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 catalytic cracking catalyst resistant to metal pollution and a preparation method thereof. The catalyst comprises a gas-phase ultrastable Y-type molecular sieve with secondary pores, a matrix material with mesopores comprising clay, aluminum sol, pseudo-boehmite and a silica binder, a phosphorus component, a rare earth component and a magnesium component; the secondary pores of the molecular sieve are connected to the mesopore channels of the matrix in a smooth and unobstructed manner. The preparation method comprises the steps of mixing unmodified NaY molecular sieve, a binder, clay and water, beating and spray drying, calcining, rare earth ion exchange, mild hydrothermal modification, gas-phase ultrastable modification, phosphorus introduction, acid treatment, rare earth salt and alkaline earth metal salt treatment and ammonia water treatment. The catalytic cracking catalyst has a high specific surface area, a high pore volume, a strong resistance to nickel and vanadium pollution, a high heavy oil conversion activity under pollution, a high gasoline yield, a high total liquid yield, and low coke selectivity and dry gas selectivity.

Description

TECHNICAL FIELD

[0001] The present application relates to a phosphorus and rare earth containing anti-metallic contamination catalytic cracking catalyst and its preparation method. 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 salt, etc., harmful metals such as nickel, vanadium, iron, sodium, calcium, etc. 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 pollution to the catalyst is one of the key measures to improve the economic and technical benefits of RFCC device.

[0003] CN1854255A discloses a preparation method of a cracking catalyst resistant to heavy metal pollution. 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 and a rare earth metal compound, and optionally an inorganic acid to prepare a binder slurry, and uniformly mixes the above clay slurry, molecular sieve slurry and binder slurry and then dries. The catalyst prepared by this method still has certain limitations in terms of resistance to nickel and vanadium pollution.

[0004] CN1334315A discloses a new matrix type FCC catalyst resistant to heavy metals and its preparation method. The catalyst composition is 20-80 m% of clay, 5-40 m% of a binder, 1-25 m% of a metal capturing component (such as rare earth oxalate), 0-30 m% of other oxides (such as active alumina), and 5-40 m% of a zeolite selected from the group consisting of faujasite with a cell constant of 2.432-2.472 nm, ZSM-5 zeolite, beta zeolite or a mixture thereof.

[0005] The above existing catalytic cracking catalyst has a certain resistance to metal pollution, but does not explain how to have better conversion capacity in the case of using rare earth anti-pollution components. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a phosphorus and rare earth containing anti-metallic contamination catalytic cracking catalyst and its preparation method.

[0007] A metal contamination resistant catalytic cracking catalyst containing phosphorus and rare earth, comprising a matrix material having mesopores, a fumed ultra-stable Y-type molecular sieve having secondary pores, a rare earth component and a phosphorus component, wherein the secondary pores of the ultra-stable Y-type molecular sieve at the interface of the ultra-stable Y-type molecular sieve particles and the matrix are connected to the mesopores of the matrix unobstructed, wherein the pore volume of the catalyst is greater than 0.4 mL·g -1 , the specific surface area is greater than 290 m 2 ·g -1 , the matrix material comprises clay, aluminum sol, pseudo-boehmite and silica binder, the content of the phosphorus component is 0.01-5% by weight as P2O5, the content of the magnesium component is 0.01-1% by weight as MgO, and the content of the rare earth is 0.5-6% by weight as RE2O3, for example 1-5.5% by weight.

[0008] The present application provides a method for preparing a catalytic cracking catalyst, which comprises:

[0009] (1) mixing an unmodified NaY molecular sieve with a binder comprising an alumina binder and a silica binder, clay and water, beating, spray drying and forming, and calcining at 280-380°C, preferably for 1-4 hours, to obtain catalyst microspheres A; wherein the alumina binder comprises aluminum sol and pseudo-boehmite;

[0010] (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 reduced sodium oxide content; wherein the rare earth solution is also referred to as a rare earth salt solution;

[0011] (3) modifying the catalyst microspheres B, and optionally drying, to obtain catalyst microspheres C containing a molecular sieve with reduced unit cell constant, wherein the modification 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 sieve in the catalyst microspheres C containing a molecular sieve with 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;

[0012] (4) contacting the catalyst microspheres C with SiCl4 gas at a temperature of 250 to 450°C, wherein the weight ratio of SiCl4 to the catalyst microspheres C on a dry basis is preferably = 0.03 to 0.2:1, and the reaction time is preferably 10 minutes to 5 hours, and then washing and filtering to obtain catalyst microspheres D; if the water content in the catalyst microspheres C is not more than 1% by weight, the catalyst microspheres C can be directly contacted with silicon tetrachloride to perform the reaction, and if the water content in the catalyst microspheres C is more than 1% by weight, the catalyst microspheres C are preferably dried to have a water content of less than 1% by weight, and then contacted with silicon tetrachloride to perform the reaction;

[0013] (5) contacting the catalyst microspheres D with a phosphorus compound to perform phosphorus modification treatment, and calcining to obtain catalyst microspheres E;

[0014] (6) contacting the catalyst microspheres E with a solution of inorganic acid and organic acid at a temperature of 40 to 70°C for at least 60 minutes, for example 60 to 120 minutes, and then filtering and washing to obtain catalyst microspheres F.

[0015] (7) mixing the catalyst microspheres F with a solution containing a rare earth salt and an alkaline earth metal salt at room temperature, for example, mixing the catalyst microspheres F with a mixed solution containing a rare earth salt and an alkaline earth metal salt at room temperature, stirring, preferably stirring for 5 to 30 minutes, filtering, and then contacting with ammonia water, for example, adding the catalyst microspheres F to ammonia water having a concentration of 5% to 15% by weight based on NH3, stirring, preferably stirring for 5 to 30 minutes, filtering, drying, and calcining to obtain a catalytic cracking catalyst, which is denoted as catalyst product G. The mixed solution containing a rare earth salt and an alkaline earth metal salt is a solution containing a rare earth salt and an alkaline earth metal salt.

[0016] In the present application, the room temperature is 10 to 30°C.

[0017] The present application further provides a catalytic cracking method, which comprises the step of contacting a hydrocarbon oil with the anti-metal contamination catalytic cracking catalyst containing phosphorus and rare earth provided by the present application or the catalytic cracking catalyst prepared by the preparation method of the catalytic cracking catalyst according to any one of the above-mentioned schemes. Preferably, the reaction temperature of the reaction is 480 to 520°C, the reaction time is 0.5 to 5 seconds, and the catalyst / oil ratio is 2 to 10 by weight. The hydrocarbon oil is preferably heavy oil, for example, one or more of atmospheric residue, vacuum residue, hydrogenated LCO, hydrogenated VGO, atmospheric gas oil, and vacuum gas oil.

[0018] The anti-metal contamination catalytic cracking catalyst containing phosphorus and rare earth provided by the application has higher activity stability, good anti-metal contamination performance, especially strong anti-nickel and vanadium contamination ability, and has better catalytic cracking effect in the case of metal contamination, higher heavy oil conversion activity, higher gasoline yield, higher liquid product yield (total liquid yield), lower dry gas selectivity and lower coke selectivity.

[0019] The preparation method of the catalytic cracking catalyst provided by the application has at least one of the following advantages, preferably multiple or all of the advantages: (1) the catalytic cracking catalyst obtained has larger specific surface area and higher pore volume, (2) the catalytic cracking catalyst obtained has good wear resistance (has better strength), (3) the catalytic cracking catalyst obtained has stronger heavy oil conversion ability, (4) the catalytic cracking catalyst obtained has higher gasoline yield and total liquid yield, (5) the catalytic cracking catalyst obtained has excellent coke selectivity and dry gas selectivity, (6) the catalytic cracking catalyst obtained has strong anti-metal (such as nickel and vanadium) contamination ability, and can have lower coke selectivity, lower dry gas selectivity, higher total liquid yield, higher gasoline yield and liquefied gas yield in the case of metal contamination. The preparation method of the catalyst provided by the application can be used to prepare the anti-metal contamination catalytic cracking catalyst containing phosphorus and rare earth provided by the application.

[0020] The catalytic cracking method provided by the application is used for processing heavy oil containing contaminated metals, has higher conversion rate in the case of metal contamination, can have higher gasoline yield, has higher total liquid yield, lower coke selectivity and lower dry gas selectivity. DETAILED DESCRIPTION

[0021] According to the catalytic cracking catalyst provided by the application, preferably, the matrix material with mesopores is a matrix material with mesopores treated by silicon tetrachloride and mixed acid.

[0022] According to the catalytic cracking catalyst provided by the application, preferably, at least part of the rare earth is in the form of deposited rare earth oxide.

[0023] According to the catalytic cracking catalyst provided by the application, preferably, the catalytic cracking catalyst further contains alkaline earth metal, and the content of the alkaline earth metal in terms of oxide is 0.01-1 wt%, for example, 0.05-0.9 wt%. At least part of the alkaline earth metal is preferably in the form of deposited oxide.

[0024] According to the catalytic cracking catalyst provided by the present invention, preferably, the catalytic cracking catalyst comprises, on a dry basis, 10 to 50 wt% of an ultrastable Y-type molecular sieve, on a dry basis, 20 to 55 wt% of clay, on a dry basis, 2 to 10 wt% of aluminum sol, on a dry basis, 5 to 25 wt% of pseudo-boehmite, on a dry basis, and 10 to 25 wt% of a silica binder, on a silica basis, 0.5 to 5 wt% of phosphorus, on a P2O5 basis, 0.5 to 6 wt% of rare earth, on a dry basis, and 0.01 to 1 wt% of magnesium, on a dry basis. The pore volume of the catalytic cracking catalyst containing phosphorus and rare earth is preferably 0.4 to 0.45 mL·g -1 The specific surface area is preferably 290-320m 2 ·g -1 , wear index does not exceed 1.5%.h -1 For example, 0.5~1.5%.h -1 .

[0025] According to the method for preparing a catalytic cracking catalyst provided by the present invention, in one embodiment, the rare earth salt is lanthanum nitrate and / or lanthanum chloride, and the alkaline earth metal salt is magnesium nitrate and / or magnesium chloride.

[0026] In the method for preparing a catalytic cracking catalyst provided by the present invention, the unmodified NaY molecular sieve is, for example, a hydrothermally synthesized NaY molecular sieve or a hydrothermally synthesized NaY molecular sieve that has only been washed with water, such as industrial water, and the pH value of the filter cake of the NaY molecular sieve after washing is measured to be 7 to 9, preferably 7.0 to 8.0. The hydrothermally synthesized NaY molecular sieve can be purchased commercially or synthesized with reference to existing technologies, for example, with reference to the methods provided in the claims or examples of U.S. Patents US3639099 and US3671191. The industrial water is well known to those skilled in the art. On a dry basis, the content of the unmodified NaY molecular sieve in the catalyst microspheres A is 10 to 50% by weight, preferably 15 to 45% by weight, for example 25 to 40% by weight.

[0027] According to the method for preparing a catalytic cracking catalyst provided by the present invention, the clay is selected from one or more clays used as cracking catalyst components, such as kaolin, diatomaceous earth, saponite, halloysite, montmorillonite, halloysite, rectorite, attapulgite, sepiolite, hydrotalcite, and bentonite. These clays are well known to those skilled in the art. Preferably, the content of the clay in the catalyst microspheres A provided by the present invention is 20 to 55% by weight, for example, 30 to 50% by weight, calculated on a dry basis.

[0028] The content of the alumina binder in the catalyst microspheres A is 10 to 40% by weight, for example, 20 to 35% by weight. The alumina binder is preferably pseudoboehmite and aluminum sol, for example, the catalyst microspheres A contain 2 to 15% by weight of aluminum sol calculated as alumina, preferably 3 to 10% by weight, and 5 to 25% by weight of pseudoboehmite calculated as alumina, preferably 5 to 15% by weight. The alumina binder according to the present application includes pseudoboehmite and aluminum sol, and can further include other alumina binders selected from one or more of various forms of alumina and hydrated alumina other than the above, which are generally used for cracking catalysts. The other alumina binders are, for example, one or more of γ-alumina, χ-alumina, η-alumina, θ-alumina, boehmite, gibbsite, and bayerite.

[0029] In the step (1), the silica binder is added during the formation of the slurry. Preferably, the content of the silica binder in the catalyst microspheres A is 10 to 30% by weight, preferably 10 to 25% by weight or 20 to 25% by weight, calculated as silica. The silica binder is preferably silica sol, which imparts higher gasoline yield and better coke selectivity to the catalyst.

[0030] In the preparation method of the catalytic cracking catalyst according to the present application, the catalyst microspheres A preferably contain 10 to 50% by weight, for example, 20 to 45% by weight, of the unmodified NaY-type molecular sieve on a dry basis, 10 to 30% by weight, for example, 15 to 25% by weight, of the silica binder calculated as silica, 10 to 40% by weight, for example, 15 to 35% by weight, of the alumina binder calculated as alumina, and 10 to 80% by weight, for example, 20 to 60% by weight, of the clay on a dry basis, based on the weight of the catalyst microspheres A; and the weight ratio of the aluminum sol calculated as alumina to the pseudoboehmite calculated as alumina is preferably 2 to 10:5 to 25.

[0031] In one embodiment, the catalyst microspheres A contain 20 to 55% by weight of the clay on a dry basis, 10 to 50% by weight of the unmodified NaY-type molecular sieve on a dry basis, 2 to 10% by weight of the aluminum sol calculated as alumina, 5 to 25% by weight of the pseudoboehmite calculated as alumina, and 10 to 25% by weight of the silica binder calculated as silica.

[0032] The method for preparing the catalytic cracking catalyst provided by the present application comprises the following steps: (1) mixing the unmodified NaY molecular sieve with a binder, clay and water to form a slurry, and then spray drying the slurry to form catalyst microspheres; and (2) calcining the catalyst microspheres.

[0033] In one embodiment, the unmodified NaY molecular sieve is mixed with the binder, clay and water at ambient temperature, such as room temperature (10-30°C), and then stirred for more than 30 minutes, such as 30-180 minutes or 30-60 minutes, to form the slurry. The mixing and stirring process can be performed without temperature aging.

[0034] According to the method provided by the present application, the method for mixing and stirring the unmodified NaY molecular sieve with the binder, clay and water has no special requirements compared with the existing method for preparing the catalytic cracking catalyst. For example, the clay, such as kaolin, and / or other clay can be mixed with water, aluminum sol and silicon sol to form a slurry, and then the pseudo-boehmite and optional other alumina and / or alumina precursor and hydrochloric acid are added to the slurry to form a second slurry. The acid-alumina ratio (molar ratio of acid to pseudo-boehmite in terms of alumina) is preferably 0.10-0.30. Then, the first slurry and the second slurry are mixed, and then mixed with the unmodified NaY molecular sieve or the slurry of the unmodified NaY molecular sieve to form a slurry, which is referred to as catalyst colloid. The solid content of the catalyst colloid is preferably 28-40% by weight. The catalyst colloid is spray dried to form catalyst microspheres A.

[0035] According to the method for preparing the catalytic cracking catalyst provided by the present application, the method for spray drying has no special requirements, and can be performed according to the existing method for spray drying in the preparation of the cracking catalyst.

[0036] In the method for preparing the catalytic cracking catalyst provided by the present application, in step (1), the catalyst microspheres are formed by spray drying, and then the catalyst microspheres are calcined. The calcination temperature is 280-380°C, and is preferably 300-350°C. The calcination time is 1-4 hours, such as 1 hour, 2 hours, 3 hours or 4 hours.

[0037] The catalyst microspheres A contain unmodified NaY type molecular sieve, and can also contain other molecular sieves in addition to the unmodified NaY type molecular sieve. The content of the other molecular sieves, on a dry basis, can be 0-40% by weight, for example 0-30% by weight or 1-20% by weight, based on the weight of the catalyst microspheres A. The other molecular sieves are selected from the molecular sieves used in catalytic cracking catalysts, for example one or more of zeolites with MFI structure, Beta zeolite, non-zeolite molecular sieves. Preferably, one or more of zeolites with MFI structure such as HZSM-5, ZRP, ZSP, Beta zeolite such as Hβ, non-zeolite molecular sieves such as aluminum phosphate molecular sieve (AlPO molecular sieve), silicon aluminum phosphorus molecular sieve (SAPO molecular sieve).

[0038] In the preparation method of the catalytic cracking catalyst provided by the present application, the ion exchange reaction in step (2) is carried out by contacting the catalyst microspheres A with a rare earth solution. The ion exchange reaction can be carried out at a temperature of 20-60°C, preferably 25-45°C, and the exchange time can be more than 60 minutes, preferably 60-120 minutes. The rare earth solution is an aqueous solution of rare earth salt. The rare earth salt is preferably a rare earth chloride and / or a rare earth nitrate. The rare earth is, for example, La, Ce, Pr, Nd or a mixed rare earth containing one or more of the above-mentioned rare earth elements. In one embodiment, the concentration of the rare earth solution in step (2) is 200-350 g / L as RE2O3, and the weight ratio of the rare earth solution to the catalyst microspheres A is 0.03-0.3. Preferably, the ion exchange is carried out so that the content of sodium oxide in the catalyst microspheres B is 1.5-2.5% by weight.

[0039] Preferably, the exchange is carried out so that the content of rare earth in the obtained catalyst microspheres B is preferably 1-5% by weight as RE2O3.

[0040] In the preparation method of the catalytic cracking catalyst provided by the present application, the modification treatment (the treatment is referred to as mild hydrothermal ultrastable modification treatment) of the catalyst microspheres B in step (3) is carried out at a temperature of 350-450°C, preferably 370-420°C.

[0041] In the preparation method of the catalytic cracking catalyst provided by the present application, the modification treatment in step (3) is carried out in an atmosphere containing 40-60% by volume of water vapor, preferably 45-55% by volume of water vapor. The atmosphere can be a mixture of one or more of air, nitrogen and water vapor.

[0042] In the preparation method of the catalytic cracking catalyst provided by the present application, the modification treatment in step (3) is carried out for a time of 4-6 hours, preferably 5-6 hours.

[0043] In the preparation method of the catalytic cracking catalyst, the reaction temperature of the reaction of the catalyst microspheres C with SiCl4 gas in step (4) is 250-450°C, preferably 280-420°C.

[0044] In the preparation method of the catalytic cracking catalyst, the reaction time of the reaction of the catalyst microspheres C with SiCl4 gas in step (4) is 10 minutes to 5 hours, for example, 0.2-2 hours, preferably 0.5 hour to 2 hours.

[0045] In the preparation method of the catalytic cracking catalyst, the reaction material weight ratio of the reaction of the catalyst microspheres C with SiCl4 gas in step (4) is SiCl4: catalyst microspheres C = 0.03-0.2:1, preferably 0.05-0.15:1.

[0046] In the catalytic cracking catalyst, the phosphorus modification treatment in step (5) is carried out. In one embodiment, the phosphorus modification treatment conditions are as follows: the catalyst microspheres D obtained after the contact with SiCl4 in step (4) are contacted with an exchange solution containing a phosphorus compound, the exchange reaction is carried out at 15-60°C for 10-100 minutes, filtration, washing, drying, and calcination; wherein the weight ratio of water to the catalyst microspheres D in the mixture formed by the contact of the exchange solution with the catalyst microspheres D is 1-3, preferably 1.5-2, and the weight ratio of phosphorus (calculated as P2O5) to the catalyst microspheres D is 0.0002-0.08, preferably 0.0005-0.015. The phosphorus compound can be selected from one or more of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate. The washing is carried out, for example, with 5-12 times the weight of the catalyst microspheres D of water, for example, de-cation or de-ion water.

[0047] Preferably, the phosphorus modification in step (5) results in the phosphorus-containing catalytic cracking catalyst containing 0.01-5% by weight of P2O5. More preferably, the phosphorus content of the phosphorus-containing catalytic cracking catalyst is, for example, 0.02-5% by weight or 0.05-1.5% by weight or 0.03-3% by weight, calculated as P2O5.

[0048] After the phosphorus modification treatment in step (5), calcination is carried out. In one embodiment, the calcination is carried out at a calcination temperature of 350-500°C for 1-3 hours.

[0049] In the catalytic cracking catalyst, the acid treatment modification of the catalyst microspheres E with an acid solution in step (6) is carried out. Preferably, the catalyst microspheres E are contacted with inorganic acid and organic acid solutions at a temperature of 40-70°C for at least 60 minutes, which can have a better effect of increasing the pore volume.

[0050] In one embodiment, in step (6), the treatment with the inorganic acid is followed by the treatment with the inorganic acid and the organic acid, and the temperature of the treatment is preferably 40 to 70°C, and the treatment time is preferably at least 60 minutes each.

[0051] In one embodiment, in step (6), the catalyst microspheres E obtained in step (5) are mixed with an inorganic acid of medium strength or higher and water, and are contacted at 40 to 70°C, preferably 50 to 60°C, for at least 60 minutes, for example 60 to 120 minutes, and then an organic acid is added, and the mixture is contacted at 40 to 70°C, preferably 50 to 60°C, for at least 60 minutes, for example 60 to 120 minutes, and then filtered, washed, and dried to obtain catalyst microspheres F. Among the preferred embodiments, the weight ratio of the organic acid to the catalyst microspheres E on a dry basis is 0.02 to 0.10:1, the weight ratio of the solution of the inorganic acid of medium strength or higher to the catalyst microspheres E on a dry basis is 6 to 12:1, and the molar concentration of the solution of the inorganic acid of medium strength or higher is preferably 0.01M to 0.15M. M represents molar concentration, and the unit is mol / L.

[0052] The organic acid is, for example, one or more of oxalic acid, malonic acid, succinic acid, methylsuccinic acid, malic acid, tartaric acid, citric acid, and salicylic acid; and the organic acid is preferably one or more of formic acid, acetic acid, citric acid, oxalic acid, and tartaric acid.

[0053] The inorganic acid of medium strength or higher is, for example, one or more of hydrochloric acid, nitric acid, and sulfuric acid.

[0054] In the method for producing a catalytic cracking catalyst according to the present application, the solution containing a rare earth salt and an alkaline earth metal salt in step (7) is also referred to as a mixed solution containing a rare earth salt and an alkaline earth metal salt, and the rare earth salt is preferably lanthanum nitrate or lanthanum chloride, and the alkaline earth metal salt is preferably magnesium nitrate or magnesium chloride. The concentration of the rare earth salt in the mixed solution containing a rare earth salt and an alkaline earth metal salt is preferably 60 to 150 g / L as RE2O3, and the concentration of the alkaline earth metal salt is preferably 30 to 80 g / L as the oxide of the alkaline earth metal (MgO for magnesium salts, and CaO for calcium salts). The mixing with the ammonia water having a concentration of 5 to 15% by weight is performed at room temperature, and the room temperature is 10 to 30°C. The ammonia water is an aqueous solution of ammonia gas, and the concentration of the ammonia water is 5 to 15% by weight as NH3. The weight ratio of the mixed solution containing a rare earth salt and an alkaline earth metal salt to the catalyst microspheres F on a dry basis is 2 to 6:1.

[0055] Preferably, in the catalytic cracking catalyst, the content of the rare earth is 1.2 to 6% by weight as RE2O3, and the content of the alkaline earth metal oxide is 0.01 to 1% by weight.

[0056] The first rare earth introduced by step (2) is called first rare earth, and the second rare earth introduced by step (7) is called second rare earth. The content of the first rare earth is preferably 1.0-4.8% by weight, the content of the second rare earth is preferably 0.2-1.2% by weight, and the total content of the first rare earth and the second rare earth is 1.2-6% by weight.

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

[0058] In the examples and comparative examples, the unmodified NaY molecular sieve (also called NaY zeolite) was provided by Qilu Branch of Sinopec Catalyst Co., Ltd., with a sodium oxide content of 13.5% by weight, a framework silica-alumina ratio (molar ratio of SiO2 / Al2O3) of 4.6, a unit cell constant of 2.470 nm, and a relative crystallinity of 90%. The NaY molecular sieve was an originally synthesized NaY molecular sieve which 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. The rare earth chlorides and nitrates (denoted as RECl3 and RE(NO3)3, respectively, and mixed rare earths, wherein the content of La2O3 was 33.6% by weight, and the content of Ce2O3 was 66.4% by weight) were industrial products produced by Baogang Rare Earth Co., Ltd. The pseudo-boehmite was an industrial product produced by Shandong Aluminum Plant, with a solid content of 61% by weight. 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., wherein the content of aluminum oxide was 21% by weight. The silicon sol was provided by Qilu Branch of Sinopec Catalyst Co., Ltd., wherein the content of silicon oxide was 25% by weight, and the pH value was 2.5.

[0059] Analysis method: In each of the comparative examples and the examples, the elemental 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 RIPP 145-90 and RIPP 146-90 (see Petroleum Chemical Industry Analysis Methods (RIPP Test Methods), Yang Cuiding, et al., Science Press, 1990). The specific surface area of the catalyst was determined by using an Autosorb-1 nitrogen adsorption-desorption instrument of Quantachrome Corporation of the United States according to the method of GB / T 5816-1995, and the sample was degassed at 300°C for 6 hours before the test. The total pore volume of the catalyst was determined according to the standard method of RIPP 151-90 (see Petroleum Chemical Industry Analysis Methods (RIPP Test Methods), Yang Cuiding, Science Press, 1990). The attrition index of the catalyst (used to represent the attrition resistance of the catalyst, also referred to as the strength of the catalyst, and the smaller the attrition index, the better the attrition resistance of the catalyst, i.e., the better the strength) was determined according to the standard method of RIPP 29-90 (see Petroleum Chemical Industry Analysis Methods (RIPP Test Methods), Yang Cuiding, Science Press, 1990).

[0060] The chemical reagents used in the comparative examples and the examples were not particularly specified, and the specifications thereof were chemical purity.

[0061] Example 1

[0062] (1) 182 kg of deionized water was added into a stirred tank, and then the following raw materials were sequentially added under stirring: 66.7 kg of kaolin (solid content of 76% by weight, purchased from Suzhou Kaolin Company), 25.7 kg of aluminum sol (alumina content of 21.5% by weight, product of Qilu Branch of Sinopec Catalyst Co., Ltd.), 64.5 kg of silica sol (SiO2 content of 25% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.), 13.2 kg of pseudoboehmite (solid content of 61% by weight, purchased from Shandong Aluminum Factory), and 8.2 L of hydrochloric acid (HCl content of 31% by weight), and stirring was performed for 150 minutes. Subsequently, 29.7 kg (dry basis) of unmodified NaY molecular sieve slurry (concentration of 53% by weight) was added, and stirring was performed for 60 minutes. Then, spray drying was performed, and the catalyst microspheres A1 were obtained by calcination at 320°C for 1 hour in a calcination furnace.

[0063] (2) The catalyst microspheres A1 prepared above were added into a 1100 L deionized water solution and stirred to mix uniformly, and 9.3 L of RE(NO3)3 solution (rare earth solution concentration of 330 g / L as RE2O3) was added, and stirring was performed, and the temperature was increased to 30°C and maintained for 1 h, and then filtration and washing were performed, and the filter cake was dried at 120°C to obtain the rare earth-containing catalyst microspheres B1 with reduced sodium oxide content.

[0064] (3) The catalyst microspheres B1 are calcined at a temperature of 410°C for 6 hours in an atmosphere containing 45% by volume of water vapor and 55% by volume of air, and then subjected to a drying treatment to reduce the water content to less than 1% by weight, to obtain catalyst microspheres C1 containing a molecular sieve having a reduced unit cell constant;

[0065] (4) The catalyst microspheres C1 are contacted with SiCl4 gas vaporized by heating at a temperature of 400°C for 20 minutes at a weight ratio of SiCl4 : catalyst microspheres C1 (dry basis) = 0.05 : 1, washed with 1100 L of deionized water, and then filtered to obtain catalyst microspheres D1;

[0066] (5) The catalyst microspheres D1 are subjected to a phosphorus modification treatment by contacting them with a phosphorus compound: the catalyst microspheres D1 are added to 3 times the weight of deionized water based on the dry catalyst, and then ammonium phosphate is added at a weight ratio of ammonium phosphate (as P2O5) : catalyst microspheres D1 (dry basis) = 0.012, and the mixture is stirred at 20°C for 50 minutes. The mixture is filtered, washed with 5 times the weight of deionized water based on the catalyst microspheres D1 (dry basis), and then dried at a temperature of 125°C for 5 hours and calcined at a temperature of 400°C for 2 hours to obtain catalyst microspheres E1.

[0067] (6) The catalyst microspheres E1 are subjected to an acid treatment modification by contacting them with an acid solution: the catalyst microspheres E1 are mixed with a 0.12 M hydrochloric acid solution, stirred at 50°C for 75 minutes, and then oxalic acid is added, and the mixture is stirred at 50°C for 70 minutes. The mixture is filtered, washed, and dried to obtain catalyst microspheres F1. The weight ratio of the 0.12 M hydrochloric acid solution : catalyst microspheres E1 (dry basis) is 8 : 1, and the weight ratio of oxalic acid : catalyst microspheres E1 (dry basis) is 0.025 : 1.

[0068] (7) 15 Kg of catalyst microspheres F1 are added to 40 L of an aqueous solution containing a rare earth salt (the concentration of the rare earth solution is 120 g / L as La2O3) and an alkaline earth metal salt (the concentration of the alkaline earth metal solution is 55 g / L as MgO), stirred for 5 minutes, filtered, and then added to 30 L of 9% by weight ammonia water, stirred for 5 minutes, filtered, dried, and calcined at a temperature of 550°C for 2 hours to obtain catalyst SCAT-1. The performance analysis results are shown in Table 1.

[0069] Example 2

[0070] (1) In a catalyst gelation kettle, 188 Kg of deionized water was added, then, under stirring, the following gelation raw materials were added in sequence: 69.6 Kg of kaolin (solid content 76 wt%, purchased from Suzhou Kaolin Co.), 20.4 Kg of aluminum sol (alumina content 21.5 wt%, product of Qilu Branch, Sinopec Catalyst Co.), 67.6 Kg of silica sol (SiO2 content 25 wt%, provided by Qilu Branch, Sinopec Catalyst Co.), 13.8 Kg of pseudoboehmite (solid content 61 wt%, purchased from Shandong Aluminum Plant), and 8.5 L of hydrochloric acid (HCl content 31 wt%), and stirring was continued for 150 minutes. Then, 27.5 Kg (dry basis) of unmodified NaY molecular sieve slurry (concentration 53 wt%) was added, and stirring was continued for 60 minutes. Then, spray drying and molding were performed, and calcination was carried out in a calcination furnace at 350°C for 1 hour, to obtain catalyst microspheres A2;

[0071] (2) The catalyst microspheres A2 prepared above were added to a 1100 L deionized water solution, and stirring was carried out to mix them uniformly, 7.2 L of RE(NO3)3 solution (rare earth solution concentration 330 g / L as RE2O3) was added, and stirring was carried out, and the temperature was raised to 40°C and maintained for 1 h, then filtration and washing were carried out, and the filter cake was dried at 120°C to obtain rare earth-containing catalyst microspheres B2 with reduced sodium oxide content;

[0072] (3) The catalyst microspheres B2 above were calcined at a temperature of 350°C in an atmosphere containing 55 vol% water vapor for 6 h, then drying treatment was carried out to reduce the water content to less than 1 wt%, to obtain catalyst microspheres C2 containing molecular sieves with reduced unit cell constant;

[0073] (4) Under the condition of a temperature of 300°C, SiCl4 gas was introduced, and the reaction was carried out for 2 h, according to the weight ratio of SiCl4 : catalyst microspheres C2 (dry basis) = 0.08 : 1, then the catalyst microspheres were washed with 1100 L of deionized water, then filtration was carried out, to obtain catalyst microspheres D2;

[0074] (5) The catalyst microspheres D2 were subjected to phosphorus modification treatment by contacting with a phosphorus compound: the catalyst microspheres D2 were added to 3 times the weight of deionized water based on the dry catalyst, then diammonium hydrogen phosphate was added, and the exchange reaction was carried out at 30°C for 40 minutes, and filtration was carried out, wherein the weight ratio of diammonium hydrogen phosphate (as P2O5) to catalyst microspheres D2 (dry basis) was 0.01, and the catalyst microspheres were washed with 5 times the weight of deionized water based on the catalyst microspheres D2 (dry basis), then drying was carried out at a temperature of 125°C for 5 hours, and calcination was carried out at 400°C for 2 hours, to obtain catalyst microspheres E2;

[0075] (6) The catalyst microspheres E2 are subjected to acid treatment modification by contacting with an acid solution: first, the catalyst microspheres E2 are mixed with a sulfuric acid solution with a molar concentration of 0.045 M, and are contacted at 60°C for 70 minutes, then citric acid and acetic acid are added, and are contacted at 50°C for 70 minutes, and after filtration, washing and drying, catalyst microspheres F2 are obtained. The weight ratio of citric acid to catalyst microspheres E2 on a dry basis is 0.015:1, the weight ratio of acetic acid to catalyst microspheres E2 on a dry basis is 0.012:1, and the weight ratio of the sulfuric acid solution with a molar concentration of 0.055 M to catalyst microspheres E2 on a dry basis is 10:1;

[0076] (7) 15 Kg of catalyst microspheres F2 are added to 45 L of a mixed solution containing rare earth salt (the concentration of the rare earth solution is 105 g / L in terms of La2O3) and alkaline earth metal salt (the concentration of the alkaline earth metal solution is 55 g / L in terms of MgO) under the condition of 25°C, stirred for 5 minutes, then filtered, and then added to 30 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 catalyst product SCAT-2, and the performance analysis results are shown in Table 1.

[0077] Example 3

[0078] (1) In a catalyst gelation kettle, 209 Kg of deionized water is added, and then under stirring, the following gelation raw materials are sequentially added: 60.8 Kg of kaolin (solid content of 76% by weight, purchased from Suzhou Kaolin Company), 15.4 Kg of aluminum sol (alumina content of 21.5% by weight, product of Qilu Branch of Sinopec Catalyst Co., Ltd.), 76.4 Kg of silica sol (SiO2 content of 25% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.), 15.7 Kg of pseudoboehmite (solid content of 61% by weight, purchased from Shandong Aluminum Factory), and 9.3 L of hydrochloric acid (HCl content of 31% by weight), and stirring is performed for 150 minutes. Then, 31.9 Kg (on a dry basis) of unmodified NaY molecular sieve slurry (concentration of 53% by weight) is added, and stirring is performed for 60 minutes. Then, spray drying and molding are performed, and calcination is performed in a calcination furnace at 300°C for 1 hour to obtain catalyst microspheres A3;

[0079] (2) The above catalyst microspheres A3 (on a dry basis) are added to 1100 L of deionized water solution, and stirring is performed to uniformly mix them, 11.4 L of RE(NO3)3 solution (the concentration of the rare earth solution is 330 g / L in terms of RE2O3) is added, stirring is performed, and the temperature is raised to 35°C and maintained for 1 h, then filtration, washing, and drying of the filter cake at 120°C are performed to obtain rare earth-containing catalyst microspheres B3 with reduced sodium oxide content;

[0080] (3) The catalyst microspheres B3 are calcined at a temperature of 390°C for 5 hours in an atmosphere containing 50% by volume of water vapor, and then subjected to a drying treatment to reduce the water content to less than 1% by weight, to obtain catalyst microspheres C3 containing a molecular sieve with a reduced unit cell constant;

[0081] (4) The catalyst microspheres C3 are contacted with SiCl4 gas vaporized by heating at a weight ratio of SiCl4 : catalyst microspheres C3 (dry basis) = 0.10 : 1 at a temperature of 350°C for 1 hour, and then washed with 1200 L of deionized water and filtered to obtain catalyst microspheres D3;

[0082] (5) The catalyst microspheres D3 are subjected to a phosphorus modification treatment by being contacted with a phosphorus compound: the catalyst microspheres D3 are added to 3 times the dry weight of the catalyst microspheres D3 of deionized water, and then diammonium hydrogen phosphate is added at a weight ratio of diammonium hydrogen phosphate (as P2O5) : catalyst microspheres D3 (dry basis) = 0.0055, and the exchange reaction is carried out at 40°C for 30 minutes, and then filtered and washed with 5 times the weight of the catalyst microspheres D3 (dry basis) of deionized water, and then dried at a temperature of 125°C for 5 hours and calcined at 400°C for 2 hours to obtain catalyst microspheres E3;

[0083] (6) The catalyst microspheres E3 are subjected to an acid treatment modification by being contacted with an acid solution: the catalyst microspheres E3 are first mixed with a nitric acid solution with a molar concentration of 0.09 M at 50°C for 75 minutes, and then formic acid is added and contacted at 50°C for 70 minutes, and then filtered, washed and dried to obtain catalyst microspheres F3; the weight ratio of formic acid : catalyst microspheres E3 (dry basis) is 0.02 : 1, and the weight ratio of the nitric acid solution with a molar concentration of 0.09 M : catalyst microspheres E3 (dry basis) is 11 : 1;

[0084] (7) 15 Kg of catalyst microspheres F3 are added to 55 L of a mixed solution containing a rare earth salt (the concentration of the rare earth solution is 85 g / L as La2O3) and an alkaline earth metal salt (the concentration of the alkaline earth metal solution is 55 g / L as MgO) at room temperature, stirred for 5 minutes, filtered, and then added to 30 L of ammonia water with a concentration of 12.5% by weight, 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.

[0085] Comparative Example 1

[0086] 2000 Kg (dry basis) of unmodified NaY type zeolite with a framework SiO2 / Al2O3 ratio of 4.6 (sodium oxide content 13.5% by weight, produced by Qilu Catalyst Branch of Sinopec) are added to a 20 m 3The water in the primary exchange tank was stirred at 25°C, then 580 L of RECl3 solution (the rare earth concentration in the RECl3 solution was 330 g / L as RE2O3) was added, and stirred for 60 minutes, then filtered, washed, and the filter cake was continuously sent to a flash drying oven for drying; then, it was sent to a calcination furnace for modification: the material atmosphere temperature was controlled at 420°C, 50% water vapor (atmosphere containing 50% water vapor by volume) was calcined for 6 hours; then, the molecular sieve material was introduced into the calcination furnace for calcination and drying treatment, the material atmosphere temperature was controlled at 500°C, dry air atmosphere (water vapor content less than 1% by volume), and calcined for 2.5 hours to make the water content less than 1% by weight; then, the molecular sieve material was directly sent to a continuous gas phase ultrastable reactor for gas phase ultrastable reaction, the gas phase ultrastable reaction process of the molecular sieve in the continuous gas phase ultrastable reactor and the subsequent tail gas absorption process were carried out according to the method of Example 1 of CN103787352A patent, and the process conditions were: SiCl4: Y-type zeolite weight ratio = 0.45: 1, the molecular sieve feed amount was 800 kg / hour, and the reaction temperature was 410°C. The molecular sieve material after the gas phase ultrastable reaction 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, the molecular sieve material added to the secondary exchange tank weighed 2000 Kg (dry basis), and was stirred uniformly, then 0.6 m 3 of 10% by weight hydrochloric acid was slowly added, and the temperature was raised to 90°C, and continued to stir for 70 minutes, then 135 Kg of citric acid was added, and continued to stir at 90°C for 70 minutes, then filtered, washed, and the molecular sieve filter cake was directly added to the exchange solution containing ammonium phosphate, the addition amount of the molecular sieve was: the weight ratio of phosphorus (as P2O5) to the molecular sieve was 0.04, and the weight ratio of water to the molecular sieve was 2.5, and the exchange reaction was carried out at 50°C for 60 minutes, then filtered, washed, to obtain the modified Y molecular sieve, and the sample was dried and oven-dried, and the sample was recorded as DZ-1.

[0087] Take 9.53 kg of alumina content of 21.5% by weight of aluminum sol into 52.34 kg of deionized water, open the stirring, add 27.63 kg of solid content of 76% by weight of kaolin dispersion for 60 minutes. Take 6.56 kg of pseudo-boehmite with 61% by weight of alumina content, add 26.07 kg of deionized water, under the condition of stirring, add 0.67 L of 36% mass concentration of hydrochloric acid, acidize for 60 minutes, then add the dispersed kaolin slurry, add 32 kg of silica sol (SiO2 content is 25% by weight, provided by Qilu Branch of Sinopec Catalyst Co., Ltd.), then add 15 kg of ground DZ1 molecular sieve (dry basis), after stirring uniformly, spray drying, calcination, washing and drying to obtain the catalyst, recorded as DC1. Among them, the obtained DC1 catalyst contains 30% by weight of DZ1 molecular sieve, 42% by weight of kaolin, 8% by weight of pseudo-boehmite, 16% by weight of silica sol and 4% by weight of aluminum sol (dry basis).

[0088] Comparative Example 2

[0089] Put 2000 Kg (dry weight) of NaY type zeolite with SiO2 / Al2O3 framework of 4.6 (sodium oxide content of 13.5%, produced by Sinopec Catalyst Qilu Branch) into a primary exchange tank containing 20 m 3 L of deionized water, stir uniformly at 90℃, then add 730 L of RECl3 solution (the rare earth concentration in the RECl3 solution is 330 g / L of RE2O3), stir for 60 minutes; filter, wash, and send the filter cake to a flash drying oven for drying; then, send the molecular sieve material to a calcination furnace for calcination and drying treatment, control the calcination temperature at 500℃, the calcination atmosphere is dry air atmosphere, and the calcination time is 2 hours, so that the water content of the molecular sieve is less than 1%; then, directly send the molecular sieve material to a continuous gas phase ultrastable reactor for gas phase ultrastable reaction, the gas phase ultrastable reaction process of the molecular sieve in the continuous gas phase ultrastable reactor and the subsequent tail gas absorption process are carried out according to the method of Example 1 of CN103787352A patent disclosure, and the process conditions are: SiCl4:Y type zeolite weight ratio = 0.25:1, the feeding amount of the molecular sieve is 800 kg / hour, and the reaction temperature is 490℃. After the gas phase ultrastable reaction, the molecular sieve material is separated by a gas-solid separator and sent to a secondary exchange tank, 20 m 3 L of deionized water is added to the secondary exchange tank, the weight of the molecular sieve material added to the secondary exchange tank is 2000 Kg (dry weight), and the stirring is uniform, then slowly add 0.95 m 3The mixture was heated to 90°C, and then stirred for 80 minutes. Then, 75 Kg of citric acid and 50 Kg of tartaric acid were added. After the mixture was stirred at 90°C for 70 minutes, the mixture was filtered and washed. The filter cake was then directly added to an exchange solution containing diammonium hydrogen phosphate. The amount of molecular sieve added was such that the weight ratio of phosphorus (as P2O5) to molecular sieve was 0.03, and the weight ratio of water to molecular sieve was 3.0. The exchange reaction was carried out at 60°C for 50 minutes. The mixture was filtered and washed to obtain the modified ultra-stable Y molecular sieve, which was labeled as DZ-2.

[0090] Referring to the preparation method of Comparative Example 1, the DZ2 molecular sieve, kaolin, water, pseudo-boehmite binder, and aluminum sol were formed into a slurry and spray-dried to prepare microspherical catalysts according to a conventional method for preparing catalytic cracking catalysts. The catalytic cracking catalyst thus prepared was labeled as DC2. In terms of dry basis, the DC2 catalyst thus obtained contained 30 wt% of the DZ2 molecular sieve, 42 wt% of kaolin, 8 wt% of pseudo-boehmite, 16 wt% of silica sol, and 4 wt% of aluminum sol.

[0091] Comparative Example 3

[0092] The catalyst was prepared according to the method of Example 1 of Patent CN1854255A, and the product was labeled as DC3.

[0093] Comparative Example 4

[0094] The catalyst was prepared according to the method of Example 1, except that the calcination temperature in step (1) was 500°C. The product was labeled as DC4.

[0095] The sodium oxide content, rare earth content, phosphorus content, magnesium content, attrition index, specific surface area, pore volume, molecular sieve unit cell constant, and relative crystallinity of the catalysts prepared in Examples 1 to 3 and Comparative Examples 1 to 4 are shown in Table 1.

[0096] Examples 4 to 6

[0097] Examples 4 to 6 were used to illustrate the method for determining the heavy metal contamination of a catalyst and the catalytic cracking performance of the catalytic cracking catalyst according to the present application.

[0098] The SCAT-1, SCAT-2, and SCAT-3 catalysts were subjected to cyclic contamination (to deposit Ni and V) in a cyclic aging device. The Ni and V contents of the catalysts after the cyclic contamination are shown in Table 3. The cyclic contamination procedure included the following steps:

[0099] (a) heating to 600°C at a temperature increase rate of 20°C / min under a nitrogen atmosphere;

[0100] (b) heating to 780°C at a temperature increase rate of 1.5°C / min, and keeping the temperature at 780°C, during which the treatment atmosphere is changed as follows:

[0101] (i) treating for 10 minutes with an atmosphere containing 40 vol% nitrogen (in which the nitrogen contains 5 vol% propylene) and 60 vol% water vapor;

[0102] (ii) treating for 10 minutes with an atmosphere containing 40 vol% nitrogen (pure nitrogen, without propylene) and 60 vol% water vapor;

[0103] (iii) treating for 10 minutes with an atmosphere containing 40 vol% air (containing 4000 μmol / mol SO2) and 60 vol% water vapor;

[0104] (iv) treating for 10 minutes with an atmosphere containing 40 vol% nitrogen and 60 vol% water vapor; and then repeating steps (i) to (iv) once more in the order mentioned above, and then repeating step (i) to end the cycle of contamination;

[0105] Then the step of aging is performed: the catalyst mixture after the cycle of contamination is aged at 788°C for 8 hours in an atmosphere containing 80 vol% water vapor and 20 vol% air;

[0106] The catalytic performance of the catalyst after the cycle of contamination and aging is then examined in an ACE apparatus, in which the feed oil is introduced at the bottom of the reactor to come into contact with the catalyst mixture, in which the catalyst loading is 9 g, the reaction temperature is 500°C, the weight hourly space velocity is 16 h －1 , the oil to catalyst ratio (weight ratio) is 5, and the feed properties in the ACE experiment are shown in Table 2, and the evaluation results are shown in Table 3.

[0107] in which the conversion = gasoline yield + liquefied gas yield + dry gas yield + coke yield

[0108] total liquid yield = gasoline yield + diesel yield + liquefied gas yield

[0109] coke selectivity = coke yield / conversion

[0110] dry gas selectivity = dry gas yield / conversion

[0111] Comparative Examples 5 to 8

[0112] Comparative Examples 5 to 8 illustrate the catalytic cracking reaction performance of the ultra-stable Y-type zeolite prepared by the method provided in Comparative Examples 1 to 4.

[0113] The DC1-DC4 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 the 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 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;

[0114] Then, the catalytic performance of the catalysts after the cyclic contamination and aging was investigated in an ACE device, wherein the feedstock oil entered the reactor at the bottom to contact the catalyst mixture, the catalyst loading was 9 g, the reaction temperature was 500°C, the weight hourly space velocity was 16 h －1 -1, the ACE experimental feedstock properties are shown in Table 2, and the evaluation results are shown in Table 3.

[0115] Table 1

[0116]

[0117] As shown by the results listed in Table 1, the catalytic cracking catalyst provided by the present application has a larger pore volume and specific surface area, and 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.

[0118] Table 2 ACE evaluation feedstock oil properties

[0119]

[0120] Table 3

[0121] Example No. Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Sample No. SCAT-1 SCAT-2 SCAT-3 DC1 DC2 DC3 DC4 Ni / ppm 2000 2000 2000 2000 2000 2000 2000 V / ppm 5000 5000 5000 5000 5000 5000 5000 Dosage oil ratio 5 5 5 5 5 5 5 Product distribution / weight % Dry gas 1.88 1.98 2.05 2.05 2.03 2.06 2.09 LPG 13.66 13.37 13.96 12.75 12.91 12.01 12.46 Coke 5.08 5.01 4.95 6.46 6.74 7.89 7.92 Gasoline 51.86 51.97 52.39 48.42 48.79 48.35 47.47 Diesel 19.47 19.66 18.98 21.45 20.91 20.25 20.48 Heavy oil 8.05 8.01 7.67 8.87 8.62 9.44 9.58 Total 100 100 100 100 100 100 100 Conversion / weight % 72.48 72.33 73.35 69.68 70.47 70.31 69.94 Total liquid yield / weight % 84.99 85 85.33 82.62 82.61 80.61 80.41 Coke selectivity / weight % 7.01 6.93 6.75 9.27 9.56 11.22 11.32 Dry gas selectivity / weight % 2.59 2.74 2.79 2.94 2.88 2.93 2.99

[0122] As shown by the results listed in Table 3, the catalytic cracking catalyst provided by the present application still has significantly lower coke selectivity, lower dry gas selectivity, higher heavy oil conversion activity, higher total liquid product yield and higher gasoline yield after being contaminated with Ni and V and aged, which indicates that the catalytic cracking catalyst provided by the present application has excellent anti-Ni, V contamination performance.

Claims

1. A metal-pollution-resistant catalytic cracking catalyst containing phosphorus and rare earth elements, comprising a mesoporous matrix material, a magnesium component, a phosphorus component, a rare earth component, and a vapor-phase ultrastable Y-type molecular sieve having secondary pores; the matrix material comprising clay, pseudo-boehmite, aluminum sol, and a silica binder; the phosphorus- and rare earth-containing metal-pollution-resistant catalytic cracking catalyst comprising, on a dry basis, 20-55 wt% of clay, 2-10 wt% of aluminum sol, 5-25 wt% of pseudo-boehmite, 10-25 wt% of silica binder, and 10-50 wt% of vapor-phase ultrastable Y-type molecular sieve having secondary pores; the magnesium component content being 0.01-1 wt% as MgO, the phosphorus component content being 0.01-5 wt% as P2O5, and the rare earth component content being 0.5-6 wt% as RE2O3; and the pore volume of the catalytic cracking catalyst being greater than 0.4 mL·g -1 , with a specific surface area greater than 290m 2 ·g -1 The secondary pores of the gas-phase ultrastable Y-type molecular sieve having secondary pores are smoothly connected to the mesoporous pores of the matrix; it is prepared by a method comprising the following steps: (1) Unmodified NaY molecular sieve, a binder including an alumina binder and a silica binder, clay, and water are formed into a slurry, spray-dried, and calcined at 280-380°C for 1-4 hours to obtain catalyst microspheres A; wherein the alumina binder includes aluminum sol and pseudo-boehmite; (2) Catalyst microspheres A are contacted with a rare earth salt solution to undergo ion exchange reaction, filtered, and washed to obtain catalyst microspheres B; (3) calcining the catalyst microspheres B at a temperature of 350-450° C. in an atmosphere containing 40-60% by volume of water vapor for 4-6 hours, and optionally drying to obtain catalyst microspheres C, wherein the water content of the catalyst microspheres C does not exceed 1% by weight; (4) Catalyst microspheres C are contacted with SiCl4 gas for reaction, washed, and filtered to obtain catalyst microspheres D; wherein, The reaction temperature is 250-450° C., the reaction time is 10 minutes to 5 hours, and the weight ratio of SiCl 4 to catalyst microspheres C on a dry basis is 0.03-0.2:1; (5) The catalyst microspheres D are contacted with a phosphorus compound for phosphorus modification treatment, and calcined to obtain catalyst microspheres E; (6) The catalyst microspheres E were treated with an inorganic acid and an organic acid solution at a temperature of 40-70°C for at least 60 minutes, and filtered to obtain catalyst microspheres F; (7) The catalyst microspheres F are mixed with a solution containing a rare earth salt and an alkaline earth metal salt at room temperature, stirred, filtered, mixed with ammonia water having a concentration of 5% to 15% by weight, stirred, filtered, and dried; the room temperature is 10-30°C.

2. The catalytic cracking catalyst containing phosphorus and rare earth according to claim 1, wherein The catalytic cracking catalyst containing phosphorus and rare earth has a pore volume of 0.4-0.45 mL·g -1 , with a specific surface area of ​​290-320 m 2 ·g -1 , wear index does not exceed 1.5%.h -1 .

3. The catalytic cracking catalyst containing phosphorus and rare earth according to claim 1, wherein Contains 1-5.5% by weight of rare earth, a small portion of which exists in the form of precipitated rare earth oxides.

4. A method for preparing a catalytic cracking catalyst as claimed in claim 1, comprising the steps of: (1) Unmodified NaY molecular sieve, a binder including an alumina binder and a silica binder, clay, and water are formed into a slurry, spray-dried, and calcined at 280-380°C for 1-4 hours to obtain catalyst microspheres A; wherein the alumina binder includes aluminum sol and pseudo-boehmite; (2) Catalyst microspheres A are contacted with a rare earth salt solution to undergo ion exchange reaction, filtered, and washed to obtain catalyst microspheres B; (3) calcining the catalyst microspheres B at a temperature of 350-450° C. in an atmosphere containing 40-60% by volume of water vapor for 4-6 hours, and optionally drying to obtain catalyst microspheres C, wherein the water content of the catalyst microspheres C does not exceed 1% by weight; (4) Catalyst microspheres C are contacted with SiCl4 gas for reaction, washed, and filtered to obtain catalyst microspheres D; wherein, The reaction temperature is 250-450° C., the reaction time is 10 minutes to 5 hours, and the weight ratio of SiCl 4 to catalyst microspheres C on a dry basis is 0.03-0.2:1; (5) The catalyst microspheres D are contacted with a phosphorus compound for phosphorus modification treatment, and calcined to obtain catalyst microspheres E; (6) The catalyst microspheres E were treated with an inorganic acid and an organic acid solution at a temperature of 40-70°C for at least 60 minutes, and filtered to obtain catalyst microspheres F; (7) The catalyst microspheres F are mixed with a solution containing a rare earth salt and an alkaline earth metal salt at room temperature, stirred, filtered, mixed with ammonia water having a concentration of 5% to 15% by weight, stirred, filtered, and dried; the room temperature is 10-30°C.

5. The method for preparing a catalytic cracking catalyst according to claim 4, characterized in that: The unmodified NaY molecular sieve described in step (1) is a hydrothermally synthesized NaY molecular sieve that is only washed with water and the pH value of the NaY molecular sieve filter cake after washing is measured to be 7-9. The calcination temperature described in step (1) is 300-350°C.

6. The method for preparing a catalytic cracking catalyst according to claim 4, wherein: The temperature of the ion exchange reaction in step (2) is 20-60° C., and the exchange time of the ion exchange reaction in step (2) is 90-120 minutes; the rare earth salt solution is an aqueous solution of a rare earth salt, and the rare earth salt is rare earth chloride and / or rare earth nitrate.

7. The method for preparing a catalytic cracking catalyst according to claim 4, characterized in that: The calcination temperature in step (3) is 370-420° C., the calcination atmosphere in step (3) is an atmosphere containing 45-55% by volume of water vapor, and the calcination time in step (3) is 5-6 hours.

8. The method for preparing a catalytic cracking catalyst according to claim 4, wherein: The temperature for the contact reaction between the catalyst microspheres C and the SiCl4 gas in step (4) is 280 to 420° C., and the reaction time for the contact reaction between the catalyst microspheres C and the SiCl4 gas in step (4) is 0.2 to 2 hours. In the contact reaction between the catalyst microspheres C and the SiCl4 gas in step (4), the weight ratio of SiCl4 to the catalyst microspheres C is 0.05 to 0.15:

1.

9. The method for preparing a catalytic cracking catalyst according to claim 4, wherein: The phosphorus modification treatment method in step (5) comprises: contacting the catalyst microspheres D with a solution containing a phosphorus compound at 15-60° C. for 10-100 minutes, filtering, washing, drying, and calcining; wherein, in the mixture formed by contacting the solution containing the phosphorus compound with the catalyst microspheres D, the weight ratio of water to the catalyst microspheres D is 1-3, and the weight ratio of the phosphorus compound calculated as P2O5 to the catalyst microspheres D is 0.0002-0.

08.

10. The method for preparing a catalytic cracking catalyst according to claim 4, characterized in that: The catalyst microspheres E described in step (6) are treated with an inorganic acid and an organic acid solution: the catalyst microspheres E obtained in step (5) are first mixed with an inorganic acid solution of medium strength or above, and a first contact is carried out at 40-70° C. The first contact time is at least 60 minutes, 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 mol / L-0.15 mol / L; then an organic acid is added, and the weight ratio of the organic acid to the catalyst microspheres E on a dry basis is 0.02-0.10:1, and a second contact is carried out at 40-70° C. The second contact time is at least 60 minutes. After filtering, washing and drying, catalyst microspheres F are obtained.

11. The method for preparing a catalytic cracking catalyst according to claim 10, characterized in that: In step (6), the weight ratio of the medium-strength or higher inorganic acid solution to the catalyst microspheres E on a dry basis is 6 to 12:1, the temperature of the first contact is 50 to 60° C., the first contact time is 60 to 120 minutes, the temperature of the second contact is 50 to 60° C., and the second contact time is 60 to 120 minutes.

12. The method for preparing a catalytic cracking catalyst according to claim 4, characterized in that: In step (7), the catalyst microspheres F are added to a mixed solution containing a rare earth salt and an alkaline earth metal salt at room temperature, stirred for 5-30 minutes, filtered, and then added to an ammonia solution having a concentration of 5% by weight to 15% by weight of NH3, stirred for 5-30 minutes, filtered, and dried; in the mixed solution containing a rare earth salt and an alkaline earth metal salt, the rare earth salt is lanthanum nitrate and / or lanthanum chloride, and the alkaline earth metal salt is magnesium nitrate and / or magnesium chloride.

13. The method for preparing a catalytic cracking catalyst according to claim 4, characterized in that: Based on the weight of the catalyst microspheres A, the catalyst microspheres A contain, on a dry basis, 10% to 50% by weight of an unmodified NaY molecular sieve, 10% to 40% by weight of an alumina binder, on a dry basis, 10% to 30% by weight of a silica binder, and 10% to 80% by weight of clay.

14. The method for preparing a catalytic cracking catalyst according to claim 4 or 13, characterized in that: The catalyst microspheres A contain: 10-50 wt% of unmodified NaY molecular sieve on a dry basis, 20-55 wt% of clay on a dry basis, 2-10 wt% of aluminum sol on a aluminum oxide basis, 5-25 wt% of pseudo-boehmite on a aluminum oxide basis, and 10-25 wt% of a silicon oxide binder on a silicon oxide basis.

15. The method for preparing a catalytic cracking catalyst according to claim 6, characterized in that: The temperature of the ion exchange reaction in step (2) is 25-45°C.

16. The method for preparing a catalytic cracking catalyst according to claim 9, characterized in that: In the mixture formed by contacting the solution containing the phosphorus compound with the catalyst microspheres D, the weight ratio of water to the catalyst microspheres D is 1.5-2, and the weight ratio of the phosphorus compound calculated as P2O5 to the catalyst microspheres D is 0.0005-0.

015.

17. The catalytic cracking catalyst obtained by the catalytic cracking catalyst preparation method according to any one of claims 4 to 16.

18. The catalytic cracking catalyst according to claim 17, characterized in that The catalytic cracking catalyst contains 0.5% to 1.5% by weight of P2O5, 0.5 to 6% by weight of rare earth calculated as RE2O3, and 0.01 to 1% by weight of MgO.

19. A catalytic cracking method comprising the step of contacting hydrocarbon oil with the catalytic cracking catalyst according to claim 1, 2, 3, 17 or 18, wherein the reaction temperature is 480-520°C, the reaction time is 0.5-5 seconds, and the catalyst-to-oil ratio is 2-10 by weight.

Images