Preparation method of Beta molecular sieve

Abstract

The invention discloses a preparation method of Beta molecular sieve, comprising: (1) stirring a template with an aluminum source; (2) stirring an alkali source and water; (3) adding the template solution obtained in step (1) to a kneader after atomization and mixing with a silicon source and Beta molecular sieve seed crystals; (4) mixing the solution obtained in step (2) with the material in the kneader after atomization, and drying and dehydrating the material; (5) transferring the crystallized dry material obtained in step (4) to a pressure-resistant palladium dryer for crystallization reaction; (6) drying and roasting the crystallized product obtained in step (5) to obtain an alkali-metal-containing Beta molecular sieve; (7) exchanging ammonium, drying and roasting the product obtained in step (6) to obtain a hydrogen-type Beta molecular sieve. The method of the present invention can prepare a molecular sieve with a large silicon-aluminum ratio, and the silicon-aluminum ratio of the molecular sieve is in the range of 7.4-1994.8, and a higher silicon source utilization rate can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of molecular sieves, and in particular relates to a preparation method of Beta molecular sieves. Background Art

[0002] Beta molecular sieve was first synthesized by Mobil Corporation using a hydrothermal method in 1967 (US3308069). This molecular sieve has a three-dimensional twelve-membered ring pore structure and good hydrothermal stability. It is widely used in petroleum refining and chemical processes such as hydrocracking, hydroisomerization, hydrorefining, hydrodewaxing, and alkylation.

[0003] Beta molecular sieves with low silicon-to-aluminum ratios have high activity as solid acid catalysts, while high silicon-to-aluminum ratio or all-silicon Beta molecular sieves also have many potential applications as supports or adsorbents for metal-supported catalysts. Although molecular sieves with ideal silicon-to-aluminum ratios can be obtained through subsequent treatments such as dealumination and aluminum addition, the performance of molecular sieves obtained through post-treatment still lags behind that of directly synthesized molecular sieves with the same silicon-to-aluminum ratio.

[0004] Furthermore, there is currently no method for producing molecular sieves with a wide range of silicon to aluminum ratios. Summary of the Invention

[0005] The object of the present invention is to provide a method for preparing Beta molecular sieve, which can prepare Beta molecular sieve with a wide range of silicon-to-aluminum ratios.

[0006] The technical solution of the present invention to solve the above technical problems is:

[0007] The preparation method of Beta molecular sieve comprises the following steps:

[0008] (1) mixing a template and an aluminum source under stirring to obtain a template containing an aluminum source;

[0009] (2) mixing an alkali source and water under stirring to obtain an alkali source aqueous solution;

[0010] (3) adding the silicon source into a kneader, atomizing the template containing the aluminum source obtained in step (1), and adding the template into the kneader at a kneading temperature of 70 to 90° C.;

[0011] (4) The solution obtained in step (2) is atomized and mixed with the material in the kneader. The mixed material is dried and dehydrated at a kneading temperature of 70 to 90° C. until the water content of the material is 15 to 20%, thereby obtaining a crystallized dry material. The water content of the dry glue material is tested using a halogen moisture meter. The test conditions are: test temperature The test time is 10 minutes.

[0012] (5) transferring the crystallized dry material obtained in step (4) to a pressure-resistant palladium dryer, and performing a crystallization reaction at a reaction temperature of 140 to 160° C., a reaction time of 60 to 96 h, and a stirring speed of 3 to 8 rpm;

[0013] (6) drying and calcining the crystallized product obtained in step (5) to obtain a Beta molecular sieve containing an alkali metal;

[0014] (7) The product obtained in step (6) is subjected to ammonium exchange, drying, and calcination to obtain hydrogen-type Beta molecular sieve.

[0015] Preferably, in step (6), the drying temperature is 90-120°C, and the drying time is 12-24 hours; the roasting temperature is 540-580°C, and the holding time is 6-10 hours. The roasting is carried out in a flowing air atmosphere with an air flow rate of 1-5 L / min.

[0016] Preferably, in step (7), the ammonium salt used for ammonium exchange is selected from one of ammonium sulfate and ammonium nitrate, the mass fraction of ammonium salt in the ammonium salt aqueous solution during the ammonium exchange process is 5-10%, the mass ratio of the ammonium salt aqueous solution to the molecular sieve during the ammonium exchange process is 7-12:1, the ammonium exchange temperature is 50-90° C., the number of ammonium exchanges is 2-3 times, and the ammonium exchange time is 0.5-3 hours.

[0017] Preferably, in step (7), the drying temperature is 90-120°C, and the drying time is 12-24 hours; the roasting temperature is 450-540°C, and the holding time is 3-6 hours. The roasting is carried out in a flowing air atmosphere with an air flow rate of 1-5 L / min.

[0018] Furthermore, in the step (3), the silicon source and the Beta molecular sieve seed crystals are first mixed in a kneader at a kneading temperature of 70 to 90° C. for a kneading time of 0.5 to 1.5 hours, and then the aluminum source-containing template obtained in the step (1) is atomized and added to the kneader to be mixed with the silicon source and the Beta molecular sieve seed crystals at a kneading temperature of 70 to 90° C. for a kneading time of 0.5 to 1.5 hours.

[0019] Furthermore, the present invention provides a method for preparing Beta molecular sieve with a silicon-aluminum ratio in the range of 20 to 150, wherein the silicon source, aluminum source, alkali source and template in the crystallized dry material in step (4) are calculated as SiO2, Al2O3, M2O and ROH respectively, and the molar ratio of the reaction raw materials is SiO2:Al2O3:M2O:ROH=20.0~150.0:1.0:0.9~3.0:2.7~17.0.

[0020] Preferably, in the step (1), the reaction is refluxed for 6 to 12 hours at a reaction temperature of 80 to 100° C. to obtain a template solution containing an aluminum source.

[0021] Preferably, the template is a 25-35% mass fraction tetraethylammonium hydroxide aqueous solution; in the step (1), the aluminum source is selected from one of aluminum sol, pseudo-boehmite, aluminum hydroxide, and aluminum sulfate; in the step (2), the alkali source is sodium hydroxide or potassium hydroxide, and the mass concentration of the configured alkali source aqueous solution is 30-40%; in the step (3), the silicon source is one of precipitated silica and silica gel; the molar ratio of SiO2 and Al2O3 contained in the Beta molecular sieve seed crystals is in the range of 20-60, and the amount of the Beta molecular sieve seed crystals added is 3-10% of the mass of SiO2 contained in the silicon source.

[0022] Preferably, in step (7), the silicon-aluminum ratio of the hydrogenated Beta molecular sieve product is in the range of 20 to 150.

[0023] Furthermore, the present invention provides a method for preparing aluminum-rich Beta molecular sieve without the assistance of fluoride, wherein the silicon source, aluminum source, alkali source and template in the crystallized dry material in step (4) are calculated as SiO2, Al2O3, M2O and ROH respectively, and the molar ratio of the reaction raw materials is SiO2:Al2O3:M2O:ROH=8~20:1:0.5~1.3:2.0~5.0.

[0024] Preferably, in step (1), the aluminum source is aluminum sol, and the template is a 25-35% by mass aqueous solution of tetraethylammonium hydroxide; in step (2), the alkali source is one of sodium hydroxide and potassium hydroxide, and the mass concentration of the prepared alkali source aqueous solution is 30-40%; the silicon source is one of precipitated silica and silica gel.

[0025] Preferably, in step (3), the molar ratio of SiO2 to Al2O3 in the Beta molecular sieve seed crystals is in the range of 20 to 30, and the amount of seed crystals added is 3-7% of the mass of SiO2 contained in the silicon source.

[0026] Furthermore, the present invention provides a method for preparing a high silicon-aluminum ratio Beta molecular sieve using Beta molecular sieve as a seed crystal and an aluminum source. In step (1), the aluminum source is a Beta molecular sieve seed crystal. In step (1), a template agent and the Beta molecular sieve seed crystal are mixed under stirring conditions, and the mixture is refluxed for 6 to 12 hours at a reaction temperature of 80 to 100° C. to obtain a template agent slurry containing the Beta molecular sieve seed crystal.

[0027] Preferably, the silicon source, aluminum source, alkali source and template in the crystallization dry material in step (4) are calculated as SiO2, Al2O3, M2O and ROH respectively, and the molar ratio of the reaction raw materials is SiO2:Al2O3:M2O:ROH=100:0.05~0.67:2.5~5.0:17~27.

[0028] Preferably, in the step (1), the molar ratio of SiO2 and Al2O3 contained in the Beta molecular sieve seed crystals is in the range of 20 to 60, and the amount of seed crystals added is 3-11% of the mass of SiO2 contained in the silicon source; in the step (1), the template is a 25-35% mass fraction tetraethylammonium hydroxide aqueous solution; in the step (2), the alkali source is sodium hydroxide or potassium hydroxide, and the mass concentration of the prepared alkali source aqueous solution is 30-40%; in the step (3), the silicon source is one of precipitated silica, silica gel, and fumed silica.

[0029] In the step (7), the silicon-aluminum ratio of the hydrogen-type Beta molecular sieve product is in the range of 150 to 2000.

[0030] The advantages and beneficial effects of the present invention are:

[0031] The preparation method of the Beta molecular sieve of the present invention comprises the following steps: subjecting raw materials such as Beta molecular sieve seed crystals, a silicon source, an aluminum source, an alkali source and a template agent to stirring and crystallizing in a pressure-resistant palladium dryer to prepare the Beta molecular sieve. The method of the present invention can prepare a molecular sieve having a wide silicon-to-aluminum ratio range, the silicon-to-aluminum ratio of the molecular sieve being in the range of 7.4-1994.8, and having a high silicon source utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is the X-ray powder diffraction pattern of the Beta molecular sieve powder prepared in Example 1;

[0033] Figure 2 This is a scanning electron microscope image of the Beta molecular sieve prepared in Example 1;

[0034] Figure 3 is the X-ray powder diffraction pattern of the powder Beta molecular sieve prepared in Example 2;

[0035] Figure 4 is the X-ray powder diffraction pattern of the powder Beta molecular sieve prepared in Example 3;

[0036] Figure 5 This is the X-ray powder diffraction pattern of Beta molecular sieve powder prepared from dry glue materials with different water contents in Example 3;

[0037] Figure 6 is the X-ray powder diffraction pattern of the Beta molecular sieve powder prepared in Example 6;

[0038] Figure 7 This is a scanning electron microscope image of Beta molecular sieve prepared in Example 6;

[0039] Figure 8 is the X-ray powder diffraction pattern of the powder Beta molecular sieve prepared in Example 7;

[0040] Figure 9 This is a scanning electron microscope image of Beta molecular sieve prepared in Example 7;

[0041] Figure 10 is the X-ray powder diffraction pattern of the powder Beta molecular sieve prepared in Example 9;

[0042] Figure 11 This is a scanning electron microscope image of Beta molecular sieve prepared in Example 9;

[0043] Figure 12 is the X-ray powder diffraction pattern of the powder Beta molecular sieve prepared in Example 11;

[0044] Figure 13 This is a scanning electron microscope image of Beta molecular sieve prepared in Example 11;

[0045] Figure 14 is the X-ray powder diffraction pattern of the powder Beta molecular sieve prepared in Example 13;

[0046] Figure 15 This is a scanning electron microscope image of Beta molecular sieve prepared in Example 13;

[0047] Figure 16 is the X-ray powder diffraction pattern of the Beta molecular sieve powder prepared in Example 15;

[0048] Figure 17 This is a scanning electron microscope image of Beta molecular sieve prepared in Example 15;

[0049] Figure 18 is the X-ray powder diffraction pattern of the Beta molecular sieve powder prepared in Example 17;

[0050] Figure 19 This is a scanning electron microscope image of Beta molecular sieve prepared in Example 17. DETAILED DESCRIPTION

[0051] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0052] Unless otherwise specified, the experimental methods in the following examples are conventional methods and were performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials and reagents used in the following examples, unless otherwise specified, were all commercially available.

[0053] The specific implementation methods of the technical solutions of the present invention are described in detail below through examples, but the present invention is not limited to the following descriptions.

[0054] Examples 1-6 provide a method for efficiently preparing Beta molecular sieves with a silicon-aluminum ratio ranging from 20 to 150 by controlling the dry glue water content.

[0055] Table 1 shows the contents of SiO2, Al2O3, and Na2O in the Beta molecular sieve seed crystals and silicon sources used in Examples 1-6, which were determined using X-ray fluorescence spectroscopy (XRF).

[0056] Table 1 XRF test of SiO2, Al2O3, and Na2O contents in Beta molecular sieve seeds and silicon sources

[0057] Sample name <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Na2O <!-- 3 -->]]> Precipitated silica 85.843％ 0.415％ 1.055％ Silicone 90.124％ 0.100％ 0.109％ Beta 20 77.165％ 6.330％ 0.053％ Beta 30 77.052％ 4.294％ 0.041％ Beta 40 77.997％ 3.303％ 0.041％ Beta 60 81.577％ 2.317％ 0.042％

[0058] Example 1

[0059] 633.58 kg of a 25 wt% tetraethylammonium hydroxide aqueous solution and 180.68 kg of an aluminum sol having an Al2O3 content of 21.20 wt% were weighed and stirred, and refluxed at a reaction temperature of 80°C for 12 hours to obtain a template solution containing an aluminum source.

[0060] Weigh 21.52 kg of sodium hydroxide and add it to an appropriate amount of deionized water to prepare a 40 wt % sodium hydroxide aqueous solution for later use.

[0061] 557.72 kg of precipitated silica and 14.36 kg of Beta 20 molecular sieve seed crystals were added to the kneader, and the mixture was mixed at a kneading temperature of 70° C. for 1.5 hours.

[0062] The template solution containing the aluminum source was atomized and then added to a kneader for mixing. The mixture was mixed at a kneading temperature of 70° C. for 1.5 hours.

[0063] The prepared sodium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 70°C until the water content of the materials reached 20.00%, and then the next step was carried out.

[0064] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 96 hours at a reaction temperature of 140° C. and a stirring speed of 3 rpm.

[0065] The amount of Beta seed crystals added was 3.0% of the mass of SiO2 contained in the silica gel, and the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 20.69. The molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 20.0:1.0:0.9:2.7.

[0066] After the crystallization reaction was completed, the resulting crystallized product was dried at 90° C. for 24 hours.

[0067] Figure 1 The powder X-ray diffraction pattern of the crystallized product shows that the product has typical Beta molecular sieve structural characteristics. Figure 2 This is a scanning electron microscope image of the crystallized product.

[0068] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 540° C. and calcined for 10 hours in a flowing air atmosphere with an air flow rate of 1 L / min and a heating rate of 2° C. / min.

[0069] After the calcination, the mass of the obtained product is weighed, and a 5% ammonium nitrate aqueous solution with a mass fraction of 12 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 50°C, the number of exchanges is 3 times, and the ammonium exchange time is 3 hours each time. After the exchange is completed, it is dried at 90°C for 24 hours. The dried product is placed in a muffle furnace and heated to 450°C in a flowing air atmosphere and calcined for 6 hours. The air flow rate is 1L / min and the heating rate is 2°C / min. After the second calcination is completed, continue to cool to 40-60°C in an air atmosphere, collect the calcined product to prepare the hydrogen type Beta molecular sieve.

[0070] The SiO2 / Al2O3 ratio of hydrogen-type Beta molecular sieve tested by XRF is 19.5.

[0071] Example 2

[0072] 480.26 kg of a 35 wt% tetraethylammonium hydroxide aqueous solution and 172.57 kg of an aluminum sol having an Al2O3 content of 21.20 wt% were weighed and stirred, and refluxed at a reaction temperature of 100°C for 6 hours to obtain a template solution containing an aluminum source.

[0073] Weigh 36.74 kg of potassium hydroxide and add it to an appropriate amount of deionized water to prepare a 30 wt % potassium hydroxide aqueous solution for later use.

[0074] 532.69 kg of precipitated silica and 45.73 kg of Beta 20 molecular sieve seed crystals were added to the kneader and mixed at a kneading temperature of 90° C. for 0.5 hour.

[0075] The template solution containing the aluminum source was atomized and then added to a kneader for mixing. The kneading temperature was 90° C. and the mixture was mixed for 0.5 hours.

[0076] The prepared potassium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 90° C. until the water content of the materials reached 15.00%, and then the next step was carried out.

[0077] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 60 hours at a reaction temperature of 160° C. and a stirring speed of 8 rpm.

[0078] The amount of Beta seed crystals added was 10.0% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 20.69, and the molar ratio of SiO2:Al2O3:K2O:ROH in the crystallization material was 20.0:1.0:1.0:3.0.

[0079] After the crystallization reaction was completed, the resulting crystallized product was dried at 120° C. for 12 hours. Figure 3 The powder X-ray diffraction pattern of the crystallized product shows that the product has typical Beta molecular sieve structural characteristics.

[0080] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 580° C. and calcined for 6 hours in a flowing air atmosphere with an air flow rate of 5 L / min and a heating rate of 2° C. / min.

[0081] After the calcination, the mass of the obtained product is weighed, and a 10% ammonium nitrate aqueous solution with a mass fraction of 7 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 90 ° C, the number of exchanges is 2, and the ammonium exchange time is 0.5 hours each time. After the exchange is completed, it is dried at 120 ° C for 12 hours. The dried product is placed in a muffle furnace and heated to 540 ° C in a flowing air atmosphere for 3 hours. The air flow rate is 5L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen type Beta molecular sieve.

[0082] The SiO2 / Al2O3 ratio of hydrogen-type Beta molecular sieve tested by XRF is 19.3.

[0083] Example 3

[0084] 638.99 kg of a 30 wt% aqueous solution of tetraethylammonium hydroxide and 32.65 kg of pseudo-boehmite with a 72.90 wt% Al2O3 content were weighed and stirred, and refluxed at a reaction temperature of 90°C for 9 hours to obtain a template solution containing an aluminum source.

[0085] Weigh 21.72 kg of sodium hydroxide and add it to an appropriate amount of deionized water to prepare a 35 wt % sodium hydroxide aqueous solution for later use.

[0086] 536.02 kg of precipitated silica and 23.00 kg of Beta 30 molecular sieve seed crystals were added to the kneader, and the mixture was mixed at a kneading temperature of 80° C. for 1.0 hour.

[0087] The template solution containing the aluminum source was atomized and then added to a kneader for mixing. The kneading temperature was 80° C. and the mixture was mixed for 1.0 hour.

[0088] The prepared sodium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80°C. When the water content of the material reached 25% and 20%, 1 kg of samples were taken respectively. When the water content of the material reached 17.00%, 3 kg of samples were taken before proceeding to the next step.

[0089] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0090] The amount of Beta seed crystals added was 5.0% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 30.45, and the molar ratio of SiO2:Al2O3:K2O:ROH in the crystallization material was 30.0:1.0:1.4:5.1.

[0091] Sample Preparation: Weigh two 1kg portions of material with a 17% water content and continue drying in an 80°C oven to 15% and 10% water content. Crystallization of the dry gelatin with water contents of 25%, 20%, 17%, 15%, and 10% was performed in a 2L laboratory autoclave at 145°C for 72 hours.

[0092] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. Figure 4 The powder X-ray diffraction pattern of the product crystallized in the pressure-resistant rake dryer shows that the product has typical Beta molecular sieve structural characteristics. Figure 5The X-ray powder diffraction patterns of the crystallized products of dry glue materials with different water contents show that as the water content decreases, the intensity of the product diffraction peak increases first and then decreases, and when the water content of the material is about 10%, the product is prone to produce miscellaneous crystal peaks.

[0093] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0094] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen type Beta molecular sieve.

[0095] The SiO2 / Al2O3 ratio of hydrogen-type Beta molecular sieve tested by XRF is 29.8.

[0096] Example 4

[0097] 586.44 kg of a 30 wt % aqueous solution of tetraethylammonium hydroxide and 24.08 kg of aluminum hydroxide with a 65.20 wt % Al 2 O 3 content were weighed and stirred, and refluxed at a reaction temperature of 90° C. for 9 hours to obtain a template solution containing an aluminum source.

[0098] Weigh 21.32 kg of sodium hydroxide and add it to an appropriate amount of deionized water to prepare a 35 wt % sodium hydroxide aqueous solution for later use.

[0099] 544.85 kg of silica gel and 24.55 kg of Beta 30 molecular sieve seed crystals were added to the kneader, and the mixture was mixed at a kneading temperature of 80° C. for 1.0 hour.

[0100] The template solution containing the aluminum source was atomized and then added to a kneader for mixing. The kneading temperature was 80° C. and the mixture was mixed for 1.0 hour.

[0101] The prepared sodium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80° C. until the water content of the materials reached 17.00%, and then the next step was carried out.

[0102] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0103] The amount of Beta seed crystals added was 5.0% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 30.45, and the molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 50.0:1.0:1.7:7.5.

[0104] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. The powder X-ray diffraction pattern of the crystallized product showed that the product had typical Beta molecular sieve structural characteristics.

[0105] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0106] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen type Beta molecular sieve.

[0107] The SiO2 / Al2O3 ratio of hydrogen-type Beta molecular sieve tested by XRF is 49.2.

[0108] Example 5

[0109] 538.13 kg of a 30 wt % aqueous solution of tetraethylammonium hydroxide and 50.37 kg of aluminum sulfate 18-hydrate were weighed and stirred, and refluxed at a reaction temperature of 90° C. for 9 hours to obtain a template solution containing an aluminum source.

[0110] Weigh 14.42 kg of sodium hydroxide and add it to an appropriate amount of deionized water to prepare a 35 wt % sodium hydroxide aqueous solution for later use.

[0111] 575.54 kg of silica gel and 25.94 kg of Beta 40 molecular sieve seed crystals were added to the kneader, and the mixture was mixed at a kneading temperature of 80° C. for 1.0 hour.

[0112] The template solution containing the aluminum source was atomized and then added to a kneader for mixing. The kneading temperature was 80° C. and the mixture was mixed for 1.0 hour.

[0113] The prepared sodium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80° C. until the water content of the materials reached 17.00%, and then the next step was carried out.

[0114] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0115] The amount of Beta seed crystals added was 5.0% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 40.07, and the molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 100.0:1.0:2.3:13.5.

[0116] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. The powder X-ray diffraction pattern of the crystallized product showed that the product had typical Beta molecular sieve structural characteristics.

[0117] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0118] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen type Beta molecular sieve.

[0119] The SiO2 / Al2O3 ratio of hydrogen-type Beta molecular sieve tested by XRF is 98.9.

[0120] Example 6

[0121] 471.08 kg of a 30 wt % aqueous solution of tetraethylammonium hydroxide and 33.71 kg of aluminum sulfate 18-hydrate were weighed and stirred, and refluxed at a reaction temperature of 90° C. for 9 hours to obtain a template solution containing an aluminum source.

[0122] Weigh 12.96 kg of sodium hydroxide and add it to an appropriate amount of deionized water to prepare a 35 wt % sodium hydroxide aqueous solution for later use.

[0123] 601.86 kg of silica gel and 27.12 kg of Beta 60 molecular sieve seed crystals were added to the kneader, and the mixture was mixed at a kneading temperature of 80° C. for 1.0 hour.

[0124] The template solution containing the aluminum source was atomized and then added to a kneader for mixing. The kneading temperature was 80° C. and the mixture was mixed for 1.0 hour.

[0125] The prepared sodium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80° C. until the water content of the materials reached 17.00%, and then the next step was carried out.

[0126] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0127] The amount of Beta seed crystals added was 5.0% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 59.73, and the molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 150.0:1.0:3.0:17.0.

[0128] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. Figure 6 The powder X-ray diffraction pattern of the crystallized product shows that the product has typical Beta molecular sieve structural characteristics. Figure 7 This is a scanning electron microscope image of the crystallized product.

[0129] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0130] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen type Beta molecular sieve.

[0131] The SiO2 / Al2O3 ratio of hydrogen-type Beta molecular sieve tested by XRF is 148.7.

[0132] Comparative Example 1

[0133] The only difference between this comparative example and Example 2 is that the order of adding the template solution containing the aluminum source and the potassium hydroxide aqueous solution is different. In this comparative example, 532.69 kg of precipitated silica and 45.73 kg of Beta 20 molecular sieve seed crystals were added to the kneader and mixed at a kneading temperature of 90° C. for 0.5 hour. Then, the prepared potassium hydroxide aqueous solution was first atomized and added to the kneader for mixing at a kneading temperature of 90° C. and mixed for 0.5 hour.

[0134] Then, the template solution containing the aluminum source was atomized and added to a kneader for mixing. The material was dried and dehydrated at a kneading temperature of 90° C. until the water content of the material reached 15.00%, and then the next step was carried out. The rest of the process was the same as in Example 2.

[0135] The powder X-ray diffraction pattern of the crystallized product prepared in this comparative example shows that the product has a weak Beta molecular sieve characteristic diffraction peak, and the relative crystallinity tested by XRD peak intensity is 65.4% (Example 2 is a standard sample).

[0136] Examples 7-12 provide a method for preparing aluminum-rich Beta molecular sieve without fluoride assistance:

[0137] Table 2 shows the contents of SiO2, Al2O3, and Na2O in the Beta molecular sieve seed crystals and silicon sources used in Examples 7-12, which were determined using X-ray fluorescence spectroscopy (XRF).

[0138] Table 2 XRF test of SiO2, Al2O3, and Na2O contents in Beta molecular sieve seeds and silicon sources

[0139] Sample name <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Na2O]]> Precipitated silica 85.843％ 0.415％ 1.055％ Silicone 90.124％ 0.100％ 0.109％ Beta 20 77.165％ 6.330％ 0.053％ Beta 25 75.321％ 5.189％ 0.045％ Beta 30 77.052％ 4.294％ 0.041％

[0140] Example 7

[0141] 214.17 kg of aluminum sol with an Al2O3 content of 21.2 wt% and 638.58 kg of a 25 wt% tetraethylammonium hydroxide aqueous solution were weighed and mixed to obtain a quaternary ammonium aluminum source template solution.

[0142] Prepare 54.63 kg of 30 wt% sodium hydroxide solution for later use.

[0143] 214.17 kg of silica gel with a SiO2 content of 90.12 wt% and 13.51 kg of Beta seed crystals were added to the kneader and mixed at a kneading temperature of 70°C for 1.5 hours.

[0144] The template solution containing the quaternary ammonium aluminum source was atomized and added to the kneader for mixing. After mixing for 1.5 hours at a kneading temperature of 70° C., the next step was carried out.

[0145] The prepared sodium hydroxide solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 70°C until the water content of the materials reached 15.00%, and then the next step was carried out.

[0146] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 96 hours at a reaction temperature of 140° C. and a stirring speed of 3 rpm.

[0147] The amount of Beta seed crystals added was 7.0% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 20.69, and the molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 8.00:1.00:0.50:2.70.

[0148] After the crystallization reaction was completed, the resulting crystallized product was dried at 90° C. for 24 hours. Figure 8 The powder X-ray diffraction pattern of the crystallized product shows that the product has typical Beta molecular sieve structural characteristics. Figure 9 This is a scanning electron microscope image of the crystallized product.

[0149] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 540° C. and calcined for 10 hours in a flowing air atmosphere with an air flow rate of 1 L / min and a heating rate of 2° C. / min.

[0150] After the calcination, the mass of the obtained product is weighed, and a 5% ammonium nitrate aqueous solution with a mass fraction of 12 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 50°C, the number of exchanges is 3 times, and the ammonium exchange time is 3 hours each time. After the exchange is completed, it is dried at 90°C for 24 hours. The dried product is placed in a muffle furnace and heated to 450°C in a flowing air atmosphere and calcined for 6 hours. The air flow rate is 1L / min and the heating rate is 2°C / min. After the second calcination is completed, continue to cool to 40-60°C in an air atmosphere, collect the calcined product to prepare the hydrogen-type aluminum-rich Beta molecular sieve.

[0151] X-ray fluorescence spectroscopy (XRF) test shows that the SiO2 / Al2O3 ratio of the hydrogen-type aluminum-rich Beta molecular sieve is 7.7. Calculated based on the silicon-aluminum ratio of the feed, the utilization rate of the silicon source is about 96%.

[0152] Example 8

[0153] 194.62 kg of aluminum sol with an Al2O3 content of 21.2 wt% and 340.52 kg of a 35 wt% tetraethylammonium hydroxide aqueous solution were weighed and mixed to obtain a quaternary ammonium aluminum source template solution.

[0154] Prepare 81.10 kg of 40 wt % potassium hydroxide aqueous solution for later use.

[0155] 215.85 kg of silica gel with a SiO2 content of 90.12 wt% and 5.84 kg of Beta seed crystals were added to the kneader and mixed at a kneading temperature of 90°C for 0.5 hours.

[0156] The template solution containing the quaternary ammonium aluminum source was atomized and added to a kneader for mixing. After mixing at a kneading temperature of 90° C. for 0.5 hours, the next step was carried out.

[0157] The prepared potassium hydroxide solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 90° C. until the water content of the materials reached 20.00%, and then the next step was carried out.

[0158] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 60 hours at a reaction temperature of 160° C. and a stirring speed of 8 rpm.

[0159] The amount of Beta seed crystals added was 3% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 30.45, and the molar ratio of SiO2:Al2O3:K2O:ROH in the crystallization material was 8.00:1.00:0.70:2.00.

[0160] After the crystallization reaction was completed, the resulting crystallized product was dried at 120° C. for 12 hours. The powder X-ray diffraction pattern of the crystallized product showed that the product had typical Beta molecular sieve structural characteristics.

[0161] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 580° C. and calcined for 6 hours in a flowing air atmosphere with an air flow rate of 5 L / min and a heating rate of 2° C. / min.

[0162] After the calcination, the mass of the obtained product is weighed, and a 10% ammonium nitrate aqueous solution with a mass fraction of 7 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 90 ° C, the number of exchanges is 2, and the ammonium exchange time is 0.5 hours each time. After the exchange is completed, it is dried at 120 ° C for 12 hours. The dried product is placed in a muffle furnace and heated to 540 ° C in a flowing air atmosphere for 3 hours. The air flow rate is 5L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen-type aluminum-rich Beta molecular sieve.

[0163] X-ray fluorescence spectroscopy (XRF) test shows that the SiO2 / Al2O3 ratio of the hydrogen-type aluminum-rich Beta molecular sieve is 7.4. Calculated based on the silicon-aluminum ratio of the feed, the utilization rate of the silicon source is about 93%.

[0164] Example 9

[0165] 131.01 kg of aluminum sol with an Al2O3 content of 21.2 wt% and 481.36 kg of a 30 wt% tetraethylammonium hydroxide aqueous solution were weighed and mixed to obtain a quaternary ammonium aluminum source template solution.

[0166] Prepare 69.89 kg of 35 wt% sodium hydroxide aqueous solution for standby use.

[0167] 272.43 kg of silica gel with a SiO2 content of 90.12 wt% and 12.28 kg of Beta seed crystals were added to the kneader and mixed at a kneading temperature of 80°C for 1.0 hour.

[0168] The template solution containing the quaternary ammonium aluminum source was atomized and added to a kneader for mixing. After mixing for 1.0 hour at a kneading temperature of 80° C., the next step was performed.

[0169] The prepared sodium hydroxide solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80°C until the water content of the materials reached 18.00%, and then the next step was carried out.

[0170] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0171] The amount of Beta seed crystals added was 5% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 24.63, and the molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 15.00:1.00:1.10:3.60.

[0172] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. Figure 10 The powder X-ray diffraction pattern of the crystallized product shows that the product has typical Beta molecular sieve structural characteristics. Figure 11 This is a scanning electron microscope image of the crystallized product.

[0173] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0174] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen-type aluminum-rich Beta molecular sieve.

[0175] X-ray fluorescence spectroscopy (XRF) test shows that the SiO2 / Al2O3 ratio of the hydrogen-type aluminum-rich Beta molecular sieve is 14.5. Calculated based on the silicon-aluminum ratio of the feed, the utilization rate of the silicon source is about 97%.

[0176] Example 10

[0177] 127.30 kg of aluminum sol with an Al2O3 content of 21.2 wt% and 519.71 kg of a 30 wt% tetraethylammonium hydroxide aqueous solution were weighed and mixed to obtain a quaternary ammonium aluminum source template solution.

[0178] Prepare 55.57 kg of 35 wt % sodium hydroxide aqueous solution for use.

[0179] 277.93 kg of precipitated silica having an SiO2 content of 85.84 wt% and 11.93 kg of Beta seed crystals were added to the kneader and mixed at a kneading temperature of 80° C. for 1.0 hour.

[0180] The template solution containing the quaternary ammonium aluminum source was atomized and added to a kneader for mixing. After mixing for 1.0 hour at a kneading temperature of 80° C., the next step was performed.

[0181] The prepared sodium hydroxide solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80°C until the water content of the materials reached 18.00%, and then the next step was carried out.

[0182] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0183] The amount of Beta seed crystals added was 5% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 24.63, and the molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 15.00:1.00:0.90:4.00.

[0184] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. The powder X-ray diffraction pattern of the crystallized product showed that the product had typical Beta molecular sieve structural characteristics.

[0185] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0186] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen-type aluminum-rich Beta molecular sieve.

[0187] X-ray fluorescence spectroscopy (XRF) test shows that the SiO2 / Al2O3 ratio of the hydrogen-type aluminum-rich Beta molecular sieve is 14.7. Calculated based on the silicon-aluminum ratio of the feed, the utilization rate of the silicon source is about 98%.

[0188] Example 11

[0189] 115.57 kg of aluminum sol with an Al2O3 content of 21.2 wt% and 554.40 kg of a 30 wt% tetraethylammonium hydroxide aqueous solution were weighed and mixed to obtain a quaternary ammonium aluminum source template solution.

[0190] Prepare 72.86 kg of 35 wt % sodium hydroxide aqueous solution for later use.

[0191] 336.42 kg of precipitated silica having an SiO2 content of 85.84 wt% and 14.40 kg of Beta seeds were added to the kneader and mixed at a kneading temperature of 80° C. for 1.0 hour.

[0192] The template solution containing the quaternary ammonium aluminum source was atomized and added to a kneader for mixing. After mixing for 1.0 hour at a kneading temperature of 80° C., the next step was performed.

[0193] The prepared sodium hydroxide solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80°C until the water content of the materials reached 17.00%, and then the next step was carried out.

[0194] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0195] The amount of Beta seed crystals added was 5% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 24.63, and the molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 20.00:1.00:1.30:4.70.

[0196] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. Figure 12 The powder X-ray diffraction pattern of the crystallized product shows that the product has typical Beta molecular sieve structural characteristics. Figure 13 This is a scanning electron microscope image of the crystallized product.

[0197] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0198] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen-type aluminum-rich Beta molecular sieve.

[0199] X-ray fluorescence spectroscopy (XRF) test shows that the SiO2 / Al2O3 ratio of the hydrogen-type aluminum-rich Beta molecular sieve is 19.6. Calculated based on the silicon-aluminum ratio of the feed, the utilization rate of the silicon source is about 98%.

[0200] Example 12

[0201] 110.77 kg of aluminum sol with an Al2O3 content of 21.2 wt% and 565.28 kg of a 30 wt% tetraethylammonium hydroxide aqueous solution were weighed and mixed to obtain a quaternary ammonium aluminum source template solution.

[0202] Prepare 72.86 kg of 35 wt% potassium hydroxide aqueous solution for later use.

[0203] 322.45 kg of precipitated silica having an SiO2 content of 85.84 wt% and 13.84 kg of Beta seed crystals were added to a kneader and mixed at a kneading temperature of 80° C. for 1.0 hour.

[0204] The template solution containing the quaternary ammonium aluminum source was atomized and added to a kneader for mixing. After mixing for 1.0 hour at a kneading temperature of 80° C., the next step was performed.

[0205] The prepared potassium hydroxide solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80° C. until the water content of the materials reached 17.00%, and then the next step was carried out.

[0206] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0207] The amount of Beta seed crystals added was 5% of the mass of SiO2 contained in the silica gel, the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 24.63, and the molar ratio of SiO2:Al2O3:K2O:ROH in the crystallization material was 20.00:1.00:1.20:5.00.

[0208] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. The powder X-ray diffraction pattern of the crystallized product showed that the product had typical Beta molecular sieve structural characteristics.

[0209] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0210] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen-type aluminum-rich Beta molecular sieve.

[0211] X-ray fluorescence spectroscopy (XRF) test shows that the SiO2 / Al2O3 ratio of the hydrogen-type aluminum-rich Beta molecular sieve is 19.3. Calculated based on the silicon-aluminum ratio of the feed, the utilization rate of the silicon source is about 97%.

[0212] Examples 13-18 are methods for preparing high silicon-to-aluminum ratio Beta molecular sieve using Beta molecular sieve as seed crystal and aluminum source.

[0213] Table 3 shows the contents of SiO2, Al2O3, and Na2O in the Beta molecular sieve seed crystals and silicon sources used in Examples 13-18, which were determined using X-ray fluorescence spectroscopy (XRF).

[0214] Table 3 XRF test of SiO2, Al2O3, and Na2O contents in Beta molecular sieve seeds and silicon sources

[0215] Sample name <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Na2O]]> Precipitated silica 85.843％ 0.415％ 1.055％ Silicone 90.124％ 0.100％ 0.109％ Fumed silica 96.980％ -- -- Beta 20 77.165％ 6.330％ 0.053％ Beta 30 77.052％ 4.294％ 0.041％ Beta 40 77.997％ 3.303％ 0.041％ Beta 60 81.577％ 2.317％ 0.042％

[0216] Note: -- indicates not detected.

[0217] Example 13

[0218] 802.44 kg of a 25 wt % aqueous solution of tetraethylammonium hydroxide and 52.31 kg of Beta 20 molecular sieve seed crystals were weighed and stirred, and refluxed at a reaction temperature of 80° C. for 12 hours to obtain a template slurry containing Beta molecular sieve seed crystals.

[0219] Weigh 16.32 kg of sodium hydroxide and add it to an appropriate amount of deionized water to prepare a 40 wt % sodium hydroxide aqueous solution for later use.

[0220] 513.92 kg of precipitated silica was added to the kneader, and the template slurry containing Beta molecular sieve seed crystals was atomized and added to the kneader for mixing. The mixture was mixed at a kneading temperature of 70° C. for 1.5 hours.

[0221] The prepared sodium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 70°C until the water content of the materials reached 20.00%, and then the next step was carried out.

[0222] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 96 hours at a reaction temperature of 140° C. and a stirring speed of 3 rpm.

[0223] The amount of Beta seed crystals added was 10.2% of the mass of SiO2 contained in the silica gel, and the molar ratio of SiO2 to Al2O3 contained in the seed crystals was approximately 20.69. The molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 100.00:0.67:2.50:17.00.

[0224] After the crystallization reaction was completed, the resulting crystallized product was dried at 90° C. for 24 hours. Figure 14 The powder X-ray diffraction pattern of the crystallized product shows that the product has typical Beta molecular sieve structural characteristics. Figure 15 This is a scanning electron microscope image of the crystallized product.

[0225] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 540° C. and calcined for 10 hours in a flowing air atmosphere with an air flow rate of 1 L / min and a heating rate of 2° C. / min.

[0226] After the calcination, the mass of the obtained product is weighed, and a 5% ammonium nitrate aqueous solution with a mass fraction of 12 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 50°C, the number of exchanges is 3 times, and the ammonium exchange time is 3 hours each time. After the exchange is completed, it is dried at 90°C for 24 hours. The dried product is placed in a muffle furnace and heated to 450°C in a flowing air atmosphere and calcined for 6 hours. The air flow rate is 1L / min and the heating rate is 2°C / min. After the second calcination is completed, continue to cool to 40-60°C in an air atmosphere, collect the calcined product to prepare the hydrogen-type high silicon-aluminum ratio Beta molecular sieve.

[0227] The SiO2 / Al2O3 ratio of the hydrogen-type high silicon-aluminum ratio Beta molecular sieve tested by XRF is 152.9.

[0228] Example 14

[0229] 635.55 kg of a 35 wt % aqueous solution of tetraethylammonium hydroxide and 22.87 kg of Beta 30 molecular sieve seed crystals were weighed and stirred, and refluxed at a reaction temperature of 100° C. for 6 hours to obtain a template slurry containing Beta molecular sieve seed crystals.

[0230] Weigh 16.32 kg of potassium hydroxide and add it to an appropriate amount of deionized water to prepare a 30 wt % potassium hydroxide aqueous solution for later use.

[0231] 508.17 kg of precipitated silica was added to the kneader, and the template slurry containing Beta molecular sieve seed crystals was atomized and added to the kneader for mixing. The mixture was mixed at a kneading temperature of 90° C. for 0.5 hour.

[0232] The prepared potassium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 90° C. until the water content of the materials reached 15.00%, and then the next step was carried out.

[0233] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 60 hours at a reaction temperature of 160° C. and a stirring speed of 8 rpm.

[0234] The amount of Beta seed crystals added was 4.5% of the mass of SiO2 contained in the silica gel, and the molar ratio of SiO2 to Al2O3 in the seed crystals was approximately 30.45. The molar ratio of SiO2:Al2O3:K2O:ROH in the crystallization material was 100.00:0.4:2.90:20.00, and the silicon-aluminum ratio of the feed was approximately 250.0.

[0235] After the crystallization reaction was completed, the resulting crystallized product was dried at 120° C. for 12 hours. The powder X-ray diffraction pattern of the crystallized product showed that the product had typical Beta molecular sieve structural characteristics.

[0236] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 580° C. and calcined for 6 hours in a flowing air atmosphere with an air flow rate of 5 L / min and a heating rate of 2° C. / min.

[0237] After the calcination, the mass of the obtained product is weighed, and a 10% ammonium nitrate aqueous solution with a mass fraction of 7 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 90 ° C, the number of exchanges is 2, and the ammonium exchange time is 0.5 hours each time. After the exchange is completed, it is dried at 120 ° C for 12 hours. The dried product is placed in a muffle furnace and heated to 540 ° C in a flowing air atmosphere for 3 hours. The air flow rate is 5L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen-type high silicon-aluminum ratio Beta molecular sieve.

[0238] The SiO2 / Al2O3 ratio of hydrogen-type high silicon-aluminum ratio Beta molecular sieve tested by XRF is 257.3.

[0239] Example 15

[0240] 790.74 kg of a 30 wt % aqueous solution of tetraethylammonium hydroxide and 24.22 kg of Beta 30 molecular sieve seed crystals were weighed and stirred, and refluxed at a reaction temperature of 90° C. for 9 hours to obtain a template slurry containing Beta molecular sieve seed crystals.

[0241] Weigh 19.99 kg of sodium hydroxide and add it to an appropriate amount of deionized water to prepare a 35 wt % sodium hydroxide aqueous solution for later use.

[0242] 474.25 kg of silica gel was added to the kneader, and the template slurry containing Beta molecular sieve seed crystals was atomized and added to the kneader for mixing. The mixture was mixed at a kneading temperature of 80° C. for 1 hour.

[0243] The prepared sodium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80° C. until the water content of the materials reached 17.00%, and then the next step was carried out.

[0244] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0245] The amount of Beta seed crystals added was 5.1% of the mass of SiO2 contained in the silica gel, and the molar ratio of SiO2 to Al2O3 in the seed crystals was approximately 30.45. The molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 100.00:0.2:3.30:21.70, and the silicon-aluminum ratio of the feed was approximately 500.

[0246] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. Figure 16 The powder X-ray diffraction pattern of the crystallized product shows that the product has typical Beta molecular sieve structural characteristics. Figure 17 This is a scanning electron microscope image of the crystallized product.

[0247] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0248] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen-type high silicon-aluminum ratio Beta molecular sieve.

[0249] The SiO2 / Al2O3 ratio of hydrogen-type high silicon-aluminum ratio Beta molecular sieve tested by XRF is 495.9.

[0250] Example 16

[0251] 805.83 kg of a 30 wt % aqueous solution of tetraethylammonium hydroxide and 15.37 kg of Beta 60 molecular sieve seed crystals were weighed and stirred, and refluxed at a reaction temperature of 90° C. for 9 hours to obtain a template slurry containing Beta molecular sieve seed crystals.

[0252] Weigh 25.01 kg of sodium hydroxide and add it to an appropriate amount of deionized water to prepare a 35 wt % sodium hydroxide aqueous solution for later use.

[0253] 472.56 kg of silica gel was added to the kneader, and the template slurry containing Beta molecular sieve seed crystals was atomized and added to the kneader for mixing. The mixture was mixed at a kneading temperature of 80° C. for 1 hour.

[0254] The prepared sodium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80° C. until the water content of the materials reached 17.00%, and then the next step was carried out.

[0255] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0256] The amount of Beta seed crystals added was 3.3% of the mass of SiO2 contained in the silica gel, and the molar ratio of SiO2 to Al2O3 in the seed crystals was approximately 59.73. The molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 100.00:0.11:4.20:22.50, and the silicon-aluminum ratio of the feed was approximately 900.0.

[0257] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. The powder X-ray diffraction pattern of the crystallized product showed that the product had typical Beta molecular sieve structural characteristics.

[0258] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0259] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen-type high silicon-aluminum ratio Beta molecular sieve.

[0260] The SiO2 / Al2O3 ratio of hydrogen-type high silicon-aluminum ratio Beta molecular sieve tested by XRF is 911.4.

[0261] Example 17

[0262] 849.01 kg of a 30 wt % aqueous solution of tetraethylammonium hydroxide and 15.53 kg of Beta 40 molecular sieve seed crystals were weighed and stirred, and refluxed at a reaction temperature of 90° C. for 9 hours to obtain a template slurry containing Beta molecular sieve seed crystals.

[0263] Weigh 27.08 kg of sodium hydroxide and add it to an appropriate amount of deionized water to prepare a 35 wt % sodium hydroxide aqueous solution for later use.

[0264] 424.94 kg of fumed silica was added to the kneader, and the template slurry containing Beta molecular sieve seed crystals was atomized and added to the kneader for mixing. The mixture was mixed at a kneading temperature of 80° C. for 1 hour.

[0265] The prepared sodium hydroxide aqueous solution was atomized and added to the kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80° C. until the water content of the materials reached 17.00%, and then the next step was carried out.

[0266] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0267] The amount of Beta seed crystals added was 3.7% of the mass of SiO2 contained in the silica gel, and the molar ratio of SiO2 to Al2O3 in the seed crystals was approximately 40.07. The molar ratio of SiO2:Al2O3:Na2O:ROH in the crystallization material was 100.00:0.07:4.70:24.50, and the silicon-aluminum ratio of the feed was approximately 1400.0.

[0268] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. Figure 18 The powder X-ray diffraction pattern of the crystallized product shows that the product has typical Beta molecular sieve structural characteristics. Figure 19 This is a scanning electron microscope image of the crystallized product.

[0269] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0270] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen-type high silicon-aluminum ratio Beta molecular sieve.

[0271] The SiO2 / Al2O3 ratio of the hydrogen-type high silicon-aluminum ratio Beta molecular sieve tested by XRF is 1394.0.

[0272] Example 18

[0273] 886.84 kg of a 30 wt % aqueous solution of tetraethylammonium hydroxide and 14.72 kg of Beta 60 molecular sieve seed crystals were weighed and stirred, and refluxed at a reaction temperature of 90° C. for 9 hours to obtain a template slurry containing Beta molecular sieve seed crystals.

[0274] Weigh 38.30 kg of potassium hydroxide and add it to an appropriate amount of deionized water to prepare a 35 wt % potassium hydroxide aqueous solution for later use.

[0275] 402.23 kg of fumed silica was added to the kneader, and the template slurry containing Beta molecular sieve seed crystals was atomized and added to the kneader for mixing. The mixture was mixed at a kneading temperature of 80° C. for 1 hour.

[0276] The prepared potassium hydroxide aqueous solution was atomized and added to a kneader for mixing. The above materials were dried and dehydrated at a kneading temperature of 80° C. until the water content of the materials reached 17.00%, and then the next step was carried out.

[0277] The dried material was transferred to a pressure-resistant rake dryer, and crystallization reaction was carried out for 72 hours at a reaction temperature of 145° C. and a stirring speed of 5 rpm.

[0278] The amount of Beta seed crystals added was 3.7% of the mass of SiO2 contained in the silica gel, and the molar ratio of SiO2 to Al2O3 in the seed crystals was approximately 59.73. The molar ratio of SiO2:Al2O3:K2O:ROH in the crystallization material was 100.00:0.05:5.00:27.00, and the silicon-aluminum ratio of the feed was approximately 2000.0.

[0279] After the crystallization reaction was completed, the resulting crystallized product was dried at 100° C. for 18 hours. The powder X-ray diffraction pattern of the crystallized product showed that the product had typical Beta molecular sieve structural characteristics.

[0280] 1.0 kg of the dried crystallized product was placed in a muffle furnace, heated to 550° C. and calcined for 7 hours in a flowing air atmosphere with an air flow rate of 2 L / min and a heating rate of 2° C. / min.

[0281] After the calcination, the mass of the obtained product is weighed, and a 7% ammonium sulfate aqueous solution with a mass fraction of 10 times the weight of the molecular sieve is added. Under stirring conditions, the ammonium exchange reaction is carried out. The ammonium exchange temperature is 70 ° C, the number of exchanges is 3, and the ammonium exchange time is 1 hour each time. After the exchange is completed, it is dried at 100 ° C for 18 hours. The dried product is placed in a muffle furnace and heated to 500 ° C in a flowing air atmosphere for 4 hours. The air flow rate is 2L / min and the heating rate is 2 ° C / min. After the second calcination is completed, continue to cool to 40-60 ° C in an air atmosphere, collect the calcined product to prepare the hydrogen-type high silicon-aluminum ratio Beta molecular sieve.

[0282] The SiO2 / Al2O3 ratio of hydrogen-type high silicon-aluminum ratio Beta molecular sieve tested by XRF is 1994.8.

[0283] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A method for preparing Beta molecular sieve, characterized in that: The following steps are involved: (1) Mixing the template and the aluminum source under stirring conditions to obtain a template containing the aluminum source; (2) mixing an alkali source and water under stirring to obtain an alkali source aqueous solution; (3) Add the silicon source into the kneader, atomize the template containing the aluminum source obtained in step (1), and add it into the kneader at a kneading temperature of 70-90°C; (4) The solution obtained in step (2) is atomized and mixed with the material in the kneader. The mixed material is dried and dehydrated at a kneading temperature of 70-90°C until the water content of the material is 15-20%, thereby obtaining a crystallized dry material; (5) transferring the crystallized dry material obtained in step (4) to a pressure-resistant palladium dryer, and performing a crystallization reaction at a reaction temperature of 140-160° C., a reaction time of 60-96 h, and a stirring speed of 3-8 rpm; (6) drying and calcining the crystallized product obtained in step (5) to obtain a Beta molecular sieve containing an alkali metal; (7) The product obtained in step (6) is subjected to ammonium exchange, drying, and calcination to obtain hydrogen-type Beta molecular sieve.

2. The method for preparing Beta molecular sieve according to claim 1, wherein: In the step (6), the drying temperature is 90-120°C, and the drying time is 12-24 hours; the roasting temperature is 540-580°C, and the holding time is 6-10 hours. The roasting is carried out in a flowing air atmosphere with an air flow rate of 1-5 L / min.

3. The method for preparing Beta molecular sieve according to claim 1, wherein: In the step (7), the ammonium salt used for ammonium exchange is selected from ammonium sulfate and ammonium nitrate, the mass fraction of ammonium salt in the ammonium salt aqueous solution during the ammonium exchange process is 5-10%, the mass ratio of the ammonium salt aqueous solution to the Beta molecular sieve during the ammonium exchange process is 7-12:1, the ammonium exchange temperature is 50-90°C, the number of ammonium exchanges is 2-3 times, and the ammonium exchange time is 0.5-3 hours; And / or in the step (7), the drying temperature is 90-120°C, and the drying time is 12-24 hours; the roasting temperature is 450-540°C, the holding time is 3-6 hours, and the roasting is carried out in a flowing air atmosphere with an air flow rate of 1-5 L / min.

4. The method for preparing Beta molecular sieve according to any one of claims 1 to 3, characterized in that: In the step (3), the silicon source and the Beta molecular sieve seed crystals are first mixed in a kneader at a kneading temperature of 70-90° C. for a kneading time of 0.5-1.5 hours. Then, the template containing the aluminum source obtained in the step (1) is atomized and added into the kneader to be mixed with the silicon source and the Beta molecular sieve seed crystals. The kneading temperature is 70-90° C. for a kneading time of 0.5-1.5 hours.

5. The method for preparing Beta molecular sieve according to claim 4, wherein: In the step (4), the silicon source, aluminum source, alkali source and template in the crystallized dry material are calculated as SiO2, Al2O3, M2O and ROH respectively, and the molar ratio of the reaction raw materials is SiO2:Al2O3:M2O:ROH=20.0~150.0:1.0:0.9~3.0:2.7~17.

0.

6. The method for preparing Beta molecular sieve according to claim 5, wherein: In the step (1), the reaction temperature is 80-100° C. and the reaction mixture is refluxed for 6-12 hours to obtain a template solution containing an aluminum source.

7. The method for preparing Beta molecular sieve according to claim 5, characterized in that: The template is a 25-35% by mass aqueous solution of tetraethylammonium hydroxide; in the step (1), the aluminum source is selected from one of aluminum sol, pseudo-boehmite, aluminum hydroxide, and aluminum sulfate; in the step (2), the alkali source is sodium hydroxide or potassium hydroxide, and the mass concentration of the prepared alkali source aqueous solution is 30-40%; in the step (3), the silicon source is one of precipitated silica and silica gel; the molar ratio of SiO2 to Al2O3 contained in the Beta molecular sieve seed crystals is in the range of 20-60, and the amount of the Beta molecular sieve seed crystals added is 3-10% of the mass of SiO2 contained in the silicon source.

8. The method for preparing Beta molecular sieve according to claim 5, characterized in that: In the step (1), the aluminum source is selected from aluminum sol; in the step (3), the molar ratio of SiO2 to Al2O3 contained in the Beta molecular sieve seed crystals is in the range of 20 to 30, and the amount of the Beta molecular sieve seed crystals added is 3 to 7% of the mass of SiO2 contained in the silicon source.

9. The method for preparing Beta molecular sieve according to claim 4, wherein: In the step (4), the silicon source, aluminum source, alkali source and template in the crystallized dry material are calculated as SiO2, Al2O3, M2O and ROH respectively, and the molar ratio of the reaction raw materials is SiO2:Al2O3: M2O: ROH=8~20:1:0.5~1.3:2.0~5.

0.

10. The method for preparing Beta molecular sieve according to claim 1, wherein: The aluminum source in step (1) is a Beta molecular sieve seed crystal, and the step (1) is to mix the template and the Beta molecular sieve seed crystal under stirring conditions, and reflux for 6 to 12 hours at a reaction temperature of 80 to 100° C. to obtain a template slurry containing the Beta molecular sieve seed crystal; and / or, In the step (4), the silicon source, aluminum source, alkali source and template in the crystallized dry material are calculated as SiO2, Al2O3, M2O and ROH respectively, and the molar ratio of the reaction raw materials is SiO2:Al2O3:M2O:ROH=100:0.05~0.67:2.5~5.0:17~27.

11. The method for preparing Beta molecular sieve according to claim 9, wherein: In the step (1), the molar ratio of SiO2 to Al2O3 contained in the Beta molecular sieve seed crystals is in the range of 20 to 60, and the amount of Beta molecular sieve seed crystals added is 3-11% of the mass of SiO2 contained in the silicon source; in the step (1), the template is a 25-35% mass fraction tetraethylammonium hydroxide aqueous solution; in the step (2), the alkali source is sodium hydroxide or potassium hydroxide, and the mass concentration of the alkali source aqueous solution is 30-40%; in the step (3), the silicon source is one of precipitated silica, silica gel, and fumed silica.

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