Carbon dioxide storage system and method based on pressure swing adsorption carbon capture and temperature swing adsorption

Abstract

The application provides a carbon dioxide storage energy system and method based on pressure swing adsorption carbon capture and temperature swing adsorption, relates to the technical field of carbon dioxide capture, utilization and storage, and the carbon dioxide storage energy system based on pressure swing adsorption carbon capture and temperature swing adsorption comprises a first adsorption tower, a second adsorption tower, a third adsorption tower, a heater, a cooler and a high-pressure carbon dioxide storage tank; the output ends of the first adsorption tower and the second adsorption tower are connected with the first input end of the third adsorption tower; the top of the first adsorption tower and the second adsorption tower is provided with a gas outlet; the first output end of the third adsorption tower is connected with the inlet of the high-pressure carbon dioxide storage tank in sequence through the hot fluid ends of multiple intercoolers; and the second output end of the third adsorption tower is connected with the cold fluid end inlets of the multiple intercoolers through a second pump. The application can improve the economy of the CCUS technology, improve the utilization rate of the captured carbon dioxide gas, realize low-pressure carbon dioxide high-density storage and real-time heat internal circulation.

Description

Technical Field

[0001] This invention relates to the technical field of carbon dioxide capture, utilization and storage, and more specifically, to a carbon dioxide energy storage system and method based on pressure swing adsorption (PSA) and temperature swing adsorption (TSA). Background Technology

[0002] Carbon capture, utilization, and storage (CCUS) is a new development trend in carbon capture and storage (CCS) technology. It involves purifying carbon dioxide emitted during production processes and then recycling it into new production processes, rather than simply storing it. The captured carbon dioxide can be compressed and transported to utilization or storage sites via pipelines and transportation. Coupled with carbon dioxide energy storage technology, CCUS can further improve carbon utilization, ensure the flexibility of the power system, provide ample space for optimal energy allocation, and achieve efficient resource utilization.

[0003] Currently, carbon dioxide capture technologies mainly fall into four categories: absorption, adsorption, membrane separation, and cryogenic separation. Absorption and adsorption methods are more economically feasible for capturing carbon dioxide from flue gas. However, chemical absorption methods suffer from easily depleted absorbents, which can corrode equipment, and the regeneration process consumes significant energy. Compared to chemical absorption, adsorption methods use adsorbents such as zeolites to capture carbon dioxide. The adsorption / regeneration process is simple, and it offers advantages such as no degradation, no corrosion, and no harmful secondary products. Therefore, it demonstrates advantages and potential in large-scale carbon dioxide capture applications.

[0004] Based on carbon dioxide's high density, high thermal conductivity, and mild critical point, compressed carbon dioxide energy storage (CCES) technology can store high-pressure carbon dioxide in artificial containers without the need for supplemental combustion and without geographical dependence, showing great application potential. However, carbon dioxide is a greenhouse gas and requires a closed-loop cycle; therefore, how to achieve high-density storage of low-pressure carbon dioxide has become an urgent problem to be solved.

[0005] In existing technologies, after capturing carbon dioxide gas using CCUS technology, the gas is directly packaged and transported without effectively utilizing the captured carbon dioxide gas, resulting in low economic benefits from adding CCUS technology. Summary of the Invention

[0006] The problems addressed by this invention are how to improve the economics of installing CCUS technology, increase the utilization rate of captured carbon dioxide gas, and solve the problem of high-density storage of low-pressure carbon dioxide gas.

[0007] To address the aforementioned problems, this invention provides a carbon dioxide energy storage system based on pressure swing adsorption (PSA) for carbon capture and temperature swing adsorption (TSA), comprising: a first adsorption tower, a second adsorption tower, a third adsorption tower, a heater, a cooler, and a high-pressure carbon dioxide storage tank.

[0008] The input ends of the first and second adsorption towers are used to pump in the raw material gas; the output ends of the first and second adsorption towers are connected to the first input end of the third adsorption tower through the first pump; the top of the first and second adsorption towers are provided with gas outlets.

[0009] The first output end of the third adsorption tower is connected to the inlet of the high-pressure carbon dioxide storage tank through the cold fluid ends of multiple intercoolers in sequence; a first compressor is also installed at the inlet of the cold fluid end of each intercooler.

[0010] The second output end of the third adsorption tower is connected to the hot fluid inlet of multiple intercoolers via the second pump, and the cold fluid outlet of the intercooler is connected to the second input end of the third adsorption tower via a heater.

[0011] The outlet of the high-pressure carbon dioxide storage tank is connected to the third input end of the third adsorption tower in sequence through the hot fluid end outlets of multiple reheaters; an expander is also installed at the hot fluid end outlet of each reheater.

[0012] The third output end of the third adsorption tower is connected to the hot fluid inlet of multiple reheaters via the third pump, and the hot fluid outlet of the reheaters is connected to the fourth input end of the third adsorption tower via a cooler.

[0013] Optionally, the adsorbents in the first, second, and third adsorption towers are 25-35% activated carbon and 65-75% 13x zeolite by mass.

[0014] Optionally, the adsorbents in the first, second, and third adsorption towers are 30% activated carbon and 70% 13x zeolite by mass.

[0015] Optionally, a second compressor is provided at the input end of the first adsorption tower and the second adsorption tower. The second compressor is used to increase the pressure input to the first adsorption tower and the second adsorption tower to 0.1-0.4 MPa.

[0016] Optionally, a second compressor is used to increase the pressure input to the first and second adsorption towers to 0.25 MPa.

[0017] Optionally, a first valve and a third valve are respectively installed on the pipelines at the input ends of the first adsorption tower and the second adsorption tower; a second valve and a fourth valve are respectively installed on the pipelines at the output ends of the first adsorption tower and the second adsorption tower; a fifth valve and a seventh valve are respectively installed on the pipelines at the gas outlets of the first adsorption tower and the second adsorption tower; the tops of the first adsorption tower and the second adsorption tower are connected by a pipeline, and a sixth valve is installed on the pipeline; an eighth valve is installed between the first output end of the third adsorption tower and the intercooler.

[0018] Secondly, the present invention provides a method for carbon dioxide energy storage based on pressure swing adsorption (PSA) carbon capture and temperature swing adsorption using the aforementioned carbon dioxide energy storage system based on pressure swing adsorption and temperature swing adsorption, comprising:

[0019] S1: The raw material gas passes through the second compressor to increase its pressure, and then enters the buffer tank;

[0020] S2: Open the first valve, the third valve, the fifth valve, and the seventh valve, and close the second valve, the fourth valve, and the sixth valve. The raw material gas enters the first adsorption tower and the second adsorption tower, where carbon dioxide is adsorbed.

[0021] S3: Close the first valve, second valve, third valve, fourth valve, fifth valve, sixth valve and seventh valve, turn on the first pump, evacuate the first adsorption tower and the second adsorption tower, so that the high-purity carbon dioxide adsorbed in the first adsorption tower and the second adsorption tower is desorbed and sent to the third adsorption tower;

[0022] S4: Open the eighth valve, and the carbon dioxide in the third adsorption tower is sent to the multi-stage first compressor through the first output end, then through the hot fluid end of the multi-stage intercooler, and then stored in the high-pressure carbon dioxide storage tank; at the same time, open the second pump, and send the carbon dioxide released from the third adsorption tower through the second output end to the cold fluid end of the multi-stage intercooler to absorb the heat of the carbon dioxide in the hot fluid end of the intercooler, and then be further heated by the heater and sent back to the third adsorption tower through the second input end of the third adsorption tower for heating the adsorbent;

[0023] S5: Carbon dioxide is released from the high-pressure carbon dioxide storage tank and enters the cold fluid end of the multi-stage reheater. Then it enters the multi-stage expander to cool the carbon dioxide. Finally, it is sent to the third adsorption tower through the third input end of the third adsorption tower to cool the adsorbent. At the same time, the third pump is turned on to send the carbon dioxide in the third adsorption tower to the hot fluid end of the multi-stage reheater through the third output end. The heat is transferred to the carbon dioxide in the cold fluid end of the reheater. After being further cooled by the cooler, it returns to the third adsorption tower through the fourth input end of the third adsorption tower to cool the adsorbent.

[0024] Optionally, in step S1, the pressure is increased to 0.1-0.4 MPa.

[0025] Optionally, between steps S2 and S3, the following steps are also included: closing the first valve, the second valve, the third valve, the fourth valve, the fifth valve, and the seventh valve, and opening the sixth valve, so that the first adsorption tower and the second adsorption tower after adsorption have ended are pressure-equalized.

[0026] Optionally, between steps S2 and S3, the following step is also included: opening the fifth valve and the seventh valve to discharge the remaining gas from the gas outlet.

[0027] The beneficial effects of the carbon dioxide energy storage system and method based on pressure swing adsorption (PSA) and temperature swing adsorption (TSA) of the present invention are as follows: PSA is used to directly capture carbon dioxide from raw materials such as flue gas and air, and the captured carbon dioxide is used as a working fluid for energy storage circulation, thereby increasing the circulation and utilization of carbon dioxide and solving the problem of low utilization rate of captured carbon dioxide gas in related technologies such as CCUS. Simultaneously, it stores the heat of compression, realizing internal heat circulation, eliminating a large amount of heat storage medium and storage tanks, resulting in better economic performance. Furthermore, the sensible heat stored in the adsorbent can improve the net output of the system. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a carbon dioxide energy storage system based on pressure swing adsorption (PSA) for carbon capture and temperature swing adsorption (TSA).

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Buffer tank; 2. Gas outlet; 3. Heater; 4. Cooler; 5. High-pressure carbon dioxide storage tank; V1. First valve; V2. Second valve; V3. Third valve; V4. Fourth valve; V5. Fifth valve; V6. Sixth valve; V7. Seventh valve; V8. Eighth valve; B1. First pump;

[0031] B2, Second Pump; B3, Third Pump; AT1, First Adsorption Tower; AT2, Second Adsorption Tower; AT3, Third Adsorption Tower; C1-C3, First Compressor; C4, Second Compressor; T1-T3, Expander; IC1-IC3, Intercooler; RH1-RH3, Reheater. Detailed Implementation

[0032] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0034] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the description below. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0035] To address the problems existing in the aforementioned related technologies, this embodiment provides a carbon dioxide energy storage system based on pressure swing adsorption for carbon capture and temperature swing adsorption.

[0036] like Figure 1 As shown, the carbon dioxide energy storage system based on pressure swing adsorption for carbon capture and temperature swing adsorption provided in this embodiment of the invention includes: a first adsorption tower AT1, a second adsorption tower AT2 and a third adsorption tower AT3, a heater 3, a cooler 4 and a high-pressure carbon dioxide storage tank 5.

[0037] Raw material gas is pumped into the input ends of the first adsorption tower AT1 and the second adsorption tower AT2. Preferably, the raw material gas can be pumped in by the second compressor C4. The first adsorption tower AT1 and the second adsorption tower AT2 are used to adsorb carbon dioxide in the raw material gas. The output ends of the first adsorption tower AT1 and the second adsorption tower AT2 are connected to the first input end of the third adsorption tower AT3 through the first pump B1. The first pump B1 delivers carbon dioxide gas to the third adsorption tower AT3 by evacuating the first adsorption tower AT1 and the second adsorption tower AT2.

[0038] Gas outlets 2 are provided at the top of the first adsorption tower AT1 and the second adsorption tower AT2 to release the gas inside the first adsorption tower AT1 and the second adsorption tower AT2. A buffer tank 1 is provided between the second compressor C4 and the input end of the first adsorption tower AT1 and the second adsorption tower AT2 to stabilize the pressure of the raw material gas input to the first adsorption tower AT1 and the second adsorption tower AT2.

[0039] The first output end of the third adsorption tower AT3 is connected to the inlet of the high-pressure carbon dioxide storage tank 5 via the hot fluid ends of multiple intercoolers. A first compressor is also installed on the hot fluid end of each intercooler to compress the gas entering the intercooler.

[0040] The second output end of the third adsorption tower AT3 is connected to the inlet of the cold fluid end of the aforementioned plurality of intercoolers via the second pump B2. The outlet of the cold fluid end of the intercooler is connected to the second input end of the third adsorption tower AT3 via the heater 3. The intercooler is used to heat the carbon dioxide entering the cold fluid end of the intercooler from the third adsorption tower AT3 using the heat from the carbon dioxide supplied by the third adsorption tower AT3 to the high-pressure carbon dioxide storage tank 5.

[0041] The outlet of the high-pressure carbon dioxide storage tank 5 is connected to the third inlet of the third adsorption tower AT3 via the cold fluid ends of multiple reheaters. An expander is also installed at the cold fluid end of each reheater to reduce the gas pressure entering the reheater.

[0042] The third output end of the third adsorption tower AT3 is connected to the inlet of the hot fluid end of each of the aforementioned reheaters via the third pump B3. The outlet of the hot fluid end of the reheaters is connected to the fourth input end of the third adsorption tower AT3 via the cooler 4. The reheaters are used to heat the carbon dioxide delivered to the third adsorption tower AT3 from the high-pressure carbon dioxide storage tank 5 using the heat from the carbon dioxide entering the hot fluid end of the reheaters in the third adsorption tower AT3.

[0043] Specifically, the adsorption tower can adsorb and desorb carbon dioxide to achieve carbon dioxide storage and release. In this embodiment, a third adsorption tower AT3 is used in conjunction with a carbon dioxide storage tank 5, replacing the cryogenic and high-temperature storage tanks used in the prior art for capturing carbon dioxide. This effectively increases the storage density of low-pressure carbon dioxide, reduces the footprint, lowers costs, and allows the system to operate independently of underground caverns, thus offering better prospects for engineering applications.

[0044] Furthermore, the intercooler and reheater used in this invention enable the system to store and release its own energy.

[0045] Before the system energy storage phase begins, carbon dioxide working medium is adsorbed and stored in the third adsorption tower AT3. Both the carbon dioxide working medium and the adsorbent are at low temperatures. The carbon dioxide released from the third adsorption tower AT3 undergoes multiple stages of compression. Figure 1 The first compressor (C1-C3, states 7-8, 9-10, 11-12) and interstage cooling ( Figure 1 After the intercoolers IC1-IC3 (states 8-9, 10-11, 12-13) complete energy storage, the energy is stored in the high-pressure carbon dioxide storage tank 5 under high pressure. During this process, the energy is transferred through the second pump B2 (… Figure 1 State 22) Carbon dioxide heat exchange medium released from the third adsorption tower AT3 (in the state 22) Figure 1 In state 21), the heat of compression is absorbed by the multi-stage intercooler. Figure 1 The states 23-26, 24-27, 25-28 are then further heated by heater 3. Figure 1 The adsorbent (in state 29) is then returned to the third adsorption tower AT3, where it is heated by contact heat exchange, accelerating the desorption of carbon dioxide. This system provides desorption heat by coupling compression heat with external heat to achieve real-time internal heat circulation. After the energy storage phase, there is essentially no carbon dioxide in the third adsorption tower AT3, and the adsorbent is at a high temperature.

[0046] carbon dioxide( Figure 1 After entering the third adsorption tower AT3 (state 20), the adsorbent is in a high-temperature state because it generates advanced adsorption heat when adsorbing carbon dioxide. However, excessively high adsorbent temperature is not conducive to its adsorption of carbon dioxide. Therefore, before the third adsorption tower AT3 performs the next carbon dioxide adsorption operation, it is necessary to prepare to cool down the adsorbent in the third adsorption tower AT3.

[0047] Following the system energy storage phase, an energy release phase is conducted to cool the adsorbent in the third adsorption tower AT3, facilitating the next carbon dioxide adsorption cycle (i.e., adsorption of carbon dioxide fed into the third adsorption tower AT3 from the first and second adsorption towers AT1 and AT2). During the energy release phase, the high-pressure carbon dioxide released from the high-pressure carbon dioxide storage tank 5 undergoes pre-stage reheating (…). Figure 1 The reheaters RH1-RH3 (states 14-15, 16-17, 18-19) and multi-stage expansion ( Figure 1 The expanders T1-T3 (states 15-16, 17-18, 19-20) in the multi-stage reheater are used to cool the adsorbent, which then enters the third adsorption tower AT3 to cool the adsorbent and lower its temperature below the desorption temperature. During this process, the carbon dioxide released from the third adsorption tower AT3 enters the high-pressure carbon dioxide storage tank 5 at the hot fluid end of the multi-stage reheater, while the carbon dioxide released from the hot fluid end enters the cold fluid end of the multi-stage reheater. Heat exchange occurs between the cold and hot fluid ends of the reheater, with the carbon dioxide at the hot fluid end transferring heat to the carbon dioxide at the cold fluid end, thus lowering the temperature of the carbon dioxide released from the third adsorption tower AT3. Figure 1 The reheaters RH1-RH3 (states 32-35, 33-36, 34-37) are used in the middle, and then the carbon dioxide released from the third adsorption tower AT3 is further cooled by cooler 4. Figure 1 After being sent back to the third adsorption tower AT3 in state 38), the adsorbent and carbon dioxide in the third adsorption tower AT3 are cooled, further reducing the temperature of the adsorbent.

[0048] The system completes a single energy storage-energy release cycle using the intercooler and reheater of this invention.

[0049] Specifically, after the raw material gas in the buffer tank 1 enters the first adsorption tower AT1 and the second adsorption tower AT2, the pressure in the first adsorption tower AT1 and the second adsorption tower AT2 rises to the predetermined adsorption pressure, which is about 1-2 MPa.

[0050] In this optional embodiment, based on the basic principle of pressure swing adsorption separation, the adsorbent adsorbs carbon dioxide from the raw gas at high pressure by utilizing the characteristic that the adsorption capacity of carbon dioxide changes with pressure.

[0051] Optionally, the adsorbents in the first adsorption tower AT1, the second adsorption tower AT2, and the third adsorption tower AT3 are 25-35% activated carbon and 65-75% 13x zeolite by mass.

[0052] Specifically, the adsorbents in the first adsorption tower AT1, the second adsorption tower AT2, and the third adsorption tower AT3 are 30% activated carbon and 70% 13x zeolite by mass.

[0053] In this optional embodiment, activated carbon and 13x zeolite have low production costs and good adsorption performance. However, zeolite molecular sieves are polar adsorbents with a strong affinity for water molecules, which significantly affects their carbon dioxide adsorption capacity under high humidity conditions. Therefore, activated carbon is added to absorb water vapor in flue gas and other raw material gases to improve adsorption capacity.

[0054] Optionally, a second compressor C4 is provided at the input end of the first adsorption tower AT1 and the second adsorption tower AT2. The second compressor C4 is used to increase the pressure input to the first adsorption tower AT1 and the second adsorption tower AT2 to 0.1-0.4 MPa.

[0055] Specifically, the second compressor C4 is used to increase the pressure input to the first adsorption tower AT1 and the second adsorption tower AT2 to 0.25 MPa.

[0056] In this optional embodiment, the pressure setting enables better adsorption in the first adsorption tower AT1 and the second adsorption tower AT2.

[0057] Optionally, a first valve V1 and a third valve V3 are respectively installed on the pipelines at the input ends of the first adsorption tower AT1 and the second adsorption tower AT2, and a second valve V2 and a fourth valve V4 are respectively installed on the pipelines at the output ends of the first adsorption tower AT1 and the second adsorption tower AT2. A fifth valve V5 and a seventh valve V7 are respectively installed on the pipelines at the gas outlets of the first adsorption tower AT1 and the second adsorption tower AT2. The tops of the first adsorption tower AT1 and the second adsorption tower AT2 are connected by a pipeline, and a sixth valve V6 is installed on the pipeline. An eighth valve V8 is installed between the first output end of the third adsorption tower AT3 and the intercooler.

[0058] Specifically, by opening the first valve V1, the third valve V3, the fifth valve V5, and the seventh valve V7, and closing the second valve V2, the fourth valve V4, and the sixth valve V6, the raw material gas in the buffer tank 1 enters the first adsorption tower AT1 and the second adsorption tower AT2. The carbon dioxide in the raw material gas is adsorbed by the zeolite in the adsorbent, and the remaining gas, such as nitrogen and other impurity gases, is discharged from the gas outlet 2 at the top of the tower. The adsorption ends when the mass transfer zone in the first adsorption tower AT1 and the second adsorption tower AT2 approaches the outlet.

[0059] Specifically, by opening the sixth valve V6, the first adsorption tower AT1 and the second adsorption tower AT2 are pressure-equalized.

[0060] In this optional embodiment, by controlling the switching of valves, the first adsorption tower AT1 and the second adsorption tower AT2 can be fully utilized to achieve the pressurization, adsorption, and pressure equalization processes of the first adsorption tower AT1 and the second adsorption tower AT2. Through the valve control of this invention, the first adsorption tower AT1 and the second adsorption tower AT2 can operate simultaneously, handling larger flow rates of raw gas, improving the overall processing capacity and separation speed, and further enhancing the system's energy efficiency. Pressure equalization aims to preserve the mechanical energy contained in the gas in the adsorption bed; utilizing pressure equalization can save energy.

[0061] Optionally, there are three intercoolers, namely intercoolers IC1-IC3, each intercooler IC1-IC3 corresponding to the first compressor C1-C3; there are three reheaters, namely reheaters RH1-RH3, each reheater RH1-RH3 corresponding to the expander T1-T3.

[0062] In this optional embodiment, three intercoolers and a reheater can provide a larger heat exchange area, enabling heat to be transferred more quickly and efficiently from the hot fluid to the cold fluid, thereby significantly improving cooling or heat exchange efficiency. Furthermore, the presence of three intercoolers and a reheater provides redundancy, reducing the risk of the entire system collapsing due to the failure of a single device.

[0063] The present invention also provides a carbon dioxide energy storage method based on pressure swing adsorption (PSA) carbon capture and temperature swing adsorption, which is mainly applied in the aforementioned carbon dioxide energy storage system based on PSA carbon capture and temperature swing adsorption.

[0064] The method includes:

[0065] S1: The raw material gas first passes through the second compressor C4 to increase its pressure, and then enters the buffer tank 1.

[0066] S2: Open the first valve V1, the third valve V3, the fifth valve V5 and the seventh valve V7 and close the second valve V2, the fourth valve V4 and the sixth valve V6. The raw material gas in the buffer tank 1 enters the first adsorption tower AT1 and the second adsorption tower AT2, where carbon dioxide is adsorbed.

[0067] S3: Close the first valve V1, the second valve V2, the third valve V3, the fourth valve V4, the fifth valve V5, the sixth valve V6 and the seventh valve V7, open the first pump B1, and evacuate the first adsorption tower AT1 and the second adsorption tower AT2 to desorb the high-purity carbon dioxide adsorbed in the first adsorption tower AT1 and the second adsorption tower AT2 and send it to the third adsorption tower AT3.

[0068] S4: Open the eighth valve V8, and the carbon dioxide in the third adsorption tower AT3 is sent to the multi-stage first compressor through the first output end to heat the carbon dioxide. Then it passes through the hot fluid end of the multi-stage intercooler and is stored in the high-pressure carbon dioxide storage tank 5. At the same time, open the second pump B2 to send the carbon dioxide in the third adsorption tower AT3 through the second output end to the cold fluid end of the multi-stage intercooler to absorb the heat of the carbon dioxide in the hot fluid end of the intercooler. Then it is further heated by the heater 3 and sent back to the third adsorption tower AT3 through the second input end of the third adsorption tower AT3 to heat the adsorbent.

[0069] S5: High-pressure carbon dioxide is released from the high-pressure carbon dioxide storage tank 5 and enters the cold fluid end of the multi-stage reheater. Then it enters the multi-stage expander to cool the carbon dioxide. Finally, it is sent to the third adsorption tower AT3 through the third input end to cool the adsorbent. At the same time, the third pump B3 is turned on to send the carbon dioxide in the third adsorption tower AT3 to the hot fluid end of the multi-stage reheater through the third output end. The heat is transferred to the carbon dioxide in the cold fluid end of the reheater. After being further cooled by the cooler 4, it returns to the third adsorption tower AT3 through the fourth input end to cool the adsorbent.

[0070] Specifically, in step S4, the system energy storage process takes place. During this process, in the third adsorption tower AT3, both the carbon dioxide working medium and the adsorbent are at low temperatures. The carbon dioxide released from the third adsorption tower AT3 undergoes multiple stages of compression (…). Figure 1 The first compressor (C1-C3, states 7-8, 9-10, 11-12) and interstage cooling ( Figure 1 After the intercoolers IC1-IC3 (states 8-9, 10-11, 12-13) complete energy storage, the energy is stored in the high-pressure carbon dioxide storage tank 5 under high pressure. At this time, the second pump B2 ( Figure 1 State 22) Carbon dioxide heat exchange medium released from the third adsorption tower AT3 (in the state 22) Figure 1 In state 21), the heat of compression is absorbed by the multi-stage intercooler. Figure 1 In states 23-26, 24-27, 25-28), it is then further heated by the heater. Figure 1 In the middle state 29), it is sent back to the third adsorption tower AT3 to heat the adsorbent and carbon dioxide in the form of contact heat exchange, thereby accelerating the desorption of carbon dioxide.

[0071] carbon dioxide( Figure 1After entering the third adsorption tower AT3 (state 20), the adsorbent is in a high-temperature state because it generates advanced adsorption heat when adsorbing carbon dioxide. However, excessively high adsorbent temperature is not conducive to its adsorption of carbon dioxide. Therefore, before the third adsorption tower AT3 performs the next carbon dioxide adsorption operation, it is necessary to prepare to cool down the adsorbent in the third adsorption tower AT3.

[0072] Specifically, in step S5, a system energy release process is performed to cool the adsorbent in the third adsorption tower AT3, facilitating the next carbon dioxide adsorption (i.e., adsorbing the carbon dioxide fed into the third adsorption tower AT3 from the first adsorption tower AT1 and the second adsorption tower AT2). During the energy release stage, the high-pressure carbon dioxide released from the high-pressure carbon dioxide storage tank 5 is preheated by the multi-stage reheater. Figure 1 The reheaters RH1-RH3 (states 14-15, 16-17, 18-19) and the expansion of the multi-stage expander ( Figure 1 The expanders T1-T3 (states 15-16, 17-18, 19-20) ultimately enter the third adsorption tower AT3 to cool the adsorbent, thus lowering its temperature below the desorption temperature. During this process, the carbon dioxide released from the third adsorption tower AT3 enters the multi-stage reheater, transferring its heat to the carbon dioxide released from the high-pressure carbon dioxide storage tank 5. Figure 1 The reheaters RH1-RH3 (states 32-35, 33-36, 34-37) are then further cooled by cooler 4. Figure 1 After being sent back to the third adsorption tower AT3 in state 38), the adsorbent and carbon dioxide in the third adsorption tower AT3 are cooled, further reducing the temperature of the adsorbent.

[0073] Optionally, in step S1, the pressure is increased to 0.1-0.4 MPa.

[0074] In this optional embodiment, the pressure setting enables better adsorption in the first adsorption tower AT1 and the second adsorption tower AT2.

[0075] Optionally, between steps S2 and S3, the following steps are also included: closing the first valve V1, the second valve V2, the third valve V3, the fourth valve V4, the fifth valve V5 and the seventh valve V7, opening the sixth valve V6, and equalizing the pressure of the first adsorption tower AT1 and the second adsorption tower AT2 after the adsorption has ended.

[0076] In this optional embodiment, by controlling the switching of valves, the first adsorption tower AT1 and the second adsorption tower AT2 can be fully utilized to achieve the pressurization, adsorption, and pressure equalization processes of the first adsorption tower AT1 and the second adsorption tower AT2. Through the valve control of this invention, the first adsorption tower AT1 and the second adsorption tower AT2 can operate simultaneously, handling larger flow rates of raw gas, improving the overall processing capacity and separation speed, and further enhancing the system's energy efficiency. Pressure equalization aims to preserve the mechanical energy contained in the gas in the adsorption bed; utilizing pressure equalization can save energy.

[0077] Optionally, between steps S2 and S3, the following steps are also included: opening the fifth valve (V5) and the seventh valve (V7) to discharge the remaining gas from the gas outlet (2).

[0078] Specifically, the remaining gas consists of nitrogen and other impurity gases remaining after carbon dioxide in the raw material gas is adsorbed.

[0079] In this embodiment, the heat of compression generated during the storage phase serves as the heat of desorption for the adsorbent. During energy release, the adsorption heat generated by the system is used to heat the high-pressure carbon dioxide, achieving real-time internal heat circulation. This method eliminates a large amount of heat storage medium and storage tanks, resulting in better economic performance. Simultaneously, during the system's energy release phase, since the sensible heat temperature is higher than the heat of compression, providing both the sensible heat and adsorption heat to the reheater can increase the turbine's net output power.

[0080] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A carbon dioxide energy storage system based on pressure swing adsorption (PSA) for carbon capture and temperature swing adsorption (TSA), characterized in that, include: The first adsorption tower (AT1), the second adsorption tower (AT2), the third adsorption tower (AT3), the heater (3), the cooler (4), and the high-pressure carbon dioxide storage tank (5). The input ends of the first adsorption tower (AT1) and the second adsorption tower (AT2) are used to pump in raw material gas; the output ends of the first adsorption tower (AT1) and the second adsorption tower (AT2) are connected to the first input end of the third adsorption tower (AT3) through the first pump (B1); the top of the first adsorption tower (AT1) and the second adsorption tower (AT2) are provided with gas outlets (2). The first output end of the third adsorption tower (AT3) is connected to the inlet of the high-pressure carbon dioxide storage tank (5) in sequence through the hot fluid ends of multiple intercoolers; a first compressor is also provided at the hot fluid end inlet of each intercooler. The second output end of the third adsorption tower (AT3) is connected to the cold fluid inlet of the plurality of intercoolers via the second pump (B2), and the cold fluid outlet of the intercooler is connected to the second input end of the third adsorption tower (AT3) via the heater (3). The outlet of the high-pressure carbon dioxide storage tank (5) is connected to the third input end of the third adsorption tower (AT3) in sequence through the cold fluid ends of multiple reheaters; an expander is also provided at the cold fluid end outlet of each reheater. The third output end of the third adsorption tower (AT3) is connected to the hot fluid inlet of the plurality of reheaters via the third pump (B3), and the hot fluid outlet of the reheaters is connected to the fourth input end of the third adsorption tower (AT3) via the cooler (4); a first valve (V1) and a third valve (V3) are respectively installed on the pipelines at the input ends of the first adsorption tower (AT1) and the second adsorption tower (AT2); a second valve (V2) and a fourth valve (V4) are respectively installed on the pipelines at the output ends of the first adsorption tower (AT1) and the second adsorption tower (AT2); a fifth valve (V5) and a seventh valve (V7) are respectively installed on the pipelines at the gas outlets of the first adsorption tower (AT1) and the second adsorption tower (AT2); the tops of the first adsorption tower (AT1) and the second adsorption tower (AT2) are connected by pipelines, and a sixth valve (V6) is installed on the pipelines; an eighth valve (V8) is installed between the first output end of the third adsorption tower (AT3) and the intercooler.

2. The carbon dioxide energy storage system based on pressure swing adsorption for carbon capture and temperature swing adsorption according to claim 1, characterized in that, The adsorbents in the first adsorption tower (AT1), the second adsorption tower (AT2), and the third adsorption tower (AT3) are activated carbon with a mass fraction of 25-35% and 13x zeolite with a mass fraction of 65-75%.

3. The carbon dioxide energy storage system based on pressure swing adsorption for carbon capture and temperature swing adsorption according to claim 1, characterized in that, The adsorbents in the first adsorption tower (AT1), the second adsorption tower (AT2), and the third adsorption tower (AT3) are 30% activated carbon and 70% 13x zeolite by mass.

4. The carbon dioxide energy storage system based on pressure swing adsorption for carbon capture and temperature swing adsorption according to claim 1, characterized in that, The input ends of the first adsorption tower (AT1) and the second adsorption tower (AT2) are equipped with a second compressor (C4), which is used to increase the pressure input to the first adsorption tower (AT1) and the second adsorption tower (AT2) to 0.1-0.4 MPa.

5. The carbon dioxide energy storage system based on pressure swing adsorption for carbon capture and temperature swing adsorption according to claim 4, characterized in that, The second compressor (C4) is used to increase the pressure input to the first adsorption tower (AT1) and the second adsorption tower (AT2) to 0.25 MPa.

6. The method for carbon dioxide energy storage based on pressure swing adsorption (PSA) carbon capture and temperature swing adsorption in the carbon dioxide energy storage system according to any one of claims 1-5, characterized in that, include: S1: The raw material gas passes through the second compressor (C4) to increase its pressure, and then enters the buffer tank (1); S2: Open the first valve (V1) and the third valve (V3) and close the second valve (V2), the fourth valve (V4), the fifth valve (V5), the sixth valve (V6) and the seventh valve (V7). The raw material gas enters the first adsorption tower (AT1) and the second adsorption tower (AT2). The first adsorption tower (AT1) and the second adsorption tower (AT2) adsorb carbon dioxide. S3: Close the first valve (V1), the second valve (V2), the third valve (V3), the fourth valve (V4), the fifth valve (V5), the sixth valve (V6), and the seventh valve (V7), and turn on the first pump (B1) to evacuate the first adsorption tower (AT1) and the second adsorption tower (AT2), so that the high-purity carbon dioxide adsorbed in the first adsorption tower (AT1) and the second adsorption tower (AT2) is desorbed and sent to the third adsorption tower (AT3); S4: Open the eighth valve (V8), and the carbon dioxide released by the third adsorption tower (AT3) is sent to the multi-stage first compressor through the first output end, then through the hot fluid end of the multi-stage intercooler, and then stored in the high-pressure carbon dioxide storage tank (5); at the same time, open the second pump (B2), and send the carbon dioxide released by the third adsorption tower (AT3) through the second output end to the cold fluid end of the multi-stage intercooler to absorb the heat of the carbon dioxide at the hot fluid end of the intercooler, and then be further heated by the heater (3), and sent back to the third adsorption tower (AT3) through the second input end of the third adsorption tower (AT3) for heating the adsorbent; S5: Carbon dioxide is released from the high-pressure carbon dioxide storage tank (5) and enters the cold fluid end of the multi-stage reheater, then enters the multi-stage expander, and finally enters the third adsorption tower (AT3) through the third input end of the third adsorption tower (AT3); at the same time, the third pump (B3) is turned on to send the carbon dioxide in the third adsorption tower (AT3) through the third output end to the hot fluid end of the multi-stage reheater, transfer heat to the carbon dioxide in the cold fluid end of the reheater, and after being further cooled by the cooler (4), it returns to the third adsorption tower (AT3) through the fourth input end of the third adsorption tower (AT3) for cooling the adsorbent.

7. The carbon dioxide energy storage method based on pressure swing adsorption for carbon capture and temperature swing adsorption according to claim 6, characterized in that, In step S1, the pressure is increased to 0.1-0.4 MPa.

8. The carbon dioxide energy storage method based on pressure swing adsorption for carbon capture and temperature swing adsorption according to claim 6, characterized in that, Between steps S2 and S3, the following steps are also included: closing the first valve (V1), the second valve (V2), the third valve (V3), the fourth valve (V4), the fifth valve (V5), and the seventh valve (V7), and opening the sixth valve (V6) to equalize the pressure of the first adsorption tower (AT1) and the second adsorption tower (AT2) after the adsorption has ended.

9. The carbon dioxide energy storage method based on pressure swing adsorption for carbon capture and temperature swing adsorption according to claim 6, characterized in that, Between steps S2 and S3, the following steps are also included: opening the fifth valve (V5) and the seventh valve (V7) to discharge the remaining gas from the gas outlet (2).

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