Carbon dioxide capture and supercritical carbon dioxide brayton cycle combined production system

Abstract

The present application relates to the technical field of carbon dioxide recovery and renewable energy utilization, in particular to a carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system. The present application combines a carbon dioxide capture and purification system and a supercritical carbon dioxide Brayton cycle power generation system, can effectively capture and purify carbon dioxide, reduce greenhouse gas emissions, and can directly use the captured carbon dioxide in the supercritical carbon dioxide Brayton cycle, provide a stable and reliable carbon dioxide supply for the cycle system, and reduce the storage and transportation cost of carbon dioxide, realize the recycling of resources, improve the overall efficiency of the system, solve the problems of the carbon dioxide capture and purification system based on the physical absorption method, such as huge energy consumption and the need for additional heat input, and the problems of the supercritical carbon dioxide Brayton cycle power generation system, such as the need for additional cold input for operation, and increase the operation cost.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide recovery and renewable energy utilization, and in particular to a carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system. Background Art

[0002] Carbon dioxide, as one of the major greenhouse gases, has a significant impact on the atmosphere and climate system. It primarily originates from the combustion of fossil fuels, industrial production processes such as steel, cement, and chemicals, and agricultural activities. The dramatic increase in carbon dioxide emissions has led to a series of serious environmental and ecological problems, including rising global temperatures, frequent extreme weather events, and rising sea levels, posing a severe challenge to human survival. To curb climate change and limit global temperature rise to 2°C, effective measures are urgently needed to reduce atmospheric carbon dioxide concentrations.

[0003] Currently, the mainstream technologies for reducing CO2 emissions include carbon dioxide capture, utilization, and storage (CCUS), chemical absorption, and physical absorption. CCUS technology primarily captures industrially emitted CO2, purifies it, and then stores it underground or on the seabed, effectively reducing atmospheric CO2 concentrations. It also provides new avenues for the utilization of industrial byproducts and economic development. Chemical absorption and physical absorption are the two main technologies for CO2 capture. Chemical absorption has high capture efficiency for low-concentration CO2 gas, but it has high requirements for equipment and materials, and the chemical absorbent is corrosive, increasing equipment construction and maintenance costs, and is prone to producing environmentally polluting byproducts. Physical absorption typically operates under low-temperature or high-pressure conditions, has high selectivity for gas components, and can effectively separate CO2 on a large scale, but it also consumes significant energy and requires additional heat input.

[0004] In the field of power generation, there are various ways of generating electricity, each with its own challenges and shortcomings. Fossil fuel power generation is still the main way of generating electricity globally, but it has a serious problem of high carbon emissions. Hydroelectric power and nuclear power provide important base load power sources, but they also have environmental and safety challenges. Wind and solar power, as clean energy, are developing rapidly, but they are limited by intermittency and efficiency problems. Supercritical fluid power generation technology, especially supercritical carbon dioxide power generation systems, has the potential to become an important direction for future power generation technology due to its high efficiency, compact design, flexibility, and environmental friendliness. The full name of supercritical carbon dioxide is Supercritical Carbon Dioxide, abbreviated as sCO2. However, the sCO2 technology is still in the development and optimization stage.

[0005] Currently, carbon dioxide capture and purification systems based on physical absorption methods can adapt to carbon capture in different industrial scenarios, but they consume a lot of energy and require additional heat input, limiting their widespread application.

[0006] The supercritical carbon dioxide Brayton cycle power generation system uses sCO2 as the working medium to achieve self-circulation digestion of CO2, but the system requires additional cold input, increasing operating costs. SUMMARY

[0007] To solve the problem of high energy consumption and the need for additional heat input in carbon dioxide capture and purification systems based on physical absorption methods, and the problem of additional cold input required for the operation of supercritical carbon dioxide Brayton cycle power generation systems, increasing operating costs, the purpose of the present invention is to provide a carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system.

[0008] The present invention can overcome the defects of carbon dioxide capture and purification systems based on physical absorption methods and supercritical carbon dioxide Brayton cycle power generation systems, and achieve the coupling and optimal operation of CCUS and supercritical carbon dioxide Brayton cycle power generation systems.

[0009] To achieve the above purpose, the technical solution of the present invention is as follows.

[0010] The present invention provides a carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system, comprising a carbon dioxide capture and purification system and a supercritical carbon dioxide Brayton cycle power generation system.

[0011] The carbon dioxide capture and purification system includes a carbon dioxide capture system and a carbon dioxide purification system connected in sequence; the carbon dioxide purification system includes a condenser, a distillation tower, a reboiler and a subcooler; the hot end outlet of the condenser is connected to the first feed inlet of the distillation tower for distilling and purifying the condensed raw gas; the first discharge port of the distillation tower is connected to the first inlet of the reboiler to heat the material after preliminary distillation and purification.

[0012] The first outlet of the reboiler is connected to the second feed port of the distillation tower to perform further distillation and purification on the heated material; the second discharge port of the distillation tower is connected to the feed port of the subcooler to cool the material after further distillation and purification.

[0013] The supercritical carbon dioxide Brayton cycle power generation system includes a recompressor, a regenerator, a heat supply device and a power generation device; the second outlet of the reboiler is connected to the inlet of the recompressor, and the outlet of the recompressor is connected to the cold end inlet of the regenerator to absorb heat from the compressed carbon dioxide; the cold end outlet of the regenerator is connected to the first inlet of the heat supply device to convert the heat-absorbed carbon dioxide into supercritical carbon dioxide; the first outlet of the heat supply device is connected to the power generation device.

[0014] The exhaust gas outlet of the power generation device is connected to the hot end inlet of the regenerator, and the hot end outlet of the regenerator is connected to the second inlet of the reboiler.

[0015] Preferably, the carbon dioxide purification system includes a refrigeration unit, and the outlet of the refrigeration unit is respectively connected to the cold end inlet of the condenser, the cold end inlet of the distillation tower, and the cold end inlet of the subcooler.

[0016] The inlet of the refrigeration unit is respectively connected to the cold end outlet of the condenser, the cold end outlet of the distillation tower and the cold end outlet of the subcooler.

[0017] The power output end of the power generation device is connected to the power interface of the refrigeration unit.

[0018] Preferably, the power generation device includes a high-pressure turbine, a low-pressure turbine and a generator set, and the output shaft of the recompressor, the output shaft of the high-pressure turbine and the output shaft of the low-pressure turbine are connected to the drive shaft of the generator set.

[0019] Preferably, the first outlet of the heat supply device is connected to the inlet of the high-pressure turbine, the outlet of the high-pressure turbine is connected to the second inlet of the heat supply device; the second outlet of the heat supply device is connected to the inlet of the low-pressure turbine.

[0020] The exhaust gas outlet of the low-pressure turbine is connected to the hot end inlet of the regenerator.

[0021] Preferably, a first check valve is provided in the connecting pipeline between the hot end outlet of the regenerator and the second inlet of the reboiler, so that the exhaust gas discharged from the hot end outlet of the regenerator enters the second inlet of the reboiler in a one-way manner.

[0022] A second check valve is provided on the connecting pipeline between the second outlet of the reboiler and the inlet of the recompressor, so that the carbon dioxide discharged from the second outlet of the reboiler can enter the inlet of the recompressor in a one-way manner for compression.

[0023] Preferably, the carbon dioxide capture system includes a buffer tank and a main compressor, the buffer tank is used to store carbon-containing raw gas; the outlet of the buffer tank is connected to the inlet of the main compressor; the outlet of the main compressor is connected to the carbon dioxide purification system.

[0024] Preferably, the carbon dioxide purification system includes a water separator and a purification combination tower.

[0025] The outlet of the main compressor is connected to the inlet of the water separator, the outlet of the water separator is connected to the inlet of the purification tower, and the outlet of the purification combination tower is connected to the hot end inlet of the condenser.

[0026] Preferably, the purification combination tower includes a drying tower, an adsorption tower and a purification tower, which are connected in sequence to purify the raw gas.

[0027] Preferably, the carbon dioxide purification system includes a CO2 storage tank, and the discharge port of the subcooler is connected to the inlet of the CO2 storage tank to store the purified carbon dioxide.

[0028] Beneficial effects of the present invention:

[0029] 1. The present invention combines a carbon dioxide capture and purification system with a supercritical carbon dioxide Brayton cycle power generation system to effectively capture and purify carbon dioxide, reduce greenhouse gas emissions, and directly use the captured carbon dioxide in the supercritical carbon dioxide Brayton cycle, providing a stable and reliable supply of carbon dioxide to the circulation system, reducing the storage and transportation costs of carbon dioxide, achieving resource recycling, and improving the overall efficiency of the system.

[0030] 2. The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system provided by the present invention can achieve complementary sharing of heat, cold energy and electrical energy between systems. The waste heat of the supercritical carbon dioxide Brayton cycle power generation system provides the required heat for the reboiler in the carbon dioxide capture and purification system, and the reboiler provides cold energy and carbon dioxide for the supercritical carbon dioxide Brayton cycle power generation system, greatly improving the overall thermal efficiency of the system. The supercritical carbon dioxide Brayton cycle power generation system provides the required electrical energy for the high-energy consumption refrigeration unit in the carbon dioxide capture and purification system.

[0031] 3. The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system provided by the present invention can simultaneously produce additional pure liquid carbon dioxide and industrial electricity, with high economic benefits. Through system integration, the equipment investment and operating costs for separate carbon dioxide processing and energy conversion are reduced. The efficient energy conversion system can increase power generation or other energy output, thereby increasing economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of a combined carbon dioxide capture and supercritical carbon dioxide Brayton cycle production system provided by one embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 1. Buffer tank; 2. Main compressor; 3. Water separator; 4. Purification combination tower; 5. Condenser; 6. Distillation tower; 7. Reboiler; 8. Subcooler; 9. CO2 storage and transportation tank; 10. Refrigeration unit; 11. Recompressor; 12. High-pressure turbine; 13. Low-pressure turbine; 14. Generator set; 15. Heating device; 16. Regenerator; 17. First check valve; 18. Second check valve. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0037] The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system of the present invention has a wide range of applications. It can be used not only in thermal power plants, but also in other industrial fields requiring efficient thermal energy conversion, such as chemical plants, steel mills, cement plants, etc.; and it has high construction flexibility, and system components such as purification combination towers can be adjusted and optimized according to different industrial needs, thereby improving the adaptability and popularity of the system.

[0038] In addition, the carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system of the present invention has a high degree of integration. Combining carbon dioxide capture and purification with the supercritical carbon dioxide Brayton cycle system can reduce intermediate links, reduce energy consumption, and improve the overall efficiency of the system. This integrated design can serve as a new model to provide innovative solutions for the fields of energy and environmental protection.

[0039] The present invention can effectively capture and purify carbon dioxide, reducing greenhouse gas emissions. The captured carbon dioxide can be directly used in the Brayton cycle, reducing storage and transportation costs and enabling resource recycling. The present invention enables the complementary sharing of heat, cooling, electricity, and carbon dioxide between systems, and can produce additional pure liquid CO2 and industrial electricity. Through system integration, the present invention reduces the equipment investment and operating costs of separate carbon dioxide processing and energy conversion. The efficient energy conversion system can increase power generation or other energy output, increasing economic benefits.

[0040] The technical solution of the present invention is further described below through specific examples. In the following examples, the methods described are conventional methods unless otherwise specified; and the equipment described are commercially available unless otherwise specified.

[0041] like Figure 1 , a carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system, including a carbon dioxide capture and purification system and a supercritical carbon dioxide Brayton cycle power generation system.

[0042] The CO2 capture and purification system is primarily used to capture, purify, and store carbon-containing feed gas. It includes a buffer tank 1, a main compressor 2, a water separator 3, a purification tower 4, a condenser 5, a distillation tower 6, a reboiler 7, a subcooler 8, a CO2 storage tank 9, and a refrigeration unit 10.

[0043] The outlet of buffer tank 1 is connected to the inlet of main compressor 2, the outlet of main compressor 2 is connected to the inlet of water separator 3, the outlet of water separator 3 is connected to the inlet of purification tower 4, the outlet of purification combination tower 4 is connected to the hot end inlet of condenser 5, the hot end outlet of condenser 5 is connected to the first feed port of distillation tower 6, the first discharge port of distillation tower 6 is connected to the first inlet of reboiler 7, the first outlet of reboiler 7 is connected to the second feed port of distillation tower 6, the second discharge port of distillation tower 6 is connected to the feed port of subcooler 8, and the discharge port of subcooler 8 is connected to the inlet of CO2 storage tank 9. The outlet of refrigeration unit 10 is respectively connected to the cold end inlet of condenser 5, the cold end inlet of distillation tower 6, and the cold end inlet of subcooler 8; the inlet of refrigeration unit 10 is respectively connected to the cold end outlet of condenser 5, the cold end outlet of distillation tower 6, and the cold end outlet of subcooler 8.

[0044] Specifically, buffer tank 1 is used to store raw gas, which is carbon-containing tail gas. For example, raw gas primarily comes from carbon-containing tail gas emitted by thermal power plants, natural gas processing plants, chemical plants, steel mills, cement plants, etc. Buffer tank 1 balances the flow and pressure of the raw gas before it enters main compressor 2.

[0045] The main compressor 2 is used to compress the raw gas from the buffer tank 1 and make the pressure of the compressed raw gas reach 0.5 MPa to 5 MPa.

[0046] The water separator 3 is used to separate the water in the raw gas after the pressure is increased, so as to remove the water and improve the purity of the raw gas.

[0047] Purification combination tower 4 is used to perform multiple purification processes on the dehydrated raw gas, such as drying, adsorption, and purification, to further remove impurities and improve the purity of the raw gas. For example, purification combination tower 4 includes a drying tower, an adsorption tower, and a purification tower, which are connected in sequence. The raw gas separated by water separator 3 enters the drying tower, adsorption tower, and purification tower in sequence for multiple purification processes to remove impurities. The purified raw gas enters the hot end inlet of condenser 5 from the outlet of purification combination tower 4.

[0048] The condenser 5 is used to cool and condense the purified raw gas. The cold source of the condenser 5 comes from the refrigeration unit 10.

[0049] The distillation tower 6 is used to perform deep distillation and separation on the condensed raw gas. The reboiler 7 is used to heat the material after preliminary distillation. Specifically, the first feed port of the distillation tower 6 is located in the middle and upper section of the distillation tower 6, the first discharge port of the distillation tower 6 is located at the bottom of the distillation tower 6, and the second feed port and the second discharge port of the distillation tower 6 are both located in the middle and lower section of the distillation tower 6. The cold end inlet and the cold end outlet of the distillation tower 6 are both located at the top of the distillation tower 6. The condensed raw gas enters the distillation tower through the first feed port of the distillation tower for further separation. The separated raw gas enters the reboiler 7 from the first outlet of the distillation tower 6 for heating, and the heated raw gas is returned to the distillation tower 6 from the second feed port of the distillation tower 6 for further separation. The material after deep distillation is sent to the supercooler 8.

[0050] The subcooler 8 is used to further cool the material after deep distillation and achieve high purity, for example, above 95%. The high purity carbon dioxide after subcooling is transported to the CO2 storage tank 9 for storage.

[0051] The refrigeration unit 10 is used to provide a cold source, which completes the cooling cycle through the cold end of the condenser 5, the top of the distillation tower 6, and the cold end of the subcooler 8, ensuring that the temperatures of the condenser 5, the distillation tower 6, and the subcooler 8 are controlled within an appropriate range.

[0052] The specific operating process of the CO2 capture and purification system is as follows: Carbon-containing tail gas feedstock from thermal power plants, natural gas processing plants, chemical plants, steel mills, cement plants, and other sources is fed into a buffer tank 1. After flow and pressure balancing, the feedstock gas enters the main compressor 2. After compression, the feedstock gas reaches a pressure of 0.5 MPa to 5 MPa. It then passes through a water separator 3 to remove moisture from the feedstock gas. The feedstock gas undergoes multiple purification steps in a purification tower 4, including a drying tower, an adsorption tower, and a purification tower, to remove impurities. The purified gas exits the purification tower 4 and enters the hot end of a condenser 5, where it is cooled and condensed. The feedstock gas then passes through the first feed port in the upper middle section of a distillation tower 6 for further separation. The first discharge port at the bottom of the distillation tower 6 enters a reboiler 7 for heating and returns to the lower middle section of the distillation tower 6 for further separation. The deeply rectified material is then fed into a subcooler 8 for further cooling and high purity. The supercooled, high-purity CO2 is then transported to a CO2 storage tank 9 for storage. The refrigeration unit 10 provides cooling, completing the cooling cycle through the cold end of the condenser 5, the top of the distillation tower 6, and the cold end of the subcooler 8, ensuring that the temperature of each part is controlled within the appropriate range.

[0053] It should be noted that the raw material gas entering the buffer tank 1 can come from the carbon-containing tail gas discharged by a natural gas treatment plant, a chemical plant, a power plant, a steel plant, a cement plant, etc., and the purification combined tower 4 can be composed of multiple types of towers with different functions, such as drying towers, adsorption towers, and purification towers. The specific number and type of combination can be determined according to the type of raw material gas. The large amount of electric energy consumed by the refrigeration unit 10 is provided by the generator set 14 in the Brayton power generation system.

[0054] Based on the above-mentioned embodiments, as a more preferred embodiment, the supercritical carbon dioxide Brayton cycle power generation system includes a re-compressor 11, a high-pressure turbine 12, a low-pressure turbine 13, a generator set 14, a heat supply device 15, and a regenerator 16.

[0055] The outlet of the re-compressor 11 is connected to the cold end inlet of the regenerator 16, the cold end outlet of the regenerator 16 is connected to the first inlet of the heat supply device 15, the first outlet of the heat supply device 15 is connected to the inlet of the high-pressure turbine 12, the outlet of the high-pressure turbine 12 is connected to the second inlet of the heat supply device 15, the second outlet of the heat supply device 15 is connected to the inlet of the low-pressure turbine 13; the output shaft of the re-compressor 11, the output shaft of the high-pressure turbine 12, and the output shaft of the low-pressure turbine 13 are connected to the drive shaft of the generator set 14, and the outlet of the low-pressure turbine 13 is connected to the hot end inlet of the regenerator 16. The power output end of the generator set 14 is connected to the power supply interface of the refrigeration unit 10.

[0056] It should be noted that the hot end outlet of the regenerator 16 is connected to the second inlet of the reboiler 7, and a first check valve 17 is connected to the connecting pipeline between the hot end outlet of the regenerator 16 and the second inlet of the reboiler 7, so that the connection between the regenerator 16 and the reboiler 7 is one-way. The second outlet of the reboiler 7 is connected to the inlet of the re-compressor 11, and a second check valve 18 is connected to the connecting pipeline between the second outlet of the reboiler 7 and the inlet of the re-compressor 11, so that the connection between the reboiler 7 and the re-compressor 11 is one-way.

[0057] Specifically, the reboiler 7 is used to provide carbon dioxide gas with a high temperature of 30-100°C and a certain pressure of 0.5-5 MPa. The carbon dioxide gas with a low temperature of -30-10°C but with a certain pressure of 0.5-5 MPa is heated by the reboiler 7 to change into carbon dioxide gas with a high temperature and a certain pressure, and then enters the re-compressor 11 for compression.

[0058] The re-compressor 11 is used to compress the carbon dioxide gas with a high temperature and a certain pressure from the reboiler 7, and the pressure of the compressed raw material gas reaches 10-25 MPa.

[0059] The regenerator 16 is used to perform heat exchange on the pressurized carbon dioxide gas, allowing the heat-absorbed carbon dioxide gas to enter the heat supply device 15. The regenerator 16 also recovers heat from the exhaust gas after expansion and work by the high-pressure turbine 12 and the low-pressure turbine 13. Specifically, the heat source for the regenerator 16 primarily comes from the exhaust gas after expansion and work by the high-pressure turbine 12 and the low-pressure turbine 13. The regenerator utilizes this heat to heat the compressed carbon dioxide from the recompressor 11.

[0060] The heating device 15 is used to further heat the absorbed carbon dioxide gas, converting it to a supercritical state, forming supercritical carbon dioxide. The supercritical carbon dioxide output by the heating device 15 is directly fed into the high-pressure turbine 12 and the low-pressure turbine 13. The heating device 15 can also reheat the supercritical carbon dioxide output by the high-pressure turbine 12, which then enters the low-pressure turbine 13 to generate electricity.

[0061] The high-pressure turbine 12 and the low-pressure turbine 13 are used to expand the supercritical carbon dioxide, generating work. This expansion drives the turbines to generate power and generate electricity. The supercritical carbon dioxide output from the high-pressure turbine 12 enters the heat supply device 15 for heat recovery. The regenerated supercritical carbon dioxide then enters the low-pressure turbine 13 for further power generation. The exhaust gas output from the low-pressure turbine 13 enters the regenerator 16 to recover heat from the exhaust gas.

[0062] The generator set 14 is connected to the recompressor 11, the high-pressure turbine 12, and the low-pressure turbine 13 via a rotor shaft. The output shafts of the high-pressure turbine 12 and the low-pressure turbine 13 are connected to the drive shaft of the generator set 14. When the blades of the high-pressure turbine 12 and the low-pressure turbine 13 are driven to rotate by the supercritical carbon dioxide fluid, the rotor shafts also rotate, thereby driving the drive shaft of the generator set 14. The high-pressure turbine 12 and the low-pressure turbine 13 utilize the pressure and temperature differences of the supercritical carbon dioxide fluid to generate kinetic energy, which is converted into mechanical energy. The mechanical energy is converted into electrical energy through the rotation of the drive shaft of the generator set 14. It should be noted that the generator set 14, the high-pressure turbine 12, and the low-pressure turbine 13 are all existing structures and can be purchased directly from the market.

[0063] The specific working process of the supercritical carbon dioxide Brayton cycle power generation system is as follows: when the entire carbon dioxide capture and purification system is operating stably, the supercritical carbon dioxide Brayton cycle power generation system is started, the first check valve 17 and the second check valve 18 are opened, and the low-temperature but pressured carbon dioxide gas is pressurized by the reboiler 7 and the recompressor 11 and enters the regenerator 16 to absorb heat, and then enters the heating device 15 to be further heated to a supercritical state; the supercritical carbon dioxide output by the heating device 15 directly enters the high-pressure turbine 12 and the low-pressure turbine 13 through expansion to drive the turbine to perform work and generate electricity. The supercritical carbon dioxide output by the high-pressure turbine 12 is then reheated by the heating device 15 and enters the low-pressure turbine 13 to generate electricity again. The exhaust gas after work enters the regenerator 16 to recover heat. The carbon dioxide output from the hot end of the regenerator 16 enters the reboiler 7 for further cooling and provides heat for the reboiling process of the distillation tower 6. Then the second outlet of the reboiler 7 is connected to the inlet of the recompressor 11 through the second check valve 18 to complete the closed recycling of the carbon dioxide until the entire system reaches stability.

[0064] It should be noted that one embodiment of the present invention combines a carbon dioxide capture and purification system with a supercritical carbon dioxide Brayton cycle power generation system, which can effectively capture and purify carbon dioxide, reduce greenhouse gas emissions, and directly use the captured carbon dioxide in the supercritical carbon dioxide Brayton cycle, providing a stable and reliable supply of carbon dioxide for the circulation system, reducing the storage and transportation costs of carbon dioxide, realizing the recycling of resources, and improving the overall efficiency of the system.

[0065] The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system provided in one embodiment of the present invention can achieve complementary sharing of heat, cold energy and electrical energy between systems. The waste heat of the supercritical carbon dioxide Brayton cycle power generation system provides the required heat to the reboiler 7 in the carbon dioxide capture and purification system, and the reboiler 7 provides cold capacity and carbon dioxide to the supercritical carbon dioxide Brayton cycle power generation system, greatly improving the overall thermal efficiency of the system. The supercritical carbon dioxide Brayton cycle power generation system provides the required electrical energy for the high-energy consumption refrigeration unit 10 in the carbon dioxide capture and purification system.

[0066] The combined carbon dioxide capture and supercritical carbon dioxide Brayton cycle production system provided in one embodiment of the present invention can simultaneously produce additional pure liquid carbon dioxide and industrial electricity, and has high economic benefits. Through system integration, the equipment investment and operating costs for separate carbon dioxide processing and energy conversion are reduced. The efficient energy conversion system can increase power generation or other energy output, thereby increasing economic benefits.

[0067] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system, characterized in that: Including carbon dioxide capture and purification system and supercritical carbon dioxide Brayton cycle power generation system; The carbon dioxide capture and purification system comprises a carbon dioxide capture system and a carbon dioxide purification system connected in sequence; the carbon dioxide purification system comprises a condenser, a distillation tower, a reboiler, and a subcooler; the hot end outlet of the condenser is connected to the first feed inlet of the distillation tower for distilling and purifying the condensed raw gas; the first discharge port of the distillation tower is connected to the first inlet of the reboiler for heating the material after preliminary distillation and purification; The first outlet of the reboiler is connected to the second feed port of the distillation tower to perform further distillation and purification on the heated material; the second discharge port of the distillation tower is connected to the feed port of the subcooler to cool the material after further distillation and purification; The supercritical carbon dioxide Brayton cycle power generation system includes a recompressor, a regenerator, a heat supply device, and a power generation device; the second outlet of the reboiler is connected to the inlet of the recompressor, and the outlet of the recompressor is connected to the cold end inlet of the regenerator to absorb heat from the compressed carbon dioxide; the cold end outlet of the regenerator is connected to the first inlet of the heat supply device to convert the heat-absorbed carbon dioxide into supercritical carbon dioxide; the first outlet of the heat supply device is connected to the power generation device; The exhaust gas outlet of the power generation device is connected to the hot end inlet of the regenerator, and the hot end outlet of the regenerator is connected to the second inlet of the reboiler.

2. The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system according to claim 1, characterized in that: The carbon dioxide purification system includes a refrigeration unit, the outlet of which is connected to the cold end inlet of the condenser, the cold end inlet of the distillation tower, and the cold end inlet of the subcooler respectively; The inlet of the refrigeration unit is connected to the cold end outlet of the condenser, the cold end outlet of the distillation tower and the cold end outlet of the subcooler respectively; The power output end of the power generation device is connected to the power interface of the refrigeration unit.

3. The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system according to claim 1, characterized in that: The power generation device includes a high-pressure turbine, a low-pressure turbine and a generator set. The output shaft of the recompressor, the output shaft of the high-pressure turbine and the output shaft of the low-pressure turbine are connected to the drive shaft of the generator set.

4. The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system according to claim 3, characterized in that: The first outlet of the heat supply device is connected to the inlet of the high-pressure turbine, and the outlet of the high-pressure turbine is connected to the second inlet of the heat supply device; the second outlet of the heat supply device is connected to the inlet of the low-pressure turbine; The exhaust gas outlet of the low-pressure turbine is connected to the hot end inlet of the regenerator.

5. The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system according to claim 1, characterized in that: A first check valve is provided in the connecting pipe between the hot end outlet of the regenerator and the second inlet of the reboiler, so that the exhaust gas discharged from the hot end outlet of the regenerator enters the second inlet of the reboiler in a one-way manner; A second check valve is provided on the connecting pipeline between the second outlet of the reboiler and the inlet of the recompressor, so that the carbon dioxide discharged from the second outlet of the reboiler can enter the inlet of the recompressor in a one-way manner for compression.

6. The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system according to claim 1, characterized in that: The carbon dioxide capture system includes a buffer tank and a main compressor. The buffer tank is used to store carbon-containing raw gas; the outlet of the buffer tank is connected to the inlet of the main compressor; and the outlet of the main compressor is connected to the carbon dioxide purification system.

7. The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system according to claim 6, characterized in that: The carbon dioxide purification system includes a water separator and a purification combination tower; The outlet of the main compressor is connected to the inlet of the water separator, the outlet of the water separator is connected to the inlet of the purification combination tower, and the outlet of the purification combination tower is connected to the hot end inlet of the condenser.

8. The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system according to claim 7, characterized in that: The purification combination tower includes a drying tower, an adsorption tower and a purification tower, which are connected in sequence and are used to purify the raw gas.

9. The carbon dioxide capture and supercritical carbon dioxide Brayton cycle combined production system according to claim 1, characterized in that: The carbon dioxide purification system includes a CO2 storage tank, and the discharge port of the supercooler is connected to the inlet of the CO2 storage tank to store the purified carbon dioxide.

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