A nitrogen-doped catalyst for removing organic sulfur from metallurgical coal gas, a preparation method therefor, and an application thereof

Abstract

The present application relates to a kind of for metallurgical coal gas to remove organic sulfur nitrogen-doped catalyst and its preparation method and application, including the following steps: with soluble aluminum salt as carrier, it is prepared with certain proportion of nitrogen source compound mixed solution, then precipitate completely in alkaline environment, after stirring, aging, drying treatment, with high temperature calcination nitrogen-doped Al2O3 catalyst is obtained.The catalyst has more nitrogen site, stronger nitrogen doping capacity, so that the basic center of catalyst increases, improves the catalytic activity when catalytic elimination carbonyl sulfur, while reducing the adsorption of H2S, improves H2S yield, reduces the formation of sulfur, ensures the activity and stability of catalyst, prolongs the life of catalyst.

Description

Technical Field

[0001] This invention relates to the field of desulfurization technology, specifically to a catalyst for removing organic sulfur from metallurgical coal gas, its preparation method, and its application. Background Technology

[0002] Metallurgical gas is an important resource produced by blast furnaces in the iron and steel production process. However, it contains high concentrations of carbonyl sulfide (COS), which can cause environmental pollution, corrosion of equipment and pipelines, and poisoning of catalysts in subsequent industrial processes. Methods commonly used for removing inorganic sulfur are ineffective at removing chemically stable carbonyl sulfide. Currently, the most accurate and cost-effective method is catalytic hydrolysis (COS + H₂O → H₂S + CO₂).

[0003] Typical carbonyl sulfide hydrolysis catalysts are prone to deactivation because during COS hydrolysis, water in the reaction gas is adsorbed onto the catalyst surface and then consumed by COS hydrolysis. Hydrogen sulfide reacts with metal sites on the catalyst surface and is subsequently oxidized by surface-adsorbed oxygen to elemental sulfur, sulfates, or combines with metals to form metal sulfides, which deposit on the catalyst surface, occupying the catalyst's basic sites. This deactivation process is irreversible. The deposition of various sulfur compounds clogs the catalyst's pore structure, covers active sites, and severely reduces catalyst activity.

[0004] Chinese patent CN110142045A discloses a catalyst for desulfurization of metallurgical coal gas and its preparation method. The catalyst consists of a support, an active component, and a co-catalyst. The support is γ-Al2O3, the active component is zinc oxide and iron oxide, and the co-catalyst is one or more of copper oxide, nickel oxide, and cerium oxide. Although the catalyst has a catalytic efficiency of over 90%, the reaction temperature is high, and the stability of the catalyst against poisoning is not explained. Summary of the Invention

[0005] Based on the above-mentioned prior art, the present invention provides a new catalyst for the removal of organic sulfur from metallurgical coal gas, avoiding catalyst deactivation and further improving the catalytic activity of the catalyst.

[0006] The first objective of this invention is to provide a nitrogen-doped catalyst for removing organic sulfur from metallurgical coal gas. This catalyst has more alkaline sites, which can adsorb the hydrolysis product H2S, resulting in less sulfur precipitation, less clogging, longer service life, and a high catalytic efficiency for a long time.

[0007] The second objective of this invention is to provide a method for preparing a catalyst for removing organic sulfur from metallurgical coal gas. The method involves preparing an Al2O3 catalyst containing basic pyridine (N) through nitrogen doping. This allows N atoms to occupy oxygen vacancies on the Al2O3 surface to form intermediates, reducing the adsorption of H2S products. N doping also converts more surface oxygen into lattice oxygen, thereby reducing sulfur formation and improving catalytic performance.

[0008] A third objective of this invention is to provide the application of nitrogen-doped Al2O3 catalysts in the removal of carbonyl sulfide from metallurgical coal gas.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A nitrogen-doped catalyst for removing organic sulfur from metallurgical coal gas, wherein the catalyst is a γ-Al2O3-based hydrolysis catalyst containing an active component, wherein the active component includes pyridine N and polymerized nitrogen, wherein the active component is obtained by precipitating a mixture of an active component precursor and a soluble aluminum salt in an alkaline environment and then calcining it at a high temperature, wherein the active component precursor is an organic nitrogen compound, and the molar ratio of the soluble aluminum salt to the active component precursor is 2:1 to 4.

[0011] Furthermore, the soluble aluminum salt includes any one of aluminum nitrate, aluminum carbonate, and aluminum chloride, or any combination thereof.

[0012] Furthermore, the organic nitrogen compound is either hexamethylenetetramine or melamine.

[0013] Furthermore, the nitrogen atoms in the organic nitrogen compound combine with aluminum atoms in the support in the form of pyridine N or in polymerized nitrogen to form a macroporous, mesoporous, or microporous structure with a uniform nitrogen source distribution.

[0014] A method for preparing a catalyst for removing organic sulfur from metallurgical coal gas includes the following steps:

[0015] (1) Soluble aluminum salt and organic nitrogen compound are mixed evenly in deionized water according to the proportion to obtain a precursor mixed solution;

[0016] (2) Adjust the pH of the precursor mixture solution to alkaline to precipitate it. The separated precipitate mixture is aged and then dried to obtain a mixture powder.

[0017] (3) The dried mixture powder is heated and calcined at high temperature to obtain the target product, nitrogen-doped Al2O3 catalyst.

[0018] Furthermore, in step (1), the soluble aluminum salt is any one of aluminum nitrate, aluminum carbonate, and aluminum chloride, the organic nitrogen compound is a cage-like amine compound, and the molar ratio of the soluble aluminum salt to the organic nitrogen compound is 2:1 to 4.

[0019] Furthermore, step (2) specifically includes adjusting the pH of the precursor mixture solution to 8-10 with NH3·H2O solution, stirring at 65°C for 2 hours, aging at the same temperature for 12 hours, and finally drying at 105°C for 10 hours to obtain the mixture powder.

[0020] Furthermore, it was calcined at 550℃ for 3 hours, with a heating rate of 5℃ / min.

[0021] The cage-like amine compounds include hexamethylenetetramine and melamine.

[0022] An application of the above-mentioned catalyst in the removal of organic sulfur from metallurgical coal gas, wherein the catalyst maintains its catalytic activity for not less than 22 hours in a low-temperature environment, and the catalyst has a conversion rate of not less than 90% for COS and hydrogen sulfide.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. In this nitrogen-doped catalyst, the organic nitrogen compound provides pyridine N, thereby increasing the number of medium and weak basic sites, promoting the COS hydrolysis reaction, and improving the COS conversion rate.

[0025] 2. In this nitrogen-doped catalyst, N atoms in the organic nitrogen compound occupy oxygen vacancies on the Al2O3 surface to form intermediates, reducing the adsorption of H2S products and resulting in a high H2S yield. The strong interaction between N and Al promotes the migration of active oxygen density to surface lattice oxygen, converting more surface oxygen into lattice oxygen, thereby reducing sulfur formation, making the catalyst less prone to clogging, and maintaining a high catalytic efficiency for a long time, thus extending the catalyst life. Attached Figure Description

[0026] Figure 1 The BET pore size distribution curves of the catalysts prepared in Examples 1 and 2;

[0027] Figure 2 The BET adsorption-desorption curves of the catalysts prepared in Examples 1 and 2 are shown in the figure. The vertical axis is not marked in this figure, but the shape of the curve indicates that the sample type is γ-Al2O3.

[0028] Figure 3 The results show the COS and H2S conversion rates of the catalyst in Example 1 under a reaction temperature of 70°C and aerobic conditions.

[0029] Figure 4 The results show the COS and H2S conversion rates of the catalyst in Example 1 under a reaction temperature of 60°C and aerobic conditions.

[0030] Figure 5 The results show the COS and H2S conversion rates of nitrogen-doped Al2O3 catalysts with different N doping amounts in Example 1 (the reaction was tested under the reaction control conditions of Example 5, with a reaction temperature of 60°C).

[0031] Figure 6 The results show the COS conversion of the catalyst prepared in Example 1 at different space velocity ratios;

[0032] Figure 7 The results show the COS and H2S conversion rates of the catalysts prepared in Examples 1 and 2 at different reaction temperatures.

[0033] Figure 8 The COS and H2S conversion stability of the catalyst in Example 1 was tested under anaerobic conditions at a reaction temperature of 80°C.

[0034] Figure 9 A schematic diagram showing the results of CO2 temperature-programmed desorption of the catalysts prepared in Examples 1 and 2. Detailed Implementation

[0035] 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.

[0036] Example 1: In-situ synthesis of nitrogen-doped Al2O3 catalyst

[0037] First, 0.05 mol (18.75 g) of Al(NO3)3·9H2O and 0.05 mol of hexamethylenetetramine were dissolved in 100 ml of deionized water and stirred until homogeneous. Then, the pH was adjusted to 8-10 with 1 mol / L NH3·H2O (approximately 250 ml) to ensure complete precipitation. The resulting mixture was stirred at 65 °C for 2 h, then aged at the same temperature for 12 h, and dried at 105 °C for 10 h. The dried powder was calcined at 550 °C for 3 h at a heating rate of 5 °C / min to obtain a nitrogen-doped Al2O3 catalyst, denoted as N-Al2O3(Y).

[0038] Example 2: One-step preparation of Al2O3 catalyst via coprecipitation

[0039] First, 0.05 mol (18.75 g) of Al(NO3)3·9H2O was dissolved in 100 ml of deionized water and stirred until homogeneous. Then, the pH was adjusted to 8-10 with approximately 250 ml of 1 mol / L NH3·H2O to ensure complete precipitation. The resulting mixture was stirred at 65 °C for 2 h, then aged at the same temperature for 12 h, and dried at 105 °C for 10 h. The dried powder was calcined at 550 °C for 3 h at a heating rate of 5 °C / min to obtain the Al2O3 catalyst.

[0040] Of the three catalysts mentioned above, Example 2 is a catalyst prepared using a commonly used alumina support. γ-Al2O3 has the characteristics of large specific surface area, high surface activity, and strong thermal stability. It also has certain hydrolytic activity, but its resistance to sulfate is poor, and it is easily poisoned and deactivated. The hydrolytic stability of the catalyst is limited. Generally, γ-Al2O3 can be modified by loading alkaline sites or active components onto the surface of the support to improve its hydrolytic performance.

[0041] In existing technologies, two types of N-doped catalysts have been mentioned in the literature: one is a MgAl N-doped catalyst (published in ELSEVIER in 2021: Boosting carbonyl sulfide catalytic hydrolysis performance over N-doped Mg-Al oxide derived from MgAl-layered double hydroxide), and the other is a KAl N-doped catalyst (published in ELSEVIER in 2023: Advantageous Role of N-doping on K@Alin COS / CS2 Hydrolysis: Diminished Oxygen Mobility and Rich basic Both types of doped catalysts are prepared by long-term high-temperature calcination of precursors in an ammonia atmosphere, which is costly and difficult to mass-produce industrially. In addition, the precursors of both catalysts are inexpensive γ-Al2O3 as a support. On this basis, alkali metals are further used to enhance the basic sites on the surface of the alumina support, thereby improving the catalyst activity. Because for alumina-based catalysts, the doping of non-metallic elements cannot generate enough basic active sites, the two existing catalysts are prepared by using alkali metals to increase the basic sites on the surface of the alumina support to obtain the precursor, and then calcining it at high temperature in an ammonia atmosphere to obtain nitrogen-doped M@Al catalysts (M represents metals such as K and Mg).

[0042] Based on existing technology, the catalyst prepared by the treatment method in Example 3 involves introducing N atoms into the prepared catalyst precursor. However, the nitrogen doping in the catalyst prepared by this method is uneven, and the catalyst reproducibility is poor.

[0043] In the in-situ synthesis method of Example 1, hexamethylenetetramine, a compound with a high nitrogen content, is used as one of the precursors. During synthesis, nitrogen atoms are directly introduced into the γ-Al₂O₃ support material. Hexamethylenetetramine is alkaline, which allows for better precipitation of aluminum nitrate during preparation. Elemental analysis of the catalyst in Example 1 using EA showed that the Ni-Al in the catalyst contained 0.335% nitrogen.

[0044] The microstructure of the nitrogen-doped Al2O3 catalyst N-Al2O3(Y) prepared in Example 1, the Al2O3 catalyst prepared in Example 2, and a commercial Al2O3 catalyst were examined together, and the results are shown in Table 1.

[0045] Table 1. Microscopic characteristics of commercial Al2O3 catalysts, Al2O3 catalysts prepared in Example 2, and nitrogen-doped Al2O3 catalysts prepared in Example 1.

[0046]

[0047] As shown in Table 1, the catalyst prepared in Example 1, compared to the existing catalyst (Example 2), exhibited increased specific surface area, total pore volume, and average pore size after doping with pyridine nitrogen. Figure 1 As shown, the N-Al2O3(Y) catalyst prepared in Example 1 has radial macropores and is shifted towards mesopores, with more mesoporous structures. This is more conducive to the desorption of H2S gas, thereby reducing sulfur deposition.

[0048] Example 3 tested the effect of different reaction temperatures on the COS and H2S conversion rates of various catalysts.

[0049] The N-Al(Y) catalyst prepared in Example 1 and the γ-Al₂O₃ catalyst prepared in Example 2 were respectively loaded into a fixed-bed quartz glass tube reactor. The gas composition introduced was COS, N₂, and H₂O, with N₂ mainly serving as an inert atmosphere. The reaction conditions were controlled as follows: COS concentration: 400 ppm, space velocity ratio: 60000 h⁻¹. -1 Water vapor concentration: 4.8%, catalyst loading: 200 mg, oxygen concentration: 0%, results as follows: Figure 7As shown, with increasing temperature, the COS and H2S conversion rates of the N-Al(Y) catalyst prepared in Example 1 continuously increased. The conversion rates of both reached their optimal values ​​at 80°C, and remained relatively stable above 80°C. Furthermore, under the reaction conditions of this example, the N-Al(Y) catalyst prepared in Example 1 continuously treated COS-containing gas for 20 hours without decreasing the COS and H2S conversion rates.

[0050] Example 4: Testing the effect of different space velocity ratios on the COS and H2S conversion rates of various catalysts.

[0051] The N-Al(Y) catalyst prepared in Example 1 was loaded into a fixed-bed quartz glass tube reactor. The introduced gas consisted of COS, N2, and H2O, with N2 primarily serving as an inert atmosphere. To facilitate rapid measurement of experimental results, the COS and H2S conversion rates of the N-Al(Y) catalyst were artificially reduced. The reaction conditions were controlled as follows: reaction temperature: 60℃, COS concentration: 400 ppm, water vapor concentration: 4.8%, oxygen concentration: 0%. Different feed space velocity ratios were selected, with a space velocity ratio of 24000 h⁻¹. -1 At that time, the catalyst loading was 500 mg; the space velocity ratio was 60000 h⁻¹. -1 At that time, the catalyst loading was 200 mg; the space velocity ratio was 34000 h⁻¹. -1 At that time, the catalyst loading was 500mg, and the results were as follows: Figure 6 As shown, at an airspeed ratio of 24000h -1 At a given time, the COS conversion of the N-Al(Y) catalyst is optimal, approaching 100%, which is significantly higher than that at a space velocity ratio of 60,000 h⁻¹. -1 Conversion rate.

[0052] Example 5: Testing the COS and H2S conversion rates of nitrogen-doped Al2O3 catalysts with different N-doping amounts

[0053] Following the preparation method in Example 1, different nitrogen-doped Al2O3 catalysts with varying amounts of nitrogen were prepared by setting the molar ratio of hexamethylenetetramine to Al(NO3)3·9H2O to 0.5:1, 1.5:1, and 2:1.

[0054] The nitrogen-doped Al₂O₃ catalysts with different nitrogen doping amounts were loaded into fixed-bed quartz glass tube reactors. The introduced gas consisted of COS, N₂, and H₂O, with N₂ serving primarily as an inert atmosphere. To facilitate rapid measurement of experimental results, the COS and H₂S conversion rates of the N-Al(Y) catalysts were artificially reduced. The reaction conditions were controlled as follows: reaction temperature: 60℃, COS concentration: 400 ppm, and space velocity ratio: 60000 h⁻¹. -1 Water vapor concentration: 4.8%, oxygen concentration: 0%, catalyst loading: 200mg, results as follows Figure 5As shown, when preparing N-Al(Y) catalyst, the optimal COS conversion and H2S conversion are achieved when the molar ratio of hexamethylenetetramine to Al(NO3)3·9H2O is 1:1, reaching 86% and 78%, respectively.

[0055] Meanwhile, the catalyst of Example 1, prepared with a molar ratio of hexamethylenetetramine to Al(NO3)3·9H2O of 1:1, showed optimal reaction temperature of 80°C and optimal space velocity of 24000 h⁻¹. -1 The catalyst loading was 500 mg. Simulating industrial conditions, the COS concentration was 400 ppm, the water vapor concentration was 4.8%, and the oxygen concentration was 0%. The test examined the catalyst's ability to achieve COS and H2S conversion rates under these conditions, as well as the time it could maintain its activity. Figure 8 As shown, the catalyst prepared in Example 1 can maintain a high conversion rate of 100% for COS and H2S for a long time (more than 22 hours).

[0056] Example 6: Testing the COS and H2S conversion rates of the catalyst under anaerobic conditions.

[0057] The N-Al(Y) catalyst prepared in Example 1, the γ-Al₂O₃ catalyst in Example 2, and the commercial γ-Al₂O₃ catalyst were respectively loaded into a fixed-bed quartz glass tube reactor. The introduced gas consisted of COS, N₂, and H₂O, with N₂ mainly serving as an inert atmosphere. The reaction conditions were controlled as follows: COS concentration of 400 ppm and space velocity ratio of 24000 h⁻¹. -1 The COS conversion rate was tested at reaction temperatures of 40℃ and 60℃ with a water vapor concentration of 4.8%, a catalyst loading of 500 mg, and an oxygen concentration of 0%. The results are shown in Table 2. The effect of increasing the catalyst loading on COS conversion at lower reaction temperatures was also investigated. Table 2 shows that the N-Al(Y) catalyst prepared in Example 1 achieved the optimal COS conversion effect at 60℃ after increasing the loading amount.

[0058] The measurement results are calculated based on the measured COS inlet and outlet concentrations and H2S outlet concentration.

[0059] COS conversion rate is calculated using the following formula:

[0060]

[0061] H2S selectivity is calculated using the following formula:

[0062]

[0063] Table 2. COS conversion results under anaerobic conditions, at different temperatures, and with different catalysts.

[0064]

[0065] Example 7: Testing the COS and H2S conversion rates of the catalyst under aerobic conditions.

[0066] The N-Al(Y) catalyst prepared in Example 1 and the γ-Al2O3 catalyst prepared in Example 2 were respectively loaded into a fixed-bed quartz glass tube reactor. The gas composition introduced was COS plus N2 and H2O, with N2 mainly serving as an inert atmosphere. The reaction conditions were controlled as follows: COS concentration of 400 ppm and space velocity ratio of 60000 h⁻¹. -1 With a water vapor concentration of 4.8% and a catalyst loading of 200 mg, the COS and H2S conversion rates of the catalyst were tested at an oxygen concentration of 4% and reaction temperatures of 60℃ and 70℃. When the catalyst loading was 200 mg, the reaction conditions were more stringent, requiring an increase in the gas hourly space velocity (GHSV) to 60000 h⁻¹. -1 The conversion efficiency of COS was tested at lower temperatures (60℃ and 70℃). The results are shown in Table 3 and... Figure 4 (Reaction temperature is 70℃) Figure 5 (The reaction temperature is 60℃).

[0067] Table 3. Results of COS and H2S conversion rates under aerobic conditions, at different temperatures, and with different catalysts.

[0068]

[0069] In the preparation of the catalyst in Example 1, hexamethylenetetramine was added to the aluminum nitrate precursor solution. When incorporated as a nitrogen source, the nitrogen atoms of hexamethylenetetramine can coordinate with aluminum atoms. This coordination enhances the interaction between the nitrogen atoms and the precursor of the alumina support. Furthermore, the molecular structure of hexamethylenetetramine contains six carbon atoms and four nitrogen atoms, with the four nitrogen atoms located in a tetrahedral structure formed by the six carbon atoms. This molecular structure allows it to provide nitrogen while forming a certain spatial structure in the γ-alumina catalyst, which can further increase the pore size of the precursor structure and improve the stability and activity of the catalyst.

[0070] In further high-temperature calcination, hexamethylenetetramine decomposes at high temperatures, and the resulting nitrogen atoms can react with hydroxyl groups on the surface of γ-alumina to generate decomposition products containing pyridine N. This increases the number of basic sites (including moderately and weakly basic sites) in the catalyst, such as... Figure 9The interaction between CO2 and the catalysts of Examples 1 and 2 was investigated using CO2 temperature-programmed desorption (CO2-TPD) to determine the desorption temperature of CO2 and the number of weak, medium, and strong base sites. Before CO2 adsorption, the samples were pretreated in pure N2 at 500°C for 30 min to analyze surface properties similar to the reaction conditions. Figure 9 As shown in the literature, the peaks at low temperatures (100-200℃) belong to weakly basic sites, attributed to the formation of bicarbonates containing unsaturated hydroxyl groups on the surface. The peaks at medium temperatures (200-400℃) are moderately basic sites, and the peaks at high temperatures (400-600℃) are highly basic sites. The results indicate that, as expected, N doping significantly improves basicity; N doping on Al significantly increases the number of moderately and weakly basic sites while reducing the number of highly basic sites.

[0071] Weakly basic and moderately basic centers promote the COS hydrolysis reaction, enhancing its activity. Strongly basic centers promote H2S oxidation and deposition, thus simultaneously increasing COS hydrolysis activity and reducing H2S deposition. On the other hand, nitrogen atoms occupy oxygen vacancies on the Al2O3 surface, forming stable nitrogen-oxygen bonds to create intermediates, which also reduces H2S adsorption and results in a higher H2S yield. Furthermore, the strong interaction between nitrogen atoms and Al promotes the migration of surface active oxygen density to surface lattice oxygen, converting more surface oxygen into lattice oxygen and reducing H2S adsorption on the catalyst surface, thereby increasing H2S yield and reducing sulfur formation, which also contributes to improved catalytic performance. At high temperatures, nitrogen atoms produced by the decomposition of hexamethylenetetramine can further polymerize to form nitrogen species. These nitrogen species can combine with the surface of γ-alumina to form polymeric nitrogen species with a specific spatial structure. These polymeric nitrogen species can serve as active components in γ-alumina catalysts, improving catalyst activity and selectivity.

[0072] Therefore, based on Examples 6 and 7, the N-Al(Y) catalyst prepared in Example 1 exhibits high COS conversion and H2S conversion rates, reaching 90% and 98% respectively, regardless of whether it is under a general industrial gas atmosphere or under a more severe gas atmosphere. Moreover, the hydrolysis reaction temperature of COS is controlled at around 70°C, resulting in relatively low energy consumption. At the same time, the catalyst maintains long-term stability, meaning that the COS conversion and H2S conversion rates remain stable within 24 hours.

Claims

1. A method for preparing a nitrogen-doped catalyst for removing organic sulfur from metallurgical coal gas, comprising the following preparation steps, (1) mixing a soluble aluminum salt and an organic nitrogen compound in deionized water in a certain proportion to obtain a precursor mixed solution; (2) adjusting the pH value of the precursor mixed solution to alkaline to precipitate, and then aging and drying the separated precipitate to obtain a mixture powder; (3) calcining the dried mixture powder at high temperature to obtain a target product, a nitrogen-doped Al2O3 catalyst. In the step (1), the soluble aluminum salt is any one of aluminum nitrate and aluminum chloride, the organic nitrogen compound is an amine compound, and the molar ratio of the soluble aluminum salt to the organic nitrogen compound is 2:1-4; the amine compound includes hexamethylenetetramine and melamine.

2. The production method according to claim 1, characterized by, The step (2) specifically comprises adjusting the pH of the precursor mixed solution to 8-10 with an NH3·H2O solution, stirring at 65°C for 2 h, then aging at the same temperature for 12 h, and finally drying at 105°C for 10 h to obtain the mixture powder.

3. The production method according to claim 2, characterized by, The high-temperature calcination condition of the step (3) is calcination at 550°C for 3 h with a temperature rising rate of 5°C / min.

4. A nitrogen-doped catalyst for the removal of organic sulfur from metallurgical gas, prepared according to the process of any one of claims 1 to 3, characterized in that, The catalyst is a γ-Al2O3-based hydrolysis catalyst containing an active component, the active component includes pyridine N and polymerized nitrogen, and the active component is obtained by precipitating a mixed solution of an active component precursor and a soluble aluminum salt in an alkaline environment and then calcining at high temperature, the active component precursor is an organic nitrogen compound, and the molar ratio of the soluble aluminum salt to the active component precursor is 2:1-4.

5. The nitrogen-doped catalyst for the removal of organic sulfur from metallurgical gas according to claim 4, characterized in that, The soluble aluminum salt includes any one or a combination of the two of aluminum nitrate and aluminum chloride.

6. The nitrogen-doped catalyst for the removal of organic sulfur from metallurgical gas according to claim 4, characterized in that, The organic nitrogen compound is any one of hexamethylenetetramine and melamine.

7. The nitrogen-doped catalyst for the removal of organic sulfur from metallurgical gas according to claim 4, characterized in that, The nitrogen atoms in the organic nitrogen compound are combined with aluminum atoms in the catalyst in the form of pyridine N or in the form of polymerized nitrogen to form a macroporous, mesoporous or microporous structure with uniform nitrogen source distribution.

8. Use of a catalyst as claimed in claim 4 for the removal of organic sulphur from metallurgical coal gas, characterised in that, The catalyst has a catalytic activity retention time of not less than 22 hours in a low-temperature environment, and a conversion rate of COS and hydrogen sulfide of not less than 90%.

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