WO2023140307A1

WO2023140307A1 - Adsorption device and air-conditioning apparatus

Info

Publication number: WO2023140307A1
Application number: PCT/JP2023/001436
Authority: WO
Inventors: 賢輝信長; 明子香村; 悠香子明山
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2022-01-20
Filing date: 2023-01-19
Publication date: 2023-07-27
Also published as: JP2023106026A

Abstract

This adsorption device is used for adsorbing and releasing prescribed components in an air flow from an air blower and comprises a carbon dioxide adsorber that repeatedly adsorbs and releases carbon dioxide and a hygroscopic material that adsorbs and releases water. The carbon dioxide adsorber contains a polymer compound having a chemical structure to which at least a functional group containing a primary amine group is linked, is porous, adsorbs and releases water, can release carbon dioxide at a temperature of 40°C or higher and can release water at a temperature lower than 40°C. The hygroscopic material can release water at a temperature lower than 100°C and a water adsorption at a water vapor equilibrium pressure of less than 1,600 Pa is at or above the water adsorption of the carbon dioxide adsorber. Because of the configuration, moisture can be satisfactorily adsorbed and released and carbon dioxide can be satisfactorily adsorbed and released from air flow generated in an air blower with a simple structure.

Description

Adsorption device and air conditioner

The present disclosure relates to an adsorption device that is used in an air conditioner or the like and is capable of adsorbing and releasing at least carbon dioxide, and an air conditioner that includes the adsorption device.

Patent Document 1 discloses a blower capable of adjusting the concentration of carbon dioxide in a room, and an air conditioner and a ventilation system equipped with this blower. This air blower includes a carbon dioxide absorbing means capable of absorbing carbon dioxide in a room and a regeneration means for regenerating the carbon dioxide, detects the concentration of carbon dioxide in the room (or a factor affecting the carbon dioxide concentration), determines whether the detection result satisfies a predetermined condition, and causes the blowing means to generate an airflow or regenerates the carbon dioxide absorption means.

As an example of the carbon dioxide absorbing means, a carbon dioxide absorbing/releasing part using polymer compound particles having an amino group is disclosed, and as an example of the regenerating means, a heating/cooling part for heating or cooling the carbon dioxide absorbing/releasing part such as a Peltier element is disclosed.

By the way, in the field of air conditioners, there are also known ones that are configured to adjust not only the indoor temperature but also the humidity. For example, Patent Literature 2 discloses an air conditioning system that includes a humidification unit and a controller. The humidifying unit has a moisture absorbing material that absorbs moisture in the air introduced from the outdoors and discharged to the outside, and releases the moisture to the air that is introduced from the outdoors and released into the target space (indoor). A ring-shaped desiccant material is exemplified as a specific moisture absorbing material, but no specific material is mentioned.

JP 2019-090546 A Japanese Patent Application Laid-Open No. 2021-055906

The air blower and the air conditioner disclosed in Patent Document 1 make it possible to adjust the concentration of carbon dioxide in the room, but do not specifically mention the adjustment of humidity. Patent Literature 1 merely describes that the blower device may be provided in a dehumidifier or a humidifier.

In the air conditioning system disclosed in Patent Document 2, it is possible to humidify the room (target space) using a moisture absorbing material, but there is no particular reference to adjusting the concentration of carbon dioxide. Patent Document 2 only discloses the use of a desiccant material as a medium for introducing outdoor moisture into the room, and does not specifically mention the direct use of the desiccant material for indoor humidity control.

In recent years, in the field of air conditioners, there has been an increasing demand not only for adjusting indoor humidity, but also for adjusting indoor carbon dioxide concentration. Therefore, there is a trend toward further improvement of indoor air quality by adjusting the concentration of carbon dioxide as well as humidity. However, very few techniques have been proposed for good control of both humidity and carbon dioxide concentration.

The present invention was made in order to solve such problems, and the object of the present invention is to enable good absorption and desorption of moisture in the air flow generated by the blower, as well as good adsorption and release of carbon dioxide, with a simple configuration.

In order to solve the above-mentioned problems, the adsorption device according to the present invention is used to adsorb and release a predetermined component contained in an air flow blown from a blower, and includes a carbon dioxide adsorbent that repeatedly adsorbs and releases carbon dioxide as one of the predetermined components, and a moisture absorbent that adsorbs and releases moisture as another one of the predetermined components. Further, it is capable of desorbing carbon dioxide at a temperature of 40 ° C. or higher and releasing moisture at a temperature of less than 40 ° C., the hygroscopic material can release moisture at a temperature of less than 100 ° C., and the adsorption amount of moisture at a water vapor equilibrium pressure of less than 1,600 Pa is equal to or greater than the moisture adsorption amount of the carbon dioxide adsorbent.

According to the above configuration, a porous carbon dioxide adsorbent containing a polymer compound having a functional group including an amine group is used together with the moisture absorbing material having moisture absorption and desorption characteristics. This makes it possible to obtain an adsorption device having moisture absorption and desorption characteristics and carbon dioxide adsorption and desorption characteristics (carbon dioxide adsorption and desorption characteristics).

Moreover, it has been newly found that the carbon dioxide adsorbent has not only carbon dioxide adsorption and desorption characteristics but also moisture absorption and desorption characteristics, and that the preferred ranges of the carbon dioxide desorption temperature and moisture release temperature are different. Therefore, the carbon dioxide adsorbent can also be used as a moisture absorbent, and by using the carbon dioxide absorbent in combination with another moisture absorbent, the moisture absorption and desorption characteristics of the adsorption device can be further improved.

Furthermore, as described above, based on the fact that the preferred ranges of the carbon dioxide desorption temperature and the water release temperature are different, it was found that the moisture absorption and desorption and the adsorption and release of carbon dioxide can be adjusted by using a combination of moisture absorbing materials that release moisture at a temperature of less than 100°C and that adsorb moisture at a water vapor equilibrium pressure of less than 1,600 Pa in excess of the amount of water adsorbed by the carbon dioxide adsorbent.

By applying such an adsorption device to an application device having a blower, such as an air conditioner, it is possible to adjust not only the humidity but also the concentration of carbon dioxide well when conditioning the indoor air.

Further, an air conditioner according to the present invention is configured to include the adsorption device having the above configuration. According to this configuration, since the adsorption device capable of favorably adsorbing or desorbing carbon dioxide and moisture is applied to the air conditioner, the function of adjusting the carbon dioxide concentration and humidity can be imparted to the air conditioner simply by providing the adsorption device.

The above object, other objects, features, and advantages of the present invention will be made clear from the following detailed description of preferred embodiments with reference to the accompanying drawings.

With the above configuration, the present invention has the effect of being able to absorb and desorb moisture well with respect to the air flow generated by the blower, and to adsorb and release carbon dioxide well, with a simple configuration.

FIG. 1 is a perspective view of an indoor unit of an air conditioner according to a representative embodiment of the present disclosure. FIG. 2 is a conceptual diagram showing a representative example of an adsorption device used in the air conditioner shown in FIG. FIG. 3 is a conceptual diagram showing polymer compounds contained in the carbon dioxide adsorbent used in the adsorption device shown in FIG. FIG. 4 is a conceptual diagram showing a specific configuration example of the adsorption device shown in FIG. 5 is a conceptual diagram showing another embodiment of the adsorption device shown in FIG. 4. FIG. 6A and 6B are conceptual diagrams showing another embodiment of the adsorption device used in the air conditioner shown in FIG. 1. FIG.

The adsorption device according to the present disclosure is used to adsorb and release predetermined components contained in an airflow blown from a blower, and includes a carbon dioxide adsorbent that repeatedly adsorbs and releases carbon dioxide as one of the predetermined components, and a moisture absorbent that adsorbs and releases moisture as another one of the predetermined components. The carbon dioxide adsorbent includes a polymer compound having a chemical structure in which a functional group including an amine group that is at least a primary amine group is bonded, is formed in a porous shape, and adsorbs and releases moisture. Further, it is configured such that carbon dioxide can be desorbed at a temperature of 40° C. or higher and moisture can be released at a temperature of less than 40° C., the hygroscopic material can release moisture at a temperature of less than 100° C., and the amount of moisture adsorbed at a water vapor equilibrium pressure of less than 1,600 Pa is greater than or equal to the amount of water adsorbed by the carbon dioxide adsorbent.

In the adsorption device having the above configuration, the carbon dioxide adsorbent may be a powder having an average particle size in the range of 400 μm or more and 1.3 mm or less.

According to the above configuration, since the carbon dioxide adsorbent is a powder within the above range, it can be easily applied to an adsorption device, and good practicality can be imparted to the carbon dioxide adsorbent.

In addition, the adsorption device having the above configuration includes a holder that holds at least the carbon dioxide adsorbent so that it can come into contact with air. The holder has a holder body formed with a plurality of cells having an internal space for containing the carbon dioxide adsorbent, an inlet for introducing air into the internal space, and an outlet for discharging the air that has passed through the internal space. It may be a configuration that

According to the above configuration, the carbon dioxide adsorbent can be distributed and dispersed in each cell by storing the carbon dioxide adsorbent in the internal spaces of the plurality of cells. As a result, the contact area of the carbon dioxide adsorbent with air can be increased, and the adsorption amount of the carbon dioxide adsorbent can be increased. Therefore, good adsorption performance of the adsorption device can be obtained. Also, the carbon dioxide adsorbent repeatedly adsorbs and releases carbon dioxide and moisture in the air. Therefore, it can be used continuously by releasing carbon dioxide and moisture from the carbon dioxide adsorbent. Therefore, it is possible to reduce the number of exchanges of the adsorption device, the work load associated with the exchange, and the cost.

Further, in the adsorption device having the above configuration, the material of the holder main body may include the moisture absorbing material.

According to the above configuration, the holder main body can contain or be made of a hygroscopic material, so that the hygroscopic material and the holder main body can be made into one member. Therefore, it is possible not only to suppress an increase in the number of members, but also to relatively increase the usage amount of the absorbent when the holder main body includes the absorbent.

Further, in the suction device having the above configuration, the material of the holder body may include at least one of resin, metal, and ceramic.

According to the above configuration, the material of the holder main body is resin, metal, or ceramic, or includes a plurality of materials, so that the holder main body can be formed of a material with high thermal conductivity. Thereby, when heating the carbon dioxide adsorbent or the hygroscopic material, they can be heated through the holder main body. Therefore, for example, when the carbon dioxide adsorbent releases carbon dioxide by heating, the carbon dioxide adsorbent can be heated well to facilitate the release of carbon dioxide.

Further, in the adsorption device having the above configuration, the covering material may include a nonwoven fabric.

According to the above configuration, by using a non-woven fabric as the covering material, the covering material can be formed relatively thin and light in weight compared to the case of using a woven fabric as the covering material, for example.

Further, in the adsorption device having the above configuration, the material of the nonwoven fabric may include the moisture absorbing material.

According to the above configuration, the covering material can contain a moisture absorbing material or the covering material itself can be made of a moisture absorbing material, so that the moisture absorbing material and the covering material can be made into one member. Therefore, an increase in the number of members can be suppressed. Moreover, when the holder main body contains a moisture absorbing material, or when the covering material contains a moisture absorbing material, it is also possible to relatively increase the usage amount of the moisture absorbing material. In particular, when both the holder main body and the covering material contain a moisture absorbing material, the usage amount of the moisture absorbing material can be further increased. Therefore, it becomes easy to set the usage amount of the moisture absorbent according to various conditions.

Further, in the adsorption device having the above configuration, the covering material may include a metal mesh.

According to the above configuration, the metal mesh can improve the durability of the covering material. Also, the thermal conductivity of the covering material can be improved. Therefore, for example, when the carbon dioxide adsorbent releases carbon dioxide by heating, it becomes easier to heat the carbon dioxide adsorbent from the outside of the adsorption device through the covering material.

Further, in the adsorption device having the above configuration, the pressure loss when air is passed through the covering material at a flow rate of 1 m/sec may be in the range of 5 Pa or more and 30 Pa or less.

According to the above configuration, the covering material can prevent the carbon dioxide adsorbent contained (held) in each cell from falling off from the holder main body, ensure good air permeability, and allow the carbon dioxide adsorbent to come into contact with air efficiently.

Further, in the adsorption device having the above configuration, the moisture absorbing material may be provided as a moisture absorbing sheet member formed into a sheet.

According to the above configuration, since the moisture absorbent is used as the moisture absorbent sheet member, for example, when it is difficult to include the moisture absorbent in the holder main body or the covering material, it is easy to apply the moisture absorbent to the adsorption device. Also, even when the holder main body or the covering material contains a moisture absorbing material, using the moisture absorbing material as a separate member makes it easy to set the usage amount of the moisture absorbing material according to various conditions.

Further, in the adsorption device having the above configuration, the carbon dioxide adsorbent may be immobilized on the moisture absorbing sheet member.

According to the above configuration, the moisture absorbing material and the carbon dioxide adsorbing material can be integrated, so it is possible not only to suppress an increase in the number of parts, but also to diversify the form of the adsorption device by processing the moisture absorbing sheet member into various shapes.

In addition, in the adsorption device having the above configuration, the moisture-absorbing sheet member may be configured to be used as a laminate obtained by laminating a plurality of moisture-absorbing sheet members, or as a cylindrical body obtained by winding the moisture-absorbing sheet members in a cylindrical shape.

According to the above configuration, by using a laminated body or a cylindrical body (rotor body), it is possible to increase the filling amount of the hygroscopic material and the carbon dioxide adsorbent with a simple shape. Therefore, it is possible to improve the performance of the adsorption device.

Further, in the adsorption device having the above configuration, the moisture absorbent may be a crosslinked hydrophilic polymer having a hydrophilic group and a crosslinked structure.

According to the above configuration, if the hygroscopic material is a crosslinked hydrophilic polymer, it becomes possible for the hydrophilic group to contain water molecules between the crosslinked structures in an adsorbed state by crosslinking the polymer. Therefore, it is possible to achieve better hygroscopicity and to release moisture at lower temperatures. This makes it possible to better control moisture absorption and desorption and carbon dioxide adsorption and desorption, respectively, when combined with a carbon dioxide adsorbent.

In addition, in the adsorption device having the above configuration, the channel cross-sectional area of the independent internal space in the flow direction of the air introduced into and discharged from the adsorption device may be in the range of 0.5 cm2 or more and 10.0 cm2 or less.

According to the above configuration, the carbon dioxide adsorbent and the hygroscopic material can be efficiently brought into contact with the air flow. Therefore, the adsorption amount or release amount of the carbon dioxide adsorbent and the moisture absorbent can be made more suitable.

In addition, the adsorption device having the above configuration may have a configuration in which the pressure loss is in the range of 40 Pa or more and 500 Pa or less when the air introduced into and discharged from the adsorption device is passed at a flow rate of 1 m/sec. According to the above configuration, the air permeability of the adsorption device can be further improved.

The air conditioner according to the present disclosure may be configured to include the adsorption device configured as described above. According to this configuration, since the adsorption device capable of favorably adsorbing or desorbing carbon dioxide and moisture is applied to the air conditioner, the function of adjusting the carbon dioxide concentration and humidity can be imparted to the air conditioner simply by providing the adsorption device.

Hereinafter, representative embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are given to the same or corresponding elements throughout all the drawings, and duplicate descriptions thereof will be omitted.

(Embodiment 1)
[Configuration example of air conditioner]
As shown in FIG. 1, an air conditioner 1 according to the present embodiment includes an indoor unit 10 and an outdoor unit, and FIG. 1 shows only the indoor unit 10 in a perspective view. The air conditioner 1 is an example of an application device that includes the adsorption device 4 . In the air conditioner 1, refrigerant circulates between the indoor unit 10 and the outdoor unit. The indoor unit 10 includes a heat exchanger 2 that exchanges heat between a refrigerant and indoor air, and a blower mechanism 3 (blower) that takes in indoor air, exchanges heat with the heat exchanger 2, and then discharges the air.

The indoor unit 10 also includes an adsorption device 4 that includes an adsorbent 5 that repeatedly adsorbs and releases a predetermined component from the airflow sent out from the air blowing mechanism 3, and a heating mechanism 6 that heats the adsorbent 5 in the adsorption device 4 to release the predetermined component.

The prescribed components in the present disclosure are carbon dioxide and moisture. Therefore, as will be described later, in the present embodiment, two types of adsorbent 5 are used: a carbon dioxide adsorbent and a moisture absorbent. Carbon dioxide adsorbents adsorb carbon dioxide in the airflow and release the adsorbed carbon dioxide into the airflow. The hygroscopic material adsorbs (absorbs) moisture in the airflow and releases (desorbs) the adsorbed moisture. Therefore, the indoor unit 10 can adjust the carbon dioxide concentration and humidity (moisture concentration) in the indoor air.

The heating mechanism 6 heats the adsorbent 5 to release the predetermined component adsorbed by the adsorbent 5, namely carbon dioxide or moisture. In the air conditioner 1 according to the present embodiment, the heat exchanger 2 and the blower mechanism 3 also serve as the heating mechanism 6 as an example. Therefore, the air conditioner 1 does not need to have a separate heating mechanism for releasing the predetermined component from the adsorbent 5 . The heat exchanger 2 heats the air by exchanging heat with the refrigerant. The blower mechanism 3 blows heated air to the adsorption device 4 .

As an example, the adsorption device 4 is arranged in the middle of the air flow passage provided inside the indoor unit 10 . The air blowing mechanism 3 generates an air flow passing through the adsorption device 4 by the air flowing through the air flow passage. The adsorption device 4 carries an adsorbent 5 .

When adjusting the carbon dioxide concentration, the air conditioner 1 is, for example, driven in either a first mode for reducing the carbon dioxide concentration in the indoor air or a second mode for increasing the carbon dioxide concentration in the indoor air. When adjusting the humidity, for example, it is driven in either the third mode for reducing the humidity in the room or the fourth mode for increasing the humidity in the room. The first mode of adjusting the carbon dioxide concentration and the third or fourth mode of adjusting the humidity can be appropriately combined. Similarly, the second mode and the third mode or the fourth mode can be combined as appropriate.

An example of these drive modes will be explained using the adjustment of the carbon dioxide concentration as an example. At the time of driving in the first mode, indoor air is blown toward the adsorbent 5 by the blowing mechanism 3 in the indoor unit 10 . Thereby, the carbon dioxide adsorbent constituting the adsorbent 5 adsorbs carbon dioxide contained in the air. Here, when there are people in the room, the concentration of carbon dioxide in the air in the room may rise to, for example, 1600 ppm or more. According to this embodiment, the carbon dioxide adsorbent adsorbs carbon dioxide in the room, so that the carbon dioxide concentration in the room, which has risen in this way, can be reduced to, for example, 1000 ppm or less.

Also, when driven in the second mode, the carbon dioxide adsorbent constituting the adsorbent 5 is heated by the heating mechanism 6 to release carbon dioxide. The released carbon dioxide is diffused in the room by air blowing from the air blowing mechanism 3 . This increases the carbon dioxide concentration in the room.

In addition, we will use humidity control as an example. When driving in the third mode, as an example, when the humidity sensor and the control unit provided in the air conditioner 1 determine that the room is in a high humidity state, the air in the room is blown by the air blowing mechanism 3 toward the adsorbent 5 in the indoor unit 10. As a result, the hygroscopic material forming the adsorbent 5 adsorbs (absorbs) moisture contained in the air.

On the other hand, when the humidity sensor, control unit, etc. determine that the room is in a dry state, the hygroscopic material forming the adsorbent 5 is heated by the heating mechanism 6 to release (moisture release) moisture. The released moisture is diffused into the room by air blowing from the air blowing mechanism 3, thereby increasing the humidity in the room.

When the air conditioner 1 continues to maintain the carbon dioxide concentration in the room at a low concentration, the carbon dioxide generated by heating the carbon dioxide adsorbent with the heating mechanism 6 may be discharged outside without being released into the room.

[Adsorbent]
As the adsorbent 5 used in the adsorption device 4 according to this embodiment, as described above, carbon dioxide adsorbents and hygroscopic materials are exemplified. Other adsorbents may be used together as necessary.

The carbon dioxide adsorbent contains a polymer compound 7 that repeatedly adsorbs and releases carbon dioxide, as illustrated in FIG. The carbon dioxide adsorbent is porous. Carbon dioxide adsorbents adsorb carbon dioxide by chemisorption. The carbon dioxide adsorption amount of the carbon dioxide adsorbent is, for example, a value in the range of 0.06 mol/kg or more and 3.91 mol/kg or less. In another example, the carbon dioxide adsorption amount of the carbon dioxide adsorbent is a value in the range of 2.0 mol/kg or more and 3.91 mol/kg or less. In another example, the carbon dioxide adsorption amount of the carbon dioxide adsorbent is a value in the range of 2.79 mol/kg or more and 3.91 mol/kg or less.

The carbon dioxide adsorbent releases the adsorbed carbon dioxide when heated at a relatively low temperature (for example, a temperature in the range of 40°C or higher and 100°C or lower). That is, the desorption temperature of carbon dioxide in the carbon dioxide adsorbent is a relatively low temperature within the range of 40°C to 100°C. In this way, the carbon dioxide adsorbent used in the present disclosure can release carbon dioxide at low temperatures, thereby reducing the energy required for release. In addition, it is possible to suppress the indoor unit 10 from being affected by the heating temperature for heating the carbon dioxide adsorbent.

Furthermore, the polymer compound 7, which is the main component of the carbon dioxide adsorbent, also has the property of repeatedly adsorbing and releasing water, as will be described later.

The specific shape of the carbon dioxide adsorbent is not particularly limited. As an example, the carbon dioxide adsorbent is powder containing a plurality of spherical particles. The carbon dioxide adsorbent according to the present embodiment is powder having an average particle size in the range of 300 μm or more and 1.3 mm or less. For example, the larger the average particle size of the carbon dioxide adsorbent, the better the handleability. Further, for example, the smaller the average particle diameter, the more the specific surface area of the carbon dioxide adsorbent is improved. Here, the average particle diameter can be measured by Coulter counter method, laser diffraction method, image analysis method, or the like. For example, according to the Coulter Counter method, the average particle size is calculated as a 50% volume average particle size.

As an example of a specific polymer compound 7, as shown in FIG. 2, the carbon dioxide adsorbent includes a polymer compound 7 having a chemical structure in which at least a functional group 7b containing an amine group, which is a primary amine group, is bonded. Note that FIG. 2 schematically shows the structure of the polymer compound 7 including a partial chemical structure.

This polymer compound 7 has a base material 7a forming a molecular skeleton and a functional group 7b containing an amine group that is chemically bonded to the base material 7a. The amine group is, for example, desirably a primary amine group, but may be a secondary amine group. Functional group 7b in the present embodiment includes, for example, a CH2--NH2 group. In this embodiment, the functional group 7b is bonded as a side chain to the main chain of the base material 7a. The base material 7a includes a resin skeleton composed of one or more resins. The base material 7a in the present embodiment includes at least a polystyrene (PS)-based resin skeleton as the resin skeleton, but is not limited to this.

As described above, since the carbon dioxide adsorbent is porous, the functional groups 7b are also present in the pores. Thereby, the carbon dioxide adsorbent adsorbs carbon dioxide even in the pores.

In the functional group 7b in the present embodiment, the amine group is located at the end of the branched chain in the chemical structure of the polymer compound 7. The chemical structure of polymer compound 7 also includes an aromatic ring (eg, a benzene ring) directly or indirectly bonded to an amine group. In the carbon dioxide adsorbent, due to the hydrophobicity of the aromatic ring, excessive bonding of water molecules to the amine group is prevented. For example, the closer the distance between the aromatic ring and the amine group, the better.

The branched chain may be derived from either the main chain (for example, the main chain of the base material 7a) or the side chain of the chemical structure of the polymer compound 7. In other words, the polymer compound 7 according to the present embodiment shown in FIG. 2 is a solid polymer in which benzylamine (BZA) is bonded to the base material 7a. The carbon dioxide adsorption amount of the carbon dioxide adsorbent using this polymer compound 7 is a value in the range of 2.79 mol/kg or more and 3.91 mol/kg or less.

The polymer compound 7 has a structure in which an amine group is bonded to a base material 7a forming a molecular skeleton via a hydrophobic group (an example of an aromatic ring) having higher hydrophobicity than an amine group. Therefore, the carbon dioxide adsorbent can release carbon dioxide at a relatively low temperature due to the action of this hydrophobic group. Also, the carbon dioxide adsorbent is kept solid within the operating temperature range of the air conditioner 1 .

Therefore, even if the carbon dioxide adsorbent is heated during the release of carbon dioxide, the decomposition and volatilization of the amine groups are prevented. Further, since the carbon dioxide adsorbent is kept solid within the operating temperature range of the air conditioner 1, a binder for binding and holding the polymer compound 7, for example, is unnecessary. As a result, it is possible to prevent the pores of the carbon dioxide adsorbent from being clogged with the binder and the adsorption performance of the carbon dioxide adsorbent to decline.

The carbon dioxide adsorbent according to the present embodiment has an amine-supported amount in the range of 2.0 mmol/g or more. In another example, the carbon dioxide adsorbent has an amine loading in the range of 2.5 mmol/g or more. As a result, the carbon dioxide adsorbent is intended to improve the amount of carbon dioxide adsorbed. The amount of amine supported by the carbon dioxide adsorbent can be measured by, for example, a quantitative analysis method such as titration, or a CHN elemental analysis method.

Specifically, in the CHN elemental analysis method, the object to be measured is combusted with oxygen to generate _H2O , _CO2 , and _NOx . It also reduces _NOx to _N2 . Then, each gas of H ₂ O, CO ₂ and N ₂ is separated by a column and introduced into a detector (TCD). Thereby, the contents of carbon, hydrogen, and nitrogen to be measured are measured, and the amount of amine supported is calculated. Here, in the CHN elemental analysis method, when the amine group is an NH ₂ group, the amount of amine supported is calculated based on the following

formulas

1 and 2.

[Formula 1]
Primary amine content to be measured (mass%) = nitrogen content to be measured (mass%) x 16 ( _NH2 molecular weight) / {14 (nitrogen atomic weight) x number of nitrogen atoms in functional groups}

[Formula 2]
Amine supported amount (mmol/g) = content of primary amine to be measured (% by mass)/{16 ( _NH2 molecular weight) x 100} x 1000

As a result of the investigation by the inventors of the present application, it was confirmed that a porous carbon dioxide adsorbent containing a polymer compound having a chemical structure in which a functional group containing an amine group, which is at least a primary amine group, is bonded can adsorb a large amount of carbon dioxide contained in the air and release the carbon dioxide adsorbed by the polymer compound at a relatively low temperature. The aforementioned polymer compound 7 is based on such findings.

The polymer compound 7 according to the present embodiment has a structure in which an amine group is bonded to a base material 7a forming a molecular skeleton via a hydrophobic group (an example of an aromatic ring) having higher hydrophobicity than an amine group. Therefore, it is considered that the carbon dioxide adsorbent containing such polymer compound 7 can selectively adsorb carbon dioxide and release carbon dioxide at a relatively low temperature due to the action of this hydrophobic group.

Also, this carbon dioxide adsorbent is kept solid within the operating temperature range of the air conditioner 1 . Therefore, even if this carbon dioxide adsorbent is heated during the release of carbon dioxide, decomposition and volatilization of the amine groups are prevented. Further, since the carbon dioxide adsorbent is kept solid within the operating temperature range of the air conditioner 1, a binder for binding and holding the polymer compound 7, for example, is unnecessary. As a result, it is possible to prevent the pores of the carbon dioxide adsorbent from being clogged with the binder and the adsorption performance of the carbon dioxide adsorbent to decline.

Although Patent Document 1 discloses that polymer compound particles having amino groups are used as a means for absorbing carbon dioxide in an air blower, it does not disclose any specific types of polymers, binding structures of amino groups to polymers, particle shapes, and the like. Moreover, Patent Document 1 describes that the carbon dioxide absorbing/releasing part is not limited to polymer compound particles having an amino group, and may be zeolite, activated carbon, or the like, and does not describe that polymer compound particles having an amino group are superior. Therefore, it is considered that the moisture absorbing/desorbing ability of carbon dioxide possessed by the polymer compound particles having amino groups disclosed in Patent Document 1 is substantially similar to that of zeolite, activated carbon, or the like.

In addition, as described above, the polymer compound 7 according to the present embodiment has a relatively low carbon dioxide desorption temperature in the range of 40° C. or higher and 100° C. or lower as a carbon dioxide adsorbent. However, when the carbon dioxide adsorption performance of general materials containing amine groups (amine-based materials) was investigated, it became clear that many of them had relatively high carbon dioxide desorption temperatures. For example, the desorption temperature of carbon dioxide in meta-xylene diamine (MXDA) is 100° C. or higher, the desorption temperature of carbon dioxide in monoethanolamine (MEA) is 80° C. or higher, and the desorption temperature of carbon dioxide in benzylamine (BZA) is 64° C. or higher.

Among common amine-based materials, polyethyleneimine (PEI), for example, has a relatively low carbon dioxide desorption temperature of 50°C or higher, compared to the aforementioned MXDA, MEA, and BZA. However, it was found that repeated use of PEI as a carbon dioxide adsorbent liquefies and volatilizes. Therefore, although PEI is a polymer material, it lacks practicality as an application for adsorbing and releasing carbon dioxide contained in an air flow blown from a blower as in the present disclosure.

As described above, the polymer compound 7 suitably used as a carbon dioxide adsorbent in the present disclosure has a structure in which BZA is bound to the polymer that is the base material 7a. Based on BZA, the desorption temperature of carbon dioxide in polymer compound 7 is considered to be 64° C. or higher. Considering the behavior of PEI, even a polymer may be liquefied and volatilized by adsorption of water.

However, the lower limit of the carbon dioxide desorption temperature of polymer compound 7 is 40° C. or more, and compared to other general amine-based materials, not only can carbon dioxide be desorbed at a lower temperature, but it also has good reusability, showing good physical properties as a carbon dioxide adsorbent. In addition, polymer compound 7 also has the property of repeatedly adsorbing and releasing water, and exhibits good physical properties as a hygroscopic material.

Here, it was thought that polymer compound 7 could selectively and abundantly adsorb carbon dioxide because its hydrophobic group excluded the adsorption of water molecules or molecules with a large polarity like water. However, as a result of further studies by the inventors of the present application, although the details are unknown at the present time, as will be described later, it became clear that the behavior of the adsorption isotherm of carbon dioxide and the adsorption isotherm of water in polymer compound 7 is different, and that the adsorption mechanism or adsorption mechanism of carbon dioxide and water is considered to be different.

Moreover, it was also found that polymer compound 7 has a different peak temperature for the release of adsorbed carbon dioxide and a peak temperature for the release of water molecules (water release). The term "carbon dioxide (of) release amount" as used herein refers to the number of carbon dioxide molecules released (the number of molecules). The term "water release amount" refers to the number of released water molecules (the number of molecules).

Specifically, although detailed experimental results are omitted, the carbon dioxide adsorbent containing polymer compound 7 was heated at a temperature increase of 5°C per minute based on the generated gas analysis method (EGA-MS), and the changes in the amount of water released and the amount of carbon dioxide released over time were graphed and evaluated.

As a result, the water release peak temperature of the carbon dioxide adsorbent (polymer compound 7) was in the range of 20°C or higher and lower than 40°C (approximately 35°C in this experimental example), and the carbon dioxide release peak temperature of the carbon dioxide adsorbent (polymer compound 7) was in the range of 40°C or higher and 80°C or lower (approximately 60°C in this experimental example). As described above, with the carbon dioxide adsorbent, the carbon dioxide release peak temperature of the polymer compound 7 and the water release amount peak temperature of the polymer compound 7 were different from each other.

In addition, although detailed experimental results are omitted, the relationship between the heating temperature of the carbon dioxide adsorbent (polymer compound 7), the carbon dioxide desorption rate from the carbon dioxide adsorbent, and the water desorption rate from the carbon dioxide adsorbent was also graphed and evaluated. The carbon dioxide desorption rate referred to herein is the number of moles of carbon dioxide desorbed by the polymer compound 7 per hour, and the water desorption rate is the weight of water desorbed by the polymer compound 7 per hour.

As a result, it was found that when the heating temperature of the carbon dioxide adsorbent is in the range of approximately 20°C or higher and less than 40°C, the carbon dioxide adsorbent preferentially releases water over carbon dioxide. It was also found that when the heating temperature of the carbon dioxide adsorbent (polymer compound 7) is in the range of about 40° C. or higher, the carbon dioxide adsorbent releases water together with carbon dioxide at the beginning of the temperature rise. After that, it was also found that as the heating temperature of the carbon dioxide adsorbent increased and approached 60° C., the increasing tendency of the released amount of carbon dioxide molecules became more pronounced than the increasing tendency of the released amount of water molecules.

As described above, it was newly revealed that the carbon dioxide adsorbent (polymer compound 7) according to the present disclosure has not only carbon dioxide adsorption and desorption characteristics but also moisture absorption and desorption characteristics, and it was also revealed that the carbon dioxide adsorbent has different suitable conditions for moisture absorption and desorption and carbon dioxide adsorption and desorption. That is, the carbon dioxide adsorbent (polymer compound 7) according to the present disclosure has a unique physical property that enables desorption of carbon dioxide at a temperature of 40°C or higher and release of moisture at a temperature of lower than 40°C.

Therefore, it was expected that the humidity control function of the adsorption device 4 would be further improved by using this carbon dioxide adsorbent in combination with a moisture absorbent. However, it has also become clear that simply combining a hygroscopic material with a carbon dioxide adsorbent cannot achieve good adsorption and desorption characteristics. In other words, simply using a hygroscopic material with a large amount of moisture absorption cannot fully utilize the characteristic that the carbon dioxide adsorbent has a different peak temperature for releasing carbon dioxide and peak temperature for releasing water.

As shown in the "reference example" of the examples described later, zeolite or activated carbon are known as moisture absorbents that absorb relatively large amounts of moisture per unit weight. It became clear that it is difficult to control the release of carbon dioxide from the carbon dioxide adsorbent (the release peak temperature is 20° C. or higher and lower than 40° C.). Considering the practicality of the adsorption device 4, it was considered preferable that the water release temperature be less than 100°C. On the other hand, it has also become clear that it is difficult to adjust the release of carbon dioxide well by simply selecting a moisture absorbent with a low moisture release temperature (regeneration temperature of the moisture absorbent).

Here, the inventors of the present application focused on the fact that the annual water vapor equilibrium pressure in Japan is less than 1,600 Pa for a period of 6 months or more. That is, by selecting a hygroscopic material that has a water release temperature of less than 100°C and a water adsorption amount at a water vapor equilibrium pressure of less than 1,600 Pa that is equal to or greater than the water adsorption amount of the carbon dioxide adsorbent (polymer compound 7), it is possible to adjust the moisture absorption and desorption and the adsorption and release of carbon dioxide.

In the adsorption device 4 according to the present disclosure, examples of materials that can be used as moisture absorbents include polymers having hydrophilicity, hygroscopicity, and water absorption. Specific examples include polyetheresters, polyetheramides, polyetheresteramides, polyamides, thermoplastic cellulose derivatives, polyvinylpyrrolidone, poly(meth)acrylates, and the like.

These polymers may be copolymers containing other monomer structures, or hydrophilic groups may form salts. For example, if the hydrophilic group is an anion, it may ionically bond with a cation such as a metal salt to form a salt. These polymers may have side chains, may have a crosslinked structure, or may be modified in a known manner. The molecular weight (number-average molecular weight Mn, weight-average molecular weight Mw, etc.) or other physical properties are also not particularly limited. These macromolecules are preferably formed in a porous state like the carbon dioxide adsorbent.

Among such polymers, a crosslinked hydrophilic polymer having a hydrophilic group and a crosslinked structure can be suitably used as the moisture absorbent according to the present disclosure. By cross-linking the polymer, it becomes possible for the hydrophilic groups to contain the water molecules between the cross-linked structures in an adsorbed state. Therefore, it is possible to achieve better hygroscopicity and to release moisture at lower temperatures. As a result, when combined with the carbon dioxide adsorbent (polymer compound 7), it becomes easier to better control moisture absorption and desorption and adsorption and desorption of carbon dioxide.

A more specific example of a crosslinked hydrophilic polymer is a crosslinked polymer containing acrylonitrile as a monomer unit (a crosslinked acrylonitrile-based polymer). The specific structure of the crosslinked acrylonitrile-based polymer is not particularly limited, but one example is the porous hygroscopic polymer disclosed in Reference 1: JP-A-2021-031635. The contents of that Reference 1 are incorporated herein by reference. Moreover, the crosslinked acrylonitrile-based polymer described in the publication may be modified within a known range.

The polymer used as the hygroscopic material in the present disclosure is not limited to a crosslinked acrylonitrile-based polymer, and may be any polymer that has a water release temperature of less than 100°C and a water adsorption amount at a water vapor equilibrium pressure of less than 1,600 Pa that is equal to or greater than the water adsorption amount of the carbon dioxide adsorbent (polymer compound 7). Alternatively, the hygroscopic material may be other materials that are not polymeric.

Other polymers used as moisture absorbents in the present disclosure may be, for example, a polymer containing (meth)acrylic acid as a main component disclosed in Reference Document 2: JP-A-2019-031633 with the addition of a basic compound, a urethane foam disclosed in Reference Document 3: JP-A-2018-002979, or a moisture absorbing/desorbing polyester disclosed in Reference Document 4: JP-A-2007-113165. These polymers may be made porous if they are not porous, and may be modified within known limits. The contents of these references 2 to 4 are incorporated herein by reference.

The absorbent material according to the present disclosure can be used in various shapes. One example is powder (particles) having an average particle diameter in the range of 400 μm or more and 1.3 mm or less, like the carbon dioxide adsorbent. As a result, the powder of the hygroscopic material can be used in the same manner as the powder of the carbon dioxide adsorbent. Note that the carbon dioxide adsorbent or moisture absorbent may not be powder as long as it is applicable to the adsorption device 4 . Also, if the carbon dioxide adsorbent or moisture absorbent is powder, the shape or size of the particles may not be the same.

[Configuration example of moisture absorption device]
The adsorption device 4 according to the present embodiment, as shown in FIG. 3, includes an adsorbent 5 and a holder 8 that holds the adsorbent 5 so as to be in contact with an air flow. The adsorbent 5 is composed of a carbon dioxide adsorbent that repeatedly adsorbs and releases carbon dioxide in the airflow and a moisture absorbent that repeatedly adsorbs and releases moisture in the airflow (absorbs or releases moisture). Both the carbon dioxide adsorbent and the moisture absorbent are porous powders, as described above. The holder 8 comprises a holder body 80 , a covering material 81 and an adhesive material 82 . In addition, in FIG. 3, the inside of the adsorption device 4 covered with the covering material 81 is indicated by a solid line.

The holder main body 80 is formed in a plate shape in this embodiment. A plurality of cells 80 a are formed in the holder body 80 . In other words, the holder main body 80 is a cell assembly. The adsorbent 5 is arranged inside each cell 80a. As a result, the adsorbents 5 are dispersedly arranged in the holder body 80 .

As shown in FIG. 3, the cell 80a has an internal space 80b that accommodates the adsorbent 5, an inlet 80c that introduces airflow into the internal space 80b, and an outlet 80d that discharges the airflow that has passed through the internal space 80b. The holder main body 80 has a plurality of inlets 80c arranged on one surface and a plurality of outlets 80d arranged on the other surface.

As shown in FIG. 3, the holder body 80 includes, for example, a plurality of hexagonal cells 80a in plan view. In the adsorption device 4, the cross-sectional shape of the internal space 80b in the direction of air flow from the inlet 80c to the outlet 80d is polygonal (eg, hexagonal). With this configuration, the shape of the cross section of the flow path of the internal space 80b of the holder body 80 can be easily maintained.

Further, the holder main body 80 in the present embodiment has an outer wall portion 80e surrounding the outer circumference and an inner wall portion 80f arranged inside the outer wall portion 80e in plan view. The outer wall portion 80 e and the inner wall portion 80 f are erected in the thickness direction of the holder main body 80 . That is, the wall surfaces of the outer wall portion 80e and the inner wall portion 80f are arranged within a plane including the thickness direction of the holder main body 80. As shown in FIG. The plurality of cells 80a are individually partitioned by the outer wall portion 80e and the inner wall portion 80f. The wall thickness dimension of the outer wall portion 80e and the inner wall portion 80f may be the same or different.

In the plurality of cells 80a, each internal space 80b is independent of each other. Adjacent internal spaces 80b are separated from each other. Therefore, the adsorbents 5 can be dispersedly held in the holder body 80 while preventing the adsorbents 5 from moving between the adjacent internal spaces 80b. Moreover, the holder main body 80 has sufficient strength to maintain its shape in its natural state. Therefore, deformation of the holder main body 80 does not block the passage of the internal space 80b.

The cross-sectional area of each internal space 80b in the direction of air flow from the inlet 80c of the adsorption device 4 to the outlet 80d can be set appropriately. As an example, the channel cross-sectional area of each internal space 80b is within the range of 0.5 cm2 or more and 10.0 cm2 or less. In the present embodiment, the channel cross-sectional area in the adsorption device 4 is the channel cross-sectional area of the internal space 80b of each cell 80a in the direction of air flow from the inlet 80c to the outlet 80d.

Note that the configuration of the adsorption device 4 is not limited to the configuration shown in FIG. The adsorbent 5 may be held by the adsorption device 4 so that it can come into contact with the airflow over a large area. For this reason, as an example, the adsorption device 4 is formed with a flow path through which air is circulated so as to bring the air into continuous contact with the adsorbent 5 . However, the channel cross-sectional area can be appropriately set depending on the configuration of the adsorption device 4 . Therefore, in the present disclosure, the channel cross-sectional area of the "independent internal space" in the flow direction of the air introduced into and discharged from the adsorption device 4 should be within the range of 0.5 cm ² or more and 10.0 cm ² or less.

For example, if the cross-sectional area of the flow path is increased within a certain range, the filling amount of the adsorbent 5 in each cell 80a can be increased, and the gas adsorption/desorption amount of the adsorption device 4 can be improved. Further, if the cross-sectional area of the flow path is reduced within a certain range, the heat dissipation of the adsorbent 5 in each cell 80a to the outside can be reduced, and the heat retaining effect of the adsorbent 5 can be improved. Moreover, the heat from the outside can be well transferred to the adsorbent 5 through the holder main body 80 .

Therefore, by appropriately setting the flow channel cross-sectional area of each internal space 80b, when the adsorbent 5 is heated, the adsorption target can be easily released to the adsorbent 5, and the time required for heating the adsorbent 5 can be shortened. In addition, the heat retaining effect of the adsorbent 5 and the effect of heat conduction from the holder main body 80 to the adsorbent 5 are enhanced, and the adsorbent 5 can be easily heated. It should be noted that when the holder main body 80 also serves as a moisture absorbing material, as in a modification described later, the holder main body 80 (hygroscopic material) can satisfactorily release moisture from the holder main body 80 (moisture absorbing material) by heating the holder main body 80 satisfactorily.

In the adsorption device 4 according to the present embodiment, as an example, the pressure loss when air is passed through the covering material 81 at a flow rate of 1 m/sec is a value in the range of 5 Pa or more and 30 Pa or less. As a result, in the adsorption device 4, the covering material 81 prevents the adsorbent 5 held in each cell 80a from falling off from the holder body 80, ensures good air permeability, and allows the adsorbent 5 to efficiently contact the air flow.

In addition, the adsorption device 4 has a pressure loss in the range of 40 Pa or more and 500 Pa or less when air is passed from the inlet 80c side to the outlet 80d side at a flow rate of 1 m/sec. In another example, this pressure loss is a value in the range of 150 Pa or more and 500 Pa or less. Thereby, the air permeability of each cell 80a can be further improved.

Incidentally, in the present embodiment, the air flow when setting the pressure loss in the adsorption device 4 is the air flow from the introduction port 80c side to the discharge port 80d side, as described above. However, the direction of the air flow is appropriately set depending on the configuration of the adsorption device 4 . Therefore, in the present disclosure, the pressure loss when the air introduced into and discharged from the adsorption device 4 is allowed to pass through at a flow rate of 1 m/sec may be within a range of, for example, 40 Pa or more and 500 Pa or less.

In the present embodiment, the material of the holder main body 80 is not particularly limited except that it contains a hygroscopic material, but as an example, it contains at least one of paper and resin. Paper and resin are examples of materials with low thermal conductivity. The material of holder main body 80 according to the present embodiment may include paper. In this manner, if the holder body 80 is configured to contain paper, the heat retaining effect of the adsorbent 5 held by the holder body 80 can be enhanced. In addition, the heat retaining effect of the hygroscopic material included in the holder main body 80 can be enhanced.

The covering material 81 has air permeability and covers the inlet 80c and the outlet 80d of the cell 80a. A peripheral portion of the inlet 80c of each cell 80a and a peripheral portion of the outlet 80d of each cell 80a are covered with a covering material 81. As shown in FIG. Thereby, the adsorbent 5 accommodated in the internal space 80b of each cell 80a is not mixed through the inlet 80c or the outlet 80d. Also, the state in which the adsorbents 5 are arranged dispersedly over the entire plate surface of the holder main body 80 is maintained. Also, the adsorbent 5 is held in each internal space 80b surrounded by the cells 80a and the covering material 81 .

Therefore, this configuration does not require a binder or the like for holding the adsorbent 5 in the cell 80a. Therefore, the adsorption performance is not deteriorated by covering the surface of the adsorbent 5 with a binder or the like (for example, when the adsorbent 5 is formed in a porous state, the pores on the surface of the adsorbent 5 are filled with the binder or the like).

The covering material 81 according to the present embodiment includes nonwoven fabric. The material of the non-woven fabric is not limited, but one example includes at least one of polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET). As further described below, the nonwoven fabric may contain a moisture absorbent material. The non-woven fabric is used, for example, to prevent the powder adsorbent 5 from dropping through the gaps of the covering material 81 . It can also be used for other known purposes.

By including at least one of PP, PE, and PET in the nonwoven fabric, the degree of freedom in designing the covering material 81 can be improved. Moreover, when the nonwoven fabric contains at least one of PP, PE, and PET, the nonwoven fabric and the holder main body 80 can be relatively easily joined by heat welding or the like without using an adhesive. As a result, the structure of the adsorption device 4 can be simplified, and the weight of the adsorption device 4 can be reduced.

The basis weight of the covering material 81 can be set as appropriate, but is a value in the range of 10 g/m ² or more and 90 g/m ² or less as an example. This prevents the adsorption material 5 from falling off from the covering material 81 and suppresses the pressure loss of the airflow passing through the adsorption device 4 . As a specific example, the adsorption device 4 has a pair of covering materials 81 arranged on both sides of the holder body 80 .

The pair of covering materials 81 are welded to each other at their peripheries while covering the holder main body 80 from both sides. As this welding, heat welding can be adopted when the coating material 81 contains a resin material or the like. The pair of coating materials 81 are integrated by melting and solidifying each other at their contact portions. Therefore, an adhesive for bonding the pair of covering materials 81 is not required. By using a non-woven fabric for the covering material 81, the covering material 81 can be made relatively thin and lightweight as compared with the case of using a woven fabric for the covering material 81, for example.

Also, the pair of covering materials 81 may not be welded to each other, and may be adhered with an adhesive, for example. In this case, for example, options for the material of the covering material 81 can be expanded. The adhesive material 82 is arranged between the coating material 81 and the holder body 80 to bond the coating material 81 and the holder body 80 together. In other words, the coating material 81 and the holder main body 80 are adhered by the adhesive material 82 . Therefore, as long as the coating material 81 and the holder main body 80 can be adhered to the adhesive material 82, the materials of the coating material 81 and the holder main body 80 may be different from each other.

The adhesive 82 is arranged on both sides of the holder body 80 . Although the material of the adhesive material 82 is not particularly limited, one example includes at least one of a thermoplastic resin-based material and an elastomer-based material. Examples of thermoplastic resin materials include vinyl acetate resin, ethylene vinyl acetate (EVA), urethane resin, and acrylic materials. Examples of elastomer-based materials include silicone resin-based materials, modified silicone resin-based materials, silylated urethane resin-based materials, and rubber-based materials.

Thus, if the adhesive 82 that bonds the covering material 81 and the holder main body 80 is used, and if the adhesive material 82 contains at least one of a thermoplastic resin-based material and an elastomer-based material, the covering material 81 can be firmly adhered to the holder main body 80 by the adhesive material 82. Therefore, it is possible to further prevent the adsorbent 5 from falling off from the holder main body 80 . Therefore, good durability can be imparted to the adsorption device 4 .

As described above, in the present embodiment, the adsorbent 5 is powder having an average particle size in the range of 400 μm or more and 1.3 mm or less. The covering material 81 has openings through which the powder does not pass. This can effectively prevent the adsorbent 5 from falling off from the covering material 81 . As shown in FIG. 1, the adsorption device 4 according to the present embodiment is arranged inside the indoor unit 10 so as to correspond to the outer surface of the heat exchanger 2, as an example. In addition, the shape of the adsorption device 4 may be processed in order to arrange the adsorption device 4 within a predetermined space.

[Modification]
The adsorption device 4 according to this embodiment is not limited to the configuration shown in FIG. 3, and includes various modifications. As a first modified example, an adsorption device 41 shown in FIG. 4 has substantially the same basic configuration as the adsorption device 4 shown in FIG. Therefore, in the adsorption device 41 shown in FIG. 4, the adsorbent 5 arranged inside each cell 80a is only the carbon dioxide adsorbent 51, and no hygroscopic material is arranged. With this configuration, the amount of carbon dioxide adsorbent accommodated in the holder body 80 can be relatively increased without increasing the number of members.

It should be noted that in the adsorption device 41 shown in FIG. 4 as well, the carbon dioxide adsorbent 51 and the moisture absorbent may be arranged inside each cell 80a in the same manner as in the adsorption device 4 shown in FIG. Thereby, the amount of moisture absorbent can be relatively increased. Whether to increase the amount of the carbon dioxide adsorbent or the moisture absorbent in the adsorbent 5 may be appropriately set according to the intended use or usage conditions of the adsorption device 41 .

As a second modification, the adsorption device 42 shown in FIG. 5 has substantially the same basic configuration as the adsorption device 4 (see FIG. 3) or the adsorption device 41 (see FIG. 4) according to the first embodiment, but the material of the nonwoven fabric 80g contains a moisture absorbent material. The nonwoven fabric 80g may be made of a moisture absorbent material, or the moisture absorbent material may be blended with a known nonwoven fabric material.

With such an adsorption device 42, since the nonwoven fabric 80g contains or is made of a moisture absorbing material, the moisture absorbing material and the nonwoven fabric 80g (or the covering material 81 containing the nonwoven fabric 80g) can be made into one member. Therefore, an increase in the number of members can be suppressed. Moreover, when the holder main body contains a moisture absorbing material, it is possible to relatively increase the amount of the moisture absorbing material used. Therefore, it becomes easy to set the usage amount of the moisture absorbent according to various conditions.

As a third modification, in the adsorption device 4 or the adsorption device 41, the covering material 81 contains a metal mesh. The material of this metal mesh is, for example, stainless steel such as SUS304. Thereby, the durability of the covering material 81 can be improved. Also, the thermal conductivity of the covering material 81 can be improved. Therefore, for example, when the adsorbent 5 is heated, the adsorbent 5 is heated through the covering material 81 from the outside of the adsorption device 4 or the adsorption device 41 . As a result, carbon dioxide can be easily released from the carbon dioxide adsorbent, and moisture can be easily released from the hygroscopic material.

In addition, if the adsorbent 5 (at least the carbon dioxide adsorbent) is a powder having an average particle diameter in the range of 400 μm or more and 1.3 mm or less as described above, in this modification, the coating material 81 includes a mesh having a mesh diameter in the range of 50 (mesh/inch) or more and 200 (mesh/inch) or less. Another example of the mesh diameter is a value in the range of 65 (mesh/inch) to 200 (mesh/inch). As a result, it is possible to prevent the powdery adsorbent 5 from coming off through the gaps of the coating material 81 while securing a good specific surface area of the adsorbent 5 .

In the adsorption device 4 according to the fourth modification, the material of the holder body 80 includes at least one of metal and ceramic. Examples of the metal include, but are not limited to, those having excellent thermal conductivity (eg, aluminum, copper, and alloys containing at least one of these). The holder main body 80 of this modification has a thermal conductivity in the range of 50 W/mK or more and 500 W/mK or less.

According to this modification, the material of the holder body 80 includes at least one of metal and ceramic, so that the holder body 80 can be made of a material with high thermal conductivity. Thereby, when the adsorbent 5 is heated, the adsorbent 5 can be heated through the holder main body 80 . Therefore, for example, when the adsorbent 5 releases a predetermined component by heating, the adsorbent 5 can be heated well to make it easier to release the adsorption target to the adsorbent 5, and the adsorbent 5 can be efficiently heated.

In the adsorption device 4 according to the fifth modified example, the adhesive material 82 is omitted, and a pair of covering materials 81 are adhered to the holder main body 80 by thermal welding. The material of the holder main body 80 includes paper. According to this modification, the weight of the adsorption device 4 can be reduced by omitting the adhesive 82 . Moreover, the manufacturing efficiency of the adsorption device 4 can be improved.

(Embodiment 2)
Unlike the adsorption device 4 (or the adsorption device 41 or the adsorption device 42) according to the first embodiment, the adsorption device according to the second embodiment does not include the holder 8 that holds the adsorbent so that it can come into contact with the air.

In this way, if the absorbent is used as the absorbent sheet member, for example, when it is difficult to include the absorbent in the holder body or the covering material, it becomes easier to apply the absorbent to the adsorption device. Also, even when the holder main body or the covering material contains a moisture absorbing material, using the moisture absorbing material as a separate member makes it easy to set the usage amount of the moisture absorbing material according to various conditions.

In addition, if the carbon dioxide adsorbent is fixed to the moisture absorbing sheet member, the moisture absorbing material and the carbon dioxide adsorbing material can be integrated, so not only can the increase in the number of parts be suppressed, but also the shape of the adsorption device can be diversified by processing the moisture absorbing sheet member into various shapes.

As an example, the adsorption device 43 shown in FIG. 6A is configured as a cylindrical body (rotor body) in which the powdery carbon dioxide adsorbent 51 is dispersed and fixed on the surface of the moisture-absorbing sheet member 83 and is wound in a cylindrical shape. As another example, the adsorption device 44 shown in FIG. 6B is configured as a laminated body in which a plurality of sheets of the moisture absorbent sheet member 83 on which the powdery carbon dioxide adsorbent 51 is dispersed and fixed are laminated.

In this way, if the moisture absorbing sheet member 83 in which the carbon dioxide adsorbent is immobilized is configured as a cylindrical body (rotor body) wound in a cylindrical shape, or as a laminate in which a plurality of moisture absorbing sheet members 83 are laminated, the density of the moisture absorbing material and the carbon dioxide adsorbent can be increased with a simple shape. Therefore, it is possible to improve the performance of the adsorption device.

Also, by fixing the carbon dioxide adsorbent to the moisture absorbent sheet member 83, the moisture absorbent and the carbon dioxide adsorbent can be integrated. Therefore, as in the adsorption device 43 having a cylindrical body (rotor body) structure shown in FIG. 6A or the adsorption device 44 having a laminate structure shown in FIG.

The method for fixing the carbon dioxide adsorbent to the moisture absorbing sheet member 83 is not particularly limited. As described above, the carbon dioxide adsorbent 51 in powder form may be dispersed on the surface of the moisture absorbent sheet member 83 and fixed using an adhesive or the like, or the carbon dioxide adsorbent 51 may be mixed in the moisture absorbent sheet member 83. If the moisture absorbing sheet member 83 is a nonwoven fabric or a woven fabric, the carbon dioxide adsorbent 51 may be processed into a fibrous form or supported on the fibers and mixed in the nonwoven fabric or woven fabric.

Also, powder of the moisture absorbent may be additionally immobilized on the moisture absorbent sheet member 83 to which the carbon dioxide adsorbent is immobilized. Alternatively, a nonwoven fabric, a woven fabric, or the like may be used as a base material, and the carbon dioxide adsorbent powder and the hygroscopic material powder may be fixed or supported on this base material. Also, the method of sheeting the hygroscopic material is not particularly limited, and it may be a nonwoven fabric, a woven fabric, or the like, a continuous porous film, or other forms.

The specific shape of the moisture absorbing sheet member 83 is also not particularly limited. For example, the thickness, width, length, etc. can be appropriately set. Also, the moisture absorbing sheet member 83 may be a flat sheet, a corrugated sheet, or a sheet having irregularities or holes. These shape characteristics can be appropriately set according to the specific shape or application of the adsorption device.

Also, the application equipment to which the adsorption device according to the present disclosure can be applied is not particularly limited, but an air conditioner can be mentioned as a representative example. This makes it possible to provide the air conditioner with a carbon dioxide concentration and humidity adjustment function simply by providing the adsorption device. Other application devices may be devices provided with a blower and used indoors. As an example, it can be applied to blowers such as electric fans, circulators, or ventilation fans.

The present invention will be described more specifically based on examples, comparative examples, and reference examples, but the present invention is not limited to these. Various changes, modifications and alterations can be made by those skilled in the art without departing from the scope of the invention.

(Reference example)
Polystyrene skeleton benzylamine (benzylamine-modified polystyrene) as an example of the carbon dioxide adsorbent (polymer compound 7 shown in FIG. 3) according to the present disclosure, activated carbon (manufactured by Osaka Gas Chemicals Co., Ltd., Granular Shirasagi G2c (product name)), silica gel (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd., granular reagent), zeolite 4A (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd., synthetic zeolite, A-4, granular), diatomaceous earth sheet (Techno Frontier Co., Ltd.) ), WSS desiccant rotor (product name)), and a crosslinked acrylonitrile-based polymer (manufactured by Nihon Exlan Kogyo Co., Ltd., Exrotor (product name)) as an example of a moisture absorbent. Water vapor adsorption isotherm data was obtained and graphed based on the method specified in JIS K1150-1994.

In addition, throughout the examples including this reference example, the polystyrene skeleton benzylamine is referred to as "solid polymer BZA" and the crosslinked acrylonitrile polymer is referred to as "hygroscopic polymer" for convenience of explanation. For the hygroscopic polymer, water vapor adsorption isotherm data was obtained in two types of forms: a sheet and a pellet. In this example, the solid polymer BZA was produced by modifying polystyrene with benzylamine by a known method (for example, the method described in WO2005/123971).

Based on the created water vapor adsorption isotherm data graph, with 1,600 Pa as the boundary and the moisture absorption amount of the solid polymer BZA as a reference, the moisture absorption amount (water vapor adsorption amount) in the water vapor equilibrium pressure region of less than 1,600 Pa (1,600 Pa <) and the water vapor equilibrium pressure region of 1,600 Pa or more (1,600 Pa ≥) was evaluated for each of the above materials.

When the amount of moisture absorption is particularly higher than that of solid polymer BZA, it is evaluated as "◎"; Table 1 shows the evaluation of the amount of moisture absorbed by each material, together with the evaluation of the moisture release temperature (the temperature at which moisture is released) of each material. The moisture release temperature was evaluated as "○" when less than 100°C and "x" when 100°C or more.

As is clear from the results in Table 1, only the hygroscopic polymer pellets and sheets exceeded the moisture absorption amount of the solid polymer BZA in both the region where the moisture release temperature was less than 100°C and the water vapor equilibrium pressure was less than 1,600 Pa and the region where the water vapor equilibrium pressure was 1,600 Pa or more. That is, based on the results of Reference Examples, it can be seen that a hygroscopic polymer is particularly preferable among a plurality of hygroscopic materials.

(Example 1)
The above-described solid polymer BZA porous powder and hygroscopic polymer porous powder were used as adsorbent powders, and these adsorbent powders were arranged in each cell 80a of the adsorption device 4 having the configuration shown in FIG. 3 to prepare an adsorption device according to Example 1. The adsorption device at this time was 100 mm×100 mm×10 mm. Further, the adsorption device according to Example 1 includes a nonwoven fabric to prevent the adsorbent powder from dropping out of the gap.

The blending ratio (blend ratio) between the solid polymer BZA porous powder (carbon dioxide adsorbent powder) that is the carbon dioxide adsorbent and the hygroscopic polymer porous powder (moisture absorbent powder) that is the hygroscopic material was set to 80% by mass when the mass ratio of the carbon dioxide adsorbent powder to the mass of all the adsorbent powder was taken. Therefore, the mass ratio of the moisture absorbent powder in the total moisture absorbent powder is 20% by mass. The definition of the compounding ratio of all adsorbents (not necessarily powder) is the same for Examples 2-5.

By preliminary experiments, mixed adsorbent powders were prepared by blending carbon dioxide adsorbent powder and moisture absorbent powder at multiple compounding ratios in the range of 100% by mass to 30% by mass. For each of the mixed adsorbent powders with these multiple compounding ratios, the amount of carbon dioxide or water adsorbed relative to the mass ratio was measured, plotted on a graph of the adsorbed amount against the compounding ratio, and approximate lines were derived for each of the carbon dioxide adsorbent and moisture absorbent.

In the preliminary experiment, the approximation line for the carbon dioxide adsorbent was Equation 3 below, and the approximation line for the moisture absorbent was Equation 4 below.

[Formula 3]
Adsorption amount of carbon dioxide (mmol/g) = 0.7788 × blending ratio of carbon dioxide adsorbent (mass%)

[Formula 4]
Water adsorption amount (moisture absorption amount, mmol / g) = -1.0234 × amount of carbon dioxide adsorbent (% by mass) + 3.5965

From the mixing ratio of the carbon dioxide adsorbent powder and the moisture absorbent powder in the adsorption device according to Example 1 and the total mass of the adsorbent powder mounted on the adsorption device, the carbon dioxide adsorption amount and water adsorption amount (moisture absorption amount) in the adsorption device according to this Example 1 were calculated. Table 2 shows the results. The calculation of the adsorption amount is the same for Examples 2 to 5 as well.

(Example 2)
An adsorption device according to Example 2 was prepared in the same manner as in Example 1 except that the adsorption device 41 (first modification of Embodiment 1) shown in FIG. 4 was used as the adsorption device, and the carbon dioxide adsorption amount and the moisture absorption amount were calculated. Table 2 shows the results.

In addition, in the adsorption device according to the second embodiment, the carbon dioxide adsorbent is powder, but the moisture absorbent is the material forming the holder body 80 (that is, the holder body 80 contains the moisture absorbent). The blending ratio of the adsorbent is 91% by mass (the blending ratio of carbon dioxide powder and hygroscopic material is 9% by mass).

(Example 3)
An adsorption device according to Example 3 was prepared in the same manner as in Example 1 except that the adsorption device 42 shown in FIG. 5 (second modification of Embodiment 1) was used as the adsorption device, and the carbon dioxide adsorption amount and the moisture absorption amount were calculated. Table 2 shows the results.

In addition, in the adsorption device according to Example 3, the carbon dioxide adsorbent is powder, but the moisture absorbent is the material forming the nonwoven fabric 80g (that is, the nonwoven fabric 80g or the covering material 81 contains the moisture absorbent). The blending ratio of the adsorbent is 92% by mass (the blending ratio of carbon dioxide powder and hygroscopic material is 8% by mass).

(Example 4)
An adsorption device according to Example 4 was prepared in the same manner as in Example 1 except that the adsorption device 43 (Embodiment 2) shown in FIG. 6A was used as the adsorption device, and the carbon dioxide adsorption amount and the moisture absorption amount were calculated. Table 2 shows the results.

In addition, in the adsorption device according to the fourth embodiment, a cylindrical body (rotor body) is formed by fixing a powdery carbon dioxide adsorbent to a moisture absorbing sheet member. The blending ratio of the adsorbent is 97% by mass (the blending ratio of carbon dioxide powder and hygroscopic material is 3% by mass).

(Example 5)
An adsorption device according to Example 5 was prepared in the same manner as in Example 1 except that the adsorption device 44 (Embodiment 2) shown in FIG. 6B was used as the adsorption device, and the carbon dioxide adsorption amount and the moisture absorption amount were calculated. Table 2 shows the results.

In addition, in the adsorption device according to Example 5, the powdery carbon dioxide adsorbent is fixed to the moisture absorbing sheet member to form a laminate. The blending ratio of the adsorbent is 97% by mass (the blending ratio of carbon dioxide powder and hygroscopic material is 3% by mass).

(Results of Example)
As is clear from the results of Examples 1 to 5, the adsorption device according to the present disclosure can achieve good results in terms of both carbon dioxide adsorption amount and moisture absorption amount (water adsorption amount). Therefore, an adsorption device having moisture absorption/desorption characteristics and carbon dioxide adsorption/desorption characteristics can be obtained. Therefore, in the present disclosure, it can be seen that a hygroscopic material, such as a hygroscopic polymer, which releases moisture at a temperature of less than 100°C and has an adsorption amount of moisture at a water vapor equilibrium pressure of less than 1,600 Pa that is equal to or greater than the moisture adsorption amount of the carbon dioxide adsorbent.

In addition, in Example 1, since the mounting space for the carbon dioxide adsorbent powder and the moisture absorbent powder is the same portion (inside the cell of the holder body), the amount of carbon dioxide adsorbent is relatively small compared to other examples. Therefore, both the amount of carbon dioxide adsorption and the amount of moisture absorbed are relatively low compared to other examples.

On the other hand, in Examples 2 and 3, since the other members of the adsorption device according to Embodiment 1 are integrated with the moisture absorbing material, both moisture absorption and desorption characteristics and carbon dioxide adsorption and release characteristics can be achieved, and a relatively high carbon dioxide adsorption amount can be achieved compared to Example 1.

In Examples 4 and 5, the blending ratio of the hygroscopic material is relatively low compared to other examples, so the moisture absorption amount is also relatively small. However, by using the hygroscopic sheet member on which the carbon dioxide adsorbent is fixed, adsorption devices with various configurations can be obtained without being limited to the configuration having a holder as in Examples 1 to 3. Further, in the case of Examples 4 and 5, it is possible to obtain a moisture absorption amount equal to or greater than that of Examples 2 and 3 by adding the moisture absorbent in the form of powder.

From the above description, many modifications and other embodiments of the invention will be apparent to those skilled in the art. Accordingly, the above description is to be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. Substantial details of construction and/or function may be changed without departing from the spirit of the invention.

In addition, the present invention is not limited to the description of the above embodiments, and various modifications are possible within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments and multiple modifications are also included in the technical scope of the present invention.

1: Air conditioner 3: Blower mechanism (blower)
4, 41, 42, 43, 44: adsorption device 5: adsorbent 7: polymer compound (carbon dioxide adsorbent)
8: holder 51: carbon dioxide adsorbent (powder)
80: Holder body 80a: Cell 80b: Internal space 80c: Inlet 80d: Outlet 80g: Nonwoven fabric 81: Covering material 83: Moisture absorbing sheet member

Claims

Used to adsorb and release predetermined components contained in the air flow blown from the blower,
a carbon dioxide adsorbent that repeatedly adsorbs and releases carbon dioxide as one of the predetermined components;
a hygroscopic material that adsorbs and releases moisture as another one of the predetermined components;
with
The carbon dioxide adsorbent contains a polymer compound having a chemical structure in which a functional group containing an amine group that is at least a primary amine group is bonded, is formed in a porous shape, and is capable of adsorbing and releasing moisture.
The hygroscopic material can release moisture at a temperature of less than 100 ° C., and the adsorption amount of moisture at a water vapor equilibrium pressure of less than 1,600 Pa is greater than or equal to the moisture adsorption amount of the carbon dioxide adsorbent. An adsorption device.
The carbon dioxide adsorbent is a powder having an average particle size in the range of 400 μm or more and 1.3 mm or less.
The adsorption device according to claim 1.
A holder that holds at least the carbon dioxide adsorbent so that it can come into contact with air,
The holder is
a holder body formed with a plurality of cells having an internal space for containing the carbon dioxide adsorbent, an inlet for introducing air into the internal space, and an outlet for discharging the air that has passed through the internal space;
a covering material having air permeability and covering the inlet and the outlet of the cell;
The carbon dioxide adsorbent is housed in the cell,
The adsorption device according to claim 1 or 2.
a material of the holder main body includes the moisture absorbing material;
The adsorption device according to claim 3.
the material of the holder body includes at least one of resin, metal and ceramic;
The adsorption device according to claim 3 or 4.
wherein said dressing comprises a non-woven fabric;
The adsorption device according to any one of claims 3-5.
The material of the nonwoven fabric contains the moisture absorbent material,
The adsorption device according to claim 6.
wherein the dressing comprises a metal mesh;
The adsorption device according to any one of claims 3-7.
The pressure loss when air is passed through the covering material at a flow rate of 1 m / sec is a value in the range of 5 Pa or more and 30 Pa or less.
The adsorption device according to any one of claims 3-8.
The moisture absorbent material is provided as a moisture absorbent sheet member formed into a sheet,
The adsorption device according to any one of claims 1-9.
The carbon dioxide adsorbent is immobilized on the moisture absorbing sheet member,
The adsorption device according to claim 10.
The hygroscopic sheet member is used as a laminate obtained by laminating a plurality of the hygroscopic sheet members, or as a cylindrical body obtained by winding the hygroscopic sheet member in a cylindrical shape.
The adsorption device according to claim 11.
The hygroscopic material is a crosslinked hydrophilic polymer having a hydrophilic group and a crosslinked structure,
The adsorption device according to any one of claims 1-12.
The flow channel cross-sectional area of the independent internal space in the flow direction of the air introduced into and discharged from the adsorption device is a value in the range of 0.5 cm or more and 10.0 cm or less.
14. The adsorption device according to any one of claims 1-13.
The pressure loss is in the range of 40 Pa or more and 500 Pa or less when the air introduced into and discharged from the adsorption device is passed at a flow rate of 1 m/sec.
15. The adsorption device according to any one of claims 1-14.
An air conditioner comprising the adsorption device according to any one of claims 1 to 15.