Highly efficient sulfur tolerant catalysts for carbonyl sulfide hydrolysis, methods of making and using the same

Abstract

The application belongs to the technical field of carbonyl sulfur hydrolysis catalysts, and discloses a high-efficiency sulfur-resistant catalyst for carbonyl sulfur hydrolysis, a preparation method and application thereof.The preparation method comprises the following steps: (1) preparing a porous ceramic carrier containing alumina, titanium dioxide and zirconium dioxide; (2) in-situ growing a metal organic framework material containing lanthanum, bismuth and cerium on the surface of the porous ceramic carrier by using a solvothermal method; (3) performing a calcination treatment on the porous ceramic carrier loaded with the metal organic framework material in an oxygen-containing atmosphere to obtain a catalyst precursor; and (4) performing a reducing gas plasma bombardment treatment on the catalyst precursor to obtain the high-efficiency sulfur-resistant catalyst.The high-efficiency sulfur-resistant catalyst has high-efficiency low-temperature activity, excellent sulfur resistance and long service life.

Description

Technical Field

[0001] This invention relates to the technical field of carbonyl sulfur hydrolysis catalysts, and more specifically, to highly efficient sulfur-resistant catalysts for carbonyl sulfur hydrolysis, their preparation methods, and applications. Background Technology

[0002] Blast furnace gas, an important by-product of iron and steel smelting, is not only a valuable secondary energy source but also a typical industrial waste gas. However, blast furnace gas typically contains organic sulfides such as carbonyl sulfide (COS) and carbon disulfide (CS2). These sulfur-containing components not only generate sulfur dioxide (SO2) upon combustion, causing severe air pollution and acid rain, harming the ecological environment and human health, but even trace amounts of sulfides can lead to severe corrosion of pipelines and equipment, and sulfur poisoning and deactivation of sensitive catalysts in downstream processes during subsequent resource utilization (such as as chemical feedstock or gas turbine fuel). Therefore, deep desulfurization treatment of blast furnace gas before utilization is crucial.

[0003] Traditional desulfurization methods, such as first converting COS into SO2 through combustion followed by alkaline absorption or adsorption, suffer from drawbacks including long process flows, complex operation, large footprint, high energy consumption, and the potential generation of secondary waste liquid. In recent years, deep desulfurization technologies at the blast furnace gas source (before combustion) have received widespread attention. Among these, catalytic hydrolysis has become a research hotspot due to its advantages such as low energy consumption, mild operating conditions, and the ability to convert difficult-to-treat COS into easily removable hydrogen sulfide (H2S). However, despite the promising prospects of catalytic hydrolysis technology, developing COS hydrolysis catalysts with low-temperature high activity and long-term stability under complex operating conditions still faces significant challenges. Existing technical solutions mainly suffer from the following shortcomings:

[0004] (1) The pore structure of traditional alumina or activated carbon supports is often relatively simple and the specific surface area is limited, which makes it difficult for the active metal components to be highly dispersed and easy to agglomerate. This makes the hydrolysis activity of the catalyst low under low temperature (<100℃) conditions, which cannot meet the low temperature desulfurization requirements of the blast furnace gas waste heat utilization area.

[0005] (2) The alkaline sites on the surface of existing metal oxide catalysts (such as pure alumina or simple modified alumina) are prone to irreversible reactions with acidic H2S or CO2, resulting in the active sites being covered (i.e., sulfur poisoning or carbonation). Especially under high concentration sulfur atmosphere, the active components are prone to sulfidation and deterioration, leading to rapid catalyst deactivation. Frequent catalyst replacement increases operating costs.

[0006] (3) In the currently commonly used impregnation method, the active components are only physically adsorbed or weakly chemically bonded to the surface of the support. Under actual working conditions containing water vapor and high-velocity airflow, the active components are prone to migration or loss, resulting in a significant decline in catalytic performance over time.

[0007] (4) Existing research shows that oxygen vacancies are the key active centers for COS hydrolysis. However, conventional calcination preparation methods are difficult to generate high concentrations and stable oxygen vacancies on the catalyst surface, which limits further improvement in catalytic efficiency.

[0008] It is evident that constructing a highly dispersed, sulfur-resistant, and oxygen-vacancy-rich active coating on the support surface remains a technological bottleneck restricting the development of this field. Therefore, there is an urgent need to develop a novel preparation method to obtain a COS hydrolysis catalyst that combines high efficiency at low temperatures, excellent sulfur resistance, and long lifespan. Summary of the Invention

[0009] The technical problem to be solved by this invention is to provide a highly efficient anti-sulfur catalyst for carbonyl sulfur hydrolysis, which combines high efficiency at low temperatures, excellent anti-sulfur performance, and long lifespan, as well as its preparation method and application. The technical solution is as follows:

[0010] A method for preparing a highly efficient sulfur-resistant catalyst for carbonyl sulfur hydrolysis includes the following steps:

[0011] (1) Preparation of porous ceramic supports containing alumina, titanium dioxide and zirconium dioxide;

[0012] (2) A metal-organic framework material containing lanthanum, bismuth and cerium was grown in situ on the surface of a porous ceramic carrier using a solvothermal method;

[0013] (3) The porous ceramic support loaded with metal-organic framework material is calcined in an oxygen-containing atmosphere to obtain the catalyst precursor;

[0014] (4) The catalyst precursor is subjected to reducing gas plasma bombardment treatment to obtain a highly efficient anti-sulfur catalyst.

[0015] As a further improvement to the above preparation method: step (1) includes the following steps:

[0016] Aluminum nitrate, zirconium nitrate, and polyvinylpyrrolidone were dissolved in pure water, and nitric acid was added to adjust the pH to 1-3. Then, an ethanol solution of tetrabutyl titanate was added and stirred to form the first mixed solution.

[0017] The first mixed solution was spray-dried to obtain precursor powder;

[0018] The precursor powder is calcined in air to obtain a porous ceramic carrier.

[0019] As a further improvement to the above preparation method: the weight parts of each component in the first mixed solution, based on oxides, are: 75-85 parts Al2O3, 5-10 parts TiO2, and 3-8 parts ZrO2; the amount of polyvinylpyrrolidone added is 0.5-1.5% of the total weight of oxides; the total mass fraction of solute in the first mixed solution is 16-20%; the inlet temperature of the spray drying is 150-180℃, and the outlet temperature is 80-100℃; the calcination temperature is 400-600℃, and the calcination time is 2-4 hours.

[0020] As a further improvement to the above preparation method: step (2) includes the following steps:

[0021] Prepare a second mixed solution containing lanthanum nitrate, bismuth nitrate, cerium nitrate, and an organic ligand;

[0022] The porous ceramic support is immersed in a second mixed solution and subjected to a solvothermal reaction in a closed reactor. After the reaction is completed, the support is washed and dried to obtain a porous ceramic support loaded with metal-organic framework material.

[0023] As a further improvement to the above preparation method: the molar ratio of the total number of metal ions to the organic ligand in the second mixed solution is 1:(0.8-1.5); the molar ratio of lanthanum, bismuth, and cerium is (1-3):(0.5-1):(3-5); the organic ligand is selected from at least one of pyromellitic acid, terephthalic acid, or 2-methylimidazole; the solvent of the second mixed solution is a mixed solvent composed of N,N-dimethylformamide, ethanol, and water in a volume ratio of (1-5):(1-5):1; the total molar concentration of metal ions in the second mixed solution is 0.1-0.5 mol / L; the solid-liquid ratio of the porous ceramic support to the second mixed solution is 20-30 mg / mL; the temperature of the solvothermal reaction is 100-140℃, the reaction time is 12-24 hours; and the solution is vacuum dried at 60-80℃.

[0024] As a further improvement to the above preparation method: in step (3), the calcination temperature is 400-500℃ and the calcination time is 2-3 hours.

[0025] As a further improvement to the above preparation method: In step (4), under a mixed atmosphere of hydrogen and argon, the volume ratio of hydrogen is 5-15%, the gas flow rate is 20-50 mL / min, and the catalyst precursor is treated by a radio frequency plasma generator at a pressure of 20-100 Pa or by a dielectric barrier discharge generator at atmospheric pressure. The treatment power is 100-300 W and the treatment time is 10-30 minutes.

[0026] As a further improvement to the above preparation method, it also includes step (5): under the conditions of vacuum degree below 1000 Pa and temperature of 120-150℃, a hydrophobic agent is grafted onto the outermost surface of the catalyst by vapor deposition, and the deposition time is 1-3 hours; the hydrophobic agent is selected from one or more of perfluorooctyltriethoxysilane, hexamethyldisilazane or octyltrimethoxysilane.

[0027] The highly efficient sulfur-resistant catalyst for carbonyl sulfur hydrolysis was prepared by the above-described method.

[0028] The purification method for carbonyl sulfide in flue gas employs the aforementioned highly efficient anti-sulfur catalyst to catalytically hydrolyze the carbonyl sulfide in the flue gas.

[0029] Therefore, the advantages of the highly efficient sulfur-resistant catalyst for carbonyl sulfur hydrolysis, its preparation method, and its application of the present invention are as follows:

[0030] (1) This invention uses porous ceramics as a skeletal support. Compared with traditional granular or powdered supports, porous ceramic supports have excellent mechanical strength, high temperature resistance, and chemical corrosion resistance, and can adapt to the harsh environment of large gas flow scouring and complex composition in blast furnace gas conditions. At the same time, porous ceramic supports have a unique three-dimensional interconnected pore structure, which can significantly reduce the pressure drop of gas passing through the catalyst bed, and at the same time enhance the diffusion and mass transfer efficiency of reactant gases inside the catalyst, solving the problem of limited mass transfer of traditional catalysts at high space velocities. The main component of porous ceramic supports, alumina, has good chemical stability, and the doped titanium dioxide and zirconium dioxide further enhance the structural and chemical stability of the support.

[0031] (2) In this invention, lanthanum, bismuth, and cerium are grown in situ on the surface of a porous ceramic support. This not only provides more effective adsorption and reaction sites for the reactants, but also the electronic interactions between the active components can change the electron cloud density of the active sites, which is beneficial to the adsorption of reactant molecules and the breaking and formation of chemical bonds, thus promoting the hydrolysis reaction. In particular, cerium has a special electronic structure that can change the electron cloud distribution on the catalyst surface, effectively inhibiting the adsorption and deposition of sulfur species, greatly reducing sulfur poisoning, and enabling the catalyst to exhibit high stability and long service life in sulfur-containing environments, ensuring the continuous and efficient catalytic reaction.

[0032] (3) This invention constructs a metal-organic framework (MOF) material layer on the surface of a porous ceramic support through in-situ growth technology. The active sites such as hydroxyl groups on the surface of the porous ceramic support form chemical bonds with MOF ligands or metal centers, thereby achieving a firm anchoring of the active components on the support surface. This not only effectively solves the problems of easy peeling and poor bonding of active coatings in traditional coating methods, but also the fact that the MOF material itself has extremely high specific surface area and porosity. The metal oxides derived after subsequent processing can perfectly inherit this porous characteristic, thereby greatly increasing the effective specific surface area of ​​the catalyst and exposing more active sites.

[0033] (4) The present invention etches the catalyst surface by bombarding the high-energy particles of plasma, which not only further enriches the microporous structure of the surface, but more importantly, induces a high concentration of surface oxygen vacancies in the metal oxide lattice. These oxygen vacancies can serve as Lewis acid sites, greatly enhancing the catalyst's ability to adsorb and activate water molecules, thereby significantly improving the catalyst's COS hydrolysis activity under low temperature conditions, enabling it to achieve extremely high desulfurization efficiency at a lower reaction temperature.

[0034] (5) The catalyst prepared by this invention has excellent anti-sulfur and anti-carbonization properties. The composite metal oxide formed by MOF derivation has a special electronic structure. Combined with the regulation of surface acidity and alkalinity by plasma modification, it effectively inhibits the competitive adsorption of H2S and CO2 on the active site and avoids catalyst poisoning and deactivation. At the same time, the high dispersion and strong interaction of the active components inhibit the sintering and loss of active metals and ensure the stability of the catalyst in long-term operation.

[0035] In summary, this invention successfully prepared a COS hydrolysis catalyst with high mechanical strength, excellent low-temperature activity, strong sulfur resistance, and long service life through the synergistic effect of porous ceramic support, MOF in-situ growth, and plasma modification technology. This solves the bottleneck problems of easy catalyst deactivation, short life, and low low-temperature efficiency in the prior art, and has broad prospects for industrial application.

[0036] The embodiments of the invention provided in this specification will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages of the embodiments of the invention provided in this specification will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the embodiments of the invention provided in this specification. Attached Figure Description

[0037] The accompanying drawings, which form part of the embodiments of the invention provided in this specification, are used to aid in understanding the embodiments of the invention provided in this specification. The content provided in the drawings and the related descriptions in the embodiments of the invention provided in this specification can be used to explain the embodiments of the invention provided in this specification, but do not constitute an undue limitation on the embodiments of the invention provided in this specification. In the drawings:

[0038] Figure 1 This is the nitrogen adsorption-desorption isotherm and pore size distribution diagram of the high-efficiency anti-sulfur catalyst in this embodiment.

[0039] Figure 2 This is a diagram of the catalytic performance testing device of the present invention. Detailed Implementation

[0040] The embodiments of the invention provided in this specification will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the embodiments of the invention provided in this specification based on these descriptions. Before describing the embodiments of the invention provided in this specification in conjunction with the accompanying drawings, it should be particularly noted that:

[0041] The technical solutions and features provided in the embodiments of the invention provided in this specification, including the following description, can be combined with each other without conflict.

[0042] Furthermore, the embodiments of the inventions provided in this specification mentioned below are generally only a portion of the embodiments of the inventions provided in this specification, and not all of them. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the inventions provided in this specification without creative effort should fall within the scope of protection of the embodiments of the inventions provided in this specification.

[0043] Regarding the terminology and units in the embodiments of the invention provided in this specification: The terms "comprising," "including," "having," and any variations thereof in the description, claims, and related parts of the embodiments of the invention provided in this specification are intended to cover non-exclusive inclusion. Furthermore, other relevant terms and units in the embodiments of the invention provided in this specification can be reasonably interpreted based on the relevant content of the embodiments of the invention provided in this specification.

[0044] Example 1

[0045] The preparation method of the highly efficient anti-sulfur catalyst for carbonyl sulfur hydrolysis in this embodiment includes the following steps:

[0046] (1) Preparation of porous ceramic carriers

[0047] Aluminum nitrate, zirconium nitrate, and polyvinylpyrrolidone were dissolved in pure water, and the pH was adjusted to between 1 and 3 by adding nitric acid. Then, an ethanol solution of tetrabutyl titanate was added and stirred thoroughly to obtain a first mixed solution. The total mass fraction of the solute in the first mixed solution was 18%, and the weight parts of each component based on oxides were: 78 parts Al2O3, 7 parts TiO2, and 5 parts ZrO2. The amount of polyvinylpyrrolidone added was 1% of the total weight of the oxides.

[0048] The first mixed solution is spray-dried, with the inlet temperature controlled at 150-180℃ and the outlet temperature at 80-100℃, to obtain precursor powder.

[0049] The precursor powder was calcined in air at 500°C for 3 hours to obtain a porous ceramic carrier containing alumina, titanium dioxide and zirconium dioxide.

[0050] (2) In-situ growth of metal-organic framework materials

[0051] The solvent used was a mixed solvent composed of N,N-dimethylformamide, ethanol and water in a volume ratio of 3:3:1. The solutes included lanthanum nitrate, bismuth nitrate, cerium nitrate and trimesic acid, and a second mixed solution was prepared. The total molar concentration of metal ions in the second mixed solution was controlled at 0.4 mol / L, the molar ratio of total metal ions to organic ligands was 1:1.5, and the molar ratio of lanthanum, bismuth and cerium was 2.5:1:4.

[0052] The porous ceramic support was impregnated in the second mixed solution, with the solid-liquid ratio controlled at 25 mg / mL. The mixture was then placed in a sealed reactor for a solvothermal reaction at 140°C for 12 hours.

[0053] After the reaction was completed, the substrate was washed and dried under vacuum at 70°C to obtain a porous ceramic support loaded with metal-organic framework material.

[0054] (3) Preparation of catalyst precursor by calcination

[0055] A porous ceramic support loaded with metal-organic framework material was placed in an oxygen-containing atmosphere for calcination. The temperature was programmed and the heating rate was controlled at 3℃ / min. The final calcination temperature was 400℃, and the temperature was maintained at this temperature for 3 hours to obtain the catalyst precursor.

[0056] (4) Plasma modification treatment

[0057] In a mixed atmosphere of hydrogen and argon, with hydrogen accounting for 10% of the volume and a gas flow rate of 30 mL / min, the catalyst precursor was treated for 20 minutes using a radio frequency plasma generator at 50 Pa and 200 W.

[0058] (5) Surface hydrophobic modification

[0059] Under conditions of vacuum below 1000 Pa and temperature of 130 °C, perfluorooctyltriethoxysilane was grafted onto the outermost surface of the catalyst using vapor deposition for 3 hours, thus obtaining a highly efficient anti-sulfur catalyst.

[0060] Tests showed that the high-efficiency anti-sulfur catalyst of this embodiment achieved a conversion rate of over 93% for carbonyl sulfur hydrolysis at 80°C for 126 hours.

[0061] Figure 1 This image shows the nitrogen adsorption-desorption isotherm and pore size distribution of the highly efficient anti-sulfur catalyst in this embodiment. Figure 1 As shown, the nitrogen adsorption-desorption isotherm of the catalyst exhibits a typical Type IV isotherm. At lower relative pressures (<0.1), nitrogen molecules mainly undergo monolayer adsorption within the micropores, resulting in a relatively gentle isotherm rise. This reflects the presence of a certain number of microporous structures in the catalyst, which can increase the loading of active components, highly disperse the active components on the support surface, increase the number of active sites, and promote the catalytic reaction. Between relative pressures of 0.4 and 0.9, a significant hysteresis loop appears in the isotherm, indicating the presence of a mesoporous structure in the catalyst. This facilitates the diffusion of reactant molecules from macropores to micropores and the diffusion of product molecules from micropores to macropores, effectively improving mass transfer efficiency. When the relative pressure approaches 1, the isotherm rises sharply due to capillary condensation in the macropores, leading to a large amount of nitrogen adsorption. This indicates the presence of a macroporous structure in the catalyst, which provides a rapid transport channel for the reactant gas, reduces diffusion resistance within the support, and allows the reactant gas to quickly reach the active sites, increasing the reaction rate.

[0062] Calculations show that the catalyst has a large specific surface area (316 m²). 2 The catalyst has a pore volume of 0.527 cm³ / g, which provides ample surface space for loading the active component and facilitates its high dispersion. Simultaneously, the catalyst also has a relatively large pore volume (0.527 cm³ / g). 3 It can accommodate more active components, and the multi-level pore size distribution synergistically improves the overall performance of the catalyst.

[0063] Example 2

[0064] Compared with Example 1, the preparation method of the high-efficiency anti-sulfur catalyst for carbonyl sulfur hydrolysis in this example is different in that: in step (1), the weight parts of each component in the first mixed solution based on oxides are: 85 parts Al2O3, 5 parts TiO2, and 3 parts ZrO2.

[0065] Tests showed that the high-efficiency sulfur-resistant catalyst of this embodiment achieved a conversion rate of over 93% for the hydrolysis of carbonyl sulfur at 80°C for a duration (T0).93 The duration is 119 hours.

[0066] Example 3

[0067] Compared with Example 1, the preparation method of the high-efficiency anti-sulfur catalyst for carbonyl sulfur hydrolysis in this example is different in that: in step (1), the weight parts of each component in the first mixed solution based on oxides are: 75 parts Al2O3, 10 parts TiO2, and 8 parts ZrO2.

[0068] Tests showed that the highly efficient sulfur-resistant catalyst of this embodiment catalyzes the hydrolysis of carbonyl sulfide at 80°C to form T. 93 It takes 122 hours.

[0069] Example 4

[0070] Compared with Example 1, the difference in the preparation method of the high-efficiency anti-sulfur catalyst for carbonyl sulfur hydrolysis in this example is that in step (2), the molar ratio of lanthanum, bismuth and cerium in the second mixed solution is 1:0.8:3.

[0071] Tests showed that the highly efficient sulfur-resistant catalyst of this embodiment catalyzes the hydrolysis of carbonyl sulfide at 80°C to form T. 93 It takes 108 hours.

[0072] Example 5

[0073] Compared with Example 1, the difference in the preparation method of the high-efficiency anti-sulfur catalyst for carbonyl sulfur hydrolysis in this example is that in step (2), the molar ratio of lanthanum, bismuth and cerium in the second mixed solution is 3:0.5:5.

[0074] Tests showed that the highly efficient sulfur-resistant catalyst of this embodiment catalyzes the hydrolysis of carbonyl sulfide at 80°C to form T. 93 It takes 113 hours.

[0075] Example 6

[0076] Compared with Example 1, the preparation method of the high-efficiency anti-sulfur catalyst for carbonyl sulfur hydrolysis in this example is different in that: in step (2), the total molar number of metal ions in the second mixed solution is 1:0.8 to the molar ratio of organic ligands, the reaction is solvothermal, the reaction temperature is 100℃, and the reaction time is 24 hours.

[0077] Tests showed that the highly efficient sulfur-resistant catalyst of this embodiment catalyzes the hydrolysis of carbonyl sulfide at 80°C to form T. 93 It takes 109 hours.

[0078] Example 7

[0079] Compared with Example 1, the preparation method of the high-efficiency anti-sulfur catalyst for carbonyl sulfur hydrolysis in this example is different in that: in step (3), the calcination temperature is 500°C and maintained at this temperature for 2 hours.

[0080] Tests showed that the highly efficient sulfur-resistant catalyst of this embodiment catalyzes the hydrolysis of carbonyl sulfide at 80°C to form T. 93 It takes 121 hours.

[0081] Compare with Example 1

[0082] Compared with Example 1, the difference in the preparation method of the highly efficient anti-sulfur catalyst for carbonyl sulfur hydrolysis in this comparative example is that in step (2), the second mixed solution contains only lanthanum nitrate and bismuth nitrate.

[0083] Tests showed that the highly efficient sulfur-resistant catalyst in this comparative example catalyzed the hydrolysis of carbonyl sulfide at 80℃. 93 It lasts for 75 hours.

[0084] Compare with Example 2

[0085] Compared with Example 1, the difference in the preparation method of the highly efficient anti-sulfur catalyst for carbonyl sulfur hydrolysis in this comparative example is that in step (2), the second mixed solution contains only lanthanum nitrate.

[0086] Tests showed that the highly efficient sulfur-resistant catalyst in this comparative example catalyzed the hydrolysis of carbonyl sulfide at 80℃. 93 It lasts for 32 hours.

[0087] Compare with Example 3

[0088] Compared with Example 1, the difference in the preparation method of the highly efficient anti-sulfur catalyst for carbonyl sulfur hydrolysis in this comparative example is that: in step (2), the second mixed solution does not contain organic ligands.

[0089] Tests showed that the highly efficient sulfur-resistant catalyst in this comparative example catalyzed the hydrolysis of carbonyl sulfide at 80℃. 93 It lasts for 65 hours.

[0090] Compare with Example 4

[0091] Compared with Example 1, the preparation method of the highly efficient anti-sulfur catalyst for carbonyl sulfur hydrolysis in this comparative example is different in that step (3) is not performed, and only steps (1), (2), (4), and (5) are performed.

[0092] Tests showed that the highly efficient sulfur-resistant catalyst in this comparative example catalyzed the hydrolysis of carbonyl sulfide at 80℃. 93 It lasts for 25 hours.

[0093] Compare with Example 5

[0094] Compared with Example 1, the preparation method of the highly efficient anti-sulfur catalyst for carbonyl sulfur hydrolysis in this comparative example is different in that step (4) is not performed, and only steps (1), (2), (3), and (5) are performed.

[0095] Tests showed that the highly efficient sulfur-resistant catalyst in this comparative example catalyzed the hydrolysis of carbonyl sulfide at 80℃. 93 It takes 92 hours.

[0096] Compare with Example 6

[0097] Compared with Example 1, the preparation method of the highly efficient anti-sulfur catalyst for carbonyl sulfur hydrolysis in this comparative example is different in that step (5) is not performed, and only steps (1), (2), (3), and (4) are performed.

[0098] Tests showed that the highly efficient sulfur-resistant catalyst in this comparative example catalyzed the hydrolysis of carbonyl sulfide at 80℃. 93 It lasts for 98 hours.

[0099] Figure 2 This is a diagram of the catalytic performance testing apparatus of the present invention. Figure 2 As shown, a fixed-bed reactor was used for activity testing. The reactor was a U-shaped tube with an inner diameter of 10 mm, filled with 6 mL of catalyst particles with a particle size of 0.45-0.90 mm, and the reaction temperature was 80℃. The simulated reaction gas was prepared in a mixing bottle according to the actual composition of blast furnace gas (0.1 vol% COS, 15 vol% CO2, 8 vol% water vapor, 1 vol% O2, and balance gas N2), with a total gas flow rate of 300 mL / min and a volumetric hourly space velocity of 3000 h⁻¹. -1 A gas chromatograph is connected to the reactor outlet to analyze the post-reaction gas in real time. The COS conversion rate is calculated using the following formula by detecting the COS concentration in the outlet gas. A COS conversion rate below 93% is considered breakthrough, and the breakthrough time is denoted as T. 93 .

[0100]

[0101] The embodiments of the highly efficient anti-sulfur catalyst for carbonyl sulfur hydrolysis of the present invention are prepared by the preparation method of any of the above embodiments.

[0102] An embodiment of the method for purifying carbonyl sulfide in flue gas according to the present invention involves preparing a highly efficient anti-sulfur catalyst using any of the preparation methods described in the above embodiments, and then catalytically hydrolyzing the carbonyl sulfide in the flue gas. The flue gas is preferably, but not limited to, blast furnace gas.

[0103] The embodiments of the invention provided in this specification have been described above. Those skilled in the art will be able to implement the embodiments of the invention provided in this specification based on these descriptions. All other preferred embodiments and implementations obtained by those skilled in the art based on the above description of the embodiments of the invention provided in this specification without inventive effort should fall within the protection scope of the embodiments of the invention provided in this specification.

Claims

1. A method for preparing a highly efficient sulfur-resistant catalyst for carbonyl sulfur hydrolysis, characterized in that: Includes the following steps: (1) Preparation of porous ceramic supports containing alumina, titanium dioxide and zirconium dioxide; (2) A metal-organic framework material containing lanthanum, bismuth and cerium was grown in situ on the surface of a porous ceramic carrier using a solvothermal method; (3) The porous ceramic support loaded with metal-organic framework material is calcined in an oxygen-containing atmosphere to obtain the catalyst precursor; (4) The catalyst precursor is subjected to reducing gas plasma bombardment treatment to obtain a highly efficient anti-sulfur catalyst.

2. The preparation method according to claim 1, characterized in that: Step (1) includes the following steps: Aluminum nitrate, zirconium nitrate, and polyvinylpyrrolidone were dissolved in pure water, and nitric acid was added to adjust the pH to 1-3. Then, an ethanol solution of tetrabutyl titanate was added and stirred to form the first mixed solution. The first mixed solution was spray-dried to obtain precursor powder; The precursor powder is calcined in air to obtain a porous ceramic carrier.

3. The preparation method according to claim 2, characterized in that: The components in the first mixed solution, by weight of oxides, are: 75-85 parts Al2O3, 5-10 parts TiO2, and 3-8 parts ZrO2; the amount of polyvinylpyrrolidone added is 0.5-1.5% of the total weight of oxides. The total mass fraction of solute in the first mixed solution is 16-20%; The inlet temperature of the spray dryer is 150-180℃, and the outlet temperature is 80-100℃. The roasting temperature is 400-600℃ and the roasting time is 2-4 hours.

4. The preparation method according to claim 1, characterized in that: Step (2) includes the following steps: Prepare a second mixed solution containing lanthanum nitrate, bismuth nitrate, cerium nitrate, and an organic ligand; The porous ceramic support is immersed in a second mixed solution and subjected to a solvothermal reaction in a closed reactor. After the reaction is completed, the support is washed and dried to obtain a porous ceramic support loaded with metal-organic framework material.

5. The preparation method according to claim 4, characterized in that: The total molar ratio of metal ions to organic ligands in the second mixed solution is 1:(0.8-1.5); the molar ratio of lanthanum, bismuth, and cerium is (1-3):(0.5-1):(3-5). The organic ligand is selected from at least one of pyromellitic acid, terephthalic acid or 2-methylimidazole; The solvent for the second mixed solution is a mixture of N,N-dimethylformamide, ethanol and water in a volume ratio of (1-5):(1-5):

1. The total molar concentration of metal ions in the second mixed solution is 0.1-0.5 mol / L; The solid-liquid ratio of the porous ceramic support to the second mixed solution is 20-30 mg / mL; The temperature of the solvothermal reaction is 100-140℃, and the reaction time is 12-24 hours; Vacuum drying at 60-80℃.

6. The preparation method according to claim 1, characterized in that: In step (3), the roasting temperature is 400-500℃ and the roasting time is 2-3 hours.

7. The preparation method according to claim 1, characterized in that: In step (4), under a mixed atmosphere of hydrogen and argon, the volume percentage of hydrogen is 5-15%, the gas flow rate is 20-50 mL / min, and the catalyst precursor is treated using a radio frequency plasma generator at a pressure of 20-100 Pa or a dielectric barrier discharge generator at atmospheric pressure. The treatment power is 100-300 W and the treatment time is 10-30 minutes.

8. The preparation method according to any one of claims 1-7: characterized in that: It also includes step (5): under conditions of vacuum degree below 1000Pa and temperature of 120-150℃, a hydrophobic agent is grafted onto the outermost surface of the catalyst by vapor deposition, and the deposition time is 1-3 hours; the hydrophobic agent is selected from one or more of perfluorooctyltriethoxysilane, hexamethyldisilazane or octyltrimethoxysilane.

9. A highly efficient sulfur-resistant catalyst for carbonyl sulfur hydrolysis, characterized in that: It is prepared by the preparation method described in any one of claims 1-8.

10. A method for purifying carbonyl sulfide in flue gas, characterized in that, The highly efficient anti-sulfur catalyst described in claim 9 is used to catalytically hydrolyze carbonyl sulfur in flue gas.

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