A method and system for carbon capture and utilization for compressed air energy storage

Abstract

The present invention discloses a method for carbon capture and utilization for compressed air energy storage, comprising: during redundant power generation period, compressing a fixed flow of air to obtain compressed air, when the compressed air pressure is not lower than the critical pressure of CO2, separating the compressed air into gas and liquid to obtain decarbonized high-pressure air and liquid CO2 and storing them separately, when the compressed air pressure is lower than the critical pressure of CO2, capturing and decarbonizing the compressed air through a CO2 adsorbent to obtain decarbonized low-pressure air for storage, desorbing the CO2 adsorbent after adsorbing CO2 to obtain gaseous CO2 for storage; during peak power consumption period, the decarbonized high-pressure air, liquid CO2 and decarbonized low-pressure air are expanded to generate power respectively, and the gaseous CO2 obtained after the liquid CO2 is expanded is stored. The present invention also discloses a system for carbon capture and utilization for compressed air energy storage. The present invention can improve the operating efficiency of the induced draft fan, the operating life of the system and the external output power during peak power consumption period.

Description

Technical Field

[0001] The present invention relates to an energy storage and carbon capture method and system, and in particular to a carbon capture and utilization method and system for compressed air energy storage. Background Art

[0002] Compressed air energy storage is a technology that stores energy by compressing air. When electricity demand is low, excess electricity is used to drive a compressor to compress the air and store it in a pressure vessel or underground cavern. When electricity demand peaks, the compressed air is released to expand through a turbine and convert into electricity. 2 The concentration is about 400ppm, corresponding to CO 2 The partial pressure is 40 Pa. When direct air carbon capture technology is used, the CO in the air is too low. 2 The partial pressure significantly reduced the CO 2 Capture efficiency, and in the process of air compression energy storage, as the air is compressed, CO 2 The partial pressure increases significantly, which is very beneficial to CO 2 Therefore, the existing technology adopts a solution of coupling compressed air energy storage with direct air carbon capture.

[0003] In these solutions, air is introduced into the coupling system through an induced draft fan. According to the air compression pressure designed by the system, in the compressed air energy storage process, the power of the induced draft fan needs to be adjusted according to the amount of redundant power to adjust the air volume entering the system. This requires the induced draft fan to adjust its operating state at any time according to the changes in redundant power, affecting the operating efficiency and service life of the induced draft fan. In addition, the captured CO 2 Usually stored and used in other applications, such as wet capture of CO 2 Cultivating light-energy microorganisms and storing CO at high pressure 2 For the production of CH 4 , C 2 H 4 Chemical products such as carbon dioxide and carbon dioxide rely solely on high-pressure stored air to generate electricity during peak hours of electricity consumption, which often has insufficient peak-shaving and valley-filling effects on the power grid. Summary of the invention

[0004] In view of the above-mentioned defects in the prior art, the task of the present invention is to provide a method for carbon capture and utilization for compressed air energy storage, and to provide a system for carbon capture and utilization for compressed air energy storage, with the aim of solving the problems of low operating efficiency of induced draft fans, low system operating life, and insufficient external output power of the system during peak electricity consumption periods.

[0005] The technical solution of the present invention is as follows: A method for carbon capture and utilization for compressed air energy storage, comprising:

[0006] During the redundant power generation period, a fixed flow of air is compressed to obtain compressed air. When the compressed air pressure is not lower than CO 2 At the critical pressure, the compressed air is separated into gas and liquid to obtain decarbonized high-pressure air and liquid CO 2 And store separately, when the compressed air pressure is lower than CO 2 At critical pressure, the compressed air is passed through CO 2 The adsorbent captures the decarbonized air to obtain decarbonized low-pressure air for storage. 2 After CO 2 The adsorbent is desorbed to obtain gaseous CO 2 To store;

[0007] During peak hours, decarbonized high-pressure air and liquid CO 2 and decarbonized low-pressure air are expanded to generate electricity, and liquid CO 2 The gaseous CO obtained after expansion work 2 for storage.

[0008] Furthermore, during the redundant power generation period, the pressure value of the compressed air obtained by compressing the fixed flow of air is predicted. When the predicted compressed air pressure is lower than the CO 2 At the critical pressure, the stored gaseous CO is compressed while a fixed flow of air is compressed. 2 Compress to obtain liquid CO 2 Store. 2 While the voltage division improves the capture efficiency, it also increases the storage capacity of redundant electric energy, further improving the external output power during peak power consumption periods.

[0009] Furthermore, during the redundant power generation period, the air is dried before the fixed flow of air is compressed, the water vapor in the air is adsorbed by the dehumidification solution, and the dehumidification solution adsorbed by the water vapor is heated and regenerated by the heat energy of the compressed air.

[0010] Furthermore, the compressed air is cooled to CO by heat exchanger. 2 The adsorption temperature range of the adsorbent is followed by gas-liquid separation or capture and decarbonization. The heat released by the compressed air is used for heating and heating before the high-pressure air expands to do work. 2 At least one of heating and heating the decarburized low-pressure air before expansion to do work.

[0011] Furthermore, the stored gaseous CO 2 Compress to obtain liquid CO 2 The heat generated during the decarbonization process is absorbed by the heat exchanger and used to heat the decarbonized high-pressure air before it expands to do work, and to heat the liquid CO 2At least one of heating and heating the decarburized low-pressure air before expansion to do work.

[0012] Another technical solution of the present invention is: a system for carbon capture and utilization of compressed air energy storage, comprising an induced draft fan, a compressor A, a pressure detection device, a gas-liquid separation device, a decarbonized high-pressure air storage tank, a high-pressure liquid CO 2 Storage tank, low pressure gaseous CO 2 Storage tank, turbine A, turbine B, CO 2 Adsorption device, CO 2 Desorption device, decarbonization low-pressure air storage tank and turbine C;

[0013] The outlet of the induced draft fan is connected to the inlet of the compressor A, and the outlet of the compressor A is connected to the gas-liquid separation device and the CO 2 The inlet of the adsorption device is controlled by the pressure detection device to be turned on or off, the gas outlet of the gas-liquid separation device is connected to the inlet of the decarbonization high-pressure air storage tank, the outlet of the decarbonization high-pressure air storage tank is connected to the turbine B, and the liquid outlet of the gas-liquid separation device is connected to the high-pressure liquid CO 2 The inlet of the storage tank, the high pressure liquid CO 2 The outlet of the storage tank is connected to the inlet of turbine A, and the outlet of turbine A is connected to the low-pressure gaseous CO 2 At the inlet of the storage tank, the CO 2 The gas outlet of the adsorption device is connected to the inlet of the decarbonized low-pressure air storage tank, and the outlet of the decarbonized low-pressure air storage tank is connected to the turbine C. 2 The gas outlet of the desorption device is connected to the low-pressure gaseous CO 2 At the inlet of the storage tank, the CO 2 Adsorption of CO in the adsorption device 2 After CO 2 The adsorbent is sent to the CO 2 The desorption device consists of the CO 2 Desorption device desorbs regenerated CO 2 The adsorbent is sent to the CO 2 Adsorption device.

[0014] Further, a compressor B is included, wherein the low-pressure gaseous CO 2 The outlet of the storage tank is connected to the inlet of compressor B, and the outlet of compressor B is connected to the high-pressure liquid CO 2 The entrance to the tank.

[0015] Furthermore, it includes a dehumidifier and a dehumidification regenerator, the outlet of the induced draft fan is connected to the inlet of the dehumidifier, the outlet of the dehumidifier is connected to the inlet of the compressor A, the dehumidification solution after adsorbing water vapor in the dehumidifier enters the dehumidification regenerator for regeneration, and the regenerated dehumidification solution returns to the dehumidifier.

[0016] Furthermore, it includes heat exchanger A, heat exchanger B and heat exchanger C, wherein heat exchanger A is used to absorb the heat of the dehumidification solution after regeneration by the dehumidification regenerator, and heat exchanger C is connected to the outlet of compressor A to absorb the heat of compressed air discharged by compressor A. The heat absorbed by heat exchanger A and heat exchanger C is used to heat the dehumidification solution after adsorbing water vapor in heat exchanger B.

[0017] Furthermore, the invention comprises a heat exchanger C, a heat exchanger D, a heat exchanger F and a heat exchanger H, wherein the heat exchanger C is connected to the outlet of the compressor A to absorb the heat of the compressed air discharged by the compressor A, and the heat exchanger D is connected to the high-pressure liquid CO 2 The outlet of the tank is used to heat the liquid CO 2 The heat exchanger F is connected to the outlet of the decarbonization high-pressure air storage tank for heating the decarbonization high-pressure air, and the heat exchanger H is connected to the outlet of the decarbonization low-pressure air storage tank for heating the decarbonization low-pressure air. The heat absorbed by the heat exchanger C is used for heating at least one of the heat exchanger D, heat exchanger F and heat exchanger H.

[0018] The advantages of the present invention compared with the prior art are:

[0019] (1) Based on the compressed air energy storage system, the present invention compresses air at a fixed flow rate and selects CO according to the different pressures of the compressed air. 2 Capture methods to improve CO2 in direct air carbon capture processes 2 To increase the partial pressure of gaseous CO 2 The capture capacity of the induced draft fan can be increased, and the induced draft fan can operate at a fixed speed in most cases, reducing fluctuations in operating conditions and improving the service life and stability of the system.

[0020] (2) Liquid CO separated under high pressure 2 During the peak hours of electricity consumption, expansion work is also performed to increase the external output power and enhance the valley filling capacity. Under low-pressure compression, part of the electrical energy is used to compress the gaseous low-pressure CO 2 Compression can further increase the external output power during peak power consumption periods.

[0021] (3) The present invention adopts a liquid dehumidification strategy to dry the air. It only needs to use part of the heat generated by the compressed air process as the heat source of the liquid dehumidification system. The heat generated by the compressed air process can be used as compressed air or CO2 for energy storage.2 The heat source is heated before expansion work is performed, which improves the energy utilization efficiency of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the system for carbon capture and utilization for compressed air energy storage in Example 1.

[0023] Figure 2 This is a schematic diagram of the system for carbon capture and utilization for compressed air energy storage in Example 2. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the embodiments, but are not intended to limit the present invention.

[0025] Example 1, please combine Figure 1 As shown, a carbon capture and utilization system for compressed air energy storage involved in this embodiment includes an induced draft fan 1, a compressor A 2, a pressure detection device 3, a gas-liquid separation device 4, a decarbonized high-pressure air storage tank 5, and a high-pressure liquid CO 2 Storage tank 6, low pressure gaseous CO 2 Storage tank 7, turbine A 8, turbine B 9, CO 2 Adsorption device 10, CO 2 Desorption device 11, decarbonized low-pressure air storage tank 12 and turbine C 13.

[0026] The outlet of the induced draft fan 1 is connected to the inlet of the compressor A2. The outlet of the compressor A2 is provided with a pressure detection device 3 and is connected to the inlet of the gas-liquid separation device 4 and the inlet of the CO2 through a three-way pipeline that can be selectively connected. 2 At the inlet of the adsorption device 10, the air delivered by the induced draft fan 1 is compressed by the compressor A2 and can be delivered to the gas-liquid separation device 4 or the CO 2 Adsorption device 10. Specifically, when the compressed air pressure output by compressor A2 is greater than or equal to CO 2 When the critical pressure (7.38MPa) is reached, the compressed air enters the gas-liquid separation device 4, and the compressed air pressure is less than the CO 2 When the critical pressure is reached, compressed air enters the CO 2 Adsorption device 10.

[0027] The gas-liquid separation device 4 separates the liquid CO 2 The compressed air is used for gas-liquid separation, the gas outlet of the gas-liquid separation device 4 is connected to the inlet of the decarbonized high-pressure air storage tank 5, and the liquid outlet of the gas-liquid separation device 4 is connected to the high-pressure liquid CO 2 The inlet of the storage tank 6. The decarbonized high-pressure air storage tank 5 stores the decarbonized high-pressure air after gas-liquid separation, the high-pressure liquid CO 2Tank 6 stores the separated liquid CO 2 .

[0028] The outlet of the decarbonized high-pressure air storage tank 5 is connected to the inlet of the turbine B 9 through the heat exchanger F. After being heated in the heat exchanger F 14, the decarbonized high-pressure air enters the turbine B 9 to expand and do work, and the turbine B 9 then drives the generator B 15 to generate electricity. High-pressure liquid CO 2 The outlet of the storage tank 6 is connected to the inlet of the turbine A 8 through the heat exchanger D 16, and the outlet of the turbine A 8 is connected to the low-pressure gaseous CO 2 Inlet of tank 7, liquid CO 2 After being heated in the heat exchanger D 16, it enters the turbine A 8 to expand and do work, and the turbine A 8 then drives the generator A 17 to generate electricity. Liquid CO 2 After expansion, it becomes gaseous CO 2 Can be stored in low pressure gaseous CO 2 Storage tank 7.

[0029] CO 2 Adsorption device 10 is lower than the pressure of CO 2 Critical pressure of compressed air for CO 2 Capture, CO 2 The gas outlet of the adsorption device 10 is connected to the inlet of the decarbonized low-pressure air storage tank 12, and the gas is discharged through the CO 2 The captured decarbonized low-pressure air is stored in the decarbonized low-pressure air storage tank 12. The outlet of the decarbonized low-pressure air storage tank 12 is connected to the inlet of the turbine C 13 through the heat exchanger H 18. After being heated by the heat exchanger H 18, the decarbonized low-pressure air enters the turbine C 13 to expand and do work, and the turbine C 13 then drives the generator C 19 to generate electricity. 2 The adsorption device 10 uses solid CO 2 Adsorbent or liquid CO 2 Adsorbent. Solid CO 2 The adsorbent is at least one of a carbon-based adsorbent material, a molecular sieve, an alkali / alkaline earth metal-based adsorbent, a loaded amine-based adsorbent, a metal organic framework adsorbent and a humidifying adsorbent, and the liquid CO 2 The adsorbent is at least one of an amine solution, an alkaline hydroxide solution and an amino acid salt solution. This embodiment uses a loaded amine-based absorbent, and its adsorption temperature is about 30°C. 2 The adsorption device 10 absorbs CO 2 After CO 2 Adsorbent feeds CO 2 The desorption device 11 performs desorption regeneration, CO 2 The desorption temperature in the desorption device 11 is 120°C, the desorption pressure is normal pressure, and the CO 2 The adsorbent is fed into the CO2 The adsorption device 10 is reused. 2 The gas outlet of the desorption device 11 is connected to the low-pressure gaseous CO 2 Inlet of tank 7, CO 2 The desorption device 11 removes CO 2 Gaseous CO removed from the adsorbent 2 From low pressure gaseous CO 2 Storage tank 7 for storage.

[0030] The main operation process of the system is as follows: During the redundant power generation period (including when renewable energy power generation generates redundant power or when thermal power plants participate in power grid peak regulation and generate excess power), the induced draft fan 1 is operated at a fixed speed to generate a fixed flow of air, which enters the compressor A2 for compression. Depending on the amount of redundant power generation and / or excess power, the compressor A2 compresses the air to different pressures. The pressure of the compressed air is determined by the pressure detection device 3. When the measured compressed air pressure is not lower than CO 2 When the critical pressure is reached, the compressed air is sent to the gas-liquid separation device 4 for gas-liquid separation to obtain decarbonized high-pressure air and liquid CO 2 , and then stored in the decarbonized high-pressure air storage tank 5 and the high-pressure liquid CO 2 Tank 6. When the measured compressed air pressure is lower than CO 2 At critical pressure, compressed air is sent into the CO 2 The adsorption device 10 captures and decarbonizes to obtain decarbonized low-pressure air, which is then stored in the decarbonized low-pressure air storage tank 12. 2 After CO 2 The adsorbent is desorbed to obtain gaseous CO 2 Then stored in low pressure gaseous CO 2 Storage tank 7.

[0031] During the peak period of electricity consumption, the decarbonized high-pressure air stored in the decarbonized high-pressure air storage tank 5 is heated and sent to the turbine B 9 to expand and do work, driving the generator B 15 to generate electricity. The decarbonized air discharged from the turbine B 9 after doing work can be discharged to the atmosphere. At the same time, the high-pressure liquid CO 2 High-pressure liquid CO stored in tank 6 2 After heating, it is sent to turbine A8 to expand and do work, driving generator A17 to generate electricity. The low-pressure CO discharged by turbine A8 after doing work 2 Stored in low pressure gaseous CO 2 Storage tank 7. In addition, the decarbonized low-pressure air stored in the decarbonized low-pressure air storage tank 12 is heated and sent to the turbine C 13 to expand and do work, driving the generator C 19 to generate electricity, and the decarbonized air discharged from the turbine C 13 after doing work can be discharged to the atmosphere.

[0032] Example 2, please combine Figure 2 As shown, the carbon capture and utilization system for compressed air energy storage involved in this embodiment includes an induced draft fan 101, a dehumidifier 102, a dehumidification regenerator 103, a compressor A 104, a compressor B 105, a pressure detection device 106, a gas-liquid separation device 107, a decarbonized high-pressure air storage tank 108, and a high-pressure liquid CO 2 Storage tank 109, low pressure gaseous CO 2 Storage tank 110, turbine A 111, turbine B 112, CO 2 Adsorption device 113, CO 2 The desorption device 114, the adsorption material storage tank 115, the regenerated adsorption material storage tank 116, the decarbonized low-pressure air storage tank 117 and the turbine C 118 also include a plurality of heat exchangers, and the specific locations of the heat exchangers will be introduced later.

[0033] The outlet of the induced draft fan 101 passes through the dehumidifier 102 and is then connected to the inlet of the compressor A 104. The outlet of the compressor A 104 passes through the heat exchanger C 119 and is provided with a pressure detection device 106. The outlet of the compressor A 104 is respectively connected to the inlet of the gas-liquid separation device 107 and the inlet of the CO 200 through a three-way pipeline that can be selectively connected. 2 At the inlet of the adsorption device 113, the air delivered by the induced draft fan 101 is compressed by the compressor A 104 and can be delivered to the gas-liquid separation device 107 or the CO 2 Adsorption device 113. Specifically, when the compressed air pressure output by compressor A 104 is greater than or equal to CO 2 When the critical pressure (7.38MPa) is reached, the compressed air cooled by the heat exchanger C 119 enters the gas-liquid separation device 107, and the compressed air pressure is less than CO 2 When the critical pressure is reached, the compressed air cooled by the heat exchanger C119 enters the CO 2 Adsorption device 113. Liquid dehumidifier is added to the dehumidifier 102 to dry the air sent by the induced draft fan 101. The liquid dehumidifier absorbs moisture in the air and becomes a dilute solution. The outlet of the dehumidifier 102 is connected to the dehumidifier regenerator 103 through the heat exchanger B 120. The dilute solution is heated by the heat exchanger B 120 and then enters the dehumidifier regenerator 103 for regeneration. The outlet of the dehumidifier regenerator 103 is connected to the dehumidifier 102 through the heat exchanger A 121. The regenerated liquid dehumidifier returns to the dehumidifier 102 for reuse after releasing heat in the heat exchanger A 121. The liquid dehumidifier in the dehumidifier 102 is LiCl, LiBr, MgCl 2 , CaCl 2 A single solution or a mixed solution containing two or more components, in this embodiment, LiCl and CaCl 2The mixed liquid has a dehumidification temperature of 30-40°C in the dehumidifier 102 and a regeneration temperature of 50-80°C in the regenerator.

[0034] The gas-liquid separation device 107 separates the liquid CO 2 The compressed air is used for gas-liquid separation, the gas outlet of the gas-liquid separation device 107 is connected to the inlet of the decarbonized high-pressure air storage tank 108, and the liquid outlet of the gas-liquid separation device 107 is connected to the high-pressure liquid CO 2 The decarbonized high-pressure air storage tank 108 stores the decarbonized high-pressure air after gas-liquid separation, and the high-pressure liquid CO 2 Tank 109 stores the separated liquid CO 2 .

[0035] The outlet of the decarbonized high-pressure air storage tank 108 is connected to the inlet of the turbine B 112 through the heat exchanger F 122. After being heated by the heat exchanger F 122, the decarbonized high-pressure air enters the turbine B 112 to expand and do work. The turbine B 112 then drives the generator B 123 to generate electricity. The exhaust outlet of the turbine B 112 is provided with a heat exchanger G 128. High-pressure liquid CO 2 The outlet of the storage tank 109 is connected to the inlet of the turbine A 111 through the heat exchanger D 124, and the outlet of the turbine A 111 is connected to the low-pressure gaseous CO 2 Inlet of storage tank 110, liquid CO 2 After being heated in the heat exchanger D 124, it enters the turbine A 111 to expand and do work, and the turbine A 111 then drives the generator A 125 to generate electricity. Liquid CO 2 After expansion, it becomes gaseous CO 2 Can be stored in low pressure gaseous CO 2 Storage tank 110.

[0036] CO 2 Adsorption device 113 is for pressure lower than CO 2 Critical pressure of compressed air for CO 2 Capture, CO 2 The gas outlet of the adsorption device 113 is connected to the inlet of the decarbonized low-pressure air storage tank 117, and the gas is discharged through the CO 2 The captured decarbonized low-pressure air is stored in the decarbonized low-pressure air storage tank 117. The outlet of the decarbonized low-pressure air storage tank 117 is connected to the inlet of the turbine C118 through the heat exchanger H126. The decarbonized low-pressure air is heated by the heat exchanger H126 and enters the turbine C118 for expansion and work. The turbine C118 then drives the generator C127 to generate electricity. The exhaust outlet of the turbine C118 is provided with a heat exchanger I129. 2 Solid CO is used in adsorption device 113 2 Adsorbent or liquid CO2 Adsorbent. CO 2 Adsorption device 113 is connected to heat exchanger J 130 and CO 2 Adsorption material storage tank 115, CO 2 Absorption of CO in adsorption device 113 2 After CO 2 The adsorbent is cooled by heat exchanger J130 and then heated to CO 2 The adsorbent material storage tank 115 stores CO. 2 The absorbed CO stored in the adsorption material storage tank 115 2 After CO 2 The adsorbent is then fed into the CO 2 The desorption device 114 performs desorption regeneration. 2 The desorption temperature in the desorption device 114 is 120°C, the desorption pressure is normal pressure, and the CO 2 The desorption device 114 is connected to the heat exchanger L131 and the regenerated CO 2 Adsorption material storage tank 115. CO after desorption and regeneration 2 The adsorbent is cooled by heat exchanger L131 and then regenerated into CO 2 The adsorbent material storage tank 115 stores the regenerated CO 2 The regenerated CO stored in the adsorbent material storage tank 115 2 The adsorbent is fed into the CO 2 Adsorption device 113 is reused. 2 The gas outlet of the desorption device 114 is connected to the low-pressure gaseous CO via a heat exchanger K 132. 2 Inlet of tank 110, CO 2 The desorption device 114 removes CO 2 Gaseous CO removed from the adsorbent 2 After cooling in heat exchanger K 132, low pressure gaseous CO 2 The storage tank 110 stores low-pressure gaseous CO 2 The outlet of the storage tank 110 is connected to the inlet of the compressor B 105, and the outlet of the compressor B 105 is connected to the high-pressure liquid CO through the heat exchanger E 133. 2 The inlet of the storage tank 109 can be used to purify the low-pressure gaseous CO 2 Low-pressure gaseous CO in storage tank 110 2 The aforementioned heat exchangers can use water, heat transfer oil or molten salt as the heat transfer medium to store or release heat. The heat stored in heat exchanger C 119 and heat exchanger E 133 is used in other heat exchangers for heating to improve the energy utilization rate of the system. It should be noted that in the case of compressed air and compressed CO 2When the heat generated is lower than the heat required by the energy storage system, the additional heat required can be provided by generating heat through solar energy or heating with electric resistance wire.

[0037] The main operation process of the system is as follows: During the redundant power generation period (including when renewable energy power generation generates redundant power or when thermal power plants participate in power grid peak regulation and generate excess power), the induced draft fan 101 is operated at a fixed speed to generate a fixed flow of air, which is dried through the dehumidifier 102 and then enters the compressor A 104 for compression. Depending on the amount of redundant power generation and / or excess power, the compressor A 104 compresses the air to different pressures. This pressure can be predicted based on the amount of redundant power generation and / or excess power. The predicted pressure is not less than CO 2 At critical pressure, only compressor A 104 is started, and the predicted pressure is lower than CO 2 At the critical pressure, compressor A 104 and compressor B 105 are started simultaneously.

[0038] The pressure of the compressed air discharged from the heat exchanger C 119 is determined by the pressure detection device 106. When the measured compressed air pressure is not lower than CO 2 When the critical pressure is reached, the compressed air is sent to the gas-liquid separation device 107 for gas-liquid separation to obtain decarbonized high-pressure air and liquid CO 2 , and then stored in the decarbonized high-pressure air storage tank 108 and the high-pressure liquid CO 2 Tank 109. When the measured compressed air pressure is lower than CO 2 At critical pressure, compressed air is sent into the CO 2 The adsorption device 113 captures and decarbonizes to obtain decarbonized low-pressure air, which is then stored in the decarbonized low-pressure air storage tank 117. 2 After CO 2 The adsorbent is desorbed to obtain gaseous CO 2 Then stored in low pressure gaseous CO 2 Storage tank 110. Compressor B 105 for low pressure gaseous CO 2 The gaseous CO stored in the storage tank 110 2 Compressed, the compressed liquid CO 2 After heat release in heat exchanger E 133, it is stored in high pressure liquid CO 2 Storage tank 109.

[0039] During the peak period of electricity consumption, the decarbonized high-pressure air stored in the decarbonized high-pressure air storage tank 108 is heated and sent to the turbine B 112 to expand and work, driving the generator B 123 to generate electricity. The decarbonized air discharged from the turbine B 112 after work is discharged to the atmosphere through the heat exchanger G 128. At the same time, the high-pressure liquid CO 2High-pressure liquid CO stored in tank 109 2 After being heated by the heat exchanger, it is sent to the turbine A111 to expand and do work, driving the generator A125 to generate electricity. The low-pressure CO2 discharged by the turbine A111 after doing work 2 Stored in low pressure gaseous CO 2 In addition, the decarbonized low-pressure air stored in the decarbonized low-pressure air storage tank 117 is heated and sent to the turbine C 118 to expand and do work, driving the generator C 127 to generate electricity. The decarbonized air discharged from the turbine C 118 after doing work passes through the heat exchanger I 129 to release heat and can be discharged to the atmosphere.

Claims

1. A method for carbon capture and utilization for compressed air energy storage, characterized in that: include: During the redundant power generation period, a fixed flow of air is compressed to obtain compressed air. When the compressed air pressure is not lower than the critical pressure of CO2, the compressed air is separated into gas and liquid to obtain decarbonized high-pressure air and liquid CO2 and stored separately. When the compressed air pressure is lower than the critical pressure of CO2, the compressed air is captured and decarbonized by a CO2 adsorbent to obtain decarbonized low-pressure air for storage. The CO2 adsorbent after adsorbing CO2 is desorbed to obtain gaseous CO2 for storage. During peak electricity consumption periods, decarbonized high-pressure air, liquid CO2 and decarbonized low-pressure air are expanded to generate electricity, and the gaseous CO2 obtained from the expansion of liquid CO2 is stored.

2. The method for carbon capture and utilization for compressed air energy storage according to claim 1, characterized in that: During the redundant power generation period, the pressure value of the compressed air obtained by compressing a fixed flow of air is predicted. When the predicted compressed air pressure is lower than the critical pressure of CO2, the stored gaseous CO2 is compressed to obtain liquid CO2 for storage while compressing the fixed flow of air.

3. The method for carbon capture and utilization for compressed air energy storage according to claim 1, characterized in that: During the redundant power generation period, the air is dried before the fixed flow of air is compressed, and the dehumidification solution adsorbs the water vapor in the air. The dehumidification solution that adsorbs the water vapor is heated and regenerated by the heat energy of the compressed air.

4. The method for carbon capture and utilization for compressed air energy storage according to claim 1, characterized in that: The compressed air is cooled to the adsorption temperature range of the CO2 adsorbent through the heat exchanger after releasing heat, and then gas-liquid separation or capture and decarbonization is carried out. The heat released by the compressed air is used for at least one of heating and raising the temperature of the decarbonization high-pressure air before expansion to do work, heating and raising the temperature of the liquid CO2 before expansion to do work, and heating and raising the temperature of the decarbonization low-pressure air before expansion to do work.

5. The method for carbon capture and utilization for compressed air energy storage according to claim 2, characterized in that: The heat generated when compressing the stored gaseous CO2 to obtain liquid CO2 is absorbed by the heat exchanger and used for at least one of heating the decarbonization high-pressure air before expansion to do work, heating the liquid CO2 before expansion to do work, and heating the decarbonization low-pressure air before expansion to do work.

6. A system for carbon capture and utilization for compressed air energy storage, characterized in that: It includes an induced draft fan, a compressor A, a pressure detection device, a gas-liquid separation device, a decarbonization high-pressure air storage tank, a high-pressure liquid CO2 storage tank, a low-pressure gaseous CO2 storage tank, a turbine A, a turbine B, a CO2 adsorption device, a CO2 desorption device, a decarbonization low-pressure air storage tank and a turbine C; The outlet of the induced draft fan is connected to the inlet of the compressor A, and the outlet of the compressor A is connected to the inlets of the gas-liquid separation device and the CO2 adsorption device after passing through the pressure detection device and is controlled by the pressure detection device to be turned on or off. The gas outlet of the gas-liquid separation device is connected to the inlet of the decarbonization high-pressure air storage tank, and the outlet of the decarbonization high-pressure air storage tank is connected to the turbine B. The liquid outlet of the gas-liquid separation device is connected to the inlet of the high-pressure liquid CO2 storage tank, and the outlet of the high-pressure liquid CO2 storage tank is connected to the inlet of the turbine A, and the outlet of the turbine A is connected to the inlet of the low-pressure gaseous CO2 storage tank. The gas outlet of the CO2 adsorption device is connected to the inlet of the decarbonization low-pressure air storage tank, and the outlet of the decarbonization low-pressure air storage tank is connected to the turbine C. The gas outlet of the CO2 desorption device is connected to the inlet of the low-pressure gaseous CO2 storage tank. The CO2 adsorbent after adsorbing CO2 in the CO2 adsorption device is sent to the CO2 desorption device, and the CO2 adsorbent desorbed and regenerated by the CO2 desorption device is sent to the CO2 adsorption device.

7. The system for carbon capture and utilization for compressed air energy storage according to claim 6, characterized in that: A compressor B is included, wherein the outlet of the low-pressure gaseous CO2 storage tank is connected to the inlet of the compressor B, and the outlet of the compressor B is connected to the inlet of the high-pressure liquid CO2 storage tank.

8. The system for carbon capture and utilization for compressed air energy storage according to claim 6, characterized in that: It includes a dehumidifier and a dehumidifier regenerator, the outlet of the induced draft fan is connected to the inlet of the dehumidifier, the outlet of the dehumidifier is connected to the inlet of the compressor A, the dehumidifier solution after adsorbing water vapor in the dehumidifier enters the dehumidifier regenerator for regeneration, and the regenerated dehumidifier solution returns to the dehumidifier.

9. The system for carbon capture and utilization for compressed air energy storage according to claim 8, characterized in that: The invention comprises heat exchanger A, heat exchanger B and heat exchanger C. Heat exchanger A is used to absorb the heat of the dehumidification solution after regeneration by the dehumidification regenerator. Heat exchanger C is connected to the outlet of compressor A to absorb the heat of the compressed air discharged by compressor A. The heat absorbed by heat exchanger A and heat exchanger C is used to heat the dehumidification solution after adsorbing water vapor in heat exchanger B.

10. The system for carbon capture and utilization for compressed air energy storage according to claim 6, characterized in that: It includes heat exchangers C, D, F and H. The heat exchanger C is connected to the outlet of the compressor A to absorb the heat of the compressed air discharged by the compressor A. The heat exchanger D is connected to the outlet of the high-pressure liquid CO2 storage tank to heat the liquid CO2. The heat exchanger F is connected to the outlet of the decarbonized high-pressure air storage tank to heat the decarbonized high-pressure air. The heat exchanger H is connected to the outlet of the decarbonized low-pressure air storage tank to heat the decarbonized low-pressure air. The heat absorbed by the heat exchanger C is used for heating at least one of the heat exchanger D, heat exchanger F and heat exchanger H.

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