Recovery treatment system and method for CO2 external exhaust gas of gas-based shaft furnace

Abstract

The invention discloses a system and a method for recycling CO2 external exhaust gas of a gas-based shaft furnace. The system comprises a sulfur incineration system, a lime slurry supply system, a desulfurization system and a gypsum preparation system, the sulfur incineration system comprises a gas scrubber and a sulfur incinerator; the CO2 external exhaust pipeline is sequentially communicated with the gas scrubber and the sulfur incinerator; the lime slurry supply system comprises a lime slurry pool; the desulfurization system comprises a dust remover, a desulfurization tower, a lime slurry pump, an oxidation air blower and a lime slurry circulating pump; a gas outlet of the sulfur incinerator is sequentially communicated with a dust remover and a gas inlet of a desulfurizing tower; a slurry outlet of the lime slurry pool is communicated with a lime slurry inlet of the desulfurization tower through a lime slurry pump, and a lime slurry outlet of the desulfurization tower is communicated with a circulating liquid inlet of the lime slurry pool through a lime slurry circulating pump. According to the system and the method, H2S in CO2 is removed, and the purposes of reducing atmospheric pollution, protecting the environment and utilizing resources are achieved.

Description

Technical Field

[0001] The present invention relates to a gas processing technology, in particular to a system and method for recovering and processing CO2 exhaust gas from a gas-based vertical furnace. Background Art

[0002] Direct reduction technology has the advantages of low carbon emissions, clean reduction products, and efficient reduction reactions. Reactor production of direct reduced iron technology will be widely used. The reducing gases usually used in reactors are natural gas and coke oven gas. In the process of gas-based vertical furnaces, in order to protect the furnace tubes of the heating furnace, DMDS (dimethyl disulfide) is injected through the sulfur addition system, and converted into H2S through catalysis and added to the process gas to avoid corrosion of the furnace tubes of the process gas heating furnace. Therefore, H2S will mix with the process gas and be discharged along the flow mixed with carbon dioxide; the production of sulfides will pollute the environment.

[0003] For the sulfides in the exhaust gas of carbon dioxide, appropriate treatment measures need to be taken to remove the sulfides and recover the CO2 for utilization, so as to reduce the harm to the environment and realize the recycling of CO2 resources. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a recovery and treatment system for gas-based vertical furnace CO2 exhaust gas which can effectively recover sulfides therein; the present invention also provides a recovery and treatment method for gas-based vertical furnace CO2 exhaust gas.

[0005] In order to solve the above technical problems, the technical solution adopted by the system of the present invention is: it includes a sulfur incineration system, a lime slurry supply system, a desulfurization system and a gypsum preparation system; The sulfur incineration system includes a gas scrubber and a sulfur incinerator; the CO2 external exhaust pipeline is connected to the gas scrubber and the sulfur incinerator in sequence; The lime slurry supply system comprises a lime slurry tank; The desulfurization system includes a dust collector, a desulfurization tower, a lime slurry pump, an oxidation blower and a lime slurry circulation pump; the gas outlet of the sulfur incinerator is connected to the dust collector and the gas inlet of the desulfurization tower in sequence; the slurry outlet of the lime slurry pool is connected to the lime slurry inlet of the desulfurization tower through the lime slurry pump, and the lime slurry outlet of the desulfurization tower is connected to the circulating liquid inlet of the lime slurry pool through the lime slurry circulation pump; the inlet of the oxidation blower is connected to the oxygen pipeline, and the outlet is connected to the oxygen inlet of the lime slurry pool; The gypsum preparation system comprises a belt filter, and the belt filter is connected to the gypsum slurry outlet of the lime slurry pool.

[0006] Furthermore, the lime slurry supply system also includes a lime silo, a compensation water pump, a compensation water tank, a lime slurry storage pump and a lime slurry storage tank; the lime silo is connected to the lime inlet of the lime slurry storage tank, and the compensation water tank is connected to the water inlet of the lime slurry storage tank through the compensation water pump; the lime slurry outlet of the lime slurry storage tank is connected to the slurry inlet of the lime slurry storage tank through the lime slurry storage pump.

[0007] Furthermore, the gypsum preparation system also includes a lime slurry pump, a gypsum slurry tank, a gypsum slurry pump and a compensation water tank; the gypsum slurry outlet of the lime slurry tank is connected to the inlet of the gypsum slurry tank through the lime slurry pump, and the outlet of the gypsum slurry tank is connected to the slurry inlet of the belt filter through the gypsum slurry pump; the filtrate outlet of the belt filter is connected to the compensation water tank.

[0008] Furthermore, the desulfurization system also includes a dust removal pool; the dust outlet of the dust collector is connected to the dust inlet of the dust removal pool.

[0009] In order to solve the above technical problems, the method of the present invention adopts the above system, and the technical solution adopted includes the following steps: 1) the CO2 exhaust gas is washed by a gas scrubber and then enters a sulfur incinerator for combustion, and the hydrogen sulfide gas in the CO2 exhaust gas is converted into SO2 and water to obtain incineration gas; 2) The incineration gas enters the desulfurization tower after dust removal, and the SO2 in the gas reacts with the lime slurry entering the desulfurization tower to generate CaSO3; the lime slurry is recycled, and after the CaSO3 content in the lime slurry is enriched, oxygen is introduced to convert the CaSO3 into CaSO4 to obtain gypsum slurry; 3) The gypsum slurry is filtered to obtain gypsum.

[0010] Furthermore, in step 2), the lime slurry is formed by mixing the lime in the lime bin with water provided by the compensation water tank.

[0011] Furthermore, in step 3), the gypsum slurry first enters a gypsum slurry tank and is then filtered through a belt filter; the filtered filtrate enters a compensation water tank.

[0012] Furthermore, in step 2), the dust generated by the dust removal enters the dust removal pool for collection.

[0013] The beneficial effects of adopting the above technical solution are: The present invention removes H2S from CO2 to achieve the goals of reducing air pollution, protecting the environment and utilizing resources; it can successfully reduce the emission of acidic gases, effectively protect the environment, and convert desulfurization products into valuable products, further increasing economic benefits. After desulfurization treatment, the CO2 content in the gas is increased, which provides an important prerequisite for CO2 refining, is conducive to improving the purity and quality of CO2, and meets the needs of different fields. This measure has not only achieved remarkable results in environmental protection, but also achieved dual benefits in economy and technology, and promoted the recycling of resources and the efficient use of energy. By scientifically and rationally setting up the desulfurization system, the operating efficiency and energy utilization rate of the production equipment are improved, and at the same time, a solid foundation is laid for the sustainable development of the enterprise. The present invention aims at removing the hydrogen sulfide gas mixed into the process gas due to the addition of DMDS during sulfur addition, and has important reference and guiding significance for enterprises that need to add DMDS in the subsequent direct reduction technology. The present invention adopts the conversion of the sulfur existing form, removes the hydrogen sulfide that is about to be discharged into the atmosphere through the desulfurization tower, prevents the hydrogen sulfide from entering the atmosphere, avoids the pollution problems caused by it, and reduces the damage to the occupational health of employees. At the same time, the product can also be oxidized, separated, and crystallized to make gypsum for product utilization.

[0014] Features and outstanding advantages of the present invention: 1. Low investment cost: The required equipment is basically non-closed equipment, and the requirements for equipment materials are not high, so the cost is low.

[0015] 2. Low operating cost: In the design of the present invention, the desulfurizing agent is lime, which is cheap and only requires sufficient water and electricity, and a small amount of coal gas and oxygen to complete the desulfurization.

[0016] 3. High desulfurization efficiency: The desulfurization tower is used to spray and atomize the desulfurizer to increase the contact area, so that the desulfurizer is fully in contact with the gas to be desulfurized, the desulfurization process is accelerated, and the desulfurization efficiency is improved.

[0017] 4. Great potential for expansion: The products generated by desulfurization can be used to make gypsum, and the gypsum factory can be expanded to produce gypsum in the future. The main component of the gas after desulfurization is carbon dioxide, and the carbon dioxide refining project can be added in the future to obtain pure carbon dioxide, which can be sold to make soda, dry ice and other products.

[0018] 5. Sulfur form conversion, better desulfurization effect: It is difficult to directly remove hydrogen sulfide, and the reaction is not thorough, so the desulfurization effect is poor. Converting hydrogen sulfide into sulfur dioxide and then removing sulfides will make the reaction more thorough and the desulfurization effect better.

[0019] 6. Easy post-maintenance: Part of the desulfurization process is the dry desulfurization process, which has mature technology, rich experience and is easy for post-maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0021] Figure 1 It is a schematic diagram of the system structure of the present invention; Figure 2 is a structural schematic diagram of the lime slurry supply system of the present invention; Figure 3 It is a structural schematic diagram of the sulfur incineration system of the present invention; Figure 4 It is a schematic diagram of the structure of the desulfurization system of the present invention; Figure 5 It is a structural schematic diagram of the gypsum preparation system of the present invention.

[0022] In the figure: 1. Lime silo; 2. Lime replenishment regulating valve; 3. Lime replenishment stop valve; 4. Compensation water pump stop valve; 5. Compensation water pump regulating valve; 6. Compensation water pump; 7. Compensation water stop valve; 8. Compensation water regulating valve; 9. Compensation water tank; 10. Lime slurry tank; 11. 1# lime slurry regulating valve; 12. 1# lime slurry stop valve; 13. Lime slurry storage pump; 14. Lime slurry storage regulating valve; 15. Lime slurry storage stop valve; 16. Lime slurry storage tank; 17. Gas scrubber; 18. Gas scrubber flue gas stop valve; 19. Gas scrubber flue gas regulating valve; 20. Chimney; 21. Reflux gas stop valve; 22. Reflux gas regulating valve; 23. Sulfur incinerator; 24. Sulfur incinerator flue gas stop valve; 25. Sulfur incinerator flue gas regulating valve; 26. Incineration dust removal stop valve; 27. Incineration dust collector regulating valve; 28. Dust collector; 29. ​​Dust removal and desulfurization stop valve; 30. Dust removal and desulfurization regulating valve; 31. Desulfurization tower; 32. Desulfurization tower flue gas stop valve; 33. Desulfurization tower flue gas regulating valve; 20. Chimney; 34. 2# lime slurry stop valve; 35. 2# lime slurry regulating valve; 36. Lime slurry pump; 37. Oxidation blower regulating valve; 38. Oxidation blower stop valve; 39. Oxidation blower; 40. Lime slurry circulation pump; 41. Dust removal pump; 42. Dust removal tank; 43. 3# lime slurry stop valve; 44. 3# lime slurry regulating valve; 45. Gypsum slurry box; 46. Gypsum slurry pump; 47. Gypsum slurry stop valve; 48. Gypsum slurry regulating valve; 49. Belt filter; 50. Gypsum storage tank. DETAILED DESCRIPTION

[0023] Figure 1As shown, the recovery and treatment system of CO2 exhaust gas from the gas-based vertical furnace includes a sulfur incineration system, a desulfurization system, a lime slurry supply system and a gypsum preparation system; the sulfur incineration system is used to incinerate CO2 exhaust gas, the desulfurization system uses lime slurry to remove sulfur from the incineration gas output by the sulfur incineration system, the lime slurry supply system is used to provide lime slurry for the desulfurization system, and the gypsum preparation system is used to prepare gypsum from the sulfur removed by the desulfurization system.

[0024] Figure 3 As shown, the gas-based vertical furnace CO2 external exhaust gas recovery and treatment system, the sulfur incineration system includes a gas scrubber 17 and a sulfur incinerator 23; the CO2 external exhaust pipeline is connected to the air inlet of the gas scrubber 17, and the gas outlet of the gas scrubber 17 is connected to the air inlet of the sulfur incinerator 23. A reflux gas stop valve 21 and a reflux gas regulating valve 22 are provided on the pipeline between the gas scrubber 17 and the sulfur incinerator 23.

[0025] Figure 2 As shown, the gas-based vertical furnace CO2 exhaust gas recovery and treatment system, the lime slurry supply system includes a lime slurry tank 10, a lime silo 1, a compensation water pump 6, a compensation water tank 9, a lime slurry storage pump 13 and a lime slurry storage tank 16. The lime silo 1 is connected to the lime inlet of the lime slurry storage tank 16, the compensation water tank 9 is connected to the water inlet of the lime slurry storage tank 16 through the compensation water pump 6; the lime slurry outlet of the lime slurry storage tank 16 is connected to the slurry inlet of the lime slurry storage tank 10 through the lime slurry storage pump 13. A compensation water stop valve 7 and a compensation water regulating valve 8 are provided on the pipeline between the compensation water tank 9 and the compensation water pump 6, a compensation water pump stop valve 4 and a compensation water pump regulating valve 5 are provided on the pipeline between the compensation water pump 6 and the lime slurry storage tank 16, a lime slurry storage regulating valve 14 and a lime slurry storage stop valve 15 are provided on the pipeline between the lime slurry storage tank 16 and the lime slurry storage pump 13, and a 1# lime slurry regulating valve 11 and a 1# lime slurry stop valve 12 are provided on the pipeline between the lime slurry storage pump 13 and the lime slurry tank 10. The lime slurry tank 10 is provided with a stirring device, and the lime slurry storage tank 16 is provided with a stirring device.

[0026] Figure 4As shown, the gas-based vertical furnace CO2 exhaust gas recovery and treatment system, the desulfurization system includes a dust collector 28, a desulfurization tower 31, a lime slurry pump 36, an oxidation blower 39, a lime slurry circulation pump 40 and a dust removal pool 42. In the sulfur incineration system, the gas outlet of the sulfur incinerator 23 is connected to the air inlet of the dust collector 28, and the gas outlet of the dust collector 28 is connected to the air inlet of the desulfurization tower 31. The desulfurization tower 31 is provided with a spray device. In the lime slurry supply system, the slurry outlet of the lime slurry pool 10 is connected to the lime slurry inlet of the desulfurization tower 31 through the lime slurry pump 36, and the lime slurry outlet of the desulfurization tower 31 is connected to the circulating liquid inlet of the lime slurry pool 10 through the lime slurry circulation pump 40; the inlet of the oxidation blower 39 is connected to the oxygen pipeline, and the outlet is connected to the oxygen inlet of the lime slurry pool 10. The ash outlet of the dust collector 28 is connected to the ash inlet of the dust removal pool 42, and the ash outlet of the dust removal pool 42 is connected to a dust removal pump 41 for discharging the dust removal liquid mixed with the collected ash and water. The pipeline between the sulfur incinerator 23 and the dust collector 28 is provided with an incineration dust removal stop valve 26 and an incineration dust collector regulating valve 27, the pipeline between the dust collector 28 and the desulfurization tower 31 is provided with a dust removal and desulfurization stop valve 29 and a dust removal and desulfurization regulating valve 30, the pipeline between the lime slurry pump 36 and the desulfurization tower 31 is provided with a 2# lime slurry stop valve 34 and a 2# lime slurry regulating valve 35, and the pipeline between the oxidation blower 39 and the lime slurry pool 10 is provided with an oxidation blower regulating valve 37 and an oxidation blower stop valve 38. The dust removal pool 42 is provided with a stirring device.

[0027] Figure 5 As shown, the gas-based vertical furnace CO2 exhaust gas recovery and treatment system, the gypsum preparation system includes a lime slurry pump 36, a gypsum slurry tank 45, a gypsum slurry pump 46, a belt filter 49 and a compensation water tank 9. The gypsum slurry outlet of the lime slurry tank 10 in the lime slurry supply system is also connected to the inlet of the gypsum slurry tank 45 through the lime slurry pump 36, the outlet of the gypsum slurry tank 45 is connected to the slurry inlet of the belt filter 49 through the gypsum slurry pump 46, the solid material outlet of the belt filter 49 is connected to the gypsum storage tank 50; the filtrate outlet of the belt filter 49 is connected to the compensation water tank 9. The pipeline between the lime slurry pump 36 and the gypsum slurry tank 45 is provided with a 3# lime slurry stop valve 43 and a 3# lime slurry regulating valve 44, and the pipeline between the gypsum slurry pump 46 and the belt filter 49 is provided with a gypsum slurry stop valve 47 and a gypsum slurry regulating valve 48. The gypsum slurry tank 45 is provided with a stirring device.

[0028] Figure 3 , Figure 4As shown, the gas-based vertical furnace CO2 external exhaust gas recovery and treatment system is also provided with a chimney 20. In the sulfur incineration system, the gas outlet of the gas scrubber 17 is also connected to the chimney 20, and the gas outlet of the sulfur incinerator 23 is also connected to the chimney 20; the pipeline between the gas scrubber 17 and the chimney 20 is provided with a gas scrubber flue gas stop valve 18 and a gas scrubber flue gas regulating valve 19, and the pipeline between the sulfur incinerator 23 and the chimney 20 is provided with a sulfur incinerator flue gas stop valve 24 and a sulfur incinerator flue gas regulating valve 25. In the desulfurization system, the exhaust port of the desulfurization tower 31 is connected to the chimney 20, and the pipeline between the desulfurization tower 31 and the chimney 20 is provided with a desulfurization tower flue gas stop valve 32 and a desulfurization tower flue gas regulating valve 33.

[0029] Figure 1-Figure 5 As shown, the recovery and treatment method of the CO2 exhaust gas of the gas-based vertical furnace includes the following steps: 1) The lime slurry is mixed with the lime in the lime silo 1 and the water provided by the compensation water tank 9. The specific operation process is: confirm that there is lime in the lime silo 1, open the lime replenishment regulating valve 2 and the lime replenishment stop valve 3, and add lime to the lime slurry storage 16; start the compensation water pump, water flows into the compensation water tank 9, open the compensation water pump stop valve 4, the compensation water pump regulating valve 5, the compensation water pump 6, the compensation water stop valve 7 and the compensation water regulating valve 8, and add water to the lime slurry storage tank 16; start the stirring device of the lime slurry storage tank 16 to stir, so that there is a certain amount of reserved lime slurry in the lime slurry storage tank 16. Start the lime slurry storage pump 13, open the lime slurry storage pump regulating valve 14, the lime slurry storage pump stop valve 15, the 1# lime slurry regulating valve 11 and the 1# lime slurry stop valve 12, and let the lime slurry flow into the lime slurry tank 10 to establish the lime slurry tank liquid level.

[0030] 2) After being washed by the gas scrubber 17, the CO2 exhaust gas enters the sulfur incinerator 23 for combustion, and the hydrogen sulfide gas in the CO2 exhaust gas is converted into SO2 and water to obtain incineration gas. The specific operation process is: first, the sulfur incinerator 23 must be started, and after the sulfur incinerator 23 is successfully ignited, the CO2 exhaust gas is connected. At this time, the sulfur incinerator flue gas stop valve 24 and the sulfur incinerator flue gas regulating valve 25 are in an open state, and the return gas stop valve 21 and the return gas regulating valve 22 are slowly opened. At the same time, the gas scrubber flue gas regulating valve 19 is adjusted to ensure that the pressure and liquid level of the gas scrubber 17 are in a normal state, and the temperature and pressure in the sulfur incinerator 23 are in a normal state. The sulfur incinerator flue gas regulating valve 25 is also adjusted synchronously to ensure smooth connection. Finally, the gas scrubber flue gas regulating valve 19 is closed, and then the gas scrubber flue gas stop valve 18 is closed; H2S is converted into SO2 in the sulfur incinerator 23. Open the incineration dust removal stop valve 26 and the incineration dust collector regulating valve 27, start the dust collector 28, and the gas enters the dust collector 28 for dust removal. Then the gas can enter the desulfurization tower 31 of the desulfurization system to prepare for desulfurization.

[0031] 3) The incineration gas enters the desulfurization tower 31 after dust removal, and the SO2 therein reacts with the lime slurry entering the desulfurization tower 31 to generate CaSO3; the lime slurry is recycled, and after the CaSO3 content in the lime slurry is enriched, oxygen is introduced to convert CaSO3 into CaSO4 to obtain gypsum slurry. The specific operation process is: first, the liquid level of the desulfurization system is established, the lime slurry pump 36 is started, and the 2# lime slurry stop valve 34 and the 2# lime slurry regulating valve 35 are opened to establish the liquid level of the desulfurization tower 31; the lime slurry circulation pump 40 is started, and the spraying device of the desulfurization tower is started to spray the desulfurization agent. The dust removal pool 42 is filled with water to adsorb the dust, and the dust removal liquid is discharged by starting the dust removal pump 41. Slowly open the dust removal and desulfurization stop valve 29 and the dust removal and desulfurization regulating valve 30 to allow the dust-removed incineration gas to enter the desulfurization tower 31 for desulfurization. Start the spray device of the desulfurization tower 31; SO2 in the incineration gas reacts with the lime slurry to generate CaSO3, which enters the lime slurry pool 10 through the lime slurry circulation pump 40; open the oxidation blower regulating valve 37 and the oxidation blower stop valve 38, start the oxidation blower 39, and convert CaSO3 into CaSO4 to provide raw materials for the subsequent gypsum preparation.

[0032] 4) The gypsum slurry first enters the gypsum slurry tank 45, and then is filtered through the belt filter 49; the filtered filtrate enters the compensation water tank 9. The specific operation process is: after step 3) desulfurization for a period of time, when there is enough CaSO4 in the lime slurry tank 10, the 3# lime slurry stop valve 43 and the 3# lime slurry regulating valve 44 can be opened to flow the gypsum slurry into the gypsum slurry tank. After the gypsum slurry tank is stored for a period of time, the gypsum slurry pump 46, the gypsum slurry stop valve 47 and the gypsum slurry regulating valve 48 are opened to flow the gypsum slurry into the belt filter 49. Through filtration, the gypsum slurry is divided into gypsum and filtrate-water, and the water enters the compensation water tank 9 to provide compensation water.

Claims

1. A system for recovering and treating CO2 exhaust gas from a gas-based vertical furnace, characterized in that: It includes a sulfur incineration system, a lime slurry supply system, a desulfurization system and a gypsum preparation system; The sulfur incineration system comprises a gas scrubber (17) and a sulfur incinerator (23); the CO2 external exhaust pipeline is connected to the gas scrubber (17) and the sulfur incinerator (23) in sequence; The lime slurry supply system comprises a lime slurry tank (10); The desulfurization system comprises a dust collector (28), a desulfurization tower (31), a lime slurry pump (36), an oxidation blower (39) and a lime slurry circulation pump (40); the gas outlet of the sulfur incinerator (23) is connected to the dust collector (28) and the gas inlet of the desulfurization tower (31) in sequence; the slurry outlet of the lime slurry pool (10) is connected to the lime slurry inlet of the desulfurization tower (31) through the lime slurry pump (36), and the lime slurry outlet of the desulfurization tower (31) is connected to the circulating liquid inlet of the lime slurry pool (10) through the lime slurry circulation pump (40); the inlet of the oxidation blower (39) is connected to the oxygen pipeline, and the outlet is connected to the oxygen inlet of the lime slurry pool (10); The gypsum preparation system comprises a belt filter (49), wherein the belt filter (49) is connected to a gypsum slurry outlet of a lime slurry pool (10).

2. A gas-based vertical furnace CO2 exhaust recovery and treatment system according to claim 1, characterized in that: The lime slurry supply system further comprises a lime silo (1), a compensation water pump (6), a compensation water tank (9), a lime slurry storage pump (13) and a lime slurry storage tank (16); the lime silo (1) is connected to a lime inlet of the lime slurry storage tank (16); the compensation water tank (9) is connected to a water inlet of the lime slurry storage tank (16) via the compensation water pump (6); and the lime slurry outlet of the lime slurry storage tank (16) is connected to a slurry inlet of the lime slurry storage tank (10) via the lime slurry storage pump (13).

3. A gas-based vertical furnace CO2 exhaust gas recovery and treatment system according to claim 1, characterized in that: The gypsum preparation system further comprises a lime slurry pump (36), a gypsum slurry tank (45), a gypsum slurry pump (46) and a compensation water tank (9); the gypsum slurry outlet of the lime slurry tank (10) is connected to the inlet of the gypsum slurry tank (45) via the lime slurry pump (36), and the outlet of the gypsum slurry tank (45) is connected to the slurry inlet of the belt filter (49) via the gypsum slurry pump (46); and the filtrate outlet of the belt filter (49) is connected to the compensation water tank (9).

4. A gas-based vertical furnace CO2 exhaust gas recovery and treatment system according to claim 1, 2 or 3, characterized in that: The desulfurization system further comprises a dust removal pool (42); an ash outlet of the dust collector (28) is connected to an ash inlet of the dust removal pool (42).

5. A method for recovering and treating CO2 exhaust gas from a gas-based vertical furnace, using the system according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: 1) the CO2 exhaust gas is washed by a gas scrubber (17) and then enters a sulfur incinerator (23) for combustion, whereby hydrogen sulfide gas in the CO2 exhaust gas is converted into SO2 and water to obtain incineration gas; 2) The incineration gas enters the desulfurization tower (31) after dust removal, and the SO2 in the incineration gas reacts with the lime slurry entering the desulfurization tower (31) to generate CaSO3; the lime slurry is recycled, and after the CaSO3 content in the lime slurry is enriched, oxygen is introduced to convert the CaSO3 into CaSO4 to obtain gypsum slurry; 3) The gypsum slurry is filtered to obtain gypsum.

6. A method for recovering and treating CO2 exhaust gas from a gas-based vertical furnace according to claim 5, characterized in that: In the step 2), the lime slurry is formed by mixing the lime in the lime bin (1) with water provided by the compensation water tank (9).

7. The method for recovering and treating CO2 exhaust gas from a gas-based vertical furnace according to claim 5, characterized in that: In the step 3, the gypsum slurry first enters the gypsum slurry tank (45), and then is filtered through the belt filter (49); the filtered filtrate enters the compensation water tank (9).

8. A method for recovering and treating CO2 exhaust gas from a gas-based vertical furnace according to claim 5, 6 or 7, characterized in that: In the step 2), dust generated by dust removal enters the dust removal pool (42) for collection.

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