A method for synthesizing a molecular sieve and a molecular sieve produced thereby

Abstract

The application discloses a method for synthesizing a molecular sieve and the molecular sieve prepared by the method. The method for synthesizing the molecular sieve comprises the following steps: (1) preparing a first solution containing an organic solvent and a silicon source; (2) preparing a second solution containing a first organic template T, an organic solvent and an aluminum source; (3) feeding the first solution and the second solution into an ultra-gravity reactor in two ways, and directly crystallizing under the action of ultra-gravity rotation stirring, so that the molecular sieve product is obtained after reaction. The method provided by the application does not need a conventional aging process, the reaction process adopts an ultra-gravity intensification technology, direct temperature rising crystallization, the synthesis time is short, and the special molecular sieve with special morphology and particle size is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for synthesizing a molecular sieve and the molecular sieve prepared by the method, and belongs to the technical field of zeolite molecular sieve synthesis. BACKGROUND

[0002] Zeolite molecular sieve is an inorganic crystalline material, which is widely used in catalysis, adsorption and ion exchange fields due to its regular pore structure, special surface performance, good thermal stability and hydrothermal stability. Today, there are more than 120 types of zeolite molecular sieves, and the pore size has been expanded from microporous to mesoporous, and the framework chemical composition has been expanded from aluminosilicate to silicoaluminate and phosphoaluminate containing various heteroatoms, which has become an indispensable catalytic and adsorptive material in petroleum processing and fine chemical industry.

[0003] CN200910072747.7 discloses a method for preparing nano ZSM-5 molecular sieve. The method is to add pre-crystallization seeds to the gel system for synthesizing nano ZSM-5 molecular sieve without a template agent, then crystallize at 160-185℃ for 12-36 hours, cool to room temperature, centrifuge, filter, wash, dry and calcine the product to obtain nano ZSM-5 molecular sieve.

[0004] CN201210287914.1 discloses a method for preparing mesoporous zeolite molecular sieve. Tetraethyl orthosilicate is used as a silicon source, sodium metaaluminate is used as an aluminum source, and a bifunctional triammonium-based quaternary ammonium salt cationic surfactant is used as a template agent to prepare mesoporous zeolite molecular sieve with microporous crystalline pore walls by hydrothermal synthesis under alkaline conditions. The mesoporous zeolite molecular sieve has a unique mesopore / micropore multiple pore structure.

[0005] CN201810015545.8 discloses a method for preparing a silicon-aluminum molecular sieve by using a high gravity method. The method uses an internal circulation high gravity reactor as a reaction device, and pumps the silicon source and the aluminum source into the high gravity reactor through liquid inlet pipes. After the two streams of raw materials are premixed, the initial gel is obtained. The reaction system is characterized by rapid mixing under the action of high gravity, which accurately controls the raw material ratio under micro conditions, and makes the nucleation and growth process uniform and controllable, so that the crystal grains grow uniformly and the particle size distribution is narrowed.

[0006] At present, although there are certain research results on the supergravity process intensification technology, the research on the process intensification technology for the preparation of molecular sieve catalysts, especially the research on the transfer / mixing process and reaction coordination mechanism in the representative hydrothermal reaction crystallization system still needs to be furthered, and the key technology for industrial preparation still needs to be broken through. In addition, in the existing molecular sieve synthesis method, the reaction solution usually firstly undergoes a conventional aging preparation process, then is subjected to a temperature rising crystallization reaction, and finally the molecular sieve product is obtained. How to directly and efficiently synthesize the molecular sieve in one step, especially the synthesis method of small particle size and uniform distribution of the molecular sieve, is less involved in the existing technology. SUMMARY

[0007] The application provides a method for synthesizing a molecular sieve and the molecular sieve prepared by the method. The method does not need a conventional aging process, adopts a supergravity process intensification technology, directly crystallizes by temperature rising, has a short synthesis time, and obtains a molecular sieve with special morphology and particle size.

[0008] The first aspect of the application provides a method for synthesizing a molecular sieve, comprising:

[0009] (1) preparing a first solution containing an organic solvent and a silicon source;

[0010] (2) preparing a second solution containing a first organic template T, an organic solvent and an aluminum source;

[0011] (3) feeding the first solution and the second solution into a supergravity reactor in two ways, directly crystallizing under the supergravity rotary stirring, and obtaining a molecular sieve product after the reaction.

[0012] Further, in the first solution of step (1), the molar ratio of the organic solvent to the silicon source (calculated as SiO2) is 5-100, preferably 5-50.

[0013] Further, in steps (1) and (2), the organic solvent is independently selected from at least one of an organic alcohol, an organic ether or an organic ketone, wherein the organic alcohol can be at least one of methanol, ethanol, isopropyl alcohol and n-butanol, the organic ether can be diethyl ether, and the organic ketone can be at least one of acetone, methyl butanone and methyl isobutyl ketone.

[0014] Further, in the first solution of step (1), the silicon source is a silicate compound selected from at least one of tetraethyl orthosilicate, isopropyl orthosilicate and tetramethyl orthosilicate, preferably tetraethyl orthosilicate.

[0015] Further, in the second solution of step (2), the molar ratio of the amount of the organic template T to the silicon source (calculated as SiO2) in the first solution is T / SiO2, and the molar ratio is 0.20-0.60, preferably 0.20-0.55.

[0016] Further, in the second solution of step (2), the molar ratio of Al2O3 / SiO2, based on the amount of Al2O3 added in the aluminum source and the amount of SiO2 added in the silicon source, is 0-2 and not 0, preferably 0.001-1.0.

[0017] Further, in the second solution of step (2), the mass ratio of the organic template T to the organic solvent is (0.5-20.0):1.

[0018] Further, in the second solution of step (2), the organic template T is at least one selected from ethylenediamine, diethanolamine, triethylamine, n-propylamine, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetramethylammonium bromide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetraethylammonium bromide, hexamethylene diisocyanate, hexamethylene diamine, hexamethylene tetramine and its derivatives (urotropine and its derivatives), preferably at least one selected from ethylenediamine, triethylamine, n-propylamine, tetrapropylammonium bromide, tetrapropylammonium hydroxide.

[0019] Further, in the second solution of step (2), the aluminum source is at least one selected from aluminum sulfate, aluminum isopropoxide, meta-aluminate, aluminate.

[0020] Further, in step (3), after the first solution and the second solution are introduced into the high gravity reactor, the crystallization is directly performed under high gravity rotation stirring without pre-mixing circulation or aging process.

[0021] Further, in step (3), after the first solution and the second solution are introduced into the high gravity reactor, the crystallization is directly performed under high gravity rotation stirring without pre-mixing circulation or aging process.

[0022] Further, in step (3), after the first solution and the second solution are introduced into the high gravity reactor, the crystallization is directly performed under high gravity rotation stirring without pre-mixing circulation or aging process.

[0023] Further, in step (3), the reaction temperature for the crystallization is 120-180℃, preferably 120-160℃, more preferably 120-150℃.

[0024] Further, in step (3), the reaction time for the crystallization is 0.1-1h, preferably 10-30min.

[0025] Further, in step (3), after the crystallization is completed, the material is removed from the high gravity reactor after being cooled to room temperature.

[0026] Further, in step (3), the material is removed from the high gravity reactor, washed, separated and dried, and then calcined to obtain the molecular sieve product.

[0027] Further, in step (3), the drying is performed at 80-120℃ for 4-12h, and the calcination is performed at 500-650℃ for 2-8h.

[0028] Further, in step (3), the molecular sieve is one or more of ZSM-5, ZSM-11, Beta, mordenite, and SAPO-34, preferably one or more of ZSM-5, ZSM-11, and SAPO-34, and more preferably ZSM-5.

[0029] The second aspect of the present application also provides a molecular sieve prepared by the method for synthesizing the molecular sieve, wherein the molecular sieve is one or more of ZSM-5, ZSM-11, Beta, mordenite, and SAPO-34, preferably one or more of ZSM-5, ZSM-11, and SAPO-34, and more preferably ZSM-5.

[0030] Further, the molecular sieve has an elliptical cylinder shape, a height of 50-200nm, and a long diameter of 460-600nm.

[0031] The third aspect of the present application also provides the use of the molecular sieve of the second aspect in a butene cracking reaction.

[0032] Further, the reaction is performed at a temperature of 500-550℃, a weight hourly space velocity of 5-10h-1, a pressure of 0-0.1MPa, and a mass content of butene of 50%-60%. -1

[0033] Compared with the prior art, the present application has the following advantages:

[0034] ​1. The present application provides a new method for synthesizing molecular sieves, wherein the method does not have a conventional aging process, and the reaction process uses a supergravity process intensification technology, two streams of solution are mixed at a specific volume ratio, stirred at a specific rotating speed and directly heated for crystallization reaction after the reaction solution enters a supergravity reactor, and no pre-mixing, aging and other processes are needed, and the crystallization time is very short. Using this method can not only greatly reduce the amount of template agent, but also reduce the aging process, and the total reaction time is greatly shortened, thereby effectively improving the synthesis efficiency, and the synthesized molecular sieves also have the characteristics of uniform particle size, and the synthesis method also has the characteristics of good parallelism, repeatability, operability and the like, and has better practicability and effectiveness.

[0035] 2. The molecular sieves prepared by the method provided by the present application have a specific morphology, and the morphology of the molecular sieves is an elliptical cylinder, the particle size height is 50-200 nm, and the long diameter is 460-600 nm.

[0036] 3. The molecular sieves prepared by the method for synthesizing molecular sieves provided by the present application are applied to a butene cracking fixed bed reaction, and when the reaction temperature is 550℃ and the weight hourly space velocity is 10h-1, the molecular sieves have good catalytic effect after 6 hours of reaction, the butene conversion rate is more than 76%, the propylene selectivity is more than 30%, and an unexpected technical effect is obtained. -1 BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is an SEM photo of the molecular sieves obtained in Example 1;

[0038] Figure 2 is an XRD spectrum of the molecular sieves obtained in Example 1;

[0039] Figure 3 is an SEM photo of the product sample obtained in Comparative Example 1;

[0040] Figure 4 is an XRD spectrum of the product sample obtained in Comparative Example 1. DETAILED DESCRIPTION

[0041] The following examples will further illustrate the method for synthesizing molecular sieves provided by the present application, but the protection scope of the present application is not limited by the examples.

[0042] In the present application, the crystal phase analysis (XRD) of raw materials and products is performed on an X'pert PRO X-ray powder diffractometer of Panalytical Company, with Cu Kα ray as an X-ray light source, tube pressure of 40 kV and tube flow of 40 mA. The scanning electron microscope (SEM) photo of the sample is taken on a Hitachi S-4800II type scanning electron microscope.

[0043]

Example 1

[0044] Synthesis method: prepare the first solution: add 280 g of tetraethyl orthosilicate into 640 g of ethanol and stir until uniform. Prepare the second solution: dissolve 2.55 g of aluminum sulfate octadecahydrate into 180 g of ethanol, then add 350 g of tetrapropylammonium hydroxide and stir until uniform. The molar ratio of aluminum source (calculated as Al2O3), organic template T, and silicon source (calculated as SiO2) is 1:175:350. The first solution and the second solution are separately fed into the high gravity reactor at a volume flow rate of 150 ml / min and 100 ml / min, respectively, while the high gravity rotational stirring is started at a rotational speed of 1500 rpm. After the feeding of all materials is completed, the high gravity reactor feeding valve is closed, the high gravity reactor oil bath heating system is started to increase the temperature, and after the reaction temperature reaches 150℃, the temperature is kept constant, and the high gravity stirring is continued for 30 minutes. Then the heating system is turned off, and the reactor is naturally cooled until the temperature is close to room temperature (below 40℃), the high gravity stirring is stopped, the reaction product is removed from the high gravity reactor, washed with ethanol solution and centrifuged once, washed with deionized water and centrifuged three times, the solid product obtained by centrifugation is dried at 80℃ for 12 hours, and then placed in a muffle furnace and calcined at 600℃ for 4 hours to obtain the product.

[0045] Figure 1 is the SEM photo of the molecular sieve obtained in Example 1, and the morphology is an elliptical cylinder. It can be seen that the particle size of the obtained product is 50-200 nm in height, 460-600 nm in length, and the particle size distribution is very uniform. Figure 2 is the XRD pattern of the molecular sieve of Example 1. It can be seen that the product has the characteristic diffraction peaks of ZSM-5 and has a high crystallinity.

[0046] The product obtained by the preparation of this example is applied to a butene cracking fixed bed reaction. When the reaction temperature is 550℃, the weight hourly space velocity is 10 h -1 , the reaction pressure is 0.1 MPa, the butene content of the reaction raw material is 60%, and the reaction time is 6 hours, the product has good catalytic effect, the butene conversion rate reaches 78%, and the propylene selectivity reaches 30%.

[0047]

Example 2

[0048] Synthesis Method: Preparation of the first solution: Add 280g of tetraethyl orthosilicate to 640g of ethanol and stir until homogeneous. Preparation of the second solution: Dissolve 2.55g of aluminum sulfate octahydrate in 180g of ethanol, then add 350g of tetrapropylammonium hydroxide and stir until homogeneous. The molar ratio of aluminum source (calculated as Al2O3), organic template agent T, and silicon source (calculated as SiO2) is 1:175:350. The first and second solutions are fed into the hypergravity reactor via two separate flow rates of 150ml / min and 100ml / min, respectively. Simultaneously, the hypergravity rotary stirrer is activated at a speed of 2000rpm. After all materials have been fed, the feed valve of the hypergravity reactor is closed, and the oil bath heating system of the hypergravity reactor is activated to begin heating. Once the reaction temperature reaches 150℃, maintain this temperature and continue stirring under hypergravity for 25 minutes. Afterwards, the heating system was turned off and the reactor was allowed to cool naturally until the temperature inside the reactor dropped to near room temperature (below 40°C). The centrifugal stirring was then stopped, and the reaction product was removed from the centrifugal reactor. The product was washed and centrifuged once with ethanol solution, then washed and centrifuged three times with deionized water. The solid product obtained by centrifugation was dried at 80°C for 12 hours and then calcined in a fluoropolymer furnace at 600°C for 4 hours to obtain the molecular sieve product.

[0049] Similar to Example 1, the molecular sieve obtained by XRD and SEM was ZSM-5. Using this new method to synthesize ZSM-5 molecular sieve, the sample obtained after 25 min of reaction already had very good crystallinity and an elliptical cylindrical morphology. It can be seen that the particle size of the obtained product is 50-200 nm in height and about 460-600 nm in long diameter, and the particle size distribution is very uniform.

[0050] The product prepared in this example was applied to a fixed-bed reaction of butene cracking at a reaction temperature of 550°C and a weight hourly space velocity of 10 h⁻¹. -1 With a reaction pressure of 0.1 MPa, a butene content of 60% in the reaction feedstock, and a reaction time of 6 hours, it exhibits good catalytic effect, with a butene conversion rate of 76% and a propylene selectivity of 32%.

[0051]

Example 3

[0052] Synthesis method: prepare the first solution: add 280 g of tetraethyl orthosilicate into 640 g of ethanol and stir until uniform. Prepare the second solution: dissolve 2.55 g of aluminum sulfate octadecahydrate in 120 g of ethanol, then add 60 g of triethylamine and stir until uniform. The molar ratio of the aluminum source (calculated as Al2O3), the organic template T, and the silicon source (calculated as SiO2) is 1:150:350. The first solution and the second solution are separately fed into the high gravity reactor at a volume flow rate of 180 ml / min and 100 ml / min, respectively. At the same time, the high gravity stirring is started at a rotation speed of 2000 rpm. After the feeding of all materials is completed, the feeding valve of the high gravity reactor is closed, the oil bath heating system of the high gravity reactor is started, and the temperature is increased until it reaches 150℃. Then the temperature is kept constant, and the high gravity stirring is continued for 20 minutes. After that, the heating system is turned off, and the temperature is naturally cooled down to room temperature (below 40℃). Then the high gravity stirring is stopped, and the reaction product is removed from the high gravity reactor. First, the reaction product is washed with ethanol solution and centrifuged once. Then, the reaction product is washed with deionized water and centrifuged three times. Finally, the solid product obtained by centrifugation is dried at 80℃ for 12 hours, and then calcined in a muffle furnace at 600℃ for 4 hours to obtain the sample product.

[0053] The analysis and characterization show that, by using this new method to replace another organic template to synthesize molecular sieves, the SEM photos and XRD spectra of the sample obtained after 20 minutes of reaction are similar to Figure 1 and Figure 2 The obtained molecular sieves are ZSM-5 molecular sieves, and the morphology is an elliptical cylinder. It can be seen that the particle size of the obtained product is 50-200 nm in height and 460-600 nm in length, and the particle size distribution is very uniform. The product has the characteristic diffraction peaks of ZSM-5 and has a high crystallinity.

[0054] The product obtained by the preparation of this example is applied to a butene cracking fixed bed reaction. When the reaction temperature is 550℃, the weight hourly space velocity is 10 h -1 , the reaction pressure is 0.1 MPa, the butene content of the reaction raw material is 60%, and the reaction time is 6 hours, the product has good catalytic effect, the butene conversion rate reaches 76%, and the propylene selectivity reaches 30%.

[0055]

Comparative Example 1

[0056] Synthesis method: prepare the first solution: add 280 g tetraethyl orthosilicate into 640 g ethanol and stir until uniform. Prepare the second solution: add 2.55 g aluminum sulfate octadecahydrate into 180 g ethanol and dissolve, then add 350 g tetrapropylammonium hydroxide and stir until uniform. Pass the first solution and the second solution into a colloid mill at a volume flow rate of 150 ml / min and 100 ml / min respectively, so that the material is effectively emulsified, dispersed, homogenized and pulverized. After 10 min, recover the slurry to obtain the crystallization precursor. Then put the crystallization precursor directly into a crystallization kettle, and put the crystallization kettle into an oven to start heating. When the temperature rises to 150°C, keep the temperature constant and let the crystallization reaction proceed for 30 min. Then turn off the heating and let it cool naturally. When the temperature in the reaction kettle approaches room temperature (below 40°C), open the reaction kettle. The reaction product is first washed with an ethanol solution, centrifuged once, then washed with deionized water, centrifuged three times. The solid product obtained by centrifugation is dried at 80°C for 12 h, then put into a muffle furnace and calcined at 600°C for 4 h to obtain the product sample.

[0057] Figure 3 SEM photograph of the product sample obtained in Comparative Example 1, Figure 4 XRD spectrum of the product sample obtained in Comparative Example 1, the obtained molecular sieve is ZSM-5 molecular sieve. As can be seen from the figure, the particle size of the obtained sample is 3-4 microns, and small particles of different sizes are attached to the surface, and the crystallinity of the obtained sample is also not high.

[0058] The product obtained by the preparation of this example is applied to a butene cracking fixed bed reaction. Under the same reaction conditions (reaction temperature 550°C, weight space velocity 10 h -1 , reaction pressure 0.1 MPa, reaction raw material butene content 60%), after 6 hours of reaction, there is no obvious catalytic reaction performance, and the butene conversion rate is only 30%.

[0059]

Comparative Example 2

[0060] Synthesis method: prepare the first solution: add 280 g of tetraethyl orthosilicate into 640 g of ethanol and stir until uniform. Prepare the second solution: dissolve 2.55 g of aluminum sulfate octadecahydrate into 180 g of ethanol, then add 350 g of tetrapropylammonium hydroxide and stir until uniform. Pass the first solution and the second solution into the high gravity reactor at a volume flow rate of 300 ml / min and 100 ml / min respectively, and start the high gravity rotating stirring at the same time, set the rotating speed to 1500 rpm. After all the materials are fed into the reactor, close the feeding valve of the high gravity reactor, start the oil bath heating system of the high gravity reactor to heat, and keep the temperature at 150°C after the temperature reaches 150°C, and continue the high gravity stirring for 30 minutes. Then, close the heating system, cool naturally, stop the high gravity stirring when the temperature in the reactor is close to room temperature (below 40°C), take out the reaction product from the high gravity reactor, wash and centrifuge once with ethanol solution, wash and centrifuge three times with deionized water, dry the solid product obtained by centrifugation at 80°C for 12 hours, and then put it into a muffle furnace to calcine at 600°C for 4 hours to obtain the product.

[0061] The obtained product sample is ZSM-5 molecular sieve, and the crystallinity is very small, most of which is amorphous substance.

[0062]

Comparative Example 3

[0063] Synthesis method: prepare the first solution: add 280 g of tetraethyl orthosilicate into 640 g of ethanol and stir until uniform. Prepare the second solution: dissolve 2.55 g of aluminum sulfate octadecahydrate into 180 g of ethanol, then add 350 g of tetrapropylammonium hydroxide and stir until uniform. Pass the first solution and the second solution into the high gravity reactor at a volume flow rate of 300 ml / min and 100 ml / min respectively, and start the high gravity rotating stirring at the same time, set the rotating speed to 1500 rpm. After all the materials are fed into the reactor, close the feeding valve of the high gravity reactor, start the oil bath heating system of the high gravity reactor to heat, and keep the temperature at 150°C after the temperature reaches 150°C, and continue the high gravity stirring for 30 minutes. Then, close the heating system, cool naturally, stop the high gravity stirring when the temperature in the reactor is close to room temperature (below 40°C), take out the reaction product from the high gravity reactor, wash and centrifuge once with ethanol solution, wash and centrifuge three times with deionized water, dry the solid product obtained by centrifugation at 80°C for 12 hours, and then put it into a muffle furnace to calcine at 600°C for 4 hours to obtain the product.

[0064] The obtained product is ZSM-5 molecular sieve, and the morphology is spherical granular, and the particle size of the product is 2-3 microns.

[0065] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including that each technical feature is combined in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A method for synthesizing a molecular sieve, comprising: (1) preparing a first solution containing an organic solvent and a silicon source; (2) preparing a second solution containing a first organic template T, an organic solvent and an aluminum source; (3) feeding the first solution and the second solution into a high gravity reactor in two ways, and directly crystallizing under high gravity rotary stirring, and then calcining to obtain a molecular sieve product; In step (3), the first solution and the second solution are fed into the high gravity reactor in two ways, wherein the volume flow ratio of the first solution to the second solution is 1.5-1.8; In step (3), the high gravity rotary stirring is started immediately after the first solution and the second solution enter the high gravity reactor, and the rotating speed of the high gravity rotary stirring is 1500-2000 rpm; In step (3), the first solution and the second solution are directly crystallized under high gravity rotary stirring after being fed into the high gravity reactor in two ways, without pre-mixing circulation or aging process; in step (3), the reaction temperature for the crystallization is 120-180℃.

2. The method of claim 1, wherein, In the first solution of step (1), the molar ratio of the organic solvent to the silicon source, calculated based on SiO2, is 5-100.

3. The method of claim 1, wherein, In steps (1) and (2), the organic solvent is independently selected from at least one of organic alcohols, organic ethers or organic ketones; in the first solution of step (1), the silicon source is a silicate compound selected from at least one of tetraethyl orthosilicate, isopropyl orthosilicate or tetramethyl orthosilicate.

4. The method of claim 1, wherein, In the second solution of step (2), the amount of the organic template T is 0.20-0.60 times the amount of the silicon source, calculated based on SiO2; in the second solution, the molar ratio of Al2O3 / SiO2 is 0-2 and not 0, based on the amount of the aluminum source calculated based on Al2O3 and the amount of the silicon source calculated based on SiO2; in the second solution, the mass ratio of the organic template T to the organic solvent is (0.5-20.0):

1.

5. The method of claim 4, wherein, In the second solution, the molar ratio of Al2O3 / SiO2 is 0.001-1.0, based on the amount of the aluminum source calculated based on Al2O3 and the amount of the silicon source calculated based on SiO2.

6. The method of claim 1, wherein, In the second solution of step (2), the organic template T is selected from at least one of ethylenediamine, diethanolamine, triethylamine, n-propylamine, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetramethylammonium bromide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetraethylammonium bromide, hexamethylene diisocyanate, hexamethylene diamine, hexamethylene tetramine and derivatives thereof; the aluminum source is at least one of aluminum sulfate, aluminum isopropoxide, meta-aluminate and aluminate.

7. The method of claim 6, wherein, In the second solution of step (2), the organic template T is selected from at least one of ethylenediamine, triethylamine, n-propylamine, tetrapropylammonium bromide and tetrapropylammonium hydroxide.

8. The method of claim 1, wherein, In step (3), after the crystallization is completed, the material is removed from the high gravity reactor after being cooled to room temperature; and the material is calcined after being washed, separated and dried after being removed from the high gravity reactor.

9. The method of claim 8, wherein, In step (3), the drying condition is 80-120℃ for 4-12h, and the calcination condition is 500-650℃ for 2-8h.

10. The molecular sieve prepared by the method of any one of claims 1-9.

11. The molecular sieve of claim 10, wherein, The molecular sieve is one or more of ZSM-5, ZSM-11, Beta, mordenite, and SAPO-34.

12. The molecular sieve of claim 10, wherein, The molecular sieve is one or more of ZSM-5, ZSM-11, and SAPO-34.

13. The molecular sieve of claim 10, wherein, The molecular sieve is ZSM-5.

14. The molecular sieve of claim 10, wherein, The morphology of the molecular sieve is an elliptical cylinder with a height of 50-200nm and a length diameter of 460-600nm.

15. The molecular sieve of any one of claims 10-14 for use in a butene cracking reaction.

16. The use according to claim 15, characterized in that, The reaction conditions are as follows: reaction temperature 500-550℃, weight space velocity 5-10h -1 , reaction pressure 0-0.1MPa, mass content of butene in reaction raw material 50%-60%.

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