Process for preparing high concentration carbonyl sulfide by desulfurizing blast furnace gas

Abstract

The application discloses a process for preparing high-concentration carbonyl sulfur by desulfurizing blast furnace gas, which comprises the following steps: S1, blast furnace gas cooling, dehydration, dechlorination and dust removal; S2, blast furnace gas hydrolysis treatment, which converts all organic sulfur into inorganic sulfur; S3, blast furnace gas desulfurization treatment; S4, separation of carbon dioxide and blast furnace gas without carbon dioxide; S5, reaction of the blast furnace gas after being heated with the adsorbent saturated with adsorption, which converts the adsorbed sulfur species into carbonyl sulfur, and high-concentration carbonyl sulfur desorption gas is obtained; and S6, separation and treatment of the carbonyl sulfur desorption gas, and high-purity liquid carbonyl sulfur liquid is obtained. The purified blast furnace gas is separated from carbon dioxide, and then the adsorbent is desorbed and treated, on the one hand, a small amount of gas can be effectively used for regeneration of the adsorbent, and the adsorbent can be recycled; on the other hand, the desorption product of the adsorbent is carbonyl sulfur, and the problem of pipeline blockage caused by solid sulfur produced in the regeneration of the adsorbent is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of atmospheric purification and environmental protection, and particularly relates to a process for preparing high-concentration carbonyl sulfide by desulfurizing blast furnace gas. BACKGROUND

[0002] In recent years, blast furnace gas source desulfurization technology has been widely applied in the domestic steel industry, aiming to reduce sulfur emissions and meet the requirements of the national double carbon policy. In the prior art, such as the blast furnace gas desulfurization processes disclosed in patents CN202323125605, CN202323094336 and CN202410636644, etc., generally include dechlorination and deoxidation pretreatment, conversion of organic sulfur COS into inorganic sulfur H2S, and reprocessing of H2S. However, the current H2S reprocessing method has some problems.

[0003] A common practice is to use disposable activated carbon adsorbents for adsorption, but this method does not achieve true desulfurization effect, because the adsorption-saturated activated carbon is only used as fuel in the sintering process of the steel plant, and the sulfur element is not effectively recovered. Another method is to oxidize the adsorption-saturated H2S to generate elemental sulfur for recovery. Although this method achieves sulfur recovery, it has high requirements for the anti-blocking device of the process and has a blocking problem.

[0004] In addition, carbonyl sulfide (COS) in blast furnace gas has high application value. High-concentration carbonyl sulfide can be used as an intermediate raw material and is widely used in the synthesis of pesticides, medicines and other chemical products; high-purity COS can also be used in the processing of electronic sheet parts precision etching products in aviation, machinery and chemical industries. If carbonyl sulfide can be purified from the large amount of blast furnace gas, it can meet the application requirements and reduce sulfur emissions.

[0005] However, the existing disposable activated carbon adsorption technology will gradually be eliminated because it does not meet the requirements of the double carbon policy. Although the reusable activated carbon technology has potential for promotion, the blocking problem in the preparation of sulfur still needs to be solved. Therefore, it is necessary to develop a more efficient and environmentally friendly blast furnace gas desulfurization technology to achieve effective recovery and utilization of sulfur in blast furnace gas and solve the blocking problem in the existing technology. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides a process for preparing high-concentration carbonyl sulfide by desulfurizing blast furnace gas, which changes the desorption atmosphere so that when the adsorption-saturated adsorbent is desorbed, it is controlled to generate only carbonyl sulfide without generating sulfur, thereby concentrating and converting low-concentration carbonyl in blast furnace gas into high-concentration carbonyl sulfide through adsorption.

[0007] The present application adopts the following technical solutions:

[0008] A process for preparing high-concentration carbonyl sulfur by desulfurizing blast furnace gas, comprising the following steps:

[0009] S1, the blast furnace gas is introduced into a pretreatment device for temperature reduction, dehydration, chlorine removal and dust removal, and then the temperature is raised to obtain blast furnace gas A;

[0010] S2, the pretreated blast furnace gas A is introduced into a COS hydrolysis device for hydrolysis treatment, so that all the organic sulfur in the blast furnace gas is converted into inorganic sulfur, and blast furnace gas B is obtained;

[0011] S3, the blast furnace gas B after hydrolysis treatment is introduced into a hydrogen sulfide adsorption device with one standby for desulfurization treatment, and blast furnace gas C is obtained;

[0012] S4, the sulfur-free blast furnace gas C after desulfurization treatment is discharged in two ways, one of which is directly exported for use, and the other is introduced into a carbon dioxide separation device through an induced draft fan for treatment, and carbon dioxide and blast furnace gas D without carbon dioxide are separated, wherein the separated carbon dioxide is stored in a liquid CO2 storage tank;

[0013] S5, the blast furnace gas D is heated by a heater and then introduced into the hydrogen sulfide adsorption device saturated with adsorbent, and reacts with the adsorbent saturated with adsorbent to convert the adsorbed sulfur species into carbonyl sulfur, so that a higher concentration of carbonyl sulfur desorption gas is obtained, and the adsorbent is regenerated, and a higher concentration of carbonyl sulfur gas is obtained, and the regenerated adsorbent can be reused after being cooled;

[0014] S6, the higher concentration of carbonyl sulfur desorption gas obtained in step S5 is separated by a high-concentration COS separation device to obtain a high-purity liquid carbonyl sulfur liquid, which is stored in a liquid COS storage tank, and the gas after separation of carbonyl sulfur is returned to the external pipe network.

[0015] In step S1, the pretreatment device dehydrates, removes chlorine ions and dust at a temperature of 0-10℃, and removes water, chlorine ions and dust in the blast furnace gas by freezing water cooling method; the temperature is raised to 50-80℃.

[0016] In step S2, the COS hydrolysis device is filled with a hydrolysis catalyst, and the hydrolysis catalyst comprises a catalytic carrier and a loaded active component, wherein the catalytic carrier is one or more compounds of carbon nitride, aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, zirconium oxide and cerium oxide, and the loaded active component is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium oxalate, potassium oxalate, sodium sulfate and potassium sulfate.

[0017] The hydrogen sulfide adsorption device in step S3 includes two in parallel, when one of the hydrogen sulfide adsorption device is saturated, the other hydrogen sulfide adsorption device starts to work, and the saturated hydrogen sulfide adsorption device starts to desorb.

[0018] The hydrogen sulfide adsorption device is filled with adsorbent, the adsorbent includes adsorbent carrier and active component, wherein the adsorbent carrier is one or more of coal activated carbon, wood activated carbon and petroleum coke activated carbon, and the active component is one or more of iron nitrate, cobalt nitrate, nickel nitrate, iron sulfate, cobalt sulfate, nickel sulfate, iron chloride, cobalt chloride, nickel chloride, iron oxalate, cobalt oxalate, nickel oxalate, copper nitrate, copper acetate, copper chloride and copper sulfate.

[0019] In step S4, the sulfur-free blast furnace gas C used for external delivery accounts for 80-95% of the total gas, and the sulfur-free blast furnace gas C transferred to the carbon dioxide separation device for treatment accounts for 5-20% of the total gas.

[0020] In step S4, the carbon dioxide separation device includes pressure swing adsorption and low-temperature condensation to separate liquid carbon dioxide, wherein the low-temperature condensation temperature is-150℃ to-50℃.

[0021] In step S5, the heating temperature of the adsorbent during regeneration is 180-220℃, and the concentration of the higher concentration of carbonyl sulfide desorption gas is 5%-20%.

[0022] In step S6, the high-concentration COS separation device includes pressure swing adsorption and low-temperature condensation to separate liquid carbonyl sulfide, wherein the low-temperature condensation temperature is-150℃ to-50℃.

[0023] In step S6, the concentration of the liquid high-purity carbonyl sulfide liquid is greater than 98%.

[0024] The technical scheme of the present application has the following advantages:

[0025] The present application can effectively remove the sulfur species in the blast furnace gas through the system processing device, and realize ultra-low emission. At the same time, a small amount of purified gas is separated for carbon dioxide, and then the adsorbent is desorbed, which can effectively use a small amount of gas for regeneration of the adsorbent, and realize the recycling of the adsorbent. On the other hand, the desorption product of the adsorbent is carbonyl sulfide, which avoids the problem of pipeline blockage caused by solid sulfur during the regeneration of the adsorbent. The separated liquid carbon dioxide can be discharged for carbon emission, and the obtained high-purity liquid carbonyl sulfide product can be used as a chemical raw material or as an electronic sheet part precision etching gas, realizing the resource utilization of sulfur in the blast furnace gas. BRIEF DESCRIPTION OF DRAWINGS

[0026] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the system structure of the process for preparing high-concentration carbonyl sulfur from blast furnace gas desulfurization according to the present invention.

[0028] The diagram is labeled as follows:

[0029] 1-Pretreatment device; 2-COS hydrolysis device; 3-Hydrogen sulfide adsorption device; 4-Exhaust fan; 5-Carbon dioxide separation device; 6-Heater; 7-High concentration COS separation device; 8-Liquid CO2 storage tank; 9-Liquid COS storage tank. Detailed Implementation

[0030] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1:

[0032] like Figure 1 As shown in the figure, this embodiment provides a process for preparing high-concentration carbonyl sulfur through blast furnace gas desulfurization, as detailed below:

[0033] 50000Nm 3 / h, 50℃ contains a COS concentration of 180mg / m³ 3 Blast furnace gas is sequentially fed into a pretreatment unit 1, a COS hydrolysis unit 2, and a hydrogen sulfide adsorption unit 3 for desulfurization. The pretreatment temperature is 5℃, and after treatment, it is raised to 60℃ before being fed into the COS hydrolysis unit 2, which is filled with a Na2CO3 / Ti-Al2O3 catalyst, for hydrolysis. Finally, it undergoes desulfurization treatment in the hydrogen sulfide adsorption unit 3 to obtain sulfur-free blast furnace gas. Both the operating and standby hydrogen sulfide adsorption units 3 are filled with Cu-Ni / wood-based activated carbon adsorbent. When the adsorbent becomes saturated and needs regeneration, a 2000Nm³ / h filter is used. 3Clean, sulfur-free blast furnace gas per hour is introduced into the carbon dioxide separator 5 for treatment. The gas, after carbon dioxide removal, is heated to 180°C by heater 6 to regenerate the adsorbent requiring regeneration. The regenerated gas is then passed into a high-concentration COS separator 7 for further treatment. The resulting liquid carbonyl sulfide, obtained by cooling at -80°C, is stored in a liquid COS storage tank 9. The remaining gas is returned to the blast furnace gas pipeline. The concentration of carbonyl sulfide in the liquid COS storage tank 9 was measured to be 98.7%.

[0034] Example 2

[0035] like Figure 1 As shown in the figure, this embodiment provides a process for preparing high-concentration carbonyl sulfur through blast furnace gas desulfurization, as detailed below:

[0036] 80000Nm 3 / h, 60℃ contains COS concentration of 100 mg / m 3 Blast furnace gas is sequentially fed into a pretreatment unit 1, a COS hydrolysis unit 2, and a hydrogen sulfide adsorption unit 3 for desulfurization. The pretreatment temperature is 10℃, and after treatment, it is raised to 50℃ before being fed into the COS hydrolysis unit 2, which is filled with a K2CO3 / Ti-Al2O3 catalyst, for hydrolysis. Finally, it undergoes desulfurization treatment in the hydrogen sulfide adsorption unit 3 to obtain sulfur-free blast furnace gas. Both the operating and standby hydrogen sulfide adsorption units 3 are filled with Cu / coal-based activated carbon adsorbent. When the adsorbent becomes saturated and needs regeneration, a 4000Nm³ / h filter is used. 3 Clean, sulfur-free blast furnace gas per hour is introduced into the carbon dioxide separator 5 for treatment. The gas, after carbon dioxide removal, is heated to 190°C by heater 6 to regenerate the adsorbent requiring regeneration. The regenerated gas is then passed into a high-concentration COS separator 7 for further treatment. The resulting liquid carbonyl sulfide, obtained by cooling at -150°C, is stored in a liquid COS storage tank 9. The remaining gas is returned to the blast furnace gas pipeline. The concentration of carbonyl sulfide in the liquid COS storage tank 9 was measured to be 98.9%.

[0037] Example 3

[0038] like Figure 1 As shown in the figure, this embodiment provides a process for preparing high-concentration carbonyl sulfur through blast furnace gas desulfurization, as detailed below:

[0039] 100000Nm 3 / h, 80℃ contains COS concentration of 100 mg / m 3The blast furnace gas is sequentially introduced into the pretreatment device 1, the COS hydrolysis device 2 and the hydrogen sulfide adsorption device 3 for desulfurization treatment. The temperature of the pretreatment is 0 DEG C, and after the treatment, the blast furnace gas is introduced into the COS hydrolysis device 2 filled with K2CO3 / Al2O3 catalyst for hydrolysis treatment, and finally, the blast furnace gas is introduced into the hydrogen sulfide adsorption device 3 for desulfurization treatment, so as to obtain sulfur-free blast furnace gas. The hydrogen sulfide adsorption device 3 is used in turn, and each of the hydrogen sulfide adsorption devices is filled with Cu-Co / petroleum coke activated carbon adsorbent. When the adsorbent is saturated and needs to be regenerated, 5000 Nm 3 / h of clean sulfur-free blast furnace gas is introduced into the carbon dioxide separation device 5 for treatment, and the gas after removal of carbon dioxide is heated to 220 DEG C by the heater 6, so as to resolve and regenerate the adsorbent. The resolved gas is introduced into the high-concentration COS separation device 7 for treatment, and the liquid carbonyl sulfur obtained by cooling at -50 DEG C is stored in the liquid COS storage tank 9, and the remaining gas is returned to the blast furnace gas pipeline. It is determined that the concentration of carbonyl sulfur in the liquid COS storage tank 9 is 99.1%.

[0040] The present application can effectively remove the sulfur species in the blast furnace gas by the system treatment device, so as to realize ultra-low emission. Meanwhile, the carbon dioxide is separated from a small amount of purified gas, and then the adsorbent is resolved and treated, so as to effectively use a small amount of gas for regeneration of the adsorbent, realize the recyclable use of the adsorbent, and avoid the pipeline blockage problem caused by the solid sulfur produced in the regeneration of the adsorbent. The separated liquid carbon dioxide can be discharged for carbon emission, the high-purity liquid carbonyl sulfur product can be used as a chemical raw material, or can be used as an electronic sheet part precision etching gas, so as to realize the resource utilization of sulfur in the blast furnace gas.

[0041] The unmentioned part of the present application is applicable to the prior art.

[0042] Obviously, the above embodiments are only examples for clearly illustrating the present application, and are not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not enumerated, and the changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A process for preparing high-concentration carbonyl sulfur from blast furnace gas through desulfurization, characterized in that, Includes the following steps: S1. After the blast furnace gas is fed into the pretreatment device (1) for cooling, dehydration, dechlorination and dust removal, the temperature is raised to obtain blast furnace gas A. S2. The pretreated blast furnace gas A is fed into the COS hydrolysis device (2) for hydrolysis treatment, so that all the organic sulfur in the blast furnace gas is converted into inorganic sulfur, and blast furnace gas B is obtained. S3. The blast furnace gas B after hydrolysis is passed into a hydrogen sulfide adsorption device (3) with one working and one standby unit for desulfurization treatment to obtain blast furnace gas C. S4. The sulfur-free blast furnace gas C after desulfurization is discharged in two ways. One way is directly transported for use, and the other way is transferred to the carbon dioxide separation device (5) through the induced draft fan (4) for processing, separating carbon dioxide and carbon dioxide-free blast furnace gas D. The separated carbon dioxide enters the liquid CO2 storage tank (8) for storage. S5. After the blast furnace gas D is heated by the heater (6), it is introduced into the hydrogen sulfide adsorption device (3) which is saturated with adsorption and reacts with the adsorbent which is saturated with adsorption, converting the adsorbed sulfur species into carbonyl sulfur and obtaining carbonyl sulfur desorption gas with a higher concentration. At this time, the adsorbent is regenerated. After the regenerated adsorbent is cooled, it can be reused. S6. The high-concentration carbonyl sulfide desorbed gas obtained in step S5 is separated by a high-concentration COS separation device (7) to obtain a liquid high-purity carbonyl sulfide liquid, which is then stored in a liquid COS storage tank (9). The gas after separating the carbonyl sulfide is returned to the external pipeline network.

2. The process for preparing high-concentration carbonyl sulfide from blast furnace gas according to claim 1, characterized in that, In step S1, the pretreatment device (1) operates at a temperature of 0-10°C for cooling and dehydration, removing chloride ions and dust, and removes water, chloride ions and dust from the blast furnace gas by means of chilled water cooling; the recovery temperature is 50-80°C.

3. The process for preparing high-concentration carbonyl sulfide from blast furnace gas according to claim 1, characterized in that, In step S2, the COS hydrolysis device (2) is filled with a hydrolysis catalyst. The hydrolysis catalyst includes a catalyst support and a supported active component. The catalyst support is one or more composites of carbon nitride, aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, zirconium oxide, and cerium oxide. The supported active component is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium oxalate, potassium oxalate, sodium sulfate, and potassium sulfate.

4. The process for preparing high-concentration carbonyl sulfide from blast furnace gas according to claim 1, characterized in that, In step S3, the hydrogen sulfide adsorption device (3) with one in use and one in standby includes two devices arranged in parallel. When one of the hydrogen sulfide adsorption devices (3) is saturated with adsorption, the other hydrogen sulfide adsorption device (3) starts adsorption. The hydrogen sulfide adsorption device (3) that is saturated with adsorption starts desorption.

5. The process for preparing high-concentration carbonyl sulfide from blast furnace gas according to claim 4, characterized in that, The hydrogen sulfide adsorption device (3) is filled with an adsorbent, which includes an adsorption carrier and a loaded active component. The adsorption carrier is one or more of the following composite materials: coal-based activated carbon, wood-based activated carbon, and petroleum coke-based activated carbon. The loaded active component is one or more of the following: ferric nitrate, cobalt nitrate, nickel nitrate, ferric sulfate, cobalt sulfate, nickel sulfate, ferric chloride, cobalt chloride, nickel chloride, ferric oxalate, cobalt oxalate, nickel oxalate, copper nitrate, copper acetate, copper chloride, and copper sulfate.

6. The process for preparing high-concentration carbonyl sulfide from blast furnace gas according to claim 1, characterized in that, In step S4, the sulfur-free blast furnace gas C used for external transmission accounts for 80-95% of the total gas, while the sulfur-free blast furnace gas C transferred to the carbon dioxide separation device (5) for processing accounts for 5-20% of the total gas.

7. The process for preparing high-concentration carbonyl sulfide from blast furnace gas according to claim 1, characterized in that, In step S4, the carbon dioxide separation device (5) includes pressure swing adsorption and low-temperature condensation to separate liquid carbon dioxide, wherein the low-temperature condensation temperature is -150℃ to -50℃.

8. The process for preparing high-concentration carbonyl sulfide from blast furnace gas according to claim 1, characterized in that, In step S5, the heating temperature during adsorbent regeneration is 180–220°C; the concentration of the higher concentration carbonyl sulfide desorption gas is 5%–20%.

9. The process for preparing high-concentration carbonyl sulfide from blast furnace gas according to claim 1, characterized in that, In step S6, the high-concentration COS separation device (7) includes pressure swing adsorption and low-temperature condensation to separate liquid carbonyl sulfide, wherein the low-temperature condensation temperature is -150℃ to -50℃.

10. The process for preparing high-concentration carbonyl sulfide from blast furnace gas according to claim 1, characterized in that, In step S6, the concentration of the high-purity carbonyl sulfide liquid is greater than 98%.

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