CN110090660A - A kind of composite material and preparation method containing Y type molecular sieve - Google Patents

Abstract

A composite material containing Y-type molecular sieve, characterized in that the composite material also contains a mesoporous alumina layer of pseudo-boehmite structure, and the mesoporous alumina layer grows on the grain surface of Y-type molecular sieve and crystallizes the molecular sieve The disordered structure of the mesoporous alumina layer extends and grows from the edge of the ordered diffraction fringes of the FAU crystal phase structure of the Y-type molecular sieve, and the two structures are built together; based on the weight of the oxide, the chemical composition of the composite The composition is (4~12)Na ₂ O·(20~60)SiO ₂ ·(30~75)Al ₂ O ₃ ; the particle size parameters of the composite material D(V,0.5)=1.8~2.5, D(V, 0.9) = 4.0 to 8.0. The particle size distribution of the composite material is narrow, the particle size is uniform, the pores of the surface mesoporous layer are unobstructed, and the accessibility of the active center is strong.

Description

A kind of composite material containing Y-type molecular sieve and preparation method thereof

technical field

The invention relates to a composite material containing Y-type molecular sieves and a preparation method thereof, more particularly a composite material in which a mesoporous layer grows on the surface of molecular sieve grains and the molecular sieve is coated therein and a preparation method thereof.

Background technique

Catalytic cracking is a very important process in the petroleum refining process. It is widely used in the petroleum processing industry and occupies a pivotal position in the refinery. In the catalytic cracking process, heavy fractions such as vacuum distillates or residues of heavier components are reacted in the presence of a catalyst to convert gasoline, distillate and other liquid cracking products and lighter gaseous cracking of up to four carbons product. The catalytic cracking reaction process follows the carbon ion reaction mechanism, so it is necessary to use acidic catalytic materials, especially catalytic materials with strong B acid centers. Amorphous silica-alumina material is an acidic catalytic material, which has both B acid centers and L acid centers, and is the main active component in early catalytic cracking catalysts. However, due to its low cracking activity and the required reaction temperature Relatively high is gradually replaced by crystalline molecular sieves. Crystalline molecular sieves are a type of porous material with a pore size of less than 2nm and a special crystal phase structure. According to the definition of IUPAC, materials with a pore size of less than 2nm are named microporous materials. Therefore, crystalline molecular sieves or zeolites generally belong to microporous materials. Molecular sieve materials have relatively complete crystal structure and special skeleton structure, so they have strong acidity and high structural stability, and show high catalytic activity in catalytic reactions, and are widely used in petroleum processing and other catalytic industries middle.

As a typical microporous molecular sieve material, Y-type molecular sieve has been widely used in catalytic cracking, hydrocracking and other fields due to its regular pore structure, good stability and strong acidity. When used in catalytic cracking catalysts, Y-type molecular sieves usually need to be modified to a certain extent, such as rare earth modification to inhibit the dealumination of the skeleton, improve the structural stability of the molecular sieve, increase the retention of acid centers, and then improve the cracking activity; or through Ultra-stabilization treatment increases the ratio of silicon to aluminum in the framework, thereby improving the stability of molecular sieves.

With the increasing depletion of oil resources, the tendency of crude oil to be heavy and inferior is obvious, and the proportion of slag is continuously increasing. At the same time, the market demand for light oil products has not decreased. For the deep processing of residue oil, many refineries have begun to blend vacuum residue oil, and even directly use atmospheric pressure residue oil as cracking raw material. Heavy oil catalytic cracking has gradually become a key technology for refineries to improve economic benefits, and the macromolecular cracking capacity of the catalyst is the focus of attention. In conventional cracking catalysts, Y-type molecular sieve is the most important cracking active component, but due to its small pore structure, it shows obvious pore restriction in macromolecular reactions. The response also showed some inhibition. Therefore, for catalytic cracking of heavy oil, it is necessary to use materials with larger pore size, no diffusion restriction on reactant molecules, and higher cracking activity.

According to the definition of IUPAC, materials with a pore size between 2 and 50 nm are mesoporous materials, and the size range of macromolecules such as heavy oil or residual oil is in this pore size range, so mesoporous materials, especially mesoporous silicon-aluminum materials The study has aroused great interest among researchers in the field of catalysis. Mesoporous materials first appeared in 1992 and were first successfully developed by Mobil Corporation of the United States (Beck J S, Vartuli J Z, Roth W J et al., J.Am.Chem.Comm.Soc., 1992, 114, 10834-10843), named It is M41S series mesoporous molecular sieve, including MCM-41 (Mobil Corporation Material-41) and MCM-48, etc. The pore size of the molecular sieve can reach 1.6-10nm, uniform and adjustable, the pore size distribution is concentrated, the specific surface area and pore volume are large, and the adsorption capacity However, because the pore wall structure of this type of molecular sieve is amorphous, its hydrothermal stability is poor and its acidity is weak, it cannot meet the operating conditions of catalytic cracking, and its industrial application is greatly restricted.

In order to solve the problem of poor hydrothermal stability of mesoporous molecular sieves, some research work focuses on increasing the pore wall thickness of molecular sieves. For example, neutral template agents can be used to obtain molecular sieves with thicker pore walls, but the disadvantage of weak acidity still exists. A new mesoporous molecular sieve is disclosed in CN1349929A. The primary and secondary structural units of zeolite are introduced into the pore wall of the molecular sieve to make it have the basic structure of a traditional zeolite molecular sieve. The mesoporous molecular sieve has strong acidity and ultra-high hydrothermal stability. sex. However, the disadvantage of this molecular sieve is that it needs to use an expensive template agent, and the pore size is only about 2.7nm. It still has a large steric hindrance effect on the cracking reaction of macromolecules. The structure is easy to collapse under high temperature hydrothermal conditions, and the cracking activity is low Difference.

In the field of catalytic cracking, silicon-alumina materials are widely used because of their strong acidic centers and good cracking performance. The introduction of the mesoporous concept also provides the possibility for the preparation of new catalysts. The current research results mostly focus on the use of expensive organic templates and organic silicon sources, and most of them have to undergo high-temperature hydrothermal post-treatment. In order to reduce the preparation cost and obtain porous materials in the mesoporous range, more research work is focused on the development of disordered mesoporous materials. US5,051,385 discloses a monodisperse mesoporous silicon-aluminum composite material, which is prepared by mixing acidic inorganic aluminum salt and silica sol and then adding alkali to react, wherein the aluminum content is 5-40% by weight, the pore diameter is 20-50nm, and the specific surface area 50-100m ² /g. US4,708,945 discloses that silica particles or hydrated silica are first loaded on porous boehmite, and then the resulting composite is hydrothermally treated at a temperature above 600°C for a certain period of time to obtain silica-loaded boehmite-like The catalyst on the surface, in which silicon oxide is combined with the hydroxyl group of the transition state boehmite, has a surface area of 100-200m ² /g and an average pore diameter of 7-7.5nm. A series of acid cracking catalysts are disclosed in US4,440,872, some of which are prepared by impregnating silane on γ-Al ₂ O ₃ and then roasting at 500°C or steam treatment. In CN1353008A, inorganic aluminum salt and water glass are used as raw materials, and a stable and clear silica-alumina sol is formed through processes such as precipitation, washing, and degumming, and then dried to obtain a white gel, and then roasted at 350 ° C to 650 ° C for 1 to 20 hours A silica-alumina catalytic material is obtained. In ^CN1565733A , a mesoporous silicon-alumina material is disclosed. The silicon-alumina material has a pseudo-boehmite structure, a concentrated pore size distribution, a specific surface area of about 200-400m2/g, a pore volume of 0.5-2.0ml/g, and an average pore diameter of Between 8-20nm, the most probable pore diameter is 5-15nm, the preparation of the mesoporous silicon-alumina material does not need to use an organic template, the synthesis cost is low, and the obtained silicon-alumina material has high cracking activity and hydrothermal stability. It exhibits good macromolecule cracking performance in catalytic cracking reaction.

Contents of the invention

The inventor found on the basis of a large number of experiments that based on the perfect crystal structure, strong acidity, excellent structural stability and catalytic activity of microporous molecular sieves, as well as the pore characteristics and Acidic characteristics, the growth of alumina mesoporous layer on the surface of microporous molecular sieve can realize the effective connection of the two structures, build the gradient distribution of the channels, and effectively strengthen the respective advantages of the two structures. Based on this, the present invention is formed.

One of the objectives of the present invention is to provide a composite material containing Y-type molecular sieve, a mesoporous alumina layer grows on the surface of the molecular sieve, the two structures are effectively connected to form a composite structure, the pore distribution is a gradient distribution, and the particle size distribution of the composite material is narrow , the particle size is more uniform, the channel of the mesoporous layer is unobstructed, and the accessibility of the acid center is strong; the second purpose of the present invention is to provide the preparation method of the composite material containing the Y-type molecular sieve.

In order to achieve one of the objectives of the present invention, the present invention provides a composite material containing Y-type molecular sieve, which is characterized in that the composite material also contains a mesoporous alumina layer of pseudo-boehmite structure, and the mesoporous alumina layer It grows on the surface of the grains of Y-type molecular sieve and evenly covers the grains of molecular sieves. The disordered structure of the mesoporous alumina layer extends and grows from the edge of the ordered diffraction fringes of the FAU crystal phase structure of the Y-type molecular sieve. The two structures Build together; in terms of oxide weight, the chemical composition of the composite material is (4~12)Na ₂ O·(20~60)SiO ₂ ·(30~75)Al ₂ O ₃ ; the particle size parameter of the composite material D(V, 0.5) = 1.8-2.5, D(V, 0.9) = 4.0-8.0.

For the composite material containing Y-type molecular sieve of the present invention, the phase is characterized by X-ray diffraction method, and its XRD spectrum is respectively at 6.2°, 10.1°, 11.9°, 15.7°, 18.7°, 20.4°, 23.7°, 27.1° °, 28°, 31.4°, 38.5°, 49° and 65°, characteristic diffraction peaks appear at The characteristic diffraction peaks at ° correspond to the FAU crystal phase structure of Y-type zeolite, while the characteristic diffraction peaks at 28°, 38.5°, 49° and 65° correspond to the pseudo-boehmite structure of the mesoporous layer.

In the composite material containing Y-type molecular sieve of the present invention, through a transmission electron microscope (TEM) photograph, it can be seen that the pseudo-boehmite disordered structure of the mesoporous alumina layer extends from the ordered diffraction fringe edge of the FAU crystal phase structure of the Y-type molecular sieve Growing, the two structures build together. A scanning electron microscope (SEM) shows that a wrinkled structure is coated on the surface of the molecular sieve crystal grains, and the molecular sieve crystal grains are uniformly coated therein.

The composite material containing Y-type molecular sieve of the present invention is measured by a laser particle size analyzer, and its particle size parameters have the characteristics of D (V, 0.5) = 1.8-2.5, D (V, 0.9) = 4.0-8.0. The measurement method using a laser particle size analyzer is to mix a small amount of the composite material of the present invention with deionized water, take a small amount of slurry and add it to the laser particle size analyzer, record several pieces of analysis data after the analysis is stable, and perform average processing to obtain the corresponding particle size distribution data.

In the compound material containing Y-type molecular sieve of the present invention, the chemical composition of the compound material is (4-12) Na ₂ O · (20-60) SiO ₂ · (30-75) Al ₂ O ₃ , the total specific surface area is 380-700m ² /g, and the total pore volume is 0.32-0.48cm ³ /g. The composite material containing Y-type molecular sieve of the present invention has the characteristic of gradient pore distribution, and its BJH pore size distribution curve shows that there are two possible pore distributions at 3-4nm and 6-9nm respectively.

In order to realize the second object of the present invention, the present invention also provides the preparation method of said composite material containing Y-type molecular sieve, it is characterized in that comprising the following steps: (1) configuration can synthesize the raw material of NaY molecular sieve, after mixing uniformly Perform static crystallization at a temperature of 95 to 105°C; (2) filter and wash the above static crystallized slurry to obtain a NaY molecular sieve filter cake; (3) combine the NaY molecular sieve filter cake obtained in step (2) with deionized After the water is mixed and beating homogeneously, the aluminum source and the alkali solution are simultaneously added to it in a co-current manner under vigorous stirring at room temperature to 85°C, and the pH value of the slurry system is controlled during the mixing process to be 9-11; (4) at room temperature Treat at a constant temperature at 90°C for 1-10 hours and recover the product.

In said preparation process, said in the step (1) can synthesize the raw material of NaY molecular sieve, generally refer to guide agent, water glass, sodium metaaluminate, aluminum sulfate and deionized water, their addition ratio can be conventional The feeding ratio of NaY molecular sieve, for example, can be Na ₂ O: Al ₂ O ₃ : SiO ₂ : H ₂ O = 1.5-8: 1: 5-18: 100-500, or it can be used to prepare NaY molecular sieve with special properties The feeding ratio, such as the feeding ratio used to prepare large-grain or small-grain NaY molecular sieves, etc., there is no special limitation on the feeding ratio and the concentration of each raw material, as long as the NaY molecular sieve with the FAU crystal phase structure can be obtained. The directing agent can be prepared according to the prior art (US3639099 and US3671191). The usual way for the directing agent is to mix silicon source, aluminum source, lye and deionized water according to (15-18) Na ₂ O:Al ₂ O ₃ : (15-17) SiO ₂ : (280-380) H ₂ O molar ratio mixed, stirred evenly, and aged at room temperature to 70°C for 0.5-48 hours. In the feeding ratio of the NaY molecular sieve, the content of Al ₂ O ₃ in the directing agent accounts for 3-15%, preferably 5-10%, of the total amount of Al ₂ O ₃ fed. The static crystallization in step (1) takes 8 to 50 hours, preferably 10 to 40 hours, more preferably 15 to 35 hours.

In said preparation method, said aluminum source in step (3) is selected from one or more in aluminum nitrate, aluminum sulfate and aluminum chloride; Described alkali solution is selected from ammoniacal liquor, potassium hydroxide, sodium hydroxide One or more of sodium metaaluminate and sodium metaaluminate, when sodium metaaluminate is used as an alkaline solution, its alumina content is included in the total alumina content. Sodium metaaluminate can be sodium metaaluminate with different caustic ratios and different concentrations. The caustic ratio is preferably 1.5-11.5, more preferably 1.65-2.55, and the concentration is preferably 40-200gAl ₂ O ₃ /L, more preferably 41-190gAl ₂ O ₃ /L.

In said preparation method, the concept of the parallel flow mode that aluminum source and alkaline solution are added simultaneously described in step (3) refers to n+1 (n≥1) kinds of materials (such as aluminum in the present invention Source and alkali solution) are added to the container at the same time for mixing, so that each material is added at a constant speed, and n+1 materials are added in the same time to complete the operation. For example, peristaltic pumps can be used in specific operations to control the flow parameters per unit time of the peristaltic pumps used to transport aluminum source and alkaline solution respectively, and carry out at a uniform speed to ensure that the two materials, aluminum source and alkaline solution, are transported at the same time. Added. The temperature of the mixing process in step (3) is from room temperature to 85°C, preferably 30-70°C.

In said preparation process, the constant temperature treatment temperature in step (4) is room temperature to 90°C, preferably 40-80°C, and the treatment time is 1-10 hours, preferably 2-8 hours; the process of recovering the product, It usually includes the processes of filtering, washing and drying the aging product, which are well known to those skilled in the art, and will not be repeated here.

Description of drawings

Fig. 1 is the scanning electron microscope SEM photograph of the sample of embodiment 1.

Fig. 2 is the transmission electron microscope TEM photograph of the sample of embodiment 1.

Fig. 3 is the X-ray diffraction spectrogram of the sample of embodiment 1.

Fig. 4 is the BJH pore size distribution curve of the sample of Example 1.

Detailed ways

The following examples will further illustrate the present invention, but do not limit the present invention thereby.

Scanning electron microscope SEM adopts Hitachi S4800 field emission scanning electron microscope from Hitachi, Japan, the acceleration voltage is 5kV, and the energy spectrum is collected and processed by Horiba 350 software.

The transmission electron microscope TEM test adopts the Tecnai F20G2S-TWIN transmission electron microscope of FEI Company, and the operating voltage is 200kV.

The phase of the sample was determined by X-ray diffraction method.

The specific surface area, pore volume and pore size distribution of the samples were determined by low-temperature nitrogen adsorption-desorption method.

The particle size distribution test is measured with a laser particle size analyzer. It is to mix a small amount of porous material with deionized water, take a small amount of slurry and add it to the laser particle size analyzer. After the analysis is stable, record several pieces of analysis data and perform average processing to obtain the corresponding particle size distribution. data.

In each embodiment, the Na ₂ O, Al ₂ O ₃ , SiO ₂ content of the sample is measured by X-ray fluorescence method (see "Petrochemical Analysis Method (RIPP Experimental Method)", edited by Yang Cuiding, etc., Science Press, 1990 publishing).

Example 1

This example illustrates the composite material containing Y-type molecular sieve of the present invention and its preparation process.

Water glass, aluminum sulfate, sodium metaaluminate, directing agent and deionized water are mixed according to the molar ratio of 8.5SiO ₂ : Al ₂ O ₃ : 2.65Na ₂ O: 210H ₂ O, wherein the mass ratio of directing agent Stir vigorously to form NaY molecular sieve gel, place the gel in a crystallization kettle for static crystallization at 100°C for 34 hours, cool down after crystallization, filter and wash the crystallization slurry to obtain NaY molecular sieve filter cake; the resulting NaY molecular sieve filter cake is mixed with an appropriate amount of deionized water for beating, after homogenization, AlCl solution (concentration 60gAl ₂ O _{3 /} L) and ammonia water (mass fraction 8 %) was added therein, and the pH value of the slurry system during the mixing process was controlled to be 10.8. After mixing for a certain period of time, it was treated at a constant temperature of 50° C. for 5 hours, filtered, washed, and dried to obtain the composite material containing Y-type molecular sieve provided by the present invention. Denote it as AFCY-1.

The SEM photo of AFCY-1 is shown in Figure 1. It can be seen that the wrinkled structure is coated on the surface of the molecular sieve grains. The transmission electron microscope (TEM) photo is shown in Figure 2. It can be seen that there is a regular and ordered diffraction fringe and a disordered structure without a fixed crystal plane orientation. The ordered diffraction fringe represents the FAU crystal structure, and the disordered structure is a pseudo-thin water In the albite structure, the disordered structure grows from the edges of the ordered diffraction fringes, and the two structures are built together.

The XRD pattern of AFCY-1 is shown in Figure 3, at 6.2°, 10.1°, 11.9°, 15.7°, 18.7°, 20.4°, 23.7°, 27.1°, 28°, 31.4°, 38.5°, 49° and 65° Diffraction peaks appear at °, where the characteristic diffraction peak marked ★ corresponds to the FAU crystal phase structure of Y-type zeolite, and the characteristic diffraction peak marked ▲ corresponds to the pseudo-boehmite structure of the mesoporous layer.

The chemical composition of AFCY-1, based on oxide weight, is 6.5Na ₂ O·22.0SiO ₂ ·71.1Al ₂ O ₃ ; its total specific surface area is 418m ² /g, and its total pore volume is 0.441cm ³ /g; The BJH pore size distribution curve is shown in Figure 4. It can be seen that there are bimodal distributions at about 3.8nm and 7.4nm respectively; the D(V, 0.5)=2.50 and D(V, 0.9)=7.80 measured by the laser particle size analyzer.

Example 2

This example illustrates the composite material containing Y-type molecular sieve of the present invention and its preparation process.

Prepare NaY molecular sieve gel according to the molar ratio in Example 1, statically crystallize at 100°C for 18 hours, cool down after the crystallization, filter and wash the crystallization slurry to obtain NaY molecular sieve filter cake; The filter cake was mixed with an appropriate amount of deionized water for beating, and after homogenization, the temperature was raised to 50°C, and AlCl ₃ solution (concentration 60gAl ₂ O ₃ /L) and NaOH solution (concentration 1M) were added to it in a co-current manner under vigorous stirring, Control the pH value of the slurry system during the mixing process to 9.4. After mixing for a certain period of time, treat at a constant temperature of 70°C for 6 hours, filter, wash, and dry to obtain the composite material containing Y-type molecular sieve provided by the present invention, which is denoted as AFCY-2 .

The scanning electron microscope SEM photo of AFCY-2 has the characteristics shown in Figure 1, and it can be seen that the wrinkled structure is coated on the surface of the molecular sieve crystal grains. The transmission electron microscope photo has the characteristics shown in Figure 2. It can be seen that there are regular and ordered diffraction fringes and a disordered structure without a fixed crystal plane direction. The disordered structure grows from the edge of the ordered diffraction fringes, and the two structures are built together.

The XRD spectrum of AFCY-2 has the characteristics shown in Figure 3, and there are FAU crystal phase structure and pseudo-boehmite structure; its chemical composition, based on the weight of oxides, is 11.7Na ₂ O·57.6SiO ₂ ·30.1Al ₂ O ₃ ; its total specific surface area is 651m ² /g, and its total pore volume is 0.350cm ³ /g; its BJH pore size distribution curve has the characteristics shown in Figure 4, and it can be seen that there are bimodal distributions at about 3.8nm and 6.6nm respectively; Its D (V, 0.5) = 1.97, D (V, 0.9) = 4.11 measured by the laser particle size analyzer.

Example 3

This example illustrates the composite material containing Y-type molecular sieve of the present invention and its preparation process.

Prepare the NaY molecular sieve gel according to the molar ratio in Example 1, statically crystallize at 100°C for 45 hours, cool down after the crystallization, filter and wash the crystallization slurry to obtain a NaY molecular sieve filter cake; the obtained NaY molecular sieve The filter cake was mixed with an appropriate amount of deionized water for beating, and after homogenization, the temperature was raised to 35°C and AlCl ₃ solution (concentration 60gAl ₂ O ₃ /L) and NaAlO ₂ solution (concentration 180gAl ₂ O ₃ /L) was added therein, and the pH value of the slurry system during the mixing process was controlled to be 10.2. After mixing for a certain period of time, the mixture was treated at a constant temperature of 65° C. for 4 hours, filtered, washed, and dried to obtain the composite material containing Y-type molecular sieve provided by the present invention. , denoted as AFCY-3.

The scanning electron microscope SEM photo of AFCY-3 has the characteristics shown in Figure 1, and it can be seen that the wrinkled structure is coated on the surface of the molecular sieve crystal grains. The transmission electron microscope photo has the characteristics shown in Figure 2. It can be seen that there are regular and ordered diffraction fringes and a disordered structure without a fixed crystal plane direction. The disordered structure grows from the edge of the ordered diffraction fringes, and the two structures are built together.

The XRD spectrum of AFCY-3 has the characteristics shown in Figure 3, and there are FAU crystal phase structure and pseudo-boehmite structure; its chemical composition, based on the weight of oxides, is 10.0Na ₂ O·48.5SiO ₂ ·41.1Al ₂ O ₃ ; its total specific surface area is 611m ² /g, and its total pore volume is 0.397cm ³ /g; its BJH pore size distribution curve has the characteristics shown in Figure 4, and it can be seen that the bimodal distribution is around 3.8nm and 8.1nm respectively; Its D(V, 0.5)=2.21, D(V, 0.9)=5.48 measured by the laser particle size analyzer.

Example 4

This example illustrates the composite material containing Y-type molecular sieve of the present invention and its preparation process.

Prepare NaY molecular sieve gel according to the molar ratio in Example 1, statically crystallize at 100°C for 26 hours, cool down after the crystallization, filter and wash the crystallization slurry to obtain NaY molecular sieve filter cake; obtain NaY molecular sieve The filter cake was mixed with an appropriate amount of deionized water for beating, and after homogenization, the temperature was raised to 45°C and Al ₂ (SO ₄ ) ₃ solution (concentration 90gAl ₂ O ₃ /L) and ammonia water (mass fraction 8%) was added therein, and the pH value of the slurry system during the mixing process was controlled to be 9.8. After mixing for a certain period of time, it was treated at a constant temperature of 55° C. for 8 hours, filtered, washed, and dried to obtain the composite material containing Y-type molecular sieve provided by the present invention. , denoted as AFCY-4.

The scanning electron microscope SEM photo of AFCY-4 has the characteristics shown in Figure 1, and it can be seen that the wrinkled structure is coated on the surface of the molecular sieve crystal grains. The transmission electron microscope photo has the characteristics shown in Figure 2. It can be seen that there are regular and ordered diffraction fringes and a disordered structure without a fixed crystal plane direction. The disordered structure grows from the edge of the ordered diffraction fringes, and the two structures are built together.

The XRD spectrum of AFCY-4 has the characteristics shown in Figure 3, and there are FAU crystal phase structure and pseudo-boehmite structure; its chemical composition, based on the weight of oxides, is 5.8Na ₂ O·31.4SiO ₂ ·62.3Al ₂ O ₃ ; its total specific surface area is 498m ² /g, and its total pore volume is 0.432cm ³ /g; its BJH pore size distribution curve has the characteristics shown in Figure 4, and it can be seen that the bimodal distribution is around 3.8nm and 7.4nm respectively; Its D(V, 0.5)=2.34, D(V, 0.9)=6.72 measured by the laser particle size analyzer.

Example 5

This example illustrates the composite material containing Y-type molecular sieve of the present invention and its preparation process.

Prepare NaY molecular sieve gel according to the molar ratio of 7.5SiO ₂ : Al ₂ O ₃ : 2.15Na ₂ O : 190H ₂ O, statically crystallize at 100°C for 40 hours, cool down after crystallization and filter the crystallization slurry and washing to obtain a NaY molecular sieve filter cake; the resulting NaY molecular sieve filter cake was mixed with an appropriate amount of deionized water for beating, homogenized and then heated to 55°C and simultaneously mixed with Al ₂ (SO ₄ ) ₃ solution ( Concentration 90gAl ₂ O ₃ /L) and NaAlO ₂ solution (concentration 102gAl ₂ O ₃ /L) were added to it, and the pH value of the slurry system was controlled to be 9.0 during the mixing process. After mixing for a certain period of time, it was treated at 60°C for 2 hours. Filtrate, wash, and dry to obtain the composite material containing Y-type molecular sieve provided by the present invention, which is designated as AFCY-5.

The scanning electron microscope SEM photo of AFCY-5 has the characteristics shown in Figure 1, and it can be seen that the wrinkled structure is coated on the surface of the molecular sieve crystal grains. The transmission electron microscope photo has the characteristics shown in Figure 2. It can be seen that there are regular and ordered diffraction fringes and a disordered structure without a fixed crystal plane direction. The disordered structure grows from the edge of the ordered diffraction fringes, and the two structures are built together.

The XRD spectrum of AFCY-5 has the characteristics shown in Figure 3, and there are FAU crystal phase structure and pseudo-boehmite structure; its chemical composition, based on the weight of oxides, is 10.8Na ₂ O·53.8SiO ₂ ·35.0Al ₂ O ₃ ; its total specific surface area is 647m ² /g, and its total pore volume is 0.377cm ³ /g; its BJH pore size distribution curve has the characteristics shown in Figure 4, and it can be seen that the bimodal distribution is around 3.8nm and 9.0nm respectively; Its D(V, 0.5)=2.13, D(V, 0.9)=5.02 measured by the laser particle size analyzer.

Example 6

This example illustrates the composite material containing Y-type molecular sieve of the present invention and its preparation process.

Prepare NaY molecular sieve gel according to the molar ratio of Example 5, statically crystallize at 100°C for 32 hours, cool down after crystallization, filter and wash the crystallization slurry to obtain NaY molecular sieve filter cake; filter the obtained NaY molecular sieve The cake was mixed with an appropriate amount of deionized water for beating, and after homogenization, the temperature was raised to 40°C and Al ₂ (SO ₄ ) ₃ solution (concentration 90gAl ₂ O ₃ /L) and NaOH solution (concentration 1M ) was added therein, and the pH value of the slurry system during the mixing process was controlled to be 10.5. After mixing for a certain period of time, it was treated at a constant temperature of 75°C for 3 hours, filtered, washed, and dried to obtain the composite material containing Y-type molecular sieve provided by the present invention. for AFCY-6.

The scanning electron microscope SEM photo of AFCY-6 has the characteristics shown in Figure 1, and it can be seen that the wrinkled structure is coated on the surface of the molecular sieve crystal grains. The transmission electron microscope photo has the characteristics shown in Figure 2. It can be seen that there are regular and ordered diffraction fringes and a disordered structure without a fixed crystal plane direction. The disordered structure grows from the edge of the ordered diffraction fringes, and the two structures are built together.

The XRD spectrum of AFCY-6 has the characteristics shown in Figure 3, and there are FAU crystal phase structure and pseudo-boehmite structure; its chemical composition, based on the weight of oxides, is 10.5Na ₂ O·58.4SiO ₂ ·30.4Al ₂ O ₃ ; its total specific surface area is 670m ² /g, and its total pore volume is 0.334cm ³ /g; its BJH pore size distribution curve has the characteristics shown in Figure 4, and it can be seen that the bimodal distribution is around 3.8nm and 6.6nm respectively; Its D(V, 0.5)=1.92, D(V, 0.9)=4.01 measured by the laser particle size analyzer.

Example 7

This example illustrates the composite material containing Y-type molecular sieve of the present invention and its preparation process.

Prepare NaY molecular sieve gel according to the molar ratio of Example 1, statically crystallize at 100°C for 20 hours, cool down after crystallization, filter and wash the crystallization slurry to obtain NaY molecular sieve filter cake; filter the obtained NaY molecular sieve The cake was mixed with an appropriate amount of deionized water for beating, and after homogenization, Al(NO ₃ ) ₃ solution (concentration 60gAl ₂ O ₃ /L) and NaAlO ₂ solution (concentration 102gAl ₂ O ₃ /L) was added therein, and the pH value of the slurry system during the mixing process was controlled to be 10.0. After mixing for a certain period of time, it was then treated at a constant temperature of 70°C for 1 hour, filtered, washed, and dried to obtain the composite compound containing Y-type molecular sieve provided by the present invention. The material is denoted as AFCY-7.

The scanning electron microscope SEM photo of AFCY-7 has the characteristics shown in Figure 1, and it can be seen that the wrinkled structure is coated on the surface of the molecular sieve crystal grains. The transmission electron microscope photo has the characteristics shown in Figure 2. It can be seen that there are regular and ordered diffraction fringes and a disordered structure without a fixed crystal plane direction. The disordered structure grows from the edge of the ordered diffraction fringes, and the two structures are built together.

The XRD spectrum of AFCY-7 has the characteristics shown in Figure 3, and there are FAU crystal phase structure and pseudo-boehmite structure; its chemical composition, based on the weight of oxides, is 8.6Na ₂ O·39.4SiO ₂ ·51.5Al ₂ O ₃ ; its total specific surface area is 558m ² /g, and its total pore volume is 0.426cm ³ /g; its BJH pore size distribution curve has the characteristics shown in Figure 4, and it can be seen that there are bimodal distributions at about 3.8nm and 7.4nm respectively; Its D(V, 0.5)=2.29, D(V, 0.9)=6.17 measured by the laser particle size analyzer.

Example 8

This example illustrates the composite material containing Y-type molecular sieve of the present invention and its preparation process.

Prepare NaY molecular sieve gel according to the molar ratio of Example 1, statically crystallize at 100°C for 30 hours, cool down after crystallization, filter and wash the crystallization slurry to obtain NaY molecular sieve filter cake; filter the obtained NaY molecular sieve The cake was mixed with an appropriate amount of deionized water for beating, and after homogenization, Al(NO ₃ ) ₃ solution (concentration 60gAl ₂ O ₃ /L) and ammonia water (mass fraction 8%) were added in parallel at 35°C under vigorous stirring Among them, the pH value of the slurry system during the mixing process is controlled to be 9.6. After mixing for a certain period of time, it is then treated at a constant temperature of 60°C for 7 hours, filtered, washed, and dried to obtain the composite material containing Y-type molecular sieve provided by the present invention, which is recorded as AFCY -8.

The scanning electron microscope SEM photo of AFCY-8 has the characteristics shown in Figure 1, and it can be seen that the wrinkled structure is coated on the surface of the molecular sieve crystal grains. The transmission electron microscope photo has the characteristics shown in Figure 2. It can be seen that there are regular and ordered diffraction fringes and a disordered structure without a fixed crystal plane direction. The disordered structure grows from the edge of the ordered diffraction fringes, and the two structures are built together.

The XRD spectrum of AFCY-8 has the characteristics shown in Figure 3, and there are FAU crystal phase structure and pseudo-boehmite structure; its chemical composition, based on the weight of oxides, is 6.0Na ₂ O·25.6SiO ₂ ·67.8Al ₂ O ₃ ; its total specific surface area is 451m ² /g, and its total pore volume is 0.428cm ³ /g; its BJH pore size distribution curve has the characteristics shown in Figure 4, and it can be seen that the bimodal distribution is around 3.8nm and 8.1nm respectively; Its D(V, 0.5)=2.42, D(V, 0.9)=7.25 measured by the laser particle size analyzer.

Claims (10)

1. a kind of composite material containing Y type molecular sieve, it is characterised in that the composite material is also containing Jie of structure of similar to thin diaspore Porous aluminum oxide layer, and meso-porous alumina layer is grown on the grain surface of Y type molecular sieve and coats zeolite crystal wherein, it is mesoporous Orderly diffraction fringe edge elongation growth of the disordered structure of alumina layer from the FAU crystal phase structure of Y type molecular sieve, two kinds of structures It builds together；In terms of oxide weight, the chemical composition of the composite material is (4~12) Na₂O (20~60) SiO₂·(30 ~75) Al₂O₃；Grain size parameter D (V, 0.5)=1.8~2.5, the D (V, 0.9)=4.0~8.0 of the composite material.

2. according to the composite material of claim 1, it is characterised in that its total specific surface area is 380~700m²/g。

3. according to the composite material of claim 1, it is characterised in that its total pore volume is 0.32~0.48cm³/g。

4. according to the composite material of claim 1, it is characterised in that there is gradient pore distribution characteristics, and respectively in 3~4nm and 6 ~9nm appearance can several pore size distributions.

5. the preparation method of the composite material containing Y type molecular sieve of one of Claims 1 to 4, it is characterised in that including following step Rapid: (1) configuration can synthesize the raw material of NaY molecular sieve, after mixing the static crystallization at a temperature of 95~105 DEG C；It (2) will be above-mentioned Slurries after static crystallization are filtered, washed, and obtain NaY molecular sieve filter cake；(3) the NaY molecular sieve filter cake for obtaining step (2) with After deionized water is mixed with beating homogeneous, room temperature to 85 DEG C, be vigorously stirred under in a manner of cocurrent silicon source and aqueous slkali added simultaneously The pH value for entering wherein to control slurry system in mixed process is 9~11；(4) then at room temperature at a temperature of 90 DEG C constant temperature processing 1~ 10 hours and recovery product.

6. according to the preparation method of claim 5, wherein described static crystallization in step (1), time are 8~50 hours.

7. according to the preparation method of claim 5, wherein the silicon source in step (3) is in aluminum nitrate, aluminum sulfate and aluminium chloride It is one or more；Described aqueous slkali is selected from one of ammonium hydroxide, potassium hydroxide, sodium hydroxide and sodium metaaluminate or a variety of.

8. according to the preparation method of claim 5, wherein in step (3) when using sodium metaaluminate as aqueous slkali, aluminium oxide contains Meter enters in total alumina content.

9. according to the preparation method of claim 5, wherein the mixed process of silicon source described in step (3) and aqueous slkali addition Temperature be 30~70 DEG C.

10. according to the preparation method of claim 5, wherein constant temperature treatment temperature in step (4) is 40~80 DEG C, when processing Between be 2~8 hours.