Silicon-containing microporous molecular sieve supported silicon-containing heteropolyacid (salt) catalysts, preparation and use

Abstract

The present application relates to a kind of catalyst for preparing ethanol by ethylene hydration and its preparation method and application.It is in the preparation process of silicon-containing microporous molecular sieve in situ introduction preparation silicon-containing heteropoly acid (salt) raw material, make silicon-containing heteropoly acid (salt) and silicon-containing microporous molecular sieve material in situ synchronous preparation, since both raw materials contain silicate component, by the bridging action of siloxane tetrahedron, the generated silicon-containing heteropoly acid (salt) will be in situ dispersed anchor in the skeleton or channel of silicon-containing microporous molecular sieve material.Not only can effectively avoid the loss of heteropoly acid (salt) active component in the reaction process, but also can further adjust the pore size, pore volume and other structure parameters of silicon-containing microporous molecular sieve.The preparation method is simple, easy to enlarge.The prepared catalyst has the advantages of low reaction temperature, active component is not easy to lose, etc., can be applied to the field of acid catalysis such as preparing ethanol by ethylene hydration, and has good industrial application prospect.

Description

Technical Field

[0001] This invention belongs to the field of new catalytic materials preparation, specifically relating to a method for preparing a silica-containing heteropolyacid (salt) / silica-containing microporous molecular sieve catalyst. Background Technology

[0002] In 2021, my country's ethylene production reached 37.47 million tons, with equivalent consumption reaching 58.32 million tons. As one of the most important basic raw materials in the petrochemical industry, ethylene is known as the "mother of petrochemicals." Ethylene can be further processed into ethanol through hydration, partially replacing existing grain-fermented ethanol production, alleviating the land competition issue between ethylene and agriculture, and expanding ethanol sources. Compared with existing ethanol production processes, ethylene hydration technology has advantages such as a simpler process, less environmental pollution, and the ability to achieve small- to medium-scale production.

[0003] Existing processes for ethylene hydration to ethanol mostly employ catalysts such as alumina and molecular sieves. These catalysts typically exhibit good activity and selectivity, but the reaction temperatures are usually above 300°C, and a high proportion of water is required for circulation, resulting in high energy consumption for the entire process. CN 1160289C reports a method for ethylene hydration by loading heteropolyacid salts onto a silicon-based support. The heteropolyacid salts are silicotungstates or phosphotungstates soluble in polar solvents below 40°C, wherein the metal in the salt is an alkali metal or alkaline earth metal. The above reaction is carried out within a pressure range of 3000-10000 kPa, therefore requiring high explosion-proof equipment.

[0004] In summary, existing ethylene hydration catalysts generally suffer from problems such as relatively high reaction temperatures and pressures, and poor catalyst lifespan.

[0005] To address the aforementioned problems, this invention develops a method for preparing a catalyst for the hydration of ethylene to ethanol. This method introduces a certain amount of raw material for preparing silica-containing heteropolyacids (salts) during the preparation of silica-containing microporous molecular sieves, enabling the silica-containing heteropolyacids (salts) and silica-containing microporous molecular sieve materials to be prepared simultaneously in situ. Since both raw materials contain silicate components, the generated silica-containing heteropolyacids (salts) are effectively dispersed and anchored within the framework or channels of the silica-containing microporous molecular sieve material through the bridging effect of silicon-oxygen tetrahedra. This not only effectively prevents the loss of the active components of the heteropolyacids (salts) during the reaction process but also allows for further adjustment of the structural parameters of the silica-containing microporous molecular sieve, such as pore size and pore volume.

[0006] Furthermore, by loading the catalyst in layers and sections from top to bottom, following a gradual increase in the loading of active components, the traditional cylindrical reaction tube is optimized into a "pagoda"-shaped reaction tube with a thinner top and thicker bottom. This further reduces the leaching effect of water vapor on the active components during the reaction, thereby further extending the catalyst's lifespan. This preparation method is relatively simple to operate and easy to scale up for production. It can be applied to acid catalysis fields such as ethylene hydration and has good industrial application prospects. Summary of the Invention

[0007] The purpose of this invention is to provide a method for preparing a catalyst for the hydration of ethylene to ethanol. The catalyst prepared by this method can effectively improve its service life while maintaining its activity and selectivity.

[0008] This invention provides a method for preparing a catalyst for the hydration of ethylene to ethanol. First, in a system with a molar ratio of 1.0 P₂O₅:(0.5-2.0)Al₂O₃:(0.1-3.0)SiO₂:(1.0-3.0)template:(30-150)H₂O, the corresponding template agent required for preparing the molecular sieve is dissolved in water. An aluminum source, phosphoric acid, a silicon source, and raw materials for preparing silica-containing heteropolyacids and / or silica-containing heteropolyacid salts are added sequentially. The mixture is stirred at 20-30°C for at least 30 minutes, then transferred to a crystallization vessel and aged at 30-50°C for 0-24 hours. Finally, it is crystallized at 100-300°C for 12-72 hours, filtered, and dried to obtain a silica-containing heteropolyacid (salt) / silica-containing microporous molecular sieve catalyst.

[0009] The active component of the catalyst contains 5%-70% by mass of silica heteropolyacids and / or silica heteropolyacid salts, preferably 10-40% by mass.

[0010] The active components containing silica heteropoly acids and / or silica heteropoly acid salts specifically include one or more of the following: silymolybdic acid, silicotungstic acid, silicotungstic vanadate, silicotungstic vanadate, sodium silicotungstic acid, sodium silicotungstic acid, ammonium silicotungstic acid, ammonium silicotungstic acid, sodium silicotungstic acid, and ammonium silicotungstic acid.

[0011] The raw materials used to prepare silica-containing heteropoly acids and / or silica-containing heteropoly acid salts specifically include: orthosilicic acid, metasilicic acid, sodium silicate, ammonium silicate, potassium silicate, sodium molybdate, ammonium molybdate, sodium tungstate, ammonium tungstate, sodium vanadate, and one or more of these are used in combination.

[0012] Silica-containing microporous molecular sieves specifically include one or more of the following molecular sieves: SAPO-5, SAPO-18, SAPO-34, SAPO-37, SAPO-41, and SAPO-44.

[0013] The template agents specifically include: one or more of the following: diethylamine, triethylamine, N,N-diisopropylethylamine, cyclohexylamine, morpholine, tetrapropylammonium hydroxide, tetrapropylammonium chloride, and tetramethylammonium hydroxide;

[0014] The silicon source specifically includes one or more of the following: tetraethyl orthosilicate, methyl orthosilicate, propyl orthosilicate, butyl orthosilicate, polyethyl orthosilicate, silica, silica sol, and water glass;

[0015] The aluminum source specifically includes one or more of the following: aluminum isopropoxide, aluminum hydroxide hydrate, boehmite, aluminum nitrate, aluminum sulfate, and aluminum chloride.

[0016] The crystallization temperature is 100-300℃ (preferably 150-200℃), the crystallization time is 12-72h (preferably 24-48h), and after filtration and drying, it is calcined at 300-500℃ (preferably 400-500℃).

[0017] The active components, including silica heteropoly acids and / or silica heteropoly acid salts, are loaded in layers and sections from top to bottom, with the reaction tube having a "pagoda" shape that is thinner at the top and thicker at the bottom.

[0018] The application of the catalyst in the hydration of ethylene to ethanol is characterized by the following conditions: a water / ethylene (molar ratio) of 2-10 under 0-3.0 MPa conditions, a reaction temperature of 100-300℃, and a mass hourly space velocity (HHSV) of ethylene feedstock of 0.01-1.5 h⁻¹. -1 It can achieve efficient conversion of ethylene while obtaining a good service life.

[0019] Compared with previously reported methods for preparing catalysts for the hydration of ethylene to ethanol, this invention has the following advantages: A certain amount of raw materials for preparing silica-containing heteropolyacids (salts) (sodium silicate, ammonium tungstate, ammonium molybdate, ammonium vanadate, etc.) are introduced during the preparation of silica-containing microporous molecular sieves, allowing the silica-containing heteropolyacids (salts) to be prepared simultaneously with the silica-containing microporous molecular sieve material. Since both raw materials contain silicate components, the generated silica-containing heteropolyacids (salts) are dispersed and anchored in the framework or channels of the silica-containing microporous molecular sieve material through the bridging effect of silicon-oxygen tetrahedra. This not only effectively prevents the loss of the heteropolyacid (salt) active components during the reaction process but also allows for further modification of the pore size, pore volume, and other structural parameters of the silica-containing microporous molecular sieve. Furthermore, by loading the catalyst in layers and segments from top to bottom according to the gradually increasing loading of the active components, the traditional cylindrical reaction tube is optimized into a "pagoda"-shaped reaction tube with a thinner top and a thicker bottom, further reducing the leaching effect of water vapor on the active components in the reaction. This further improves its service life. The preparation method is simple to operate and easy to scale up. The prepared catalyst has advantages such as relatively low reaction temperature and pressure, and the active components are not easily deactivated, making it applicable to acid catalysis fields such as ethylene hydration.

[0020] Using the catalyst of this invention, the reaction conditions are as follows: 0-3.0 MPa, water / ethylene (molar ratio) = 2-10, reaction temperature 100-300℃, and ethylene mass hourly space velocity (HHSV) of 0.01-1.5 h⁻¹. -1 Under suitable conditions, this method enables efficient conversion of ethylene while maintaining a good service life. The preparation method is simple to operate and easy to scale up. The prepared catalyst has advantages such as low reaction temperature and minimal loss of active components, making it suitable for acid catalysis applications such as ethylene hydration, and shows promising industrial application prospects. Detailed Implementation

[0021] Example 1:

[0022] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of pseudoboehmite was added, followed by 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Under stirring, solution B was added dropwise to solution A. Subsequently, sodium silicate and ammonium tungstate were added at a 30% mass loading of silicotungstic acid. Stirring was continued for 2 h, and the mixture was transferred to a stainless steel crystallization vessel lined with polytetrafluoroethylene. After aging at 38 °C for 24 h, crystallization was carried out at 200 °C for 24 h. After filtration, drying at 100 °C for 6 h, and calcination at 350 °C for 4 h, a silicotungstic acid / SAPO-34 catalyst with a loading of 30 wt% was obtained. The pore size was measured to be 0.5-0.7 nm by nitrogen adsorption.

[0023] Comparative Example 1:

[0024] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of boehmite was added, followed by another 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Under stirring, solution B was added dropwise to solution A. Stirring continued for 2 hours, then the mixture was transferred to a stainless steel crystallization vessel lined with polytetrafluoroethylene (PTFE). After aging at 38°C for 24 hours, crystallization was performed at 200°C for 24 hours. The mixture was then filtered, dried at 100°C for 6 hours, and calcined at 350°C for 4 hours. The resulting SAPO-34 catalyst had a pore size of 0.3-0.5 nm as measured by nitrogen adsorption. Comparative Example 2:

[0025] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of boehmite was added, followed by 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Under stirring, solution B was added dropwise to solution A. Stirring was continued for 2 hours, and the solution was transferred to a stainless steel crystallization vessel lined with polytetrafluoroethylene. After aging at 38 °C for 24 hours, crystallization was carried out at 200 °C for 24 hours. After filtration, drying at 100 °C for 6 hours, and calcination at 350 °C for 4 hours, SAPO-34 support was obtained. Silicotungstic acid was then supported on the SAPO-34 surface using an equal-volume impregnation method at a loading of 30%. A silicotungstic acid / SAPO-34 catalyst with a loading of 30 wt% was obtained. The pore size of the catalyst, measured by nitrogen adsorption, was 0.2-0.4 nm.

[0026] Example 2: Active component loading

[0027] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of pseudoboehmite was added, followed by another 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Solution B was added dropwise to solution A under stirring. Subsequently, sodium silicate and ammonium tungstate were added at a 5% wt% loading of silicotungstic acid. Stirring was continued for 2 hours, and the mixture was transferred to a stainless steel crystallization reactor lined with polytetrafluoroethylene. After aging at 38°C for 24 hours, crystallization was performed at 200°C for 24 hours. The resulting solution was filtered, dried at 100°C for 6 hours, and calcined at 350°C for 4 hours. A 5 wt% silicotungstic acid / SAPO-34 catalyst was obtained, with pore sizes of 0.4–0.6 nm as measured by nitrogen adsorption.

[0028] Example 3: Active component loading

[0029] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of pseudoboehmite was added, followed by 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Under stirring, solution B was added dropwise to solution A. Subsequently, sodium silicate and ammonium tungstate were added at a 60% wt% loading of silicotungstic acid. The mixture was stirred for 2 hours and then transferred to a stainless steel crystallization vessel lined with polytetrafluoroethylene. After aging at 38 °C for 24 hours, crystallization was carried out at 200 °C for 24 hours. After filtration, drying at 100 °C for 6 hours, and calcination at 350 °C for 4 hours, a silicotungstic acid / SAPO-34 catalyst with a loading of 60 wt% was obtained. The pore size was measured to be 0.6-0.8 nm by nitrogen adsorption.

[0030] Example 4: Types of active components containing silica heteropolyacids (salts)

[0031] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of pseudoboehmite was added, followed by 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Under stirring, solution B was added dropwise to solution A. Subsequently, sodium silicate and ammonium molybdate were added at a 10% mass loading of silicotungstic acid. Stirring was continued for 2 h, and the mixture was transferred to a stainless steel crystallization vessel with a polytetrafluoroethylene liner. After aging at 38 °C for 24 h, crystallization was carried out at 200 °C for 24 h. After filtration, drying at 100 °C for 6 h, and calcination at 300 °C for 4 h, a silicotungstic acid / SAPO-34 catalyst with a loading of 10 wt% was obtained. The pore size was measured to be 0.4-0.6 nm by nitrogen adsorption.

[0032] Example 5: Types of active components containing silica heteropolyacids (salts)

[0033] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of pseudoboehmite was added, followed by another 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Solution B was added dropwise to solution A under stirring. Subsequently, sodium silicate, ammonium tungstate, and sodium vanadate were added at a 10% mass loading of silicotungstic acid. Stirring was continued for 2 hours, and the mixture was transferred to a stainless steel crystallization vessel lined with polytetrafluoroethylene. After aging at 38 °C for 24 hours, crystallization was performed at 200 °C for 24 hours. The resulting product was filtered, dried at 100 °C for 6 hours, and calcined at 350 °C for 4 hours. A 10 wt% silicotungstic vanadate / SAPO-34 catalyst was obtained, with pore sizes of 0.4–0.6 nm as measured by nitrogen adsorption.

[0034] Example 6: Types of Silica-Containing Microporous Molecular Sieves (AFI)

[0035] 8.1 g of phosphoric acid was dissolved in 12 ml of deionized water to obtain solution A; 14.4 g of aluminum isopropoxide was dissolved in 40 ml of deionized water to obtain solution B; solution A was added dropwise to solution B under stirring; then 4.2 g of cyclohexylamine was added, and stirring was continued for 90 min, followed by the addition of 21.3 g of silica sol and stirring for another 10 min. Subsequently, sodium silicate, ammonium tungstate, and ammonium vanadate were added at a mass loading of 20% silicotungsten vanadate, and stirring was continued for 2 h. The mixture was then transferred to a stainless steel crystallization vessel with a polytetrafluoroethylene liner, aged at 38 °C for 24 h, crystallized at 200 °C for 24 h, filtered, dried at 100 °C for 6 h, and calcined at 500 °C for 4 h. A silicotungsten vanadate / SAPO-5 catalyst with a loading of 20 wt% was obtained, with a pore size of 0.5-0.7 nm as measured by nitrogen adsorption.

[0036] Example 7: Types of Silica-Containing Microporous Molecular Sieves (CHA)

[0037] 34.59 g of phosphoric acid was dissolved in 90 ml of deionized water. Under mechanical stirring, 21.86 g of boehmite was added to obtain solution A. 27.36 g of silica sol and 28.27 g of cyclohexylamine were added to 60 ml of deionized water to obtain solution B. Solution B was added dropwise to solution A under stirring. Subsequently, ammonium silicate and ammonium molybdate were added at a 20% mass loading of silicotungstic acid. Stirring was continued for 2 hours, and the mixture was transferred to a stainless steel crystallization vessel lined with polytetrafluoroethylene. After aging at 38 °C for 24 hours, crystallization was carried out at 190 °C for 48 hours. The mixture was then filtered, dried at 100 °C for 6 hours, and calcined at 350 °C for 4 hours. An ammonium molybdate / SAPO-44 catalyst with a loading of 20 wt% was obtained, with a pore size of 0.6–0.8 nm as determined by nitrogen adsorption.

[0038] Example 8: Types of Silicon Sources

[0039] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of pseudoboehmite was added, followed by 10 ml of deionized water to obtain solution A. 4.09 g of water glass and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Solution B was added dropwise to solution A under stirring. Subsequently, sodium silicate and ammonium tungstate were added at a 15% wt% silicotungstic acid loading. Stirring was continued for 2 hours, and the mixture was transferred to a stainless steel crystallization vessel lined with polytetrafluoroethylene. After aging at 38 °C for 24 hours, crystallization was performed at 200 °C for 24 hours. The mixture was then filtered, dried at 100 °C for 6 hours, and calcined at 350 °C for 4 hours. A silicotungstic acid / SAPO-34 catalyst with a loading of 15 wt% was obtained, with pore sizes of 0.4–0.7 nm as determined by nitrogen adsorption.

[0040] Example 9: Types of Silicon Sources

[0041] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of pseudoboehmite was added, followed by 10 ml of deionized water to obtain solution A. 6.36 g of silica and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Solution B was added dropwise to solution A under stirring. Subsequently, sodium silicate and ammonium tungstate were added at a 40% wt% loading of silicotungstic acid. Stirring was continued for 2 hours, and the mixture was transferred to a stainless steel crystallization vessel lined with polytetrafluoroethylene. After aging at 38 °C for 24 hours, crystallization was performed at 200 °C for 24 hours. The mixture was then filtered, dried at 100 °C for 6 hours, and calcined at 350 °C for 4 hours. A 40 wt% silicotungstic acid / SAPO-34 catalyst was obtained, with a pore size of 0.5–0.8 nm as determined by nitrogen adsorption.

[0042] Example 10: Types of Aluminum Sources

[0043] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 5.2 g of aluminum isopropoxide was added, followed by 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Under stirring, solution B was added dropwise to solution A. Subsequently, sodium silicate and ammonium tungstate were added at a 30% mass loading of silicotungstic acid. Stirring was continued for 2 h, and the mixture was transferred to a stainless steel crystallization vessel lined with polytetrafluoroethylene. After aging at 38 °C for 24 h, crystallization was carried out at 200 °C for 24 h. After filtration, drying at 100 °C for 6 h, and calcination at 400 °C for 4 h, a silicotungstic acid / SAPO-34 catalyst with a loading of 30 wt% was obtained. The pore size was measured to be 0.4-0.7 nm by nitrogen adsorption.

[0044] Example 11: Types of Aluminum Sources

[0045] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 4.2 g of aluminum nitrate was added, followed by 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 11.62 g of morpholine were added to 34 ml of deionized water to obtain solution B. Solution B was added dropwise to solution A under stirring. Subsequently, sodium silicate and ammonium tungstate were added at a 60% wt% loading of silicotungstic acid. Stirring was continued for 2 hours, and the mixture was transferred to a stainless steel crystallization vessel lined with polytetrafluoroethylene. After aging at 38 °C for 24 hours, crystallization was performed at 200 °C for 24 hours. The mixture was then filtered, dried at 100 °C for 6 hours, and calcined at 350 °C for 4 hours. A silicotungstic acid / SAPO-34 catalyst with a loading of 60 wt% was obtained, with a pore size of 0.5–0.8 nm as determined by nitrogen adsorption.

[0046] Example 12: Types of Template Agents

[0047] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of pseudoboehmite was added, followed by 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 10.52 g of cyclohexane were added to 34 ml of deionized water to obtain solution B. Under stirring, solution B was added dropwise to solution A. Subsequently, sodium silicate and ammonium tungstate were added at a 30% mass loading of silicotungstic acid, and stirring was continued for 2 h. The mixture was then transferred to a stainless steel crystallization vessel with a polytetrafluoroethylene liner, aged at 38 °C for 24 h, crystallized at 200 °C for 24 h, filtered, dried at 100 °C for 6 h, and calcined at 350 °C for 4 h. A silicotungstic acid / SAPO-34 catalyst with a loading of 30 wt% was obtained, with a pore size of 0.5-0.7 nm as measured by nitrogen adsorption.

[0048] Example 13: Types of Template Agents

[0049] 15.37 g of phosphoric acid was dissolved in 18 ml of deionized water. Under mechanical stirring, 9.2 g of pseudoboehmite was added, followed by 10 ml of deionized water to obtain solution A. 16.36 g of silica sol and 9.48 g of triethylamine were added to 34 ml of deionized water to obtain solution B. Under stirring, solution B was added dropwise to solution A. Subsequently, sodium silicate and ammonium tungstate were added at a 50% silicotungstic acid loading, and stirring was continued for 2 hours. The mixture was then transferred to a stainless steel crystallization reactor lined with polytetrafluoroethylene (PTFE). After aging at 38 °C for 24 hours, crystallization was carried out at 200 °C for 24 hours. After filtration, drying at 100 °C for 6 hours, and calcination at 350 °C for 4 hours, a 50 wt% silicotungstic acid / SAPO-34 catalyst was obtained, with a pore size of 0.5-0.8 nm as measured by nitrogen adsorption.

[0050] Example 14: Water / Ethylene Molar Ratio

[0051] The catalysts obtained in Examples 2, 5, 1, and 13 with loadings of 5, 10, 30, and 50 wt% were respectively compressed into tablets to obtain 40-60 mesh samples. These samples were then subjected to reaction at 1.0 MPa, a reaction temperature of 200 °C, a water to ethylene molar ratio of 2, and an ethylene mass hourly space velocity of 0.01 h⁻¹. -1 Online chromatographic analysis of product components showed a single-pass conversion rate of 50% for ethylene and a selectivity of 90% for ethanol. No inactivation was observed after 1000 hours of continuous operation.

[0052] Example 15: Water / Ethylene Molar Ratio

[0053] The catalysts obtained in Examples 2, 7, 9, and 11, with loadings of 5, 20, 40, and 60 wt%, were respectively pressed into tablets to obtain 40-60 mesh samples. These samples were then subjected to reaction at 3.0 MPa, a reaction temperature of 300 °C, a water to ethylene molar ratio of 10, and an ethylene mass hourly space velocity of 1.5 h⁻¹. -1 Online chromatographic analysis of product components shows that the conversion rate of raw material ethylene can reach 60%, and the selectivity of ethanol can reach 92%.

[0054] Example 16:

[0055] The catalyst prepared by the method described in this invention was pressed into tablets to obtain 40-60 mesh samples, which were then used for ethylene hydration to produce ethanol.

[0056] The best result (Example 1) showed no deactivation after 2000 hours of continuous operation. Comparative Example 1, which is pure SAPO-34 material without the addition of heteropolyacid components, had lower ethylene conversion, ethanol yield, and stability than other examples. Comparative Example 2, which is a silicotungstic acid / SAPO-34 catalyst prepared by the impregnation method, also showed lower reaction performance than the samples in the other examples.

[0057] The table below lists the corresponding reaction results of the catalyst prepared by the method described in this invention. The specific reaction conditions are: 1.0 MPa, water / ethylene (molar ratio) = 5, and reaction temperature of 200 °C.

[0058]

[0059]

Claims

1. The application of a silica-containing microporous molecular sieve-supported catalyst containing silica-containing heteropolyacids and / or silica-containing heteropolyacid salts in the ethylene hydration to ethanol reaction, characterized in that: The preparation method is as follows: First, in a system with a molar ratio of P2O5:Al2O3:SiO2:template:H2O=1.0:(0.5-2.0):(0.1-3.0):(1.0-3.0):(30-150), the corresponding template agent, aluminum source, phosphoric acid, and silicon source required for the preparation of molecular sieves are added to water, and the raw materials for preparing silica-containing heteropoly acids and / or silica-containing heteropoly acid salts are added. The mixture is stirred at 20-30 °C for more than 30 minutes, then transferred to a crystallization kettle and aged at 30-50 °C for 0-24 h. Then, it is crystallized at 100-300 °C for 12-72 h, filtered, and dried. A silica-containing microporous molecular sieve was used to support a catalytic material containing silica-containing heteropolyacids and / or silica-containing heteropolyacid salts. The template agents specifically include: one or more of the following: diethylamine, triethylamine, N,N-diisopropylethylamine, cyclohexylamine, morpholine, tetrapropylammonium hydroxide, tetrapropylammonium chloride, and tetramethylammonium hydroxide; The hydration of ethylene to ethanol reaction is carried out under the following conditions: 1.0-3.0 MPa, water / ethylene molar ratio of 2-10, reaction temperature of 100-300 °C, and ethylene mass hourly space velocity of 0.01-1.5 h⁻¹. -1 .

2. The application according to claim 1, characterized in that: The active component of the catalyst contains 5%-70% by mass of silica heteropolyacids and / or silica heteropolyacid salts.

3. The application according to claim 2, characterized in that: The active component of the catalyst contains 10-40% by mass of silica heteropolyacids and / or silica heteropolyacid salts.

4. The application according to claim 1, characterized in that: The active components containing silica heteropoly acids and / or silica heteropoly acid salts specifically include one or more of the following: silymolybdic acid, silicotungstic acid, silicotungstic vanadate, silicotungstic vanadate, sodium silicotungstic acid, sodium silicotungstic acid, ammonium silicotungstic acid, ammonium silicotungstic acid, sodium silicotungstic acid, and ammonium silicotungstic acid.

5. The application according to claim 1, 2, or 3, characterized in that: The raw materials used to prepare silica-containing heteropoly acids and / or silica-containing heteropoly acid salts specifically include: one or more of orthosilicic acid, metasilicic acid, sodium silicate, ammonium silicate, and potassium silicate, as well as one or more of sodium molybdate, ammonium molybdate, sodium tungstate, ammonium tungstate, sodium vanadate, and ammonium vanadate used in combination.

6. The application according to claim 1, characterized in that: Silica-containing microporous molecular sieves specifically include one or more of the following: SAPO-5, SAPO-18, SAPO-34, SAPO-37, SAPO-41, and SAPO-44 molecular sieves.

7. The application according to claim 1, characterized in that: The silicon source specifically includes one or more of the following: tetraethyl orthosilicate, methyl orthosilicate, propyl orthosilicate, butyl orthosilicate, polyethyl orthosilicate, silica, silica sol, and water glass; The aluminum source specifically includes one or more of the following: aluminum isopropoxide, aluminum hydroxide hydrate, boehmite, aluminum nitrate, aluminum sulfate, and aluminum chloride.

8. The application according to claim 1, characterized in that: The crystallization temperature is 100-300 °C, the crystallization time is 12-72 h, and after filtration and drying, it is calcined at 300-500 °C.

9. The application according to claim 1, characterized in that: The crystallization temperature is 150-200 °C, the crystallization time is 24-48h, and after filtration and drying, it is calcined at 400-500 °C.

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