Sodium-alkali desulfurization absorbent regeneration and resource utilization system
By designing a sodium-base method desulfurization absorber regeneration and resource utilization system, the problem of low-salt wastewater treatment in the existing technology has been solved, the regeneration of desulfurization absorber and the resource utilization of ammonium sulfate by-products has been realized, the risk of environmental pollution is reduced and the resource utilization efficiency is improved.
Patent Information
- Application Number
- CN202421933508.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-12
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2034-08-12
AI Technical Summary
Among the existing sodium-alkali desulfurization technology, the high-salt wastewater treatment process is long, the energy consumption is high, the area covers a large area, and the wastewater treatment effect is not ideal, which has the problems of high effluent COD and wastewater discharge not meeting the standards.
A sodium-base desulfurization absorber regeneration and resource utilization system is designed, including a desulfurization absorption tower, a carbonization tower, an ammonium carbon thickener, a mixing tank, a stirred reactor, a reactor centrifugal filter, an absorber preparation tank, a primary evaporation crystallization device, a cooling crystallizer, a secondary evaporation crystallization device and an ammonia water storage tank. Through the combined use of these devices, the regeneration of the desulfurization absorber and the generation of ammonium sulfate by-products are realized.
Through the regeneration of absorbents, the amount of desulfurization absorbents is reduced, the risk of environmental pollution is reduced, and the generated ammonium sulfate by-products are used as nitrogen fertilizers to resource utilization, improving resource utilization efficiency.
Smart Images
Figure CN222956163U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of desulfurization product treatment, and particularly relates to a sodium alkali method desulfurization absorbent regeneration and resource utilization system. Background Art
[0002] SO 2 is one of the main air pollutants faced today. The ways to control SO 2 include: using low-sulfur fuels and clean energy substitution, fuel desulfurization, in-process desulfurization during combustion, and end-of-pipe flue gas desulfurization. The sodium desulfurization process has the characteristics of high desulfurization efficiency, the desulfurization products are not easy to scale and block in the absorption tower and absorbent circulation system, few system failures, and low investment, and has been widely used in flue gas desulfurization. During the process of flue gas desulfurization using the sodium alkali method, it is necessary to control the pH value, salt content, chloride ions, etc. of the absorption tower slurry. Inevitably, a large amount of high-salt wastewater will be generated. The high-salt wastewater is treated through a clarifier, an oxidation tank, and a drain filter, and the separated solid waste residue is transported out and landfilled, resulting in waste of resources and the risk of environmental pollution.
[0003] In the existing sodium alkali method desulfurization technology, generally, the high-salt water discharged from the absorption tower is blown with oxidation air to reduce the COD, and the filter residue is separated by precipitation and flocculation and then discharged. The generated waste residue is transported out and landfilled. The wastewater treatment process flow is long, the energy consumption is high, the floor area is large, and there are also problems such as high COD in the effluent and unqualified wastewater discharge.
[0004] To realize the resource utilization of the sodium alkali method desulfurization products, some studies have proposed measures such as pretreatment, evaporation concentration, freeze crystallization, and miscellaneous salt drying to recover sodium sulfate. However, usually, the recovery process is complex, and the recovery operation cost is greater than the economic benefit of sodium sulfate. There is a patent that proposes to use the salting-out method to crystallize and separate anhydrous Na 2 SO 3 , but the solubility of the main components such as Na 2 SO 3 , Na 2 SO 4 in the desulfurization waste liquid is similar, the recovery rate is low, the output and purity of the separated Na 2 SO 3 product are low, and the generated mixed salt will cause a large amount of secondary pollution, and the environmental pollution problem brought by the desulfurization waste liquid cannot be effectively treated. Summary of the Utility Model
[0005] Aiming at the above problems, the purpose of the utility model is to provide a sodium alkali method desulfurization absorbent regeneration and resource utilization system.
[0006] The specific technical solution is as follows:
[0007] A sodium alkali method desulfurization absorbent regeneration and resource utilization system, comprising a desulfurization absorption tower, a carbonization tower, an ammonium bicarbonate thickener, a mixing tank, a stirred reactor, a reactor centrifugal filter, an absorbent preparation tank, a primary evaporation crystallization device, a cooling crystallizer, a secondary evaporation crystallization device and an ammonia water storage tank. The top of the desulfurization absorption tower is connected to the carbonization tower through a pipeline, the ammonia water storage tank is connected to the carbonization tower, the bottom of the carbonization tower is connected to the ammonium bicarbonate thickener, the top of the ammonium bicarbonate thickener is connected back to the carbonization tower, and the bottom of the ammonium bicarbonate thickener and the bottom of the desulfurization absorption tower are respectively connected to the mixing tank through pipelines. The bottom of the mixing tank is connected to the stirred reactor through a pipeline, the bottom of the stirred reactor is connected to the reactor centrifugal filter, and the solution outlet pipeline of the reactor centrifugal filter is divided into two pipelines, which are respectively connected to the primary evaporation crystallization device and the mixing tank. Another outlet pipeline of the reactor centrifugal filter is connected to the absorbent preparation tank. The outlet pipeline of the absorbent preparation tank is divided into two pipelines, which are respectively connected to the desulfurization absorption tower and the reactor centrifugal filter. The bottom outlet pipeline of the primary evaporation crystallization device is connected to a primary evaporation crystallization centrifuge separator. The sodium sulfate outlet pipeline of the primary evaporation crystallization centrifuge separator is connected to the mixing tank. The mother liquor outlet pipeline of the primary evaporation crystallization centrifuge separator is connected to the cooling crystallizer. The outlet pipeline of the cooling crystallizer is connected to a cooling crystallization centrifuge separator. The mixed salt outlet pipeline of the cooling crystallization centrifuge separator is connected back to the primary evaporation crystallization device. The mother liquor outlet pipeline of the cooling crystallization centrifuge separator is connected to the secondary evaporation crystallization device, and the secondary evaporation crystallization device is connected back to the cooling crystallizer.
[0008] Further, the top of the desulfurization absorption tower is divided into two pipelines. One pipeline is connected to the chimney, and the other pipeline is connected to the carbonization tower through a booster fan. The flue gas outlet pipeline at the top of the carbonization tower converges and connects with the pipeline connected to the chimney.
[0009] Further, the ammonia water storage tank is connected to the carbonization tower through an ammonia water pump. The top outlet pipeline of the ammonium bicarbonate thickener is connected to an ammonium bicarbonate storage tank, and the ammonium bicarbonate storage tank is divided into multiple pipelines and connected back to the carbonization tower through an ammonium bicarbonate solution circulation pump.
[0010] Further, an ammonium bicarbonate external discharge pump is provided on the pipeline connecting the bottom of the ammonium bicarbonate thickener to the mixing tank. An absorption tower discharge pump is provided on the pipeline connecting the bottom of the desulfurization absorption tower to the mixing tank. A feed pump is provided on the pipeline connecting the bottom of the mixing tank to the stirred reactor.
[0011] Further, the primary evaporation crystallization device includes a primary evaporation crystallizer and a primary evaporation crystallization heater. The solution outlet pipeline of the reactor centrifugal filter is divided into two pipelines. One pipeline is connected to the mixing tank, and the other pipeline is sequentially connected to a mother liquor buffer tank, a mother liquor discharge pump and the primary evaporation crystallizer. The primary evaporation crystallizer and the primary evaporation crystallization heater are connected in a cycle.
[0012] Further, the bottom outlet pipeline of the first-stage evaporation crystallizer is successively connected to the first-stage evaporation crystallization discharge pump and the first-stage evaporation crystallization centrifuge separator.
[0013] Further, the mixed salt outlet pipeline of the cooling crystallization centrifuge separator is connected to the mother liquor buffer tank. The second-stage evaporation crystallization device includes a second-stage evaporation crystallizer and a second-stage evaporation crystallization heater. The mother liquor outlet pipeline of the cooling crystallization centrifuge separator is connected to the second-stage evaporation crystallizer, and the second-stage evaporation crystallizer and the second-stage evaporation crystallization heater are connected in a cycle.
[0014] Further, the bottom outlet pipeline of the second-stage evaporation crystallizer is successively connected to the ammonium sulfate thickener and the ammonium sulfate centrifuge. The mother liquor pipeline of the ammonium sulfate centrifuge is connected to the cooling crystallizer.
[0015] The beneficial effects of the present utility model are as follows:
[0016] By setting the filter, the absorbent preparation tank and the reflux design between the devices, the regeneration of the desulfurization absorbent is realized, the treatment problem of high-salt wastewater discharged from the sodium alkali method desulfurization is avoided, and the environmental pollution risk is reduced;
[0017] Through the regeneration of the absorbent, the supplement amount of the desulfurization absorbent is reduced, and the by-product ammonium sulfate generated can be used as a nitrogen fertilizer. Description of the Drawings
[0018] Figure 1 is the device flow chart of the present utility model;
[0019] In the figure: 1, desulfurization absorption tower; 2, carbonization tower; 3, ammonium bicarbonate thickener; 4, mixing tank; 5, stirring reactor; 6, reactor centrifugal filter; 7, absorbent preparation tank; 8, cooling crystallizer; 9, ammonia water storage tank; 10, first-stage evaporation crystallization centrifuge separator; 11, cooling crystallization centrifuge separator; 12, booster fan; 13, ammonia water pump; 14, ammonium bicarbonate storage tank; 15, ammonium bicarbonate solution circulation pump; 16, ammonium bicarbonate external discharge pump; 17, absorption tower discharge pump; 18, feed pump; 19, first-stage evaporation crystallizer; 20, first-stage evaporation crystallization heater; 21, mother liquor buffer tank; 22, mother liquor discharge pump; 23, first-stage evaporation crystallization discharge pump; 24, second-stage evaporation crystallizer; 25, second-stage evaporation crystallization heater; 26, ammonium sulfate thickener; 27, ammonium sulfate centrifuge. Detailed Embodiments
[0020] The following further describes the present utility model in conjunction with the drawings of the specification, but the protection scope of the present utility model is not limited thereto.
[0021] Such as Figure 1As shown in the figure, it includes a desulfurization absorption tower 1, a carbonization tower 2, an ammonium bicarbonate thickener 3, a mixing tank 4, a stirred reactor 5, a reactor centrifugal filter 6, an absorbent preparation tank 7, a cooling crystallizer 8, an ammonia water storage tank 9, a primary evaporation crystallization centrifugal separator 10, a cooling crystallization centrifugal separator 11, an ammonium bicarbonate storage tank 14, a primary evaporation crystallizer 19, a primary evaporation crystallization heater 20, a mother liquor buffer tank 21, a secondary evaporation crystallizer 24, a secondary evaporation crystallization heater 25, an ammonium sulfate thickener 26, and an ammonium sulfate centrifuge 27. The top of the desulfurization absorption tower 1 is divided into two pipelines. One pipeline is connected to the chimney, and the other pipeline is connected to the carbonization tower 2 through a booster fan 12. The flue gas outlet pipeline at the top of the carbonization tower 2 converges with the pipeline connected to the chimney. The ammonia water storage tank 9 is connected to the carbonization tower 2 through an ammonia water pump 13. The bottom of the carbonization tower 2 is connected to the ammonium bicarbonate thickener 3. The bottoms of the ammonium bicarbonate thickener 3 and the desulfurization absorption tower 1 are respectively connected to the mixing tank 4 through pipelines. An ammonium bicarbonate external discharge pump 16 is provided on the pipeline connecting the bottom of the ammonium bicarbonate thickener 3 to the mixing tank 4. An absorption tower discharge pump 17 is provided on the pipeline connecting the bottom of the desulfurization absorption tower 1 to the mixing tank 4. The top outlet pipeline of the ammonium bicarbonate thickener 3 is connected to the ammonium bicarbonate storage tank 14. The ammonium bicarbonate storage tank 14 is divided into two pipelines and reflux-connected to the carbonization tower 2 through an ammonium bicarbonate solution circulation pump 15. The bottom of the mixing tank 4 is connected to the stirred reactor 5 through a pipeline. A feed pump 18 is provided on the pipeline connecting the bottom of the mixing tank 4 to the stirred reactor 5. The bottom of the stirred reactor 5 is connected to the reactor centrifugal filter 6. The solution outlet pipeline of the reactor centrifugal filter 6 is divided into two pipelines. One pipeline is connected to the mixing tank 4, and the other pipeline is sequentially connected to the mother liquor buffer tank 21, a mother liquor discharge pump 22, and the primary evaporation crystallizer 19. The primary evaporation crystallizer 19 is connected to the primary evaporation crystallization heater 20 in a cycle. The other outlet pipeline of the reactor centrifugal filter 6 is connected to the absorbent preparation tank 7. The outlet pipeline of the absorbent preparation tank 7 is divided into two pipelines, which are respectively connected to the desulfurization absorption tower 1 and the reactor centrifugal filter 6. The bottom outlet pipeline of the primary evaporation crystallizer 19 is sequentially connected to a primary evaporation crystallization discharge pump 23 and the primary evaporation crystallization centrifugal separator 10. The sodium sulfate outlet pipeline of the primary evaporation crystallization centrifugal separator 10 is connected to the mixing tank 4. The mother liquor outlet pipeline of the primary evaporation crystallization centrifugal separator 10 is connected to the cooling crystallizer 8. The outlet pipeline of the cooling crystallizer 8 is connected to the cooling crystallization centrifugal separator 11. The mixed salt outlet pipeline of the cooling crystallization centrifugal separator 11 is connected to the mother liquor buffer tank 21. The mother liquor outlet pipeline of the cooling crystallization centrifugal separator 11 is connected to the secondary evaporation crystallizer 24. The secondary evaporation crystallizer 24 is connected to the secondary evaporation crystallization heater 25 in a cycle. The bottom outlet pipeline of the secondary evaporation crystallizer 24 is sequentially connected to the ammonium sulfate thickener 26 and the ammonium sulfate centrifuge 27. The mother liquor pipeline of the ammonium sulfate centrifuge 27 is connected to the cooling crystallizer 8.
[0022] A method for regenerating and resourcefully utilizing a sodium-based desulfurization absorbent includes the following steps:
[0023] 1) Part of the clean flue gas after passing through the desulfurization absorption tower 1 is pressurized by the booster fan 12 and enters the carbonization tower 2 from the bottom of the carbonization tower 2. The ammonia water in the ammonia water storage tank 9 is sprayed into the carbonization tower 2 through the ammonia water pump 13. The clean flue gas contacts the ammonia water countercurrently. The carbon dioxide in the flue gas reacts with the ammonia water to generate ammonium bicarbonate. The flue gas after removing carbon dioxide enters the chimney for emission. The material at the bottom of the carbonization tower 2 is transported to the ammonium bicarbonate thickener 3 for concentration. The concentrated ammonium bicarbonate solution is obtained at the bottom of the ammonium bicarbonate thickener 3 and enters the mixing tank 4 through the ammonium bicarbonate external discharge pump 16. The supernatant at the top of the ammonium bicarbonate thickener 3 enters the ammonium bicarbonate storage tank 14 for storage. The ammonium bicarbonate in the ammonium bicarbonate storage tank 14 is recycled and sprayed back into the carbonization tower 2 through the ammonium bicarbonate solution circulation pump 15;
[0024] 2) The desulfurization absorbent in the desulfurization absorption tower 1 is transported to the mixing tank 4 through the absorption tower discharge pump 17, mixed with ammonium bicarbonate, sodium sulfate and washing liquid, and then transported to the stirred reactor 5 through the feed pump 18. In the stirred reactor 5, the desulfurized absorbent reacts with ammonium bicarbonate to generate sodium bicarbonate and ammonium sulfate in the absorbent regeneration reaction. The progress of the absorbent regeneration reaction is controlled by adjusting the rotation speed of the stirrer, the residence time of the mixed liquid and the reaction temperature;
[0025] 3) The solution after the absorbent regeneration reaction in step 2) is separated by the reactor centrifuge filter 6 to obtain a sodium bicarbonate filter cake and a separated mother liquor. The separated mother liquor enters the mother liquor buffer tank 21;
[0026] 4) The sodium bicarbonate filter cake is washed to remove residual sodium sulfate, ammonium bicarbonate and ammonium sulfate to obtain sodium bicarbonate solid and washing liquid. The washing liquid enters the mixing tank 4, and the sodium bicarbonate solid enters the absorbent preparation tank 7. The sodium bicarbonate solid is mixed with industrial water to prepare a desulfurization absorbent solution. Part of the desulfurization absorbent solution is transported to the desulfurization absorption tower 1 for flue gas desulfurization, and part of the desulfurization absorbent is used for washing the sodium bicarbonate filter cake;
[0027] 5) After adjusting the pH of the separated mother liquor in step 4) by adding sulfuric acid solution, it enters the first-stage evaporation crystallizer 19. At 80 - 100 °C, part of the sodium sulfate is separated by evaporation crystallization and enters the first-stage evaporation crystallization centrifuge separator 10 for separation. The sodium sulfate enters the mixing tank 4, and the mother liquor enters the cooling crystallizer 8 and is cooled to 10 - 30 °C. It is separated by the cooling crystallization centrifuge separator 11. The separated mixed salt enters the mother liquor buffer tank 21, and the separated mother liquor enters the second-stage evaporation crystallizer 24. At 60 - 100 °C, ammonium sulfate is separated by evaporation crystallization. The ammonium sulfate enters the ammonium sulfate thickener 26 for concentration, and after separation by the ammonium sulfate centrifuge 27, ammonium sulfate by-products are obtained, and the mother liquor returns to the cooling crystallizer 8.
Claims
1. A sodium-alkali desulfurization absorbent regeneration and resource utilization system, characterized in that: The invention comprises a desulfurization absorption tower (1), a carbonization tower (2), an ammonium carbonate thickener (3), a mixing tank (4), a stirring reactor (5), a reactor centrifugal filter (6), an absorbent preparation tank (7), a primary evaporation crystallization device, a cooling crystallizer (8), a secondary evaporation crystallization device and an ammonia water storage tank (9). The top of the desulfurization absorption tower (1) is connected to the carbonization tower (2) through a pipeline, the ammonia water storage tank (9) is connected to the carbonization tower (2), the bottom of the carbonization tower (2) is connected to the ammonium carbonate thickener (3), the top of the ammonium carbonate thickener (3) is connected to the carbonization tower (2) reflux, the bottom of the ammonium carbonate thickener (3) and the bottom of the desulfurization absorption tower (1) are respectively connected to the mixing tank (4) through pipelines, the bottom of the mixing tank (4) is connected to the stirring reactor (5) through a pipeline, the bottom of the stirring reactor (5) is connected to the reactor centrifugal filter (6), and the solution outlet pipeline of the reactor centrifugal filter (6) is divided into two pipelines respectively connected to A primary evaporation crystallization device and a mixing tank (4); another outlet pipeline of the reactor centrifugal filter (6) is connected to an absorbent preparation tank (7); the outlet pipeline of the absorbent preparation tank (7) is divided into two pipelines, which are respectively connected to the desulfurization absorption tower (1) and the reactor centrifugal filter (6); the bottom outlet pipeline of the primary evaporation crystallization device is connected to a primary evaporation crystallization centrifugal separator (10); the sodium sulfate outlet pipeline of the primary evaporation crystallization centrifugal separator (10) is connected to the mixing tank (4); the mother liquor outlet pipeline of the primary evaporation crystallization centrifugal separator (10) is connected to a cooling crystallizer (8); the outlet pipeline of the cooling crystallizer (8) is connected to a cooling crystallization centrifugal separator (11); the mixed salt outlet pipeline of the cooling crystallization centrifugal separator (11) is refluxed and connected to the primary evaporation crystallization device; the mother liquor outlet pipeline of the cooling crystallization centrifugal separator (11) is connected to a secondary evaporation crystallization device; and the secondary evaporation crystallization device is refluxed and connected to the cooling crystallizer (8).
2. A sodium-alkali desulfurization absorbent regeneration and resource utilization system as claimed in claim 1, characterized in that: The top of the desulfurization absorption tower (1) is divided into two pipelines, one pipeline is connected to the chimney, and the other pipeline is connected to the carbonization tower (2) through the booster fan (12), and the flue gas outlet pipeline at the top of the carbonization tower (2) is connected to the pipeline connected to the chimney.
3. A sodium-alkali desulfurization absorbent regeneration and resource utilization system as claimed in claim 2, characterized in that: The ammonia water storage tank (9) is connected to the carbonation tower (2) via an ammonia water pump (13), the top outlet pipeline of the ammonium carbonate thickener (3) is connected to the ammonium carbonate storage tank (14), and the ammonium carbonate storage tank (14) is divided into multiple pipelines and reflux-connected to the carbonation tower (2) via an ammonium carbonate solution circulation pump (15).
4. A sodium-alkali desulfurization absorbent regeneration and resource utilization system as claimed in claim 3, characterized in that: A pipeline connecting the bottom of the ammonium carbonate thickener (3) and the mixing tank (4) is provided with an ammonium carbonate discharge pump (16), a pipeline connecting the bottom of the desulfurization absorption tower (1) and the mixing tank (4) is provided with an absorption tower discharge pump (17), and a pipeline connecting the bottom of the mixing tank (4) and the stirred reactor (5) is provided with a feed pump (18).
5. A sodium-alkali desulfurization absorbent regeneration and resource utilization system as claimed in claim 4, characterized in that: The primary evaporation crystallization device comprises a primary evaporation crystallizer (19) and a primary evaporation crystallization heater (20); the solution outlet pipeline of the reactor centrifugal filter (6) is divided into two pipelines, one pipeline is connected to the mixing tank (4), and the other pipeline is connected in sequence to the mother liquid buffer tank (21), the mother liquid discharge pump (22) and the primary evaporation crystallizer (19); the primary evaporation crystallizer (19) is cyclically connected to the primary evaporation crystallizer (20).
6. A sodium-alkali desulfurization absorbent regeneration and resource utilization system as claimed in claim 5, characterized in that: The bottom outlet pipeline of the primary evaporation crystallizer (19) is connected in sequence to the primary evaporation crystallization discharge pump (23) and the primary evaporation crystallization centrifugal separator (10).
7. A sodium-alkali desulfurization absorbent regeneration and resource utilization system as claimed in claim 6, characterized in that: The mixed salt outlet pipeline of the cooling crystallization centrifugal separator (11) is connected to the mother liquid buffer tank (21), the secondary evaporation crystallization device comprises a secondary evaporation crystallizer (24) and a secondary evaporation crystallization heater (25), the mother liquid outlet pipeline of the cooling crystallization centrifugal separator (11) is connected to the secondary evaporation crystallizer (24), and the secondary evaporation crystallizer (24) and the secondary evaporation crystallizer (25) are cyclically connected.
8. A sodium-alkali desulfurization absorbent regeneration and resource utilization system as claimed in claim 7, characterized in that: The bottom outlet pipeline of the secondary evaporation crystallizer (24) is connected to the ammonium sulfate thickener (26) and the ammonium sulfate centrifuge (27) in sequence, and the mother liquor pipeline of the ammonium sulfate centrifuge (27) is connected to the cooling crystallizer (8).