A catalyst for removing organic sulfur from coal gas and a method for preparing and using the same

Abstract

This invention discloses a catalyst for removing organic sulfur from coal gas, and its preparation and application methods. The catalyst is composed of a composite support, a COS catalytic hydrolysis active component, and an H2S catalytic oxidation active component, with a mass ratio of 100:2-6:4. The composite support is C pp -ZrO2 porous material: The active component for COS catalytic hydrolysis is NaOH doped into the composite support lattice; the active component for H2S catalytic oxidation is manganese hydroxide. The preparation steps include the synthesis of soft template agent modified UiO-66 (Zr), and high-temperature carbonization to prepare C. pp The catalyst is supported by ZrO2, with lattice-doped NaOH and manganese hydroxyl oxide. All catalyst application processes are carried out in the liquid phase, preventing reaction products from clogging the catalyst pores. The absorbent is a diphenylamine-sulfolane composite reagent; the combined use of physical and chemical absorption accelerates the mass transfer process. Diphenylamine also acts as an antioxidant, improving the stability and lifespan of the composite absorbent.

Description

Technical Field

[0001] This invention belongs to the field of organic sulfur treatment technology, specifically relating to a catalyst for removing organic sulfur from coal gas and its preparation and application methods. Background Technology

[0002] Coal gas is a common gaseous fuel processed from coal. It contains various combustible components such as CO, hydrogen, and hydrocarbons. The national standard stipulates that the sulfur content of standard coal is 1%, while the sulfur content of high-sulfur coal exceeds 3%. Sulfur exists in coal in various forms, so solid sulfur and gaseous sulfur are produced during coal gasification. Solid sulfur is mainly sulfate dust, while gaseous sulfur includes various inorganic and organic sulfur compounds such as sulfur dioxide, hydrogen sulfide, carbonyl sulfide (COS), and carbon disulfide (CS2). These sulfides are either highly irritating and extremely toxic, harming the environment and human health, or flammable and explosive, threatening production and personal safety.

[0003] To control air pollution caused by sulfur emissions, coal gas products must undergo desulfurization to meet standards before they can be sold and used. Coal gas contains over 70% organic sulfur and less than 30% inorganic sulfur. Flue gas desulfurization typically employs a wet desulfurization process using alkaline spraying, which is effective at absorbing and removing hydrogen sulfide from the gas, but less efficient at absorbing some organic sulfur compounds such as carbonyl sulfide.

[0004] Based on the form of the desulfurizing agent, coal gas desulfurization methods can be divided into two main categories: wet and dry methods. Wet desulfurization uses liquid absorption to separate and remove sulfides, and based on the absorption force, it can be further divided into physical absorption, chemical absorption, and physicochemical absorption methods. Wet desulfurization technology is mature, but the equipment is large and the operating cost is high. Dry desulfurization uses solid adsorbents or catalysts to remove sulfides, such as the zinc oxide method, cobalt-molybdenum hydrogenation method, and molecular sieves. The above methods can only separate organic sulfur or convert it into more easily processed sulfides. Hydrolysis-oxidation coupling technology can oxidize the hydrolysis product H2S of COS to elemental sulfur, which has good application prospects. However, the preparation of coupling catalysts is still immature. Solid elemental sulfur is prone to clogging the pores of the catalyst, leading to deactivation. How can elemental sulfur be detached from the catalyst pores and surface without clogging the pores and causing a decrease in catalytic performance? Can elemental sulfur be recovered to generate economic benefits while removing COS and generating environmental benefits? Developing new organic sulfur hydrolysis oxidation catalysts and their application methods is the key to solving the above problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a catalyst for removing organic sulfur from coal gas, along with its preparation and application methods. This addresses issues such as the immaturity of current hydrolysis-oxidation coupled catalyst preparation, the susceptibility of solid sulfur to clogging and causing catalyst deactivation, and the waste of resources due to the inability to recover elemental sulfur.

[0006] To address the existing problems, the technical solution adopted by this invention is as follows: A catalyst for removing organic sulfur from coal gas, the catalyst comprising a composite support, a COS catalytic hydrolysis active component, and an H2S catalytic oxidation active component, wherein the mass ratio of the three components is 100:2-6:4, wherein the composite support is C pp -ZrO2 porous material: COS catalytic hydrolysis active component is NaOH doped into the composite support lattice; H2S catalytic oxidation active component is manganese hydroxyoxide.

[0007] Furthermore, the C pp - The pore size range of ZrO2 porous materials is 5-17 nm.

[0008] A method for preparing a catalyst for removing organic sulfur from coal gas includes the following steps: Step 1: Zirconium chloride, terephthalic acid, and a soft template agent were dissolved in a mixed solvent of N,N-dimethylformamide and chloroform. The solution was then transferred to a reaction vessel and sealed. The reaction was carried out at 130 °C for 24 h. After cooling, the product was washed 1-5 times with N,N-dimethylformamide and ethanol, respectively. The product was then dried under vacuum at 150 °C to obtain UiO-66 (Zr) modified with the soft template agent. Step 2: The UiO-66(Zr) obtained in Step 1 is subjected to high-temperature treatment at 600℃ for 6 hours to prepare C. pp -ZrO2 porous composite support, in which PTA and P123 provide carbon source and zirconium chloride provides zirconium source. Based on the three-dimensional porous framework of UiO-66, the template agent P123 and porous UiO-66 carbonize and decompose together to form a porous structure. Step 3: Dissolve a certain mass of NaOH in deionized water, then dissolve the C obtained in step 2. pp -ZrO2 porous composite support was dispersed in NaOH solution, magnetically stirred for 12 h, dried at 80 °C, and then calcined at 600 °C for 4 h to prepare NaOH-doped C2. pp -ZrO2; Step 4: Prepare a solution of manganese nitrate and sodium chlorate, and add lattice-doped NaOH C pp ZrO2 was stirred thoroughly and then transferred to a reaction vessel. The mixture was then heated to 150°C and reacted for 8 hours in a homogeneous reactor. The product was then centrifuged, washed, and dried at 120°C for 12 hours to obtain the final product, denoted as Na. x Mn OH / C pp -ZrO2, where x=2-6.

[0009] Furthermore, in step 1, the soft template agent is a triblock copolymer P123, and the mass ratio of zirconium chloride, terephthalic acid and the soft template agent is 2.8:2:1; the volume ratio of N,N-dimethylformamide and acetone mixed solvent is 4:1.

[0010] Furthermore, the pyrolysis furnace used in step 2 is a tubular furnace. Before high-temperature treatment, it needs to be purged with 99.999% high-purity nitrogen for 20 minutes, and then high-temperature treatment is carried out in an inert atmosphere of high-purity nitrogen.

[0011] Furthermore, in step 3, NaOH, deionized water, and C pp The mass ratio of ZrO2 support is 2-6:80:100.

[0012] Furthermore, in step 4, manganese nitrate, sodium chlorate, and lattice-doped NaOH are added to the C... pp The mass ratio of ZrO2 to the three components is 1:1.2:50.

[0013] A method for applying a catalyst for removing organic sulfur from coal gas involves dispersing the catalyst in an absorbent liquid of a liquid-phase reactor, introducing COS waste gas under magnetic stirring and heating, and then dissolving and absorbing the COS waste gas in the absorbent liquid. The COS then diffuses and adsorbs onto the catalyst surface and inside the pores. The COS catalytic process first involves the hydrolysis of the active component of the catalyst to generate H2S. The generated H2S is then oxidized by the active component of the catalyst to generate elemental sulfur and sulfate. The elemental sulfur and sulfate are separated from the catalyst surface and pores under stirring and fluid flushing, thereby achieving the removal of COS.

[0014] Furthermore, the hydrolysis and oxidation of organic sulfur by the catalyst are carried out in the liquid phase, which can avoid the reaction products clogging the catalyst pores; the air inlet of the liquid phase reactor is equipped with an aeration head to facilitate the contact between the waste gas and the absorbent; the absorbent is a diphenylamine-sulfolane compound reagent with a mass ratio of 1:8, in which diphenylamine is both a COS absorbent and an antioxidant, while sulfolane is a physical absorbent for COS and H2S, and the absorption reaction temperature is 60-90℃.

[0015] Compared with the prior art, the coal gas organic sulfur hydrolysis oxidation catalyst in this invention is made of C pp The composition consists of a ZrO2 porous composite support, a COS catalytic hydrolysis active component, and an H2S catalytic oxidation active component. A soft template agent is added during the preparation of UiO-66 (Zr), followed by high-temperature carbonization under an inert atmosphere to obtain C. pp -ZrO2 porous composite material can be used as a catalyst support for both organic sulfur hydrolysis and oxidation reactions; NaOH is doped into C as the active component for COS catalytic hydrolysis. ppThe ZrO2 lattice exhibits higher stability; the hydroxyl groups in manganese hydroxyl oxide (MnOOH), a component active in the catalytic oxidation of H2S, can chemically adsorb H2S to generate H2S. - It also promotes the generation of free radicals (O*) from O2, which further interact with HS. - Elemental sulfur (S) is generated, thus completing the hydrolysis and oxidation of organic sulfur. The treated S can detach from the catalyst pores and surface, preventing reaction products from clogging the catalyst pores; furthermore, it can be recycled, thus offering both environmental and economic benefits. Specifically, all reaction processes in this invention are carried out in the liquid phase, using a diphenylamine-sulfolane composite absorbent. The combined use of physical and chemical absorption accelerates the mass transfer process. Diphenylamine is also an antioxidant, improving the stability and lifespan of the composite absorbent. Attached Figure Description

[0016] Figure 1 The curves showing the change in COS absorption capacity of the absorbent over time at 60℃-90℃ are presented. Figure 2 The curves showing the COS removal rate of the catalysts prepared in Examples 1-3 of this invention at 60°C over time are shown. Figure 3 The curves showing the COS removal rate of the catalysts prepared in Example 2 and Comparative Examples 1-3 of this invention at 60°C as a function of time are shown. Figure 4 The curves showing the COS removal rate of the catalysts prepared in Example 2 and Comparative Examples 4-6 of this invention at 60°C as a function of time are shown. Figure 5 The curve showing the change in COS removal rate over time for the catalyst prepared in Example 2 of the invention at 60℃-90℃. Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Example 1

[0018] The catalyst was prepared and tested according to the following steps: (1) Zirconium chloride, terephthalic acid (PTA) and triblock copolymer P123 were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and chloroform in a mass ratio of 2.8:2:1 and a volume ratio of 4:1. The solution was then transferred to a reaction vessel and reacted at 130 °C for 24 h. After cooling, the product was washed three times with DMF and ethanol respectively and dried under vacuum at 150 °C to obtain white UiO-66 (Zr). (2) UiO-66 (Zr) was placed in a tube furnace and purged with high-purity nitrogen for 20 min. Then, it was heated to 600 °C for 6 h under this atmosphere to prepare C. pp -ZrO2 porous composite carrier; (3) Add NaOH, deionized water and C pp -ZrO2 porous composite carriers were mixed at a mass ratio of 2:80:100, magnetically stirred for 12 h, dried at 80 °C, and then calcined at 600 °C for 4 h to prepare lattice-doped NaOH C. pp -ZrO2 catalyst; (4) Prepare a solution of manganese nitrate and sodium chlorate, and add lattice-doped NaOH C pp The ZrO2 catalyst, with a mass ratio of 1:1.2:50, was stirred thoroughly and transferred to a reaction vessel. The mixture was then heated to 150℃ and reacted for 8 hours in a homogeneous reactor. The product was then centrifuged, washed, and dried at 120℃ for 12 hours to obtain C co-doped with manganese hydroxide (MnOOH) and NaOH. pp -ZrO2 bifunctional catalyst, labeled as Na2Mn OH / C pp -ZrO2, where Na2 represents the content of NaOH as 2wt%, which is the proportion of NaOH in the composite carrier C pp -Mass fraction of ZrO2, Mn OH Represents MnOOH; (5) The obtained Na2Mn OH / C pp The ZrO2 catalyst is dispersed in the absorbent of a liquid-phase reactor. The absorbent is a diphenylamine-sulfolane compound reagent with a mass ratio of 1:8. Under magnetic stirring and heating at 60-90℃, a certain concentration of COS waste gas is introduced through an aeration head. The concentrations of COS and H2S in the waste gas are detected at the gas inlet and outlet. After the COS waste gas is introduced, it is first dissolved and absorbed by the absorbent, and then diffuses and adsorbs onto the catalyst surface and inside the pores. COS is catalytically hydrolyzed to generate H2S, and the generated H2S is catalytically oxidized to generate elemental sulfur and sulfate. Under stirring and fluid flushing, the H2S is separated from the catalyst surface and pores. This test demonstrates the catalyst's hydrolytic oxidation performance for organic sulfur. Example 2

[0019] The catalyst was prepared and tested according to the following steps: (1) Zirconium chloride, terephthalic acid (PTA) and triblock copolymer P123 were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and chloroform in a mass ratio of 2.8:2:1 and a volume ratio of 4:1. The solution was then transferred to a reaction vessel and reacted at 130 °C for 24 h. After cooling, the product was washed three times with DMF and ethanol respectively and dried under vacuum at 150 °C to obtain white UiO-66 (Zr). (2) UiO-66 (Zr) was placed in a tube furnace and purged with high-purity nitrogen for 20 min. Then, it was heated to 600 °C for 6 h under this atmosphere to prepare C.pp -ZrO2 porous composite carrier; (3) Add NaOH, deionized water and C pp -ZrO2 porous composite carriers were mixed at a mass ratio of 4:80:100, magnetically stirred for 12 h, dried at 80 °C, and then calcined at 600 °C for 4 h to prepare lattice-doped NaOH C. pp -ZrO2 catalyst; (4) Prepare a solution of manganese nitrate and sodium chlorate, and add lattice-doped NaOH C pp The ZrO2 catalyst, with a mass ratio of 1:1.2:50, was stirred thoroughly and transferred to a reaction vessel. The mixture was then heated to 150℃ and reacted for 8 hours in a homogeneous reactor. The product was then centrifuged, washed, and dried at 120℃ for 12 hours to obtain C co-doped with manganese hydroxide (MnOOH) and NaOH. pp -ZrO2 bifunctional catalyst, labeled as Na4Mn OH / C pp -ZrO2, where Na4 represents the content of NaOH as 4wt%, which is the proportion of NaOH in the composite carrier C pp -Mass fraction of ZrO2, Mn OH Represents MnOOH; (5) The obtained Na4Mn OH / C pp The ZrO2 catalyst is dispersed in the absorbent of a liquid-phase reactor. The absorbent is a diphenylamine-sulfolane compound reagent with a mass ratio of 1:8. Under magnetic stirring and heating at 60-90℃, a certain concentration of COS waste gas is introduced through an aeration head. The concentrations of COS and H2S in the waste gas are detected at the gas inlet and outlet. After the COS waste gas is introduced, it is first dissolved and absorbed by the absorbent, and then diffuses and adsorbs onto the catalyst surface and inside the pores. COS is catalytically hydrolyzed to generate H2S, and the generated H2S is catalytically oxidized to generate elemental sulfur and sulfate. Under stirring and fluid flushing, the H2S is separated from the catalyst surface and pores. This test demonstrates the catalyst's hydrolytic oxidation performance for organic sulfur. Example 3

[0020] The catalyst was prepared and tested according to the following steps: (1) Zirconium chloride, terephthalic acid (PTA) and triblock copolymer P123 were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and chloroform in a mass ratio of 2.8:2:1 and a volume ratio of 4:1. The solution was then transferred to a reaction vessel and reacted at 130 °C for 24 h. After cooling, the product was washed three times with DMF and ethanol respectively and dried under vacuum at 150 °C to obtain white UiO-66 (Zr). (2) UiO-66 (Zr) was placed in a tube furnace and purged with high-purity nitrogen for 20 min. Then, it was heated to 600 °C for 6 h under this atmosphere to prepare C. pp -ZrO2 porous composite carrier; (3) Add NaOH, deionized water and C pp -ZrO2 porous composite carriers were mixed at a mass ratio of 6:80:100, magnetically stirred for 12 h, dried at 80 °C, and then calcined at 600 °C for 4 h to prepare lattice-doped NaOH C. pp -ZrO2 catalyst; (4) Prepare a solution of manganese nitrate and sodium chlorate, and add lattice-doped NaOH C pp The ZrO2 catalyst, with a mass ratio of 1:1.2:50, was stirred thoroughly and transferred to a reaction vessel. The mixture was then heated to 150℃ and reacted for 8 hours in a homogeneous reactor. The product was then centrifuged, washed, and dried at 120℃ for 12 hours to obtain C co-doped with manganese hydroxide (MnOOH) and NaOH. pp -ZrO2 bifunctional catalyst, labeled as Na6Mn OH / C pp -ZrO2, where Na6 represents the content of NaOH as 6wt%, and NaOH accounts for 6wt% of the composite carrier C pp -Mass fraction of ZrO2, Mn OH Represents MnOOH; (5) The catalyst is dispersed in the absorbent of the liquid phase reactor. The absorbent is a compound reagent of diphenylamine-sulfolane with a mass ratio of 1:8. Under magnetic stirring and heating at 60-90℃, a certain concentration of COS waste gas is introduced through the aeration head. The concentrations of COS and H2S in the waste gas are detected at the inlet and outlet of the gas. After the COS waste gas is introduced, it is first dissolved and absorbed by the absorbent, and then diffuses and adsorbs on the surface and inside the pores of the catalyst. COS is catalytically hydrolyzed to generate H2S. The generated H2S is catalytically oxidized to generate elemental S and sulfate. Under stirring and fluid flushing, it is separated from the surface and pores of the catalyst. Thus, the hydrolytic oxidation performance of the catalyst on organic sulfur is tested.

[0021] Comparative Example 1 The catalyst was prepared and tested according to the following steps: (1) Zirconium chloride, terephthalic acid (PTA) and triblock copolymer P123 were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and chloroform in a mass ratio of 2.8:2:1 and a volume ratio of 4:1. The solution was then transferred to a reaction vessel and reacted at 130 °C for 24 h. After cooling, the product was washed three times with DMF and ethanol respectively and dried under vacuum at 150 °C to obtain white UiO-66 (Zr). (2) UiO-66 (Zr) was placed in a tube furnace and purged with high-purity nitrogen for 20 min. Then, it was heated to 600℃ for 6 h under this atmosphere to prepare C-ZrO2 porous composite support, which served as a blank control example without the active component. The sample was labeled as C pp -ZrO2, where C pp This represents a carbon support formed by the co-carbonization of PTA and P123.

[0022] (3) The catalyst is dispersed in the absorbent of the liquid phase reactor. The absorbent is a compound reagent of diphenylamine-sulfolane with a mass ratio of 1:8. Under magnetic stirring and heating at 60-90℃, a certain concentration of COS waste gas is introduced through the aeration head. The concentrations of COS and H2S in the waste gas are detected at the inlet and outlet of the gas. After the COS waste gas is introduced, it is first dissolved and absorbed by the absorbent, and then diffuses and adsorbs on the surface and inside the pores of the catalyst. COS is catalytically hydrolyzed to generate H2S. The generated H2S is catalytically oxidized to generate elemental S and sulfate. Under stirring and fluid flushing, it is separated from the surface and pores of the catalyst. Thus, the hydrolytic oxidation performance of the catalyst on organic sulfur is tested.

[0023] Comparative Example 2 The catalyst was prepared and tested according to the following steps:

[0024] (1) Zirconium chloride, terephthalic acid (PTA) and triblock copolymer P123 were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and chloroform in a mass ratio of 2.8:2:1 and a volume ratio of 4:1. The solution was then transferred to a reaction vessel and reacted at 130 °C for 24 h. After cooling, the product was washed three times with DMF and ethanol respectively and dried under vacuum at 150 °C to obtain white UiO-66 (Zr). (2) UiO-66 (Zr) was placed in a tube furnace and purged with high-purity nitrogen for 20 min. Then, it was heated to 600 °C for 6 h under this atmosphere to prepare C. pp -ZrO2 porous composite carrier; (3) Add NaOH, deionized water and C pp -ZrO2 porous composite carriers were mixed at a mass ratio of 4:80:100, magnetically stirred for 12 h, dried at 80 °C, and then calcined at 600 °C for 4 h to prepare lattice-doped NaOH C. pp -ZrO2 catalyst, labeled Na4 / C pp -ZrO2, where Na4 represents the content of NaOH as 4wt%, which is the proportion of NaOH in the composite carrier C pp -Mass fraction of ZrO2, C pp A carbon support formed by the co-carbonization of PTA and P123; (4) The catalyst is dispersed in the absorbent of the liquid phase reactor. The absorbent is a diphenylamine-sulfolane compound reagent with a mass ratio of 1:8. Under magnetic stirring and heating at 60-90℃, a certain concentration of COS waste gas is introduced through the aeration head. The concentrations of COS and H2S in the waste gas are detected at the gas inlet and outlet. After the COS waste gas is introduced, it is first dissolved and absorbed by the absorbent, and then diffuses and adsorbs on the surface and inside the pores of the catalyst. COS is catalytically hydrolyzed to generate H2S. The generated H2S is catalytically oxidized to generate elemental S and sulfate. Under stirring and fluid flushing, it is separated from the surface and pores of the catalyst. Thus, the hydrolytic oxidation performance of the catalyst on organic sulfur is tested.

[0025] Comparative Example 3 The catalyst was prepared and tested according to the following steps:

[0026] (1) Zirconium chloride, terephthalic acid (PTA) and triblock copolymer P123 were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and chloroform in a mass ratio of 2.8:2:1 and a volume ratio of 4:1. The solution was then transferred to a reaction vessel and reacted at 130 °C for 24 h. After cooling, the product was washed three times with DMF and ethanol respectively and dried under vacuum at 150 °C to obtain white UiO-66 (Zr). (2) UiO-66 (Zr) was placed in a tube furnace and purged with high-purity nitrogen for 20 min. Then, it was heated to 600 °C for 6 h under this atmosphere to prepare C. pp -ZrO2 porous composite carrier; (3) Prepare a solution of manganese nitrate and sodium chlorate, and add C pp The ZrO2 catalyst, along with the other three components in a mass ratio of 1:1.2:50, was stirred thoroughly and then transferred to a reaction vessel. The mixture was then heated to 150°C and reacted for 8 hours in a homogeneous reactor. The product was then centrifuged, washed, and dried at 120°C for 12 hours to obtain manganese hydroxide (MnOOH)-doped C2O3. pp -ZrO2 bifunctional catalyst, labeled Mn OH / C pp -ZrO2, Mn OH It represents MnOOH.

[0027] (4) The catalyst is dispersed in the absorbent of the liquid phase reactor. The absorbent is a diphenylamine-sulfolane compound reagent with a mass ratio of 1:8. Under magnetic stirring and heating at 60-90℃, a certain concentration of COS waste gas is introduced through the aeration head. The concentrations of COS and H2S in the waste gas are detected at the gas inlet and outlet. After the COS waste gas is introduced, it is first dissolved and absorbed by the absorbent, and then diffuses and adsorbs on the surface and inside the pores of the catalyst. COS is catalytically hydrolyzed to generate H2S. The generated H2S is catalytically oxidized to generate elemental S and sulfate. Under stirring and fluid flushing, it is separated from the surface and pores of the catalyst. Thus, the hydrolytic oxidation performance of the catalyst on organic sulfur is tested.

[0028] Comparative Example 4 The catalyst was prepared and tested according to the following steps:

[0029] (1) Zirconium chloride and terephthalic acid (PTA) were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and chloroform in a mass ratio of 1.4:1 and a volume ratio of 4:1. The mixture was then transferred to a reaction vessel and reacted at 130 °C for 24 h. After cooling, the product was washed three times with DMF and ethanol respectively and dried under vacuum at 150 °C to obtain white UiO-66 (Zr). (2) UiO-66 (Zr) was placed in a tube furnace and purged with high-purity nitrogen for 20 min. Then, it was heated to 600 °C for 6 h under this atmosphere to prepare C. p -ZrO2 porous composite carrier; (3) Add NaOH, deionized water and C p -ZrO2 porous composite carriers were mixed at a mass ratio of 4:80:100, magnetically stirred for 12 h, dried at 80 °C, and then calcined at 600 °C for 4 h to prepare lattice-doped NaOH C. p -ZrO2 catalyst; (4) Manganese nitrate and sodium chlorate were prepared into a solution, and NaOH-doped C-ZrO2 catalyst was added. The mass ratio of the three was 1:1.2:50. After stirring evenly, the solution was transferred to a reaction vessel. The mixture was then heated to 150℃ in a homogeneous reactor and reacted for 8 hours. The product was then centrifuged, washed, and dried at 120℃ for 12 hours to obtain C-ZrO2 catalyst co-doped with manganese hydroxide (MnOOH) and NaOH. p -ZrO2 bifunctional catalyst, labeled as Na4Mn OH / C p -ZrO2, where Na4 represents the content of NaOH as 4wt%, Mn OH Represents MnOOH, C p A carbon support representing PTA carbonization; (5) The obtained Na4Mn OH / C p The ZrO2 catalyst is dispersed in the absorbent of a liquid-phase reactor. The absorbent is a diphenylamine-sulfolane compound reagent with a mass ratio of 1:8. Under magnetic stirring and heating (60-90℃), a certain concentration of COS waste gas is introduced through an aeration head. The concentrations of COS and H2S in the waste gas are detected at the gas inlet and outlet. After the COS waste gas is introduced, it is first dissolved and absorbed by the absorbent, and then diffuses and adsorbs onto the catalyst surface and inside the pores. COS is catalytically hydrolyzed to generate H2S, and the generated H2S is catalytically oxidized to generate elemental sulfur and sulfate. Under stirring and fluid flushing, the H2S is separated from the catalyst surface and pores. This test demonstrates the catalyst's hydrolytic oxidation performance for organic sulfur.

[0030] Comparative Example 5 The catalyst was prepared and tested according to the following steps:

[0031] (1) Zirconium chloride, terephthalic acid (PTA) and triblock copolymer P123 were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and chloroform in a mass ratio of 2.8:2:1 and a volume ratio of 4:1. The solution was then transferred to a reaction vessel and reacted at 130 °C for 24 h. After cooling, the product was washed three times with DMF and ethanol respectively and dried under vacuum at 150 °C to obtain white UiO-66 (Zr). (2) UiO-66 (Zr) was placed in a tube furnace and purged with high-purity nitrogen for 20 min. Then, it was heated to 600 °C for 6 h under this atmosphere to prepare C. pp -ZrO2 porous composite carrier; (3) Add NaOH, deionized water and C pp -ZrO2 porous composite carriers were mixed at a mass ratio of 4:80:100, magnetically stirred for 12 h, dried at 80 °C, and then calcined at 600 °C for 4 h to prepare lattice-doped NaOH C. pp -ZrO2 catalyst; (4) Prepare a solution of manganese nitrate, and add C doped with NaOH. pp -ZrO2 catalyst, with a mass ratio of 1:50, was magnetically stirred for 8 hours, dried at 120℃ for 12 hours, and then calcined at 400℃ for 5 hours to obtain C co-doped with manganese dioxide (MnO2) and NaOH. pp -ZrO2 bifunctional catalyst, labeled as Na4MnO2 / C pp -ZrO2, where Na4 represents the content of NaOH as 4wt%; (5) The obtained Na4MnO2 / C ppThe ZrO2 catalyst is dispersed in the absorbent of a liquid-phase reactor. The absorbent is a diphenylamine-sulfolane compound reagent with a mass ratio of 1:8. Under magnetic stirring and heating (60-90℃), a certain concentration of COS waste gas is introduced through an aeration head. The concentrations of COS and H2S in the waste gas are detected at the gas inlet and outlet. After the COS waste gas is introduced, it is first dissolved and absorbed by the absorbent, and then diffuses and adsorbs onto the catalyst surface and inside the pores. COS is catalytically hydrolyzed to generate H2S, and the generated H2S is catalytically oxidized to generate elemental sulfur and sulfate. Under stirring and fluid flushing, the H2S is separated from the catalyst surface and pores. This test demonstrates the catalyst's hydrolytic oxidation performance for organic sulfur.

[0032] Comparative Example 6 The catalyst was prepared and tested according to the following steps: (1) Zirconium chloride, terephthalic acid (PTA) and triblock copolymer P123 were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and chloroform in a mass ratio of 2.8:2:1 and a volume ratio of 4:1. The solution was then transferred to a reaction vessel and reacted at 130 °C for 24 h. After cooling, the product was washed three times with DMF and ethanol respectively and dried under vacuum at 150 °C to obtain white UiO-66 (Zr). (2) UiO-66 (Zr) was placed in a tube furnace and purged with high-purity nitrogen for 20 min. Then, it was heated to 600 °C for 6 h under this atmosphere to prepare C. pp -ZrO2 porous composite carrier; (3) Add NaOH, deionized water and C pp -ZrO2 porous composite carriers were mixed at a mass ratio of 4:80:100, magnetically stirred for 12 h, dried at 80 °C, and then calcined at 600 °C for 4 h to prepare lattice-doped NaOH C. pp -ZrO2 catalyst; (4) Prepare a solution of manganese nitrate and sodium chlorate, and add C doped with NaOH. pp The ZrO2 catalyst, with a mass ratio of 1:1.2:50, was stirred thoroughly and transferred to a reaction vessel. The mixture was then heated to 150℃ and reacted for 8 hours in a homogeneous reactor. The product was then centrifuged, washed, and dried at 120℃ for 12 hours to obtain C co-doped with manganese hydroxide (MnOOH) and NaOH. pp -ZrO2 bifunctional catalyst, labeled as Na4Mn OH / C pp -ZrO2, where Na4 represents the content of NaOH as 4wt%, Mn OH Represents MnOOH; (5) The catalyst is loaded into the gas-solid catalytic reactor, and the concentrations of COS and H2S in the exhaust gas are detected at the gas inlet and outlet. After the exhaust gas is introduced, it first diffuses and adsorbs on the surface and inside the pores of the catalyst. Then COS is catalytically hydrolyzed to generate H2S. The generated H2S is catalytically oxidized to generate elemental S and sulfate. Thus, the performance of the catalyst in hydrolysis and oxidation of organic sulfur is tested.

[0033] To avoid the influence of absorption performance on catalytic performance when testing the COS hydrolysis and oxidation activity of the catalyst in the liquid-phase absorbent as in Examples 1-3 and Comparative Examples 1-5, the absorption saturation time of the compound reagent for COS should be measured first, and the catalytic performance should be tested after absorption saturation. Using 1L of diphenylamine-sulfolane compound reagent as the absorbent, with a mass fraction of 12% and a mass ratio of diphenylamine to sulfolane of 1:8, COS gas was introduced, and the absorption / adsorption saturation time of COS was tested at 60℃-90℃. The critical time for absorption / adsorption saturation was defined as when the outlet COS gas concentration was the same as the inlet COS concentration. The results are shown in Table 1. The catalyst in Comparative Example 6 undergoes catalytic hydrolysis and oxidation in the gas phase, involving relatively fast gas diffusion, adsorption, hydrolysis, and oxidation reaction rates; therefore, it is not necessary to test its adsorption saturation time separately before testing its catalytic performance.

[0034] Table 1. Saturation time of COS absorption by liquid-phase absorbent at 60℃-90℃ Diphenylamine and sulfolane compound reagent 65 80 60 45 Table 1 shows that the absorption of COS by the diphenylamine and sulfolane compound reagent can be divided into physical absorption (sulfolane) and chemical absorption (diphenylamine). The COS absorption saturation times at 60℃-90℃ are 65 min, 80 min, 60 min, and 45 min, respectively. The COS absorption of the compound reagent over time is shown in the following curves. Figure 1 As shown, after the aforementioned absorption saturation time, the COS absorption amounts at 60℃-90℃ reached their respective maximum values ​​of 1.25 g / L, 1.75 g / L, 1.1 g / L, and 0.73 g / L. The rate of increase in absorption amount decreased progressively until absorption saturation, at which point the curve essentially flattened out, indicating that the absorption rate was the same as the regeneration rate at this point.

[0035] The experiments were conducted according to the catalyst preparation and performance testing methods in Examples 1-3 and Comparative Examples 1-5. The first activity test was conducted 2 hours after COS gas was introduced. As can be seen from the absorption saturation time of the absorbent for COS measured in Table 1, 2 hours can ensure that the absorbent can reach absorption saturation at 60℃-90℃. This avoids the influence of absorption performance on catalytic performance when testing the COS hydrolysis and oxidation activity of the catalyst in the liquid phase absorbent.

[0036] The catalysts prepared in Examples 1-3 showed the following activity results for the hydrolysis and oxidation of organic sulfur: Figure 2 As shown, the COS removal rate of the three catalysts was close to 100% in the first 2 hours. However, the COS removal rate of the different catalysts decreased to varying degrees as the reaction time increased. Figure 2 The COS removal rates of the three catalysts first showed a significant decrease at 12h, 14h, and 12h, respectively. The COS removal rates first dropped below 95% at 16h, 20h, and 18h, respectively, and after 20h, the COS removal rates decreased to 93.4%, 94.8%, and 94.1%, respectively. This indicates that all three catalysts possess high activity. When the NaOH doping concentration is 4% (i.e., Na₄Mn₄), the COS removal rate is significantly lower. OH / C pp -ZrO2) exhibits the best activity.

[0037] Example 2 (Na4Mn) exhibits the best catalytic performance. OH / C pp -ZrO2) and undoped MnOOH (Comparative Example 2, Na4 / C) pp -ZrO2), undoped NaOH (Comparative Example 3, Mn OH / C pp -ZrO2) and catalysts neither of which are doped (Comparative Example 1, C pp The activity of -ZrO2) was compared, and the results are as follows: Figure 3 As shown. With Na4Mn OH / C pp Compared to ZrO2's near 100% COS removal rate, C pp The COS removal rate of ZrO2 was approximately 42.6%, and remained essentially unchanged over a 20-hour reaction time. This is due to C pp ZrO2 can only hydrolyze COS to H2S, but cannot further oxidize H2S. Although it does not have the problem of S blockage and its catalytic hydrolysis activity is stable, the activity is very low, and it cannot recover S. (Compared to Na4Mn) OH / C pp Compared to ZrO2, Na4 / C pp The initial COS removal rate of ZrO2 was also close to 100%, which is attributed to the fact that both contain the COS hydrolysis active component Na and the content is the same. However, after 8 hours of reaction, Na4C... pp The COS removal rate of ZrO2 began to decrease, dropping to 87.8% after 20 hours. (Na4 / C) pp- ZrO2 contains the active component MnOOH, which oxidizes H2S. Therefore, the H2S produced by COS hydrolysis cannot be further oxidized to elemental sulfur, eliminating the sulfur blockage problem. However, sulfur cannot be recovered, and there is no synergistic hydrolysis effect between MnOOH and NaOH, resulting in a significant decrease in hydrolysis performance after 8 hours of reaction. (The last sentence appears to be incomplete and possibly refers to a different topic.) OH / C pp Compared to ZrO2, Mn OH / C pp -ZrO2 lacks Na, the active component for COS hydrolysis, so its COS hydrolysis activity is only 54.7%, which in turn leads to low COS hydrolysis oxidation activity.

[0038] Example 2 (Na4Mn) exhibits the best catalytic performance. OH / C pp -ZrO2) and Comparative Example 4 (Na4Mn) OH / C p -ZrO2), Comparative Example 5 (Na4MnO2 / C pp -ZrO2) and Comparative Example 6 (Na4Mn) OH / C pp Compared to the activity of -ZrO2(gas)), the results are as follows Figure 4 As shown. The times when the COS removal rate of the four catalysts first showed a significant decrease were 14h, 10h, 10h, and 4h, respectively; the times when the COS removal rate first dropped below 95% were 20h, 16h, 12h, and 6h, respectively; and the COS removal rates after 20h of reaction decreased to 94.8%, 92.7%, 89.6%, and 85.4%, respectively. (Compared to Example 2 (Na4Mn)) OH / C pp Compared to ZrO2, Comparative Example 4 (Na4Mn) OH / C p The activity of -ZrO2) decreased slightly, while that of comparative example 5 (Na4MnO2 / C) was slightly reduced. pp The activity of -ZrO2) decreased more significantly, indicating that replacing the active component manganese hydroxyl oxide (MnOOH) with manganese dioxide (MnO2) has a greater impact on the COS removal rate, while changing the carbon support preparation method has a relatively smaller impact on the COS removal rate.

[0039] The catalyst used in Example 2 and Comparative Example 6 was Na4Mn. OH / C pp -ZrO2, the former was tested in the liquid phase for COS hydrolysis and oxidation activity, while the latter was tested in the gas phase. The times when the COS removal rate first showed a significant decrease were 14h and 4h, respectively, and the times when it first dropped below 95% were 20h and 6h, respectively. At 20h, the COS removal rate decreased to 94.8% and 85.4%, respectively. Therefore, it can be seen that Na4MnOH / C pp - The COS (Cosine Oxidation) performance of ZrO2 in liquid phase hydrolysis and oxidation is far superior to that in gas phase hydrolysis and oxidation. This is because the products of the liquid phase catalytic reaction can detach from the catalyst channels and surface and enter the liquid phase during stirring, thus avoiding product blockage of the catalyst channels. In addition, the absorbent uses a combination of physical and chemical reagents, which can accelerate the reaction mass transfer. The absorbent also has antioxidant properties. All these factors together improve the stability and service life of the catalyst.

[0040] Example 2 (Na4Mn) was the most common among all samples. OH / C pp The COS (-ZrO2) exhibits the best liquid-phase hydrolysis oxidation performance, with a COS removal rate still as high as 94.8% after 20 hours and an attenuation rate of only 5.2%, demonstrating extremely high catalytic activity and stability.

[0041] Reaction temperature is a crucial factor affecting the catalytic hydrolysis and oxidation performance of COS. Example 2 (Na₄Mn₄) exhibits the best catalytic performance. OH / C pp Using ZrO2 as a representative, its COS liquid-phase hydrolysis oxidation performance was tested at 60℃, 70℃, 80℃, and 90℃, respectively. The results are as follows: Figure 5 As shown, the COS removal rates first showed a significant decrease at 14h, 16h, 12h, and 10h in the four tests, respectively. After 20h of reaction, the COS removal rates decreased to 94.8%, 96.7%, 94.5%, and 94.3%, respectively, with attenuation rates of 5.2%, 3.3%, 5.5%, and 5.7%. The COS hydrolysis oxidation activity initially improved with increasing reaction temperature, reaching a peak at 70℃. Further increases in reaction temperature led to a gradual decrease in activity. This trend is because the COS hydrolysis oxidation activity is jointly controlled by physical and chemical reactions. At lower reaction temperatures, the chemisorption of the catalyst is weaker than physisorption; higher reaction temperatures enhance chemisorption but inhibit physisorption, resulting in a decrease in the physicochemical synergistic adsorption-degradation capacity.

Claims

1. A catalyst for removing organic sulfur from coal gas, characterized in that, The catalyst is composed of a composite support, a COS catalytic hydrolysis active component, and an H2S catalytic oxidation active component, with a mass ratio of 100:2-6:4, wherein the composite support is C pp -ZrO2 porous material, the active component for COS catalytic hydrolysis is NaOH doped into the composite support lattice, and the active component for H2S catalytic oxidation is manganese hydroxide; the preparation method of this catalyst is as follows: Step 1, zirconium chloride, terephthalic acid and soft template agent are dissolved in a mixed solvent of N,N-dimethylformamide and chloroform, and then transferred to a reaction vessel for sealing. The reaction is carried out at 130 °C for 24 h. After cooling, the product is washed 1-5 times with N,N-dimethylformamide and ethanol respectively, and then dried under vacuum at 150 °C to obtain UiO-66(Zr) modified with soft template agent. Step 2: The UiO-66 (Zr) obtained in Step 1 is subjected to high temperature treatment at 600℃ for 6h to prepare Cpp-ZrO2 porous composite support; Step 3: Dissolve a certain mass of NaOH in deionized water, then dissolve the C obtained in step 2. pp -ZrO2 porous composite support was dispersed in NaOH solution, magnetically stirred for 12 h, dried at 80 °C, and then calcined at 600 °C for 4 h to prepare NaOH-doped C2. pp -ZrO2; Step 4: Prepare a solution of manganese nitrate and sodium chlorate, add Cpp-ZrO2 with NaOH lattice doped into it, stir until homogeneous, transfer to a reaction vessel, and then react in a homogeneous reactor at 150℃ for 8 hours. Afterward, centrifuge and wash the product, and dry it at 120℃ for 12 hours to obtain the final product, denoted as Na. x Mn OH / C pp -ZrO2, where x=2-6.

2. The catalyst for removing organic sulfur from coal gas according to claim 1, characterized in that, The C pp - The pore size range of ZrO2 porous materials is 5-17 nm.

3. A method for preparing a catalyst for removing organic sulfur from coal gas, characterized in that, Includes the following steps: Step 1: Zirconium chloride, terephthalic acid, and a soft template agent were dissolved in a mixed solvent of N,N-dimethylformamide and chloroform. The solution was then transferred to a reaction vessel and sealed. The reaction was carried out at 130 °C for 24 h. After cooling, the product was washed 1-5 times with N,N-dimethylformamide and ethanol, respectively. The product was then dried under vacuum at 150 °C to obtain UiO-66 (Zr) modified with the soft template agent. Step 2: The UiO-66 (Zr) obtained in Step 1 is subjected to high temperature treatment at 600℃ for 6h to prepare Cpp-ZrO2 porous composite support; Step 3: Dissolve a certain mass of NaOH in deionized water, then dissolve the C obtained in step 2. pp -ZrO2 porous composite support was dispersed in NaOH solution, magnetically stirred for 12 h, dried at 80 °C, and then calcined at 600 °C for 4 h to prepare NaOH-doped C2. pp -ZrO2; Step 4: Prepare a solution of manganese nitrate and sodium chlorate, add Cpp-ZrO2 with NaOH lattice doped into it, stir until homogeneous, transfer to a reaction vessel, and then react in a homogeneous reactor at 150℃ for 8 hours. Afterward, centrifuge and wash the product, and dry it at 120℃ for 12 hours to obtain the final product, denoted as Na. x Mn OH / C pp -ZrO2, where x=2-6.

4. The method for preparing the catalyst for removing organic sulfur from coal gas according to claim 3, characterized in that, In step 1, the soft template agent is a triblock copolymer P123, and the mass ratio of zirconium chloride, terephthalic acid and soft template agent is 2.8:2:1; the volume ratio of N,N-dimethylformamide and chloroform in the mixed solvent is 4:

1.

5. The method for preparing the catalyst for removing organic sulfur from coal gas according to claim 3, characterized in that, The pyrolysis furnace used in step 2 is a tube furnace. Before high-temperature treatment, it needs to be purged with high-purity nitrogen for 20 minutes, and then high-temperature treatment is carried out in an inert atmosphere of high-purity nitrogen.

6. The method for preparing the catalyst for removing organic sulfur from coal gas according to claim 3, characterized in that, In step 3, NaOH, deionized water, and C pp The mass ratio of ZrO2 support is 2-6:80:

100.

7. The method for preparing the catalyst for removing organic sulfur from coal gas according to claim 3, characterized in that, In step 4, manganese nitrate, sodium chlorate, and lattice-doped NaOH are used in C pp The mass ratio of ZrO2 to the three components is 1:1.2:

50.

8. The method of applying the catalyst for removing organic sulfur from coal gas as described in claim 1 or 2, characterized in that, The catalyst is dispersed in the absorbent liquid of a liquid-phase reactor. COS waste gas is introduced under magnetic stirring and heating. After entering the liquid-phase reactor, the COS waste gas is dissolved and absorbed by the absorbent liquid, and then diffuses and adsorbs onto the catalyst surface and inside the pores. COS catalysis first involves the hydrolysis of the active component of the catalyst to generate H2S. The generated H2S is then oxidized by the active component of the catalyst to generate elemental S and sulfate. Elemental S and sulfate are separated from the catalyst surface and pores under stirring and fluid flushing, thereby achieving the removal of COS.

9. The method of applying the catalyst for removing organic sulfur from coal gas according to claim 8, characterized in that... The inlet of the liquid phase reactor is equipped with an aeration head; the absorption liquid is a compound reagent of diphenylamine and sulfolane, with a mass ratio of 1:8, and the absorption reaction temperature is 60-90℃.

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