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

Abstract

The invention discloses a process for preparing high-concentration carbonyl sulfide by desulfurizing blast furnace gas. The process comprises the following steps: S1, cooling, dehydrating, dechlorinating and dedusting the blast furnace gas; s2, carrying out hydrolysis treatment on the blast furnace gas, and completely converting organic sulfur into inorganic sulfur; s3, blast furnace gas desulfurization treatment; s4, separating out carbon dioxide and blast furnace gas without carbon dioxide; s5, after the blast furnace gas is heated, the blast furnace gas reacts with the adsorbent saturated in adsorption, adsorbed sulfur species are converted into carbonyl sulfide, carbonyl sulfide desorbed gas with high concentration is obtained, and S6, the carbonyl sulfide desorbed gas is subjected to separation treatment, and liquid high-purity carbonyl sulfide liquid is obtained. According to the invention, the purified coal gas is subjected to carbon dioxide separation, and then the adsorbent is subjected to desorption treatment, so that on one hand, a small amount of gas can be effectively used for regenerating the adsorbent, and recycling of the adsorbent is realized; on the other hand, desorption products of the adsorbent are carbonyl sulfide, so that the problem of pipeline blockage caused by solid sulfur generated during regeneration of the adsorbent is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of atmosphere purification and environmental protection, and in particular to a process for preparing high-concentration carbonyl sulfide by desulfurizing blast furnace gas. Background Art

[0002] In recent years, blast furnace gas source desulfurization technology has been widely used in the domestic steel industry to reduce sulfur emissions and meet the requirements of the national dual carbon policy. In the prior art, such as patents CN202323125605, CN202323094336 and CN202410636644, the blast furnace gas desulfurization process usually includes dechlorination and deoxidation pretreatment, conversion of organic sulfur COS into inorganic sulfur H 2 S, and reprocess H2S. However, the current H 2 There are some problems with the S reprocessing method.

[0003] A common practice is to use disposable activated carbon adsorbents for adsorption, but this method does not achieve a true desulfurization effect because the adsorbed 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 adsorb the saturated H 2 S is oxidized to generate sulfur for recovery. Although this method can achieve sulfur recovery, it has extremely high requirements for the anti-blocking device of the process and there is a blockage 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 precision etching products of electronic thin-film parts in the aviation, machinery and chemical industries. The amount of blast furnace gas is very large. If carbonyl sulfide can be purified from it, it can meet the above application needs and reduce sulfur emissions at the same time.

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

[0006] In view of the shortcomings of the prior art, the present invention provides a process for preparing high-concentration carbonyl sulfide by desulfurizing blast furnace gas. By changing the decomposition atmosphere, when the adsorbent saturated with adsorption is decomposed, it is controlled not to produce sulfur but only to generate carbonyl sulfide, and the low-concentration carbonyl in the blast furnace gas is converted into high-concentration carbonyl sulfide through adsorption concentration.

[0007] The present invention adopts the following technical solution:

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

[0009] S1, passing blast furnace gas into a pretreatment device for cooling, dehydration, dechlorination and dust removal, and then raising the temperature to obtain blast furnace gas A;

[0010] S2, the pre-treated blast furnace gas A is passed into the COS hydrolysis device for hydrolysis treatment, so that all the organic sulfur in the blast furnace gas is converted into inorganic sulfur to obtain blast furnace gas B;

[0011] S3, the blast furnace gas B after hydrolysis treatment is passed into a hydrogen sulfide adsorption device for desulfurization treatment to obtain blast furnace gas C;

[0012] S4. The sulfur-free blast furnace gas C after desulfurization treatment is discharged in two ways, one of which is directly transported for external use, and the other is transferred to the carbon dioxide separation device through the induced draft fan for treatment to separate carbon dioxide and carbon dioxide-free blast furnace gas D. The separated carbon dioxide enters the liquid CO 2 Tank storage;

[0013] S5. After the blast furnace gas D is heated by the heater, it is passed into the saturated hydrogen sulfide adsorption device to react with the saturated adsorbent to convert the adsorbed sulfur species into carbonyl sulfide to obtain a higher concentration of carbonyl sulfide analysis gas. At this time, the adsorbent is regenerated and a higher concentration of carbonyl sulfide gas can be obtained. The regenerated adsorbent can be reused after cooling.

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

[0015] In step S1, the working temperature of the pretreatment device for cooling and dehydrating chlorine ions and dust is 0-10°C, and the water, chlorine ions and dust in the blast furnace gas are removed by the chilled water cooling method; the recovery temperature is 50-80°C.

[0016] In step S2, the COS hydrolysis device is filled with a hydrolysis catalyst, and the hydrolysis catalyst includes a catalytic carrier and a loaded active component, wherein the catalytic carrier is one or more composites 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] In the step S3, the hydrogen sulfide adsorption device, one for use and one for standby, includes two devices arranged in parallel. When one of the hydrogen sulfide adsorption devices is saturated with adsorption, the other hydrogen sulfide adsorption device starts adsorption, and the saturated hydrogen sulfide adsorption device starts desorption.

[0018] The hydrogen sulfide adsorption device is filled with an adsorbent, which includes an adsorption carrier and a loaded active component, wherein the adsorption carrier is one or more composites of coal-based activated carbon, wood-based activated carbon, and petroleum coke-based activated carbon, and the loaded active component is one or more of 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.

[0019] In step S4, the sulfur-free blast furnace gas C for external use 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 cryogenic condensation to separate liquid carbon dioxide, wherein the cryogenic condensation temperature is -150°C to -50°C.

[0021] In the step S5, the heating temperature during adsorbent regeneration is 180-220°C; the concentration of the relatively high concentration 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°C to -50°C.

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

[0024] The technical solution of the present invention has the following advantages:

[0025] The present invention can effectively remove sulfur species from blast furnace gas through a systematic processing device to achieve ultra-low emissions. At the same time, by separating carbon dioxide from a small amount of purified gas and then analyzing the adsorbent, on the one hand, a small amount of gas can be effectively used to regenerate the adsorbent, thereby achieving the recyclability of the adsorbent; on the other hand, the analytical products of the adsorbent are all carbonyl sulfide, thereby avoiding the problem of pipeline blockage caused by solid sulfur generated during adsorbent regeneration. The separated liquid carbon dioxide can reduce carbon emissions, and the obtained high-purity liquid carbonyl sulfide product can be used as a chemical raw material, and can also be used as a precision etching gas for electronic thin-film parts, thereby achieving resource utilization of sulfur in blast furnace gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 The present invention is a schematic diagram of the system structure of the process for preparing high-concentration carbonyl sulfide by desulfurizing blast furnace gas.

[0028] The following are marked in the figure:

[0029] 1- pretreatment device; 2- COS hydrolysis device; 3- hydrogen sulfide adsorption device; 4- induced draft fan; 5- carbon dioxide separation device; 6- heater; 7- high concentration COS separation device; 8- liquid CO 2 Storage tank; 9-Liquid COS storage tank. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Embodiment 1:

[0032] like Figure 1 As shown, this embodiment provides a process for preparing high-concentration carbonyl sulfide by desulfurization of blast furnace gas, which is as follows:

[0033] 50000Nm 3 / h, 50℃, COS concentration is 180mg / m 3 The blast furnace gas is sequentially passed into the pretreatment device 1, COS hydrolysis device 2 and hydrogen sulfide adsorption device 3 for desulfurization treatment. The pretreatment temperature is 5°C, and after treatment, it is raised to 60°C and passed into the Na 2 CO 3 / Ti-Al 2 O 3 The COS hydrolysis device 2 of the catalyst is hydrolyzed, and finally desulfurized by the hydrogen sulfide adsorption device 3 to obtain sulfur-free blast furnace gas. The hydrogen sulfide adsorption device 3, which is used in one and used in another, is filled with Cu-Ni / wood activated carbon adsorbent. When the adsorbent is saturated and needs to be regenerated, 2000Nm 3 / h of clean sulfur-free blast furnace gas is introduced into the carbon dioxide separation device 5 for treatment. After the gas from which carbon dioxide is removed is heated to 180°C by the heater 6, the adsorbent to be regenerated is analyzed and regenerated. The analyzed gas is introduced into the high-concentration COS separation device 7 for treatment. The liquid carbonyl sulfide obtained by low-temperature cooling at -80°C is stored in the liquid COS storage tank 9, and the rest of the gas is returned to the blast furnace gas pipeline network. The carbonyl sulfide concentration in the liquid COS storage tank 9 is measured to be 98.7%.

[0034] Example 2

[0035] like Figure 1 As shown, this embodiment provides a process for preparing high-concentration carbonyl sulfide by desulfurization of blast furnace gas, which is as follows:

[0036] 80000Nm 3 / h, 60℃, COS concentration is 100mg / m 3 The blast furnace gas is sequentially passed into the pretreatment device 1, COS hydrolysis device 2 and hydrogen sulfide adsorption device 3 for desulfurization treatment. The pretreatment temperature is 10°C, and after treatment, it is raised to 50°C and passed into the K 2 CO 3 / Ti-Al 2 O 3 The COS hydrolysis device 2 of the catalyst is hydrolyzed, and finally desulfurized by the hydrogen sulfide adsorption device 3 to obtain sulfur-free blast furnace gas. The hydrogen sulfide adsorption device 3, which is used in one and used in another, is filled with Cu / coal-based activated carbon adsorbent. When the adsorbent is saturated and needs to be regenerated, 4000Nm 3 / h of clean sulfur-free blast furnace gas is introduced into the carbon dioxide separation device 5 for treatment. After the gas from which carbon dioxide is removed is heated to 190°C by the heater 6, the adsorbent to be regenerated is analyzed and regenerated. The analyzed gas is passed into the high-concentration COS separation device 7 for treatment. The liquid carbonyl sulfide obtained by low-temperature cooling at -150°C is stored in the liquid COS storage tank 9, and the rest of the gas is returned to the blast furnace gas pipeline network. The carbonyl sulfide concentration in the liquid COS storage tank 9 is measured to be 98.9%.

[0037] Example 3

[0038] like Figure 1 As shown, this embodiment provides a process for preparing high-concentration carbonyl sulfide by desulfurization of blast furnace gas, which is as follows:

[0039] 100000Nm 3 / h, 80℃, COS concentration is 100mg / m 3 The blast furnace gas is sequentially passed into the pretreatment device 1, COS hydrolysis device 2 and hydrogen sulfide adsorption device 3 for desulfurization treatment. The pretreatment temperature is 0°C, and after treatment, it is raised to 80°C and passed into the K2 CO 3 / Al 2 O 3 The COS hydrolysis device 2 of the catalyst is hydrolyzed, and finally desulfurized by the hydrogen sulfide adsorption device 3 to obtain sulfur-free blast furnace gas. The hydrogen sulfide adsorption device 3, which is used in one and used in another, is filled with Cu-Co / petroleum coke activated carbon adsorbent. When the adsorbent is saturated and needs to be regenerated, 5000Nm 3 / h of clean sulfur-free blast furnace gas is introduced into the carbon dioxide separation device 5 for treatment. After the gas from which carbon dioxide is removed is heated to 220°C by the heater 6, the adsorbent to be regenerated is analyzed and regenerated. The analyzed gas is passed into the high-concentration COS separation device 7 for treatment. The liquid carbonyl sulfide obtained by low-temperature cooling at -50°C is stored in the liquid COS storage tank 9, and the rest of the gas is returned to the blast furnace gas pipeline network. The carbonyl sulfide concentration in the liquid COS storage tank 9 is measured to be 99.1%.

[0040] The present invention can effectively remove sulfur species from blast furnace gas through a systematic processing device to achieve ultra-low emissions. At the same time, by separating carbon dioxide from a small amount of purified gas and then analyzing the adsorbent, on the one hand, a small amount of gas can be effectively used to regenerate the adsorbent, thereby achieving the recyclability of the adsorbent; on the other hand, the analytical products of the adsorbent are all carbonyl sulfide, thereby avoiding the problem of pipeline blockage caused by solid sulfur generated during adsorbent regeneration. The separated liquid carbon dioxide can reduce carbon emissions, and the obtained high-purity liquid carbonyl sulfide product can be used as a chemical raw material, and can also be used as a precision etching gas for electronic thin-film parts, thereby achieving resource utilization of sulfur in blast furnace gas.

[0041] Any matters not described in the present invention are applicable to the prior art.

[0042] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. However, the obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A process for preparing high-concentration carbonyl sulfide by desulfurization of blast furnace gas, characterized in that: The following steps are involved: S1, passing blast furnace gas into a pretreatment device (1) for cooling, dehydration, dechlorination and dust removal, and then raising the temperature to obtain blast furnace gas A; S2, the pre-treated blast furnace gas A is introduced 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 to obtain blast furnace gas B; S3, the blast furnace gas B after hydrolysis treatment is passed into a hydrogen sulfide adsorption device (3) for desulfurization treatment to obtain blast furnace gas C; S4, the sulfur-free blast furnace gas C after desulfurization treatment is discharged in two ways, one of which is directly transported for use, and the other is transferred to the carbon dioxide separation device (5) through the induced draft fan (4) for treatment to separate carbon dioxide and carbon dioxide-free blast furnace gas D, wherein 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 passed into the saturated hydrogen sulfide adsorption device (3), reacts with the saturated adsorbent, converts the adsorbed sulfur species into carbonyl sulfide, and obtains a carbonyl sulfide analysis gas with a higher concentration. At this time, the adsorbent is regenerated, and the regenerated adsorbent can be reused after cooling; S6. The high-concentration COS desorption gas obtained in step S5 is separated and processed by a high-concentration COS separation device (7) to obtain liquid high-purity COS liquid, which is stored in a liquid COS storage tank (9). The gas after separation of COS is returned to the external pipeline network.

2. The process for preparing high-concentration carbonyl sulfide by desulfurization of blast furnace gas according to claim 1, characterized in that: In step S1, the working temperature of the pretreatment device (1) for cooling and dehydrating the chlorine ions and dust is 0-10°C, and the water, chlorine ions and dust in the blast furnace gas are removed by the chilled water cooling method; the recovery temperature is 50-80°C.

3. The process for preparing high-concentration carbonyl sulfide by desulfurization of blast furnace gas according to claim 1, characterized in that: In the step S2, the COS hydrolysis device (2) is filled with a hydrolysis catalyst, and the hydrolysis catalyst includes a catalytic carrier and a loaded active component, wherein the catalytic carrier is one or more composites 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.

4. The process for preparing high-concentration carbonyl sulfide by desulfurization of blast furnace gas according to claim 1, characterized in that: In the step S3, the hydrogen sulfide adsorption device (3) for use and for 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, and the saturated hydrogen sulfide adsorption device (3) starts desorption.

5. The process for preparing high-concentration carbonyl sulfide by desulfurization of 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, wherein the adsorption carrier is one or more composites of coal-based activated carbon, wood-based activated carbon, and petroleum coke-based activated carbon, and the loaded active component is one or more of 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 by desulfurization of blast furnace gas according to claim 1, characterized in that: In the step S4, the sulfur-free blast furnace gas C for external use accounts for 80-95% of the total gas, and the sulfur-free blast furnace gas C transferred to the carbon dioxide separation device (5) for treatment accounts for 5-20% of the total gas.

7. The process for preparing high-concentration carbonyl sulfide by desulfurization of blast furnace gas according to claim 1, characterized in that: In the step S4, the carbon dioxide separation device (5) comprises pressure swing adsorption and cryogenic condensation to separate liquid carbon dioxide, wherein the cryogenic condensation temperature is -150°C to -50°C.

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

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

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

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