Cement kiln flue gas desulfurization and decarbonization device and method

Abstract

The application belongs to the technical field of energy saving and environmental protection, and discloses a cement kiln flue gas desulfurization and decarburization device and method. The device comprises a reaction tower which is divided into a desulfurization zone, a decarburization zone and a washing zone. The desulfurization zone is provided with a desulfurizer input device and a flue gas inlet pipe. The desulfurizer input device is communicated with a desulfurizer storage tank. The gypsum slurry outlet of the desulfurization zone is communicated with a gypsum slurry storage tank. The top of the desulfurization zone is communicated with the decarburization zone. The decarburization zone is provided with a gypsum slurry input device and an ammonia water input device. The gypsum slurry input device is communicated with the gypsum slurry storage tank. The ammonia water input device is communicated with an ammonia water storage tank. The calcium carbonate slurry outlet of the decarburization zone is communicated with a liquid-solid separator. Two outlets of the liquid-solid separator are respectively connected with an evaporator and the desulfurizer storage tank. The gas outlet of the evaporator is communicated with the desulfurizer storage tank. The top of the decarburization zone is communicated with the washing zone. The application can effectively recycle most of the raw materials, and the use of the purification and impurity removal equipment is less. The treatment efficiency is improved, and the equipment investment and the operation cost are reduced.

Description

Technical Field

[0001] This invention belongs to the field of energy conservation and environmental protection technology, specifically relating to a desulfurization and decarbonization device and method for cement kiln flue gas. Background Technology

[0002] In existing cement plant technologies, desulfurization and carbon dioxide capture of flue gas are often achieved using separate desulfurization and decarbonization systems. One widely used desulfurization technology is wet desulfurization, which uses calcium carbonate as a desulfurizing agent. Decarbonization technologies also utilize ammonia and calcium sulfate for carbon dioxide mineralization. While these technologies achieve both desulfurization and decarbonization, they require both systems, including corresponding reaction equipment, raw material storage equipment, and pipeline pumps, leading to high equipment and maintenance costs. Furthermore, calcium carbonate and calcium sulfate serve as raw materials and products in the desulfurization and decarbonization systems, respectively, and current technologies lack the means to recycle them throughout the entire process. This results in the need to purchase raw materials externally, leading to high operating costs. Additionally, the pollution and impurities generated during the reaction require additional equipment and purification. The recycling costs of these two main raw materials are also high, and the recycling rate is low. Summary of the Invention

[0003] The purpose of this invention is to provide a desulfurization and decarbonization device for cement kiln flue gas, which solves the technical problems of high equipment cost and inability to fully recycle the two main raw materials, calcium carbonate and calcium sulfate, in the existing desulfurization and decarbonization system.

[0004] A cement kiln flue gas desulfurization and decarbonization device includes a reaction tower, a desulfurizing agent storage tank, a gypsum slurry storage tank, an ammonia water storage tank, a liquid-solid separator, and an evaporator. The reaction tower is divided into a desulfurization zone, a decarbonization zone, and a washing zone by two layers of partitions from bottom to top. The desulfurization zone is equipped with a desulfurizing agent input device and a flue gas inlet pipe. The desulfurizing agent input device is connected to the desulfurizing agent storage tank via a pipeline. The gypsum slurry outlet at the bottom of the desulfurization zone is connected to the gypsum slurry storage tank. The top area of ​​the desulfurization zone is connected to the decarbonization zone via a first flue gas supply pipe. The decarbonization zone is equipped with a gypsum slurry input device and an ammonia water input device. The gypsum slurry input device is connected to the gypsum slurry storage tank via a pipeline, and the ammonia water input device is connected to the ammonia water storage tank via a pipeline. The calcium carbonate slurry outlet at the bottom of the decarbonization zone is connected to the liquid-solid separator. The liquid outlet and solid outlet of the liquid-solid separator are respectively connected to the evaporator and the desulfurizing agent storage tank. The gas outlet of the evaporator is connected to the desulfurizing agent storage tank for recovering evaporation water. The top area of ​​the decarbonization zone is connected to the washing zone via a second flue gas pipe. The bottom of the washing zone is connected to the ammonia water storage tank via an ammonia water recovery pipe, and a water spraying device is provided at the top. A flue gas outlet is provided at the top of the washing zone.

[0005] Preferably, the desulfurization zone, the decarbonization zone, and the washing zone are all equipped with flue gas input devices, which are upward-jetting jet devices. The inlet of the flue gas input device in the desulfurization zone receives untreated cement kiln flue gas through the flue gas inlet and pipeline. The desulfurization zone and the decarbonization zone each have two flue gas input devices arranged vertically. In the same area, the two flue gas input devices are an upper jet device and a lower jet device arranged vertically, and the two receive the same type of flue gas through branch pipelines.

[0006] Preferably, the desulfurizing agent input device, the gypsum slurry input device, the ammonia water input device, and the water spraying device are all spraying devices, and there are two of each of the desulfurizing agent input device and the gypsum slurry input device; after the sprayed liquid falls, it forms a liquid pool at the bottom of the corresponding area, the position of the lower jet device is lower than the liquid surface of the liquid pool in the corresponding area, and the position of the upper jet device is higher than the liquid surface.

[0007] Preferably, there are two desulfurizing agent input devices, one located below the upper jet device and above the liquid pool in the area, and the other located above the upper jet device and below the inlet of the first flue gas pipe in the area; there are also two gypsum slurry input devices, one located below the upper jet device and above the liquid pool in the area, and the other located above the upper jet device and below the inlet of the second flue gas pipe in the area.

[0008] Preferably, the bottom of the liquid pool in the desulfurization zone is also equipped with an oxygen replenishment device. This oxygen replenishment device is a jetting device, located inside the liquid pool and connected to an oxidation blower outside the reaction tower via pipeline, to replenish oxygen to the corresponding liquid pool.

[0009] Preferably, both the gypsum slurry storage tank and the ammonia water storage tank are equipped with corresponding replenishment ports, the desulfurizing agent storage tank is equipped with a mixing mechanism, the cement kiln flue gas desulfurization and decarbonization device is also equipped with a heat pump, the heat pump recovers the waste heat of the untreated flue gas through a heat exchange medium, the evaporator uses the waste heat recovered by the heat exchange medium to evaporate the ammonium sulfate mother liquor, and a condensation recovery device is provided between the evaporator and the desulfurizing agent.

[0010] The present invention also provides a method for desulfurization and decarbonization of cement kiln flue gas, which uses a cement kiln flue gas desulfurization and decarbonization device as described above, and includes the following steps.

[0011] The untreated flue gas is first heated by a heat pump before being transported to the desulfurization zone.

[0012] In the desulfurizing agent storage tank, calcium carbonate and water are stirred and mixed into a slurry and transported to the desulfurization zone for spraying. At the same time, the oxygen supply device delivers oxygen to the liquid pool in the desulfurization zone. The slurry in the corresponding liquid pool is recovered to the gypsum slurry storage tank after the reaction.

[0013] In the decarbonization zone, the flue gas drawn from the top of the desulfurization zone is transported to the decarbonization zone.

[0014] After being replenished with sufficient ammonia water, the ammonia water storage tank is fed into the decarbonization zone for spraying. At the same time, after being replenished with sufficient gypsum slurry, the gypsum slurry storage tank is also fed into the decarbonization zone for spraying. The slurry in the corresponding liquid pool is then transported to the liquid-solid separator after the reaction.

[0015] The liquid-solid separator separates the ammonium sulfate solution and calcium carbonate solid. The calcium carbonate solid is recovered and transported to the desulfurizing agent storage tank, while the ammonium sulfate solution is sent to the evaporator for evaporation and crystallization. After evaporation, ammonium sulfate crystals are obtained, and the evaporation water generated is recovered to the desulfurizing agent storage tank for pulping.

[0016] In the washing zone, a water spray device washes the flue gas containing ammonia. When the concentration of ammonia water after washing reaches a certain level, the ammonia water in the corresponding liquid pool is introduced into the ammonia water storage tank through pipelines.

[0017] Preferably, the flue gas is input in two separate paths in both the desulfurization zone and the decarbonization zone. The upper path delivers 30% of the flue gas to the upper jet injector, and the lower path delivers 70% of the flue gas to the lower jet injector. Similarly, the desulfurizing agent input device and the gypsum slurry input device are also input in two separate paths. The upper desulfurizing agent input device delivers 70% of the desulfurizing agent slurry, and the lower path delivers 30%. Likewise, the upper gypsum slurry input device delivers 70% of the gypsum slurry, and the lower path delivers 30%.

[0018] This invention has the following advantages: It utilizes a reaction tower divided into different zones and related equipment to form a system capable of simultaneously achieving desulfurization, decarbonization, and preventing ammonia escape. The system contains significantly fewer reaction devices and purification / removal devices than existing desulfurization and decarbonization systems. Furthermore, this solution leverages the correlation between the raw materials and products of the desulfurization and decarbonization reactions. Through rational system assembly and corresponding treatment methods, it achieves the recycling and reuse of raw materials such as calcium carbonate and calcium sulfate within the system. Although the system requires the replenishment of calcium sulfate and ammonia water, it still effectively recovers and reuses most of the raw materials, reducing the leakage of residual materials or contamination of the system products. This process requires minimal purification / removal equipment, thus improving processing efficiency while reducing equipment investment and operating costs.

[0019] This solution also simplifies the original gypsum dewatering process in wet desulfurization systems, directly utilizing gypsum slurry. Compared to traditional ammonia-based carbon capture, using gypsum slurry efficiently converts ammonium carbonate generated during carbon capture into ammonium sulfate, absorbing the heat generated during carbon capture and reducing the decomposition of ammonium carbonate and ammonia escape. The gypsum is recycled from the desulfurization zone and also supplemented from external sources, such as external solid waste gypsum, thus offering significant environmental benefits.

[0020] This solution utilizes continuously replenished ammonia water to generate valuable ammonium sulfate during the decarbonization process. The washing process in the washing zone effectively prevents environmental pollution caused by ammonia escape. The washed-off ammonia can be further utilized as a mineralization raw material. Any excess ammonia water that may exist in the decarbonization zone's liquid pool is treated during subsequent evaporation and water recovery, preventing ammonia escape and atmospheric pollution. This solution effectively solves the problem of requiring dedicated equipment to treat escaped ammonia in existing cement production processes, saving costs. Attached Figure Description

[0021] Figure 1 This is a flowchart of a cement kiln flue gas desulfurization and decarbonization device according to the present invention.

[0022] Figure 2 for Figure 1 A schematic diagram of the reaction tower shown.

[0023] The reference numerals in the accompanying drawings of the instruction manual include: 1. Reaction tower; 2. Desulfurizing agent storage tank; 3. Liquid-solid separator; 4. Gypsum slurry storage tank; 5. Ammonia water storage tank; 6. Evaporator; 7. Oxidation fan; 8. Desulfurization zone; 9. Decarbonization zone; 10. Scrubbing zone; 11. Baffle plate; 12. Oxygen supplementation device; 13. Flue gas input device; 14. Ammonia water input device; 15. Gypsum slurry input device; 16. Water spray device; 17. Desulfurizing agent input device; 18. Swirl plate; 19. Demister. Detailed Implementation

[0024] The following detailed description of the embodiments, with reference to the accompanying drawings, will further illustrate the specific implementation of the present invention, in order to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the inventive concept and technical solution of the present invention.

[0025] like Figures 1-2As shown, this invention provides a desulfurization and decarbonization device for cement kiln flue gas, including a reaction tower 1, a desulfurizing agent storage tank 2, a gypsum slurry storage tank 4, an ammonia water storage tank 5, a liquid-solid separator 3, and an evaporator 6. The reaction tower 1 is divided into a desulfurization zone 8, a decarbonization zone 9, and a washing zone 10 by two layers of partitions 11 from bottom to top. The desulfurization zone 8 is equipped with a desulfurizing agent input device 17 and a flue gas inlet pipe. The desulfurizing agent input device 17 is connected to the desulfurizing agent storage tank 2 through a pipeline. The gypsum slurry outlet at the bottom of the desulfurization zone 8 is connected to the gypsum slurry storage tank 4. The top area of ​​the desulfurization zone 8 is connected to the decarbonization zone 9 through a first flue gas supply pipe. The decarbonization zone 9 is equipped with a gypsum slurry input device 15 and an ammonia water input device. 14. The gypsum slurry input device 15 is connected to the gypsum slurry storage tank 4 via a pipeline. The ammonia water input device 14 is connected to the ammonia water storage tank 5 via a pipeline. The calcium carbonate slurry outlet at the bottom of the decarbonization zone 9 is connected to the liquid-solid separator 3. The liquid outlet and solid outlet of the liquid-solid separator 3 are respectively connected to the evaporator 6 and the desulfurizing agent storage tank 2. The gas outlet of the evaporator 6 is connected to the desulfurizing agent storage tank 2 for recovering evaporation water. The top area of ​​the decarbonization zone 9 is connected to the washing zone 10 via a second flue gas pipe. The bottom of the washing zone 10 is connected to the ammonia water storage tank 5 via an ammonia water recovery pipe, and a water spraying device 16 is provided at the top. A flue gas outlet is provided at the top of the washing zone 10.

[0026] Each of the desulfurization zone 8, the decarbonization zone 9, and the scrubbing zone 10 is equipped with a flue gas input device 13. The flue gas input device 13 is an upward-jetting jet device, including an inlet, a hollow body, and several outlets. The hollow body receives flue gas through a pipeline connected to the inlet, and the outlets are located on the upper surface of the hollow body. The outlets are evenly distributed across the horizontal cross-section within the reaction tower 1. The inlet of the flue gas input device 13 in the desulfurization zone 8 receives untreated cement kiln flue gas through the inlet and pipeline. Each of the desulfurization zone 8 and the decarbonization zone 9 has two flue gas input devices 13. Within the same zone, the two flue gas input devices 13 are an upper jetting device and a lower jetting device, respectively, and both receive the same type of flue gas through branch pipelines.

[0027] The desulfurizing agent input device 17, the gypsum slurry input device 15, the ammonia water input device 14, and the water spraying device 16 are all spraying devices. The spray nozzles of the spraying devices are evenly distributed downwards on the horizontal cross-section inside the reaction tower 1. After the sprayed liquid falls, it forms a liquid pool at the bottom of the corresponding area. The lower jet device is positioned below the liquid surface of the liquid pool in the corresponding area, while the upper jet device is positioned above the liquid surface. The upper jet device inputs 30% of the total input flue gas, while the lower jet device inputs 70% of the total input flue gas. This allows the flue gas to be delivered to the inside and above the liquid pool respectively. The flue gas above the liquid surface can be washed and absorbed by the sprayed liquid, while the liquid pool produces a bubbling phenomenon under the action of the lower jet device, improving the mixing and reaction efficiency of the substances in the liquid pool. There is only one set of flue gas input devices 13 in the washing zone 10, which is located below the liquid surface of the liquid pool in this area, thus ensuring full contact with the liquid.

[0028] There are two desulfurizing agent input devices 17: one located below the upper jet device and above the liquid tank in this area, and the other located above the upper jet device and below the inlet of the first flue gas pipe. Similarly, there are also two gypsum slurry input devices 15: one located below the upper jet device and above the liquid tank in this area, and the other located above the upper jet device and below the inlet of the second flue gas pipe. The ammonia water input device 14 is located above the upper jet device in the decarbonization zone 9 and below the inlet of the second flue gas pipe. The water spray device 16 is located above the washing zone 10 and above the liquid tank in this area.

[0029] An oxygen supply device 12 is also provided at the bottom of the liquid pool in the desulfurization zone 8. The oxygen supply device 12 is also a jetting device with the same structure as the flue gas input device 13. The oxygen supply device 12 is located in the liquid pool and is connected to the oxidation blower 7 outside the reaction tower 1 through a pipeline to supplement oxygen into the corresponding liquid pool, so that calcium sulfite is oxidized to calcium sulfate. In the decarbonization zone 9, a swirl plate 18 is provided between the uppermost spray device and the inlet of the first flue gas pipe. The swirl plate 18 has several blades that, under the action of the rotation of the swirl plate 18, guide solid particles and droplets in the flue gas to be thrown onto the inner wall of the reaction tower 1. In the washing zone 10, a demister 19 is provided between the flue gas outlet and the water spray device 16 to remove water vapor in the flue gas.

[0030] Both the gypsum slurry storage tank 4 and the ammonia water storage tank 5 are equipped with corresponding replenishment ports for replenishing gypsum slurry mixed with calcium sulfate and ammonia water from the outside, respectively. The desulfurizing agent storage tank 2, the gypsum slurry storage tank 4, and the ammonia water storage tank 5 are all equipped with corresponding delivery pumps to provide liquid raw materials to the spraying device and maintain pressure. The delivery pumps for the desulfurizing agent and gypsum slurry are mud pumps because the liquid medium being transported contains mixed oil-solid substances. Booster pumps can be installed on the flue gas inlet pipe, the first flue gas delivery pipe, and the second flue gas delivery pipe to pressurize the flue gas delivery, ensuring the flue gas flow rate and bubbling effect.

[0031] Untreated flue gas often contains a significant amount of waste heat. Therefore, this device is also equipped with a heat pump and a heat exchange medium to recover the waste heat from the untreated flue gas. The evaporator 6 utilizes the waste heat recovered by the heat exchange medium to evaporate the ammonium sulfate mother liquor entering it. The gas outlet of the evaporator 6 is connected to the desulfurizing agent storage tank 2 via a pipeline to a condensate recovery unit for recovering evaporated water. The desulfurizing agent storage tank 2 is equipped with a mixing mechanism. The recovered evaporated water and the calcium carbonate separated by the liquid-solid separator 3 are mixed in the desulfurizing agent storage tank 2 using the mixing mechanism to form a slurry, i.e., the desulfurizing agent.

[0032] In addition to the above-mentioned desulfurization and decarbonization device for cement kiln flue gas, the present invention also provides a method for desulfurization and decarbonization of cement kiln flue gas, as detailed below.

[0033] First, the untreated flue gas is heated by a heat pump before being transported to desulfurization zone 8. 30% of the flue gas is transported to the upper jet generator via the upper route, and 70% of the flue gas is transported to the lower jet generator via the lower route.

[0034] In desulfurization zone 8, calcium carbonate has been mixed with water in desulfurizing agent storage tank 2 to form a slurry, which is then transported to desulfurization zone 8 for spraying. 70% of the desulfurizing agent slurry is transported upstream, and 30% is transported downstream. This allows the flue gas to react with the desulfurizing agent slurry. The flue gas and oxygen in the liquid pool also create a bubbling effect after input, disturbing the solid-liquid slurry in desulfurization zone 8. This ensures that unreacted calcium carbonate reacts completely with sulfur oxides, and any sulfur oxides that escape into the gas are removed and converted by the sprayed desulfurizing agent slurry. Simultaneously with the input of flue gas, oxidation fan 7 also inputs oxygen into desulfurization zone 8. Oxygen supplementation device 12 delivers oxygen to the liquid pool in desulfurization zone 8, oxidizing the calcium sulfite produced in the reaction into calcium sulfate. Finally, all the products obtained from desulfurization are transported to gypsum slurry storage tank 4.

[0035] In decarbonization zone 9, the flue gas drawn from the top of desulfurization zone 8 is again transported to decarbonization zone 9 via two routes. The upper route delivers 30% of the flue gas to the upper jet generator, and the lower route delivers 70% of the flue gas to the lower jet generator. Previously, after replenishing sufficient ammonia water in ammonia storage tank 5, the ammonia water is introduced into decarbonization zone 9 for spraying. The ammonia water contacts the flue gas and absorbs carbon dioxide to form ammonium carbonate. Simultaneously, after replenishing sufficient gypsum slurry (mainly composed of calcium sulfate) in gypsum slurry in ammonia storage tank 4, the gypsum slurry is also introduced into decarbonation zone 9 via two routes for spraying. In this way, carbon dioxide in the flue gas is absorbed by the ammonia water and then reacts with calcium sulfate to produce ammonium sulfate and calcium carbonate. Calcium carbonate is insoluble in water and precipitates out, and the reaction continues. The reaction equation is as follows:

[0036] CaSO4·2H2O+CO2+2NH4OH→(NH4)2SO4+CaCO3+H2O.

[0037] The flue gas in the liquid pool of decarbonization zone 9 also has a bubbling effect after being introduced, disturbing the slurry in the liquid pool and intensifying the mineralization reaction of the gas-liquid-solid three phases, ultimately producing ammonium sulfate and calcium carbonate. In order to ensure that all the carbon dioxide generated during desulfurization reacts with the original carbon dioxide in the flue gas, the gypsum slurry and ammonia water introduced into this area need to be in slightly excess to ensure that the carbon dioxide is fully absorbed.

[0038] Since the top layer of the decarbonization zone 9 is also equipped with a swirl plate 18, the flue gas after desulfurization and decarbonization enters the swirl plate 18 tangentially. During the rotation of the swirl plate 18, due to the action of the blades, the small calcium carbonate particles and liquid containing ammonium sulfate carried in the flue gas are thrown onto the tower wall under the action of centrifugal force, thus achieving separation from the desulfurization and decarbonization flue gas. Therefore, this method ensures that the desulfurization and decarbonization flue gas entering the washing zone 10 does not contain other impurities.

[0039] After desulfurization and decarbonization, the flue gas enters the scrubbing zone 10. In the decarbonization zone 9, due to the use of ammonia water for mineralization, a large amount of escaped ammonia is generated and enters the scrubbing zone 10 through the flue gas conveying pipeline. Therefore, the water spray device 16 in the scrubbing zone 10 scrubs the flue gas containing ammonia. An ammonia concentration monitor is installed in the liquid pool of the scrubbing zone 10. When the ammonia concentration after scrubbing reaches a certain level, the ammonia water in the liquid pool is introduced into the ammonia water storage tank 5 through pipeline. To ensure the supply of ammonia water (which is continuously consumed during decarbonization), the ammonia water storage tank 5 needs to be replenished in a timely manner to continue its use as a raw material for the mineralization reaction. To ensure that the desulfurized and decarbonized flue gas emitted into the atmosphere is free of water vapor, a demister 19 is added at the top of the scrubbing zone 10 to remove water vapor from the flue gas.

[0040] The slurry in the decarbonation zone 9 liquid tank is pumped into the liquid-solid separator 3 for separation using a mud pump. The separated solid portion is mainly calcium carbonate, which is formed by the reaction of carbon dioxide originally present in the flue gas and carbon dioxide produced in the desulfurization reaction. Therefore, when used for desulfurization, it is in excess relative to sulfur oxides in the flue gas, ensuring sufficient desulfurization. During system operation, a portion of this excess calcium carbonate can be removed and used for cement production.

[0041] Although the separated calcium carbonate still contains a small amount of residual calcium sulfate, its impact on the desulfurization effect is minimal. It can be directly recycled as a desulfurizing agent into the desulfurizing agent storage tank 2 for mixing and forming a desulfurizing agent slurry, which can then be used as a wet desulfurizing agent. The ammonium sulfate solution obtained after separation is fed into the evaporator 6 and heated and evaporated using heat recovered from the heat pump, thereby causing the ammonium sulfate to crystallize. The water vapor and a small amount of ammonia produced by evaporation are then transported through pipelines to the condenser for condensation, and further transported to the desulfurizing agent storage tank 2 to mix with the calcium carbonate.

[0042] The evaporation water contains a small amount of ammonia during transportation. This process uses closed pipelines to prevent leakage, and the ammonia is absorbed by the evaporation water and dissolved into the desulfurizing agent slurry during condensation. When the desulfurizing agent slurry is input into desulfurization zone 8, the ammonium ions in it react with carbon dioxide and sulfur oxides in the flue gas to produce ammonium carbonate and ammonium sulfate. When these are transported to the gypsum slurry storage tank 4 for replenishing calcium sulfate, the ammonium carbonate reacts to produce ammonium sulfate and calcium carbonate precipitates, which enter the decarbonization zone 9 along with the gypsum slurry. In the above process, the raw materials and products of the decarbonization and desulfurization reactions are interconnected. With the setup of this device, the products can be directly recycled without complex purification, maintaining the stability of system operation, while the impurity content and types of the products are controllable.

[0043] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A desulfurization and decarbonization device for cement kiln flue gas, characterized in that: The system includes a reaction tower (1), a desulfurizing agent storage tank (2), a gypsum slurry storage tank (4), an ammonia water storage tank (5), a liquid-solid separator (3), and an evaporator (6). The reaction tower (1) is divided into a desulfurization zone (8), a decarbonization zone (9), and a washing zone (10) by two layers of partitions (11) from bottom to top. The desulfurization zone (8) is equipped with a desulfurizing agent input device (17) and a flue gas inlet pipe. The desulfurizing agent input device (17) is connected to the desulfurizing agent storage tank (2) through a pipeline. The gypsum slurry outlet at the bottom of the desulfurization zone (8) is connected to the gypsum slurry storage tank (4). The top area of ​​the desulfurization zone (8) is connected to the decarbonization zone (9) through a first flue gas inlet pipe. The decarbonization zone (9) is equipped with a gypsum slurry input device (15) and an ammonia water input device (14). The slurry input device (15) is connected to the gypsum slurry storage tank (4) through a pipeline, the ammonia water input device (14) is connected to the ammonia water storage tank (5) through a pipeline, the calcium carbonate slurry outlet at the bottom of the decarbonization zone (9) is connected to the liquid-solid separator (3), the liquid outlet and solid outlet of the liquid-solid separator (3) are respectively connected to the evaporator (6) and the desulfurizing agent storage tank (2), the gas outlet of the evaporator (6) is connected to the desulfurizing agent storage tank (2) for recycling evaporation water; the top sampling of the decarbonization zone (9) is connected to the washing zone (10) through the second flue gas pipe, the bottom of the washing zone (10) is connected to the ammonia water storage tank (5) through the ammonia water recovery pipe and the upper part is equipped with a water spray device (16), and the top of the washing zone (10) is equipped with a flue gas outlet; The desulfurization zone (8), the decarbonization zone (9) and the washing zone (10) are all equipped with flue gas input devices (13), and the flue gas input devices (13) are upward jetting devices; the inlet of the flue gas input device (13) of the desulfurization zone (8) is used to input untreated cement kiln flue gas through the flue gas inlet and pipeline; the desulfurization zone (8) and the decarbonization zone (9) are each provided with two flue gas input devices (13) set up vertically; in the same area, the two flue gas input devices (13) are respectively the upper jetting device and the lower jetting device set up vertically, and the two are used to input the same type of flue gas through branch pipelines; The bottom of the liquid pool in the desulfurization zone (8) is also equipped with an oxygen replenishment device (12). The oxygen replenishment device (12) is a jetting device. The oxygen replenishment device (12) is located in the liquid pool and is connected to the oxidation blower (7) outside the reaction tower (1) through a pipeline to replenish oxygen to the corresponding liquid pool.

2. The desulfurization and decarbonization device for cement kiln flue gas according to claim 1, characterized in that: The desulfurizing agent input device (17), the gypsum slurry input device (15), the ammonia water input device (14), and the water spraying device (16) are all spraying devices. There are two desulfurizing agent input devices (17) and two gypsum slurry input devices (15). After the sprayed liquid falls, it forms a liquid pool at the bottom of the corresponding area. The position of the lower jet device is lower than the liquid surface of the liquid pool in the corresponding area, and the position of the upper jet device is higher than the liquid surface.

3. The desulfurization and decarbonization device for cement kiln flue gas according to claim 2, characterized in that: There are also two desulfurizing agent input devices (17), one located below the upper jet device in the corresponding area and above the liquid pool, and the other located above the upper jet device in the area and below the inlet of the first flue pipe; there are also two gypsum slurry input devices (15), one located below the upper jet device in the corresponding area and above the liquid pool, and the other located above the upper jet device in the area and below the inlet of the second flue pipe.

4. The desulfurization and decarbonization device for cement kiln flue gas according to claim 1, characterized in that: The gypsum slurry storage tank (4) and the ammonia water storage tank (5) are both equipped with corresponding replenishment ports. The desulfurizing agent storage tank (2) is equipped with a mixing mechanism. The cement kiln flue gas desulfurization and decarbonization device is also equipped with a heat pump. The heat pump recovers the waste heat of the untreated flue gas through the heat exchange medium. The evaporator (6) uses the waste heat recovered by the heat exchange medium to evaporate the ammonium sulfate mother liquor. A condenser recovery device is provided between the evaporator (6) and the desulfurizing agent.

5. A method for desulfurization and decarbonization of cement kiln flue gas, characterized in that: Using a cement kiln flue gas desulfurization and decarbonization device according to any one of claims 1-4, comprising: The untreated flue gas is first used to recover heat using a heat pump, and then transported to the desulfurization zone (8); In the desulfurizing agent storage tank (2), calcium carbonate and water are stirred and mixed into a slurry and transported to the desulfurization zone (8) for spraying. At the same time, the oxygen supply device (12) transports oxygen to the liquid pool of the desulfurization zone (8), and the slurry in the corresponding liquid pool is recovered to the gypsum slurry storage tank (4) after the reaction. In the decarbonization zone (9), the flue gas drawn from the top of the desulfurization zone (8) is transported to the decarbonization zone (9); After replenishing sufficient ammonia water, the ammonia water storage tank (5) inputs ammonia water into the decarbonization zone (9) for spraying. At the same time, after replenishing sufficient gypsum slurry, the gypsum slurry storage tank (4) also inputs gypsum slurry into the decarbonization zone (9) for spraying. The slurry in the corresponding liquid pool is then transported to the liquid-solid separator (3) after the reaction. The liquid-solid separator (3) completes the separation of ammonium sulfate solution and calcium carbonate solid. The calcium carbonate solid is recovered and transported to the desulfurizing agent storage tank (2). The ammonium sulfate solution is sent to the evaporator (6) for evaporation and crystallization. After evaporation, ammonium sulfate crystals are obtained. The evaporation water generated is recovered to the desulfurizing agent storage tank (2) for pulping. In the washing zone (10), the water spraying device (16) washes the flue gas containing ammonia. When the concentration of ammonia water after washing reaches a certain level, the ammonia water in the corresponding liquid pool is introduced into the ammonia water storage tank (5) through the pipeline.

6. The method for desulfurization and decarbonization of cement kiln flue gas according to claim 5, characterized in that: The flue gas is input in two separate paths in both the desulfurization zone (8) and the decarbonization zone (9). The upper path delivers 30% of the flue gas to the upper jet device, and the lower path delivers 70% of the flue gas to the lower jet device. The desulfurizing agent input device (17) and the gypsum slurry input device (15) are both input in two separate paths. The upper desulfurizing agent input device (17) delivers 70% of the desulfurizing agent slurry, and the lower desulfurizing agent input device (17) delivers 30% of the desulfurizing agent slurry. The upper gypsum slurry input device (15) delivers 70% of the gypsum slurry, and the lower gypsum slurry input device (15) delivers 30% of the gypsum slurry.

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