside the suction / desorption cylinder 51 and a method of supplying a gas other than carbon dioxide to the suction / desorption cylinder 51. Examples of the gas other than carbon dioxide include helium gas, hydrogen gas, argon gas, outside air, air discharged from the room, and the like. As the gas other than carbon dioxide, the outside air or the air discharged from the room is preferable, and the outside air is more preferable because it can be discharged to the outside of the system.

When the carbon dioxide adsorbed on the adsorbent in the suction / desorption cylinder 51 is sufficiently desorbed, the valve B1 is closed and the dampers D3 and D5 are opened. The pressure inside the suction / desorption cylinder 51 returns to normal pressure, and the air to be processed flows in. Part or all of the carbon dioxide in the air to be treated comes into contact with the adsorbent and is adsorbed by the adsorbent in the suction / desorption cylinder 51. The treated air having a reduced carbon dioxide concentration flows from the air discharge portion L7 to the pipe L11 via the damper D5.

The dampers D4 and D6 are closed and the valve B2 is opened while the suction / desorption cylinder 51 is adsorbing carbon dioxide. The pump P1 is operated to reduce the pressure inside the suction / detachment cylinder 52. When the pressure inside the suction / desorption cylinder 52 is reduced, the carbon dioxide adsorbed on the adsorbent in the suction / desorption cylinder 52 is desorbed due to the pressure difference (desorption step). The desorbed carbon dioxide is supplied from the carbon dioxide discharge unit L10 to the pipe L12 via the branch 103.
The pump P1 may be in a constantly operating state when it corresponds to the building air conditioning system (whole building, all floors) described later.

The pressure inside the suction / desorption cylinder 52 in the desorption step is the same as the pressure inside the suction / desorption cylinder 51 in the desorption step. The pressure inside the suction / desorption cylinder 52 in the desorption step may be the same as or different from the pressure inside the suction / desorption cylinder 51 in the desorption step.

In the suction / desorption cylinder 52, carbon dioxide adsorbed on the adsorbent may be desorbed by lowering the partial pressure of carbon dioxide.
In this case, the partial pressure of carbon dioxide is the same as in the case of the suction / desorption cylinder 51. The partial pressure of carbon dioxide in the suction / desorption cylinder 52 may be the same as or different from the partial pressure of carbon dioxide in the suction / desorption cylinder 51.
The method of reducing the partial pressure of carbon dioxide in the suction / desorption cylinder 52 is the same as that in the case of the suction / desorption cylinder 51. When a gas other than carbon dioxide is supplied to the suction / desorption cylinder 52, the type of gas other than carbon dioxide is the same as in the case of the suction / desorption cylinder 51.

In the present embodiment, since the suction / desorption cylinder 51 and the suction / desorption cylinder 52 are arranged in parallel, the air to be treated can be passed through and carbon dioxide can be discharged at the same time. Therefore, the air to be treated can be continuously treated, and the efficiency of treating the air to be treated can be further improved. In addition, carbon dioxide can be stably supplied.
In the present embodiment, by controlling the opening and closing of the damper and the valve, it is possible to alternately switch between the suction process and the desorption process.
In the present embodiment, the air to be treated (return air) having a high carbon dioxide concentration discharged from the carbon dioxide increasing unit 40 can be supplied to the suction / desorption cylinders 51 and 52. Therefore, more carbon dioxide can be more easily adsorbed on the adsorbent.

The treated air that has passed through the pipe L11 is discharged to the outside of the air conditioning system 1 by opening the damper D7.
The treated air that has passed through the pipe L11 is supplied to the mixing unit 20 via the branch 104 and the pipe L13 by closing the damper D7 and opening the damper D8.

By opening the damper D1, the outside air is supplied from the air supply unit 10 to the mixing unit 20 via the pipes L0 and L1.

In the mixing unit 20, the outside air and the treated air are mixed to form a mixed fluid.
By having the mixing unit 20, the amount of outside air introduced from the air supply unit 10 can be reduced, and the air conditioning load due to the outside air load can be reduced.
In the present embodiment, the mixing unit 20 is located after the suction / desorption unit 50. Therefore, a mixed fluid having a reduced carbon dioxide concentration can be obtained.
The mixed fluid is supplied to the air conditioning unit 30 via the pipe L2.

The carbon dioxide concentration in the mixed fluid is, for example, preferably 100 to 5000 ppm, more preferably 200 to 4000 ppm, further preferably 300 to 3000 ppm, further preferably 400 to 2000 ppm, particularly preferably 500 to 1500 ppm, and most preferably 600 to 1000 ppm. .. When the carbon dioxide concentration in the mixed fluid is at least the above lower limit value, more carbon dioxide can be adsorbed on the adsorbent, and more carbon dioxide can be desorbed in the desorption step. When the carbon dioxide concentration in the mixed fluid is not more than the above upper limit value, cleaner air can be supplied to the carbon dioxide increasing unit 40.

The temperature and humidity of the mixed fluid supplied to the air conditioning unit 30 are adjusted in the air conditioning unit 30 after the dirt such as dust is removed by the filter 32. By operating the blower A1, the mixed fluid whose temperature and humidity have been adjusted is supplied as clean air to the carbon dioxide increasing portion 40 via the pipe L3 and the air supply ports 41 and 42.

The temperature inside the air conditioning unit 30 is not particularly limited, but is preferably 0 to 60 ° C, more preferably 0 to 40 ° C, still more preferably 5 to 35 ° C, and particularly preferably 10 to 30 ° C. When the temperature in the air conditioning unit 30 is within the above numerical range, air having a comfortable temperature can be supplied to the carbon dioxide increasing unit 40.
The temperature inside the air conditioning unit 30 can be adjusted by, for example, a heater (not shown), a refrigerant, or the like.

The humidity in the air conditioning unit 30 is not particularly limited, but is preferably 5 to 95% RH, more preferably 10 to 80% RH, and even more preferably 20 to 70% RH. When the humidity in the air conditioning portion 30 is within the above numerical range, the humidity inside the carbon dioxide increasing portion 40 can be made more comfortable.
The humidity in the air conditioning unit 30 can be adjusted by, for example, a humidifier or a dehumidifier.

For example, the mixed fluid supplied to the carbon dioxide increasing portion 40 has an increased carbon dioxide concentration due to human activity, and is supplied as the air to be treated from the exhaust port 43 to the suction / desorption portion 50 via the pipe L4. Will be done.

In the present embodiment, the suction / desorption portion 50 is located after the carbon dioxide increasing portion 40. Therefore, the air to be processed having an increased carbon dioxide concentration can be supplied to the suction / desorption portion 50. As a result, more carbon dioxide can be adsorbed by the adsorbent in the desorption cylinders 51 and 52.
In addition, it is possible to reduce the amount of carbon dioxide emitted by not exhausting the post-activity air (air to be treated) that was conventionally discharged to the outside.

<Recovery process>
The carbon dioxide supplied to the pipe L12 is supplied to the recovery unit 60 via the branch 105 and the pipe L14 (recovery step). At this time, it may be combined with carbon dioxide discharged from another air conditioning system and passed through the pipe L14.

The recovered carbon dioxide can be stored in a cylinder or the like and can be effectively used as a carbon source (carbon recycling).
As described above, in the recovery step, carbon dioxide having a higher concentration can be recovered.

The concentration of the recovered carbon dioxide may be, for example, 1000 ppm or more, preferably 1000 to 750000 ppm, 1000 to 500,000 ppm, 1000 to 250,000 ppm, 1000 to 100,000 ppm, more preferably 1000 to 10000 ppm, still more preferably 2000 to 10000 ppm. , 2000-5000 ppm is particularly preferable. When the concentration of the recovered carbon dioxide is equal to or higher than the above lower limit, more carbon dioxide can be effectively used. When the concentration of the recovered carbon dioxide is not more than the above upper limit, the management becomes easier.
The concentration of the recovered carbon dioxide can be adjusted by the type and amount of the adsorbent, the pressure inside the desorption portion 50, the temperature inside the desorption portion 50, the time in the desorption step, and a combination thereof.

In the present embodiment, the desorption step due to the pressure difference has been described, but the present invention is not limited to the above-described embodiment.
The desorption step may be desorption based on the principle of temperature swing adsorption (TSA) using a temperature difference, or may be desorption based on both a pressure difference and a temperature difference.
Carbon dioxide can be desorbed more efficiently by desorbing due to both the pressure difference and the temperature difference.
As the temperature difference, for example, 10 to 200 ° C. is preferable, 20 to 180 ° C. is more preferable, and 30 to 160 ° C. is further preferable. When the temperature difference is equal to or higher than the above lower limit, more carbon dioxide can be desorbed. When the temperature difference is not more than the above upper limit value, deterioration of the adsorbent can be suppressed. In addition, it can save energy.

≪Building air conditioning system≫
The building air conditioning system of the present invention is provided with a plurality of the above-mentioned air conditioning systems on different floors. In a building air conditioning system, one or more air conditioning systems of the present invention may be installed on one floor.
For example, by providing an air conditioning system on two or more floors, the amount of carbon dioxide recovered can be increased. In this case, carbon dioxide emitted from air conditioning systems on different floors may be stored on each floor, or may be stored together in one place. The amount of carbon dioxide that can be stored can increase with the number of air conditioning systems.

An example of the building air conditioning system of the present invention will be described.
The building air conditioning system 200 of FIG. 2 has a plurality of air conditioning units 210, a carbon dioxide emission unit L20, a pipe L21, and a recovery unit 60.
The air conditioning unit 210 is provided on each ground floor A of the building 201. The pipe L21 extends in the vertical direction in the building 201 and reaches the basement floor B from the top floor above the ground. The pipe L21 is connected to the recovery unit 60 of the basement floor B via the vacuum pump 212. The air conditioning unit 210 of each ground floor A is connected to the pipe L21 via the carbon dioxide emission unit L20.
Examples of the carbon dioxide discharging unit L20 include piping similar to those of the carbon dioxide discharging units L9 and L10.
Examples of the pipe L21 include a duct similar to the pipe L14.

The air conditioning unit 210 is a device excluding the pipe L12, the pipe L14, and the recovery unit 60 in the air conditioning system 1 of FIG.

In the building air conditioning system 200 of the present embodiment, the carbon dioxide discharged from the air conditioning unit 210 of each ground floor A passes through the carbon dioxide discharge unit L20 and reaches the pipe L21. The carbon dioxide that has reached the pipe L21 flows down the pipe L21 and is filled in the recovery unit 60 by the vacuum pump 212.
In this way, by recovering carbon dioxide on each floor and collecting it, more carbon dioxide can be recovered.

As described above, according to the air conditioning system of the present embodiment, carbon dioxide can be removed from the outside air and the air in the living room. Therefore, treated air with a reduced concentration of carbon dioxide can be supplied to the living room.
According to the air conditioning system of the present embodiment, the removed carbon dioxide can be recovered. Therefore, the recovered carbon dioxide can be used as an energy source such as a carbon source.
According to the air conditioning system of the present embodiment, the treated air can be circulated and used, so that it is not necessary to rely on the outside air for the air supplied to the living room. Therefore, the outside air load, which is said to occupy 40% of the air conditioning load, can be reduced.
According to the air conditioning system of the present embodiment, the air conditioning load can be reduced, so that the air conditioning cost can be reduced and the energy required for air conditioning can be reduced. This leads to a reduction in carbon dioxide emissions at the power plant.
According to the air conditioning system of the present embodiment, carbon dioxide in the outside air can be directly recovered, and if it is widely used, it will lead to reduction of carbon dioxide in the whole earth. In addition, since carbon dioxide in the outside air can be directly recovered, a large amount and stable carbon dioxide can be recovered as compared with the conventional technique in which carbon dioxide is absorbed only from indoor exhaust gas.
The carbon dioxide adsorbed and recovered by the air conditioning system, the building air conditioning system, or the carbon dioxide recovery method of the present embodiment can stably supply the amount required for industrial use. Therefore, the recovered carbon dioxide is a material for synthesizing C1 compounds such as carbon monoxide, methane, methanol and formic acid, and a material for synthesizing C2 compounds such as ethane, ethylene and ethanol by chemical engineering processes such as artificial photosynthesis. , Or as a material for synthesizing olefin compounds such as propylene and butene.
As described above, the technique of the present invention is a technique useful for the global environment.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiment, and various aspects are described within the scope of the claims of the present invention. It can be changed.

In the above-described embodiment, the invention has two suction / detachment cylinders, but the present invention is not limited thereto.
For example, the number of suction / detachment cylinders may be one or three or more.
When the number of suction / desorption cylinders is one, carbon dioxide can be adsorbed and desorbed by one suction / desorption cylinder.
When the number of suction / desorption cylinders is three or more, carbon dioxide can be adsorbed by any suction / desorption cylinder, and carbon dioxide can be desorbed by any other suction / desorption cylinder. After switching between the adsorption and desorption of carbon dioxide, carbon dioxide is desorbed by any desorption cylinder, and carbon dioxide is adsorbed by any other desorption cylinder. The number of arbitrary suction / desorption cylinders and the number of other arbitrary suction / desorption cylinders are not particularly limited, but considering the balance between carbon dioxide adsorption and desorption, the number of arbitrary suction / desorption cylinders and other It is preferable that the number of arbitrary suction / detachment tubes is equal to each other.
The number of suction / detachment cylinders is preferably two because the air conditioning system can be made more compact.

In the above-described embodiment, the suction / desorption portion has a suction / desorption cylinder, but the suction / desorption portion does not have a suction / desorption cylinder, and even if it is a device such as an air handling unit having a regeneration zone and a processing zone, for example. good.
In the above-described embodiment, the carbon dioxide increasing unit 40 has two air supply ports, but the number of air supply ports may be one or three or more.
In the above-described embodiment, the carbon dioxide increasing unit 40 has one exhaust port, but the number of exhaust ports may be two or more.
In the above-described embodiment, one air conditioning system is installed on one floor, but the number of air conditioning systems may be two or more on one floor.

1 ... Air conditioning system, 10 ... Air supply section, 12 ... Outside air intake, A1, A2 ... Blower, 20 ... Mixing section, 30 ... Air conditioning section, 32 ... Filter, 40 ... Carbon dioxide increase section, 41, 42 ... Air supply port, 43 ... Exhaust port, 50 ... Suction / detachment section, 51, 52 ... Suction / detachment tube, 60 ... Recovery section, D1, D3, D4, D5, D6, D7, D8 ... Damper, L7, L8 ... Air discharge Unit, L9, L10, L20 ... Carbon dioxide emission unit, L0, L1, L2, L3, L4, L5, L6, L11, L12, L13, L14, L21 ... Piping, P1 ... Pump, 101, 102, 103, 104 , 105 ... branch, 200 ... building air conditioning system, 201 ... building, 210 ... air conditioning unit, 212 ... vacuum pump

Claims (6)

It has a carbon dioxide increasing part, an adsorption / desorption part, and a recovery part where the concentration of carbon dioxide increases.
The suction / desorption portion has an adsorbent having a carbon dioxide adsorbing ability, and has an adsorbent.
By supplying the treatment target air containing carbon dioxide from the carbon dioxide increasing portion to the suction / desorption portion and bringing the treatment target air into contact with the adsorbent, a part or all of the carbon dioxide from the treatment target air. Is adsorbed on the adsorbent to obtain treated air, and the treated air is discharged from the suction / desorption portion.
An air conditioning system that desorbs carbon dioxide adsorbed on the adsorbent, discharges the desorbed carbon dioxide from the suction / desorption section, and supplies the desorbed carbon dioxide to the recovery section. An air supply unit that supplies outside air to the carbon dioxide increase unit,
It has a mixing section for mixing the outside air and the treated air, and has.
The air conditioning system according to claim 1, wherein the mixing portion is located after the suction / desorption portion. The suction / desorption portion has two or more suction / desorption cylinders filled with the adsorbent.
Two or more of the suction / desorption cylinders are arranged in parallel, and air volume regulators are provided before and after the suction / desorption cylinders.
The carbon dioxide is adsorbed by any of the suction / desorption cylinders, and the carbon dioxide is desorbed by any other suction / desorption cylinder.
The air conditioning system according to claim 1 or 2, wherein the adsorption of carbon dioxide and the desorption of carbon dioxide are alternately switched between the arbitrary suction / desorption cylinder and any other suction / desorption cylinder. The air conditioning system according to any one of claims 1 to 3, wherein the suction / desorption portion desorbs the carbon dioxide adsorbed on the adsorbent by reducing the internal pressure. A building air conditioning system provided with a plurality of air conditioning systems according to any one of claims 1 to 4 on different floors. An adsorption step in which a part or all of the carbon dioxide is adsorbed by the adsorbent by contacting the air to be treated containing carbon dioxide discharged from the carbon dioxide increase portion where the concentration of carbon dioxide increases with the adsorbent.
A desorption step of desorbing the carbon dioxide adsorbed on the adsorbent by the adsorbent on which the carbon dioxide is adsorbed by a pressure difference and / or a temperature difference.
A carbon dioxide recovery method comprising a recovery step for recovering the desorbed carbon dioxide.

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