CN116689017A - A kind of anti-metal pollution catalytic cracking catalyst and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of catalyst preparation, and relates to a method for preparing a catalytic cracking catalyst resistant to metal pollution. After the catalyst microspheres are treated with an organic acid and an inorganic acid, they are firstly treated with a mixed solution of a rare earth salt and an alkaline earth metal salt, and then contacted with ammonia water. step, wherein the preparation method of the catalyst microspheres comprises calcining microspheres comprising unmodified NaY molecular sieves, alumina binders, silica binders, and clay at 280-380°C, and performing rare earth Ion exchange, treated at a temperature of 350-450°C, containing 40-60% by volume of water vapor, and super-stable modification with SiCl ₄ gas phase, the catalytic cracking catalyst prepared by this method has higher pore volume, higher specific surface area, and good strength , Strong resistance to nickel and vanadium pollution, used for heavy oil conversion, high activity, high gasoline yield, high total liquid yield and good selectivity for dry gas and coke.

Description

A kind of anti-metal pollution catalytic cracking catalyst and preparation method thereof

technical field

The invention relates to a metal pollution-resistant catalytic cracking catalyst and a preparation method thereof.

Background technique

With the heavy and inferior quality of crude oil in the world in recent years, the catalytic cracking technology (FCC) of blending or fully refining heavy oil and residual oil is particularly important. Compared with distillate catalytic cracking feedstock oil, the content of harmful metals in heavy oil or residual oil is much higher than that in distillate oil. It exists in raw oil in the form of porphyrin compounds, naphthenates, inorganic salts, etc. Harmful metals such as nickel, vanadium, iron, sodium, calcium, etc., are decomposed and enriched on the balancer during the catalytic cracking reaction process. The action of molecular sieve destroys the crystal lattice structure of the catalyst, weakens the acidity of the molecular sieve, makes the activity and selectivity of the catalyst worse, and then affects the product distribution and product quality. Effectively suppressing the pollution of heavy metals to the catalyst is one of the key measures to improve the economic and technical benefits of RFCC devices.

CN1854255A discloses a preparation method of a heavy metal pollution-resistant cracking catalyst. In the method, clay, deionized water and optional additives are uniformly mixed to obtain clay slurry, and molecular sieves, deionized water and optional additives are uniformly mixed to obtain molecular sieves. Slurry, mix the binder, deionized water, alkaline earth metal compound and rare earth metal compound, and optional inorganic acid evenly to prepare the binder slurry; mix the above clay slurry, molecular sieve slurry and binder slurry evenly and then dry . The cracking catalyst prepared by this method has good resistance to nickel and vanadium pollution. 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 does not use alkaline earth metal Compounds and rare earth metal compounds are mainly distributed in the interior of the catalyst, and its ability to resist nickel and vanadium pollution will be limited to a certain extent.

Catalytic cracking catalysts usually contain binders and active components, and the active components have a great influence on the activity of catalytic cracking catalysts and coke selectivity. A commonly used active component in catalytic cracking catalysts is Y-type molecular sieve. In order to improve the activity and coke selectivity of Y molecular sieve for heavy oil conversion, Y molecular sieve is usually super-stabilized and modified before being mixed with binders. It is difficult to further improve the performance of catalysts containing ultra-stable Y-type molecular sieves in the prior art when they are used for heavy oil conversion.

CN102806096A discloses a preparation method of a rare earth-containing Y-type molecular sieve cracking catalyst, the method comprising: (1) mixing NaY molecular sieve without ion exchange with a matrix, beating and spray drying to obtain a catalyst precursor; (2) Carrying out the first roasting of the catalyst precursor at a temperature of 200°C to less than 400°C, and subjecting the product obtained after the first roasting to ammonium ion exchange; and (3) subjecting the product obtained after the ammonium ion exchange to at least one second Calcination and at least one rare earth ion exchange, the rare earth ion exchange is performed after the second roasting; the temperature of the ammonium ion exchange is higher than the temperature of the rare earth ion exchange; the temperature of the second roasting is higher than the temperature of the first roasting. However, the catalyst obtained by the method is not stable in heavy oil catalytic cracking reaction activity, and the heavy oil conversion activity of the product after introducing the anti-metal pollution component is not high.

Contents of the invention

The technical problem to be solved by the present invention is to provide a new method for preparing a metal-pollution-resistant catalytic cracking catalyst containing an ultra-stable Y-type molecular sieve.

The invention provides a method for preparing an anti-metal pollution catalytic cracking catalyst, comprising the following steps:

(S1): forming the first microspheres comprising Y-type molecular sieve, alumina binder, silica binder, and clay;

(S2): The first microsphere is contacted with an inorganic acid and an organic acid solution to remove the non-skeleton aluminum of the molecular sieve, filtered, and washed to obtain a second microsphere;

(S3): The second microspheres are contacted with a mixed solution containing rare earth salts and alkaline earth metal salts, filtered, then contacted with aqueous ammonia, filtered, dried, and roasted to obtain a finished catalytic cracking catalyst.

The weight ratio of the alumina binder calculated as alumina to the silica binder calculated as silica in the first microsphere is 2-15:10-30;

The weight ratio of the Y-type molecular sieve in dry basis to the silicon oxide binder in silicon oxide in the first microsphere is preferably 10-50:10-30.

The weight ratio of clay in dry basis to silica binder in silica in the first microsphere is preferably 10-80:10-30.

In step (S2), the first microspheres are contacted with the inorganic acid solution and the organic acid solution, and the contact is preferably carried out at a temperature of 25-70°C; they can be contacted with the inorganic acid solution and the organic acid solution successively, or at the same time The solution containing inorganic acid and organic acid contacts, and the molar concentration of inorganic acid in the solution containing inorganic acid (inorganic acid solution or the solution containing both inorganic acid and organic acid) is preferably 0.01mol/L-0.15mol/L, containing inorganic acid The weight ratio of the solution to the first microspheres calculated on a dry basis is 6-12:1; the weight ratio of the organic acid to the first microspheres calculated on a dry basis is 0.02-0.10:1.

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

The rare earths mentioned in the present invention are La, Ce, Pr, Nd or mixed rare earths including one or more of the above rare earth elements.

The alkaline earth metal such as one or more of Be, Mg, Ca, Sr, Ba, preferably Mg and/or Ca, more preferably Mg;

The rare earth salt described 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.

Preferably, in step (S3), the concentration of the rare earth salt in the solution containing the rare earth salt and the alkaline earth metal salt is 60-150 g/L as RE ₂ O ₃ , and the concentration of the alkaline earth metal salt is calculated as the oxide of the alkaline earth metal 30-80g/L.

The concentration of the ammonia water is preferably 5-15% by weight based on NH ₃ .

The weight ratio of the mixed solution containing rare earth salts and alkaline earth metal salts to the second microspheres on a dry basis is preferably 3˜6:1.

Preferably, based on RE ₂ O ₃ , the rare earth content in the finished catalytic cracking catalyst obtained in step (S3) is 0.2 wt% to 1 wt% higher than that of the second microspheres.

The rare earth content calculated as RE ₂ O ₃ in the finished catalytic cracking catalyst obtained in step (S3) is preferably 1-6% by weight, for example, 1.2-5.8% by weight.

The preparation method of the catalyst provided by the invention can improve the anti-metal pollution effect of the anti-metal pollution catalyst, and the heavy oil conversion activity of the catalytic cracking catalyst is relatively high under the condition of metal pollution. Preferably, the catalytic cracking catalyst preparation method provided by the present invention can prepare catalysts with larger specific surface area, higher pore volume, better strength (good wear resistance), higher gasoline yield, higher total liquid A catalytic cracking catalyst with better yield and coke selectivity and stronger heavy oil conversion ability. The catalytic cracking catalyst preparation method provided by the invention can obtain a catalytic cracking catalyst with a sodium oxide content of less than 0.15% by weight, and the preparation process effectively solves the urgent problem of ammonia nitrogen pollution in the production of catalytic cracking catalysts.

Detailed ways

The present invention provides a kind of anti-metal pollution catalytic cracking catalyst preparation method, preferably, the method comprises:

(1) Mix unmodified NaY molecular sieve with alumina binder, silicon oxide binder (also known as silicon binder in the present invention), clay and water, make a slurry, spray dry and form it, and heat it at 280-380°C Lower roasting is preferably roasting for 1-4 hours to obtain catalyst microspheres A; the alumina binder is aluminum sol;

(2) contacting the catalyst microsphere A with the rare earth solution for ion exchange reaction, filtering and washing to obtain the rare earth-containing catalyst microsphere B with reduced sodium oxide content; wherein the rare earth solution is also called a rare earth salt solution;

(3) The catalyst microspheres B are subjected to modification treatment, optionally dried to obtain catalyst microspheres C containing molecular sieves with reduced unit cell constants, and the modification treatment is to treat the catalyst microspheres B at a temperature of 350- Roasting for 4-6 hours at 450°C in an atmosphere containing 40-60% water vapor by volume (also called 40-60% water vapor by volume or 40-60% water vapor); the molecular sieve containing the reduced unit cell constant The unit cell constant of the molecular sieve in the catalyst microsphere C is preferably 24.61nm-24.64nm; wherein, the water content of the catalyst microsphere C is preferably no more than 1% by weight;

(4) making the catalyst microspheres C and SiCl ₄ gas contact and react at a temperature of 250-450° C., wherein the weight ratio of SiCl ₄ : catalyst microspheres C on a dry basis=0.03-0.2:1, Reaction times 10 minutes to 5 hours, then through washing, filtering, obtain catalyst microsphere D; If the water content in the catalyst microsphere C that step (3) modification process obtains is no more than 1% by weight, can directly be mixed with silicon tetrachloride Performing the reaction by contacting, if the water content in the catalyst microsphere C exceeds 1% by weight, preferably, the catalyst microsphere C is dried to make the water content less than 1% by weight, and then contacted with silicon tetrachloride for reaction;

(5) contacting the catalyst microsphere D with the inorganic acid and organic acid solution at a temperature of 25-70° C. for at least 60 minutes, such as 60-120 minutes, after filtering, washing and drying, to obtain the catalyst microsphere E;

(6) The catalyst microsphere E is contacted with a mixed solution containing a rare earth salt and an alkaline earth metal salt, filtered, then contacted with ammonia water, filtered, dried, and roasted; preferably, the catalyst microsphere E is heated at room temperature Add it into the mixed solution containing rare earth salt and alkaline earth metal salt and stir for a preferred stirring time of 5-30 minutes, then filter it, then add it into ammonia water with a _NH3 concentration of 10-15% by weight, and stir for a preferred stirring time of 5-30 minutes minute, filtered, dried, and roasted to obtain the finished catalyst product F, which is the catalytic cracking catalyst provided by the present invention. Wherein, the mixed solution of the 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 temperature of the room temperature is preferably 10 to 30°C. This preferred preparation method can prepare catalytic cracking catalysts with larger specific surface area, higher pore volume, better strength (good wear resistance), higher gasoline yield, better coke selectivity, and stronger heavy oil conversion ability . The sodium oxide content of the obtained catalytic cracking catalyst can be lower than 0.15% by weight, which effectively solves the urgent problem of ammonia nitrogen pollution in the production of the catalytic cracking catalyst. The catalytic cracking catalyst obtained by the above-mentioned preferred catalytic cracking catalyst preparation method has higher activity stability in the case of metal pollution, and has higher heavy oil conversion activity when used in heavy oil catalytic cracking reactions, and the gasoline yield is higher. Lower coke selectivity and dry gas selectivity.

In the catalytic cracking catalyst preparation method provided by the present invention, make unmodified NaY molecular sieve and alumina binding agent, silica binding agent, clay and water mix in step (1), wherein, the oxidized The weight ratio of the aluminum binder and the unmodified NaY molecular sieve in dry basis is 2-15:10-50, the silicon oxide binder in silicon oxide and the unmodified NaY molecular sieve in dry basis The weight ratio of the NaY molecular sieve is 10-30:10-50, and the weight ratio of the clay calculated on a dry basis to the unmodified NaY molecular sieve calculated on a dry basis is 10-80:10-50.

In the catalytic cracking catalyst preparation method provided by the present invention, in step (1), unmodified NaY molecular sieve is mixed with alumina binding agent, silica binding agent, clay and water, beating to form slurry, and this process can be in Operate without heat aging. No heating during the mixing and beating process can prevent the slurry from being too viscous to be transported due to the increase in temperature, which is conducive to increasing the solid content of the slurry, improving production efficiency, and reducing energy consumption, thereby reducing production costs.

In one embodiment, the mixing and beating is performed by mixing the unmodified NaY molecular sieve, aluminum sol and silica sol binders, clay and water at ambient temperature, such as room temperature (room temperature is 10-30° C.), Then stir for more than 30 minutes, such as 30-180 minutes or 30-60 minutes, for beating, and the mixing and beating process can be aged without heating.

According to the preparation method of the catalytic cracking catalyst provided by the present invention, use unmodified NaY molecular sieve and aluminum binder such as aluminum sol and silicon oxide binder such as silica sol binder, clay and water mixing, beating, mixing Compared with the existing catalytic cracking catalyst preparation method, the beating method has no special requirements. For example, clay such as kaolin and/or other clays can be beaten with aluminum sol and silica sol to make a matrix slurry, and then the matrix slurry is mixed with unmodified NaY molecular sieve or unmodified NaY molecular sieve slurry to obtain Catalyst gel. The solid content of the catalyst colloid is preferably 28-40% by weight.

According to the catalytic cracking catalyst preparation method provided by the present invention, on a dry basis, the content of the unmodified NaY type molecular sieve in the catalyst microsphere A is 10-50% by weight, preferably 15-45% by weight or 20-50% by weight. % by weight is, for example, 25-40% by weight.

In the catalytic cracking catalyst preparation method provided by the present invention, described unmodified NaY molecular sieve is preferably the NaY molecular sieve of hydrothermal synthesis only through water such as industrial water washing and the pH value of the filter cake of measuring NaY molecular sieve after washing is 7 -9 is preferably 7.0-8.0. The hydrothermally synthesized NaY molecular sieve can be purchased commercially or synthesized with reference to the prior art, for example, with reference to the methods provided in the claims or examples of US Pat. No. 3,639,099 and US 3,671,191. Said industrial water is well known to those skilled in the art.

According to the catalytic cracking catalyst preparation method provided by the present invention, preferably, the content of the clay in the catalyst microspheres A provided by the present invention is 20-55% by weight, such as 30-50% by weight or 40-50% by weight on a dry basis. weight%. The clay is selected from one or more clays used as cracking catalyst components, such as kaolin, halloysite, montmorillonite, diatomaceous earth, attapulgite, saponite, rectorite, sepiolite , hydrotalcite, bentonite in one or more. These clays are well known to those of ordinary skill in the art.

According to the preparation method of catalytic cracking catalyst provided by the present invention, the alumina binder is aluminum sol, preferably, the catalyst microsphere A contains 2-15% by weight based on alumina, such as 2-10% by weight, preferably 3 - 5% by weight of aluminum sol.

The silicon oxide binder is for example silica sol, calculated as silicon oxide, the content of silica sol in the catalyst microspheres A is 10-30% by weight, preferably 10-25% by weight or 20-25% by weight.

Preferably, based on the weight of the catalyst microsphere A, the catalyst microsphere A contains 10% by weight to 50% by weight of unmodified NaY molecular sieve on a dry basis, and 2% by weight to 15% by weight of aluminum oxide. Alumina binder, 10-30% by weight silica binder, and 10-80% clay by weight on a dry basis. For example, the catalyst microsphere A contains: 20-50% by weight of unmodified NaY molecular sieve based on dry basis, 20-55% by weight of clay based on dry basis, 3-5% by weight of aluminum oxide Aluminum sol and 10-25% by weight of silica sol based on silica.

According to the catalytic cracking catalyst preparation method provided by the present invention, other molecular sieves other than the unmodified NaY type molecular sieves can also be added in the mixing and beating process, based on the weight of the catalyst microspheres A, the catalyst microspheres A The content of other molecular sieves described in may be 0-40% by weight, for example, 0-30% by weight or 1-20% by weight on a dry basis. The other molecular sieves are molecular sieves used in catalytic cracking catalysts, such as one or more of zeolites with MFI structure, Beta zeolites, and non-zeolite molecular sieves. The MFI structure zeolite such as one or more of ZRP, HZSM-5, ZSP zeolite, the beta zeolite such as Hβ, the non-zeolite molecular sieve such as aluminum phosphate molecular sieve (AlPO molecular sieve) or silicon aluminum phosphorus molecular sieve One or more of (SAPO molecular sieves).

According to the preparation method of catalytic cracking catalyst provided by the present invention, in step (1), the spray drying method has no special requirements, and can be carried out according to the spray drying method in the existing cracking catalyst preparation process.

In the preparation method of the catalytic cracking catalyst provided by the present invention, in step (1), the catalyst microspheres are obtained by spray-drying and molding, and then the catalyst microspheres are calcined at a temperature of 280-380° C., preferably 300-350° C. °C; the calcination time is 1-4 hours, such as 1 hour, 2 hours, 3 hours or 4 hours.

In the catalytic cracking catalyst preparation method provided by the present invention, in step (2), the catalyst microsphere A is contacted with the rare earth solution to carry out the ion exchange reaction, and the temperature of the ion exchange reaction can be 20-60°C, preferably 25-45°C. °C, the exchange time can be more than 60 minutes, preferably 60 to 120 minutes. The rare earth salt solution (referred to as rare earth solution) is an aqueous solution of rare earth salt, and the rare earth salt is preferably rare earth chloride and/or rare earth nitrate. In one embodiment, the concentration of the rare earth salt solution is 200-350 g/L calculated as RE ₂ O ₃ , and the weight ratio of the rare earth salt solution to the catalyst microsphere A is 0.03-0.3.

Preferably, the ion exchange makes the obtained catalyst microspheres B have a rare earth content of 1-5% by weight calculated as RE ₂ O ₃ .

In the catalytic cracking catalyst preparation method provided by the present invention, in step (3), the temperature at which the catalyst microspheres B is modified (the process is called moderate hydrothermal ultra-stable modification treatment) or the temperature of roasting 350-450°C, preferably 370-420°C.

In the catalytic cracking catalyst preparation method provided by the present invention, the modified treatment atmosphere condition in step (3) is an atmosphere containing 40-60% water vapor by volume, preferably an atmosphere containing 45-55% water vapor by volume.

In the preparation method of the catalytic cracking catalyst provided by the present invention, the modification treatment time or roasting time in step (3) is 4-6 hours, preferably 5-6 hours.

In the catalytic cracking catalyst preparation method provided by the present invention, the reaction temperature of the contact reaction between the catalyst microspheres C and SiCl ₄ gas in step (4) is 250-450°C, preferably 280-420°C.

In the catalytic cracking catalyst preparation method provided by the present invention, the catalyst microsphere C described in step (4) and SiCl The reaction time of the gas contact reaction is 10 minutes to ₅ hours such as 0.2-2 hours, preferably 0.5 hours to 2 hours Hour.

In the catalytic cracking catalyst preparation method provided by the present invention, the reaction material weight ratio SiCl ₄ : catalyst microsphere C weight ratio of the catalyst microsphere C and _SiCl4 gas contact reaction described in step (4) is 0.03～0.2:1 , preferably 0.05 to 0.15:1.

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

In one embodiment, in step (5), the catalyst microspheres D obtained in step (4) are first mixed with an inorganic acid solution of medium strength or higher, and contacted at 25-70°C, preferably 40-60°C, for at least 60 minutes, for example 60-120 minutes, then add organic acid, contact at 25-70°C, preferably 40-60°C, for at least 60 minutes, such as 60-120 minutes, filter, wash and dry to obtain catalyst microspheres E. Wherein it is preferred that the weight ratio of the above-medium strength inorganic acid solution to the catalyst microsphere D on a dry basis is 6-12:1, and the above-mentioned medium-strength inorganic acid solution is a mixture of medium-strength and above inorganic acid Aqueous solution, wherein, the molar concentration of the inorganic acid above medium strength is 0.01M-0.15M. The weight ratio of the organic acid to the catalyst microsphere D on a dry basis is 0.02-0.10:1.

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

In the catalytic cracking catalyst preparation method provided by the present invention, the mixed solution containing rare earth salt and alkaline earth metal salt described in step (6), wherein, rare earth salt can be lanthanum nitrate and/or lanthanum chloride, and alkaline earth metal salt is nitric acid Magnesium and/or magnesium chloride; Said ammoniacal liquor in step (6) is the aqueous solution of ammonia gas, and the temperature that catalyst microsphere E contacts with the mixed solution that contains rare earth salt and alkaline earth metal salt is room temperature, and the described temperature that contacts with ammoniacal liquor is room temperature, and the room temperature is 10-30°C.

The following examples will further illustrate the present invention, but do not limit the present invention thereby.

In the examples and comparative examples, the unmodified NaY molecular sieve (also known as NaY zeolite) was provided by Qilu Branch of Sinopec Catalyst Co., Ltd., the sodium oxide content was 13.5% by weight, and the skeleton silicon-aluminum ratio (SiO ₂ /Al ₂ O ₃ molar ratio)=4.6, unit cell constant is 2.470nm, and relative crystallinity is 90%, and it is that the NaY molecular sieve of original synthesis is through industrial water washing and the filter cake pH value after washing is 7.6; Magnesium chloride, magnesium nitrate, chlorine Lanthanum chloride and lanthanum nitrate are chemically pure reagents produced by Beijing Chemical Plant. Rare earth chloride and rare earth nitrate (respectively denoted as RECl ₃ and RE(NO ₃ ) ₃ , mixed rare earth, wherein La ₂ O ₃ content is 33.6% by weight, Ce ₂ O ₃ content is 66.4% by weight) is an industrial product produced by Baotou Steel Rare Earth Company. Kaolin is special kaolin for cracking catalyst produced by Suzhou China Kaolin Company, with a solid content of 76% by weight; aluminum sol is provided by Qilu Branch of Sinopec Catalyst Co., Ltd., wherein the alumina content is 21% by weight; silica sol is provided by Qilu Branch of Sinopec Catalyst Co., Ltd. Branches are provided, wherein the silicon oxide content is 25% by weight and the pH value is 2.5.

Analytical method: in each comparative example and embodiment, the elemental content of catalyst is measured by X-ray fluorescence spectrometry; The unit cell constant of zeolite in the catalyst, relative crystallinity are adopted RIPP145-90, RIPP146 by X-ray powder diffraction method (XRD). -90 standard method (see "Petrochemical Analysis Method" (RIPP Test Method) edited by Yang Cuiding, etc., Science Press, published in 1990) for determination. According to the GB/T5816-1995 method, the specific surface area of the catalyst was detected by the Autosorb-1 nitrogen adsorption and desorption instrument of the American Quanta Company. The sample needs to be degassed at 300 ° C for 6 hours before the test. According to the RIPP151-90 standard method (see "Petrochemical Analysis Method" (RIPP test method), edited by Yang Cuiding, etc., Science Press, published in 1990) to detect the total pore volume of the catalyst. According to the RIPP29-90 standard method (seeing "Petrochemical Analysis Method" (RIPP test method), edited by Yang Cuiding, etc., Science Press, published in 1990) to detect the wear index of the catalyst (used to characterize the wear resistance, the smaller the wear index better abrasion resistance).

The chemical reagents used in the comparative examples and examples are not specified, and their specifications are chemically pure.

Example 1

(1) Add 150Kg of decationized water to the catalyst gelling kettle, then, add the gelling raw materials successively under stirring: 52.1Kg kaolin (solid content is 76% by weight, purchased from Suzhou Kaolin Company), 21Kg aluminum sol (aluminum oxide Content is 21.5%, Sinopec Catalyst Co., Ltd. Qilu branch product), 86.4Kg silica sol (SiO ₂ content is 25% by weight, Sinopec Catalyst Co., Ltd. Qilu branch product, pH value is 2.5), stirred for 30 minutes. Afterwards, 24.3 Kg (calculated on NaY dry basis) of unmodified NaY molecular sieve slurry (concentration 53% by weight, product of Sinopec Catalyst Co., Ltd. Qilu Branch) was added and stirred for 60 minutes. Then carry out spray-drying molding, and bake at 310 ℃ for 2 hours in a roasting furnace to obtain catalyst microspheres A1;

(2) Add the catalyst microspheres A1 prepared above into 900L decationized aqueous solution and stir to make it evenly mixed, add 7.36L of RE(NO ₃ ) ₃ solution (the concentration of the rare earth solution is 330g/L in terms of RE ₂ O ₃ ), stirred, heated to 30°C for 1 hour, then filtered and washed, and the filter cake was dried at 120°C to obtain rare earth-containing catalyst microspheres B1 with reduced sodium oxide content;

(3) The catalyst microspheres B1 were calcined at a temperature of 410° C. in an atmosphere containing 45% by volume of water vapor for 6 hours, and then dried so that the water content was lower than 1% by weight to obtain a molecular sieve with a reduced unit cell constant. Catalyst microspheres C1;

(4) According to the weight ratio of SiCl ₄ : catalyst microspheres C1 (dry basis) = 0.05: 1, feed SiCl ₄ gas that has been vaporized by heating, and react for 30 minutes at a temperature of 400°C to obtain catalyst microspheres D1;

(5) The catalyst microsphere D1 is contacted with an acid solution for acid treatment modification. Add the catalyst microspheres D1 to the hydrochloric acid solution with a molar concentration of 0.08M, the weight ratio of the 0.08M hydrochloric acid solution to the catalyst microspheres on a dry basis is 10:1, stir at 50°C for 75 minutes, then add lemon Acid, wherein the weight ratio of citric acid to catalyst on a dry basis is 0.02:1, stirred at 50°C for 70 minutes, filtered and washed to obtain catalyst microspheres E1.

(6) Under the condition of 25°C, take 10Kg of catalyst microspheres E1 and add to 25L a mixed solution containing LaCl ₃ (concentration is 120g/L as La ₂ O ₃ ) and MgCl ₂ (concentration is 55g/L as MgO) After stirring in medium for 5 minutes, filter, then add 22 liters of ammonia water with a concentration of 11% by weight, stir for 5 minutes, filter, dry, and roast at 550°C for 2 hours to obtain the finished catalyst SCAT-1, and its performance analysis results See Table 1.

Example 2

(1) Add 154Kg decationized water to the catalyst gelling kettle, then, add the gelling raw materials successively under stirring: 59.3Kg kaolin (solid content is 76% by weight, purchased from Suzhou Kaolin Company), 16.8Kg aluminum sol (oxidized Aluminum content is 21.5% by weight, provided by Qilu branch of Sinopec Catalyst Co., Ltd.), 79.2Kg silica sol (SiO ₂ content is 25% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.), stirred for 30 minutes. Afterwards, 22.5 Kg (calculated on NaY dry basis) unmodified NaY molecular sieve slurry (concentration 53% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.) was added and stirred for 60 minutes. Then carry out spray-drying molding, and roast at 350 ℃ for 1 hour in a roasting furnace to obtain catalyst microspheres A2;

(2) Add the catalyst microspheres A2 prepared above into 900L decationized aqueous solution and stir to make it evenly mixed, add 6.1L of RE(NO ₃ ) ₃ solution (the concentration of the rare earth solution is 330g/L in terms of RE ₂ O ₃ ), stirred, heated to 40°C for 1 hour, then filtered and washed, and the filter cake was dried at 120°C to obtain rare earth-containing catalyst microspheres B2 with reduced sodium oxide content;

(3) The catalyst microspheres B2 were calcined for 6 hours at a temperature of 350° C. in an atmosphere containing 55% by volume of water vapor, and then dried so that the water content was lower than 1% by weight to obtain a molecular sieve with a reduced unit cell constant. Catalyst microspheres C2;

(4) According to the weight ratio of SiCl ₄ : catalyst microspheres C2 (dry basis) = 0.08: 1, SiCl ₄ gas that has been vaporized by heating is introduced, and the temperature is 300°C for 2 hours. After that, use 900L Washing with decationized water, then filtering, and drying the filter cake at 120°C for 5 hours to obtain catalyst microspheres D2;

(5) The catalyst microsphere D2 is contacted with an acid solution for acid treatment modification. First add the catalyst microspheres D2 to the sulfuric acid solution with a molar concentration of 0.05M, the weight ratio of the sulfuric acid solution with a molar concentration of 0.05M to the catalyst microspheres D2 on a dry basis is 8:1, stir at 60°C for 90 Minutes, then warm up to 85°C and add tartaric acid, wherein the weight ratio of tartaric acid to catalyst on a dry basis is 0.025:1, stir at 85°C for 80 minutes, filter and wash to obtain catalyst microspheres E2.

(6) Take 10Kg of catalyst microspheres E2 and add them to 30L containing La(NO ₃ ) ₃ (concentration is 100g/L as La ₂ O ₃ ) and Mg(NO ₃ ) ₂ (concentration is 45g/L as MgO) at room temperature. /L) in the mixed solution of stirred for 5 minutes and then filtered, then added to 30L of 11% by weight ammonia water, stirred for 5 minutes, filtered, dried, and roasted at 550°C for 2 hours to obtain the finished catalyst SCAT-2. The analysis results are shown in Table 1.

Example 3

(1) Add 171Kg of decationized water to the catalyst gelling kettle, and then add the gelling raw materials successively under stirring: 52.2Kg kaolin (solid content is 76% by weight, purchased from Suzhou Kaolin Company), 16.8Kg aluminum sol (oxidized Aluminum content is 21.5% by weight, provided by Qilu branch of Sinopec Catalyst Co., Ltd.), 82.8Kg silica sol (SiO ₂ content is 25% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.), stirred for 30 minutes. Afterwards, 26.1 Kg (calculated on NaY dry basis) unmodified NaY molecular sieve slurry (concentration 53% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.) was added, and stirred rapidly for 60 minutes. Then carry out spray-drying molding, and roast at 300 ℃ in the roasting furnace for 3 hours to obtain catalyst microspheres A3;

(2) Add the catalyst microspheres A3 prepared above into 900L decationized aqueous solution and stir to make it evenly mixed, then add 9.3L of RE(NO ₃ ) ₃ solution (the concentration of the rare earth solution is 330g/L in terms of RE ₂ O ₃ ), stirred, heated to 35°C for 1 hour, then filtered and washed, and the filter cake was dried at 120°C to obtain rare earth-containing catalyst microspheres B3 with reduced sodium oxide content;

(3) The above-mentioned catalyst microspheres B3 are calcined at a temperature of 390° C. in an atmosphere containing 50% by volume of water vapor for 5 hours, and then dried so that the water content is lower than 1% by weight to obtain a molecular sieve with a reduced unit cell constant. Catalyst microspheres C3;

(4) According to the weight ratio of SiCl ₄ : catalyst microspheres C3 (dry basis) = 0.10:1, SiCl ₄ gas that has been vaporized by heating is introduced, and the reaction is carried out at a temperature of 350°C for 1 hour. Washing with decationized water, then filtering, and drying the filter cake at 120°C for 5 hours to obtain catalyst microspheres D3;

(5) The catalyst microsphere D3 is contacted with an acid solution for acid treatment modification. Add catalyst microspheres D3 to nitric acid solution with a molar concentration of 0.07M, contact at 45°C for 90 minutes, then add oxalic acid, contact at 45°C for 80 minutes, filter, wash and dry to obtain catalyst microspheres E3 Wherein, the weight ratio of oxalic acid to the catalyst on a dry basis is 0.05:1, and the weight ratio of the nitric acid solution with a molar concentration of 0.07M to the catalyst microspheres D3 on a dry basis is 12:1.

(6) Add the catalyst microspheres E1 to a mixed solution containing 35L of LaCl ₃ (concentration is 75g/L as La ₂ O ₃ ) and MgCl ₂ (concentration is 35g/L as MgO) at 25°C Stir in medium for 5 minutes and filter, then add to 35L of 8% by weight ammonia water, stir for 5 minutes, filter, dry, and roast at 550°C for 2 hours to obtain the finished catalyst SCAT-3. The performance analysis results are shown in Table 1.

Comparative example 1

2000Kg (dry basis weight) skeleton SiO ₂ /Al ₂ O _4.6 NaY type zeolite (sodium oxide content 13.5% by weight, produced by Sinopec Catalyst Qilu Branch) joins ^20m in the primary exchange tank of water at 25 After stirring evenly at ℃, add 581L of RECl ₃ solution (the rare earth concentration in RECl ₃ solution is 330g/L as RE ₂ O ₃ ), continue stirring for 60 minutes, filter, wash, and send the filter cake into a flash drying oven for drying. Drying; then, send it to a roasting furnace for 6 hours at a temperature of 400°C, in an atmosphere of 60% water vapor and 40% by volume of air; then, at a temperature of 500°C, in a dry air atmosphere (water vapor content less than 1% by volume) for roasting After 2.5 hours, the water content is lower than 1% by weight, and then, the materials are directly sent into a continuous gas-phase ultra-stable reactor for gas-phase ultra-stable reaction. The gas-phase ultra-stable reaction process of molecular sieves in the continuous gas-phase ultra-stable reactor and its subsequent tail gas absorption process are carried out according to the method of Example 1 disclosed in the CN103787352A patent. The process conditions are, SiCl ₄ : The weight ratio of Y-type zeolite=0.38: 1. The feed rate of molecular sieve is 800kg/hour, and the reaction temperature is 420°C. The molecular sieve material after the gas-phase ultra-stable reaction is separated by the gas-solid separator and sent to the secondary exchange tank. The secondary exchange tank is pre-added with ^20m3 of water, and the weight of the molecular sieve material added to the secondary exchange tank is 2000Kg (dry Basis weight), stir evenly, after that, add ^0.65m3 hydrochloric acid with a concentration of 10% by weight, and heat up to 90°C, stir for 70 minutes, then add 125Kg citric acid, continue stirring for 60 minutes at 90°C, filter, wash , dried to obtain a modified Y-type molecular sieve, denoted as DZ-1.

Get 11.62 kg of aluminum sol with an alumina content of 21.5% by weight and add it to 69.5 kg of decationized water, start stirring, add 27.63 kg of kaolin with a solid content of 76% by weight and disperse for 60 minutes, then add 46Kg of silica sol (SiO ₂ content is 25% by weight %, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.), stirred for 30 minutes. Then add 15 kg (dry basis) of finely ground DZ1 molecular sieves, stir rapidly for 60 minutes, spray dry, roast and wash, and dry to obtain the catalyst, which is denoted as DC1. On a dry basis, the obtained DC1 catalyst contains 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.

Comparative example 2

2000Kg (dry basis weight) skeleton SiO ₂ /Al ₂ O ₃ NaY type zeolite (sodium oxide content 13.5% by weight, produced by Sinopec Catalyst Qilu Branch) of 4.6 is added to the primary exchange tank with ^20m decationized water , at 90°C, stir evenly, then add 685L RECl ₃ solution (the rare earth concentration in RECl ₃ solution is 330g/L in terms of RE ₂ O ₃ ), stir for 60 minutes; filter, wash, and send the filter cake to flash evaporation Drying furnace for drying; then, sent to a roasting furnace at a temperature (atmosphere temperature) of 440 ° C and 70% water vapor atmosphere for 6 hours; then, the molecular sieve material enters the roasting furnace for roasting and drying treatment, the roasting temperature is 500 ° C, and the atmosphere is dry In an air atmosphere, the roasting time is 2 hours, so that the water content is lower than 1% by weight; then, the Y-type molecular sieve material with reduced unit cell constant is directly sent into a continuous gas-phase ultra-stable reactor for gas-phase ultra-stable reaction. The gas-phase ultra-stable reaction process of molecular sieves in the continuous gas-phase ultra-stable reactor and its subsequent tail gas absorption process are carried out according to the method of Example 1 disclosed in the CN103787352A patent, and the process conditions are: SiCl ₄ : Weight ratio of Y-type zeolite=0.30: 1. The feed rate of molecular sieve is 800kg/hour, and the reaction temperature is 470°C. The molecular sieve material after the gas-phase ultra-stable reaction is separated by the gas-solid separator and sent to the secondary exchange tank. The secondary exchange tank is pre-added with ^20m3 decationized water, and the weight of the molecular sieve material added to the secondary exchange tank is 2000Kg (dry basis weight), stir evenly, after that, add the sulfuric acid solution ^0.85m that concentration is 7% by weight Minutes later, filter, wash, and dry to obtain a modified Y-type molecular sieve product, which is designated as DZ-2.

With reference to the preparation method of Comparative Example 1, DZ2 molecular sieve, kaolin, water, silica sol binder and aluminum sol were beaten to make a catalyst slurry, spray-dried, roasted, washed and dried to prepare a microsphere catalyst, and the prepared catalytic cracking The catalyst is noted as DC2. On a dry basis, the obtained DC2 catalyst contains 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.

Comparative example 3

Catalyst was prepared according to the method of Patent Application CN1854255A Example 1, and the product was denoted as DC3.

Comparative example 4

The catalyst was prepared according to the method of Example 1, except that after the catalyst was spray-dried and formed, the catalyst microspheres were calcined in a calciner at 500° C. for 1 hour to obtain the catalyst DC4.

Comparative example 5

The catalyst of comparative example 1 introduces rare earth oxide and magnesia with reference to the step (6) of embodiment 1, obtains catalyst DC5

Embodiment 4～6

Examples 4-6 are used to illustrate the heavy metal pollution method of the catalyst and the catalytic cracking performance of the catalytic cracking catalyst of the present invention.

The SCAT-1, SCAT-2, and SCAT-3 catalysts are first subjected to cyclic pollution (to deposit Ni and V) on the cyclic aging device, and the catalyst Ni and V contents after the cyclic pollution are shown in Table 3, wherein the cyclic pollution steps include: After the catalyst introduces heavy metals (Ni and V) by the Michel impregnation method, then the catalyst introduced after the heavy metals is loaded into the D-100 device (small fixed fluidized bed), and the D-100 device is processed as follows:

(a) Heating to 600°C at a heating rate of 20°C/min under a nitrogen atmosphere;

(b) With a heating rate of 1.5°C/min, after heating to 780°C, keep the temperature at 780°C, and replace the treatment atmosphere according to the following steps during the constant temperature process:

(i) process 10 minutes in an atmosphere containing 40% by volume of nitrogen (wherein nitrogen contains 5% by volume of propylene), 60% by volume of water vapor;

(ii) process 10 minutes in an atmosphere containing 40% by volume of nitrogen (pure nitrogen, no propylene), and 60% by volume of water vapor;

(iii) Treat for 10 minutes in an atmosphere containing 40% by volume of air (containing 4000 μmol/mol SO ₂ ) and 60% by volume of water vapor;

(iv) Treat 10 minutes in an atmosphere containing 40% by volume of nitrogen and 60% by volume of water vapor; then repeat cycle steps (i)-(iv) once in the aforementioned order, then repeat step (i), and end the cycle contamination step;

Then carry out the step of aging: the catalyst mixture after circulating pollution is aged at 788° C. in an atmosphere containing 80% by volume of water vapor and 20% by volume of air for 8 hours;

Then, the catalytic performance of the catalyst after cycle pollution-aging was investigated on the ACE device, wherein the raw material oil entered into contact with the catalyst mixture at the bottom of the reactor, wherein the catalyst loading was 9g, the reaction temperature was 500°C, and the weight hourly space velocity was 16h ^-1 , the agent-to-oil ratio (weight ratio) is 5, the properties of the raw materials in the ACE experiment are shown in Table 2, and the evaluation results are shown in Table 3.

Among them, conversion rate = gasoline yield + liquefied gas yield + dry gas yield + coke yield

Total liquid yield = gasoline yield + diesel yield + liquefied gas yield

Coke selectivity = coke yield / conversion

Dry gas selectivity = dry gas yield / conversion

Comparative example 6-10

Comparative Examples 6-10 illustrate the reactivity of the catalytic cracking catalyst prepared by the method provided in Comparative Examples 1-5.

The DC1-DC5 catalysts were subjected to cyclic pollution (to deposit Ni and V) on the cyclic aging device. The contents of Ni and V in the catalysts after cyclic pollution are shown in Table 3, and the cyclic pollution steps are shown in Example 4. Then carry out the step of aging: the catalyst mixture after circulating pollution is aged at 788° C. in an atmosphere containing 80% by volume of water vapor and 20% by volume of air for 8 hours;

Then, the catalytic performance of the catalyst after cycle pollution-aging was investigated on the ACE device, wherein the raw material oil entered into contact with the catalyst mixture at the bottom of the reactor, wherein the catalyst loading was 9g, the reaction temperature was 500°C, and the weight hourly space velocity was 16h ^-1 , the agent-to-oil ratio (weight ratio) is 5, the properties of the raw materials in the ACE experiment are shown in Table 2, and the evaluation results are shown in Table 3.

Table 1

As can be seen from the results listed in table 1, the catalytic cracking catalyst provided by the present invention has larger pore volume and specific surface area, and at the same time, has better strength, and the sodium oxide content in the catalyst is low, and the relative crystallization of molecular sieve in the catalyst high degree.

Table 2 ACE evaluation of raw oil properties

table 3

As can be seen from Table 3, the catalytic cracking catalyst provided by the present invention still has significantly lower coke selectivity after being polluted and aged by Ni and V, the dry gas selectivity is low, the total liquid product yield and gasoline yield are higher, The heavy oil conversion activity is high, indicating that the catalytic cracking catalyst provided by the invention has excellent resistance to Ni and V pollution.

Claims (11)

1. a method for preparing an anti-metal pollution catalytic cracking catalyst, comprising the following steps: (S1): forming the first microspheres comprising an ultra-stable Y-type molecular sieve, an alumina binder, a silica binder, and clay; (S2): The first microsphere is contacted with an inorganic acid and an organic acid solution to remove non-skeletal aluminum in the molecular sieve, filtered, and washed to obtain a second microsphere; (S3): The second microspheres are contacted with a mixed solution containing rare earth salts and alkaline earth metal salts, filtered, then contacted with aqueous ammonia, filtered, dried, and roasted to obtain a finished catalytic cracking catalyst. 2. according to the described catalytic cracking catalyst preparation method of claim 1, it is characterized in that, in the described first microsphere, the aluminum oxide binding agent in aluminum oxide and the silicon oxide binding agent weight ratio in silicon oxide are: 2-15:10-30; The weight ratio of ultra-stable Y-type molecular sieve in dry basis to silicon oxide binder in silicon oxide in the first microsphere is preferably 10-50:10-30; The weight ratio of clay in dry basis to silica binder in silica in the first microsphere is preferably 10-80:10-30; In step (S2), the first microspheres are contacted with the inorganic acid and the organic acid solution, preferably at a temperature of 25-70°C. They can be contacted with the inorganic acid solution and the organic acid solution successively, or can be contacted with the inorganic acid solution at the same time. In contact with a solution of an organic acid, the molar concentration of the inorganic acid in the solution containing the inorganic acid is preferably 0.01mol/L-0.15mol/L, and the weight ratio of the solution containing the inorganic acid to the first microspheres on a dry basis is 6- 12:1; the weight ratio of the organic acid to the first microspheres on a dry basis is 0.02-0.10:1; In step (S3), in one way, the second microspheres are contacted with a solution containing rare earth salts and alkaline earth metal salts at room temperature, preferably for a contact time of 5-30 minutes, then filtered, and then contacted with ammonia water Preferably filter for 5-30 minutes, dry, and roast to obtain the finished catalytic cracking catalyst; In step (S3), the rare earths are La, Ce, Pr, Nd or mixed rare earths including one or more of the above rare earth elements. The alkaline earth metal such as one or more of Be, Mg, Ca, Sr, Ba, preferably Mg and/or Ca, more preferably Mg; The rare earth salt described 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; Preferably, the concentration of the rare earth salt in the solution containing the rare earth salt and the alkaline earth metal salt is 60-150 g/L as RE ₂ O ₃ , and the concentration of the alkaline earth metal salt is 30-80 g/L as the oxide of the alkaline earth metal ; The concentration of the ammonia water is preferably 5 to 15% by weight in terms of NH ₃ ; The weight ratio of the mixed solution containing rare earth salts and alkaline earth metal salts to the second microspheres on a dry basis is preferably 3-6:1; Preferably, based on RE ₂ O ₃ , the rare earth content in the finished catalytic cracking catalyst obtained in step (S3) is 0.2 wt% to 1 wt% higher than that of the second microspheres. 3. according to the described catalytic cracking catalyst preparation method of claim 1, it is characterized in that, comprises the following steps: (1) Mix the unmodified NaY molecular sieve with alumina binder, silica binder, clay and water, beat and spray dry, and roast at 280-380°C, preferably for 1-4 hours, Obtain catalyst microsphere A; Described alumina binding agent is aluminum sol; (2) contacting the catalyst microsphere A with the rare earth salt solution to carry out ion exchange reaction, filtering and washing to obtain the catalyst microsphere B; (3) The catalyst microsphere B is calcined for 4-6 hours at a temperature of 350-450° C. in an atmosphere containing 40-60% by volume of water vapor, and optionally dried to obtain a catalyst microsphere C. The catalyst microsphere C The water content of preferably does not exceed 1% by weight; (4) The catalyst microsphere C is contacted with _SiCl4 gas for reaction, and then washed and filtered to obtain the catalyst D; wherein, the weight ratio of _SiCl4 : catalyst microsphere C on a dry basis=0.03～0.2:1 , the reaction temperature is 250-450°C, and the reaction time is 10 minutes to 5 hours; (5) contacting the catalyst microsphere D with the inorganic acid and organic acid solution at a temperature of 25-70° C. for at least 60 minutes, and obtaining the catalyst microsphere E after filtering and washing; (6) The catalyst microsphere E is contacted with a mixed solution containing a rare earth salt and an alkaline earth metal salt, filtered, then contacted with ammonia water, filtered, dried, and roasted; preferably, the catalyst microsphere E is heated at room temperature Add it into the mixed solution containing rare earth salt and alkaline earth metal salt, preferably stir for 5-30 minutes, filter, and then add it into the ammonia water, the concentration of the ammonia water is preferably 10% by weight-15% by weight, and preferably stir for 5-30 minutes. After 30 minutes, filter, dry, and roast to obtain the finished catalyst product F, and the room temperature is 10-30°C. 4. according to the described catalytic cracking catalyst preparation method of claim 3, it is characterized in that, in step (1), described unmodified NaY molecular sieve is the NaY molecular sieve of hydrothermal synthesis only through water washing such as with industrial water Washing and measuring the pH value of the NaY molecular sieve filter cake after washing is 7-9, and the calcination temperature of the catalyst microspheres described in step (1) is 300-350° C. 5. according to the described catalytic cracking catalyst preparation method of claim 3, it is characterized in that, the temperature of the ion exchange reaction described in step (2) is 20-60 ℃; In step (2), the temperature of the ion exchange reaction is preferably 25-45° C., and the exchange time is 90-120 minutes. The rare earth salt solution is an aqueous solution of a rare earth salt, and the rare earth salt is preferably rare earth chloride and/or Or rare earth nitrate; the rare earths are such as La, Ce, Pr, Nd or mixed rare earths including one or more of the above rare earth elements. 6. according to the described catalytic cracking catalyst preparation method of claim 3, it is characterized in that, in step (3), the temperature of described roasting is preferably 370-420 ℃; The atmosphere of described roasting is preferably containing 45-55 An atmosphere of volume % water vapor; the time of said roasting is preferably 5-6 hours. 7. according to the described catalytic cracking catalyst preparation method of claim 3, it is characterized in that, in step (4), described catalyst microsphere C and _SiCl The temperature of gas contact reaction is 280～420 ℃; Described catalyst The reaction time of microsphere C and _SiCl4 gas contact reaction is preferably 0.2 hour to 2 hours; Described catalyst microsphere C and _SiCl4 gas contact reaction, described _SiCl4 and the weight of catalyst microsphere C in dry basis The ratio is preferably 0.05-0.15:1. 8. according to the described catalytic cracking catalyst preparation method of claim 3, it is characterized in that, the catalyst microsphere D described in step (5) contacts with inorganic acid and organic acid solution, first the catalyst microsphere that step (4) obtains Ball D is mixed with a medium-strength inorganic acid solution, contacted at 25-70°C, preferably 40-60°C, for at least 60 minutes, such as 60-120 minutes, and then added organic acid, contacted at 25-70°C, preferably 40-60°C At least 60 minutes, eg 60-120 minutes, filter, wash and dry. 9. according to the described catalytic cracking catalyst preparation method of claim 8, it is characterized in that, the weight ratio of organic acid and catalyst microsphere D in dry basis is 0.02-0.10: 1, and the inorganic acid solution above medium strength and with The weight ratio of the catalyst microspheres D on a dry basis is 6-12:1, and the molar concentration of the inorganic acid with a medium strength or above in the inorganic acid solution with a medium strength or above is preferably 0.01mol/L-0.15mol/L; Preferably, the mixed solution of rare earth salt and alkaline earth metal salt described in step (6), wherein, rare earth salt is lanthanum nitrate or lanthanum chloride, and alkaline earth metal salt is magnesium nitrate or magnesium chloride; Said in step (6) The ammonia water is an aqueous solution of ammonia gas, the temperature at which the catalyst microspheres E contacts the mixed solution containing rare earth salts and alkaline earth metal salts is room temperature, the temperature at which the ammonia water contacts is at room temperature, and the room temperature is 10-30°C. 10. according to the described catalytic cracking catalyst preparation method of claim 3, it is characterized in that, take the weight of catalyst microsphere A as a basis, described catalyst microsphere A contains 10% by weight-50% by weight of unmodified NaY type molecular sieve, 2% by weight of alumina binder based on alumina, 10% by weight of silicon binder based on silicon oxide and 10% by weight of clay of 80% by weight based on dry basis; Alternatively, the catalyst microsphere A contains: 20-50% by weight of unmodified NaY molecular sieve on a dry basis, 20-55% by weight of clay on a dry basis, 3-5% by weight of aluminum oxide Aluminum sol and 10-25% by weight of silica sol based on silica. 11. The catalytic cracking catalyst obtained by the catalytic cracking catalyst preparation method described in any one of claims 1-10.