Molecular sieve / alumina composite catalyst for carbonyl sulfide low temperature and chlorine hydrolysis resistance and preparation method thereof

Abstract

The preparation method comprises the following steps: uniformly mixing a molecular sieve with a carbonyl sulfide hydrolysis catalyst, then adding a dispersing solvent, mixing by adopting a liquid-assisted grinding method, and then drying and calcining to obtain the carbonyl sulfide low-temperature chlorine-hydrolysis-resistant molecular sieve / alumina composite catalyst. The molecular sieve / alumina composite catalyst for carbonyl sulfide low temperature and chlorine hydrolysis resistance is obtained. The carbonyl sulfide hydrolysis catalyst is used as an active component of carbonyl sulfide hydrolysis reaction, and the molecular sieve aid is used for adsorbing, regulating and controlling a slow-release water-gas component and an HCl poisoning component, so that the low-temperature activity and chlorine poisoning resistance of the active component are improved; the composite catalyst provided by the invention reduces the reaction temperature for catalyzing hydrolysis of carbonyl sulfide, improves the chlorine poisoning resistance, realizes low-temperature, low-energy-consumption and stable removal of carbonyl sulfide in blast furnace gas, and solves the technical problem of deep desulfurization of blast furnace gas in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of gas purification technology, specifically relating to a molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis and its preparation method, which can be used at relatively low temperatures (60-70°C). o C) Removes carbonyl sulfur from the gas, and the catalyst is resistant to poisoning interference from high concentrations (500 ppm) of HCl, making it suitable for low-energy consumption and high-stability deep desulfurization of industrial gas sources. Background Technology

[0002] Carbonyl sulfide (COS), a typical sulfur-containing pollutant, not only severely damages the atmospheric environment, induces acid rain, and harms human health, but also has a significant negative impact on the global climate change process. Blast furnace gas is one of the three major byproducts of the steel industry. Due to its large output and low calorific value (approximately 3500 kJ / m³), it is produced in large quantities. 3 Blast furnace gas is typically discharged directly. The discharged gas usually contains trace amounts of organic sulfur (mainly COS) and inorganic sulfur (mainly H2S). After combustion, it generates sulfur dioxide (SO2), causing acid rain, corroding industrial pipelines and equipment, poisoning catalysts in downstream processes, and failing to meet the ultra-low emission policy requirements of the steel industry. Therefore, implementing source control of blast furnace gas and achieving precise desulfurization is imperative.

[0003] Carbonyl sulfide constitutes a large proportion (approximately 70%) of blast furnace gas and is difficult to remove. Industrially, it is typically converted into easily removable hydrogen sulfide. Methods for converting COS to H2S mainly include hydrolysis (COS + H2O = H2S + CO2) and hydrotreating (COS + 4H2 = H2S + CH4 + H2O). Hydrolysis, due to its mild operating conditions, lack of byproducts, and good economic performance, significantly reduces energy consumption and equipment investment, and is widely used in industry. COS hydrolysis is mainly divided into low-temperature hydrolysis (50~90°C). o C) and medium-high temperature hydrolysis (100~200) o(C) Low-temperature hydrolysis can utilize low-grade heat sources such as industrial waste heat to achieve fine desulfurization, offering advantages such as low operating costs and strong operational adaptability, making it a currently popular blast furnace gas desulfurization technology. However, the hydrolysis efficiency of carbonyl sulfide is limited at low temperatures, typically requiring the aid of a hydrolysis catalyst to achieve the process target. Therefore, the key to the low-temperature hydrolysis process of carbonyl sulfide is the hydrolysis catalyst; the catalyst support, active components, and additives all affect the carbonyl sulfide hydrolysis rate. Carbonyl sulfide hydrolysants can be divided into supported and unsupported types, with unsupported catalysts mainly consisting of hydrotalcite. For supported hydrolysis catalysts, γ-Al₂O₃, TiO₂, ZrO₂, and activated carbon are used to support active components, including alkali metals, transition metal oxides, and rare earth metal oxides. Among them, alkali metal K-modified γ-Al2O3 is often used as a carbonyl sulfide hydrolysis agent. Although it can improve catalytic activity by forming HO-Al-OK interfacial active sites, its activity is easily affected by the water vapor content in the reaction system (Reference: Renda S, Barba D, Palma V. Recent solutions for efficient carbonyl sulfide hydrolysis: A review[J]. Industrial & Engineering Chemistry Research, 2022, 61(17): 5685-5697.). Alumina-based catalysts are highly hydrophilic and are prone to surface condensation under high humidity conditions, which can block active sites and further reduce catalytic performance. In common carbonyl sulfide hydrolysis reaction systems, the water vapor content (approximately 5 vol%) is much higher than that of COS (approximately 100-300 ppm). Excess unreacted water vapor and COS molecules compete for adsorption on the catalyst surface, occupying a large number of adsorption sites. This makes it difficult for COS to be effectively adsorbed onto the active site to participate in the hydrolysis reaction, resulting in a significant decrease in catalytic activity (Reference: Yang K, Chen J, Mi J, et al. More than just a reactant: H2O promotes carbonyl sulfide hydrolysis activity over Ni-MgAl-LDO by inhibiting H2S poisoning[J]. Fuel, 2023, 333: 126503.).Furthermore, the presence of chlorine-containing components (such as HCl) in blast furnace gas can interact with K and Al species on the catalyst surface or directly adhere to active sites, damaging their surface chemical properties and further weakening hydrolysis performance (Reference: Wu P, Zhang Y, Xu Y, et al. Revelation of HClpoisoning and enhancement mechanism on N-modified Al2O3catalysts for COS and CS2hydrolysis[J]. Fuel, 2024, 363: 130785.). Therefore, improving the tolerance to water vapor fluctuations and resistance to chlorine poisoning is a key modification direction for carbonyl sulfide low-temperature hydrolysis catalysts.

[0004] Existing technologies mostly focus on higher temperatures (>80°C) o The improvement of carbonyl sulfur hydrolysis activity under C) and the use of molecular sieve modified carbonyl sulfur hydrolysants are mostly concentrated in hydrolysis reactions under high temperature and chlorine-free conditions (Patents: [1] Pan Licheng, Wang Guangjian, Cui Fang, et al. A catalyst support for carbonyl sulfur hydrolysis of blast furnace gas and its preparation process: CN117019209A. [2] Wang Rongtao, Lu Chuanrui, Tian Bojun, et al. A flexible coking gas carbonyl sulfur hydrolysis catalyst and its preparation method: CN118594598A.), and there is no technology to regulate the carbonyl sulfur hydrolysis temperature and improve the chlorine resistance of the catalyst. Summary of the Invention

[0005] To address the problems of water vapor fluctuation interference, surface condensation, and poor chlorine resistance in existing catalysts during the low-temperature hydrolysis of carbonyl sulfur, the present invention aims to provide a molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant hydrolysis of carbonyl sulfur and its preparation method. This catalyst lowers the reaction temperature of carbonyl sulfur hydrolysis and improves its resistance to chlorine poisoning, achieving low-temperature, low-energy, and stable removal of carbonyl sulfur from blast furnace gas. It is suitable for the hydrolysis of carbonyl sulfur in industrial gases (such as blast furnace gas) and solves the technical problem of deep desulfurization of existing blast furnace gas.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant hydrolysis of carbonyl sulfur, wherein the composite catalyst comprises a molecular sieve and a carbonyl sulfur hydrolysis catalyst, and the mass of the molecular sieve is 2.5-10% of the total mass of the composite catalyst.

[0007] Furthermore, the molecular sieve is of type A, type NaY, type ZSM-5, or coal-based solid waste molecular sieve.

[0008] A method for preparing a molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis includes the following steps: Molecular sieves and carbonyl sulfur hydrolysis catalysts were mixed evenly, then a dispersing solvent was added, and the mixture was mixed by liquid-assisted grinding. After drying and calcination, a molecular sieve / alumina composite catalyst for low-temperature and chlorine-resistant hydrolysis of carbonyl sulfur was obtained.

[0009] Furthermore, the dispersing solvent is water, ethanol, or acetone.

[0010] Furthermore, the ratio of the amount of dispersing solvent to the amount of the mixture of molecular sieve and carbonyl sulfur hydrolysis catalyst is 1-5 ml: 1 g.

[0011] Furthermore, liquid-assisted grinding involves ball milling at 50-200 r / min.

[0012] Furthermore, the mass of the molecular sieve is 2.5-10% of the total mass of the composite catalyst.

[0013] Furthermore, the molecular sieve is of type A, type NaY, type ZSM-5, or coal-based solid waste molecular sieve.

[0014] Furthermore, the drying temperature is 70-100°C. o C, the time is 6-12 hours.

[0015] Furthermore, the calcination temperature is 400-600℃. o C, the time is 4-8 hours.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The molecular sieve / alumina composite catalyst of this invention is a homogeneous composite structure of molecular sieve and carbonyl sulfide hydrolysis catalyst. The carbonyl sulfide hydrolysis catalyst serves as the active component in the carbonyl sulfide hydrolysis reaction, while the molecular sieve auxiliary agent adsorbs and regulates the slow release of water vapor components and HCl poisoning components, thereby improving the low-temperature activity and chlorine poisoning resistance of the active component. The composite catalyst of this invention lowers the catalytic temperature of the carbonyl sulfide hydrolysis reaction and improves its chlorine poisoning resistance, achieving low-temperature, low-energy-consumption, and stable removal of carbonyl sulfide from blast furnace gas, thus solving the technical problem of deep desulfurization of existing blast furnace gas.

[0017] Furthermore, the molecular sieve additives in this invention are widely available, including various types of commercial molecular sieves and inexpensive molecular sieves based on coal solid waste.

[0018] This invention prepares a composite catalyst by mixing, grinding, and calcining a molecular sieve with a carbonyl sulfur hydrolysis catalyst. The catalyst's porous structure adsorbs and slowly releases water vapor components and HCl toxic components from the desulfurization atmosphere. A buffer zone is constructed around Al2O3 in the carbonyl sulfur hydrolysis catalyst to regulate and stabilize the hydrolysis reaction process, resisting HCl poisoning of the active centers, lowering the catalytic temperature of the carbonyl sulfur hydrolysis reaction, and improving its resistance to chlorine poisoning. This achieves low-temperature, low-energy, and stable removal of carbonyl sulfur from blast furnace gas, suitable for the hydrolysis of carbonyl sulfur in industrial gases (such as blast furnace gas). It solves the technical difficulties of deep desulfurization of existing blast furnace gas. The preparation method of this invention is simple and easy for industrial production.

[0019] Furthermore, the catalyst in this invention is prepared by liquid-assisted grinding, which is a mechanical synthesis method with low solvent consumption and energy-saving and environmentally friendly process.

[0020] Furthermore, in order to achieve efficient composite between two heterogeneous solid components, molecular sieve and alumina, this invention employs a mechanical grinding mechanism. By using a small amount of liquid solvent to wet the solid particles and form liquid film tension, the uniformity of particle composite during the grinding process is improved. Compared with liquid phase composite methods, this method is simpler to operate, easier to scale up, and has lower product separation difficulty.

[0021] Furthermore, the appropriate liquid / solid ratio has a significant impact on the degree of particle composite. Too little solvent is insufficient to fully wet the solid particles, resulting in severe particle pulverization during grinding and easy destruction of some structural components. Too much solvent will lead to difficulties in subsequent liquid-solid separation and incomplete drying.

[0022] Furthermore, the ratio of molecular sieve to alumina has a significant impact on the carbonyl sulfur hydrolysis performance of the composite catalyst. Excessive addition of molecular sieve is equivalent to diluting the active component, which is not conducive to the reaction, while insufficient addition of molecular sieve is not enough to form an effective water vapor buffer and capture HCl poisoning components. Attached Figure Description

[0023] Figure 1 This is a powder X-ray diffraction image of Example 1. Detailed Implementation

[0024] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0025] The room temperature in this invention is 25-30℃.

[0026] The present invention relates to a molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant hydrolysis of carbonyl sulfide, wherein the composite catalyst is composed of a molecular sieve and a carbonyl sulfide hydrolysis catalyst.

[0027] Molecular sieves account for 2.5-10% of the total mass of the composite catalyst; Molecular sieves include type A, type NaY, type ZSM-5, and the molecular sieve prepared from coal gangue in a mild and green manner (i.e., coal-based solid waste molecular sieve) as described in patent CN116947067B. The carbonyl sulfur hydrolysis catalyst is model W504 (manufactured by Wuhan Kelin Chemical Group Co., Ltd.), and its composition is K / Al2O3. The main component is γ-Al2O3 modified with alkali metal K; The preparation method of the molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide is as follows: First, a certain amount of molecular sieve and carbonyl sulfur hydrolysis catalyst are stirred and mixed evenly. After adding a certain amount of dispersing solvent, the mixture is prepared using a liquid-assisted grinding method. Then, the dispersing solvent is removed by drying, and the mixture is calcined and solidified. Wherein: The dispersion solvent is water, ethanol, or acetone; The ratio of dispersant solvent to solid material (the solid material is a mixture of molecular sieve and K / γ-Al2O3) is 1-5 ml: 1 g; Liquid-assisted grinding method is ball milling; ball milling speed: 50-200 r / min; Drying temperature is 70-100 o C, the time is 6-12 hours; Calcination temperature is 400-600 o C, the time is 4-8 hours.

[0028] Apparatus for evaluating the activity of molecular sieve / alumina composite catalyst and its experimental conditions: The carbonyl sulfur hydrolysis reaction was carried out in a fixed-bed reactor equipped with a temperature control device. This fixed-bed reactor mainly consisted of a U-shaped reaction tube with an inner diameter of 6 mm and an oil bath heating device. The reaction temperature was controlled at 60°C. o C or 70 o C, catalyst loading amount is 0.1 ml, volumetric space velocity (GHSV) is 15000 h⁻¹ -1 The total gas volumetric flow rate was 25 ml / min. The reaction mixture contained 300 ppm-COS, 500 ppm-HCl, and 5 vol.%-H2O, with Ar serving as the balance gas. The flow rates of COS and Ar were controlled by mass flow meters, while water and HCl were introduced via a micro-injection pump and thoroughly mixed through a vaporization device. All gas pipelines in the apparatus were made of polytetrafluoroethylene and subjected to 80°C corrosion protection. oTemperature control (C) was applied to prevent gas adsorption and water condensation within the pipeline, which could lead to the formation of dilute hydrochloric acid droplets and accelerate corrosion of the metal pipes. The composition of the gases at the reactor inlet and outlet was monitored in real-time using a gas chromatograph equipped with an FPD detector. Quantitative analysis was performed using the index method, and COS or H2S standard curves were plotted. A 1 mL sample of the reaction gas was analyzed.

[0029] The following are specific examples.

[0030] Example 1 (1) A certain amount of 4A molecular sieve and carbonyl sulfur hydrolysis catalyst were calcined at 500℃ for 6 h under N2 atmosphere to remove their organic impurities, and the treated 4A molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.95 g of the treated carbonyl sulfur hydrolysis catalyst and 0.05 g of the treated 4A molecular sieve powder, mix them, add 2 ml of deionized water, and mix them under ball milling conditions of 200 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 70°C. o C. Remove water from an oil bath system with a stirring speed of 20 r / min for 6 h; (4) Expose the solid after water removal in step (3) to air at 550°C. o At C (heating rate 5) o After calcination at C / min for 8 h, 4A molecular sieve / alumina composite catalyst was obtained, which is a molecular sieve / alumina composite catalyst for low-temperature carbonyl sulfur and resistant to chlorine hydrolysis.

[0031] See Figure 1 As can be seen, the obtained composite catalyst simultaneously possesses the XRD characteristic diffraction peaks of both 4A molecular sieve and γ-Al2O3, indicating that the two are effectively combined and retain their original crystal phase structure.

[0032] Example 2 (1) A certain amount of 4A molecular sieve and carbonyl sulfur hydrolysis catalyst were calcined at 400°C for 6 hours under N2 atmosphere to remove their organic impurities, and the treated 4A molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.975 g of the treated carbonyl sulfur hydrolysis catalyst and 0.025 g of the treated 4A molecular sieve powder, mix them, add 2 ml of deionized water, and mix them under ball milling conditions of 200 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 70°C. o C. Remove water from an oil bath system with a stirring speed of 20 r / min for 6 h; (4) Expose the solid after water removal in step (3) to air at 550°C. o At C (heating rate 5)o After calcination at C / min for 8 h, 4A molecular sieve / alumina composite catalyst was obtained, which is a molecular sieve / alumina composite catalyst for low-temperature carbonyl sulfur and resistant to chlorine hydrolysis.

[0033] Example 3 (1) Appropriate amounts of 4A molecular sieve and carbonyl sulfur hydrolysis catalyst were calcined at 600°C for 6 hours under N2 atmosphere to remove their organic impurities, and the treated 4A molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.9 g of the treated carbonyl sulfur hydrolysis catalyst and 0.1 g of the treated 4A molecular sieve powder, mix them, add 2 ml of deionized water, and mix them under ball milling conditions of 200 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 70°C. o C. Remove water from an oil bath system with a stirring speed of 20 r / min for 6 h; (4) Expose the solid after water removal in step (3) to air at 550°C. o At C (heating rate 5) o After calcination at C / min for 8 h, 4A molecular sieve / alumina composite catalyst was obtained, which is a molecular sieve / alumina composite catalyst for low-temperature carbonyl sulfur and resistant to chlorine hydrolysis.

[0034] Example 4 (1) Appropriate amounts of NaY molecular sieve and carbonyl sulfur hydrolysis catalyst were calcined at 500°C for 6 hours under N2 atmosphere to remove their organic impurities, and the treated NaY molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.9 g of the treated carbonyl sulfur hydrolysis catalyst and 0.1 g of the treated NaY molecular sieve powder, mix them, add 1 ml of deionized water, and mix them under ball milling conditions of 50 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 70°C. o C. Remove water from an oil bath system with a stirring speed of 20 r / min for 6 h; (4) Expose the solid after water removal in step (3) to air at 500°C. o At C (heating rate 2.5) o After calcination at C / min for 6 h, NaY molecular sieve / alumina composite catalyst was obtained, which is a molecular sieve / alumina composite catalyst for low-temperature carbonyl sulfur and resistant to chlorine hydrolysis.

[0035] Example 5 (1) A certain amount of NaY molecular sieve and carbonyl sulfur hydrolysis catalyst were calcined at 600℃ for 6 hours under N2 atmosphere to remove their organic impurities, and the treated NaY molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.975 g of the treated carbonyl sulfur hydrolysis catalyst and 0.025 g of the treated NaY molecular sieve powder, mix them, add 5 ml of deionized water, and mix them under ball milling conditions of 50 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 100°C. o C. Remove water from an oil bath system with a stirring speed of 20 r / min for 12 h; (4) Expose the solid after water removal in step (3) to air at 400°C. o At C (heating rate 5) o After calcination at C / min for 4 h, NaY molecular sieve / alumina composite catalyst was obtained, which is a molecular sieve / alumina composite catalyst for low-temperature carbonyl sulfur and resistance to chlorine hydrolysis.

[0036] Example 6 (1) A certain amount of ZSM-5 molecular sieve and carbonyl sulfur hydrolysis catalyst were calcined at 500°C for 6 hours under N2 atmosphere to remove their organic impurities, and the treated ZSM-5 molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.9 g of the treated carbonyl sulfur hydrolysis catalyst and 0.1 g of the treated ZSM-5 molecular sieve powder, mix them, add 2 ml of deionized water, and mix them under ball milling conditions of 100 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 80°C. o C. Remove water from the oil bath system at a stirring speed of 50 r / min for 12 hours; (4) Expose the solid after water removal in step (3) to air at 550°C. o At C (heating rate 5) o ZSM-5 molecular sieve / alumina composite catalyst was obtained after calcination for 8 h at C / min. This catalyst is a molecular sieve / alumina composite catalyst for low-temperature carbonyl sulfur and resistance to chlorine hydrolysis.

[0037] Example 7 (1) A suitable amount of ZSM-5 molecular sieve and carbonyl sulfur hydrolysis catalyst were calcined at 600°C for 6 hours under N2 atmosphere to remove their organic impurities, and the treated ZSM-5 molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.95 g of the treated carbonyl sulfur hydrolysis catalyst and 0.05 g of the treated ZSM-5 molecular sieve powder, mix them, add 1 ml of deionized water, and mix them under ball milling conditions of 200 r / min to obtain a solid powder mixture; (3) Heat the mixture sample from step (2) at a temperature of 80°C. o C. Remove water from the oil bath system at a stirring speed of 50 r / min for 12 hours; (4) Expose the solid after water removal in step (4) to air at 550°C. o At C (heating rate 5) o ZSM-5 molecular sieve / alumina composite catalyst was obtained after calcination for 8 h at C / min. This catalyst is a molecular sieve / alumina composite catalyst for low-temperature carbonyl sulfur and resistance to chlorine hydrolysis.

[0038] Example 8 (1) Appropriate amounts of coal-based solid waste molecular sieve (the molecular sieve prepared from coal gangue in a mild and green manner in patent CN116947067B) and carbonyl sulfur hydrolysis catalyst were calcined at 600°C for 6 hours under N2 atmosphere to remove their organic impurities, and the treated coal-based solid waste molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.9 g of the treated carbonyl sulfur hydrolysis catalyst and 0.1 g of the treated coal-based solid waste molecular sieve, mix them, add 2 ml of deionized water, and mix them under ball milling conditions of 200 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 70°C. o C. Remove water from the oil bath system at a stirring speed of 50 r / min for 12 hours; (4) Expose the solid after water removal in step (3) to air at 600°C. o At C (heating rate 5) o After calcination at C / min for 6 h, a coal-based solid waste molecular sieve / alumina composite catalyst was obtained, which is a molecular sieve / alumina composite catalyst for low-temperature carbonyl sulfur and resistant to chlorine hydrolysis.

[0039] Example 9 (1) Appropriate amounts of coal-based solid waste molecular sieve (the molecular sieve prepared from coal gangue in a mild and green manner in patent CN116947067B) and carbonyl sulfur hydrolysis catalyst were calcined at 500°C for 6 hours under N2 atmosphere to remove their organic impurities, and the treated coal-based solid waste molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.975 g of treated carbonyl sulfur hydrolysis catalyst and 0.025 g of treated coal-based solid waste molecular sieve, mix them, add 2 ml of ethanol, and mix them under ball milling conditions of 100 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 70°C. o C. Remove ethanol from an oil bath system with a stirring speed of 50 r / min for 6 h; (5) Expose the solid after removing ethanol in step (4) to air at 600°C. o At C (heating rate 5) o After calcination at C / min for 8 hours, a coal-based solid waste molecular sieve / alumina composite catalyst was obtained, which is a molecular sieve / alumina composite catalyst for low-temperature carbonyl sulfur and resistant to chlorine hydrolysis.

[0040] Example 10 (1) Appropriate amounts of coal-based solid waste molecular sieve (the molecular sieve prepared from coal gangue in a mild and green manner in patent CN116947067B) and carbonyl sulfur hydrolysis catalyst were calcined at 500°C for 6 hours under N2 atmosphere to remove their organic impurities, and the treated coal-based solid waste molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.95 g of the treated carbonyl sulfur hydrolysis catalyst and 0.05 g of the treated coal-based solid waste molecular sieve, mix them, add 5 ml of acetone, and mix them under ball milling conditions of 200 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 70°C. o C. Remove acetone in an oil bath system with a stirring speed of 50 r / min for 12 h; (4) The solid after removing acetone in step (3) is placed in an air atmosphere at 600°C. o At C (heating rate 5) o After calcination at C / min for 6 hours, a coal-based solid waste molecular sieve / alumina composite catalyst was obtained, which is a molecular sieve / alumina composite catalyst for low-temperature carbonyl sulfur and resistant to chlorine hydrolysis.

[0041] Comparative Example 1 The industrial carbonyl sulfur hydrolysis catalyst was calcined at 600°C for 6 hours in air to remove its organic impurities, and then used as a comparative sample for carbonyl sulfur hydrolysis testing.

[0042] Comparative Example 2 (1) Appropriate amounts of SAPO-34 molecular sieve and carbonyl sulfur hydrolysis catalyst were calcined at 600°C for 6 hours under N2 atmosphere to remove their organic impurities, and the treated SAPO-34 molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.9 g of the treated carbonyl sulfur hydrolysis catalyst and 0.1 g of the treated SAPO-34 molecular sieve powder, mix them, add 2 ml of deionized water, and mix them under ball milling conditions of 200 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 70°C. o C. Remove water from an oil bath system with a stirring speed of 20 r / min for 6 h; (4) Expose the solid after water removal in step (3) to air at 550°C. o Calcination at C for 8 hours (heating rate 5) o After (C / min), SAPO-34 molecular sieve / alumina composite catalyst was obtained.

[0043] Comparative Example 3 (1) Calcine appropriate amounts of 13X molecular sieve and carbonyl sulfur hydrolysis catalyst at 600°C for 6 hours under N2 atmosphere to remove their organic impurities and obtain the treated 13X molecular sieve and carbonyl sulfur hydrolysis catalyst. (2) Take 0.9 g of the treated carbonyl sulfur hydrolysis catalyst and 0.1 g of the treated 13X molecular sieve powder, mix them, add 2 ml of deionized water, and mix them under ball milling conditions of 200 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 70°C. o C. Remove water from an oil bath system with a stirring speed of 20 r / min for 6 h; (4) Expose the solid after water removal in step (3) to air at 550°C. o Calcination at C for 8 hours (heating rate 5) o After (C / min), a 13X molecular sieve / alumina composite catalyst was obtained.

[0044] Comparative Example 4 (1) Appropriate amounts of 4A molecular sieve and carbonyl sulfur hydrolysis catalyst were calcined at 600°C for 6 hours under N2 atmosphere to remove their organic impurities, and the treated 4A molecular sieve and carbonyl sulfur hydrolysis catalyst were obtained. (2) Take 0.75 g of the treated carbonyl sulfur hydrolysis catalyst and 0.25 g of the treated 4A molecular sieve powder, mix them, add 2 ml of deionized water, and mix them under ball milling conditions of 200 r / min to obtain a mixture sample; (3) Heat the mixture sample from step (2) at a temperature of 70°C. o C. Remove water from an oil bath system with a stirring speed of 20 r / min for 6 h; (4) Expose the solid after water removal in step (3) to air at 550°C. o Calcination at C for 8 hours (heating rate 5) o After (C / min), 4A molecular sieve / alumina composite catalyst was obtained.

[0045] Table 1 compares the carbonyl sulfide removal rates of the hydrolysis catalysts in the comparative examples and the embodiments.

[0046] Note: The improvement ratio is defined as the percentage performance improvement of the example compared to Comparative Example 1.

[0047] Table 2 compares the low-temperature performance and chlorine resistance of the hydrolysis catalysts in the comparative examples and embodiments.

[0048] Note 1) Low temperature performance is defined as 70 o Catalytic lifetime with carbonyl sulfide removal rate greater than 90% at C, in hours; 2) Chlorine resistance is defined as 70. o Catalytic lifetime in a reaction system containing acid (500 ppm HCl) at C, with a carbonyl sulfide removal rate greater than 90%, in hours; 3) The improvement ratio is defined as the percentage improvement in performance of the example compared to Comparative Example 1.

[0049] By comparing the examples and comparative examples, it can be seen that the composite catalyst in this invention has better performance than the carbonyl sulfur hydrolysis catalyst. The molecular sieve in this invention is also screened. Other molecular sieves, such as SAPO-34 molecular sieve or 13X molecular sieve, cannot achieve the catalytic effect of this invention. Furthermore, the amount of molecular sieve used cannot exceed the ratio range between the amount of molecular sieve and the amount of carbonyl sulfur hydrolysis catalyst.

[0050] The above description is only of the preferred embodiment of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All variations made within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis, characterized in that, The composite catalyst includes a molecular sieve and a carbonyl sulfur hydrolysis catalyst, wherein the mass of the molecular sieve is 2.5-10% of the total mass of the composite catalyst.

2. The molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis according to claim 1, characterized in that, The molecular sieves are of type A, type NaY, type ZSM-5, or coal-based solid waste molecular sieves.

3. A method for preparing a molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis, characterized in that, Includes the following steps: Molecular sieves and carbonyl sulfur hydrolysis catalysts were mixed evenly, then a dispersing solvent was added, and the mixture was mixed by liquid-assisted grinding. After drying and calcination, a molecular sieve / alumina composite catalyst for low-temperature and chlorine-resistant hydrolysis of carbonyl sulfur was obtained.

4. The method for preparing the molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis according to claim 3, characterized in that, The dispersion solvent is water, ethanol, or acetone.

5. The method for preparing the molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis according to claim 3, characterized in that, The ratio of the amount of dispersing solvent to the amount of the mixture of molecular sieve and carbonyl sulfur hydrolysis catalyst is 1-5 ml: 1 g.

6. The method for preparing the molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis according to claim 3, characterized in that, Liquid-assisted grinding is ball milling at 50-200 r / min.

7. The method for preparing the molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis according to claim 3, characterized in that, The mass of the molecular sieve is 2.5-10% of the total mass of the composite catalyst.

8. The method for preparing the molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis according to claim 3, characterized in that, The molecular sieves are of type A, type NaY, type ZSM-5, or coal-based solid waste molecular sieves.

9. The method for preparing the molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis according to claim 3, characterized in that, Drying temperature is 70-100 o C, the time is 6-12 hours.

10. The method for preparing the molecular sieve / alumina composite catalyst for low-temperature, chlorine-resistant carbonyl sulfide hydrolysis according to claim 3, characterized in that, Calcination temperature is 400-600 o C, the time is 4-8 hours.

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