Carbon Dioxide Capture System

Abstract

To provide a carbon dioxide recovery system that can be improved in recovery efficiency of carbon dioxide.SOLUTION: A carbon dioxide recovery system is provided, comprising: a supply passage; carbon dioxide adsorption unit; lead-out passage; carbon dioxide separator; recovery passage; circulation passage; and regeneration passage. The carbon dioxide adsorption unit has a processing area in which carbon dioxide is adsorbed to an adsorbent, and a regeneration area in which the adsorbent is regenerated. The carbon dioxide separator acquires fluid for regeneration with carbon dioxide concentration lowered, from a discharge fluid for regeneration. The recovery passage recovers separated carbon dioxide. The circulation passage is connected to the regeneration area and the carbon dioxide separator, and leads the discharge fluid for regeneration to the carbon dioxide separator. The regenerating passage leads the fluid for regeneration with the carbon dioxide concentration lowered from the carbon dioxide separator to the regeneration area. The carbon dioxide recovery system circulates the fluid for regeneration through the circulation passage and the regenerating passage to recover the carbon dioxide included in air.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to carbon dioxide capture systems. [Background technology]

[0002] Patent Document 1 discloses a direct air capture (DAC) technology that captures carbon dioxide from the air. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-169079 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above techniques may result in low carbon dioxide capture efficiency.

[0005] In view of the above circumstances, an object of the present disclosure is to provide a carbon dioxide capture system that can improve the efficiency of carbon dioxide capture. [Means for solving the problem]

[0006] One aspect of the carbon dioxide capture system according to the present disclosure comprises a supply path for leading air, a carbon dioxide adsorption section having a treatment area for adsorbing carbon dioxide contained in the air onto an adsorbent, and a regeneration area for regenerating the adsorbent using a regenerating fluid, an outlet path for leading the air whose carbon dioxide concentration has been reduced by the treatment area, a regeneration path for leading the regenerating fluid to the regeneration area, a circulation path for leading a regeneration discharge fluid discharged by regenerating the adsorbent with the regenerating fluid, and a carbon dioxide separator for obtaining the regenerating fluid by separating at least a portion of the carbon dioxide from the regeneration discharge fluid. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a carbon dioxide capture system capable of increasing the efficiency of carbon dioxide capture. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a carbon dioxide capture system according to a first embodiment. [Diagram 2] FIG. 11 is a schematic diagram of a portion of a carbon dioxide capture system according to a second embodiment. [Diagram 3] FIG. 11 is a schematic diagram of a portion of a carbon dioxide capture system according to a third embodiment. [Figure 4] FIG. 11 is a schematic diagram of a carbon dioxide capture system according to a fourth embodiment. [Diagram 5] FIG. 11 is a schematic diagram of a carbon dioxide capture system according to a fifth embodiment. [Figure 6] FIG. 13 is a schematic diagram of a carbon dioxide capture system according to a sixth embodiment. [Figure 7] FIG. 13 is a schematic diagram of a carbon dioxide capture system according to a seventh embodiment. [Figure 8] FIG. 13 is a schematic diagram of a carbon dioxide capture system according to an eighth embodiment. [Figure 9] FIG. 13 is a schematic diagram of a carbon dioxide capture system according to a ninth embodiment. [Figure 10] FIG. 23 is a schematic diagram of a carbon dioxide capture system according to a tenth embodiment. [Figure 11] FIG. 23 is a schematic diagram of a carbon dioxide capture system according to an eleventh embodiment. [Figure 12] FIG. 23 is a schematic diagram of a carbon dioxide capture system according to a twelfth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the scope of the present disclosure is not limited to the following embodiments, and may be modified as desired within the scope of the technical concept of the present disclosure.

[0010] Embodiment 1 FIG. 1 is a schematic diagram showing a carbon dioxide capture system in the first embodiment. As shown in FIG. 1, the carbon dioxide capture system 1 includes a supply path 2, a carbon dioxide adsorption section 3, an extraction path 4, a regeneration path 5, a circulation path 6, a carbon dioxide separator 7, a heat pump unit (heat exchange unit) 8, an introduction path 9, a compressor 10, and a pressure reducer 11.

[0011] The supply path 2 is connected to the treatment area 31 of the carbon dioxide adsorption unit 3. The supply path 2 guides air (fluid to be treated) such as outside air to the treatment area 31. The supply path 2 is provided with, for example, a blower 21 for sending air to the treatment area 31.

[0012] The carbon dioxide adsorption section 3 includes a first region 31A and a second region 32A. In the example shown in Fig. 1, the first region 31A is a treatment region 31. The second region 32A is a regeneration region 32. The treatment region 31 includes, for example, an adsorbent and a container that accommodates the adsorbent. The regeneration region 32 includes, for example, an adsorbent to be regenerated and a container that accommodates the adsorbent.

[0013] Examples of the adsorbent include amine, silica gel, zeolite, activated carbon, diatomaceous earth, and alumina. Specifically, carbon dioxide contained in the air can be separated from other components by being adsorbed by the adsorbent. The adsorbent may be in a granular or powdered form. The granular form may be, for example, a bead (spherical) or pellet (cylindrical) form. When a powdered adsorbent is used, the adsorbent may be supported on the surface of a substrate. The substrate may be in a honeycomb shape.

[0014] In the treatment region 31, at least a portion of the carbon dioxide contained in the air is removed by adsorption, so that air with a reduced concentration of carbon dioxide is obtained.

[0015] The regeneration area 32 regenerates the adsorbent that has adsorbed carbon dioxide in the treatment area 31, using a regenerating fluid F1. The regeneration area 32 has a function of desorbing carbon dioxide from the adsorbent. The regeneration area 32 is equipped, for example, with a heating device that heats the adsorbent. The heating device desorbs carbon dioxide from the adsorbent by heating the adsorbent in the presence of the regenerating fluid F1. The adsorbent is regenerated by the desorption of carbon dioxide. The regenerating fluid F1 containing the carbon dioxide desorbed from the adsorbent is discharged from the regeneration area 32 as a "regeneration discharge fluid F2".

[0016] The regeneration zone 32 may include a pressure reducing device, such as a vacuum pump, that subjects the adsorbent to reduced pressure to facilitate desorption of carbon dioxide from the adsorbent.

[0017] The outlet path 4 is connected to the treatment area 31. The outlet path 4 supplies the air, the concentration of carbon dioxide of which has been reduced by the treatment area 31, to the living space (supply receiving space) 100.

[0018] The regeneration path 5 is connected to the regeneration region 32 of the carbon dioxide adsorption section 3 and the carbon dioxide separator 7. The regeneration path 5 guides the regeneration fluid F1 from the carbon dioxide separator 7 to the regeneration region 32. The regeneration fluid F1 may be, for example, nitrogen (N 2 ), hydrogen (H 2 ), methane, etc.

[0019] The circulation path 6 is connected to the regeneration region 32 of the carbon dioxide adsorption section 3 and the carbon dioxide separator . The circulation path 6 guides the regeneration discharge fluid F2 discharged from the regeneration region 32 to the carbon dioxide separator .

[0020] The carbon dioxide separator 7 separates at least a portion of the carbon dioxide contained in the regeneration discharge fluid F2 using a separation method such as liquefaction separation, membrane separation, adsorption separation, etc. The carbon dioxide separator 7 may employ one of these separation methods or a combination of two or more of them.

[0021] The carbon dioxide separator 7 using liquefaction separation liquefies a specific component and separates it from other components (gases), for example. Specifically, for example, carbon dioxide is liquefied under high pressure and low temperature conditions and separated from other components (gases).

[0022] The carbon dioxide separator 7 using membrane separation separates a specific component from other components, for example, by using a separation membrane that allows components with small molecular sizes to permeate. Specifically, for example, a separation membrane that selectively allows carbon dioxide to permeate is used. This separation membrane separates carbon dioxide from a mixed fluid that contains carbon dioxide and other components (nitrogen, hydrogen, methane, etc.). Examples of separation membranes include organic membranes (dendrimer membranes, etc.) and inorganic membranes (zeolite membranes, silica membranes, carbon membranes, etc.).

[0023] The carbon dioxide separator 7 using adsorption separation separates specific components by, for example, adsorbing them onto an adsorbent. Examples of the adsorbent include amines, silica gel, zeolite, activated carbon, diatomaceous earth, and alumina. Specifically, for example, carbon dioxide can be separated from other components by adsorbing it onto the adsorbent.

[0024] The regeneration discharge fluid F2, in which the concentration of carbon dioxide has been reduced by the separation of carbon dioxide, is discharged from the carbon dioxide separator 7 through the regeneration path 5 as a "regeneration fluid F1".

[0025] The heat pump unit 8 includes a heater (first heat exchanger) 81, an expander 82, a cooler (second heat exchanger) 83, a compressor 84, and a circulation path 85. The heater 81 heats the regenerating fluid F1 by heat exchange with the heat transfer fluid F3. The expander 82 reduces the pressure of the heat transfer fluid F3. The cooler 83 cools the regeneration discharge fluid F2 by heat exchange with the heat transfer fluid F3. The compressor 84 increases the pressure of the heat transfer fluid F3. The heater 81 , the expander 82 , the cooler 83 and the compressor 84 are provided in a circulation path 85 .

[0026] The circulation path 85 is a looped path. The circulation path 85 circulates a heat transfer medium fluid F3. The heat transfer medium fluid F3 circulates so as to pass through a heater 81, an expander 82, a cooler 83, and a compressor 84 in this order. Examples of the heat transfer medium fluid F3 include carbon dioxide, a fluorocarbon alternative, propane, and dimethyl ether. When carbon dioxide is used as the heat transfer fluid F3, an appropriate heating temperature (e.g., 90°C to 120°C) by the heater 81 and an appropriate cooling temperature (e.g., -30°C to -20°C) by the cooler 83 can be achieved by applying an existing heat pump unit 8.

[0027] The heat pump unit 8 may, for example, constitute an air conditioner. The air conditioner performs at least one of cooling and heating by utilizing heat absorption or heat release of the heat medium fluid F3. The heater 81 is, for example, installed in one of the indoor unit and the outdoor unit. The cooler 83 is, for example, installed in the other of the indoor unit and the outdoor unit.

[0028] The heat pump unit 8 may constitute, for example, a refrigerator / freezer device. The refrigerator / freezer device performs cooling by a cooler 83, utilizing the heat absorption of the heat transfer medium fluid F3.

[0029] The introduction path 9 is connected to the supply path 2. The introduction path 9 introduces the indoor air discharged from the living space 100 into the supply path 2. The compressor 10 is provided in the circulation path 6. The compressor 10 increases the pressure of the regeneration discharge fluid F2. The pressure reducer 11 is provided in the regeneration path 5. The pressure reducer 11 reduces the pressure of the regeneration fluid F1. A cooler may be provided downstream of the compressor 10 in order to lower the temperature of the regeneration discharge fluid F2 that has become hot due to the pressure increase by the compressor 10.

[0030] Next, an example of a carbon dioxide capture method using the carbon dioxide capture system 1 will be described. Air such as outside air is guided to treatment area 31 of carbon dioxide adsorption unit 3 via supply path 2. In treatment area 31, the carbon dioxide contained in the air is adsorbed by an adsorbent, thereby removing at least a portion of the carbon dioxide. The air with a reduced carbon dioxide concentration is supplied to living space (supply-receiving space) 100 via outlet path 4. The process of removing at least a portion of the carbon dioxide by adsorption in the treatment area 31 is referred to as the "adsorption process."

[0031] The adsorbent that has adsorbed carbon dioxide in the treatment region 31 is regenerated in the regeneration region 32. More specifically, in the regeneration region 32, carbon dioxide is desorbed from the adsorbent in the presence of a regenerating fluid F1. The adsorbent is regenerated by the desorption of carbon dioxide. The regenerating fluid F1 containing the carbon dioxide desorbed from the adsorbent is discharged from the regeneration region 32 as a "regeneration discharge fluid F2." The process of regenerating the adsorbent in the regeneration zone 32 is referred to as the "regeneration process."

[0032] The switching between the treatment region and the regeneration region in the carbon dioxide adsorption section 3 will now be described. When the adsorbent that has adsorbed carbon dioxide in the treatment area 31 is regenerated in the regeneration area 32, the adsorbent can be switched between the treatment area 31 and the regeneration area 32. For example, the adsorbent in the treatment area 31 is moved together with its container to the regeneration area 32, and the adsorbent regenerated in the regeneration area 32 is moved together with its container to the treatment area 31. In this manner, the treatment area and the regeneration area can be switched.

[0033] The adsorbent can also be replaced by removing the adsorbent in the treatment area 31 from its container and moving it to the regeneration area 32, and at the same time removing the adsorbent regenerated in the regeneration area 32 from its container and moving it to the treatment area 31.

[0034] The treatment area and the regeneration area can also be switched by changing the path. In Fig. 1, the first area 31A (the left part in Fig. 1) of the carbon dioxide adsorption section 3 is the treatment area 31. The supply path 2 and the discharge path 4 are connected to the first area 31A. The second area 32A (the right part in Fig. 1) is the regeneration area 32. The regeneration path 5 and the circulation path 6 are connected to the second area 32A.

[0035] By operating a valve provided in a branch path (not shown), the supply path 2 and the discharge path 4 are connected to the second region 32A. The regeneration path 5 and the circulation path 6 are connected to the first region 31A. By this operation, the first region 31A becomes a regeneration region. The second region 32A becomes a processing region. In this manner, it is possible to switch between the processing region and the regeneration region. By operating a valve, the first region 31A can also be returned to the processing region. The second region 32A can also be returned to the regeneration region.

[0036] The regeneration discharge fluid F2 is discharged from the regeneration region 32 through the circulation path 6. The pressure of the regeneration discharge fluid F2 is increased by the compressor 10. The regeneration discharge fluid F2 is cooled by heat exchange with the heat transfer fluid F3 in the cooler 83. The cooler 83 can cool the regeneration discharge fluid F2, for example, until the temperature of the regeneration discharge fluid F2 in the carbon dioxide separator 7 corresponds to the specifications of the carbon dioxide separator 7, which will be described later. The regeneration exhaust fluid F2 is led to the carbon dioxide separator 7.

[0037] The carbon dioxide separator 7 separates at least a portion of the carbon dioxide contained in the regeneration discharge fluid F2 using a separation method such as liquefaction separation, membrane separation, adsorption separation, etc. The concentrated carbon dioxide is recovered through a recovery line 71.

[0038] The regeneration discharge fluid F2, in which the concentration of carbon dioxide has been reduced by the separation of carbon dioxide, is discharged from the carbon dioxide separator 7 through the regeneration path 5 as a "regeneration fluid F1".

[0039] The regenerating fluid F1 is heated in the heater 81 by heat exchange with the heat transfer fluid F3. The heater 81 can heat the regenerating fluid F1 so that the temperature of the regenerating fluid F1 in the regenerating region 32 is 90°C to 120°C, for example. The regenerating fluid F1 is depressurized in the depressurizer 11 as necessary. The regenerating fluid F1 is introduced into the regenerating region 32 through the regenerating path 5.

[0040] In the heat pump unit 8, the heat transfer fluid F3 circulates through the circulation path 85. The heat transfer fluid F3 is cooled in the heater 81 by heat exchange with the regenerating fluid F1. The heat transfer fluid F3 is depressurized in the expander 82. The heat transfer fluid F3 is heated in the cooler 83 by heat exchange with the regenerating discharge fluid F2. The heat transfer fluid F3 is increased in pressure by the compressor 84 and then directed to the heater 81. In this way, the heat transfer fluid F3 heats the regenerating fluid F1 and cools the regenerating discharge fluid F2.

[0041] The carbon dioxide capture system 1 includes a circulation path 6 that guides the regeneration discharge fluid F2 from the regeneration region 32, and a carbon dioxide separator 7 that generates a regeneration fluid F1 having a low carbon dioxide concentration from the regeneration discharge fluid F2. The carbon dioxide capture system 1 circulates the regeneration fluid F1, thereby making it possible to increase the carbon dioxide capture efficiency in the carbon dioxide separator 7.

[0042] The carbon dioxide recovery system 1 circulates and uses the regenerating fluid F1 and the regenerating discharge fluid F2, so that the thermal energy of the regenerating fluid F1 and the regenerating discharge fluid F2 can be effectively utilized, thereby improving the energy efficiency of the entire system. The carbon dioxide capture system 1 captures carbon dioxide from the air by the carbon dioxide adsorption section 3 and guides the regeneration discharge fluid F2 containing carbon dioxide to the carbon dioxide separator 7, thereby making it possible to increase the efficiency of carbon dioxide capture.

[0043] The carbon dioxide capture system 1 includes a compressor 10, a heater 81, and a cooler 83. The heater 81 heats the regenerating fluid F1 to adjust the temperature in the regeneration region 32 to an appropriate level, thereby enabling efficient regeneration of the adsorbent. The compressor 10 increases the pressure of the regeneration discharge fluid F2 to efficiently separate carbon dioxide in the carbon dioxide separator 7. The cooler 83 cools the regeneration discharge fluid F2 to adjust the temperature in the carbon dioxide separator 7 to an appropriate level, thereby enabling efficient separation of carbon dioxide. In the carbon dioxide capture system 1, the compressor 10 and the cooler 83 can reduce the volume of the regeneration discharge fluid F2, so that the size of the device can be reduced.

[0044] The heater 81 heats the regenerating fluid F1 by heat exchange with the heat transfer fluid F3. The cooler 83 cools the regenerating discharge fluid F2 by heat exchange with the heat transfer fluid F3. The carbon dioxide recovery system 1 exchanges heat with the regenerating fluid F1 and the regenerating discharge fluid F2 via the common heat transfer fluid F3, thereby improving energy efficiency.

[0045] The carbon dioxide separator 7 using liquefaction separation can efficiently separate carbon dioxide. The carbon dioxide separator 7 using liquefaction separation can reduce the volume of carbon dioxide by liquefaction, so the device can be made smaller. The carbon dioxide separator 7 using membrane separation can efficiently separate carbon dioxide. The carbon dioxide separator 7 using membrane separation has fewer restrictions on pressure, temperature, etc. compared to cases where other separation methods are adopted. Therefore, the energy required for pressurization, cooling, etc. can be reduced. Therefore, carbon dioxide can be captured at low cost.

[0046] When carbon dioxide is used as the heat transfer fluid F3, an appropriate heating temperature (e.g., 90°C to 120°C) by the heater 81 and an appropriate cooling temperature (e.g., -30°C to -20°C) by the cooler 83 can be achieved by applying an existing heat pump unit 8. Therefore, the carbon dioxide recovery system 1 can be constructed at low cost.

[0047] At least the heater 81 and the cooler 83 may constitute an air conditioner. In that case, the carbon dioxide capture system 1 can be constructed using the heater 81 and the cooler 83 of the air conditioner, so that costs can be reduced compared to the case where a dedicated heater and cooler are used. At least the heater 81 and the cooler 83 may constitute a freezer-refrigerator device. In that case, the carbon dioxide capture system 1 can be constructed using the heater 81 and the cooler 83 of the freezer-refrigerator device, so that costs can be reduced compared to the case where a dedicated heater and cooler are used. Heater 81 and cooler 83 may constitute both an air conditioner and a freezer-refrigerator device.

[0048] Embodiment 2 Next, a carbon dioxide capture system according to embodiment 2 will be described. Since the carbon dioxide capture system according to this embodiment has a common configuration with embodiment 1, differences from embodiment 1 will be mainly described. The same components as those in embodiment 1 will be denoted by the same reference numerals and will not be described.

[0049] FIG. 2 is a schematic diagram of a part of a carbon dioxide capture system according to the second embodiment. As shown in FIG. 2, the carbon dioxide recovery system 101 includes a heat pump unit 108 instead of the heat pump unit 8 (see FIG. 1). The heat pump unit 108 differs from the heat pump unit 8 (see FIG. 1) in that it includes a plurality of compressors 184A and 184B instead of the compressor 84 (see FIG. 1). The compressors 184A and 184B are provided in a circulation path 85. The compressor 184A is a first compressor 184A. The compressor 184B is a second compressor 184B. The second compressor 184B is downstream of the first compressor 184A in the flow direction of the heat medium fluid F3. The first compressor 184A and the second compressor 184B are arranged in series in the circulation path 85.

[0050] In the carbon dioxide capture system 101, the heat pump unit 108 includes a plurality of compressors 184A, 184B, so that the pressure of the heat medium fluid F3 can be increased. This allows the operating range of heating and cooling in the heat pump unit 108 to be expanded. This improves the performance of the carbon dioxide capture system, and allows carbon dioxide to be captured efficiently.

[0051] 2, the heat pump unit 108 has two compressors, but the number of compressors is not limited to two. The number of compressors may be more than one (any number equal to or greater than two).

[0052] Embodiment 3 Next, a description will be given of a carbon dioxide capture system according to embodiment 3. Configurations that are the same as those in other embodiments will be given the same reference numerals and descriptions thereof will be omitted.

[0053] FIG. 3 is a schematic diagram of a part of a carbon dioxide capture system according to the third embodiment. As shown in FIG. 3, the carbon dioxide capture system 201 includes a heat pump unit 208 instead of the heat pump unit 8 (see FIG. 1). The heat pump unit 208 includes a heater (first heat exchanger) 281, a first expander 282, an intermediate heat exchanger 287, a first compressor 284, a first circulation path 285, a second expander 288, a cooler (second heat exchanger) 283, a second compressor 289, and a second circulation path 290.

[0054] The heater 281 heats the regenerating fluid F1 by heat exchange with the first heat transfer fluid F3A. The first expander 282 reduces the pressure of the first heat transfer fluid F3A. The intermediate heat exchanger 287 cools the second heat transfer fluid F3B by heat exchange with the first heat transfer fluid F3A. The first compressor 284 increases the pressure of the first heat transfer fluid F3A. The heater 281 , the first expander 282 , the intermediate heat exchanger 287 and the first compressor 284 are provided on a first circulation path 285 . The first circulation path 285 is a looped path. The first circulation path 285 circulates the first heat medium fluid F3A through the heater 281, the first expander 282, the intermediate heat exchanger 287, and the first compressor 284 in this order.

[0055] The second expander 288 reduces the pressure of the second heat transfer fluid F3B. The cooler 283 cools the regeneration discharge fluid F2 by heat exchange with the second heat transfer fluid F3B. The second compressor 289 increases the pressure of the second heat transfer fluid F3B. The intermediate heat exchanger 287 , the second expander 288 , the cooler 283 and the second compressor 289 are provided on a second circulation path 290 . The second circulation path 290 is a looped path. The second circulation path 290 circulates the second heat medium fluid F3B through the intermediate heat exchanger 287, the second expander 288, the cooler 283, and the second compressor 289 in this order.

[0056] The first heat medium fluid F3A and the second heat medium fluid F3B have different physical properties such as boiling points. An example of the first heat medium fluid F3A is carbon dioxide. An example of the second heat medium fluid F3B is a fluorocarbon alternative. The second heat medium fluid F3B is operated at a lower temperature than the first heat medium fluid F3A.

[0057] Of the heat pump unit 208, a portion (first portion) through which the first heat medium fluid F3A flows can be constructed, for example, by utilizing a heat pump for a water heater. The first portion includes, for example, a heater 281, a first expander 282, a first compressor 284, and a first circulation path 285. Of the heat pump unit 208, a portion (second portion) through which the second heat medium fluid F3B flows can be constructed, for example, by utilizing a heat pump for refrigeration and freezing. The second portion includes, for example, a second expander 288, a cooler 283, a second compressor 289, and a second circulation path 290. The intermediate heat exchanger 287 is included in one of the first and second sections.

[0058] The carbon dioxide recovery system 201 includes a heat pump unit 208 having a heater 281, an intermediate heat exchanger 287, and a cooler 283. In the heat pump unit 208, the first heat medium fluid F3A and the second heat medium fluid F3B are used, so that the operating range of heating and cooling can be expanded. Therefore, the performance of the carbon dioxide recovery system can be improved, and carbon dioxide can be efficiently recovered.

[0059] Embodiment 4 Next, a description will be given of a carbon dioxide capture system according to embodiment 4. Configurations that are the same as those in other embodiments will be given the same reference numerals and descriptions thereof will be omitted.

[0060] FIG. 4 is a schematic diagram of a carbon dioxide capture system according to the fourth embodiment. As shown in FIG. 4, the carbon dioxide capture system 301 differs from the carbon dioxide capture system 1 (see FIG. 1) in that an air purifier 312 is provided in the introduction path 9.

[0061] The air purifier 312 purifies the air by collecting suspended matter such as pollen, dust, viruses, mold, bacteria, house dust, smoke, odorous substances, and volatile chemicals. The air purifier 312 includes, for example, a filter that collects suspended matter. The air purifier 312 may include an electric field generating device that generates an electric field between electrodes. The electric field generating device can kill or inactivate pollen, viruses, mold, bacteria, and the like.

[0062] Since the carbon dioxide capture system 301 includes the air purifier 312, it can purify the indoor air discharged from the living space 100 and introduce it into the supply path 2. This can increase the cleanliness of the air supplied to the living space 100. Since the carbon dioxide capture system 301 supplies clean air to the carbon dioxide adsorption section 3, it can increase the efficiency of carbon dioxide capture in the carbon dioxide adsorption section 3.

[0063] Embodiment 5. Next, a carbon dioxide capture system according to embodiment 5 will be described. The same components as those in the other embodiments will be given the same reference numerals and the description will be omitted.

[0064] FIG. 5 is a schematic diagram of a carbon dioxide capture system according to the fifth embodiment. As shown in Fig. 5, carbon dioxide capture system 401 differs from carbon dioxide capture system 1 (see Fig. 1) in that exhaust path 413 is connected to outlet path 4. Exhaust path 413 can exhaust part of the air flowing through outlet path 4 to the outside of the system. The gas exhausted from exhaust path 413 is released, for example, into the atmosphere.

[0065] The carbon dioxide capture system 401 can take in outside air from the supply path 2 by discharging a portion of the air flowing through the outlet path 4 from the exhaust path 413. By performing ventilation by discharging and taking in air, the cleanliness of the air in the living space 100 can be increased. The carbon dioxide capture system 401 can keep the amount of carbon dioxide emissions low because it discharges the gas after capturing carbon dioxide from the exhaust path 413 into the atmosphere. This makes it suitable for environmental conservation.

[0066] Embodiment 6 Next, a carbon dioxide capture system according to embodiment 6 will be described. Configurations that are the same as those in other embodiments will be given the same reference numerals and descriptions thereof will be omitted.

[0067] FIG. 6 is a schematic diagram of a carbon dioxide capture system according to the sixth embodiment. As shown in FIG. 6, carbon dioxide capture system 501 differs from carbon dioxide capture system 1 (see FIG. 1) in that an air purifier 312 is provided in inlet path 9, and that an exhaust path 413 is connected to outlet path 4.

[0068] Since the carbon dioxide capture system 501 includes the air purifier 312, clean air can be introduced into the supply path 2. Since the carbon dioxide capture system 501 includes the exhaust path 413, ventilation can be performed. This can increase the cleanliness of the air in the living space 100. Since the carbon dioxide capture system 501 exhausts the gas after capturing carbon dioxide from the exhaust path 413 into the atmosphere, it can keep the amount of carbon dioxide emissions low. This is therefore preferable in terms of environmental conservation.

[0069] Embodiment 7 Next, a carbon dioxide capture system according to an embodiment 7 will be described. The same components as those in the other embodiments will be given the same reference numerals and the description will be omitted.

[0070] FIG. 7 is a schematic diagram of a carbon dioxide capture system according to the seventh embodiment. 7, the carbon dioxide capture system 601 includes a carbon dioxide adsorption section 603 instead of the carbon dioxide adsorption section 3 (see FIG. 1). The carbon dioxide adsorption section 603 includes a first treatment area 31, a second treatment area 633, and a regeneration area 32. The first processing region 31 has a configuration similar to that of the processing region 31 (see FIG. 1). The second processing region 633 includes an adsorbent, similar to the first processing region 31. The adsorbent in the second processing region 633 may be the same as the adsorbent in the first processing region 31. The adsorbents in the first treatment region 31 and the second treatment region 633 can be regenerated by a regeneration process.

[0071] The second treatment area 633 is connected to the inlet path 9. The inlet path 9 guides the air discharged from the living space 100 to the second treatment area 633. The second treatment area 633 removes at least a portion of the carbon dioxide contained in the air by adsorption. The air with a reduced carbon dioxide concentration is discharged from the second treatment area 633 to the outside of the system through the exhaust path 634.

[0072] Since the carbon dioxide capture system 601 has the second treatment area 633, it is possible to capture carbon dioxide contained in the air discharged from the living space 100. Therefore, it is possible to increase the efficiency of capturing carbon dioxide. In the carbon dioxide capture system 601, the air discharged from the living space 100 is not reused, but is discharged to the outside of the system through the exhaust path 634. This reduces the risk of airborne and droplet infection of infectious diseases such as viruses. In addition, the cleanliness of the air in the living space 100 can be improved. The carbon dioxide capture system 601 discharges the gas after capturing carbon dioxide into the atmosphere through the exhaust path 413, so that the amount of carbon dioxide emissions can be kept low. This is therefore preferable in terms of environmental conservation.

[0073] Embodiment 8 Next, a carbon dioxide capture system according to an eighth embodiment will be described. The same components as those in the other embodiments will be given the same reference numerals and the description will be omitted.

[0074] FIG. 8 is a schematic diagram of a carbon dioxide capture system according to the eighth embodiment. As shown in Fig. 8, the carbon dioxide capture system 701 differs from the carbon dioxide capture system 601 (see Fig. 7) in that a heat exchanger 714 is provided. The heat exchanger 714 is provided across the outlet path 4 and the inlet path 9. The heat exchanger 714 exchanges heat and humidity between the air supplied to the living space 100 by the outlet path 4 and the air discharged from the living space 100 by the inlet path 9. The heat exchanger 714 can adjust the temperature and humidity of the air supplied to the living space 100 to suit the environment within the living space 100.

[0075] Since the carbon dioxide recovery system 701 includes the heat exchanger 714, the air supplied to the living space 100 through the outlet path 4 can be temperature-adjusted by heat exchange with the exhaust air, thereby optimizing the temperature and humidity. This can improve energy efficiency.

[0076] The carbon dioxide separator is preferably one or both of liquefaction separation and membrane separation. Below, configuration examples of the carbon dioxide capture system are shown for the cases where liquefaction separation is used, where membrane separation is used, and where both liquefaction separation and membrane separation are used.

[0077] Embodiment 9 A carbon dioxide capture system according to a ninth embodiment will be described. Configurations that are the same as those in the other embodiments will be given the same reference numerals and descriptions thereof will be omitted.

[0078] FIG. 9 is a schematic diagram of a carbon dioxide capture system according to a ninth embodiment. As shown in Fig. 9, in a carbon dioxide recovery system 801, a carbon dioxide separator 7 is a liquefaction separator that separates carbon dioxide by liquefaction separation. Since the carbon dioxide separator 7 is a liquefaction separator, high pressure and low temperature are required. The regeneration discharge fluid F2 is made high pressure by a compressor 10. The regeneration discharge fluid F2 is made low temperature by a cooler 83. The conditions for liquefying carbon dioxide are, for example, a temperature of -20 to -30°C and a pressure of 2 MPa.

[0079] The carbon dioxide capture system 801 includes a cooler 815. The cooler 815 is provided downstream of the compressor 10 in the circulation path 6. The cooler 815 is provided, for example, between the compressor 10 and the cooler 83. The cooler 815 is, for example, a water-cooled cooler. The cooler 815 cools the regenerated discharge fluid F2 by heat exchange with a refrigerant (water). The temperature of the regenerated discharge fluid F2 increases due to the pressure increase by the compressor 10, but the cooler 815 lowers the temperature of the regenerated discharge fluid F2. Therefore, the load on the cooler 83 can be reduced.

[0080] The carbon dioxide separator 7 liquefies and separates at least a portion of the carbon dioxide contained in the regeneration discharge fluid F2 that has passed through the cooler 83. The concentrated carbon dioxide is recovered through the recovery line 71.

[0081] The carbon dioxide capture system 801 employs liquefaction separation, and therefore can efficiently separate carbon dioxide. The carbon dioxide capture system 801 can reduce the volume of carbon dioxide through liquefaction, and therefore the device can be made smaller.

[0082] Although the above-mentioned cooler 815 is described as a water-cooled cooler, the cooling method of the cooler is not limited to this, and for example, cooling by circulating the regenerating fluid F1 may be adopted. As a result, the regenerating fluid F1 is heated, and a system with higher thermal efficiency is realized.

[0083] Embodiment 10 Next, a carbon dioxide capture system according to a tenth embodiment will be described. The same components as those in the other embodiments will be given the same reference numerals and the description will be omitted.

[0084] FIG. 10 is a schematic diagram of a carbon dioxide capture system according to the tenth embodiment. 10, in the carbon dioxide recovery system 901, the carbon dioxide separator 907 is a membrane separator that separates carbon dioxide by membrane separation. The carbon dioxide separator 907 is equipped with, for example, a separation membrane that selectively allows carbon dioxide to permeate. The carbon dioxide separator 907 separates at least a portion of the carbon dioxide contained in the regeneration discharge fluid F2 by membrane separation. The concentrated carbon dioxide is recovered through the recovery path 71.

[0085] The carbon dioxide capture system 901 employs membrane separation, so it can efficiently separate carbon dioxide. Compared to cases where other separation methods are employed, the carbon dioxide capture system 901 has fewer restrictions on pressure, temperature, etc. Since it is possible to reduce the energy required for pressurization, cooling, etc., it is possible to capture carbon dioxide at low cost.

[0086] Embodiment 11 Next, a description will be given of a carbon dioxide capture system according to an eleventh embodiment. The same components as those in the other embodiments will be given the same reference numerals and the description will be omitted.

[0087] FIG. 11 is a schematic diagram of a carbon dioxide capture system according to an eleventh embodiment. As shown in FIG. 11, a carbon dioxide capture system 1001 employs both liquefaction separation and membrane separation as carbon dioxide separation methods in a carbon dioxide separator.

[0088] The carbon dioxide capture system 1001 includes a supply path 2, a carbon dioxide adsorption section 3, an outlet path 4, a regeneration path 5, a circulation path 6, a heat pump unit 8, an introduction path 9, a first compressor 10, a first cooler 1015, a first carbon dioxide separator 1007, a return path 1002, a second compressor 1010, a second cooler 1016, a second carbon dioxide separator 7, and a pressure reducer 11. The first carbon dioxide separator 1007 and the second carbon dioxide separator 7 are examples of carbon dioxide separators.

[0089] The carbon dioxide capture system 1001 differs from the carbon dioxide capture system 1 (see FIG. 1) in that it includes a first cooler 1015, a first carbon dioxide separator 1007, a return path 1002, a second compressor 1010, and a second cooler 1016. The first cooler 1015 and the second cooler 1016 are, for example, water-cooled coolers. The first cooler 1015 and the second cooler 1016 cool the fluid by heat exchange with a refrigerant (water). The first carbon dioxide separator 1007 is a membrane separator. The first carbon dioxide separator 1007 has, for example, a separation membrane that selectively allows carbon dioxide to permeate. The second carbon dioxide separator 7 is a liquefaction separator.

[0090] The return line 1002 connects the non-permeation side outlet of the first carbon dioxide separator 1007 to the circulation line 6 (at a position upstream of the first compressor 10).

[0091] In the carbon dioxide recovery system 1001, the regeneration discharge fluid F2 is pressurized by the first compressor 10, cooled by the first cooler 1015, and guided to the first carbon dioxide separator 1007. The carbon dioxide contained in the regeneration discharge fluid F2 is concentrated by the first carbon dioxide separator 1007. The permeate side fluid F4 in which carbon dioxide has been concentrated flows to the second compressor 1010.

[0092] The non-permeated side fluid F5 that has not permeated the separation membrane of the first carbon dioxide separator 1007 is returned to the circulation path 6 (a position upstream of the first compressor 10) by the return path 1002. This makes it possible to improve the efficiency of carbon dioxide separation in the first carbon dioxide separator 1007.

[0093] The permeate side fluid F4 has its pressure increased by the second compressor 1010, and is then cooled by the second cooler 1016 and the cooler 83 and guided to the second carbon dioxide separator 7. The second carbon dioxide separator 7 liquefies and separates at least a portion of the carbon dioxide contained in the permeate side fluid F4. The concentrated carbon dioxide is recovered through the recovery line 71.

[0094] The carbon dioxide recovery system 1001 can increase the efficiency of carbon dioxide recovery by employing both liquefaction separation and membrane separation.

[0095] Here, the first cooler 1015 and the second cooler 1016 are described as being water-cooled, but are not limited thereto, and for example, cooling by circulating the regenerating fluid F1 may be adopted. This heats the regenerating fluid F1, thereby realizing a system with higher thermal efficiency.

[0096] Embodiment 12 Next, a description will be given of a carbon dioxide capture system according to embodiment 12. Configurations that are the same as those in other embodiments will be given the same reference numerals and descriptions thereof will be omitted.

[0097] FIG. 12 is a schematic diagram of a carbon dioxide capture system according to the twelfth embodiment. As shown in FIG. 12, the carbon dioxide capture system 1101 differs from the carbon dioxide capture system 1001 (see FIG. 11) in that it has a return path 1102 instead of the return path 1002 (see FIG. 11). The return line 1102 connects the non-permeated side outlet of the first carbon dioxide separator 1007 to the regeneration line 5 (at a position upstream of the heater 81). The non-permeated side fluid F5 discharged from the first carbon dioxide separator 1007 is guided to the regeneration line 5 by the return line 1102. The non-permeated side fluid F5 is used as a part of the regeneration fluid F1.

[0098] The carbon dioxide capture system 1101 can increase the carbon dioxide capture efficiency by employing both liquefaction separation and membrane separation. Since the carbon dioxide capture system 1101 performs membrane separation prior to liquefaction separation, it is possible to reduce the energy required for cooling for liquefaction separation. Therefore, carbon dioxide can be captured at low cost. In the carbon dioxide recovery system 1101, the non-permeated side fluid F5 with a reduced carbon dioxide concentration is used as the regenerating fluid F1, so that the energy efficiency can be improved.

[0099] The technical scope of the present disclosure is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present disclosure. For example, one or more concentrators may be provided in the circulation path 6. The concentrators increase the concentration of carbon dioxide in the regeneration discharge fluid F2 by, for example, liquefaction separation, membrane separation, adsorption separation, or other techniques. This can improve the energy efficiency in the carbon dioxide separator 7. The concentrators may be provided in the supply path 2. In addition, the pressure reducer 11 is provided downstream of the heater 81, but is not limited to this and may be provided upstream of the heater 81 depending on the system equipment specifications.

[0100] Known heat exchangers can be used as the heat exchanger such as the heater, cooler, intermediate heat exchanger, etc. Examples of the heat exchanger that can be used include a multi-tube heat exchanger, a plate heat exchanger, a coil heat exchanger, a double-tube heat exchanger, and a spiral heat exchanger. Although air has been exemplified as the fluid to be treated, the carbon dioxide capture system of the embodiment can also be applied to fluids to be treated other than air (nitrogen gas, hydrogen gas, oxygen gas, methane, etc.). [Explanation of symbols]

[0101] 1,101,201,301,401,501,601,701,801,901,1001,1101...Carbon dioxide capture system 2...Supply path 3...Carbon dioxide adsorption section 4...Extraction path 5...Regeneration path 6...Circulation path 7,907...Carbon dioxide separator 7...Second carbon dioxide separator 9...Introduction path 10...Compressor 31...Treatment area 32...Regeneration area 81,281...Heater 83,283...Cooler 84...Compressor 184A...First compressor (compressor) 184B...Second compressor (compressor) 287...Intermediate heat exchanger 413...Exhaust path 1002...Return path 1007...First carbon dioxide separator (carbon dioxide separator) F1...Regeneration fluid F2...Regeneration discharge fluid F4...Permeate side fluid F5...Non-permeate side fluid

Claims

1. A supply path for guiding air; a carbon dioxide adsorption section having a treatment region for adsorbing carbon dioxide contained in the air into an adsorbent, and a regeneration region for regenerating the adsorbent by discharging carbon dioxide desorbed from the adsorbent together with a regeneration fluid as a regeneration discharge fluid; an outlet path for guiding the air whose carbon dioxide concentration has been reduced by the treatment area; a carbon dioxide separator for separating at least a portion of the carbon dioxide from the regeneration discharge fluid to obtain the regeneration fluid; A recovery path connected to the carbon dioxide separator and configured to recover separated carbon dioxide; a circulation path connected to the regeneration area and the carbon dioxide separator, for leading the regeneration discharge fluid to the carbon dioxide separator; a regeneration passage connected to the carbon dioxide separator and the regeneration area and configured to guide the regeneration fluid to the regeneration area; A first carbon dioxide separator which is a membrane separator provided in the circulation path and has a separation membrane which selectively permeates the carbon dioxide of the regeneration discharge fluid; a passage for guiding a non-permeate side fluid that has not permeated the separation membrane to the regeneration passage; Equipped with The carbon dioxide concentration of the regenerating fluid is reduced in the carbon dioxide separator, and the regenerating fluid is circulated through the circulation path and the regenerating path to recover the carbon dioxide contained in the air; The carbon dioxide separator is a second carbon dioxide separator which is a liquefaction separator that liquefies and separates carbon dioxide in the permeate side fluid that has permeated the separation membrane. Carbon dioxide capture system.

2. A compressor for increasing the pressure of the regeneration exhaust fluid led to the carbon dioxide separator; a cooler for cooling the regeneration discharge fluid that is pressurized by the compressor and guided to the carbon dioxide separator; A heater for heating the regenerating fluid; Further comprising:

2. The carbon dioxide capture system of claim 1.

3. The heater heats the regenerating fluid by heat exchange with a heat transfer fluid, The cooler cools the regeneration discharge fluid by heat exchange with the heat transfer fluid. The carbon dioxide capture system of claim 2.

4. Further comprising a heat transfer medium compressor for increasing the pressure of the heat transfer medium fluid, and an expander for decreasing the pressure of the heat transfer medium fluid, The heat medium compressor, the heater, the expander, and the cooler constitute a heat pump unit in which the heat medium fluid circulates in this order. The carbon dioxide capture system of claim 3.

5. Further comprising an intermediate heat exchanger; The heater heats the regenerating fluid by heat exchange with a first heat transfer fluid, the intermediate heat exchanger cools a second heat medium fluid by heat exchange with the first heat medium fluid; The cooler cools the regeneration discharge fluid by heat exchange with the second heat transfer fluid. The carbon dioxide capture system of claim 2.

6. The heat transfer fluid is carbon dioxide. The carbon dioxide capture system of claim 3.

7. The heater and the cooler constitute at least an air conditioning device. The carbon dioxide capture system of claim 3.

8. The heater and the cooler constitute at least a refrigerator-freezer device. The carbon dioxide capture system of claim 3.

9. An exhaust path that discharges a portion of the air flowing through the outlet path is connected to the outlet path.

2. The carbon dioxide capture system of claim 1.

10. The regenerating fluid includes a fluid that can exist as a gas under pressure and temperature conditions at which carbon dioxide is liquefied; 2. The carbon dioxide capture system of claim 1.

11. In the circulation path, the pressure of the regeneration discharge fluid discharged from the regeneration region is lower than the pressure of the regeneration discharge fluid introduced into the carbon dioxide separator; In the regeneration path, the pressure of the regeneration fluid discharged from the carbon dioxide separator is lower than the pressure of the regeneration fluid introduced into the regeneration area; 2. The carbon dioxide capture system of claim 1.

12. An introduction path for introducing a second air is connected to the supply path, An air purifier for purifying the second air is provided in the introduction path.

2. The carbon dioxide capture system of claim 1.

13. A supply path for guiding air; a carbon dioxide adsorption section having a first treatment area for adsorbing carbon dioxide contained in the air into an adsorbent, a second treatment area for adsorbing carbon dioxide contained in exhaust air discharged from the space into the adsorbent, and a regeneration area for regenerating the adsorbent by discharging carbon dioxide desorbed from the adsorbent together with a regeneration fluid as a regeneration exhaust fluid; an outlet path for guiding the air whose carbon dioxide concentration has been reduced by the first treatment area; and a carbon dioxide separator for separating at least a portion of the carbon dioxide from the regeneration exhaust fluid to obtain the regeneration fluid. A recovery path connected to the carbon dioxide separator and configured to recover separated carbon dioxide; a circulation path connected to the regeneration area and the carbon dioxide separator, for leading the regeneration discharge fluid to the carbon dioxide separator; a regeneration passage connected to the carbon dioxide separator and the regeneration area and configured to guide the regeneration fluid to the regeneration area; Equipped with The regenerating fluid has a carbon dioxide concentration reduced in the carbon dioxide separator, and is circulated through the circulation path and the regenerating path to recover carbon dioxide contained in the air. Carbon dioxide capture system.

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