Recovery system for target fluids

Abstract

This invention provides a fluid recovery system suitable for reducing the energy required to recover target fluids such as carbon dioxide. [Solution] The target fluid recovery system 100 comprises an adsorption unit 10 that adsorbs the target fluid in a detachable state, and a heat transfer unit 20 containing a working fluid that circulates in a sealed internal space. The heat transfer unit 20 has a first part 21 that heats or cools the adsorption unit 10 by the latent heat of the working fluid, and a second part 22 into which the working fluid absorbs or releases heat.

Description

[Technical Field]

[0001] This invention relates to a system for recovering target fluids. [Background technology]

[0002] Various technologies have been proposed for recovering target fluids such as carbon dioxide and water using adsorbents. For example, in the Direct Air Capture (DAC) technology for directly separating and recovering carbon dioxide contained in the atmosphere, exhaust gas, etc., carbon dioxide is recovered by heating the adsorbent that has adsorbed carbon dioxide, thereby desorbing the carbon dioxide from the adsorbent. For example, Patent Document 1 describes a method in which carbon dioxide is desorbed from the adsorbent by filling the chamber with water vapor to expel oxygen and then heating the adsorbent using a heat exchanger. The method described in Patent Document 1 is classified as the SA-VSA (Steam Assist Vacuum Swing Adsorption) method. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 6622302 [Overview of the project] [Problems that the invention aims to solve]

[0004] Conventional desorption methods, such as those described in Patent Document 1, are not sufficiently energy-efficient and tend to result in large systems, thus leaving room for improvement.

[0005] Therefore, the present invention aims to provide a fluid recovery system that is energy-efficient and suitable for miniaturization of the system. [Means for solving the problem]

[0006] The present invention An adsorption unit that adsorbs the target fluid in a detachable state, and a heat transfer unit containing a working fluid that circulates in a sealed internal space, The heat transfer unit has a first portion that heats or cools the adsorption unit by latent heat of the working fluid, and a second portion where the working fluid absorbs or releases heat, a target fluid recovery system, is provided. ADVANTAGEOUS EFFECTS OF INVENTION

[0007] According to the present invention, energy efficiency is improved, and the system can be downsized. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] [Figure 1] FIG. 2 is a schematic configuration diagram illustrating an example of a recovery system according to an embodiment of the present invention. [Figure 2A] FIG. 3 is a schematic configuration diagram illustrating an example of a heat transfer unit during execution of a desorption mode. [Figure 2B] FIG. 4 is a schematic configuration diagram illustrating an example of a heat transfer unit during execution of a cooling mode. [Figure 3] FIG. 2 is a perspective view schematically showing an example of part III in FIG. 1. [Figure 4] FIG. 5 is a perspective view schematically showing an example of an adsorption unit. [Figure 5] FIG. 6 is a perspective view schematically showing another example of the adsorption unit. [Figure 6] FIG. 7 is a schematic configuration diagram of Modification 1 of the recovery system. [Figure 7] FIG. 7 is a perspective view schematically showing an example of part VII in FIG. 6. [Figure 8] FIG. 8 is a schematic configuration diagram of Modification 2 of the recovery system. [Figure 9] FIG. 9 is a schematic configuration diagram of Modification 3 of the recovery system. [Figure 10] FIG. 10 is a schematic configuration diagram of Modification 4 of the recovery system. DETAILED DESCRIPTION OF EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0009] A target fluid recovery system according to a first aspect of the present invention comprises, an adsorption unit that adsorbs a target fluid in a desorbable state, and a heat transfer unit containing a working fluid that circulates in a sealed internal space, wherein the heat transfer unit has a first portion that heats or cools the adsorption unit by latent heat of the working fluid, and a second portion where the working fluid absorbs or releases heat.

[0010] In a second aspect of the present invention, for example, in the target fluid recovery system according to the first aspect, the heat transfer unit includes at least one selected from the group consisting of a heat pipe and a vapor chamber.

[0011] In a third aspect of the present invention, for example, in the target fluid recovery system according to the first or second aspect, in the vertical direction, the first portion of the heat transfer unit is located above the second portion.

[0012] In a fourth aspect of the present invention, for example, the target fluid recovery system according to any one of the first to third aspects further comprises a heating path connecting the second portion of the heat transfer unit and a heating source.

[0013] In a fifth aspect of the present invention, for example, the target fluid recovery system according to any one of the first to fourth aspects further comprises a cooling path connecting the second portion of the heat transfer unit and a cooling source.

[0014] In a sixth aspect of the present invention, for example, in the target fluid recovery system according to any one of the first to fifth aspects, the heat transfer unit has a closed loop structure in which the first portion and the second portion are connected.

[0015] In a seventh aspect of the present invention, for example, the target fluid recovery system according to any one of the first to sixth aspects further comprises a case in which the adsorption unit is accommodated, and the first portion of the heat transfer unit is disposed inside the case or on an outer wall of the case.

[0016] In the eighth aspect of the present invention, for example, in a fluid recovery system for a target fluid according to any one of the first to seventh aspects, the adsorption unit comes into contact with a mixed gas containing an acidic gas as the target fluid, adsorbs the acidic gas contained in the mixed gas, and desorbs the acidic gas by heating while the acidic gas is adsorbed.

[0017] The details of the present invention will be described below, but the following description is not intended to limit the present invention to any particular embodiment.

[0018] [Target fluid recovery system] The fluid recovery system according to this embodiment is a system for recovering a target fluid, such as carbon dioxide, from a raw material fluid. The recovery system comprises an adsorption unit that adsorbs the target fluid in a detachable state, and a heat transfer unit containing a working fluid circulating in a sealed internal space. The heat transfer unit has a first part that heats or cools the adsorption unit by the latent heat of the working fluid, and a second part in which the working fluid absorbs or releases heat. The adsorption unit adsorbs and desorbs the target fluid, such as carbon dioxide, contained in the raw material fluid. Examples of working fluids that can be used include water, ethanol, methanol, acetone, naphthalene, ammonia, etc. The working fluid absorbs heat from a high heat source, such as a heating source or heat transfer medium. Examples of heating sources or heat transfer mediums that heat the working fluid include exhaust gas from a factory, waste hot water, geothermal energy, etc. The working fluid releases heat to a low heat source, such as a cooling source or heat transfer medium. As a cooling source or heat transfer medium for cooling the working fluid, for example, air, water, or a mixed liquid of water and ethylene glycol or propylene glycol may be used. In the heat transfer section, heat transfer occurs from the second section to the first section, or vice versa, due to the temperature difference between the second section and the first section. As a result, the adsorption section is heated or cooled, so that the target fluid can be detached from the adsorption section or the adsorption section can be cooled. According to the recovery system of this embodiment, the energy required to recover the target fluid such as carbon dioxide can be reduced, and the system can be miniaturized.

[0019] In the following, the mode in which the target fluid, such as carbon dioxide, is desorbed from the adsorption unit will be called the "desorption mode." The mode in which the target fluid, such as carbon dioxide, contained in the raw material fluid, is adsorbed onto the adsorption unit will be called the "adsorption mode." The mode in which the adsorption unit, from which the target fluid has been desorbed, is cooled will be called the "cooling mode." By performing the cooling mode between the desorption mode and the adsorption mode, the adsorption unit from which the target fluid has been desorbed can be cooled. As a result, the adsorption unit is regenerated and can adsorb acidic gases again. The adsorption mode, desorption mode, and cooling mode may be repeated in this order.

[0020] Figure 1 is a schematic diagram showing an example of a recovery system 100 according to this embodiment. The recovery system 100 is a system for recovering acidic gases such as carbon dioxide as a target fluid from a mixed gas G1 as a raw material fluid. The recovery system 100 comprises an adsorption unit 10 and a heat transfer unit 20. The adsorption unit 10 adsorbs the acidic gas contained in the mixed gas G1 in a state that can be desorbed. The heat transfer unit 20 contains a working fluid that circulates in a sealed internal space. The heat transfer unit 20 has a first part 21 that heats or cools the adsorption unit 10 by the latent heat of the working fluid, and a second part 22 in which the working fluid absorbs or releases heat.

[0021] According to the recovery system 100, for example, when the desorption mode is performed, the working fluid in the second part 22 of the heat transfer unit 20 receives heat from the heat source 81 or the heat medium heated by the heat source 81, thereby creating a temperature difference between the second part 22 and the first part 21. This causes heat transfer from the second part 22 to the first part 21. In the process of this heat transfer, the heat transfer unit 20 transfers heat to the adsorption unit 10 through the first part 21. As a result, the adsorption unit 10 is heated. This causes the adsorption unit 10 to desorb the adsorbed acidic gas. By desorbing the acidic gas, the adsorption unit 10 is regenerated. Also, for example, when the cooling mode is performed, the working fluid in the second part 22 of the heat transfer unit 20 releases heat to the cooling source 82 or the heat medium cooled by the cooling source 82, thereby creating a temperature difference between the second part 22 and the first part 21. This causes heat transfer from the first part 21 to the second part 22. During this heat transfer process, the heat transfer unit 20 absorbs heat from the adsorption unit 10 and transfers the heat. As a result, the adsorption unit 10, from which the acidic gas has been desorbed, is cooled. This allows the adsorption unit 10 to regenerate and become capable of adsorbing acidic gas again.

[0022] In the recovery system 100 according to this embodiment, the heat transfer unit 20 heats or cools the adsorption unit 10 using the latent heat of the working fluid. For example, when performing the desorption mode, the heat from the heat source 81 or the heat medium heated by the heat source 81 can be transferred to the adsorption unit 10. The heat transfer unit 20 can, for example, transfer heat of about 100°C from the heat source 81 or the heat medium heated by the heat source 81 to the adsorption unit 10. Therefore, heat mediums that are not sufficiently high in temperature (for example, around 100°C) can be effectively utilized. The recovery system 100 can reduce the energy required to heat or cool the adsorption unit 10. In addition, the heat transfer unit 20 has less heat unevenness and excellent heating speed. Therefore, the amount of carbon dioxide recovered per unit energy also increases. Furthermore, for example, when the adsorption unit 10 is directly heated using steam as the heat medium, an apparatus for generating steam is required, and energy is needed to generate the steam, thus reducing energy efficiency. When the adsorption unit 10 is directly heated using a carrier gas as a heat transfer medium, the concentration of the target fluid, such as carbon dioxide, to be recovered decreases. When the adsorption unit 10 is directly heated using exhaust gas from a factory as a heat transfer medium, the adsorption unit 10 may deteriorate due to chemical substances such as nitrogen oxides, sulfur oxides, and oxygen contained in the exhaust gas. When the adsorption unit 10 is indirectly heated using waste hot water as a heat transfer medium, energy loss occurs due to conversion efficiency during heat exchange when generating waste hot water, resulting in decreased energy efficiency and increased costs for the heat exchanger. When the adsorption unit 10 is directly heated using waste hot water as a heat transfer medium, the adsorption unit 10 needs to be water-resistant, and energy is required to generate the hot water, thus decreasing energy efficiency. However, in the recovery system 100 according to this embodiment, the adsorption unit 10 can be heated without direct contact between the heat transfer medium and the adsorption unit 10, thus avoiding the above problems. According to the recovery system 100 of this embodiment, energy efficiency is improved and the system can be miniaturized.

[0023] The heat transfer medium heated by the heat source 81 has a temperature higher than room temperature (25°C). The lower limit of the temperature of the heat transfer medium heated by the heat source 81 may be, for example, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, or even 90°C. The upper limit of the temperature of the heat transfer medium heated by the heat source 81 is, for example, 400°C. The upper limit of the temperature of the heat transfer medium heated by the heat source 81 may be 350°C, 300°C, 250°C, or even 200°C.

[0024] The heat transfer medium cooled by the cooling source 82 has a temperature below room temperature (25°C). The upper limit of the temperature of the heat transfer medium cooled by the cooling source 82 may be, for example, 20°C, 15°C, or even 10°C. The lower limit of the temperature of the heat transfer medium cooled by the cooling source 82 is, for example, -30°C. The lower limit of the temperature of the heat transfer medium cooled by the cooling source 82 may be -20°C, -10°C, or even 0°C.

[0025] Figure 2A is a schematic diagram showing an example of a heat transfer section 20. The heat transfer section 20 includes, for example, a container 26 having a sealed internal space 25, a working fluid 27 sealed in the internal space 25, and a capillary structure 28 formed on the inner wall of the container 26. The working fluid 27 is typically water or steam. With a heat transfer section 20 having such a configuration, the absorption and release of heat resulting from the temperature difference between the second section 22 and the first section 21 is efficiently performed.

[0026] The operating mechanism of the heat transfer section 20 during the desorption mode will be explained in detail with reference to Figure 2A. The arrows inside the heat transfer section 20 shown in Figure 2A indicate the flow of the working fluid 27 during the desorption mode. The dashed arrows outside the heat transfer section 20 shown in Figure 2A indicate the flow of heat during the desorption mode. First, the second part 22 of the heat transfer section 20 is heated by the heat source 81 or a heat transfer medium heated by the heat source 81, and the temperature of the second part 22 becomes higher than the temperature of the first part 21. As a result, in the second part 22, the liquid working fluid 27a absorbs heat and evaporates, becoming the gaseous working fluid 27b. At this time, the gaseous working fluid 27b absorbs the heat (latent heat) during the phase change (evaporation). That is, during the desorption mode, the second part 22 functions as a heat absorber. The gaseous working fluid 27b moves from the second part 22 towards the lower temperature first part 21 through the internal space 25. The gaseous working fluid 27b that reaches the first section 21 is cooled and condenses to become a liquid working fluid 27a. At this time, the liquid working fluid 27a releases heat (latent heat) during the phase change (condensation). As a result, the adsorption section 10 is heated. In other words, when the desorption mode is performed, the first section 21 functions as a heat dissipation section. The liquid working fluid 27 that has released heat returns to the second section 22 via the capillary structure 28 by capillary action. In this way, when the desorption mode is performed, the working fluid 27 circulates in the internal space 25 of the heat transfer section 20 due to the temperature difference between the second section 22 and the first section 21, and heat transfer occurs from the second section 22 to the first section 21. During the heat transfer process, the heat transfer section 20 absorbs heat from the heat source 81 or the heat transfer medium heated by the heat source 81 and transfers the heat to the adsorption section 10 through the internal space 25.

[0027] The operating mechanism of the heat transfer unit 20 during the cooling mode will be explained in detail with reference to Figure 2B. The arrows inside the heat transfer unit 20 shown in Figure 2B indicate the flow of the working fluid 27 during the cooling mode. The dashed arrows outside the heat transfer unit 20 shown in Figure 2B indicate the flow of heat during the cooling mode. First, the second part 22 of the heat transfer unit 20 is cooled by the cooling source 82 or the heat transfer medium cooled by the cooling source 82, and the temperature of the second part 22 becomes lower than the temperature of the first part 21. As a result, in the first part 21, the liquid working fluid 27a absorbs heat and evaporates, becoming the gaseous working fluid 27b. At this time, the gaseous working fluid 27b absorbs the heat (latent heat) during the phase change (evaporation). That is, during the cooling mode, the first part 21 functions as a heat absorber. The gaseous working fluid 27b moves from the first part 21 to the lower temperature second part 22 through the internal space 25. The gaseous working fluid 27b that reaches the second section 22 is cooled and condenses to become a liquid working fluid 27a. At this time, the liquid working fluid 27a releases heat (latent heat) during the phase change (condensation). In other words, when the cooling mode is performed, the second section 22 functions as a heat dissipation section. The liquid working fluid 27 that has released heat returns to the first section 21 via the capillary structure 28 by capillary action. In this way, when the cooling mode is performed, the working fluid 27 circulates inside the heat transfer section 20 due to the temperature difference between the second section 22 and the first section 21, and heat transfer occurs from the first section 21 to the second section 22. During the heat transfer process, the heat transfer section 20 absorbs heat from the adsorption section 10 and transfers heat through the internal space 25. As a result, the adsorption section 10 is cooled.

[0028] The internal space 25 of the heat transfer section 20 is in a vacuum state. When the internal space 25 of the heat transfer section 20 is in a vacuum state, evaporation and condensation of the working fluid 27 occur more easily, and the absorption and release of heat caused by the temperature difference between the second section 22 and the first section 21 are carried out more efficiently.

[0029] The heat transfer section 20 may include at least one selected from the group consisting of a heat pipe and a vapor chamber. For example, when SA-VSA is adopted as the desorption method, if water vapor is introduced when the temperature of the adsorption section 10 is low, the water vapor may cool and condensate may be generated. This condensate can degrade the performance of the adsorption section 10. However, by using a heat pipe and / or a vapor chamber as the heat transfer section 20, the adsorption section 10 can be kept at a high temperature when the desorption mode is performed. This makes it possible to suppress the generation of condensate.

[0030] A heat pipe performs one-dimensional heat conduction. A heat pipe typically has a tubular shape. A heat pipe can transfer heat linearly from the second section 22 to the first section 21 or from the first section 21 to the second section 22. A vapor chamber performs two-dimensional heat conduction. A vapor chamber typically has a flattened shape. A vapor chamber can uniformly diffuse heat in a planar direction from the second section 22 to the first section 21 or from the first section 21 to the second section 22. The heat transfer section 20 may be a heat pipe or a vapor chamber. The heat transfer section 20 may consist of both a heat pipe and a vapor chamber.

[0031] As shown in Figure 1, the first portion 21 of the heat transfer section 20 may be positioned above the second portion 22 in the vertical direction. With this configuration, for example, when the desorption mode is performed, the gaseous working fluid 27 can easily move from the second portion 22 to the first portion 21 of the heat transfer section 20. Also, for example, when the cooling mode is performed, the liquid working fluid 27 can easily move from the first portion 21 to the second portion 22 of the heat transfer section 20. Therefore, the utilization efficiency of the heat transfer section 20 is improved. In the example in Figure 1, the first portion 21 of the heat transfer section 20 is positioned above the second portion 22 in the vertical direction.

[0032] The recovery system 100 further includes a heating path 31 connecting the second portion 22 of the heat transfer unit 20 and the heat source 81. With this configuration, for example, when the desorption mode is performed, the heat from the heat medium heated by the heat source 81 can be smoothly transferred to the second portion 22 of the heat transfer unit 20. Although not shown in the figures, the heating path 31 may further be provided with a flow control valve to adjust the flow rate of the heat medium flowing through the heating path 31.

[0033] The recovery system 100 may further include a cooling path 32 connecting the second part 22 of the heat transfer unit 20 to the cooling source 82. With such a configuration, for example, when the cooling mode is implemented, the heat from the heat transfer medium cooled by the cooling source 82 can be smoothly transferred to the second part 22 of the heat transfer unit 20. Although not shown in the figures, the cooling path 32 may further be provided with a flow control valve to adjust the flow rate of the heat transfer medium flowing through the cooling path 32.

[0034] The recovery system 100 further comprises a case 11 in which the adsorption unit 10 is housed. The first portion 21 of the heat transfer unit 20 may be located inside the case 11 or on the outer wall of the case 11. With this configuration, for example, when the desorption mode is performed, heat can be transferred from the first portion 21 of the heat transfer unit 20 to the adsorption unit 10 while the adsorption unit 10 is housed in the case 11.

[0035] In the example shown in Figure 1, the first portion 21 of the heat transfer unit 20 is located inside the case 11. This allows the first portion 21 of the heat transfer unit 20 to be in direct contact with the adsorption unit 10. With this configuration, for example, when performing the desorption mode, heat can be transferred from the first portion 21 of the heat transfer unit 20 to the adsorption unit 10 while the adsorption unit 10 is housed in the case 11. The heated adsorption unit 10 then desorbs the acidic gas.

[0036] Although not shown in the diagram, the first portion 21 of the heat transfer section 20 may be located on the outer wall of the case 11. This allows the first portion 21 of the heat transfer section 20 to be indirectly in contact with the adsorption section 10. Even with this configuration, for example, when the desorption mode is performed, heat can be transferred from the first portion 21 of the heat transfer section 20 to the adsorption section 10 while the adsorption section 10 is housed in the case 11.

[0037] In the recovery system 100, the desorption mode is performed with the adsorption unit 10, which has adsorbed the acidic gas, housed in the case 11. The cooling mode is performed with the adsorption unit 10, after the acidic gas has been desorbed, housed in the case 11. The adsorption mode is performed with the regenerated adsorption unit 10, housed in the case 11. In other words, in all three modes—adsorption, cooling, and desorption—the adsorption unit 10 is housed in the same case 11. To put it another way, in the recovery system 100, the adsorption mode, cooling mode, and desorption mode are performed inside a single case 11. With this configuration, for example, it is easier to switch between the adsorption mode and the desorption mode compared to a case where different cases are used for the adsorption mode and the desorption mode. Also, since there is no need to prepare separate cases for each mode, the recovery system 100 can be made compact.

[0038] Furthermore, since the recovery system 100 can perform the desorption mode without creating a vacuum inside the case 11, the case 11 can have a simple configuration. Also, the shape of the case 11 can be freely designed to match the shape of the adsorption part 10. Examples of materials for the case 11 include resin and metal. As shown in Figure 1, the shape of the case 11 may be a rectangular parallelepiped. However, the shape of the case 11 is not limited to a rectangular parallelepiped. The shape of the case 11 may be, for example, cylindrical.

[0039] As shown in Figure 1, the recovery system 100 may have a heat transfer space 50 for the second portion 22 of the heat transfer section 20 to absorb or release heat. For example, the temperature of the heat transferred to the second portion 22 of the heat transfer section 20 may be adjusted by controlling the temperature of the heat transfer medium flowing into the heat transfer space 50.

[0040] Figure 3 is a schematic perspective view showing an example of part III of Figure 1. As shown in Figure 3, a single common case 16 may comprise a case 11 housing the adsorption unit 10 and a heat transfer space 50 for the second part 22 of the heat transfer unit 20 to absorb or release heat. However, in case 16, the internal space of case 11 housing the adsorption unit 10 and the heat transfer space 50 are independent of each other. With such a configuration, for example, when performing the desorption mode, by simply setting up case 16 so that the heat transfer space 50 is in contact with the heat source 81 or a heat medium heated by the heat source 81, the acidic gas can be desorbed and recovered from the adsorption unit 10 that is adsorbing the acidic gas. For example, if the heat source 81 is geothermal energy, the desorption mode can be performed using geothermal energy by burying only the heat transfer space 50 of case 16 in the ground.

[0041] As shown in Figure 3, the recovery system 100 may include a plurality of heat transfer sections 20. In other words, the heat transfer section 20 may be an assembly of a plurality of heat transfer sections 20. In this case, each of the plurality of heat transfer sections 20 has a first section 21 and a second section 22. With such a configuration, the energy required to recover the target fluid such as carbon dioxide can be further reduced.

[0042] As shown in Figure 1, the heating path 31 and the cooling path 32 may merge into a common path 33 at a confluence point 33p. The common path 33 may be connected to the second part 22 of the heat transfer unit 20. With this configuration, by switching the path connected to the common path 33 between the heating path 31 and the cooling path 32, the temperature difference between the second part 22 and the first part 21 of the heat transfer unit 20 can be controlled according to the mode being implemented. Specifically, the temperature of the second part 22 of the heat transfer unit 20 can be made higher or lower than the temperature of the first part 21.

[0043] As shown in Figure 1, a switching valve 41 for switching between the heating path 31 and the cooling path 32 may be provided at the confluence point 33p. With this configuration, the heating path 31 and the cooling path 32 can be easily switched by operating the switching valve 41. The switching valve 41 is typically a three-way valve. However, instead of the switching valve 41, on / off valves may be provided in the heating path 31 and the cooling path 32, respectively.

[0044] In the case 16 shown in Figure 3, the heating path 31 may be used as a common path 33. In this case, by switching the path connected to the common path 33 between the heating path 31 and the cooling path 32, the temperature difference between the second part 22 and the first part 21 of the heat transfer section 20 can be controlled according to the mode being implemented.

[0045] As shown in Figure 1, the downstream side of the common path 33 may be configured to discharge the heat transfer medium after heating the heat transfer section 20 or after cooling the heat transfer medium.

[0046] The recovery system 100 further includes a raw gas path 35, an adsorbed gas path 36, and a non-adsorbed gas path 37 as fluid pathways.

[0047] The raw material gas path 35 is connected to the gas inlet 11a of the case 11 and is a path for supplying the mixed gas G1 into the case 11. As will be described later, the mixed gas G1 may be atmospheric air. When the mixed gas G1 is atmospheric air, the raw material gas path 35 may have an intake port 35a that opens into the atmosphere, and may be configured to continuously draw in atmospheric air from the intake port 35a. As shown in Figure 1, the intake port 35a may be provided with a blowing mechanism 35b such as a fan to supply atmospheric air to the raw material gas path 35. The raw material gas path 35 may be connected to, for example, a tank (not shown) that stores the mixed gas G1.

[0048] A shut-off valve 42 may be provided in the raw material gas path 35. Although not shown in the figures, the raw material gas path 35 may further be provided with a flow control valve to adjust the flow rate of the mixed gas G1 flowing through the raw material gas path 35.

[0049] During the adsorption mode, the adsorption unit 10 comes into contact with the mixed gas G1 by supplying the mixed gas G1 to the inside of the case 11. As a result, the adsorption unit 10 adsorbs the acidic gas contained in the mixed gas G1.

[0050] In the example shown in Figure 1, the raw material gas path 35 is connected to a gas inlet 11a located on the upper side of the rectangular parallelepiped case 11. With this configuration, for example, in adsorption mode, the mixed gas G1 can be supplied evenly to the adsorption unit 10 housed in the case 11. However, the connection location of the raw material gas path 35 is not limited to the example shown in Figure 1. For example, the raw material gas path 35 may be connected to the entire side of the rectangular parallelepiped case 11.

[0051] The adsorption gas path 36 is connected to the gas outlet 11b of case 11 and is a path for discharging the adsorption gas G2 from case 11. The adsorption gas path 36 may be connected to a tank (not shown) for recovering the adsorption gas G2. The adsorption gas path 36 may be connected to a condenser (not shown) for increasing the concentration of the adsorption gas G2. The condenser may be connected to the recovery tank.

[0052] An on-off valve 43 may be provided in the adsorption gas path 36. Although not shown in the figures, the adsorption gas path 36 may further be provided with a flow control valve to adjust the flow rate of the adsorption gas G2 flowing through the adsorption gas path 36.

[0053] In the example shown in Figure 1, the adsorption gas path 36 is connected to a gas outlet 11b located on the upper surface of the rectangular parallelepiped case 11. With this configuration, for example, in the desorption mode, the adsorption gas G2 containing acidic gas desorbed from the adsorption unit 10 can be easily discharged to the outside of the case 11. However, the connection position of the adsorption gas path 36 is not limited to the example shown in Figure 1.

[0054] The non-adsorbent gas path 37 is connected to the gas outlet 11c of the case 11 and is a path for discharging the non-adsorbent gas G3 from the case 11. The non-adsorbent gas path 37 is, for example, open to the atmosphere. If the mixed gas G1 is the atmosphere, the non-adsorbent gas path 37 may have a configuration that continuously draws in the non-adsorbent gas G3. The non-adsorbent gas path 37 may be connected to a tank (not shown) for recovering the non-adsorbent gas G3.

[0055] An on-off valve 44 may be provided in the non-adsorbent gas path 37. Although not shown in the figures, the non-adsorbent gas path 37 may further be provided with a flow control valve to adjust the flow rate of the non-adsorbent gas G3 flowing through the non-adsorbent gas path 37.

[0056] In the example shown in Figure 1, the non-adsorbed gas path 37 is connected to a gas outlet 11c provided on the upper surface of the rectangular parallelepiped case 11. With this configuration, for example, in the adsorption mode, the non-adsorbed gas G3 that was not adsorbed by the adsorption unit 10 can be easily discharged to the outside of the case 11. However, the connection position of the non-adsorbed gas path 37 is not limited to the example shown in Figure 1. For example, the non-adsorbed gas path 37 may be connected to the entire side surface of the rectangular parallelepiped case 11.

[0057] Each of the pathways of the recovery system 100 consists of, for example, metal or resin piping, unless otherwise specified.

[0058] The recovery system 100 further includes a controller 60 that controls each component of the recovery system 100. The controller 60 is a DSP (Digital Signal Processor) that includes, for example, an A / D conversion circuit, an input / output circuit, an arithmetic circuit, a memory device, etc. The controller 60 stores a program for properly operating the recovery system 100. For example, in the adsorption mode, the controller 60 brings the adsorption unit 10 into contact with the mixed gas G1 by controlling the operation of the raw material gas path 35. For example, in the desorption mode, the controller 60 heats the adsorption unit 10 through the heat transfer unit 20 by controlling the operation of the heating path 31. For example, in the cooling mode, the controller 60 cools the adsorption unit 10 through the heat transfer unit 20 by controlling the operation of the cooling path 32.

[0059] The recovery system 100 may further include a switching mechanism (not shown) for switching between adsorption mode and desorption mode. The switching mechanism includes, for example, an on-off valve 42 located in the raw material gas path 35, a switching valve 41 located in the heating path 31, and a controller 60. The controller 60 controls each valve, and by switching between the raw material gas path 35 and the heating path 31, the adsorption mode and desorption mode can be switched.

[0060] [Raw fluid] In this embodiment, the raw material fluid is typically a gas. Examples of gaseous raw material fluids include mixed gases containing acidic gases such as carbon dioxide, and water vapor. When the raw material fluid is a mixed gas containing acidic gases such as carbon dioxide, the target fluid is the acidic gas such as carbon dioxide. When the raw material fluid is water vapor, the target fluid is water.

[0061] As described above, in the example in Figure 1, the raw material fluid is a mixed gas G1 containing an acidic gas such as carbon dioxide. Mixed gas G1 may further contain other gases other than acidic gases, for example. Mixed gas G1 is preferably air. Mixed gas G1 may also be exhaust gas such as combustion gas.

[0062] The acidic gas content in mixed gas G1 is not particularly limited, and is, for example, 0.01 vol% (100 vol ppm) or more, preferably 0.04 vol% (400 vol ppm) or more, and may be 0.1 vol% or more. The upper limit of the acidic gas content in mixed gas G1 is not particularly limited, and is, for example, 20 vol%. The pressure of mixed gas G1 is typically equal to atmospheric pressure in the operating environment of the recovery system 100.

[0063] Examples of acidic gases include carbon dioxide, hydrogen sulfide, carbonyl sulfide, sulfur oxides (SOx), hydrogen cyanide, nitrogen oxides (NOx), etc., with carbon dioxide being preferred.

[0064] [Adsorption part] In this embodiment, the adsorption unit comes into contact with the raw material fluid containing the target fluid, such as carbon dioxide, to adsorb the target fluid contained in the raw material fluid, and then, while the target fluid is adsorbed, it is heated to release the target fluid.

[0065] As described above, in the example in Figure 1, the raw material fluid is a mixed gas G1 containing an acidic gas such as carbon dioxide, and the target fluid is an acidic gas such as carbon dioxide. The adsorption unit 10 may adsorb the acidic gas contained in the mixed gas G1 by coming into contact with the mixed gas G1 containing the acidic gas, and may also desorb the acidic gas by heating while the acidic gas is adsorbed.

[0066] Figure 4 is a schematic perspective view showing an example of an adsorption section 10. The adsorption section 10A shown in Figure 4 is a structure comprising a main body 12 and a ventilation path 14. The ventilation path 14 functions as a path through which a mixed gas G1 or the like passes. It is preferable that the adsorption section 10A is arranged such that the ventilation path 14 extends in the flow direction of the mixed gas G1. Typically, the adsorption section 10A is a honeycomb structure having a plurality of ventilation paths 14 extending in the same direction.

[0067] The main body 12 of the suction part 10A typically has the shape of a sheet. The suction part 10A may also include a support that supports the main body 12, along with the sheet-shaped main body 12.

[0068] As shown in Figure 4, the adsorption portion 10A may comprise a unit 15 in which a corrugated body portion 12A and a flat body portion 12B are stacked. In the body portion 12A, a plurality of peaks 13a and a plurality of valleys 13b may be arranged alternately. In this case, a ventilation path 14 is formed between the peaks 13a or valleys 13b of the body portion 12A and the body portion 12B. Thus, the ventilation path 14 is surrounded by the body portions 12A and 12B.

[0069] The configuration of the adsorption section 10 is not limited to the example shown in Figure 4. Figure 5 is a schematic perspective view showing another example of the adsorption section 10. The adsorption section 10B shown in Figure 5 is a structure having a shape in which one unit 15 is wound around a central tube (not shown). Except for this, the configuration of the adsorption section 10B shown in Figure 5 is the same as the configuration of the adsorption section 10A shown in Figure 4. It is preferable that the adsorption section 10B is arranged such that the central tube extends in the flow direction of the mixed gas G1, etc., in the case 11 (not shown in Figure 5). The case 11 capable of housing the adsorption section 10B may be cylindrical (especially cylindrical). Because the unit 15 is wound around the central tube, in the main body section 12A, the multiple peaks 13a and multiple valleys 13b are, in detail, arranged alternately in the circumferential direction of the central tube.

[0070] If the adsorption unit 10 is designed to adsorb and desorb acidic gases contained in the mixed gas G1, it is preferable that the adsorption unit 10 be suitable for the TSA method. For example, the adsorption unit 10 adsorbs acidic gases at room temperature (around 25°C) and desorbs them when heated.

[0071] The material of the adsorption portion 10 is not particularly limited, and examples include inorganic materials and organic materials. Examples of inorganic materials include metal oxides such as cerium oxide, zeolites, silica gel, and activated carbon. Examples of organic materials include polymer P having an amino group and amine compounds other than polymer P. In this embodiment, it is preferable that the adsorption portion 10 contains polymer P having an amino group.

[0072] In DACs employing the TSA method, nanoparticles such as silica supporting amines are sometimes used as the adsorption part. Conventionally, in order to avoid the elution of amines from the adsorption part, methods of indirectly heating the adsorbent with hot water or the like were often employed. However, in such indirect heating methods, the degree of contact between the heat transfer surface and the adsorption part affects the heating performance, so if the adsorbent swells or shrinks, the thermal conductivity between the adsorption part and the heat transfer surface may be impaired. To avoid such problems, it is conceivable to fix the adsorption part using adhesives, fasteners, etc., but this is undesirable as it makes installation and replacement complicated. In contrast, in the recovery system 100 according to this embodiment, when the desorption mode is performed, the adsorption part 10 is heated while housed in the case 11, so even if the adsorption part 10 swells or shrinks, the impact on heating performance can be suppressed to a low extent. Therefore, there is no need to fix the adsorption part 10 to the case 11.

[0073] The adsorption unit 10 containing the polymer P having amino groups swells in water, but the elution of amines is kept low compared to conventional amine-based solid adsorbents. For example, when the adsorption unit 10 is immersed in water at 25°C for 15 hours, the remaining amount of polymer P can be 90% or more. Therefore, the adsorption unit 10 containing the polymer P having amino groups is particularly suitable for the recovery system 100 according to this embodiment, which employs a direct heating method.

[0074] The remaining polymer P can be determined, for example, by the following method: A sample body is prepared by punching out an adsorption part 10 (250 μm thick) to a size of 20 mm × 30 mm in an environment of 25°C and 50% humidity. The weight of the dry sample body after vacuum drying at 100°C for 120 minutes is measured and this is taken as the polymer P content R1 in the dry state. If the adsorption part 10 contains a support, the weight of the support contained in the 20 mm × 30 mm × 250 μm thickness is subtracted to determine the polymer P content R1 (wt%) in the dry state. Next, the sample body is immersed in water at 25°C for 15 hours. The weight of the dry sample body after vacuum drying at 100°C for 120 minutes is measured and this is taken as the polymer P content R2 (wt%) after immersion. If the adsorption part 10 contains a support, the weight of the carrier contained in the 20 mm × 30 mm × 250 μm thickness is subtracted to determine the polymer P content R2 after immersion. The remaining polymer P D after immersing the adsorption part 10 in water at 25°C for 15 hours can be calculated using the following formula (1). D=1-{(R1-R2) / R1}×100...(1)

[0075] The adsorption portion 10 is not limited to honeycomb structures such as the adsorption portions 10A and 10B described above. For example, the adsorption portion 10 may be a block-shaped structure formed by stacking sheet-shaped adsorbent materials, or it may be an aggregate of bead-shaped adsorbent materials.

[0076] The adsorption portion 10 may have a porous structure. For example, the adsorption portion 10 may include a porous body S containing a polymer P as a sheet-like or block-like main body portion 12.

[0077] The porous body S preferably has a three-dimensional network-like framework containing polymer P. The three-dimensional network-like framework may further contain other components besides polymer P. For example, in the porous body S, the above-mentioned three-dimensional network-like framework extends continuously. The pores contained in the porous body S are preferably continuous pores formed in a three-dimensional manner. The porous body S may have independent pores or through pores penetrating the porous body S.

[0078] The porous body S preferably has an average pore diameter of 0.1 μm or more and 50 μm or less. The larger the average pore diameter of the porous body S, the more the diffusion of acidic gas can be maintained without clogging the pores even when the adsorption part 10 contains water. The lower limit of the average pore diameter of the porous body S may be 0.2 μm or more, 0.3 μm or more, or even 0.5 μm or more. In the present specification, the average pore diameter of the porous body S means the median diameter measured by a mercury porosimetry method. The mercury porosimetry method is performed using a commercially available pore distribution analyzer (for example, AutoPore V9620 manufactured by Micromeritics Inc.) under the condition of an initial pressure of 21 kPa.

[0079] The porous body S preferably has a specific surface area of 0.5 m 2 / g or more and 100 m 2 / g or less. The larger the specific surface area of the porous body S, the larger the contact area with the acidic gas, so the rate of adsorbing the acidic gas increases. The lower limit of the specific surface area of the porous body S may be 0.5 m 2 / g or more, 1.0 m 2 / g or more, 2.0 m 2 / g or more, 3.0 m 2 / g or more, 4.0 m 2 / g or more, 5.0 m 2 / g or more, 6.0 m 2 / g or more, 7.0 m 2 / g or more, or even 8.0 m 2 / g or more. The specific surface area of the porous body S means a BET (Brunauer-Emmett-Teller) specific surface area measured by nitrogen gas adsorption. The specific surface area of the porous body S can be measured by a method conforming to the provisions of JIS Z8830:2013.

[0080] The porous body S preferably has a pore volume of 0.1 cm 3 / g or more and 5.0 cm 3 / g or less. The larger the pore volume of the porous body S, the more the diffusivity of the acidic gas in the pores is improved, so the rate of adsorbing the acidic gas can increase. The lower limit of the pore volume of the porous body S may be 0.2 cm 3 / g or more, 0.3 cm 3 / g or more, 0.5 cm3 / g or more, 1.0cm 3 / g or more, and also 2.0cm 3 It may be greater than or equal to / g. The upper limit of the pore volume of the porous body S is 4.0 cm³. 3 It may be less than / g, and 3.0cm 3 The concentration may be less than or equal to / g. The pore volume of the porous body S can be measured by the mercury intrusion method. The mercury intrusion method is performed using a commercially available pore distribution analyzer (for example, the Autopore V9620 manufactured by Micromeristics) under an initial pressure of 21 kPa.

[0081] (Polymer P) The polymer P is preferably an amine polymer containing a constituent unit U1 derived from an epoxy monomer. This amine polymer includes, for example, a reaction product P1 from a group of compounds containing an amine monomer and an epoxy monomer.

[0082] The group of compounds for forming reactant P1 includes amine monomers and epoxy monomers, as described above. Reactant P1 may be, for example, a polymer of the group of monomers including amine monomers and epoxy monomers (particularly a polymer of amine monomers and epoxy monomers). Reactant P1 may also be a crosslinked product in which the amine monomer is crosslinked with the epoxy monomer.

[0083] Examples of amine monomers include ethylamine, ethylenediamine, 1,4-butylenediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, iminobispropylamine, bis(hexamethylene)triamine, 1,3,6-trisaminomethylhexane, tris(2-aminoethyl)amine, N,N'-bis(3-aminopropyl)ethylenediamine, polymethylenediamine, trimethylhexamethylenediamine, poly Examples include aliphatic amines such as ether diamines; alicyclic amines such as isophorone diamine, menthane diamine, piperazine, N-aminoethylpiperazine, 3,9-bis(3-aminopropyl)2,4,8,10-tetraoxaspiro(5,5)undecane adduct, bis(4-amino-3-methylcyclohexyl)methane, bis(4-aminocyclohexyl)methane, and modified versions thereof; aliphatic polyamines such as polyethyleneimines and polyalkylene polyamines; (meth)acrylic polymers having amino groups such as aminoethylated acrylic polymers; and aliphatic polyamidoamines formed by the reaction of polyamines with dimer acids. Amine monomers can be used alone or in combination of two or more.

[0084] Examples of epoxy monomers include monofunctional epoxy compounds such as n-butyl glycidyl ether, higher alcohol glycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, p-sec-butylphenyl glycidyl ether, and t-butylphenyl glycidyl ether; diepoxyalkanes such as 1,5-hexadiene diepoxide, 1,7-octadiene diepoxide, and 1,9-decadiene diepoxide; and (poly)ethylene glycol diglycidyl ether. Examples include polyfunctional epoxy compounds having an ether group, such as ether, (poly)propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane polyglycidyl ether, and sorbitol polyglycidyl ether; and polyfunctional epoxy compounds having an amino group, such as N,N,N',N'-tetraglycidylmetoxylendiamine and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane.

[0085] The epoxy monomer may, in some cases, be an aromatic epoxy resin, a non-aromatic epoxy resin, etc. Examples of aromatic epoxy resins include polyphenyl-based epoxy resins, epoxy resins containing fluorene rings, epoxy resins containing triglycidyl isocyanurate, and epoxy resins containing heteroaromatic rings (e.g., triazine rings). Examples of polyphenyl-based epoxy resins include bisphenol A type epoxy resins, brominated bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD ​​type epoxy resins, stilbene type epoxy resins, biphenyl type epoxy resins, bisphenol A novolac type epoxy resins, cresol novolac type epoxy resins, diaminodiphenylmethane type epoxy resins, and tetrakis(hydroxyphenyl)ethane-based epoxy resins. Examples of non-aromatic epoxy resins include aliphatic glycidyl ether type epoxy resins, aliphatic glycidyl ester type epoxy resins, alicyclic glycidyl ether type epoxy resins, alicyclic glycidylamine type epoxy resins, and alicyclic glycidyl ester type epoxy resins.

[0086] Epoxy monomers can be used individually or in combination of two or more. When using monofunctional epoxy compounds, it is preferable to use them in combination with other epoxy monomers containing two or more epoxy groups. Monofunctional epoxy compounds can also be used as reactive diluents to adjust the viscosity of the monomer group for forming reactant P1.

[0087] As described above, polymer P as an amine polymer contains constituent units U1 derived from epoxy monomers. When polymer P is reactant P1, polymer P further contains constituent units U2 derived from amine monomers. The content of constituent units U1 in polymer P, particularly reactant P1, is, for example, 20 wt% to 70 wt%. The content of constituent units U2 in polymer P, particularly reactant P1, is, for example, 30 wt% or more, preferably 50 wt% or more. The upper limit of the content of constituent units U2 is not particularly limited, but is, for example, 80 wt%.

[0088] The glass transition temperature Tg of polymer P is not particularly limited, and is, for example, 40°C or lower, preferably 30°C or lower, more preferably 20°C or lower, even more preferably 15°C or lower, and may be 10°C or lower, 5°C or lower, or 0°C or lower. When the glass transition temperature Tg of polymer P is this low, the rate of adsorption of acidic gases in the adsorption portion 10 tends to be high. The lower limit of the glass transition temperature Tg of polymer P is, for example, -100°C, preferably -50°C, and more preferably -10°C, from the viewpoint of ensuring sufficient adsorption of acidic gases in the adsorption portion 10 and from the viewpoint of heat resistance. In this specification, the glass transition temperature Tg is the intermediate glass transition temperature (T) determined in accordance with the provisions of JIS K7121:1987. mg This means that polymer P is a solid. Polymer P is typically a thermosetting resin. Polymer P is solid at, for example, 25°C, preferably in the range of 25°C to 80°C.

[0089] The weight-average molecular weight of polymer P is not particularly limited, but is, for example, 500 or more, preferably 1000 or more, more preferably 100000 or more, and even more preferably 100000 or more. The upper limit of the weight-average molecular weight of polymer P is, for example, 10000000 or less.

[0090] The adsorption portion 10 may contain polymer P as its main component, or it may be composed substantially of polymer P alone. The adsorption portion 10 may also contain other components besides polymer P. Examples of other components include a carrier for supporting polymer P, a reaction accelerator, a plasticizer, a pigment, a dye, an antioxidant, a conductive material, an antistatic agent, an ultraviolet absorber, a flame retardant, an antioxidant, and the like.

[0091] Examples of carriers include fibers and fiber structures containing fibers. Examples of fibers include glass fibers; natural fibers such as wood pulp, cotton, and hemp (e.g., Manila hemp); and chemical fibers (synthetic fibers) such as polyester fibers, rayon, vinylon, acetate fibers, polyvinyl alcohol (PVA) fibers, polyamide fibers, polyolefin fibers, and polyurethane fibers. Examples of fiber structures include woven fabrics, nonwoven fabrics, and paper. A specific example of a fiber structure is glass paper.

[0092] Reaction accelerators are used, for example, when synthesizing polymer P. Examples of reaction accelerators include tertiary amines such as triethylamine and tributylamine; and imidazoles such as 2-phenol-4-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenol-4,5-dihydroxyimidazole. These reaction accelerators can accelerate reactions, for example, to synthesize polymer P.

[0093] The polymer P content R1 in the adsorption section 10 is, for example, 5 wt% or more, and may be 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, or even 35 wt% or more. The higher the polymer P content R1, the greater the amount of acidic gas adsorbed by the adsorption section 10 tends to be. The upper limit of the polymer P content R1 is, for example, 80 wt% or less, and may be 60 wt% or less.

[0094] The polymer P content R1 can be measured, for example, by the following method. First, the adsorption unit 10 is placed in a simultaneous thermal analysis DSC / TGA instrument. At this time, the temperature is set to 30°C. Next, using this instrument, the temperature is raised from 30°C to 100°C at a heating rate of 10°C / min under a nitrogen atmosphere and held at that temperature for 40 minutes (Operation 1). According to Operation 1, water contained in the adsorption unit 10 can be removed. Next, the temperature is raised from 100°C to 800°C at a heating rate of 10°C / min and held at that temperature for 5 minutes (Operation 2). According to Operation 2, polymer P can be removed from the adsorption unit 10. The ratio (100 × (W1-W2) / W1) of the difference between the weight W1(g) of the adsorption unit 10 immediately after Operation 1 and the weight W2(g) of the adsorption unit 10 immediately after Operation 2 can be considered as the polymer P content R1 in the adsorption unit 10.

[0095] (Support) The support, for example, supports the sheet-like main body portion 10 and is in direct contact with the sheet-like main body portion 12. The suction portion 10 (for example, the suction portion 10A shown in Figure 4) may or may not further include fixing means for fixing the sheet-like main body portion 12 and the support. Specific examples of fixing means include adhesives, and more specifically, adhesive sheets containing adhesives. In this specification, the term "adhesive" is used to encompass pressure-sensitive adhesives.

[0096] Furthermore, the adsorption portion 10 may not have a support and may consist only of a sheet-like main body portion 12. In other words, the adsorption portion 10 may be formed from a self-supporting film (single-layer film) of the sheet-like main body portion 12.

[0097] The support material is not particularly limited and may include, for example, ceramics such as cordierite, alumina, cordierite-α-alumina, silicon nitride, zircon mullite, scia pyroxene, alumina-silica-magnesia, zircon silicate, sillimanite, magnesium silicate, zircon, feldspar, and aluminosilicate; metals such as aluminum, titanium, copper, stainless steel, Fe-Cr alloy, and Cr-Al-Fe alloy; and silicone resin, polyolefin, polyester, polyurethane, polycarbonate, and polyetheretherketone. Examples of suitable materials include polyphenylene oxide, polyethersulfone, melamine, polyamide, poly(meth)acrylate, polystyrene, poly(meth)acrylonitrile, polyimide, polyfurfural alcohol, phenolfurfuryl alcohol, melamine formaldehyde, resorcinol formaldehyde, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycyanurate, poly(meth)acrylamide, epoxy resin, agar, agarose, cellulose, and other resins. The support material is preferably excellent in thermal conductivity and durability, and less susceptible to deterioration due to rust formation or hydrolysis when in contact with water.

[0098] The support may or may not have a porous structure. Examples of supports having a porous structure include paper, nonwoven fabric, foam, and mesh. If the support has a porous structure, for example, the polymer P can be placed inside the pores of the support. However, the polymer P does not necessarily have to be located inside the pores of the support. Examples of supports not having a porous structure include non-porous sheets and foils. The support may also be an aluminum sheet, paper, or nonwoven fabric.

[0099] The support may function as a planar heater, and may be a planar thermoelectric heater or a Peltier element.

[0100] If the support is in sheet form, the thickness of the support may be, for example, 1000 μm or less, but may also be 500 μm or less, 300 μm or less, or even 250 μm or less. The lower limit of the support thickness may be, for example, 50 μm or more, or even 100 μm or more.

[0101] [Methods for recovering acidic gases] Next, an example of a method for recovering acidic gas using the recovery system 100 described above will be explained. The method for recovering acidic gas using the recovery system 100 includes an adsorption step in which a mixed gas G1 containing acidic gas is brought into contact with an adsorption unit 10 to adsorb the acidic gas contained in the mixed gas G1 onto the adsorption unit 10, and a desorption step in which the adsorbed gas G2 containing acidic gas is desorbed from the adsorption unit 10 that has adsorbed the acidic gas. The adsorption step is a step corresponding to the adsorption mode described for the recovery system 100. The desorption step is a step corresponding to the desorption mode described for the recovery system 100. According to this recovery method, energy efficiency is improved and the system can be miniaturized.

[0102] The desorption process is performed with the adsorption unit 10, which adsorbs acidic gas, housed in the case 11. During the desorption process, in the heat transfer unit 20, the working fluid 27 circulates through the internal space 25 of the heat transfer unit 20 due to the temperature difference between the second part 22 and the first part 21, causing heat transfer from the second part 22 to the first part 21. During the heat transfer process, the heat transfer unit 20 absorbs heat from the heat source 81 or the heat transfer medium heated by the heat source 81 and transfers the heat to the adsorption unit 10 through the internal space 25. As a result, the adsorption unit 10 is heated. According to this recovery method, acidic gas can be desorbed from the adsorption unit 10 by directly heating the adsorption unit 10 inside the case 11.

[0103] In this recovery method, the adsorption and desorption processes are performed within the same case 11. With this configuration, for example, it is easier to switch between the adsorption and desorption processes compared to a case where the case for the adsorption process and the case for the desorption process are separate.

[0104] The recovery method may further include a cooling step between the desorption step and the adsorption step, in which the adsorption section 10 from which the acidic gas has been desorbed is cooled. The cooling step corresponds to the cooling mode described for the recovery system 100.

[0105] The cooling process is performed with the adsorption unit 10, from which the acidic gas has been desorbed, housed in the case 11. During the cooling process, the working fluid 27 circulates within the internal space 25 of the heat transfer unit 20 due to the temperature difference between the second part 22 and the first part 21, causing heat transfer from the first part 21 to the second part 22. In the process of heat transfer, the heat transfer unit 20 absorbs heat from the adsorption unit 10 and transfers the heat through the internal space 25. This cools the adsorption unit 10. By performing a cooling process between the desorption process and the adsorption process, the adsorption unit 10 from which the acidic gas has been desorbed can be cooled. As a result, the adsorption unit 10 is regenerated and can adsorb acidic gas again.

[0106] Next, we will explain in more detail the method for recovering acidic gases using the recovery system 100, with reference to Figure 1.

[0107] The adsorption process is carried out, for example, as follows: First, the on-off valves 42 and 44 are opened, and the mixed gas G1 is supplied into the case 11 through the raw material gas passage 35. At this time, the on-off valve 43 and the switching valve 41 are closed. As a result, the gas remaining in the case 11 is replaced with the mixed gas G1. At this time, the adsorption section 10, which has desorbed, for example, the acidic gas, is located inside the case 11. The mixed gas G1 is, for example, air. The acidic gas is, for example, carbon dioxide.

[0108] If the adsorption unit 10 is the adsorption unit 10A shown in Figure 4, the mixed gas G1 supplied to the case 11 moves along the ventilation path 14 and comes into contact with the main body 12 (12A and 12B). The main body 12, upon contact with the mixed gas G1, adsorbs the acidic gas contained in the mixed gas G1.

[0109] The mixed gas G1 (non-adsorbent gas G3) processed inside case 11 is discharged from the gas outlet 11c of case 11 and released into the atmosphere, for example, through the non-adsorbent gas path 37.

[0110] Non-adsorbed gas G3 has a lower acidic gas content compared to the desorbed gas (adsorbed gas G2). The acidic gas content in non-adsorbed gas G3 is, for example, 0.1 vol% or more, preferably 1 vol% or more, lower than that of adsorbed gas G2. The acidic gas content in non-adsorbed gas G3 is, for example, 0.003 vol% or more and 10 vol% or less.

[0111] After the adsorption process, a desorption process is performed. During the desorption process, the adsorption unit 10, which has adsorbed the acidic gas, is located inside the case 11.

[0112] The desorption process is carried out, for example, as follows: First, the on-off valve 42 is closed. At this time, the on-off valve 44 and / or on-off valve 43 are open. Next, the switching valve 41 is switched to the heating path 31, and the second part 22 of the heat transfer section 20 is heated through the heating path 31 by the heating source 81 or the heat transfer medium heated by the heating source 81. As a result, heat transfer occurs from the second part 22 to the first part 21 of the heat transfer section 20, and the adsorption section 10 is heated.

[0113] If the adsorption unit 10 is the adsorption unit 10A shown in Figure 4, the main body 12 of the adsorption unit 10 receives heat and desorbs the acidic gas. This generates adsorbed gas G2 containing the acidic gas desorbed from the adsorption unit 10. The adsorbed gas G2 is discharged from the gas outlet 11b of the case 11 and stored, for example, in a tank for recovering the adsorbed gas G2 via the adsorption gas path 36.

[0114] Adsorbed gas G2 has a higher acidic gas content compared to non-adsorbed gas G3. The acidic gas content in adsorbed gas G2 is, for example, greater than 5 vol% and less than or equal to 100 vol%.

[0115] A cooling step may be performed after the desorption step. During the cooling step, the adsorption unit 10, from which the acidic gas has been desorbed, is located inside the case 11.

[0116] The cooling process is carried out, for example, as follows: First, the switching valve 41 is switched to the cooling path 32, and the second portion 22 of the heat transfer section 20 is cooled through the cooling path 32 by the cooling source 82 or the heat medium cooled by the cooling source 82. This causes heat transfer from the first portion 21 to the second portion 22 of the heat transfer section 20, and the adsorption section 10 is cooled.

[0117] An example of the recovery system according to this embodiment has been described using Figures 1 to 5, but the recovery system according to this embodiment is not limited to the example described above. Hereinafter, modifications 1 to 3 of the recovery system according to this embodiment will be described using Figures 6 to 9. In modifications 1 to 3, elements common to the recovery system 100 described above will be given the same reference numerals and their descriptions may be omitted.

[0118] (Variation 1) Figure 6 is a schematic diagram of a modified example 1 of the recovery system according to this embodiment. In the recovery system 101 of modified example 1, the second portion 22 of the heat transfer section 20 has portion A 22a and portion B 22b. Portion A 22a may or may not be continuous with portion B 22b. In the example of Figure 6, portion A 22a is continuous with portion B 22b. The heating path 31 connects portion A 22a to the heating source 81. The cooling path 32 connects portion B 22b to the cooling source 82. Except for these, the recovery system 101 has the same configuration as the recovery system 100 described above.

[0119] According to the recovery system 101 of the modified example 1, the temperature difference between the second part 22 and the first part 21 of the heat transfer section 20 can be controlled depending on the mode being implemented by switching the path used to the heating path 31 or the cooling path 32. Specifically, by switching the path used to the heating path 31, the temperature of the second part 22 (part A 22a) of the heat transfer section 20 can be made higher than the temperature of the first part 21 when the desorption mode is implemented. By switching the path used to the cooling path 32, the temperature of the second part 22 (part B 22b) of the heat transfer section 20 can be made lower than the temperature of the first part 21 when the cooling mode is implemented.

[0120] A shut-off valve 45 may be provided in the heating path 31. Although not shown in the figures, a flow control valve may be further provided in the heating path 31 to adjust the flow rate of the heat transfer medium flowing through the heating path 31.

[0121] A shut-off valve 46 may be provided in the cooling path 32. Although not shown in the figures, a flow control valve may be further provided in the cooling path 32 to adjust the flow rate of the heat transfer medium flowing through the cooling path 32.

[0122] As shown in Figure 6, the downstream side of the heating path 31 may be configured to discharge the heat transfer medium after heating the heat transfer section 20.

[0123] As shown in Figure 6, the downstream side of the cooling path 32 may be configured to discharge the heat transfer medium after it has cooled the heat transfer section 20.

[0124] As shown in Figure 6, in the vertical direction, portion A 22a of the heat transfer section 20 may be located below portion B 22b. With this configuration, for example, when the desorption mode is performed, the gaseous working fluid 27 can easily move from portion A 22a of the heat transfer section 20 toward the first portion 21. Therefore, the utilization efficiency of the heat transfer section 20 is improved. In the example in Figure 6, in the vertical direction, portion A 22a is located below portion B 22b.

[0125] As shown in Figure 6, the recovery system 101 may have a heat transfer space 51 and a heat transfer space 52 as the heat transfer space 50. The heat transfer space 51 is the space for portion A 22a of the heat transfer section 20 to absorb heat. The heat transfer space 52 is the space for portion B 22b of the heat transfer section 20 to dissipate heat.

[0126] Figure 7 is a schematic perspective view showing an example of part VII of Figure 6. As shown in Figure 7, a single common case 17 may comprise a case 11 housing the adsorption unit 10, a heat transfer space 51 for heat absorption by part A 22a of the heat transfer unit 20, and a heat transfer space 52 for heat dissipation by part B 22b of the heat transfer unit 20. However, in case 17, the internal space of case 11 housing the adsorption unit 10, the heat transfer space 51, and the heat transfer space 52 are independent of each other. With such a configuration, for example, when performing the desorption mode, the acidic gas can be desorbed and recovered from the adsorption unit 10 that is adsorbing the acidic gas simply by setting up case 17 so that the heat transfer space 51 is in contact with the heat source 81 or a heat transfer medium heated by the heat source 81.

[0127] Case 17, shown in Figure 7, has the same configuration as Case 16, shown in Figure 3, except that the heat transfer space 50 is divided into a heat transfer space 51 and a heat transfer space 52.

[0128] In the example shown in Figure 7, portion A 22a of the heat transfer section 20 is not continuous with portion B 22b. As shown in Figure 7, in the vertical direction, portion B 22b may be located above the adsorption section 10. That is, portion B 22b may be located above the adsorption section 10, and portion A 22a may be located below it. With such a configuration, for example, when the desorption mode is performed, the gaseous working fluid 27 can easily move in the direction from portion A 22a of the heat transfer section 20 toward the first portion 21. Also, for example, when the cooling mode is performed, the liquid working fluid 27 can easily move in the direction from portion B 22b of the heat transfer section 20 toward the first portion 21.

[0129] In the method for recovering acidic gas using the recovery system 101 of Modified Example 1, the desorption process is carried out, for example, as follows. First, the on-off valve 42 is closed. At this time, the on-off valve 44 and / or on-off valve 43 are open. Also, the on-off valve 46 is closed. Next, the on-off valve 45 is opened, and the heat transfer section 20 is heated by the heat medium heated by the heat source 81 through the heating path 31. As a result, heat transfer occurs from section A 22a of the heat transfer section 20 to the first section 21, and the adsorption section 10 is heated.

[0130] In the method for recovering acidic gas using the recovery system 101 of Modified Example 1, the cooling step is carried out, for example, as follows: First, the on-off valve 45 is closed. Next, the on-off valve 46 is opened, and the heat transfer section 20 is cooled by the heat medium cooled by the cooling source 82 through the cooling path 32. This causes heat transfer from the first section 21 to section B 22b of the heat transfer section 20, and the adsorption section 10 is cooled.

[0131] (Modification 2) Figure 8 is a schematic diagram of a modified example 2 of the recovery system according to this embodiment. In the recovery system 102 of modified example 2, the heat transfer section 20 includes a first heat transfer section 20c and a second heat transfer section 20d. The first heat transfer section 20c has a first portion 21c and a second portion 22c. The second heat transfer section 20d has a first portion 21d and a second portion 22d. The heating path 31 connects the second portion 22c of the first heat transfer section 20c to the heating source 81. The cooling path 32 connects the second portion 22d of the second heat transfer section 20d to the cooling source 82. Except for these, the recovery system 102 has the same configuration as the recovery system 101 described above.

[0132] The recovery system 102 of the modified example 2 also allows the temperature difference between the second part 22 and the first part 21 of the heat transfer section 20 to be controlled according to the mode being implemented by switching the path used to the heating path 31 or the cooling path 32. Specifically, by switching the path used to the heating path 31, the temperature of the second part 22c of the first heat transfer section 20c can be made higher than the temperature of the first part 21 when the desorption mode is implemented. By switching the path used to the cooling path 32, the temperature of the second part 22d of the second heat transfer section 20d can be made lower than the temperature of the first part 21 when the cooling mode is implemented.

[0133] As shown in Figure 8, in the vertical direction, the second portion 22c of the first heat transfer section 20c may be located below the second portion 22d of the second heat transfer section 20d. With this configuration, for example, when the desorption mode is performed, the gaseous working fluid 27 can easily move from the second portion 22c of the first heat transfer section 20c toward the first portion 21. As a result, the utilization efficiency of the heat transfer section 20 is improved.

[0134] In the example shown in Figure 8, the second portion 22d of the second heat transfer section 20d is located below the adsorption section 10 in the vertical direction. Although not shown in the figure, the second portion 22d of the second heat transfer section 20d may be located above the adsorption section 10 in the vertical direction. That is, the second portion 22d of the second heat transfer section 20d may be located above the adsorption section 10, and the second portion 22c of the first heat transfer section 20c may be located below it. With such a configuration, for example, when the desorption mode is performed, the gaseous working fluid 27 can easily move in the direction from the second portion 22c of the first heat transfer section 20c toward the first portion 21. Also, for example, when the cooling mode is performed, the liquid working fluid 27 can easily move in the direction from the second portion 22d of the second heat transfer section 20d toward the first portion 21.

[0135] The method for recovering acidic gas using the recovery system 102 in Modification 2 is basically the same as the method for recovering acidic gas using the recovery system 101 described above, so its explanation will be omitted.

[0136] (Variation 3) Figure 9 is a schematic diagram of a modified example 3 of the recovery system according to this embodiment. In the recovery system 103 of modified example 3, the heat transfer section 20 has a closed-loop structure in which the first section 21 and the second section 22 are connected. Except for this, the recovery system 103 has the same configuration as the recovery system 100 described above.

[0137] In the heat transfer section 20 having a closed-loop structure, the liquid working fluid 27a moves in a first direction along the capillary structure 28, and the gaseous working fluid 27b moves in a second direction opposite to the first direction through the internal space 25. Therefore, according to the recovery system 103 of the modified example 3, the working fluid 27 can be circulated inside the heat transfer section 20 having a closed-loop structure, so that heat can be transferred more efficiently.

[0138] The heat transfer section 20 having a closed-loop structure includes a root heat pipe. By using a root heat pipe as the heat transfer section 20 having a closed-loop structure, it is easier to maintain a high temperature in the adsorption section 10, for example, when the desorption mode is being performed. This makes it possible to further suppress the generation of condensed water.

[0139] The method for recovering acidic gas using the recovery system 103 in Modification 3 is basically the same as the method for recovering acidic gas using the recovery system 100 described above, so its explanation will be omitted.

[0140] (Modification 4) Figure 10 is a schematic diagram of a modified example 4 of the recovery system according to this embodiment. In the recovery system 104 of modified example 4, the adsorption mode is performed outside the case 11. Except for this, the recovery system 104 has generally the same configuration as the recovery system 100 described above. The dashed arrows in the pre-case 11p shown in Figure 1 indicate an example of the flow direction of the mixed gas G1.

[0141] In the example shown in Figure 10, the recovery system 104 further includes a pre-case 11p for housing the adsorption unit 10 and a moving mechanism (not shown) for moving the adsorption unit 10, which is adsorbing acidic gas, into the case 11 during the adsorption mode. That is, in the recovery system 104, the case for performing the adsorption mode is different from the case for performing the desorption mode and the cooling mode. However, as long as the adsorption mode is performed outside the case 11, the configuration of the recovery system 104 is not limited to the example shown in Figure 10. For example, in the adsorption mode, the adsorption unit 10 removed from the case 11 may be exposed to the atmosphere, causing the adsorption unit 10 to come into direct contact with the atmosphere. In the adsorption mode, a blowing mechanism such as a fan may be used to bring the mixed gas G1 into contact with the adsorption unit 10 removed from the case 11. The recovery system 104 allows for case designs tailored to each mode.

[0142] The configuration of the moving mechanism is not particularly limited, as long as the suction part 10 can be moved from the pre-case 11p to the case 11. For example, the suction part 10 can be moved up and down by using a crane or the like as the moving mechanism.

[0143] The shape of case 11 and the shape of pre-case 11p may be the same or different.

[0144] In the recovery system 104 of the modified example 4, the pre-case 11p is a case for performing the adsorption mode. As shown in Figure 10, the pre-case 11p is connected to a raw material gas path 35 and a non-adsorbent gas path 37. The non-adsorbent gas path 37 is connected to the gas outlet 11c of the pre-case 11p and is a path for discharging non-adsorbent gas G3 from the pre-case 11p. An on / off valve 44 is provided in the non-adsorbent gas path 37.

[0145] In the recovery system 104 of the modified example 4, the case 11 is a case for performing the desorption mode and the cooling mode. As shown in Figure 10, a heat transfer section 20 is arranged in the internal space of the case 11. A common path 33 and an adsorption gas path 36 are connected to the case 11. The common path 33 is connected to the second part 22 of the heat transfer section 20. The heating path 31 and the cooling path 32 merge into the common path 33 at the confluence point 33p. A switching valve 41 for switching between the heating path 31 and the cooling path 32 is provided at the confluence point 33p. The adsorption gas path 36 is connected to the gas outlet 11b of the case 11 and is a path for discharging the adsorption gas G2 from the case 11. An on / off valve 43 is provided in the adsorption gas path 36.

[0146] The descriptions of each embodiment and each modification described above are interchangeable, insofar as they do not conflict with technical standards. Furthermore, each embodiment and each modification may be combined with each other, insofar as they do not conflict with technical standards. [Industrial applicability]

[0147] The recovery system according to this embodiment is suitable for recovering acidic gases, particularly carbon dioxide. [Explanation of Symbols]

[0148] 100, 101, 102, 103, 104 Recovery System 10, 10A, 10B Adsorption section 11 cases 11p Pre-case 11a Gas Inlet 11b, 11c Gas outlet 12, 12A, 12B Main Unit 13a Yamabe 13b Tanibe 14. Ventilation paths 15 units 16, 17 cases 20 Heat transfer section 20c First heat transfer section 20d Second heat transfer section 21,21c,21d Part 1 22,22c,22d 2nd part 22a A part 22b B part 31 Heating path 32 Cooling path 33 Common Route 33p Confluence 35. Raw material gas route 35a Intake 35b Air blower mechanism 36 Adsorption gas pathway 37 Non-adsorbent gas pathway 41 Switching valve 42, 43, 44, 45, 46 Shut-off valves 50, 51, 52 Heat transfer space 60 Controllers 81 Heating source 82 Cooling source G1 mixed gas G2 Adsorbent Gas G3 Non-adsorbent gas

Claims

1. An adsorption unit that adsorbs the target fluid in a detachable state, It comprises a heat transfer section containing a working fluid circulating in a sealed internal space, The heat transfer section comprises a first portion that heats or cools the adsorption section by the latent heat of the working fluid, and a second portion in which the working fluid absorbs or releases heat. A system for recovering the target fluid.

2. The heat transfer section includes at least one selected from the group consisting of a heat pipe and a vapor chamber. A fluid recovery system for the target fluid as described in claim 1.

3. In the vertical direction, the first portion of the heat transfer section is located above the second portion. A fluid recovery system for the target fluid as described in claim 1.

4. The heat transfer section is further provided with a heating path connecting the second portion and the heating source. A fluid recovery system for the target fluid as described in claim 1.

5. The heat transfer section is further provided with a cooling path connecting the second portion and the cooling source. A fluid recovery system for the target fluid as described in claim 4.

6. The heat transfer section has a closed-loop structure in which the first part and the second part are connected. A fluid recovery system for the target fluid as described in claim 1.

7. The case further comprises the aforementioned suction part, The first portion of the heat transfer section is located inside the case or on the outer wall of the case. A fluid recovery system for the target fluid as described in claim 1.

8. The adsorption portion, by coming into contact with the mixed gas containing the acidic gas as the target fluid, adsorbs the acidic gas contained in the mixed gas, and by being heated while the acidic gas is adsorbed, desorbs the acidic gas. A fluid recovery system for the target fluid as described in claim 1.

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