Hydrodesulfurization, deoxidation and hydrogen cyanide removal multifunctional purification catalyst applicable to ultra-low emission and comprehensive use of industrial tail gas and use thereof

Abstract

A hydrodesulfurization, deoxidation and hydrogen cyanide removal multifunctional purification catalyst applicable to ultra-low emission and comprehensive use of industrial tail gas, and the use thereof. Said catalyst uses activated carbon as a support, and is loaded with copper sulfate and titanium sulfate, the mass percentage of copper sulfate relative to the mass of the support being 5-15%, and the mass percentage of titanium sulfate relative to the mass of the support being 3-12%. Said catalyst is applicable to multifunctional purification of COS, CS2 and SO2 in low-hydrogen high-oxygen industrial tail gas such as blast furnace gas, carbon black tail gas and calcium carbide tail gas via hydrogenation conversion, deoxidization and hydrogen cyanide removal, solves the problem that traditional alumina-based cobalt-molybdenum, nickel-molybdenum or iron-molybdenum catalysts are prone to deactivation and have poor hydrogenation activity in said atmospheres, and exhibits low side reactions of carbon monoxide shift, thus facilitating source treatment and ultra-low emission of the described industrial tail gas while facilitating comprehensive use of subsequently recovered CO and hydrogen.

Description

Multifunctional purification catalyst for hydrodesulfurization, deoxygenation and decyanation suitable for ultra-low emission comprehensive utilization of industrial tail gas and its application Technical Field

[0001] The present invention belongs to the field of industrial tail gas purification, relates to the field of ultra-low emission and comprehensive utilization of industrial tail gas, and specifically relates to a multifunctional purification catalyst for hydrodesulfurization, deoxygenation and decyanation of industrial tail gas and its application. Background Art

[0002] Industrial exhaust gases such as calcium carbide exhaust, carbon black exhaust, and blast furnace gas usually contain major gas components such as CO, CO2, H2, CH4, and N2. They also contain a certain amount of sulfides such as COS, H2S, SO2, and poisons and pollutants such as hydrocyanic acid, and generally contain 0.1-1% O2. These exhaust gases need to be treated for toxic pollutants such as sulfides and cyanides when they are processed, utilized, or discharged. The difficulty in treating sulfides is the conversion and removal of organic sulfur.

[0003] The hydroconversion and removal of organic sulfur is a mature catalytic technology, usually using alumina-based cobalt-molybdenum, nickel-molybdenum or iron-molybdenum catalysts. However, these catalysts require a relatively low oxygen content in the gas source (generally 0.1-0.3%), a relatively high hydrogen content (generally a hydrogen-oxygen ratio of at least greater than 10), and a relatively low CO content. Traditional molybdenum-based catalysts including cobalt-molybdenum, nickel-molybdenum, and iron-molybdenum are generally suitable for gas sources with a CO content below 8% and an olefin content below 5%.

[0004] Huashuo Technology Co., Ltd. has obtained a Chinese invention patent ZL 2011102501788, which discloses a multifunctional raw gas purifier and its preparation and application methods. The multifunctional purifier is characterized by using alumina as a carrier to load ammonium molybdate and one or two of copper, zinc, lead, nickel, and vanadium, and also load one of magnesium chloride, potassium carbonate, and sodium carbonate. The multifunctional purifier is suitable for purifying impurities such as COS, CS2, HCN, SO2, SO3, and O2 from water gas, semi-water gas, coke oven gas, or IGCC power generation fuel gas raw gas. The conversion rates of COS, CS2, HCN, SO2, and SO3 are all ≥90%, and the O2 removal rate is ≥95%.

[0005] Industrial tail gas, due to its diverse sources, typically has a unique gas composition, characterized by low hydrogen and high oxygen. For example, calcium carbide tail gas typically contains CO~60%, H2~10%, and O2~1%; blast furnace gas contains CO~25%, H2~3%, and O2~0.5%; and carbon black tail gas contains CO~10%, H2~14%, and O2~0.4%. These tail gases also typically contain certain amounts of COS and CS2, and some also contain SO2 and HCN. To achieve standard emissions or comprehensive utilization of these tail gases, in addition to traditional post-combustion SO2 removal, organic sulfur and HCN removal must also be considered. Furthermore, for traditional cobalt-molybdenum, nickel-molybdenum, or iron-molybdenum catalysts used for organic sulfur hydroconversion, the presence of a certain amount of O2 in the gas source can easily cause catalyst deactivation due to sulfation, posing challenges to the hydrogenation catalyst. Furthermore, the organic sulfur conversion reaction of these catalysts is often accompanied by a significant carbon monoxide shift side reaction, which can adversely affect carbon reduction and pollution reduction and comprehensive utilization of some industrial tail gases.

[0006] Summary of the Invention

[0007] The purpose of the present invention is to address the deficiencies in the existing technology and provide a multifunctional purification catalyst for hydrodesulfurization, deoxygenation and decyanation suitable for ultra-low emission comprehensive utilization of industrial tail gas and its application, so as to solve the technical problems of COS, CS2, SO2 hydrogenation conversion and deoxygenation and decyanation of low-hydrogen and high-oxygen industrial tail gas such as calcium carbide tail gas, carbon black tail gas and blast furnace gas, and overcome the problems that traditional alumina-based cobalt-molybdenum, nickel-molybdenum or iron-molybdenum catalysts are easily deactivated by sulfation and have poor hydrogenation activity and high CO side reaction in the low-hydrogen and high-oxygen industrial tail gas atmosphere.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] The invention discloses a multifunctional purification catalyst for hydrodesulfurization, deoxygenation and decyanation suitable for ultra-low emission comprehensive utilization of industrial tail gas. The catalyst uses activated carbon as a carrier and is loaded with copper sulfate and titanium sulfate. The copper sulfate accounts for 5 to 15% of the carrier mass, and the titanium sulfate accounts for 3 to 12% of the carrier mass.

[0010] According to the above scheme, the applicable temperature of the multifunctional purification catalyst is 280-340°C. In low-hydrogen, high-oxygen industrial tail gases such as calcium carbide tail gas, carbon black tail gas, and blast furnace gas, directly heating the temperature to 280-340°C can achieve the hydrogenation conversion of COS, CS2, and SO2, with COS and CS2 conversion rates exceeding 85%, SO2 conversion rate exceeding 95%, deoxygenation rate exceeding 95%, and HCN conversion rate exceeding 90%. In addition, the H2 increase caused by the CO shift side reaction is less than 0.2%.

[0011] According to the above scheme, the multifunctional purification catalyst can be used for industrial tail gas hydrodesulfurization, deoxygenation and decyanation, and can be specifically used for industrial tail gas purification, and is suitable for COS, CS2, SO2 hydrogenation conversion and deoxygenation, decyanation and decyanation of industrial tail gas.

[0012] According to the above scheme, the industrial tail gas is one or a combination of calcium carbide tail gas, carbon black tail gas, and blast furnace gas.

[0013] According to the above scheme, the industrial tail gas is low-hydrogen and high-oxygen industrial tail gas, with an oxygen content of >0.3% and a hydrogen-oxygen ratio of less than 10.

[0014] According to the above scheme, the multifunctional purification catalyst can purify industrial tail gas with relatively high CO content, such as industrial tail gas with CO content higher than 8%.

[0015] According to the above scheme, the specific surface area of ​​the activated carbon carrier is 800 to 1200 m 2 / g, iodine adsorption value 800~1000mg / g.

[0016] A second aspect of the present invention provides a method for preparing the multifunctional purification catalyst. The method comprises impregnating an activated carbon support with an aqueous solution of copper sulfate and titanium sulfate, and drying the loaded catalyst to obtain the catalyst. The drying temperature can be selected from 100 to 160 degrees Celsius.

[0017] According to the above scheme, the equal amount impregnation method is adopted in the preparation process, and the support is impregnated with equal amounts of copper sulfate and titanium sulfate.

[0018] According to the above scheme, during the preparation of the aqueous solution of copper sulfate and titanium sulfate, a small amount of co-solvent such as dilute sulfuric acid can be added to assist dissolution according to the dissolution requirements to prepare the copper sulfate and titanium sulfate solutions.

[0019] The third aspect of the present invention provides the use of a multifunctional hydrodesulfurization, deoxygenation and decyanation purification catalyst in the hydrodesulfurization, deoxygenation and decyanation of industrial tail gas.

[0020] According to the above scheme, the industrial tail gas is an atmosphere containing reducing gases CO and H2, including but not limited to one or more of calcium carbide tail gas, carbon black tail gas, and blast furnace gas.

[0021] According to the above scheme, the industrial tail gas is low-hydrogen and high-oxygen industrial tail gas, with an oxygen content of >0.3% and a hydrogen-oxygen ratio of less than 10.

[0022] According to the above scheme, the CO content in the industrial tail gas is higher than 8%. The multifunctional hydrodesulfurization, deoxygenation, and decyanation catalyst of the present invention is suitable for the multifunctional purification of industrial tail gas with relatively high CO content, such as higher than 8%. According to the above scheme, the multifunctional purification temperature is 280-340°C. It can achieve the hydroconversion of COS, CS2, and SO2, with COS and CS2 conversion rates exceeding 85%, SO2 conversion rate exceeding 95%, deoxygenation rate exceeding 95%, and HCN conversion rate exceeding 90%. Furthermore, the H2 increase caused by the CO shift side reaction is less than 0.2%.

[0023] Calculations based on polycrystal electron diffraction analysis data before and after use of the catalyst, along with comparisons to a database, indicate that the catalyst's crystal structure after use differs from typical sulfate, oxide, or sulfide forms, likely adopting a face-centered cubic structure. This structure exhibits strong sulfur tolerance, excellent hydrogenation activity, and minimal CO shift side reactions. It is speculated that the catalyst, using copper sulfate and titanium sulfate as active components, forms a solid solution of sulfide, oxide, and sulfate in an atmosphere of reducing gases (CO and H₂) at 280-340°C.

[0024] The multifunctional catalyst of the present invention is a composite catalyst system of copper sulfate and titanium sulfate supported by activated carbon, which is resistant to sulfation and does not require roasting or sulfurization before use.

[0025] The application of the multifunctional purification catalyst of the present invention is not only beneficial to the ultra-low emission source control of industrial tail gas, but also beneficial to the subsequent comprehensive utilization of CO and hydrogen extraction.

[0026] The beneficial effects of the present invention are:

[0027] The composite catalytic system of activated carbon loaded with copper sulfate and titanium sulfate adopts activated carbon as a carrier and copper sulfate and titanium sulfate as active components, thus avoiding the problem of sulfation deactivation of the alumina carrier and active components such as Mo / Ni / Co, having excellent catalytic activity, and requiring no sulfurization before use. In the active temperature range of 280 to 340° C., the system is used in low-hydrogen and high-oxygen industrial tail gases such as calcium carbide tail gas, carbon black tail gas, and blast furnace gas, and exhibits excellent COS, CS2, and SO2 hydrogenation conversion performance, deoxidation, and HCN conversion capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is an X-ray photoelectron spectrum of the catalyst prepared in Example 10;

[0029] FIG2 is a scanning electron microscope image of the catalyst sample prepared in Example 10;

[0030] FIG3 is a polycrystalline electron diffraction pattern of the catalyst prepared in Example 10 after use. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is described in detail below through specific embodiments, but the protection scope of the present invention is not limited to the embodiments.

[0032] Example 1: Take a specific surface area of ​​1000m 2 / g, iodine adsorption value of 850mg / g of coal-based activated carbon 100g, 18.75g of copper sulfate pentahydrate and 12g of titanium sulfate were dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading, and the catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 1.

[0033] Example 2: Take a specific surface area of ​​1000m 2 / g, iodine adsorption value of 850mg / g of coal-based activated carbon 100g, 18.75g of copper sulfate pentahydrate and 3g of titanium sulfate were dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading, and the catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 2.

[0034] Example 3: Take a specific surface area of ​​1100m 2 / g, iodine adsorption value of 900mg / g of coal-based activated carbon 100g, 18.75g of copper sulfate pentahydrate and 8g of titanium sulfate were dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading. The catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 3.

[0035] Example 4: Take a specific surface area of ​​1200m 2 / g, iodine adsorption value of 950mg / g of coal-based activated carbon 100g, 7.8g of copper sulfate pentahydrate and 12g of titanium sulfate were dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading, and the catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 4.

[0036] Example 5: Take a specific surface area of ​​900m 2 / g, iodine adsorption value of 900mg / g of coal-based activated carbon 100g, 15.6g of copper sulfate pentahydrate and 10g of titanium sulfate were dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading, and the catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 5.

[0037] Example 6: Take a specific surface area of ​​1200m 2 / g, iodine adsorption value of 1000mg / g of coal-based activated carbon 100g, 12.5g of copper sulfate pentahydrate and 7.5g of titanium sulfate were dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading, and the catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 6.

[0038] Example 7: Take a specific surface area of ​​1100m 2 / g, iodine adsorption value of 950mg / g of coal-based activated carbon 100g, 7.8g of copper sulfate pentahydrate and 3g of titanium sulfate were dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading, and the catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 7.

[0039] Example 8: Take a specific surface area of ​​1000m 2 / g, iodine adsorption value of 900mg / g of coal-based activated carbon 100g, 23.4g of copper sulfate pentahydrate and 12g of titanium sulfate were dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading, and the catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 8.

[0040] Example 9: Take a specific surface area of ​​900m 2 / g, iodine adsorption value of 800mg / g of coal-based activated carbon 100g, 15.6g of copper sulfate pentahydrate and 5g of titanium sulfate were dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading, and the catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 9.

[0041] Example 10: Take a specific surface area of ​​1000m 2 / g, iodine adsorption value of 850mg / g of coal-based activated carbon 100g, 15.6g of copper sulfate pentahydrate and 8g of titanium sulfate were dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading, and the catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 10.

[0042] Comparative Example 1: Take a specific surface area of ​​1000m 2 / g, iodine adsorption value of 850mg / g of coal-based activated carbon 100g, 15.6g of copper sulfate pentahydrate was dissolved in 65g of water, and a small amount of dilute sulfuric acid was added to assist dissolution. The prepared solution was poured onto the activated carbon carrier for impregnation loading, and the catalyst was continuously turned over and left for 4h, and then the catalyst was dried at 120℃ for 2h to obtain sample 11.

[0043] Comparative Example 2: Pure copper sulfate pentahydrate

[0044] When used, pure copper sulfate pentahydrate (sample 12) was directly used as the catalyst and filled with 30 mL.

[0045] The X-ray photoelectron spectrum of the catalyst of the present invention is shown in FIG1 , and the scanning electron microscope image of the catalyst is shown in FIG2 ;

[0046] The electron diffraction pattern of the catalyst polycrystal is shown in Figure 3.

[0047] The samples obtained in Examples 1-10 and Comparative Examples 1-2 were evaluated for activity using the following method:

[0048] Gas source: CO 30% + O2 0.5% + H2 2% + H2S 100ppm + COS 1000ppm + CS2 100ppm + 30ppm SO2, remaining N2, 30℃ saturated water vapor; catalyst loading 30mL, space velocity 3000h -1 , pressure 0.1MPa, reaction temperature 300℃. The activity test results of the above catalyst samples are as follows:

[0049] In addition, due to the strong toxicity of HCN, the laboratory was unable to simulate it, so the above typical samples were directly tested on an industrial device for trial operation. Under the conditions of inlet HCN 100-200ppm and outlet HCN 1-10ppm, the HCN conversion rate was >90%.

[0050] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A multifunctional purification catalyst for hydrodesulfurization, deoxygenation and decyanation suitable for comprehensive utilization of ultra-low emission of industrial tail gas, characterized by: The activated carbon is used as a carrier and loaded with copper sulfate and titanium sulfate, wherein the mass percentage of the copper sulfate to the carrier is 5-15%, and the mass percentage of the titanium sulfate to the carrier is 3-12%.

2. The multifunctional purification catalyst according to claim 1, characterized in that: The specific surface area of ​​the activated carbon carrier is 800 to 1200 m 2 / g, iodine adsorption value 800~1000mg / g.

3. The method for preparing the multifunctional purification catalyst according to claim 1, characterized in that: The copper sulfate and titanium sulfate aqueous solution is impregnated and loaded on an activated carbon carrier, and the catalyst loaded with active components is dried to obtain a catalyst.

4. The preparation method according to claim 3, wherein: The equal amount impregnation method is adopted in the preparation process, and the carrier is impregnated with equal amounts of copper sulfate and titanium sulfate.

5. Use of the multifunctional purification catalyst according to claim 1 in the hydrodesulfurization, deoxygenation and decyanation of industrial tail gas.

6. The use according to claim 5, characterized in that: The industrial tail gas is an atmosphere containing reducing gases CO and H2; the industrial tail gas is selected from one or a combination of calcium carbide tail gas, carbon black tail gas, and blast furnace gas.

7. The use according to claim 5, characterized in that: It is used for the multifunctional purification of COS, CS2, SO2 hydrogenation conversion, deoxygenation and decyanation of industrial tail gas. The COS and CS2 conversion rates are greater than 85%, the SO2 conversion rate is greater than 95%, the deoxygenation rate is greater than 95%, the HCN conversion rate is greater than 90%, and the H2 increase caused by the CO conversion side reaction is less than 0.2%.

8. The use according to claim 5, characterized in that: The industrial tail gas is low-hydrogen and high-oxygen industrial tail gas, with an oxygen content of more than 0.3% and a hydrogen-oxygen ratio of less than 10.

9. The use according to claim 5, characterized in that: The CO content in industrial exhaust gas is higher than 8%.

10. The use according to claim 5, characterized in that: The multifunctional purification temperature is 280~340℃.

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