CN-121988124-A - Multi-tower collaborative carbon capture system based on thermal mass circulation and operation method thereof

CN121988124ACN 121988124 ACN121988124 ACN 121988124ACN-121988124-A

Abstract

A multi-tower collaborative carbon capture system based on thermal mass circulation and an operation method thereof belong to the technical field of carbon capture. Comprises a multi-tower cooperative system, a heat exchange system and a carbon sealing system. According to the carbon trapping system, through the cooperative operation strategy of the multiple towers, the three adsorption towers are used for respectively carrying out adsorption, desorption and purging processes, so that the carbon trapping of smoke discharged from a power plant in full time is ensured, the concentration of CO 2 is increased through purging, the energy consumption in the carbon sealing process is reduced, the cost of a carbon trapping technology is reduced, and after the cycle is ended, the adsorption towers return to an initial state, so that the safe and efficient operation of the next cycle is ensured. In the system circulation process, the adsorption heat generated in the adsorption process, the desorption heat provided by the power plant and the compression heat generated in the carbon sealing process are stored in the adsorption tower, and the heat is used for heating the circulated CO 2 or supplying heat to a heat supply network, so that the energy utilization rate is improved, and the carbon emission reduction and the cost reduction are further promoted.

Inventors

GAO JIANMIN
DU QIAN
ZHANG YU
Cao Yihuai
DONG HEMING
LI XIMEI

Assignees

哈尔滨工业大学

Dates

Publication Date: 20260508
Application Date: 20260213

Claims (6)

1. A multi-tower collaborative carbon capture system based on thermal mass circulation is characterized by comprising The multi-tower cooperative system comprises three adsorption towers, wherein each adsorption tower is provided with two inlet pipelines, two outlet pipelines and an exhaust pipeline, and each pipeline is provided with a valve for controlling to be opened and closed; the heat exchange system comprises a heat exchanger (24), a heater (25) and a cooler (26); The carbon sealing system comprises a first compressor (20), a first intercooler (21), a second compressor (22) and a second intercooler (23) which are sequentially connected in series.
2. The multi-tower collaborative carbon capture system based on thermal mass circulation according to claim 1, wherein the three adsorption towers are a first adsorption tower (2), a second adsorption tower (3) and a third adsorption tower (4), respectively; The first adsorption tower (2) is connected with the flue gas inlet pipeline (1) through a first valve (5), is connected with the heat exchanger (24) through a second valve (8), is connected with the heater (25) through a third valve (11), is connected with the first compressor (20) through a fourth valve (17), and is exhausted through a fifth valve (14); The second adsorption tower (3) is connected with the flue gas inlet pipeline (1) through a sixth valve (6), is connected with the heat exchanger (24) through a seventh valve (9), is connected with the heater (25) through an eighth valve (12), is connected with the first compressor (20) through a ninth valve (18), and is exhausted through a tenth valve (15); The third adsorption tower (4) is connected with the flue gas inlet pipeline (1) through an eleventh valve (7), is connected with the cooler (26) through a twelfth valve (10), is connected with the heater (25) through a thirteenth valve (13), is connected with the first compressor (20) through a fourteenth valve (19), and is exhausted through a fifteenth valve (16).
3. A method of operating a thermal mass circulation based multi-tower collaborative carbon capture system, characterized in that the method is implemented based on the system of claim 1 or claim 2, comprising the steps of: Step one, initial state The first adsorption tower (2) is introduced into the flue gas to start adsorbing CO 2 , and the discharged heat is absorbed by the circulated CO 2 ; The second adsorption tower (3) carries out high-temperature desorption, one part of desorbed CO 2 enters a compression sealing system, compression heat is absorbed by the other part of CO 2 , and the temperature is raised to the desorption temperature through the heat exchanger (24) and the heater (25); The adsorption capacity of CO 2 in the third adsorption tower (4) is the maximum, free flue gas is contained in the space in the tower, and the free flue gas is purged; Step two, switching to the next stage Stopping adsorption by the first adsorption tower (2) and purging free flue gas; the second adsorption tower (3) is continuously desorbed and regenerated, one part of CO 2 is sealed, and the other part of CO 2 is circulated and used for assisting the purging of the first adsorption tower (2) and self-desorption heat supply; the third adsorption tower (4) carries out a desorption regeneration process and seals CO 2 , and after the adsorption tower is emptied, flue gas is introduced to start adsorbing CO 2 , and adsorption heat release transmits heat to a heat supply network; And thirdly, completing one-time circulation and resetting the state.
4. The method of claim 3, wherein in step one, when the thermal mass cycle of the carbon capture system is in an initial state, The first adsorption tower (2) is in an emptying state and almost contains no gas, a first valve (5) and a second valve (8) of the first adsorption tower (2) are opened, the first adsorption tower (2) is introduced into flue gas to separate CO 2 , and the discharged heat is absorbed by the circulated CO 2 through a heat exchanger (24); The adsorption capacity of CO 2 in the second adsorption tower (3) is the maximum value, and the space in the tower hardly contains impurity gas, the eighth valve (12) and the ninth valve (18) of the second adsorption tower (3) are opened, one part of CO 2 desorbed at high temperature enters a carbon sealing system and is converted into a normal-temperature high-pressure liquid state through a compressor and an intercooler, the compression heat is absorbed by the other part of CO 2 , the part of CO 2 continuously absorbs the heat of flue gas through a heat exchanger (24), and the waste heat of a power plant is absorbed through a heater (25) to reach the desorption temperature; The adsorption quantity of CO 2 in the third adsorption tower (4) is the maximum value, free flue gas is contained in the space in the tower, And a thirteenth valve (13) and a fifteenth valve (16) of the third adsorption tower (4) are opened, CO 2 passing through the heat exchange system sweeps the space in the tower to discharge free flue gas, the fifteenth valve (16) is closed after the concentration of the CO 2 in the exhaust pipeline reaches the standard, and the fourteenth valve (19) is opened to complete the sweeping.
5. The method of operating a thermal mass circulation based multi-tower collaborative carbon capture system according to claim 4, wherein: in the second step, the second step is to carry out the process, When the adsorption capacity of the first adsorption tower (2) reaches the maximum, the third valve (11) and the fifth valve (14) are opened, high-temperature circulating CO 2 is introduced into the first adsorption tower (2) to purge the space, and the flue gas is discharged; The second adsorption tower (3) still contains CO 2 , desorption regeneration is continued, one part of CO 2 is sealed, and the other part of CO 2 assists the purging work of the first adsorption tower (2) and the desorption regeneration of the second adsorption tower (3); The third adsorption tower (4) is used for desorbing CO 2 to an emptying state, an eleventh valve (7) and a twelfth valve (10) are opened, the rest valves are closed, flue gas is introduced, the flue gas after capturing CO 2 brings heat in the adsorption tower out, and the heat is transmitted to a heat supply network through a cooler (26).
6. The method of operating a thermal mass circulation based multi-tower collaborative carbon capture system according to claim 5, wherein: in the third step, the step of the method, The first adsorption tower (2) is purged, the adsorption capacity is maximum and almost no impurities are contained, the second adsorption tower (3) is in an empty state, the adsorption capacity of CO 2 in the third adsorption tower (4) is maximum, free flue gas is contained in the space in the tower, the initial states of the first adsorption tower (2) and the second adsorption tower (3) are exchanged, the third adsorption tower (4) is restored to the initial state, and the carbon capture system completes one cycle.

Description

Multi-tower collaborative carbon capture system based on thermal mass circulation and operation method thereof Technical Field The invention belongs to the technical field of carbon capture, and particularly relates to a multi-tower collaborative carbon capture system based on thermal mass circulation and an operation method thereof. Background With the continuous promotion of urban production in China, the central heating area and the heating capacity in the north are gradually increased year by year, and the urban heating pressure is gradually increased. At present, the urban heat supply main body is still a coal-fired and gas-fired cogeneration unit, which not only consumes a great deal of fossil energy, but also causes serious pollutant emission problem. Carbon capture technology is rapidly evolving. However, the high energy consumption and high cost make carbon capture technology always impractical for large-scale commercial applications. In the carbon capturing process, the electric energy and the heat energy are consumed to different degrees in both the adsorbent regeneration and the carbon sealing process, and adsorption heat generated in the adsorption process, desorption heat cooled after regeneration, compression heat in the sealing process and the like are often dissipated in the external environment, so that energy waste is caused, and the cost of carbon capturing is also increased. In addition, the cogeneration unit regulates and controls the electric load and the thermal load by regulating the back pressure of the steam turbine, thereby meeting the demand change of the thermoelectric load in the city in heating seasons. The heat load and the electric load demand in the daytime are higher, the thermoelectric ratio is relatively smaller, the heat load is easy to meet in the backpressure pressure range of the turbine, the electric load is reduced at night, the heat load change is smaller, the thermoelectric ratio is larger at the moment, the turbine of the cogeneration unit has the minimum steam flow limit, the heat supply demand is difficult to meet, the heat supply boiler is required to supplement the heat supply at the moment, and compared with the heat and power cogeneration, the heat and power cogeneration unit has more energy quality degradation, so that the great energy waste is caused, and the carbon emission is further increased. Therefore, the carbon capture technology can be used as a transfer station of heat while capturing carbon. When the thermoelectric is relatively large, the adsorption process is performed to generate adsorption waste heat to relieve heating pressure, and when the thermoelectric is relatively small, the desorption regeneration process is performed to consume heat energy. However, the complex thermal mass change process clearly places higher demands on the continuous operation strategy of the carbon capture system. In addition, the existing carbon capture technology still needs to solve the following problems: 1. The carbon trapping technology adopts a physical adsorption method or a chemical absorption method to trap carbon, the adsorbent has maximum adsorption capacity, thermal desorption regeneration is needed to recover adsorption capacity, and a carbon trapping empty window period exists; 2. Adsorption heat is generated in the adsorption process, desorption heat is needed in the desorption process, the adsorbent is cooled after regeneration to recover the adsorption capacity, and the heat in the whole circulation process needs to be utilized efficiently; 3. In northern heating seasons, the electric load demand is large in daytime, the heat load demand is relatively small, the electric load demand is small at night, and the heat load demand is relatively large, so that the pressure of a power plant is relieved, and thermal decoupling is needed. Disclosure of Invention The invention aims at meeting the continuous carbon capturing and heat supply requirements of a heat supply network of a power plant, and provides a multi-tower collaborative carbon capturing system based on thermal mass circulation and an operation method thereof. The method comprises the steps of sequentially carrying out adsorption, desorption, purging and other processes of each tower through cooperation of a plurality of towers, capturing CO 2 in a relay manner, supplying heat load to a heat supply network through displacement of heat in the adsorption process of the adsorption towers, and storing heat in the desorption process of the adsorption towers and discharging CO 2 to realize heat energy consumption and CO 2 sealing of a power plant. The technical scheme adopted by the invention is as follows: a multi-tower collaborative carbon capture system based on thermal mass circulation comprising The multi-tower cooperative system comprises three adsorption towers, wherein each adsorption tower is provided with two inlet pipelines, two outlet pipelines and an exhaust pipeline, and each pipeli