A dry purification device and process for removing total sulfur from blast furnace gas

Abstract

The invention relates to a dry purification device and process for removing total sulfur from blast furnace gas. The device comprises a catalytic hydrolysis tower, a desulfurization tower, a pneumatic conveying device (19) and a gas replacement system. After dust removal and waste heat and waste pressure power generation, the blast furnace gas passes through the catalytic hydrolysis tower and the desulfurization tower in sequence. Organic sulfur such as carbonyl sulfide (COS) and carbon disulfide (CS2) are catalytically hydrolyzed and converted into hydrogen sulfide (H2S) in the catalytic hydrolysis tower. A desulfurizing agent is supplied to the desulfurization tower through the pneumatic conveying device to absorb hydrogen sulfide (H2S), sulfur dioxide (SO2), hydrogen chloride (HCl) and other acidic gases, thereby achieving the removal of sulfur-containing substances in the blast furnace gas and solving the problem of excessive sulfur dioxide (SO2) from the source. At the same time, the coordinated removal of hydrogen chloride (HCl) controls the problem of gas pipeline corrosion to a certain extent.

Description

Technical Field

[0001] The present invention relates to a dry purification device and process for removing total sulfur from blast furnace gas, and in particular to a dry purification device and process capable of removing sulfur-containing substances such as COS, CS2, H2S, SO2 and the like from blast furnace gas and synergistically removing HCl. The present invention belongs to a pollutant control technology in the field of environmental protection engineering technology, and is used for removing total sulfur from blast furnace gas in a set of processes. Background Art

[0002] Blast furnace gas is the combustible gas with the largest output in steel enterprises, with a statistical output of up to 70-80 billion cubic meters per month. The existing blast furnace gas purification and subsequent applications mainly use bag dust removal to remove particulate matter, and then after TRT residual pressure power generation, it is sent to blast furnace hot blast furnaces, steel rolling heating furnaces, gas power generation and other user units for use as fuel, but blast furnace gas still contains harmful substances such as sulfur and chlorine. With the promulgation of the "Opinions on Promoting the Implementation of Ultra-low Emissions in the Steel Industry", the steel industry has officially entered the "ultra-low emission" era. Users such as blast furnace hot blast furnaces, steel rolling heating furnaces, and gas power generation all require that the combustion tail gas SO2 reach ultra-low emission limits, but the existing blast furnace gas purification process cannot meet the SO2 control requirements.

[0003] The current technical routes mainly include source control and end-of-pipe treatment after combustion. If the end-of-pipe treatment method is adopted, desulfurization facilities need to be set up at multiple points. At the same time, the amount of waste gas after coal gas combustion is large, and the scale of treatment facilities becomes larger; if the source control method is adopted, centralized treatment can be carried out, and the amount of coal gas treated is only about 60% of the flue gas after combustion. Therefore, the total investment is low, the total area is small, the operating cost is low, and the management is convenient. At the same time, source treatment promotes the life of the pipeline network and combustion efficiency. Implementing the full sulfur removal of blast furnace gas and reducing the sulfur content in coal gas can greatly reduce the pressure of end-of-pipe treatment and even save end-of-pipe treatment facilities.

[0004] The removal of total sulfur from blast furnace gas is a new technological development direction. Currently, there are many single organic sulfur hydrolysis technologies and dry adsorption removal technologies, and there are also relevant application examples of blast furnace gas dechlorination technology. However, there are no reports or engineering cases on the technology for the removal of total sulfur from blast furnace gas. Therefore, the technology for the removal of total sulfur from blast furnace gas is still in the frontier exploration stage. Summary of the invention

[0005] The object of the present invention is to provide a dry purification device capable of achieving total sulfur removal from blast furnace gas, preferably a dry purification device capable of achieving the removal of sulfur-containing substances such as COS, CS2, H2S, SO2 in blast furnace gas and the coordinated removal of HCl, so as to solve the above-mentioned technical problems.

[0006] In order to solve the above technical problems, a dry purification device for removing all sulfur from blast furnace gas is provided, preferably a dry purification device that can remove sulfur-containing substances such as carbonyl sulfide (COS), carbon disulfide (CS2), hydrogen sulfide (H2S), sulfur dioxide (SO2) and the like in blast furnace gas and synergistically remove hydrogen chloride (HCl). The dry purification device comprises a catalytic hydrolysis tower, a desulfurization tower, a pneumatic conveying device (19) and a gas replacement system; the catalytic hydrolysis tower is filled with a hydrolysis catalyst for catalyzing the hydrolysis of the blast furnace gas introduced into the catalytic hydrolysis tower, and the catalytic hydrolysis tower is connected and arranged on A blast furnace gas inlet (20) on one side of the desulfurization tower is used to deliver the blast furnace gas after hydrolysis catalytic treatment into the desulfurization tower for treatment; a pneumatic conveying device (19) is connected to the top of the desulfurization tower and is used to deliver a desulfurizer into the desulfurization tower to remove all sulfur from the blast furnace gas; a clean blast furnace gas outlet (21) is provided on the other side of the desulfurization tower and is used to discharge the clean blast furnace gas after all sulfur is removed through the clean blast furnace gas outlet (21) and deliver it to the blast furnace gas pipeline network; a gas replacement system is connected to the replacement gas interface of the desulfurization tower and is used to replace the gas in the desulfurization tower with a replacement gas before replacing the desulfurizer.

[0007] The catalytic hydrolysis tower comprises a catalytic hydrolysis tower inlet flue, a catalytic hydrolysis tower shell (2), a catalytic hydrolysis tower outlet flue, a catalyst support net (4), a feed port (3), a discharge port (5) and a sewage outlet (6); the top of the catalytic hydrolysis tower shell (2) is connected to the catalytic hydrolysis tower inlet flue for feeding blast furnace gas into the catalytic hydrolysis tower; the lower end of the catalytic hydrolysis tower shell (2) is connected to the catalytic hydrolysis tower outlet flue; the catalytic hydrolysis tower outlet flue is connected to the blast furnace gas inlet (20) of the desulfurization tower for feeding the blast furnace gas after hydrolysis catalytic treatment into the desulfurization tower for treatment; the catalyst support net (4) is arranged in the catalytic hydrolysis tower shell (2) for supporting the hydrolysis catalyst; the bottom end of the catalytic hydrolysis tower shell (2) is provided with a sewage outlet (6); the catalytic hydrolysis tower shell (2) is provided with a feed port (3) and a discharge port (5) for feeding and discharging the hydrolysis catalyst.

[0008] The catalytic hydrolysis tower shell (2) has a conical upper portion, a cylindrical middle portion, and a conical lower portion; the catalytic hydrolysis tower inlet flue is arranged at the top of the upper cone, the sewage outlet (6) is arranged at the bottom of the lower cone, the catalytic hydrolysis tower outlet flue is arranged on the lower cone, and is located above the sewage outlet (6); the catalyst support net (4) is arranged in the middle cylindrical shape.

[0009] The catalyst is one or more of a honeycomb, rod, Raschig ring, or spherical shape, and catalytically hydrolyzes organic sulfur such as carbonyl sulfide (COS) and carbon disulfide (CS2) in blast furnace gas into H2S. The active components of the catalyst are one or more of Na, K, Fe, Cu, and Ni salts, and the carrier is one or more of activated alumina, activated carbon, cordierite, and hydrotalcite.

[0010] The catalyst is in the form of a Raschig ring, which is randomly piled up from large to small on the catalyst support net (4) in the catalytic hydrolysis tower. The catalyst is filled with a certain volume so that the catalytic reaction space velocity is 500-4000h -1 , the gas flow rate is 0.5-2m / s; preferably, in the catalytic hydrolysis tower, 80%-95% volume fraction of carbonyl sulfide (COS) and carbon disulfide (CS2) in the blast furnace gas are catalytically converted into H2S.

[0011] The desulfurization tower is in the form of a gas-solid cross-flow moving bed, which has low gas pressure drop, small desulfurizer wear, uniform gas-solid two-phase contact, and large flexibility in adjusting the desulfurizer residence time. Preferably, the gas flow rate in the desulfurization tower is controlled at 0.5-3m / s to ensure uniform air distribution; preferably, the temperature of the blast furnace gas inlet (20) is 40-90°C, and the temperature of the clean blast furnace gas outlet (21) remains basically unchanged.

[0012] The outlet flue of the catalytic hydrolysis tower is connected to the blast furnace gas inlet (20) of the desulfurization tower, and a plurality of desulfurization agent bins are sequentially arranged on the right side of the blast furnace gas inlet (20), preferably 4 desulfurization agent bins.

[0013] A single desulfurizing agent bin is provided with a desulfurizing agent inlet (7), a first inlet shut-off valve (8), an inlet buffer bin (9), a second inlet shut-off valve (11), a reaction bin (12), a first outlet shut-off valve (14), an outlet buffer bin (16), a second outlet shut-off valve (17) and a desulfurizing agent outlet (18) in sequence from top to bottom; the replacement gas interface comprises a first replacement gas interface (10) and a second replacement gas interface (15); the first replacement gas interface (10) is provided on the side of the inlet buffer bin (9), and the second replacement gas interface (15) is provided on the side of the outlet buffer bin (16); the gas replacement system is connected to the inlet buffer bin (9) via the first replacement gas interface (10), and the gas replacement system is connected to the outlet buffer bin (16) via the second replacement gas interface (15), and is used for replacing the coal gas in the buffer bin with nitrogen before replacing the desulfurizing agent, so as to ensure that the coal gas does not leak.

[0014] The first inlet shut-off valve (8) is arranged between the desulfurizing agent inlet (7) and the inlet buffer bin (9) and is used to open or close the connection between the desulfurizing agent inlet (7) and the inlet buffer bin (9); the second inlet shut-off valve (11) is arranged between the inlet buffer bin (9) and the reaction bin (12) and is used to open or close the connection between the buffer bin (9) and the reaction bin (12); the first outlet shut-off valve (14) is arranged between the reaction bin (12) and the outlet buffer bin (16) and is used to open or close the connection between the reaction bin (12) and the outlet buffer bin (16); the second outlet shut-off valve (17) is arranged between the outlet buffer bin (16) and the desulfurizing agent outlet (18) and is used to open or close the connection between the outlet buffer bin (16) and the desulfurizing agent outlet (18).

[0015] Wherein, both sides of the inlet buffer bin (9), the reaction bin (12) and the outlet buffer bin (16) are provided with a vibration motor for regularly vibrating the bin wall to maintain the fluidized state of the desulfurizer. Preferably, the blast furnace gas reacts with the desulfurizer in the reaction bin (12) to remove all sulfur, and the gas inlet and outlet sides of the reaction bin (12) are provided with a desulfurizer baffle (23), which ensures that the desulfurizer does not leak and plays a role in uniform distribution of airflow. Preferably, an observation window (13) is provided on the side of the reaction bin (12) for real-time observation of the situation in the reaction bin (12) during operation.

[0016] The desulfurizer is a porous column, the carrier is a mixture of zeolite and pumice, the molar ratio of pumice to zeolite is between 0.2-0.5; the active ingredients are mainly one or more of iron oxide, manganese oxide, potassium hydroxide and sodium carbonate, and the active ingredients account for 3%-10% of the mass fraction of the desulfurizer.

[0017] The desulfurization agent is filled with a certain volume so that the desulfurization reaction space velocity is 500-5000h -1 , ensuring efficient removal of pollutants in blast furnace gas.

[0018] The pneumatic conveying device (19) is connected to the desulfurizing agent inlet (7) at the top of the desulfurizing agent bin, and is used to deliver the desulfurizing agent into the reaction bin (12) to remove all sulfur from the blast furnace gas.

[0019] The gas replacement system comprises a first gas replacement valve (25), a first relief valve (24), a first compressed air pipeline, a first nitrogen pipeline, a second compressed air pipeline, a second nitrogen pipeline, a second gas replacement valve (27) and a second relief valve (26); the first nitrogen pipeline and the first compressed air pipeline are connected to the first replacement gas interface (10) through the first gas replacement valve (25), the second nitrogen pipeline and the second compressed air pipeline are connected to the second replacement gas interface (15) through the second gas replacement valve (27), and the first relief valve (24) and the second relief valve (26) are arranged on the relief pipeline to control the release of the replaced coal gas.

[0020] The present invention also relates to a dry purification process capable of achieving total sulfur removal from blast furnace gas, preferably a dry purification process capable of achieving the removal of sulfur-containing substances such as COS, CS2, H2S, SO2 and the like in blast furnace gas and the coordinated removal of HCl; the dry purification process comprises the following steps:

[0021] (1) Inlet blast furnace gas (1) first enters the catalytic hydrolysis tower for treatment, and the catalyst loaded in the catalytic hydrolysis tower catalytically converts COS and CS2 in the blast furnace gas into H2S;

[0022] (2) The generated H2S enters the desulfurization tower along with the blast furnace gas, and the desulfurizer is sent into the desulfurization tower through the pneumatic conveying device (19), absorbing H2S, SO2, HCl and other acidic gases, thereby removing the sulfur-containing substances in the blast furnace gas; preferably, the desulfurizer is transported by truck;

[0023] (3) The blast furnace gas treated by the desulfurization tower is discharged through the clean blast furnace gas outlet (21) and sent to the blast furnace gas pipeline network, thereby achieving blast furnace gas desulfurization.

[0024] Among them, the desulfurization tower has multiple desulfurizer bins, one of which is on standby, and the other desulfurizer bins are in operation. Preferably, there are 4 desulfurizer bins, three of which are in use and one is on standby. During operation, multiple desulfurizer bins take turns to replace desulfurizers at certain time intervals to ensure the desulfurization effect.

[0025] During the normal operation of the desulfurization tower, the first inlet shut-off valve (8), the second inlet shut-off valve (11), the first outlet shut-off valve (14) and the second outlet shut-off valve (17) are all in a closed state; if the desulfurizer needs to be replaced, the first outlet shut-off valve (14) is first opened to discharge the desulfurizer in the reaction chamber (12) into the outlet buffer chamber (16); then the first outlet shut-off valve (14) is closed, the second gas replacement valve (27) and the second release valve (26) of the gas replacement system are opened, nitrogen is introduced into the outlet buffer chamber (16), the coal gas in the chamber is replaced and released; then the second gas replacement valve (27) and the second release valve (26) are closed, the second outlet shut-off valve (17) is opened, the desulfurizer in the outlet buffer chamber (16) is discharged, and the nitrogen is introduced into the outlet buffer chamber (16) to replace the coal gas in the chamber. The sulphurizing agent is discharged through the desulphurizing agent outlet (18), preferably transported by a truck, and the second outlet shut-off valve (17) is closed; in the next step, the desulphurizing agent preferably transported by a truck is added to the desulphurizing agent inlet (7) through the pneumatic conveying device (19), the first gas replacement valve (25) and the first relief valve (24) are opened, nitrogen is introduced into the inlet buffer bin (9), the coal gas in the bin is replaced and released; then the first gas replacement valve (25) and the first relief valve (24) are closed, the first inlet shut-off valve (8) is opened, the desulphurizing agent is discharged into the inlet buffer bin (9), the first inlet shut-off valve (8) is closed, the second inlet shut-off valve (11) is opened, the desulphurizing agent is discharged into the reaction bin (12), the second inlet shut-off valve (11) is closed, and the desulphurizing agent replacement process is completed. The use of the buffer bin and gas replacement method can prevent the blast furnace gas from leaking, thereby ensuring the safe operation of the system. If the desulfurization tower needs to be inspected and repaired, after the desulfurization agent is emptied in the above-mentioned manner, the first inlet shut-off valve (8) and the second outlet shut-off valve (17) are closed, the second inlet shut-off valve (11) and the first outlet shut-off valve (14) are opened, the second gas replacement valve (27) and the second vent valve (26) are opened, and nitrogen is introduced into the entire desulfurization tower to replace the coal gas in the tower and release it, and then the entire system is purged with compressed air to ensure the safety of the maintenance personnel.

[0026] Preferably, the present invention relates to a dry purification device capable of achieving full sulfur removal from blast furnace gas, preferably a dry purification device capable of achieving the removal of sulfur-containing substances such as COS, CS2, H2S, SO2 and the like in blast furnace gas and the coordinated removal of HCl, the dry purification device comprising a catalytic hydrolysis tower, a desulfurization tower, a pneumatic conveying device (19) and a gas replacement system; the pneumatic conveying device (19) is connected to the desulfurization tower and is used to deliver a desulfurizer into the desulfurization tower; the catalytic hydrolysis tower is filled with a hydrolysis catalyst for hydrolyzing and catalytically treating the blast furnace gas introduced from the upper part of the catalytic hydrolysis tower; the catalytic hydrolysis tower is connected to the blast furnace gas inlet (20) of the desulfurization tower and is used to deliver the blast furnace gas treated with hydrolysis and catalysis into the desulfurization tower for treatment; a clean blast furnace gas discharge port (21) is provided on the side of the desulfurization tower and is used to discharge the blast furnace gas treated by the desulfurization tower through the clean blast furnace gas discharge port (21) and deliver it into the blast furnace gas pipeline network.

[0027] Preferably, the flue at the outlet of the catalytic hydrolysis tower is connected to the blast furnace gas inlet (20) of the desulfurization tower, and four desulfurizer bins are arranged in sequence on the right side of the desulfurization tower gas inlet. A single desulfurizer bin is provided with a desulfurizer inlet (7), a first inlet shut-off valve (8), an inlet buffer bin (9), a second inlet shut-off valve (11), a reaction bin (12), a first outlet shut-off valve (14), an outlet buffer bin (16), an outlet shut-off valve (17) and a desulfurizer outlet (18) from top to bottom; and replacement gas interfaces (10) and (15) are respectively arranged on the sides of the inlet buffer bin (9) and the outlet buffer bin (16) for replacing the gas in the buffer bin with nitrogen before replacing the desulfurizer to ensure that the gas does not leak.

[0028] Preferably, there are 3 desulfurizing agent bins in the desulfurizing tower and 1 in reserve. During operation, the 4 desulfurizing agent bins are replaced with desulfurizing agent in turn at a certain time interval to ensure the desulfurization effect. During normal operation, the first inlet shut-off valve (8), the second inlet shut-off valve (11), the first outlet shut-off valve (14) and the second outlet shut-off valve (17) are all in a closed state. If the desulfurizer needs to be replaced, first open the first outlet shut-off valve (14) to discharge the desulfurizer in the reaction chamber into the outlet buffer chamber (16), then close the first outlet shut-off valve (14), open the second gas replacement valve (27) and the second release valve (26), introduce nitrogen into the outlet buffer chamber (16), replace the coal gas in the chamber and release it; then close the second gas replacement valve (27) and the second release valve (26), open the second outlet shut-off valve (17), discharge the desulfurizer in the outlet buffer chamber (16) through the desulfurizer outlet (18), transport it away by truck, and close the second outlet shut-off valve (17); In one step, the desulfurizer transported by the truck is added to the desulfurizer inlet (7) through the pneumatic conveying device (19), the first gas replacement valve (25) and the first release valve (24) are opened, and nitrogen is introduced into the inlet buffer bin (9) to replace the gas in the bin and release it; then the first gas replacement valve (25) and the first release valve (24) are closed, the first inlet shut-off valve (8) is opened, the desulfurizer is discharged into the inlet buffer bin (9), the first inlet shut-off valve (8) is closed, the second inlet shut-off valve (11) is opened, the desulfurizer is discharged into the reaction bin (12), and the second inlet shut-off valve (11) is closed to complete the desulfurizer replacement process. The use of the buffer bin and gas replacement method can prevent the blast furnace gas from leaking and ensure the safe operation of the system. If the desulfurization tower needs to be inspected and repaired, after the desulfurization agent is emptied in the above-mentioned manner, the first inlet shut-off valve (8) and the second outlet shut-off valve (17) are closed, the second inlet shut-off valve (11) and the first outlet shut-off valve (14) are opened, the second gas replacement valve (27) and the second vent valve (26) are opened, and nitrogen is introduced into the entire desulfurization tower to replace the coal gas in the tower and release it, and then the entire system is purged with compressed air to ensure the safety of the maintenance personnel.

[0029] The principle of the present invention is that COS and CS2 in blast furnace gas are catalytically converted into H2S in the catalytic hydrolysis tower; the desulfurizer in the desulfurization tower absorbs acidic gases such as H2S, SO2, and HCl in the gas; the treated clean gas is discharged from the desulfurization tower and merged into the pipeline network. This process realizes the removal of sulfur-containing substances in blast furnace gas, solves the problem of excessive SO2 from the source, and the coordinated removal of HCl controls the corrosion problem of gas pipelines to a certain extent.

[0030] The present invention provides a dry purification process with simple technical process, low cost and good reliability, especially capable of removing H2S, SO2, HCl and other acid gases in blast furnace gas within a temperature range of 40-90°C.

[0031] Beneficial effects of the present invention: The present invention provides a dry purification process for simultaneously removing H2S, SO2, HCl and other acid gases from blast furnace gas. The purification process of the present invention first catalytically converts organic sulfur such as COS and CS2 into H2S, and then absorbs acid gases such as H2S, SO2, HCl in the gas through a desulfurizer in a desulfurization tower. This process can provide steel mills and environmental protection companies with accurate process layout plans and operating parameters for controlling sulfur pollutants in blast furnace gas, solving the problem of excessive SO2 from the source. At the same time, the coordinated removal of HCl controls the corrosion problem of gas pipelines to a certain extent. The process is simple, the reliability is good, the operation is stable, and the cost of pollutant control is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a process flow chart of a dry purification device for blast furnace gas desulfurization;

[0033] Figure 2 It is the layout diagram of the dry purification device for blast furnace gas desulfurization;

[0034] Figure 3 It is a side view of a dry purification device for blast furnace gas desulfurization;

[0035] Figure 4 Detailed drawing of desulfurizer baffle

[0036] Figure 5 This is a diagram of the removal process of sulfur pollutants.

[0037] Markings in the figure: 1-inlet blast furnace gas, 2-catalytic hydrolysis tower shell, 3-catalytic hydrolysis tower feeding port, 4-catalyst support net, 5-catalytic hydrolysis tower unloading port, 6-catalytic hydrolysis tower sewage outlet, 7-desulfurizer inlet, 8-first inlet shut-off valve, 9-inlet buffer bin, 10-first replacement gas interface, 11-second inlet shut-off valve, 12-reaction bin, 13-observation window, 14-first outlet shut-off valve, 15-second replacement gas interface, 16-outlet buffer bin, 17-second outlet shut-off valve, 18-desulfurizer outlet, 19-pneumatic conveying device, 20-blast furnace gas inlet, 21-blast furnace gas outlet, 22-rapping motor, 23-desulfurizer baffle, 24-first relief valve, 25-first gas replacement valve, 26-second relief valve, 27-second gas replacement valve. DETAILED DESCRIPTION

[0038] like Figure 1 , 2, 3, and 4, a dry purification device for removing all sulfur from blast furnace gas is provided, preferably a dry purification device that can remove sulfur-containing substances such as carbonyl sulfide (COS), carbon disulfide (CS2), hydrogen sulfide (H2S), sulfur dioxide (SO2) and the like in blast furnace gas, and synergistically remove hydrogen chloride (HCl), the dry purification device comprising a catalytic hydrolysis tower, a desulfurization tower, a pneumatic conveying device 19 and a gas replacement system; the catalytic hydrolysis tower is filled with a hydrolysis catalyst for catalyzing the hydrolysis of the blast furnace gas introduced into the catalytic hydrolysis tower, and the catalytic hydrolysis tower is connected to the desulfurization tower. The blast furnace gas inlet 20 on one side of the desulfurization tower is used to send the blast furnace gas after hydrolysis catalytic treatment into the desulfurization tower for treatment; the pneumatic conveying device 19 is connected to the top of the desulfurization tower, and is used to send the desulfurizer into the desulfurization tower to remove all sulfur from the blast furnace gas; the other side of the desulfurization tower is provided with a clean blast furnace gas outlet 21, which is used to discharge the clean blast furnace gas after all sulfur is removed through the clean blast furnace gas outlet 21 and send it into the blast furnace gas pipeline network; the gas replacement system is connected to the replacement gas interface 10, 15 of the desulfurization tower, and is used to replace the gas in the desulfurization tower with the replacement gas before replacing the desulfurizer.

[0039] like Figure 2 As shown, the catalytic hydrolysis tower comprises a catalytic hydrolysis tower inlet flue, a catalytic hydrolysis tower shell 2, a catalytic hydrolysis tower outlet flue, a catalyst support net 4, a feed port 3, a discharge port 5 and a sewage outlet 6. The top end of the catalytic hydrolysis tower shell is connected to the catalytic hydrolysis tower inlet flue for feeding blast furnace gas into the catalytic hydrolysis tower. The lower end of the catalytic hydrolysis tower shell is connected to the catalytic hydrolysis tower outlet flue. The catalytic hydrolysis tower outlet flue is connected to the blast furnace gas inlet 20 of the desulfurization tower for feeding the blast furnace gas after hydrolysis catalytic treatment into the desulfurization tower for treatment. The catalyst support net 4 is arranged in the catalytic hydrolysis tower shell 2 for supporting the hydrolysis catalyst. The bottom end of the catalytic hydrolysis tower shell is provided with a sewage outlet 6. The catalytic hydrolysis tower shell is provided with a feed port 3 and a discharge port 5 for feeding and discharging the hydrolysis catalyst. The upper part of the catalytic hydrolysis tower shell is conical, the middle part is cylindrical, and the lower part is conical; the inlet flue of the catalytic hydrolysis tower is arranged at the top of the upper cone, the sewage outlet 6 is arranged at the bottom of the lower cone, and the outlet flue of the catalytic hydrolysis tower is arranged on the lower cone and located at the upper part of the sewage outlet 6; the catalyst support net 4 is arranged on the middle cylindrical shape. The catalyst is one or more of honeycomb, rod, Raschig ring, and spherical, and catalytically hydrolyzes organic sulfur such as COS and CS2 in blast furnace gas into H2S. The active components of the catalyst are one or more of Na, K, Fe, Cu, and Ni salts, and the carrier is one or more of activated alumina, activated carbon, cordierite, and hydrotalcite. The catalyst configuration is preferably a Raschig ring catalyst, which is randomly piled up from large to small on the catalyst support net 4 in the catalytic hydrolysis tower, and the catalyst is filled with a certain volume so that the catalytic reaction space velocity is 500-4000h -1, the gas flow rate is 0.5-2m / s; preferably, in the catalytic hydrolysis tower, 80%-95% volume fraction of COS and CS2 in the blast furnace gas is catalytically converted into H2S.

[0040] like Figure 1 , 2 As shown in Figures 3 and 4, the desulfurization tower is in the form of a gas-solid cross-flow moving bed, with low gas pressure drop, small desulfurizer wear, uniform gas-solid two-phase contact, and large flexibility in adjusting the desulfurizer residence time. The gas flow rate in the desulfurization tower is controlled at 0.5-3m / s to ensure uniform air distribution; the preferred blast furnace gas inlet temperature is 40-90°C, and the outlet temperature remains basically unchanged. The outlet flue of the catalytic hydrolysis tower is connected to the blast furnace gas inlet 20 of the desulfurization tower, and four desulfurizer bins are arranged in sequence on the right side of the desulfurization tower gas inlet. A single desulfurizer bin is arranged from top to bottom with a desulfurizer inlet 7, a first inlet shut-off valve 8, an inlet buffer bin 9, a second inlet shut-off valve 11, a reaction bin 12, a first outlet shut-off valve 14, an outlet buffer bin 16, a second outlet shut-off valve 17, and a desulfurizer outlet 18; replacement gas interfaces 10 and 15 are respectively arranged on the sides of the inlet buffer bin 9 and the outlet buffer bin 16, which are used to replace the gas in the buffer bin with nitrogen before replacing the desulfurizer to ensure that the gas does not leak. Vibrating motors 22 are provided on both sides of the desulfurization tower inlet buffer bin 9, reaction bin 12 and outlet buffer bin 16 to regularly vibrate the bin walls to maintain the fluidized state of the desulfurizer. Desulfurizer baffles 23 are provided on the gas inlet and outlet sides of the reaction bin 12 to ensure that the desulfurizer does not leak and to distribute the airflow evenly. An observation window 13 is provided on the side of the reaction bin 12 to observe the situation in the bin in real time during operation. Preferably, the desulfurizer is placed directly in the desulfurization tower and divided into four modules, which are separated by a desulfurizer baffle 23 in the middle to facilitate the individual replacement of the desulfurizer in each module. The desulfurizer baffle 23 is as shown in FIG. Figure 4 As shown, the desulfurizer baffle 23 has holes, the desulfurizer can be blocked, but the coal gas can pass through. Preferably, the blast furnace gas inlet 20 is a hole opened on the reaction bin 12, which is an interface on the reaction bin. The coal gas directly enters the desulfurization tower through the inlet 20. Each reaction bin is in the desulfurization tower and is separated by the desulfurizer baffle 23.

[0041] Among them, the first inlet shut-off valve 8 is arranged between the desulfurizer inlet 7 and the inlet buffer bin 9, and is used to open or close the connection between the desulfurizer inlet 7 and the inlet buffer bin 9; the second inlet shut-off valve 11 is arranged between the inlet buffer bin 9 and the reaction bin 12, and is used to open or close the connection between the buffer bin 9 and the reaction bin 12; the first outlet shut-off valve 14 is arranged between the reaction bin 12 and the outlet buffer bin 16, and is used to open or close the connection between the reaction bin 12 and the outlet buffer bin 16; the second outlet shut-off valve 17 is arranged between the outlet buffer bin 16 and the desulfurizer outlet 18, and is used to open or close the connection between the outlet buffer bin 16 and the desulfurizer outlet 18. Among them, the pneumatic conveying device 19 is connected to the desulfurizer inlet 7 at the top of the desulfurizer bin, and is used to deliver the desulfurizer into the reaction bin 12 to remove all sulfur from the blast furnace gas. Among them, the gas replacement system includes a first gas replacement valve 25, a first release valve 24, a first compressed air pipeline, a first nitrogen pipeline, a second compressed air pipeline, a second nitrogen pipeline, a second gas replacement valve 27 and a second release valve 26; the first nitrogen pipeline and the first compressed air pipeline are connected to the first replacement gas interface 10 through the first gas replacement valve 25, the second nitrogen pipeline and the second compressed air pipeline are connected to the second replacement gas interface 15 through the second gas replacement valve 27, and the first release valve 24 and the second release valve 26 are arranged on the release pipeline for controlling the release of the replaced coal gas.

[0042] like Figure 2As shown, there are 4 desulfurizer bins 3 in the desulfurization tower and 1 in reserve. During operation, the 4 desulfurizer bins take turns to replace the desulfurizer at certain time intervals to ensure the desulfurization effect. During normal operation, the first inlet shut-off valve 8, the second inlet shut-off valve 11, the first outlet shut-off valve 14 and the second outlet shut-off valve 17 are all in a closed state. If the desulfurizer needs to be replaced, first open the first outlet shut-off valve 14 to discharge the desulfurizer in the reaction bin into the outlet buffer bin 16, then close the first outlet shut-off valve 14, open the second gas replacement valve 27 and the second release valve 26, introduce nitrogen into the outlet buffer bin 16 to replace the coal gas in the bin and release it; then close the second gas replacement valve 27 and the second release valve 26, open the second outlet shut-off valve 17, discharge the desulfurizer in the outlet buffer bin 16 through the desulfurizer outlet 18, and transport it away by truck, and close the second outlet shut-off valve 17; Next, the desulfurizer transported by the truck is added to the desulfurizer inlet 7 through the pneumatic conveying device 19, the first gas replacement valve 25 and the first relief valve 24 are opened, and nitrogen is introduced into the inlet buffer bin 9 to replace the gas in the bin and release it; then the first gas replacement valve 25 and the first relief valve 24 are closed, the first inlet shut-off valve 8 is opened, the desulfurizer is discharged into the inlet buffer bin 9, the first inlet shut-off valve 8 is closed, the second inlet shut-off valve 11 is opened, the desulfurizer is discharged into the reaction bin 12, and the second inlet shut-off valve 11 is closed to complete the desulfurizer replacement process. The use of the buffer bin and gas replacement method can prevent the blast furnace gas from leaking and ensure the safe operation of the system. If the desulfurization tower needs to be inspected and repaired, after draining the desulfurizer in the above manner, close the first inlet shut-off valve 8 and the second outlet shut-off valve 17, open the second inlet shut-off valve 11 and the first outlet shut-off valve 14, open the second gas replacement valve 27 and the second vent valve 26, and introduce nitrogen into the entire desulfurization tower to replace the coal gas in the tower and release it, and then purge the entire system with compressed air to ensure the safety of the maintenance personnel.

[0043] like Figure 2 As shown, the desulfurizer is a porous column, the carrier is a mixture of zeolite and pumice, the molar ratio of pumice to zeolite is between 0.2-0.5; the active ingredients are mainly one or more of iron oxide, manganese oxide, potassium hydroxide, and sodium carbonate, wherein the active ingredients account for 3%-10% of the mass fraction of the desulfurizer. The desulfurizer is filled with a certain volume so that the desulfurization reaction space velocity is 500-5000h -1 , ensuring efficient removal of pollutants in blast furnace gas.

[0044] like Figure 1 , 2 As shown, a dry purification process capable of achieving full sulfur removal from blast furnace gas, preferably a dry purification process capable of achieving the removal of sulfur-containing substances such as COS, CS2, H2S, SO2 and the coordinated removal of HCl in blast furnace gas, preferably, the purification process is to adopt Figure 1 ,2 A dry purification process for removing all sulfur from blast furnace gas is shown; it is characterized in that it comprises the following steps:

[0045] (1) The inlet blast furnace gas 1 first enters the catalytic hydrolysis tower for treatment, and the catalyst loaded in the catalytic hydrolysis tower catalytically converts COS and CS2 in the blast furnace gas into H2S;

[0046] (2) The generated H2S enters the desulfurization tower along with the blast furnace gas. The desulfurizer transported by truck is sent to the desulfurization tower through the pneumatic conveying system to absorb H2S, SO2, HCl and other acidic gases, thereby removing the sulfur-containing substances in the blast furnace gas.

[0047] (3) The blast furnace gas treated by the desulfurization tower is discharged through the clean blast furnace gas outlet 21 and sent to the blast furnace gas pipeline network, thereby achieving blast furnace gas desulfurization.

[0048] During operation, the replacement frequency of the desulfurizer is adjusted according to the concentration of H2S in the export gas, so as to remove the sulfur-containing substances in the blast furnace gas and solve the problem of excessive SO2 from the source. At the same time, the coordinated removal of HCl controls the corrosion problem of the gas pipeline to a certain extent.

[0049] The process of the present invention is as follows: the combustible gas (containing nitrogen (N2), carbon monoxide (CO), carbon dioxide (CO2), hydrogen (H2), hydrocarbons, a small amount of sulfur-containing compounds and dust) produced as a by-product in the blast furnace ironmaking production process is used as the inlet blast furnace gas 1 of the purification process described in the present invention after gravity dust removal, bag dust removal and residual pressure turbine power generation device (TRT). The blast furnace gas passes through a catalytic hydrolysis tower, which is filled with a catalyst. The catalyst uses one or more of activated alumina, activated carbon, cordierite, and hydrotalcite as carriers, one or more of Na, K, Fe, Cu, and Ni salts as active ingredients, and the catalyst configuration is a Raschig ring catalyst. The catalyst is filled with a certain volume so that the catalytic reaction space velocity is 500-4000h -1 , the gas flow rate is 0.5-2m / s, so that in the catalytic hydrolysis tower, 80%-95% volume fraction of COS and CS2 in the blast furnace gas is catalytically converted into H2S. Figure 2 The desulfurization tower is filled with a desulfurizer, which is a porous column, and the carrier is a mixture of zeolite and pumice, with the molar ratio of pumice to zeolite being between 0.2-0.5; the active ingredients are mainly one or more of iron oxide, manganese oxide, potassium hydroxide, and sodium carbonate, of which the active ingredients account for 3%-10% of the mass fraction of the desulfurizer. The desulfurizer is filled with a certain volume so that the desulfurization reaction space velocity is 500-5000h -1 , ensuring efficient removal of pollutants in blast furnace gas.

[0050] like Figure 5 As shown, in the catalytic hydrolysis tower, blast furnace gas and water react as follows under the action of the catalyst:

[0051] COS+H20=CO2+H2S;

[0052] CS2+H20=COS+H2S;

[0053] CS2+2H2O=2H2S+CO2.

[0054] The H2S produced by the reaction and the small amount of HCl, SO2 and other acidic gases existing in the blast furnace gas react with the desulfurizer as follows:

[0055] Fe2O3.H2O+3H2S=Fe2S3.H2O+3H2O

[0056] MnO+H2S=MnO+H2O

[0057] H2S+2KOH=K2S+2H2O, SO2+2KOH=K2SO3+H2O, HCl+KOH=KCl+H2O

[0058] H2S+2Na2CO3=Na2S+2NaHCO3, SO2+2Na2CO3+H2O=2NaHCO3+Na2SO3, HCl+Na2CO3=NaCl+NaHCO3

[0059] In the presence of O2, Na2SO3 can be oxidized to Na2SO4.

[0060] Example:

[0061] The blast furnace gas of a steel plant adopts the device and process of the present invention, the inlet gas temperature of the catalytic hydrolysis tower is 90°C, and the COS and CS2 contents are 120mg / Nm 3 , H2S content is 50mg / Nm 3 , inlet gas flow rate is 5000Nm 3 / h, the catalytic hydrolysis tower is filled with 2.5m 3 The cross-sectional area of ​​the catalyst perpendicular to the flue gas flow direction is 1.5m 2 The flue gas velocity in the catalytic hydrolysis tower is 1m / s. After the catalytic hydrolysis tower, the proportion of COS and CS2 catalytically converted into H2S is 91%. Blast furnace gas enters the desulfurization tower through the gas inlet on the side of the desulfurization tower. The gas channel of the desulfurization tower is square with a side length of 1.2m. The apparent flow rate of the gas is 0.9m / s. There are 4 desulfurizer silos, 3 for use and 1 for backup. The volume of a single desulfurizer silo is 4m 3, the outlet gas temperature is 85℃. After this dry purification process, the COS and CS2 conversion efficiency is greater than 90%, and the outlet H2S concentration is less than 15mg / Nm 3 .

[0062] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A dry purification device for removing total sulfur from blast furnace gas, characterized in that: The dry purification device comprises a catalytic hydrolysis tower, a desulfurization tower, a pneumatic conveying device (19) and a gas replacement system; the catalytic hydrolysis tower is filled with a hydrolysis catalyst for catalytically hydrolyzing the blast furnace gas introduced into the catalytic hydrolysis tower; the catalytic hydrolysis tower is connected to a blast furnace gas inlet (20) arranged on one side of the desulfurization tower, and is used to send the blast furnace gas after the hydrolysis catalytic treatment into the desulfurization tower for treatment; the pneumatic conveying device (19) is connected to the top of the desulfurization tower, and is used to send a desulfurizer into the desulfurization tower to remove all sulfur from the blast furnace gas; a clean blast furnace gas outlet (21) is provided on the other side of the desulfurization tower, and is used to discharge the clean blast furnace gas after the all sulfur is removed through the clean blast furnace gas outlet (21) and send it into the blast furnace gas pipeline network; the gas replacement system is connected to the replacement gas interface of the desulfurization tower, and is used to replace the gas in the desulfurization tower with the replacement gas before replacing the desulfurizer; The outlet flue of the catalytic hydrolysis tower is connected to the blast furnace gas inlet (20) of the desulfurization tower, and a plurality of desulfurizer bins are sequentially arranged on the right side of the blast furnace gas inlet (20); a single desulfurizer bin is sequentially provided with a desulfurizer inlet (7), a first inlet shut-off valve (8), an inlet buffer bin (9), a second inlet shut-off valve (11), a reaction bin (12), a first outlet shut-off valve (14), an outlet buffer bin (16), a second outlet shut-off valve (17) and a desulfurizer outlet (18) from top to bottom; the replacement gas interface comprises a first replacement gas interface (10) and a second replacement gas interface (15), the first replacement gas interface (10) being arranged on the side of the inlet buffer bin (9), and the second replacement gas interface (15) being arranged on the side of the outlet buffer bin (16), the gas replacement system being connected to the inlet buffer bin (9) via the first replacement gas interface (10), and the gas replacement system being connected to the outlet buffer bin (16) via the second replacement gas interface (15), and being used for using nitrogen to replace the gas in the buffer bin before replacing the desulfurizer. The first inlet shut-off valve (8) is arranged between the desulfurizing agent inlet (7) and the inlet buffer bin (9), and is used to open or close the connection between the desulfurizing agent inlet (7) and the inlet buffer bin (9); the second inlet shut-off valve (11) is arranged between the inlet buffer bin (9) and the reaction bin (12), and is used to open or close the connection between the inlet buffer bin (9) and the reaction bin (12); the first outlet shut-off valve (14) is arranged between the reaction bin (12) and the outlet buffer bin (16), for opening or closing the connection between the reaction bin (12) and the outlet buffer bin (16); a second outlet shut-off valve (17) is arranged between the outlet buffer bin (16) and the desulfurizing agent outlet (18), for opening or closing the connection between the outlet buffer bin (16) and the desulfurizing agent outlet (18); and vibrating motors are arranged on both sides of the inlet buffer bin (9), the reaction bin (12) and the outlet buffer bin (16), for regularly vibrating the bin wall to maintain the fluidized state of the desulfurizing agent.

2. The dry purification device according to claim 1, characterized in that: The catalytic hydrolysis tower comprises a catalytic hydrolysis tower inlet flue, a catalytic hydrolysis tower shell (2), a catalytic hydrolysis tower outlet flue, a catalyst support net (4), a feed port (3), a discharge port (5) and a sewage outlet (6); the top end of the catalytic hydrolysis tower shell (2) is connected to the catalytic hydrolysis tower inlet flue for feeding blast furnace gas into the catalytic hydrolysis tower; the lower end of the catalytic hydrolysis tower shell (2) is connected to the catalytic hydrolysis tower outlet flue; the catalytic hydrolysis tower outlet flue is connected to the blast furnace gas inlet (20) of the desulfurization tower for feeding the blast furnace gas after hydrolysis catalytic treatment into the desulfurization tower for treatment; the catalyst support net (4) is arranged in the catalytic hydrolysis tower shell (2) for supporting the hydrolysis catalyst; A sewage outlet (6) is provided at the bottom of the catalytic hydrolysis tower shell (2); a feed port (3) and a discharge port (5) are provided on the catalytic hydrolysis tower shell (2) for feeding and discharging the hydrolysis catalyst.

3. The dry purification device according to claim 2, characterized in that: The upper part of the catalytic hydrolysis tower shell (2) is conical, the middle part is cylindrical, and the lower part is conical; the catalytic hydrolysis tower inlet flue is arranged at the top of the upper part of the catalytic hydrolysis tower shell, the sewage outlet (6) is arranged at the bottom end of the lower part of the catalytic hydrolysis tower shell, and the catalytic hydrolysis tower outlet flue is arranged on the lower part of the catalytic hydrolysis tower shell and is located above the sewage outlet (6); the catalyst support net (4) is arranged in the middle part of the catalytic hydrolysis tower shell.

4. The dry purification device according to any one of claims 1 to 3, characterized in that: The catalyst is in one or more of a honeycomb, rod, Raschig ring, or spherical shape, and catalytically hydrolyzes carbonyl sulfide (COS) and carbon disulfide (CS2) in blast furnace gas into H2S. The catalyst active component is one or more of Na, K, Fe, Cu, and Ni salts, and the carrier is one or more of activated alumina, activated carbon, cordierite, and hydrotalcite.

5. The dry purification device according to claim 4, characterized in that: The catalyst is a Raschig ring-shaped catalyst, which is randomly piled up from large to small on a catalyst support net (4) in the catalytic hydrolysis tower.

6. The dry purification device according to any one of claims 1 to 3, characterized in that: The desulfurization tower is in the form of a gas-solid cross-flow moving bed.

7. The dry purification device according to any one of claims 1 to 3, characterized in that: The blast furnace gas reacts with the desulfurizing agent in the reaction chamber (12) to remove all sulfur. Desulfurizing agent baffles (23) are provided at the gas inlet and outlet sides of the reaction chamber (12) to ensure that the desulfurizing agent does not leak out and to distribute the gas flow evenly.

8. The dry purification device according to any one of claims 1 to 3, characterized in that: An observation window (13) is arranged on the side of the reaction chamber (12) for observing the situation in the reaction chamber (12) in real time during operation.

9. The dry purification device according to any one of claims 1 to 3, characterized in that: The desulfurizer is a porous column type, the carrier is a mixture of zeolite and pumice, the molar ratio of pumice to zeolite is between 0.2-0.5; the active ingredient is one or more of iron oxide, manganese oxide, potassium hydroxide and sodium carbonate, wherein the active ingredient accounts for 3%-10% of the mass fraction of the desulfurizer.

10. The dry purification device according to any one of claims 1 to 3, characterized in that: The pneumatic conveying device (19) is connected to the desulfurizing agent inlet (7) at the top of the desulfurizing agent bin and is used to deliver the desulfurizing agent into the reaction bin (12) to remove all sulfur from the blast furnace gas.

11. The dry purification device according to any one of claims 1 to 3, characterized in that: The gas replacement system comprises a first gas replacement valve (25), a first relief valve (24), a first compressed air pipeline, a first nitrogen pipeline, a second compressed air pipeline, a second nitrogen pipeline, a second gas replacement valve (27) and a second relief valve (26); the first nitrogen pipeline and the first compressed air pipeline are connected to a first replacement gas interface (10) via the first gas replacement valve (25), the second nitrogen pipeline and the second compressed air pipeline are connected to a second replacement gas interface (15) via the second gas replacement valve (27), and the first relief valve (24) and the second relief valve (26) are arranged on the relief pipeline to control the release of the replaced coal gas.

12. A dry purification process capable of achieving total sulfur removal from blast furnace gas, the dry purification process being a dry purification process using the dry purification device according to any one of claims 1 to 11; characterized in that: It includes the following steps: (1) Inlet blast furnace gas (1) first enters the catalytic hydrolysis tower for treatment, and the catalyst loaded in the catalytic hydrolysis tower catalytically converts COS and CS2 in the blast furnace gas into H2S; (2) The generated H2S enters the desulfurization tower along with the blast furnace gas, and the desulfurizer is sent into the desulfurization tower through the pneumatic conveying device (19) to absorb H2S, SO2, HCl and other acidic gases, thereby removing the sulfur-containing substances in the blast furnace gas; (3) The blast furnace gas treated by the desulfurization tower is discharged through the clean blast furnace gas outlet (21) and sent to the blast furnace gas pipeline network, thereby achieving blast furnace gas desulfurization.

13. The method according to claim 12, characterized in that The desulfurization tower has multiple desulfurization agent bins, one of which is standby and the other desulfurization agent bins are in operation.

14. The method according to claim 12 or 13, characterized in that During normal operation of the desulfurization tower, the first inlet shut-off valve (8), the second inlet shut-off valve (11), the first outlet shut-off valve (14) and the second outlet shut-off valve (17) are all in a closed state; when it is necessary to replace the desulfurizer, the first outlet shut-off valve (14) is first opened to discharge the desulfurizer in the reaction chamber (12) into the outlet buffer chamber (16); then the first outlet shut-off valve (14) is closed, the second gas replacement valve (27) and the second release valve (26) of the gas replacement system are opened, nitrogen is introduced into the outlet buffer chamber (16), the coal gas in the chamber is replaced and released; then the second gas replacement valve (27) and the second release valve (26) are closed, the second outlet shut-off valve (17) is opened, and the outlet buffer chamber (16) is filled with nitrogen. 6) is discharged through the desulfurizing agent outlet (18), and the second outlet shut-off valve (17) is closed; in the next step, the transported desulfurizing agent is added to the desulfurizing agent inlet (7) through the pneumatic conveying device (19), the first gas replacement valve (25) and the first release valve (24) are opened, and nitrogen is introduced into the inlet buffer bin (9) to replace the coal gas in the bin and release it; then the first gas replacement valve (25) and the first release valve (24) are closed, the first inlet shut-off valve (8) is opened, the desulfurizing agent is discharged into the inlet buffer bin (9), the first inlet shut-off valve (8) is closed, the second inlet shut-off valve (11) is opened, the desulfurizing agent is discharged into the reaction bin (12), and the second inlet shut-off valve (11) is closed to complete the desulfurizing agent replacement process.

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