Catalyst for inhibiting methane generation, method for preparing the same, and use thereof

Abstract

The present application relates to the field of catalysis technology, and is a catalyst for inhibiting methane generation, a preparation method and application thereof, which comprises the following steps: mixing a required amount of a carrier and toluene to obtain a first mixture; adding a silicon source, an aluminum source, an alkali and a template agent into a solvent, and mixing under a required temperature condition to obtain a second mixture; adding a required amount of crystal seeds and the first mixture into the second mixture, and stirring and mixing to obtain a third mixture; performing dynamic crystallization on the third mixture, and drying to obtain catalyst carrier powder; and impregnating the catalyst carrier powder in an aqueous solution containing a compound of elements Ca and Mg, and performing calcination treatment to obtain the catalyst for inhibiting methane generation.The catalyst has a large specific surface area, and can regulate acid centers and promote catalytic performance through the synergistic effect between metal elements.When the catalyst is used for catalyzing the reaction of methanol coupling light hydrocarbon to olefin, the carbon-based yield of low-carbon olefin is high, and the generation of reaction by-products, i.e., methane, can be significantly inhibited.

Description

Technical Field

[0001] This invention relates to the field of catalysis technology, specifically a catalyst for inhibiting methane formation, its preparation method, and its application. Background Technology

[0002] Symbiotic molecular sieves often produce unexpected results. Through symbiosis, their pore and framework structures can be improved, their acidity can be modulated, and thus their catalytic performance can be affected. ZSM-5 and ZSM-11 molecular sieves are similar in structure, both consisting of eight 5-membered rings [5]. 8 ] units, these [5 8 The units form a five-silicon chain (Pentasil chain) parallel to the C-axis through shared edges. Adjacent Pentasil chains are connected in a centrosymmetric manner to form the ZSM-5 structure, while they are connected in a mirror-symmetric manner to form the ZSM-11 structure. Due to their excellent shape selectivity, ZSM-5 / ZSM-11 has been applied in many fields.

[0003] Ethylene, propylene, and other low-carbon olefins are important basic chemical raw materials with high demand. They are mainly produced via petroleum routes, but with increasing difficulty in petroleum resource extraction, the supply of raw materials for traditional ethylene and propylene production is becoming increasingly tight, leading to rising costs. Based on my country's resource characteristics, routes for producing ethylene and propylene from methanol obtained through coal chemical processes have also developed rapidly, such as methanol-to-olefins (MTO) and methanol-to-propylene (MTP) technologies. In addition, methanol-coupled light hydrocarbon reactions to produce olefins (hydrocracking of light naphtha, reforming residue oil, and reforming topping oil) have also attracted research attention in recent years. This involves introducing methanol as an activator in light hydrocarbon cracking reactions, resulting in heat and mass coupling. The reaction conditions are mild and controllable, with high feedstock conversion and product yield. However, methane is generated as a byproduct in the methanol-coupled light hydrocarbon olefin production process. To produce high-quality low-carbon olefins, a demethanizer is required in subsequent processes. Because methane is stable, especially when the reaction products contain high levels of methane, separation becomes more difficult and complex, directly increasing production costs.

[0004] Chinese patent document CN102875297A discloses a method for preparing low-carbon olefins using methanol and naphtha. This invention mainly addresses the problem of low yield of low-carbon olefins in the prior art. It adopts a fluidized bed, with naphtha feedstock entering riser I and contacting the regenerator. The product and catalyst enter the settling tank, and after gas-solid separation, the product stream enters the separation section. The separated C4 and above hydrocarbons enter riser II and contact the regenerated catalyst. The technical solution where the inlet ends of risers I and II are located in the regenerator and the outlet ends are located in the settling tank effectively solves the problem of low yield of low-carbon olefins. The carbon-based yield of low-carbon olefins can reach up to 62.19%. However, this process uses a fluidized bed reaction process, which is relatively harsh and requires a high reaction temperature. The reaction temperature at which the carbon-based yield of low-carbon olefins is highest is 650℃.

[0005] Chinese invention patent CN116768225A discloses a method for preparing SAPO eutectic molecular sieves using a methanol-to-olefins (MTO) catalyst. This method uses the MTO catalyst as part of the silicon, aluminum, and phosphorus source in the synthesis raw materials, then mixes it with silicon, aluminum, phosphorus, organic amine R, and deionized water, followed by hydrothermal crystallization, centrifugation, washing, and drying to obtain the SAPO eutectic molecular sieve. This invention, using an MTO catalyst to prepare SAPO eutectic molecular sieves, solves the problem of large-scale emissions of MTO waste catalysts while also achieving efficient and rapid utilization of the waste catalyst. The SAPO eutectic molecular sieve synthesized by this invention has excellent performance, but its primary objective is not to reduce the methane content of the byproduct while ensuring a low-carbon olefin yield.

[0006] Chinese invention patent CN104109070A discloses a product separation method for methanol-to-propylene, providing an olefin stream (11); the olefin stream (11) is divided into a gaseous stream I and a liquid stream I in compression zone A; the gaseous stream I is partially deoxygenated and CO is removed in the second mixture in the washing zone, and the gaseous hydrocarbon stream (16) and the liquid stream I from compression zone A are sent to a gas-liquid separator C; the gaseous stream II flowing out of separator C goes to a gas dryer D, and after drying, it becomes dried stream I; dried stream I and dried stream II are sent to a separation tower; the top stream II of the separation tower H is returned to the methanol-to-propylene reactor as a reactant. This technical solution effectively solves these problems and can be applied to the industrial production of methanol-to-propylene. This invention mainly solves the technical problems of large propylene loss, complex process flow, and high energy consumption in the prior art, but does not reduce the methane content or the energy consumption of the equipment from the root cause of the problem.

[0007] Chinese invention patent CN111072438A discloses a methanol-to-olefins (MTO) reverse reprocess and a method for separating the products. In the product separation, the demethanizer temperature is higher than in existing technologies. By appropriately increasing the pressure, components such as methane and hydrogen are separated, and ethylene and propylene are effectively recovered. The separation process temperature of this invention is relatively high, and the refrigerant temperature used is higher than that of other ethylene and propane refrigerants.

[0008] Therefore, given the characteristics of existing technologies, there is an urgent need to prepare a catalyst for the catalytic coupling of light hydrocarbons to olefins reaction system, which can achieve high yield of low-carbon olefin carbon-based products under mild and controllable reaction conditions, while filling the technological gap in existing technologies where the methane content of the byproduct is high. Summary of the Invention

[0009] This invention provides a catalyst for inhibiting methane formation, overcoming the shortcomings of the prior art, and effectively solving the problem of high methane content in the byproduct generated during the existing methanol-coupled light hydrocarbon to olefins reaction.

[0010] One of the technical solutions of the present invention is achieved through the following measures: a method for preparing a catalyst to inhibit methane formation, comprising the following steps: Step 1: Mix the required amount of carrier and toluene to obtain the first mixture; Step 2: Add silicon source, aluminum source, alkali, and template agent to the solvent and mix them under the required temperature conditions to obtain a second mixture; Step 3: Add the required amount of seed crystals and the first mixture to the second mixture, stir and mix to obtain the third mixture; Step 4: Dynamically crystallize the third mixture and dry it to obtain catalyst support powder; Step 5: Impregnate the catalyst support powder in an aqueous solution containing Ca and Mg elements, wash and filter to obtain a filter cake; Step 6: Calcine the filter cake to obtain a powdered catalyst for inhibiting methane formation.

[0011] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions: In step one above, the support is one of boehmite (represented by Al2O3), sepiolite (represented by Mg8Si6), and diatomite (represented by SiO2), and the grain size of the support is ≤1000μm; the mass ratio of the support to toluene is 1:1 to 10.

[0012] In step two above, the silicon source is one of tetraethyl orthosilicate, silica sol, silica gel, and solid silica; the aluminum source is one or more of aluminum sulfate, aluminum chloride, aluminum nitrate, and aluminum isopropoxide; the alkali is one of ammonia and potassium hydroxide; the template agent is one or more of tetrabutylammonium hydroxide, tetrabutylammonium bromide, n-butylamine, or di-n-octylamine; and the solvent is one of ethanol, propanol, and toluene.

[0013] In step two above, the composition of silicon source, alkali, aluminum source, template agent and solvent is in molar parts: silicon source is 10 to 600 parts of SiO2, alkali is 0.02 to 0.2 parts, aluminum source is 1.0 part of Al2O3, template agent is 0.5 to 5.0 parts and solvent is 100 to 3000 parts.

[0014] In step two above, the stirring temperature is from room temperature to 100°C, and the stirring time is from 2 hours to 10 hours.

[0015] In step three above, the seed crystal is one or both of ZSM-5 / ZSM-11 symbiotic molecular sieve and ZSM-11 molecular sieve; the mass ratio of seed crystal to support is 1:0.01 to 1.

[0016] In step three above, the stirring temperature is room temperature, and the stirring time is 0.5h to 5h.

[0017] In step four above, dynamic crystallization includes a second stage of crystallization following a first stage of crystallization; the first stage crystallization temperature is 80℃ to 200℃, and the hydrothermal crystallization time is 12h to 48h; the second stage crystallization temperature is 140℃ to 220℃, and the hydrothermal crystallization time is 24h to 84h; the dynamic crystallization rotation speed is 50r / h to 300r / h.

[0018] In step four above, the drying conditions are 60℃ to 180℃ for 4 to 24 hours.

[0019] In step five above, the compound containing Ca is one or more of CaO, CaCO3, Ca(NO3)2, CaSO4, and CaCl2; the compound containing Mg is one or more of MgCO3, Mg(NO3)2, MgSO4, and MgCl2; and in the aqueous solution containing the compounds containing Ca and Mg, the mass concentration of Ca is 1% to 15% and the mass concentration of Mg is 1% to 15%.

[0020] In step five above, the impregnation is performed using an equal-volume impregnation method, the impregnation temperature is from room temperature to 120°C, and the impregnation time is from 12 hours to 48 hours.

[0021] In step six above, the calcination conditions are: calcination temperature of 400℃ to 800℃, calcination time of 2 hours to 10 hours. Preferably, the muffle furnace calcination temperature is 500℃ to 700℃, and the calcination time is 4 hours to 6 hours.

[0022] The second technical solution of the present invention is achieved by the following measures: a catalyst for inhibiting methane generation prepared according to the preparation method of the catalyst for inhibiting methane generation according to one of the above technical solutions.

[0023] The third technical solution of the present invention is achieved through the following measures: the application of a catalyst for inhibiting methane formation in the catalytic reaction of methanol coupled with light hydrocarbons to produce olefins.

[0024] The following are further optimizations and / or improvements to the third technical solution of the above invention: The above-mentioned methanol-to-olefins reaction process coupled with light hydrocarbons includes the following steps: Methanol and light hydrocarbons are added to a reactor pre-loaded with a catalyst to inhibit methane formation, and the reaction takes place under the required temperature, pressure, and space velocity conditions. The aforementioned light hydrocarbons include one or more of the following: reformate residue oil, reformate topping oil, pentane oil, hydrocracking naphtha, n-butane, n-pentane, and n-hexane; the reactor is a fixed-bed reactor, a moving-bed reactor, or a fluidized-bed reactor, preferably a fixed-bed reactor; the reaction temperature is 360℃ to 600℃, the pressure is 0 to 1.0 MPa, and the space velocity is 0.5 h⁻¹. -1 Up to 5 hours -1 .

[0025] This invention provides a multilayered ZSM-5 / ZSM-11 symbiotic molecular sieve with moderate acidity. The acidity centers of the catalyst are controlled by metal modification, resulting in a large specific surface area. The acidity centers are regulated and catalytic performance is enhanced through the synergistic effect between metal elements. Under mild and controllable process conditions, when this catalyst is used to catalyze the methanol-to-olefins reaction coupled with light hydrocarbons, the yield of low-carbon olefins is high, and the formation of the reaction byproduct methane is significantly suppressed. This eliminates the need for a demethanizer or reduces the load on the methane tower, simplifying subsequent separation processes. Consequently, it eliminates the need for a large amount of refrigeration equipment, shortens the process flow, improves the safety factor of the equipment, fundamentally improves the reliability of the technology, reduces investment and operating costs, and meets carbon emission reduction requirements. It fills the technological gap in existing technologies that produce high methane content as a byproduct, and is more in line with future environmental protection requirements. Detailed Implementation

[0026] This invention is not limited to the following embodiments, and specific implementation methods can be determined according to the technical solutions and actual conditions of this invention. Unless otherwise specified, all chemical reagents and chemicals mentioned in this invention are well-known and commonly used chemical reagents and chemicals in the prior art; unless otherwise specified, all percentages in this invention are mass percentages; unless otherwise specified, all solutions in this invention are aqueous solutions with water as the solvent, for example, hydrochloric acid solution is an aqueous solution of hydrochloric acid; room temperature in this invention generally refers to a temperature between 15°C and 25°C, generally defined as 25°C.

[0027] The present invention will be further described below with reference to embodiments: Example 1: The preparation method of this catalyst for inhibiting methane formation includes the following steps: Step 1: Mix the required amount of carrier and toluene to obtain the first mixture; Step 2: Add silicon source, aluminum source, alkali, and template agent to the solvent and mix them under the required temperature conditions to obtain a second mixture; Step 3: Add the required amount of seed crystals and the first mixture to the second mixture, stir and mix to obtain the third mixture; Step 4: Dynamically crystallize the third mixture and dry it to obtain catalyst support powder; Step 5: Impregnate the catalyst support powder in an aqueous solution containing Ca and Mg elements, wash and filter to obtain a filter cake; Step 6: Calcine the filter cake to obtain a powdered catalyst for inhibiting methane formation.

[0028] Example 2: As an optimization of the above example, in step one, the support is one of boehmite (represented by Al2O3), sepiolite (represented by Mg8Si6) and diatomite (represented by SiO2), and the grain size of the support is ≤1000μm; the mass ratio of the support to toluene is 1:1 to 10.

[0029] Example 3: As an optimization of the above examples, in step two, the silicon source is one of tetraethyl orthosilicate, silica sol, silica gel and solid silica; the aluminum source is one or more of aluminum sulfate, aluminum chloride, aluminum nitrate and aluminum isopropoxide; the alkali is one of ammonia and potassium hydroxide; the template agent is one or more of tetrabutylammonium hydroxide, tetrabutylammonium bromide, n-butylamine or di-n-octylamine; and the solvent is one of ethanol, propanol and toluene.

[0030] Example 4: As an optimization of the above example, in step two, the composition of silicon source, alkali, aluminum source, template agent and solvent is as follows, in molar parts: silicon source is 10 to 600 parts of SiO2, alkali is 0.02 to 0.2 parts, aluminum source is 1.0 part of Al2O3, template agent is 0.5 to 5.0 parts and solvent is 100 to 3000 parts.

[0031] Example 5: As an optimization of the above example, in step two, the stirring temperature is room temperature to 100°C, and the stirring time is 2 hours to 10 hours.

[0032] Example 6: As an optimization of the above example, in step three, the seed crystal is one or both of ZSM-5 / ZSM-11 symbiotic molecular sieve and ZSM-11 molecular sieve; the mass ratio of seed crystal to support is 1:0.01 to 1.

[0033] Example 7: As an optimization of the above example, in step three, the stirring temperature is room temperature and the stirring time is 0.5h to 5h.

[0034] Example 8: As an optimization of the above embodiment, in step four, dynamic crystallization includes a first-stage crystallization followed by a second-stage crystallization; the first-stage crystallization temperature is 80°C to 200°C, and the hydrothermal crystallization time is 12h to 48h; the second-stage crystallization temperature is 140°C to 220°C, and the hydrothermal crystallization time is 24h to 84h; the dynamic crystallization rotation speed is 50r / h to 300r / h. Specifically, the dynamic crystallization of the third mixture is carried out in a polytetrafluoroethylene-lined crystallization reactor; preferably, the first-stage crystallization temperature is 120°C to 180°C, and the hydrothermal crystallization time is 18h to 36h; the second-stage crystallization temperature is 150°C to 180°C, and the second-stage crystallization time is 48h to 72h.

[0035] Example 9: As an optimization of the above embodiment, in step four, the drying conditions are 60°C to 180°C for 4 to 24 hours. Preferably, the drying conditions are 80°C to 150°C for 6 to 18 hours.

[0036] Example 10: As an optimization of the above example, in step five, the compound containing Ca is one or more of CaO, CaCO3, Ca(NO3)2, CaSO4, and CaCl2; the compound containing Mg is one or more of MgCO3, Mg(NO3)2, MgSO4, and MgCl2; in the aqueous solution containing the compounds containing Ca and Mg, the mass concentration of Ca is 1% to 15%, and the mass concentration of Mg is 1% to 15%.

[0037] Example 11: As an optimization of the above example, in step five, the impregnation is an equal volume impregnation method, the impregnation temperature is room temperature to 120°C, and the impregnation time is 12h to 48h.

[0038] Example 12: As an optimization of the above example, in step six, the calcination conditions are: calcination temperature of 400℃ to 800℃, calcination time of 2h to 10h. Preferably, the muffle furnace calcination temperature is 500℃ to 700℃, and the calcination time is 4h to 6h.

[0039] After calcination, the catalyst product is crushed into powder to obtain a symbiotic molecular sieve powder with a multi-layered coating structure (denoted as Y%Z%@ZSM-5 / ZSM-11@X, where Y represents the mass concentration of the impregnating element, Z represents the impregnated element, and X represents the support). This is the extruded form of the methane-inhibiting catalyst of the present invention. As needed, the powdered methane-inhibiting catalyst is extruded using a 0.1 mol / L oxalic acid solution as a binder. After extrusion, it is dried at 60°C to 200°C for 4 to 48 hours, preferably at 80°C to 160°C for 6 to 24 hours. Then, it is calcined again in a muffle furnace at a temperature of 450°C to 800°C for 2 to 12 hours, preferably at 500°C to 700°C for 4 to 8 hours, to obtain a multi-layered coated methane-inhibiting catalyst, which can be used in the catalytic reaction of methanol coupled with light hydrocarbons to olefins. The catalyst for inhibiting methane formation prepared in this invention is a Y%Z%@ZSM-5 / ZSM-11@X symbiotic molecular sieve with a multilayer coating structure. It has the characteristics of small crystal size, large specific surface area and moderate acidity, and has good prospects for industrial application.

[0040] Example 13: The catalyst for inhibiting methane formation prepared by the method described above.

[0041] Example 14: Application of the catalyst that inhibits methane formation in the catalytic reaction of methanol coupled with light hydrocarbons to olefins.

[0042] Example 15: As an optimization of the above examples, the methanol-coupled light hydrocarbon to olefin reaction process includes the following steps: Methanol and light hydrocarbons are added to a reactor pre-loaded with a catalyst to suppress methane formation, and the reaction takes place under the required temperature, pressure, and space velocity conditions.

[0043] Example 16: As an optimization of the above examples, the light hydrocarbons include one or more of reformate raffinate, reformate topping oil, pentane oil, hydrocracking naphtha, n-butane, n-pentane, and n-hexane; the reactor is a fixed-bed reactor, a moving-bed reactor, or a fluidized-bed reactor, preferably a fixed-bed reactor; the reaction temperature is 360°C to 600°C, the pressure is 0 to 1.0 MPa, and the space velocity is 0.5 h⁻¹. -1 Up to 5 hours -1 .

[0044] Example 17: The preparation process and application of this catalyst for inhibiting methane formation are as follows: S1. Mix and dissolve 5.3g of diatomaceous earth with 8.9g of toluene to obtain the first mixture.

[0045] S2. Mix 82.8g of tetraethyl orthosilicate, 1.26g of aluminum sulfate, 0.12g of ammonia (25% by mass), 6.5g of tetrabutylammonium bromide and 23.5g of ethanol at 50°C for 2 hours to obtain a second mixture.

[0046] S3. Add 0.2g of seed ZSM-5 / ZSM-11 symbiotic molecular sieve and the first mixture to the second mixture, stir at room temperature for 2h to obtain the third mixture.

[0047] S4. The third mixture is transferred to a crystallization vessel with a polytetrafluoroethylene liner for two-stage dynamic crystallization. The first stage of crystallization is hydrothermal crystallization at 100°C for 24 hours, and the second stage of crystallization is hydrothermal crystallization at 200°C for 36 hours. The stirring rate during dynamic crystallization is 120 r / h. The mixture after dynamic crystallization is cooled, filtered, and dried at 100°C for 10 hours to obtain ZSM-5 / ZSM-11@SiO2 powder.

[0048] S5. Weigh CaO and MgCO3 according to the loading of 2% Ca and 10% Mg and the equal volume impregnation method to prepare a solution. Impregnate the prepared ZSM-5 / ZSM-11@SiO2 powder at room temperature for 20 h, and record it as 2%Ca10%Mg@ZSM-5 / ZSM-11@SiO2. Filter and wash until neutral to obtain filter cake.

[0049] S6. The filter cake was dried at 120℃ for 14 hours and then calcined in a muffle furnace at 480℃ for 6 hours to obtain 2%Ca10%Mg@ZSM-5 / ZSM-11@SiO2 powder with a multi-layer coating structure.

[0050] S7. Using 0.1 mol / L oxalic acid solution as a binder, 2%Ca10%Mg@ZSM-5 / ZSM-11@SiO2 powder was extruded into strips, then dried at 100℃ for 12 h, and calcined in a muffle furnace at 450℃ for 12 h to obtain 2%Ca10%Mg@ZSM-5 / ZSM-11@SiO2 strip catalyst with a multi-layered coating structure after extrusion.

[0051] The 2%Ca10%Mg@ZSM-5 / ZSM-11@SiO2 strip catalyst of this embodiment is used as the catalyst for the methanol-to-olefins reaction coupled with light hydrocarbons. In a fixed-bed reactor, methanol:raffinate oil = 5:5 (mass ratio) is used as the feedstock, and the reaction is carried out at 400°C, 0.5 MPa, and 0.5 h. -1 The reaction was carried out under specific conditions. After the reaction was completed, the product composition was analyzed by gas chromatography. The product yielded 100% methanol conversion, 45.7% low-carbon olefin carbon-based yield, and 0.06% methane carbon-based yield.

[0052] Example 18: The preparation process and application of this catalyst for inhibiting methane formation are as follows: S1. Mix and dissolve 8.6g of pseudoboehmite (Al2O3) with 15.7g of toluene to obtain the first mixture.

[0053] S2. Mix 36.9g of tetraethyl orthosilicate, 1.8g of aluminum chloride, 0.1g of ammonia (25% by mass), 29.8g of tetrabutylammonium hydroxide and 94.7g of propanol at 40°C for 6 hours to obtain a second mixture.

[0054] S3. Add 1.1g of seed ZSM-5 / ZSM-11 symbiotic molecular sieve and the first mixture to the second mixture, stir at room temperature for 4h to obtain the third mixture.

[0055] S4. The third mixture is transferred to a crystallization vessel with a polytetrafluoroethylene liner for two-stage dynamic crystallization. The first stage of crystallization is hydrothermal crystallization at 160℃ for 24 hours, and the second stage of crystallization is hydrothermal crystallization at 180℃ for 48 hours. The stirring rate during dynamic crystallization is 100 r / h. The mixture after dynamic crystallization is cooled, filtered, and dried at 80℃ for 12 hours to obtain ZSM-5 / ZSM-11@Al2O3 powder.

[0056] S5. Weigh CaCO3 and MgSO4 according to the loading of 5% Ca and 5% Mg and the equal volume impregnation method to prepare a solution. Impregnate the prepared ZSM-5 / ZSM-11@Al2O3 powder at 30℃ for 24h, and record it as 2%Ca5%Mg@ZSM-5 / ZSM-11@Al2O3. Filter and wash until neutral to obtain filter cake.

[0057] S6. The filter cake was dried at 80℃ for 24 hours and then calcined in a muffle furnace at 500℃ for 10 hours to obtain 2%Ca5%Mg@ZSM-5 / ZSM-11@Al2O3 powder with a multi-layer coating structure.

[0058] S7. Using 0.1 mol / L oxalic acid solution as a binder, 2%Ca5%Mg@ZSM-5 / ZSM-11@Al2O3 powder was extruded into strips, then dried at 120℃ for 24 h and calcined in a muffle furnace at 560℃ for 6 h to obtain 2%Ca5%Mg@ZSM-5 / ZSM-11@Al2O3 strip catalyst with a multi-layered coating structure after extrusion.

[0059] The 2%Ca5%Mg@ZSM-5 / ZSM-11@Al2O3 strip catalyst of this embodiment is used as the catalyst for the methanol-to-olefins reaction coupled with light hydrocarbons. In a fixed-bed reactor, with methanol:topping oil = 2:8 (mass ratio) as feedstock, the reaction is carried out at 460℃, 0MPa, and 1.5h. -1 The reaction was carried out under specific conditions. After the reaction was completed, the product composition was analyzed by gas chromatography. The product showed a methanol conversion rate of 100%, a low-carbon olefin carbon-based yield of 43.2%, and a methane carbon-based yield of 0.10%.

[0060] Example 19: The preparation process and application of this catalyst for inhibiting methane formation are as follows: S1. Mix and dissolve 7.3g of diatomaceous earth (represented by SiO2) with 21.6g of toluene to obtain the first mixture.

[0061] S2. Mix 236.9g of tetraethyl orthosilicate, 1.52g of aluminum sulfate, 0.35g of potassium hydroxide, 14.6g of di-n-octylamine and 108.6g of toluene at room temperature for 6 hours to obtain a second mixture.

[0062] S3. Add 0.5g of seed ZSM-11 symbiotic molecular sieve and the first mixture to the second mixture, stir at room temperature for 5h to obtain the third mixture.

[0063] S4. The third mixture is transferred to a crystallization vessel with a polytetrafluoroethylene liner for two-stage dynamic crystallization. The first stage of crystallization is hydrothermal crystallization at 120°C for 48 hours, and the second stage of crystallization is hydrothermal crystallization at 170°C for 24 hours. The stirring rate during dynamic crystallization is 160 r / h. The mixture after dynamic crystallization is cooled, filtered, and dried at 120°C for 14 hours to obtain ZSM-5 / ZSM-11@SiO2 powder.

[0064] S5. Weigh CaCO3 and Mg(NO3)2 according to the loading of 10% Ca and 6% Mg and the equal volume impregnation method to prepare a solution. Impregnate the prepared ZSM-5 / ZSM-11@SiO2 powder at 30℃ for 48h, and record it as 10%Ca6%Mg@ZSM-5 / ZSM-11@SiO2. Filter and wash until neutral to obtain filter cake.

[0065] S6. The filter cake was dried at 100℃ for 36 hours and calcined in a muffle furnace at 540℃ for 8 hours to obtain 10%Ca6%Mg@ZSM-5 / ZSM-11@SiO2 powder with a multi-layer coating structure.

[0066] S7. Using 0.1 mol / L oxalic acid solution as a binder, 10%Ca6%Mg@ZSM-5 / ZSM-11@SiO2 powder was extruded into strips, then dried at 80℃ for 24 h, and calcined in a muffle furnace at 480℃ for 10 h to obtain 10%Ca6%Mg@ZSM-5 / ZSM-11@SiO2 strip catalyst with a multi-layer coating structure after extrusion.

[0067] The 10%Ca6%Mg@ZSM-5 / ZSM-11@SiO2 strip catalyst of this embodiment is used as the catalyst for the methanol-to-olefins reaction coupled with light hydrocarbons. In a fixed-bed reactor, methanol:pentane oil = 3:7 (mass ratio) is used as the feedstock, and the reaction is carried out at 500°C, 1.0 MPa, and 1.0 h⁻¹. -1The reaction was carried out under specific conditions. After the reaction was completed, the composition of the product was analyzed by gas chromatography. The product showed a methanol conversion rate of 100%, a low-carbon olefin carbon-based yield of 51.8%, and a methane carbon-based yield of 0.08%.

[0068] Example 20: The preparation process and application of this catalyst for inhibiting methane formation are as follows: S1. Mix and dissolve 6.2g of sepiolite with 32.8g of toluene to obtain the first mixture.

[0069] S2. Mix 65.8g of silica, 1.2g of aluminum isopropoxide, 0.15g of ammonia (25% by mass), 4.8g of n-butylamine and 168.9g of propanol at 80°C for 1 hour to obtain a second mixture.

[0070] S3. Add 2.1g of seed ZSM-11 symbiotic molecular sieve and the first mixture to the second mixture, stir at room temperature for 1 hour to obtain the third mixture.

[0071] S4. The third mixture is transferred to a crystallization vessel with a polytetrafluoroethylene liner for two-stage dynamic crystallization. The first stage of crystallization is hydrothermal crystallization at 140℃ for 24 hours, and the second stage of crystallization is hydrothermal crystallization at 165℃ for 24 hours. The stirring rate during dynamic crystallization is 80 r / h. The mixture after dynamic crystallization is cooled, filtered, and dried at 140℃ for 12 hours to obtain ZSM-5 / ZSM-11@Mg8Si6 powder.

[0072] S5. Weigh CaO and MgCl2 according to the loading of 12% Ca and 4% Mg and the equal volume impregnation method to prepare a solution. Impregnate the prepared ZSM-5 / ZSM-11@Mg8Si6 powder at 40℃ for 12h, and record it as 12%Ca4%Mg@ZSM-5 / ZSM-11@Mg8Si6. Filter and wash until neutral to obtain filter cake.

[0073] S6. The filter cake was dried at 90℃ for 30h and calcined in a muffle furnace at 580℃ for 8h to obtain 12%Ca4%Mg@ZSM-5 / ZSM-11@Mg8Si6 powder with a multi-layer coating structure.

[0074] S7. Using 0.1 mol / L oxalic acid solution as a binder, 12%Ca4%Mg@ZSM-5 / ZSM-11@Mg8Si6 powder was extruded into strips, then dried at 140℃ for 6 h and calcined in a muffle furnace at 520℃ for 8 h to obtain 12%Ca4%Mg@ZSM-5 / ZSM-11@Mg8Si6 strip catalyst with a multi-layer coating structure after extrusion.

[0075] The 12%Ca4%Mg@ZSM-5 / ZSM-11@Mg8Si6 strip catalyst of this embodiment is used as the catalyst for the methanol-to-olefins reaction coupled with light hydrocarbons. In a fixed-bed reactor, with methanol:n-hexane = 7:3 (mass ratio) as raw material, the reaction is carried out at 520°C, 2.0 MPa, and 0.8 h. -1 The reaction was carried out under specific conditions. After the reaction was completed, the composition of the product was analyzed by gas chromatography. The product showed a methanol conversion rate of 100%, a low-carbon olefin carbon-based yield of 46.9%, and a methane carbon-based yield of 0.09%.

[0076] Example 21: The preparation process and application of this catalyst for inhibiting methane formation are as follows: S1. Mix and dissolve 3.5g of diatomaceous earth with 24.6g of toluene to obtain the first mixture.

[0077] S2. Mix 85.8g silica sol (30% by mass), 3.3g aluminum nitrate, 0.23g ammonia (25% by mass), 23.5g tetrabutylammonium hydroxide and 174.1g ethanol at 70°C for 5 hours to obtain a second mixture.

[0078] S3. Add 0.9g of seed ZSM-5 / ZSM-11 symbiotic molecular sieve and the first mixture to the second mixture, stir at room temperature for 3.5h to obtain the third mixture.

[0079] S4. The third mixture is transferred to a crystallization vessel with a polytetrafluoroethylene liner for two-stage dynamic crystallization. The first stage of crystallization is hydrothermal crystallization at 180°C for 20 hours, and the second stage of crystallization is hydrothermal crystallization at 180°C for 36 hours. The stirring rate during dynamic crystallization is 200 r / h. The mixture after dynamic crystallization is cooled, filtered, and dried at 90°C for 10 hours to obtain ZSM-5 / ZSM-11@SiO2 powder.

[0080] S5. Weigh CaCl2 and MgCl2 according to the loading of 7% Ca and 8% Mg and the equal volume impregnation method to prepare a solution. Impregnate the prepared ZSM-5 / ZSM-11@SiO2 powder at 35℃ for 18h, and record it as 7%Ca10%Mg@ZSM-5 / ZSM-11@SiO2. Filter and wash until neutral to obtain filter cake.

[0081] S6. The filter cake was dried at 160℃ for 6 hours and then calcined in a muffle furnace at 550℃ for 5 hours to obtain 7%Ca10%Mg@ZSM-5 / ZSM-11@SiO2 powder with a multi-layer coating structure.

[0082] S7. Using 0.1 mol / L oxalic acid solution as a binder, 7%Ca10%Mg@ZSM-5 / ZSM-11@SiO2 powder was extruded into strips, then dried at 150℃ for 8 h and calcined at 600℃ in a muffle furnace for 4 h to obtain 7%Ca10%Mg@ZSM-5 / ZSM-11@SiO2 strip catalyst with a multi-layer coating structure after extrusion.

[0083] The 7%Ca10%Mg@ZSM-5 / ZSM-11@SiO2 strip catalyst of this embodiment is used as the catalyst for the methanol-to-olefins reaction coupled with light hydrocarbons. In a fixed-bed reactor, methanol:raffinate oil = 2:8 (mass ratio) is used as the feedstock, and the reaction is carried out at 600℃, 0MPa, and 1.5h. -1 The reaction was carried out under specific conditions. After the reaction was completed, the product composition was analyzed by gas chromatography. The product showed a methanol conversion rate of 100%, a low-carbon olefin carbon-based yield of 55.9%, and a methane carbon-based yield of 0.05%.

[0084] Example 22: The preparation process and application of this catalyst for inhibiting methane formation are as follows: S1. Mix and dissolve 9.1g of boehmite with 17.2g of toluene to obtain the first mixture.

[0085] S2. Mix 15.4g silica sol (30% by mass), 0.98g aluminum sulfate, 0.17g ammonia (25% by mass), 5.9g tetrabutylammonium bromide and 156.4g toluene at 100°C for 3 hours to obtain a second mixture.

[0086] S3. Add 2.6g of seed ZSM-11 symbiotic molecular sieve and the first mixture to the second mixture, stir at room temperature for 4.5h to obtain the third mixture.

[0087] S4. The third mixture is transferred to a crystallization vessel with a polytetrafluoroethylene liner for two-stage dynamic crystallization. The first stage of crystallization is hydrothermal crystallization at 180°C for 24 hours, and the second stage of crystallization is hydrothermal crystallization at 140°C for 48 hours. The stirring rate during dynamic crystallization is 180 r / h. The mixture after dynamic crystallization is cooled, filtered, and dried at 120°C for 12 hours to obtain ZSM-5 / ZSM-11@Al2O3 powder.

[0088] S5. Weigh Ca(NO3)2 and Mg(NO3)2 according to the loading of 9% Ca and 15% Mg and the equal volume impregnation method to prepare a solution. Impregnate the prepared ZSM-5 / ZSM-11@Al2O3 powder at 50℃ for 36h, and record it as 9%Ca15%Mg@ZSM-5 / ZSM-11@Al2O3. Filter and wash until neutral to obtain filter cake.

[0089] S6. The filter cake was dried at 150℃ for 10h and calcined in a muffle furnace at 620℃ for 4h to obtain 9%Ca15%Mg@ZSM-5 / ZSM-11@Al2O3 powder with a multi-layer coating structure.

[0090] S7. Using 0.1 mol / L oxalic acid solution as a binder, 9%Ca15%Mg@ZSM-5 / ZSM-11@Al2O3 powder was extruded into strips, then dried at 110℃ for 36 h and calcined at 700℃ in a muffle furnace for 2 h to obtain 9%Ca15%Mg@ZSM-5 / ZSM-11@Al2O3 strip catalyst with a multi-layered coating structure after extrusion.

[0091] The 9%Ca15%Mg@ZSM-5 / ZSM-11@Al2O3 strip catalyst of this embodiment is used as the catalyst for the methanol-to-olefins reaction coupled with light hydrocarbons. In a fixed-bed reactor, methanol:n-butane = 1:9 (mass ratio) is used as the feedstock, and the reaction is carried out at 550°C, 1.0 MPa, and 1.0 h⁻¹. -1 The reaction was carried out under specific conditions. After the reaction was completed, the composition of the product was analyzed by gas chromatography. The product showed a methanol conversion rate of 100%, a low-carbon olefin carbon-based yield of 48.5%, and a methane carbon-based yield of 0.07%.

[0092] Example 23: The preparation process and application of this catalyst for inhibiting methane formation are as follows: S1. Mix and dissolve 7.3g of sepiolite with 19.8g of toluene to obtain the first mixture.

[0093] S2. Mix 82.1g silica sol (30% by mass), 1.26g aluminum sulfate, 0.15g potassium hydroxide, 4.3g n-butylamine and 132.1g propanol at 80°C for 4 hours to obtain a second mixture.

[0094] S3. Add 1.6g of seed ZSM-5 / ZSM-11 symbiotic molecular sieve and the first mixture 7 to the second mixture, stir at room temperature for 2.5h to obtain the third mixture.

[0095] S4. The third mixture is transferred to a crystallization vessel with a polytetrafluoroethylene liner for two-stage dynamic crystallization. The first stage of crystallization is hydrothermal crystallization at 160℃ for 36 hours, and the second stage of crystallization is hydrothermal crystallization at 175℃ for 72 hours. The stirring rate during dynamic crystallization is 260 r / h. The mixture after dynamic crystallization is cooled, filtered, and dried at 110℃ for 14 hours to obtain ZSM-5 / ZSM-11@Mg8Si6 powder.

[0096] S5. Weigh CaSO4 and MgCO3 according to the loading of 15% Ca and 4% Mg and the equal volume impregnation method to prepare a solution. Impregnate the prepared ZSM-5 / ZSM-11@Mg8Si6 powder at 60℃ for 12h, and record it as 15%Ca4%Mg@ZSM-5 / ZSM-11@Mg8Si6. Filter and wash until neutral to obtain filter cake.

[0097] S6. The filter cake K7 was dried at 120℃ for 24 hours and calcined in a muffle furnace at 530℃ for 5 hours to obtain 15%Ca4%Mg@ZSM-5 / ZSM-11@Mg8Si6 powder with a multi-layer coating structure.

[0098] S7. Using 0.1 mol / L oxalic acid solution as a binder, 15%Ca4%Mg@ZSM-5 / ZSM-11@Mg8Si6 powder was extruded into strips, then dried at 100℃ for 18 h, and calcined in a muffle furnace at 650℃ for 6 h to obtain 15%Ca4%Mg@ZSM-5 / ZSM-11@Mg8Si6 strip catalyst with a multi-layered coating structure after extrusion.

[0099] The 15%Ca4%Mg@ZSM-5 / ZSM-11@Mg8Si6 strip catalyst of this embodiment is used as the catalyst for the methanol-to-olefins reaction coupled with light hydrocarbons. In a fixed-bed reactor, with methanol:topping oil = 6:4 (mass ratio) as feedstock, the reaction is carried out at 490℃, 0.2MPa, and 0.5h. -1 The reaction was carried out under specific conditions. After the reaction was completed, the product composition was analyzed by gas chromatography. The product showed a methanol conversion rate of 100%, a low-carbon olefin carbon-based yield of 52.9%, and a methane carbon-based yield of 0.06%.

[0100] Example 24: The preparation process and application of this catalyst for inhibiting methane formation are as follows: S1. Mix and dissolve 5.9g of diatomaceous earth with 20.9g of toluene to obtain the first mixture.

[0101] S2. Mix 92.9g silicon dioxide, 1.21g aluminum sulfate, 0.09g potassium hydroxide, 88.5g di-n-octylamine and 183.1g ethanol at 60°C for 5 hours to obtain a second mixture.

[0102] S3. Add 4.5g of seed ZSM-11 symbiotic molecular sieve and the first mixture to the second mixture, stir at room temperature for 1.5h to obtain the third mixture.

[0103] S4. The third mixture is transferred to a crystallization vessel with a polytetrafluoroethylene liner for two-stage dynamic crystallization: the first stage is hydrothermal crystallization at 150°C for 24 hours, and the second stage is hydrothermal crystallization at 120°C for 84 hours. The stirring rate during dynamic crystallization is 100 r / h. The mixture after dynamic crystallization is cooled, filtered, and dried at 140°C for 6 hours to obtain ZSM-5 / ZSM-11@SiO2 powder.

[0104] S5. Weigh CaSO4 and MgCO3 according to the loading of 9% Ca and 8% Mg and the equal volume impregnation method to prepare a solution. Impregnate the prepared ZSM-5 / ZSM-11@SiO2 powder at room temperature for 48 hours, and record it as 9%Ca8%Mg@ZSM-5 / ZSM-11@SiO2. Filter and wash until neutral to obtain filter cake.

[0105] S6. The filter cake was dried at 100℃ for 48 hours and calcined in a muffle furnace at 520℃ for 8 hours to obtain 9%Ca8%Mg@ZSM-5 / ZSM-11@SiO2 powder with a multi-layer coating structure.

[0106] S7. Using 0.1 mol / L oxalic acid solution as a binder, 9%Ca8%Mg@ZSM-5 / ZSM-11@SiO2 powder was extruded into strips, then dried at 80℃ for 36 h and calcined at 600℃ in a muffle furnace for 8 h to obtain 9%Ca8%Mg@ZSM-5 / ZSM-11@SiO2 strip catalyst with a multi-layer coating structure after extrusion.

[0107] The 9%Ca8%Mg@ZSM-5 / ZSM-11@SiO2 strip catalyst of this embodiment is used as the catalyst for the methanol-to-olefins reaction coupled with light hydrocarbons. In a fixed-bed reactor, methanol:n-pentane = 5:5 (mass ratio) is used as the feedstock, and the reaction is carried out at ℃, 0.5MPa, and 0.5h. -1 The reaction was carried out under specific conditions. After the reaction was completed, the composition of the product was analyzed by gas chromatography. The product showed a methanol conversion rate of 100%, a low-carbon olefin carbon-based yield of 47.8%, and a methane carbon-based yield of 0.05%.

[0108] Example 25: The preparation process and application of this catalyst for inhibiting methane formation are as follows: S1. Mix and dissolve 6.6g of sepiolite with 12.3g of toluene to obtain the first mixture.

[0109] S2. Mix 18.9g silica sol (30% by mass), 2.2g aluminum sulfate, 0.2g ammonia (25% by mass), 17.9g tetrabutylammonium hydroxide and 112.6g propanol at 90°C for 2.5h to obtain a second mixture.

[0110] S3. Add 2.7g of seed ZSM-5 / ZSM-11 symbiotic molecular sieve and the first mixture 9 to the second mixture, stir at room temperature for 3h to obtain the third mixture.

[0111] S4. The third mixture is transferred to a crystallization vessel with a polytetrafluoroethylene liner for two-stage dynamic crystallization. The first stage of crystallization is hydrothermal crystallization at 160℃ for 48 hours, and the second stage of crystallization is hydrothermal crystallization at 165℃ for 24 hours. The stirring rate during dynamic crystallization is 240 r / h. The mixture after dynamic crystallization is cooled, filtered, and dried at 100℃ for 10 hours to obtain ZSM-5 / ZSM-11@Mg8Si6 powder.

[0112] S5. Weigh Ca(CO3)2 and Mg(NO3)2 according to the loading of 12% Ca and 10% Mg and the equal volume impregnation method to prepare a solution. Impregnate the prepared ZSM-5 / ZSM-11@Mg8Si6 powder at 40℃ for 24h, and record it as 12%Ca10%Mg@ZSM-5 / ZSM-11@Mg8Si6. Filter and wash until neutral to obtain filter cake.

[0113] S6. The filter cake was dried at 150℃ for 24 hours and then calcined in a muffle furnace at 550℃ for 10 hours to obtain 12%Ca10%Mg@ZSM-5 / ZSM-11@Mg8Si6 powder with a multi-layer coating structure.

[0114] S7. Using 0.1 mol / L oxalic acid solution as a binder, 12%Ca10%Mg@ZSM-5 / ZSM-11@Mg8Si6 powder was extruded into strips, then dried at 140℃ for 12 h, and calcined in a muffle furnace at 550℃ for 7 h to obtain 12%Ca10%Mg@ZSM-5 / ZSM-11@Mg8Si6 strip catalyst with a multi-layered coating structure after extrusion.

[0115] The 12%Ca10%Mg@ZSM-5 / ZSM-11@Mg8Si6 strip catalyst of this embodiment is used as the catalyst for the methanol-to-olefins reaction coupled with light hydrocarbons. In a fixed-bed reactor, methanol:hydrocracking naphtha = 4:6 (mass ratio) is used as the feedstock, and the reaction is carried out at 575°C, 0 MPa, and 2.0 h. -1 The reaction was carried out under specific conditions. After the reaction was completed, the product composition was analyzed by gas chromatography. The product showed a methanol conversion rate of 100%, a low-carbon olefin carbon-based yield of 54.5%, and a methane carbon-based yield of 0.04%.

[0116] Comparative Example 1: The difference from Example 21 is that toluene was not added in step S1 (i.e., the first mixture only contained 3.5 g of diatomaceous earth), while the other steps were the same. The prepared catalyst was applied to the methanol-coupled light hydrocarbon to olefin reaction (reaction conditions were the same as in Example 21), and the resulting product showed a methanol conversion rate of 92%, a low-carbon olefin carbon-based yield of 32.2%, and a methane carbon-based yield of 1.5%.

[0117] Comparative Example 2: The difference from Example 23 is that steps S2 to S4 of Example 23 are omitted. The first mixture obtained in step S1 is filtered and dried at 110°C for 14 hours to obtain @Mg8Si6 powder. Then, a 15%Ca4%Mg@Mg8Si6 strip catalyst is prepared according to the conditions of steps S5 to S7 in Example 23. The prepared catalyst is applied to the methanol-coupled light hydrocarbon to olefin reaction (reaction conditions are the same as in Example 23), yielding a methanol conversion of 88%, a low-carbon olefin carbon-based yield of 29.3%, and a methane carbon-based yield of 1.2%.

[0118] Comparative Example 3: The difference from Example 25 is that steps S5 and S6 in Example 25 are omitted, while the remaining steps are the same. That is, after obtaining ZSM-5 / ZSM-11@Mg8Si6 powder through steps S1 to S4, the @ZSM-5 / ZSM-11@Mg8Si6 strip catalyst is directly obtained according to the conditions of step S7. The prepared catalyst is applied to the methanol-coupled light hydrocarbon to olefin reaction (reaction conditions are the same as in Example 25), resulting in a methanol conversion rate of 95%, a low-carbon olefin carbon-based yield of 39.1%, and a methane carbon-based yield of 2.5%.

[0119] In summary, this invention provides a method for preparing a catalyst to suppress methane formation and its application. This method yields a ZSM-5 / ZSM-11 symbiotic molecular sieve with a multi-layered coating structure, moderate acidity and acidity, a large specific surface area, and synergistic regulation among metal elements. It exhibits excellent catalytic performance in methanol-coupled light hydrocarbon-to-olefins reactions. The catalyst of this invention, while ensuring a high yield of carbon-based low-carbon olefins, can significantly suppress the formation of methane as a byproduct, eliminating the need for a demethanator or reducing the load on the methane tower. This simplifies the subsequent separation process, thereby eliminating the need for a large amount of refrigeration equipment, shortening the process flow, improving the safety factor of the equipment, fundamentally improving technical reliability, reducing investment and operating costs, meeting carbon emission reduction requirements, and enhancing the market competitiveness of methanol-coupled light hydrocarbon-to-olefins technology and similar technologies.

[0120] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A method for preparing a catalyst to inhibit methane formation, characterized in that... Includes the following steps: Step 1: Mix the required amount of carrier and toluene to obtain the first mixture; Step 2: Add silicon source, aluminum source, alkali, and template agent to the solvent and mix them under the required temperature conditions to obtain a second mixture; Step 3: Add the required amount of seed crystals and the first mixture to the second mixture, stir and mix to obtain the third mixture; Step 4: Dynamically crystallize the third mixture and dry it to obtain catalyst support powder; Step 5: Impregnate the catalyst support powder in an aqueous solution containing Ca and Mg elements, wash and filter to obtain a filter cake; Step 6: Calcine the filter cake to obtain a powdered catalyst for inhibiting methane formation.

2. The method for preparing the catalyst for inhibiting methane formation according to claim 1, characterized in that... In step one, the support is one of boehmite, sepiolite and diatomite, and the grain size of the support is ≤1000μm; the mass ratio of the support to toluene is 1:1 to 10.

3. The method for preparing the catalyst for inhibiting methane formation according to claim 1 or 2, characterized in that... In step two, the silicon source is one of tetraethyl orthosilicate, silica sol, silica gel, and solid silica; the aluminum source is one or more of aluminum sulfate, aluminum chloride, aluminum nitrate, and aluminum isopropoxide; the alkali is one of ammonia and potassium hydroxide; the template agent is one or more of tetrabutylammonium hydroxide, tetrabutylammonium bromide, n-butylamine, or di-n-octylamine; and the solvent is one of ethanol, propanol, and toluene. Alternatively, in step two, the composition of the silicon source, alkali, aluminum source, template agent, and solvent, in molar parts, is: silicon source (SiO2) 10 to 600 parts, alkali 0.02 to 0.2 parts, aluminum source (Al2O3) 1.0 part, template agent 0.5 to 5.0 parts, and solvent 100 to 3000 parts. Alternatively, in step two, the stirring temperature is room temperature to 100°C, and the stirring time is 2 to 10 hours.

4. The method for preparing the catalyst for inhibiting methane formation according to any one of claims 1 to 3, characterized in that... In step three, the seed crystals are one or both of ZSM-5 / ZSM-11 symbiotic molecular sieves and ZSM-11 molecular sieves, and the mass ratio of seed crystals to support is 1:0.01 to 1; or / and, in step three, the stirring temperature is room temperature and the stirring time is 0.5h to 5h.

5. The method for preparing the catalyst for inhibiting methane formation according to any one of claims 1 to 4, characterized in that... In step four, dynamic crystallization includes a first-stage crystallization followed by a second-stage crystallization. The first-stage crystallization temperature is 80℃ to 200℃, and the hydrothermal crystallization lasts for 12 to 48 hours. The second-stage crystallization temperature is 140℃ to 220℃, and the hydrothermal crystallization lasts for 24 to 84 hours. The dynamic crystallization rotation speed is 50 r / h to 300 r / h. Or / and, in step four, the drying conditions are 60℃ to 180℃ for 4 to 24 hours.

6. The method for preparing the catalyst for inhibiting methane formation according to any one of claims 1 to 5, characterized in that... In step five, the compound containing Ca is one or more of CaO, CaCO3, Ca(NO3)2, CaSO4, and CaCl2, and the compound containing Mg is one or more of MgCO3, Mg(NO3)2, MgSO4, and MgCl2. In the aqueous solution containing the compounds containing Ca and Mg, the mass concentration of Ca is 1% to 15%, and the mass concentration of Mg is 1% to 15%; or / and, in step five, the impregnation is an equal-volume impregnation method, the impregnation temperature is room temperature to 120°C, and the impregnation time is 12h to 48h.

7. The method for preparing the catalyst for inhibiting methane formation according to any one of claims 1 to 6, characterized in that... In step six, the calcination conditions are: calcination temperature of 400℃ to 800℃, calcination time of 2 hours to 10 hours.

8. A catalyst for inhibiting methane formation prepared by the method according to any one of claims 1 to 7.

9. The application of the catalyst for inhibiting methane formation according to claim 8 in the catalytic reaction of methanol coupled with light hydrocarbons to produce olefins.

10. The application of the catalyst for inhibiting methane formation according to claim 9 in the catalytic reaction of methanol coupled with light hydrocarbons to produce olefins, characterized in that... The methanol-to-olefins reaction process coupled with light hydrocarbons includes the following steps: Methanol and light hydrocarbons are added to a reactor pre-loaded with a catalyst to inhibit methane formation, and the reaction takes place under the required temperature, pressure, and space velocity conditions. The light hydrocarbons include one or more of the following: reforming residue oil, reforming topping oil, pentane oil, hydrocracking naphtha, n-butane, n-pentane, and n-hexane; the reactor is a fixed-bed reactor, a moving-bed reactor, or a fluidized-bed reactor; the reaction temperature is 360℃ to 600℃, the pressure is 0 to 1.0 MPa, and the space velocity is 0.5 h⁻¹. -1 Up to 5 hours -1 .