Gas Adsorption Separation System

Abstract

A gas adsorption separation system including at least two adsorption mechanisms 10, at least one thermoelectric converter 20, at least two supply mechanisms and at least two discharge mechanisms, where each of the adsorption mechanisms 10 is arranged adjacent to each other, and the two adjacent adsorption mechanisms 10 can alternately exist in the adsorption stage and the regeneration stage. The thermoelectric converter is arranged between the two adjacent adsorption mechanisms and is used to extract heat from the adsorption mechanism in the adsorption stage by changing the flow direction of the current and transfer the heat to the adsorption mechanism in the regeneration stage. The supply mechanism is used to supply the mixed gas to the adsorption mechanism. The discharge mechanism is used to discharge the adsorbate discharged by the adsorption mechanism in the regeneration stage and to discharge the residual gas, excluding the adsorbate, in the mixed gas discharged by the adsorption mechanism in the adsorption stage. By realizing thermal coupling between the two adjacent adsorption mechanisms via the thermoelectric converter, the heat required in the regeneration stage is shuttled between the two adsorption mechanisms, realizing multiple utilization of heat and reducing energy consumption.

Description

[Technical Field]

[0001] The present invention relates to the technical field of gas separation and thermoelectric conversion in energy chemical engineering processes, and in particular to gas adsorption separation systems. [Background technology]

[0002] Gas adsorption separation technology utilizes the differences in adsorption capacities of adsorbents to separate mixed gases. It is widely used in processes such as natural gas purification (e.g., low-concentration gas or biogas), carbon dioxide capture from industrial exhaust gases, and air purification (removal of volatile organic compounds). Depending on the control conditions, gas adsorption processes can be divided into temperature swing adsorption (TSA), pressure swing adsorption (PSA), and vacuum swing adsorption (VSA). A complete adsorption separation cycle includes two stages: adsorption and desorption (regeneration). Some more complex adsorption processes also include additional stages such as cooling or heating. Taking the temperature swing adsorption process of biogas purification as an example (shown in Figures 1 and 2), cyclical separation and purification of mixed gases can be achieved by controlling the cyclic oscillation of the temperature of the adsorption bed 1 and the corresponding operation of the inlet valve 3, first outlet valve 4, and second outlet valve 5. If waste heat is available, the adsorption bed can be heated during the regeneration stage by injecting hot gas or indirectly heating a heat exchanger, and cooled during the adsorption (or cooling) stage by injecting cold gas. If no waste heat is available, the regeneration process must be driven by active energy consumption methods such as electrical heating (heat wire 2) or gas heating.

[0003] In the temperature swing adsorption process, the adsorption bed must be heated at each desorption step and cooled at each regeneration step, which creates two problems: (1) The heat supplied to the adsorption bed in the regeneration step is directly dissipated into the environment in the subsequent adsorption step, resulting in a significant energy loss and making the adsorption separation process an energy-intensive process. (2) The adsorbent is a porous medium with poor heat transfer performance, making it difficult for heat to enter and exit quickly. As a result, the regeneration stage is excessively long and the duty cycle of the adsorption stage is low, resulting in a low average separation rate of the mixed gas. Summary of the Invention [Problem to be solved by the invention]

[0004] The technical problem that the present invention aims to solve is to provide a gas adsorption separation system that can reduce energy consumption. [Means for solving the problem]

[0005] The present application provides a gas adsorption separation system comprising at least two adsorption mechanisms, at least one thermoelectric converter, at least two feed mechanisms, and at least two exhaust mechanisms.

[0006] The at least two adsorption mechanisms are arranged adjacent to each other, and each adjacent adsorption mechanism may alternately be in an adsorption stage and a regeneration stage, in which the adsorption mechanism adsorbs an adsorbate in the mixed gas in the adsorption stage and desorbs the adsorbed adsorbate in the regeneration stage.

[0007] The thermoelectric converter is disposed between two adjacent adsorption mechanisms and is used to extract heat from the adsorption mechanisms in the adsorption stage by changing the direction of current flow and transfer the heat to the adsorption mechanisms in the regeneration stage.

[0008] The supply mechanism is used to supply the mixed gas to the adsorption mechanism.

[0009] The discharge mechanism is used to discharge the adsorbate discharged by the adsorption mechanism in the regeneration stage, and to discharge the residual gas, excluding the adsorbate, in the mixed gas discharged by the adsorption mechanism in the adsorption stage. [Effects of the Invention]

[0010] According to the gas adsorption separation system of the above embodiment, the heat of the adsorption mechanism in the adsorption stage is transferred to the adsorption mechanism in the regeneration stage by the thermoelectric converter, thereby realizing the gas adsorption separation process. In addition, by realizing thermal coupling between the two adsorption mechanisms via the thermoelectric converter, the heat required in the regeneration stage is shuttled between the two adsorption mechanisms, thereby realizing multiple utilization of heat and reducing energy consumption in the adsorption separation process. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of a gas adsorption separation device according to the prior art. [Figure 2] 1 is an adsorption isotherm of a gas adsorption separation device according to the prior art. [Figure 3] 1 is a schematic configuration diagram of a gas adsorption separation system according to a first embodiment. [Figure 4] 1 shows an adsorption isotherm of the gas adsorption separation system according to the first embodiment. [Figure 5] FIG. 10 is a schematic configuration diagram of a gas adsorption separation system according to a second embodiment. [Figure 6] 10 is an adsorption isotherm of a gas adsorption separation system according to a second embodiment. [Figure 7] FIG. 10 is a schematic configuration diagram of a gas adsorption separation system according to a third embodiment. [Figure 8] 10 is an adsorption isotherm of a gas adsorption separation system according to a third embodiment. [Figure 9] 1 is a schematic configuration diagram of an adsorption mechanism in one embodiment of a gas adsorption separation system according to the present embodiment. [Figure 10] FIG. 2 is a schematic configuration diagram of a thermoelectric converter in one embodiment of the gas adsorption separation system according to the present embodiment. [Figure 11] FIG. 4 is a schematic configuration diagram of an adsorption mechanism in another embodiment of the gas adsorption separation system according to the present embodiment. [Figure 12] FIG. 4 is a schematic configuration diagram of a thermoelectric converter in another embodiment of the gas adsorption separation system according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in more detail below through specific embodiments and accompanying drawings. Similar components in different embodiments are designated by the same reference numerals. The detailed descriptions in the following embodiments are provided to facilitate a better understanding of the present invention. However, those skilled in the art will readily recognize that some features may be omitted or replaced with other components, materials, and methods in different situations. To avoid obscuring the core of the present invention with excessive description, some operations according to the present invention may not be shown or described in the specification. Those skilled in the art will not need to be specifically described about these related operations, and will be able to fully understand the related operations according to the description in this specification and general technical knowledge in the art.

[0013] It should be noted that the features, operations, or characteristics described herein may be combined in any suitable manner to form various embodiments. Additionally, the steps or actions in the method descriptions may be reordered or adjusted in ways apparent to those skilled in the art. Accordingly, any order in the specification and drawings is solely for the purpose of clarifying one embodiment and does not imply a required order unless a specific order must be followed.

[0014] The part numbers in this specification, such as "first", "second", etc., are used only to distinguish the objects described and do not have any ordering or technical meaning. Note that "connection" described in the present invention includes direct and indirect connection unless otherwise specified.

[0015] In an embodiment of the present invention, thermoelectric conversion technology is employed, combining thermoelectric conversion technology with gas adsorption and separation technology. Thermoelectric conversion technology realizes the direct conversion of thermal energy to electrical energy in a solid medium. Under the action of a certain temperature difference or input current, the movement of charge carriers (electrons or holes) in a specific direction can realize power generation and cooling (heat pump) functions, respectively. Compared to conventional heat engines, the movement of charge carriers in a thermoelectric system is equivalent to the flow of a working medium (such as water vapor or refrigerant) in a conventional power generation or cooling (heat pump) system. Since no moving parts such as compressors or liquid pumps are required, thermoelectric conversion technology offers advantages such as long cycle life, low maintenance costs, zero emissions, and no noise or vibration during operation. In the field of power generation, thermoelectric conversion technology has been used as the only long-cycle power supply solution for space exploration missions since the 1960s. In recent years, the performance of thermoelectric materials has improved. As the global energy and environmental situation becomes increasingly severe, academic and industrial communities have begun to explore the use of thermoelectric conversion technology in applications such as automobile exhaust gas recovery and waste heat recovery in industrial systems. In the field of heat pumps (cooling), thermoelectric conversion technology has shown great value in applications such as chip heat dissipation, infrared imaging, temperature control of scientific instruments, and small portable cooling devices, with annual demand for thermoelectric cooling devices reaching 180 million units. Because thermoelectric devices are compact and have fast response times, when used as heat pumps, they can quickly reverse heat flow by switching the direction of the power supply current. Therefore, thermoelectric devices can provide energy management solutions that save energy and reduce costs in industrial processes with cyclic temperature fluctuations.

[0016] <Embodiment 1> See Figures 3 and 4. Embodiment 1 provides a gas adsorption separation system including at least two adsorption mechanisms 10, at least one thermoelectric converter 20, at least two supply mechanisms, and at least two discharge mechanisms.

[0017] The adsorption mechanisms 10 are arranged adjacent to each other, and two adjacent adsorption mechanisms 10 can alternately be in the adsorption stage and the regeneration stage. As shown in Fig. 4, when one of the two adjacent adsorption mechanisms 10 is in the adsorption stage, the other adsorption mechanism 10 is in the regeneration stage, and when one of the adsorption mechanisms 10 is in the regeneration stage, the other adsorption mechanism 10 is in the adsorption stage. The durations of the regeneration stage and the adsorption stage shown in Fig. 4 are the same.

[0018] Each adsorption mechanism 10 corresponds to one supply mechanism and one discharge mechanism. In the first embodiment, each adsorption mechanism 10 can adsorb an adsorbate in a mixed gas in an adsorption stage, and each adsorption mechanism 10 can desorb the adsorbed adsorbate in a regeneration stage. The supply mechanism is used to supply a mixed gas to the corresponding adsorption mechanism 10. The mixed gas contains an adsorbate that can be adsorbed by the adsorption mechanism 10 and other gases in the mixed gas excluding the adsorbate. The discharge mechanism is used to discharge the adsorbate discharged by the adsorption mechanism 10 in the regeneration stage, and to discharge residual gases in the mixed gas discharged by the adsorption mechanism 10 in the adsorption stage excluding the adsorbate.

[0019] During the adsorption stage, the adsorption mechanism 10 must be cooled during the adsorption process. This is typically achieved by external cooling or ventilation. During the regeneration stage, the adsorption mechanism 10 must be heated during the desorption process. This is typically achieved by waste heat or active heating. To achieve the goal of energy conservation, embodiment 1 employs thermoelectric conversion technology. By utilizing the principle of heat removal due to current flow within the thermoelectric converter 20, heat is extracted from the adsorption mechanism 10 during the adsorption stage and transferred to the adsorption mechanism 10 during the regeneration stage. This achieves the goals of cooling the adsorption mechanism 10 during the adsorption stage and heating the adsorption mechanism 10 during the regeneration stage, thereby avoiding unnecessary energy loss during each adsorption stage and each regeneration stage and reducing energy consumption. Furthermore, this thermoelectric conversion technology improves the heat transfer coefficient and increases the duty cycle of the adsorption stage.

[0020] In some embodiments, the adsorption mechanism 10 is filled with an adsorbent. The adsorbent is preferably a solid adsorbent, typically silica gel, activated carbon, or molecular sieves. When gas molecules migrate to the surface of the solid adsorbent, the residual attraction of the atoms on the solid adsorbent surface temporarily causes the adsorbate molecules in the gas to remain on the solid adsorbent surface. As the temperature decreases, these molecules on the solid adsorbent surface increase in concentration and are adsorbed onto the solid adsorbent. This process constitutes the adsorption phase of the adsorption mechanism 10. Conversely, as the temperature increases, the adsorbate molecules desorb and precipitate from the solid adsorbent surface. This process constitutes the regeneration phase of the adsorption mechanism 10.

[0021] In the following embodiments, the mixed gas is described using biogas as an example and PEI SiO2 as an adsorbent. In the following embodiments, two adsorption mechanisms 10 and one thermoelectric converter 20 are arranged, and each adsorption mechanism 10 is arranged with one supply mechanism and one discharge mechanism.

[0022] Biogas primarily contains methane and carbon dioxide. The adsorption mechanisms 10 primarily adsorb carbon dioxide, releasing methane during the adsorption process and separating the methane and carbon dioxide. First, one supply mechanism supplies biogas to the corresponding adsorption mechanism 10. The carbon dioxide in the biogas is adsorbed by the adsorption mechanism 10, and when the adsorption mechanism 10 reaches saturation and is ready to transition to the regeneration phase, the other supply mechanism supplies biogas to the corresponding adsorption mechanism 10. During the process of adsorbing the carbon dioxide in the biogas by the other adsorption mechanism 10, the heat of the other adsorption mechanism 10 is extracted by the thermoelectric converter 20 and transferred to one adsorption mechanism 10. That is, the heat of the adsorption mechanism 10 in the adsorption phase is transferred to the adsorption mechanism 10 in the regeneration phase, at which point one adsorption mechanism enters the regeneration phase and the other adsorption mechanism enters the adsorption phase. As the process progresses, when the other adsorption mechanism 10 reaches saturation and is ready to transition to the regeneration phase, one adsorption mechanism 10 completely desorbs the adsorbate and can transition to the adsorption phase, and the above process is repeated. This back-and-forth cycling avoids energy waste, improves heat transfer rates, and increases the duty cycle of the adsorption stage.

[0023] Continuing to refer to FIG. 1 , each adsorption mechanism 10 has a supply end, a first discharge end, and a second discharge end. Each supply mechanism is connected to the supply end of the adsorption mechanism 10 and includes a supply valve 31 for supplying the mixed gas to the adsorption mechanism 10. The discharge mechanism includes a first discharge valve 41 and a second discharge valve 42. The first discharge valve 41 is connected to the first discharge end of the adsorption mechanism 10 and is used to discharge the adsorbate discharged by the adsorption mechanism 10 in the regeneration stage. The second discharge valve 42 is connected to the second discharge end of the adsorption mechanism 10 and is used to discharge the residual gas, excluding the adsorbate, in the mixed gas discharged by the adsorption mechanism 10 in the adsorption stage.

[0024] In the first embodiment, the two supply valves 31 share one supply pipe 310, and the two supply valves 31 can be opened and closed to supply gas to the corresponding adsorption mechanisms 10. The two first exhaust valves 41 share one first exhaust pipe 410, and the two first exhaust valves 41 can be opened and closed to discharge the adsorbate discharged by the corresponding adsorption mechanisms 10. The two second exhaust valves 42 share one second exhaust pipe 420, and the two second exhaust valves 42 can be opened and closed to discharge the residual gas discharged by the corresponding adsorption mechanisms 10.

[0025] When the adsorption mechanism 10 is in the adsorption stage, the supply valve 31 and the second exhaust valve 42 corresponding to the adsorption mechanism 10 are open, thereby providing the mixed gas to the adsorption mechanism 10 via the supply valve 31 and discharging the residual gas via the second exhaust valve 42. The first exhaust valve 41 corresponding to the adsorption mechanism 10 is closed so that the adsorbate is adsorbed by the adsorption mechanism 10. When the adsorption mechanism 10 switches from the adsorption stage to the regeneration stage, the supply valve 31 and the second exhaust valve 42 corresponding to the adsorption mechanism are closed to stop the supply of the mixed gas to the adsorption mechanism 10 and to prevent the adsorbate desorbed from the adsorption mechanism 10 from being discharged through the second exhaust valve 42. The first exhaust valve 41 corresponding to the adsorption mechanism 10 is opened so that the adsorbate desorbed from the adsorption mechanism 10 is discharged through the first exhaust valve 41.

[0026] If the adsorption time of the adsorption stage is different from the regeneration time of the regeneration stage, the adsorption and regeneration stages will not be well matched, so this can be compensated for by adding a cooling stage before the adsorption stage or a heating stage before the regeneration stage so that the sum of the cooling times and the sum of the heating times of the two adsorption mechanisms are equal.

[0027] 3 , when the adsorption time of one of two adjacent adsorption mechanisms 10 in the adsorption stage is longer than the regeneration time of the other adsorption mechanism 10 in the regeneration stage, a heating stage is appropriately added before the regeneration stage of the other adsorption mechanism 10, and the sum of the regeneration time of the regeneration stage of the other adsorption mechanism 10 and the heating time of the added heating stage is made equal to the adsorption time of the other adsorption mechanism 10 in the adsorption stage. During the heating stage added before the regeneration stage of the other adsorption mechanism 10, the supply valve 31, the first exhaust valve 41, and the second exhaust valve 42 corresponding to the other adsorption mechanism 10 are maintained in a closed state. On the other hand, during the entire adsorption stage of the one adsorption mechanism 10, the supply valve 31 and the second exhaust valve 42 corresponding to the one adsorption mechanism 10 are maintained in an open state, and the first exhaust valve 41 is maintained in a closed state. In this way, heat from one adsorption mechanism 10 is extracted by the thermoelectric converter 20 and transferred to the other adsorption mechanism 10, and a heating step is added before the regeneration step of the other adsorption mechanism 10, heating the other adsorption mechanism 10 and increasing its temperature.

[0028] Continuing to refer to FIG. 3 , if the regeneration time of the regeneration stage of one of two adjacent adsorption mechanisms 10 is longer than the adsorption time of the adsorption stage of the other adsorption mechanism 10, a cooling stage is added before the adsorption stage of the other adsorption mechanism 10, and the sum of the adsorption time of the adsorption stage of the other adsorption mechanism 10 and the cooling time of the added cooling stage is equal to the regeneration time of the regeneration stage of the one adsorption mechanism 10. During the cooling stage added before the adsorption stage of the other adsorption mechanism 10, the supply valve 31, the first exhaust valve 41, and the second exhaust valve 42 corresponding to the other adsorption mechanism 10 are maintained in a closed state. Meanwhile, during the entire regeneration stage of the one adsorption mechanism 10 described above, the supply valve 31 and the second exhaust valve 42 corresponding to the one adsorption mechanism 10 are maintained in a closed state, and the first exhaust valve 41 is maintained in an open state. In this way, the heat of the other adsorption mechanism 10 is extracted by the thermoelectric converter 20 and transferred to one of the adsorption mechanisms 10, and further, a cooling step is added before the adsorption step of the other adsorption mechanism 10, thereby cooling the other adsorption mechanism 10.

[0029] See Figures 9 and 11. The adsorption mechanism 10 may be a flat-plate adsorption mechanism or an annular adsorption mechanism. The flat-plate adsorption mechanisms may be arranged circumferentially or two adjacent to each other, and the annular adsorption mechanisms may be arranged coaxially. See Figures 10 and 12. The thermoelectric converter 20 may be a flat-plate thermoelectric converter or an annular thermoelectric converter. The flat-plate thermoelectric converter is arranged between two adjacent flat-plate adsorption mechanisms, and the annular thermoelectric converter is arranged coaxially and between two adjacent annular adsorption mechanisms.

[0030] Each adsorption mechanism 10 includes an adsorption bed 18 filled with an adsorbent, and a heat exchanger 19. The heat exchanger 19 is preferably a finned heat exchanger 19, with fins inserted into the adsorption bed 18 and the heat exchanger 19 in contact with a thermoelectric converter 20.

[0031] It will be appreciated that in the case of a flat plate adsorption system, the adsorbent bed 18 and the heat exchanger 19 are both of flat plate construction, and in the case of an annular adsorption system, the adsorbent bed 18 and the heat exchanger 19 are both of annular construction.

[0032] 10 and 12, each of the two thermoelectric converters 20 includes a first base 211, a second base 212, and a corresponding thermoelectric unit. The first base 211 and the second base 212 are disposed on either side of the thermoelectric unit to insulate the thermoelectric unit and are in contact with the adsorption bed 18 to transfer heat to two adjacent adsorption mechanisms. Here, the thermoelectric unit includes a plurality of P-type thermoelectric units 213, a plurality of N-type thermoelectric units 214, a plurality of first electrodes 215, and a plurality of second electrodes 216. Each P-type thermoelectric unit 213 and each N-type thermoelectric unit 214 are alternately connected in series, with the first electrode 215 connected to the top of the adjacent P-type thermoelectric unit 213 and N-type thermoelectric unit 214, and the second electrode 216 connected to the bottom of the adjacent P-type thermoelectric unit 213 and N-type thermoelectric unit 214.

[0033] <Embodiment 2> After the adsorption mechanism completes the regeneration phase, the overall temperature of the adsorption mechanism is relatively high and therefore unable to contribute to adsorption of the adsorbate. If the adsorption mechanism were to switch directly to the adsorption phase, the adsorption capacity would be relatively weak in the initial stage of adsorption. In embodiment 2, a cooling step is added before the adsorption phase to cool the adsorption mechanism as it completes the regeneration phase and is about to switch to the adsorption phase, thereby improving the adsorption capacity of the adsorption mechanism. Similarly, the regeneration phase requires high temperature conditions, and after the adsorption mechanism completes the adsorption phase, the overall temperature of the adsorption mechanism is relatively low. If the adsorption mechanism were to switch directly to the regeneration phase, the regeneration capacity would be relatively weak in the initial stage of regeneration. In embodiment 2, a heating step is added before the adsorption phase to heat the adsorption mechanism as it completes the adsorption phase and is about to switch to the regeneration phase, thereby improving the regeneration capacity of the adsorption mechanism.

[0034] Please refer to Figures 5 and 6. For ease of explanation, Figure 5 shows three adsorption mechanisms and three thermoelectric converters. To distinguish from other embodiments, the three adsorption mechanisms are defined as a first adsorption mechanism 11, a second adsorption mechanism 12, and a third adsorption mechanism 13, respectively, and the three thermoelectric converters are defined as a first thermoelectric converter 21, a second thermoelectric converter 22, and a third thermoelectric converter 23, respectively. The first thermoelectric converter 21 is located between the first adsorption mechanism 11 and the second adsorption mechanism 12, the second thermoelectric converter 22 is located between the second adsorption mechanism 12 and the third adsorption mechanism 13, and the third thermoelectric converter 23 is located between the third adsorption mechanism 13 and the first adsorption mechanism 11.

[0035] In the second embodiment, the first adsorption mechanism 11, the second adsorption mechanism 12, and the third adsorption mechanism 13 are respectively in the adsorption stage, the cooling stage, and the regeneration stage, and the heat of the first adsorption mechanism 11 extracted by the third thermoelectric converter 23 and the heat of the second adsorption mechanism 12 extracted by the second thermoelectric converter 22 are transferred to the third adsorption mechanism 13. By cooling the first adsorption mechanism 11 and the second adsorption mechanism 12 and heating the third adsorption mechanism 13, the adsorption capacity of the third adsorption mechanism is improved.

[0036] In another embodiment, the first adsorption mechanism 11, the second adsorption mechanism 12, and the third adsorption mechanism 13 are in the adsorption stage, the cooling stage, and the regeneration stage, respectively, and the heat of the first adsorption mechanism 11 extracted by the first thermoelectric converter 21 is transferred to the second adsorption mechanism 12, and the heat of the second adsorption mechanism 11 extracted by the third thermoelectric converter 23 is transferred to the third adsorption mechanism 13. By heating the second adsorption mechanism 12 and the third adsorption mechanism 13 and cooling the first adsorption mechanism 11, the regeneration capacity of the first adsorption mechanism is improved.

[0037] Compared with the two adsorption mechanisms in Embodiment 1, the three adsorption mechanisms used in Embodiment 2 include a cooling or heating step before the adsorption step, which allows the adsorption step to have a relatively low temperature, maintain a high adsorption capacity, and increase the amount of adsorbate adsorbed in each adsorption cycle. Furthermore, the regeneration step has a relatively high temperature, maintain a high regeneration capacity, and increase the amount of adsorbate desorbed in each adsorption cycle.

[0038] <Embodiment 3> In the third embodiment, the adsorption mechanism 10 generates an adsorption temperature during the adsorption stage and a regeneration temperature during the regeneration stage. The difference between the adsorption temperature and the regeneration temperature is typically within a preset temperature range, e.g., 30°C to 60°C. If the difference between the adsorption temperature and the regeneration temperature is greater than the preset temperature range, e.g., 100°C to 200°C, the thermoelectric converter 20 between the two adsorption mechanisms 10 must perform heat flow to overcome the larger temperature difference. However, the small heat flow rate of the thermoelectric converter makes it difficult to accommodate the large adsorption and regeneration temperature ranges. To ensure that the thermoelectric converter can reliably complete the active thermal control task, the large temperature difference range may be divided into two relatively small temperature difference ranges based on the temperature change characteristics during the adsorption process. Therefore, in the third embodiment, four adsorption mechanisms and four thermoelectric converters are employed.

[0039] Specifically, when the difference between the adsorption temperature of the adsorption mechanism 10 in the adsorption stage and the regeneration temperature of the adsorption mechanism 10 in the regeneration stage is greater than a predetermined temperature difference range, the adsorption stage is divided into an early adsorption stage and a late adsorption stage, and the regeneration stage is divided into an early regeneration stage and a late regeneration stage. The four adsorption mechanisms are arranged circumferentially and can alternate between the early adsorption stage, the early regeneration stage, the late adsorption stage, and the late regeneration stage. The four adsorption mechanisms are arranged clockwise and circumferentially in the early adsorption stage, the early regeneration stage, the late adsorption stage, and the late regeneration stage. Heat from the adsorption mechanism in the early adsorption stage is extracted by a thermoelectric converter between the adsorption mechanism in the early adsorption stage and the adsorption mechanism in the late regeneration stage and transferred to the adsorption mechanism in the late regeneration stage. Heat from the adsorption mechanism in the late adsorption stage is extracted by a thermoelectric converter between the adsorption mechanism in the late adsorption stage and the adsorption mechanism in the early regeneration stage and transferred to the adsorption mechanism in the early regeneration stage. The above operation allows the thermoelectric converter to operate at a temperature difference that is only half the difference between the adsorption temperature and the regeneration temperature, reducing the requirements for the heat transfer capability of the thermoelectric converter across the temperature difference.

[0040] As shown in Figures 7 and 8, when the difference between the adsorption temperature of the adsorption mechanism 10 in the adsorption stage and the regeneration temperature of the adsorption mechanism 10 in the regeneration stage is greater than a predetermined temperature difference range, the adsorption stage is divided into an early adsorption stage and a late adsorption stage, and the regeneration stage is divided into an early regeneration stage and a late regeneration stage. Here, the temperatures in the early adsorption stage and the late regeneration stage are relatively high, and the temperatures in the late adsorption stage and the early regeneration stage are relatively low. To distinguish from the previous embodiment, the adsorption mechanism in the early adsorption stage is defined as the fourth adsorption mechanism 14, the adsorption mechanism in the early regeneration stage as the fifth adsorption mechanism 15, the adsorption mechanism in the late adsorption stage as the sixth adsorption mechanism 16, and the adsorption mechanism in the late regeneration stage as the seventh adsorption mechanism 17. The fourth adsorption mechanism 14, the fifth adsorption mechanism 15, the sixth adsorption mechanism 16, and the seventh adsorption mechanism 17 are arranged clockwise and circumferentially. The thermoelectric converter between the fourth adsorption mechanism 14 and the fifth adsorption mechanism 15 is defined as a fourth thermoelectric converter 24, the thermoelectric converter between the fifth adsorption mechanism 15 and the sixth adsorption mechanism 16 is defined as a fifth thermoelectric converter 25, the thermoelectric converter between the sixth adsorption mechanism 16 and the seventh adsorption mechanism 17 is defined as a sixth thermoelectric converter 26, and the thermoelectric converter between the seventh adsorption mechanism 17 and the fourth adsorption mechanism 14 is defined as a seventh thermoelectric converter 27. 7th thermoelectric converter 27 and the heat of the sixth adsorption mechanism 16 is extracted by the fifth thermoelectric converter 25 and transferred to the fifth adsorption mechanism 15 .

[0041] In view of the above, compared with a single adsorption mechanism, the system provided in the present application in which two or more adsorption mechanisms are coupled with a thermoelectric converter has the following advantages: (1) First, two or more adsorption mechanisms operate alternately, with one adsorption mechanism always in the adsorption stage, thereby realizing a continuous gas separation process. (2) Next, by realizing thermal coupling between two adjacent adsorption mechanisms via a thermoelectric converter, the heat required for the regeneration process is shuttled between the two adsorption mechanisms, realizing multiple utilization of heat, thereby reducing energy consumption in the adsorption separation process. Generally, the energy consumption intensity of a gas adsorption separation system decreases as the system scale increases, but the energy consumption intensity of a small system is relatively high, which means that there is ample room for energy saving. Therefore, the gas adsorption separation system provided in embodiment 3 provides a feasible solution for energy saving in a small adsorption separation system. (3) Furthermore, currently, gas adsorption separation devices with multiple adsorption mechanisms using heat recovery technology often use working fluids such as liquid water or steam as heat transfer media. To circulate the heat transfer media between the adsorption mechanisms, devices such as liquid pumps, compressors, and solenoid valves are required, making the system complex. Furthermore, such passive heat recovery can only be performed under a positive temperature difference, resulting in a low heat recovery rate. The gas adsorption separation system proposed by the present invention uses electric current as the transfer media, eliminating the need for the aforementioned support equipment and enabling active heat regulation even under a negative temperature difference. Therefore, the system not only achieves sufficient heat recovery, but also allows for a compact system. (4) Finally, the rapid active thermal control capability of the thermoelectric converter accelerates heat transfer between the adsorption mechanisms, shortening cycle times. A notable feature of small systems compared to large systems is their rapid startup and operation capabilities. Therefore, the speed advantage of the gas adsorption separation system provided in embodiment 3 is particularly important for small adsorption separation systems.

[0042] Although the present invention has been described in detail above using specific examples, the above embodiments are merely for the purpose of deepening understanding of the present invention and are not intended to limit the present invention. Those skilled in the art to which the present invention pertains may make other simple deductions, modifications, or substitutions based on the spirit of the present invention. [Explanation of symbols]

[0043] 10 Adsorption mechanism 11 First suction mechanism 12 Second suction mechanism 13 Third suction mechanism 14 4th suction mechanism 15 Fifth adsorption mechanism 16 6th suction mechanism 17 7th adsorption mechanism 18 Adsorption bed 19 Heat exchanger 20 Thermoelectric converter 21 First thermoelectric converter 22 Second thermoelectric converter 23 Third thermoelectric converter 24 Fourth thermoelectric converter 25 5th thermoelectric converter 26 6th thermoelectric converter 277th thermoelectric converter 211 First base 212 Second base 213 P-type thermoelectric unit 214 N-type thermoelectric unit 215 1st electrode 216 2nd electrode 31 Supply valve 310 Supply pipe 41 First discharge valve 410 1st discharge pipe 42 Second discharge valve 420 2nd discharge pipe

Claims

1. A gas adsorption separation system including three circumferentially arranged adsorption mechanisms, three thermoelectric converters, a supply mechanism, and a discharge mechanism, The three thermoelectric converters are respectively disposed between two adjacent adsorption mechanisms, and are used to extract heat from the adsorption mechanisms in the adsorption stage by changing the direction of current flow, and transfer the heat to the adsorption mechanisms in the regeneration stage; the three adsorption mechanisms are sequentially arranged in a clockwise direction, in an adsorption stage, a cooling stage, and a regeneration stage, and heat from the two adsorption mechanisms other than the regeneration stage is extracted by two thermoelectric converters adjacent to the adsorption mechanism in the regeneration stage and transferred to the adsorption mechanism in the regeneration stage; or the three adsorption mechanisms are sequentially arranged in a clockwise direction, in an adsorption stage, a heating stage, and a regeneration stage, and heat from the adsorption mechanism in the adsorption stage is extracted by two thermoelectric converters adjacent to the adsorption mechanism in the adsorption stage and transferred to the remaining two adsorption mechanisms, respectively; the adsorption mechanisms adsorb the adsorbate in the mixed gas in the adsorption stage and desorb the adsorbed adsorbate in the regeneration stage; the supply mechanism is used to supply a mixed gas to the adsorption mechanism, a gas adsorption separation system, characterized in that the discharge mechanism is used to discharge the adsorbate discharged by the adsorption mechanism in the regeneration stage, and to discharge residual gas, excluding the adsorbate, from the mixed gas discharged by the adsorption mechanism in the adsorption stage.

2. 2. The gas adsorption separation system according to claim 1, wherein the adsorption mechanism has a supply end, a first discharge end, and a second discharge end; the supply mechanism is connected to the supply end and includes a supply valve for supplying the mixed gas to the adsorption mechanism; the discharge mechanism includes a first discharge valve and a second discharge valve; the first discharge valve is connected to the first discharge end and is used to discharge the adsorbate discharged by the adsorption mechanism in the regeneration step; and the second discharge valve is connected to the second discharge end and is used to discharge the residual gas, excluding the adsorbate, in the mixed gas discharged by the adsorption mechanism in the adsorption step.

3. 3. The gas adsorption separation system according to claim 2, wherein during the adsorption stage, the supply valve and the second exhaust valve are open and the first exhaust valve is closed, and during the regeneration stage, the supply valve and the second exhaust valve are closed and the first exhaust valve is open.

4. 2. The gas adsorption separation system according to claim 1, wherein the adsorption mechanism includes an adsorption bed and a heat exchanger inserted inside the adsorption bed, the heat exchanger being maintained in thermal contact with the thermoelectric converter.

5. 2. The gas adsorption separation system of claim 1, wherein the thermoelectric converter includes a first base, a second base, and a thermoelectric unit, the first base and the second base being disposed on either side of the thermoelectric unit to insulate the thermoelectric unit and being in thermal contact with the adsorption beds of the adsorption mechanisms to transfer heat to two adjacent adsorption mechanisms, and the thermoelectric unit includes a plurality of P-type thermoelectric units and a plurality of N-type thermoelectric units, the plurality of P-type thermoelectric units and the plurality of N-type thermoelectric units being alternately connected in series.

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