A system and method for desulfurizing blast furnace gas

Abstract

The present application provides a system and method for desulfurizing blast furnace gas, which uses a regenerable desulfurizer to perform adsorption desulfurization on blast furnace gas. After the desulfurizer is saturated with adsorption, the desulfurizer is regenerated in situ using the blast furnace gas after pretreatment (i.e., before hydrolysis), and the desorbed gas is transported to the sintering section as fuel for combustion. The desulfurizer maintains good performance after regeneration and can be reused many times. Regenerating the desulfurizer using the gas before hydrolysis can reduce the total amount of gas processing, thereby reducing the scale and investment cost of the hydrolysis device and the dry desulfurization device.

Description

Technical Field

[0001] The present application relates to the technical field of blast furnace gas purification, and in particular to a system and method for desulfurizing blast furnace gas. Background Art

[0002] Blast furnace gas is the most abundant combustible gas in the production process of steel enterprises, with a gas output of 1500-2000 m3 per ton of iron and steel. 3 Its main components include: CO, CO2, N2, H2, hydrocarbons and sulfides, with a total sulfur content of about 100-200 mg / m 3 , mainly including organic sulfur and inorganic sulfur. Organic sulfur includes COS, CS2, etc., accounting for about 70% of the total sulfur content, and inorganic sulfur is mainly H2S, accounting for 30%.

[0003] At present, the fine desulfurization technology of blast furnace gas in the steel industry is mainly divided into dry desulfurization and wet desulfurization. Since organic sulfur in coal gas is difficult to remove, the mainstream process of dry or wet desulfurization is to convert organic sulfur into inorganic sulfur before removal, or directly remove organic sulfur and inorganic sulfur at the same time. Since the wet desulfurization process is complex, the process is long, the investment is large, and it has a great impact on the temperature of blast furnace gas, while the dry method is environmentally friendly, low-cost, and has no effect on TRT and coal gas temperature, it has a high application prospect.

[0004] Dry adsorption uses porous solid adsorbents to enrich sulfides on the surface and then remove them. Common processes include zinc oxide method, iron oxide method, activated carbon method, molecular sieve method and microcrystalline adsorption method. Since some adsorbents have poor adsorption effects on organic sulfur, it is necessary to combine front-end hydrolysis to convert organic sulfur into inorganic sulfur before removal. Dry desulfurization is widely used in industry due to its strong applicability, simple operation and high desulfurization efficiency. Combined with the characteristics of large gas volume, low sulfur concentration and high organic sulfur content of steel blast furnaces, suitable process routes for dry desulfurization include activated carbon adsorption after hydrolysis or microcrystalline adsorption.

[0005] Desulfurizers are divided into renewable and non-renewable types. The economic benefits of non-renewable desulfurizers are poor and have been gradually replaced by renewable desulfurizers. Renewable desulfurizers include iron-based desulfurizers and activated carbon. After adsorption saturation, these desulfurizers can be regenerated by air, nitrogen, treated clean coal gas, etc. However, according to experiments, the regeneration performance of iron-based desulfurizers is not good and cannot be recycled for many times; the regeneration performance of activated carbon is also poor. Sulfides will cause activated carbon to block pores and reduce strength, so it cannot be recycled for many times.

[0006] For example, the prior art CN113477027A relates to an integrated device and method for blast furnace gas desulfurization adsorption, regeneration and cooling recovery, which belongs to the field of atmospheric purification and environmental protection process technology. The device includes a number of parallel adsorbers, a main pipeline that can change the air intake direction of the adsorbers, a circulating heating system that forms a loop with the adsorbers, and a sulfur-containing steam cooling recovery system connected to the circulating heating system. The adsorbers adsorb the gas entering the air intake pipeline, and the circulating heating system and the sulfur-containing steam cooling recovery system desorb sulfur from the adsorbent.

[0007] CN113583721B discloses an oxygen-free high-water content blast furnace gas desulfurization system and process, which adopts adsorption desulfurization after hydrolysis. Part of the blast furnace gas after desulfurization and purification is heated to 180°C~200°C through a heat exchanger, and then introduced into the layered tower body of the adsorbent that needs to be regenerated in the adsorption tower. The adsorbent is regenerated by the reducing atmosphere in the purified blast furnace gas, and all of it uses clean gas for regeneration.

[0008] In the existing dry blast furnace gas desulfurization process, for the regenerable desulfurizer, the desulfurizer is generally heated and regenerated by using the purified coal gas. When the desulfurizer is regenerated by using the purified coal gas, the entire coal gas needs to be purified, which not only requires a large amount of coal gas to be processed, but also requires a large scale of hydrolysis and desulfurization equipment, resulting in high investment costs. Summary of the invention

[0009] In order to solve the above problems, the present application provides a system and method for desulfurizing blast furnace gas, which uses a regenerable desulfurizer to perform adsorption desulfurization on blast furnace gas. After the desulfurizer is saturated with adsorption, the desulfurizer is regenerated in situ using the pre-treated blast furnace gas. The desulfurizer maintains good performance after regeneration and can be reused many times. Regenerating the desulfurizer using the pre-treated gas can reduce the total amount of hydrolyzed gas and the total amount of desulfurized gas processed, effectively reducing the scale and investment cost of the hydrolysis device and the dry desulfurization device.

[0010] In a first aspect, the present application provides a system for desulfurizing blast furnace gas, the system comprising: a heater (1) and at least one desulfurization tower (2);

[0011] The desulfurization tower (2) is provided with an air inlet (21) at a first end and an air outlet (22) at a second end;

[0012] The air inlet (21) of the desulfurization tower (2) is connected to a first ventilation pipe (211), and the air outlet (22) is connected to a second ventilation pipe (221);

[0013] The first ventilation pipe (211) is connected to a first air intake pipe (212) and a second air intake pipe (213); the second air intake pipe (213) is provided with an adjusting member (23);

[0014] The second ventilation pipe (221) is connected to a first exhaust pipe (222) and a second exhaust pipe (223); the air inlet end of the heater (1) is connected to the first exhaust pipe (222), and the air outlet end is connected to the second exhaust pipe (223).

[0015] Optionally, one end of the second air intake pipe (213) is connected to a shunt pipe (214), and one end of the shunt pipe (214) away from the second air intake pipe (213) is connected to the first exhaust pipe (222).

[0016] Optionally, one end of the first ventilation pipe (211) away from the desulfurization tower (2) is connected to a first gas collecting pipe (215).

[0017] Optionally, one end of the second ventilation pipe (221) away from the desulfurization tower (2) is connected to a second gas collecting pipe (224).

[0018] Optionally, the regulating member (23) includes a regulating valve (231) or a fan (232);

[0019] When the regulating member (23) is the regulating valve (231), the regulating valve (231) is arranged on the second air intake pipe (213);

[0020] When the regulating member (23) is the fan (232), the fan (232) is connected to the second air inlet pipe (213).

[0021] In a second aspect, the present application provides a method for desulfurizing blast furnace gas applicable to the first aspect, the method comprising:

[0022] Blast furnace gas pretreatment: After blast furnace gas is dusted, dechlorinated, and separated into gas and liquid, the pretreated gas is obtained;

[0023] Hydrolysis treatment: the pre-treated coal gas is subjected to hydrolysis treatment to obtain hydrolyzed coal gas;

[0024] Desulfurization treatment: the hydrolyzed coal gas enters the first ventilation pipe (211) along the first air inlet pipe (212), and then enters the desulfurization tower (2) filled with a regenerable desulfurizer through the air inlet (21) to undergo desulfurization treatment to obtain clean coal gas, which is discharged along the air outlet (22) and the second ventilation pipe (221);

[0025] Regeneration of the regenerable desulfurizer: when the regenerable desulfurizer in the desulfurization tower (2) is saturated with adsorption, the pre-treated coal gas used for cooling treatment is introduced into the first exhaust pipe (222) along the second ventilation pipe (221) as regeneration gas, and enters the heater (1) through the first exhaust pipe (222) to be heated to 120-300° C. The heated regeneration gas enters the desulfurization tower (2) along the second exhaust pipe (223) and the second ventilation pipe (221), and the saturated regenerable desulfurizer is regenerated;

[0026] Blow-cooling treatment: the pre-treated coal gas enters the desulfurization tower (2) along the second air inlet pipe (213) and the first ventilation pipe (211) to undergo the blow-cooling treatment, so that the regenerated regenerable desulfurizer is cooled to 60-90° C.;

[0027] Each of the desulfurization towers (2) desulfurizes the blast furnace gas in a cyclic sequence of desulfurization treatment → regeneration of a regenerable desulfurizer → cooling treatment → desulfurization treatment.

[0028] Optionally, one end of the second air intake pipe (213) is connected to a shunt pipe (214), and one end of the shunt pipe (214) away from the second air intake pipe (213) is connected to the first exhaust pipe (222);

[0029] The method further comprises:

[0030] In the later stage of regeneration of the regenerable desulfurizer, when the cooling treatment is finished, the pre-treated coal gas enters the first exhaust pipe (222) along the second air inlet pipe (213) and the diverter pipe (214), and then enters the heater (1) along the first exhaust pipe (222) to be heated to 120-300° C., thereby serving as the regenerated gas;

[0031] The regenerated gas is transported to the desulfurization tower (2) along the second exhaust pipe (223) and the second ventilation pipe (221), and the regeneration of the regenerable desulfurizer is continued until the regeneration is completed.

[0032] Optionally, the regulating member (23) includes a regulating valve (231) or a fan (232);

[0033] The method further comprises:

[0034] When the regulating member (23) is the fan (232), the pre-treated coal gas is transported to the fan (232) through the second air inlet pipe (213), and the fan (232) blows the pre-treated coal gas into the first ventilation pipe (211), and then enters the desulfurization tower (2) along the air inlet (21) for the cooling treatment.

[0035] Optionally, the regeneration gas accounts for 1-10% of the volume of the pre-treated coal gas.

[0036] Optionally, one end of the first ventilation pipe (211) away from the desulfurization tower (2) is connected to a first gas collecting pipe (215);

[0037] During the regeneration of the regenerable desulfurizer, the regenerated gas is regenerated and then discharged into the first gas collecting pipe (215) along the first ventilation pipe (211), and then discharged through the first gas collecting pipe (215).

[0038] In summary, the present application includes at least one of the following beneficial technical effects:

[0039] The present application provides a method for desulfurizing blast furnace gas, in which a desulfurizer is used to purify the hydrolyzed gas, and after the regenerable desulfurizer is saturated with adsorption, the desulfurizer is regenerated with the pre-treated gas. The performance of the desulfurizer after regeneration is almost unchanged and can be reused. The use of the pre-treated gas to regenerate the desulfurizer not only reduces the total gas volume of the gas treatment (including the gas volume of the hydrolysis treatment and the gas volume of the desulfurization treatment), but also reduces the scale of the hydrolysis device and the dry desulfurization device, effectively reducing the investment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0041] Figure 1 The system structure diagram of blast furnace gas desulfurization proposed in the embodiment of the present application is shown;

[0042] Figure 2 Another system structure diagram of blast furnace gas desulfurization proposed in an embodiment of the present application is shown;

[0043] Figure 3 A flow chart of a method for desulfurization of blast furnace gas proposed in an embodiment of the present application is shown;

[0044] Figure 4 The desulfurization timing diagram of blast furnace gas desulfurization proposed in the embodiment of the present application is shown.

[0045] Description of reference numerals:

[0046] 1. Heater;

[0047] 2. Desulfurization tower; 21. Air inlet; 211. First ventilation pipe; 212. First air inlet pipe; 213. Second air inlet pipe; 214. Diverter pipe; 215. First air collecting pipe; 22. Air outlet; 221. Second ventilation pipe; 222. First exhaust pipe; 223. Second exhaust pipe; 224. Second air collecting pipe; 23. Adjustment member; 231. Adjustment valve; 232. Fan. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] In the drawings, the size of the constituent elements, the thickness of the layer or the area may be exaggerated for the sake of clarity. Therefore, any implementation of the present disclosure is not necessarily limited to the size shown in the drawings, and the shapes and sizes of the components in the drawings do not reflect the true proportions. In addition, the drawings schematically show ideal examples, and any implementation of the present disclosure is not limited to the shapes or values ​​shown in the drawings.

[0050] The present application provides a system and method for desulfurizing blast furnace gas, which utilizes pre-treated gas, i.e., unhydrolyzed gas, to regenerate a desulfurizer, thereby reducing the scale of the device and investment costs and improving the utilization rate of the desulfurizer.

[0051] First, Figure 1 The system structure diagram of blast furnace gas desulfurization proposed in the embodiment of the present application is shown, which specifically includes:

[0052] A heater 1 and at least one desulfurization tower 2;

[0053] The desulfurization tower 2 is provided with an air inlet 21 at the first end and an air outlet 22 at the second end;

[0054] The air inlet 21 of the desulfurization tower 2 is connected to a first ventilation pipe 211, and the air outlet 22 is connected to a second ventilation pipe 221;

[0055] The first ventilation pipe 211 is connected to a first air intake pipe 212 and a second air intake pipe 213 , and the second air intake pipe 213 is provided with an adjusting member 23 ;

[0056] The second ventilation pipe 221 is connected to a first exhaust pipe 222 and a second exhaust pipe 223 . The air inlet end of the heater 1 is connected to the first exhaust pipe 222 , and the air outlet end is connected to the second exhaust pipe 223 .

[0057] When the above system is in operation, the coal gas for desulfurization treatment flows into the first ventilation pipe through the first air inlet pipe, then reaches the air inlet through the first ventilation pipe, and then enters the desulfurization tower along the air inlet, and the coal gas is transported from bottom to top; the gas in the desulfurization tower is then discharged upward along the air outlet into the second ventilation pipe, and finally discharged through the second ventilation pipe;

[0058] The coal gas for cooling treatment is transported to the first ventilation pipe through the second air inlet pipe, and then transported to the desulfurization tower through the air inlet, and the cooling treatment is carried out from bottom to top. Since the amount of gas for cooling is small, the second air inlet pipe and the regulating member are provided to separately transport the coal gas for desulfurization treatment and the coal gas for cooling treatment.

[0059] The coal gas after the cooling treatment is discharged upward along the gas outlet to the second ventilation pipe, then enters the first exhaust pipe through the second ventilation pipe, and finally enters the heater through the first exhaust pipe for heating.

[0060] The heated coal gas flows from the gas outlet of the heater to the second exhaust pipe, diffuses to the second ventilation pipe of the corresponding desulfurization tower through the second exhaust pipe, and finally enters the desulfurization tower downward through the gas outlet.

[0061] It should be noted that a switch valve is provided at the connection between the first ventilation pipe and the first air inlet pipe and the second air inlet pipe on each desulfurization tower, and a switch valve is also provided at the connection between the second ventilation pipe and the first exhaust pipe and the second exhaust pipe on each desulfurization tower. The switch valve is used to control the air intake of each pipeline, and the control method of the switch valve is not specifically limited in the embodiments of the present application.

[0062] In some embodiments, the system further includes a pre-treatment device; the pre-treatment device is used to perform dust removal, chlorine removal, gas-liquid separation and other treatments on the blast furnace gas. The blast furnace gas contains a large amount of dust and granular impurities, and the blast furnace gas is subjected to dust removal and other treatments by the pre-treatment device to protect the reagents for subsequent treatment.

[0063] In some embodiments, the system further comprises a hydrolysis device;

[0064] The hydrolysis device needs to use multiple hydrolysis towers in parallel according to the gas processing volume. The hydrolysis tower can use a radial bed or a multi-layer packed tower. The hydrolysis tower is filled with a hydrolyzing agent, which is used to hydrolyze the pre-treated coal gas to convert the organic sulfur in the coal gas into H2S, so that the subsequent desulfurization agent can remove the sulfide in the coal gas.

[0065] In some embodiments, an air inlet is opened at the bottom (first end) of the desulfurization tower, and the coal gas enters the desulfurization tower from bottom to top.

[0066] In some embodiments, the second air inlet pipe is disposed at the bottom (first end) of the desulfurization tower, so that the coal gas for cooling is transported from bottom to top into the desulfurization tower for cooling treatment.

[0067] In some embodiments, since the coal gas for cooling is transported from bottom to top, the first exhaust pipe is arranged at the top (second end) of the desulfurization tower, and the coal gas after the cooling treatment is transported to the heater for heating.

[0068] In some embodiments, one end of the second air inlet pipe 213 is connected to a shunt pipe 214 , and one end of the shunt pipe 214 away from the second air inlet pipe 213 is connected to the first exhaust pipe 222 .

[0069] The pre-treated coal gas is transported to the diversion pipe along the second air inlet pipe, the coal gas enters the heater along the diversion pipe to be heated, the heated coal gas flows along the second exhaust pipe to the second ventilation pipe, and finally enters the desulfurization tower through the second ventilation pipe and the air outlet to regenerate the desulfurizer.

[0070] In some embodiments, the end of the first ventilation pipe 211 away from the desulfurization tower 2 is connected to the first gas collecting pipe 215. Since the desulfurization tower is large in size, in order to avoid excessive dispersion of the coal gas and increase the difficulty of processing, a first gas collecting pipe is set to collect the coal gas and discharge it uniformly.

[0071] In some embodiments, the second ventilation pipe 221 is connected to a second gas collecting pipe 224 at one end away from the desulfurization tower 2. Since the processing gas volume is generally large, in order to avoid excessive dispersion of the clean coal gas and increase the difficulty of processing, the clean coal gas is collected upward along the second ventilation pipe into the second gas collecting pipe and discharged uniformly from the second gas collecting pipe.

[0072] In some embodiments, the regulating member 23 includes a regulating valve 231 or a fan 232;

[0073] See also Figure 1 When the regulating member 23 is a regulating valve 231, the regulating valve 231 is disposed on the second air inlet pipe 213. Since the amount of air required for the cold blowing process is small, the amount of air in the second air inlet pipe is adjusted by setting a regulating valve to avoid excessive gas delivery and waste.

[0074] See also Figure 2 , Figure 2 Another system structure diagram of blast furnace gas desulfurization proposed in an embodiment of the present application is shown. When the regulating member 23 is a fan 232, the fan 232 is connected to the second air inlet pipe 213. Specifically, the air inlet and the air outlet of the fan are respectively connected to the second air inlet pipe. During operation, the fan blows the gas entering the second air inlet pipe into the first ventilation pipe, and the gas then enters the desulfurization tower along the first ventilation pipe and the air inlet. At the same time, the fan can also be used to control the air intake in the second air inlet pipe.

[0075] It should be noted that when the gas pressure in the first gas collecting pipe is high, the pre-treated gas will be insufficient in power and difficult to enter the desulfurization tower smoothly. The gas needs to be blown to the first ventilation pipe by a fan to increase the pressure so that the pre-treated gas can flow smoothly into the desulfurization tower.

[0076] When the gas pressure in the first gas collecting pipe is low, the pre-treated gas has enough power to enter the desulfurization tower. At this time, there is no need to set up a fan. The gas can smoothly enter the desulfurization tower through the second air inlet pipe by its own power. Only a regulating valve is set in the system to control the air intake in the second air inlet pipe.

[0077] In some embodiments, when the regulating member is a fan, preferably two fans are provided;

[0078] The air inlets of the two fans are connected in parallel through pipelines, and the air outlets are also connected in parallel through pipelines; one end of the air inlets of the fans connected in parallel and one end of the air outlets connected in parallel are both connected to the second air inlet pipe.

[0079] It should be noted that during the operation of the system, when the regulating component is a fan, the two fans are set to operate separately, specifically:

[0080] The gas is transported to one of the fans along the second air inlet pipe, and the fan blows the gas into the first ventilation pipe. When the fan is damaged, another fan is started to blow the gas to ensure that at least one fan is operating normally when the system is running.

[0081] Second, Figure 3 The method flow chart of blast furnace gas desulfurization proposed in the embodiment of the present application is shown, which specifically includes:

[0082] Blast furnace gas pretreatment: Specifically, the blast furnace gas is subjected to dust removal, chlorine removal, and gas-liquid separation to obtain pre-treated gas;

[0083] Hydrolysis treatment: Specifically, the pre-treated coal gas is subjected to hydrolysis treatment to obtain hydrolyzed coal gas;

[0084] Desulfurization treatment: Specifically, the hydrolyzed coal gas enters the first ventilation pipe 211 along the first air inlet pipe 212, and then enters the desulfurization tower 2 filled with a regenerable desulfurizer through the air inlet 21 to undergo desulfurization treatment to obtain clean coal gas, which is then discharged into the second gas collecting pipe 224 along the air outlet 22 and the second ventilation pipe 221, and then discharged through the second gas collecting pipe 224;

[0085] Regeneration of the regenerable desulfurizer: When the regenerable desulfurizer in the desulfurization tower 2 is saturated with adsorption, the pre-treated coal gas used for the cooling treatment is introduced into the first exhaust pipe 222 along the second ventilation pipe 221 as the regeneration gas, and enters the heater 1 through the first exhaust pipe 222 to be heated to 120-300°C. The heated regeneration gas enters the desulfurization tower 2 along the second exhaust pipe 223 and the second ventilation pipe 221 to regenerate the saturated regenerable desulfurizer;

[0086] Blow-cooling treatment: The pre-treated coal gas enters the desulfurization tower 2 along the second air inlet pipe 213 and the first ventilation pipe 211, and is blown-cooling treated to cool the regenerated regenerable desulfurizer to 60-90°C;

[0087] Each desulfurization tower 2 performs desulfurization and regeneration of blast furnace gas in a cycle sequence of desulfurization treatment → regeneration of regenerable desulfurizer → cooling treatment → desulfurization treatment;

[0088] It should be noted that after the pre-treated coal gas is hydrolyzed, the organic sulfur in the coal gas is converted into H2S, and then the hydrolyzed coal gas is transported to the desulfurization tower through the first air inlet pipe and the first ventilation pipe for desulfurization treatment to obtain clean coal gas. After the regenerable desulfurizer is saturated with adsorption, it is regenerated using the pre-treated coal gas. On the one hand, the regenerable desulfurizer can be reused for desulfurization treatment, thereby improving the utilization efficiency of the regenerable desulfurizer; on the other hand, it has been experimentally verified that the regenerable desulfurizer can be regenerated using the pre-treated coal gas (i.e., the coal gas before hydrolysis), and does not require the addition of other reagents or the use of clean coal gas, which helps to reduce the amount of coal gas treated by hydrolysis and the amount of coal gas treated by desulfurization, and can also save energy, providing a new use for the pre-treated coal gas. The performance of the regenerated desulfurizer remains good, and it still has a strong desulfurization ability after multiple regenerations, and can be repeatedly used in desulfurization treatment;

[0089] When the regenerated desulfurizer is regenerated, the temperature of the regenerated gas is as high as 120-300°C. Therefore, after the regeneration treatment, the temperature in the desulfurization tower needs to be reduced to 60-90°C through a cold blowing treatment so that the regenerated desulfurizer can be desulfurized again. The cold blowing treatment uses the pre-treated coal gas, so after the cold blowing treatment is completed, the pre-treated coal gas is transported to the heater through the first exhaust pipe for heating as the regenerated gas to regenerate the saturated regenerated desulfurizer.

[0090] In some embodiments, the blast furnace gas is subjected to dust removal, chlorine removal, and gas-liquid separation treatment, specifically including:

[0091] After the blast furnace gas comes out from the furnace top, it first passes through the TRT (blast furnace gas residual pressure turbine power generation device) and is cooled to 40-80℃; then it passes through the gravity dust removal device, using the effect of gravity to settle the larger particles and dust in the gas, thereby reducing the dust content in the gas;

[0092] The coal gas after gravity dust removal further enters the bag dust removal device, where filter cloth is used to capture fine dust in the coal gas, further reducing the dust content to below 10 mg / cubic meter to protect the hydrolyzing agent.

[0093] The coal gas after dust removal is then introduced into a hydrolysis device, where the organic sulfur is converted into H2S using a hydrolyzing agent.

[0094] The above-mentioned hydrolysis agent includes but is not limited to metal oxide catalysts prepared by using Al2O3, TiO2, etc. as carriers and loading K2O, Fe2O3, ZrO2.

[0095] In some embodiments, the regenerable desulfurizing agent is selected from a regenerable supported desulfurizing agent provided in the related patent CN117563556B.

[0096] In some embodiments, preferably, when regenerating the regenerable desulfurizer, the pre-treated coal gas is introduced into the heater along the first exhaust pipe and heated to 150-200°C.

[0097] The regenerated gas can be used to regenerate the adsorption saturated regenerable desulfurizer after being heated, so as to restore the adsorption capacity of the desulfurizer.

[0098] In some embodiments, Figure 4 The desulfurization timing diagram of blast furnace gas desulfurization proposed in the embodiment of the present application is shown. Figure 4 The figure takes 6 desulfurization towers as an example to show the desulfurization sequence of blast furnace gas desulfurization treatment. The A tower, B tower, C tower, D tower, E tower, and F tower displayed vertically on the left represent the 6 desulfurization towers, and "T / h" represents time; the "A" on the right represents desulfurization treatment, "H" represents regeneration of regenerable desulfurizer, "C" represents cooling treatment, and "ISO" represents static treatment. Figure 4 It can be obtained that in the first 20 hours, 4 towers are carrying out desulfurization treatment, 1 tower is regenerating the regenerable desulfurizer, and 1 tower is carrying out cooling treatment. Among them, Tower B is subjected to 15 hours of static treatment after 5 hours of cooling treatment. The static treatment means that the desulfurization tower is in a static state and there is no ventilation in the tower to avoid wasting the regenerated gas.

[0099] In some embodiments, during the regeneration of the regenerable desulfurizer, the coal gas after the regeneration treatment enters the first gas collecting pipe along the first ventilation pipe and is discharged through the first gas collecting pipe. The discharged coal gas can be used as fuel for sintering, etc., to achieve resource recycling.

[0100] In some embodiments, the method further includes: in the later stage of regeneration of the regenerable desulfurizer, when the cooling treatment is finished, the pre-treated coal gas enters the first exhaust pipe 222 along the second air inlet pipe 213 and the diverter pipe 214, and then enters the heater 1 along the first exhaust pipe 222 to be heated to 120-300° C., as the regeneration gas;

[0101] The regenerated gas is transported to the desulfurization tower 2 along the second exhaust pipe 223 and the second ventilation pipe 221, and the regeneration of the regenerable desulfurizer is continued until the regeneration is completed.

[0102] exist Figure 4 In the process, since the time of cold blowing treatment is short, for example, in the 30th to 40th hour, no desulfurization tower is in cold blowing treatment, but the D tower needs to regenerate the desulfurizer. In order to replenish the regenerated gas, the pre-treated coal gas is transported to the diverter pipe along the second air inlet pipe, and then enters the first exhaust pipe along the diverter pipe, enters the heater through the first exhaust pipe for heating, and the heated regenerated gas enters the D tower along the second exhaust pipe and the second ventilation pipe for regenerating the desulfurizer. In order to replenish the regenerated gas in time, the regeneration treatment of the regenerable desulfurizer in the desulfurization tower can be carried out continuously.

[0103] In some embodiments, when the pressure of the first gas collecting pipe is low, the power of the pre-treated coal gas itself is sufficient to pass through the desulfurization tower smoothly. At this time, the regulating component is a regulating valve, and only the regulating valve needs to be used to control the intake amount of gas in the second intake pipe.

[0104] In some embodiments, the above method further includes: when the regulating member 23 is a fan 232, the pre-treated coal gas is transported to the fan 232 through the second air inlet pipe 213, and the fan 232 blows the pre-treated coal gas into the first ventilation pipe 211, and then enters the desulfurization tower 2 along the air inlet 21 for cooling treatment. At this time, the pressure of the first gas collecting pipe is relatively high, and the power of the pre-treated coal gas itself is not enough to pass through the desulfurization tower smoothly, so the regulating member is set as a fan, and the fan is used to increase the power of the coal gas, so that the coal gas flows more smoothly in the desulfurization tower.

[0105] In some embodiments, the regeneration gas accounts for 1-10% of the volume of the pre-treated coal gas.

[0106] In the present method, the amount of regeneration gas used is very small. A small amount of regeneration gas is sufficient to regenerate the saturated desulfurizer in the desulfurization tower after being heated. There is no need to use available resources such as clean coal gas and nitrogen to regenerate the desulfurizer, thus reducing the waste of available resources.

[0107] In some embodiments, during the regeneration of the regenerable desulfurizer, the regenerated gas is discharged into the first collecting pipe 215 along the first ventilation pipe 211 after the regeneration treatment, and is discharged through the first collecting pipe 215 to facilitate centralized treatment of the regenerated gas after the regeneration treatment.

[0108] In order to enable those skilled in the art to understand the present application more clearly, a system and method for desulfurization of blast furnace gas described in the present application are now described in detail through the following examples. The following examples are all modifications of the above-mentioned basic structure and method.

[0109] Example

[0110] Example 1

[0111] Six desulfurization towers are set up for regeneration and desulfurization, including:

[0112] 1. Blast furnace gas pretreatment: Blast furnace gas is passed into the pretreatment device for dust removal, chlorine removal, and gas-liquid separation to obtain pretreated gas;

[0113] 2. Hydrolysis treatment: The pre-treated coal gas is passed into the hydrolysis device, and the organic sulfur is converted into H2S using a hydrolyzing agent;

[0114] 3. Desulfurization treatment: The hydrolyzed gas is desulfurized to 600,000 Nm 3 / h flow rate to the first air inlet pipe, so that the hydrolyzed coal gas diffuses into the first ventilation pipe along the first air inlet pipe, and then enters the A tower, D tower, E tower and F tower respectively equipped with 30 tons of regenerable desulfurizer through the air inlet, wherein the A tower performs desulfurization treatment for 80 hours, the D tower performs desulfurization treatment for 20 hours, the E tower performs desulfurization treatment for 40 hours, and the F tower performs desulfurization treatment for 60 hours to obtain clean coal gas, which enters the second ventilation pipe along the air outlet on the corresponding desulfurization tower, and is finally discharged through the second gas collecting pipe;

[0115] Meanwhile, tower B firstly undergoes 5 hours of cooling treatment, then stands for 15 hours, and then undergoes 80 hours of desulfurization treatment; tower C firstly undergoes 20 hours of regeneration of the regenerable desulfurizer, then undergoes 5 hours of cooling treatment and 15 hours of standing, and then undergoes 80 hours of desulfurization treatment;

[0116] 4. Regeneration of regenerable desulfurizer: After the desulfurization treatment of tower A, tower B, tower C, tower D, tower E or tower F has been carried out for a corresponding period of time, the pre-treated coal gas in the desulfurization tower that has completed the cooling treatment is used as the regeneration gas, and is introduced into the first exhaust pipe along the gas outlet and the second ventilation pipe, and then enters the heater along the first exhaust pipe to be heated to 180°C. The heated regeneration gas is transported to the gas outlet along the second exhaust pipe, and then enters the desulfurization tower that needs to regenerate the desulfurizer through the gas outlet, and the regenerated desulfurizer that is saturated with adsorption is regenerated. The coal gas that has completed the regeneration treatment flows out along the gas inlet and is collected in the first gas collecting pipe, and finally discharged along the first gas collecting pipe;

[0117] When there is no desulfurization tower for cooling treatment, in order to ensure that the desulfurizer in the desulfurization tower can be regenerated, the pre-treated coal gas is transported to the diverter pipe through the second air inlet pipe, and then transported to the heater through the diverter pipe to be heated to 180°C, so as to replenish the regeneration gas in time and complete the regeneration of the desulfurizer;

[0118] 5. Blow-cooling treatment: After the regenerable desulfurizer in Tower A, Tower B, Tower C, Tower D, Tower E or Tower F is regenerated in sequence, the pre-treated coal gas is controlled by the regulating valve to enter the first ventilation pipe along the second air inlet pipe, and then flows along the first ventilation pipe to Tower A, Tower B, Tower C, Tower D, Tower E or Tower F, so that the temperature in the tower that has just finished regeneration is reduced to 80°C. After the temperature is reduced, Tower A, Tower B, Tower C, Tower D, Tower E or Tower F is subjected to corresponding static treatment, and then desulfurization treatment is carried out after static treatment;

[0119] Specifically, during the treatment, a cycle of 120 hours is taken as one cycle. Within the cycle, each desulfurization tower shall complete 80 hours of desulfurization treatment, 20 hours of regeneration of the regenerable desulfurizer, 5 hours of cooling treatment and 15 hours of standing. The timing sequence is shown in Figure 4 .

[0120] Example 2

[0121] The difference between Example 2 and Example 1 is that the pressure of the first gas collecting pipe is different. In Example 2, the pressure of the first gas collecting pipe is higher, so the regulating part used in the cold blowing treatment is a fan, and part of the pre-treated coal gas is pressurized by the fan along the second air inlet pipe, so that the pre-treated coal gas has enough power to enter the desulfurization tower, and then the pre-treated coal gas is blown into the first ventilation pipe. And when there is no desulfurization tower for cold blowing treatment, in order to ensure that the desulfurizer in the desulfurization tower can be regenerated, the pre-treated coal gas is pressurized by the fan and sent to the second air inlet pipe, and then transported to the diversion pipe through the second air inlet pipe.

[0122] Except for the above steps, the remaining steps are exactly the same as those in Example 1.

[0123] Comparative Example 1 is set based on Examples 1-2

[0124] Comparative Example 1

[0125] The only difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, clean coal gas is used to regenerate the regenerable desulfurizer.

[0126] The regenerable desulfurizers in Examples 1-2 and Comparative Example 1 were regenerated more than 100 times with the coal gas before hydrolysis, and the H2S content in the obtained clean coal gas was still less than 10 mg / m 3On the one hand, it can be shown that the desulfurizer provided in the embodiment of the present application can be regenerated more than 100 times with the pre-treated coal gas, and its performance remains good, and can achieve a regeneration effect almost the same as that of clean coal gas. On the other hand, compared with regenerating the desulfurizer with clean coal gas, the system provided by the present application has a smaller device scale and lower investment cost.

[0127] In summary, the system structure of blast furnace gas desulfurization provided by the present application is simple, easy to install and use, and the method of blast furnace gas desulfurization implemented by the system selects a desulfurizing agent for regenerating the gas after pretreatment, and the performance of the desulfurizing agent after regeneration is almost unchanged, and it can be repeatedly used in the desulfurization treatment, effectively reducing the scale of the device and the investment cost. The desulfurizing agent for regenerating the gas after pretreatment helps to reduce the amount of gas to be hydrolyzed, and about 5% of the total amount of gas to be treated does not need to be desulfurized, especially it can reduce the amount of desulfurizing agent used during the desulfurization treatment, and improve the use efficiency of the desulfurizing agent.

[0128] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0129] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0130] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0131] The above is a detailed introduction to the system and method for blast furnace gas desulfurization provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A system for desulfurizing blast furnace gas, characterized in that: The system comprises: A heater (1) and at least one desulfurization tower (2); The desulfurization tower (2) is provided with an air inlet (21) at a first end and an air outlet (22) at a second end; The air inlet (21) of the desulfurization tower (2) is connected to a first ventilation pipe (211), and the air outlet (22) is connected to a second ventilation pipe (221); The first ventilation pipe (211) is connected to a first air intake pipe (212) and a second air intake pipe (213), and the second air intake pipe (213) is provided with an adjusting member (23); The second ventilation pipe (221) is connected to a first exhaust pipe (222) and a second exhaust pipe (223); the air inlet end of the heater (1) is connected to the first exhaust pipe (222), and the air outlet end is connected to the second exhaust pipe (223); the coal gas for cooling treatment is transported to the first ventilation pipe (211) through the second air inlet pipe (213), and then transported to the desulfurization tower (2) through the air inlet (21) for cooling treatment; the coal gas after cooling treatment is discharged to the second ventilation pipe (221) along the air outlet (22), enters the first exhaust pipe (222) through the second ventilation pipe (221), and finally enters the heater (1) for heating; the heated coal gas flows to the second exhaust pipe (223), diffuses to the corresponding second ventilation pipe (221) through the second exhaust pipe (223), and finally enters the desulfurization tower (2) to regenerate the desulfurizer.

2. The system for desulfurizing blast furnace gas according to claim 1, characterized in that: One end of the second air intake pipe (213) is connected to a shunt pipe (214), and one end of the shunt pipe (214) away from the second air intake pipe (213) is connected to the first exhaust pipe (222).

3. The system for desulfurizing blast furnace gas according to claim 1, characterized in that: One end of the first ventilation pipe (211) away from the desulfurization tower (2) is connected to a first gas collecting pipe (215).

4. The system for desulfurizing blast furnace gas according to claim 1, characterized in that: One end of the second ventilation pipe (221) away from the desulfurization tower (2) is connected to a second gas collecting pipe (224).

5. The system for desulfurizing blast furnace gas according to claim 1, characterized in that: The regulating member (23) comprises a regulating valve (231) or a fan (232); When the regulating member (23) is the regulating valve (231), the regulating valve (231) is arranged on the second air intake pipe (213); When the regulating member (23) is the fan (232), the fan (232) is connected to the second air inlet pipe (213).

6. A method for desulfurizing blast furnace gas, characterized in that: The method is applicable to the system for desulfurization of blast furnace gas according to any one of claims 1 to 5, and the method comprises: Blast furnace gas pretreatment: After blast furnace gas is treated with dust removal, chlorine removal, and gas-liquid separation, pre-treated gas is obtained; Hydrolysis treatment: the pre-treated coal gas is subjected to hydrolysis treatment to obtain hydrolyzed coal gas; Desulfurization treatment: the hydrolyzed coal gas enters the first ventilation pipe (211) along the first air inlet pipe (212), and then enters the desulfurization tower (2) filled with a regenerable desulfurizer through the air inlet (21) to undergo desulfurization treatment to obtain clean coal gas, which is discharged along the air outlet (22) and the second ventilation pipe (221); Regeneration of the regenerable desulfurizer: when the regenerable desulfurizer in the desulfurization tower (2) is saturated with adsorption, the pre-treated coal gas used for cooling treatment is introduced into the first exhaust pipe (222) along the second ventilation pipe (221) as regeneration gas, and enters the heater (1) through the first exhaust pipe (222) to be heated to 120-300° C. The heated regeneration gas enters the desulfurization tower (2) along the second exhaust pipe (223) and the second ventilation pipe (221), and the saturated regenerable desulfurizer is regenerated; Blow-cooling treatment: the pre-treated coal gas enters the desulfurization tower (2) along the second air inlet pipe (213) and the first ventilation pipe (211) to undergo the blow-cooling treatment, so that the regenerated regenerable desulfurizer is cooled to 60-90° C.; Each of the desulfurization towers (2) desulfurizes the blast furnace gas in a cyclic sequence of desulfurization treatment → regeneration of a regenerable desulfurizer → cooling treatment → desulfurization treatment.

7. The method for desulfurizing blast furnace gas according to claim 6, characterized in that: One end of the second air intake pipe (213) is connected to a shunt pipe (214), and one end of the shunt pipe (214) away from the second air intake pipe (213) is connected to the first exhaust pipe (222); The method further comprises: In the later stage of regeneration of the regenerable desulfurizer, when the cooling treatment is finished, the pre-treated coal gas enters the first exhaust pipe (222) along the second air inlet pipe (213) and the diverter pipe (214), and then enters the heater (1) along the first exhaust pipe (222) to be heated to 120-300° C., thereby serving as the regenerated gas; The regenerated gas is transported to the desulfurization tower (2) along the second exhaust pipe (223) and the second ventilation pipe (221), and the regeneration of the regenerable desulfurizer is continued until the regeneration is completed.

8. The method for desulfurizing blast furnace gas according to claim 6, characterized in that: The regulating member (23) comprises a regulating valve (231) or a fan (232); The method further comprises: When the regulating member (23) is the fan (232), the pre-treated coal gas is transported to the fan (232) through the second air inlet pipe (213), and the fan (232) blows the pre-treated coal gas into the first ventilation pipe (211), and then enters the desulfurization tower (2) along the air inlet (21) for the cooling treatment.

9. The method for desulfurizing blast furnace gas according to claim 6, characterized in that: The regeneration gas accounts for 1-10% of the volume of the pre-treated coal gas.

10. The method for desulfurizing blast furnace gas according to claim 6, characterized in that: One end of the first ventilation pipe (211) away from the desulfurization tower (2) is connected to a first gas collecting pipe (215); During the regeneration of the regenerable desulfurizer, the regenerated gas is regenerated and then discharged into the first gas collecting pipe (215) along the first ventilation pipe (211), and then discharged through the first gas collecting pipe (215).

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