System for capturing carbon dioxide in post-flue gas

Abstract

The utility model relates to the technical field of flue gas treatment after a desulfurizing tower, in particular to a system for capturing carbon dioxide in post flue gas, which comprises an absorption tower, the rear flue gas conveying mechanism is arranged between the desulfurization tower and the absorption tower; the alkali liquor conveying mechanism is used for conveying an alkali solution into the absorption tower to form an absorption solution; the absorption liquid spraying mechanism is used for absorbing the absorption liquid, spraying the absorption liquid out of the absorption tower and making contact with the rear flue gas to form rich liquid; the pH detection unit is arranged in the absorption tower; an acid liquor conveying mechanism; a reaction tank; the calcium hydroxide conveying mechanism is used for conveying a calcium hydroxide solution into the reaction tank; the rich solution conveying mechanism is used for conveying the rich solution in the absorption tower to the reaction tank and reacting the rich solution with the calcium hydroxide solution to obtain a reaction tank product; the centrifugal machine is used for separating reaction tank products. According to the invention, acidic wastewater and alkaline wastewater generated after a resin regeneration process can be recycled in a boiler water supply system, and meanwhile, carbon dioxide in post-flue gas can be captured and utilized.

Description

TECHNICAL FIELD

[0001] The utility model relates to a desulfurizing tower rear flue gas treatment technical field, specifically, a carbon dioxide capture system in rear flue gas. BACKGROUND

[0002] In the boiler makeup water system of the thermal power plant, ion exchange resin is widely used to remove ion impurities in water and ensure water supply quality. After the resin is used for a period of time, the active groups inside the resin will gradually combine with cations or anions in water, causing the exchange capacity to decrease. In order to restore the exchange capacity of the resin, it needs to be regenerated regularly, that is, the resin needs to be subjected to a resin regeneration process. In the regeneration process, hydrochloric acid and sodium hydroxide solution are usually used as regenerants to remove cations and anions on the resin respectively. However, after the acid and the base react with the resin, a large amount of wastewater containing high concentrations of salt and unreacted acid and base components is produced. Direct discharge of such wastewater not only pollutes the environment, but also changes the pH value of the receiving water body, thereby affecting the living environment of aquatic organisms.

[0003] In order to solve this problem, the thermal power plant usually uses neutralization method to treat wastewater. By adjusting the acidity and alkalinity of the wastewater, it is neutralized and then reused in the plant. Although this method can reduce environmental pollution, it does not fully utilize the resources in the wastewater, and the water quality after treatment may still not meet the requirements of certain specific applications.

[0004] On the other hand, a large amount of flue gas (i.e. rear flue gas) is generated during the desulfurization process in the thermal power plant, of which the volume fraction of carbon dioxide is about 10% to 15%. Carbon dioxide, as a rich resource, is rarely used to produce high-value-added products. If effective carbon dioxide capture technology can be developed and converted into valuable chemicals or other products, it will help to improve the economic benefits of the thermal power plant, reduce greenhouse gas emissions, and achieve the goal of environmentally friendly and sustainable development. At present, although some research has focused on the resource utilization of carbon dioxide, mature technology and solutions are still lacking in actual industrial applications. UTILITY MODEL CONTENTS

[0005] The purpose of the utility model is to provide a carbon dioxide capture system in rear flue gas, which can regenerate and utilize the acidic wastewater and alkaline wastewater generated after the resin regeneration process in the boiler makeup water system, and simultaneously realize the capture and utilization of carbon dioxide in the rear flue gas.

[0006] The technical solution of the utility model is as follows:

[0007] A carbon dioxide capture system in rear flue gas is used to treat the rear flue gas generated by a desulfurizing tower, which comprises:

[0008] absorption tower;

[0009] a post flue gas conveying mechanism arranged between the desulfurization tower and the absorption tower, for conveying the post flue gas generated by the desulfurization tower into the absorption tower;

[0010] a lye conveying mechanism, for conveying lye into the absorption tower, the lye conveyed into the absorption tower forming absorption liquid;

[0011] an absorption liquid spraying mechanism, for absorbing absorption liquid and spraying the absorption liquid in the absorption tower, and the sprayed absorption liquid contacting the post flue gas to form rich liquid;

[0012] a pH detection unit arranged in the absorption tower, for detecting the pH of the absorption liquid or the rich liquid in the absorption tower in real time;

[0013] an acid liquid conveying mechanism, for conveying acid liquid into the absorption tower to adjust the pH of the rich liquid;

[0014] a reaction tank;

[0015] a calcium hydroxide conveying mechanism, for conveying calcium hydroxide solution into the reaction tank;

[0016] a rich liquid conveying mechanism, for conveying the rich liquid in the absorption tower into the reaction tank, the rich liquid in the reaction tank reacting with the calcium hydroxide solution to obtain reaction tank product;

[0017] a centrifuge, for separating the reaction tank product.

[0018] Further, the lye conveying mechanism comprises a lye pool, a lye conveying pipe and a lye conveying pump, the lye conveying pipe is provided with a first electric valve, the alkaline wastewater generated after the resin regeneration process is introduced into the lye pool through the lye conveying pipe, and the input end and the output end of the lye conveying pump are respectively connected to the lye pool and the absorption tower through pipelines.

[0019] Further, the acid liquid conveying mechanism comprises an acid liquid pool, an acid liquid conveying pipe and an acid liquid conveying pump, the acid liquid conveying pipe is provided with a second electric valve, the acidic wastewater generated after the resin regeneration process is introduced into the acid liquid pool through the acid liquid conveying pipe, and the input end and the output end of the acid liquid conveying pump are respectively connected to the acid liquid pool and the absorption tower through pipelines.

[0020] Further, the post flue gas conveying mechanism comprises a post flue gas conveying pipe and a booster fan, the booster fan is arranged in the post flue gas conveying pipe, and the post flue gas generated by the desulfurization tower is introduced into the absorption tower through the post flue gas conveying pipe.

[0021] Further, the absorption liquid spraying mechanism comprises an absorption liquid circulating pump, a liquid suction pipe, a liquid spraying pipe and a nozzle.

[0022] The input end of the absorption liquid circulating pump is connected to the absorption liquid in the bottom of the absorption tower through the liquid suction pipe, and the output end of the absorption liquid circulating pump is connected to the upper part of the absorption tower through the liquid injection pipe, and the end of the liquid injection pipe is provided with the nozzle.

[0023] Further, the part of the liquid injection pipe in the absorption tower is a liquid injection section, a plurality of nozzles are arranged on the liquid injection pipe, and the spraying direction of the nozzles is downward;

[0024] The end of the rear flue gas conveying mechanism is connected to the nozzle.

[0025] A demister is arranged in the absorption tower above the nozzle, and an outlet end of the absorption tower is provided with a chimney.

[0026] Further, the calcium hydroxide conveying mechanism comprises a calcium hydroxide container and a calcium hydroxide conveying pump, and the input end and the output end of the calcium hydroxide conveying pump are respectively connected to the calcium hydroxide container and the reaction pool through pipelines.

[0027] Further, the rich liquid conveying mechanism comprises a rich liquid conveying pump, and the input end and the output end of the rich liquid conveying pump are respectively connected to the bottom of the absorption tower and the reaction pool through pipelines.

[0028] Further, a feed pump is arranged between the reaction pool and the centrifugal machine, and the input end and the output end of the feed pump are respectively connected to the reaction pool and the centrifugal machine through pipelines.

[0029] Further, the centrifugal machine has a lye outlet and a solid outlet, the lye outlet is connected to a recovery container, and a recovery pump is arranged between the recovery container and the lye conveying mechanism, and the recovery pump is used to convey the lye in the recovery container to the lye conveying mechanism.

[0030] Compared with the prior art, the beneficial effects of the present application are:

[0031] In the boiler make-up water system, ion exchange resins in the ion exchange system are widely used to remove ionic impurities in water, and acidic wastewater and alkaline wastewater are generated after the resin regeneration process.

[0032] The application provides a system for capturing carbon dioxide in post flue gas, wherein the post flue gas generated by a desulfurization tower is introduced into an absorption tower through a post flue gas suction mechanism, the alkaline wastewater generated after a resin regeneration process can be transported into the absorption tower through an alkali delivery mechanism to form an absorption liquid, and the absorption liquid is sprayed in the absorption tower through an absorption liquid spraying mechanism to contact with the post flue gas to form a rich liquid, and then the carbon dioxide in the post flue gas is absorbed, and the pH of the rich liquid is monitored in real time through a pH detection unit; when the pH of the rich liquid is high, the acidic wastewater generated after the resin regeneration process is transported through an acid liquid delivery mechanism, and the acidic wastewater is transported into the absorption tower to adjust the pH of the rich liquid, so that the pH of the rich liquid ranges between 10 and 11. The rich liquid for absorbing carbon dioxide is transported into a reaction tank through a rich liquid delivery mechanism, reacts with the calcium hydroxide solution transported by a calcium hydroxide delivery mechanism to generate calcium carbonate and sodium hydroxide, and the product of the reaction tank can be transported into a centrifuge for centrifugal treatment to realize solid-liquid separation, the solid product calcium carbonate can be reused as a desulfurizer in a desulfurization system (a desulfurization tower), and the liquid product (mainly sodium hydroxide) can be reused in an alkali delivery mechanism to continue the recycling. Through the system for capturing carbon dioxide in post flue gas, the acidic wastewater and the alkaline wastewater generated after the resin regeneration process can be regenerated and utilized, the carbon dioxide in the post flue gas can be captured and utilized simultaneously by using the acidic wastewater and the alkaline wastewater, high-value-added products can be obtained, and better economic benefits can be brought to a thermal power plant. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0034] Figure 1 The figure is a whole flow chart of the system for capturing carbon dioxide in post flue gas.

[0035] In the figure:

[0036] 11-first electric valve; 12-alkali pool; 13-alkali delivery pump; 14-second electric valve; 15-acid pool; 16-acid delivery pump; 17-desulfurization tower; 18-boosting fan; 19-absorption tower; 191-nozzle; 192-mist eliminator; 110-pH meter; 111-absorption liquid circulating pump;

[0037] 21-rich liquid delivery pump; 22-calcium hydroxide delivery pump; 23-reaction tank;

[0038] 31-feed pump; 32-centrifuge; 33-recovery container; 34-recovery pump;

[0039] 4 - chimney. DETAILED DESCRIPTION

[0040] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0042] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0043] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0044] In addition, the terms "horizontal", "vertical", "overhang" and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0045] In the description of the utility model, still need explaining, unless another explicit provision and limitation, term "arrangement", "installation", "link", "connection" should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected;Can be mechanical connection, also can be electrical connection;Can be directly connected, also can pass through the indirect connection of intermediate medium, can be two elements inside the intercommunication of. For ordinary skilled person in the art, the above-mentioned terms can be understood in the specific meaning in the utility model according to specific circumstances.

[0046] The utility model will be described in detail below in combination with some embodiments of the drawings.In the case of no conflict, the following examples and features in examples can be combined with each other.

[0047] Example 1

[0048] Reference Figure 1 The embodiment provides a carbon dioxide capture system in rear flue gas, applied to handle the rear flue gas generated by desulfurizing tower 17 or desulfurizing system, it includes:

[0049] Absorber 19, absorber 19 is the equipment for realizing absorption operation;

[0050] Rear flue gas conveying mechanism, is arranged between desulfurizing tower 17 and absorber 19, for the rear flue gas generated by desulfurizing tower 17 is sucked to absorber 19;

[0051] Lye conveying mechanism, for conveying alkaline solution to absorber 19, the alkaline solution conveyed to absorber 19 forms absorption liquid;

[0052] Absorption liquid spraying mechanism, for sucking absorption liquid and spraying in absorber 19, and the absorption liquid sprayed and the rear flue gas contact and form rich liquid;

[0053] pH detection unit, is arranged in absorber 19, for real-time detection of the pH of absorption liquid or rich liquid in absorber 19;

[0054] Acid liquid conveying mechanism, for conveying acidic solution to absorber 19 to adjust the pH of rich liquid;

[0055] Reaction pool 23, reaction pool 23 as chemical reaction place;

[0056] Calcium hydroxide conveying mechanism, for conveying calcium hydroxide solution to reaction pool 23;

[0057] Rich liquid conveying mechanism, for conveying the rich liquid in absorber 19 to reaction pool 23, and the rich liquid in reaction pool 23 reacts with calcium hydroxide solution and obtains reaction pool product;

[0058] Centrifuge 32, for separating reaction pool product.

[0059] It should be noted that "post flue gas" refers to flue gas discharged from industrial equipment (such as boilers, desulfurization towers 17, etc.). Specifically, in a thermal power plant, the post flue gas is usually flue gas treated by purification devices such as desulfurization towers 17. The harmful substances (such as sulfur dioxide, particulate matter, etc.) in such flue gas have been removed to varying degrees, but may still contain other components that have not been completely removed, such as carbon dioxide, which accounts for about 10% to 15% by volume. Through the post flue gas carbon dioxide capture system of the present application, carbon dioxide in the post flue gas is captured and converted into valuable products such as calcium carbonate and sodium hydroxide, thereby achieving resource utilization and environmental benefits.

[0060] "Rich liquid" refers to the liquid after absorbing carbon dioxide after being sprayed by the absorption liquid in the absorption tower 19. Specifically, the rich liquid refers to the liquid containing a high concentration of carbonate flowing out of the absorption tower 19. This liquid contains a large amount of carbon dioxide, which can be further processed through subsequent chemical reactions to generate valuable products such as calcium carbonate and sodium hydroxide. Specifically:

[0061] 1. Formation of rich liquid:

[0062] In the absorption tower 19, alkaline wastewater (pH value range 11-13) is sprayed and contacted with flue gas in counterflow, absorbing carbon dioxide in the flue gas.

[0063] Through this process, the original alkaline wastewater becomes a rich liquid containing a high concentration of carbonate.

[0064] 2. Treatment of rich liquid:

[0065] The rich liquid is transported to the reaction tank 23 by the rich liquid transport mechanism, and in the reaction tank 23, the rich liquid reacts with calcium hydroxide solution to generate calcium carbonate and sodium hydroxide. Calcium carbonate can be reused as a desulfurizer in the desulfurization system, and sodium hydroxide is reused in the alkali tank 12.

[0066] In short, "rich liquid" refers to the liquid after absorbing carbon dioxide in the absorption tower 19, which contains a high concentration of carbonate and is an important raw material for subsequent chemical reactions. Through further processing, the components in the rich liquid can be converted into useful products.

[0067] The specific structure is described below:

[0068] The post flue gas transport mechanism includes a post flue gas transport pipe and a booster fan 18. The booster fan 18 is arranged in the post flue gas transport pipe, and the two ends of the flue gas transport pipe are connected to the desulfurization tower 17 and the absorption tower 19, respectively. Under the suction action of the booster fan 18, the post flue gas generated by the desulfurization tower 17 is transported into the absorption tower 19 through the post flue gas transport pipe.

[0069] In the boiler make-up water system, specifically in the ion exchange system, the regeneration ability of ion exchange resin is restored through resin regeneration process. After the resin regeneration process, alkaline wastewater (pH value range of 11-13) and acidic wastewater (pH value range of 1-3) are generated.

[0070] The alkali solution conveying mechanism includes an alkali solution pool 12, an alkali solution conveying pipe, and an alkali solution conveying pump 13. The alkali solution conveying pipe is provided with a first electric valve 11.

[0071] The alkaline wastewater generated after the resin regeneration process is introduced into the alkali solution pool 12 through the alkali solution conveying pipe. The alkali solution pool 12 collects and contains the alkaline wastewater. The input end and the output end of the alkali solution conveying pipe are connected to the alkali solution pool 12 and the absorption tower 19 through pipelines, respectively. By opening the first electric valve 11 and then running the alkali solution conveying pump 13, the alkaline wastewater contained in the alkali solution pool 12 can be conveyed into the absorption tower 19 to form absorption liquid.

[0072] The absorption liquid spraying mechanism includes an absorption liquid circulating pump 111, a liquid suction pipe, a liquid spraying pipe, and a nozzle 191.

[0073] The input end of the absorption liquid circulating pump 111 is connected to the absorption liquid at the bottom of the absorption tower 19 through the liquid suction pipe. The output end of the absorption liquid circulating pump 111 is connected to the upper part of the absorption tower 19 through the liquid spraying pipe. The end of the liquid spraying pipe is provided with the nozzle 191.

[0074] In this embodiment, the part of the liquid spraying pipe located in the absorption tower 19 is a liquid spraying section. A plurality of nozzles 191 are arranged on the liquid spraying pipe, and the spraying direction of the nozzles 191 is downward. The end of the flue gas conveying mechanism is located below the nozzles 191. The downwardly sprayed absorption liquid contacts the flue gas entering the absorption tower 19 in countercurrent, and the absorption liquid absorbs carbon dioxide in the flue gas to form rich liquid falling into the bottom of the absorption tower 19.

[0075] A demister 192 is arranged in the absorption tower 19 above the nozzles 191. An outlet end of the absorption tower 19 is provided with a chimney 4. The demister 192 mainly removes liquid droplets and fine particulate matters in the flue gas in the absorption tower 19. The chimney 4 has the following functions:

[0076] 1. Discharging treated flue gas: The chimney 4 is the final outlet for flue gas discharge, ensuring that the treated flue gas can be smoothly discharged into the atmosphere.

[0077] 2. System pressure balance: The chimney 4 helps maintain the pressure balance inside the system, ensuring smooth flue gas discharge.

[0078] 3. Auxiliary ventilation and diffusion: The height and design of the chimney 4 help the flue gas diffuse better, improving the discharge efficiency.

[0079] A pH detection unit, which can be a pH meter 110, is used to monitor the pH of the absorption liquid or rich liquid in real time. When the pH of the rich liquid is too high, the acidic wastewater generated after the resin regeneration process can be introduced into the absorption tower 19 through an acidic wastewater delivery mechanism to reduce the pH of the rich liquid to an appropriate level.

[0080] The acidic wastewater delivery mechanism includes an acidic wastewater pool 15, an acidic wastewater delivery pipe, and an acidic wastewater delivery pump 16. The acidic wastewater delivery pipe is provided with a second electric valve 14. The acidic wastewater generated after the resin regeneration process is introduced into the acidic wastewater pool 15 through the acidic wastewater delivery pipe. The input and output ends of the acidic wastewater delivery pump 16 are connected to the acidic wastewater pool 15 and the absorption tower 19, respectively, through pipes. The acidic wastewater delivery pump 16 is used to deliver the acidic wastewater to the absorption tower 19 to adjust the pH of the rich liquid to 10-11.

[0081] The rich liquid delivery mechanism includes a rich liquid delivery pump 21. The input and output ends of the rich liquid delivery pump 21 are connected to the bottom of the absorption tower 19 and the reaction pool 23, respectively, through pipes. The calcium hydroxide delivery mechanism includes a calcium hydroxide container and a calcium hydroxide delivery pump 22. The input and output ends of the calcium hydroxide delivery pump 22 are connected to the calcium hydroxide container and the reaction pool 23, respectively, through pipes. The rich liquid that has absorbed carbon dioxide is delivered to the reaction pool 23 by the rich liquid delivery pump 21 and reacts with the calcium hydroxide solution delivered by the calcium hydroxide delivery pump 22 to generate calcium carbonate and sodium hydroxide (i.e., the reaction pool product).

[0082] A feed pump 31 is arranged between the reaction pool 23 and the centrifuge 32. The input and output ends of the feed pump 31 are connected to the reaction pool 23 and the centrifuge 32, respectively, through pipes. The centrifuge 32 has a lye outlet and a solid outlet. The lye outlet leads to a recovery container 33. A recovery pump 34 is arranged between the recovery container 33 and the lye delivery mechanism. The recovery pump 34 is used to deliver the lye in the recovery container 33 to the lye delivery mechanism. The reaction pool product is delivered to the centrifuge 32 by the feed pump 31 for centrifugal treatment, achieving solid-liquid separation. The solid product, calcium carbonate, is reused as a desulfurizing agent in the desulfurization system (desulfurization tower 17). The liquid product (mainly sodium hydroxide) is reused in the lye pool 12 for continuous recycling.

[0083] The control system is also included. All electronic components in the post-flue gas carbon dioxide capture system are electrically connected to the control system, such as all electric valves, all pumps, a booster fan, the centrifuge 32, a demister 192, etc. The control system is a conventional technology and will not be described here.

[0084] In summary, the specific process for recycling the post-flue gas using the acidic wastewater and the alkaline wastewater generated after the resin regeneration process of the boiler feedwater system is as follows:

[0085] The basic waste water of the ion exchange system is stored in the lye tank 12, the acidic waste water is stored in the acid tank 15, the tail flue gas generated by the desulfurization tower 17 is introduced into the absorption tower 19 through the booster fan 18, the basic waste water of the lye tank 12 is transported into the absorption tower 19 through the lye delivery pump 13 and is circulated and sprayed in the absorption tower 19 through the absorption liquid circulating pump 111, is sprayed through the nozzle 191, is contacted with the flue gas in countercurrent, the carbon dioxide in the flue gas is absorbed, the rich liquid pH is monitored in real time through the pH meter 110, the acidic waste water is transported into the absorption tower 19 through the acid delivery pump 16 to adjust the rich liquid pH value to 10-11. The rich liquid for absorbing carbon dioxide is transported into the reaction tank 23 through the rich liquid delivery pump 21, reacts with the calcium hydroxide solution transported by the calcium hydroxide delivery pump 22 to generate calcium carbonate and sodium hydroxide, the reaction tank product is transported into the centrifuge 32 through the feed pump 31 to realize solid-liquid separation, the solid product calcium carbonate is reused as a desulfurizing agent to the desulfurization system, and the liquid product (main component sodium hydroxide) is reused to the lye tank 12 to continue cyclic utilization.

[0086] Embodiment 2

[0087] The embodiment provides a carbon dioxide capturing system in tail flue gas, which is different from the technical scheme of the embodiment 1, in that, in the embodiment, sodium hydroxide solution can be used instead of basic waste water, and hydrochloric acid solution can be used instead of acidic waste water.

[0088] The beneficial effects of the technical scheme of the utility model are:

[0089] Compared with the prior art, the carbon dioxide capturing system in tail flue gas can fully utilize the acidic waste water and the basic waste water generated after the resin regeneration process, realizes resource utilization of the acidic and basic waste water, simultaneously realizes carbon dioxide capturing and utilization in flue gas, and can obtain a product with high added value, so that better economic benefits can be brought to the thermal power plant.

[0090] Finally, it should be noted that: the above embodiments are only used to illustrate the technical scheme of the utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical scheme recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical scheme deviate from the scope of the technical scheme of the embodiments of the utility model.

[0091] The above only describes the preferred embodiments of the utility model, and is not used to limit the utility model, and for those skilled in the art, the utility model can have various changes and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A system for capturing carbon dioxide in a post flue gas, for treating a post flue gas produced by a desulphurization tower (17), characterized in that, The application relates to a desulfurization system, which comprises the following components: an absorption tower (19); a rear flue gas conveying mechanism arranged between a desulfurization tower (17) and the absorption tower (19) and used for sucking the rear flue gas generated by the desulfurization tower (17) into the absorption tower (19); a lye conveying mechanism used for conveying a lye solution into the absorption tower (19), wherein the lye solution conveyed into the absorption tower (19) forms an absorption liquid; an absorption liquid spraying mechanism used for sucking the absorption liquid and spraying the absorption liquid in the absorption tower (19), and the sprayed absorption liquid contacts with the rear flue gas to form a rich liquid; a pH detection unit arranged in the absorption tower (19) and used for detecting the pH of the absorption liquid or the rich liquid in the absorption tower (19) in real time; an acid solution conveying mechanism used for conveying an acid solution into the absorption tower (19) to adjust the pH of the rich liquid; a reaction tank (23); a calcium hydroxide conveying mechanism used for conveying a calcium hydroxide solution into the reaction tank (23); a rich liquid conveying mechanism used for conveying the rich liquid in the absorption tower (19) into the reaction tank (23), wherein the rich liquid in the reaction tank (23) reacts with the calcium hydroxide solution to obtain a reaction tank product; a centrifuge (32) used for separating the reaction tank product.

2. The post- flue gas carbon dioxide capture system of claim 1, wherein, The lye conveying mechanism comprises a lye pool (12), a lye conveying pipe and a lye conveying pump (13), the lye conveying pipe is provided with a first electric valve (11), the lye conveying pipe is used for conveying the alkaline wastewater generated after a resin regeneration process into the lye pool (12), and the input end and the output end of the lye conveying pump (13) are connected to the lye pool (12) and the absorption tower (19) through pipelines respectively.

3. The post- flue gas carbon dioxide capture system of claim 1, wherein, The acid solution conveying mechanism comprises an acid solution pool (15), an acid solution conveying pipe and an acid solution conveying pump (16), the acid solution conveying pipe is provided with a second electric valve (14), the acid solution conveying pipe is used for conveying the acidic wastewater generated after the resin regeneration process into the acid solution pool (15), and the input end and the output end of the acid solution conveying pump (16) are connected to the acid solution pool (15) and the absorption tower (19) through pipelines respectively.

4. The post- flue gas carbon dioxide capture system of claim 1, wherein, The rear flue gas conveying mechanism comprises a rear flue gas conveying pipe and a booster fan (18), the booster fan (18) is arranged in the rear flue gas conveying pipe, and the rear flue gas generated by the desulfurization tower (17) is conveyed into the absorption tower (19) through the rear flue gas conveying pipe.

5. The post- flue gas carbon dioxide capture system of claim 1, wherein, The absorption liquid spraying mechanism comprises an absorption liquid circulating pump (111), a liquid suction pipe, a liquid spraying pipe and a nozzle (191). The input end of the absorption liquid circulating pump (111) is connected to the absorption liquid in the bottom of the absorption tower (19) through the liquid suction pipe, the output end of the absorption liquid circulating pump (111) is connected to the upper part in the absorption tower (19) through the liquid spraying pipe, and the end of the liquid spraying pipe is provided with the nozzle (191).

6. The post-combustion carbon dioxide capture system of claim 5, wherein, The part of the liquid spraying pipe in the absorption tower (19) is a liquid spraying section, a plurality of nozzles (191) are arranged on the liquid spraying pipe, and the spraying direction of the nozzles (191) is arranged downward. The end of the rear flue gas conveying mechanism is arranged below the nozzles (191). A demister (192) is arranged in the absorption tower (19) above the nozzle (191), and a chimney (4) is arranged at the top of the absorption tower (19).

7. The post- flue gas CO2 capture system of claim 1, wherein, The calcium hydroxide conveying mechanism comprises a calcium hydroxide container and a calcium hydroxide conveying pump (22), and the input end and the output end of the calcium hydroxide conveying pump (22) are respectively connected with the calcium hydroxide container and the reaction tank (23) through pipelines.

8. The post- flue gas carbon dioxide capture system of claim 1, wherein, The rich liquid conveying mechanism comprises a rich liquid conveying pump (21), and the input end and the output end of the rich liquid conveying pump (21) are respectively connected with the bottom of the absorption tower (19) and the reaction tank (23) through pipelines.

9. The post- flue gas CO2 capture system of claim 1, wherein, A feed pump (31) is arranged between the reaction tank (23) and the centrifugal machine (32), and the input end and the output end of the feed pump (31) are respectively connected with the reaction tank (23) and the centrifugal machine (32) through pipelines.

10. The post- flue gas carbon dioxide capture system of claim 1, wherein, The centrifugal machine (32) has a lye outlet and a solid outlet, the lye outlet is connected with a recovery container (33), and a recovery pump (34) is arranged between the recovery container (33) and the lye conveying mechanism, and the recovery pump (34) is used for conveying the lye in the recovery container (33) to the lye conveying mechanism.

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