A flue gas carbon dioxide capture and sequestration system

Abstract

The present application provides a flue gas carbon dioxide capture and storage system, which comprises an absorption tower, a regeneration tower, a separator, a storage unit and an absorption refrigerating machine, the absorption tower has a flue gas inlet for the flue gas, the regeneration tower is connected with the absorption tower, the absorbent in the absorption tower reacts with the flue gas to form saturated absorbent and enters the regeneration tower, the regeneration tower is used for desorbing the saturated absorbent and then entering the absorption tower, the separator is connected with the regeneration tower, the storage unit comprises a compression assembly and a drying assembly, the compression assembly is connected with the separator, the drying assembly is connected with the compression assembly, the drying assembly comprises a drying tower and a heater, the heater is connected with the drying tower, the hot side inlet of the absorption refrigerating machine is connected with the vapor outlet of the heater, and the cold side outlet of the absorption refrigerating machine is connected with at least one of the separator and the absorption tower. The flue gas carbon dioxide capture and storage system has high energy utilization rate and low overall consumption.

Description

Technical Field

[0001] This invention relates to the field of carbon dioxide capture technology, and more specifically, to a flue gas carbon dioxide capture and storage system. Background Technology

[0002] Besides contributing to global warming, carbon dioxide can also be used as a chemical feedstock. Furthermore, captured and purified carbon dioxide can be injected into oil reservoirs in a supercritical state to improve oil recovery. It can be predicted that with the development and improvement of capture technology and the continuous expansion of its application, carbon dioxide will become an important resource for improving oilfield development and increasing crude oil recovery in my country.

[0003] Currently, carbon dioxide capture and purification processes mainly rely on absorption and desorption towers, using amine solutions as absorbents. High-purity carbon dioxide gas is obtained through chemical absorption and desorption. The main energy consumption in this process occurs in the reboiler at the bottom of the desorption tower, where steam is used to heat the rich liquid to desorb carbon dioxide. During absorption and desorption, energy is not fully utilized in many areas, resulting in low energy efficiency. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of the present invention propose a flue gas carbon dioxide capture and storage system, which has high energy utilization and low overall consumption.

[0005] The flue gas carbon dioxide capture and storage system of this invention includes:

[0006] An absorption tower having a flue gas inlet for introducing pretreated flue gas;

[0007] A regeneration tower is connected to the absorption tower. The absorbent in the absorption tower reacts with the flue gas to form a saturated absorbent, which is then introduced into the regeneration tower. The regeneration tower is used to desorb the saturated absorbent before it is introduced into the absorption tower.

[0008] A separator connected to the regeneration tower, so that the regeneration gas discharged from the regeneration tower undergoes gas-liquid separation within the separator;

[0009] The sealing unit includes a compression assembly and a drying assembly. The compression assembly is connected to the separator to compress the gas discharged from the separator, and the drying assembly is connected to the compression assembly to dry a portion of the gas in the compression assembly.

[0010] The drying assembly includes a drying tower and a heater, the heater being connected to the drying tower for heating the desiccant discharged from the drying tower and then introducing the heated desiccant into the drying tower;

[0011] An absorption chiller, wherein the hot-side inlet of the absorption chiller is connected to the vapor outlet of the heater, and the cold-side outlet of the absorption chiller is connected to at least one of the separator and the absorption tower.

[0012] The flue gas carbon dioxide capture and storage system of this invention can use the excess heat generated by the storage unit as the driving heat source of the absorption chiller, and then pass the cold energy generated by the absorption chiller into the separator and / or absorption tower to realize the utilization of the cold energy, improve the energy utilization rate of the system, and reduce the energy loss of the overall system.

[0013] In some embodiments, the flue gas carbon dioxide capture and storage system of the present invention further includes a lean-rich liquid heat exchanger, which is connected to both the absorption tower and the regeneration tower, so that the saturated absorbent discharged from the absorption tower exchanges heat with the desorbed absorbent discharged from the regeneration tower, and the desorbed absorbent is used to be introduced into the absorption tower, and the saturated absorbent is used to be introduced into the regeneration tower.

[0014] In some embodiments, the flue gas carbon dioxide capture and storage system of the present invention further includes a preheating heat exchanger. The absorber includes a first spray section, a second spray section, and a third spray section arranged sequentially along the flue gas flow direction. The first spray section, the second spray section, and the third spray section are respectively connected to a first spray pipeline, a second spray pipeline, and a third spray pipeline. The second spray pipeline has a rich liquid outlet, and the rich liquid outlet is connected to the lean-rich liquid heat exchanger through a rich liquid pipe. The preheating heat exchanger is connected to the first spray pipeline and the rich liquid pipe so that the rich liquid pipe and the first spray pipeline exchange heat in the preheating heat exchanger.

[0015] In some embodiments, the flue gas carbon dioxide capture and storage system of the present invention further includes a phase separator, the phase separator having a phase separation inlet, a first phase separation outlet and a second phase separation outlet, the phase separation inlet being connected to the rich liquid outlet, the first phase separation outlet being connected to the spray inlet of the second spray section, and the second phase separation outlet being connected to the rich liquid pipeline.

[0016] In some embodiments, a cooler is provided on the third spray pipe, and the cooling outlet of the absorption chiller is connected to the cooler.

[0017] In some embodiments, the third spray pipeline has an absorbent drain port, which is connected to the regeneration tower.

[0018] In some embodiments, the separator has a regeneration gas inlet, the regeneration gas outlet of the regeneration tower is connected to the regeneration gas inlet, and the cooling outlet of the absorption chiller is connected to the regeneration gas inlet.

[0019] In some embodiments, the flue gas carbon dioxide capture and storage system of the present invention further includes a regenerator, wherein the hot-side inlet of the regenerator is connected to the regenerated gas outlet of the regeneration tower, the hot-side outlet of the regenerator is connected to the regenerated gas inlet, and the cold-side inlet of the regenerator is connected to the cooling outlet of the absorption chiller.

[0020] In some embodiments, the separator further has a separation liquid outlet, the third spray line further has an absorbent inlet, the absorbent inlet is located downstream of the absorbent outlet and upstream of the cooler, and the separation liquid outlet is connected to the absorbent inlet.

[0021] In some embodiments, the third spray pipeline is further provided with a mixer, which is connected to the separation liquid outlet. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the flue gas carbon dioxide capture and storage system according to an embodiment of the present invention.

[0023] Figure label:

[0024] 1. Absorption tower; 11. First spray section; 12. Second spray section; 13. Third spray section; 14. Flue gas inlet.

[0025] 2. Regeneration tower,

[0026] 3. Separator, 31. Regeneration gas inlet, 32. Separated liquid outlet,

[0027] 4. Sealing unit; 41. Compression assembly; 42. Drying assembly; 421. Drying tower; 422. Heater.

[0028] 5. Absorption chiller

[0029] 6. Rich and poor liquid heat exchanger,

[0030] 7. Preheat heat exchanger,

[0031] 81. First spray pipe; 82. Second spray pipe; 83. Third spray pipe; 831. Absorbent drain port; 832. Absorbent inlet port; 84. Cooler; 85. Mixer.

[0032] 9. Phase splitter,

[0033] 10. Regenerated water cooler. Detailed Implementation

[0034] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0035] like Figure 1 As shown, the flue gas carbon dioxide capture and storage system of this embodiment includes: an absorption tower 1, a regeneration tower 2, a separator 3, a storage unit 4, and an absorption chiller 5.

[0036] Absorption tower 1 has a flue gas inlet 14 for introducing pretreated flue gas. Regeneration tower 2 is connected to absorption tower 1. The absorbent in absorption tower 1 reacts with the flue gas to form a saturated absorbent, which is then introduced into regeneration tower 2. Regeneration tower 2 desorbs the saturated absorbent before it is reintroduced into absorption tower 1. Separator 3 is connected to regeneration tower 2 to allow gas-liquid separation of the regenerated gas discharged from regeneration tower 2. Storage unit 4 includes a compression assembly 41 and a drying assembly 42. Compression assembly 41 is connected to separator 3 to compress the gas discharged from separator 3. Drying assembly 42 is connected to compression assembly 41 to dry a portion of the gas in compression assembly 41. Drying assembly 42 includes a drying tower 421 and a heater 422. Heater 422 is connected to drying tower 421 to heat the desiccant discharged from drying tower 421 and then reintroducing the heated desiccant into drying tower 421. The hot-side inlet of the absorption chiller 5 is connected to the steam outlet of the heater 422, and the cold-side outlet of the absorption chiller 5 is connected to at least one of the separator 3 and the absorption tower 1.

[0037] Specifically, such as Figure 1 As shown, the flue gas discharged from the boiler typically contains a large amount of impurities, such as particulate matter. Before entering the absorption tower 1, the flue gas undergoes pretreatment, including dust removal and cooling, to ensure better reaction between the flue gas and the absorbent upon entering the absorption tower 1. As the flue gas enters the absorption tower 1, the absorbent is sprayed into it, causing a chemical reaction between the absorbent and pollutants (such as sulfur dioxide or nitrogen oxides) in the flue gas to form a saturated solution. These saturated solutions are then transported to the regeneration tower 2. In the regeneration tower 2, pollutants are desorbed using physical or chemical methods, allowing the absorbent to be regenerated and recycled. Optionally, the absorbent can be an organic amine solution.

[0038] Separator 3 can be a gas-liquid separation device. Separator 3 is connected to regeneration tower 2 to separate the liquid component (saturated solution carried by the absorbent) and the gas component in the regeneration gas discharged from regeneration tower 2. This allows the regenerated absorbent to be returned to absorption tower 1 dry, while the gas can be discharged or further processed.

[0039] The compression assembly 41 is used to increase the pressure of the low-pressure gas (regenerated gas carrying water vapor) discharged from the separator 3 for further processing or storage. The drying assembly 42 is used to remove moisture from the compressed gas, ensuring the gas is dry and providing the necessary conditions for subsequent storage.

[0040] The hot-side inlet of the absorption chiller 5 is connected to the steam outlet of the heater 422 so that the high-temperature steam generated by the heater 422 can be used as a driving heat source to drive the chiller. The cold-side outlet of the chiller can be connected to the separator 3, or to the absorption tower 1, or to both the separator 3 and the absorption tower 1, so as to provide the required cooling capacity to the separator 3 and the absorption tower 1 and reduce the use of external energy.

[0041] In other words, the flue gas carbon dioxide capture and storage system of this embodiment can use the excess heat generated by the storage unit 4 as the driving heat source of the absorption chiller 5, and then pass the cold energy generated by the absorption chiller 5 into the separator 3 and / or absorption tower 1 to realize the utilization of the cold energy, improve the energy utilization rate of the system, and reduce the energy loss of the overall system.

[0042] Therefore, the flue gas carbon dioxide capture and storage system of this invention not only utilizes the waste heat generated by the system, but also provides the cooling capacity required by the system, thereby achieving efficient energy utilization and reducing the consumption of external energy.

[0043] In some embodiments, the flue gas carbon dioxide capture and storage system of the present invention further includes a lean-rich liquid heat exchanger 6, which is connected to both the absorption tower 1 and the regeneration tower 2, so that the saturated absorbent discharged from the absorption tower 1 exchanges heat with the desorbed absorbent discharged from the regeneration tower 2, and the desorbed absorbent is used to be introduced into the absorption tower 1, and the saturated absorbent is used to be introduced into the regeneration tower 2.

[0044] Understandably, in absorber 1, the flue gas reacts chemically with the sprayed absorbent, which absorbs pollutants (such as sulfur dioxide or nitrogen oxides) from the flue gas, forming a saturated solution. The saturated absorbent is then discharged from absorber 1 and flows into lean-rich liquid heat exchanger 6.

[0045] In the heat exchanger, the saturated absorbent (rich solution) exchanges heat with the unsaturated absorbent (lean solution) from regeneration tower 2. Heat from the rich solution is transferred to the lean solution, causing its temperature to rise while the rich solution's temperature decreases. After the heat exchange, the lean solution absorbs more heat, enhancing its absorption capacity, allowing it to re-enter absorption tower 1 to absorb even more pollutants. The rich solution, having released heat, has a lower saturation level, becoming a relatively lean absorbent before being introduced into regeneration tower 2, making it easier to release the absorbed pollutants.

[0046] In other words, after the rich liquid discharged from absorption tower 1 and the lean liquid discharged from regeneration tower 2 pass through the lean-rich liquid heat exchanger 6, the heat of the saturated absorbent discharged from absorption tower 1 is effectively utilized. This allows the absorbent discharged from regeneration tower 2 to continue absorbing pollutants after being fed back into absorption tower 1, thereby improving the efficiency of the entire system. This not only reduces the system's energy consumption but also optimizes the reaction process of the lean and rich liquids being fed into absorption tower 1 and regeneration tower 2 respectively, further reducing absorbent consumption and extending its service life.

[0047] In some embodiments, the flue gas carbon dioxide capture and storage system of the present invention further includes a preheating heat exchanger 7. The absorber includes a first spray section 11, a second spray section 12, and a third spray section 13 arranged sequentially along the flue gas flow direction. The first spray section 11, the second spray section 12, and the third spray section 13 are respectively connected to a first spray pipe 81, a second spray pipe 82, and a third spray pipe 83. The second spray pipe 82 has a rich liquid outlet, which is connected to a lean-rich liquid heat exchanger 6 through a rich liquid pipe. The preheating heat exchanger 7 is connected to the first spray pipe 81 and the rich liquid pipe so that the rich liquid pipe and the first spray pipe 81 exchange heat in the preheating heat exchanger 7.

[0048] Specifically, such as Figure 1 As shown, the first spray section 11, the second spray section 12 and the third spray section 13 are arranged in sequence from bottom to top. Spray pumps are installed on the first spray pipe 81, the second spray pipe 82 and the third spray pipe 83. The spray pumps can spray the absorbent into the absorption tower 1, and the absorbent can also circulate between the absorption tower 1 and the spray pipes.

[0049] Understandably, by arranging multiple spray sections sequentially, the flue gas temperature changes in a gradient (i.e., the temperature gradually decreases as the altitude increases), and the flue gas has more opportunities to contact the absorbent, thereby improving the absorbent's absorption efficiency for flue gas pollutants. Specifically, the flue gas undergoes its first removal reaction in the first spray section 11. The absorbent after the reaction contains many impurities and has a low recycling rate; therefore, the reacted absorbent can be fed into the power plant's wastewater treatment system for further treatment. In the second spray section 12, the absorbent reacts with the flue gas to form a saturated absorbent (rich liquid), which is then regenerated in the regeneration tower 2, enabling the absorption of the absorbent for reuse.

[0050] In other words, the absorbent that reacts with the flue gas in the second spray section 12 can exchange heat with the absorbent that reacts with the flue gas discharged from the first spray section 11 and the absorbent that reacts with the flue gas discharged from the second spray section 12 in the preheating heat exchanger 7 between the two liquids passing through the lean and rich liquid heat exchanger 6. This ensures the temperature of the absorbent discharged from the second spray section 12 during transportation, realizes heat recovery, and also improves the efficiency of absorbent regeneration.

[0051] In some embodiments, the flue gas carbon dioxide capture and storage system of the present invention further includes a phase separator 9, which has a phase separator inlet, a first phase separator outlet and a second phase separator outlet. The phase separator inlet is connected to the rich liquid outlet, the first phase separator outlet is connected to the spray inlet of the second spray section 12, and the second phase separator outlet is connected to the rich liquid pipeline.

[0052] Specifically, such as Figure 1 As shown, the second phase-separating outlet is located at the bottom of the phase separator 9. The phase separator 9 is connected to the drain port of the second spray section 12, and the absorbent discharged from the second spray section 12 can be stored in the phase separator 9. In the phase separator 9, due to the density difference between the lean liquid and the rich liquid, the rich liquid collects at the bottom of the phase separator 9, while the lean liquid is located above the rich liquid. Using a pump, the lean liquid and the rich liquid can be extracted separately. The extracted lean liquid can be fed into the second spray section 12 to react with the flue gas again, while the extracted rich liquid is fed into the regeneration tower 2 for regeneration after passing through the preheating heat exchanger 7.

[0053] Understandably, the use of the phase separator 9 to separate the lean and rich liquids of the absorbent in the second spray section 12 ensures the circulation of the absorbent in the second spray pipeline 82 and also facilitates the preheating and regeneration of the rich liquid.

[0054] In some embodiments, a cooler 84 is provided on the third spray pipe 83, and the cooling outlet of the absorption chiller 5 is connected to the cooler 84. Specifically, as Figure 1 As shown, the third spray pipe 83 is connected to the cooler 84 so that the cooler 84 can cool the third spray pipe 83, thereby reducing the temperature of the absorbent in the third spray pipe 83.

[0055] In other words, after the absorbent in the third spray section 13 reacts with the flue gas, the temperature of the absorbent rises, which reduces its removal effect on pollutants in the flue gas. Therefore, the absorbent in the third spray pipe 83 is cooled by the cooler 84 to ensure the removal effect of the absorbent and avoid energy waste.

[0056] In some embodiments, the third spray pipe 83 has an absorbent drain port 831, which is connected to the regeneration tower 2. It is understood that, as Figure 1 As shown, after the absorbent in the third spray section 13 reacts with the flue gas, it will gradually change from lean liquid to rich liquid. The rich liquid in the third spray section 13 is extracted by the third spray pipeline 83 and introduced into the regeneration tower 2 through the absorbent discharge port 831 so that the absorbent can be regenerated.

[0057] In some embodiments, the separator 3 has a regeneration gas inlet 31, the regeneration gas outlet of the regeneration tower 2 is connected to the regeneration gas inlet 31, and the cooling outlet of the absorption chiller 5 is connected to the regeneration gas inlet 31. It is understood that, as Figure 1As shown, the third spray pipe 83 feeds the rich liquid in the third spray section 13 into the regeneration tower 2 for regeneration. This reduces the total amount of absorbent in the third spray section 13, affecting the reaction between the absorbent and the flue gas. Therefore, the absorbent separated in the separator 3 is fed into the third spray section 13 to maintain sufficient absorbent in the third spray section 13 for the reaction with the flue gas.

[0058] In addition, the regenerated gas discharged from the regeneration tower 2 still has a certain temperature. The cooling capacity discharged from the cooling outlet of the absorption chiller 5 is used to cool this part of the regenerated gas, which is beneficial for the regenerated gas to be separated in the separator 3, and further improves the separation effect between the regenerated gas and the absorbent.

[0059] In some embodiments, the flue gas carbon dioxide capture and storage system of the present invention further includes a regenerator 10, the hot side inlet of the regenerator 10 being connected to the regenerated gas outlet of the regeneration tower 2, the hot side outlet of the regenerator 10 being connected to the regenerated gas inlet 31, and the cold side inlet of the regenerator 10 being connected to the cooling outlet of the absorption chiller 5.

[0060] It is understandable that, such as Figure 1 As shown, the cooling capacity discharged from the cooling outlet of the absorption chiller 5 can cool the cooling medium in the regenerator 10, so that the cooled medium can exchange heat with the regenerated gas. This avoids the cooling capacity discharged from the cooling outlet of the absorption chiller 5 directly mixing with the regenerated gas, thereby avoiding the mixing of other impurity gases in the regenerated gas and facilitating the separation of the regenerated gas.

[0061] In some embodiments, the separator 3 further has a separation liquid outlet 32, and the third spray pipe 83 further has an absorbent inlet 832, which is located downstream of the absorbent outlet 831 and upstream of the cooler 84. The separation liquid outlet 32 ​​is connected to the absorbent inlet 832.

[0062] It is understandable that, such as Figure 1 As shown, the absorbent discharged from the separation liquid outlet 32 ​​can be introduced into the third spray pipe 83 for re-spraying the third spray section 13. The absorbent inlet 832 is located upstream of the cooler 84 so that the absorbent discharged from the separation liquid outlet 32 ​​can be mixed with the absorbent in the third spray pipe 83 and then cooled by the cooler 84, thereby ensuring the overall concentration and temperature of the absorbent and improving the reaction effect between the absorbent and the flue gas.

[0063] In some embodiments, a mixer 85 is further provided on the third spray line 83, and the mixer 85 is connected to the separated liquid outlet 32. It is understood that, as Figure 1As shown, the absorbent inlet 832 is located on the mixer 85. The absorbent discharged from the separation liquid outlet 32 ​​and the absorbent in the third spray pipe 83 can be fully mixed in the mixer 85 to ensure the solution concentration of the absorbent, which is beneficial to the reaction between the absorbent and the flue gas.

[0064] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0065] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0066] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0068] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A flue gas carbon dioxide capture and storage system, characterized in that, include: An absorption tower having a flue gas inlet for introducing pretreated flue gas; A regeneration tower is connected to the absorption tower. The absorbent in the absorption tower reacts with the flue gas to form a saturated absorbent, which is then introduced into the regeneration tower. The regeneration tower is used to desorb the saturated absorbent before it is introduced into the absorption tower. A separator connected to the regeneration tower, so that the regeneration gas discharged from the regeneration tower undergoes gas-liquid separation within the separator; The sealing unit includes a compression assembly and a drying assembly. The compression assembly is connected to the separator to compress the gas discharged from the separator, and the drying assembly is connected to the compression assembly to dry a portion of the gas in the compression assembly. The drying assembly includes a drying tower and a heater, the heater being connected to the drying tower for heating the desiccant discharged from the drying tower and then introducing the heated desiccant into the drying tower; An absorption chiller, wherein the hot-side inlet of the absorption chiller is connected to the vapor outlet of the heater, and the cold-side outlet of the absorption chiller is connected to at least one of the separator and the absorption tower; It also includes a preheating heat exchanger. The absorber includes a first spray section, a second spray section, and a third spray section arranged sequentially along the flue gas flow direction. The first spray section, the second spray section, and the third spray section are respectively connected to a first spray pipeline, a second spray pipeline, and a third spray pipeline. The second spray pipeline has a rich liquid outlet, which is connected to the regeneration tower through a rich liquid pipeline. The preheating heat exchanger is connected to the first spray pipeline and the rich liquid pipeline so that the rich liquid pipeline and the first spray pipeline can exchange heat in the preheating heat exchanger.

2. The flue gas carbon dioxide capture and storage system according to claim 1, characterized in that, It also includes a lean-rich liquid heat exchanger, which is connected to both the absorption tower and the regeneration tower, so that the saturated absorbent discharged from the absorption tower exchanges heat with the desorbed absorbent discharged from the regeneration tower, and the desorbed absorbent is used to enter the absorption tower, while the saturated absorbent is used to enter the regeneration tower.

3. The flue gas carbon dioxide capture and storage system according to claim 1, characterized in that, It also includes a phase separator, which has a phase separation inlet, a first phase separation outlet and a second phase separation outlet. The phase separation inlet is connected to the rich liquid outlet, the first phase separation outlet is connected to the spray inlet of the second spray section, and the second phase separation outlet is connected to the rich liquid pipeline.

4. The flue gas carbon dioxide capture and storage system according to claim 1, characterized in that, A cooler is provided on the third spray pipe, and the cooling outlet of the absorption chiller is connected to the cooler.

5. The flue gas carbon dioxide capture and storage system according to claim 4, characterized in that, The third spray pipeline has an absorbent drain port, which is connected to the regeneration tower.

6. The flue gas carbon dioxide capture and storage system according to claim 5, characterized in that, The separator has a regeneration gas inlet, the regeneration gas outlet of the regeneration tower is connected to the regeneration gas inlet, and the cooling outlet of the absorption chiller is connected to the regeneration gas inlet.

7. The flue gas carbon dioxide capture and storage system according to claim 6, characterized in that, It also includes a regenerator, the hot side inlet of which is connected to the regeneration gas outlet of the regeneration tower, the hot side outlet of which is connected to the regeneration gas inlet, and the cold side inlet of which is connected to the cooling outlet of the absorption chiller.

8. The flue gas carbon dioxide capture and storage system according to claim 7, characterized in that, The separator also has a separation liquid outlet, and the third spray pipe also has an absorbent inlet. The absorbent inlet is located downstream of the absorbent outlet and upstream of the cooler. The separation liquid outlet is connected to the absorbent inlet.

9. The flue gas carbon dioxide capture and storage system according to claim 8, characterized in that, The third spray pipe is also equipped with a mixer, which is connected to the outlet of the separated liquid.

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