USY molecular sieve and preparation and application thereof

Abstract

The invention discloses a USY molecular sieve as well as preparation and application thereof. The USY molecular sieve has the following properties: the pore volume of mesopores accounts for 30-60% of the total pore volume of the molecular sieve; the total acid amount at 200 DEG C is 400-480 [mu] mol / g, and the total acid amount at 350 DEG C is 120-150 [mu] mol / g. When the molecular sieve is used for a hydrocracking catalyst, the activity and selectivity of the catalyst are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of Y molecular sieve preparation, and specifically relates to a USY molecular sieve and a preparation method and application thereof. Background Art

[0002] Hydrocracking catalysts are bifunctional catalysts, and Y molecular sieves are widely used as the main cracking component in hydrocracking catalysts. However, the pore size of Y molecular sieves is limited, and the reaction performance is limited by the pore structure during the reaction. Therefore, it is necessary to synthesize a stable Y molecular sieve with a multi-level pore structure to remove the diffusion limitation of macromolecular reactants.

[0003] At present, there are many methods for modifying Y molecular sieves, but they are basically conventional post-treatment modifications. This method has limited effect on the properties of Y molecular sieves, and it is difficult for other atoms to enter the Y molecular sieve framework. CN101723399A discloses a method for preparing a framework silicon-rich Y molecular sieve, which first uses alkali solution to desiliconize the NaY molecular sieve, and then performs ammonium exchange and dealumination and silicon supplementation on the molecular sieve after alkali treatment. The mesopores of the obtained Y molecular sieve are increased, but the increase is not large. US5601798 discloses a method for preparing a Y molecular sieve containing mesopores, which uses HY or USY as raw materials, mixes it with NH4NO3 solution or a mixed solution of NH4NO3 and HNO3 in an autoclave, and treats it at a temperature of 115 to 250°C for 2 to 20 hours to obtain a Y molecular sieve containing mesopores. However, NH4NO3 solution or a mixed solution of NH4NO3 and HNO3 is an acidic solution. At high temperatures of 115 to 250°C, the solution generates its own pressure, and the dealumination depth of the acid treatment increases significantly, resulting in a significant decrease in crystallinity and micropore volume.

[0004] In summary, how to construct heteroatom-modified Y molecular sieves during the synthesis of Y molecular sieves, and then regulate the relevant properties of the molecular sieves, simplify the modification steps of Y molecular sieves, and then prepare hydrocracking catalysts with better performance is an urgent problem to be solved. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a USY molecular sieve and a preparation method and application thereof. When the molecular sieve of the present invention is used as a hydrocracking catalyst, the catalyst activity and selectivity are significantly improved.

[0006] The first aspect of the present invention provides a USY molecular sieve, wherein the properties of the USY molecular sieve are as follows: the mesopore volume accounts for 30% to 60% of the total pore volume of the molecular sieve, preferably 38% to 55%; the total acid content at 200°C is 400 to 480 μmol / g, and the total acid content at 350°C is 120 to 150 μmol / g.

[0007] Furthermore, in the USY molecular sieve, the ratio of the amount of B acid to the amount of L acid at 200° C. is 1.20-1.40, and the ratio of the amount of B acid to the amount of L acid at 350° C. is 1.10-1.25.

[0008] Furthermore, in the USY molecular sieve, the most probable pore diameter is 23 to 30 nm.

[0009] Furthermore, the properties of the USY molecular sieve are as follows: the specific surface area is 500-600m 2 / g, and the pore volume is 0.350~0.410mL / g.

[0010] Furthermore, in the USY molecular sieve, the average crystallite size is 0.4 to 1.4 μm, preferably 450 to 650 nm.

[0011] Furthermore, the unit cell constant of the USY molecular sieve is

[0012] Furthermore, in the USY molecular sieve, the SiO2 / Al2O3 molar ratio is 14.0 to 25.0.

[0013] The second aspect of the present invention provides a method for preparing USY molecular sieve, comprising the following steps:

[0014] (1) preparing a Y molecular sieve guide containing B and Mg;

[0015] (2) mixing a second aluminum source, a second magnesium source, a second silicon source, a second B source, a second alkali source, and water with the guide body of step (1) to obtain a gel;

[0016] (3) crystallizing the gel of step (2);

[0017] (4) The crystallized product obtained in step (3) is subjected to ammonium exchange and hydrothermal treatment to obtain a heteroatom-modified Y molecular sieve, namely, USY molecular sieve.

[0018] Furthermore, in step (1), the preparation method of the Y molecular sieve guide containing B and Mg comprises: mixing a first aluminum source, a first magnesium source, a first alkali source, a first B source, a first silicon source and water, and standing to obtain a Y molecular sieve guide containing B and Mg. The first B source is selected from at least one of sodium metaborate, boric acid, ammonium fluoroborate and borax. The first aluminum source is selected from at least one of sodium metaaluminate and aluminum sulfate, the first magnesium source is selected from at least one of magnesium nitrate, magnesium chloride and magnesium sulfate, the first alkali source is selected from at least one of NaOH and KOH, and the first silicon source is selected from at least one of silica sol and water glass.

[0019] Furthermore, in step (1), in the method for preparing a Y molecular sieve guide containing B and Mg, the first aluminum source is calculated as Al2O3, the first magnesium source is calculated as MgO, the first alkali source is calculated as NaOH, the first B source is calculated as B2O3, and the first silicon source is calculated as SiO2, and the molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O is 1:0.1~5.0:11~42:0.07~20.0:5~25:180~450, preferably 1:0.1~3.0:15~35:0.07~12.0:5~18:180~400.

[0020] Furthermore, in step (1), in the method for preparing the Y molecular sieve guide containing B and Mg, the standing temperature is 10 to 50° C. and the standing time is 15 to 35 hours.

[0021] Furthermore, in step (1), in the method for preparing a Y molecular sieve guide containing B and Mg, preferably, after the first aluminum source, the first boron source and the first alkali source are mixed and dissolved with water, the first magnesium source and the first silicon source are added in sequence, the mixture is mixed evenly, and the mixture is allowed to stand to obtain a Y molecular sieve guide containing B.

[0022] Furthermore, in step (2), the matrix mixed solution is a second aluminum source, a second magnesium source, a second silicon source, a second B source, a second alkali source and water.

[0023] Furthermore, in step (2), the second B source is selected from at least one of sodium metaborate, boric acid, ammonium fluoroborate, and borax. The second aluminum source is selected from at least one of sodium metaaluminate and aluminum sulfate. The second magnesium source is selected from at least one of magnesium nitrate, magnesium chloride, and magnesium sulfate. The second alkali source is selected from at least one of NaOH and KOH. The second silicon source is selected from at least one of silica sol and water glass.

[0024] Furthermore, in step (2), in the matrix mixed solution, the second aluminum source is calculated as Al2O3, the second magnesium source is calculated as MgO, the second alkali source is calculated as NaOH, the second B source is calculated as B2O3, and the second silicon source is calculated as SiO2, and the molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O is 1:0.1~4.5:1.5~15.0:0.07~15.0:1.5~12.0:80~400, preferably 1:0.1~2.5:1.5~10.0:0.07~8.0:1.5~8.0:80~350.

[0025] Furthermore, in step (2), the amount of the Y molecular sieve guide containing B and Mg added is 10.0% to 45.0% of the total mass of the matrix mixed solution.

[0026] Furthermore, in step (2), the second B source is introduced into the reaction system in the form of a second B source feed, and the second B source feed is preferably prepared in at least one of the following ways:

[0027] a. at least part of the second B source and at least part of the second silicon source are used to form a second B source feed,

[0028] b. at least part of the second B source and at least part of the second aluminum source are used to form a second B source feed,

[0029] c. At least part of the second B source, at least part of the second aluminum source and at least part of the second silicon source are used to form a second B source feed.

[0030] Furthermore, in step (2), the mass content of B (calculated as oxide) in the second B source feed is 2.0% to 18.0%, preferably 10.0% to 18.0%.

[0031] Further, in step (2), preferably, the second B source feed is subjected to ultrasonic treatment and then to a standing process (preferably, the standing time is 1 to 48 hours, preferably 12 to 24 hours), and then introduced into the reaction system. Preferably, the ultrasonic treatment conditions are as follows: temperature 20 to 80° C., preferably 20 to 60° C., ultrasonic frequency 20 to 45 kHz, time 1 to 8 hours, preferably 1 to 4 hours.

[0032] Furthermore, in step (2), the matrix mixture (second aluminum source, second magnesium source, second silicon source, second B source, second alkali source and water) is mixed with the guide body of step (1) to obtain a gel. Specifically, the second alkali source and the second silicon source are mixed with water and then the guide body, second B source, second aluminum source and second magnesium source obtained in step (1) are added in sequence and mixed to obtain a gel.

[0033] Furthermore, in step (2), the matrix mixture (second aluminum source, second silicon source, second B source, second alkali source and water) is mixed with the guide body of step (1) to obtain a gel. Preferably, the second B source is introduced into the reaction system in the form of a second B source feed. Specifically, the second alkali source and the remaining second silicon source are mixed with water, and then the guide body, the second B source feed, the remaining second aluminum source and the second magnesium source obtained in step (1) are added in sequence and mixed to obtain a gel, wherein the remaining second silicon source or the remaining second aluminum source refers to the remaining second silicon source or the second aluminum source other than the second silicon source or the second aluminum source used in preparing the second B source feed.

[0034] Furthermore, in step (3), the crystallization adopts three-stage temperature rising crystallization, the primary crystallization temperature is 30-40° C., the secondary crystallization temperature is 30-35° C. higher than the primary temperature, the tertiary crystallization temperature is 25-50° C. higher than the secondary temperature, and the highest temperature does not exceed 110° C. The crystallization time of each stage is 12-36 hours, preferably 15-24 hours.

[0035] Furthermore, in the crystallized product obtained in step (3), namely the B-Mg-NaY molecular sieve, the content of Mg in terms of MgO is 1.0% to 1.5% based on the B-Mg-NaY molecular sieve.

[0036] Furthermore, in step (4), the ammonium exchange is a conventional ammonium exchange. The ammonium salt used may be one or more of ammonium chloride, ammonium nitrate, and ammonium sulfate, wherein the concentration of the ammonium salt solution is 0.1 to 3.0 mol / L, and the pH value is 1.0 to 7.0, preferably 2.0 to 7.0. The ammonium exchange temperature is 30 to 90° C., preferably 40 to 60° C., and the number of ammonium exchanges is 1 to 5 times. The solid-liquid volume ratio of each ammonium exchange is 1:10 to 1:20, and the treatment time of each ammonium exchange is 3 to 6 hours.

[0037] Furthermore, in step (4), the hydrothermal treatment is performed 1 to 3 times, preferably 2 times, and the conditions for each hydrothermal treatment are as follows: the temperature is 500 to 650° C., the treatment time is 1 to 6 hours under the condition of 100% steam treatment. The steam treatment can be a closed steam treatment or a flowing steam treatment, preferably a flowing steam treatment.

[0038] Furthermore, in the USY molecular sieve, the mesopore volume accounts for 30% to 60% of the total pore volume of the molecular sieve, preferably 38% to 55%.

[0039] Furthermore, in the USY molecular sieve, the total acid content at 200°C is 400-480 μmol / g, and the total acid content at 350°C is 120-150 μmol / g.

[0040] Furthermore, in the USY molecular sieve, the ratio of the amount of B acid to the amount of L acid at 200° C. is 1.20-1.40, and the ratio of the amount of B acid to the amount of L acid at 350° C. is 1.10-1.25.

[0041] Furthermore, in the USY molecular sieve, the most probable pore diameter is 23 to 30 nm.

[0042] Furthermore, the properties of the USY molecular sieve are as follows: the specific surface area is 500-600m 2 / g, and the pore volume is 0.350~0.410mL / g.

[0043] Furthermore, in the USY molecular sieve, the average crystallite size is 0.4 to 1.4 μm, preferably 450 to 650 nm.

[0044] Furthermore, the unit cell constant of the USY molecular sieve is

[0045] Furthermore, in the USY molecular sieve, the SiO2 / Al2O3 molar ratio is 14.0 to 25.0.

[0046] The third aspect of the present invention provides the use of the above-mentioned USY molecular sieve in a hydrocracking catalyst.

[0047] Furthermore, the application is to use USY molecular sieve in the manufacture of flexible hydrocracking catalyst.

[0048] Furthermore, the hydrocracking catalyst comprises USY molecular sieve and hydrogenation active metal components. The hydrogenation active metal is preferably a metal of Group VIB and Group VIII, and more preferably molybdenum, tungsten and nickel. Based on the weight of the catalyst, the content of USY molecular sieve is 15.0%-40.0%, the content of molybdenum in terms of oxide is 8.0%-20.0%, the content of tungsten in terms of oxide is 2.0%-10.0%, and the content of nickel in terms of oxide is 2.0%-8.0%.

[0049] Furthermore, the hydrocracking catalyst also includes aluminum oxide, and the content of aluminum oxide is 40%-75% based on the weight of the catalyst.

[0050] Furthermore, the hydrocracking catalyst is particularly suitable for catalytic cracking of polycyclic macromolecules, the raw material can be vacuum wax oil, the initial distillation point is 350-365°C, the final distillation point is 515-535°C, and the main target products are heavy naphtha and jet fuel.

[0051] Furthermore, the hydrogenation catalyst may be presulfurized according to conventional methods in the art before use. The presulfurization method may be: presulfurizing the hydrogenation catalyst with sulfur, hydrogen sulfide or a sulfur-containing raw material in the presence of hydrogen at 160-315°C.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] Conventional Y molecular sieve framework is relatively stable, even if the number of mesopores formed by hydrothermal treatment is still very limited. Single heteroatom modified Y molecular sieve is matched with the hydrothermal treatment process, although the pore structure of Y molecular sieve is improved to a certain extent, but it will also cause the loss of acidic centers of Y molecular sieve during hydrothermal treatment. The present invention adopts a method of introducing double heteroatoms in stages, and heteroatom B is introduced in the form of auxiliary solvent, while Mg is directly introduced into the preparation process of molecular sieve at an appropriate time, which can reduce the competition between the two introduced atoms to the greatest extent, so that heteroatom B and Mg atoms cooperate with each other to modify Y molecular sieve, and finally the number of mesopores of ultra-stable Y molecular sieve is significantly increased, and the acid amount of molecular sieve can also be significantly improved.

[0054] The present invention introduces two heteroatoms (B and Mg) into the Y molecular sieve synthesis process in stages, which can promote the instability of the framework, combine with the hydrothermal treatment process, increase the number of mesopores of the ultra-stable Y molecular sieve, and also make up for the loss of acidic centers during the dealumination of the molecular sieve. When the Y molecular sieve is used for hydrocracking, the molecular sieve has better adsorption, diffusivity, and shape selectivity, and has better reaction performance.

[0055] The method of the present invention can obtain a USY molecular sieve with a high silicon-to-aluminum ratio, a large specific surface area, a large pore volume, and a specific acid ratio. The flexible hydrocracking catalyst prepared therefrom has significantly improved activity and selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is the XRD pattern of the B-Mg-USY molecular sieve obtained in Example 1. DETAILED DESCRIPTION

[0057] The technical solutions and effects of the present invention are further described below in conjunction with embodiments, but are not limited to the following embodiments.

[0058] In the present invention, the B acid amount, L acid amount and total acid amount are measured and calculated by pyridine adsorption infrared spectroscopy, and the unit is μmol / g, wherein the total acid amount is the sum of the B acid amount and the L acid amount, the total acid amount at 200°C is the sum of the B acid amount and the L acid amount at 200°C, and the total acid amount at 350°C is the sum of the B acid amount and the L acid amount at 350°C.

[0059] In the present invention, a physical adsorption instrument is used to measure the pore volume, pore distribution, most probable pore size and specific surface area of ​​the molecular sieve by nitrogen low temperature adsorption and desorption method, wherein the pore volume and pore size distribution are obtained by the BJH method, and the specific surface area is obtained by the BET method.

[0060] In the present invention, an X-ray diffractometer (XRD) is used to determine the phase and unit cell constant of the molecular sieve, and the Breck-Flanigen formula is used to calculate the silicon-aluminum ratio of the molecular sieve. The experimental conditions are: CuKα radiation, tube voltage 40kv, tube current 40mA.

[0061] In the present invention, a scanning electron microscope is used to statistically analyze the particle size distribution of the molecular sieve.

[0062] In the present invention, the distillation range of heavy naphtha is 65-177°C, and the distillation range of aviation kerosene is 177-260°C.

[0063] In the present invention, the yield of heavy naphtha refers to the mass ratio of heavy naphtha to fresh hydrocracking feedstock (vacuum gas oil) in the hydrocracking product, and the yield of jet fuel refers to the mass ratio of jet fuel to fresh hydrocracking feedstock in the hydrocracking product.

[0064] Example 1

[0065] (1) Preparation of a Y molecular sieve guide containing B and Mg: The first B source is sodium metaborate, the first aluminum source is sodium metaaluminate, the first alkali source is NaOH, the first magnesium source is magnesium chloride, and the first silicon source is silica sol. After the first aluminum source and the first alkali source are mixed and dissolved in water, the first B source, the first magnesium source, and the first silicon source are added in sequence, mixed evenly, and allowed to stand to obtain a Y molecular sieve guide containing B and Mg. Among them, the first aluminum source is calculated as Al2O3, the first alkali source is calculated as NaOH, the first B source is calculated as B2O3, the first magnesium source is calculated as MgO, and the first silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.35:30:0.50:15:300. The standing temperature is 25°C and the standing time is 22 hours.

[0066] (2) Prepare a matrix mixed solution; in the matrix mixed solution, the second B source is sodium metaborate, the second aluminum source is sodium metaaluminate and aluminum sulfate (the molar ratio of sodium metaaluminate and aluminum sulfate is 1:0.52), the second magnesium source is selected from magnesium chloride, the second alkali source is selected from NaOH, and the second silicon source is water glass. In the matrix solution, the second aluminum source is calculated as Al2O3, the second alkali source is calculated as NaOH, the second magnesium source is calculated as MgO, the second B source is calculated as B2O3, and the second silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.30:5.2:0.45:5.6:120. The amount of the Y molecular sieve guide containing B and Mg added in step (1) is 15.0% of the total mass of the matrix mixed solution. The second B source is dissolved in the second aluminum source sodium metaaluminate aqueous solution, wherein the mass content of B (calculated as oxide) is 12.0%, and after ultrasonic (30kHz) treatment for 4 hours and a standing process, the standing time is 18 hours, to obtain the second B source feed. The second alkali source and the second silicon source are mixed with the remaining water, and then the guide obtained in step (1), the second B source feed, the second aluminum source aluminum sulfate, and the second magnesium source are added in sequence, and mixed evenly to obtain a gel.

[0067] (3) The gel obtained in step (2) is crystallized; the crystallization adopts three-stage temperature rising crystallization, the first stage crystallization temperature is 30° C., the second stage crystallization temperature is 65° C., and the third stage crystallization temperature is 100° C. The crystallization time of each stage is 18 hours.

[0068] (4) The crystallized product obtained in step (3) (i.e., B-Mg-NaY molecular sieve) is subjected to ammonium exchange and hydrothermal treatment to obtain USY molecular sieve. The ammonium exchange is a conventional ammonium exchange. The ammonium salt used is ammonium nitrate, wherein the concentration of the ammonium salt solution is 0.1 mol / L and the pH value is 6.8. The ammonium exchange temperature is 60°C and the number of ammonium exchanges is 2 times. The solid-liquid volume ratio of each ammonium exchange is 1:10, and the treatment time of each ammonium exchange is 6 hours. The hydrothermal treatment is performed twice, and the conditions of each hydrothermal treatment are as follows: the temperature is 620°C, under 100% water vapor treatment conditions, the treatment time is 6 hours. The water vapor treatment process is a flowing water vapor treatment.

[0069] In the B-Mg-NaY molecular sieve obtained in Example 1, the content of Mg in terms of MgO is 1.17%.

[0070] Example 2

[0071] (1) Preparation of a Y molecular sieve guide containing B and Mg: The first B source is sodium metaborate, the first aluminum source is sodium metaaluminate, the first alkali source is NaOH, the first magnesium source is magnesium chloride, and the first silicon source is silica sol. After the first aluminum source and the first alkali source are mixed and dissolved in water, the first B source, the first magnesium source, and the first silicon source are added in sequence, mixed evenly, and allowed to stand to obtain a Y molecular sieve guide containing B and Mg. Among them, the first aluminum source is calculated as Al2O3, the first alkali source is calculated as NaOH, the first B source is calculated as B2O3, the first magnesium source is calculated as MgO, and the first silicon source is calculated as SiO2. The molar ratio of the Y molecular sieve guide Al2O3:MgO:NaOH:B2O3:SiO2:H2O is 1:0.35:35:0.4:18:350. The standing temperature is 45°C and the standing time is 28 hours.

[0072] (2) Prepare a matrix mixed solution; in the matrix mixed solution, the second B source is ammonium fluoroborate, the second aluminum source is sodium aluminate and aluminum sulfate (the molar ratio of sodium aluminate and aluminum sulfate is 1:0.52), the second magnesium source is selected from magnesium chloride, the second alkali source is selected from NaOH, and the second silicon source is water glass. In the matrix solution, the second aluminum source is calculated as Al2O3, the second alkali source is calculated as NaOH, the second magnesium source is calculated as MgO, the second B source is calculated as B2O3, and the second silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.3:4.8:0.4:6.2:180. The amount of the Y molecular sieve guide containing B and Mg added in step (1) is 15.0% of the total mass of the matrix mixed solution. The second B source is dissolved in the second aluminum source sodium metaaluminate aqueous solution, wherein the mass content of B (calculated as oxide) is 14.0%, and after ultrasonic (35kHz) treatment for 4 hours and a standing process, the standing time is 18 hours, to obtain the second B source feed. The second alkali source and the second silicon source are mixed with the remaining water, and then the guide obtained in step (1), the second B source feed, the second aluminum source aluminum sulfate, and the second magnesium source are added in sequence, and mixed evenly to obtain a gel.

[0073] (3) The gel obtained in step (2) is crystallized; the crystallization adopts three-stage temperature rising crystallization, the first stage crystallization temperature is 30° C., the second stage crystallization temperature is 65° C., and the third stage crystallization temperature is 100° C. The crystallization time of each stage is 18 hours.

[0074] (4) The crystallized product obtained in step (3) is subjected to ammonium exchange and hydrothermal treatment to obtain USY molecular sieve. The ammonium exchange is a conventional ammonium exchange. The ammonium salt used is ammonium nitrate, wherein the concentration of the ammonium salt solution is 0.1 mol / L and the pH value is 6.8. The ammonium exchange temperature is 60°C and the number of ammonium exchanges is 2 times. The solid-liquid volume ratio of each ammonium exchange is 1:10, and the treatment time of each ammonium exchange is 6 hours. The hydrothermal treatment is performed twice, and the conditions of each hydrothermal treatment are as follows: the temperature is 620°C, under 100% water vapor treatment conditions, the treatment time is 6 hours. The water vapor treatment process is a flowing water vapor treatment.

[0075] In the B-Mg-NaY molecular sieve obtained in Example 2, the content of Mg in terms of MgO is 1.31%.

[0076] Example 3

[0077] (1) Preparation of a Y molecular sieve guide containing B and Mg: The first B source is sodium metaborate, the first aluminum source is sodium metaaluminate, the first alkali source is NaOH, the first magnesium source is magnesium chloride, and the first silicon source is silica sol. After the first aluminum source and the first alkali source are mixed and dissolved in water, the first B source, the first magnesium source, and the first silicon source are added in sequence, mixed evenly, and allowed to stand to obtain a Y molecular sieve guide containing B and Mg. Among them, the first aluminum source is calculated as Al2O3, the first alkali source is calculated as NaOH, the first B source is calculated as B2O3, the first magnesium source is calculated as MgO, and the first silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.35:30:0.5:15:300. The standing temperature is 25°C and the standing time is 22 hours.

[0078] (2) Prepare a matrix mixed solution; in the matrix mixed solution, the second B source is sodium metaborate, the second aluminum source is sodium metaaluminate and aluminum sulfate (the molar ratio of sodium metaaluminate and aluminum sulfate is 1:0.52), the second magnesium source is selected from magnesium chloride, the second alkali source is selected from NaOH, and the second silicon source is water glass. In the matrix solution, the second aluminum source is calculated as Al2O3, the second alkali source is calculated as NaOH, the second magnesium source is calculated as MgO, the second B source is calculated as B2O3, and the second silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.30:5.2:0.45:5.6:120. The amount of the Y molecular sieve guide containing B and Mg added in step (1) is 10.0% of the total mass of the matrix mixed solution. The second B source is dissolved in the second aluminum source sodium metaaluminate aqueous solution, wherein the mass content of B is 16.0%, and after ultrasonic (40kHz) treatment for 4 hours and a standing process, the standing time is 12 hours, to obtain the second B source feed. The second alkali source and the second silicon source are mixed with the remaining water, and then the guide obtained in step (1), the second B source feed, the second aluminum source aluminum sulfate, and the second magnesium source are added in sequence, and mixed evenly to obtain a gel.

[0079] (3) The gel obtained in step (2) is crystallized; the crystallization adopts three-stage temperature rising crystallization, the first stage crystallization temperature is 30° C., the second stage crystallization temperature is 65° C., and the third stage crystallization temperature is 100° C. The crystallization time of each stage is 18 hours.

[0080] (4) The crystallized product obtained in step (3) is subjected to ammonium exchange and hydrothermal treatment to obtain USY molecular sieve. The ammonium exchange is a conventional ammonium exchange. The ammonium salt used is ammonium nitrate, wherein the concentration of the ammonium salt solution is 0.1 mol / L and the pH value is 6.8. The ammonium exchange temperature is 60°C and the number of ammonium exchanges is 2 times. The solid-liquid volume ratio of each ammonium exchange is 1:10, and the treatment time of each ammonium exchange is 6 hours. The hydrothermal treatment is performed twice, and the conditions of each hydrothermal treatment are as follows: the temperature is 620°C, under 100% water vapor treatment conditions, the treatment time is 6 hours. The water vapor treatment process is a flowing water vapor treatment.

[0081] In the B-Mg-NaY molecular sieve obtained in Example 3, the content of Mg in terms of MgO is 1.22%.

[0082] Example 4

[0083] (1) Preparation of a Y molecular sieve guide containing B and Mg: The first B source is sodium metaborate, the first aluminum source is sodium metaaluminate, the first alkali source is NaOH, the first magnesium source is magnesium chloride, and the first silicon source is silica sol. After the first aluminum source and the first alkali source are mixed and dissolved in water, the first B source, the first magnesium source, and the first silicon source are added in sequence, mixed evenly, and allowed to stand to obtain a Y molecular sieve guide containing B and Mg. Among them, the first aluminum source is calculated as Al2O3, the first alkali source is calculated as NaOH, the first B source is calculated as B2O3, the first magnesium source is calculated as MgO, and the first silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.35:30:0.5:15:300. The standing temperature is 25°C and the standing time is 22 hours.

[0084] (2) Prepare a matrix mixed solution; in the matrix mixed solution, the second B source is sodium metaborate, the second aluminum source is sodium metaaluminate and aluminum sulfate (the molar ratio of sodium metaaluminate and aluminum sulfate is 1:0.5), the second alkali source is selected from NaOH, and the second silicon source is water glass. In the matrix solution, the second aluminum source is calculated as Al2O3, the second alkali source is calculated as NaOH, the second magnesium source is calculated as MgO, the second B source is calculated as B2O3, and the second silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.30:5.2:0.45:5.6:120. The amount of the Y molecular sieve guide containing B and Mg added in step (1) is 15.0% of the total mass of the matrix mixed solution. The second B source is dissolved in the second aluminum source aluminum sulfate aqueous solution, wherein the mass content of B is 18.0%, and after ultrasonic (45kHz) treatment for 4 hours and a standing process, the standing time is 18 hours, to obtain the second B source feed. The second alkali source and the second silicon source are mixed with the remaining water, and then the guide obtained in step (1), the second B source feed, the second aluminum source sodium metaaluminate, and the second magnesium source are added in sequence, and mixed evenly to obtain a gel.

[0085] (3) The gel obtained in step (2) is crystallized; the crystallization adopts three-stage temperature rising crystallization, the first stage crystallization temperature is 40° C., the second stage crystallization temperature is 75° C., and the third stage crystallization temperature is 110° C. The crystallization time of each stage is 12 hours.

[0086] (4) The crystallized product obtained in step (3) is subjected to ammonium exchange and hydrothermal treatment to obtain USY molecular sieve. The ammonium exchange is a conventional ammonium exchange. The ammonium salt used is ammonium nitrate, wherein the concentration of the ammonium salt solution is 0.1 mol / L and the pH value is 6.8. The ammonium exchange temperature is 60°C and the number of ammonium exchanges is 2 times. The solid-liquid volume ratio of each ammonium exchange is 1:10, and the treatment time of each ammonium exchange is 6 hours. The hydrothermal treatment is performed twice, and the conditions of each hydrothermal treatment are as follows: the temperature is 620°C, under 100% water vapor treatment conditions, the treatment time is 6 hours. The water vapor treatment process is a flowing water vapor treatment.

[0087] In the B-Mg-NaY molecular sieve obtained in Example 4, the content of Mg in terms of MgO is 1.28%.

[0088] Example 5

[0089] (1) Preparation of a Y molecular sieve guide containing B and Mg: The first B source is sodium metaborate, the first aluminum source is sodium metaaluminate, the first alkali source is NaOH, the first magnesium source is magnesium chloride, and the first silicon source is silica sol. After the first aluminum source and the first alkali source are mixed and dissolved in water, the first B source, the first magnesium source, and the first silicon source are added in sequence, mixed evenly, and allowed to stand to obtain a Y molecular sieve guide containing B and Mg. Among them, the first aluminum source is calculated as Al2O3, the first alkali source is calculated as NaOH, the first B source is calculated as B2O3, the first magnesium source is calculated as MgO, and the first silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.35:30:0.5:15:300. The standing temperature is 25°C and the standing time is 22 hours.

[0090] (2) Prepare a matrix mixed solution; in the matrix mixed solution, the second B source is sodium metaborate, the second aluminum source is sodium metaaluminate and aluminum sulfate (the molar ratio of sodium metaaluminate and aluminum sulfate is 1:0.52), the second alkali source is selected from NaOH, and the second silicon source is water glass. In the matrix solution, the second aluminum source is calculated as Al2O3, the second alkali source is calculated as NaOH, the second magnesium source is calculated as MgO, the second B source is calculated as B2O3, and the second silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.30:5.2:0.45:5.6:120. The amount of the Y molecular sieve guide containing B and Mg added in step (1) is 15.0% of the total mass of the matrix mixed solution. The second B source is dissolved in the second silicon source water glass solution, wherein the mass content of B is 10.0%, and after ultrasonic (25kHz) treatment for 4 hours and a standing process, the standing time is 18 hours, to obtain the second B source feed. The second alkali source is mixed with the remaining water, and then the guide body obtained in step (1), the second B source feed, the second aluminum source sodium aluminate, the second aluminum source aluminum sulfate, and the second magnesium source are added in sequence, and mixed evenly to obtain a gel.

[0091] (3) The gel obtained in step (2) is crystallized; the crystallization adopts three-stage temperature rising crystallization, the first stage crystallization temperature is 30° C., the second stage crystallization temperature is 65° C., and the third stage crystallization temperature is 100° C. The crystallization time of each stage is 18 hours.

[0092] (4) The crystallized product obtained in step (3) is subjected to ammonium exchange and hydrothermal treatment to obtain USY molecular sieve. The ammonium exchange is a conventional ammonium exchange. The ammonium salt used is ammonium chloride, wherein the concentration of the ammonium salt solution is 0.1 mol / L and the pH value is 5.2. The ammonium exchange temperature is 80°C and the number of ammonium exchanges is 3 times. The solid-liquid volume ratio of each ammonium exchange is 1:10, and the treatment time of each ammonium exchange is 4 hours. The hydrothermal treatment is performed twice, and the conditions of each hydrothermal treatment are as follows: the temperature is 600°C, under 100% water vapor treatment conditions, and the treatment time is 4 hours. The water vapor treatment process is a flowing water vapor treatment.

[0093] In the B-Mg-NaY molecular sieve obtained in Example 5, the content of Mg in terms of MgO is 1.34%.

[0094] Example 6

[0095] (1) Preparation of a Y molecular sieve guide containing B and Mg: The first B source is sodium metaborate, the first aluminum source is sodium metaaluminate, the first alkali source is NaOH, the first magnesium source is magnesium chloride, and the first silicon source is silica sol. After the first aluminum source and the first alkali source are mixed and dissolved in water, the first B source, the first magnesium source, and the first silicon source are added in sequence, mixed evenly, and allowed to stand to obtain a Y molecular sieve guide containing B and Mg. Among them, the first aluminum source is calculated as Al2O3, the first alkali source is calculated as NaOH, the first B source is calculated as B2O3, the first magnesium source is calculated as MgO, and the first silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.35:30:0.50:15:300. The standing temperature is 25°C and the standing time is 22 hours.

[0096] (2) Prepare a matrix mixed solution; in the matrix mixed solution, the second B source is sodium metaborate, the second aluminum source is sodium metaaluminate and aluminum sulfate (the molar ratio of sodium metaaluminate and aluminum sulfate is 1:0.52), the second magnesium source is selected from magnesium chloride, the second alkali source is selected from NaOH, and the second silicon source is water glass. In the matrix solution, the second aluminum source is calculated as Al2O3, the second alkali source is calculated as NaOH, the second magnesium source is calculated as MgO, the second B source is calculated as B2O3, and the second silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O in the feed is 1:0.30:5.2:0.45:5.6:120. The amount of the Y molecular sieve guide containing B and Mg added in step (1) is 15.0% of the total mass of the matrix mixed solution. The second B source is dissolved in water, wherein the mass content of B (calculated as oxide) is 12.0%, and after ultrasonic (30kHz) treatment for 4 hours and a standing process for 18 hours, a second B source feed is obtained. The second alkali source and the second silicon source are mixed with the remaining water, and then the guide obtained in step (1), the second B source feed, the second aluminum source sodium aluminate, the second aluminum source aluminum sulfate, and the second magnesium source are added in sequence, and mixed evenly to obtain a gel.

[0097] (3) The gel obtained in step (2) is crystallized; the crystallization adopts three-stage temperature rising crystallization, the first stage crystallization temperature is 30° C., the second stage crystallization temperature is 65° C., and the third stage crystallization temperature is 100° C. The crystallization time of each stage is 18 hours.

[0098] (4) The crystallized product obtained in step (3) (i.e., B-Mg-NaY molecular sieve) is subjected to ammonium exchange and hydrothermal treatment to obtain USY molecular sieve. The ammonium exchange is a conventional ammonium exchange. The ammonium salt used is ammonium nitrate, wherein the concentration of the ammonium salt solution is 0.1 mol / L and the pH value is 6.8. The ammonium exchange temperature is 60°C and the number of ammonium exchanges is 2 times. The solid-liquid volume ratio of each ammonium exchange is 1:10, and the treatment time of each ammonium exchange is 6 hours. The hydrothermal treatment is performed twice, and the conditions of each hydrothermal treatment are as follows: the temperature is 620°C, under 100% water vapor treatment conditions, the treatment time is 6 hours. The water vapor treatment process is a flowing water vapor treatment.

[0099] In the B-Mg-NaY molecular sieve obtained in Example 6, the content of Mg in terms of MgO is 1.17%.

[0100] Example 7

[0101] Compared with Example 1, the difference is that the water vapor treatment process in step (4) is a closed treatment.

[0102] Comparative Example 1

[0103] Compared with Example 1, the difference is that the first B source is not added to the Y molecular sieve guide body prepared in step (1), but the first aluminum source, the first magnesium source, the first alkali source, the first silicon source and water are mixed and allowed to stand to obtain the Y molecular sieve guide body.

[0104] Comparative Example 2

[0105] Compared with Example 1, the difference is that the amount of the Y molecular sieve guide containing B and Mg added to the matrix mixed solution in step (2) is 8.0% of the total material mass of the matrix solution.

[0106] Comparative Example 3

[0107] Compared with Example 1, the difference is that in step (3), a three-stage temperature increase crystallization process is not adopted, but the crystallization temperature is 65° C. for 54 hours.

[0108] Application Examples

[0109] The present invention provides the use of each example of molecular sieve in a flexible hydrocracking catalyst: the molecular sieve, aluminum oxide, molybdenum oxide, tungsten oxide, nickel oxide and sesbania powder prepared in each example are uniformly mixed in a certain proportion, an inorganic acid is added as a binder, the powder is uniformly rolled and formed, and after drying at 120° C. for 4 hours and calcining at 500° C. for 6 hours, a hydrocracking catalyst is obtained, the properties of which are shown in Table 2, and the catalyst numbers are A-1 to A-7 and D-1 to D-3, respectively.

[0110] Evaluation of the catalyst: The above-prepared catalysts were evaluated on a 200mL small hydrogenation unit, and the catalysts were pre-sulfurized before the reaction. The properties of the feedstock oil used in the evaluation test are shown in Table 3. The process conditions and reaction performance results of the evaluation test are shown in Tables 4 and 5. When evaluating the flexible hydrocracking catalyst, the feedstock oil passed through two beds of the hydrorefining catalyst and the above-prepared flexible hydrocracking catalyst in sequence. Among them, when passing through the hydrorefining catalyst bed, the organic nitrogen content in the feedstock oil was controlled to be less than 10ppm.

[0111] Table 1 Properties of the molecular sieves prepared in each example

[0112]

[0113]

[0114] Table 1 Properties of the molecular sieves prepared in each example

[0115]

[0116] Table 2 Composition of hydrocracking catalyst

[0117]

[0118] Table 3 Properties of the feedstock oil used in the evaluation test

[0119] <![CDATA[Density (20 °C), g / cm 3 > 0.91 Distillation range, ℃ IBP / EBP 361 / 523 Pour point, ℃ 34 Carbon residue, wt% 0.23 S, wt% 1.6 N, wt% 0.12

[0120] Table 4 Process conditions and reaction performance results of the evaluation test of the catalyst of the present invention

[0121]

[0122]

[0123] Table 5 Process conditions and reaction performance results of comparative catalyst evaluation tests (continued)

[0124]

[0125] It can be seen from Table 4 and Table 5 that when the conversion rate of the controlled reaction is the same, the reaction activity and selectivity of the target product using the catalyst of the present invention are better.

[0126] The embodiments of the present invention are only detailed descriptions of the technical solutions of the present invention, but the present invention is not limited to the above embodiments, that is, the present invention can be implemented without relying on the steps described in the above embodiments. In summary, any improvements made by those skilled in the art to the present invention, including replacement of the raw materials and additives described in the present invention, selection of specific implementation methods, etc., all belong to the protection scope and disclosure scope of the present invention.

Claims

1. A USY molecular sieve, wherein: The properties of the USY molecular sieve are as follows: the mesopore volume accounts for 30% to 60% of the total pore volume of the molecular sieve, preferably 38% to 55%; the total acid content is 400 to 480 μmol / g at 200°C, and the total acid content is 120 to 150 μmol / g at 350°C.

2. The molecular sieve according to claim 1, characterized in that: In the USY molecular sieve, the ratio of the amount of B acid to the amount of L acid at 200° C. is 1.20-1.40, and the ratio of the amount of B acid to the amount of L acid at 350° C. is 1.10-1.

25.

3. The molecular sieve according to claim 1, characterized in that: The specific surface area of ​​the USY molecular sieve is 500-600m 2 / g, pore volume is 0.350~0.410mL / g; And / or, in the USY molecular sieve, the average crystal size is 0.4 to 1.4 μm, preferably 450 to 650 nm; And / or, the unit cell constant of the USY molecular sieve is And / or, in the USY molecular sieve, the SiO2 / Al2O3 molar ratio is 14.0 to 25.0; And / or, in the USY molecular sieve, the most probable pore diameter is 23-30 nm.

4. A method for preparing USY molecular sieve, comprising the following steps: (1) preparing a Y molecular sieve guide containing B and Mg; (2) mixing a second aluminum source, a second magnesium source, a second silicon source, a second B source, a second alkali source, and water with the guide body of step (1) to obtain a gel; (3) crystallizing the gel of step (2); (4) The crystallized product obtained in step (3) is subjected to ammonium exchange and hydrothermal treatment to obtain USY molecular sieve.

5. The preparation method according to claim 4, characterized in that: In step (1), the preparation method of the Y molecular sieve guide containing B and Mg includes: mixing a first aluminum source, a first magnesium source, a first alkali source, a first B source, a first silicon source and water, and letting the mixture stand to obtain a Y molecular sieve guide containing B and Mg.

6. The preparation method according to claim 5, characterized in that: The first aluminum source is calculated as Al2O3, the first magnesium source is calculated as MgO, the first alkali source is calculated as NaOH, the first B source is calculated as B2O3, and the first silicon source is calculated as SiO2, and the molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O is 1:0.1-5.0:11-42:0.07-20.0:5-25:180-450, preferably 1:0.1-3.0:15-35:0.07-12.0:5-18:180-400; And / or, the standing temperature is 10 to 50° C. and the standing time is 15 to 35 hours.

7. The preparation method according to claim 4, characterized in that: In step (2), the second aluminum source is calculated as Al2O3, the second magnesium source is calculated as MgO, the second alkali source is calculated as NaOH, the second B source is calculated as B2O3, and the second silicon source is calculated as SiO2. The molar ratio of Al2O3:MgO:NaOH:B2O3:SiO2:H2O is 1:0.1~4.5:1.5~15.0:0.07~15.0:1.5~12.0:80~400, preferably 1:0.1~2.5:1.5~10.0:0.07~8.0:1.5~8.0:80~350.

8. The preparation method according to claim 1, characterized in that: In step (2), the second B source is introduced into the reaction system in the form of a second B source feed, and the second B source feed is prepared in at least one of the following ways: a. at least part of the second B source and at least part of the second silicon source are used to form a second B source feed, b. at least part of the second B source and at least part of the second aluminum source are used to form a second B source feed, c. preparing a second B source feed with at least a portion of the second B source, at least a portion of the second aluminum source, and at least a portion of the second silicon source; Preferably, the second B source feed is subjected to ultrasonic treatment and then to a standing process (preferably, the standing time is 1 to 48 hours, preferably 12 to 24 hours) before being introduced into the reaction system.

9. The preparation method according to claim 8, characterized in that: In the second B source feed, the mass content of B is 2.0% to 18.0% in terms of oxide; and / or, the ultrasonic treatment conditions are as follows: temperature 20 to 80° C., preferably 20 to 60° C., ultrasonic frequency 20 to 45 kHz, time 1 to 8 h, preferably 1 to 4 h.

10. The preparation method according to claim 8 or 9, characterized in that: In step (2), the second alkali source and the remaining second silicon source are mixed with water and then the guide obtained in step (1), the second B source feed, the remaining second aluminum source and the second magnesium source are added in sequence and mixed to obtain a gel.

11. The preparation method according to claim 4, characterized in that: In step (2), the amount of the Y molecular sieve guide containing B and Mg added is 10.0% to 45.0% of the total material mass of the matrix mixed liquid, and the matrix mixed liquid is a second aluminum source, a second magnesium source, a second silicon source, a second B source, a second alkali source and water.

12. The preparation method according to claim 4 or 5, characterized in that: The first B source or the second B source is independently selected from at least one of sodium metaborate, boric acid, ammonium fluoroborate, and borax; the first magnesium source or the second magnesium source is independently selected from at least one of magnesium nitrate, magnesium chloride, and magnesium sulfate; the first aluminum source or the second aluminum source is independently selected from at least one of sodium metaaluminate and aluminum sulfate; the first alkali source or the second alkali source is independently selected from at least one of NaOH and KOH, and the first silicon source or the second silicon source is independently selected from at least one of silica sol and water glass.

13. The preparation method according to claim 4, characterized in that: The crystallization adopts three-stage temperature rising crystallization, the first-stage crystallization temperature is 30-40°C, the second-stage crystallization temperature is 30-35°C higher than the first-stage temperature, the third-stage crystallization temperature is 25-50°C higher than the second-stage temperature, and the highest temperature does not exceed 110°C; the crystallization time of each stage is 12-36 hours, preferably 15-24 hours.

14. The preparation method according to claim 4, characterized in that: The first hydrothermal treatment or the second hydrothermal treatment is independently selected from: the hydrothermal treatment is performed 1 to 3 times, and the conditions of each hydrothermal treatment are as follows: the temperature is 500 to 650° C., under 100% water vapor treatment conditions, the treatment time is 1 to 6 hours; Preferably, the water vapor treatment is a closed water vapor treatment or a flowing water vapor treatment, preferably a flowing water vapor treatment.

15. Use of the USY molecular sieve according to any one of claims 1 to 3 or the USY molecular sieve prepared by any one of claims 4 to 14 in a hydrocracking catalyst.

16. The use according to claim 15, characterized in that: USY molecular sieve is used to manufacture flexible hydrocracking catalyst.

17. The use according to claim 15 or 16, characterized in that: The hydrocracking catalyst comprises USY molecular sieve and hydrogenation active metal components. The hydrogenation active metal is preferably a metal of Group VIB and Group VIII, and more preferably molybdenum, tungsten and nickel.

18. The use according to claim 17, characterized in that: In the catalyst, based on the weight of the catalyst, the content of USY molecular sieve is 15.0%-40.0%, the content of molybdenum in terms of oxide is 8.0%-20.0%, the content of tungsten in terms of oxide is 2.0%-10.0%, and the content of nickel in terms of oxide is 2.0%-8.0%; And / or, the hydrocracking catalyst comprises alumina, and the content of alumina is 40%-75% based on the weight of the catalyst.

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