CN112708477A

CN112708477A - Method for increasing combustion heat value of blast furnace gas and simultaneously removing organic sulfur and inorganic sulfur

Info

Publication number: CN112708477A
Application number: CN202110005131.9A
Authority: CN
Inventors: 王学谦; 钟磊; 王郎郎; 陶雷
Original assignee: Kunming University of Science and Technology
Current assignee: Kunming University of Science and Technology
Priority date: 2021-01-05
Filing date: 2021-01-05
Publication date: 2021-04-27
Anticipated expiration: 2041-01-05
Also published as: CN112708477B

Abstract

The invention relates to a method for improving the combustion heat value of blast furnace gas and simultaneously removing organic sulfur and inorganic sulfur, aiming at the low heat value and the desulfurization requirement of the blast furnace gas, a certain amount of coke oven gas with high heat value is introduced into the blast furnace gas to improve the heat value of the blast furnace gas so as to achieve the purposes of resource utilization and process cost reduction; in addition, the hydrogen in the coke oven gas can be used as a hydrogen source to carry out the hydro-conversion reaction on the organic sulfur (COS and CS) in the blast furnace gas under the action of a catalyst₂) Conversion to inorganic sulfur (H)₂S), finally, inorganic sulfur is removed through a desulfurization catalyst; the method has the advantages of no generation of waste gas and byproducts, low operation cost, good desulfurization effect and very high practical application prospect.

Description

Method for increasing combustion heat value of blast furnace gas and simultaneously removing organic sulfur and inorganic sulfur

Technical Field

The invention relates to a method for improving the combustion heat value of blast furnace gas and simultaneously removing organic sulfur and inorganic sulfur, belonging to the technical field of industrial waste gas purification.

Background

In order to reduce the energy consumption of enterprises, the blast furnace gas can be used as fuel for steel plants after being purified. Height ofNon-combustible component (as N) in the coal gas component₂And CO₂Mainly) is more (about 70 percent) and the calorific value is low (3500 kJ/m)³Left and right). The coke oven gas which is also present in steel plants is mainly composed of hydrogen (56%) and methane (27%), and the calorific value is as high as 18250kJ/m³. The heat value of the coke oven gas is much higher than that of the blast furnace gas with the same volume. In general, blast furnace gas having a low calorific value is not easily burned, and in order to increase the thermal effect of combustion, the blast furnace gas must be preheated in addition to air. Therefore, when blast furnace gas is used for heating, one half of the heat storage chambers of the ascending air flow of the combustion system is used for preheating air, and the other half of the heat storage chambers of the ascending air flow of the combustion system is used for preheating gas. Therefore, in order to achieve better combustion of the blast furnace gas, enterprises invest certain capital for preheating the blast furnace gas, which is contrary to the concept of resource utilization of the blast furnace gas.

With the increasing environmental protection requirements of iron and steel enterprises, the iron making process becomes an important link for energy conservation and emission reduction, and blast furnace gas generated in the iron and steel smelting process is used as an important pollutant in the iron and steel smelting industry, wherein the blast furnace gas contains organic sulfur (COS and CS)₂、C₄H₄S, etc.), inorganic sulfur (H)₂S) and the like, and the existence of the harmful gases seriously restricts the resource utilization of the blast furnace gas. COS and H₂S is the main component of pollutants in blast furnace gas, and accounts for more than 95%, so the research on the removal technology of the two substances is particularly critical.

Patent CN201610971597.3 discloses "a modified activated carbon, a modification method and its use", in which the activated carbon modified by saturated copper sulfate solution is used as an activated carbon column, and hydrogen sulfide in gas is adsorbed by the activated carbon column. However, the method needs water-carrying treatment of the dried modified activated carbon, and a large amount of wastewater is generated in the process, so that the cost of industrial application is increased.

The patent CN201710791711.9 discloses a method for recycling hydrogen sulfide and carbonyl sulfide based on molten salt resource, which comprises the steps of heating liquid functional molten salt to 450-750 ℃, and then adding carbon powder into the heated liquid functional molten salt; then introducing hydrogen sulfide and carbonyl sulfide gas into molten salt to be fully contacted and then absorbed by reaction; after the gas is stopped to be introduced, calcium salt or barium salt is supplemented into the molten salt system after the reaction, the mixture is stirred and mixed, and then sulfide generated by the standing precipitation reaction is led out of the molten salt system at high temperature for recycling. The reaction has high requirement on temperature, secondary pollutants such as waste water, solid waste and the like can be generated in the reaction process, and the process cost is indirectly increased.

COS removal can be generally divided into a dry method and a wet method; the dry method mainly includes a hydroconversion method, a hydrolysis conversion method, an oxidation conversion method, and the like. Wet removal of carbonyl sulfide can be classified into physical absorption, chemical absorption and physical-chemical methods, such as organic amine solvent absorption, liquid-phase catalytic hydrolysis conversion, and the like. Because of the poor activity of the organic sulfur, although the traditional solution absorption method and the solid adsorption method can remove a certain amount of organic sulfur, the conversion process has good hydrolysis effect on the organic sulfur, but the requirement of fine desulfurization cannot be met.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a method for improving the combustion heat value of blast furnace gas and simultaneously removing organic sulfur and inorganic sulfur with low cost and high efficiency₂And S together realize the removal of hydrogen sulfide gas under the action of a desulfurization catalyst.

The method comprises the following steps:

(1) improving the heat value of blast furnace gas: the method is characterized in that the coke oven gas with a certain volume is introduced into the blast furnace gas by utilizing the characteristics of high proportion of combustible components and high heat value of the coke oven gas, so that the volume ratio of the coke oven gas to the blast furnace gas is 6: 1-12: 1, the combustible components in the blast furnace gas are improved to increase the heat value, the process cost during the combustion of the blast furnace gas is reduced, and the proportion of hydrogen in the blast furnace gas is correspondingly improved after the coke oven gas is introduced;

(2) dust removal, deoxidation and dechlorination: carrying out dust removal, deoxidation and dechlorination on the mixed gas in the step (1) to remove dust, oxygen and chlorine in the gas; to protect the hydrolytic agent from waterThe poisoning and inactivation of the lytic agent are realized, the service life is prolonged, and the corrosion to the pipeline and the TRT blade is reduced, so that the influence of the substances on the subsequent process is eliminated; after dust removal, the dust concentration in the flue gas is 5mg/m³The following; after deoxidation and dechlorination, the concentrations of oxygen and hydrogen chloride are respectively reduced to 0.05% and 10mg/m³The following;

(3) conversion of organic sulfur to inorganic sulfur: by using H in coal gas₂O and H produced by the introduction of coke oven gas₂Under the action of an organic sulfur hydrolysis catalyst, organic sulfur in the mixed gas is subjected to catalytic hydrolysis reaction and hydrogenation conversion reaction at 100-200 ℃ to generate inorganic sulfur, the introduction of hydrogen improves the conversion efficiency of the inorganic sulfur, the conversion rate is stably maintained at more than 95%, and CO gas is generated in the hydrogenation conversion process at the same time, so that the recycling of coal gas is facilitated; the reaction principle equation of the step is as follows: COS + H₂→H₂S+CO；COS+H₂O→H₂S+CO₂；CS₂+H₂O→H₂S+CO₂；

(4) Cooling and oxygenating by a heat exchanger: hydrolyzing the mixed gas to convert organic sulfur (COS, CS)₂) Then, reducing the temperature of the mixed gas to 80-150 ℃ by using a heat exchanger;

(5) inorganic sulfur removal: adding a certain amount of oxygen into the mixed gas before the mixed gas is sent into a hydrogen sulfide removal tower, so that the oxygen content is controlled to be 0.05-0.8%; under the action of desulfurizing agent, the original H in the gas₂S and H converted in step (3)₂S is subjected to catalytic oxidation reaction at 80-150 ℃ to generate elemental sulfur, metal sulfide and sulfate, the elemental sulfur, the metal sulfide and the sulfate are adsorbed on a catalyst, and the total sulfur content in the purified gas is 20mg/m³The following; the reaction principle equation of the step is as follows: h₂S+O₂→S+H₂O；H₂S+MO→MS+H₂O；H₂S + O + MO → sulfate + H₂O (M is a metal supported by the catalyst);

(6) and (3) regeneration of a desulfurizing agent: and (5) after the desulfurization catalyst in the step (5) is deactivated, regenerating by a chemical method, and realizing the recycling of the desulfurizer.

The organic sulfur hydrolysis catalyst is prepared from active carbon, alumina and moleculesOne of the sieves is taken as a carrier, and one or more solutions of molybdenum salt, potassium salt, magnesium salt, cerium salt, cobalt salt, magnesium salt and aluminum salt are taken as impregnants; the impregnant (M) is added into the carrier in one time or in several times according to the equal volume impregnation method_X：M_Carrier= 1-10%; x is a metal loaded by the catalyst), soaking for 6-24 h at 20-60 ℃, filtering, drying the solid for 6-12 h at 80-120 ℃, and roasting for 2-5 h at 300-400 ℃ to obtain the organic sulfur hydrolysis catalyst.

The desulfurization catalyst takes one of active carbon, alumina and molecular sieve as a carrier, takes one or more of copper salt, cerium salt, iron salt, cobalt salt, manganese salt, lanthanum salt and silver salt as impregnant, and the impregnant (M) is added to the carrier in one step or in several steps according to the equal volume impregnation method_X:M_Carrier= 1-10%; x is a metal loaded by the catalyst), soaking for 6-24 h at 20-60 ℃, filtering, drying for 6-12 h at 80-120 ℃, and roasting for 2-5 h at 300-400 ℃ to obtain the desulfurization catalyst.

The catalyst regeneration is to take potassium hydroxide or sodium hydroxide solution with the mass concentration of 2-10% as regeneration liquid, put the deactivated desulfurization catalyst into the regeneration liquid to be soaked for 2-5 hours for 2-5 times until the color of the impregnation liquid is colorless, and then wash away the regeneration liquid on the surface of the desulfurizer by deionized water at the temperature of 15-40 ℃; and drying the mixture for 6 to 15 hours at the temperature of between 80 and 120 ℃ to obtain the regenerated desulfurizer.

The invention has the advantages that:

(1) according to the method, the coke oven gas is introduced into the blast furnace gas, so that the heat value of the blast furnace gas is improved, and hydrogen required by tail gas treatment is brought to the blast furnace gas; the process and the tail gas treatment cost are reduced, and the resource utilization is realized to a certain extent;

(2) the method comprises adding organic sulfur (COS, CS) by selecting appropriate catalyst₂) Conversion to inorganic sulfur (H)₂S), then, the sulfur is converted into elemental sulfur, sulfate and metal sulfide through a fine desulfurization catalyst; so that COS and H in the tail gas emission₂The content of S is reduced to 20.0mg/m³Simultaneously, the fine desulfurization catalyst is regenerated, thereby not only eliminating the environmental pollution caused by the exhaust gas discharged into the air, but also improving the resource benefitA rate of utilization;

(3) the method of the invention is simple, the investment is low, and the operating cost is low.

Drawings

FIG. 1 is a schematic flow chart of the method of the present invention.

Detailed Description

The present invention is further illustrated in detail by the following figures and examples, but the scope of the present invention is not limited to the above description, and the deoxidation and dechlorination processes in examples 1 to 4 use a conventional adsorption method to remove oxygen and hydrogen chloride from the mixed gas by using a commercially available deoxidation and dechlorination adsorbent.

Example 1

1. Adding a molybdenum nitrate solution into a carrier by using activated carbon as the carrier and a molybdenum nitrate solution as an impregnation solution according to an isometric impregnation method, wherein M is_Mo:M_Carrier= 5%; soaking at 20 deg.C for 20h, filtering, drying the solid at 80 deg.C for 6h, and roasting at 300 deg.C for 5h to obtain organic sulfur hydrolysis catalyst A;

2. respectively adding ferric nitrate and cobalt nitrate solution into a carrier by using alumina as the carrier and a solution containing ferric nitrate and cobalt nitrate as an impregnation solution according to an isometric impregnation method, wherein M is_Fe+M_Co:M_Carrier=5%，M_Fe:M_Co1:1, soaking at room temperature for 12h, filtering, drying the solid at 80 ℃ for 6h, and then roasting at 300 ℃ for 5h to prepare a desulfurization catalyst A;

3. in volume ratio V_{Blast furnace}：V_{Coke oven}Introducing coke oven gas into blast furnace gas in a ratio of =6:1, and measuring and calculating the smoke gas amount of mixed gas to be 4000m³The concentration of COS in the flue gas is 130mg/m³Carbon disulfide 10mg/m³Hydrogen sulfide 40mg/m³The oxygen concentration is 0.5%, the hydrogen concentration is 8.6%, and the hydrogen chloride concentration is 50mg/m³The flue gas temperature is 130 ℃, and the dust concentration is 400mg/m³The calorific value is 5000kJ/m³；

4. As shown in figure 1, the mixed flue gas is firstly dedusted by a bag-type deduster, and the dust concentration is reduced to 4mg/m³(ii) a Before entering the catalytic hydrolysis process, fixed bed adsorbent is deoxidized and dechlorinated, oxygen is addedThe concentration of hydrogen chloride is reduced to 0.03 percent and 8mg/m respectively³Then the mixture is sent into a desulfurizing tower 1 filled with organic sulfur hydrolysis catalyst, carbonyl sulfur and carbon disulfide are converted into hydrogen sulfide through hydrogenation conversion and catalytic hydrolysis under the condition that the temperature is 130 ℃, and the total conversion efficiency reaches 95 percent; the converted flue gas is sent into a desulfurizing tower 2 filled with a desulfurizing catalyst to purify hydrogen sulfide after the temperature of the converted flue gas is reduced to 100 ℃ through a heat exchanger, meanwhile, oxygen is added into the mixed gas, the concentration of the oxygen is increased to 0.1%, and the hydrogen sulfide is catalytically oxidized and converted into elemental sulfur, metal sulfide and sulfate under the action of the desulfurizing catalyst; the total sulfur content in the purified flue gas is 15mg/m³(ii) a Then the purified flue gas is sent into a smelting furnace for combustion; soaking the deactivated desulfurizer in 5wt% sodium hydroxide solution for 3 times until the sodium hydroxide solution is colorless, washing the regenerated solution on the surface of the desulfurizer with deionized water at 20 ℃, drying at 80 ℃ for 14h, and controlling the total sulfur discharge amount to be 20mg/m after 3 times of cyclic regeneration³The following.

Example 2

1. Adding a molybdenum nitrate solution into a carrier by using a ZSM-5 molecular sieve as the carrier and a molybdenum nitrate solution and a potassium carbonate solution as impregnation solutions according to an isometric impregnation method, wherein M is_Mo：M_Carrier= 5%; soaking at room temperature for 8h, filtering, drying the solid at 100 deg.C for 8h, and adding the dried solid into potassium carbonate solution according to the equal volume soaking method, wherein M is_K：M_Carrier= 3%; soaking at 30 ℃ for 15h, drying the filtered solid at 90 ℃ for 8h, and roasting at 350 ℃ for 4h to obtain an organic sulfur hydrolysis catalyst B;

2. respectively adding copper acetate and cerium acetate solution to a carrier by using a 3A molecular sieve as the carrier and a solution containing copper acetate and cerium acetate as impregnation liquid according to an isometric impregnation method, wherein M is_Cu+M_Ce:M_Carrier=5%，M_Fe:M_Co1:1, soaking at 30 ℃ for 15h, filtering, drying the solid at 80 ℃ for 6h, and then roasting at 350 ℃ for 4h to prepare a desulfurization catalyst B;

3. in volume ratio V_{Blast furnace}：V_{Coke oven}Introducing coke oven gas into blast furnace gas in a ratio of =8: 1; warp beamThe smoke gas amount of the mixed gas is measured and calculated to be 5000m³The concentration of COS in the flue gas is 135mg/m³The carbon disulfide concentration is 8mg/m³Hydrogen sulfide concentration of 45mg/m³The oxygen concentration is 0.8%, the hydrogen concentration is 7.6%, and the hydrogen chloride concentration is 35mg/m³The flue gas temperature is 150 ℃, and the dust concentration is 500mg/m³The heat value is 5700kJ/m³；

4. The mixed flue gas is firstly dedusted by a bag-type deduster, and the dust concentration is reduced to 3mg/m³(ii) a Before entering the catalytic hydrolysis process, fixed bed adsorbent is deoxidized and dechlorinated, and the concentrations of oxygen and hydrogen chloride are respectively reduced to 0.04 percent and 10mg/m³Then the mixture is sent into a desulfurizing tower 1 filled with organic sulfur hydrolysis catalyst, carbonyl sulfur and carbon disulfide are converted into hydrogen sulfide through hydrogenation conversion and catalytic hydrolysis under the condition that the temperature is 150 ℃, and the total conversion efficiency reaches 98 percent; the converted flue gas is cooled to 120 ℃ through a heat exchanger, and then is sent into a desulfurizing tower 2 filled with a desulfurizing catalyst to purify hydrogen sulfide, and the hydrogen sulfide is converted into elemental sulfur, metal sulfide and sulfate through catalytic oxidation under the action of a desulfurizing agent; the total sulfur content in the purified flue gas is 10mg/m³(ii) a Then the purified flue gas is sent into a smelting furnace for combustion; soaking the mixture for 4 times after soaking the mixture by using 5wt% of potassium hydroxide solution until the potassium hydroxide solution is colorless, washing the regeneration solution on the surface of a desulfurizing agent by using 30 ℃ deionized water, drying the mixture for 14 hours at 80 ℃, and controlling the total sulfur discharge amount to be 20mg/m after 3 times of circulating and regenerating the desulfurization catalyst³The following.

Example 3

1. Adding magnesium nitrate solution into the carrier by using alumina as a carrier and magnesium nitrate and potassium carbonate as impregnation liquid according to an equal-volume impregnation method, wherein M is_Mg：M_Carrier=3%, standing at room temperature for 12h, drying at 100 deg.C for 12h, and adding the dried solid into potassium carbonate solution by isovolumetric immersion method, wherein M is_K：M_Carrier= 1%; standing at 55 ℃ for 7h, drying at 100 ℃ for 12h, and roasting at 300 ℃ for 3h to obtain an organic sulfur hydrolysis catalyst C;

2. 5A molecular sieve is taken as a carrier, cerium acetate is taken as a steeping fluid, and the volume is equal to that of the carrierImpregnation by adding a solution of cerium acetate to the support, wherein M_Mg：M_Carrier= 3%; standing at 55 ℃ for 24h, drying at 100 ℃ for 12h, and roasting at 400 ℃ for 2h to obtain a desulfurization catalyst C;

3. according to volume ratio V_{Blast furnace}：V_{Coke oven}=10:1, introducing coke oven gas into blast furnace gas, and measuring and calculating flue gas amount of mixed gas to be 8000m³The concentration of COS in the flue gas is 125mg/m³The carbon disulfide concentration is 5mg/m³The concentration of hydrogen sulfide is 35mg/m³The oxygen concentration is 0.7%, the hydrogen concentration is 6.2%, and the hydrogen chloride concentration is 40mg/m³The flue gas temperature is 180 ℃, and the dust concentration is 550mg/m³The calorific value is 5000kJ/m³；

4. The mixed flue gas is firstly dedusted by a bag-type deduster, and the dust concentration is reduced to 3mg/m³(ii) a Before entering the catalytic hydrolysis process, fixed bed adsorbent is deoxidized and dechlorinated, and the concentrations of oxygen and hydrogen chloride are respectively reduced to 0.03 percent and 7 mg/m³Then the mixture is sent into a desulfurizing tower 1 filled with organic sulfur hydrolysis catalyst, carbonyl sulfur and carbon disulfide are converted into hydrogen sulfide through hydrogenation conversion and catalytic hydrolysis under the condition that the temperature is 180 ℃, and the total conversion efficiency reaches 96 percent; the converted flue gas is cooled to 120 ℃ through a heat exchanger, and then is sent into a desulfurizing tower 2 filled with a desulfurizing catalyst to purify hydrogen sulfide, and the hydrogen sulfide is converted into elemental sulfur, metal sulfide and sulfate through catalytic oxidation under the action of a desulfurizing agent; the total sulfur content in the purified flue gas is 10mg/m³(ii) a Then the purified flue gas is sent into a smelting furnace for combustion; soaking the desulfurizer in 8wt% sodium hydroxide solution for 5 times until the sodium hydroxide solution is colorless, washing the regenerant on the surface of the desulfurizer with deionized water at 20 ℃, drying the desulfurizer at 80 ℃ for 14 hours, and recycling the desulfurization catalyst for 3 times to control the total sulfur emission to be 20mg/m³The following.

Example 4

1. Taking alumina as a carrier and magnesium nitrate, potassium carbonate and molybdenum nitrate as impregnation liquid, sequentially adding a magnesium nitrate solution, a potassium carbonate solution and a molybdenum nitrate solution into the carrier according to an equal-volume impregnation method, adding one solution each time, standing for 6 hours,drying at 100 deg.C for 8 hr until the last solution is added; wherein M is_Mg+M_K+M_Mo:M_Carrier=4%，M_Mg:M_K:M_MoSoaking at 40 ℃ for 12h, drying at 100 ℃ for 24h, and roasting at 350 ℃ for 4h to obtain the organic sulfur hydrolysis catalyst, wherein the ratio is 1:1: 2;

2. adding copper acetate solution into carrier by using 10X molecular sieve as carrier and copper acetate as impregnation liquid according to equal volume impregnation method, wherein M is_Cu:M_Carrier=5%, soaking at 40 ℃ for 12h, drying at 100 ℃ for 24h, and roasting at 350 ℃ for 4h to obtain the desulfurization catalyst;

3. mixed gas (V) for simulating blast furnace gas and coke oven gas prepared in laboratory_{Blast furnace}:V_{Coke oven}=12: 1) gas flow is 500mL/min, and COS concentration in the flue gas is 115mg/m³The carbon disulfide concentration is 5mg/m³Hydrogen sulfide concentration of 30mg/m³The oxygen concentration is 0.6%, the hydrogen concentration is 5.7%, and the hydrogen chloride concentration is 45mg/m³CO concentration of 20% CO₂The concentration is 20 percent, and the methane concentration is 3 percent;

4. oxygen concentration and hydrogen chloride were reduced to 0.02% and 5mg/m, respectively, by deoxidation and dechlorination with adsorbents in a fixed bed before organic sulfur conversion was carried out³Then sending the mixture into a fixed bed filled with an organic sulfur hydrolysis catalyst, and converting carbonyl sulfur and carbon disulfide into hydrogen sulfide at the temperature of 200 ℃, wherein the total conversion efficiency reaches 99%; then, the mixed gas is cooled by a cooling bottle and is sent into a fixed bed filled with a desulfurization catalyst, the reaction temperature is 120 ℃, and hydrogen sulfide is converted into elemental sulfur, metal sulfide and sulfate by catalytic oxidation under the action of a desulfurizing agent; the total sulfur content in the purified flue gas is 5mg/m³。

Claims

1. A method for improving the combustion heat value of blast furnace gas and simultaneously removing organic sulfur and inorganic sulfur is characterized in that: mixing blast furnace gas and coke oven gas according to the volume ratio of 6-12: 1, dedusting, deoxidizing and dechlorinating the mixed gas, and enabling organic sulfur in the mixed gas to pass through catalytic hydrolysis reaction and hydrogenation conversion reaction at 100-200 ℃ under the action of an organic sulfur hydrolysis catalystGenerating inorganic sulfur, hydrolyzing the mixed gas to convert organic sulfur, reducing the temperature of the mixed gas to 80-150 ℃ by using a heat exchanger, introducing oxygen into the mixed gas to ensure that the oxygen content is 0.05-0.8% by volume, and under the action of a desulfurization catalyst, adding H in the mixed gas₂S is subjected to catalytic oxidation reaction at 80-150 ℃ to generate elemental sulfur, metal sulfides and sulfates, and the elemental sulfur, the metal sulfides and the sulfates are adsorbed on a catalyst, so that the purpose of improving the combustion heat value of blast furnace gas and simultaneously removing organic sulfur and inorganic sulfur is achieved.

2. The method for increasing the combustion heat value of blast furnace gas while removing organic sulfur and inorganic sulfur according to claim 1, wherein: the dust concentration after dust removal is less than 5mg/m³(ii) a After deoxidation and dechlorination, the concentrations of oxygen and hydrogen chloride are reduced to 0.05% and 10mg/m respectively³The following.

3. The method for increasing the combustion heat value of blast furnace gas while removing organic sulfur and inorganic sulfur according to claim 1, wherein: the organic sulfur hydrolysis catalyst is prepared by using one of active carbon, alumina and molecular sieve as a carrier and one or more of molybdenum salt, potassium salt, magnesium salt, cerium salt and cobalt salt as an impregnant through the steps of impregnation by an equal-volume impregnation method, drying and roasting.

4. The method for increasing the combustion heat value of blast furnace gas while removing organic sulfur and inorganic sulfur according to claim 1, wherein: the desulfurization catalyst is prepared by taking one of active carbon, alumina and molecular sieve as a carrier and one or more of copper salt, cerium salt, iron salt and cobalt salt as an impregnant through soaking, drying and roasting by an equal volume soaking method.