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

Abstract

The invention provides a carbon dioxide energy storage system and method based on pressure swing adsorption carbon capture and temperature swing adsorption, and relates to the technical field of carbon dioxide capture, utilization and storage. 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, 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; gas outlets are formed in the tops of the first adsorption tower and the second adsorption tower; a first output end of the third adsorption tower is connected with an inlet of a high-pressure carbon dioxide storage tank through hot fluid ends of a plurality of intercoolers in sequence; and a second output end of the third adsorption tower is connected with cold fluid end inlets of the plurality of intercoolers through a second pump. The economical efficiency of a CCUS adding technology can be improved, the utilization rate of captured carbon dioxide gas is increased, and high-density storage and real-time heat internal circulation of low-pressure carbon dioxide are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide capture, utilization and storage, and in particular to a carbon dioxide energy storage system and method based on pressure swing adsorption carbon capture and temperature swing adsorption. Background Art

[0002] Carbon capture, utilization and storage (CCUS) is a new development trend of carbon dioxide capture and storage (CCS), which is to purify the carbon dioxide emitted in the production process and then put it into the new production process for recycling, rather than simply storing it. The captured carbon dioxide can be compressed and transported to the utilization or storage site through pipelines, transportation and other means. The coupling of CCUS and carbon dioxide energy storage technology can further improve carbon utilization, ensure the flexibility of the power system, provide broad space for energy optimization configuration, and realize the effective use of resources.

[0003] At present, there are four main types of carbon dioxide capture technologies: absorption, adsorption, membrane separation and low-temperature separation. Absorption and adsorption are more economically feasible in capturing flue gas carbon dioxide. However, the absorbent of the chemical absorption method is easily worn out, and the absorbent will corrode the equipment, and the regeneration energy consumption during operation is high. Compared with the chemical absorption method, the adsorption method uses adsorbents such as zeolite to capture carbon dioxide. The adsorption / regeneration process is simple to operate, has the advantages of no degradation and no corrosion, and no harmful secondary products are generated. It shows advantages and potential in large-scale carbon dioxide capture applications.

[0004] Based on the properties of high density, high thermal conductivity and mild critical point of carbon dioxide, compressed carbon dioxide energy storage (CCES) technology can store high-pressure carbon dioxide in artificial containers without supplementary combustion and geographical dependence, which has good application potential. However, carbon dioxide is a greenhouse gas and requires a closed cycle, so how to achieve high-density storage of low-pressure carbon dioxide has become an urgent problem to be solved.

[0005] In the existing technology, after the CCUS technology is installed to capture the carbon dioxide gas, it is directly packaged and transported, and the captured carbon dioxide gas is not effectively utilized, resulting in low economic benefits of installing the CCUS technology. Summary of the invention

[0006] The problem solved by the present invention is how to improve the economic efficiency of installing CCUS technology, improve the utilization rate of captured carbon dioxide gas, and how to solve the problem of high-density storage of low-pressure carbon dioxide gas.

[0007] In order to solve the above problems, the present invention provides a carbon dioxide energy storage system based on pressure swing adsorption carbon capture and temperature swing adsorption, 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 adsorption tower and the second adsorption tower are used to pump in the raw gas; the output ends of the first adsorption tower and the second adsorption tower are connected to the first input end of the third adsorption tower through the first pump; the tops of the first adsorption tower and the second adsorption tower 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 provided 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 end inlets of the plurality of intercoolers through the second pump, and the cold fluid end outlet of the intercooler is connected to the second input end of the third adsorption tower through the heater;

[0011] The outlet of the high-pressure carbon dioxide storage tank is connected to the third input end of the third adsorption tower through the hot fluid end outlets of multiple reheaters in sequence; an expander is also provided 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 end inlets of multiple reheaters through the third pump, and the hot fluid end outlet of the reheater is connected to the fourth input end of the third adsorption tower through the cooler.

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

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

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

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

[0017] Optionally, a first valve and a third valve are respectively arranged 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 arranged 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 arranged 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 arranged on the pipeline; an eighth valve is arranged between the first output end of the third adsorption tower and the intercooler.

[0018] In a second aspect, the present invention provides a method for storing carbon dioxide based on pressure swing adsorption carbon capture and temperature swing adsorption using the above-mentioned carbon dioxide energy storage system based on pressure swing adsorption carbon capture and temperature swing adsorption, comprising:

[0019] S1: The raw gas passes through the second compressor to increase the 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, and the raw gas enters the first adsorption tower and the second adsorption tower, and the first adsorption tower and the second adsorption tower adsorb carbon dioxide;

[0021] S3: close the first valve, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve and the seventh valve, turn on the first pump, evacuate the first adsorption tower and the second adsorption tower, desorb the high-purity carbon dioxide adsorbed in the first adsorption tower and the second adsorption tower, and send it to the third adsorption tower;

[0022] S4: Open the eighth valve, the carbon dioxide in the third adsorption tower is sent to the multi-stage first compressor through the first output end, then passes through the hot fluid end of the multi-stage intercooler, and then is stored in the high-pressure carbon dioxide storage tank; at the same time, open the second pump, and send the carbon dioxide released by the third adsorption tower to the cold fluid end of the multi-stage intercooler through the second output end to absorb the heat of the carbon dioxide at the hot fluid end of the intercooler, and then is further heated by the heater and sent back to the third adsorption tower through the second input end of the third adsorption tower to be used 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 enters the multi-stage expander to cool the carbon dioxide, and finally 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, and the heat is transferred to the carbon dioxide at the cold fluid end of the reheater. After further cooling through the cooler, the carbon dioxide 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 to allow the first adsorption tower and the second adsorption tower where adsorption is completed to be pressure-equalized.

[0026] Optionally, between step S2 and step 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 carbon capture and temperature swing adsorption of the present invention are: carbon dioxide is directly captured from raw materials such as flue gas and air by the pressure swing adsorption method, and the captured carbon dioxide is used as a storage cycle working fluid, thereby increasing the circulation and utilization of carbon dioxide, solving the problem of low utilization rate of carbon dioxide gas captured in CCUS technology in related technologies; at the same time, compression heat is stored to realize internal heat circulation, eliminating a large amount of heat storage medium and storage tanks, having good economic performance, and the sensible heat stored in the adsorbent can improve the net output of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of a carbon dioxide energy storage system based on pressure swing adsorption carbon capture and temperature swing adsorption.

[0029] Description of reference numerals:

[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 DESCRIPTION

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes 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 meanings as those commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application;

[0034] The term "including" and its variations used in this article are open inclusions, that is, "including but not limited to"; the term "based on" is "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first" and "second" mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more.

[0035] In view of the problems existing in the above-mentioned related technologies, this embodiment provides a carbon dioxide energy storage system based on pressure swing adsorption carbon capture and temperature swing adsorption.

[0036] like Figure 1 As shown, the carbon dioxide energy storage system based on pressure swing adsorption carbon capture and temperature swing adsorption provided in an embodiment of the present 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] The input ends of the first adsorption tower AT1 and the second adsorption tower AT2 are pumped with raw gas, preferably, the raw gas can be pumped in through the second compressor C4, and the first adsorption tower AT1 and the second adsorption tower AT2 are used to adsorb carbon dioxide in the raw 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, and 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] The top of the first adsorption tower AT1 and the second adsorption tower AT2 is provided with a gas outlet 2 for releasing the gas in 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 ends of the first adsorption tower AT1 and the second adsorption tower AT2 for stabilizing the pressure of the raw 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 through the hot fluid ends of multiple intercoolers in sequence. A first compressor is also provided 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 inlets of the cold fluid ends of the above-mentioned multiple intercoolers through the second pump B2, and the outlet of the cold fluid end of the intercooler is connected to the second input end of the third adsorption tower AT3 through the heater 3. The intercooler is used to use the heat of the carbon dioxide transported to the high-pressure carbon dioxide storage tank 5 by the third adsorption tower AT3 to heat the carbon dioxide at the cold fluid end of the intercooler entering the third adsorption tower AT3.

[0041] The outlet of the high-pressure carbon dioxide storage tank 5 is connected to the third input end of the third adsorption tower AT3 through the cold fluid ends of multiple reheaters in turn. An expander is also provided on 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 the above-mentioned multiple reheaters through the third pump B3, and the outlet of the hot fluid end of the reheater is connected to the fourth input end of the third adsorption tower AT3 through the cooler 4. The reheater is used to use the heat of the carbon dioxide at the hot fluid end of the reheater entering the third adsorption tower AT3 to heat the carbon dioxide transported to the third adsorption tower AT3 by the high-pressure carbon dioxide storage tank 5.

[0043] Specifically, the adsorption tower can adsorb and desorb carbon dioxide to achieve storage and release of carbon dioxide. In this embodiment, the third adsorption tower AT3 is used in conjunction with the carbon dioxide storage tank 5 to replace the low-temperature storage tank and high-temperature storage tank used in the prior art to capture carbon dioxide, which can effectively increase the storage density of low-pressure carbon dioxide, reduce the floor space, reduce costs, make the system independent of the underground cave, and have better engineering application prospects.

[0044] In addition, the intercooler and reheater used in the present invention can realize the energy storage and energy release of the system itself.

[0045] Before the system energy storage phase begins, the carbon dioxide working medium is adsorbed and stored in the third adsorption tower AT3. The carbon dioxide working medium and the adsorbent are both in a low temperature state. 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 intercooler IC1-IC3 in the state 8-9, 10-11, 12-13) completes the energy storage, and is stored in the high-pressure carbon dioxide storage tank 5 under high pressure. In this process, the second pump B2 ( Figure 1 The carbon dioxide heat exchange medium ( Figure 1 state 21) enters the multi-stage intercooler to absorb the compression heat ( Figure 1 23-26, 24-27, 25-28) and then further heated by heater 3 ( Figure 1 The adsorbent and carbon dioxide in the third adsorption tower AT3 are heated in the form of contact heat exchange to accelerate the desorption of carbon dioxide. The system provides desorption heat by coupling compression heat with external heat to achieve real-time internal heat circulation. After the energy storage stage, there is basically no carbon dioxide in the third adsorption tower AT3, and the adsorbent is in a high temperature state.

[0046] carbon dioxide( Figure 1 After entering the third adsorption tower AT3 in state 20), the adsorbent is in a high-temperature state due to the high-order adsorption heat generated when the adsorbent adsorbs carbon dioxide. However, too high an 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, preparation work for cooling the adsorbent in the third adsorption tower AT3 is required.

[0047] After the system energy storage stage, the energy release stage is carried out, the purpose of which is to cool down the adsorbent in the third adsorption tower AT3 to facilitate the next carbon dioxide adsorption (i.e., adsorb the carbon dioxide input from the first adsorption tower AT1 and the second adsorption tower AT2 to the third adsorption tower AT3). In the energy release stage, the high-pressure carbon dioxide released from the high-pressure carbon dioxide storage tank 5 is reheated by the pre-stage ( Figure 1 Reheater RH1-RH3, states 14-15, 16-17, 18-19) and multi-stage expansion ( Figure 1 The expansion machine T1-T3 in the process, states 15-16, 17-18, 19-20) is used to achieve cooling, and finally enters the third adsorption tower AT3, which is used to cool the adsorbent in the third adsorption tower AT3, so that the temperature of the adsorbent is lower than the desorption temperature. In this process, the carbon dioxide released from the third adsorption tower AT3 enters the hot fluid end of the multi-stage reheater, and the carbon dioxide released from the high-pressure carbon dioxide storage tank 5 enters the cold fluid end of the multi-stage reheater. The cold fluid end and the hot fluid end of the reheater perform heat exchange, and the carbon dioxide at the hot fluid end of the reheater transfers heat to the carbon dioxide at the cold fluid end of the reheater, so as to achieve the temperature reduction of the carbon dioxide released from the third adsorption tower AT3 ( Figure 1 The carbon dioxide released from the third adsorption tower AT3 is then further cooled by the cooler 4 ( Figure 1 The adsorbent is then sent back to the third adsorption tower AT3 to cool the adsorbent and carbon dioxide in the third adsorption tower AT3, thereby further reducing the temperature of the adsorbent.

[0048] Through the intercooler and reheater of the present invention, the system completes a single energy storage-energy release cycle.

[0049] Specifically, after the raw 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 a predetermined adsorption pressure, ie, about 1-2 MPa.

[0050] In this optional embodiment, based on the basic principle of pressure swing adsorption separation, the adsorbent adsorbs carbon dioxide in 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% by mass of activated carbon and 65-75% by mass of 13x zeolite.

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

[0053] In this optional embodiment, activated carbon and 13x zeolite have low production costs and good adsorption properties, but zeolite molecular sieves are polar adsorbents and have a strong affinity for water molecules, which has a significant effect on the adsorption capacity of carbon dioxide under high humidity conditions. Therefore, activated carbon is added to absorb water vapor in raw gases such as flue gas to improve the 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, and the second compressor C4 is used to increase the pressure of the 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 can better perform adsorption in the first adsorption tower AT1 and the second adsorption tower AT2.

[0057] Optionally, the first valve V1 and the third valve V3 are respectively provided on the pipelines at the input ends of the first adsorption tower AT1 and the second adsorption tower AT2, and the second valve V2 and the fourth valve V4 are respectively provided on the pipelines at the output ends of the first adsorption tower AT1 and the second adsorption tower AT2. The fifth valve V5 and the seventh valve V7 are respectively provided 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 provided on the pipeline. An eighth valve V8 is provided 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 gas in the buffer tank 1 enters the first adsorption tower AT1 and the second adsorption tower AT2, the carbon dioxide in the raw gas is adsorbed by the zeolite in the adsorbent, and residual gases such as nitrogen and other impurity gases are discharged from the gas outlet 2 at the top of the tower, and the adsorption is terminated when the mass transfer zones in the first adsorption tower AT1 and the second adsorption tower AT2 are close to 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 switching control between valves, the first adsorption tower AT1 and the second adsorption tower AT2 can be fully utilized to realize the pressure increase, adsorption and pressure equalization process of the first adsorption tower AT1 and the second adsorption tower AT2. Through the valve control of the present invention, the first adsorption tower AT1 and the second adsorption tower AT2 can work simultaneously, can process a larger flow of raw gas, improve the overall processing capacity and separation speed, and can further improve the energy efficiency of the system. The purpose of pressure equalization is to preserve the mechanical energy contained in the gas in the adsorption bed, and the use of pressure equalization can save energy.

[0061] Optionally, the number of intercoolers is 3, namely intercoolers IC1-IC3, each intercooler IC1-IC3 corresponds to the first compressor C1-C3; the number of reheaters is 3, namely reheaters RH1-RH3, each reheater RH1-RH3 corresponds to the expansion machine T1-T3.

[0062] In this optional embodiment, three intercoolers and reheaters can provide a larger heat exchange area, so that heat can be transferred from the hot fluid to the cold fluid more quickly and fully, thereby significantly improving the cooling or heat exchange efficiency. In addition, the presence of three intercoolers and reheaters provides a certain degree of redundancy, reducing the risk of the entire system crashing due to a single device failure.

[0063] The embodiment of the present invention also provides a carbon dioxide energy storage method based on pressure swing adsorption carbon capture and temperature swing adsorption, which is mainly used in the above-mentioned carbon dioxide energy storage system based on pressure swing adsorption carbon capture and temperature swing adsorption.

[0064] The method includes:

[0065] S1: The raw gas first passes through the second compressor C4 to increase the 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 gas in the buffer tank 1 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.

[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, evacuate the first adsorption tower AT1 and the second adsorption tower AT2, 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, and then 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, and send the carbon dioxide in the third adsorption tower AT3 to the cold fluid end of the multi-stage intercooler through the second output end to absorb the heat of the carbon dioxide at the hot fluid end of the intercooler, and then 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 for heating 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 enters the multi-stage expander to cool the carbon dioxide, and finally is sent to the third adsorption tower AT3 through the third input end of the third adsorption tower AT3 for cooling the adsorbent; at the same time, the third pump B3 is turned on, and the carbon dioxide in the third adsorption tower AT3 is sent to the hot fluid end of the multi-stage reheater through the third output end, and the heat is transferred to the carbon dioxide at the cold fluid end of the reheater. After further cooling through the cooler 4, the carbon dioxide returns to the third adsorption tower AT3 through the fourth input end of the third adsorption tower AT3 for cooling the adsorbent.

[0070] Specifically, in step S4, the system energy storage process is carried out. In this process, in the third adsorption tower AT3, the carbon dioxide working medium and the adsorbent are both in a low temperature state, and 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 intercooler IC1-IC3 in the state 8-9, 10-11, 12-13) completes the energy storage, and is stored in the high-pressure carbon dioxide storage tank 5 under high pressure. At this time, the second pump B2 ( Figure 1 The carbon dioxide heat exchange medium ( Figure 1 state 21) enters the multi-stage intercooler to absorb the compression heat ( Figure 1 23-26, 24-27, 25-28) and then further heated by the heater ( Figure 1 The adsorbent is then 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 in state 20), the adsorbent is in a high-temperature state due to the high-order adsorption heat generated when the adsorbent adsorbs carbon dioxide. However, too high an 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, preparation work for cooling the adsorbent in the third adsorption tower AT3 is required.

[0072] Specifically, in step S5, the system energy release process is carried out, the purpose of which is to cool down the adsorbent in the third adsorption tower AT3 to facilitate the next carbon dioxide adsorption (i.e., adsorb the carbon dioxide input from the first adsorption tower AT1 and the second adsorption tower AT2 to the third adsorption tower AT3). In the energy release stage, the high-pressure carbon dioxide released from the high-pressure carbon dioxide storage tank 5 is reheated by the pre-stage of the multi-stage reheater ( Figure 1 The reheater RH1-RH3, states 14-15, 16-17, 18-19) and the expansion of the multi-stage expander ( Figure 1 The carbon dioxide released from the third adsorption tower AT3 enters the multi-stage reheater, and the heat therein is transferred to the carbon dioxide released from the high-pressure carbon dioxide storage tank 5 ( Figure 1 The reheater RH1-RH3 in the state 32-35, 33-36, 34-37) is then further cooled by cooler 4 ( Figure 1 The adsorbent is then sent back to the third adsorption tower AT3 to cool the adsorbent and carbon dioxide in the third adsorption tower AT3, thereby 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 can better perform 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 is completed.

[0076] In this optional embodiment, by switching control between valves, the first adsorption tower AT1 and the second adsorption tower AT2 can be fully utilized to realize the pressure increase, adsorption and pressure equalization process of the first adsorption tower AT1 and the second adsorption tower AT2. Through the valve control of the present invention, the first adsorption tower AT1 and the second adsorption tower AT2 can work simultaneously, can process a larger flow of raw gas, improve the overall processing capacity and separation speed, and can further improve the energy efficiency of the system. The purpose of pressure equalization is to preserve the mechanical energy contained in the gas in the adsorption bed, and the use of pressure equalization can save energy.

[0077] Optionally, between step S2 and step S3, the following step is 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 residual gas is nitrogen and other impurity gases remaining after carbon dioxide in the raw gas is adsorbed.

[0079] In this embodiment, the compression heat generated in the storage stage is used as the desorption heat of the adsorbent. In the energy release process, the adsorption heat generated by the system is used to heat the high-pressure carbon dioxide to achieve a real-time internal heat cycle. This method eliminates a large amount of heat storage medium and storage tanks and has good economic performance. At the same time, in the energy release stage of the system, since the sensible heat temperature is higher than the compression heat, providing the sensible heat and the adsorption heat together to the reheater can increase the net output power of the turbine.

[0080] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A carbon dioxide energy storage system based on pressure swing adsorption carbon capture and temperature swing adsorption, characterized in that: include: A first adsorption tower (AT1), a second adsorption tower (AT2), a third adsorption tower (AT3), a heater (3), a cooler (4) and a 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 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 a first pump (B1); the tops 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) through the hot fluid ends of multiple intercoolers in sequence; a first compressor is also provided at the inlet of the hot fluid end of each intercooler; The second output end of the third adsorption tower (AT3) is connected to the cold fluid end inlets of the plurality of intercoolers respectively through the second pump (B2), and the cold fluid end outlet of the intercooler is connected to the second input end of the third adsorption tower (AT3) through 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) through the cold fluid ends of multiple reheaters in sequence; an expander is also provided at the outlet of the cold fluid end of each reheater; The third output end of the third adsorption tower (AT3) is connected to the hot fluid end inlets of the multiple reheaters through the third pump (B3), and the hot fluid end outlet of the reheater is connected to the fourth input end of the third adsorption tower (AT3) through the cooler (4).

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

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

4. The carbon dioxide energy storage system based on pressure swing adsorption carbon capture and temperature swing adsorption according to claim 1 is characterized in that: The input ends of the first adsorption tower (AT1) and the second adsorption tower (AT2) are provided with a second compressor (C4), and the second compressor (C4) is used to increase the pressure of the 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 carbon capture and temperature swing adsorption according to claim 5 is 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 carbon dioxide energy storage system based on pressure swing adsorption carbon capture and temperature swing adsorption according to claim 1 is characterized in that: A first valve (V1) and a third valve (V3) are respectively arranged 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 arranged 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 arranged 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 through a pipeline, and a sixth valve (V6) is arranged on the pipeline; an eighth valve (V8) is arranged between the first output end of the third adsorption tower (AT3) and the intercooler.

7. The carbon dioxide energy storage method based on pressure swing adsorption carbon capture and temperature swing adsorption according to the carbon dioxide energy storage system based on pressure swing adsorption carbon capture and temperature swing adsorption according to any one of claims 1 to 6, characterized in that: include: S1: The raw gas passes through the second compressor (C4) to increase the 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), and the raw gas enters the first adsorption tower (AT1) and the second adsorption tower (AT2), and the first adsorption tower (AT1) and the second adsorption tower (AT2) adsorb carbon dioxide; S3: closing 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 opening the first pump (B1) to evacuate the first adsorption tower (AT1) and the second adsorption tower (AT2), so as to desorb the high-purity carbon dioxide adsorbed in the first adsorption tower (AT1) and the second adsorption tower (AT2) and send the desorbed carbon dioxide to the third adsorption tower (AT3); S4: Open the eighth valve (V8), the carbon dioxide released by the third adsorption tower (AT3) is sent to the multi-stage first compressor through the first output end, then passes through the hot fluid end of the multi-stage intercooler, and is then stored in the high-pressure carbon dioxide storage tank (5); at the same time, open the second pump (B2), the carbon dioxide released by the third adsorption tower (AT3) is sent to the cold fluid end of the multi-stage intercooler through the second output end to absorb the heat of the carbon dioxide at the hot fluid end of the intercooler, and then is further heated by the heater (3), and is sent back to the third adsorption tower (AT3) through the second input end of the third adsorption tower (AT3) to be used 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 expansion machine, and finally is sent to the third adsorption tower (AT3) through the third input end of the third adsorption tower (AT3) for cooling 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, and the heat is transferred to the carbon dioxide at the cold fluid end of the reheater. After further cooling through the cooler (4), the carbon dioxide returns to the third adsorption tower (AT3) through the fourth input end of the third adsorption tower (AT3) for cooling the adsorbent.

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

9. The carbon dioxide energy storage method based on pressure swing adsorption carbon capture and temperature swing adsorption according to claim 7 is 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 allow the first adsorption tower (AT1) and the second adsorption tower (AT2) to be pressure-equalized after the adsorption is completed.

10. The carbon dioxide energy storage method based on pressure swing adsorption carbon capture and temperature swing adsorption according to claim 7 is characterized in that: Between step S2 and step 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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