Flue gas low temperature purification carbon capture system

Abstract

The present invention discloses a flue gas low-temperature purification carbon capture system, including a low-temperature purification capture tower, the inner cavity of the low-temperature purification capture tower is sequentially separated into a low-temperature chamber, an adsorption chamber, a heating chamber, an absorption chamber and a spray chamber from bottom to top, the low-temperature chamber is used to cool the flue gas to a first temperature and transport it to the adsorption chamber, the adsorption chamber is used to adsorb and purify the cooled flue gas and transport the adsorbed clean flue gas to the heating chamber, the heating chamber is used to heat the adsorbed clean flue gas to a second temperature and transport it to the absorption chamber, the absorption chamber is used to absorb carbon dioxide in the heated clean flue gas and transport the absorbed clean flue gas to the spray chamber. The flue gas low-temperature purification carbon capture system of the present invention realizes the miniaturization of the tower, which can not only save space, but also reduce manufacturing costs, and has the characteristics of high integration. The material transportation time and transportation cost are reduced, and the carbon capture efficiency of the flue gas is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon capture, and in particular to a flue gas low-temperature purification carbon capture system. Background Art

[0002] In the related technology, the flue gas discharged from the coal-fired boiler is purified by low-temperature adsorption desulfurization and denitrification, and then the purified flue gas is passed into the CCUS system for carbon capture, utilization and storage to reduce the concentration of carbon dioxide in the atmosphere, thereby mitigating the impact of carbon dioxide on global warming and climate change.

[0003] Specifically, the high-temperature flue gas discharged from the coal-fired boiler is first cooled in a spray cooling tower to a low-temperature flue gas below zero degrees, for example, and then the low-temperature flue gas is input into an adsorption tower for low-temperature adsorption. The pollutants (sulfide and nitrogen oxide) in the low-temperature flue gas are adsorbed and removed by the adsorbent in the adsorption tower, and the adsorbent saturated with adsorption is sent to the adsorption regeneration tower for heating desorption regeneration, and the regenerated adsorbent is sent back to the adsorption tower for recycling. The clean flue gas adsorbed in the adsorption tower is transported to the absorption tower in the CCUS system, and the carbon dioxide in the clean flue gas is adsorbed and removed by the absorbent in the absorption tower. The saturated absorbent is sent to the absorption regeneration tower in the CCUS system for heating desorption regeneration, and the regenerated absorbent is sent back to the absorption tower for recycling, and the desorbed carbon dioxide is captured. However, the related art requires a large number of towers to be separately set up, resulting in a large footprint for the overall system, a large number of equipment, and complex pipeline connections, high energy consumption and high cost. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention provides a flue gas low temperature purification carbon capture system.

[0005] The flue gas low-temperature purification carbon capture system of the embodiment of the present invention includes a low-temperature purification capture tower, the inner cavity of the low-temperature purification capture tower is sequentially separated into a low-temperature chamber, an adsorption chamber, a heating chamber, an absorption chamber and a spray chamber along the direction from bottom to top, the low-temperature chamber has a flue gas inlet, the flue gas inlet is used to transport the flue gas discharged from the coal-fired boiler into the low-temperature chamber, the low-temperature chamber is used to cool the flue gas to a first temperature and transport it to the adsorption chamber, the adsorption chamber is used to adsorb and purify the cooled flue gas and transport the adsorbed clean flue gas to the heating chamber, the heating chamber is used to heat the adsorbed clean flue gas to a second temperature and transport it to the absorption chamber, the absorption chamber is used to absorb carbon dioxide in the heated clean flue gas and transport the absorbed clean flue gas to the spray chamber, the spray chamber is used to spray the absorbed clean flue gas, and the spray chamber has a flue gas outlet for discharging the sprayed clean flue gas, wherein the first temperature is below zero degrees and the second temperature is above zero degrees.

[0006] Optionally, a first heat exchange tube is provided in the heating chamber, the first heat exchange tube has a first inlet and a first outlet, the absorption chamber has an absorbent inlet and an absorbent outlet, the absorbent outlet is connected with the first inlet so that the absorbent in the absorption chamber enters the first heat exchange tube, the absorbent inlet is connected with the first outlet so that the absorbent in the first heat exchange tube flows back into the absorption chamber, and the first heat exchange tube is used to exchange heat with the flue gas after adsorption from the adsorption chamber to cool the absorbent.

[0007] Optionally, a second heat exchange tube is further provided in the heating chamber, the second heat exchange tube has a second inlet and a second outlet, the spray chamber has a spray liquid inlet and a spray liquid outlet, the spray liquid outlet is connected with the second inlet so that the spray liquid in the spray chamber enters the second heat exchange tube, the spray liquid inlet is connected with the second outlet so that the spray liquid in the second heat exchange tube flows back into the spray chamber, and the second heat exchange tube is used to exchange heat with the flue gas after adsorption from the adsorption chamber to cool the spray liquid.

[0008] Optionally, the heating chamber includes a first chamber and a second chamber, the first chamber is located below the second chamber and is connected to the adsorption chamber, the second chamber is respectively connected to the first chamber and the absorption chamber, the clean flue gas after adsorption discharged from the adsorption chamber enters the first chamber and exchanges heat with the first heat exchange tube, the clean flue gas after heat exchange in the first chamber enters the second chamber and exchanges heat with the second heat exchange tube, and the clean flue gas after heat exchange in the second chamber is transported to the absorption chamber.

[0009] Optionally, the first heat exchange tube is arranged in a serpentine shape in the up-down direction; and / or the second heat exchange tube is arranged in a serpentine shape in the up-down direction.

[0010] Optionally, a first partition is provided between the first chamber and the adsorption chamber, and a plurality of first smoke holes are provided on the first partition. A second partition is provided between the first chamber and the second chamber, and a plurality of second smoke holes are provided on the second partition.

[0011] Optionally, the flue gas low-temperature purification carbon capture system of an embodiment of the present invention also includes a first liquid replenishment pipe and a first liquid discharge pipe, the first liquid replenishment pipe is connected to the absorbent inlet, the first liquid replenishment pipe is used to replenish the lean liquid absorbent into the absorption chamber, the first liquid replenishment pipe is provided with a first control valve, the first liquid discharge pipe is connected to the absorbent outlet, the first liquid discharge pipe is used to discharge the rich liquid absorbent in the absorption chamber, and the first liquid replenishment pipe is provided with a second control valve.

[0012] Optionally, the flue gas low-temperature purification carbon capture system of an embodiment of the present invention further includes a second liquid replenishing pipe, which is connected to the spray liquid inlet and is used to replenish spray liquid into the spray chamber. A third control valve is provided on the second liquid replenishing pipe.

[0013] Optionally, the absorbent in the absorption chamber is a liquid absorbent, and the absorbent in the adsorption chamber is a solid absorbent.

[0014] Optionally, the first temperature is -80°C to -5°C; and / or the second temperature is 15°C to 45°C.

[0015] The flue gas low-temperature purification carbon capture system of the embodiment of the present invention realizes flue gas cooling and low-temperature adsorption. Flue gas heating and carbon capture not only improve the flue gas purification effect, can achieve near-zero emissions, but also realize the capture of carbon dioxide in the flue gas. Moreover, the flue gas cooling, adsorption, heating and carbon capture are integrated into one tower. Compared with the related technology, the number of equipment is reduced and the miniaturization of the tower is realized, which not only saves space but also reduces manufacturing costs, and has the characteristics of high integration. The highly integrated tower body also shortens the transportation distance of the flue gas between the cooling, adsorption, heating and carbon capture processes, reduces the amount of insulation materials used, reduces energy losses, further reduces construction costs, reduces material transportation time and transportation costs, and improves the flue gas carbon capture efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of a low-temperature purification capture tower according to an embodiment of the present invention.

[0017] Reference numerals:

[0018] 100. Low-temperature purification capture tower; 1. Low-temperature chamber; 101. Flue gas inlet; 2. Adsorption chamber; 3. Heating chamber; 301. First chamber; 302. Second chamber; 4. Absorption chamber; 401. Absorbent inlet; 402. Absorbent outlet; 5. Spray chamber; 501. Flue gas outlet; 502. Spray liquid inlet; 503. Spray liquid outlet; 6. First heat exchange tube; 601. First inlet; 602. First outlet; 7. Second heat exchange tube; 701. Second inlet; 702. Second outlet; 8. First partition; 801. First smoke hole; 9. Second partition; 901. Second smoke hole; 10. First liquid replenishment pipe; 11. First liquid discharge pipe; 12. First control valve; 13. Second control valve; 14. Second liquid replenishment pipe; 15. Third control valve. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0020] like Figure 1 As shown, the flue gas low temperature purification carbon capture system of the embodiment of the present invention includes a low temperature purification capture tower 100, and the inner cavity of the low temperature purification capture tower 100 is sequentially separated into a low temperature chamber 1, an adsorption chamber 2, a heating chamber 3, an absorption chamber 4 and a spray chamber 5 from bottom to top. The low temperature chamber 1 has a flue gas inlet 101, and the flue gas inlet 101 is used to transport the flue gas discharged from the coal-fired boiler into the low temperature chamber 1. The low temperature chamber 1 is used to cool the flue gas to a first temperature and transport it to the adsorption chamber 2. The adsorption chamber 2 is used to adsorb and purify the cooled flue gas and transport the adsorbed clean flue gas to the heating chamber 3. The heating chamber 3 is used to heat the adsorbed clean flue gas to a second temperature and transport it to the absorption chamber 4. The absorption chamber 4 is used to absorb carbon dioxide in the heated clean flue gas and transport the absorbed clean flue gas to the spray chamber 5. The spray chamber 5 is used to spray the absorbed clean flue gas. The spray chamber 5 has a flue gas outlet 501 for discharging the sprayed clean flue gas. The first temperature is below zero degrees, and the second temperature is above zero degrees.

[0021] Specifically, during the use of the flue gas low-temperature purification carbon capture system of the embodiment of the present invention, the high-temperature flue gas discharged from the coal-fired boiler enters the low-temperature chamber 1 through the flue gas inlet 101, and the high-temperature flue gas is cooled to low-temperature flue gas (below zero degrees) by the low-temperature chamber 1. The inventors have found through research that the lower the flue gas temperature, the more favorable it is for adsorption purification. The flue gas discharged from the coal-fired boiler is cooled to low-temperature flue gas below zero degrees, so that the adsorbent adsorbs the flue gas at low temperature, improves the adsorption effect, and can achieve near-zero emissions. The low-temperature chamber 1 transports the cooled flue gas to the adsorption chamber 2, and the adsorbent in the adsorption chamber 2 adsorbs and purifies the low-temperature flue gas to remove sulfides and nitrogen oxides in the flue gas, thereby achieving flue gas purification.

[0022] It should be noted that the suitable temperature for carbon capture absorbents to absorb carbon dioxide is usually above zero degrees, but the temperature of clean flue gas after low-temperature adsorption purification is still very low (around zero degrees). If the temperature is too low, the chemical reaction rate of the absorbent will slow down, the absorption efficiency will decrease, and it will be unfavorable for the absorbent to absorb carbon dioxide in the flue gas, thus affecting the efficiency of carbon capture. Therefore, it is necessary to heat the clean flue gas after adsorption and make it above zero degrees. Within this temperature range, the chemical reaction activity of the absorbent is higher, and it can react more effectively with carbon dioxide to form carbonates or other forms of compounds, thereby achieving carbon dioxide capture.

[0023] The clean flue gas after adsorption in the adsorption chamber 2 is transported to the heating chamber 3 for heating. The heating chamber 3 heats the clean flue gas after adsorption to the second temperature and then transports it to the absorption chamber 4. The absorbent in the absorption chamber 4 absorbs the carbon dioxide in the clean flue gas after heating, thereby capturing carbon dioxide. The clean flue gas absorbed in the absorption chamber 4 is transported to the spray chamber 5. The spray chamber 5 is used to spray the clean flue gas after carbon dioxide absorption, and the sprayed flue gas is discharged into the atmosphere through the flue gas outlet 501. The spray chamber 5 sprays the flue gas mainly for the following two purposes: on the one hand, the flue gas is cooled to the discharge temperature, and on the other hand, the absorbent in the flue gas is sprayed out to prevent the absorbent from entering the atmosphere with the flue gas and polluting the atmosphere.

[0024] The flue gas low-temperature purification carbon capture system of the embodiment of the present invention realizes flue gas cooling and low-temperature adsorption. Flue gas heating and carbon capture not only improve the flue gas purification effect, can achieve near-zero emissions, but also realize the capture of carbon dioxide in the flue gas. Moreover, the flue gas cooling, adsorption, heating and carbon capture are integrated into one tower. Compared with the related technology, the number of equipment is reduced and the miniaturization of the tower is realized, which not only saves space but also reduces manufacturing costs, and has the characteristics of high integration. The highly integrated tower body also shortens the transportation distance of the flue gas between the cooling, adsorption, heating and carbon capture processes, reduces the amount of insulation materials used, reduces energy losses, further reduces construction costs, reduces material transportation time and transportation costs, and improves the flue gas carbon capture efficiency.

[0025] Optionally, the first temperature is -80°C to -5°C, and more preferably, the temperature of the low-temperature flue gas is -20°C to -10°C. Although the lower the flue gas temperature, the more favorable it is for adsorption purification, if the flue gas temperature is too low, the structure of the low-temperature chamber 1 will be complicated and the energy consumption will increase. For example, the pipeline sealing between the low-temperature chamber 1 and the adsorption chamber 2 will require high requirements, which will increase the cost. Therefore, it is beneficial to cool the flue gas temperature to -20°C to -10°C.

[0026] Optionally, the second temperature is 15°C-45°C.

[0027] It should be noted that the suitable temperature for carbon capture absorbents to absorb carbon dioxide is usually between 15°C and 45°C. Within this temperature range, the chemical reaction activity of the absorbent is higher and it can react more effectively with carbon dioxide to form carbonates or other forms of compounds, thereby achieving the capture of carbon dioxide.

[0028] If the temperature is too low, the chemical reaction rate will slow down and the absorption efficiency will decrease. If the temperature is too high, although the reaction rate will increase, it may cause the degradation of the absorbent or increase energy consumption, and may also reduce the solubility of carbon dioxide, affecting the absorption effect.

[0029] In some embodiments, a first heat exchange tube 6 is provided in the temperature raising chamber 3, and the first heat exchange tube 6 has a first inlet 601 and a first outlet 602. The absorption chamber 4 has an absorbent inlet 401 and an absorbent outlet 402, and the absorbent outlet 402 is connected to the first inlet 601 so that the absorbent in the absorption chamber 4 enters the first heat exchange tube 6. The absorbent inlet 401 is connected to the first outlet 602 so that the absorbent in the first heat exchange tube 6 flows back into the absorption chamber 4. The first heat exchange tube 6 is used to exchange heat with the flue gas adsorbed from the adsorption chamber 2 to cool the absorbent.

[0030] It should be noted that the process of the absorbent absorbing carbon dioxide in the absorption chamber 4 is an exothermic reaction. Therefore, in order to maintain the appropriate adsorption temperature of the absorbent in the absorption chamber 4, the absorbent needs to be cooled continuously so that the absorbent maintains a high absorption efficiency.

[0031] In the embodiment of the present invention, the absorbent in the absorption chamber 4 flows out through the absorbent outlet 402, and enters the first heat exchange tube 6 through the first inlet 601, and exchanges heat with the low-temperature flue gas entering the temperature-raising chamber 3 through the first heat exchange tube 6 to cool the absorbent so that the absorbent is always at the optimal absorption temperature. The cooled absorbent flows out of the first heat exchange tube 6 through the first outlet 602, and flows back into the absorption chamber 4 through the absorbent inlet 401.

[0032] Therefore, the flue gas low-temperature purification carbon capture system of the embodiment of the present invention effectively utilizes the cold energy in the flue gas after low-temperature adsorption to exchange heat with the heat generated by the absorbent absorbing carbon dioxide, thereby raising the flue gas temperature and lowering the temperature of the absorbent, so that both the absorbent and the flue gas are at the optimal absorption temperature of the absorbent, thereby avoiding the use of external energy consumption to cool the absorbent and to heat the flue gas, which not only helps to reduce the energy consumption of the system and improve the efficiency of the system, but also reduces heat emissions to the environment, further reducing the impact on the environment.

[0033] In some embodiments, a second heat exchange tube 7 is further provided in the temperature raising chamber 3, and the second heat exchange tube 7 has a second inlet 701 and a second outlet 702. The spray chamber 5 has a spray liquid inlet 502 and a spray liquid outlet 503, and the spray liquid outlet 503 is connected with the second inlet 701 so that the spray liquid in the spray chamber 5 enters the second heat exchange tube 7, and the spray liquid inlet 502 is connected with the second outlet 702 so that the spray liquid in the second heat exchange tube 7 flows back to the spray chamber 5. The second heat exchange tube 7 is used to exchange heat with the flue gas adsorbed from the adsorption chamber 2 to cool the spray liquid.

[0034] It should be noted that, since the temperature of the spray liquid will rise after spraying the absorbed flue gas, the spray liquid needs to be continuously cooled. In the embodiment of the present invention, the spray liquid in the spray chamber 5 flows out through the spray liquid outlet 503, and enters the second heat exchange tube 7 through the second inlet 701, and exchanges heat with the low-temperature flue gas entering the temperature-raising chamber 3 through the second heat exchange tube 7 to cool the spray liquid, so that the spray liquid is always at the optimal spraying temperature. After cooling, the spray liquid flows out of the second heat exchange tube 7 through the second outlet 702, and flows back to the spray chamber 5 through the spray liquid inlet 502.

[0035] Therefore, the flue gas low-temperature purification carbon capture system of the embodiment of the present invention effectively utilizes the cold in the flue gas after low-temperature adsorption and the heat in the spray liquid for heat exchange, thereby raising the flue gas temperature and lowering the temperature of the spray liquid, so that both the spray liquid and the flue gas are at the optimal absorption temperature of the absorbent, thereby avoiding the use of external energy consumption to cool the spray liquid and to heat the flue gas, which not only helps to reduce the energy consumption of the system and improve the efficiency of the system, but also reduces heat emissions to the environment, further reducing the impact on the environment.

[0036] In some embodiments, the temperature rising chamber 3 includes a first chamber 301 and a second chamber 302 , the first chamber 301 is located below the second chamber 302 and communicates with the adsorption chamber 2 , and the second chamber 302 is communicated with the first chamber 301 and the absorption chamber 4 , respectively.

[0037] Specifically, the clean flue gas after adsorption discharged from the adsorption chamber 2 enters the first chamber 301 and exchanges heat with the first heat exchange tube 6, the clean flue gas after heat exchange in the first chamber 301 enters the second chamber 302 and exchanges heat with the second heat exchange tube 7, and the clean flue gas after heat exchange in the second chamber 302 is transported to the absorption chamber 4. In other words, the flue gas after adsorption in the adsorption chamber 2 first enters the first chamber 301 and exchanges heat with the first heat exchange tube 6, and then enters the second chamber 302 and exchanges heat with the second heat exchange tube 7 for the second time. Through the step utilization, the flue gas is gradually heated in different chambers, so that the heat in the absorbent and the spray liquid can be more efficiently utilized to achieve the heating of the flue gas, so that the external heat source can be greatly reduced or even avoided to heat the flue gas in the heating chamber 3, which not only reduces the waste of energy, but also because the heat is used step by step, a large number of independent cooling equipment is not required, thereby further reducing the scale and floor space of the overall tower.

[0038] Optionally, the first heat exchange tube 6 is arranged in a serpentine shape in the vertical direction. In the flue gas low-temperature purification carbon capture system, the serpentine-arranged heat exchange tube can absorb the flow path of the agent to increase the flow time in the temperature-raising chamber 3. This arrangement enables the flue gas to more fully exchange heat with the low-temperature flue gas when passing through the heat exchange tube, thereby improving the efficiency of heat exchange. In addition, the serpentine arrangement also helps to reduce the number of heat exchange tubes, simplify the system structure, and reduce the complexity and cost of the system. At the same time, this arrangement is also convenient for maintenance and cleaning, improving the reliability and economy of the system.

[0039] Optionally, the second heat exchange tube 7 is arranged in a serpentine shape in the vertical direction. In the flue gas low-temperature purification carbon capture system, the serpentine-arranged heat exchange tube can spray the flow path of the liquid to increase the flow time in the temperature-raising chamber 3. This arrangement enables the flue gas to more fully exchange heat with the low-temperature flue gas when passing through the heat exchange tube, thereby improving the efficiency of heat exchange. In addition, the serpentine arrangement also helps to reduce the number of heat exchange tubes, simplify the system structure, and reduce the complexity and cost of the system. At the same time, this arrangement is also convenient for maintenance and cleaning, improving the reliability and economy of the system.

[0040] In some embodiments, a first partition plate 8 is provided between the first chamber 301 and the adsorption chamber 2, and a plurality of first smoke holes 801 are provided on the first partition plate 8. A second partition plate 9 is provided between the first chamber 301 and the second chamber 302, and a plurality of second smoke holes 901 are provided on the second partition plate 9.

[0041] The first partition 8 is provided to ensure that the clean flue gas after adsorption can be evenly distributed when entering the first chamber 301, so as to fully exchange heat with the first heat exchange tube 6. Similarly, the second smoke holes 901 on the second partition 9 are also to ensure that the clean flue gas can be evenly distributed when entering the second chamber 302, and fully exchange heat with the second heat exchange tube 7. Ensure that the flow and temperature distribution of the flue gas between each chamber are uniform, thereby improving the performance and reliability of the entire system. At the same time, the spaced arrangement of the smoke holes can also reduce the eddy currents and disturbances of the flue gas during the flow process, which helps to keep the temperature and composition of the flue gas stable, which is very important for the subsequent carbon dioxide capture.

[0042] In addition, the first partition 8 can also prevent the temperature between the adsorption chamber 2 and the first chamber 301 from affecting each other, and the second partition 9 can also prevent the temperature between the first chamber 301 and the second chamber 302 from affecting each other, which is beneficial to improving the working reliability between the adsorption chamber 2, the first chamber 301 and the second chamber 302.

[0043] In some embodiments, the flue gas low temperature purification carbon capture system of the embodiment of the present invention further includes a first liquid replenishment pipe 10 and a first liquid discharge pipe 11. The first liquid replenishment pipe 10 is connected to the absorbent inlet 401, and the first liquid replenishment pipe 10 is used to replenish the lean liquid absorbent into the absorption chamber 4, and a first control valve 12 is provided on the first liquid replenishment pipe 10. The first liquid discharge pipe 11 is connected to the absorbent outlet 402, and the first liquid discharge pipe 11 is used to discharge the rich liquid absorbent in the absorption chamber 4, and a second control valve 13 is provided on the first liquid replenishment pipe 10.

[0044] The lean liquid absorbent generally refers to the absorbent that has captured a certain amount of carbon dioxide during the absorption process but has not yet reached a saturated state. The lean liquid absorbent is replenished through the first liquid replenishment pipe 10 to maintain the concentration of the absorbent in the absorption chamber 4 and ensure continuous and efficient carbon dioxide capture. The first liquid replenishment pipe 10 is provided with a first control valve 12 for adjusting the flow rate and pressure of the replenishment to meet different absorption requirements.

[0045] Rich liquid absorbent generally refers to absorbent that has captured a large amount of carbon dioxide and is close to or has reached a saturated state. Discharging the rich liquid absorbent through the first liquid discharge pipe 11 can release the pressure in the absorption chamber 4 and make room for the replenishment of the lean liquid absorbent. The first liquid discharge pipe 11 is provided with a second control valve 13, which is used to adjust the flow rate and pressure of the discharge to control the liquid level and pressure balance of the system. The rich liquid absorbent can be discharged to the absorption regeneration tower for heating to desorb the carbon dioxide in the absorbent for the next step of utilization and sealing process.

[0046] Optionally, the adsorption chamber has an adsorbent inlet and an adsorbent outlet, the adsorbent inlet is used to add the sprayed liquid adsorbent into the adsorption chamber, and the adsorbent outlet is used to discharge the rich liquid adsorbent in the adsorption chamber.

[0047] In some embodiments, the flue gas low-temperature purification carbon capture system of the embodiment of the present invention also includes a second liquid replenishment pipe 14, which is connected to the spray liquid inlet 502, and the second liquid replenishment pipe 14 is used to replenish the spray liquid into the spray chamber 5. A third control valve 15 is provided on the second liquid replenishment pipe 14.

[0048] The spray liquid plays a role in cooling the flue gas during the low-temperature purification process. The flue gas is cooled to a suitable temperature through spraying so that it can be discharged into the atmosphere. Replenishing the spray liquid can ensure the stability of the liquid level in the spray chamber 5 and the continuity of the spray cooling effect. The second liquid replenishing pipe 14 is provided with a third control valve 15 for adjusting the flow rate and pressure of the replenishing liquid. The supply amount of the spray liquid can be controlled by the third control valve 15, and the spray intensity and cooling effect can be adjusted according to the needs of flue gas treatment.

[0049] In some embodiments, the absorbent in the absorption chamber 4 is a liquid absorbent, and the absorbent in the absorption chamber 2 is a solid absorbent.

[0050] For example, the absorbent is an organic amine, and the adsorbent is activated carbon or activated coke. Organic amine is a class of highly active chemical substances. In the field of carbon capture, organic amine solution is used as an absorbent to react chemically with carbon dioxide in flue gas to form unstable salts, thereby achieving carbon dioxide capture and facilitating the flow, transportation and heat exchange of the absorbent. Since the desulfurization process of organic amine is not easy to achieve in a low-temperature environment, activated carbon or activated coke solid adsorbents can achieve integrated desulfurization and denitrification in a low-temperature environment, and the lower the temperature, the higher the removal efficiency.

[0051] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0052] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0053] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0055] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0056] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A flue gas low temperature purification carbon capture system, characterized in that: include: A low-temperature purification and capture tower, wherein the inner cavity of the low-temperature purification and capture tower is sequentially separated into a low-temperature chamber, an adsorption chamber, a heating chamber, an absorption chamber and a spray chamber from bottom to top, wherein the low-temperature chamber has a flue gas inlet, and the flue gas inlet is used to transport the flue gas discharged from the coal-fired boiler into the low-temperature chamber, wherein the low-temperature chamber is used to cool the flue gas to a first temperature and transport it to the adsorption chamber, wherein the adsorption chamber is used to adsorb and purify the cooled flue gas and transport the adsorbed clean flue gas to the heating chamber, wherein the heating chamber is used to heat the adsorbed clean flue gas to a second temperature and transport it to the absorption chamber, wherein the absorption chamber is used to absorb carbon dioxide in the heated clean flue gas and transport the absorbed clean flue gas to the spray chamber, wherein the spray chamber is used to spray the absorbed clean flue gas, and wherein the spray chamber has a flue gas outlet for discharging the sprayed clean flue gas, wherein the first temperature is below zero degrees, and the second temperature is above zero degrees.

2. The flue gas low temperature purification carbon capture system according to claim 1, characterized in that: A first heat exchange tube is provided in the temperature rising chamber, the first heat exchange tube has a first inlet and a first outlet, the absorption chamber has an absorbent inlet and an absorbent outlet, the absorbent outlet is connected with the first inlet so that the absorbent in the absorption chamber enters the first heat exchange tube, the absorbent inlet is connected with the first outlet so that the absorbent in the first heat exchange tube flows back into the absorption chamber, and the first heat exchange tube is used to exchange heat with the flue gas after adsorption from the adsorption chamber to cool the absorbent.

3. The flue gas low temperature purification carbon capture system according to claim 2, characterized in that: A second heat exchange tube is also provided in the temperature rising chamber, the second heat exchange tube has a second inlet and a second outlet, the spray chamber has a spray liquid inlet and a spray liquid outlet, the spray liquid outlet is connected with the second inlet so that the spray liquid in the spray chamber enters the second heat exchange tube, the spray liquid inlet is connected with the second outlet so that the spray liquid in the second heat exchange tube flows back into the spray chamber, and the second heat exchange tube is used for exchanging heat with the flue gas after adsorption from the adsorption chamber to cool the spray liquid.

4. The flue gas low temperature purification carbon capture system according to claim 3, characterized in that: The temperature-raising chamber includes a first chamber and a second chamber. The first chamber is located below the second chamber and is connected to the adsorption chamber. The second chamber is respectively connected to the first chamber and the absorption chamber. The clean flue gas after adsorption discharged from the adsorption chamber enters the first chamber and exchanges heat with the first heat exchange tube. The clean flue gas after heat exchange in the first chamber enters the second chamber and exchanges heat with the second heat exchange tube. The clean flue gas after heat exchange in the second chamber is transported to the absorption chamber.

5. The flue gas low temperature purification carbon capture system according to claim 4, characterized in that: The first heat exchange tubes are arranged in a serpentine shape in the vertical direction; and / or The second heat exchange tubes are arranged in a serpentine shape in the up-down direction.

6. The flue gas low temperature purification carbon capture system according to claim 4, characterized in that: A first partition is provided between the first chamber and the adsorption chamber, and a plurality of first smoke holes are provided on the first partition. A second partition is provided between the first chamber and the second chamber, and a plurality of second smoke holes are provided on the second partition.

7. The flue gas low temperature purification carbon capture system according to claim 2, characterized in that: It also includes a first liquid replenishment pipe and a first liquid discharge pipe, the first liquid replenishment pipe is connected to the absorbent inlet, the first liquid replenishment pipe is used to replenish the lean liquid absorbent into the absorption chamber, the first liquid replenishment pipe is provided with a first control valve, the first liquid discharge pipe is connected to the absorbent outlet, the first liquid discharge pipe is used to discharge the rich liquid absorbent in the absorption chamber, and the first liquid replenishment pipe is provided with a second control valve.

8. The flue gas low temperature purification carbon capture system according to claim 3, characterized in that: It also includes a second liquid replenishing pipe, which is connected to the spray liquid inlet and is used to replenish the spray liquid into the spray chamber. The second liquid replenishing pipe is provided with a third control valve.

9. The flue gas low temperature purification carbon capture system according to claim 1, characterized in that: The absorbent in the absorption chamber is a liquid absorbent, and the absorbent in the adsorption chamber is a solid absorbent.

10. The flue gas low temperature purification carbon capture system according to any one of claims 1 to 9, characterized in that: The first temperature is -80°C to -5°C; and / or The second temperature is 15°C-45°C.

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