Silico-aluminum material and method for its preparation

Abstract

The application provides a silicon-aluminum material and a preparation method thereof. After being calcined at 500-700 DEG C, the silicon-aluminum material has the following properties: the content of silicon dioxide is 20-40 wt%, the pore volume is no less than 0.70 mL / g, and the specific surface area is 280-400 m 2 / g. The preparation method of the silicon-aluminum material comprises the following steps: (1) mixing a first silicon source, a first additive and water to obtain a sol; (2) mixing the sol with alcohol and performing heat treatment to obtain a first material flow; (3) reacting a second silicon source, an acidic aluminum-containing compound and an alkaline aluminum-containing compound to obtain a mixed solution; (4) mixing the mixed solution with a second additive to obtain a slurry; (5) mixing the slurry with the first material flow and performing hydrothermal treatment, and then performing washing, drying and calcination to obtain the silicon-aluminum material. The silicon-aluminum material has the characteristics of molecular sieve, hierarchical pore distribution and high B acid content, and is suitable for being used as a carrier of a catalytic material.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalytic materials, and relates to a silicon-aluminum material and a preparation method thereof. BACKGROUND

[0002] Molecular sieve materials are widely used in petroleum refining, especially in hydrocracking processes, due to their strong acid centers and high reactivity. However, with the continuous exploitation of traditional light petroleum, the reserves are decreasing, leading to an increasing dependence on petroleum resources such as residual oil.

[0003] However, the molecular sieve channels are relatively small, and the residual oil feedstock has characteristics such as large molecules and high impurity content, so the channel restriction on large molecules such as residual oil is more obvious, which can easily lead to coking and plugging of the pore mouth, thereby causing rapid deactivation, and the molecular sieve is not suitable for catalytic reactions of large molecules such as residual oil, which limits its application in residual oil hydrogenation processes. The large-pore silicon-aluminum material has a suitable channel structure, good hydrothermal stability, and both B acid centers and L acid centers, and has a certain cracking capacity, and is particularly suitable for use in residual oil hydrocracking processes. However, the large-pore silicon-aluminum material prepared by conventional methods usually has insufficient acidity, which is not conducive to the cracking of polycyclic aromatic hydrocarbons.

[0004] CN201710382457.7 discloses a high-activity silicon-aluminum material and a manufacturing method thereof. The active silicon-aluminum material contains 15-45% of silicon and 55-85% of aluminum by weight of oxide, has a BET total specific surface area of 300-500 m2 / g, a micropore specific surface area accounting for ≯8% of the BET total specific surface area, and an average pore diameter of 5-18 nm; c represents the Al / Si atomic ratio on the surface of the material measured by the XPS method, and d represents the Al / Si atomic ratio in the bulk phase of the material measured by the XRF method, and c / d = 1.2-1.9.

[0005] CN201710382466.6 discloses a porous silicon-aluminum material and a preparation method thereof. The porous silicon-aluminum material is characterized in that a diffused diffraction peak appears at a 2θ angle of about 25°-27° in an XRD spectrum of the material, and a trace of FAU crystal phase structure exists; in the chemical composition by weight of oxide, silicon is 50-80%, and aluminum is 20-50%; the average pore diameter is 20-50 nm; the total specific surface area is ≯250 m2 / g, wherein the micropore specific surface area accounts for ≯28% of the total specific surface area; when the surface Al / Si atomic ratio measured by the XPS method is a, and the bulk phase Al / Si atomic ratio measured by the XRF method is b, a / b = 1.2-1.7. 2 / g, wherein the micropore specific surface area accounts for ≯28% of the total specific surface area; when the surface Al / Si atomic ratio measured by the XPS method is a, and the bulk phase Al / Si atomic ratio measured by the XRF method is b, a / b = 1.2-1.7. SUMMARY

[0006] To overcome the shortcomings in the prior art, the main object of the present application is to provide a silicon-aluminum material and a preparation method thereof. The silicon-aluminum material exhibits molecular sieve characteristics, has a hierarchical pore distribution, and has a high B acid content, and is suitable for use as a carrier of a catalytic material, in particular, as a carrier of a heavy oil hydrogenation catalyst.

[0007] The silicon-aluminum material of the first aspect of the present application has the following properties after being calcined at 500-700°C: a silicon dioxide content of 20-40 wt%, preferably 25-35 wt%; a pore volume of not less than 0.70 mL / g, preferably more than 0.80 mL / g, and generally 0.70-1.5 mL / g; a specific surface area of 280-400 m 2 / g, preferably 300-400 m 2 / g.

[0008] Further, in the silicon-aluminum material, as a preferred embodiment, the calcined form of the silicon-aluminum material after calcination has the XRD pattern shown in the following table:

[0009] 2 theta d-spacing, nm Relative intensity 7.9 0.08-0.12 VS 8.8 0.06-0.10 S 24.5 0.22-0.26 VS

[0010] Defining the intensity value of the strongest diffraction peak in the XRD pattern as 100, then W represents weak, i.e. the relative intensity is >0 to ≤20, M represents medium, i.e. the relative intensity is >20 to ≤40, S represents strong, i.e. the relative intensity is >40 to ≤60, and VS represents very strong, i.e. the relative intensity is >60 to ≤100.

[0011] Further, in the silicon-aluminum material, as a preferred embodiment, in the nuclear magnetic resonance aluminum spectrum of the silicon-aluminum material, there are relatively strong absorption peaks near the chemical shifts of 59 ppm and 7 ppm.

[0012] Further, in the silicon-aluminum material, as a preferred embodiment, in the nuclear magnetic resonance silicon spectrum of the silicon-aluminum material, there is a relatively strong absorption peak near the chemical shift of -88 ppm and a weak absorption peak at -111 ppm.

[0013] Further, in the silicon-aluminum material, as a preferred embodiment, the B acid content of the silicon-aluminum material is greater than 0.10 mmol / g, preferably 0.10-0.3 mmol / g, and further preferably 0.15-0.30 mmol / g.

[0014] Further, in the silicon-aluminum material, as a preferred embodiment, the ratio of B acid to L acid of the silicon-aluminum material is 0.5-1.2, preferably 0.5-1.0.

[0015] Further, in the silicon-aluminum material, as a preferred embodiment, the pore size distribution of the silicon-aluminum material has the following characteristics: the pore volume of pores with a pore diameter < 10 nm accounts for ≤ 15% of the total pore volume, the pore volume of pores with a pore diameter of 10-50 nm accounts for 50-80% of the total pore volume, and the pore volume of pores with a pore diameter > 50 nm accounts for 5-35% of the total pore volume; preferably, the pore volume of pores with a pore diameter < 10 nm accounts for ≤ 10% of the total pore volume, the pore volume of pores with a pore diameter of 10-50 nm accounts for 60-80% of the total pore volume, and the pore volume of pores with a pore diameter > 50 nm accounts for 10-30% of the total pore volume.

[0016] Further, in the silicon-aluminum material, as a preferred embodiment, the Na2O content of the silicon-aluminum material is less than 0.5 wt%, preferably less than 0.3 wt%.

[0017] The second aspect of the present application provides a preparation method of a silicon-aluminum material, which comprises the following steps:

[0018] (1) mixing a first silicon source, a first additive and water under mixing conditions to obtain a sol;

[0019] (2) mixing the sol obtained in step (1) with alcohol, and then performing heat treatment to obtain a first stream;

[0020] (3) adding a second silicon source, an acidic aluminum-containing compound and an alkaline aluminum-containing compound into a reactor containing bottom water under contact conditions, and obtaining a mixed solution after reaction;

[0021] (4) mixing the mixed solution obtained in step (3) with a second additive under contact conditions to obtain a slurry;

[0022] (5) mixing the slurry obtained in step (4) and the first stream obtained in step (2) under contact conditions and performing hydrothermal treatment, and then obtaining the silicon-aluminum material after washing, drying and calcination.

[0023] Further, in the preparation method of the above-mentioned silicon-aluminum material, as a specific embodiment, the first silicon source in step (1) is one or more of tetraethyl orthosilicate, tetramethyl orthosilicate and silica sol, preferably tetraethyl orthosilicate.

[0024] Further, in the preparation method of the above-mentioned silicon-aluminum material, as a specific embodiment, the first additive in step (1) can be one or more of tetrapropylammonium hydroxide and tetrapropylammonium bromide; preferably tetrapropylammonium hydroxide.

[0025] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the alcohol in step (2) is C1-C3 alcohol, which can be one or more of monohydric alcohol, dihydric alcohol, and polyhydric alcohol; and the specific alcohol can be one or more of ethanol, ethylene glycol, and glycerol, and is preferably glycerol.

[0026] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the mass ratio of the first silicon source, the first additive, water, and alcohol is 3-6:5-8:2-4:0.5-5.

[0027] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the heat treatment temperature in step (2) is 60-100°C, and is preferably 80-100°C; and the treatment time is not more than 24 hours, and is preferably 8-12 hours.

[0028] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the second silicon source in step (3) is one or more of water glass and alkaline silica sol, and is preferably alkaline silica sol.

[0029] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the acidic aluminum-containing compound in step (3) is a water-soluble acidic aluminum-containing compound, which is preferably a water-soluble acidic inorganic aluminum-containing compound, and is particularly a water-soluble inorganic strong acid aluminum salt, and is more preferably one or more selected from aluminum sulfate, aluminum nitrate, and aluminum chloride, and is preferably aluminum sulfate.

[0030] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the alkaline aluminum-containing compound in step (3) is an alkali metal meta-aluminate solution; and is specifically one or more selected from sodium meta-aluminate and potassium meta-aluminate, and is preferably sodium meta-aluminate.

[0031] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the pH value of the mixed solution in step (3) is 4-7, and is preferably 5-6. The pH value of the mixed solution is controlled by the amount of the acidic aluminum-containing compound.

[0032] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the temperature in step (3) is 50-90°C, and is preferably 50-80°C.

[0033] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the aluminum content of the acidic aluminum-containing compound in step (3) is 10-70 g Al2O3 / L, the aluminum content of the basic aluminum-containing compound is 70-170 g Al2O3 / L, and the silicon content of the second silicon source is 20-80 g SiO2 / L.

[0034] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the amount of water in step (3) is 10%-20% of the total volume of the reaction system, preferably 13%-20%.

[0035] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the second additive in step (4) is a nonionic surfactant, and the second additive is one or more of polyethylene glycol, alkyl alcohol amide, and polyether; the alkyl alcohol amide is one or more of lauryl diethanolamine and coconut oil fatty acid diethanolamide; the polyether is one or more of AEO-6 and AEO-9; and the molecular weight of the polyethylene glycol is 200-1000, preferably 200-700.

[0036] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the temperature in step (4) is 50°C-90°C, preferably 50°C-80°C.

[0037] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the mass ratio of the first stream obtained in step (2) to the slurry in step (4) is 1:80-100.

[0038] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the hydrothermal treatment conditions in step (5) are as follows: the treatment temperature is 100°C-180°C, preferably 110°C-160°C, and further preferably 120°C-150°C; the treatment pressure is 0.1-0.5 MPa, preferably 0.1-0.3 MPa; and the treatment time is 0.5 h-10 h, preferably 0.5 h-6 h.

[0039] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the washing in step (5) is washing with water, and the washing temperature is 70-90°C, and the washing is performed several times until the liquid is neutral.

[0040] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the drying conditions in step (5) are as follows: the drying temperature is 100-150°C, and the drying time is 6-10 hours.

[0041] Further, in the preparation method of the silicon-aluminum material, as a specific embodiment, the calcination conditions in step (5) are as follows: the calcination temperature is 500-700 DEG C, and the calcination time is 4-8 hours.

[0042] Compared with the prior art, the silicon-aluminum material, the preparation method and the application thereof have the following advantages:

[0043] (1) The silicon-aluminum material has a large pore volume, a mesopore-macropore two-stage gradient pore channel, a molecular sieve property, a high B acid content of the molecular sieve, a low impurity content (especially a low sodium content), and the like, and is suitable for being used as a carrier of a catalytic material, in particular, a carrier of a heavy oil hydrogenation catalyst.

[0044] (2) In the preparation method of the silicon-aluminum material, when the semi-crystallized precursor is prepared, the second additive is added to control the over-crystallization of the precursor, and then the precursor is added into the silicon-aluminum material, so that the silicon-aluminum material grows on the surface of the silicon-aluminum material to form a high surface acidity and a mesopore-macropore gradient pore channel structure.

[0045] (3) In the preparation method of the silicon-aluminum material, the precursor provides a crystal nucleus for a subsequent reaction, and the acidified silica gel group and the aluminum hydroxide colloid are adsorbed on the crystal nucleus formed by the precursor, so that the crystal grain of the prepared silicon-aluminum material is increased, and the silicon-aluminum material with a large pore volume, a large pore size and a strong acidity is formed.

[0046] (4) In the preparation method of the silicon-aluminum material, in the preferred case, the soluble silicon species in the slurry is exchanged with the same ions on the surface of the second additive micelle to be adsorbed on the surface of the micelle, and also reacts with the second additive molecules in the liquid phase to form a new inorganic-organic complex, and the adsorbed silicon species micelle and the complex molecules form a mesoporous material with a stable structure at a lower temperature under the action of ionic bonds, hydrogen bonds and intermolecular dispersion forces through multiple thermodynamic equilibria. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 The XRD graph of the silicon-aluminum material prepared in Example 1 of the present application.

[0048] Figure 2 The nuclear magnetic resonance aluminum spectrum graph of the silicon-aluminum material prepared in Example 1 of the present application.

[0049] Figure 3 The nuclear magnetic resonance silicon spectrum graph of the silicon-aluminum material prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0050] The specific embodiments of the present application will be described in detail in the following with reference to the drawings and specific examples, but it should be noted that the scope of protection of the present application is not limited by these specific embodiments, but is determined by the claims.

[0051] In the context of the present specification, the pore volume, specific surface area and pore size distribution of the silica-alumina material are measured by low temperature nitrogen adsorption. The total acid, B acid and L acid are measured by pyridine infrared adsorption.

[0052] In the context of the present specification, all percentages, parts, ratios, etc. mentioned are based on weight, and pressure is bar.

[0053] In the context of the present specification, any two or more embodiments of the present application can be combined arbitrarily, and the technical solutions thus formed are part of the original disclosure of the present specification and also fall within the scope of protection of the present application.

[0054] Example 1

[0055] An aluminum sulfate solution with a concentration of 50 g Al203 / L and a silica sol solution with a concentration of 60 g Si02 / L are prepared for use.

[0056] A sodium metaaluminate solution with a caustic ratio of 1.20 and a concentration of 150 g Al203 / L is prepared for use.

[0057] A sol is prepared by mixing 50 g of tetraethyl orthosilicate (TEOS), 70 g of tetrapropylammonium hydroxide (TPAOH) and 30 g of deionized water, and then mixing and stirring the mixture with 15 g of glycerol at 60°C for 18 h to obtain a precursor solution.

[0058] 500 mL of deionized water is added to a 5000 mL reactor as a bottom water, the stirring is started and heated, after the deionized water is heated to 65°C, the prepared aluminum sulfate solution is added to the reactor at a rate of 16 mL / min, and the prepared sodium metaaluminate and silica sol are added in parallel flow, the pH of the reaction is controlled to be 7.0 by adjusting the flow rate of the sodium metaaluminate and silica sol, and the temperature and pH of the slurry in the reactor are kept constant. After the reaction is completed, 20 g of polyethylene glycol 200 is added to the reactor under stirring conditions, and then 40 g of the precursor solution is added to the above solution and stirred until uniform.

[0059] The slurry was put into a reactor, and treated at 100°C and 0.2 MPa for 8 h under stirring. The treated slurry was washed with hot water at 90°C until neutral, dried at 150°C for 6 h to obtain a dried sample AO-1, and calcined at 600°C for 8 h to obtain a silicon-aluminum material A-1, whose properties are shown in Table 1.

[0060] Example 2

[0061] An aluminum sulfate solution with a concentration of 60 g Al2O3 / L and a silica sol solution with a concentration of 70 g SiO2 / L were prepared for use.

[0062] A sodium aluminate solution with a causticity ratio of 1.20 and a concentration of 140 g Al2O3 / L was prepared for use.

[0063] A sol was prepared by mixing 50 g of tetraethyl orthosilicate (TEOS), 70 g of tetrapropylammonium hydroxide (TPAOH), and 30 g of deionized water, and then mixing and stirring the mixture with 15 g of glycerol at 60°C for 18 h to obtain a precursor solution.

[0064] A 5000 mL reactor was charged with 500 mL of deionized water as a bottom water, and stirring was started and heating was started. After the deionized water was heated to 65°C, the prepared aluminum sulfate solution was added to the reactor at a rate of 18 mL / min, and the prepared sodium aluminate and silica sol were added in a concurrent flow. The pH of the reaction was controlled to be 6.5 by adjusting the flow rates of the sodium aluminate and the silica sol, and the temperature and the pH of the slurry in the reactor were kept constant. After the reaction was completed, 5 g of polyethylene glycol 800 was added to the reactor under stirring, and then 40 g of the precursor solution was added to the above solution and stirred until mixed uniformly.

[0065] The slurry was put into a reactor, and treated at 100°C and 0.1 MPa for 8 h under stirring. The treated slurry was washed with hot water at 90°C until neutral, dried at 150°C for 6 h to obtain a dried sample AO-2, and calcined at 600°C for 8 h to obtain a silicon-aluminum material A-2, whose properties are shown in Table 1.

[0066] Example 3

[0067] An aluminum chloride solution with a concentration of 30 g Al2O3 / L and a water glass solution with a concentration of 30 g SiO2 / L and a modulus of 2.5 were prepared for use.

[0068] A sodium aluminate solution with a causticity ratio of 1.20 and a concentration of 100 g Al2O3 / L was prepared for use.

[0069] A sol was prepared by mixing 60 g of methyl orthosilicate, 80 g of tetrapropylammonium hydroxide (TPAOH), and 40 g of deionized water, and then mixing the mixture with 50 g of ethanol and aging the mixture at 80°C for 8 hours to obtain a precursor solution.

[0070] A 5000 mL reactor was charged with 700 mL of deionized water as a bottom water, and stirring and heating were started. After the deionized water was heated to 70°C, an aluminum chloride solution prepared beforehand was added to the reactor at a rate of 14 mL / min, and a sodium metaaluminate solution and a water glass solution prepared beforehand were added in a concurrent manner. The pH of the reaction was controlled to be 6.0 by adjusting the flow rates of the sodium metaaluminate solution and the water glass solution, and the temperature and pH of the slurry in the reactor were kept constant. After the reaction was completed, 10 g of lauryl diethanolamide was added to the reactor under stirring, and then 45 g of the precursor solution was added to the above solution and stirred until the mixture was homogeneous.

[0071] The slurry was placed in a reactor, and was treated at a temperature of 120°C and a pressure of 0.2 MPa for 4 hours under stirring. The treated slurry was washed with hot water at 70°C until the liquid was neutral, and was dried at 120°C for 8 hours to obtain a dried sample AO-3, which was calcined at 650°C for 6 hours to obtain a silica-alumina material A-3. The properties of the silica-alumina material A-3 are shown in Table 1.

[0072] Example 4

[0073] An aluminum chloride solution having a concentration of 10 g Al2O3 / L and a water glass solution having a concentration of 20 g SiO2 / L and a modulus of 2.5 were prepared and used as needed.

[0074] A sodium metaaluminate solution having a caustic ratio of 1.20 and a concentration of 70 g Al2O3 / L was prepared and used as needed.

[0075] A sol was prepared by mixing 60 g of methyl orthosilicate, 80 g of tetrapropylammonium hydroxide (TPAOH), and 40 g of deionized water, and then mixing the mixture with 50 g of ethanol and aging the mixture at 80°C for 8 hours to obtain a precursor solution.

[0076] A 5000 mL reactor was charged with 700 mL of deionized water as a bottom water, and stirring and heating were started. After the deionized water was heated to 70°C, an aluminum chloride solution prepared beforehand was added to the reactor at a rate of 14 mL / min, and a sodium metaaluminate solution and a water glass solution prepared beforehand were added in a concurrent manner. The pH of the reaction was controlled to be 6.0 by adjusting the flow rates of the sodium metaaluminate solution and the water glass solution, and the temperature and pH of the slurry in the reactor were kept constant. After the reaction was completed, 10 g of lauryl diethanolamide was added to the reactor under stirring, and then 45 g of the precursor solution was added to the above solution and stirred until the mixture was homogeneous.

[0077] The slurry was put into a reactor, and treated at 120°C and 0.2 MPa for 4 h under stirring. The treated slurry was washed with hot water at 70°C until neutral, and dried at 120°C for 8 h to obtain a dried sample AO-4. The sample AO-4 was calcined at 650°C for 6 h to obtain a silica-alumina material A-4, the properties of which are shown in Table 1.

[0078] Example 5

[0079] An aluminum nitrate solution with a concentration of 70 g Al203 / L and a silica sol solution with a concentration of 80 g Si02 / L were prepared for use.

[0080] A potassium aluminate solution with a causticity ratio of 1.20 and a concentration of 170 g Al203 / L was prepared for use.

[0081] 30 g of silica sol, 50 g of tetrapropylammonium hydroxide (TPAOH), and 20 g of deionized water were stirred to prepare a sol, and then 15 g of ethylene glycol was added to the sol to age at 80°C for 8 h to obtain a precursor solution.

[0082] 1000 mL of deionized water was added to a 5000 mL reactor as a bottom water, and stirring was started and heating was started. After the deionized water was heated to 70°C, the prepared aluminum nitrate solution was added to the reactor at a rate of 18 mL / min, and the prepared potassium aluminate and silica sol were added in a concurrent flow. The pH of the reaction was controlled to be 6.0 by adjusting the flow rates of the potassium aluminate and the silica sol, and the temperature and the pH of the slurry in the reactor were kept constant. After the reaction was completed, 10 g of AEO-9 was added to the reactor under stirring, and then 50 g of the precursor solution was added to the above solution and stirred until the mixture was uniform.

[0083] The slurry was put into a reactor, and treated at 180°C and 0.5 MPa for 0.5 h under stirring. The treated slurry was washed with hot water at 80°C until neutral, and dried at 100°C for 10 h to obtain a dried sample AO-5. The sample AO-5 was calcined at 700°C for 4 h to obtain a silica-alumina material A-5, the properties of which are shown in Table 1.

[0084] Example 6

[0085] An aluminum nitrate solution with a concentration of 40 g Al203 / L and a silica sol solution with a concentration of 60 g Si02 / L were prepared for use.

[0086] A potassium aluminate solution with a causticity ratio of 1.20 and a concentration of 140 g Al203 / L was prepared for use.

[0087] A sol was prepared by mixing 30 g of silica sol, 50 g of tetrapropylammonium hydroxide (TPAOH), and 20 g of deionized water, and then mixing and stirring the mixture with 15 g of ethylene glycol to obtain a precursor solution, which was aged at 80°C for 8 h.

[0088] A 5000 mL reactor was charged with 1000 mL of deionized water as a bottom water, and stirring was started and heating was performed. After the deionized water was heated to 70°C, an aluminum nitrate solution prepared in advance was added to the reactor at a rate of 18 mL / min, and a potassium meta-aluminate solution and a silica sol prepared in advance were added in a concurrent manner. The pH of the reaction was controlled to be 6.0 by adjusting the flow rates of the potassium meta-aluminate solution and the silica sol, and the temperature and pH of the slurry in the reactor were maintained constant. After the reaction was completed, 1600 mL of aluminum nitrate, 800 mL of potassium meta-aluminate, and 1500 mL of silica sol were added to the reactor under stirring, and then 10 g of AEO-6 was added to the solution. Subsequently, 50 g of the precursor solution was added to the solution, and the mixture was stirred until it was homogeneous.

[0089] The slurry was placed in a reactor, and was treated at a temperature of 180°C and a pressure of 0.5 MPa for 0.5 h under stirring. The treated slurry was washed with hot water at 80°C until the liquid became neutral, and was dried at 100°C for 10 h to obtain a dried sample AO-6. The sample was calcined at 700°C for 4 h to obtain a silica-alumina material A-6, and the properties of the material are shown in Table 1.

[0090] Comparative Example 1

[0091] An aluminum sulfate solution having a concentration of 50 g Al2O3 / L and a silica sol solution having a concentration of 60 g SiO2 / L were prepared in advance.

[0092] A sodium meta-aluminate solution having a caustic ratio of 1.20 and a concentration of 150 g Al2O3 / L was prepared in advance.

[0093] A sol was prepared by mixing 50 g of tetraethyl orthosilicate (TEOS) and 30 g of deionized water, and then mixing and stirring the mixture with 15 g of glycerol to obtain a precursor solution, which was aged at 60°C for 18 h.

[0094] A 5000 mL reactor was charged with 500 mL of deionized water as a bottom water, and stirring was started and heating was performed. After the deionized water was heated to 65°C, an aluminum sulfate solution prepared in advance was added to the reactor at a rate of 16 mL / min, and a sodium meta-aluminate solution and a silica sol prepared in advance were added in a concurrent manner. The pH of the reaction was controlled to be 7.0 by adjusting the flow rates of the sodium meta-aluminate solution and the silica sol, and the temperature and pH of the slurry in the reactor were maintained constant. After the reaction was completed, 1320 mL of aluminum sulfate, 580 mL of sodium meta-aluminate, and 1160 mL of silica sol were added to the reactor under stirring, and then 20 g of polyethylene glycol 200 was added to the solution. Subsequently, 40 g of the precursor solution was added to the solution, and the mixture was stirred until it was homogeneous.

[0095] The slurry was put into a reactor, and treated at 100°C and 0.2 MPa for 8 h under stirring. The treated slurry was washed with hot water at 90°C until the liquid was neutral, and dried at 150°C for 6 h to obtain a dried sample BO-1, which was calcined at 600°C for 8 h to obtain a silica-alumina material B-1. The properties of the silica-alumina material B-1 are shown in Table 1.

[0096] Comparative Example 2

[0097] An aluminum chloride solution with a concentration of 30 g Al2O3 / L and a water glass solution with a concentration of 30 g SiO2 / L and a modulus of 2.5 were prepared.

[0098] A sodium metaaluminate solution with a causticity ratio of 1.20 and a concentration of 100 g Al2O3 / L was prepared.

[0099] A sol was prepared by stirring 60 g of methyltrimethoxysilane, 80 g of tetrapropylammonium hydroxide (TPAOH), and 40 g of deionized water, and then mixing the sol with 50 g of ethanol and aging at 80°C for 8 h to obtain a precursor solution.

[0100] A 5000 mL reactor was charged with 700 mL of deionized water as a bottom water, and stirring was started and heating was started. After the deionized water was heated to 70°C, the prepared aluminum chloride solution was added to the reactor at a rate of 14 mL / min, and the prepared sodium metaaluminate and water glass were added in a concurrent flow. The pH of the reaction was controlled to be 6.0 by adjusting the flow rates of the sodium metaaluminate and the water glass, and the temperature and pH of the slurry in the reactor were kept constant. After the reaction was completed, the amount of the aluminum chloride was 1100 mL, the amount of the sodium metaaluminate was 500 mL, and the amount of the water glass was 950 mL. Then, 45 g of the precursor solution was added to the above solution, and stirring was performed until the mixture was uniform.

[0101] The slurry was put into a reactor, and treated at 120°C and 0.2 MPa for 4 h under stirring. The treated slurry was washed with hot water at 70°C until the liquid was neutral, and dried at 120°C for 8 h to obtain a dried sample AO-3, which was calcined at 650°C for 6 h to obtain a silica-alumina material A-3. The properties of the silica-alumina material A-3 are shown in Table 1.

[0102] Comparative Example 3

[0103] An aluminum nitrate solution with a concentration of 70 g Al2O3 / L and a silica sol solution with a concentration of 80 g SiO2 / L and a modulus of 2.8 were prepared.

[0104] A potassium metaaluminate solution with a causticity ratio of 1.20 and a concentration of 170 g Al2O3 / L was prepared.

[0105] 30 g of silica sol, 20 g of deionized water were stirred to prepare a sol, then 15 g of ethylene glycol was mixed and aged at 80 °C for 8 h to obtain a precursor solution.

[0106] 1000 mL of deionized water was added to a 5000 mL reactor as a bottom water, stirring was started and heating was started, after the deionized water was heated to 70 °C, the prepared aluminum nitrate solution was added to the reactor at a rate of 18 mL / min, while the prepared potassium metaaluminate and silica sol were added in parallel, the pH of the reaction was controlled at 6.0 by adjusting the flow rate of potassium metaaluminate and silica sol, and the temperature and pH of the slurry in the reactor were kept constant. After the reaction was completed, the amount of aluminum nitrate was 1500 ml, the amount of potassium metaaluminate was 700 mL, and the amount of silica sol was 1300 ml, then 50 g of the precursor solution was added to the above solution and stirred until uniform.

[0107] The slurry was placed in a reactor under stirring, the treatment temperature was 180 °C, the treatment pressure was 0.5 MPa, and the treatment time was 0.5 h. The treated slurry was washed with hot water at 80 °C until the liquid was neutral, and then dried at 100 °C for 10 h to obtain a dried sample BO-3, which was calcined at 700 °C for 4 h to obtain a silicon-aluminum material B-3, the properties of which are shown in Table 1.

[0108] Table 1 Properties of silicon-aluminum material products

[0109] Sample name A-1 A-2 A-3 A-4 A-5 A-6 B-1 B-2 B-3 Specific surface area, m 2 / g]] 345 350 331 351 346 342 421 381 412 Pore volume, mL / g 1.35 1.33 1.12 1.15 1.21 1.28 0.73 0.82 0.78 Average pore size, nm 21.1 20.2 18.1 17.8 18.3 19.8 6.9 8.6 7.6 Pore size distribution, % <10 nm 9.72 9.81 12.86 14.43 14.68 13.34 70.56 64.62 68.96 10-50 nm 67.43 68.51 79.28 78.62 65.93 61.85 20.67 26.20 22.32 > 50 nm 22.85 21.68 7.86 6.95 19.39 22.81 8.77 9.18 8.72 B acid, mmol / g 0.231 0.220 0.196 0.184 0.187 0.182 0.105 0.126 0.103 B / L ratio 1.19 1.09 0.92 0.95 0.89 0.84 0.42 0.52 0.36 Na20 content, wt% 0.28 0.31 0.38 0.34 0.19 0.21 0.45 0.24 0.19 SiO2content, wt% 32.3 34.1 28.5 36.4 32.5 35.6 32.3 28.5 32.5

Claims

1. A silicon-aluminum material, wherein the silicon-aluminum material, after calcination at 500–700℃, has the following properties: silicon dioxide content of 20 wt%–40 wt%, pore volume of not less than 0.70 mL / g, and specific surface area of ​​280–400 m². 2 / g, the Brønsted acid content of the silicon-aluminum material is greater than 0.10 mmol / g; the pore size distribution of the silicon-aluminum material has the following characteristics: the pore volume of pores with a diameter <10 nm accounts for ≤15% of the total pore volume, the pore volume of pores with a diameter of 10–50 nm accounts for 50%–80% of the total pore volume, and the pore volume of pores with a diameter >50 nm accounts for 5%–35% of the total pore volume; the calcination form of the silicon-aluminum material after calcination has the XRD pattern shown in the table below. If the intensity value of the strongest diffraction peak in the XRD pattern is defined as 100, then W represents weak (relative intensity >0 to ≤20), M represents moderate (relative intensity >20 to ≤40), S represents strong (relative intensity >40 to ≤60), and VS represents very strong (relative intensity >60 to ≤100).

2. The silicon-aluminum material according to claim 1, characterized in that: The properties of silicon-aluminum materials after calcination at 500–700℃ are as follows: silicon dioxide content 25wt%–35wt%, pore volume greater than 0.80mL / g, and specific surface area 300–400m². 2 / g.

3. The silicon-aluminum material according to claim 1, characterized in that: The properties of silicon-aluminum materials after calcination at 500–700℃ are as follows: pore volume is 0.70–1.5 mL / g.

4. The silicon-aluminum material according to claim 1, characterized in that: In the NMR aluminum spectrum of the silicon-aluminum material, there are strong absorption peaks near chemical shifts of 59 ppm and 7 ppm.

5. The silicon-aluminum material according to claim 1, characterized in that: In the NMR silicon spectrum of the silicon-aluminum material, there is a strong absorption peak near the chemical shift of -88 ppm and a weak absorption peak at -111 ppm.

6. The silicon-aluminum material according to claim 1, characterized in that: The Brønsted acid content of the silicon-aluminum material is 0.10–0.3 mmol / g.

7. The silicon-aluminum material according to claim 1, characterized in that: The Brønsted acid content of the silicon-aluminum material is 0.15–0.3 mmol / g.

8. The silicon-aluminum material according to claim 1, characterized in that: The ratio of Brønsted acid to Lewis acid in the silicon-aluminum material is 0.5 to 1.

2.

9. The silicon-aluminum material according to claim 1, characterized in that: The ratio of Brønsted acid to Lewis acid in the silicon-aluminum material is 0.5 to 1.

0.

10. The silicon-aluminum material according to claim 1, characterized in that: The pore size distribution of the silicon-aluminum material has the following characteristics: the pore volume of pores with a diameter <10nm accounts for ≤10% of the total pore volume, the pore volume of pores with a diameter of 10-50nm accounts for 60%-80% of the total pore volume, and the pore volume of pores with a diameter >50nm accounts for 10%-30% of the total pore volume.

11. The silicon-aluminum material according to claim 1, characterized in that: The Na2O content of the silicon-aluminum material is less than 0.5 wt%.

12. The silicon-aluminum material according to claim 1, characterized in that: The Na2O content of the silicon-aluminum material is less than 0.3 wt%.

13. A method for preparing the silicon-aluminum material according to any one of claims 1-12, the method comprising the following steps: (1) Under mixed conditions, the first silicon source, the first additive and water are mixed to obtain a sol; The first auxiliary agent is one or more of tetrapropylammonium hydroxide and tetrapropylammonium bromide; (2) The sol obtained in step (1) is mixed with alcohol and then heat-treated to obtain the first material stream; (3) Under contact conditions, the second silicon source, acidic aluminum compound and alkaline aluminum compound are added to a reactor containing bottom water, and a mixed solution is obtained after the reaction; the pH value of the mixed solution is 4 to 7. (4) Under contact conditions, the mixed solution obtained in step (3) is mixed with the second auxiliary agent to obtain a slurry; the second auxiliary agent is a nonionic surfactant, which is one or more of alkylolamides and polyethers; the pH value of the slurry is 7.5 to 10.5; (5) Under contact conditions, the slurry obtained in step (4) and the first material flow obtained in step (2) are mixed and subjected to hydrothermal treatment. After treatment, the material is washed, dried and calcined to obtain silicon-aluminum material.

14. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The first silicon source in step (1) is one or more of tetraethyl orthosilicate, methyl orthosilicate, and silica sol.

15. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The first silicon source in step (1) is tetraethyl orthosilicate.

16. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The first auxiliary agent in step (1) is tetrapropylammonium hydroxide.

17. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The alcohol in step (2) is a C1-C3 alcohol.

18. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The alcohol in step (2) is one or more of ethanol, ethylene glycol, and glycerol.

19. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The alcohol in step (2) is glycerol.

20. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The mass ratio of the first silicon source, the first additive, water, and alcohol is 3-6:5-8:2-4:0.5-5.

21. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The heat treatment temperature in step (2) is 60-100℃, and the treatment time is no more than 24 hours.

22. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The heat treatment temperature in step (2) is 80-100℃, and the treatment time is 8-12 hours.

23. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The second silicon source in step (3) is one or more of water glass and alkaline silica sol.

24. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The second silicon source in step (3) is alkaline silica sol.

25. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The acidic aluminum compound in step (3) is a water-soluble acidic aluminum compound.

26. The method for preparing the silicon-aluminum material according to claim 13 or 25, characterized in that: The acidic aluminum-containing compound in step (3) is a water-soluble acidic inorganic aluminum-containing compound.

27. The method for preparing the silicon-aluminum material according to claim 13 or 25, characterized in that: The acidic aluminum-containing compound in step (3) is a water-soluble inorganic strong acid aluminum salt, selected from one or more of aluminum sulfate, aluminum nitrate, and aluminum chloride.

28. The method for preparing the silicon-aluminum material according to claim 13 or 25, characterized in that: The acidic aluminum-containing compound in step (3) is aluminum sulfate.

29. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The alkaline aluminum-containing compound in step (3) is an alkali metal aluminate solution; selected from one or more of sodium aluminate and potassium aluminate.

30. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The alkaline aluminum-containing compound in step (3) is sodium aluminate.

31. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The pH value of the mixed solution in step (3) is 5 to 6.

32. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The temperature in step (3) is 50℃~90℃.

33. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The temperature in step (3) is 50℃~80℃.

34. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: In step (3), the aluminum content of the acidic aluminum-containing compound is 10-70 gAl2O3 / L, the aluminum content of the alkaline aluminum-containing compound is 70-170 gAl2O3 / L, and the silicon content of the second silicon source is 20-80 gSiO2 / L.

35. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The amount of water used in step (3) is 10% to 20 vol of the total volume of the reaction system.

36. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The amount of water used in step (3) is 13% to 20 vol of the total volume of the reaction system.

37. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The second additive in step (4) is polyethylene glycol.

38. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The pH value of the slurry in step (4) is 8.0 to 10.

5.

39. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The pH value of the slurry in step (4) is 8.5 to 10.

5.

40. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The temperature in step (4) is 50℃~90℃.

41. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The temperature in step (4) is 50℃~80℃.

42. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The mass ratio of the first material flow obtained in step (2) to the slurry in step (4) is 1:80~100.

43. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The hydrothermal treatment conditions in step (5) are: treatment temperature of 100℃~180℃, treatment pressure of 0.1~0.5MPa, and treatment time of 0.5h~10h.

44. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The hydrothermal treatment conditions in step (5) are: treatment temperature of 110℃~160℃, treatment pressure of 0.1~0.3MPa, and treatment time of 0.5h~6h.

45. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The hydrothermal treatment conditions in step (5) are: the treatment temperature is 120℃~150℃.

46. ​​The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The washing in step (5) is done with water at a temperature of 70-90°C.

47. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The drying conditions in step (5) are: drying temperature of 100-150℃ and drying time of 6-10 hours.

48. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The roasting conditions in step (5) are: roasting temperature of 500-700℃ and roasting time of 4-8 hours.

49. The method for preparing the silicon-aluminum material according to claim 13, characterized in that: The second additive is polyethylene glycol.

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