A metal contamination resistant catalytic cracking catalyst and a method for preparing the same

Abstract

The present application belongs to the technical field of catalyst preparation, and relates to a preparation method of a catalytic cracking catalyst resistant to metal pollution. After the catalyst microspheres are treated with organic acid and inorganic acid, the catalyst microspheres are first treated with a mixed solution of rare earth salt and alkaline earth metal salt and then treated with ammonia water. The preparation method of the catalyst microspheres comprises the following steps: calcining microspheres comprising unmodified NaY molecular sieve, an alumina binder, a silica binder and clay at 280-380 DEG C, performing rare earth ion exchange, treating at a temperature of 350-450 DEG C and under a condition of containing 40-60% by volume of water vapor, and modifying by using SiCl4 gas phase ultra-stability. The catalytic cracking catalyst prepared by the method has high pore volume, high specific surface area, good strength, strong resistance to nickel and vanadium pollution, and is used for heavy oil conversion, has high activity, high gasoline yield, high total liquid yield, and good dry gas and coke selectivity.

Description

TECHNICAL FIELD

[0001] The present application relates to a catalytic cracking catalyst resistant to metal contamination and a preparation method thereof. BACKGROUND

[0002] With the heavy and poor quality of crude oil in the world in recent years, catalytic cracking technology (FCC) of blending or full refining heavy oil and residual oil is particularly important. Compared with distillate catalytic cracking feedstock oil, the harmful metal content in heavy oil or residual oil is much higher than that in distillate oil. In the form of porphyrin compounds, naphthenate, inorganic salts and the like, harmful metals such as nickel, vanadium, iron, sodium and calcium exist in the feedstock oil, which decompose and enrich on the equilibrium agent during the catalytic cracking reaction process, interact with the molecular sieve, destroy the crystal lattice structure of the catalyst, weaken the acidity of the molecular sieve, and make the catalyst activity and selectivity worse, thereby affecting the product distribution and product quality. Effective inhibition of heavy metal contamination of the catalyst is one of the key measures to improve the economic and technical benefits of the RFCC device.

[0003] CN1854255A discloses a preparation method of a cracking catalyst resistant to heavy metal contamination. The method uniformly mixes clay, deionized water and optional additives to prepare a clay slurry, uniformly mixes molecular sieve, deionized water and optional additives to prepare a molecular sieve slurry, uniformly mixes a binder, deionized water, an alkaline earth metal compound, a rare earth metal compound and an optional inorganic acid to prepare a binder slurry, and uniformly mixes the above clay slurry, molecular sieve slurry and binder slurry and then dries. The cracking catalyst prepared by the method has good resistance to nickel and vanadium contamination, and when the nickel content on the catalyst is high, it can still maintain high conversion rate and light oil yield. However, the catalyst prepared by this method has the alkaline earth metal compound and the rare earth metal compound mainly distributed in the interior of the catalyst, and the resistance to nickel and vanadium contamination is limited to a certain extent.

[0004] The catalytic cracking catalyst usually contains a binder and an active component, and the active component has a great influence on the activity and coke selectivity of the catalytic cracking catalyst. A commonly used active component in the catalytic cracking catalyst is Y-type molecular sieve. In order to improve the activity and coke selectivity of Y molecular sieve for heavy oil conversion, the Y molecular sieve is usually modified by ultrastabilization and then mixed with a binder and the like to be slurried. The catalyst containing ultrastable Y-type molecular sieve in the prior art is difficult to further improve the performance when used for heavy oil conversion.

[0005] CN102806096A discloses a preparation method of a rare earth-containing Y-type molecular sieve cracking catalyst, which comprises the following steps: (1) mixing, beating and spray-drying a NaY molecular sieve which has not been ion-exchanged with a matrix to obtain a catalyst precursor; (2) performing first calcination on the catalyst precursor at a temperature of 200 DEG C to less than 400 DEG C, and performing ammonium ion exchange on the product obtained after the first calcination; and (3) performing at least one second calcination and at least one rare earth ion exchange on the product obtained after the ammonium ion exchange, wherein the rare earth ion exchange is performed after the second calcination; the temperature of the ammonium ion exchange is higher than that of the rare earth ion exchange; and the temperature of the second calcination is higher than that of the first calcination. However, the catalyst obtained by the method has low activity stability in a heavy oil catalytic cracking reaction, and the heavy oil conversion activity of the product is not high after the introduction of a metal pollution-resistant component. SUMMARY

[0006] The present application aims to provide a new preparation method of a metal pollution-resistant catalytic cracking catalyst containing a Y-type molecular sieve.

[0007] The present application provides a preparation method of a metal pollution-resistant catalytic cracking catalyst, which comprises the following steps:

[0008] (S1): forming first microspheres comprising a Y-type molecular sieve, an alumina binder, a silica binder and clay;

[0009] (S2): contacting the first microspheres with a solution of inorganic acid and organic acid to remove non-framework aluminum of the molecular sieve, filtering, washing, and obtaining second microspheres;

[0010] (S3): contacting the second microspheres with a mixed solution containing a rare earth salt and an alkaline earth metal salt, filtering, then contacting with ammonia water, filtering, drying and calcining to obtain a finished catalytic cracking catalyst.

[0011] The weight ratio of the alumina binder calculated as alumina to the silica binder calculated as silicon oxide in the first microspheres is 2-15:10-30;

[0012] The weight ratio of the Y-type molecular sieve calculated as dry basis to the silica binder calculated as silicon oxide in the first microspheres is preferably 10-50:10-30.

[0013] The weight ratio of the clay calculated as dry basis to the silica binder calculated as silicon oxide in the first microspheres is preferably 10-80:10-30.

[0014] In step (S2), the first microspheres are contacted with a solution of inorganic acid and organic acid, preferably at a temperature of 25-70°C; the contacting can be performed sequentially with a solution of inorganic acid and a solution of organic acid, or with a solution containing both inorganic acid and organic acid; the molar concentration of inorganic acid in the solution containing inorganic acid (solution of inorganic acid or solution containing both inorganic acid and organic acid) is preferably 0.01-0.15 mol / L, and the weight ratio of the solution containing inorganic acid to the first microspheres (dry basis) is 6-12:1; the weight ratio of organic acid to the first microspheres (dry basis) is 0.02-0.10:1.

[0015] In step (S3), in one way, the second microspheres are contacted with a solution containing rare earth salt and alkaline earth metal salt at room temperature for 5-30 minutes, then filtered, then contacted with ammonia water for 5-30 minutes, filtered, dried, and calcined to obtain the finished catalytic cracking catalyst.

[0016] The rare earths in the present application are, for example, La, Ce, Pr, Nd, or a mixed rare earth containing one or more of the above-mentioned rare earth elements.

[0017] The alkaline earth metal is, for example, one or more of Be, Mg, Ca, Sr, Ba, preferably Mg and / or Ca, and more preferably Mg.

[0018] The rare earth salt in step (S3) is preferably lanthanum nitrate and / or lanthanum chloride, and the alkaline earth metal salt is preferably magnesium nitrate and / or magnesium chloride.

[0019] Preferably, in step (S3), the concentration of rare earth salt in the solution containing rare earth salt and alkaline earth metal salt is 60-150 g / L as RE2O3, and the concentration of alkaline earth metal salt is 30-80 g / L as the oxide of the alkaline earth metal.

[0020] The concentration of ammonia water is preferably 5-15% by weight as NH3.

[0021] The weight ratio of the mixed solution containing rare earth salt and alkaline earth metal salt to the second microspheres (dry basis) is preferably 3-6:1.

[0022] Preferably, the content of rare earth in the finished catalytic cracking catalyst obtained in step (S3) is 0.2-1% by weight higher than the content of rare earth in the second microspheres, as RE2O3.

[0023] The content of rare earth in the finished catalytic cracking catalyst obtained in step (S3) is preferably 1-6% by weight, for example 1.2-5.8% by weight, as RE2O3.

[0024] The catalyst preparation method provided by the present application can improve the anti-metal contamination effect of the anti-metal contamination catalyst, and the heavy oil conversion activity of the catalytic cracking catalyst is higher in the presence of metal contamination. Preferably, the catalytic cracking catalyst preparation method provided by the present application can prepare a catalytic cracking catalyst with a larger specific surface area, a higher pore volume, a better strength (good wear resistance), a higher gasoline yield, a higher total liquid yield, a better coke selectivity, and a stronger heavy oil conversion capacity. The catalytic cracking catalyst preparation method provided by the present application can obtain a catalytic cracking catalyst with a sodium oxide content of less than 0.15% by weight, and effectively solves the ammonia-nitrogen pollution problem that urgently needs to be solved in the production of catalytic cracking catalysts. DETAILED DESCRIPTION

[0025] The present application provides a preparation method of an anti-metal contamination catalytic cracking catalyst, preferably, the method comprises:

[0026] (1) mixing an unmodified NaY molecular sieve with an alumina binder, a silica binder (also referred to as a silicon binder in the present application), clay and water, beating, spray drying and forming, and calcining at 280-380°C, preferably for 1-4 hours, to obtain catalyst microspheres A; the alumina binder is an aluminum sol;

[0027] (2) contacting the catalyst microspheres A with a rare earth solution to perform an ion exchange reaction, filtering and washing to obtain rare earth-containing catalyst microspheres B with a reduced sodium oxide content; the rare earth solution is also referred to as a rare earth salt solution;

[0028] (3) modifying the catalyst microspheres B, and optionally drying to obtain catalyst microspheres C containing molecular sieves with a reduced unit cell constant, wherein the modification treatment is calcining the catalyst microspheres B at a temperature of 350-450°C in an atmosphere containing 40-60% by volume of water vapor (also referred to as a 40-60% by volume water vapor atmosphere or 40-60% water vapor) for 4-6 hours; the unit cell constant of the molecular sieves in the catalyst microspheres C containing molecular sieves with a reduced unit cell constant is preferably 24.61-24.64 nm; wherein the water content of the catalyst microspheres C is preferably not more than 1% by weight;

[0029] (4) contacting the catalyst microspheres C with SiCl4 gas at a temperature of 250 to 450° C., wherein the weight ratio of SiCl4 to catalyst microspheres C on a dry basis is 0.03 to 0.2:1, and the reaction time is 10 minutes to 5 hours, followed by washing and filtering to obtain catalyst microspheres D; if the water content of the catalyst microspheres C obtained by the modification treatment in step (3) does not exceed 1% by weight, the catalyst microspheres C can be directly contacted with silicon tetrachloride to carry out the reaction; if the water content of the catalyst microspheres C exceeds 1% by weight, preferably, the catalyst microspheres C are dried to reduce the water content to less than 1% by weight, and then contacted with silicon tetrachloride for reaction;

[0030] (5) contacting the catalyst microspheres D with an inorganic acid and an organic acid solution at a temperature of 25-70° C. for at least 60 minutes, for example, 60-120 minutes, and filtering, washing, and drying to obtain catalyst microspheres E;

[0031] (6) The catalyst microspheres E are contacted with a mixed solution containing a rare earth salt and an alkaline earth metal salt, filtered, and then contacted with ammonia water, filtered, dried, and calcined. Preferably, the catalyst microspheres E are added to a mixed solution containing a rare earth salt and an alkaline earth metal salt at room temperature, stirred, preferably for 5-30 minutes, and then filtered. Then, the catalyst microspheres E are added to an ammonia water with an NH3 concentration of 10-15% by weight, stirred, preferably for 5-30 minutes, filtered, dried, and calcined to obtain a finished catalyst F, i.e., the catalytic cracking catalyst provided by the present invention. In the mixed solution of rare earth salt and alkaline earth metal salt, the rare earth salt is preferably lanthanum nitrate and / or lanthanum chloride, and the alkaline earth metal salt is magnesium nitrate and / or magnesium chloride. The room temperature is preferably 10-30°C. This preferred preparation method can prepare a catalytic cracking catalyst with a large specific surface area, a high pore volume, good strength (good wear resistance), a high gasoline yield, good coke selectivity, and a stronger heavy oil conversion ability. The resulting catalytic cracking catalyst can contain less than 0.15% sodium oxide by weight, effectively addressing the urgent ammonia nitrogen pollution problem in catalytic cracking catalyst production. The catalytic cracking catalyst obtained by the preferred catalytic cracking catalyst preparation method exhibits high activity stability despite metal contamination. When used in heavy oil catalytic cracking reactions, it exhibits high heavy oil conversion activity, high gasoline yield, and low coke selectivity and dry gas selectivity.

[0032] The catalytic cracking catalyst preparation method provided by the present application, in step (1), the unmodified NaY molecular sieve is mixed with an alumina binder, a silica binder, clay and water, wherein the weight ratio of the alumina binder calculated based on alumina and the unmodified NaY molecular sieve calculated based on dry basis is 2-15:10-50, the weight ratio of the silica binder calculated based on silica and the unmodified NaY molecular sieve calculated based on dry basis is 10-30:10-50, and the weight ratio of the clay calculated based on dry basis and the unmodified NaY molecular sieve calculated based on dry basis is 10-80:10-50.

[0033] The catalytic cracking catalyst preparation method provided by the present application, in step (1), the unmodified NaY molecular sieve is mixed with an alumina binder, a silica binder, clay and water, and is slurried to form a slurry, which can be operated without heating and aging. The mixing and slurring process without heating can avoid the viscosity of the slurry caused by heating, which cannot be transported, and is beneficial to improve the solid content of the slurry, improve the production efficiency, and also beneficial to reduce the energy consumption, thereby reducing the production cost.

[0034] In one embodiment, the mixing and slurring is performed at ambient temperature, for example, room temperature (room temperature is 10-30℃), the unmodified NaY molecular sieve, the aluminum sol and silica sol binder, clay and water are mixed, and then stirred for more than 30 minutes, for example, 30-180 minutes or 30-60 minutes for slurring, and the mixing and slurring process can be performed without heating and aging.

[0035] According to the catalytic cracking catalyst preparation method provided by the present application, the unmodified NaY molecular sieve is mixed with an aluminum binder such as aluminum sol and a silica binder such as silica sol, clay and water, and is slurried, and the mixing and slurring method has no special requirements compared with the existing catalytic cracking catalyst preparation method. For example, the clay such as kaolin and / or other clay can be slurried with the aluminum sol and the silica sol to prepare a matrix slurry, and then the matrix slurry is mixed and slurried with the unmodified NaY molecular sieve or the unmodified NaY molecular sieve slurry to obtain a catalyst colloid. The solid content of the catalyst colloid is preferably 28-40% by weight.

[0036] According to the catalytic cracking catalyst preparation method provided by the present application, the content of the unmodified NaY molecular sieve in the catalyst microspheres A calculated based on dry basis is 10-50% by weight, preferably 15-45% by weight or 20-50% by weight, for example, 25-40% by weight.

[0037] The unmodified NaY molecular sieve used in the preparation of the catalytic cracking catalyst according to the present application is preferably a hydrothermally synthesized NaY molecular sieve which is washed only with water, for example, industrial water, and the pH value of the filter cake of the NaY molecular sieve after washing is 7 to 9, preferably 7.0 to 8.0. The hydrothermally synthesized NaY molecular sieve can be commercially available or synthesized according to the prior art, for example, according to the method provided in the claims or examples of U.S. Patents Nos. 3,639,099 and 3,671,191. The industrial water is well known to those skilled in the art.

[0038] According to the preparation method of the catalytic cracking catalyst provided by the present application, the content of the clay in the catalyst microspheres A is preferably 20 to 55 wt%, for example, 30 to 50 wt% or 40 to 50 wt% on a dry basis. The clay is selected from one or more of the clays used as a component of a cracking catalyst, for example, one or more of kaolin, halloysite, montmorillonite, diatomite, attapulgite, saponite, rectorite, sepiolite, hydrotalcite, and bentonite. These clays are well known to those skilled in the art.

[0039] According to the preparation method of the catalytic cracking catalyst provided by the present application, the alumina binder is an aluminum sol, and preferably, the catalyst microspheres A contain 2 to 15 wt% of the aluminum sol, for example, 2 to 10 wt%, preferably 3 to 5 wt% on an alumina basis.

[0040] The content of the silica binder, for example, a silica sol, in the catalyst microspheres A is 10 to 30 wt%, preferably 10 to 25 wt% or 20 to 25 wt% on a silica basis.

[0041] Preferably, the catalyst microspheres A contain 10 to 50 wt% of the unmodified NaY molecular sieve on a dry basis, 2 to 15 wt% of the alumina binder on an alumina basis, 10 to 30 wt% of the silica binder on a silica basis, and 10 to 80 wt% of the clay on a dry basis, based on the weight of the catalyst microspheres A. For example, the catalyst microspheres A contain 20 to 50 wt% of the unmodified NaY molecular sieve on a dry basis, 20 to 55 wt% of the clay on a dry basis, 3 to 5 wt% of the aluminum sol on an alumina basis, and 10 to 25 wt% of the silica sol on a silica basis.

[0042] According to the preparation method of the catalytic cracking catalyst provided by the present application, other molecular sieves besides the unmodified NaY type molecular sieve can also be added in the mixing and beating process. The content of the other molecular sieves in the catalyst microspheres A can be 0-40 wt%, for example, 0-30 wt% or 1-20 wt% based on the dry basis and with the weight of the catalyst microspheres A as the basis. The other molecular sieves are selected from the molecular sieves used in the catalytic cracking catalyst, for example, one or more of the following: a zeolite with MFI structure, a Beta zeolite, and a non-zeolite molecular sieve. The zeolite with MFI structure is for example one or more of the following: ZRP, HZSM-5, and ZSP zeolite; the beta zeolite is for example Hβ; and the non-zeolite molecular sieve is for example one or more of the following: an aluminum phosphate molecular sieve (AlPO molecular sieve) or a silicon-aluminum-phosphorus molecular sieve (SAPO molecular sieve).

[0043] According to the preparation method of the catalytic cracking catalyst provided by the present application, in step (1), the method of spray drying has no special requirements and can be performed according to the method of spray drying in the existing preparation process of the cracking catalyst.

[0044] According to the preparation method of the catalytic cracking catalyst provided by the present application, in step (1), the spray drying is performed to form the catalyst microspheres, and then the catalyst microspheres are calcined. The calcination temperature is 280-380°C, preferably 300-350°C; and the calcination time is 1-4 hours, for example, 1 hour, 2 hours, 3 hours, or 4 hours.

[0045] According to the preparation method of the catalytic cracking catalyst provided by the present application, in step (2), the catalyst microspheres A are contacted with a rare earth solution to perform an ion exchange reaction. The temperature of the ion exchange reaction can be 20-60°C, preferably 25-45°C, and the exchange time can be more than 60 minutes, preferably 60-120 minutes. The rare earth salt solution (referred to as a rare earth solution) is an aqueous solution of a rare earth salt, and the rare earth salt is preferably a rare earth chloride and / or a rare earth nitrate. In one embodiment, the concentration of the rare earth salt solution is 200-350 g / L in terms of RE2O3, and the weight ratio of the rare earth salt solution to the catalyst microspheres A is 0.03-0.3.

[0046] Preferably, the content of the rare earth in the catalyst microspheres B obtained by the ion exchange is 1-5 wt% in terms of RE2O3.

[0047] According to the preparation method of the catalytic cracking catalyst provided by the present application, in step (3), the catalyst microspheres B are subjected to a modification treatment (the treatment is referred to as a mild hydrothermal ultrastable modification treatment) at a temperature or a calcination temperature of 350-450°C, preferably 370-420°C.

[0048] The modification treatment atmosphere in step (3) of the preparation method of the catalytic cracking catalyst provided by the present application is an atmosphere containing 40-60% by volume of water vapor, preferably an atmosphere containing 45-55% by volume of water vapor.

[0049] The modification treatment time or the calcination time in step (3) of the preparation method of the catalytic cracking catalyst provided by the present application is 4-6 hours, preferably 5-6 hours.

[0050] The reaction temperature of the contact reaction of the catalyst microspheres C with SiCl4 gas in step (4) of the preparation method of the catalytic cracking catalyst provided by the present application is 250-450°C, preferably 280-420°C.

[0051] The reaction time of the contact reaction of the catalyst microspheres C with SiCl4 gas in step (4) of the preparation method of the catalytic cracking catalyst provided by the present application is 10 minutes to 5 hours, for example 0.2-2 hours, preferably 0.5 hour to 2 hours.

[0052] The weight ratio of the reactants SiCl4 and the catalyst microspheres C in the contact reaction of the catalyst microspheres C with SiCl4 gas in step (4) of the preparation method of the catalytic cracking catalyst provided by the present application is 0.03-0.2:1, preferably 0.05-0.15:1.

[0053] In step (5) of the preparation method of the catalytic cracking catalyst provided by the present application, the catalyst microspheres D are contacted with an acid solution for acid treatment modification. The acid is an organic acid and an inorganic acid. Preferably, the catalyst microspheres D are contacted with the inorganic acid and the organic acid solution at a temperature of 25-70°C for at least 60 minutes, which can have a better effect of increasing the pore volume. In an embodiment, the catalyst microspheres D are first treated with the inorganic acid and then treated with the inorganic acid and the organic acid, and the treatment temperature is preferably 25-70°C, and the treatment time is preferably at least 60 minutes for each. The inorganic acid is preferably an inorganic acid with a medium strength or above. In the acid solution, the molar concentration of the inorganic acid with a medium strength or above is preferably 0.01-0.15 mol / L (M). The molar concentration of the organic acid in the acid solution is preferably 0.004-0.1 mol / L, for example 0.01-0.05 mol / L. The weight ratio of water in the solution to the catalyst microspheres D (dry basis) is preferably 5-15:1.

[0054] In one embodiment, in step (5), the catalyst microspheres D obtained in step (4) are mixed with a solution of an inorganic acid of medium strength or above, and are contacted at 25-70°C, preferably 40-60°C, for at least 60 minutes, for example 60-120 minutes, then an organic acid is added, and the mixture is contacted at 25-70°C, preferably 40-60°C, for at least 60 minutes, for example 60-120 minutes, and then filtered, washed and dried to obtain catalyst microspheres E. Preferably, the weight ratio of the solution of the inorganic acid of medium strength or above to catalyst microspheres D (on a dry basis) is 6-12:1, the solution of the inorganic acid of medium strength or above is an aqueous solution of an inorganic acid of medium strength or above, wherein the molar concentration of the inorganic acid of medium strength or above is 0.01M-0.15M, and the weight ratio of the organic acid to catalyst microspheres D (on a dry basis) is 0.02-0.10:1.

[0055] The inorganic acid of medium strength or above is, for example, one or more of hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid; and the organic acid is, for example, one or more of formic acid, acetic acid, citric acid, oxalic acid and tartaric acid.

[0056] In the preparation method of the catalytic cracking catalyst provided by the present application, in step (6), the mixed solution containing rare earth salt and alkaline earth metal salt, wherein the rare earth salt can be lanthanum nitrate and / or lanthanum chloride, and the alkaline earth metal salt can be magnesium nitrate and / or magnesium chloride; the ammonia water in step (6) is an aqueous solution of ammonia gas; the temperature for contacting catalyst microspheres E with the mixed solution containing rare earth salt and alkaline earth metal salt is room temperature; and the temperature for contacting catalyst microspheres E with ammonia water is room temperature, and the room temperature is 10-30°C.

[0057] The following examples will further illustrate the present application, but are not intended to limit the present application.

[0058] The unmodified NaY molecular sieve (also referred to as NaY zeolite) used in the examples and comparative examples was provided by Qilu Branch of Sinopec Catalyst Co., Ltd., with a sodium oxide content of 13.5% by weight, a framework silicon-aluminum ratio (molar ratio of SiO2 / Al2O3) = 4.6, a unit cell constant of 2.470 nm, and a relative crystallinity of 90%, which was an originally synthesized NaY molecular sieve that was subjected to industrial water washing and the pH value of the filter cake after washing was 7.6; the magnesium chloride, magnesium nitrate, lanthanum chloride, and lanthanum nitrate were chemical pure reagents produced by Beijing Chemical Plant, and the chlorinated rare earth and nitric acid rare earth (denoted as RECl3 and RE(NO3)3, respectively, mixed rare earth, with a La2O3 content of 33.6% by weight and a Ce2O3 content of 66.4% by weight) were industrial products produced by Baogang Rare Earth Co., Ltd. The kaolin was a special kaolin for cracking catalyst produced by Suzhou China Kaolin Co., Ltd., with a solid content of 76% by weight; the aluminum sol was provided by Qilu Branch of Sinopec Catalyst Co., Ltd., with an aluminum oxide content of 21% by weight; and the silicon sol was provided by Qilu Branch of Sinopec Catalyst Co., Ltd., with a silicon oxide content of 25% by weight and a pH value of 2.5.

[0059] Analysis method: In each of the comparative examples and examples, the element content of the catalyst was determined by X-ray fluorescence spectrometry; the unit cell constant and the relative crystallinity of the zeolite in the catalyst were determined by X-ray powder diffraction (XRD) according to the standard methods of RIPP145-90 and RIPP146-90 (see Petroleum Chemical Industry Analysis Methods (RIPP Test Methods), edited by Yang Cuiding, et al., Science Press, published in 1990). The specific surface area of the catalyst was detected by an Autosorb-1 nitrogen adsorption-desorption instrument of Quantachrome Corporation of the United States according to the method of GB / T5816-1995, and the sample needed to be degassed at 300°C for 6 hours before testing. The total pore volume of the catalyst was detected according to the standard method of RIPP151-90 (see Petroleum Chemical Industry Analysis Methods (RIPP Test Methods), edited by Yang Cuiding, et al., Science Press, published in 1990). The attrition index of the catalyst (used to represent the attrition resistance, and the smaller the attrition index, the better the attrition resistance) was detected according to the standard method of RIPP29-90 (see Petroleum Chemical Industry Analysis Methods (RIPP Test Methods), edited by Yang Cuiding, et al., Science Press, published in 1990).

[0060] The specifications of the chemical reagents used in the comparative examples and examples were not specifically indicated, which were chemical pure.

[0061] Example 1

[0062] (1) In a catalyst gelation kettle, 150 Kg of deionized water was added, then, under stirring, the following gelation raw materials were added in sequence: 52.1 Kg of kaolin (solid content 76 wt%, purchased from Suzhou Kaolin Co.), 21 Kg of aluminum sol (alumina content 21.5%, product of Qilu Branch, Sinopec Catalyst Co., Ltd.), 86.4 Kg of silica sol (SiO2 content 25 wt%, product of Qilu Branch, Sinopec Catalyst Co., Ltd., pH value 2.5), and stirring was performed for 30 minutes. Then, 24.3 Kg (based on dry NaY) of unmodified NaY molecular sieve slurry (concentration 53 wt%, product of Qilu Branch, Sinopec Catalyst Co., Ltd.) was added, and stirring was performed for 60 minutes. Then, spray drying was performed, and calcination was performed in a calcination furnace at 310°C for 2 hours, to obtain catalyst microspheres A1;

[0063] (2) The catalyst microspheres A1 prepared above were added to a 900 L deionized water solution, and stirring was performed to uniformly mix them, 7.36 L of RE(NO3)3 solution (rare earth solution concentration 330 g / L based on RE2O3) was added, stirring was performed, and the temperature was raised to 30°C and maintained for 1 h, then filtration and washing were performed, and the filter cake was dried at 120°C to obtain rare earth-containing catalyst microspheres B1 with reduced sodium oxide content;

[0064] (3) The catalyst microspheres B1 above were calcined at a temperature of 410°C in an atmosphere containing 45 vol% water vapor for 6 h, then drying treatment was performed to reduce the water content to less than 1 wt%, to obtain catalyst microspheres C1 containing molecular sieves with reduced unit cell constant;

[0065] (4) SiCl4 gas was introduced in a heated and vaporized state under the condition of a temperature of 400°C for 30 min, according to a weight ratio of SiCl4 : catalyst microspheres C1 (dry basis) = 0.05 : 1, to obtain catalyst microspheres D1;

[0066] (5) The catalyst microspheres D1 were subjected to acid treatment modification by being contacted with an acid solution. The catalyst microspheres D1 were added to a 0.08 M hydrochloric acid solution, the weight ratio of the 0.08 M hydrochloric acid solution to the catalyst microspheres (dry basis) was 10:1, stirring was performed at 50°C for 75 min, then citric acid was added, the weight ratio of the citric acid to the catalyst (dry basis) was 0.02:1, stirring was performed at 50°C for 70 min, and filtration and washing were performed, to obtain catalyst microspheres E1.

[0067] (6) 10 Kg of the catalyst microspheres E1 were added into a mixed solution containing LaCl3 (concentration of 120 g / L as La2O3) and MgCl2 (concentration of 55 g / L as MgO) in 25 L and stirred for 5 minutes, then filtered, and then added into 22 L of ammonia water with a concentration of 11% by weight, stirred for 5 minutes, filtered, dried, and calcined at 550°C for 2 hours to obtain the catalyst product SCAT-1, and the performance analysis results are shown in Table 1.

[0068] Example 2

[0069] (1) 154 Kg of deionized water was added into a catalyst gelation kettle, and then the gelation raw materials were sequentially added under stirring: 59.3 Kg of kaolin (solid content of 76% by weight, purchased from Suzhou Kaolin Company), 16.8 Kg of aluminum sol (alumina content of 21.5% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.), and 79.2 Kg of silica sol (SiO2 content of 25% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.), and stirred for 30 minutes. Then, 22.5 Kg (based on dry NaY) of unmodified NaY molecular sieve slurry (concentration of 53% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.) was added, and stirred for 60 minutes. Then, spray drying and molding were performed, and calcination was performed in a calcination furnace at 350°C for 1 hour to obtain catalyst microspheres A2;

[0070] (2) The catalyst microspheres A2 prepared above were added into a 900 L deionized water solution and stirred to mix uniformly, and 6.1 L of RE(NO3)3 solution (rare earth solution concentration of 330 g / L as RE2O3) was added, stirred, and heated to 40°C for 1 h, and then filtered, washed, and the filter cake was dried at 120°C to obtain rare earth-containing catalyst microspheres B2 with reduced sodium oxide content;

[0071] (3) The catalyst microspheres B2 above were calcined at a temperature of 350°C in an atmosphere containing 55% by volume of water vapor for 6 h, and then dried to a water content of less than 1%, to obtain catalyst microspheres C2 containing molecular sieves with reduced unit cell constant;

[0072] (4) SiCl4 gas was introduced according to a weight ratio of SiCl4: catalyst microspheres C2 (dry basis) = 0.08:1, and the SiCl4 gas was vaporized by heating, and the reaction was performed at a temperature of 300°C for 2 h, and then washed with 900 L of deionized water, and then filtered, and the filter cake was dried at 120°C for 5 hours to obtain catalyst microspheres D2;

[0073] (5) The catalyst microspheres D2 were modified by acid treatment by contacting with an acid solution. The catalyst microspheres D2 were added to a 0.05 M sulfuric acid solution, the weight ratio of the 0.05 M sulfuric acid solution to the catalyst microspheres D2 on a dry basis was 8:1, and the mixture was stirred at 60°C for 90 minutes. Then, tartaric acid was added, the weight ratio of the tartaric acid to the catalyst on a dry basis was 0.025:1, and the mixture was stirred at 85°C for 80 minutes. After filtration and washing, catalyst microspheres E2 were obtained.

[0074] (6) 10 Kg of the catalyst microspheres E2 were added to a 30 L mixed solution containing La(NO3)3(concentration of 100 g / L as La2O3) and Mg(NO3)2(concentration of 45 g / L as MgO) under room temperature conditions, stirred for 5 minutes, and then filtered. Then, the catalyst microspheres E2 were added to 30 L of 11% by weight of ammonia water, stirred for 5 minutes, filtered, dried, and calcined at 550°C for 2 hours to obtain the finished catalyst SCAT-2. The performance analysis results of the catalyst SCAT-2 are shown in Table 1.

[0075] Example 3

[0076] (1) In a catalyst gelation kettle, 171 Kg of deionized water was added, and then, under stirring, the following gelation raw materials were sequentially added: 52.2 Kg of kaolin (solid content of 76% by weight, purchased from Suzhou Kaolin Company), 16.8 Kg of aluminum sol (alumina content of 21.5% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.), and 82.8 Kg of silica sol (SiO2 content of 25% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.). The mixture was stirred for 30 minutes. Then, 26.1 Kg (based on the dry NaY) of the unmodified NaY molecular sieve slurry (concentration of 53% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.) was added, and the mixture was rapidly stirred for 60 minutes. Then, the mixture was spray-dried and formed, and was calcined in a calcination furnace at 300°C for 3 hours to obtain catalyst microspheres A3.

[0077] (2) The catalyst microspheres A3 prepared above were added to 900 L of a deionized water solution and stirred to uniformly mix the mixture. Then, 9.3 L of an RE(NO3)3 solution (concentration of the rare earth solution of 330 g / L as RE2O3) was added, and the mixture was stirred and heated to 35°C for 1 hour. Then, the mixture was filtered, washed, and the filter cake was dried at 120°C to obtain rare earth-containing catalyst microspheres B3 with reduced sodium oxide content.

[0078] (3) The catalyst microspheres B3 above were calcined at a temperature of 390°C in an atmosphere containing 50% by volume of water vapor for 5 hours. Then, the mixture was dried to have a water content of less than 1%, and catalyst microspheres C3 containing molecular sieves with reduced unit cell constant were obtained.

[0079] (4) According to the weight ratio of SiCl4: catalyst microspheres C3 (dry basis) = 0.10:1, the heated and vaporized SiCl4 gas was introduced at a temperature of 350°C for 1 h, and then washed with 900 L of de-cationic water, followed by filtration, and the filter cake was dried at 120°C for 5 hours to obtain catalyst microspheres D3;

[0080] (5) The catalyst microspheres D3 were subjected to acid treatment modification by being contacted with an acid solution. The catalyst microspheres D3 were first added to a 0.07 M nitric acid solution, and then contacted at 45°C for 90 minutes, followed by the addition of oxalic acid, and then contacted at 45°C for 80 minutes, and then filtered, washed and dried to obtain catalyst microspheres E3; wherein the weight ratio of oxalic acid to catalyst (dry basis) was 0.05:1, and the weight ratio of the 0.07 M nitric acid solution to catalyst microspheres D3 (dry basis) was 12:1.

[0081] (6) The catalyst microspheres E1 were added to a mixed solution containing 35 L of LaCl3 (concentration of 75 g / L as La2O3) and MgCl2 (concentration of 35 g / L as MgO) at 25°C, stirred for 5 minutes, and then filtered, and then added to 35 L of 8% by weight of ammonia water, stirred for 5 minutes, filtered, dried, and calcined at 550°C for 2 hours to obtain catalyst product SCAT-3, and the performance analysis results are shown in Table 1.

[0082] Comparative Example 1

[0083] 2000 Kg (dry weight) of NaY type zeolite with a skeleton SiO2 / Al2O3 of 4.6 (sodium oxide content of 13.5 wt%, produced by Qilu Catalyst Branch of Sinopec) was added to a 20 m 3The water in the primary exchange tank was stirred at 25°C, then 581 L of RECl3 solution (the rare earth concentration in the RECl3 solution was 330 g / L as RE2O3) was added, and stirring was continued for 60 minutes. After filtration and washing, the filter cake was sent to a flash drying oven for drying. Then, it was sent to a calcination furnace for calcination at a temperature of 400°C, in an atmosphere of 60% water vapor and 40% air by volume, for 6 hours. Then, it was calcined at a temperature of 500°C, in a dry air atmosphere (water vapor content less than 1% by volume) for 2.5 hours, so that the water content was less than 1% by weight. Then, the material was directly sent to a continuous gas phase ultra-stable reactor for gas phase ultra-stable reaction. The gas phase ultra-stable reaction process of the molecular sieve in the continuous gas phase ultra-stable reactor and the subsequent tail gas absorption process were carried out according to the method of Example 1 in the patent CN103787352A, and the process conditions were as follows: SiCl4: Y-type zeolite weight ratio = 0.38: 1, the feeding amount of the molecular sieve was 800 kg / hour, and the reaction temperature was 420°C. After the gas phase ultra-stable reaction, the molecular sieve material was separated by a gas-solid separator and sent to a secondary exchange tank. 20 m 3 of water was pre-added to the secondary exchange tank, and the weight of the molecular sieve material added to the secondary exchange tank was 2000 Kg (dry basis). After stirring, 0.65 m 3 of 10% by weight hydrochloric acid was added, and the temperature was raised to 90°C. After stirring for 70 minutes, 125 Kg of citric acid was added. After continuous stirring at 90°C for 60 minutes, filtration, washing, and drying, the modified Y-type molecular sieve was obtained, which was recorded as DZ-1.

[0084] 11.62 kg of aluminum sol with an alumina content of 21.5% by weight was added to 69.5 kg of de-cation water, and stirring was started. After 60 minutes of stirring, 27.63 kg of kaolin with a solid content of 76% by weight was added, and then 46 kg of silica sol (SiO2 content of 25% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.) was added after 30 minutes of stirring. Then, 15 kg of finely ground DZ1 molecular sieve (dry basis) was added, and rapid stirring was continued for 60 minutes. After spray drying, calcination, and washing treatment, the catalyst was dried to obtain a catalyst, which was recorded as DC1. Among them, the DC1 catalyst obtained contained 30% by weight of DZ1 molecular sieve, 42% by weight of kaolin, 23% by weight of silica sol binder, and 5% by weight of aluminum sol (dry basis).

[0085] Comparative Example 2

[0086] 2000 Kg (dry basis) of NaY-type zeolite with a skeleton SiO2 / Al2O3 ratio of 4.6 (sodium oxide content of 13.5% by weight, produced by Qilu Branch of Sinopec Catalyst Co., Ltd.) was added to a 20 m 3The de-cationic water in the first exchange tank was stirred at 90°C, then 685L RECl3 solution (the concentration of rare earth in the RECl3 solution was 330g / L in terms of RE2O3) was added, and stirred for 60 minutes. After filtration and washing, the filter cake was sent to a flash drying oven for drying. Then, the material was sent to a calcination furnace for calcination and drying treatment at a temperature (atmosphere temperature) of 440°C and 70% water vapor atmosphere for 6 hours. Then, the molecular sieve material was sent to a calcination furnace for calcination and drying treatment at a temperature of 500°C and a dry air atmosphere for 2 hours, so that the water content was less than 1% by weight. Then, the Y-type molecular sieve material with reduced cell constants was directly sent to a continuous gas phase stabilization reactor for gas phase stabilization reaction. The gas phase stabilization reaction process of the molecular sieve in the continuous gas phase stabilization reactor and the subsequent tail gas absorption process were carried out according to the method of Example 1 in the patent CN103787352A, and the process conditions were as follows: the weight ratio of SiCl4 to Y-type zeolite was 0.30:1, the feeding amount of the molecular sieve was 800kg / hour, and the reaction temperature was 470°C. After the gas phase stabilization reaction, the molecular sieve material was separated by a gas-solid separator and then sent to a second exchange tank. 20m 3 of de-cationic water was added to the second exchange tank, and the molecular sieve material added to the second exchange tank weighed 2000Kg (dry basis). After stirring, 0.85m 3 of 7% by weight sulfuric acid solution was added, and the temperature was raised to 85°C. After stirring for 80 minutes, 65Kg of citric acid and 55Kg of tartaric acid were added. After continuous stirring at 85°C for 80 minutes, filtration, washing, and drying were performed to obtain a modified Y-type molecular sieve product, which was recorded as DZ-2.

[0087] According to the preparation method of Reference Example 1, DZ2 molecular sieve, kaolin, water, silica sol binder, and aluminum sol were slurried to prepare a catalyst slurry, which was spray dried, calcined, washed, and dried to prepare a microspherical catalyst. The prepared catalytic cracking catalyst was recorded as DC2. Among them, the DC2 catalyst contained 30% by weight of DZ2 molecular sieve, 42% by weight of kaolin, 23% by weight of silica sol binder, and 5% by weight of aluminum sol.

[0088] Reference Example 3

[0089] According to the method of Example 1 in the patent application CN1854255A, a catalyst was prepared, and the product was recorded as DC3.

[0090] Reference Example 4

[0091] According to the method of Example 1, a catalyst was prepared, except that after the catalyst was spray dried and formed, the catalyst microspheres were calcined in a calcination furnace at 500°C for 1 hour to obtain a catalyst DC4.

[0092] Reference Example 5

[0093] The catalyst of Comparative Example 1 was introduced with rare earth oxide and magnesium oxide according to the procedure (6) of Example 1 to obtain catalyst DC5

[0094] Examples 4-6

[0095] Examples 4-6 were used to illustrate the heavy metal contamination method of the catalyst and the catalytic cracking performance of the catalytic cracking catalyst of the present application.

[0096] The SCAT-1, SCAT-2 and SCAT-3 catalysts were first subjected to a cyclic contamination (to deposit Ni and V) in a cyclic aging apparatus. The Ni and V contents of the catalysts after the cyclic contamination are shown in Table 3. The cyclic contamination procedure included: the catalyst was introduced with heavy metals (Ni and V) by the Mitchell impregnation method, and then the catalyst introduced with heavy metals was loaded into a D-100 apparatus (a small fixed fluidized bed). The catalyst was treated in the D-100 apparatus according to the following procedure:

[0097] (a) heated to 600°C at a temperature increasing rate of 20°C / min under a nitrogen atmosphere;

[0098] (b) heated to 780°C at a temperature increasing rate of 1.5°C / min, and then kept at 780°C. During the constant temperature process, the treatment atmosphere was changed according to the following procedure:

[0099] (i) treated with an atmosphere containing 40% by volume of nitrogen (containing 5% by volume of propylene) and 60% by volume of water vapor for 10 minutes;

[0100] (ii) treated with an atmosphere containing 40% by volume of nitrogen (pure nitrogen without propylene) and 60% by volume of water vapor for 10 minutes;

[0101] (iii) treated with an atmosphere containing 40% by volume of air (containing 4000 μmol / mol SO2) and 60% by volume of water vapor for 10 minutes;

[0102] (iv) treated with an atmosphere containing 40% by volume of nitrogen and 60% by volume of water vapor for 10 minutes; and then the cyclic steps (i)-(iv) were repeated once again in the above order, and then step (i) was repeated once again to end the cyclic contamination procedure;

[0103] Then, the step of aging was carried out: the catalyst mixture after the cyclic contamination was aged at 788°C for 8 hours in an atmosphere containing 80% by volume of water vapor and 20% by volume of air;

[0104] Then, the catalytic performance of the catalyst after the cyclic contamination and aging was investigated in an ACE apparatus. The raw oil entered the reactor at the bottom to contact with the catalyst mixture. The catalyst loading was 9 g, the reaction temperature was 500°C, and the weight hourly space velocity was 16 h－1 The ACE experiment raw material properties are shown in Table 2, and the evaluation results are shown in Table 3.

[0105] Conversion rate = gasoline yield + liquefied gas yield + dry gas yield + coke yield

[0106] Total liquid yield = gasoline yield + diesel yield + liquefied gas yield

[0107] Coke selectivity = coke yield / conversion rate

[0108] Dry gas selectivity = dry gas yield / conversion rate

[0109] Comparative Examples 6-10

[0110] Comparative Examples 6-10 illustrate the reaction performance of the catalytic cracking catalysts prepared by the method provided in Comparative Examples 1-5.

[0111] The DC1-DC5 catalysts were first subjected to cyclic contamination (to deposit Ni and V) in a cyclic aging device, and the Ni and V contents of the catalysts after cyclic contamination are shown in Table 3. The cyclic contamination step is shown in Example 4. Then, the step of aging was performed: the mixture of the catalysts after cyclic contamination was aged at 788°C for 8 hours in an atmosphere containing 80% by volume of water vapor and 20% by volume of air;

[0112] Then, the catalytic performance of the catalysts after cyclic contamination-aging was investigated in an ACE device, wherein the raw oil entered the reactor at the bottom to contact with the catalyst mixture, wherein the catalyst loading was 9g, the reaction temperature was 500°C, and the weight hourly space velocity was 16h －1 The ACE experiment raw material properties are shown in Table 2, and the evaluation results are shown in Table 3.

[0113] Table 1

[0114]

[0115] As can be seen from the results listed in Table 1, the catalytic cracking catalyst provided by the present application has a larger pore volume and specific surface area, at the same time, has better strength, and the content of sodium oxide in the catalyst is low, and the relative crystallinity of the molecular sieve in the catalyst is high.

[0116] Table 2 ACE evaluation raw oil properties

[0117]

[0118] Table 3

[0119]

[0120] As shown in Table 3, the catalytic cracking catalyst provided by the present application still has obviously lower coke selectivity, lower dry gas selectivity, higher total liquid product yield and gasoline yield, and higher heavy oil conversion activity after being contaminated by Ni and V and aging, indicating that the catalytic cracking catalyst provided by the present application has excellent anti-Ni and V contamination performance.

Claims

1. A process for the preparation of a catalytic cracking catalyst, characterized in that, The process comprises the following steps: (1) mixing unmodified NaY molecular sieve with alumina binder, silica binder, clay and water, beating and spray drying, and calcining at 280-380℃ for 1-4 hours to obtain catalyst microspheres A; the alumina binder is aluminum sol; based on the weight of the catalyst microspheres A, the catalyst microspheres A contain 10-50% by weight of unmodified NaY molecular sieve on a dry basis, 2-15% by weight of alumina binder in terms of alumina, 10-30% by weight of silica binder in terms of silicon, and 10-80% by weight of clay on a dry basis; (2) contacting the catalyst microspheres A with a rare earth salt solution to perform ion exchange reaction, filtering and washing to obtain catalyst microspheres B; (3) calcining the catalyst microspheres B at a temperature of 350-450℃ in an atmosphere containing 40-60% by volume of water vapor for 4-6 hours, and optionally drying to obtain catalyst microspheres C, the water content of the catalyst microspheres C being not more than 1% by weight; (4) contacting the catalyst microspheres C with SiCl4 gas to react, and then washing and filtering to obtain catalyst D; wherein the weight ratio of SiCl4 to the catalyst microspheres C on a dry basis is 0.03-0.2:1, the reaction temperature is 250-450℃, and the reaction time is 10 minutes to 5 hours; (5) mixing the catalyst microspheres D obtained in step (4) with a solution of inorganic acid with medium strength or above, contacting at 25-70℃ for at least 60 minutes, then adding organic acid, contacting at 25-70℃ for at least 60 minutes, filtering, washing and drying to obtain catalyst microspheres E; (6) contacting the catalyst microspheres E with a mixed solution containing rare earth salt and alkaline earth metal salt, filtering, then contacting with ammonia water, filtering, drying and calcining to obtain catalyst product F. In step (1), the unmodified NaY molecular sieve is hydrothermally synthesized NaY molecular sieve which is only washed with water and the pH value of the NaY molecular sieve filter cake after washing is 7-9, and the calcination temperature of the catalyst microspheres in step (1) is 300-350℃.

2. The process for preparing a catalytic cracking catalyst according to claim 1, characterized in that, The ion exchange reaction temperature in step (2) is 20-60℃; 3. The process for preparing a catalytic cracking catalyst according to claim 1, characterized in that, The rare earth salt solution is an aqueous solution of rare earth salt; the rare earth is La, Ce, Pr, Nd or a mixed rare earth containing one or more of the above rare earth elements. In step (3), the calcination temperature is 370-420℃; the calcination atmosphere is an atmosphere containing 45-55% by volume of water vapor; and the calcination time is 5-6 hours.

4. The process for preparing a catalytic cracking catalyst according to claim 1, characterized in that, In step (4), the catalyst microspheres C contact with SiCl4 gas at a temperature of 280-420℃; the reaction time of the catalyst microspheres C contacting with SiCl4 gas is 0.2 hours to 2 hours; and the weight ratio of SiCl4 to the catalyst microspheres C on a dry basis is 0.05-0.15:

1.

5. The process for preparing a catalytic cracking catalyst according to claim 1, characterized in that, ​ 6. The process for preparing a catalytic cracking catalyst according to claim 1, characterized in that, The weight ratio of the organic acid to the catalyst microspheres D on a dry basis is 0.02-0.10:1, the weight ratio of the inorganic acid solution of medium strength or above to the catalyst microspheres D on a dry basis is 6-12:1, and the molar concentration of the inorganic acid of medium strength or above in the inorganic acid solution of medium strength or above is 0.01-0.15 mol / L; The mixed solution of the rare earth salt and the alkaline earth metal salt in step (6), wherein the rare earth salt is lanthanum nitrate or lanthanum chloride, and the alkaline earth metal salt is magnesium nitrate or magnesium chloride; the ammonia water in step (6) is an aqueous solution of ammonia gas; the temperature at which the catalyst microspheres E are contacted with the mixed solution containing the rare earth salt and the alkaline earth metal salt is room temperature; the temperature at which the catalyst microspheres E are contacted with the ammonia water is room temperature; and the room temperature is 10-30℃.

7. The process for preparing a catalytic cracking catalyst according to claim 3, characterized in that, The catalyst microspheres A contain 20-50% by weight of unmodified NaY molecular sieves on a dry basis, 20-55% by weight of clay on a dry basis, 3-5% by weight of aluminum sol calculated as aluminum oxide, and 10-25% by weight of silicon sol calculated as silicon oxide.

8. The process for preparing a catalytic cracking catalyst according to claim 1, characterized in that, In step (6), the catalyst microspheres E are added to the mixed solution containing the rare earth salt and the alkaline earth metal salt at room temperature, stirred for 5-30 minutes, filtered, then added to the ammonia water, the concentration of the ammonia water is 10-15% by weight, stirred for 5-30 minutes, filtered, dried, and calcined, and the room temperature is 10-30℃.

9. The process for preparing a catalytic cracking catalyst according to claim 3, characterized in that, In step (2), the ion exchange reaction is carried out at a temperature of 25-45℃ for 90-120 minutes, and the rare earth salt is a rare earth chloride and / or a rare earth nitrate.

10. The process for preparing a catalytic cracking catalyst according to claim 1, characterized in that, In step (5), after mixing with the inorganic acid solution, the mixture is contacted at 40-60℃ for 60-120 minutes; after adding the organic acid, the mixture is contacted at 40-60℃ for 60-120 minutes.

11. A catalytic cracking catalyst prepared by the method of any one of claims 1-10.

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