Hydrocracking catalyst carrier, hydrocracking catalyst and preparation method thereof
Technical Field
The invention relates to a chemical hydrocracking catalyst carrier, a hydrocracking catalyst and a preparation method thereof, in particular to a chemical hydrocracking catalyst carrier, a hydrocracking catalyst and a preparation method thereof for producing high-quality catalytic reforming raw materials and ethylene cracking raw materials.
Background
With the increasing of the quality deterioration degree of crude oil and the stricter environmental regulations, the demand of the market for clean oil products is increasing, the hydrogenation technology for producing clean fuel is concerned, and the application prospect is more and more extensive. The hydrocracking technology has become the core of oil-chemical-fiber combination of refineries due to the strong raw oil adaptability, large production flexibility, good product quality, and the capability of directly converting various heavy and poor raw materials into high-quality jet fuel, diesel oil, lubricating oil base stock, ethylene raw materials produced by steam cracking of chemical naphtha and tail oil, and the like which are urgently needed by the market.
The increase in the level of hydrocracking catalysts, which are the core of hydrocracking technology, is dependent on improvements in the performance of the hydrocracking catalysts. The hydrocracking catalyst is a bifunctional catalyst and simultaneously contains an acidic component and a hydrogenation component, wherein the hydrogenation component is generally a metal oxide selected from the VIII group and the VIB group in the periodic table, and the acidic component is mainly provided by a molecular sieve and an inorganic oxide. Molecular sieves are the most critical components of hydrocracking catalysts, and the performance of molecular sieves determines the performance of the catalysts. At present, molecular sieves used in hydrocracking catalysts are mainly modified Y-type molecular sieves. The aperture is only about 0.7nm, molecules with larger diameters in reaction raw materials are difficult to diffuse into the pore channels of the molecular sieve, and the smaller pore channel structure also hinders the rapid diffusion of product molecules, so that the target product is subjected to secondary cracking, and the yield of middle distillate oil is reduced. Therefore, scientific research institutes in various countries around the world are all dedicated to developing hydrocracking catalytic materials with novel molecular sieves with large pore diameters.
CN101450320B discloses a hydrocracking catalyst containing Y molecular sieve and a preparation method thereof, wherein the Y type molecular sieve is prepared by firstly preparing aluminum salt and acid into a mixed solution, and then treating the Y molecular sieve after hydrothermal treatment with the mixed solution to finally prepare the catalyst.
CN102049277A discloses a hydrocracking catalyst for producing naphtha and ethylene raw materials, which adopts a double-crystal Y molecular sieve as a main acidic component to prepare the hydrocracking catalyst capable of producing high-quality tail oil ethylene cracking raw materials. However, the method only carries out innovation of a molecular sieve method aiming at improvement of tail oil quality, and the improvement of catalytic performance is limited.
CN105618117A discloses a preparation method of a hydrocracking catalyst, which comprises the following steps: uniformly mixing the modified Y molecular sieve and amorphous silicon-aluminum and/or aluminum oxide according to a certain proportion, adding dilute nitric acid to form slurry, extruding and molding, drying and roasting to obtain a silicon-aluminum carrier containing the modified Y molecular sieve, then impregnating an active component, drying and roasting to obtain the hydrocracking catalyst.
The reaction activity, the target product yield and the product quality of the existing hydrocracking catalyst used in the hydrocracking reaction process need to be further improved.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a hydrocracking catalyst carrier, a hydrocracking catalyst and a preparation method thereof. The hydrocracking catalyst prepared by adopting the hydrocracking catalyst carrier has excellent comprehensive performance, and is used for the hydrocracking reaction process, and the heavy naphtha yield is high, and the product quality is excellent.
(I) hydrocracking catalyst support
In a first aspect, the present invention provides a hydrocracking catalyst carrier, which comprises: the composite molecular sieve comprises a Y/Al-SBA-15 composite molecular sieve and alumina, wherein the acid content of medium strong acid of the Y/Al-SBA-15 composite molecular sieve is 0.6-1.2 mL/g, preferably 0.7-1.0 mL/g, and the ratio of B acid to L acid is less than 1.2.
Further, the ratio of B acid to L acid in the Y/Al-SBA-15 composite molecular sieve is less than 1.0, more preferably less than 0.6, still more preferably more than 0.1, and specifically can be 0.1, 0.2, 0.3, 0.4 or 0.5.
Further, the Y/Al-SBA-15 composite molecular sieve has the following properties: the specific surface area is 550-1000 m2Preferably 680 to 800 m/g2The total pore volume is 0.4 to 1.0mL/g, preferably 0.5 to 0.8 mL/g.
Furthermore, in the Y/Al-SBA-15 composite molecular sieve, the mass content of alumina is 2-85%, preferably 5-82%, and more preferably 7.5-79.5%. In the Y/Al-SBA-15 composite molecular sieve, the content of alumina can be adjusted within a wide range, such as 10.5%, 15.5%, 16.5%, 18.2%, 20.5%, 25.5%, 30.2%, 32.5%, 35.5%, 40.1%, 45.5%, 50.5%, 55.3%, 60.5%, 70.5%, 78.5% and the like.
Further, the pore distribution of the Y/Al-SBA-15 composite molecular sieve comprises: the pore volume of the pores with the pore diameter of 4-15 nm accounts for 42-72%, preferably 45-65%, and more preferably 55-65% of the total pore volume.
Further, the mass content of the Y/Al-SBA-15 composite molecular sieve is 10-90%, preferably 25-85%.
Further, the hydrocracking catalyst carrier takes the weight of the catalyst carrier as a reference, and the weight content of the Y/Al-SBA-15 composite molecular sieve is 35% -50%; the weight content of the alumina is preferably 55-72%.
Further, the properties of the alumina are as follows: the pore volume is 0.80 mL/g-1.2 mL/g, the specific surface area is 140m2/g~360m2(ii)/g, the average pore diameter is 10 to 14 nm.
Further, the preparation method of the Y/Al-SBA-15 composite molecular sieve comprises the following steps: amorphous silica-alumina dry gel is used as a raw material, P123 triblock copolymer is used as a template agent to carry out first crystallization to synthesize the Al-SBA-15 molecular sieve, and then ultrastable Y molecular sieve slurry is added to carry out second crystallization to obtain the Y/Al-SBA-15 composite molecular sieve.
Further, the amorphous silica-alumina dry gel has the following properties: the surface area is 400-650 m2Per g, preferably 450 to 600m2The pore volume is 0.52-1.8 ml/g, preferably 0.85-1.5 ml/g, and the pore distribution is as follows: the pore volume with the pore diameter of 4-15 nm accounts for 85% -95% of the total pore volume, and the pore volume with the pore diameter of more than 15nm accounts for less than 5% of the total pore volume.
Further, in the amorphous silica-alumina dry gel, the mass content of alumina is 2-85%. The mass content of the alumina can be adjusted within a wide range, and can be, for example, 5%, 10%, 15%, 16%, 18%, 20%, 25%, 30%, 32%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, 75%, and the like.
Further, the properties of the ultrastable Y molecular sieve are as follows: SiO 22/Al2O3The molar ratio is 25-150, and the specific surface area is 550-1000 m2(iv)/g, the total pore volume is 0.30-0.60 mL/g.
Furthermore, the ultrastable Y molecular sieve slurry can be prepared by adding water into an ultrastable Y molecular sieve and pulping, and the mass content of the ultrastable Y molecular sieve in the slurry is 20-40%.
Further, the specific preparation method of the Y/Al-SBA-15 composite molecular sieve comprises the following steps:
(1) mixing amorphous silica-alumina dry gel and water to form slurry;
(2) preparing an acidic solution containing a P123 triblock copolymer;
(3) and (2) mixing the slurry prepared in the step (1) with the acidic aqueous solution containing the P123 triblock copolymer prepared in the step (2), performing first crystallization, adding the ultrastable Y molecular sieve slurry, and performing second crystallization to prepare the Y/Al-SBA-15 composite molecular sieve.
According to the method, the amorphous silica-alumina in the step (1) is prepared by a carbonization method, and can be prepared by the following steps:
a. respectively preparing a sodium aluminate solution and a sodium silicate solution;
b. adding part or all of sodium silicate solution into sodium aluminate solution, and introducing CO2Controlling the reaction temperature of the gas to be 10-40 ℃, preferably 15-35 ℃, and controlling the pH value of the gel to be 8-11; wherein when CO is introduced2When the gas amount accounts for 40-100 percent of the total input amount, preferably 50-80 percent, adding the rest sodium silicate solution;
c. b, ventilating and stabilizing the mixture for 10-30 minutes under the temperature and pH value control of the step b;
d. c, filtering the solid-liquid mixture obtained in the step c, and washing a filter cake;
e. d, pulping the filter cake obtained in the step d, then carrying out hydro-thermal treatment, filtering and drying to obtain the amorphous silica-alumina dry gel; the hydrothermal treatment conditions were as follows: treating for 2-10 hours at 120-150 ℃ and under the water vapor pressure of 0.5-4.0 MPa.
Further, in the step a, the concentration of the sodium aluminate solution is 15-55 gAl2O3A further optional amount of 15 to 35gAl2O3L, the concentration of the sodium silicate solution is 50-200 gSiO2A further amount of 50 to 150g SiO2/L。
Further, in the step b, part or all of the sodium silicate solution is added, namely 5wt% -100 wt% of the total added sodium silicate solution. The CO is2The concentration of the gas is 30-60 v%. And c, ventilating and stirring in the gelling process in the step b.
Further, the specific process of step b is as follows: (1) adding all sodium silicate into sodium aluminate, and introducing CO2A gas; (2) adding part of sodium silicate into sodium aluminate, and introducing all CO2Gas, then adding the remaining sodium silicate solution to the mixture; (3) after adding part of sodium silicate to sodium aluminate, part of CO is introduced2Gas, then CO is introduced2The gas was added to the remaining sodium silicate solution.
Further, filtering the slurry obtained in the step d, washing the slurry with deionized water at the temperature of 50-95 ℃ until the slurry is nearly neutral,
and further, mixing the filter cake obtained in the step e according to a solid-liquid volume ratio of 8: 1-12: 1, adding water and pulping.
Further, the drying in the step e can be performed by a conventional method, and can be performed for 6-8 hours at 110-130 ℃.
Further, the mass ratio of the amorphous silica-alumina dry gel to water in the step (1) is 10: 90-30: 70, preferably 15: 85-25: 75.
further, the pH value of the acidic aqueous solution in the step (2) is 1-5, preferably 1.2-2.3, and the mass content of the P123 triblock copolymer in the acidic aqueous solution is 0.5-5.0%, preferably 0.8-2.8%.
Further, in step (2), the P123 triblock copolymer is added to a dilute acid (such as dilute hydrochloric acid) at a concentration of H+0.05 to 0.3mol/L, preferably 0.1 to 0.2mol/L, and more preferablySelecting 0.13-0.18 mol/L; in order to sufficiently dissolve the P123 triblock copolymer, the temperature system is controlled to 10 to 60 ℃, preferably 20 to 40 ℃, and more preferably 25 to 35 ℃.
Further, in the step (3), the slurry prepared in the step (1) is mixed with the acidic aqueous solution containing the P123 triblock copolymer prepared in the step (2), and the amounts of the slurry prepared in the step (1) and the acidic aqueous solution containing the P123 triblock copolymer prepared in the step (2) are such that the mass ratio of the P123 triblock copolymer to the amorphous silica-alumina in the mixed system is 0.5:1 to 5:1, preferably 1:1 to 5:1, and more preferably 1:1 to 3: 1.
Further, the conditions of the first crystallization in the step (3) are: the crystallization temperature is 80-120 ℃, and preferably 90-110 ℃; the crystallization time is 10-35 h, preferably 16-24 h; the pH value in the crystallization process is controlled to be 2.0-5.0, preferably 3.2-4.8.
Further, the conditions of the second crystallization in the step (3) are: the crystallization temperature is 80-130 ℃, and preferably 90-120 ℃; the crystallization time is 4-20 h, preferably 10-15 h; the pH value is controlled to be 2.0-5.0, preferably 4.2-5.0 in the crystallization process.
Further, after the crystallization step of step (3), the Y/Al-SBA-15 composite molecular sieve may be separated from the obtained mixture by any conventionally known means, such as filtration, washing, drying, etc. The filtration can adopt suction filtration. The washing can be performed by using deionized water as a washing solution. The drying can be carried out at 80-150 ℃, preferably 90-130 ℃, and the drying time is 2-12 hours, preferably 3-6 hours. The drying may be carried out at atmospheric pressure.
Further, the composite molecular sieve prepared by the above method may be calcined to remove the template agent and water and the like if necessary. The roasting can be carried out according to any mode conventionally known in the field, the roasting temperature is controlled to be 450-600 ℃, preferably 480-580 ℃, further preferably 500-560 ℃, and the roasting time is 2-10 hours, preferably 3-6 hours. In addition, the calcination is generally carried out in an oxygen-containing atmosphere, such as air or oxygen.
Preparation method of (II) hydrocracking catalyst carrier
In a second aspect, the present invention provides a preparation method of a hydrocracking catalyst carrier, comprising: preparing a Y/Al-SBA-15 composite molecular sieve, adding the Y/Al-SBA-15 composite molecular sieve and alumina dry glue powder into an acid solution, and drying and roasting after forming to obtain the hydrocracking catalyst carrier.
Further, the acidic solution is at least one of acetic acid or nitric acid. The mass concentration of the acid solution is 2.3-4.5 wt%; the acid solution contains guar gum, and the mass content of the guar gum in the acid solution is 0.2-1 wt%.
Further, the drying conditions were as follows: the drying temperature is 80-150 ℃, preferably 90-120 ℃, and the drying time is 0.5-20.0 h, preferably 3.0-6.0 h; the calcination conditions were as follows: the roasting temperature is 450-650 ℃, preferably 500-650 ℃, and the roasting time is 0.5-20.0 h, preferably 3.0-6.0 h. The drying and calcination may be carried out in an oxygen-containing atmosphere, the oxygen concentration is not particularly limited, such as an air atmosphere, etc., and may also be carried out in an inert atmosphere, such as a nitrogen atmosphere, etc.
The hydrocracking catalyst carrier can be shaped according to the requirement, such as a dentate sphere, a clover shape or a cylindrical strip shape.
(III) hydrocracking catalyst
In a third aspect, the present invention provides a hydrocracking catalyst, which comprises the above hydrocracking catalyst carrier and an active metal component.
The active component comprises a VIB group metal and a VIII group metal, wherein the VIB group metal is preferably molybdenum and/or tungsten, and the VIII group metal is preferably cobalt and/or nickel.
Furthermore, the content of the VIB group metal calculated by oxide is 10wt% -18 wt%, and the content of the VIII group metal calculated by oxide is 4wt% -8 wt% based on the weight of the hydrocracking catalyst.
Further, the hydrocracking catalyst had the following properties: specific surface areaIs 200 to 500m2Preferably 220 to 300 m/g2The pore volume is 0.30 to 0.65mL/g, preferably 0.35 to 0.60 mL/g.
Furthermore, the hydrocracking catalyst may further comprise a certain auxiliary agent, such as P, B, Ti, Zr, etc., wherein the content of the auxiliary agent is less than 10% of the weight of the hydrocracking catalyst, and may be 0.1% to 8.0% by weight.
Preparation method of (IV) hydrocracking catalyst
In a fourth aspect, the present invention provides a method for preparing a hydrocracking catalyst, comprising: and (3) impregnating the hydrocracking catalyst carrier with active metal components, and then drying and roasting to obtain the hydrocracking catalyst.
Further, the impregnation may be carried out by methods conventional in the art, such as isovolumetric impregnation, supersaturated impregnation, stepwise impregnation, co-impregnation, etc., preferably isovolumetric co-impregnation.
Further, the drying temperature is 80-150 ℃, preferably 90-120 ℃, and the drying time is 0.5-20.0 h, preferably 3.0-6.0 h; the roasting temperature is 400-550 ℃, preferably 450-500 ℃, and the roasting time is 0.5-20.0 h, preferably 3.0-6.0 h.
Application of hydrocracking catalyst
The fifth aspect of the invention provides an application of the hydrocracking catalyst.
Further, the application is the application of the hydrocracking catalyst in a hydrocracking process for producing a catalytic reforming raw material and an ethylene cracking raw material.
Further, the operating conditions of the application are as follows: the reaction temperature is 340-430 ℃, the preferable temperature is 355-385 ℃, the hydrogen partial pressure is 5-20 MPa, the preferable pressure is 8-15 MPa, the volume ratio of hydrogen to oil is 500-2000: 1, the preferable pressure is 750-1500: 1, and the liquid hourly space velocity is 0.5-1.8 h-1Preferably 0.7 to 1.5 hours-1。
Furthermore, the hydrocracking catalyst is suitable for treating heavy raw oil including vacuum distillate oil, coking gas oil, catalytic cracking gas oil and catalytic crackingOne or more of cycle oil and other raw oil, hydrocarbon with boiling point of 300-600 deg.C, nitrogen content of 50-2800 mg.g-1。
Compared with the prior art, the hydrocracking catalyst carrier and the preparation method thereof have the following advantages:
the hydrocracking catalyst carrier provided by the invention contains the hydrocracking catalyst prepared by taking the Y/Al-SBA-15 composite molecular sieve with adjustable acidity and good hydrothermal stability as an acidic component, the acidity of the catalyst can be flexibly adjusted, and especially the contents of B acid and L acid can be adjusted. The B/L ratio is controlled in a certain range, the activity and the selectivity of the catalyst are improved, and the nitrogen resistance of the cracking catalyst can be improved. Meanwhile, after the composite molecular sieve is used, the dispersion degree of active components is increased, more hydrogenation active sites are generated, the hydrogenation function and the cracking function of the catalyst are well matched, the pore volume is improved, the conversion capability of the catalyst on macromolecular hydrocarbon compounds is improved, and high-quality catalytic reforming raw material products and ethylene cracking raw materials with low tail oil BMCI (bulk density index) values are produced.
Detailed Description
In the present invention, the Al-SBA-15 molecular sieve means that aluminum atoms are introduced into the SBA-15 molecular sieve, the existence state of the aluminum atoms in the SBA-15 molecular sieve is not particularly limited, and a part of the aluminum atoms are generally distributed on the framework of the SBA-15 molecular sieve.
In the invention, the determination of the L acid or the B acid adopts an infrared spectroscopy, an instrument adopts an American Nicot Fourier infrared spectrometer-6700, and the determination method comprises the following steps: weighing 20mg of sample with granularity less than 200 meshes, pressing into sheet with diameter of 20mm, placing on sample rack of absorption cell, placing 200mg of sample in cup of instrument, connecting absorption cell and adsorption tube, vacuumizing until vacuum degree reaches 4 × 10-2And Pa, heating to 500 ℃, keeping for 1 hour to remove adsorbates on the surface of the sample, cooling to room temperature, adsorbing pyridine to saturation, continuously heating to 160 ℃, balancing for 1 hour, and desorbing the physically adsorbed pyridine to obtain the acid content of infrared total acid, B acid and L acid, wherein the unit of the B acid and the L acid is mmol/L.
In the invention, the amount of the medium-strong acid is extractedBy NH3TPD method. The adopted instrument is an Auto-Chem II 2920 chemical adsorption instrument of Mike instruments. Ammonia gas is used as an adsorption and desorption medium, helium gas is used as carrier gas, and the acid quantities of different desorption temperature areas are obtained by adopting temperature programming desorption and chromatographic analysis, wherein the ammonia gas desorption temperature corresponding to the acid quantity of the medium-strong acid is 250-400 ℃, and the acid quantity unit is as follows: mL/g is the amount of ammonia adsorbed per gram of molecular sieve.
In the invention, the specific surface area, the pore volume and the pore distribution are measured by adopting an ASAP2405 physical adsorption instrument, and the measuring method comprises the following steps: after the sample is processed, liquid N2Used as adsorbate, the adsorption temperature is-196 ℃, and analysis and test are carried out. Wherein the specific surface area is calculated by a BET method, and the pore volume and the pore distribution are calculated by a BJH method.
In order to better illustrate the patent, the invention is further illustrated below with reference to examples and comparative examples. However, the scope of the present invention is not limited to these examples, and% are mass percentages in the following examples and comparative examples unless otherwise specified.
Example 1
Preparation of hydrocracking catalyst carrier
(1) Preparation of amorphous silica-alumina dry gel powder A1 and slurry: sodium aluminate solution concentration 20gAl2O3Per L, sodium silicate solution concentration 100gSiO2Putting 0.75L of sodium aluminate solution into a gelling tank, adding 0.35L of sodium silicate solution, controlling the reaction temperature to be 20 ℃, and introducing 40 v% CO2Gas, introduction of CO2When the gas accounts for 50 percent of the total input amount, 0.15L of sodium silicate solution is added while introducing gas, the pH value of the formed gel is controlled to be 9.5, then the ventilation is stabilized for 20 minutes, the slurry is filtered and washed to be neutral by deionized water at 65 ℃, a filter cake is added with water according to the solid-liquid volume ratio of 10: 1 for pulping, the treatment is carried out for 2 hours at the temperature of 130 ℃ and the water vapor pressure of 3.5MPa, and after the drying is carried out for 6 hours at the temperature of 120 ℃, the amorphous silica-alumina product A1 is obtained by crushing and sieving. The properties of the amorphous silica-alumina dry gel powder A1 are shown in Table 1. Mixing the prepared amorphous silica-alumina A1 with deionized water, and pulping to form slurry; wherein the mass ratio of the amorphous silica-alumina dry gel to water is 18: 82;
(2) preparing an acidic aqueous solution containing a P123 triblock copolymer; adding the P123 triblock copolymer into dilute hydrochloric acid, wherein the concentration of a dilute hydrochloric acid solution is 0.13mol/L, the pH value of an acidic aqueous solution containing the P123 triblock copolymer is 1.2, the temperature of the acidic aqueous solution containing the P123 triblock copolymer is 25 ℃, and the mass content of the P123 triblock copolymer in the acidic aqueous solution containing the P123 triblock copolymer is 1.6 wt%;
(3) mixing the slurry prepared in the step (1) with the acidic aqueous solution containing the P123 triblock copolymer prepared in the step (2); the mass ratio of the P123 triblock copolymer to the amorphous silica-alumina in the mixed system is 1.2:1, the crystallization temperature is 90 ℃, and the crystallization time is 20 hours; controlling the pH value to be 3.3 in the crystallization process;
(4) slurry containing 12g of USY molecular sieve (wherein the USY molecular sieve has the following properties of 785m of specific surface area2Per g, pore volume 0.53 mL. g-1,SiO2/Al2O3The USY molecular sieve slurry is prepared by pulping the USY molecular sieve and water at a molar ratio of 45) and pumping into the mixed system prepared in the step (3) by using a vacuum pump, drying for 3h at 100 ℃ after the crystallization time is 10h at a pH value of 4.6 and a temperature of 90 ℃, and roasting for 3h at 550 ℃ to obtain a finished product YAS-1.
45g of YAS-1 mesoporous-microporous composite molecular sieve and 55g of alumina (the pore volume is 0.98mL/g, the specific surface area is 335 m)2Per g, average pore diameter of 12 nm), adding into a rolling machine for rolling, adding an aqueous solution containing guar gum (0.4 wt%) and nitric acid (2.2 wt%) after 20 minutes of rolling, rolling into paste, extruding into strips, drying the extruded strips at 120 ℃ for 3 hours, and roasting at 550 ℃ for 3 hours to obtain the carrier Z1.
(II) catalyst preparation
The carrier Z1 is impregnated by impregnation liquid containing Mo, Ni and P in equal volume, dried for 3h at 120 ℃, and roasted for 2h at 420 ℃, and finally the obtained catalyst is marked as C-1, and the properties of the catalyst are shown in Table 2.
Example 2
Preparation of hydrocracking catalyst carrier
(1) Amorphous silica-alumina dry gel powder A2 and slurryThe preparation of (1): sodium aluminate solution concentration 20gAl2O3Per L, sodium silicate solution concentration 35gSiO2L, putting 0.3L of sodium aluminate solution into a gelling tank, then adding 0.2L of sodium silicate solution, controlling the reaction temperature to be 22 ℃, and introducing 35 v% CO2Gas, introduction of CO2When the gas accounts for 50% of the total input amount, 0.2L of sodium silicate solution is added while introducing gas, the pH value of the formed gel is controlled to be 9.5, then the ventilation is stabilized for 20 minutes, the slurry is filtered and washed to be neutral by deionized water at 75 ℃, a filter cake is added with water according to the solid-liquid volume ratio of 8:1 for pulping, the obtained product is treated for 2 hours at 120 ℃ under the water vapor pressure of 3.0MPa, the obtained product is dried for 8 hours at 120 ℃, crushed and sieved to obtain an amorphous silica-alumina product A2, and the properties of the amorphous silica-alumina dry gel powder A2 are shown in Table 1. Mixing the prepared amorphous silica-alumina A2 with deionized water, and pulping to form slurry; wherein the mass ratio of the amorphous silica-alumina dry gel to water is 23: 77;
(2) preparing an acidic aqueous solution containing a P123 triblock copolymer; adding the P123 triblock copolymer into dilute hydrochloric acid, wherein the concentration of a dilute hydrochloric acid solution is 0.15mol/L, the pH value of an acidic aqueous solution containing the P123 triblock copolymer is 1.4, the temperature of the acidic aqueous solution containing the P123 triblock copolymer is 28 ℃, and the mass content of the P123 triblock copolymer in the acidic aqueous solution containing the P123 triblock copolymer is 2.3 wt%;
(3) mixing the slurry prepared in the step (1) with the acidic aqueous solution containing the P123 triblock copolymer prepared in the step (2); the mass ratio of the P123 triblock copolymer to the amorphous silica-alumina in the mixed system is 1.2:1, the crystallization temperature is 92 ℃, and the crystallization time is 18 hours; controlling the pH value to be 3.4 in the crystallization process;
(4) slurry containing 56.98g of USY molecular sieve (wherein the USY molecular sieve has the following properties: specific surface area 823 m2Per g, pore volume 0.52 mL. g-1,SiO2/Al2O3The USY molecular sieve slurry is prepared by pulping the USY molecular sieve and water at a molar ratio of 47) and pumping into the mixed system prepared in the step (3) by using a vacuum pump, drying at 100 ℃ for 4h and roasting at 550 ℃ for 3h after the crystallization time is 11h at the pH value of 4.8 and the temperature of 95 ℃, so as to obtain a finished product YAS-2.
48g of YAS-2 mesoporous-microporous composite molecular sieve and 52g of alumina (same as in example 1) are added into a rolling machine for rolling, after 23 minutes of rolling, an aqueous solution containing guar gum (0.4 wt%) and nitric acid (2.3 wt%) is added, the mixture is rolled into paste, strips are extruded, the extruded strips are dried for 3 hours at 120 ℃, and the obtained product is roasted for 3 hours at 550 ℃ to obtain a carrier Z2.
(II) catalyst preparation
The carrier Z2 is impregnated by impregnation liquid containing Mo, Ni and P in equal volume, dried at 120 ℃ for 3h, and roasted at 430 ℃ for 2h to finally obtain the catalyst C-2, and the properties of the catalyst are shown in Table 2.
Example 3
Preparation of hydrocracking catalyst carrier
(1) Preparation of amorphous silica-alumina dry gel powder A3 and slurry: sodium aluminate solution concentration 21gAl2O3Per L, sodium silicate working solution concentration 65gSiO2L, putting 0.83L of sodium aluminate solution into a gel forming tank, then adding 0.5L of sodium silicate solution, controlling the reaction temperature to be 32 ℃, and introducing 52 v% CO2Stopping gas when the pH value reaches 9.8, then ventilating and stabilizing for 20 minutes, washing to be neutral, adding water into a filter cake according to the solid-liquid volume ratio of 9: 1 for pulping, treating for 3 hours at 130 ℃ under the water vapor pressure of 3.9MPa, drying for 8 hours at 130 ℃, crushing and sieving to obtain an amorphous silica-alumina product A3. The properties of the amorphous silica-alumina dry gel powder A3 are shown in Table 1. Mixing the prepared amorphous silica-alumina A3 with deionized water, and pulping to form slurry; wherein the mass ratio of the amorphous silica-alumina dry gel to water is 19: 81;
(2) preparing an acidic aqueous solution containing a P123 triblock copolymer; adding the P123 triblock copolymer into dilute hydrochloric acid, wherein the concentration of a dilute hydrochloric acid solution is 0.16mol/L, the pH value of an acidic aqueous solution containing the P123 triblock copolymer is 1.8, the temperature of the acidic aqueous solution containing the P123 triblock copolymer is 33 ℃, and the mass content of the P123 triblock copolymer in the acidic aqueous solution containing the P123 triblock copolymer is 1.9 wt%;
(3) mixing the slurry prepared in the step (1) with the acidic aqueous solution containing the P123 triblock copolymer prepared in the step (2); the mass ratio of the P123 triblock copolymer to the amorphous silica-alumina in the mixed system is 1.3:1, the crystallization temperature is 96 ℃, and the crystallization time is 12 hours; the pH value is controlled to be 3.6 in the crystallization process,
(4) slurry containing 50.9g of USY molecular sieve (wherein the USY molecular sieve has the following properties of specific surface area of 795m2Per g, pore volume 0.54 mL. g-1,SiO2/Al2O3The molar ratio is 43: 1, pulping the USY molecular sieve with water) and pumping the USY molecular sieve and water into the mixed system prepared in the step (3) by using a vacuum pump, drying the USY molecular sieve at 100 ℃ for 4h and roasting the USY molecular sieve at 550 ℃ for 3h after the pH value is 4.9 and the temperature is 95 ℃ and the crystallization time is 10h, thus obtaining the finished product YAS-3.
50g of YAS-3 mesoporous-microporous composite molecular sieve and 60g of alumina (same as example 1) are added into a rolling machine for rolling, after 23 minutes of rolling, an aqueous solution containing guar gum (0.4 wt%) and nitric acid (2.3 wt%) is added, the mixture is rolled into paste, strips are extruded, the extruded strips are dried for 3 hours at 120 ℃, and the obtained product is roasted for 3 hours at 550 ℃ to obtain a carrier Z3.
(II) catalyst preparation
The carrier Z3 is impregnated by impregnation liquid containing Mo, Ni and P in equal volume, dried at 120 ℃ for 3h, and roasted at 430 ℃ for 2h to finally obtain the catalyst C-3, and the properties of the catalyst are shown in Table 2.
Example 4
Preparation of hydrocracking catalyst carrier
(1) Preparation of amorphous silica-alumina dry gel powder A4 and slurry: sodium aluminate solution concentration 25gAl2O3Per L, sodium silicate solution concentration 55gSiO2L, putting 0.5L of sodium aluminate solution into a gel forming tank, then adding 0.15L of sodium silicate solution, controlling the reaction temperature to be 35 ℃, and introducing 60v% CO2Stopping gas when the pH value reaches 9.5, then ventilating and stabilizing for 20 minutes, washing to be neutral, adding water into a filter cake according to the solid-liquid volume ratio of 8:1 for pulping, treating for 2.5 hours at the temperature of 130 ℃ under the water vapor pressure of 3.2MPa, drying for 8 hours at the temperature of 130 ℃, crushing and sieving to obtain an amorphous silica-alumina product A4. The properties of the amorphous silica-alumina dry gel powder A4 are shown in Table 1. Mixing the prepared amorphous silica-alumina A4 andmixing deionized water and pulping to form slurry; wherein the mass ratio of the amorphous silica-alumina dry gel to water is 24: 76;
(2) preparing an acidic aqueous solution containing a P123 triblock copolymer; adding the P123 triblock copolymer into dilute hydrochloric acid, wherein the concentration of a dilute hydrochloric acid solution is 0.16mol/L, the pH value of an acidic aqueous solution containing the P123 triblock copolymer is 1.8, the temperature of the acidic aqueous solution containing the P123 triblock copolymer is 33 ℃, and the mass content of the P123 triblock copolymer in the acidic aqueous solution containing the P123 triblock copolymer is 1.5 wt%;
(3) mixing the slurry prepared in the step (1) with the acidic aqueous solution containing the P123 triblock copolymer prepared in the step (2); the mass ratio of the P123 triblock copolymer to the amorphous silica-alumina in the mixed system is 1.8:1, the crystallization temperature is 96 ℃, and the crystallization time is 12 hours; controlling the pH value to be 3.6 in the crystallization process;
(4) slurry containing 79.25g of USY molecular sieve (wherein the USY molecular sieve has the following properties that the specific surface area is 798m2Per g, pore volume 0.51 mL. g-1,SiO2/Al2O3The USY molecular sieve slurry is prepared by pulping USY molecular sieve and water, and the USY molecular sieve slurry is prepared by beating the USY molecular sieve and water), pumping the USY molecular sieve slurry and the water into the mixed system prepared in the step (3) by using a vacuum pump, drying the USY molecular sieve slurry for 4 hours at the temperature of between 110 ℃ after the crystallization time is 12 hours at the pH value of 5.0, and roasting the USY molecular sieve slurry for 4 hours at the temperature of between 540 ℃ to obtain a finished product YAS-4.
46g of YAS-4 mesoporous-microporous composite molecular sieve and 54g of alumina (same as example 1) are added into a rolling machine for rolling, after 25 minutes of rolling, an aqueous solution containing guar gum (0.43 wt%) and nitric acid (2.3 wt%) is added, the mixture is rolled into paste, strips are extruded, the extruded strips are dried for 4 hours at the temperature of 120 ℃, and the extruded strips are roasted for 3 hours at the temperature of 550 ℃ to obtain a carrier Z4.
(II) catalyst preparation
The carrier Z4 is impregnated by impregnation liquid containing Mo, Ni and P in equal volume, dried for 3h at 120 ℃, and calcined for 3h at 440 ℃, and finally the obtained catalyst is marked as C-4, and the properties of the catalyst are shown in Table 1.
Comparative example 1
Preparation of hydrocracking catalyst carrier
Respectively weighing template agent triblock copolymer P123 and silicon source tetraethoxysilane, wherein the mass of the template agent P123 is 5.5g, and the mass of tetraethoxysilane is 10.2 g; adding a template agent and a silicon source into an HCl solution with the pH value of 2.8, and fully stirring for 30 hours at the temperature of 28 ℃; standing and crystallizing the stirred mixture for 20h at 120 ℃, washing with deionized water, and drying to obtain SBA-15. Pulping the obtained SBA-15 molecular sieve with a solid-to-liquid ratio of 1:10, adding the obtained SBA-15 molecular sieve into hydrochloric acid solution containing 23g of aluminum isopropoxide, heating to 100 ℃, stirring for 20 hours, and cooling to room temperature to obtain a mixed system F.
Pumping 12g of USY molecular sieve slurry (same as example 1) into a mixed system of the mixed solution F by a vacuum pump, drying at 110 ℃ for 4h after crystallization time of 12h at the pH value of 3.7 and the temperature of 100 ℃, and roasting at 540 ℃ for 4h to obtain a finished product YAS-5.
45g of YAS-5 molecular sieve and 55g of alumina (same as example 1) are added into a rolling machine for rolling, after 25 minutes of rolling, an aqueous solution containing guar gum (0.43 wt%) and nitric acid (2.3 wt%) is added, the mixture is rolled into paste, extruded strips are obtained, the extruded strips are dried for 4 hours at the temperature of 120 ℃, and the extruded strips are roasted for 3 hours at the temperature of 550 ℃ to obtain a carrier Z5.
(II) catalyst preparation
The carrier Z5 is impregnated by impregnation liquid containing Mo, Ni and P in equal volume, dried for 3h at 120 ℃, and calcined for 3h at 440 ℃, and finally the obtained catalyst is marked as C-5, and the properties of the catalyst are shown in Table 2.
Comparative example 2
Preparation of hydrocracking catalyst carrier
Adding 5g of P123 into 2mol/L125mL hydrochloric acid solution, and stirring at 40 ℃ until the P123 is completely dissolved; adding 8.5g of tetraethoxysilane into hydrochloric acid solution containing P123, stirring for 4 hours, adding aluminum nitrate to enable the molar ratio of silicon to aluminum to be 35, continuing to stir for 20 hours, adding the solution into a 250mL reaction kettle, stirring for 48 hours at 100 ℃, cooling to room temperature, adjusting the pH value to 7.5 by using 4mol of ammonia water solution, continuously stirring, heating to 100 ℃, stirring for 72 hours, and cooling to 40 ℃ to obtain mixed solution A for later use.
Pumping slurry containing 12g of USY molecular sieve (same as example 1) into a mixed system of the mixed solution A by a vacuum pump, drying at 110 ℃ for 4h after crystallization time of 12h at the pH value of 3.5 and the temperature of 100 ℃, and roasting at 540 ℃ for 4h to obtain a finished product YAS-6.
50g of YAS-6 molecular sieve and 60g of alumina (same as example 1) are added into a rolling machine for rolling, after 25 minutes of rolling, an aqueous solution containing guar gum (0.43 wt%) and nitric acid (2.3 wt%) is added, the mixture is rolled into paste, extruded strips are obtained, the extruded strips are dried for 4 hours at the temperature of 120 ℃, and the extruded strips are roasted for 3 hours at the temperature of 550 ℃ to obtain a carrier Z6.
(II) catalyst preparation
The carrier Z6 is impregnated by impregnation liquid containing Mo, Ni and P in equal volume, dried for 3h at 120 ℃, and calcined for 3h at 440 ℃, and finally the obtained catalyst is marked as C-6, and the properties of the catalyst are shown in Table 2.
Examples 5 to 9
Catalyst activity evaluation experiments were carried out using the catalysts C-1 to C-4 prepared in examples 1 to 4, respectively, specifically:
the properties of the feed oil used in the one-stage series process carried out on a 200mL small scale hydrogenation unit are shown in Table 3. The operating conditions were as follows: the reaction temperature is 371 ℃, the hydrogen partial pressure is 14.5MPa, and the volume ratio of hydrogen to oil is 1200: 1, liquid hourly space velocity of 1.5h-1. The results of the catalyst activity tests are shown in Table 4.
Comparative examples 3 to 4
The catalysts C-5 and C-6 prepared in comparative examples 1 to 2 were used for evaluation of catalyst activity, and the specific method was the same as in examples 5 to 9.
TABLE 1 Properties of Y/Al-SBA-15 composite molecular sieves obtained in examples and comparative examples
Item
|
YAS-1
|
YAS-2
|
YAS-3
|
YAS-4
|
YAS-5
|
YAS-6
|
Alumina content, wt%
|
23.56
|
31.53
|
35.17
|
61.3
|
17.49
|
20.56
|
Specific surface area, m2/g
|
769
|
756
|
782
|
763
|
716
|
718
|
Pore volume, mL/g
|
0.58
|
0.62
|
0.57
|
0.63
|
0.44
|
0.47
|
Relative degree of crystallinity after firing at 900%
|
98
|
97
|
98
|
98
|
87
|
86
|
Acid amount of medium strong acid, mL/g
|
0.72
|
0.76
|
0.82
|
0.85
|
0.63
|
0.67
|
B/L
|
0.228
|
0.245
|
0.233
|
0.251
|
1.20
|
1.26
|
Hole distribution,%
|
|
|
|
|
|
|
4~15nm
|
55.25
|
56.37
|
62.08
|
61.03
|
35.47
|
32.32
|
>15nm
|
4.86
|
3.28
|
4.35
|
4.15
|
15.37
|
11.03 |
TABLE 2 Properties of catalysts obtained in examples and comparative examples
Catalyst numbering
|
C-1
|
C-2
|
C-3
|
C-4
|
C-5
|
C-6
|
Molecular sieve content,%
|
36.0
|
38.06
|
40.1
|
36.61
|
36.0
|
40.5
|
MoO3,%
|
15.3
|
15.5
|
14.9
|
15.1
|
15.6
|
15.2
|
NiO,%
|
5.6
|
5.2
|
4.9
|
5.3
|
5.1
|
4.8
|
Specific surface area, m2/g
|
238
|
245
|
243
|
239
|
186
|
192
|
Pore volume, mL/g
|
0.38
|
0.39
|
0.41
|
0.37
|
0.31
|
0.32 |
TABLE 3 Properties of the feed oils
Density (20 ℃ C.)/g.cm-3 |
0.898
|
Distillation range/. degree.C
|
|
IBP/10%
|
332/387
|
30%/50%
|
432/468
|
70%/90%
|
506/569
|
93%
|
575
|
S,μg·g-1 |
12300
|
N,μg·g-1 |
1058 |
TABLE 4 evaluation results of catalyst performances obtained in examples and comparative examples
Catalyst numbering
|
C-1
|
C-2
|
C-3
|
C-4
|
C-5
|
C-6
|
Yield of light naphtha,%
|
1.8
|
1.5
|
1.7
|
2.1
|
3.2
|
2.8
|
Heavy naphtha yield,%
|
40.5
|
41.6
|
40.1
|
41.8
|
35.2
|
34.3
|
Heavy naphtha arena%
|
62.5
|
62.8
|
62.3
|
63.1
|
58.6
|
59.3
|
Jet fuel yield%
|
18.9
|
18.2
|
17.8
|
17.3
|
21.8
|
22.3
|
Jet fuel smoke point, mm
|
29
|
30
|
28
|
29
|
22
|
21
|
Yield of diesel oil,% of
|
10.5
|
10.8
|
10.3
|
10.1
|
12.3
|
12.6
|
Cetane index of diesel oil
|
75.8
|
75.6
|
74.9
|
75.1
|
73.1
|
72.7
|
Yield of tail oil,%
|
27.8
|
27.1
|
28.9
|
27.6
|
27.3
|
27.4
|
BMCI value
|
6.5
|
6.8
|
6.3
|
6.6
|
11.5
|
10.8 |
As can be seen from Table 4, the hydrocracking catalyst of the present invention has high heavy naphtha yield and excellent product quality.
TABLE 5 Properties of amorphous silica-alumina
Amorphous silica-alumina numbering
|
A1
|
A2
|
A3
|
A4
|
Specific surface area, m2/g
|
485
|
511
|
503
|
518
|
Pore volume, mL/g
|
1.31
|
1.27
|
1.30
|
1.33
|
Hole distribution,%
|
|
|
|
|
4~15nm
|
91
|
86
|
85
|
88
|
>15nm
|
2.5
|
3.8
|
4.7
|
4.2 |