SO2 absorption device for renewable desulfurization process
By adopting a mixed spray desulfurization technology of rich and semi-liquid liquid in the absorption tower, the problem of excessive steam consumption in the existing desulfurization process is solved, and the ultra-low emission of SO2 in the flue gas and a significant reduction in steam consumption is achieved.
Patent Information
- Application Number
- CN202421931913.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-09
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-08-09
AI Technical Summary
The steam consumption in the existing desulfurization process is too large, especially when flue gas treatment with low SO2 concentration, resulting in high energy consumption and insufficient tail discharge standards.
The absorption tower design is adopted, including the liquid-rich circulation desulfurization section, the semi-liquid circulation desulfurization section and the water-washing circulation section. Through the mixed spraying of the rich and semi-liquid liquid, the use of lean liquid is reduced and steam consumption is reduced.
It achieves ultra-low emissions of SO2 in flue gas, reduces steam consumption, saves 70% steam consumption, and improves the desulfurization effect.
Smart Images
Figure CN222918422U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of chemical engineering, in particular to a renewable desulfurization process SO 2 absorption device. Background Technique
[0002] The renewable desulfurization technology is a wet desulfurization technology. Through the absorbent in the absorption tower packing layer and the SO in the flue gas 2 fully reverse contact, a mass transfer reaction occurs to remove SO 2 The flue gas after that meets the discharge standards. Absorb SO in the flue gas 2 to form a solution rich in SO 2 (also known as rich liquor). The rich liquor is then desorbed by steam (stripped) to form a solution with a lower SO content 2 (also known as lean liquor) and sent to the so-called absorption device for recycling. The desorbed SO 2 can be processed into products such as sulfuric acid, sulfur, liquid SO 2 etc., to resourceify SO 2 .
[0003] The SO-containing flue gas generated in each production activity has different concentrations. For the flue gas with extremely high or low SO 2 concentration, the desulfurization process system will face problems such as high construction investment cost, high operation energy consumption, and even non-compliance of tail gas discharge. 2 Among them, through the analysis of the operation status of multiple desulfurization projects, the steam consumption cost accounts for more than 50% of the total operation cost of the project. For the flue gas with a lower SO
[0004] concentration, in order to meet the environmental protection requirements, the lean liquor spraying amount of the renewable desulfurization absorption device must be greater than the minimum spraying amount. However, when the lean liquor spraying amount of the desulfurization absorption device is close to the minimum spraying amount, the SO content in the formed rich liquor is still low 2 That is, when recovering one ton of SO 2 the amount of rich liquor generated reaches hundreds of tons, and desorbing to produce one ton of SO 2 requires dozens of tons or even hundreds of tons of steam, and the energy consumption of the entire process operation is very high. 2 Content of the Utility Model
[0005] In order to overcome the deficiencies of the prior art, the technical problem to be solved by the utility model is: how to improve the problem of excessive steam consumption in the existing desulfurization process.
[0006] The technical solution adopted by the utility model to solve its technical problem is:
[0007] Renewable desulfurization process SO 2Absorption device, including an absorption tower, in which a rich liquid circulating desulfurization section, a semi-lean liquid circulating desulfurization section, and a water washing circulating section are sequentially arranged from bottom to top. A rich liquid inlet pipe and a lean liquid inlet pipe are respectively and communicatively arranged for the rich liquid circulating desulfurization section and the semi-lean liquid circulating desulfurization section; a semi-lean liquid circulation system is also provided. The inlet end of the semi-lean liquid circulation system communicates with the semi-lean liquid circulating desulfurization section, and the outlet end communicates with the rich liquid inlet pipe and the lean liquid inlet pipe respectively; when the flue gas passes through the rich liquid circulating desulfurization section, the rich liquid in the rich liquid inlet pipe and the semi-lean liquid in the semi-lean liquid circulation system are mixed and sprayed onto the flue gas. When the flue gas passes through the semi-lean liquid circulating desulfurization section, the lean liquid in the lean liquid inlet pipe and the semi-lean liquid in the semi-lean liquid circulation system are mixed and sprayed onto the flue gas; the semi-lean liquid in the semi-lean liquid circulation system circulates between the semi-lean liquid circulation system and the semi-lean liquid circulating desulfurization section.
[0008] Further, the semi-lean liquid circulation system includes a semi-lean liquid circulation tank. A circulation inlet pipe is communicatively arranged between the semi-lean liquid circulation tank and the lean liquid circulation section. The liquid outlet end of the semi-lean liquid circulation tank is communicatively arranged with a circulation outlet pipe. One end of the circulation outlet pipe far from the semi-lean liquid circulation tank communicates with the rich liquid inlet pipe and the lean liquid inlet pipe respectively. A lean liquid circulation pump is arranged on the circulation outlet pipe.
[0009] Further, a rich liquid storage part is arranged at the bottom of the absorption tower. The rich liquid inlet pipe communicates with the rich liquid storage part. A rich liquid circulation pump is arranged on the rich liquid inlet pipe. And a rich liquid discharge pipe for discharging liquid to an external desorption device is communicatively arranged on the rich liquid storage part. A rich liquid pump is arranged on the rich liquid discharge pipe.
[0010] Further, a rich liquid desulfurization spraying pipe and a lean liquid desulfurization spraying pipe are respectively arranged on the upper parts of the rich liquid circulating desulfurization section and the semi-lean liquid circulating desulfurization section. The rich liquid desulfurization spraying pipe and the lean liquid desulfurization spraying pipe are both provided with spraying liquid outlets. The rich liquid inlet pipe and the circulation outlet pipe are both communicatively arranged with the rich liquid desulfurization spraying pipe; the lean liquid inlet pipe and the circulation outlet pipe are both communicatively arranged with the lean liquid desulfurization spraying pipe.
[0011] Further, a water washing outlet pipe is communicatively arranged for the water washing circulating section. The water washing outlet pipe is communicatively arranged with a water washing circulation tank. The water washing circulation tank is provided with a water washing inlet pipe communicating with the water washing circulating section. A water washing circulation pump is arranged on the water washing inlet pipe.
[0012] Further, a water supply pipe for supplementing demineralized water to the water washing circulating section is connected to the water washing inlet pipe.
[0013] Further, a communicating pipe is arranged between the water washing outlet pipe and the rich liquid discharge pipe.
[0014] The beneficial effects of the present utility model are:
[0015] Flue gas enters the rich liquor circulation desulfurization section at the bottom of the absorption tower for primary desulfurization treatment. The treated flue gas then enters the semi-lean liquor circulation desulfurization section for secondary desulfurization treatment. The two-stage desulfurization treatment ensures that the SO 2 in the flue gas can meet the ultra-low emission standards; the lean liquor in the lean liquor inlet pipe and the semi-lean liquor in the semi-lean liquor circulation system are mixed and then sprayed for desulfurization in the semi-lean liquor circulation desulfurization section. At this time, the amount of lean liquor required is less than that in the process of using lean liquor alone for desulfurization, that is, the amount of lean liquor used after desorption is reduced, further reducing the steam consumption. Moreover, when the SO 2 content in the flue gas is low, the semi-lean liquor is mixed with the rich liquor and the lean liquor respectively for primary desulfurization and secondary desulfurization, and then the SO 2 content in the rich liquor that needs to be desorbed is high, thereby further reducing the unnecessary energy loss in the desorption process. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 is a schematic diagram of the connection structure of the present utility model;
[0017] In the figure, the markings are as follows: 1 - absorption tower, 2 - rich liquor circulation desulfurization section, 3 - semi-lean liquor circulation desulfurization section, 4 - water washing circulation section, 5 - rich liquor inlet pipe, 6 - lean liquor inlet pipe, 7 - circulation outlet pipe, 8 - semi-lean liquor circulation tank, 9 - circulation inlet pipe, 10 - lean liquor circulation pump, 11 - rich liquor storage part, 12 - rich liquor circulation pump, 13 - rich liquor pump, 14 - rich liquor discharge pipe, 15 - water washing inlet pipe, 16 - water washing circulation pump, 17 - water washing circulation tank, 18 - water washing outlet pipe, 19 - water supply pipe, 20 - connecting pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0018] The present utility model will be further described below with reference to the accompanying drawings.
[0019] As Figure 1 shown, an embodiment of the present application provides a renewable desulfurization process SO 2 absorption device, including an absorption tower 1. The rich liquor circulation desulfurization section 2, the semi-lean liquor circulation desulfurization section 3 and the water washing circulation section 4 are sequentially arranged in the absorption tower 1 from bottom to top. The rich liquor inlet pipe 5 and the lean liquor inlet pipe 6 are respectively connected to the rich liquor circulation desulfurization section 2 and the semi-lean liquor circulation desulfurization section 3; a semi-lean liquor circulation system is also provided. The inlet end of the semi-lean liquor circulation system is connected to the semi-lean liquor circulation desulfurization section 3, and the outlet end is respectively connected to the rich liquor inlet pipe 5 and the lean liquor inlet pipe 6; when the flue gas passes through the rich liquor circulation desulfurization section 2, the rich liquor in the rich liquor inlet pipe 5 and the semi-lean liquor in the semi-lean liquor circulation system are mixed and sprayed onto the flue gas. When the flue gas passes through the semi-lean liquor circulation desulfurization section 3, the lean liquor in the lean liquor inlet pipe 6 and the semi-lean liquor in the semi-lean liquor circulation system are mixed and sprayed onto the flue gas; the semi-lean liquor in the semi-lean liquor circulation system circulates between the semi-lean liquor circulation system and the semi-lean liquor circulation desulfurization section 3.
[0020] First of all, it should be stated that the flue gas enters the rich liquid circulation desulfurization section 2 from the bottom of the absorption tower 1 for primary desulfurization treatment to remove most of the SO 2 After that, the treated flue gas enters the semi-lean liquid circulation desulfurization section 3 for secondary desulfurization treatment to remove the SO in the flue gas 2 to ≤ 35 mg / Nm 3 , and the two-stage desulfurization treatment ensures that the SO2 in the flue gas can meet the ultra-low emission standard; moreover, the lean liquid in the lean liquid inlet pipe 6 and the semi-lean liquid in the semi-lean liquid circulation system are mixed and then sprayed for desulfurization in the semi-lean liquid circulation desulfurization section 3. At this time, the amount of lean liquid required is less than that in the process of using lean liquid alone for desulfurization, that is, the usage amount of the lean liquid after desorption is reduced, and further the steam consumption is reduced; and when the SO 2 content in the flue gas is low, the semi-lean liquid is mixed with the rich liquid and the lean liquid respectively for primary desulfurization and secondary desulfurization, and then the SO in the rich liquid that needs to be desorbed 2 has a higher content, thus further reducing the unnecessary energy loss in the desorption process; specifically, in the improved process, the lean liquid required for desorption during the desulfurization process is only 30% of that before improvement, which is equivalent to saving 70% of the steam.
[0021] Moreover, the above lean liquid circulation system includes a semi-lean liquid circulation tank 8. A circulation inlet pipe 9 is connected between the semi-lean liquid circulation tank 8 and the lean liquid circulation section. The outlet end of the semi-lean liquid circulation tank 8 is connected with a circulation outlet pipe 7. The circulation outlet pipe 7 and one end of the semi-lean liquid circulation tank 8 are respectively connected with the rich liquid inlet pipe 5 and the lean liquid inlet pipe 6. The circulation outlet pipe 7 is provided with a lean liquid circulation pump 10. That is to say, the semi-lean liquid in the semi-lean liquid circulation tank 8 can be mixed with the rich liquid in the rich liquid inlet pipe 5 to carry out the desulfurization process in the rich liquid circulation desulfurization section 2, and the semi-lean liquid in the semi-lean liquid circulation tank 8 can also be mixed with the lean liquid in the lean liquid inlet pipe 6 to carry out the desulfurization process in the semi-lean liquid circulation desulfurization section 3. By mixing the semi-lean liquid and the lean liquid, the amount of lean liquid required in the semi-lean liquid circulation desulfurization section 3 can be reduced, thereby reducing the amount of lean liquid that needs to be desorbed. Moreover, by mixing the rich liquid and the semi-lean liquid in the rich liquid circulation desulfurization section 2, a desulfurizer with a certain SO 2 absorbing capacity can be generated, and this desulfurizer can absorb most of the SO in the flue gas to a certain extent 2 ; through primary desulfurization and secondary desulfurization, the SO in the flue gas can be efficiently absorbed 2 , and the usage amount of the lean liquid can be reduced, the steam usage amount in the desorption process can be reduced, and the operation cost can be reduced. And the semi-lean liquid in the semi-lean liquid circulation tank 8 is formed by the reflux of the solution after the desulfurization in the semi-lean liquid circulation desulfurization section 3, forming a semi-lean liquid with an SO 2 content higher than that of the lean liquid and lower than that of the rich liquid.
[0022] Moreover, the above-mentioned water washing circulation section 4 can recover the desulfurizer entrained in the flue gas through the way of circulating water washing, reducing the desulfurizer entrained in the flue gas. Specifically, a water washing effluent pipe 18 is connected to the water washing circulation section 4. The water washing effluent pipe 18 is connected to a water washing circulation tank 17. A water washing inlet pipe 15 connected to the water washing circulation section 4 is arranged on the water washing circulation tank 17. A water washing circulation pump 16 is arranged on the water washing inlet pipe 15. The water washing circulation tank 17 sprays the circulating water to the water washing circulation section 4 through the action of the water washing circulation pump 16 through the water washing inlet pipe 15 to wash the desulfurizer in the flue gas. A water supply pipe 19 for supplementing demineralized water to the water washing circulation section 4 is connected to the water washing inlet pipe 15. The demineralized water continuously provided by the water supply pipe 19 can supplement the water balance. Moreover, a connecting pipe 20 is arranged between the water washing effluent pipe 18 and the rich liquid drain pipe 14, which can guide the circulating liquid containing more desulfurizer from the water washing circulation section 4 to the rich liquid drain pipe 14 to be discharged outwards for subsequent reuse of the desulfurizer, reducing the internal circulation content of the desulfurizer in the water washing circulation tank 17, ensuring a lower desulfurizer content in the circulating liquid, and thus achieving the purpose of recovering the desulfurizer in the circulating liquid.
[0023] Furthermore, in order to reduce energy consumption, a rich liquid storage part 11 is arranged at the bottom of the above-mentioned absorption tower 1. The rich liquid inlet pipe 5 is connected to the rich liquid storage part 11. A rich liquid circulation pump 12 is arranged on the rich liquid inlet pipe 5. Moreover, a rich liquid drain pipe 14 for discharging liquid to an external desorption device is also connected to the rich liquid storage part 11. A rich liquid pump 13 is arranged on the rich liquid drain pipe 14. That is to say, the rich liquid in the rich liquid inlet pipe 5 comes from the rich liquid after desulfurization in the absorption tower 1. A part of the rich liquid in the rich liquid storage part 11 is discharged and desorbed to form lean liquid, and the other part is sent to the rich liquid circulating desulfurization section 2 through the rich liquid inlet pipe 5 for action, reducing the amount of rich liquid discharged and desorbed externally, thereby further reducing the steam consumption.
[0024] The above-mentioned rich liquid pump 13 can discharge part of the rich liquid in the rich liquid storage part 11 to the desorption device through the rich liquid drain pipe 14, and the lean liquid formed after the desorption reaction of the rich liquid by the desorption device is sent into the lean liquid inlet pipe 6 to participate in the reaction of the absorption tower 1 again.
[0025] Rich liquid desulfurization spray pipes and lean liquid desulfurization spray pipes are respectively arranged on the upper parts of the above-mentioned rich liquid circulating desulfurization section 2 and the semi-lean liquid circulating desulfurization section 3. The spray density of the spray pipes of the rich liquid circulating desulfurization section 2 and the semi-lean liquid circulating desulfurization section 3 is 4 - 20m 3 / m 2.h, where the ratio of semi-lean liquid to lean liquid in the semi-lean liquid circulating desulfurization section 3 is 2 - 10:1; both the rich liquid desulfurization spraying pipe and the lean liquid desulfurization spraying pipe are provided with spraying liquid outlets, and both the rich liquid inlet pipe 5 and the circulating outlet pipe 7 are communicated with the rich liquid desulfurization spraying pipe; both the lean liquid inlet pipe 6 and the circulating outlet pipe 7 are communicated with the lean liquid desulfurization spraying pipe. That is to say, the rich liquid from the rich liquid inlet pipe 5 and the semi-lean liquid from the circulating outlet pipe 7 come into contact and mix in advance before spraying out from the corresponding spraying liquid outlets, so that the mixed liquid sprayed from the spraying liquid outlets is more evenly mixed and has a better effect.
[0026] In one embodiment, the flue gas contains SO 2 of 1100 - 11000 mg / m 3 , the flue gas volume is 200000 Nm 3 / h. The data before improvement are: the diameter of the desulfurization tower is about 7 m, the spraying amount of the desulfurizer is about 135 t / h, and the SO 2 in the flue gas discharged after desulfurization is 150 - 400 mg / m 3 ; in the improved scheme, the diameter of the desulfurization tower is about 7 m, the mixed liquid of semi-lean liquid and lean liquid sprayed in the semi-lean liquid circulating desulfurization section is about 250 t / h, and the desulfurizer spraying density in the semi-lean liquid circulating desulfurization section 3 is 6.5 m 3 / m 2 .h; the amount of lean liquid coming from desorption is 50 t / h, the semi-lean liquid in the lean liquid circulating tank is 200 t / h, and the ratio of semi-lean liquid to lean liquid is 4:1; the mixed liquid of semi-lean liquid and rich liquid sprayed in the rich liquid circulating desulfurization section 2 is 270 t / h, and the desulfurizer spraying density in the rich liquid circulating desulfurization section is 7 m 3 / m 2 .h; the amount of semi-lean liquid coming from the lean liquid circulating tank is 50 t / h, the rich liquid is 220 t / h, and the SO 2 in the flue gas discharged after desulfurization is ≤ 35 mg / m 3 ; It can be concluded from the actual data that the scheme in the embodiment of the present application not only reduces the consumption of lean liquid after desorption, thereby reducing steam consumption, but also has a better desulfurization effect.
Claims
1. A regenerative desulfurization process SO2 absorption device, characterized in that: The invention comprises an absorption tower (1), wherein a rich liquid circulating desulfurization section (2), a semi-lean liquid circulating desulfurization section (3) and a water washing circulating section (4) are sequentially arranged in the absorption tower (1) from bottom to top, wherein the rich liquid circulating desulfurization section (2) and the semi-lean liquid circulating desulfurization section (3) are respectively connected to a rich liquid inlet pipe (5) and a lean liquid inlet pipe (6); a semi-lean liquid circulating system is also arranged, wherein the inlet end of the semi-lean liquid circulating system is connected to the semi-lean liquid circulating desulfurization section (3) and the outlet end is respectively connected to the semi-lean liquid circulating desulfurization section (3). The rich liquid inlet pipe (5) and the lean liquid inlet pipe (6) are connected; when the flue gas passes through the rich liquid circulating desulfurization section (2), the rich liquid in the rich liquid inlet pipe (5) and the semi-lean liquid in the semi-lean liquid circulating system are mixed and then sprayed onto the flue gas; when the flue gas passes through the semi-lean liquid circulating desulfurization section (3), the lean liquid in the lean liquid inlet pipe (6) and the semi-lean liquid in the semi-lean liquid circulating system are mixed and then sprayed onto the flue gas; the semi-lean liquid in the semi-lean liquid circulating system circulates between the semi-lean liquid circulating system and the semi-lean liquid circulating desulfurization section (3).
2. The regenerative desulfurization process SO2 absorption device according to claim 1 is characterized in that: The semi-lean liquid circulation system comprises a semi-lean liquid circulation tank (8), a circulating liquid inlet pipe (9) is connected between the semi-lean liquid circulation tank (8) and the semi-lean liquid circulation desulfurization section (3), the liquid outlet end of the semi-lean liquid circulation tank (8) is connected with a circulating liquid outlet pipe (7), the circulating liquid outlet pipe (7) is respectively connected with the rich liquid inlet pipe (5) and the lean liquid inlet pipe (6), and the circulating liquid outlet pipe (7) is provided with a lean liquid circulation pump (10).
3. The regenerative desulfurization process SO2 absorption device according to claim 2 is characterized in that: A rich liquid storage section (11) is provided at the bottom of the absorption tower (1), the rich liquid inlet pipe (5) is connected to the rich liquid storage section (11), the rich liquid inlet pipe (5) is provided with a rich liquid circulation pump (12), and the rich liquid storage section (11) is also connected to a rich liquid discharge pipe (14) for discharging liquid to an external desorption device, and the rich liquid discharge pipe (14) is provided with a rich liquid pump (13).
4. The regenerative desulfurization process SO2 absorption device according to claim 3 is characterized in that: A rich liquid desulfurization spray pipe and a lean liquid desulfurization spray pipe are respectively arranged at the upper part of the rich liquid circulating desulfurization section (2) and the semi-lean liquid circulating desulfurization section (3); the rich liquid desulfurization spray pipe and the lean liquid desulfurization spray pipe are both provided with liquid spraying ports; the rich liquid inlet pipe (5) and the circulating liquid outlet pipe (7) are both connected to the rich liquid desulfurization spray pipe; the lean liquid inlet pipe (6) and the circulating liquid outlet pipe (7) are both connected to the lean liquid desulfurization spray pipe.
5. The regenerative desulfurization process SO2 absorption device according to claim 3 is characterized in that: The water washing circulation section (4) is connected to a water washing liquid outlet pipe (18), the water washing liquid outlet pipe (18) is connected to a water washing circulation tank (17), the water washing circulation tank (17) is provided with a water washing liquid inlet pipe (15) connected to the water washing circulation section (4), and the water washing liquid inlet pipe (15) is provided with a water washing circulation pump (16).
6. The regenerative desulfurization process SO2 absorption device according to claim 5 is characterized in that: The water washing liquid inlet pipe (15) is connected to a water supply pipe (19) for replenishing desalted water to the water washing circulation section (4).
7. The regenerative desulfurization process SO2 absorption device according to claim 6 is characterized in that: A connecting pipe (20) is provided between the water washing liquid outlet pipe (18) and the rich liquid discharge pipe (14).