Blast furnace gas dedusting and desulfurization reactor and blast furnace gas integrated desulfurization and dust removal system

Abstract

This invention discloses a blast furnace gas dust removal and desulfurization reactor and an integrated blast furnace gas desulfurization and dust removal system, belonging to the field of blast furnace gas purification technology. To remove organic sulfur and dust from blast furnace gas, the blast furnace gas dust removal and desulfurization reactor (4) contains an inlet chamber (42) and a clean gas chamber (43). A porous partition (44) is installed between the inlet chamber (42) and the clean gas chamber (43). A catalytic filter tube (5) is installed on the partition (44). The catalytic filter tube (5) contains a tube body with filter channels. Organic sulfur hydrolysis catalysts are arranged on the inner surface, outer surface, and surface of the filter channels of the tube body. The blast furnace gas dust removal and desulfurization reactor can remove organic sulfur while simultaneously removing dust. The integrated blast furnace gas desulfurization and dust removal system can pre-treat blast furnace gas, greatly extending the lifespan of the organic sulfur hydrolysis catalyst; it eliminates the need for a conventional hydrolysis desulfurization tower, saving space and reducing resistance.

Description

Technical Field

[0001] This invention relates to the field of blast furnace gas purification technology, specifically a blast furnace gas dust removal and desulfurization reactor, or an integrated blast furnace gas desulfurization and dust removal system. Background Technology

[0002] Sulfur in blast furnace gas is mainly introduced from the furnace charge, primarily consisting of iron ore, fuel, and a small amount of flux. The sulfur exists in the forms of carbonyl sulfide, carbon disulfide, and hydrogen sulfide. It is classified into organic and inorganic sulfur. Organic sulfur is predominantly carbonyl sulfide (COS), accounting for approximately 70%, while inorganic sulfur is predominantly hydrogen sulfide (H2S), accounting for approximately 30%. The total sulfur concentration is 100 Nm³ / Nm³. 3 -200mg / Nm 3 Under normal circumstances, the H2S content in blast furnace gas is 30 mg / Nm³. 3 -60mg / Nm 3 Organic sulfur (COS, CS2) content 80 mg / Nm 3 -150mg / Nm 3 .

[0003] Blast furnace gas, as a secondary energy source generated during the ironmaking process, is generally used as fuel gas in user units such as blast furnace hot blast stoves, sintering furnaces, steel rolling heating furnaces, gas power generation plants, and lime kilns. The SO2 content in the combustion flue gas can reach 100 mg / m³. 3 -250 mg / m 3 The above cannot meet the ultra-low emission standards.

[0004] Current desulfurization processes are divided into source control and end-of-pipe treatment. End-of-pipe treatment removes SO2 from the flue gas after blast furnace gas combustion to meet emission standards. However, end-of-pipe treatment faces challenges due to its diverse applications, numerous users, large flue gas volumes, dispersed equipment, and fragmented management. Desulfurization at the tail end of the flue gas would result in high investment, high operating costs, large land area requirements, and large quantities of difficult-to-treat desulfurization byproducts. Therefore, directly desulfurizing the blast furnace gas at the source offers better economic benefits.

[0005] Existing blast furnace gas desulfurization processes mainly include adsorption and catalytic hydrolysis. Both processes are used, but each has its own drawbacks. In the blast furnace gas purification process, the removal of organic sulfur is the core of gas desulfurization. Since direct removal of organic sulfur is difficult, it can first be hydrolyzed into H2S before further removal. Current organic sulfur removal processes are all set up after the dust collector, or multiple desulfurization towers are added after the dust collector, such as adding a hydrolysis desulfurization tower + hydrogen sulfide absorption tower; or multiple desulfurization towers are added after the dust collector, such as adding several microcrystalline adsorption towers. Currently, the most widely used organic sulfur hydrolysis catalyst is γ-Al2O3 supported on alkali metal oxides. HCl will damage the support structure, causing the loss of active components of the catalyst, resulting in a decrease or disappearance of the activity of the organic sulfur hydrolysis catalyst. - Catalyst deactivation occurs in two ways: first, it reduces the alkaline centers on the surface of the organic sulfur hydrolysis catalyst; second, the salts generated block the pores. As a result, the catalyst lifespan is only a few months.

[0006] Definitions:

[0007] Coal gas desulfurization: Removing organic sulfur (COS, CS2) and inorganic sulfur (H2S) from coal gas.

[0008] Flue gas desulfurization: Removing SO2 and SO3 from flue gas.

[0009] TRT: Blast Furnace Gas Residual Pressure Turbine Power Generation Unit. Summary of the Invention

[0010] To remove organic sulfur and dust from blast furnace gas, this invention provides a blast furnace gas dust removal and desulfurization reactor and an integrated blast furnace gas desulfurization and dust removal system. The blast furnace gas dust removal and desulfurization reactor can remove organic sulfur while removing dust. The integrated blast furnace gas desulfurization and dust removal system can pre-treat blast furnace gas, greatly extending the life of the organic sulfur hydrolysis catalyst; it eliminates the need for a conventional hydrolysis desulfurization tower, saving space and reducing resistance.

[0011] The technical solution adopted by this invention to solve its technical problem is:

[0012] A blast furnace gas dust removal and desulfurization reactor includes an inlet chamber and a clean gas chamber, with a partition between them. A catalytic filter tube is installed on the partition, and the catalytic filter tube contains a tube body with filter channels. An organic sulfur hydrolysis catalyst is arranged on the inner surface, outer surface, and surface of the filter channels of the tube body. The blast furnace gas in the inlet chamber can enter the clean gas chamber through the filter channels of the catalytic filter tube, and the organic sulfur in the blast furnace gas can contact the organic sulfur hydrolysis catalyst and undergo a hydrolysis reaction to be converted into hydrogen sulfide.

[0013] The blast furnace gas dust removal and desulfurization reactor is a vertical cylindrical structure. The blast furnace gas dust removal and desulfurization reactor contains an outer shell, and the clean gas chamber and the inlet gas chamber are arranged vertically. The partition is sealed and fixed to the outer shell.

[0014] The catalytic filter tube is in an upright position and is located in the air intake chamber. The upper end of the catalytic filter tube is in an open state, and the lower end of the catalytic filter tube is in a closed state. The tube body is a ceramic fiber filter tube.

[0015] The partition plate is provided with multiple filter tube mounting holes, and the upper end of the catalytic filter tube is sealed and connected to the filter tube mounting holes one by one.

[0016] The blast furnace gas dust removal and desulfurization reactor also includes a reverse-flushing cleaning device, which contains multiple jet nozzles. The jet nozzles are directed downwards and correspond one-to-one with the upper end of the catalytic filter tube.

[0017] The blast furnace gas dust removal and desulfurization reactor also contains an ash collection chamber, which is located below the inlet chamber. The inlet of the blast furnace gas dust removal and desulfurization reactor is located at the bottom of the inlet chamber, and the outlet of the blast furnace gas dust removal and desulfurization reactor is located at the top of the clean gas chamber.

[0018] An integrated desulfurization and dust removal system for blast furnace gas is provided. The integrated desulfurization and dust removal system for blast furnace gas includes a blast furnace gas dust removal and desulfurization reactor and a hydrogen sulfide absorption device arranged in sequence. The blast furnace gas dust removal and desulfurization reactor is the aforementioned blast furnace gas dust removal and desulfurization reactor. The gas discharged from the blast furnace gas dust removal and desulfurization reactor can enter the hydrogen sulfide absorption device.

[0019] The integrated desulfurization and dust removal system for blast furnace gas also includes a raw gas pipeline. The outlet of the raw gas pipeline is connected to the inlet of the blast furnace gas dust removal and desulfurization reactor. The raw gas pipeline is connected to a deacidifying agent supply device, which can spray deacidifying agent into the raw gas pipeline.

[0020] The integrated desulfurization and dust removal system for blast furnace gas includes multiple blast furnace gas dust removal and desulfurization reactors connected in parallel. It also includes a blast furnace gas residual pressure turbine power generation unit and a pressure regulating valve group connected in parallel. A hydrogen sulfide absorption unit is located between the blast furnace gas dust removal and desulfurization reactors and the blast furnace gas residual pressure turbine power generation unit. The filtered gas discharged from the blast furnace gas dust removal and desulfurization reactors can first enter the hydrogen sulfide absorption unit and then enter the blast furnace gas residual pressure turbine power generation unit or the pressure regulating valve group. Alternatively, the blast furnace gas residual pressure turbine power generation unit is located between the blast furnace gas dust removal and desulfurization reactors and the hydrogen sulfide absorption unit. The filtered gas discharged from the blast furnace gas dust removal and desulfurization reactors first enters the blast furnace gas residual pressure turbine power generation unit or the pressure regulating valve group and then enters the hydrogen sulfide absorption unit.

[0021] When the hydrogen sulfide absorption device is located between the blast furnace gas dust removal and desulfurization reactor and the blast furnace gas residual pressure turbine power generation device, the hydrogen sulfide absorption device is a dry desulfurization device; when the blast furnace gas residual pressure turbine power generation device is located between the blast furnace gas dust removal and desulfurization reactor and the hydrogen sulfide absorption device, the hydrogen sulfide absorption device is either a dry desulfurization device or a wet desulfurization device.

[0022] The beneficial effects of this invention are:

[0023] 1. By using the aforementioned blast furnace gas dust removal and desulfurization reactor, dust removal and organic sulfur removal can be completed simultaneously in the reactor. Combined with the hydrogen sulfide absorption device, fine desulfurization of blast furnace gas can be achieved, solving the problem of excessive SO2 concentration in flue gas caused by blast furnace gas combustion.

[0024] 2. By adopting the aforementioned blast furnace gas dust removal and desulfurization reactor, the source treatment of coal gas can be achieved, and subsequent user units no longer need to configure separate end-of-pipe treatment facilities; centralized treatment is achieved, which completely solves the problems of high investment, high energy consumption, high operating costs, large land area, and large management workload of decentralized treatment.

[0025] 3. Dechlorination is first carried out by spraying in a deacidifying agent to protect the organic sulfur hydrolysis catalyst from Cl. - It is non-toxic; and through normal backflushing cleaning, it does not accumulate dust, thus avoiding blockage and clogging problems. Because a dust cake forms on the filter tube surface, particulate matter and harmful impurities in the gas are efficiently filtered in the dust cake layer, effectively preventing direct contact between toxic substances and the catalyst. The dust cake layer formed on the filter tube surface also assists in dechlorination. This significantly extends the service life of the hydrolysis catalyst on the catalytic filter tube. The deacidifying agent removes H2S while removing HCl, reducing the load on the hydrogen sulfide absorption unit.

[0026] 4. The blast furnace gas dust removal and desulfurization reactor replaces the traditional bag filter system, eliminating the need for traditional filter bags and preventing increased system resistance. The catalytic filter tubes are cleaned via backflushing, eliminating the risk of clogging. Its integrated functionality and equipment integration result in minimal system temperature drop and low resistance, which is beneficial for subsequent TRT power generation.

[0027] 5. The dust removal reactor is designed in parallel, with valves at the inlet and outlet, allowing for separate maintenance without affecting ironmaking production.

[0028] 6. The catalytic filter tube is rich in organic sulfur hydrolysis catalyst. The catalytic filter tube contains a tube body made of ceramic fiber. One of the main components of the ceramic fiber is alumina, which is heat-resistant and will not burn due to excessively high coal temperature at the blast furnace outlet. It also has thermal shock resistance and is not affected by thermal expansion and contraction, thus preventing breakage. The ceramic fiber does not readily react with chemical substances and has good chemical stability.

[0029] 7. The contact time between the catalytic filter tube and the blast furnace gas is as long as 1s-6s, and the organic sulfur in it can be fully removed by hydrolysis.

[0030] 8. Implementing source treatment of blast furnace gas desulfurization can ensure ultra-low SO2 emissions for downstream users and avoid the construction of decentralized end-of-pipe treatment facilities. This is of great significance for promoting ultra-low emission transformation of the entire steel industry process and promoting the green development of the steel industry. Attached Figure Description

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0032] Figure 1 This is a schematic diagram of the hydrogen sulfide absorption device of the integrated desulfurization and dust removal system for blast furnace gas described in this invention, located upstream of the blast furnace gas residual pressure turbine power generation device.

[0033] Figure 2 This is a schematic diagram of the hydrogen sulfide absorption device of the integrated desulfurization and dust removal system for blast furnace gas described in this invention, located downstream of the blast furnace gas residual pressure turbine power generation device.

[0034] Figure 3 This is a schematic diagram of a blast furnace gas dust removal and desulfurization reactor.

[0035] Figure 4 This is a cross-sectional schematic diagram of the catalytic filter tube.

[0036] Figure 5 yes Figure 4 Enlarged diagram of part A in the middle.

[0037] Figure 6 This is a schematic diagram of the partition.

[0038] The annotations in the attached figures are explained as follows:

[0039] 1. Gravity dust collector; 2. Raw coal gas pipeline; 3. Inlet valve; 4. Blast furnace gas dust removal and desulfurization reactor; 5. Catalytic filter tube; 6. Outlet valve; 7. Clean coal gas pipeline; 8. Hydrogen sulfide absorption device; 9. Pressure regulating valve group; 10. Blast furnace gas residual pressure turbine power generation device; 11. Deacidifying agent supply device; 12. Backflushing cleaning device;

[0040] 41. Ash collection chamber; 42. Air inlet chamber; 43. Clean air chamber; 44. Partition plate; 45. Outer shell; 46. Filter tube mounting through hole;

[0041] 51. Ceramic fiber; 52. Organic sulfur hydrolysis catalyst;

[0042] 121. Jet nozzle. Detailed Implementation

[0043] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0044] A blast furnace gas dust removal and desulfurization reactor 4 includes an inlet chamber 42 and a clean gas chamber 43. A partition 44 is provided between the inlet chamber 42 and the clean gas chamber 43. The partition 44 is connected to a catalytic filter tube 5. The catalytic filter tube 5 contains a tube body with filter channels connecting the inside and outside of the catalytic filter tube 5. Organic sulfur hydrolysis catalysts are arranged on the inner surface, outer surface, and surface of the filter channels of the tube body. Blast furnace gas in the inlet chamber 42 can enter the clean gas chamber 43 through the filter channels of the catalytic filter tube 5. During this process, dust is removed, and the organic sulfur in the blast furnace gas can contact the organic sulfur hydrolysis catalyst and undergo a hydrolysis reaction to transform into hydrogen sulfide and carbon dioxide. Figures 1 to 4 As shown.

[0045] Dust removal and organic sulfur removal can be completed simultaneously in the blast furnace gas dust removal and desulfurization reactor 4. The catalytic filter tube 5 can efficiently filter particulate matter and harmful impurities in the gas, effectively preventing toxic substances from directly contacting the organic sulfur hydrolysis catalyst. The powder cake layer formed on the surface of the catalytic filter tube can assist in dechlorination. This greatly extends the service life of the organic sulfur hydrolysis catalyst in the catalytic filter tube.

[0046] In this embodiment, the blast furnace gas dust removal and desulfurization reactor 4 is an upright cylindrical structure. The reactor 4 includes an outer shell 45, a clean gas chamber 43, and an inlet chamber 42 arranged vertically. A partition 44 is sealed and fixed to the outer shell 45. The catalytic filter tube 5 is upright and located inside the inlet chamber 42. The height of the clean gas chamber 43 matches the length of the catalytic filter tube 5, facilitating filter tube maintenance and replacement. The upper end of the catalytic filter tube 5 is open, and the lower end is closed. The upper end of the catalytic filter tube 5 is connected to the partition 44. Figures 4 to 6 As shown.

[0047] The catalytic filter tube 5 comprises a tube body, an organic sulfur hydrolysis catalyst 52, and additives. The tube body can be an existing ceramic fiber filter tube, serving as the substrate of the catalytic filter tube 5. The tube body is made of ceramic fiber 51 and has a tubular structure with one closed end and the other open. The tube body has high porosity. Using the tube body as a carrier, the organic sulfur hydrolysis catalyst is uniformly loaded to form the catalytic filter tube 5. The organic sulfur hydrolysis catalyst 52 on the catalytic filter tube 5 can be granular or sheet-like. The catalytic filter tube 5 also possesses rigidity, being self-supporting and requiring no bag cage; it is an external filtration type. During the process of blast furnace gas entering the interior of the catalytic filter tube 5 through the filter channels, dust particles are blocked and filtered, while organic sulfur is catalytically hydrolyzed. Therefore, the catalytic filter tube 5 simultaneously has dust removal and organic sulfur removal functions through catalytic hydrolysis.

[0048] The ceramic fiber 51 used in the tube body can be existing aluminosilicate fiber, one of its main components being alumina, with an Al2O3 content of 43%-49%. The organic sulfur hydrolysis catalyst 52 can be a product of existing technology. Alumina-based COS hydrolysis catalyst is currently the most commonly used organic sulfur hydrolysis catalyst. The organic sulfur hydrolysis catalyst uses Al2O3 as a carrier to load active components and additives, and is made by impregnating or spraying a certain amount of organic sulfur hydrolysis catalyst and additives onto the catalytic filter tube 5. The additives can be products of existing technology. For example, additives can be of many types, including substances that increase the catalytic activity of the catalyst; dispersants that facilitate uniform distribution of the catalyst during loading; and binders that increase the bonding strength between the organic sulfur hydrolysis catalyst and the ceramic fiber used in the tube body. The organic sulfur hydrolysis catalyst can remove organic sulfur from blast furnace gas in the range of 80℃-300℃. The catalytic filter tube 5 has a sufficient thickness (10mm-30mm) to ensure the strength of the catalytic filter tube 5 and the loading of active components. The filtration velocity of the catalytic filter tube 5 is controlled within the range of 0.2m / min-1.5m / min.

[0049] In this embodiment, the partition plate 44 is provided with multiple filter tube mounting through holes 46. The upper end of the catalytic filter tube 5 is sealed and connected to the filter tube mounting through holes 46 one by one. The integrated desulfurization and dust removal system for blast furnace gas also includes a reverse-flushing cleaning device 12. A part of the reverse-flushing cleaning device 12 is located in the clean gas chamber 43. The reverse-flushing cleaning device 12 contains multiple jet nozzles 121. The jet nozzles 121 are directed downwards, and the jet nozzles 121 correspond one-to-one with the upper end of the catalytic filter tube 5. Figures 4 to 5 As shown.

[0050] In this embodiment, the blast furnace gas dust removal and desulfurization reactor 4 also includes an ash collection chamber 41, which is located below the inlet chamber 42 and is connected to the inlet chamber 42. An ash discharge port may be provided at the lower end of the ash collection chamber 41, through which the dust collected in the ash collection chamber 41 can be discharged. The inlet of the blast furnace gas dust removal and desulfurization reactor 4 is located at the lower part of the inlet chamber 42, and the outlet of the blast furnace gas dust removal and desulfurization reactor 4 is located at the upper part of the clean gas chamber 43.

[0051] As the blast furnace gas in the inlet chamber 42 passes through the filtration channels of the catalytic filter tube 5 into the clean gas chamber 43, dust in the blast furnace gas is intercepted and removed on the surface and inside of the catalytic filter tube 5. When the gas flows through the catalytic filter tube 5, it comes into contact with the organic sulfur hydrolysis catalyst (catalyst on the inner, outer, and inner surfaces) loaded on the catalytic filter tube 5, and the organic sulfur is hydrolyzed and converted into inorganic sulfur (H2S) and removed. The clean gas after dust removal and organic sulfur removal enters the clean gas chamber 43 from the inside of the catalytic filter tube 5 and is then discharged from the outlet at the top of the clean gas chamber 43. A back-flushing cleaning device 12 is installed in the clean gas chamber 43 for back-flushing cleaning of the catalytic filter tube 5. The cleaned ash falls into the ash collection chamber 41 and is then discharged. Nitrogen gas is used as the cleaning medium.

[0052] The following describes an integrated desulfurization and dust removal system for blast furnace gas. The integrated desulfurization and dust removal system for blast furnace gas includes a blast furnace gas dust removal and desulfurization reactor 4 and a hydrogen sulfide absorption device 8 arranged in sequence. The gas discharged from the blast furnace gas dust removal and desulfurization reactor 4 can enter the hydrogen sulfide absorption device 8.

[0053] In this embodiment, the integrated desulfurization and dust removal system for blast furnace gas also includes a raw gas pipeline 2. The outlet of the raw gas pipeline 2 is connected to the inlet of the blast furnace gas dust removal and desulfurization reactor 4. The raw gas pipeline 2 is connected to a deacidifying agent supply device 11, which can spray deacidifying agent into the raw gas pipeline 2.

[0054] HCl in blast furnace gas is acidic, which increases the acidic sites on the surface of organic sulfur hydrolysis catalysts, leading to a decrease in catalyst activity. To protect the organic sulfur hydrolysis catalysts and extend their service life, a pre-dechlorination stage is set up upstream of the blast furnace gas dust removal and desulfurization reactor 4. Deacidifying agent is injected into the raw gas pipeline 2 through the deacidifying agent supply device 11 to remove HCl. Simultaneously, the deacidifying agent can also remove inorganic sulfur (H2S) from the raw gas. The deacidifying agent can be alkaline substances such as NaHCO3, Ca(OH)2, and Na2CO3.

[0055] In this embodiment, the integrated desulfurization and dust removal system for blast furnace gas also includes a gravity dust collector 1, with the inlet of the raw gas pipeline 2 connected to the outlet of the gravity dust collector 1. The inlet of the gravity dust collector 1 is connected to the inlet of the blast furnace, and the dust- and sulfur-containing high-temperature and high-pressure raw gas generated during blast furnace production first enters the gravity dust collector 1. An inlet valve 3 is installed on the raw gas pipeline 2, and a clean gas pipeline 7 is connected to the outlet of the blast furnace gas dust removal and desulfurization reactor 4, with an outlet valve 6 installed on the clean gas pipeline 7.

[0056] In this embodiment, the integrated desulfurization and dust removal system for blast furnace gas includes multiple blast furnace gas dust removal and desulfurization reactors 4 arranged in parallel. Each blast furnace gas dust removal and desulfurization reactor 4 has an inlet valve 3 at its inlet and an outlet valve 6 at its outlet. The number of blast furnace gas dust removal and desulfurization reactors 4 in operation can be controlled by the inlet valves 3 and the outlet valves 6. Offline maintenance or replacement of the catalytic filter tubes 5 of the blast furnace gas dust removal and desulfurization reactors 4 can be performed without affecting the normal production of the blast furnace. Figures 1 to 2 As shown.

[0057] In this embodiment, the integrated desulfurization and dust removal system for blast furnace gas also includes a blast furnace gas residual pressure turbine power generation device 10 and a pressure regulating valve group 9 connected in parallel; the hydrogen sulfide absorption device 8 is located between the blast furnace gas dust removal and desulfurization reactor 4 and the blast furnace gas residual pressure turbine power generation device 10, that is, the blast furnace gas dust removal and desulfurization reactor 4, the hydrogen sulfide absorption device 8, and the blast furnace gas residual pressure turbine power generation device 10 are connected in sequence through pipelines, and the pressure regulating valve group 9 is connected in parallel with the blast furnace gas residual pressure turbine power generation device 10. The filtered gas discharged from the blast furnace gas dust removal and desulfurization reactor 4 can first enter the hydrogen sulfide absorption device 8 and then enter the blast furnace gas residual pressure turbine power generation device 10 or the pressure regulating valve group 9, such as... Figure 1 As shown. At this time, the hydrogen sulfide absorption device 8 is an existing dry desulfurization device. For example, the dry desulfurization device utilizes the iron oxide method or the zinc oxide method for desulfurization.

[0058] Alternatively, the blast furnace gas residual pressure turbine power generation unit 10 is located between the blast furnace gas dust removal and desulfurization reactor 4 and the hydrogen sulfide absorption unit 8. That is, the blast furnace gas dust removal and desulfurization reactor 4, the blast furnace gas residual pressure turbine power generation unit 10, and the hydrogen sulfide absorption unit 8 are connected sequentially via pipelines. The pressure regulating valve group 9 is connected in parallel with the blast furnace gas residual pressure turbine power generation unit 10. The filtered gas discharged from the blast furnace gas dust removal and desulfurization reactor 4 first enters the blast furnace gas residual pressure turbine power generation unit 10 or the pressure regulating valve group 9 before entering the hydrogen sulfide absorption unit 8. Figure 2As shown. At this time, the hydrogen sulfide absorption device 8 can be an existing dry desulfurization device or a wet desulfurization device, that is, the hydrogen sulfide absorption device 8 utilizes either dry or wet desulfurization. For example, the dry desulfurization can be the iron oxide method, the zinc oxide method, or the activated carbon method; the wet desulfurization can be the alkaline absorption method, the saline solution chemical absorption method, the iron oxide suspension absorption method, the organic catalyst absorption oxidation method, etc. Among these, the saline solution needs to facilitate regeneration, using a strong base-weak acid salt, and also has a pH buffering effect. This type of method has many absorbents, with Na2CO3 solution being the most commonly used.

[0059] The integrated desulfurization and dust removal system for blast furnace gas includes, for example, a gravity dust collector 1, a raw gas pipeline 2, a blast furnace gas dust removal and desulfurization reactor 4, a clean gas pipeline 7, a hydrogen sulfide absorption device 8, and a blast furnace gas residual pressure turbine power generation device 10 connected in sequence. Its working process is described below.

[0060] For example, the dust- and sulfur-containing high-temperature and high-pressure raw coal gas produced in blast furnace production (its normal pressure is 0.16MPa-0.21MPa, maximum 0.25MPa, temperature as high as 150℃-300℃, and dust content is about 10g / Nm³) 3 -15g / Nm 3 HCl content is 100 mg / Nm 3 -200mg / Nm 3 The inorganic sulfur (H2S) content is approximately 30 mg / Nm³. 3 -60mg / Nm 3 The organic sulfur (COS, CS2) content is approximately 80 mg / Nm³. 3 -150mg / Nm 3 First, the particles pass through gravity dust collector 1 for initial dust removal, removing coarse particulate matter (dust concentration reduced to 3 mg / Nm³). 3 -6g / Nm 3 This reduces the load on subsequent dust removal.

[0061] After initial dust removal, the deacidifying agent supply device 11 sprays the deacidifying agent into the raw coal gas pipeline 2. The deacidifying agent is sprayed evenly through the nozzle and mixes thoroughly with the raw coal gas. The HCl and inorganic sulfur H2S in the coal gas react with the deacidifying agent and are removed (HCl content ≤ 10 mg / Nm³). 3 Inorganic sulfur (H2S) content ≤10mg / Nm 3 The byproducts of the reaction, along with the dust in the raw coal gas, flow into the blast furnace gas dust removal and desulfurization reactor 4. The deacidifying agent is supplied by the deacidifying agent supply device 11 and is injected into the raw coal gas pipeline 2 through metering and pneumatic conveying. The addition of the deacidifying agent effectively protects the organic sulfur hydrolysis catalyst 52 in the catalytic filter tube 5.

[0062] Raw coal gas enters the inlet chamber 42 through the inlet valve 3 of the blast furnace gas dust removal and desulfurization reactor 4, and then flows through the catalytic filter tube 5. Dust and desulfurization byproducts are trapped on the surface of the catalytic filter tube 5, while some fine particles enter the fiber gaps of the catalytic filter tube 5, thus completing dust removal (dust concentration ≤ 5 mg / Nm³). 3 Simultaneously, the organic sulfur in the coal gas comes into contact with the hydrolysis catalyst supported on the catalytic filter tube 5, where the organic sulfur undergoes a hydrolysis reaction and is converted into easily removed hydrogen sulfide, thereby removing the difficult-to-treat organic sulfur (organic sulfur (COS, CS2) content ≤10mg / Nm³). 3 The clean coal gas after dust removal and desulfurization flows into the clean gas chamber 43 from the inside of the catalytic filter tube 5, and then is discharged from the clean coal gas outlet and outlet valve 6 above the clean gas chamber 43 and enters the clean coal gas pipeline 7.

[0063] Subsequently, the purified coal gas enters the hydrogen sulfide absorption unit 8 to complete the removal of H2S (inorganic sulfur H2S content ≤10mg / Nm³). 3 Finally, the clean gas is either generated by the TRT (blast furnace gas residual pressure turbine power generation device 10) or depressurized by the pressure regulating valve group 9 (its pressure is reduced to 9kPa-15kPa and its temperature is reduced to 50℃-120℃) before entering the plant's blast furnace gas pipeline network.

[0064] During the above operation, when the thickness of the dust cake on the surface of the catalytic filter tube 5 increases and the pressure loss of the blast furnace gas dust removal and desulfurization reactor 4 reaches the set value, the backflushing cleaning device 12 is activated. The backflushing cleaning device 12 sprays high-pressure nitrogen into the catalytic filter tube 5, and the dust on the outer surface and in the pores of the catalytic filter tube 5 is carried out by the backflushing airflow and falls into the dust collection chamber 41. After cleaning, the catalytic filter tube 5 restores its dust removal capacity, and at the same time, the catalytic active centers that were previously covered are exposed again and their activity is restored.

[0065] When the hydrogen sulfide absorption device 8 is installed after the TRT (blast furnace gas residual pressure turbine power generation device 10) and the pressure regulating valve group 9, the clean gas is de-heated and depressurized before H2S absorption. The hydrogen sulfide absorption device 8 is an atmospheric pressure vessel and can be used by dry or wet methods.

[0066] The following section describes the specific implementation and comparison of the integrated desulfurization and dust removal system for blast furnace gas.

[0067] Example 1:

[0068] A certain 1200m 3 Blast furnace raw gas pressure: normal 0.18MPa, maximum 0.20MPa; gas temperature: fluctuating between approximately 150℃ and 250℃; normal gas production: 240,000 Nm³. 3 / h, maximum gas production: 270000 Nm³ 3 / h; Dust content is approximately 13g / Nm 3HCl content is 100 mg / Nm 3 Inorganic sulfur (H2S) content: 40 mg / Nm³ 3 Organic sulfur (COS, CS2) content 120 mg / Nm 3 The raw blast furnace gas first enters gravity dust collector 1, and the outlet dust level drops to 5 g / Nm³. 3 Then, the raw coal gas enters raw coal gas pipeline 2, where it mixes with NaHCO3 injected from the deacidifying agent supply system. Acidic substances such as HCl and H2S react with the NaHCO3 to be removed, reducing the HCl content to ≤10 mg / Nm³. 3 The inorganic sulfur (H2S) content was reduced to ≤5 mg / Nm³. 3 .

[0069] After removing the toxic HCl from the hydrolysis catalyst, the raw coal gas enters the inlet chamber 42 of the blast furnace gas dust removal and desulfurization reactor 4 through inlet valve 3. Inside the inlet chamber 42, the gas flow rate decreases significantly, and some larger dust particles naturally settle into the ash collection chamber 41. The remaining dust flows with the coal gas towards the catalytic filter tube 5. The filtration velocity of the filter tube is controlled at 0.4 m / min. Through filtration, deposition, interception, and microporous retention on the filter tube surface, the dust is removed, and the concentration is reduced to ≤5 mg / Nm³. 3 The catalytic filter tube 5 is 18mm thick, and the blast furnace gas penetration time through the filter tube is >2.5s. The hydrolysis catalyst fully contacts and reacts with organic sulfur, converting it into easily treatable H2S. The organic sulfur (COS, CS2) content is ≤5mg / Nm³. 3 As filtration progresses, the filter cake layer on the surface of the filter tube gradually thickens. The system measures the pressure difference between the inlet chamber 42 and the clean air chamber 43. When the pressure difference exceeds 1500 Pa, the backflushing cleaning device 12 automatically starts, and the catalytic filter tube 5 is cleaned. The pressure difference decreases, the dust removal capacity is restored, and the activity of the hydrolysis catalyst covered on the surface and in the pores of the filter tube is restored. Due to the pre-removal of HCl and frequent backflushing cleaning, the lifespan of the catalytic filter tube 5 is greatly extended, reaching up to 2 years or more.

[0070] After dust removal and organic sulfur removal, the clean coal gas flows into the clean gas chamber 43 through the catalytic filter tube 5. The height of the clean gas chamber 43 is 3.5m. After the reactor is offline, maintenance and filter tube replacement can be carried out in the clean gas chamber 43. The clean coal gas is discharged from the top of the clean gas chamber 43 through the outlet valve 6 into the clean coal gas pipeline 7. Then it enters the hydrogen sulfide absorption unit 8, which adopts the dry absorption-iron oxide method. The absorbent has a large sulfur capacity. The saturated absorbent is sent to the sintering plant for batching. The generated SO2 is removed by the sintering flue gas desulfurization system. The inorganic sulfur (H2S) content in the clean coal gas at the outlet of the hydrogen sulfide absorption unit is ≤10mg / Nm³. 3The high-temperature, high-pressure purified blast furnace gas is then sent to the blast furnace gas residual pressure turbine power generation unit 10 for power generation. After power generation, the temperature of the purified blast furnace gas drops to 70℃ and the pressure drops to 10kPa, and it is then connected to the plant's gas pipeline network for use by various users. At the user's location, the SO2 content in the flue gas produced after the combustion of the blast furnace gas is ≤20mg / Nm³. 3 It meets ultra-low emission standards, so there is no need to consider tail-end flue gas desulfurization.

[0071] Example 2:

[0072] A certain 4000m 3 Blast furnace raw gas pressure: normal 0.2MPa, maximum 0.22MPa; gas temperature: approximately 160℃-300℃; normal gas production: 600,000 Nm³ 3 / h, maximum gas production: 700,000 Nm³ 3 / h; dust content is approximately 15g / Nm 3 The HCl content is 105 mg / Nm³. 3 Inorganic sulfur (H2S) content: 30 mg / Nm 3 Organic sulfur (COS, CS2) content 100 mg / Nm 3 The raw blast furnace gas first enters gravity dust collector 1, and the outlet dust level drops to 6 g / Nm³. 3 Then, the raw coal gas enters raw coal gas pipe 2, where it mixes with Ca(OH)2 injected by the deacidifying agent supply system. Acidic substances HCl and H2S react with Ca(OH)2 to be removed, reducing the HCl content to ≤10 mg / Nm³. 3 The inorganic sulfur (H2S) content was reduced to ≤20 mg / Nm³. 3 .

[0073] After removing the toxic HCl from the hydrolysis catalyst, the raw coal gas enters the inlet chamber 42 through inlet valve 3. Inside the inlet chamber 42, the coal gas flow rate decreases significantly, and some larger dust particles naturally settle into the dust collection chamber 41. The remaining dust particles flow with the coal gas towards the catalytic filter tube 5. The filtration velocity of the filter tube is controlled at 1.1 m / min. Through filtration, deposition, interception, and microporous retention on the filter tube surface, the dust is removed, and the concentration is reduced to ≤5 mg / Nm³. 3 The catalytic filter tube 5 is 20mm thick, and the blast furnace gas penetration time through the filter tube is >1s. This ensures the hydrolysis catalyst fully contacts and reacts with organic sulfur, converting it into easily treatable H2S. The organic sulfur (COS, CS2) content is ≤10mg / Nm³. 3As filtration progresses, the filter cake layer on the surface of the filter tube gradually thickens. The system employs timed cleaning, with the backflushing cleaning device 12 automatically starting every 2 hours to clean the catalytic filter tube 5. This restores the dust removal capacity and the activity of the hydrolysis catalyst covered on the surface and in the pores of the filter tube. Due to the pre-removal of HCl and frequent backflushing cleaning, the lifespan of the catalytic filter tube 5 is greatly extended, reaching up to 2 years or more.

[0074] The system is equipped with twenty blast furnace gas dust removal and desulfurization reactors 4, eighteen of which are in normal operation and two are on standby. During production, when the dust concentration in the clean gas chamber 42 of a certain blast furnace gas dust removal and desulfurization reactor 4 exceeds the standard, the inlet valve 3 and outlet valve 6 of the reactor are closed, and the blast furnace gas dust removal and desulfurization reactor 4 is taken offline for maintenance and replacement of the catalytic filter tube 5. When the reactor is offline, the standby blast furnace gas dust removal and desulfurization reactor 4 is put into operation to ensure the stability and reliability of the system and not affect the normal production of the blast furnace.

[0075] After dust removal and organic sulfur removal, the clean coal gas flows into the clean gas chamber 43 through the catalytic filter tube 5. The clean coal gas is then discharged from the upper part of the clean gas chamber 43 through the outlet valve 6 into the clean coal gas pipeline 7. The high-temperature, high-pressure clean coal gas is then sent to the blast furnace gas residual pressure turbine power generation unit 10 for power generation. When the blast furnace gas residual pressure turbine power generation unit 10 is under maintenance, the coal gas is depressurized through the pressure regulating valve group 9. After power generation or depressurization, the temperature of the clean coal gas drops to 80℃ and the pressure drops to 12kPa. It then enters the hydrogen sulfide absorption unit 8, using a wet absorption-NaOH alkaline solution absorption method. No new absorption tower is added this time; instead, the existing alkali spraying and chlorine washing tower of the existing system is utilized. After countercurrent spraying and washing inside the tower, the inorganic sulfur (H2S) content in the outlet clean coal gas is ≤5mg / Nm³. 3 The gas is integrated into the plant's gas pipeline network for use by various users; at the user's location, the SO2 content in the flue gas produced after blast furnace gas combustion is ≤20mg / Nm³. 3 It meets ultra-low emission standards, so there is no need to consider tail-end flue gas desulfurization.

[0076] The following is an introduction

[0077] Comparative Example 1:

[0078] A certain 1200m 3 Blast furnace, normal gas production: 240,000 Nm³ 3 / h, maximum gas production: 270000 Nm³ 3 / h; HCl content is 100 mg / Nm 3 Inorganic sulfur (H2S) content: 40 mg / Nm³ 3 Organic sulfur (COS, CS2) content 120 mg / Nm 3The desulfurization and dust removal equipment of this patent was not used, nor were other coal gas desulfurization processes. The clean coal gas was fed into the coal gas pipeline network after dust removal and TRT power generation, and was sent to user units such as the blast furnace hot blast stove, sintering, steel rolling heating furnace, coal gas power plant, and lime kiln for use as fuel.

[0079] After the combustion of clean coal gas, the SO2 concentration in the flue gas from hot blast stoves, steel rolling furnaces, and coal gas power plants can reach as high as 150 mg / Nm³. 3 -230mg / Nm 3 (The emissions will vary depending on the excess air coefficient), exceeding the emission standards of the corresponding facilities. Therefore, one new flue gas desulfurization system will be built in the hot blast stove area; for safety reasons, the flue gas and coal smoke from the rolling mill heating furnace will be emitted separately, therefore two new flue gas desulfurization systems will be built for each heating furnace in the rolling mill heating furnace area; one new flue gas desulfurization system will be built in the coal gas power plant. SO2 generated from the combustion of sintering ignition gas will be treated in the sintering flue gas desulfurization system; the lime kiln system is an alkaline environment, and desulfurization is currently not exceeding standards, so no flue gas desulfurization system will be installed. The hot blast stove of this blast furnace uses 40% self-produced coal gas, the heating furnace, gas power generation, lime kiln, and sintering use 50% coal gas, and the remaining 10% coal gas is used by other small, scattered users, for which no flue gas desulfurization system will be installed. The corresponding SO2 emission concentration for this portion is approximately 200 mg / Nm³. 3 SO2 emissions are 67,000 kg / year.

[0080] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical solutions, and embodiments of the present invention can be freely combined and used together.

Claims

1. An integrated desulfurization and dust removal system for blast furnace gas, characterized in that, The integrated desulfurization and dust removal system for blast furnace gas includes a blast furnace gas dust removal and desulfurization reactor (4) and a hydrogen sulfide absorption device (8) arranged in sequence. The gas discharged from the blast furnace gas dust removal and desulfurization reactor (4) can enter the hydrogen sulfide absorption device (8). The blast furnace gas dust removal and desulfurization reactor (4) contains an inlet chamber (42) and a clean gas chamber (43). A partition (44) is provided between the inlet chamber (42) and the clean gas chamber (43). A catalytic filter tube (5) is installed on the partition (44). The catalytic filter tube (5) contains a tube body. The tube body has filter channels. Organic sulfur hydrolysis catalyst (52) is arranged on the inner surface of the tube body, the outer surface of the tube body and the surface of the filter channels. The blast furnace gas in the inlet chamber (42) can enter the clean gas chamber (43) through the filter channels of the catalytic filter tube (5). The organic sulfur in the blast furnace gas can contact the organic sulfur hydrolysis catalyst (52) and undergo hydrolysis reaction to be converted into hydrogen sulfide. The blast furnace gas dust removal and desulfurization reactor (4) is a vertical cylindrical structure. The blast furnace gas dust removal and desulfurization reactor (4) contains an outer shell (45), a clean gas chamber (43) and an inlet chamber (42) are arranged vertically, and a partition (44) is sealed and fixed to the outer shell (45). The catalytic filter tube (5) is in an upright state and is located in the air intake chamber (42). The upper end of the catalytic filter tube (5) is in an open state and the lower end of the catalytic filter tube (5) is in a closed state. The tube body is a ceramic fiber filter tube. The partition (44) is provided with multiple filter tube mounting through holes (46), and the upper end of the catalytic filter tube (5) is sealed and connected to the filter tube mounting through holes (46) one by one. The blast furnace gas dust removal and desulfurization reactor (4) also includes a backflushing cleaning device (12), which contains multiple jet nozzles (121). The jet nozzles (121) are directed downwards, and each jet nozzle (121) corresponds to the upper end of the catalytic filter tube (5). The integrated desulfurization and dust removal system for blast furnace gas also includes a raw gas pipeline (2), the outlet of which is connected to the inlet of the blast furnace gas dust removal and desulfurization reactor (4), and the raw gas pipeline (2) is connected to a deacidifying agent supply device (11), which can spray deacidifying agent into the raw gas pipeline (2). The integrated desulfurization and dust removal system for blast furnace gas includes multiple blast furnace gas dust removal and desulfurization reactors (4) arranged in parallel. Each blast furnace gas dust removal and desulfurization reactor (4) is equipped with an inlet valve (3) outside its inlet. The integrated desulfurization and dust removal system for blast furnace gas also includes a blast furnace gas residual pressure turbine power generation device (10) and a pressure regulating valve group (9) arranged in parallel. The hydrogen sulfide absorption device (8) is located between the blast furnace gas dust removal and desulfurization reactor (4) and the blast furnace gas residual pressure turbine power generation device (10). The filtered gas discharged from the blast furnace gas dust removal and desulfurization reactor (4) can first enter the hydrogen sulfide absorption device (8) and then enter the blast furnace gas residual pressure turbine power generation device (10) or the pressure regulating valve group (9). The hydrogen sulfide absorption device (8) is a dry desulfurization device.

2. The integrated desulfurization and dust removal system for blast furnace gas according to claim 1, characterized in that, The blast furnace gas dust removal and desulfurization reactor (4) also contains an ash collection chamber (41), which is located below the inlet chamber (42). The inlet of the blast furnace gas dust removal and desulfurization reactor (4) is located at the lower part of the inlet chamber (42), and the outlet of the blast furnace gas dust removal and desulfurization reactor (4) is located at the upper part of the clean gas chamber (43).

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