Mesoporous silicon-phosphorus-aluminum composite oxide and method for preparing the same

Abstract

The application provides a preparation method of mesoporous silicon phosphorus aluminum composite oxide, which comprises the following steps: step a, preparing hierarchical pore Y molecular sieve by using a crystallization method, and separating the crystallization product to obtain hierarchical pore Y molecular sieve and slurry containing hierarchical pore Y molecular sieve microcrystals; step b, preparing SAPO-34 molecular sieve by using a crystallization method, and taking the hierarchical pore Y molecular sieve obtained in step a as part of a silicon source, and the crystallization product is slurry containing SAPO-34 molecular sieve microcrystals; and step c, mixing the slurry containing hierarchical pore Y molecular sieve microcrystals in step a with the slurry containing SAPO-34 molecular sieve microcrystals in step b, and then performing solid-liquid separation to obtain Y / SAPO-34 molecular sieve. The mesoporous silicon phosphorus aluminum composite oxide prepared by the method contains Y molecular sieve and SAPO-34 molecular sieve microcrystals, and can fully utilize the strong acid sites on the outer surface of the Y / SAPO-34 microporous molecular sieve microcrystals, so that the acid amount and acid strength are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of molecular sieve materials, in particular to a mesoporous silicon-phosphorus-aluminum composite oxide and a preparation method thereof. BACKGROUND

[0002] Molecular sieves are widely used in adsorption, separation, catalysis and other fields due to their unique pore structure, especially in petroleum and chemical industry. With the continuous development of molecular sieve catalytic applications, single-pore molecular sieves cannot meet the diverse needs of catalyst preparation. Microporous molecular sieves are mainly characterized by strong acidity and high structural stability in heterogeneous catalysis applications. However, due to the small pore size and long and narrow pore channel of microporous molecular sieves, it is difficult for large molecules in heavy oil to diffuse into the pore channel, which reduces the utilization rate of acid sites inside the microporous molecular sieve pore channel. In addition, the narrow and long pore channel has a large diffusion resistance, which affects the rapid diffusion of reaction product molecules, and easily leads to deep cracking and coking. Mesoporous molecular sieves can make up for the limitations of microporous molecular sieves in internal diffusion of reactants and reaction products, but the structural stability of mesoporous molecular sieves is often poor, which also limits their catalytic applications. Micro-mesoporous composite molecular sieve materials can produce good synergistic effect and catalytic performance by taking the advantages of each other in performance, and their comprehensive performance is better than that of the original component materials. This kind of molecular sieve with multiple structures and superimposed functions can avoid the defects of single-pore structure, and the multi-level pore system can provide pores of different sizes, which will be very helpful to solve the problem of mass transfer of large molecules.

[0003] CN201610452842.X provides a Y / ZSM-22 / SAPO-34 / ASA / MOF composite material and a preparation method thereof, which comprises the following steps: preparing a ZSM-22 / SAPO-34 molecular sieve slurry, synthesizing a Y / ZSM-22 / SAPO-34 composite molecular sieve by using a hydrothermal crystallization method, then adding a surfactant and an alkaline aluminum source into the slurry containing the molecular sieve, adjusting the pH value to obtain a solid product, washing, drying and calcining the product to obtain a Y / ZSM-22 / SAPO-34 / ASA composite material, then mixing and stirring the material with a metal salt aqueous solution uniformly, and drying to obtain a metal-loaded Y / ZSM-22 / SAPO-34 / ASA composite material. A carboxyl-containing organic acid is added into an alcohol and an amide organic solvent to obtain an organic mixture. The Y / ZSM-22 / SAPO-34 / ASA material loaded with metal is added into the above organic mixture, stirred uniformly, and reacted to obtain a product. The total pore volume of the composite material in the present application is 0.54-0.58 mL / g, which is relatively low.

[0004] CN201710519563.5 provides a Y / SAPO-34 / ZSM-11 / ASA multi-level porous material preparation method, which comprises the following steps: first, synthesizing a Y molecular sieve directing agent, adding treated SAPO-34 and ZSM-11 molecular sieve mixed slurry into a Y molecular sieve synthesis system, synthesizing Y / SAPO-34 / ZSM-11 composite molecular sieve by using a hydrothermal crystallization method, then adding a surfactant, an alkaline aluminum source and / or an alkaline silicon source solution into the slurry of the Y / SAPO-34 / ZSM-11 molecular sieve, and washing, drying and calcining the product to obtain a mesoporous Y / SAPO-34 / ZSM-11 / ASA multi-level porous material; the total pore volume of the composite material is 0.52-0.62 mL / g, and the pore volume is relatively low.

[0005] Therefore, the molecular sieve composite material still needs to be further studied in the art. SUMMARY

[0006] The main purpose of the present application is to provide a mesoporous silicon phosphorus aluminum composite oxide and a preparation method thereof, so as to overcome the defects of weak surface acidity and few mesoporous structures of the mesoporous silicon phosphorus aluminum composite oxide used as a catalyst carrier in the prior art.

[0007] In order to achieve the above purpose, the present application provides a preparation method of a mesoporous silicon phosphorus aluminum composite oxide, comprising the following steps:

[0008] Step a, preparing a multi-level porous Y molecular sieve by using a crystallization method, and separating the crystallization product to obtain a multi-level porous Y molecular sieve and a slurry containing multi-level porous Y molecular sieve microcrystals;

[0009] Step b, preparing a SAPO-34 molecular sieve by using a crystallization method, and taking the multi-level porous Y molecular sieve obtained in step a as part of the silicon source, and separating the crystallization product to obtain a slurry containing SAPO-34 molecular sieve microcrystals;

[0010] Step c, mixing the slurry containing multi-level porous Y molecular sieve microcrystals in step a with the slurry containing SAPO-34 molecular sieve microcrystals in step b, and separating the solid and liquid to obtain a Y / SAPO-34 molecular sieve.

[0011] The preparation method of the mesoporous silicon phosphorus aluminum composite oxide provided by the present application further comprises the following steps in the preparation method of the Y / SAPO-34 molecular sieve:

[0012] Step d, ion exchanging the Y / SAPO-34 molecular sieve with an ammonium salt solution.

[0013] In the preparation method of the mesoporous silicon phosphorus aluminum composite oxide provided by the present application, step a is: mixing a silicon source, an aluminum source, a directing agent, a pore expanding agent and water, crystallizing, and separating the crystallization product to obtain a multi-level porous Y molecular sieve and a slurry containing multi-level porous Y molecular sieve microcrystals.

[0014] The preparation method of the mesoporous silicon phosphorus aluminum composite oxide, wherein the pore expanding agent is at least one of hydroxypropyl methyl cellulose, PEG1000 and AES.

[0015] The preparation method of the mesoporous silicon phosphorus aluminum composite oxide, wherein the preparation method of the directing agent is: mixing an aluminum source, a silicon source and water, and aging to obtain the directing agent.

[0016] The preparation method of the mesoporous silicon phosphorus aluminum composite oxide, wherein step b is: mixing a silicon source, a template agent and water to form solution A, mixing a titanium modified aluminum source and an inorganic acid with water to form solution B, mixing solution A and solution B, and crystallizing to obtain a slurry containing SAPO-34 molecular sieve microcrystals.

[0017] The silicon source includes the hierarchical pore Y molecular sieve obtained in step a.

[0018] The preparation method of the mesoporous silicon phosphorus aluminum composite oxide, wherein the template agent includes at least one of triethylamine and morpholine.

[0019] The preparation method of the mesoporous silicon phosphorus aluminum composite oxide, wherein the amount of each substance in step a satisfies the molar ratio of (5.5-6.5)Na2O:Al2O3:(11.5-12.5)SiO2:(230-270)H2O.

[0020] The preparation method of the mesoporous silicon phosphorus aluminum composite oxide, wherein the amount of each substance in step b satisfies the molar ratio of (1.2-1.3)Al2O3:(1.2-1.3)P2O5:(1.2-1.3)SiO2:(1.5-2.5)template agent:(65-75)H2O.

[0021] To achieve the above purpose, the application further provides the mesoporous silicon phosphorus aluminum composite oxide obtained by the above preparation method.

[0022] The application has the following beneficial effects:

[0023] The mesoporous silicon phosphorus aluminum composite oxide prepared by the method of the application contains Y molecular sieve and SAPO-34 molecular sieve microcrystals, can fully utilize the strong acid sites on the outer surface of Y / SAPO-34 microporous molecular sieve microcrystals, and improve the acid amount and acid strength; in addition, the mesoporous silicon phosphorus aluminum composite oxide obtained by the method of the application has rich mesoporous structure, a specific surface area of 440-550m 2 / g, a pore volume of 1.2-1.6mL / g, and an average pore diameter of 10-12nm, and can improve the diffusion performance of reactants. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 XRD pattern of the product of Example 1;

[0025] Figure 2 XRD pattern of the product of Example 2;

[0026] Figure 3 XRD pattern of the product of Example 3. DETAILED DESCRIPTION

[0027] The technical solutions of the present application are described in detail below. The following embodiments are implemented on the premise of the technical solutions of the present application, and detailed implementation processes are given. However, the protection scope of the present application is not limited to the following embodiments. The structures or experimental methods not specified in the following embodiments are usually implemented according to conventional conditions.

[0028] The present application provides a preparation method of mesoporous silicon phosphorus aluminum composite oxide, comprising the following steps:

[0029] Step a, preparing hierarchical pore Y zeolite by using crystallization method, and separating the crystallization product to obtain hierarchical pore Y zeolite and slurry containing hierarchical pore Y zeolite microcrystals;

[0030] Step b, preparing SAPO-34 zeolite by using crystallization method, and using the hierarchical pore Y zeolite obtained in step a as part of the silicon source. The crystallization product is slurry containing SAPO-34 zeolite microcrystals;

[0031] Step c, mixing the slurry containing hierarchical pore Y zeolite microcrystals in step a with the slurry containing SAPO-34 zeolite microcrystals in step b, and separating the solid and liquid to obtain Y / SAPO-34 zeolite.

[0032] The mesoporous silicon phosphorus aluminum composite oxide prepared by the method of the present application contains Y zeolite and SAPO-34 zeolite microcrystals, which can fully utilize the strong acid sites on the outer surface of Y / SAPO-34 microporous zeolite microcrystals, thereby improving the acid amount and acid strength. In addition, the mesoporous silicon phosphorus aluminum composite oxide obtained by the method of the present application has abundant mesoporous structure, a specific surface area of 440-550 m 2 / g, further 480-520 m 2 / g, a pore volume of 1.2-1.6 mL / g, further 1.48-1.52 mL / g, and an average pore diameter of 10-12 nm, further 10.5-11.5 nm, which can improve the diffusion performance of reactants.

[0033] In step a, the preparation of hierarchical pore Y zeolite by using crystallization method can be performed by using the conventional method for preparing Y zeolite in the art. For example, the silicon source, aluminum source, directing agent, pore-expanding agent, and water are mixed, and then crystallization is performed. The crystallization product is separated to obtain hierarchical pore Y zeolite and slurry containing hierarchical pore Y zeolite microcrystals.

[0034] In one embodiment, the method for preparing hierarchical pore Y molecular sieve by crystallization comprises the following steps:

[0035] The directing agent, aluminum sulfate solution (calculated as Al2O3), low-alkali sodium metaaluminate solution (calculated as Al2O3 and Na2O), and pore-expanding agent are added into the water glass solution (calculated as SiO2), and then deionized water is added after stirring to prepare a reaction mixture of NaY molecular sieve. The mixture is crystallized at 90-100℃ for 12-48h to obtain a mixed slurry. After solid-liquid separation, hierarchical pore Y molecular sieve and slurry containing hierarchical pore Y molecular sieve microcrystals are obtained.

[0036] In one embodiment, the pore-expanding agent is at least one of hydroxypropyl methyl cellulose, PEG1000, and AES.

[0037] In one embodiment, the method for preparing the directing agent comprises the following steps: high-alkali sodium metaaluminate solution (calculated as Al2O3 and Na2O) and water glass solution (calculated as SiO2) are sequentially added into deionized water, and then aging is performed at 20-50℃ for 10-24h to prepare the directing agent.

[0038] In the method for preparing hierarchical pore Y molecular sieve by crystallization, the amounts of the various substances satisfy the following molar ratio: (5-7) Na2O:Al2O3:(11-13) SiO2:(200-300) H2O. The Na2O is derived from sodium metaaluminate solution and water glass solution, the Al2O3 is derived from sodium metaaluminate solution and aluminum sulfate solution, and the SiO2 is derived from water glass solution.

[0039] Step b is: preparing SAPO-34 molecular sieve by crystallization, and using the hierarchical pore Y molecular sieve obtained in step a as part of the silicon source. The crystallization product is slurry containing SAPO-34 molecular sieve microcrystals.

[0040] In one embodiment, the method for preparing SAPO-34 molecular sieve by crystallization comprises the following steps: mixing a silicon source, a template agent, and water to form solution A, mixing a titanium-modified aluminum source and an inorganic acid with water to form solution B, mixing solution A and solution B, and crystallizing to obtain slurry containing SAPO-34 molecular sieve microcrystals.

[0041] In one embodiment, the hierarchical pore Y molecular sieve obtained in step a accounts for 7-38wt% of the total amount of all silicon sources in solution A.

[0042] In one embodiment, the method for preparing SAPO-34 molecular sieve by crystallization comprises the following steps:

[0043] A solution A is formed by using a multi-level hole Y-type molecular sieve as part of the silicon source (7-38 wt% of all silicon sources in A, dry basis), adding silica sol (calculated as SiO2), a template agent and deionized water, a solution B is formed by adding phosphoric acid (calculated as H3PO4) to deionized water, and then adding titanium dioxide modified pseudo-boehmite (calculated as Al2O3), solution A is slowly added to solution B, the pH value is adjusted to 6.5-7.5, and the slurry containing SAPO-34 molecular sieve microcrystals (TiO2 / Y / SAPO-34 molecular sieve microcrystals) is obtained by crystallization at 150-200°C for 8-24 hours.

[0044] In the preparation of the SAPO-34 molecular sieve by the crystallization method, the amounts of the various substances satisfy the following molar ratio: (1-1.5) Al2O3:(1-1.5) P2O5:(1-1.5) SiO2:(1-3) template agent:(50-90) H2O. The Al2O3 is derived from pseudo-boehmite, the P2O5 is derived from phosphoric acid, and the SiO2 is derived from silica sol and Y-type molecular sieve.

[0045] In an embodiment, the template agent of the present application is triethylamine, morpholine, etc. The titanium-modified aluminum source of the present application is not particularly limited, for example, the content of titanium on the aluminum source is 1-3 wt%. The method for modifying the titanium-modified aluminum source of the present application is not particularly limited, and the conventional modification method in the art can be used.

[0046] Step c is: mixing the slurry containing the multi-level hole Y-type molecular sieve microcrystals of step a with the slurry containing the SAPO-34 molecular sieve microcrystals of step b, and then solid-liquid separation to obtain the Y / SAPO-34 molecular sieve.

[0047] In an embodiment, the mixing ratio of the slurry containing the multi-level hole Y-type molecular sieve microcrystals of step a to the slurry containing the SAPO-34 molecular sieve microcrystals of step b is 1:1. In another embodiment, the slurry containing the multi-level hole Y-type molecular sieve microcrystals of step a is slowly added to the slurry containing the SAPO-34 molecular sieve microcrystals of step b, and stirring is continuously performed, and the pH value of the system is adjusted to 8-9 by using hydrochloric acid, and finally the above obtained solid mixture is filtered, washed, dried at 90-110°C for 1-2 hours, and calcined at 400-600°C for 4-6 hours to obtain the mesoporous silicon phosphorus aluminum titanium composite oxide containing Y / SAPO-34 molecular sieve microcrystals.

[0048] In an embodiment, the preparation method of the Y / SAPO-34 molecular sieve of the present application further comprises:

[0049] Step d is: ion exchange of the Y / SAPO-34 molecular sieve with an ammonium salt solution.

[0050] In another embodiment, the step of ion-exchanging the Y / SAPO-34 molecular sieve with the ammonium salt solution is: mixing the mesoporous silicon phosphorus aluminum titanium composite oxide containing Y / SAPO-34 molecular sieve microcrystals and the ammonium sulfate solution at a mass ratio of 1:1, adjusting the pH value to 3.5-4.5, ion-exchanging for 1-3 hours, to obtain the Y / SAPO-34 molecular sieve microcrystal mesoporous silicon phosphorus aluminum titanium composite oxide material for a hydrofining catalyst, wherein the concentration of the ammonium sulfate solution is 0.5-1.5 mol / L.

[0051] As a specific preferred embodiment, the preparation method of the mesoporous silicon phosphorus aluminum composite oxide of the present application comprises the following steps:

[0052] (1) First, the sodium aluminate solution A (the content of Al2O3 is 4-7 wt% of the total solution, the content of Na2O is 20-30 wt% of the total solution) and the water glass solution (the content of SiO2 is 20-30 wt% of the total solution) are sequentially added to deionized water, and the mixture is aged at 20-50°C for 10-24 hours to prepare a directing agent. Second, 5-15 wt% of the directing agent, an aluminum sulfate solution (the content of Al2O3 is 2-4 wt%), a sodium aluminate solution B (the content of Al2O3 is 5-10 wt% of the total solution, the content of Na2O is 5-15 wt% of the total solution), and 1-10 wt% of a pore-expanding agent based on the total amount of solid product are added to the water glass solution (the content of SiO2 is 20-30 wt% of the total solution), and deionized water is added after the mixture is uniformly stirred to prepare a reaction mixture for synthesizing NaY molecular sieve. The mixture is crystallized at 90-100°C for 12-48 hours to obtain a slurry containing a hierarchical pore Y-type molecular sieve, and the slurry containing the hierarchical pore Y-type molecular sieve microcrystals is obtained after the solid and liquid are separated.

[0053] The addition amounts of the substances satisfy the following molar ratio: (5-7) Na2O:Al2O3:(11-13) SiO2:(200-300) H2O.

[0054] (2) The hierarchical pore Y-type molecular sieve is used as part of the silicon source (7-38 wt% of the total amount of dry silicon source in the solution), and a silica sol (the content of SiO2 is 20-40 wt% of the total solution), a template agent, and deionized water are added to form a solution C. A phosphoric acid solution (the content of H3PO4 is 75-85%) is added to deionized water, and then a modified pseudoboehmite (the content of Al2O3 is 60-75 wt%) containing 1-3 wt% of titanium dioxide based on the total amount of pseudoboehmite is added to form a solution D. The solution C is slowly added to the solution D, the pH value is adjusted to 6.5-7.5, and the mixture is crystallized at 150-200°C for 8-24 hours to obtain a slurry containing TiO2 / Y / SAPO-34 molecular sieve microcrystals.

[0055] The adding amount of each substance satisfies the following molar ratio: (1-1.5)Al2O3:(1-1.5)P2O5:(1-1.5)SiO2:(1-3)template agent:(50-90)H2O.

[0056] (3) The slurry containing the hierarchical Y molecular sieve microcrystal in step (1) is added into the slurry containing the TiO2 / Y / SAPO-34 molecular sieve microcrystal in step (2) at a mass ratio of 1:1, and the pH value of the system is adjusted to 8-9 with hydrochloric acid while stirring. Finally, the obtained solid mixture is filtered, washed, dried at 90-110°C for 1-2 hours, and calcined at 400-600°C for 4-6 hours to obtain a mesoporous silicon phosphorus aluminum titanium composite oxide material containing Y / SAPO-34 molecular sieve microcrystals.

[0057] As another specific preferred embodiment, the preparation method of the mesoporous silicon phosphorus aluminum composite oxide of the present application comprises the following steps:

[0058] (1) First, the sodium aluminate solution A (the content of Al2O3 is 5-6 wt% of the total solution, and the content of Na2O is 23-27 wt% of the total solution) and the water glass solution (the content of SiO2 is 24-26 wt% of the total solution) are sequentially added into deionized water, and the mixture is aged at 30-40°C for 14-20 hours to prepare a directing agent. Second, 7-12 wt% of the directing agent, an aluminum sulfate solution (the content of Al2O3 is 2-3 wt% of the total solution), a sodium aluminate solution B (the content of Al2O3 is 5-8 wt% of the total solution, and the content of Na2O is 5-10 wt%), and 4-6 wt% of a pore-expanding agent are added into the water glass solution (the content of SiO2 is 24-26 wt% of the total solution), and deionized water is further added after uniform stirring to prepare a reaction mixture for synthesizing NaY molecular sieve. The reaction mixture is crystallized at 95-100°C for 24-36 hours to obtain a slurry containing hierarchical Y molecular sieve, and the hierarchical Y molecular sieve and the slurry containing hierarchical Y molecular sieve microcrystals are obtained after separation of the solid and the liquid.

[0059] The adding amount of each substance satisfies the following molar ratio: (5.5-6.5)Na2O:Al2O3:(11.5-12.5)SiO2:(230-270)H2O.

[0060] (2) taking the hierarchical pore Y-type molecular sieve as part of the silicon source (4-6 wt% of the total amount of silicon source in solution), adding silica sol (SiO2 content 20-40 wt%), a template agent and deionized water to form solution C, adding phosphoric acid (H3PO4 content 78-82%) to deionized water, then adding modified pseudo-boehmite (Al2O3 content 60-75 wt%) accounting for 1.5-2 wt% of the total amount of pseudo-boehmite and 1.5-2 wt% of TiO2 to form solution D, slowly adding solution C to solution D, adjusting the pH value to 6.7-7.3, and crystallizing at 180-200 ℃ for 12-16 hours to obtain a slurry containing TiO2 / Y / SAPO-34 molecular sieve microcrystals.

[0061] The addition amount of each substance satisfies the following molar ratio: (1.2-1.3) Al2O3:(1.2-1.3) P2O5:(1.2-1.3) SiO2:(1.5-2.5) template agent:(65-75) H2O. Al2O3 is derived from pseudo-boehmite, P2O5 is derived from phosphoric acid, and SiO2 is derived from silica sol and Y-type molecular sieve.

[0062] (3) According to a mass ratio of 1:1, the slurry containing hierarchical pore Y-type molecular sieve microcrystals in step (1) is added to the slurry containing TiO2 / Y / SAPO-34 molecular sieve microcrystals in step (2) while stirring, and the pH value of the system is adjusted to 8.3-8.7 with hydrochloric acid. Finally, the above obtained solid mixture is filtered, washed, ammonium ion exchanged, dried at 100 ℃ for 1.5 hours, and calcined at 500 ℃ for 5 hours to obtain a mesoporous silicon phosphorus aluminum titanium composite oxide material containing Y / SAPO-34 molecular sieve microcrystals.

[0063] The application provides a preparation method of a hydrofining catalyst.

[0064] Step 1, the metal complex solution is sprayed after being pressurized, and the gas flow is sprayed in a direction perpendicular to the spraying direction of the metal complex solution to impact the metal complex solution, so that the metal complex solution forms a humid atmosphere;

[0065] Step 2, the mesoporous silicon phosphorus aluminum composite oxide prepared in the above step is contacted with the humid atmosphere in step 1 and adsorbed to obtain a Y / SAPO-34 molecular sieve loaded with metal;

[0066] Step 3, the mesoporous silicon phosphorus aluminum composite oxide loaded with metal is mixed with a binder to obtain a hydrofining catalyst.

[0067] The present application improves the metal dispersion on the catalyst, increases the number of effective active centers, reduces the catalyst plugging caused by local excess of metal, and the problems of specific surface area and pore volume loss, and improves the specific surface area and pore volume of the catalyst.

[0068] The metal complex solution refers to a solution formed by the reaction of a metal precursor and a complexing agent. In an embodiment, the metal precursor is at least one of a tungsten-containing compound, a molybdenum-containing compound, a cobalt-containing compound, and a nickel-containing compound, and further, for example, at least one of a tungsten salt, a molybdenum salt, a cobalt salt, and a nickel salt. The complexing agent is one of sodium tripolyphosphate and disodium nitrilotriacetate.

[0069] First, the metal complex solution needs to be subjected to pressurization treatment, for example, at a pressure of 1-2 MPa, and then the pressurized metal complex is sprayed, for example, into a container. At the same time, a gas is sprayed in a direction perpendicular to the spraying direction of the metal complex solution, so that the gas collides with the sprayed metal complex solution, and the metal complex solution is dispersed in the form of fine droplets in the container, forming a humid atmosphere of the metal complex solution in the container. In an embodiment, the spraying speed of the gas is 5-10 m 3 / min. The present application does not particularly limit the gas, which can be nitrogen or air.

[0070] At the same time, the mesoporous silicon-aluminum-phosphorus composite oxide powder and the alumina powder are fully mixed and rapidly stirred to contact and adsorb the humid atmosphere of the metal complex solution of step 1, so that the metal complex is uniformly dispersed on the Y / SAPO-34 molecular sieve and the alumina.

[0071] In an embodiment, the alumina of the present application is macroporous alumina. The mesoporous silicon-aluminum-phosphorus composite oxide of the present application is a composite oxide containing Y molecular sieve crystallites and SAPO-34 molecular sieve crystallites.

[0072] Step 3 is to mix the metal-loaded mesoporous silicon-aluminum-phosphorus composite oxide with an aluminum-containing organic acidic binder to obtain a hydrofining catalyst.

[0073] In an embodiment, the method for mixing the metal-loaded mesoporous silicon-aluminum-phosphorus composite oxide and the binder is as follows: the binder is pressurized and sprayed, and a gas stream is sprayed in a direction perpendicular to the spraying direction of the binder to collide with the binder, so that the binder forms a humid atmosphere; then, the metal-loaded mesoporous silicon-aluminum-phosphorus composite oxide is mixed and adsorbed with the binder forming the humid atmosphere to obtain a hydrogenation catalyst.

[0074] The pressure of the binder after being pressed can be 1-2 MPa, the gas is sprayed along the vertical direction of the binder spraying direction, the binder is impacted, and then the binder is dispersed in the container in the form of micro-droplets, and then the mesoporous silicon phosphorus aluminum composite oxide loaded with metal is mixed and adsorbed with the binder dispersed in the form of micro-droplets, and the tooth ball-shaped catalyst is obtained after shaping. The binder is dispersed in a humid atmosphere, and the metal dispersibility can be further improved.

[0075] In an embodiment, the spraying speed of the gas is 5-10 m 3 / min. The gas is not particularly limited in the present application, and can be nitrogen, air, etc.

[0076] In an embodiment, the amount of the mesoporous silicon phosphorus aluminum composite oxide is 20-55 wt%, the amount of the alumina is 20-55 wt%, the amount of the binder is 15-25 wt%, and the amount of the metal complex solution is 15-25 wt% based on the total mass of the mesoporous silicon phosphorus aluminum composite oxide, the alumina and the binder.

[0077] In a specific embodiment, the preparation method of the hydrofining catalyst is as follows:

[0078] First, 15-25 wt% of the metal complex solution is sprayed out after being pressed to 1-2 MPa, and then high-speed gas is sprayed out along the direction perpendicular to the spraying direction at a flow rate of 5-10 m 3 / min to form a humid atmosphere of the high-dispersed metal solution in the container, and then the mesoporous silicon phosphorus aluminum titanium composite oxide containing 20-50 wt% of Y / SAPO-34 molecular sieve crystallites and the macroporous alumina material are uniformly adsorbed, and the Y / SAPO-34 molecular sieve crystallite mesoporous silicon phosphorus aluminum titanium composite oxide material loaded with metal is obtained after drying at 80-100 for 1-2 hours. Secondly, 15-25 wt% of the binder mixture is sprayed out after being pressed to 1-2 MPa, and then high-speed gas is sprayed out along the direction perpendicular to the spraying direction at a flow rate of 5-10 m 3 / min to form a binder humid atmosphere in the container, and then the Y / SAPO-34 molecular sieve crystallite mesoporous silicon phosphorus aluminum titanium composite oxide material loaded with metal is uniformly adsorbed, and the tooth ball-shaped catalyst is obtained after shaping.

[0079] The hydrofining catalyst obtained by the method of the present application is tooth ball-shaped, and has a specific surface area of 285-350 m 2 / g and a pore volume of 0.60-1.0 mL / g.

[0080] The present application can improve the surface acidity of the catalyst carrier, solve the problem of weak acidity of the conventional alumina material as the carrier of the hydrofining catalyst, and improve the hydrogen denitrification performance of the catalyst, and the catalytic reactivity is improved and the reaction temperature is significantly reduced compared with the conventional preparation method.

[0081] The technical solutions of the present application will be further described in detail through specific examples.

[0082] Comparative Example 1

[0083] 65g of silica sol was added to 12g of deionized water to form solution A, 29g of phosphoric acid (H3PO4 content 85%) was added to 51g of deionized water, and then 16g of pseudoboehmite (containing 2wt% titanium dioxide) was added to form solution B, solution A was slowly added to solution B, and the pH value was adjusted to 8.5-9.5 to obtain a titanium-modified amorphous silica-aluminum material.

[0084] Example 1

[0085] (1) Synthesis of hierarchical pore Y-type molecular sieve: 87g of sodium aluminate solution A (Al2O3 content 4wt%, Na2O content 20wt%) and 120g of water glass solution (SiO2 content 20wt%) were sequentially added to 35g of deionized water, and the mixture was aged at 30℃ for 24h to prepare a directing agent. 15g of the directing agent, 80g of aluminum sulfate solution (Al2O3 content 2wt%), 80g of sodium aluminate solution B (Al2O3 content 5wt%, Na2O content 5wt%), and 10g of pore-expanding agent PEG2000 were added to 90g of water glass solution (SiO2 content 20wt%), and 5g of deionized water was added after stirring to prepare a reaction mixture for synthesizing NaY molecular sieve. The mixture was crystallized at 95-100℃ for 17h to obtain a slurry containing hierarchical pore Y-type molecular sieve, and the solid and liquid were separated to obtain hierarchical pore Y molecular sieve and slurry containing hierarchical pore Y molecular sieve crystals.

[0086] (2) Take 2 g of the hierarchical Y zeolite obtained in step (1) as part of the silicon source, add 65 g of silica sol, 17 g of morpholine and 12 g of deionized water to form solution C, add 29 g of phosphoric acid (H3PO4 content 85%) to 51 g of deionized water, and then add 16 g of pseudoboehmite (containing 2 wt% of titanium dioxide) to form solution D. Slowly add solution C to solution D, adjust the pH value to 6.5-7.5, and crystallize at 200°C for 12 hours to obtain a slurry containing TiO2 / Y / SAPO-34 zeolite microcrystals.

[0087] (3) According to a mass ratio of 1:1, add the slurry containing hierarchical Y zeolite microcrystals obtained in step (1) to the slurry containing TiO2 / Y / SAPO-34 zeolite microcrystals obtained in step (2), add while stirring, and adjust the pH value of the system to 8-9 with hydrochloric acid. Finally, filter, wash, ammonium ion exchange, dry at 110°C for 1 hour, and calcine at 500°C for 5 hours on the above obtained solid mixture to obtain a mesoporous silicon phosphorus aluminum titanium composite oxide containing Y / SAPO-34 zeolite microcrystals.

[0088] Example 2

[0089] (1) Synthesis of hierarchical Y zeolite: add 77 g of sodium aluminate solution A (Al2O3 content 5.5 wt%, Na2O content 24 wt%) and 100 g of water glass solution (SiO2 content 25 wt%) to 65 g of deionized water in sequence, and age at 30°C for 24 h to prepare a directing agent. Add 10 g of the directing agent, 65 g of aluminum sulfate solution (Al2O3 content 3 wt%), 65 g of sodium aluminate solution B (Al2O3 content 8 wt%, Na2O content 9 wt%), and 5 g of pore-expanding agent hydroxypropyl methyl cellulose to 75 g of water glass solution (SiO2 content 25 wt%), stir uniformly, and then add 50 g of deionized water to prepare a reaction mixture for synthesizing NaY zeolite. Crystallize at 95-100°C for 24 h to obtain a slurry containing hierarchical Y zeolite. After separation of the solid and liquid, hierarchical Y zeolite and a slurry containing hierarchical Y zeolite microcrystals are obtained.

[0090] (2) Take 2 g of the hierarchical Y zeolite obtained in step (1) as part of the silicon source, add 65 g of silica sol, 17 g of morpholine and 12 g of deionized water to form solution C, add 29 g of phosphoric acid (H3PO4 content 85%) to 51 g of deionized water, and then add 16 g of pseudoboehmite (containing 2 wt% of titanium dioxide) to form solution D. Slowly add solution C to solution D, adjust the pH value to 6.5-7.5, and crystallize at 200°C for 12 hours to obtain a slurry containing TiO2 / Y / SAPO-34 zeolite microcrystals.

[0091] (3) According to the mass ratio of 1:1, the slurry containing the microcrystalline of the Y / SAPO-34 molecular sieve in step (1) is added into the slurry containing the microcrystalline of the TiO2 / Y / SAPO-34 molecular sieve in step (2) while stirring, and the pH value of the system is adjusted to 8-9 by using hydrochloric acid. Finally, the solid mixture obtained above is filtered, washed, exchanged by ammonium ion, dried at 100°C for 2 hours, and calcined at 400°C for 6 hours to obtain the mesoporous silicon phosphorus aluminum titanium composite oxide containing the microcrystalline of the Y / SAPO-34 molecular sieve.

[0092] Example 3

[0093] (1) Synthesis of the hierarchical Y molecular sieve: 65 g of sodium metaaluminate solution A (Al2O3 content of 7 wt%, Na2O content of 30 wt%) and 82 g of water glass solution (SiO2 content of 30 wt%) are sequentially added into 100 g of deionized water, and the mixture is aged at 35°C for 10 hours to prepare a directing agent. 5 g of the directing agent, 70 g of aluminum sulfate solution (Al2O3 content of 2 wt%), 40 g of sodium metaaluminate solution B (Al2O3 content of 10 wt%, Na2O content of 15 wt%), and 2 g of a pore-expanding agent hydroxypropyl methyl cellulose are added into 63 g of water glass solution (SiO2 content of 30 wt%), and 82 g of deionized water is added after the mixture is uniformly stirred to prepare a reaction mixture for synthesizing NaY molecular sieve. The reaction mixture is crystallized at 95°C for 48 hours to obtain a slurry containing the hierarchical Y molecular sieve. The solid and liquid are separated to obtain the hierarchical Y molecular sieve and the slurry containing the microcrystalline of the hierarchical Y molecular sieve.

[0094] (2) 10 g of the hierarchical Y molecular sieve is used as a part of the silicon source, 40 g of silica sol, 12 g of triethylamine, and 20 g of deionized water are mixed to form solution C, 20 g of phosphoric acid (H3PO4 content of 85%) is added into 38 g of deionized water, and 10 g of pseudoboehmite (3 wt% of titanium dioxide) is added to form solution D. Solution C is slowly added into solution D, and the pH value is adjusted to 6.5-7.5. The mixture is crystallized at 200°C for 12 hours to obtain the slurry containing the microcrystalline of the TiO2 / Y / SAPO-34 molecular sieve.

[0095] (3) According to the mass ratio of 1:1, the slurry containing the microcrystalline of the Y / SAPO-34 molecular sieve in step (1) is added into the slurry containing the microcrystalline of the TiO2 / Y / SAPO-34 molecular sieve in step (2) while stirring, and the pH value of the system is adjusted to 8-9 by using hydrochloric acid. Finally, the solid mixture obtained above is filtered, washed, exchanged by ammonium ion, dried at 100°C for 2 hours, and calcined at 600°C for 4 hours to obtain the mesoporous silicon phosphorus aluminum titanium composite oxide containing the microcrystalline of the Y / SAPO-34 molecular sieve.

[0096] Table 1 Properties of the mesoporous silicon phosphorus aluminum composite oxide containing the microcrystalline of the Y / SAPO-34 molecular sieve

[0097]

[0098] Table 2 Mesoporous silica-alumina-phosphorus composite oxide acidity of Y / SAPO-34 molecular sieve crystallites

[0099]

[0100] Example 4

[0101] A support was prepared by thoroughly mixing 15 wt% of the above-mentioned aluminum-containing organic acid binder with 50 wt% of the mesoporous silica-alumina-phosphorus-titanium composite oxide containing Y / SAPO-34 molecular sieve crystallites and 35 wt% of the macroporous alumina material in the three above-mentioned examples, and extruding the mixture into a strip. A solution containing 15 wt% of molybdenum oxide, 5 wt% of tungsten oxide and 5 wt% of nickel oxide was prepared by dissolving molybdenum oxide, ammonium metavanadate and nickel nitrate in water. The support obtained by extruding the mixture into a strip was impregnated by adsorbing the solution. Three kinds of hydrofining catalysts were obtained. The raw material for catalyst evaluation is shown in Table 3, and the evaluation results are shown in Table 4.

[0102] Table 3 Raw material for evaluation

[0103]

[0104] Table 4 Results of catalyst comparison evaluation

[0105] Catalyst Comparative Example 1 Example 1 Example 2 Example 3 Reaction temperature, °C 372 372 372 372 Refined oil nitrogen content, ppm 50 14.8 12 9

[0106] Process conditions: reaction pressure 15 MPa, hydrogen to oil volume ratio 800, volume space velocity 1.2 h -1 .

[0107] Of course, the present application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications to the present application according to the present application without departing from the spirit and essence of the present application. However, these corresponding changes and modifications should all belong to the protection scope of the claims of the present application.

Claims

1. A method for preparing a mesoporous silica-alumina composite oxide, characterized in that, Includes the following steps: Step a: Prepare hierarchical porous Y molecular sieve using crystallization method, and separate the crystallization product into solid and liquid to obtain hierarchical porous Y molecular sieve and slurry containing hierarchical porous Y molecular sieve microcrystals; Step b: Mix silicon source, template agent and water to form solution A; mix titanium-modified aluminum source, inorganic acid and water to form solution B; mix solution A and solution B and crystallize to obtain a slurry containing SAPO-34 molecular sieve microcrystals; the silicon source includes the hierarchical porous Y molecular sieve obtained in step a; Step c: Mix the slurry containing hierarchical porous Y molecular sieve microcrystals from step a with the slurry containing SAPO-34 molecular sieve microcrystals from step b, and perform solid-liquid separation to obtain Y / SAPO-34 molecular sieve.

2. The method for preparing mesoporous silica-alumina composite oxide according to claim 1, characterized in that, The preparation method of the Y / SAPO-34 molecular sieve further includes: Step d involves ion exchange between the Y / SAPO-34 molecular sieve and an ammonium salt solution.

3. The method for preparing mesoporous silica-alumina composite oxide according to claim 1, characterized in that, Step a is as follows: Mix silicon source, aluminum source, directing agent, pore-expanding agent and water, crystallize, and separate the crystallization product into solid and liquid to obtain multi-level porous Y molecular sieve and slurry containing multi-level porous Y molecular sieve microcrystals.

4. The method for preparing mesoporous silica-alumina composite oxide according to claim 3, characterized in that, The pore-expanding agent is at least one of hydroxypropyl methylcellulose, PEG1000, and AES.

5. The method for preparing mesoporous silica-alumina composite oxide according to claim 3, characterized in that, The directing agent is prepared by mixing an aluminum source, a silicon source, and water, and aging the mixture to obtain the directing agent.

6. The method for preparing mesoporous silica-alumina composite oxide according to claim 1, characterized in that, The template agent includes at least one of triethylamine and morphine.

7. The method for preparing mesoporous silica-alumina composite oxide according to claim 3, characterized in that, The amounts of each substance used in step a satisfy the molar ratio: (5.5~6.5) Na2O : Al2O3 : (11.5~12.5) SiO2 : (230~270) H2O.

8. The method for preparing mesoporous silica-alumina composite oxide according to claim 1, characterized in that, The amounts of each substance in step b satisfy the molar ratio: (1.2~1.3)Al2O3:(1.2~1.3)P2O5:(1.2~1.3)SiO2:(1.5~2.5)template agent:(65~75)H2O.

9. The mesoporous silica-alumina composite oxide obtained by the preparation method according to any one of claims 1-8.

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