Carbon dioxide capture system

Abstract

To provide a carbon dioxide recovery system capable of increasing carbon dioxide recovery efficiency.SOLUTION: This carbon dioxide recovery system comprises: a supply path; a carbon dioxide suction unit; a derivation path; an introduction path; a carbon dioxide separator; a recovery path; a circulation path; a reproduction path; a heat exchanger; and an air cleaner. The carbon dioxide suction unit includes a processing region and a reproduction region. The carbon dioxide separator obtains a reproduction fluid lowered in carbon dioxide concentration from a reproduction discharge fluid. The circulation path is connected to the reproduction region and the carbon dioxide separator, and guides the reproduction discharge fluid to the carbon dioxide separator. The reproduction path guides the reproduction fluid lowered in carbon dioxide concentration from the carbon dioxide separator to the reproduction region. The reproduction fluid is lowered in carbon dioxide concentration at the carbon dioxide separator. The carbon dioxide recovery system recovers carbon dioxides contained in air by means of circulation through the circulation path and the reproduction path.SELECTED DRAWING: Figure 1

Description

Technical Field

[0004] ,

[0006] , , , , , ,

[0005] , , , , , ,

[0001] The present disclosure relates to a carbon dioxide recovery system.

Background Art

[0002] Patent Document 1 discloses a DAC (Direct Air Capture) technology for recovering carbon dioxide from air.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above technology, the carbon dioxide recovery efficiency may be low.

[0005] In view of the above circumstances, an object of the present disclosure is to provide a carbon dioxide recovery system capable of increasing the carbon dioxide recovery efficiency.

Means for Solving the Problems

[0006] One aspect of the carbon dioxide recovery system according to the present disclosure includes a supply path for guiding air, a treatment region for adsorbing carbon dioxide contained in the air to an adsorbent, and a regeneration region for regenerating the adsorbent using a regeneration fluid, a carbon dioxide adsorption unit having a regeneration region, a discharge path for guiding the air with a reduced carbon dioxide concentration by the treatment region, a regeneration path for guiding the regeneration fluid to the regeneration region, a circulation path for guiding a regeneration discharge fluid discharged by regenerating the adsorbent with the regeneration fluid, and a carbon dioxide separator for obtaining the regeneration fluid by separating at least a part of carbon dioxide from the regeneration discharge fluid.

Effects of the Invention

[0007] According to this disclosure, a carbon dioxide capture system that can improve the efficiency of carbon dioxide capture can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the carbon dioxide capture system according to Embodiment 1. [Figure 2] This is a schematic diagram of a part of the carbon dioxide capture system according to Embodiment 2. [Figure 3] This is a schematic diagram of a part of the carbon dioxide capture system according to Embodiment 3. [Figure 4] This is a schematic diagram of the carbon dioxide capture system according to Embodiment 4. [Figure 5] This is a schematic diagram of the carbon dioxide capture system according to Embodiment 5. [Figure 6] This is a schematic diagram of the carbon dioxide capture system according to Embodiment 6. [Figure 7] This is a schematic diagram of the carbon dioxide capture system according to Embodiment 7. [Figure 8] This is a schematic diagram of the carbon dioxide capture system according to Embodiment 8. [Figure 9] This is a schematic diagram of the carbon dioxide capture system according to Embodiment 9. [Figure 10] This is a schematic diagram of the carbon dioxide capture system according to Embodiment 10. [Figure 11] This is a schematic diagram of the carbon dioxide capture system according to Embodiment 11. [Figure 12] This is a schematic diagram of the carbon dioxide capture system according to Embodiment 12. [Modes for carrying out the invention]

[0009] Embodiments of this disclosure will be described below with reference to the drawings. However, the scope of this disclosure is not limited to the embodiments described below and can be modified at will within the scope of the technical idea of ​​this disclosure.

[0010] Embodiment 1 FIG. 1 is a schematic diagram showing a carbon dioxide recovery system according to Embodiment 1. As shown in FIG. 1, the carbon dioxide recovery system 1 includes a supply path 2, a carbon dioxide adsorption unit 3, a derivation 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 decompressor 11.

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

[0012] The carbon dioxide adsorption unit 3 includes a first region 31A and a second region 32A. In the example shown in FIG. 1, the first region 31A is the processing region 31. The second region 32A is the regeneration region 32. The processing region 31 includes, for example, an adsorbent and a container for housing the adsorbent. The regeneration region 32 includes, for example, an adsorbent to be regenerated and a container for housing the adsorbent.

[0013] Examples of the adsorbent include amine, silica gel, zeolite, activated carbon, diatomaceous earth, alumina, etc. Specifically, by adsorbing carbon dioxide contained in air onto the adsorbent, it can be separated from other components. The adsorbent may be granular, powdery, etc. The granular form is, for example, bead-shaped (spherical), pellet-shaped (cylindrical), etc. When using a powdery adsorbent, the adsorbent may be supported on the surface of a substrate. The substrate may be in a honeycomb shape.

[0014] In the processing region 31, at least a part of the carbon dioxide contained in the air is removed by adsorption, so that air with a lower carbon dioxide concentration can be obtained.

[0015] The regeneration region 32 regenerates the adsorbent that has adsorbed carbon dioxide in the treatment region 31 using the regeneration fluid F1. The regeneration region 32 has a function of desorbing carbon dioxide from the adsorbent. The regeneration region 32 includes, for example, 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 regeneration fluid F1. When carbon dioxide is desorbed, the adsorbent is regenerated. The regeneration fluid F1 containing the carbon dioxide desorbed from the adsorbent is discharged from the regeneration region 32 as the "regenerated exhaust fluid F₂".

[0016] The regeneration region 32 may include a decompression device such as a decompression pump. The decompression device promotes the desorption of carbon dioxide from the adsorbent by placing the adsorbent under reduced pressure.

[0017] The derivation path 4 is connected to the treatment region 31. The derivation path 4 supplies the air with a reduced carbon dioxide concentration in the treatment region 31 to the living space (the supplied space) 100.

[0018] The regeneration path 5 is connected to the regeneration region 32 of the carbon dioxide adsorbing 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. Examples of the regeneration fluid F1 include nitrogen (N₂), hydrogen (H₂), methane, and the like.

[0019] The circulation path 6 is connected to the regeneration region 32 of the carbon dioxide adsorbing section 3 and the carbon dioxide separator 7. The circulation path 6 guides the regenerated exhaust fluid F2 discharged from the regeneration region 32 to the carbon dioxide separator 7.

[0020] [[ID=2,0]]The carbon dioxide separator 7 separates at least a part of the carbon dioxide contained in the regenerated exhaust fluid F2 using separation methods such as liquefaction separation, membrane separation, and adsorption separation. In the carbon dioxide separator 7, one of these separation methods may be adopted, or two or more of them may be combined.

[0021] The carbon dioxide separator 7, which uses liquefaction separation, separates a specific component from other components (gases) by liquefying it. Specifically, for example, it separates carbon dioxide from other components (gases) by liquefying it under high pressure and low temperature conditions.

[0022] A carbon dioxide separator 7 using membrane separation separates specific components from other components by using a separation membrane that allows small molecular sizes to pass through. Specifically, for example, a separation membrane that selectively allows carbon dioxide to pass through is used. This separation membrane separates carbon dioxide from a mixed fluid containing 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, which uses adsorption separation, separates specific components by adsorbing them onto an adsorbent. Examples of adsorbents 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 an adsorbent.

[0024] The recycled emission fluid F2, whose carbon dioxide concentration has been reduced by the separation of carbon dioxide, is then discharged from the carbon dioxide separator 7 through the recycling path 5 as "recycled fluid F1".

[0025] The heat pump unit 8 comprises 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 regeneration fluid F1 through 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 regenerated 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, expander 82, cooler 83, and compressor 84 are located in the circulation path 85.

[0026] The circulation path 85 is a ring-shaped path. The circulation path 85 circulates the heat transfer fluid F3. The heat transfer fluid F3 circulates through the heater 81, expander 82, cooler 83, and compressor 84 in that order. Examples of heat transfer fluid F3 include carbon dioxide, alternative fluorocarbons, 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 adapting an existing heat pump unit 8.

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

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

[0029] The intake path 9 is connected to the supply path 2. The intake path 9 introduces indoor air discharged from the living space 100 into the supply path 2. The compressor 10 is located in the circulation path 6. The compressor 10 increases the pressure of the regenerated discharge fluid F2. The pressure reducer 11 is located 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 to lower the temperature of the regenerated discharge fluid F2, which 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 through the supply path 2 to the processing area 31 of the carbon dioxide adsorption unit 3. In the processing area 31, at least a portion of the carbon dioxide contained in the air is removed by adsorption onto an adsorbent. The air with a reduced carbon dioxide concentration is supplied to the living space (supplied space) 100 through the discharge path 4. The process of removing at least a portion of the carbon dioxide in the processing area 31 by adsorption is called the "adsorption process".

[0031] The adsorbent that adsorbed carbon dioxide in the processing area 31 is regenerated in the regeneration area 32. Specifically, in the regeneration area 32, carbon dioxide is desorbed from the adsorbent in the presence of the regeneration fluid F1. The adsorbent is regenerated by the desorption of carbon dioxide. The regeneration fluid F1 containing the carbon dioxide desorbed from the adsorbent is discharged from the regeneration area 32 as "regeneration discharge fluid F2". The process of regenerating the adsorbent in the regeneration area 32 is called the "regeneration process".

[0032] The switching between the processing area and the regeneration area in the carbon dioxide adsorption unit 3 will be explained. When regenerating the adsorbent that has adsorbed carbon dioxide in the processing area 31 in the regeneration area 32, the adsorbent can be exchanged between the processing area 31 and the regeneration area 32. For example, the adsorbent in the processing area 31 can be moved to the regeneration area 32 along with its container, and the adsorbent regenerated in the regeneration area 32 can be moved back to the processing area 31 along with its container. In this way, the processing area and the regeneration area can be switched.

[0033] The adsorbent can also be replaced by removing the adsorbent from the processing area 31 from the container and moving it to the regeneration area 32, and then removing the regenerated adsorbent from the regeneration area 32 from the container and moving it to the processing area 31.

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

[0035] The supply path 2 and the output path 4 are connected to the second region 32A by operating valves located in branch paths (not shown). The regeneration path 5 and the circulation path 6 are connected to the first region 31A. This operation makes the first region 31A a regeneration region, and the second region 32A a processing region. In this way, the processing region and the regeneration region can be switched. The first region 31A can also be returned to the processing region by operating valves, and the second region 32A can also be returned to the regeneration region.

[0036] The regenerated discharge fluid F2 is drawn out from the regeneration region 32 through the circulation path 6. The pressure of the regenerated discharge fluid F2 is increased by the compressor 10. The regenerated discharge fluid F2 is cooled in the cooler 83 by heat exchange with the heat transfer fluid F3. The cooler 83 can cool the regenerated discharge fluid F2 to a temperature corresponding to the specifications of the carbon dioxide separator 7, which will be described later, for example. The recycled waste 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 regenerated emission fluid F2 using separation methods such as liquefaction separation, membrane separation, and adsorption separation. The concentrated carbon dioxide is recovered through the recovery pathway 71.

[0038] The recycled emission fluid F2, whose carbon dioxide concentration has been reduced by the separation of carbon dioxide, is then discharged from the carbon dioxide separator 7 through the recycling path 5 as "recycled fluid F1".

[0039] The regeneration fluid F1 is heated in the heater 81 by heat exchange with the heat transfer fluid F3. The heater 81 can heat the regeneration fluid F1 so that its temperature in the regeneration region 32 is, for example, 90°C to 120°C. The regeneration fluid F1 is depressurized in the pressure reducer 11 as needed. The regeneration fluid F1 is introduced into the regeneration region 32 through the regeneration 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 regeneration 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 regeneration discharge fluid F2. After its pressure is increased by the compressor 84, the heat transfer fluid F3 proceeds to the heater 81. In this way, the heat transfer fluid F3 heats the regeneration fluid F1 and cools the regeneration discharge fluid F2.

[0041] The carbon dioxide capture system 1 includes a circulation path 6 that guides the regenerated discharge fluid F2 from the regeneration area 32, and a carbon dioxide separator 7 that generates a regeneration fluid F1 with a low carbon dioxide concentration from the regenerated discharge fluid F2. Because the carbon dioxide capture system 1 circulates the regeneration fluid F1, it can increase the carbon dioxide capture efficiency in the carbon dioxide separator 7.

[0042] Since carbon dioxide capture system 1 recycles and uses the regenerating fluid F1 and the regenerating emission fluid F2, it can effectively utilize the thermal energy contained in the regenerating fluid F1 and the regenerating emission fluid F2. Therefore, the overall energy efficiency of the system can be improved. The carbon dioxide capture system 1 can improve carbon dioxide capture efficiency by capturing carbon dioxide from the air using the carbon dioxide adsorption unit 3 and guiding the regenerated emission fluid F2 containing carbon dioxide to the carbon dioxide separator 7.

[0043] The carbon dioxide capture system 1 comprises a compressor 10, a heater 81, and a cooler 83. The heater 81 efficiently regenerates the adsorbent by heating the regeneration fluid F1 to an appropriate temperature in the regeneration region 32. The compressor 10 efficiently separates carbon dioxide in the carbon dioxide separator 7 by increasing the pressure of the regeneration discharge fluid F2. The cooler 83 efficiently separates carbon dioxide by cooling the regeneration discharge fluid F2 to an appropriate temperature in the carbon dioxide separator 7. The carbon dioxide capture system 1 can reduce the volume of the regenerated discharge fluid F2 using the compressor 10 and cooler 83, thus enabling the device to be made smaller.

[0044] The heater 81 heats the regeneration fluid F1 through heat exchange with the heat transfer fluid F3. The cooler 83 cools the regeneration discharge fluid F2 through heat exchange with the heat transfer fluid F3. The carbon dioxide capture system 1 can improve energy efficiency because it performs heat exchange with the regeneration fluid F1 and the regeneration discharge fluid F2 via a common heat transfer fluid F3.

[0045] The carbon dioxide separator 7, which uses liquefaction separation, can efficiently separate carbon dioxide. Because the volume of carbon dioxide can be reduced by liquefaction, the carbon dioxide separator 7, which uses liquefaction separation, can be made smaller. The carbon dioxide separator 7, which uses membrane separation, can efficiently separate carbon dioxide. Compared to other separation methods, the carbon dioxide separator 7 using membrane separation has fewer constraints on pressure, temperature, etc. Therefore, energy required for pressurization and cooling can be reduced. Thus, carbon dioxide can be recovered at a 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 adapting an existing heat pump unit 8. Therefore, a carbon dioxide recovery system 1 can be constructed at low cost.

[0047] The heater 81 and cooler 83 may constitute at least an air conditioning system. In that case, the carbon dioxide recovery system 1 can be constructed using the heater 81 and cooler 83 of the air conditioning system, which makes it possible to reduce costs compared to using dedicated heaters and coolers. The heater 81 and cooler 83 may constitute at least a refrigerator / freezer system. In that case, the carbon dioxide capture system 1 can be constructed using the heater 81 and cooler 83 of the refrigerator / freezer system, which makes it possible to reduce costs compared to using dedicated heaters and coolers. The heater 81 and the cooler 83 may constitute both an air conditioning system and a refrigerator / freezer system.

[0048] Embodiment 2. Next, a carbon dioxide capture system according to Embodiment 2 will be described. Since this embodiment of the carbon dioxide capture system has a configuration common to Embodiment 1, the differences from Embodiment 1 will be mainly described. Components that are the same as those in Embodiment 1 are denoted by the same reference numerals and their descriptions are omitted.

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

[0050] The carbon dioxide capture system 101 has a heat pump unit 108 equipped with multiple compressors 184A and 184B, which allows for increased pressure of the heat transfer fluid F3. This expands the operating range of heating and cooling in the heat pump unit 108. As a result, the performance of the carbon dioxide capture system is improved, and carbon dioxide can be captured more efficiently.

[0051] In the carbon dioxide capture system 101 shown in Figure 2, the heat pump unit 108 has two compressors, but the number of compressors is not limited to two. There may be multiple compressors (any number of two or more).

[0052] Embodiment 3. Next, a carbon dioxide capture system according to Embodiment 3 will be described. Components that are the same as those in the other embodiments are denoted by the same reference numerals and their description is omitted.

[0053] Figure 3 is a schematic diagram of a part of the carbon dioxide capture system according to Embodiment 3. As shown in Figure 3, the carbon dioxide capture system 201 is equipped with a heat pump unit 208 in place of the heat pump unit 8 (see Figure 1). The heat pump unit 208 comprises 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 regeneration fluid F1 through 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 exchanging heat 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 located in the first circulation path 285. The first circulation path 285 is an annular path. The first circulation path 285 circulates the first heat transfer fluid F3A through the heater 281, the first expander 282, the intermediate heat exchanger 287, and the first compressor 284 in that order.

[0055] The second expander 288 reduces the pressure of the second heat transfer fluid F3B. The cooler 283 cools the regenerated discharge fluid F2 through 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 located in the second circulation path 290. The second circulation path 290 is an annular path. The second circulation path 290 circulates the second heat transfer fluid F3B through the intermediate heat exchanger 287, the second expander 288, the cooler 283, and the second compressor 289 in that order.

[0056] The first heat transfer fluid F3A and the second heat transfer fluid F3B have different physical properties, such as boiling points. An example of the first heat transfer fluid F3A is carbon dioxide. An example of the second heat transfer fluid F3B is alternative fluorocarbons. The second heat transfer fluid F3B is used at lower temperatures than, for example, the first heat transfer fluid F3A.

[0057] The portion of the heat pump unit 208 through which the first heat transfer fluid F3A flows (the first portion) can be constructed, for example, using 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. The portion of the heat pump unit 208 through which the second heat transfer fluid F3B flows (the second portion) can be constructed, for example, using a heat pump for refrigeration. 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 either the first part or the second part.

[0058] The carbon dioxide capture system 201 includes a heat pump unit 208 having a heater 281, an intermediate heat exchanger 287, and a cooler 283. The heat pump unit 208 uses a first heat transfer fluid F3A and a second heat transfer fluid F3B, thereby expanding the operating range of heating and cooling. This enhances the performance of the carbon dioxide capture system and enables efficient carbon dioxide capture.

[0059] Embodiment 4. Next, a carbon dioxide capture system according to Embodiment 4 will be described. Components that are the same as those in the other embodiments are denoted by the same reference numerals and their description is omitted.

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

[0061] The air purifier 312 cleans the air by capturing airborne particles such as pollen, dust, viruses, mold, bacteria, house dust, smoke, odor-causing substances, and volatile chemicals. The air purifier 312 includes, for example, a filter for capturing airborne particles. The air purifier 312 may also include an electric field generator that forms an electric field between electrodes. The electric field generator can kill or inactivate pollen, viruses, mold, bacteria, etc.

[0062] The carbon dioxide capture system 301 is equipped with an air purifier 312, which allows it to purify the indoor air discharged from the living space 100 and introduce it into the supply path 2. Therefore, the purity of the air supplied to the living space 100 can be increased. Because the air supplied to the carbon dioxide adsorption unit 3 is purified, the carbon dioxide capture system 301 can improve the carbon dioxide capture efficiency in the carbon dioxide adsorption unit 3.

[0063] Embodiment 5. Next, a carbon dioxide capture system according to Embodiment 5 will be described. Components that are the same as those in the other embodiments are denoted by the same reference numerals and their description is omitted.

[0064] Figure 5 is a schematic diagram of the carbon dioxide capture system according to Embodiment 5. As shown in Figure 5, the carbon dioxide capture system 401 differs from the carbon dioxide capture system 1 (see Figure 1) in that the exhaust path 413 is connected to the outlet path 4. The exhaust path 413 can discharge a portion of the air flowing through the outlet path 4 outside the system. The gas discharged from the exhaust path 413 is released into the atmosphere, for example.

[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 through the discharge and intake of air, the air purity within the living space 100 can be increased. Since the carbon dioxide capture system 401 discharges the gas after carbon dioxide capture into the atmosphere from the exhaust path 413, the amount of carbon dioxide emitted can be kept low. Therefore, it is suitable in terms of environmental protection.

[0066] Embodiment 6. Next, a carbon dioxide capture system according to Embodiment 6 will be described. Components that are the same as those in other embodiments are denoted by the same reference numerals and their description is omitted.

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

[0068] The carbon dioxide capture system 501 is equipped with an air purifier 312, allowing clean air to be introduced into the supply path 2. The carbon dioxide capture system 501 is equipped with an exhaust path 413, enabling ventilation. Therefore, the air quality within the living space 100 can be improved. The carbon dioxide capture system 501 discharges the gas remaining after carbon dioxide capture into the atmosphere through the exhaust path 413, thus keeping carbon dioxide emissions low. For this reason, it is suitable in terms of environmental protection.

[0069] Embodiment 7. Next, a carbon dioxide capture system according to Embodiment 7 will be described. Components that are the same as those in other embodiments are denoted by the same reference numerals and their description is omitted.

[0070] Figure 7 is a schematic diagram of the carbon dioxide capture system according to Embodiment 7. As shown in Figure 7, the carbon dioxide capture system 601 includes a carbon dioxide adsorption unit 603 in place of the carbon dioxide adsorption unit 3 (see Figure 1). The carbon dioxide adsorption unit 603 includes a first processing area 31, a second processing area 633, and a regeneration area 32. The first processing area 31 has the same configuration as the processing area 31 (see Figure 1). The second processing area 633, like the first processing area 31, is equipped with an adsorbent. The adsorbent in the second processing area 633 may be the same as the adsorbent in the first processing area 31. The adsorbents in the first processing area 31 and the second processing area 633 can be regenerated by a regeneration process.

[0071] The second processing area 633 is connected to the introduction path 9. The introduction path 9 guides the air discharged from the living space 100 to the second processing area 633. The second processing 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 processing area 633 to the outside of the system through the exhaust path 634.

[0072] Since the carbon dioxide capture system 601 has a second processing area 633, it can capture carbon dioxide contained in the air emitted from the living space 100. Therefore, the carbon dioxide capture efficiency can be increased. In the carbon dioxide capture system 601, the air emitted from the living space 100 is not reused but is discharged outside the system through the exhaust path 634. Therefore, the risk of airborne and droplet transmission of infectious diseases caused by viruses, etc., can be reduced. In addition, the air purity within the living space 100 can be improved. Since the carbon dioxide capture system 601 discharges the gas after carbon dioxide capture into the atmosphere through the exhaust path 413, the amount of carbon dioxide emitted can be kept low. Therefore, it is suitable in terms of environmental protection.

[0073] Embodiment 8. Next, a carbon dioxide capture system according to Embodiment 8 will be described. Components that are the same as those in other embodiments are denoted by the same reference numerals and their description is omitted.

[0074] Figure 8 is a schematic diagram of the carbon dioxide capture system according to Embodiment 8. As shown in Figure 8, the carbon dioxide recovery system 701 differs from the carbon dioxide recovery system 601 (see Figure 7) in that it is equipped with a heat exchanger 714. The heat exchanger 714 spans both 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 via the outlet path 4 and the air discharged from the living space 100 via the inlet path 9. The heat exchanger 714 can adjust the temperature and humidity of the air supplied to the living space 100 to match the environment within the living space 100.

[0075] The carbon dioxide capture system 701 is equipped with a heat exchanger 714, which allows it to regulate the temperature of the air supplied to the living space 100 through the discharge path 4 by heat exchange with the exhaust air, thereby optimizing its temperature and humidity. This improves energy efficiency.

[0076] For carbon dioxide separators, it is preferable to employ either liquefaction separation, membrane separation, or both. Below, examples of carbon dioxide recovery system configurations are shown for cases employing liquefaction separation, membrane separation, and both liquefaction separation and membrane separation.

[0077] Embodiment 9. A carbon dioxide capture system according to Embodiment 9 will now be described. Components identical to those in other embodiments are denoted by the same reference numerals and their descriptions are omitted.

[0078] Figure 9 is a schematic diagram of the carbon dioxide capture system according to Embodiment 9. As shown in Figure 9, in the carbon dioxide capture system 801, the carbon dioxide separator 7 is a liquefaction separator that separates carbon dioxide by liquefaction. Since the carbon dioxide separator 7 is a liquefaction separator, high pressure and low temperature are required. The regenerated discharge fluid F2 is made high pressure by the compressor 10. The regenerated discharge fluid F2 is made low temperature by the 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 is equipped with a cooler 815. The cooler 815 is located downstream of the compressor 10 in the circulation path 6. The cooler 815 is located, 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 exhaust fluid F2 by heat exchange with a refrigerant (water). The temperature of the regenerated exhaust fluid F2 rises due to the pressure increase by the compressor 10, but the cooler 815 lowers the temperature of the regenerated exhaust 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 regenerated exhaust fluid F2 that has passed through the cooler 83. The concentrated carbon dioxide is recovered through the recovery path 71.

[0081] The carbon dioxide capture system 801 employs liquefaction separation, enabling efficient separation of carbon dioxide. Because liquefaction reduces the volume of carbon dioxide, the carbon dioxide capture system 801 allows for a more compact device.

[0082] Although the cooler 815 described above was explained as a water-cooled cooler, the cooling method of the cooler is not limited to this. For example, cooling by circulating a regeneration fluid F1 may be employed. This heats the regeneration fluid F1, resulting in a system with higher thermal efficiency.

[0083] Embodiment 10. Next, a carbon dioxide capture system according to Embodiment 10 will be described. Components that are the same as those in other embodiments are denoted by the same reference numerals and their description is omitted.

[0084] Figure 10 is a schematic diagram of a carbon dioxide capture system according to Embodiment 10. As shown in Figure 10, in the carbon dioxide capture 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 permeates carbon dioxide. The carbon dioxide separator 907 separates at least a portion of the carbon dioxide contained in the regenerative discharge fluid F2 by membrane separation. The concentrated carbon dioxide is recovered through the capture pathway 71.

[0085] The carbon dioxide capture system 901 employs membrane separation, enabling efficient carbon dioxide separation. Compared to other separation methods, the carbon dioxide capture system 901 has fewer constraints on pressure, temperature, etc. Because it can reduce energy consumption for pressurization and cooling, it can capture carbon dioxide at a low cost.

[0086] Embodiment 11. Next, a carbon dioxide capture system according to Embodiment 11 will be described. Components that are the same as those in other embodiments are denoted by the same reference numerals and their description is omitted.

[0087] Figure 11 is a schematic diagram of a carbon dioxide capture system according to Embodiment 11. As shown in Figure 11, the carbon dioxide capture system 1001 employs both liquefaction separation and membrane separation as methods for separating carbon dioxide in the carbon dioxide separator.

[0088] The carbon dioxide recovery system 1001 includes a supply path 2, a carbon dioxide adsorption unit 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 Figure 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 permeates carbon dioxide. The second carbon dioxide separator 7 is a liquefaction separator.

[0090] The return route 1002 connects the non-permeable outlet of the first carbon dioxide separator 1007 to the circulation route 6 (located upstream of the first compressor 10).

[0091] In the carbon dioxide capture system 1001, the regenerated exhaust fluid F2 is pressurized by the first compressor 10, then cooled by the first cooler 1015, and led to the first carbon dioxide separator 1007. The carbon dioxide contained in the regenerated exhaust fluid F2 is concentrated by the first carbon dioxide separator 1007. The permeate fluid F4, with the concentrated carbon dioxide, is then directed to the second compressor 1010.

[0092] The non-permeable fluid F5 that does not permeate the separation membrane of the first carbon dioxide separator 1007 is returned to the circulation path 6 (located upstream of the first compressor 10) via the return path 1002. This improves the carbon dioxide separation efficiency in the first carbon dioxide separator 1007.

[0093] The permeate fluid F4 is pressurized by the second compressor 1010, then cooled by the second cooler 1016 and cooler 83, and led 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 fluid F4. The concentrated carbon dioxide is recovered through the recovery path 71.

[0094] The carbon dioxide capture system 1001 can improve carbon dioxide capture efficiency by employing both liquefaction separation and membrane separation.

[0095] Here, the first cooler 1015 and the second cooler 1016 have been described as water-cooled, but the system is not limited to this. For example, cooling by circulating a regeneration fluid F1 may also be employed. This heats up the regeneration fluid F1, resulting in a system with higher thermal efficiency.

[0096] Embodiment 12. Next, a carbon dioxide capture system according to Embodiment 12 will be described. Components that are the same as those in other embodiments are denoted by the same reference numerals and their description is omitted.

[0097] Figure 12 is a schematic diagram of the carbon dioxide capture system according to Embodiment 12. As shown in Figure 12, the carbon dioxide capture system 1101 differs from the carbon dioxide capture system 1001 (see Figure 11) in that it has a return route 1102 instead of the return route 1002 (see Figure 11). The return route 1102 connects the impermeable outlet of the first carbon dioxide separator 1007 to the regeneration route 5 (located upstream of the heater 81). The impermeable fluid F5 discharged from the first carbon dioxide separator 1007 is guided to the regeneration route 5 via the return route 1102. The impermeable fluid F5 is used as part of the regeneration fluid F1.

[0098] The carbon dioxide capture system 1101 can improve carbon dioxide capture efficiency by employing both liquefaction separation and membrane separation. Because the carbon dioxide capture system 1101 performs membrane separation prior to liquefaction separation, it can reduce the energy required for cooling during liquefaction separation. Therefore, carbon dioxide can be captured at a low cost. In the carbon dioxide capture system 1101, the impermeable fluid F5, which has a low concentration of carbon dioxide, is used as the regenerative fluid F1, thereby improving energy efficiency.

[0099] The technical scope of this disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of this 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 regenerated discharge fluid F2 by methods such as liquefaction separation, membrane separation, or adsorption separation. This improves the energy efficiency of the carbon dioxide separator 7. The concentrators may also be provided in the supply path 2. In addition, although the pressure reducer 11 is provided downstream of the heater 81, it is not limited to this and may be provided upstream of the heater 81 depending on the system equipment specifications.

[0100] Any genuine heat exchanger can be used as a heat exchanger, such as a heater, cooler, or intermediate heat exchanger. Examples of heat exchangers that can be used include multi-tube heat exchangers, plate heat exchangers, coil heat exchangers, double-tube heat exchangers, and spiral heat exchangers. Although air was used as an example of the fluid to be treated, the carbon dioxide recovery system of this embodiment can also be applied to fluids other than air (such as nitrogen gas, hydrogen gas, oxygen gas, and methane). [Explanation of Symbols]

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

Claims

1. A supply path for guiding air, A carbon dioxide adsorption unit having a processing region for adsorbing carbon dioxide contained in the air onto an adsorbent, and a regeneration region for regenerating the adsorbent by discharging the carbon dioxide desorbed from the adsorbent together with a regeneration fluid as a regenerated discharge fluid, An outlet path that guides the air, whose carbon dioxide concentration has been reduced by the processing area, to the supply space, An introduction path for guiding the air from the space to be supplied, A carbon dioxide separator that separates at least a portion of the carbon dioxide contained in the regenerative discharge fluid to obtain the regenerative fluid, A recovery path connected to the carbon dioxide separator for recovering the separated carbon dioxide, A circulation path is connected to the outlet of the regeneration area and the inlet of the carbon dioxide separator, and guides the regeneration discharge fluid to the carbon dioxide separator. A regeneration path is connected to the outlet of the carbon dioxide separator and the inlet of the regeneration area, and guides the regeneration fluid to the regeneration area. The introduction path includes at least one of a heat exchanger and an air purifier, Equipped with, The regeneration fluid has a lower carbon dioxide concentration than the regeneration discharge fluid introduced into the carbon dioxide separator, and the carbon dioxide contained in the air is recovered by circulating it through the circulation path and the regeneration path. Carbon dioxide capture system.

2. A heater provided in the regeneration path for heating the regeneration fluid introduced into the regeneration region, A compressor that increases the pressure of the regenerated discharge fluid that is led to the carbon dioxide separator, The compressor increases the pressure of the regenerated discharge fluid, which is then guided to the carbon dioxide separator. The cooler further comprises a cooler for cooling the discharge fluid. The cooler is provided downstream of the compressor. The carbon dioxide capture system according to claim 1.

3. The compressor increases the pressure of the regenerated discharge fluid, which is led to the carbon dioxide separator, to the pressure required for separation in the carbon dioxide separator. The carbon dioxide capture system according to claim 2.

4. The heater heats the regeneration fluid by heat exchange with the heat transfer fluid, The cooler cools the regenerated discharge fluid by heat exchange with the heat transfer fluid. The carbon dioxide capture system according to claim 2 or 3.

5. The system further comprises a heat transfer fluid compressor that increases the pressure of the heat transfer fluid, and an expander that decreases the pressure of the heat transfer fluid, The heat transfer fluid compressor, the heater, the expander, and the cooler constitute a heat pump unit in which the heat transfer fluid circulates in this order. The carbon dioxide capture system according to claim 4.

6. It is further equipped with an intermediate heat exchanger, The heater heats the regeneration fluid by heat exchange with the first heat transfer fluid, The intermediate heat exchanger cools the second heat transfer fluid by heat exchange with the first heat transfer fluid, The carbon dioxide recovery system according to claim 2, wherein the cooler cools the regenerated discharge fluid by heat exchange with the second heat transfer fluid.

7. The carbon dioxide separator separates the carbon dioxide contained in the regenerated discharge fluid by liquefaction separation. The carbon dioxide capture system according to claim 1.

8. The carbon dioxide separator separates the carbon dioxide contained in the regenerated exhaust fluid by membrane separation. The carbon dioxide capture system according to claim 1.

9. The heat transfer fluid is carbon dioxide. The carbon dioxide capture system according to claim 4.

10. The heater and the cooler constitute at least an air conditioning system. The carbon dioxide capture system according to claim 4.

11. The heater and the cooler constitute at least one of the refrigerator and freezer devices. The carbon dioxide capture system according to claim 4.

12. An exhaust path is connected to the aforementioned outlet path to discharge a portion of the air flowing through the outlet path. The carbon dioxide capture system according to claim 1.

13. A first carbon dioxide separator is provided in the circulation path and is a membrane separator having a separation membrane that selectively permeates the carbon dioxide of the regenerated discharge fluid, The system further includes a return path that returns the non-permeable fluid, which has not permeated the separation membrane, to the upstream side of the circulation path from the first carbon dioxide separator, The carbon dioxide separator is a second carbon dioxide separator, which is a liquefaction separator that liquefies and separates the carbon dioxide of the permeate fluid that has permeated through the separation membrane. The carbon dioxide capture system according to claim 1.

14. A first carbon dioxide separator is provided in the circulation path and is a membrane separator having a separation membrane that selectively permeates the carbon dioxide of the regenerated discharge fluid, The system further comprises a path for guiding the non-permeable fluid that has not permeated the separation membrane to the regeneration path, The carbon dioxide separator is a second carbon dioxide separator, which is a liquefaction separator that liquefies and separates the carbon dioxide of the permeate fluid that has permeated through the separation membrane. The carbon dioxide capture system according to claim 1.

15. The regeneration fluid includes a fluid that can exist as a gas under the pressure and temperature conditions in which carbon dioxide liquefies. The carbon dioxide capture system according to claim 1.

16. In the circulation path, the pressure of the regenerated discharge fluid drawn out from the regeneration region is lower than the pressure of the regenerated 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 region. The carbon dioxide capture system according to claim 1.

17. An introduction path for introducing a second air is connected to the aforementioned supply path. The second air purifier for purifying the air is installed in this introduction path. The carbon dioxide capture system according to claim 1.

18. A supply path for guiding air, A carbon dioxide adsorption unit having a processing region for adsorbing carbon dioxide contained in the air onto an adsorbent, and a regeneration region for regenerating the adsorbent by discharging the carbon dioxide desorbed from the adsorbent together with a regeneration fluid as a regenerated discharge fluid, An outlet path for guiding the air whose carbon dioxide concentration has been reduced by the processing region, A carbon dioxide separator that separates at least a portion of the carbon dioxide contained in the regenerative discharge fluid to obtain the regenerative fluid, A recovery path connected to the carbon dioxide separator for recovering the separated carbon dioxide, A circulation path is connected to the outlet of the regeneration area and the inlet of the carbon dioxide separator, and guides the regeneration discharge fluid to the carbon dioxide separator. A regeneration path is connected to the outlet of the carbon dioxide separator and the inlet of the regeneration area, and guides the regeneration fluid to the regeneration area. A compressor that increases the pressure of the regenerated discharge fluid that is led to the carbon dioxide separator, A pressure reducer is provided in the regeneration path for reducing the pressure of the regeneration fluid introduced into the regeneration region, Equipped with, The regeneration fluid has a lower carbon dioxide concentration than the regeneration discharge fluid introduced into the carbon dioxide separator, and the carbon dioxide contained in the air is recovered by circulating it through the circulation path and the regeneration path. Carbon dioxide capture system.

19. A cooler for cooling the regenerative discharge fluid, which is pressurized by the compressor and led to the carbon dioxide separator, A heater for heating the regeneration fluid introduced into the regeneration region, Furthermore, The carbon dioxide capture system according to claim 18.

Images