阅读说明：本技术 镁碱沸石及其制备方法和应用 (Ferrierite, process for its preparation and its use ) 是由 徐亚荣 龚涛 陈蓝天 樊金龙 许磊 魏书梅 贺春梅 聂宏元 于 2020-05-20 设计创作，主要内容包括：本发明涉及一种镁碱沸石及其制备方法和应用,所述镁碱沸石的制备方法包括如下步骤：1)将硅源、碱源和水进行混合,经加热搅拌、过滤、干燥,得到含硅前驱体；2)将所述含硅前驱体、铝源、有机模板剂和水通过加热搅拌混合,得到胶体；3)将所述胶体进行晶化处理,经过滤、干燥,得到镁碱沸石。本发明提供的镁碱沸石的制备方法,无需加入晶种,即可制备得到小晶粒的镁碱沸石；而且制备方法简单,易操作,有利于镁碱沸石的工业化生产。(The invention relates to ferrierite and a preparation method and application thereof, wherein the preparation method of the ferrierite comprises the following steps: 1) mixing a silicon source, an alkali source and water, heating, stirring, filtering and drying to obtain a silicon-containing precursor; 2) heating, stirring and mixing the silicon-containing precursor, the aluminum source, the organic template and water to obtain colloid; 3) and crystallizing the colloid, filtering and drying to obtain the ferrierite. According to the preparation method of the ferrierite, provided by the invention, the ferrierite with small crystal grains can be prepared without adding seed crystals; and the preparation method is simple and easy to operate, and is beneficial to the industrial production of the ferrierite.)

1. A preparation method of ferrierite is characterized by comprising the following steps:

1) mixing a silicon source, an alkali source and water, heating, stirring, filtering and drying to obtain a silicon-containing precursor;

2) heating, stirring and mixing the silicon-containing precursor, the aluminum source, the organic template and water to obtain colloid;

3) and crystallizing the colloid, filtering and drying to obtain the ferrierite.

2. The preparation method according to claim 1, wherein the step 1) is as follows:

mixing a silicon source, an alkali source and water, stirring for 1-12h at 30-100 ℃, filtering, washing and drying to obtain the precursor containing silicon.

3. The method according to claim 1 or 2, wherein step 2) is as follows:

and stirring and reacting the silicon-containing precursor, an aluminum source, an organic template and water at the temperature of 30-100 ℃ for 1-12h to obtain colloid.

4. The method as claimed in any one of claims 1 to 3, wherein the crystallization treatment is performed at 100 ℃ and 190 ℃ for 40 to 80 hours.

5. The method according to any one of claims 1 to 3, wherein the silicon source is selected from silica sol, sodium silicate, ethyl orthosilicate, white carbon or silica gel;

the alkali source is selected from alkali metal hydroxides;

the aluminum source is selected from aluminum nitrate, aluminum chloride, aluminum sulfate, sodium metaaluminate, pseudo-boehmite, aluminum hydroxide or aluminum isopropoxide;

the organic template is selected from pyridine, piperidine, ethylenediamine, propylenediamine, butylenediamine, tetrahydrofuran, pyrrolidine, 2, 4-pentanedione, cyclohexylamine or n-butylamine.

6. The method according to any one of claims 1 to 5, wherein the silicon source is silica, the aluminum source is alumina, and the molar ratio of the alkali source to the silicon source is (0.05 to 0.75): 1;

the molar ratio of silicon to aluminum of the silicon source to the aluminum source is (15.5-30.6): 1;

the molar ratio of the silicon source to the organic template is (1.25-2): 1.

7. a preparation method of a catalyst is characterized by comprising the following steps:

subjecting ferrierite to a first calcination treatment, wherein the ferrierite is prepared by the preparation method of claims 1-6;

and (3) carrying out ion exchange on the product after the first roasting treatment and an ammonium salt solution, drying, and roasting for the second time to obtain the catalyst.

8. The method for preparing the catalyst as claimed in claim 7, wherein the first calcination treatment and the second calcination treatment are both calcination at 350-550 ℃ for 4-10 h.

9. A catalyst, characterized in that it is prepared by the process of claims 7-8.

10. A process for producing isobutene wherein the catalyst of claim 9 is used to catalyze the isomerization of n-butene.

Technical Field

The invention relates to the technical field of catalysts, in particular to ferrierite and a preparation method and application thereof.

Background

The molecular sieve has ion exchange performance, uniform molecular pore canals, excellent catalytic activity, good thermal stability, hydrothermal stability, chemical stability and other performances, and is widely applied to the fields of petrochemical industry, light industry, building materials, environmental protection and the like.

Ferrierite (e.g. ZSM-35), as a prominent representative of molecular sieves, is commonly used in chemical reactions such as isomerization, alkylation and disproportionation of organic compounds in the field of petrochemical industry, and has good selectivity for isoolefins, particularly in reactions in which linear olefins are isoolefins. However, during the catalytic reaction, hydrocarbon compounds are easily adsorbed in the channels of the ferrierite, and part of the hydrocarbon compounds are carbonized to gradually accumulate by-products in the channels, thereby affecting the catalytic activity of the ferrierite.

Aiming at the problem that carbon deposition of the ferrierite affects the catalytic activity of the ferrierite in the catalytic reaction, the ferrierite is generally provided with short and regular pore channels by reducing the grain size of the ferrierite, so that the diffusion rate of reactants and products is improved, the accumulation of byproducts is reduced, and the ferrierite keeps better catalytic activity.

At present, the preparation process of small-grain ferrierite has been reported. The application number is CN201410784583.1, the invention name is 'synthetic method of small crystal grain ZSM-35 molecular sieve', discloses a preparation method of ferrierite, which specifically comprises the following steps: completely dissolving an aluminum source and an alkali source in water to obtain a solutionLiquid A; uniformly mixing a silicon source and a template agent ethylenediamine to obtain a solution B; then dropwise adding the solution B into the solution A while stirring, and continuously stirring for 0.5-2h after dropwise adding is finished to obtain a colloidal solution, wherein the molar ratio of each component in the colloidal solution is as follows: SiO 2₂/Al₂O₃18.5-28.6 percent of template agent ethylenediamine/SiO₂＝0.81-1.25、OH^－/SiO₂＝0.03-0.18、H₂O/SiO₂10-26; adding ZSM-35 molecular sieve seed crystal with the particle size of 0.5-1 mu m into the colloidal solution; the colloid solution added with the seed crystal is dynamically crystallized in two sections at different temperatures, the stirring speed is 20-300r/m, the temperature is increased from room temperature to 15-80 ℃ at the speed of 1-5 ℃/min for crystallization for 5-30 hours, and then the temperature is increased to 150-200 ℃ at the speed of 2-10 ℃/min for continuous crystallization for 10-30 hours; after crystallization, filtering, washing and drying are carried out, and the ZSM-35 molecular sieve with small crystal grains is prepared. Although the method can obtain the ZSM-35 molecular sieve with small crystal grains, the added seed crystal is not easy to obtain, thereby being not beneficial to the industrial production of the ferrierite.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides a preparation method of ferrierite, which can prepare small-grain ferrierite without adding seed crystals in the preparation process; and the preparation process is simple and easy to operate, and is beneficial to the industrial production of the ferrierite.

The invention also provides a preparation method of the catalyst, which adopts the ferrierite as a raw material and leads the prepared catalyst to have better catalytic activity and isomerization selectivity through the working procedures of roasting, ion exchange and the like.

The invention also provides a catalyst prepared by the preparation method of the catalyst, and the catalyst has better catalytic activity and isomerization selectivity.

The invention also provides a preparation method of isobutene, wherein the catalyst is adopted in the method, and the catalyst has good catalytic activity and good selectivity on isobutene, so that the yield of isobutene is improved.

The invention firstly provides a preparation method of ferrierite, which comprises the following steps:

1) mixing a silicon source, an alkali source and water, heating, stirring, filtering and drying to obtain a silicon-containing precursor;

2) heating, stirring and mixing the silicon-containing precursor, the aluminum source, the organic template and water to obtain colloid;

3) crystallizing the colloid, filtering, and drying to obtain ferrierite.

The preparation method of the ferrierite, provided by the invention, comprises the steps of firstly preparing a silicon-containing precursor with a porous structure, then mixing the precursor with other raw materials, and carrying out working procedures such as crystallization and the like to obtain the ferrierite with the grain size of 0.5-2 mu m. In the preparation method, the small-grain ferrierite can be prepared without adding seed crystals; and the preparation process is simple and easy to operate, and is beneficial to the industrial production of the ferrierite. The inventors speculate that the principle is as follows based on the above preparation method: the silicon of the silicon-containing precursor slowly released under the action of alkali can form crystals in the pore channels, and the crystals are prevented from agglomerating and growing due to the limitation of the size of the pore channels, so that the prepared ferrierite has smaller-sized crystals.

In some embodiments of the invention, step 1) comprises the following steps:

mixing a silicon source, an alkali source and water, stirring for 1-12h at 30-100 ℃, filtering, washing and drying to obtain a silicon-containing precursor; the silicon source can be dissolved more fully by controlling a proper stirring speed, for example, stirring is carried out by maintaining the rotation speed of 500-1500r/min during the mixing operation, and then the precursor containing silicon is obtained by filtering, washing and drying.

In some embodiments of the invention, the step 2) comprises the following steps:

and stirring and reacting the silicon-containing precursor, an aluminum source, an organic template and water at the temperature of 30-100 ℃ for 1-12h to obtain colloid. Appropriate heating agitation can be provided to facilitate the aging of the colloid, for example, by controlling the agitation rate at 500-1500 r/min.

In the specific embodiment of the invention, the small-grained ferrierite can be obtained by crystallizing the colloid, wherein the crystallizing treatment refers to crystallizing for 40-80h at the temperature of 100-190 ℃.

In the whole crystallization process, after the crystallization is carried out for a certain time, the crystallinity of the ferrierite tends to be stable, and the crystallization time is prolonged, so that the improvement range of the crystallinity is not obvious, and therefore, the ferrierite with the required crystallinity is obtained under the condition of minimum energy consumption by adopting the proper crystallization time. In the specific embodiment of the invention, the crystallization time is within 40-80h, and the obtained ferrierite has higher crystallinity and can meet the requirement of subsequent application.

In addition, the crystallization treatment in the invention is static crystallization treatment, and different crystallization treatment modes, namely segmented temperature rise crystallization and constant temperature crystallization, can be adopted.

In some embodiments of the present invention, the step-wise heating crystallization is performed as follows: firstly, heating to 100-140 ℃ at the speed of 0.2-2 ℃/min, and preserving heat for 20-32 h; and then heating to 150-190 ℃ at the speed of 2-6 ℃/min, and after heat preservation is carried out for 20-48 h, finishing crystallization.

In some embodiments of the invention, the constant temperature crystallization is performed at a constant temperature of 100-190 ℃ for 40-80 h.

And (3) carrying out solid-liquid separation on the crystallized product to obtain a solid product, and washing, filtering and drying the solid product to obtain the small-grain ferrierite. The washing, filtration and drying conditions can be adjusted by the person skilled in the art in accordance with the usual methods.

In the method for preparing ferrierite of the present invention, the silicon source is not particularly limited, and may be various commonly used silicon sources for preparing ferrierite by those skilled in the art. In some embodiments of the present invention, the silicon source may be, but is not limited to, ethyl orthosilicate, silica gel, silica sol, sodium silicate, and silica white. In a particular embodiment of the invention, the source of silicon is selected from the group consisting of silica sol and solid silica gel.

In the process for preparing ferrierite of the present invention, the alkali source is not particularly limited, and may be any of various common alkali sources used in the preparation of ferrierite by those skilled in the art. In some embodiments of the invention, the alkali source may be selected from alkali metal hydroxides, such as sodium hydroxide and potassium hydroxide.

In the method for producing ferrierite of the present invention, the aluminum source is not particularly limited, and may be any of various commonly used aluminum sources for producing ferrierite by those skilled in the art. In some embodiments of the present invention, the aluminum source may be, but is not limited to, aluminum nitrate, aluminum chloride, aluminum sulfate, sodium metaaluminate, pseudoboehmite, aluminum hydroxide, and aluminum isopropoxide. In a particular embodiment of the invention, the aluminium source is selected from aluminium nitrate, aluminium sulphate and sodium metaaluminate.

In the method for preparing ferrierite of the present invention, the organic template is not particularly limited, and may be various common organic templates used in preparing ferrierite by those skilled in the art. In some embodiments of the present invention, the organic templating agent can be, but is not limited to, pyridine, piperidine, ethylenediamine, propylenediamine, butylenediamine, tetrahydrofuran, pyrrolidine, 2, 4-pentanedione, cyclohexylamine, butylenediamine, and n-butylamine. In a particular embodiment of the invention, the organic templating agent is selected from the group consisting of ethylenediamine, tetrahydrofuran, cyclohexylamine, and pyrrolidine.

In some embodiments of the invention, the molar ratio of the alkali source to the silicon source is (0.05-0.75): 1, the molar ratio of silicon to aluminum of the silicon source to the aluminum source is (15.5-30.6): 1, the molar ratio of the silicon source to the organic template is (1.25-2): 1.

the invention also provides ferrierite which is prepared by the preparation method of any one of the embodiments, and the obtained ferrierite has a sheet structure, the thickness of the sheet structure is 30-90nm, the grain size is 0.5-2 mu m, and the specific surface area is 300-400 m-²(ii) in terms of/g. When the catalyst is applied to a catalyst, the catalyst has better carbon deposition resistance, catalytic activity and isomerization selectivity.

The invention also provides a preparation method of the catalyst, which comprises the following steps:

subjecting the ferrierite prepared by the method for preparing ferrierite according to any one of the embodiments to a first calcination treatment;

and (3) carrying out ion exchange on the product after the first roasting treatment and an ammonium salt solution to obtain hydrogen type ferrierite with better catalytic activity, drying and roasting for the second time to obtain the catalyst.

Specifically, the ferrierite is roasted for the first time at the temperature of 350-550 ℃, and the roasting time is 4-10h, so that the organic template agent in the ferrierite can be removed; and then carrying out ion exchange on the product after the first roasting and ammonium salt, washing and drying the product after the ion exchange, and then carrying out second roasting at the temperature of 350-550 ℃, and roasting for 4-10h to obtain the ferrierite catalyst.

Further, the above ammonium salts may be, but not limited to, ammonium chloride, ammonium nitrate and ammonium sulfate. In a particular embodiment of the invention, the ammonium salt is selected from ammonium chloride.

In addition, the hydrogen ferrierite is prepared by the invention, and the ferrierite can be ion-exchanged with other ions to obtain other types of ferrierite such as ammonium type, magnesium type or zinc type. After ion exchange, the density of acid sites on the surface of ferrierite is reduced and its catalytic activity is increased.

In addition, the invention also provides a catalyst prepared by the preparation method. The catalyst has good anti-carbon deposition capability, catalytic activity and isomerization selectivity.

Based on the characteristics of good carbon deposition resistance, good catalytic activity and good isomerization selectivity of the catalyst, the invention also provides a preparation method of isobutene, isobutene is prepared by using a n-butene skeletal isomerization method, wherein the catalyst is adopted in the preparation process. The catalyst prepared by the method has better catalytic activity and selectivity to isobutene, so that the yield of isobutene can be improved.

Specifically, a normal pressure fixed bed flow reaction device is adopted for carrying out catalytic reaction, and the preparation steps are as follows:

1) filling a ferrierite catalyst in a constant temperature area of a reactor in the reaction device, wherein quartz sand with 10-20 meshes is arranged at two ends of the constant temperature area;

2) introducing nitrogen into a constant-temperature area of the reactor through an inlet in the reactor, and heating to activate the ferrierite catalyst;

3) and introducing n-butene feed gas diluted by nitrogen into a constant-temperature area of the reactor through an inlet of the reactor to perform reaction.

Furthermore, the reaction product obtained in the invention is analyzed on line by a chromatographic analysis system, and the analysis result is shown in table 1. Table 1 shows that the small-grained ferrierite prepared by the present invention is used in a catalyst, which can make the catalyst have better catalytic activity and higher yield and selectivity for isobutene obtained by the reaction.

The embodiment of the invention has at least the following beneficial effects:

1) according to the preparation method of the ferrierite, provided by the invention, the ferrierite with small crystal grains can be prepared without adding seed crystals; the preparation process is simple and easy to operate, and is beneficial to the industrial production of the ferrierite;

2) according to the preparation method of the catalyst, the ferrierite is used as a raw material, the catalyst can be quickly prepared, and the catalyst has good catalytic activity and isomerization selectivity;

3) the catalyst provided by the invention has better catalytic activity and isomerization selectivity due to the adoption of the preparation method of the catalyst;

4) the invention provides the application of the catalyst in the preparation of isobutene, and the catalyst has better catalytic activity and better selectivity to isobutene, so that the yield of isobutene can be improved.

Drawings

Figure 1 is an X-ray diffraction (XRD) pattern of ferrierite of example 1 of the present invention.

FIG. 2 is a Scanning Electron Microscope (SEM) image of ferrierite of example 1 of the present invention.

Figure 3 is an X-ray diffraction (XRD) pattern of ferrierite of example 2 of the present invention.

FIG. 4 is a Scanning Electron Microscope (SEM) image of ferrierite of example 2 of the present invention.

Figure 5 is an X-ray diffraction (XRD) pattern of ferrierite of example 3 of the present invention.

FIG. 6 is a Scanning Electron Microscope (SEM) image of ferrierite of example 3 of the present invention.

FIG. 7 is a Scanning Electron Microscope (SEM) image of ferrierite of example 4 of the present invention.

FIG. 8 is a Scanning Electron Microscope (SEM) image of ferrierite of example 5 of the present invention.

FIG. 9 is a Scanning Electron Microscope (SEM) image of ferrierite of example 6 of the present invention.

FIG. 10 is a Scanning Electron Microscope (SEM) image of ferrierite of example 7 of the present invention.

FIG. 11 is a Scanning Electron Microscope (SEM) image of ferrierite of example 8 of the present invention.

Fig. 12 is a Scanning Electron Microscope (SEM) image of ferrierite of comparative example 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless otherwise specified, the chemical materials and instruments used in the following examples are all conventional chemical materials and conventional instruments, and are commercially available.

Example 1

This example provides a method for preparing ferrierite, comprising the following steps:

1) adding 60g of 30 wt% silica sol into a beaker filled with 273g of deionized water, after the silica sol is completely dissolved, dropwise adding 8.3g of 50 wt% sodium hydroxide solution, heating to 30 ℃, and stirring at the speed of 500r/min for reaction for 5 hours to obtain a mixture; carrying out vacuum filtration on the mixture to obtain a solid, washing the solid to be neutral by 450g of water, and then placing the solid in an oven to be dried for 2h at 100 ℃ to obtain a silicon-containing precursor;

2) pouring all the silicon-containing precursors into a beaker, adding 300g of deionized water, dropwise adding 5.5g of 50 wt% sodium hydroxide solution while stirring at 800r/min, heating to 50 ℃, maintaining stirring and reacting for 1h, sequentially adding 3.5g of 25 wt% sodium metaaluminate and 8.5g of ethylenediamine, and continuously stirring and reacting for 2h to obtain a colloid;

3) and transferring the colloid into a reaction kettle, crystallizing at 150 ℃ for 52 hours, carrying out solid-liquid separation on the crystallized product to obtain a solid product, washing the solid product with water, filtering, and drying at 100 ℃ for 2-4 hours to obtain the ferrierite.

Fig. 1 is an XRD pattern of the ferrierite of this example, and as can be seen from fig. 1, the 2 theta angle has distinct diffraction peaks at 9.3, 12.5, 12.7, 13.4, 22.3, 22.7, 23.6, 25.2 and 25.7, and the zeolite prepared in this example is ferrierite molecular sieve by comparing with FER molecular sieve standard diffraction pattern of international molecular sieve association. The same characterization procedure was used for the zeolites prepared in the subsequent examples to obtain the same results, i.e., the prepared zeolites were ferrierite molecular sieves.

FIG. 2 is an SEM image of the ferrierite of this example, and it can be seen from FIG. 2 that the ferrierite obtained has a plate-like structure and a crystal grain size of 0.5-1 μm.

The ferrierite of this example was determined to have a specific surface area of 341m by a specific surface area and pore size analyzer²/g。

The embodiment also provides a preparation method of the catalyst, which comprises the following steps:

1) placing the ferrierite in a muffle furnace, and roasting for 6 hours at 550 ℃ to obtain powder;

2) and (2) carrying out ion exchange reaction on the powder and 1M ammonium chloride solution to obtain hydrogen type ferrierite, washing and drying the ferrierite, and roasting at 520 ℃ for 4 hours to obtain the ferrierite catalyst, wherein the number of the ferrierite catalyst is A-1.

Example 2

This example provides a method for preparing ferrierite, comprising the following steps:

1) adding 60g of 30 wt% silica sol into a beaker filled with 273g of deionized water, after the silica sol is completely dissolved, dropwise adding 8.3g of 50 wt% sodium hydroxide solution, heating to 30 ℃, and stirring at the speed of 500r/min for reaction for 3 hours to obtain a mixture; carrying out vacuum filtration on the mixture to obtain a solid, washing the solid to be neutral by 450g of water, and then placing the solid in an oven to be dried for 2h at 100 ℃ to obtain a silicon-containing precursor;

2) pouring all the silicon-containing precursors into a beaker, adding 300g of deionized water, dropwise adding 5.5g of 50 wt% sodium hydroxide solution while stirring at 800r/min, heating to 50 ℃, keeping stirring and reacting for 1h, sequentially adding 11.5g of 30 wt% aluminum nitrate and 7.5g of ethylenediamine, and continuously stirring and reacting for 2h to obtain a colloid;

3) and transferring the colloid into a reaction kettle, crystallizing at 150 ℃ for 52 hours, carrying out solid-liquid separation on the crystallized product to obtain a solid product, washing the solid product with water, filtering, and drying at 100 ℃ for 2-4 hours to obtain the ferrierite.

FIG. 3 is an XRD pattern of ferrierite of this example, which is compared with the standard diffraction pattern of FER molecular sieve of International molecular sieves Association, and the zeolite prepared in this example is ferrierite molecular sieve.

FIG. 4 is an SEM image of the ferrierite of this example, and it can be seen from FIG. 4 that the ferrierite has a plate-like structure with an average grain size of 0.5. mu.m.

The ferrierite of this example had a specific surface area of 354m as measured by a specific surface area and pore size analyzer²/g。

The embodiment also provides a preparation method of the catalyst, which comprises the following steps:

1) placing the ferrierite in a muffle furnace, and roasting for 6 hours at 550 ℃ to obtain powder;

2) and (2) carrying out ion exchange reaction on the powder and 1M ammonium chloride solution to obtain hydrogen type ferrierite, washing and drying the ferrierite, and roasting at 520 ℃ for 4 hours to obtain the ferrierite catalyst, wherein the number of the ferrierite catalyst is A-2.

Example 3

This example provides a method for preparing ferrierite, comprising the following steps:

1) adding 18g of solid silica gel into a beaker filled with 273g of deionized water, after the solid silica gel is completely dispersed, dropwise adding 8.3g of 50 wt% sodium hydroxide solution, heating to 30 ℃, and stirring at the speed of 500r/min for reaction for 3 hours to obtain a mixture; carrying out vacuum filtration on the mixture to obtain a solid, washing the solid to be neutral by 450g of water, and then placing the solid in an oven to be dried for 2h at 100 ℃ to obtain a silicon-containing precursor;

2) pouring all the silicon-containing precursors into a beaker, adding 300g of deionized water, dropwise adding 5.5g of 50 wt% sodium hydroxide solution while stirring at 800r/min, heating to 50 ℃, maintaining stirring and reacting for 1h, sequentially adding 11.5g of 30 wt% aluminum sulfate and 12.5g of pyrrolidine, and continuously stirring and reacting for 2h to obtain a colloid;

3) and transferring the colloid into a reaction kettle, crystallizing at 150 ℃ for 46h, performing solid-liquid separation on the crystallized product to obtain a solid product, washing the solid product with water, filtering, and drying at 100 ℃ for 2-4 h to obtain the ferrierite.

FIG. 5 is an XRD pattern of the ferrierite of this example, which is compared with the standard diffraction pattern of FER molecular sieve of International molecular Sieve Association, and the zeolite prepared in this example is ferrierite molecular sieve.

FIG. 6 is an SEM photograph of the ferrierite of this example, and it can be seen from FIG. 6 that ferrierite has a plate-like structure with a mean grain size of 1 μm.

In addition, the ferrierite of this example has a specific surface area of 373m as measured by a specific surface area and pore size analyzer²/g。

The embodiment also provides a preparation method of the catalyst, which comprises the following steps:

1) placing the ferrierite in a muffle furnace, and roasting for 6 hours at 550 ℃ to obtain powder;

2) and (2) carrying out ion exchange reaction on the powder and 1M ammonium chloride solution to obtain hydrogen type ferrierite, washing and drying the ferrierite, and roasting at 520 ℃ for 4 hours to obtain the ferrierite catalyst, wherein the number of the ferrierite catalyst is A-3.

Example 4

This example provides a method for preparing ferrierite, comprising the following steps:

1) adding 18g of solid silica gel into a beaker filled with 273g of deionized water, after the solid silica gel is completely dispersed, dropwise adding 8.3g of 50 wt% sodium hydroxide solution, heating to 30 ℃, and stirring at the speed of 500r/min for reaction for 3 hours to obtain a mixture; carrying out vacuum filtration on the mixture to obtain a solid, washing the solid to be neutral by 450g of water, and then placing the solid in an oven to be dried for 2h at 100 ℃ to obtain a silicon-containing precursor;

2) pouring all the silicon-containing precursors into a beaker, adding 300g of deionized water, dropwise adding 5.5g of 50 wt% sodium hydroxide solution while stirring at 800r/min, heating to 50 ℃, maintaining stirring and reacting for 1h, sequentially adding 3.2g of 25 wt% sodium metaaluminate and 18.5g of cyclohexylamine, and continuously stirring and reacting for 2h to obtain a colloid;

3) and transferring the colloid into a reaction kettle, crystallizing at 150 ℃ for 72 hours, carrying out solid-liquid separation on the crystallized product to obtain a solid product, washing the solid product with water, filtering, and drying at 100 ℃ for 2-4 hours to obtain the ferrierite.

FIG. 7 is an SEM image of the ferrierite of this example, and it can be seen from FIG. 7 that the ferrierite has a plate-like structure with a crystallite size of 1-1.5 μm.

In addition, the ferrierite of this example had a specific surface area of 367m as measured by a specific surface area and pore size analyzer²/g。

The embodiment also provides a preparation method of the catalyst, which comprises the following steps:

1) placing the ferrierite in a muffle furnace, and roasting for 6 hours at 550 ℃ to obtain powder;

2) and (2) carrying out ion exchange reaction on the powder and 1M ammonium chloride solution to obtain hydrogen type ferrierite, washing and drying the ferrierite, and roasting at 520 ℃ for 4 hours to obtain the ferrierite catalyst, wherein the number of the ferrierite catalyst is A-4.

Example 5

This example provides a method for preparing ferrierite, comprising the following steps:

1) adding 60g of 30 wt% silica sol into a beaker filled with 273g of deionized water, after the silica sol is completely dissolved, dropwise adding 8.3g of 50 wt% sodium hydroxide solution, heating to 30 ℃, and stirring at the speed of 500r/min for reaction for 3 hours to obtain a mixture; carrying out vacuum filtration on the mixture to obtain a solid, washing the solid to be neutral by 450g of water, and then placing the solid in an oven to be dried for 2h at 100 ℃ to obtain a silicon-containing precursor;

2) pouring all the silicon-containing precursors into a beaker, adding 300g of deionized water, dropwise adding 5.5g of 50 wt% sodium hydroxide solution while stirring at 800r/min, heating to 50 ℃, keeping stirring and reacting for 1h, sequentially adding 11.5g of 30 wt% aluminum sulfate and 7.5g of ethylenediamine, and continuously stirring and reacting for 2h to obtain a colloid;

3) and (2) transferring the colloid into a reaction kettle, heating to 120 ℃ at the speed of 1 ℃/min, crystallizing for 20 hours, heating to 175 ℃ at the speed of 5 ℃/min, crystallizing for 40 hours, carrying out solid-liquid separation on the crystallized product to obtain a solid product, washing with water, filtering, and drying at 100 ℃ for 2-4 hours to obtain the ferrierite.

FIG. 8 is an SEM image of the ferrierite of this example, and it can be seen from FIG. 8 that ferrierite has a plate-like structure with a grain size of 0.5-1 μm.

In addition, the ferrierite of this example had a specific surface area of 383m as measured by a specific surface area and pore size analyzer²/g。

The embodiment also provides a preparation method of the catalyst, which comprises the following steps:

1) placing the ferrierite in a muffle furnace, and roasting for 6 hours at 550 ℃ to obtain powder;

2) and (2) carrying out ion exchange reaction on the powder and 1M ammonium chloride solution to obtain hydrogen type ferrierite, washing and drying the ferrierite, and roasting at 520 ℃ for 4 hours to obtain the ferrierite catalyst, wherein the number of the ferrierite catalyst is A-5.

Example 6

This example provides a method for preparing ferrierite, comprising the following steps:

1) adding 18g of solid silica gel into a beaker filled with 273g of deionized water, after the solid silica gel is completely dispersed, dropwise adding 8.5g of 50 wt% sodium hydroxide solution, heating to 30 ℃, and stirring at the speed of 500r/min for reacting for 3 hours to obtain a mixture; carrying out vacuum filtration on the mixture to obtain a solid, washing the solid to be neutral by 450g of water, and then placing the solid in an oven to be dried for 2h at 100 ℃ to obtain a silicon-containing precursor;

2) pouring all the silicon-containing precursors into a beaker, adding 300g of deionized water, dropwise adding 5.3g of 50 wt% sodium hydroxide solution while stirring at 800r/min, heating to 50 ℃, maintaining stirring and reacting for 1h, sequentially adding 13.5g of 30 wt% aluminum sulfate and 15g of tetrahydrofuran, and continuously stirring and reacting for 2h to obtain a colloid;

3) and (2) transferring the colloid into a reaction kettle, heating to 120 ℃ at the speed of 1 ℃/min, crystallizing for 20 hours, heating to 175 ℃ at the speed of 5 ℃/min, crystallizing for 40 hours, carrying out solid-liquid separation on the crystallized product to obtain a solid product, washing with water, filtering, and drying at 100 ℃ for 2-4 hours to obtain the ferrierite.

FIG. 9 is an SEM photograph of the ferrierite of this example, and it can be seen from FIG. 9 that the ferrierite has a plate-like structure with an average grain size of 0.5. mu.m.

In addition, the ferrierite of this example had a specific surface area of 375m as measured by a specific surface area and pore size analyzer²/g。

The embodiment also provides a preparation method of the catalyst, which comprises the following steps:

1) placing the ferrierite in a muffle furnace, and roasting for 6 hours at 550 ℃ to obtain powder;

2) and (2) carrying out ion exchange reaction on the powder and 1M ammonium chloride solution to obtain hydrogen type ferrierite, washing and drying the ferrierite, and roasting at 520 ℃ for 4 hours to obtain the ferrierite catalyst, wherein the number of the ferrierite catalyst is A-6.

Example 7

This example provides a method for preparing ferrierite, comprising the following steps:

1) adding 18g of solid silica gel into a beaker filled with 273g of deionized water, after the solid silica gel is completely dispersed, dropwise adding 8.5g of 50 wt% sodium hydroxide solution, heating to 30 ℃, and stirring at the speed of 500r/min for reacting for 3 hours to obtain a mixture; carrying out vacuum filtration on the mixture to obtain a solid, washing the solid to be neutral by 450g of water, and then placing the solid in an oven to be dried for 2h at 100 ℃ to obtain a silicon-containing precursor;

2) pouring all the silicon-containing precursors into a beaker, adding 300g of deionized water, dropwise adding 5.3g of 50 wt% sodium hydroxide solution while stirring at 800r/min, heating to 50 ℃, maintaining stirring and reacting for 1h, sequentially adding 13.5g of 30 wt% aluminum sulfate and 15g of tetrahydrofuran, and continuously stirring and reacting for 2h to obtain a colloid;

3) and transferring the colloid into a reaction kettle, crystallizing at 150 ℃ for 72 hours, carrying out solid-liquid separation on the crystallized product to obtain a solid product, washing the solid product with water, filtering, and drying at 100 ℃ for 2-4 hours to obtain the ferrierite.

FIG. 10 is an SEM photograph of the ferrierite of this example, and it can be seen from FIG. 10 that the ferrierite has a plate-like structure with a grain size of 0.2-0.5. mu.m.

In addition, the ferrierite of this example had a specific surface area of 375m as measured by a specific surface area and pore size analyzer²/g。

The embodiment also provides a preparation method of the catalyst, which comprises the following steps:

1) placing the ferrierite in a muffle furnace, and roasting for 6 hours at 550 ℃ to obtain powder;

2) and (2) carrying out ion exchange reaction on the powder and 1M ammonium chloride solution to obtain hydrogen type ferrierite, washing and drying the ferrierite, and roasting at 520 ℃ for 4 hours to obtain the ferrierite catalyst, wherein the number of the ferrierite catalyst is A-7.

Example 8

1) Adding 60g of 30 wt% silica sol into a beaker filled with 273g of deionized water, after the silica sol is completely dissolved, dropwise adding 8.3g of 50 wt% sodium hydroxide solution, heating to 30 ℃, and stirring at the speed of 500r/min for reaction for 3 hours to obtain a mixture; carrying out vacuum filtration on the mixture to obtain a solid, washing the solid to be neutral by 450g of water, and then placing the solid in an oven to be dried for 2h at 100 ℃ to obtain a silicon-containing precursor;

2) pouring all the silicon-containing precursors into a beaker, adding 300g of deionized water, dropwise adding 5.5g of 50 wt% sodium hydroxide solution while stirring at 800r/min, heating to 50 ℃, maintaining stirring and reacting for 1h, sequentially adding 3.5g of 25 wt% sodium metaaluminate and 13.2g of butanediamine, and continuously stirring and reacting for 2h to obtain colloid;

3) and transferring the colloid into a reaction kettle, crystallizing at 150 ℃ for 52 hours, carrying out solid-liquid separation on the crystallized product to obtain a solid product, washing the solid product with water, filtering, and drying at 100 ℃ for 2-4 hours to obtain the ferrierite.

FIG. 11 is an SEM photograph of the ferrierite of this example, and it can be seen from FIG. 11 that the ferrierite has a plate-like structure and a crystal grain size of 0.5-1 μm.

In addition, the ferrierite of this example had a specific surface area of 357m as measured by a specific surface area and pore size analyzer²/g。

The embodiment also provides a preparation method of the catalyst, which comprises the following steps:

1) placing the ferrierite in a muffle furnace, and roasting for 6 hours at 550 ℃ to obtain powder;

2) and (2) carrying out ion exchange reaction on the powder and 1M ammonium chloride solution to obtain hydrogen type ferrierite, washing and drying the ferrierite, and roasting at 520 ℃ for 4 hours to obtain the ferrierite catalyst, wherein the number of the ferrierite catalyst is A-8.

Comparative example 1

The comparative example provides a process for preparing ferrierite comprising the steps of:

1) adding 60g of 30 wt% silica sol into a beaker filled with 273g of deionized water, after the silica sol is completely dissolved, dropwise adding 8.3g of 50 wt% sodium hydroxide solution, heating to 50 ℃, stirring at the speed of 500r/min for reaction for 1h, sequentially adding 11.5g of 30 wt% aluminum nitrate and 7.5g of ethylenediamine, and continuously stirring for reaction for 2h to obtain a colloid;

2) and transferring the colloid into a reaction kettle, crystallizing at 150 ℃ for 52 hours, carrying out solid-liquid separation on the crystallized product to obtain a solid product, washing the solid product with water, filtering, and drying at 100 ℃ for 2-4 hours to obtain the ferrierite.

FIG. 12 is an SEM image of ferrierite of this comparative example, and it can be seen from FIG. 4 that ferrierite has a plate-like structure with a crystal grain average size of 5 μm.

In addition, the ferrierite of this comparative example has a specific surface area of 247m as determined by a specific surface area and pore size analyzer²/g。

The comparative example also provides a method of preparing a catalyst, comprising the steps of:

1) placing the ferrierite in a muffle furnace, and roasting for 6 hours at 550 ℃ to obtain powder;

2) and (2) carrying out ion exchange reaction on the powder and 1M ammonium chloride solution to obtain hydrogen type ferrierite, washing and drying the ferrierite, and roasting at 520 ℃ for 4 hours to obtain the ferrierite catalyst, wherein the number of the ferrierite catalyst is A-9.

Test examples

The catalysts prepared in examples 1 to 8 and comparative example 1 were used in a skeletal isomerization process of n-butene to prepare isobutene, which employed an atmospheric fixed bed flow reaction apparatus and analyzed the butene conversion, isobutene yield and selectivity on line by a chromatography system, with the results shown in table 1. The isobutene is prepared by a n-butene skeletal isomerization method through the following specific steps:

1) filling 5g of ferrierite catalyst in a constant temperature area of a reactor in a normal pressure fixed bed flow reaction device, wherein quartz sand with 10-20 meshes is arranged at two ends of the constant temperature area;

2) introducing nitrogen into a constant temperature area inside the reactor through an inlet in the reactor, and heating the reactor to 330 ℃ to activate the ferrierite catalyst;

3) introducing a nitrogen diluted n-butene feed gas into a constant temperature region through an inlet of the reactor for reaction, wherein the molar ratio of nitrogen to n-butene is 2:1, and the space velocity is 5h^-1。

In the above test examples, the following calculation formulas were used to simplify the calculation of the butene conversion, the isobutene yield and the isobutene selectivity.

1) Conversion of n-butene

X: conversion rate of n-butene;

C₀: total n-butene content in the feed gas;

c: total n-butene content in the product.

2) Isobutene yield

X₁: the yield of isobutene is increased;

C₀: total n-butene content in the feed gas;

C₁: the content of isobutene in the feed gas;

C₂: isobutylene content in the product.

3) Selectivity to isobutene

S: isobutene selectivity;

X₁: the yield of isobutene is increased;

x: conversion of n-butene.

Products with reaction time of 1h, 24h and 72h were extracted through the outlet of the reactor, and the products were put into a chromatographic analysis system for on-line analysis to obtain n-butene conversion, isobutene yield and selectivity, with the results shown in table 1.

TABLE 1

The test results of examples 1-8 and comparative example 1 in table 1 above show that the ferrierite prepared by the present invention can provide a catalyst with better catalytic activity and higher yield and selectivity to isobutylene obtained by the reaction when used in the catalyst.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.