Carbon dioxide hunting system and method

Abstract

The present application relates to a kind of carbon dioxide hunting system and method, comprising: reactor, with flue gas input end, gaseous material output end, return material ash input end, calcium-based absorbent input end, heat input end and thermometer installation end;Flue gas input part;Gas recovery part, including dust collector and gas recovery processing component;The gas output end of the dust collector is connected with the gas recovery processing component, the gas input end of the dust collector is connected with the gaseous material output end by gas output pipeline component, the return material ash output end of the dust collector is connected with the return material ash input end by return material ash pipeline component;Ejector has output end, first input end and second input end;The first input end is used to be connected with the supply equipment of calcium-based absorbent, the second input end is connected with the gas output pipeline component by shunt pipeline component, simultaneously have the advantages of obtaining high concentration carbon dioxide, reducing system construction time fund investment, reducing the cost of transformation.

Description

Technical Field

[0001] This invention relates to the technical field of carbon dioxide capture, and in particular to a carbon dioxide capture system and method. Background Technology

[0002] Coal-fired power plants are major emitters of carbon dioxide, and carbon dioxide capture, utilization, and storage (CCUS) technology is one of the most effective methods for large-scale carbon dioxide reduction. Currently, for coal-fired units, carbon dioxide capture technologies mainly include:

[0003] (1) Decarbonization before combustion: coal gasification technology is used to convert coal into syngas, and then carbon monoxide is converted into carbon dioxide and captured.

[0004] (2) Decarbonization during combustion: High concentration of oxygen is directly used to participate in the combustion reaction to obtain high concentration of carbon dioxide for capture.

[0005] (3) Post-combustion decarbonization: In the tail gas separation and recovery of carbon dioxide in coal-fired power units, the main post-combustion decarbonization methods are physical and chemical methods.

[0006] Calcium-based absorption and desorption of carbon dioxide is a post-combustion chemical decarbonization technology. Currently, the mainstream calcium-based carbon dioxide capture technology mainly adopts a dual-reaction, dual-cycle decarbonization process. Its main process includes: flue gas reacts with CaO (calcium-based absorbent) in a carbonation reactor (carbon dioxide absorption reactor) to remove carbon dioxide, generating gaseous substances that are discharged. The solid substance (CaCO3) enters a calcination reactor (carbon dioxide desorption reactor) to generate high-purity carbon dioxide gas for capture, and the generated solid CaO is returned to the carbonation reactor (carbon dioxide absorption reactor) as an absorbent for further reaction.

[0007] For this type of dual-reaction, dual-cycle decarbonization process, the absorption stage (carbonation reaction stage) involves flue gas reacting with CaO at a temperature of approximately 650℃; the desorption stage (calcination reaction stage) involves CaCO3 calcination at a temperature of approximately 950℃. The transfer of high-temperature materials CaO and CaCO3 between the two reactors is a significant industry challenge. Furthermore, the dual-reactor system requires substantial investment, occupies a large area, and incurs high operating and maintenance costs, preventing the technology from achieving large-scale application. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the defects in the prior art, thereby providing a carbon dioxide search and capture system and method.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A carbon dioxide search and capture system, comprising:

[0011] The reactor has a flue gas inlet, a gaseous product outlet, a return ash inlet, a calcium-based absorbent inlet, a heat inlet for connecting to an external heat source delivery device, and a thermometer mounting end for inserting a thermometer.

[0012] A flue gas inlet section is connected to the flue gas inlet end;

[0013] The gas recovery unit includes a dust collector and a gas recovery processing assembly; the gas output end of the dust collector is connected to the gas recovery processing assembly, the gas input end of the dust collector is connected to the gaseous output end through a gas output pipeline assembly, and the return ash output end of the dust collector is connected to the return ash input end through a return ash pipeline assembly.

[0014] The ejector has an output end, a first input end, and a second input end; the output end is connected to the calcium-based absorbent input end through a calcium-based absorbent delivery pipeline assembly; the first input end is used to connect to a calcium-based absorbent supply device, and the second input end is connected to the gas output pipeline assembly through a diversion pipeline assembly, and delivers gas at a preset pressure to the ejector to deliver the calcium-based absorbent to the reactor.

[0015] Preferably, the gas output pipeline assembly includes a first pipe, a compressor, a second pipe, and a gas collection valve;

[0016] The gaseous output end, the first pipe, the compressor, the second pipe and the gas input end of the dust collector are connected in sequence, and the gas collection valve is installed on the second pipe;

[0017] The diversion pipeline assembly includes a diversion pipe and a recirculation valve disposed on the diversion pipe. One end of the diversion pipe is connected to the output end of the compressor, and the other end is connected to the second input end.

[0018] Preferably, it also includes a high-temperature heat exchanger, which is located upstream of the compressor;

[0019] And / or,

[0020] It also includes a low-temperature heat exchanger, which is located upstream of the dust collector and downstream of the circulating gas valve.

[0021] Preferably, it further includes:

[0022] A high-temperature heat exchanger has a first high-temperature heat exchange channel and a second high-temperature heat exchange channel. The first high-temperature heat exchange channel is connected to a pipe section of the gas output pipeline assembly near the gas output end, and the second high-temperature heat exchange channel is connected to the calcium-based absorbent delivery pipeline assembly.

[0023] And / or,

[0024] The low-temperature heat exchanger has a first low-temperature heat exchange channel and a second low-temperature heat exchange channel. The first low-temperature heat exchange channel is connected to the pipe section of the gas output pipeline assembly away from the gaseous output end, and the second low-temperature heat exchange channel is connected to the return ash pipeline assembly.

[0025] Preferably, the flue gas inlet includes a raw flue gas pipe, a raw flue gas valve, and a raw flue gas analyzer;

[0026] The raw flue gas pipe is connected to the flue gas input end, and the raw flue gas valve and the raw flue gas analyzer are both installed on the raw flue gas pipe;

[0027] The gas recovery and processing assembly includes a carbon dioxide collection pipe, a carbon dioxide collection control valve, a clean flue gas discharge pipe, a clean flue gas valve, and a clean flue gas analyzer.

[0028] The carbon dioxide collection control valve is installed on the carbon dioxide collection pipe, and the clean flue gas valve is installed on the clean flue gas discharge pipe;

[0029] The clean flue gas analyzer is installed upstream of the carbon dioxide collection control valve and the clean flue gas valve.

[0030] A carbon dioxide capture method based on the above-mentioned carbon dioxide capture system includes the following steps:

[0031] System startup preparation includes supplying raw flue gas into the reactor;

[0032] The gas output from the reactor is pressurized to a preset pressure and delivered to an ejector to deliver the calcium-based absorbent delivered to the ejector back to the reactor;

[0033] The return ash output from the gas recovery unit is transported to the reactor;

[0034] Control the reactor to be in a carbonation reaction state;

[0035] The reactor's operating state is switched from the carbonation reaction state to the calcination reaction state. When the carbon dioxide concentration in the clean flue gas discharged from the gas recovery unit after calcination reaches the preset collection concentration, the gas output from the reactor is collected.

[0036] Preferably, the method further includes the following steps: using a high-temperature heat exchanger to exchange heat between the calcium-based absorbent and the gas output from the reactor; and / or using a low-temperature heat exchanger to exchange heat between the return ash output from the dust collector and the gas output from the compressor.

[0037] Preferably, the system startup preparation steps include:

[0038] When the reactor is heated to the preset temperature, the original flue gas valve, the collected gas valve, and the clean flue gas valve are opened to allow the flue gas in the entire system to flow in a balanced manner for a preset time.

[0039] When the compressor output gas pressure reaches the preset pressure, the recirculation gas valve is opened.

[0040] Preferably, the control of switching the reactor operating state from the carbonation reaction state to the calcination reaction state specifically includes the following steps:

[0041] After the carbonation reaction has continued for a preset reaction time, the supply of raw flue gas to the reactor is stopped. It is determined whether the carbon dioxide concentration of the gas output from the gas recovery unit is not greater than the standard switching concentration. If yes, the state is switched; otherwise, the carbon dioxide absorption state is maintained.

[0042] or,

[0043] After the carbonation reaction has continued for a preset reaction time, the supply of calcium-based absorbent to the reactor is stopped, and the state is switched directly.

[0044] Preferably, the method further includes the following steps:

[0045] The carbon dioxide removal efficiency is calculated based on the carbon dioxide concentration in the original flue gas and the carbon dioxide concentration in the clean flue gas discharged from the gas recovery unit.

[0046] Determine if the carbon dioxide removal efficiency is lower than the set removal efficiency value. If so, replace the calcium-based absorbent in the reactor.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] The aforementioned solution provides a carbon dioxide capture system with a reactor equipped with a flue gas inlet, a gaseous material outlet, a returned ash inlet, a calcium-based absorbent inlet, a heat inlet, and a thermometer mounting end. This system enables the reuse of returned ash and the replenishment of the calcium-based absorbent to meet the target requirement of collecting high-purity carbon dioxide. Furthermore, it allows for temperature control within the reactor, enabling carbonation and calcination reactions to be completed within the same reactor. This effectively solves the problem of difficult and costly high-temperature material transport caused by conducting carbonation and calcination reactions in separate reactors in existing technologies, significantly reducing initial investment and system modification costs. In addition, the ejector directly utilizes pre-pressurized gas within the system to transport the calcium-based absorbent to the reactor, reducing the need for external kinetic energy supply and further achieving energy savings, lower operating costs, and reduced manufacturing costs. Correspondingly, the carbon dioxide capture method based on this system offers the advantages of obtaining high-concentration carbon dioxide, reducing initial investment in system construction, and lowering system modification costs. Attached Figure Description

[0049] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0050] Figure 1 A schematic diagram of one example of the system provided by the present invention.

[0051] Figure 2 for Figure 1 A schematic diagram of the system in the startup phase (the gas in the system is in equilibrium flow state).

[0052] Figure 3 for Figure 1 A schematic diagram of the system in the carbonation reaction stage.

[0053] Figure 4 for Figure 1 A schematic diagram of the system in the calcination reaction stage.

[0054] Explanation of reference numerals in the attached figures:

[0055] 100. Gas output pipeline assembly; 101. First pipe; 102. Compressor; 103. Second pipe; 104. Collecting gas valve; 200. Return ash pipeline assembly; 201. Return ash pipe; 202. Return ash blower; 300. Calcium-based absorbent conveying pipeline assembly; 400. Diversion pipeline assembly; 401. Diversion pipe; 402. Circulating gas valve; 500. Waste residue discharge pipeline assembly; 501. Waste residue discharge pipe; 502. Slag discharge valve; 600. Calcium-based absorbent supply pipeline assembly; 601. Calcium-based absorbent supply pipe; 602. Calcium-based absorbent feed valve; 1. Reactor; 11. Flue gas inlet; 12. Gaseous output; 13. Return ash inlet; 14. Calcium-based absorbent inlet. 15. Heat input end; 16. Thermometer installation end; 17. Waste discharge end; 2. Flue gas input section; 21. Raw flue gas pipe; 22. Raw flue gas valve; 23. Raw flue gas analyzer; 3. Gas recovery section; 31. Dust collector; 32. Gas recovery and treatment assembly; 321. Carbon dioxide collection pipe; 322. Carbon dioxide collection control valve; 323. Clean flue gas discharge pipe; 324. Clean flue gas valve; 325. Clean flue gas analyzer; 4. Ejector; 40. Output end; 41. First input end; 42. Second input end; 5. High-temperature heat exchanger; 51. First high-temperature heat exchange channel; 52. Second high-temperature heat exchange channel; 6. Low-temperature heat exchanger; 61. First low-temperature heat exchange channel; 62. Second low-temperature heat exchange channel. Detailed Implementation

[0056] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., 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 the invention and for simplifying the description, and do not 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 the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0058] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0059] See Figures 1 to 4 The present invention provides a carbon dioxide capture system, including a reactor 1, a flue gas inlet 2, a gas recovery unit 3, and an ejector 4.

[0060] Specifically, reactor 1 has a flue gas inlet 11, a gaseous material outlet 12, a return ash inlet 13, a calcium-based absorbent inlet 14, a heat inlet 15 for connection to an external heat source conveying device, and a thermometer mounting end 16 for inserting a thermometer. Flue gas inlet 2 is connected to flue gas inlet 11 and is used to convey raw flue gas to flue gas inlet 11. The gas recovery unit 3 includes a dust collector 31 and a gas recovery processing assembly 32. The gas output end of the dust collector 31 is connected to the gas recovery processing assembly 32, the gas input end of the dust collector 31 is connected to the gaseous output end 12 through the gas output pipeline assembly 100, and the return ash output end of the dust collector 31 is connected to the return ash input end 13 through the return ash pipeline assembly 200. It can be seen that the gas output from the gaseous output end 12 of the reactor 1 is first dedusted by the dust collector 31 before being transported to the gas recovery processing assembly 32, while the return ash output from the dust collector 31 can be transported back to the reactor 1 through the return ash pipeline assembly 200 as the reaction raw material of the reactor 1. The ejector 4 has an output end 40, a first input end 41, and a second input end 42. The output end 40 is connected to the calcium-based absorbent input end 14 through the calcium-based absorbent delivery pipeline assembly 300. The first input end 41 is used to connect to the calcium-based absorbent supply equipment, and the second input end 42 is connected to the gas output pipeline assembly 100 through the diversion pipeline assembly 400, and delivers gas at a preset pressure to the ejector 4 to deliver the calcium-based absorbent to the reactor 1.

[0061] Through the above scheme, reactor 1 is equipped with a flue gas inlet 11, a gaseous material outlet 12, a returned ash inlet 13, a calcium-based absorbent inlet 14, a heat inlet 15, and a thermometer mounting end 16. This allows for the reuse of returned ash and the replenishment of the calcium-based absorbent to meet the target requirement of collecting high-purity carbon dioxide. Furthermore, it enables temperature control of reactor 1, allowing the carbonation and calcination reactions to be completed within the same reactor. This effectively solves the problem of difficult and costly high-temperature material transportation caused by conducting carbonation and calcination reactions in different reactors in existing technologies, thus significantly reducing capital investment during system construction and lowering system modification costs. In addition, the ejector 4 directly utilizes the pre-pressurized gas within the system to transport the calcium-based absorbent to reactor 1, reducing the need for external kinetic energy supply and further achieving energy savings, reduced operating costs, and lower manufacturing costs.

[0062] It is known that the external heat source delivery device connected through the heat input terminal 15 and the thermometer inserted through the thermometer mounting terminal 16 can control the temperature inside the reactor 1. When a carbonation reaction occurs inside the reactor 1, the temperature inside the reactor 1 can be controlled to be maintained at the first preset temperature (generally set to about 650°C); when a calcination reaction occurs inside the reactor 1, the temperature inside the reactor 1 can be controlled to be maintained at the second preset temperature (generally set to about 950°C).

[0063] Furthermore, the gas output pipeline assembly 100 includes a first pipe 101, a compressor 102, a second pipe 103, and a gas collection valve 104; the gas output end 12, the first pipe 101, the compressor 102, the second pipe 103, and the gas input end of the dust collector 31 are connected in sequence, and the gas collection valve 104 is disposed on the second pipe 103; the diversion pipeline assembly 400 includes a diversion pipe 401 and a recirculation valve 402 disposed on the diversion pipe 401, one end of the diversion pipe 401 is connected to the output end of the compressor 102, and the other end is connected to the second input end 42; through the cooperation of the gas collection valve 104, the recirculation valve 402, and the compressor 102, gas at a preset pressure can be delivered to the ejector 4.

[0064] To ensure the stable operation of the dust collector 31 and the compressor 102 within a safe temperature range, this embodiment also includes a high-temperature heat exchanger 5 and a low-temperature heat exchanger 6. The high-temperature heat exchanger 5 is located upstream of the compressor 102; the low-temperature heat exchanger 6 is located upstream of the dust collector 31 and downstream of the circulating gas valve 402, thereby ensuring that the circulating gas delivered to the ejector 4 has a certain temperature to preheat the calcium-based absorbent. Of course, in other embodiments, either the high-temperature heat exchanger 5 or the low-temperature heat exchanger 6 can be provided, or multiple heat exchangers can be provided.

[0065] Specifically, the high-temperature heat exchanger 5 has a first high-temperature heat exchange channel 51 and a second high-temperature heat exchange channel 52. The first high-temperature heat exchange channel 51 is connected to a pipe section of the gas output pipeline assembly 100 near the gas output end 12, and the second high-temperature heat exchange channel 52 is connected to the calcium-based absorbent delivery pipeline assembly 300.

[0066] Furthermore, the low-temperature heat exchanger 6 has a first low-temperature heat exchange channel 61 and a second low-temperature heat exchange channel 62. The first low-temperature heat exchange channel 61 is connected to the pipe section of the gas output pipeline assembly 100 away from the gaseous output end 12, and the second low-temperature heat exchange channel 62 is connected to the return ash pipeline assembly 200. On the one hand, it can realize the cascade utilization of the heat of the gas discharged from the reactor 1; on the other hand, it can preheat the calcium-based absorbent and return ash fed into the reactor 1, so as to facilitate the uniform heating of the calcium-based absorbent and return ash fed into the reactor 1 to the preset reaction temperature.

[0067] To facilitate monitoring of carbon dioxide concentrations in raw flue gas (flue gas from the desulfurization outlet) and clean flue gas (flue gas after dust removal by dust collector 31), in this embodiment, the flue gas inlet 2 includes a raw flue gas pipe 21, a raw flue gas valve 22, and a raw flue gas analyzer 23; the raw flue gas pipe 21 is connected to the flue gas inlet 11, and both the raw flue gas valve 22 and the raw flue gas analyzer 23 are installed on the raw flue gas pipe 21; the gas recovery and processing assembly 32 includes a carbon dioxide collection pipe 321, a carbon dioxide collection control valve 322, a clean flue gas outlet pipe 323, a clean flue gas valve 324, and a clean flue gas analyzer 325; the carbon dioxide collection control valve 322 is installed on the carbon dioxide collection pipe 321, and the clean flue gas valve 324 is installed on the clean flue gas outlet pipe 323; the clean flue gas analyzer 325 is installed upstream of the carbon dioxide collection control valve 322 and the clean flue gas valve 324.

[0068] It is known that during the carbonation reaction (i.e., reactor 1 is in the carbon dioxide absorption state), the carbon dioxide concentration in the clean flue gas can be monitored by the clean flue gas analyzer 325, thereby determining the degree of carbon dioxide absorption in the original flue gas and further determining whether the operating state of reactor 1 can be switched. During the calcination reaction (i.e., reactor 1 is in the carbon dioxide desorption state), the carbon dioxide concentration in the clean flue gas can be monitored by the clean flue gas analyzer 325, thereby determining when to collect the clean flue gas to obtain high-purity carbon dioxide. In addition, the concentration of the original flue gas can be measured by the original flue gas analyzer 23, and the concentration of the clean flue gas can be measured by the clean flue gas analyzer 325. Therefore, during the carbonation reaction (i.e., reactor 1 is in the carbon dioxide absorption state), the carbon dioxide removal efficiency can be calculated, thereby determining the performance of the calcium-based absorbent in reactor 1.

[0069] Specifically, the carbon dioxide removal efficiency can be calculated using the following formula:

[0070]

[0071] In the formula, η is the carbon dioxide removal efficiency, %; C i The inlet instrument displays the carbon dioxide concentration, in ppm; C o The outlet instrument displays the carbon dioxide concentration in ppm. The calcium-based absorbent can be replaced when the calculated carbon dioxide removal efficiency is lower than the set removal efficiency value.

[0072] In this embodiment, the reactor 1 also has a waste discharge end 17, which is connected to a waste discharge pipeline assembly 500. Specifically, the waste discharge pipeline assembly 500 includes a waste discharge pipe 501 and a slag discharge valve 502.

[0073] In this embodiment, the return ash pipeline assembly 200 includes a return ash pipe 201 and a return ash blower 202.

[0074] In this embodiment, the first input terminal 41 is connected to the calcium-based absorbent supply device through the calcium-based absorbent supply pipeline assembly 600. The calcium-based absorbent supply pipeline assembly 600 includes a calcium-based absorbent supply pipe 601 and a calcium-based absorbent feed valve 602.

[0075] Based on the above carbon dioxide capture system, the working principle / process of the system is as follows:

[0076] See Figures 2 to 4 For ease of description, "solid line pipeline" in the diagram represents the operating state, and "dashed line pipeline" represents the shutdown state.

[0077] (I) Initial Stage

[0078] All valves in the system (collecting gas valve 104, circulating gas valve 402, slag discharge valve 502, raw flue gas valve 22, carbon dioxide collection control valve 322, clean flue gas valve 324, calcium-based absorbent feed valve 602) are in the closed state.

[0079] (II) Start-up Phase

[0080] See Figure 2 The dust collector 31 and the external heat source conveying device connected to the heat input terminal 15 are turned on to heat the reactor 1. When the reactor 1 reaches a certain temperature, the compressor 102, the return ash fan 202, the raw flue gas valve 22, the collecting gas valve 104, and the clean flue gas valve 324 are turned on to ensure the balanced flow of gas in the system. At this time, the gas output pipeline assembly 100 and the return ash pipeline assembly 200 are in the conducting state.

[0081] See Figure 3 When the output gas pressure of the compressor 102 reaches the preset pressure, the circulating gas valve 402 is opened, which in turn delivers gas at the preset pressure to the ejector 4, so that the gas with the preset pressure delivers the calcium-based absorbent delivered to the ejector 4 to the high-temperature heat exchanger 5 for heat exchange. The preheated gas and calcium-based absorbent are then delivered to the reactor 1.

[0082] (III) Reactor 1 is in the carbonation reaction stage

[0083] See Figure 3The reactor 1 is heated and maintained at a first preset temperature (generally around 650°C). The flue gas introduced into the reactor 1 through the flue gas inlet 2 reacts with the calcium-based absorbent to undergo a carbonation reaction. The unreacted flue gas is pressurized by the compressor 102 of the gas output pipeline assembly 100, and a portion is sent to the ejector 4, which continues to transport the calcium-based absorbent to the high-temperature heat exchanger 5 for heat exchange. The preheated gas and calcium-based absorbent are then sent back to the reactor 1. The other portion is sent to the dust collector 31 for dust removal and then to the gas recovery and treatment assembly 32, and discharged through the clean flue gas discharge pipe 323 of the gas recovery and treatment assembly 32 (the clean flue gas valve 324 is open, and the carbon dioxide collection control valve 322 is closed). At the same time, the return ash output from the dust collector 31 is transported to the reactor 1 through the return ash pipeline assembly as raw material for the calcination or carbonation reaction in the reactor 1.

[0084] (iv) Operation of reactor 1 from the carbonation reaction stage to the calcination reaction stage

[0085] In one example, after the carbonation reaction continues for a preset reaction time (which can be set according to actual conditions, such as the required content of high-purity carbon dioxide to be collected), the supply of raw flue gas to reactor 1 is stopped (specifically, the raw flue gas valve 22 is closed), and the carbon dioxide concentration of the discharged clean flue gas is analyzed in real time by the clean flue gas analyzer 325 to determine whether the carbon dioxide concentration of the gas output (clean flue gas) of the gas recovery unit 3 is not greater than the standard switching concentration. If so, reactor 1 is switched to the calcination reaction state stage; otherwise, the carbon dioxide absorption state is maintained.

[0086] In another example, after the carbonation reaction has continued for a preset reaction time, the supply of calcium-based absorbent to reactor 1 can be stopped (specifically, the calcium-based absorbent feed valve 602 can be used), and the state can be switched directly. Alternatively, after the carbonation reaction has continued for a preset reaction time, the supply of calcium-based absorbent and flue gas to reactor 1 can be stopped directly (specifically, the original flue gas valve 22 and the calcium-based absorbent feed valve 602 can be closed simultaneously).

[0087] (V) Reactor 1 is in the calcination reaction stage

[0088] See Figure 4 The reactor 1 is heated and maintained at a second preset temperature (generally around 950℃). The products of the carbonation reaction in the reactor 1 are calcined to generate carbon dioxide. At the same time, the original flue gas valve 22, the circulating gas valve 402, and the calcium-based absorbent feed valve 602 are closed.

[0089] During the calcination reaction, the carbon dioxide concentration of the discharged flue gas is analyzed in real time by the flue gas analyzer 325. When the carbon dioxide concentration in the flue gas reaches the preset collection concentration, the flue gas valve 324 is closed and the carbon dioxide collection control valve 322 is opened to collect the high concentration of carbon dioxide. At the same time, the return ash output from the dust collector 31 is transported to the reactor 1 through the return ash pipeline assembly as raw material for the calcination or carbonation reaction in the reactor 1.

[0090] In addition, it is worth noting that when the calculated carbon dioxide removal efficiency is lower than the set value of the removal efficiency of the calcium-based absorbent, the slag discharge valve 502 can be opened to replace the calcium-based absorbent, which is not shown in the figure.

[0091] Furthermore, it is worth noting that when reactor 1 is in the carbonation reaction stage, dust collector 31 can maintain the environmental emission requirements of the discharged clean flue gas, while the return ash collected by dust collector 31 is heat-exchanged through low-temperature heat exchanger 6 to form high-temperature return ash, which then enters reactor 1 to participate in the carbonation reaction. Correspondingly, when reactor 1 is in the calcination reaction stage, the high-temperature return ash formed by dust collector 31 enters reactor 1 to participate in the calcination reaction.

[0092] Based on the above-described carbon dioxide capture system, this embodiment also provides a carbon dioxide capture method, which specifically includes the following steps:

[0093] System startup preparation includes feeding raw flue gas into reactor 1;

[0094] The gas output from reactor 1 is pressurized to a preset pressure and delivered to ejector 4 to deliver the calcium-based absorbent delivered to ejector 4 back to reactor 1;

[0095] The return ash output from the gas recovery unit 3 is transported to the reactor 1;

[0096] Control reactor 1 to be in a carbonation reaction state;

[0097] The operating state of reactor 1 is switched from carbonation reaction state to calcination reaction state. When the carbon dioxide concentration in the clean flue gas discharged from the gas recovery unit 3 after calcination reaches the preset collection concentration, the gas output from reactor 1 is collected.

[0098] Specifically, the system startup preparation steps include:

[0099] When reactor 1 is heated to the preset temperature, the raw flue gas valve 22, the collected gas valve 104, and the clean flue gas valve 324 are opened to allow the flue gas in the entire system to flow in a balanced manner for a preset time.

[0100] When the output gas pressure of compressor 102 reaches the preset pressure, the recirculating gas valve 402 is opened.

[0101] Specifically, controlling the operation of reactor 1 from the carbonation reaction state to the calcination reaction state includes the following steps:

[0102] After the carbonation reaction has continued for a preset reaction time, the supply of raw flue gas to reactor 1 is stopped;

[0103] If the concentration of carbon dioxide in the output gas of the gas recovery unit 3 is not greater than the standard switching concentration, the state is switched if it is, otherwise the carbon dioxide absorption state is maintained.

[0104] It is understood that this scheme allows the flue gas fed into reactor 1 to react as completely as possible, thereby reducing the carbon dioxide concentration of the gas output from gas recovery unit 3 and reducing carbon emissions to a certain extent. Of course, in other embodiments, the feeding of calcium-based absorbent into reactor 1 can be stopped directly after the carbonation reaction has continued for a preset reaction time, and the state can be switched directly to reduce the loss of calcium-based absorbent. Alternatively, the feeding of both calcium-based absorbent and flue gas into reactor 1 can be stopped directly after the carbonation reaction has continued for a preset reaction time.

[0105] Furthermore, the method also includes the following steps: using a high-temperature heat exchanger 5 to exchange heat between the calcium-based absorbent and the gas output from the reactor 1; and using a low-temperature heat exchanger 6 to exchange heat between the return ash output from the dust collector 31 and the gas output from the compressor 102.

[0106] Furthermore, the method also includes the following steps:

[0107] The carbon dioxide removal efficiency is calculated based on the carbon dioxide concentration in the original flue gas and the carbon dioxide concentration in the clean flue gas discharged from the gas recovery unit 3.

[0108] Determine if the carbon dioxide removal efficiency is lower than the set removal efficiency value. If so, replace the calcium-based absorbent in the reactor.

[0109] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A carbon dioxide search and capture system, characterized in that, include: The reactor (1) has a flue gas inlet (11), a gaseous material outlet (12), a return ash inlet (13), a calcium-based absorbent inlet (14), a heat inlet (15) for connection to an external heat source conveying device, and a thermometer mounting end (16) for inserting a thermometer; the temperature inside the reactor (1) is adjustable so that a carbonation reaction or a calcination reaction can occur inside the reactor (1); The flue gas inlet (2) is connected to the flue gas inlet (11); The gas recovery unit (3) includes a dust collector (31) and a gas recovery processing assembly (32); the gas output end of the dust collector (31) is connected to the gas recovery processing assembly (32), the gas input end of the dust collector (31) is connected to the gaseous output end (12) through a gas output pipeline assembly (100), and the return ash output end of the dust collector (31) is connected to the return ash input end (13) through a return ash pipeline assembly (200); The ejector (4) has an output end (40), a first input end (41), and a second input end (42); the output end (40) is connected to the calcium-based absorbent input end (14) through a calcium-based absorbent delivery pipeline assembly (300); the first input end (41) is used to connect to a calcium-based absorbent supply device, and the second input end (42) is connected to the gaseous output end (12) through a diversion pipeline assembly (400) and the gas output pipeline assembly (100), and delivers gaseous material with a preset pressure output from the reactor (1) to the ejector (4).

2. The carbon dioxide search and capture system according to claim 1, characterized in that, The gas output pipeline assembly (100) includes a first pipe (101), a compressor (102), a second pipe (103), and a gas collection valve (104). The gas output terminal (12), the first pipe (101), the compressor (102), the second pipe (103) and the gas input terminal of the dust collector (31) are connected in sequence, and the gas collection valve (104) is set on the second pipe (103); The diversion pipeline assembly (400) includes a diversion pipe (401) and a recirculation valve (402) disposed on the diversion pipe (401). One end of the diversion pipe (401) is connected to the output end of the compressor (102), and the other end is connected to the second input end (42).

3. The carbon dioxide search and capture system according to claim 2, characterized in that, It also includes a high-temperature heat exchanger (5), which is located upstream of the compressor (102); And / or, It also includes a low-temperature heat exchanger (6), which is located upstream of the dust collector (31) and downstream of the circulating gas valve (402).

4. A carbon dioxide detection system according to any one of claims 1 to 3, characterized in that, Also includes: The high-temperature heat exchanger (5) has a first high-temperature heat exchange channel (51) and a second high-temperature heat exchange channel (52). The first high-temperature heat exchange channel (51) is connected to the pipe section of the gas output pipeline assembly (100) near the gas output end (12). The second high-temperature heat exchange channel (52) is connected to the calcium-based absorbent delivery pipeline assembly (300). And / or, The low-temperature heat exchanger (6) has a first low-temperature heat exchange channel (61) and a second low-temperature heat exchange channel (62). The first low-temperature heat exchange channel (61) is connected to the pipe section of the gas output pipeline assembly (100) away from the gas output end (12). The second low-temperature heat exchange channel (62) is connected to the return ash pipeline assembly (200).

5. A carbon dioxide search and capture system according to claim 1, characterized in that, The flue gas inlet (2) includes a raw flue gas pipe (21), a raw flue gas valve (22), and a raw flue gas analyzer (23). The original flue gas pipe (21) is connected to the flue gas input end (11), and the original flue gas valve (22) and the original flue gas analyzer (23) are both installed on the original flue gas pipe (21); The gas recovery and processing assembly (32) includes a carbon dioxide collection pipe (321), a carbon dioxide collection control valve (322), a clean flue gas discharge pipe (323), a clean flue gas valve (324), and a clean flue gas analyzer (325). The carbon dioxide collection control valve (322) is installed on the carbon dioxide collection pipe (321), and the clean flue gas valve (324) is installed on the clean flue gas discharge pipe (323); The clean flue gas analyzer (325) is installed upstream of the carbon dioxide collection control valve (322) and the clean flue gas valve (324).

6. A carbon dioxide detection method based on the carbon dioxide detection system according to any one of claims 1 to 5, characterized in that, Includes the following steps: System startup preparation includes feeding raw flue gas into the reactor (1); The gas output from the reactor (1) is pressurized to a preset pressure and delivered to the ejector (4) to deliver the calcium-based absorbent delivered to the ejector (4) back to the reactor (1). The return ash output from the gas recovery unit (3) is transported to the reactor (1); Control the reactor (1) to be in a carbonation reaction state; The operating state of the control reactor (1) is switched from the carbonation reaction state to the calcination reaction state. When the carbon dioxide concentration in the clean flue gas discharged from the gas recovery unit (3) after calcination reaches the preset collection concentration, the gas output from the reactor (1) is collected.

7. The carbon dioxide capture method according to claim 6, characterized in that, It also includes the following steps: using a high-temperature heat exchanger (5) to exchange heat between the calcium-based absorbent and the gas output from the reactor (1); and / or using a low-temperature heat exchanger (6) to exchange heat between the return ash output from the dust collector (31) and the gas output from the compressor (102).

8. The carbon dioxide capture method according to claim 6, characterized in that, The system startup preparation steps include: When the reactor (1) is heated to the preset temperature, the original flue gas valve (22), the collected gas valve (104), and the clean flue gas valve (324) are opened to allow the flue gas in the whole system to flow in a balanced manner for a preset time. When the output gas pressure of the compressor (102) reaches the preset pressure, the circulating gas valve (402) is opened.

9. The carbon dioxide capture method according to claim 6, characterized in that, The control reactor (1) is switched from the carbonation reaction state to the calcination reaction state, specifically including the following steps: After the carbonation reaction has continued for a preset reaction time, the original flue gas is stopped from being supplied to the reactor (1). It is determined whether the carbon dioxide concentration of the gas output by the gas recovery unit (3) is not greater than the standard switching concentration. If yes, the state is switched; if no, the carbon dioxide absorption state is maintained. or, After the carbonation reaction has continued for a preset reaction time, the supply of calcium-based absorbent to the reactor (1) is stopped, and the state is switched directly.

10. The carbon dioxide capture method according to claim 6, characterized in that, It also includes the following steps: The carbon dioxide removal efficiency is calculated based on the carbon dioxide concentration in the original flue gas and the carbon dioxide concentration in the clean flue gas discharged from the gas recovery unit (3). Determine if the carbon dioxide removal efficiency is lower than the set removal efficiency value. If so, replace the calcium-based absorbent in the reactor.

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