JP7590364B2 - Gas Concentrator - Google Patents

Description

Article 30, paragraph 2 of the Patent Act applies. Publication date: January 31, 2021. Published via telecommunications at the publication address (https://www.sgkz.or.jp/project/newtech/106/document_03.html).

The present invention relates to a gas concentration device that concentrates gas, and in particular to a gas concentration device that can efficiently concentrate carbon dioxide from various gases.

In recent years, there has been a call for the reduction of carbon dioxide (CO ₂ ) gas with the aim of realizing carbon neutrality, which is the reduction of greenhouse gas emissions to zero overall. However, a supply of carbon dioxide is necessary for plant growth.

In particular, greenhouses are often closed during the winter, which can lead to a shortage of carbon dioxide, which is necessary for the growth of cultivated plants such as strawberries and tomatoes.

In addition, plants grown in greenhouses and other environments absorb carbon dioxide during the day through photosynthesis, and the carbon dioxide concentration around the leaves becomes lower than the carbon dioxide concentration in the atmosphere (approximately 400 ppm).

In this case, the photosynthesis of the cultivated plants is suppressed, resulting in a decrease in the yield and sugar content of the cultivated plants, so a process is carried out in which carbon dioxide is forcibly supplied from outside to improve the yield of the cultivated plants. Specifically, carbon dioxide is supplied by burning kerosene or by using a liquefied carbon dioxide cylinder.

However, these conventional methods of supplying carbon dioxide increase the amount of carbon dioxide in the environment, which is contrary to the reduction of carbon dioxide gas, such as the carbon neutral approach mentioned above, and cleaner methods of supplying carbon dioxide are required.

In terms of adjusting the air conditioning in a vinyl greenhouse, air conditioners and methods that use a desiccant rotor to adjust temperature and humidity have been known for some time (e.g., Patent Documents 1 to 5). By applying these to a vinyl greenhouse, it is possible to adjust the air conditioning in the greenhouse and to assist the growth of cultivated plants to some extent, but they do not supply carbon dioxide.

In addition, in conventional technology that combines a desiccant rotor with a heat pump (for example, Patent Document 1 above), when supplying gas from the adsorption outlet side of the desiccant rotor to the supply destination, it is necessary to install, for example, a heat exchanger or an outdoor unit on the regeneration outlet side of the desiccant rotor in order to balance the heat of the heat pump, and using an outdoor unit poses the problem of increased device size.

Therefore, the applicant has been developing a gas concentrator as a carbon dioxide supply device using a honeycomb rotor for some time now, with the aim of supplying clean gas that is environmentally friendly and does not require the hassle of replacement.

For example, a known conventional gas concentration device is an air conditioner that cools return air from inside a room through an evaporator in a heat pump cycle, passes the cooled air through an adsorption zone of a honeycomb rotor that has carbon dioxide adsorption properties and uses an ion exchange resin or the like as an adsorbent that has the ability to adsorb moisture and carbon dioxide, and passes heated outside air through a condenser in the heat pump cycle to the desorption zone of the honeycomb rotor (see, for example, Patent Document 6).

For example, a conventional gas concentration device has a carbon dioxide removal rotor that holds an amine-based absorbent having carbon dioxide absorption function, and the carbon dioxide removal rotor is divided into at least an adsorption zone and a desorption zone. The air to be treated is ventilated through the adsorption zone, so that the carbon dioxide contained in the air to be treated is absorbed by the retained absorbent in the carbon dioxide removal rotor, separated and removed, and supplied to the supply destination. In the desorption zone, regeneration air that has recovered the latent heat and sensible heat of the regeneration exhaust from the desorption zone in a total heat exchanger is ventilated, so that the retained absorbent desorbs the carbon dioxide absorbed in the adsorption zone, thereby regenerating the retained absorbent (see, for example, Patent Document 7).

Furthermore, for example, a conventional gas concentration device is one that removes carbon dioxide from the air to be treated by contacting the air to be treated containing carbon dioxide with an amine-based absorbent to absorb the carbon dioxide into the absorbent, and then contacting the absorbent with regeneration air to desorb the carbon dioxide from the absorbent. In this case, an absorption-type removal and concentration device is known in which the enthalpy of the regeneration air is made greater than that of the air to be treated by either or both of a means for lowering the enthalpy of the air to be treated (e.g., a heat pump evaporator) and a means for increasing the enthalpy of the regeneration air (e.g., a heat pump condenser) to desorb carbon dioxide from the absorbent (see, for example, Patent Document 8).

JP 2010-276317 A JP 2011-92163 A JP 2012-172880 A JP 2014-206376 A JP 2019-66155 A JP 2011-94821 A JP 2020-89891 A JP 2017-154063 A

However, even with gas concentrators such as those described in Patent Documents 7 and 8, the amine-based absorbent adsorbs carbon dioxide under low-temperature conditions (e.g., below 20°C), and in summer, the high outdoor air temperature makes it difficult for carbon dioxide to be adsorbed and desorbed via the honeycomb rotor, making it impossible to supply gas with a high carbon dioxide concentration, even when a heat pump is used.

In addition, the regeneration temperature of the amine absorbents used in Patent Documents 7 and 8 is about 40°C. When attempting to supply carbon dioxide adsorbed to the amine absorbent to tomatoes grown in the summer, the temperature difference between the regeneration temperature of the amine absorbent and the outside air temperature is so small that adsorption and desorption of carbon dioxide is difficult to occur, and there is also the problem that the concentration of carbon dioxide supplied does not increase.

Because the outdoor air temperature is high in the summer and low in the winter, the heat pump cannot balance with the outdoor air temperature throughout the year, making it difficult to operate the heat pump properly to adsorb and desorb carbon dioxide, and creating the problem of being unable to provide a stable supply of gas with a high concentration of carbon dioxide throughout the year.

The present invention aims to provide a gas concentrator that solves the above problems, can supply high-concentration carbon dioxide even in the summer, and can stably supply high-concentration carbon dioxide all year round while reducing running costs.

As a result of extensive research, the inventors have devised innovative heat pump structures, discovered a new gas concentrator that can concentrate and supply carbon dioxide all year round, and have completed the present invention.

The gas concentration device disclosed in this application is capable of adsorbing and desorbing carbon dioxide contained in a specified raw gas, and is equipped with a honeycomb rotor in which at least an adsorption zone for adsorbing the carbon dioxide and a desorption zone for desorbing the carbon dioxide are set, a cooling section for cooling the raw gas introduced into the adsorption zone of the honeycomb rotor, a heating section for heating the raw gas introduced into the desorption zone of the honeycomb rotor, a heat exchanger for heating or cooling the adsorbed gas that has passed through the adsorption zone of the honeycomb rotor, and a heat pump having an evaporator constituting the cooling section and a condenser constituting the heating section.

In this way, the gas concentration device disclosed in the present application is capable of adsorbing and desorbing carbon dioxide contained in a predetermined raw gas, and is equipped with a honeycomb rotor in which at least an adsorption zone for adsorbing the carbon dioxide and a desorption zone for desorbing the carbon dioxide are set, a cooling section for cooling the raw gas introduced into the adsorption zone of the honeycomb rotor, a heating section for heating the raw gas introduced into the desorption zone of the honeycomb rotor, a heat exchanger for heating or cooling the adsorbed gas that has passed through the adsorption zone of the honeycomb rotor, and a heat pump having an evaporator constituting the cooling section and a condenser constituting the heating section. The heat equivalent to the difference between the amount of heat absorbed in the cooling section and the amount of heat released in the heating section is released by heating the adsorbed gas in the heat exchanger, or absorbed by cooling the adsorbed gas in the heat exchanger. This allows the adsorption zone inlet temperature to be lowered in the summer to supply high-concentration carbon dioxide, and the desorption zone inlet temperature to be raised in the winter to supply high-concentration carbon dioxide. This allows a stable supply of high-concentration carbon dioxide all year round, and by using a heat pump instead of a heater, it is possible to operate with less energy than when a heater is used, thereby reducing running costs.

In addition, the gas concentration device disclosed in the present application is configured so that the heat pump heat medium can flow in and out of the heat exchanger as necessary, and heat exchange between the heat pump heat medium and the adsorbed gas is performed to heat or cool the adsorbed gas. In this way, the gas concentration device disclosed in the present application is configured so that the heat pump heat medium can flow in and out of the heat exchanger, and heat exchange between the heat pump heat medium and the adsorbed gas is performed to heat or cool the adsorbed gas. Therefore, the thermal equilibrium between the heat absorption side and heat release side of the heat pump is maintained by diverting the adsorbed gas in the system. Even if a difference in the amount of heat absorption in the cooling section and the amount of heat release in the heating section occurs due to a difference in the temperature of the raw material gas (outside air) due to seasonal changes, etc., the thermal equilibrium between the heat absorption side and heat release side of the heat pump is easily maintained, and the operation of the heat pump and the adsorption and desorption in the rotor can be stabilized.

The gas concentration device disclosed in the present application also includes one or more switching means for switching the heat medium flow path of the heat pump leading to the heat exchanger, so that when the amount of heat dissipated in the heating section is greater than the amount of heat absorbed in the cooling section, the heat exchanger serves as another evaporator of the heat pump and is connected in parallel to the cooling section, and when the amount of heat dissipated in the heating section is less than the amount of heat absorbed in the cooling section, the heat exchanger serves as another condenser of the heat pump and is connected in parallel to the heating section, as necessary.

In this way, the gas concentration device disclosed in the present application is equipped with one or more switching means for switching the heat medium flow path of the heat pump leading to the heat exchanger so that when the amount of heat released in the heating section is greater than the amount of heat absorbed in the cooling section, the heat exchanger is connected in parallel to the cooling section as another evaporator of the heat pump, and when the amount of heat released in the heating section is less than the amount of heat absorbed in the cooling section, the heat exchanger is connected in parallel to the heating section as another condenser of the heat pump. Therefore, by switching using the switching means, the heat exchanger is appropriately performed, and thermal equilibrium between the heat absorption side and heat release side of the heat pump is maintained. Even if a difference occurs between the amount of heat absorbed in the cooling section and the amount of heat released in the heating section due to a difference in temperature of the raw gas (outside air) due to seasonal changes, etc., the thermal equilibrium between the heat absorption side and heat release side of the heat pump is optimally maintained by the switching means, and the operation of the heat pump and the adsorption and desorption in the honeycomb rotor can be stabilized.

The gas concentration device disclosed in the present application is provided, as necessary, with a first blower disposed between the adsorption zone of the honeycomb rotor and the heat exchanger, which attracts the adsorbed gas and sends it to the heat exchanger, and a second blower as a forced blower which sends the raw gas toward the desorption zone of the honeycomb rotor. In this way, the gas concentration device disclosed in the present application is provided between the adsorption zone of the honeycomb rotor and the heat exchanger, with a first blower which attracts the adsorbed gas and sends it to the heat exchanger, and a second blower as a forced blower which sends the raw gas toward the desorption zone of the honeycomb rotor. Therefore, the pressure on the desorption zone side of the rotor is made higher than the pressure on the adsorption zone side, and the raw gas heading toward the adsorption zone of the rotor is not mixed with the desorbed gas that has passed through the desorption zone of the rotor (through gaps, etc.), and the concentration of carbon dioxide in the desorbed gas can be maintained.

In addition, in the gas concentration device disclosed in the present application, the second blower is disposed between the desorption zone of the honeycomb rotor and the condenser of the heat pump as necessary, and sends the raw gas that has passed through the condenser to the desorption zone. In this way, in the gas concentration device disclosed in the present application, the second blower is disposed between the desorption zone of the honeycomb rotor and the condenser of the heat pump, and sends the raw gas that has passed through the condenser to the desorption zone. Therefore, the first and second blowers are disposed near the honeycomb rotor, and the honeycomb rotor, the first and second blowers, and the heat pump can be made into individual units. It is also possible to easily add a heat pump to a conventional concentration device that is composed only of a honeycomb rotor, a blower, and a desorption heater, and this makes it possible to simplify the device and facilitate transportation and maintenance.

In addition, the gas concentration device disclosed in the present application is provided, as necessary, with a third blower that attracts the adsorbed gas from the heat exchanger and discharges it to the outside, and the third blower further introduces external gas into the heat exchanger by attraction, and discharges the external gas that has passed through the heat exchanger to the outside together with the adsorbed gas. In this way, the gas concentration device disclosed in the present application is equipped with a third blower that attracts the adsorbed gas from the heat exchanger and discharges it to the outside. The third blower further introduces external gas into the heat exchanger by attraction, and discharges the external gas that has passed through the heat exchanger to the outside together with the adsorbed gas. This means that there is an object for heat exchange with the heat pump's heat medium other than the adsorbed gas that has left the adsorption zone of the honeycomb rotor, and heat dissipation in the heat exchanger can be reliably performed, especially in the summer when the outside air temperature is high, and the heat exchanger can handle the increased amount of heat dissipation with ease, maintaining a constant heating in the heating section of the heat pump and stabilizing desorption in the rotor.

The gas concentration device disclosed in this application also includes, as necessary, another heat exchanger that cools the desorbed gas that has passed through the desorption zone of the honeycomb rotor by heat exchange with the heat medium of the heat pump, and the heat medium flow path of the heat pump that leads to the other heat exchanger is connected in series or parallel to the cooling unit, or in series or parallel to the heating unit.

In this way, the gas concentrating device disclosed in the present application includes another heat exchanger that cools the desorbed gas that has passed through the desorption zone of the honeycomb rotor by heat exchange with the heat medium of the heat pump, and the heat medium flow path of the heat pump that leads to the other heat exchanger is connected in series or parallel to the cooling unit, or in series or parallel to the heating unit, so that the other heat exchanger functions as a so-called aftercooler or afterheater that heats or cools the desorbed gas, and can prevent high-temperature damage to plants, etc., caused by the high-temperature desorbed gas being supplied to an external plant house (vinyl house) at a high temperature in summer, and can prevent low-temperature damage to plants, etc., caused by the low-temperature desorbed gas being supplied to an external plant house (vinyl house) at a low temperature in winter, making it possible to provide the desorbed gas to the outside at a temperature suitable for cultivation all year round.

The gas concentration device disclosed in the present application is also provided with an amine-based absorbent that is supported on the rotor body of the honeycomb rotor as necessary and that can adsorb and desorb carbon dioxide. In this way, since the amine-based absorbent is supported on the rotor body of the honeycomb rotor and can adsorb and desorb carbon dioxide, the temperature range in which the amine-based absorbent can adsorb and desorb carbon dioxide matches the operating temperature range of the heat pump, allowing optimal operation. No external heat control is required, and optimal carbon dioxide desorption is possible only by the operation of the heat pump, making it possible to stabilize adsorption and desorption in the honeycomb rotor.

The gas concentration device disclosed in the present application also includes, as necessary, a moisture absorber supported on the rotor body of the honeycomb rotor, and an amine-based absorbent supported on the moisture absorber, which can adsorb and desorb carbon dioxide. As described above, the gas concentration device disclosed in the present application includes a moisture absorber supported on the rotor body of the honeycomb rotor, and an amine-based absorbent supported on the moisture absorber, which can adsorb and desorb carbon dioxide. Since the moisture absorber itself adsorbs moisture, excess moisture can be appropriately removed during the adsorption and desorption of carbon dioxide by the amine-based absorbent, making it possible to provide adsorbed or desorbed gas of higher quality.

FIG. 1 shows a configuration diagram (summer) of a gas concentrating device according to a first embodiment of the present invention. FIG. 1 shows a configuration diagram (winter) of a gas concentrating device according to a first embodiment of the present invention. 1A to 1C show various aspects of a honeycomb structure of a gas concentrating device according to a first embodiment of the present invention. 3A to 3C are explanatory diagrams of the operation of the honeycomb rotor of the gas concentrating device according to the first embodiment of the present invention. FIG. 13 shows a configuration diagram (summer) of a gas concentrating device according to a second embodiment of the present invention. FIG. 13 shows a configuration diagram (winter) of a gas concentrating device according to a second embodiment of the present invention. FIG. 11 is an explanatory diagram of a third blower of a gas concentrating device according to a second embodiment of the present invention. FIG. 13 shows a configuration diagram (summer) of a gas concentrating device according to a third embodiment of the present invention. FIG. 13 shows a configuration diagram (winter) of a gas concentrating device according to a third embodiment of the present invention.

(First embodiment)
As shown in Figures 1 and 2, the gas concentration device of the first embodiment is capable of adsorbing and desorbing carbon dioxide contained in a specified raw gas, and is configured to include a honeycomb rotor 1 in which at least an adsorption zone A for adsorbing the carbon dioxide and a desorption zone B for desorbing the carbon dioxide are set, a cooling section 2a for cooling the raw gas introduced into the adsorption zone A of the honeycomb rotor 1, a heating section 2b for heating the raw gas introduced into the desorption zone B of the honeycomb rotor 1, a heat exchanger 2c for heating or cooling the adsorbed gas 100a that has passed through the adsorption zone A of the honeycomb rotor 1, and a heat pump 2 having an evaporator constituting the cooling section 2a and a condenser constituting the heating section 2b.

The adsorbed gas 100b that has passed through this desorption zone B is rich in carbon dioxide, and can therefore be used in a variety of applications that require the supply of carbon dioxide. For example, as shown in FIG. 1, it can be supplied to a plant house 200 (vinyl house).

The specified raw material gas is not particularly limited as long as it contains carbon dioxide. For example, exhaust gases emitted from factories and automobiles are also applicable since they contain carbon dioxide, but it is preferable to use the atmosphere 100. When the atmosphere 100 is used, an inexpensive and clean gas is used, which is environmentally friendly and allows for the procurement of raw materials at low cost.

The honeycomb rotor 1 is a rotor with a honeycomb structure formed into a drum shape with a circular cross section. The cross section of this honeycomb rotor 1 is divided into two sections 1a and 1b, forming an adsorption zone A and a desorption zone B, respectively. More preferably, the circular cross section of this honeycomb rotor 1 is divided in half by the diameter of the circle into two semicircular cross sections, forming the adsorption zone A and the desorption zone B, respectively. Note that the zone division of the cross section of the honeycomb rotor 1 is not limited to a semicircular cross section, and may be changed as appropriate as necessary.

As shown in Figure 3, this honeycomb structure includes, in the narrow sense, a honeycomb structure in which hollow regular hexagonal columns are lined up without gaps, like a honeycomb shape, but is not limited to this shape. In the broad sense, the honeycomb structure includes a structure in which any hollow three-dimensional shape, not limited to hollow regular hexagonal columns, is lined up without gaps. For example, a honeycomb structure includes a structure in which non-flammable inorganic fiber paper is processed into a cardboard shape (corrugated shape) and stacked to form a rotor shape.

This honeycomb structure increases the surface area of the treatment portion of the rotor body of the honeycomb rotor 1, allowing carbon dioxide to be adsorbed and desorbed effectively.

The rotor body of this honeycomb rotor 1 contains an absorbent that can adsorb and desorb carbon dioxide, and this absorbent can be either a chemical absorbent or a physical absorbent as long as it can absorb carbon dioxide.

Of these, it is preferable to use a chemical absorbent due to its high efficiency in adsorbing carbon dioxide, and an amine-based absorbent is one example. For example, the rotor body of this honeycomb rotor 1 can be configured to support an amine-based absorbent that can adsorb and desorb carbon dioxide.

The amine-based absorbent is not particularly limited as long as it is an absorbent made of a compound having an amine group as a functional group, and examples thereof include alkanolamines such as methanolamine, 2-aminoalcohol, diethanolamine, triethanolamine, N-methylethanolamine, N,N-dimethylethanolamine, propanolamine, heptaminol, isoethanolamine, and methyldiethanolamine, as well as amino acids and amino acid salts and derivatives thereof.

As for the type of amine-based absorbent, it is preferable to use a primary amine (R-NH ₂ ) or a secondary amine (R ₁ R ₂ -NH), since the NH bond enables sufficient absorption and desorption of carbon dioxide even under low temperature conditions.

There are no particular limitations on the carbon dioxide absorption and desorption temperature of the amine-based absorbent, but it is preferable to lower the regeneration temperature in order to reduce odors and thermal degradation caused by oxidative decomposition. For example, adsorption and desorption can be performed at temperatures in the range of 10°C to 50°C, and adsorption and desorption can be performed under low-temperature conditions, such as an adsorption temperature of 15°C and a desorption temperature of 45°C.

The reaction between amine absorbents and carbon dioxide proceeds according to the chemical reaction formula below. The arrows below indicate adsorption reactions with right-facing arrows (→) and desorption reactions with left-facing arrows (←).

(Chemical formula 1)
Primary amine (R-NH ₂ )
[1] 2R-NH ₂ + CO ₂ ⇔ R-NH ₃ ⁺ + R-NH-COO ^-
[2a] R-NH ₂ + CO ₂ + H ₂ O ⇔ R-NH ₃ ⁺ + HCO ₃ ^-
[2b] R-NH-COO ^- + H ₂ O ⇔ R-NH ₂ + HCO ₃ ^-
Secondary amines (R ₁ R ₂ -NH)
[3] 2R ₁ R ₂ -NH + CO ₂ ⇔R ₁ R ₂ -NH ⁺ + R ₁ R ₂ -N-COO ^-
[4a] R ₁ R ₂ -NH + CO ₂ + H ₂ O ⇔ R ₁ R ₂ -NH ₂ ⁺ + HCO ₃ ^-
[4b] R ₁ R ₂ -N-COO ^- + H ₂ O ⇔ R ₁ R ₂ -NH + HCO ₃ ^-

As shown in the above chemical formula, this amine-based absorbent itself can adsorb carbon dioxide, including moisture, via moisture (water). For example, under low-temperature conditions of an adsorption temperature of 15°C and a desorption temperature of 45°C, in the presence of moisture (water), the carbon dioxide absorbing solution can absorb carbon dioxide through the equilibrium reactions of the above pathways [2a], [2b], [4a], and [4b]. This results in a smaller reaction heat than the reactions shown in pathways [1] or [3], and the energy required for adsorption and desorption of carbon dioxide can be reduced, thereby improving processing efficiency.

In addition to the above-mentioned configuration in which the amine-based absorbent 12 is supported on the rotor body 11 of the honeycomb rotor 1, various configurations are possible for providing the amine-based absorbent 12 on the honeycomb rotor 1. For example, a configuration is possible in which the honeycomb rotor 1 includes a moisture absorber supported on the rotor body of the honeycomb rotor 1 and an amine-based absorbent supported on the moisture absorber that can adsorb and desorb carbon dioxide.

This moisture absorber is not particularly limited as long as it is a material capable of retaining moisture, but examples that can be used include silica gel, zeolite, or activated alumina.

An evaporator can be used as the cooling section 2a that cools the raw gas introduced into the adsorption zone A of this honeycomb rotor 1. Also, a condenser can be used as the heating section 2b that heats the raw gas introduced into the desorption zone B of this honeycomb rotor 1.

The heat pump 2 has an evaporator that constitutes the cooling section 2a, and a condenser that constitutes the heating section 2b. As shown in FIG. 1, the heat pump 2 is equipped with expansion valves 21a and 21b that control the expansion of the gas, and a compressor 22 that compresses the gas, thereby expanding and compressing the gas and exchanging heat, and transferring heat from the low-temperature section to the high-temperature section.

The heat exchanger 2c is not particularly limited in terms of the connection configuration with the heat medium of the heat pump 2, but it is preferable that it be connectable to the heat medium of the heat pump 2 as shown in Figure 1.

The gas concentration device according to this embodiment can be configured with one or more switching means 3 for switching the heat medium flow path of the heat pump 2 leading to the heat exchanger 2c, so that when the amount of heat dissipated in the heating section 2b is greater than the amount of heat absorbed in the cooling section 2a, the heat exchanger 2c serves as another evaporator of the heat pump 2 and is connected in parallel to the cooling section 2a, and when the amount of heat dissipated in the heating section 2b is less than the amount of heat absorbed in the cooling section 2a, the heat exchanger 2c serves as another condenser of the heat pump 2 and is connected in parallel to the heating section 2b, as shown in FIG. 1.

As shown in FIG. 1, valves 3a, 3b, 3c, and 3d can be used as the switching means 3. By switching these valves, the flow direction of the heat medium flow path of the heat pump 2 can be changed depending on the outside air temperature (e.g., summer or winter).

The location of this heat exchanger 2c is not particularly limited, and it can be placed inside or outside the heat pump 2. However, by placing this heat exchanger 2c inside the heat pump 2 as shown in FIG. 1, the condenser and evaporator inside the heat pump 2 can be easily and directly connected, and the device can be designed to be small in scale, resulting in a simple device configuration, which is preferable.

The heat exchanger 2c is not particularly limited in terms of its connection to the heat medium of the heat pump 2, but it is preferable that it be connectable to the heat medium of the heat pump 2 as shown in FIG. 1. In this case, the heat exchanger 2c is capable of allowing the heat medium of the heat pump 2 to flow in and out, and the heat medium of the heat pump 2 and the adsorbed gas 100a can be heat exchanged to heat or cool the adsorbed gas 100a.

In addition, from the viewpoint of improving the quality of gas concentration, it is important to reliably send the adsorbed gas 100a obtained from the raw gas to the heat exchanger 2c and not to mix the adsorbed gas 100a with the desorbed gas 100b. From this viewpoint, it is preferable to subject the raw gas to forced convection driven from the outside rather than natural convection alone, and for example, it is preferable to provide an appropriate blower for the raw gas.

The position of such a blower is not particularly limited, but as shown in FIG. 1, it can be configured to include a first blower 4 disposed between the adsorption zone A of the honeycomb rotor 1 and the heat exchanger 2c, which attracts the adsorbed gas 100a and sends it to the heat exchanger 2c, and a second blower 5 acting as a forced blower to send the raw gas toward the desorption zone B of the honeycomb rotor 1.

The location of the second blower 5 is not particularly limited, but it is preferable to place it between the desorption zone B of the honeycomb rotor 1 and the condenser of the heat pump 2, so that the raw gas that has passed through the condenser can be efficiently sent to the desorption zone B.

With the above configuration, the gas concentration operation of the gas concentration device according to this embodiment will be explained below with reference to Figure 1.

(1) Operation in Summer (1-1) Adsorption For operation in summer, as shown in Fig. 1, for example, air 100 (carbon dioxide concentration of about 400 ppm) can be used as a raw gas containing carbon dioxide. In summer, the air temperature is high, so the air 100 as the raw gas rises to, for example, 35°C. The evaporator of the heat pump 2 as the cooling unit 2a cools the air 100 at 35°C to about 10°C.

The raw material gas, atmospheric air 100, is drawn into the adsorption zone A of the honeycomb rotor 1 by forced convection (e.g., 300 ^m3 /h) of a first blower 4 disposed between the adsorption zone A of the honeycomb rotor 1 and the heat exchanger 2c.

In this adsorption zone A, the rotor body of the honeycomb rotor 1 is supported with an amine-based absorbent capable of adsorbing and desorbing carbon dioxide. This amine-based absorbent has the property of being able to adsorb carbon dioxide at low temperatures (e.g., 10°C), and works optimally in line with the operating temperature range of the heat pump 2 (e.g., the ability to cool the atmosphere 100 to 10°C), so that carbon dioxide is efficiently adsorbed from the atmosphere 100.

In addition, other configurations of the amine-based absorbent in the adsorption zone A can include a moisture absorber supported on the rotor body of the honeycomb rotor 1, and an amine-based absorbent supported on the moisture absorber that can adsorb and desorb carbon dioxide. In this case, since the moisture absorber itself adsorbs moisture, it is possible to properly remove excess moisture when the amine-based absorbent adsorbs carbon dioxide, making it possible to provide adsorbed gas 100a of higher quality.

The operation of this honeycomb rotor 1 is as follows: the cooled air 100 is sent into the adsorption zone A of the honeycomb rotor 1, and as shown in FIG. 4(a), the carbon dioxide in the air 100 is adsorbed by the amine-based absorbent in the adsorption zone A on one cross-section 1a side of the honeycomb rotor 1, and the adsorbed gas 100a is discharged. In this case, the carbon dioxide is adsorbed by the amine-based absorbent on one cross-section 1a side of the honeycomb rotor 1. After this, as shown in FIG. 4(b), the one cross-section 1a side of the honeycomb rotor 1 is positioned in the desorption zone B by the rotor rotation, and the carbon dioxide is adsorbed in the desorption zone B.

This heat exchanger 2c heats the adsorbed gas 100a at about 20°C to about 40°C in summer as a condenser by the above-mentioned switching means 3. This heating by heat exchange makes it possible to maintain a heat balance with the cooling function of the evaporator of the heat pump 2, which is necessary to drastically cool the raw gas, for example, air 100 at 35°C in summer, to the adsorption temperature of about 10°C in order to send it to the adsorption zone A of the honeycomb rotor 1. As a result, it is possible to supply the plants with _CO2 gas with a high concentration at the regeneration outlet. In addition, the size of the device can be made smaller than that of an outdoor unit. In addition, by switching between the condenser and the evaporator depending on the outdoor air temperature, it is possible to use it all year round.

In this way, the heat exchanger 2c allows the heat medium of the heat pump 2 to flow in and out, and heat is exchanged between the heat medium of the heat pump 2 and the adsorbed gas 100a to heat the adsorbed gas 100a. This means that the thermal equilibrium between the heat absorption side and heat release side of the heat pump 2 is maintained by diverting the adsorbed gas 100a within the system. Even if a difference in the amount of heat absorbed in the cooling section 2a and the amount of heat released in the heating section 2b occurs due to differences in the temperature of the raw gas (outside air) due to seasonal changes, etc., the thermal equilibrium between the heat absorption side and heat release side of the heat pump 2 is easily maintained, and the operation of the heat pump 2 and the adsorption and desorption in the rotor can be stabilized.

(1-2) Desorption Next, the condenser as the heating section 2b of the heat pump 2 heats the raw gas. For example, the air 100 can be used as the raw gas. In summer, the air temperature is high, so the air 100 as the raw gas rises to, for example, 35°C. The condenser heats the air 100 from 35°C in summer to about 40°C.

The second blower 5 serves as a forced draft blower and sends out the raw material gas heated to about 40° C. by forced convection (for example, 300 m ³ /h) toward the desorption zone B of the honeycomb rotor 1 .

The second blower 5 is not particularly limited in its position, but as shown in FIG. 1, it is disposed between the desorption zone B of the honeycomb rotor 1 and the condenser of the heat pump 2, and the raw gas that has passed through the condenser can be sent to the desorption zone B. In this case, the first and second blowers 5 are disposed near the rotor, and the rotor, the first and second blowers 5, and the heat pump 2 can be made into individual units. It is also possible to easily add the heat pump 2 to a conventional concentrating device that is composed only of a rotor, a blower, and a desorption heater, which simplifies the device and facilitates maintenance.

As shown in FIG. 4(b) above, one cross section 1a of the honeycomb rotor 1, which maintains the state in which carbon dioxide is adsorbed, forms a desorption zone B by rotor rotation. The raw gas heading toward the adsorption zone A of the rotor passes through the desorption zone B of the rotor, where carbon dioxide is desorbed from the amine absorbent, and carbon dioxide-rich desorbed gas 100b (e.g., carbon dioxide concentration 800 to 1000 ppm) is obtained, and this desorbed gas 100b is smoothly supplied to the plant house 200 (vinyl house) by forced convection by the second blower 5.

Regarding the desorption of carbon dioxide in this adsorption zone A, the rotor body of this honeycomb rotor 1 is supported on a rotor, and is configured to include an amine-based absorbent capable of adsorbing and desorbing carbon dioxide. The amine-based absorbent has the property of being able to desorb carbon dioxide at a relatively low temperature (e.g., 40°C), and works optimally in line with the operating temperature range of the heat pump 2 (e.g., the ability to heat the air 100 to 40°C), making it easy to optimally desorb carbon dioxide.

As for the desorption of carbon dioxide in this desorption zone B, another possible configuration of the amine-based absorbent is one that includes a moisture absorber supported on the rotor body of this honeycomb rotor 1, and an amine-based absorbent that is supported on this moisture absorber and can adsorb and desorb carbon dioxide. In this case, since the moisture absorber itself desorbs moisture, it is possible to promote the desorption of carbon dioxide by the amine-based absorbent and provide a higher quality desorbed gas 100b.

In addition, since the first blower 4 and the second blower 5 are provided for this desorbed gas 100b, the pressure on the desorption zone B side of the rotor is made higher than the pressure on the adsorption zone A side, so that the raw gas heading toward the adsorption zone A of the rotor is not mixed into the desorbed gas 100b that has passed through the desorption zone B of the rotor (through gaps, etc.), and the concentration of carbon dioxide in the desorbed gas 100b can be maintained.

(2) Operation in Winter (2-1) Adsorption In operation in winter, as shown in Fig. 2, for example, air 100 (carbon dioxide concentration of about 400 ppm) can be used as the raw gas. In winter, the air temperature is low, so the air 100 as the raw gas drops to, for example, 15°C. The evaporator of the heat pump 2 as the cooling unit 2a cools the air 100 at 15°C to about 10°C.

The air 100 cooled to about 10° C. is drawn into the adsorption zone A of the honeycomb rotor 1 by forced convection (e.g., 300 ^m3 /h) of a first blower 4 disposed between the adsorption zone A of the honeycomb rotor 1 and the heat exchanger 2c. Similar to the summer season, the carbon dioxide contained in the cooled air 100 is adsorbed in the adsorption zone A.

This cooled air 100 is sent into the adsorption zone A of the honeycomb rotor 1, whereby the carbon dioxide contained in the air 100 is adsorbed by the amine-based absorbent in the adsorption zone A of the honeycomb rotor 1, and the adsorbed gas 100a is discharged.

A first blower 4 disposed between the adsorption zone A of the honeycomb rotor 1 and the heat exchanger 2c draws the adsorbed gas 100a by forced convection (for example, 300 m ³ /h) and sends it to the heat exchanger 2c.

This heat exchanger 2c cools the adsorbed gas 100a as an evaporator in winter using the switching means 3. This cooling by heat exchange makes it possible to maintain a heat balance with the heating function of the condenser of the heat pump 2, which is required to heat the raw gas, for example, air 100 at 15°C in winter, to the desorption temperature of approximately 40°C in order to send it to the desorption zone B of the honeycomb rotor 1, making energy-saving operation possible even when the outside air temperature is low (for example, 15°C).

In this way, with a configuration that includes this switching means 3, the heat exchanger 2c can be switched appropriately by the switching means 3, and the thermal equilibrium between the heat absorption side and heat release side of the heat pump 2 is maintained. Even if there is a difference between the amount of heat absorbed in the cooling section 2a and the amount of heat released in the heating section 2b due to differences in the temperature of the raw gas (outside air) caused by seasonal changes, etc., the thermal equilibrium between the heat absorption side and heat release side of the heat pump 2 is optimally maintained by this switching means, and the operation of the heat pump 2 and the adsorption and desorption in the rotor can be stabilized.

In this way, the heat exchanger 2c allows the heat medium of the heat pump 2 to flow in and out, and exchanges heat between the heat medium of the heat pump 2 and the adsorbed gas 100a to cool the adsorbed gas 100a. This allows the thermal equilibrium between the heat absorption side and heat release side of the heat pump 2 to be maintained by diverting the adsorbed gas 100a within the system. Even if a difference in the temperature of the raw gas (outside air) due to seasonal changes or the like causes a difference in the amount of heat absorbed in the cooling section 2a and the amount of heat released in the heating section 2b, the thermal equilibrium between the heat absorption side and heat release side of the heat pump 2 is easily maintained, and the operation of the heat pump 2 and the adsorption and desorption in the rotor can be stabilized.

(2-2) Desorption Next, the condenser serving as the heating section 2b of the heat pump 2 heats the raw gas. For example, the air 100 can be used as the raw gas. In winter, the air temperature is low, so the air 100 serving as the raw gas is cooled to, for example, 15°C. The condenser heats the air 100 from 15°C in winter to about 40°C.

The second blower 5 serves as a forced draft blower to send out the raw gas toward the desorption zone B of the honeycomb rotor 1 by forced convection (for example, 300 m ³ /h).

The raw gas, heated to about 40°C and heading toward the adsorption zone A of the rotor, passes through the desorption zone B of the rotor, and carbon dioxide is desorbed from the amine absorbent in desorption zone B, just as in the summer, to obtain carbon dioxide-rich desorbed gas 100b (e.g., carbon dioxide concentration 800 to 1000 ppm), which is then smoothly supplied to the plant house 200 (vinyl house) by forced convection using the second blower 5.

In addition, since the first blower 4 and the second blower 5 are both provided for this desorbed gas 100b, the pressure on the desorption zone B side of the rotor is made higher than the pressure on the adsorption zone A side, so that the raw gas heading toward the adsorption zone A of the rotor does not mix with the desorbed gas 100b that has passed through the desorption zone B of the rotor (through gaps, etc.), and the concentration of carbon dioxide in the desorbed gas 100b can be maintained.

In this way, the gas concentration device according to this embodiment is capable of adsorbing and desorbing carbon dioxide contained in a predetermined raw gas, and is equipped with a honeycomb rotor 1 in which at least an adsorption zone A for adsorbing the carbon dioxide and a desorption zone B for desorbing the carbon dioxide are set, a cooling section 2a for cooling the raw gas introduced into the adsorption zone A of the honeycomb rotor 1, a heating section 2b for heating the raw gas introduced into the desorption zone B of the honeycomb rotor 1, a heat exchanger 2c for heating or cooling the adsorbed gas 100a that has passed through the adsorption zone A of the honeycomb rotor 1, and a heat pump 2 having an evaporator constituting the cooling section 2a and a condenser constituting the heating section 2b. Therefore, the heat equivalent to the difference between the amount of heat absorbed in the cooling section 2a and the amount of heat released in the heating section 2b is released by heating the adsorbed gas 100a in the heat exchanger 2c, or is absorbed by cooling the adsorbed gas 100a in the heat exchanger 2c. This allows the adsorption zone A inlet temperature to be lowered in the summer to supply high-concentration carbon dioxide, and the desorption zone B inlet temperature to be raised in the winter to supply high-concentration carbon dioxide. This allows a stable supply of high-concentration carbon dioxide all year round, and since the heat pump 2 is used instead of a heater, it can be operated with less energy than when a heater is used, and running costs can be reduced.

In a system using a desiccant rotor combined with a conventional heat pump 2, an evaporator or condenser is installed at the regeneration outlet to balance the heat quantity in order to supply gas from the adsorption outlet of the rotor, whereas the gas concentration device of this embodiment has a heat exchanger 2c installed at the adsorption outlet to balance the heat quantity in order to supply gas from the regeneration outlet of the rotor to external cultivated plants, etc. This difference in configuration makes it possible to make the device more compact than a system using a desiccant rotor combined with a conventional heat pump 2.

Second Embodiment
The gas concentration device of the second embodiment, like the first embodiment, comprises the honeycomb rotor 1, the cooling section 2a, the heating section 2b, the heat exchanger 2c, the heat pump 2, the first blower 4, and the second blower 5, and further comprises a third blower 6 that attracts the adsorbed gas 100a from the heat exchanger 2c and discharges it to the outside, as shown in Figures 5 and 6, and this third blower 6 further introduces an external gas (e.g., the atmosphere 100) into the heat exchanger 2c by attraction, and discharges this external gas (e.g., the atmosphere 100) that has passed through the heat exchanger 2c to the outside together with the adsorbed gas 100a.

The third blower 6 draws the adsorbed gas 100a by forced convection (e.g., 300 ^m3 /h) and discharges it to the outside. When drawing the adsorbed gas 100a and discharging it to the outside, the third blower 6 takes in an external gas (e.g., air 100) into the adsorbed gas 100a and sends it to the heat exchanger 2c, as shown in Fig. 7.

In this way, the gas concentration device according to this embodiment is equipped with a third blower 6 that attracts the adsorbed gas 100a from the heat exchanger 2c and discharges it to the outside. This third blower 6 further introduces external gas into the heat exchanger 2c by attraction, and discharges the external gas that has passed through the heat exchanger 2c together with the adsorbed gas 100a to the outside. This means that there is another object for heat exchange with the heat medium of the heat pump 2 in addition to the adsorbed gas 100a that has left the adsorption zone A of the rotor. This ensures that heat is dissipated in the heat exchanger 2c, especially in the summer when the outside air temperature is high, and the heat exchanger 2c can handle the increased amount of heat dissipation with ease. This maintains constant heating in the heating section 2b of the heat pump 2, making desorption in the rotor stable.

Third Embodiment
The gas concentration device of the third embodiment, like the second embodiment, comprises the honeycomb rotor 1, the cooling section 2a, the heating section 2b, the heat exchanger 2c, the heat pump 2, the first blower 4, the second blower 5, and the third blower 6, and further comprises another heat exchanger 7 that cools the desorbed gas 100b that has passed through the desorption zone B of the honeycomb rotor 1 by heat exchange with the heat medium of the heat pump 2, as shown in Figures 8 and 9, and is configured so that the heat medium flow path of the heat pump 2 leading to this other heat exchanger 7 is connected in series or parallel to the cooling section 2a, or in series or parallel to the heating section 2b.

The other heat exchanger 7 can be connected in series or in parallel with the cooling section 2a of the heat pump 2. It can also be connected in series or in parallel with the heating section 2b of the heat pump 2.

Whether this other heat exchanger 7 is connected to the cooling section 2a or the heating section 2b can be controlled using valves 3e, 3f, 3g, and 3h of the control means 3, as shown in Figures 8 and 9. This other heat exchanger 7 makes it possible to extract a portion of the heat medium of the heat pump 2 and perform further heat exchange (heating or cooling) on the desorbed gas 100b that has passed through the desorption zone B of the honeycomb rotor 1.

For example, as shown in FIG. 8, in summer, the desorbed gas 100b is heated by the outside air, so the other heat exchanger 7 can be connected in series or parallel to the cooling section 2a of the heat pump 2 by the control means 3 to function as an aftercooler that cools the desorbed gas 100b. In this case, as shown in FIG. 8, in order to make the other heat exchanger 7 function optimally as an aftercooler, an expansion valve 21c may be added to cool the heat medium from the heat pump 2 just before the other heat exchanger 7.

Also, for example, as shown in FIG. 9, in winter, the temperature of the desorbed gas 100b is lowered by the outside air, so the other heat exchanger 7 can be connected in series or parallel to the heating section 2b of the heat pump 2 by the control means 3 to function as an after-heater that heats the desorbed gas 100b.

In this way, the gas concentration device according to this embodiment functions as a so-called aftercooler or afterheater, in which the other heat exchanger 7 heats or cools the desorbed gas 100b, and can prevent the high-temperature desorbed gas 100b from being supplied to the external plant house 200 (vinyl greenhouse) at a high temperature in the summer, and can prevent the low-temperature desorbed gas 100b from being supplied to the external plant house 200 (vinyl greenhouse) at a low temperature in the winter, making it possible to provide the desorbed gas 100b to the outside at a temperature suitable for cultivation all year round.

In addition, with regard to the gas concentration device according to each of the above embodiments, the second blower 5, which serves as a forced draft blower and sends the raw gas toward the desorption zone B of the honeycomb rotor 1, may be provided with a heating device that preliminarily heats the raw gas sent toward the desorption zone B of the honeycomb rotor 1. This makes it possible to more reliably send the raw gas at a high temperature toward the desorption zone B of the honeycomb rotor 1, and promotes the desorption of carbon dioxide in the desorption zone B.

The following examples are provided to more specifically illustrate the features of this embodiment, but the present embodiment is not limited to these examples.

(Example)
A gas concentrating device according to the first embodiment has been constructed. The main components are described below.
Heat pump: A coil (heat exchanger 2c) was installed at the adsorption outlet to balance the heat.
Rotor: Amine-based absorbent-supporting honeycomb rotor 1
〇 Components: Main unit (2 blowers + 1 honeycomb rotor), 2 heat pumps (coil, compressor)
Operating method: The mode was changed to winter, mid-season, or summer depending on the outside temperature.

An evaporator was installed at the adsorption inlet to lower the outside air temperature, and a condenser was installed at the regeneration inlet (desorption zone B inlet) to raise the temperature, thereby adsorbing and desorbing carbon dioxide. Unlike a normal combination of a desiccant rotor and heat pump, a coil (heat exchanger) for balancing the heat quantity was installed at the adsorption zone A outlet to supply gas at the regeneration outlet (desorption zone B outlet), making it possible to switch between the evaporator and condenser. Furthermore, since the energy required for heating and cooling by heat pump 2 differs between summer and winter (summer = approximately 6 kW, winter = 2 to 3 kW), by making the compressor an inverter specification, it became possible to achieve energy savings even in winter, as shown in the results below.

During testing at an outside air temperature of 27°C and a _CO2 concentration of 445 ppm, energy savings were achieved as follows:
Without heat pump: Supply _CO2 concentration = 588 ppm, power 2.1 kW, running cost = 209 yen/kg ( _CO2 )
With heat pump: Supply _CO2 concentration = 653 ppm, power 1.4 kW, running cost = 122 yen/kg ( _CO2 )
As the outside temperature rises in summer, the supplied _CO2 concentration is expected to decrease further without a heat pump.

1 Honeycomb rotor 1a First cross section 1b Second cross section 2 Heat pump 21a Expansion valve 21b Expansion valve 21c Expansion valve 22 Compressor 2a Cooling section 2b Heating section 2c Heat exchanger 3 Switching means 3a Valve 3b Valve 3c Valve 3d Valve 3e Valve 3f Valve 3g Valve 3h Valve 4 First blower 5 Second blower 6 Third blower 7 Other heat exchanger 100 Atmosphere 100a Adsorbed gas 100b Desorbed gas 200 Plant house A Adsorption zone B Desorption zone

Claims (7)

a honeycomb rotor capable of adsorbing and desorbing carbon dioxide contained in a predetermined raw material gas, in which at least an adsorption zone for adsorbing the carbon dioxide and a desorption zone for desorbing the carbon dioxide are set;
a cooling section for cooling the raw material gas introduced into the adsorption zone of the honeycomb rotor;
a heating section for heating the raw material gas introduced into the desorption zone of the honeycomb rotor;
a heat exchanger for heating or cooling the adsorbed gas that has passed through the adsorption zone of the honeycomb rotor;
a heat pump having an evaporator that constitutes the cooling unit and a condenser that constitutes the heating unit ,
The heat exchanger is configured to allow the heat medium of the heat pump to flow in and out, and exchanges heat between the heat medium of the heat pump and the adsorbed gas;
When the amount of heat dissipated in the heating unit is greater than the amount of heat absorbed in the cooling unit, the heat exchanger is connected in parallel with the cooling unit as another evaporator of the heat pump,
A gas concentrating device comprising one or more switching means for switching a heat medium flow path of the heat pump leading to the heat exchanger so that the heat exchanger is connected in parallel to the heating unit as another condenser of the heat pump when the amount of heat dissipated in the heating unit is smaller than the amount of heat absorbed in the cooling unit . 2. The gas concentrating device according to claim 1 ,
a first blower disposed between the adsorption zone of the honeycomb rotor and the heat exchanger, for drawing the adsorbed gas and sending it to the heat exchanger;
and a second blower serving as a forced draft blower for blowing the raw gas toward the desorption zone of the honeycomb rotor. 3. The gas concentrating apparatus according to claim 2 ,
a second blower disposed between the desorption zone of the honeycomb rotor and a condenser of the heat pump, and sends the raw gas that has passed through the condenser to the desorption zone. In the gas concentration device according to any one of claims 1 to 3 ,
a third blower that draws the adsorbed gas from the heat exchanger and discharges it to the outside;
The third blower further introduces external gas into the heat exchanger by induction, and discharges the external gas that has passed through the heat exchanger to the outside together with the adsorbed gas. In the gas concentration device according to any one of claims 1 to 4 ,
a heat pump that heats or cools the desorbed gas that has passed through the desorption zone of the honeycomb rotor by heat exchange with the heat medium of the heat pump;
a heat medium flow path of the heat pump leading to the other heat exchanger is connected in series or parallel to the cooling unit, or in series or parallel to the heating unit. In the gas concentration device according to any one of claims 1 to 5 ,
A gas concentrating device comprising an amine-based absorbent supported on a rotor body of the honeycomb rotor and capable of adsorbing and desorbing carbon dioxide. In the gas concentration device according to any one of claims 1 to 5 ,
a moisture absorber supported on a rotor body portion of the honeycomb rotor;
A gas concentrating device comprising: an amine-based absorbent supported on the moisture absorbent and capable of adsorbing and desorbing carbon dioxide.

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