A catalytic cracking catalyst with high thermal wear resistance and its preparation method

Abstract

The present invention discloses a catalytic cracking catalyst with high thermal wear resistance and a preparation method thereof. The raw materials of the catalytic cracking catalyst include a zeolite molecular sieve, a matrix, and a binder. The matrix is ​​composed of a γ-alumina precursor with a peptization index of 50% or less and clay. The binder includes a phosphorus-containing compound, an aluminum-containing compound, and a binder modifier. The binder modifier includes a multidentate chelating ligand, a metal-centered ligand, an alcohol, and an organic acid. The metal-centered ligand contains at least two metal ions. The catalytic cracking catalyst is prepared in a high-shear emulsifier. Compared with existing catalytic cracking catalysts, the phosphorus- and zeolite-containing catalytic cracking catalyst provided by the present invention has higher wear resistance, larger pore volume, higher molecular sieve content, higher solids content, and excellent reaction performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts, and in particular relates to a catalytic cracking catalyst with high thermal wear resistance and a preparation method thereof. Background Art

[0002] The catalytic cracking process has become the most important process for heavy oil processing due to its significant advantages, including high heavy oil conversion efficiency, high product quality, lack of hydrogen, and low operating pressure. However, as heavy oil becomes increasingly degraded and heavier, harmful impurities such as vanadium, nickel, alkali metals, alkaline earth metals, and alkaline nitrogen increase, and slag content continues to increase, making heavy oil difficult to crack, resulting in increased coke formation on the catalyst and faster deactivation. Therefore, there is a need to develop catalytic cracking catalysts with higher activity, enhanced heavy oil conversion capabilities, greater heavy metal tolerance, and improved coke selectivity.

[0003] To achieve these goals, it is necessary to increase the molecular sieve content in catalytic cracking catalysts or increase the pore volume of catalytic cracking catalysts. The preparation of catalysts with macroporous structures is one solution. Furthermore, the development of new catalytic cracking technologies, such as short or ultra-short contact times and technologies for reducing olefin catalytic cracking, also requires catalysts with high molecular sieve content and / or macroporous structures. The binder in catalytic cracking catalysts provides a certain amount of heat capacity during the catalytic cracking reaction. Furthermore, the binder's performance directly affects the catalyst's physicochemical properties, such as particle size, attrition index, and pore volume. Therefore, current catalyst research has largely focused on binder modification.

[0004] However, in the prior art, when the binder is adjusted to develop a catalytic cracking catalyst with higher activity, stronger heavy oil conversion ability, stronger heavy metal resistance, and better coke selectivity, increasing the content of the active component molecular sieve and increasing the pore volume of the catalytic cracking catalyst often leads to a deterioration in the catalyst's anti-wear performance (especially thermal wear performance at high temperatures), and then causing problems such as fluidization abnormalities, catalyst leakage, smoke exhaust fouling, and increased oil slurry solids content, which affect the long-term operation of the catalytic cracking unit.

[0005] For example, Chinese patent document CN201680055564.2 discloses a method for producing a fluidized catalytic cracking catalyst additive composition using a novel binder. The steps involve mixing an alumina source with water to form a slurry; adding a certain amount of a PO source to the alumina slurry; then stirring the slurry and reacting it under controlled temperature and time conditions to form an aluminum phosphate binder; adding zeolite, a certain amount of silica binder, and a certain amount of clay to the aluminum phosphate binder; and spray drying the slurry to form catalyst additive particles. The catalyst additive composition comprises approximately 35 to 65 weight percent zeolite; approximately 0 to 10 weight percent silica; approximately 15 to 50 weight percent clay; and an aluminum phosphate binder comprising approximately 2.5 to 5 weight percent amorphous or pseudo-boehmite alumina and approximately 7 to 15 weight percent phosphoric acid. However, the aluminum phosphate binder prepared by this method provides limited improvement in catalyst strength and has a low pore volume.

[0006] US Patent No. 4407730 discloses a catalyst carrier which is basically composed of a magnesium oxide-aluminum oxide-aluminum phosphate matrix after being calcined at 500°C for 10 hours. The average pore size of the carrier is 10-300 angstroms and the specific surface area is 100-350 m 2 / g, pore volume 0.3-1.5 ml / g, wherein the magnesium oxide content is 0.5 to less than 10 mol% or 25-75 mol%, the aluminum oxide content is 2-90 mol%, and the aluminum phosphate content is 3-95 mol%. The catalyst carrier is prepared by mixing an aqueous aluminum nitrate solution with a magnesium nitrate and 85% phosphoric acid solution, then adding ammonium hydroxide solution, precipitating at pH 9, filtering, drying, and calcining at 500°C for approximately 10 hours. The catalytic cracking catalyst prepared by mixing the catalyst carrier with zeolite has high gasoline selectivity and can be used as a catalyst for cracking high-metal-content feedstocks. In this document, magnesium oxide is added during the preparation of the binder to capture high-content metal ions in the feedstock, thereby achieving the purpose of processing high-metal-content feedstocks. However, the introduction of metal ions into the binder causes them to form a fixed crystalline phase with the aluminum phosphate binder. In actual reactions, the magnesium ion capture reduces the binder's bonding properties. Furthermore, the use of the aluminum phosphate binder reduces the catalyst's pore volume and specific surface area, and it is prone to cracking at high temperatures, resulting in poor high-temperature wear resistance.

[0007] U.S. Patent No. 5,286,369 discloses a method for catalytic cracking of hydrocarbon feedstocks. The method comprises reacting a hydrocarbon feedstock under catalytic cracking process conditions in the presence of a catalyst. The catalyst comprises a zeolite selected from ultrastable Y zeolite, ZSM-5 zeolite, Beta zeolite, SAPO zeolite, and ALPO zeolite, and a crystalline aluminum phosphate binder having a specific surface area of ​​less than 20 m² / g and a pore volume of less than 0.1 ml / g. However, the specific surface area and pore volume of the crystalline aluminum phosphate binder in this method are relatively small, and the reaction performance of the resulting catalyst needs further improvement.

[0008] Chinese patent document CN201110180891.X discloses an inorganic binder containing a phosphorus-aluminum compound and a preparation method thereof. The binder comprises 15-40% by weight of Al2O3, 45-80% by weight of P2O5, and 1-40% by weight of clay, with a P / Al weight ratio of 1-6, a pH of 1-3.5, and a solids content of 15-60% by weight. The preparation method comprises: beating and dispersing acid-soluble aluminum hydroxide and / or aluminum oxide and clay with deionized water to form a slurry with a solids content of 15-45% by weight, adding concentrated phosphoric acid to the slurry with stirring at a P / Al weight ratio of 1-6, and then reacting at 50-99°C for 15-90 minutes. However, the binder produced by this preparation method has a small pore volume and is prone to cracking at high temperatures. Catalysts produced using this binder also exhibit poor thermal wear resistance.

[0009] Chinese patent document CN99126287.5 discloses a phosphorus- and zeolite-containing catalytic cracking catalyst comprising zeolite, clay, and a binder. The catalyst further comprises a phosphorus- and aluminum-containing additive uniformly dispersed in the catalyst. The zeolite content, based on the total weight of the catalyst, is 25-70 weight percent; the clay content is 5-55 weight percent; the binder content is 5-50 weight percent; and the phosphorus- and aluminum-containing additive content, calculated as additive solids content, is 0.5-20 weight percent. The phosphorus- and aluminum-containing additive is a reaction product obtained by reacting a phosphoric acid solution with aluminum oxide and / or hydroxide, has a specific gravity of 1.2-1.7 g / ml, and an atomic ratio of phosphorus to aluminum of greater than 1 to 12. However, this solution still uses conventional binders to prepare catalytic cracking catalysts and adds a small amount of aluminum phosphate binder. Due to the small amount added, the wear index of the catalyst cannot be significantly improved. At the same time, the phosphorus in the introduced aluminum phosphate additive exists in a free state and migrates into the active center molecular sieve during the roasting process, destroying the molecular sieve structure and affecting the reaction performance. On the other hand, the colloidal particles of conventional binders such as aluminum sol and acidified pseudo-boehmite are small in size, filling the pores between the matrix and the active components, resulting in a small pore volume of the catalyst.

[0010] As previously mentioned, the aluminum phosphate sol (or aluminum phosphate solution) used in the prior art is prepared by reacting a phosphorus compound with aluminum sol or silica sol at a controlled pH of >3; or by precipitating a phosphoric acid solution of aluminum nitrate and magnesium nitrate with an ammonium hydroxide solution at a pH of 9; or by precipitating a solution containing phosphoric acid and rare earth ions with an alkaline solution; or by precipitating a solution containing aluminum ions, phosphate, and hydrogen phosphate with an alkaline solution; or by directly adding an ammonium salt selected from phosphoric acid, ammonium orthophosphite, and an ammonium salt of hypophosphoric acid, and a phosphorus compound of phosphoric acid to a slurry containing silica, clay, and zeolite; or by directly adding an aluminum phosphate solution at a pH of 0-1 to a slurry containing silica, clay, and zeolite. While the above methods can improve the catalyst's attrition resistance to a certain extent, they are still insufficient when the catalyst contains a high molecular sieve content or has a large pore volume. It was also found that when the molecular sieve content in the catalyst was high or the catalyst pore volume was large, the catalyst particles cracked to varying degrees when prepared using the existing aluminum phosphate sol, especially after high-temperature steam aging. This is because when the phosphoric acid binder is prepared using the above method, the binder is mixed with the matrix material and molecular sieve for a long time. The matrix material and molecular sieve contain a large amount of chlorine, ammonium, nitrate and various metal ions, resulting in the formation of aluminum phosphate crystals doped with impurities. At high temperatures, especially in the presence of water vapor, the crystal structure easily collapses. The chlorine, ammonium and nitrate that are stably bound to the binding component become unstable, generating gases such as hydrogen chloride, ammonia, nitrogen and oxygen respectively. The generation of these gases causes a large number of "bubbles" to form inside the catalyst particles. When the temperature rises, these bubbles will burst out from the catalyst interior, resulting in damage to the catalyst particle shape. In severe cases, the catalyst particles will crack, thereby reducing the bonding effect of the various binders and significantly reducing the anti-wear performance of the catalyst. Summary of the Invention

[0011] In response to the problems existing in the prior art and the areas that need improvement, the present invention provides a catalytic cracking catalyst with high thermal wear resistance and a preparation method thereof. Compared with existing catalytic cracking catalysts, the phosphorus- and zeolite-containing catalytic cracking catalyst provided by the present invention has higher wear resistance, and at the same time has a large pore volume, a high molecular sieve content and excellent reaction performance.

[0012] To achieve the above object, the present invention provides the following technical solutions:

[0013] A catalytic cracking catalyst with high thermal wear resistance, wherein the raw materials of the catalytic cracking catalyst include a zeolite molecular sieve, a matrix and a binder, wherein the matrix is ​​composed of a γ-alumina precursor with a peptization index of ≤50% and clay, and the binder includes a phosphorus-containing compound, an aluminum-containing compound and a binder modifier;

[0014] The binder modifier is composed of a multi-dentate chelating ligand, a coordinating metal, an alcohol and an organic acid, wherein the metal center ligand contains at least two metal ions;

[0015] The catalytic cracking catalyst is prepared in a high shear emulsifier.

[0016] Optionally, in the catalytic cracking catalyst provided by the present invention, the multidentate chelating ligand is a bidentate chelating ligand having at least two coordinating atoms, and the coordinating atoms are P, O or N, O; preferably, the multidentate chelating ligand is selected from any one of aminotris(methylene phosphonic acid), hydroxyethylidenediphosphonic acid, ethylenediaminetetra(methylene phosphonic acid), diethylenetriaminepenta(methylene phosphonic acid), 2-phosphonobutane-1,2,4-tricarboxylic acid, 2-hydroxyphosphonoacetic acid, bis(1,6-hexamethylenetriaminepenta(methylene phosphonic acid), hexamethylenediaminetetra(methylene phosphonic acid), ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid and 1,2-ethylenediamine; more preferably, the coordinating atoms in the multidentate chelating ligand are P and O.

[0017] Optionally, in the catalytic cracking catalyst provided by the present invention, the metal ions in the metal-centered ligand are selected from rare earth metal ions and transition metal ions. Preferably, the rare earth metal ions are selected from light rare earth metal ions. More preferably, the rare earth metal ions are selected from rare earth metal ions such as one or more of lanthanum ions, cerium ions, neodymium ions, and samarium ions; and the transition metal ions are selected from one or more of copper, silver, nickel, zinc, cobalt, and cadmium. The metal-centered ligand is selected from chlorides or nitrates of rare earth metals and transition metals.

[0018] Optionally, in the catalytic cracking catalyst provided by the present invention, the usage ratio of various metal ions in the metal-centered ligand is not specifically limited and can be adjusted according to actual conditions. The metal ions in the metal-centered ligand recommended by the present invention are selected from transition metal ions and rare earth metal ions, and the molar ratio of the transition metal ions to the rare earth metal ions is 1:5 to 10; the molar ratio of the multi-dentate chelating ligand to the metal ions in the metal-centered ligand is 2 to 5:1.

[0019] Optionally, in the catalytic cracking catalyst provided by the present invention, the organic acid is one or more of benzoic acid, lactic acid, propionic acid, formic acid, acetic acid, sorbic acid and malic acid;

[0020] The alcohol is selected from C1-C3 monohydric alcohols, preferably one or more of methanol, ethanol and propanol.

[0021] Optionally, in the catalytic cracking catalyst provided by the present invention, the content of the binder modifier is 1% to 3%, based on the total mass of the catalytic cracking catalyst on a dry basis being 100%.

[0022] Optionally, in the catalytic cracking catalyst provided by the present invention, the molar ratio of phosphorus in the phosphorus-containing compound to aluminum in the aluminum-containing compound is 4 to 10:1, and preferably the molar ratio of phosphorus in the phosphorus-containing compound to aluminum in the aluminum-containing compound is 5 to 8:1. The aluminum-containing compound and the phosphorus-containing compound are not specifically limited, and conventional ones in the industry can be used. The aluminum-containing compound includes but is not limited to aluminum oxides, aluminum hydroxides, aluminum-containing organic compounds, etc., such as aluminum oxide, aluminum hydroxide, boehmite, sodium metaaluminate, aluminum chloride, aluminum isopropoxide, etc.; the phosphorus-containing compound includes but is not limited to phosphorus oxides, phosphorus oxyacids, phosphates, etc., such as phosphoric acid, diammonium hydrogen phosphate, phosphorus pentoxide, organic phosphonic acid, sodium phosphate, calcium phosphate, etc.

[0023] Optionally, in the catalytic cracking catalyst provided by the present invention, the peptization index of the γ-alumina precursor is 20% to 30%; preferably, the XRD spectrum of the γ-alumina precursor shows characteristic peaks near 2θ of 14±1°, 28±1°, 38±1°, and 49±1°, such as pseudo-boehmite, boehmite, and the like.

[0024] Optionally, in the catalytic cracking catalyst provided by the present invention, the mass ratio of the γ-alumina precursor to the clay is 1:1-9, preferably 1:3-7.

[0025] Optionally, in the catalytic cracking catalyst provided by the present invention, the clay in the matrix can be any clay commonly used in the art, which can meet the requirements of the present invention, such as one or more of kaolin, halloysite, montmorillonite, diatomaceous earth, bentonite, halloysite, etc., which are commonly used components of catalytic cracking catalysts. Preferably, the clay is selected from kaolin, halloysite, halloysite, or mixtures thereof.

[0026] Optionally, in the catalytic cracking catalyst provided by the present invention, any zeolite molecular sieve commonly used in the art can meet the requirements of the present invention. For example, it can be one or more of the various large-pore and medium-pore zeolite molecular sieves currently used as active components of catalytic cracking catalysts. Specifically, the zeolite molecular sieve can be selected from one or more of faujasite molecular sieve, ZSM series zeolite molecular sieve, Beta zeolite molecular sieve, and mordenite molecular sieve.

[0027] Optionally, in the catalytic cracking catalyst provided by the present invention, based on the total dry weight of the catalytic cracking catalyst as 100%, the content of the zeolite molecular sieve is 25wt% to 60wt%, preferably 35wt% to 50wt%; the content of the matrix is ​​30wt% to 50wt%; the content of the binder is 10wt% to 25wt%, preferably 15wt% to 20wt%; and the solid content of the catalytic cracking catalyst is 35wt% to 60wt%, preferably 40wt% to 50wt%.

[0028] The method for preparing the catalytic cracking catalyst with high thermal wear resistance recommended by the present invention comprises the following steps:

[0029] The mixed slurry of zeolite molecular sieve and matrix is ​​mixed with a binder in a high shear emulsifier within 3 minutes, spray-formed, dried, calcined, and ion-exchanged to obtain the catalytic cracking catalyst with high thermal wear resistance.

[0030] By controlling the mixing time of the mixed slurry of zeolite molecular sieve and matrix with the prepared binder in a high shear emulsifier to no more than 3 minutes, it is equivalent to achieving instantaneous and sufficient mixing, and immediately outputting and spray-molding and drying after mixing, thus realizing the continuous process of "mixing, conveying, drying and molding", avoiding the long-term contact between the mixed slurry and the binder, which would trigger the migration of phosphorus, causing phosphorus to destroy the crystal structure and surface acid distribution of the molecular sieve, and at the same time deteriorate the bonding effect of the binder.

[0031] Optionally, in the preparation method of the catalytic cracking catalyst with high thermal wear resistance provided by the present invention, the mixed slurry of the zeolite molecular sieve and the matrix is ​​a well-known operation in the art. Specifically, the zeolite molecular sieve, the matrix and deionized water are mixed and slurried without special requirements.

[0032] Optionally, in the preparation method of the above-mentioned catalytic cracking catalyst with high thermal wear resistance provided by the present invention, the spray forming and drying refers to the granulation, forming and drying of the material, which is a technology well known to those skilled in the art and can be carried out using existing parameters. For example, the preparation of catalytic cracking catalysts generally uses the following process conditions for spray forming and drying: the furnace temperature of the spray tower is controlled at 450-600°C, and the spray exhaust temperature is controlled at 150-300°C.

[0033] Optionally, in the method for preparing the catalytic cracking catalyst with high thermal wear resistance provided by the present invention, the ion exchange step is used to remove various impurity ions introduced in various steps during the preparation process, including Na + , SO 4- , Cl -The ion exchange process conditions recommended by the present invention are: acid exchange or ammonium exchange, pH value 3.0-3.5, and exchange time 0.3-2 hours.

[0034] Optionally, in the method for preparing a catalytic cracking catalyst with high thermal wear resistance provided by the present invention, the preparation of the binder comprises the following steps:

[0035] adding alcohol to the organic acid solution of the multi-dentate chelating ligand and mixing the mixture to obtain a multi-dentate chelating ligand solution;

[0036] Adding alcohol to the organic acid solution of the metal center ligand and mixing well to obtain a metal center ligand solution;

[0037] Adding the multi-dentate chelating ligand solution and the metal center ligand solution into a high shear dispersing emulsifier, and adjusting the pH value of the system to 5-8; obtaining a binder modifier solution;

[0038] After heating an aqueous solution of a phosphorus-containing compound with a pH value of ≤5 to 60-80°C, adding an aluminum-containing compound and mixing, then adding the mixed solution to a high shear emulsifier and reacting at 60-80°C to obtain a phosphorus-aluminum binder, adding the binder modifier solution and continuing to react at 60-80°C in the high shear emulsifier, and after the reaction is completed, obtaining the binder.

[0039] Optionally, in the preparation steps of the binder provided herein, the aqueous solution of the phosphorus-containing compound having a pH value of ≤5 is obtained by fully dissolving the phosphorus-containing compound in deionized water and then adjusting the pH with an acid. The acid is not specifically limited; inorganic acids and organic acids commonly used in this field can meet the requirements. Preferably, the pH of the aqueous solution of the phosphorus-containing compound is ≤3. However, when the phosphorus-containing compound is a phosphorus-containing organic or inorganic acid, no acid or a small amount of acid may be added, depending on the actual conditions of the slurry, to ensure that the pH value is within this range.

[0040] The specific preparation method of the catalytic cracking catalyst with high thermal wear resistance recommended by the present invention comprises the following steps:

[0041] S1: Clay, γ-alumina precursor and deionized water are mixed and homogenized, and then acid is added to maintain the slurry temperature at 40-80°C for acidification and peptization to prepare a matrix slurry;

[0042] S2: mixing the multidentate chelating ligand with the organic acid solution to prepare an organic acid solution of the multidentate chelating ligand, adding the alcohol solution, and mixing uniformly to obtain a multidentate chelating ligand solution (preferably, the molar concentration of the multidentate chelating ligand solution is 0.2 to 1.0 mol / L, the concentration of the organic acid is 10% to 30%, and the concentration of ethanol is 5% to 20%);

[0043] S3: adding the metal-centered ligand to the organic acid solution, adding the alcohol solution after it is completely dissolved, and mixing them uniformly to obtain a metal-centered ligand solution; (preferably, the concentration of the organic acid is 10% to 30%, and the concentration of the ethanol is 5% to 20%);

[0044] S4: adding the multidentate chelating ligand solution to a high shear dispersing emulsifier, maintaining the temperature at 30-50° C., adding an equal volume of the metal center ligand solution, and adjusting the pH value of the system to 5-8; the molar ratio of the multidentate chelating ligand in the multidentate chelating ligand solution to the metal ion in the metal center ligand solution is 2-5:1. After the reaction is completed, a multimetallic composite chelating modifier solution is obtained;

[0045] S5: After heating an aqueous solution of a phosphorus-containing compound with a pH value of ≤5 to 60-80°C, adding an aluminum-containing compound and mixing, then adding the mixed solution into a high shear emulsifier, reacting at 60-80°C to obtain a phosphorus-aluminum binder, adding the binder modifier solution and continuing to react at 60-80°C in the high shear emulsifier, and after the reaction is completed, obtaining the binder.

[0046] S6: Add the matrix slurry obtained in S1 to a high shear emulsifier, homogenize until uniform, add the pre-mixed molecular sieve slurry (the pre-mixed molecular sieve slurry is formed by mixing the molecular sieve with deionized water), mix evenly, and obtain a mixed slurry; preferably, the mixing time of the mixed slurry of the zeolite molecular sieve and the matrix and the binder in the high shear emulsifier is not more than 3 minutes.

[0047] S7: spray forming, drying, calcining, and ion exchange to obtain the catalytic cracking catalyst with high thermal wear resistance.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] Beneficial effect 1: The catalytic cracking catalyst provided by the present invention adopts an in-situ prepared multi-metal chelate as a modifier to modify the aluminum phosphate binder, and the obtained modified binder replaces the aluminum sol, silica sol, acidified pseudo-boehmite and other binders in the existing catalyst. The aluminum phosphate binder is modified by the in-situ prepared multi-metal chelate, which can not only prevent the high content of binder from clogging the pores in the catalyst during the catalyst preparation process; but also can reduce the amount of acid added during the catalyst preparation process, increase the pH value of the slurry, and thereby reduce the corrosion of the acid on the zeolite molecular sieve structure and improve the catalyst activity.

[0050] In the catalytic cracking catalyst provided by the present invention, a low peptization index γ-alumina precursor is used in the matrix. First, it can reduce the peptization of the γ-alumina precursor by the acidic medium during the catalyst preparation process, thereby reducing the pores of the catalyst and the pores of the zeolite molecular sieve blocked by the peptized alumina, while accurately controlling the presence of free metallic aluminum in the catalyst system to avoid excessive reaction with the effective components of the binder, affecting the bonding properties of the binder, and a small portion of the peptized γ-alumina precursor can react with the phosphorus-containing compound in the binder under specific conditions to form a binder. Second, the γ-alumina precursor with a low peptization index can form a large number of mesopores during the catalyst curing process, thereby increasing the pore volume of the catalyst. Third, the use of a low peptization index γ-alumina precursor can break the limitation that the solid content of the catalyst cannot be increased. The viscosity of the catalyst slurry can be adjusted by controlling the peptization solubility, greatly improving the solid content of the catalyst slurry, which is of great significance for improving the sphericity of the catalyst.

[0051] The catalytic cracking catalyst provided by the present invention can maintain excellent abrasion resistance while having a high molecular sieve content and a large pore volume, through the mutual coordination between the components and the use of a high shear emulsifier to disperse the components during the preparation process.

[0052] Beneficial effect 2: In the binder of the catalytic cracking catalyst provided by the present invention, a metal-centered ligand composed of a multi-dentate chelate ligand and a plurality of metals is introduced. Under the promotion of organic acid and alcohol, a multi-metal chelate modifier can be prepared in situ during the preparation of the binder. Compared with directly using commercially available metal chelates, the in-situ prepared multi-metal chelate modifier has better water solubility, can promote the combination of the modifier with the phosphorus aluminum sol, and has a better modification effect; on the other hand, the use of multi-dentate chelate ligands can chelate with a variety of metal ions to form a multi-metal chelate ligand, reducing the solubility problem between different solvents in the binder preparation process and reducing the interaction between different chelate ligands; at the same time, the ratio of different metals can be flexibly controlled to achieve the effect of accurately regulating the performance of the binder; again, the in-situ preparation of the multi-metal chelate modifier can break the limitation of the small number of commercially available metal chelates and expand the applicability of the binder preparation. Finally, it is preferred to use a multi-dentate chelate ligand with N, P, and O as the coordinating atoms to reduce the introduction of too many heteroatoms into the binder, affecting the performance of the binder, and reducing the impact on the catalyst performance.

[0053] Beneficial Effect 3: The binder for the catalytic cracking catalyst provided by the present invention incorporates an in-situ prepared multi-metal chelate modifier to improve the properties of the phosphate binder. The transition metal ions and light rare earth metal ions in the multi-metal chelate strengthen the interaction between the aluminum phosphate and the matrix, improving strength. Experiments have shown that the modification with the composite metal ions significantly reduces thermal collapse under high-temperature hydrothermal conditions, significantly improving the catalyst's thermal wear resistance. It also prevents premature hardening of the colloid during catalyst molding and drying, and increases the pore volume of the binder after curing. Extensive test results demonstrate that the addition of the multi-metal chelate modifier can form micropores and mesopores within the binder during the preparation process without affecting the binder's bonding properties.

[0054] Beneficial effect 4: The preparation method of the catalytic cracking catalyst provided by the present invention adopts a high shear emulsifier in the catalyst preparation process. On the one hand, the γ-alumina precursor with a low solubility index can be dispersed into a uniform viscous emulsion slurry and efficiently mixed with the zeolite molecular sieve, thereby overcoming the technical difficulty that the low solubility index γ-alumina precursor has poor solubility and cannot form a uniform slurry; at the same time, the γ-alumina precursor exists in a non-free state, avoiding the transition reaction with the phosphorus-containing compound in the binder. On the other hand, the application of the high shear emulsifier solves the problem that the metal chelate formed in situ cannot be fully mixed with the aluminum phosphate binder, promotes the mutual reaction between the aluminum phosphate binder and the metal chelate, effectively regulates the microenvironment such as the supersaturation distribution in the reactor, and enhances the role of the binder modification component multi-metal chelate. Crucially, the use of a high-shear emulsifier enables efficient, short-term mixing of the binder, molecular sieve, and matrix slurry. This allows for the emulsification of the low-peptization-index gamma-alumina precursor and the complete homogenization of the binder and slurry. After uniform mixing, spray drying is immediately performed to prevent phosphorus migration caused by prolonged contact between the binder and molecular sieve, effectively encapsulating and localizing phosphorus within the aluminum phosphate binder. This plays an irreplaceable role in improving the catalyst's reactivity. DETAILED DESCRIPTION

[0055] The present invention is described in detail below by way of examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Those skilled in the art may make some non-essential improvements and adjustments to the present invention based on the above disclosure.

[0056] If no specific experimental steps or conditions are specified in the Examples and Comparative Examples, the conventional experimental steps or conditions described in the literature in the field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0057] The raw materials and equipment involved in the present invention are all commercially available and can meet the implementation of the technical solution of the present invention. However, for the convenience of comparison, the raw materials from the following sources are used in the following examples:

[0058] ReY molecular sieve, ultra-stable Y molecular sieve, ZSM-5 molecular sieve, Beta molecular sieve, and aluminum sol were collected from Lanzhou Petrochemical Company;

[0059] Phosphoric acid, aluminum hydroxide, diammonium hydrogen phosphate, aluminum chloride, phosphonic acid, phosphorus pentoxide, sodium metaaluminate, sodium phosphate, aluminum isopropoxide, hexamethylenediaminetetramethylenephosphonic acid, benzoic acid, 1-propanol, nickel nitrate, neodymium sulfate, lactic acid, cobalt chloride, samarium chloride, 1,2-ethylenediamine, ethylenediaminetetraacetic acid, hydroxyethylidene diphosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, diethylenetriaminepenta(methylenephosphonic acid), formic acid, acetic acid, ethanol, copper nitrate, lanthanum chloride, silver nitrate, cerium nitrate, propionic acid, methanol, zinc sulfate, copper chelate (ethylenediaminetetraacetic acid), lanthanum chelate (hydroxyethylethylenediaminetriacetic acid); all analytically pure and produced by Sinopharm Group.

[0060] Pseudoboehmite, boehmite, and boehmite are produced by China Aluminum Shandong Aluminum Co., Ltd.

[0061] Evaluation and analysis methods:

[0062] The surface area of ​​the catalyst was determined by the low-temperature nitrogen adsorption-desorption method (NB / SH / T 0959);

[0063] The pore volume of the catalyst was tested using the water drop method (NB / SH / T 0955);

[0064] The catalyst wear index was determined using the straight tube method (NB / SH / T 0964);

[0065] The thermal collapse rate of the catalyst was tested on a laboratory small-scale fixed fluidized bed (all parts are made of stainless steel) wear system. The specific steps are as follows:

[0066] The catalyst in the fluidized bed is constantly fluidized and worn under the action of fluidized air. The extremely fine powder particles under wear flow out of the fluidized bed with the gas through the filter element, while the larger particles are blocked by the filter element and remain in the fluidized bed to continue wearing. There are 5 air inlet holes evenly distributed at the front end and around the air guide tube, with a pore size of 1mm, and the filtration accuracy of the filter element is 1μm. During the experiment, first weigh 100g of the prepared catalyst, recorded as w1, and then add it to the fluidized bed. Heat the preheater to 150℃ and the fluidized bed temperature to 200℃, turn on the air generator, adjust the gas flow rate to 40m / s, and the apparent gas velocity in the reactor to 0.8m / s. After 4h of fluidized wear, weigh the remaining catalyst mass in the reactor and record it as w2. Change the preheater temperature to 650℃ and the fluidized bed temperature to 680℃. Keep other conditions unchanged and repeat the measurement of the remaining catalyst weight, recorded as w3. The thermal collapse rate L is:

[0067] L=(w2-w3) / w2×100%

[0068] The catalyst reaction performance was tested on a small fixed fluidized bed microreactor according to the NB / SH / T0952-2017 method.

[0069] Example 1

[0070] The catalytic cracking catalyst provided in this embodiment, based on the total weight of the catalytic cracking catalyst on a dry basis as 100%, based on the solid content of the catalytic cracking catalyst slurry being 35wt%, has a content of ReY molecular sieve of 25wt%, a content of boehmite (peptization index of 0) of 25wt%, a content of kaolin of 25wt%, and a content of binder of 25wt%.

[0071] The binder has a phosphorus / aluminum molar ratio of 4:1, the phosphorus-containing compound is phosphoric acid, and the aluminum-containing compound is aluminum hydroxide. The binder contains a binder modifier at a content of 1.25 wt% (based on 100% total dry mass of the catalyst). The multidentate chelating ligand in the binder modifier is 1,2-ethylenediamine, the organic acid is formic acid, the alcohol is ethanol, the transition metal ion compound is copper nitrate, and the rare earth metal ion compound is lanthanum chloride. The molar ratio of copper ion to lanthanum ion is 1:5.

[0072] Preparation of matrix slurry:

[0073] Kaolin, boehmite (peptization index is 0) and deionized water are mixed and homogenized, and then a small amount of hydrochloric acid is slowly added. The slurry temperature is raised and maintained at about 45°C for acidification and peptization to prepare a matrix slurry.

[0074] Preparation of binder modifier:

[0075] S1: Mixing a bidentate chelating ligand 1,2-ethylenediamine with a formic acid solution to prepare an organic acid solution of the bidentate chelating ligand, and adding an ethanol solution after uniform mixing to prepare a 1,2-ethylenediamine ligand solution; wherein the molar concentration of 1,2-ethylenediamine in the solution is 0.2 mol / L, the concentration of the organic acid is 30%, and the concentration of the ethanol is 20%.

[0076] S2: Add lanthanum chloride and copper nitrate to a formic acid solution. Once completely dissolved, add ethanol solution and mix thoroughly to obtain a mixed metal-centered ligand precursor solution. The formic acid concentration in the precursor solution is 30%, the ethanol concentration is 20%, and the molar concentration of the mixed metal in the precursor solution is 0.1 mol / L.

[0077] S3: The 1,2-ethylenediamine ligand solution obtained in S1 and the metal-centered ligand precursor solution obtained in S2 are added into a high shear dispersing emulsifier in a volume ratio of 1:1. The temperature is maintained at 50°C. Ammonia water is added to adjust the pH value of the system to 8. The reaction is carried out for 30 minutes to obtain a multi-metal complex chelating modifier solution.

[0078] Preparation of adhesive:

[0079] Concentrated phosphoric acid (concentration 85%) was diluted with deionized water to 40 wt%, and then aluminum hydroxide was added in proportion and stirred at 80°C until completely dissolved, and the pH value was controlled to be 1.0. The mixture of phosphoric acid and aluminum hydroxide was then added to a high shear emulsifier and the reaction temperature was maintained at 80°C for a rapid reaction for 10 minutes. The previously prepared binder modifier was then added in proportion, and the temperature was maintained and the reaction was continued for 5 minutes to obtain a binder.

[0080] Preparation of catalytic cracking catalysts

[0081] The matrix slurry is added to a high-shear emulsifier, and after homogenization, the pre-mixed molecular sieve slurry (molecular sieve is mixed with deionized water to form a molecular sieve slurry) is added. The mixed slurry of the above-mentioned binder, the zeolite molecular sieve and the matrix is ​​added to the high-speed shear emulsifier, and immediately discharged after high-speed emulsification for 2 minutes, and spray-formed and dried. The spray-forming conditions are as follows: the spray tower furnace temperature is controlled at 580°C, the spray tail gas temperature is controlled at 160°C, the obtained material is calcined at 450°C for 1 hour, and then ion exchange is carried out with an ammonium chloride solution with a pH value of 3.0-3.5 for 0.5 hour to obtain a catalytic cracking catalyst.

[0082] The physical and chemical properties and catalytic performance of the catalyst are shown in Table 2.

[0083] Example 2

[0084] The catalytic cracking catalyst provided in this embodiment, based on the total weight of the catalytic cracking catalyst on a dry basis as 100%, based on the solid content of the catalytic cracking catalyst slurry being 50 wt%, has a ReY molecular sieve content of 60 wt%, a boehmite content of 3 wt% (peptization index of 50%), a kaolin content of 27 wt%, and a binder content of 10 wt%.

[0085] The binder has a phosphorus / aluminum molar ratio of 10:1, the phosphorus-containing compound is diammonium hydrogen phosphate, and the aluminum-containing compound is aluminum chloride. The binder contains a binder modifier at a content of 2.0 wt% (based on 100% total dry mass of the catalyst). The multidentate chelating ligand in the binder modifier is a hexadentate chelating ligand, ethylenediaminetetraacetic acid, the organic acid is acetic acid, the alcohol is ethanol, the transition metal ion compound is silver nitrate, the rare earth metal ion compound is cerium nitrate, and the molar ratio of silver ion to cerium ion is 1:10.

[0086] The preparation method of the above-mentioned catalytic cracking catalyst is as follows:

[0087] Preparation of matrix slurry:

[0088] Kaolin, boehmite (peptization index of 50%) and deionized water were mixed and homogenized, and then a small amount of hydrochloric acid was slowly added. The slurry temperature was raised and maintained at about 75° C. to carry out acidification and peptization to prepare a matrix slurry.

[0089] Preparation of binder modifier:

[0090] S1: Mixing a hexadentate chelating ligand EDTA with an acetic acid solution to prepare an acetic acid solution of an EDTA multidentate chelating ligand, and adding an ethanol solution after uniform mixing to prepare an EDTA ligand solution, wherein the molar concentration of the EDTA is 1 mol / L, the concentration of the organic acid in the solution is 10%, and the concentration of the ethanol is 5%.

[0091] S2: Add cerium nitrate and silver nitrate to an acetic acid solution. After complete dissolution, add ethanol solution and mix thoroughly to obtain a mixed metal central ligand precursor solution. The concentration of acetic acid in the precursor solution is 10%, the concentration of ethanol is 5%, and the molar concentration of the mixed metal in the precursor solution is 0.2 mol / L.

[0092] S3: The ethylenediaminetetraacetic acid ligand solution obtained in S1 and the metal center ligand precursor solution obtained in S2 are added into a high shear dispersing emulsifier in a volume ratio of 1:1. The temperature is maintained at 30°C. Ammonia water is added to adjust the pH value of the system to 5. The reaction is carried out for 50 minutes to obtain a multi-metal composite chelating modifier solution.

[0093] Preparation of the binder: Dissolve diammonium hydrogen phosphate in deionized water and adjust the pH to 5.0 with hydrochloric acid, heat to 60°C, then add aluminum chloride in proportion and stir until completely dissolved. Then add the mixed solution into a high shear emulsifier and keep the reaction temperature at 60°C for rapid reaction for 10 minutes. Then add the previously prepared binder modifier in proportion and continue to react at 60°C for 5 minutes to obtain the binder.

[0094] Preparation of catalytic cracking catalyst:

[0095] At room temperature, the matrix slurry is added to a high-shear emulsifier, and after homogenization, the pre-mixed molecular sieve slurry is added. The mixed slurry of the above-mentioned binder, the zeolite molecular sieve and the matrix is ​​added to a high-speed shear emulsifier, and immediately discharged after high-speed emulsification for 2 minutes, and spray-molded and dried. The spray molding conditions are as follows: the spray tower furnace temperature is controlled at 580°C, the spray exhaust temperature is controlled at 160°C, the obtained material is calcined at 450°C for 1 hour, and then ion exchange is carried out with an ammonium sulfate solution with a pH value of 3.0-3.5 for 0.3 hour to obtain a catalytic cracking catalyst.

[0096] The physical and chemical properties and catalytic performance of the catalyst are shown in Table 2.

[0097] Example 3

[0098] The catalytic cracking catalyst provided in this embodiment, based on the total weight of the catalytic cracking catalyst on a dry basis as 100%, based on the solid content of the catalytic cracking catalyst slurry being 40 wt%, the content of ReY molecular sieve is 40 wt%, the content of Beta molecular sieve is 10 wt%, the content of pseudo-boehmite is 8.75 wt% (peptization index is 20%), the content of halloysite is 26.25 wt%, and the content of binder is 15 wt%.

[0099] The binder has a phosphorus / aluminum molar ratio of 5:1, an organic phosphonic acid (80% concentration) as the phosphorus-containing compound, and aluminum hydroxide as the aluminum-containing compound. The binder contains a binder modifier at 3.0 wt% (based on 100% dry catalyst mass). The multidentate chelating ligand in the binder modifier is a tetradentate chelating ligand (hydroxyethylidene diphosphonic acid), the organic acid is propionic acid, the alcohol is methanol, the transition metal ion compound is zinc sulfate, the rare earth metal ion compound is neodymium sulfate, and the molar ratio of zinc ion to neodymium ion is 1:6.

[0100] The preparation method of the above-mentioned catalytic cracking catalyst is as follows:

[0101] Preparation of matrix slurry:

[0102] Halloysite, pseudo-boehmite (peptization index is 20%) and deionized water are mixed and homogenized, and then a small amount of hydrochloric acid is slowly added. The slurry temperature is raised and maintained at about 50° C. to perform acidification and peptization to prepare a matrix slurry.

[0103] Preparation of binder modifier:

[0104] S1: Mixing a tetradentate chelating ligand hydroxyethylidene diphosphonic acid with a propionic acid solution to prepare a propionic acid solution of a hydroxyethylidene diphosphonic acid multidentate chelating ligand, and adding a methanol solution after mixing evenly to prepare a hydroxyethylidene diphosphonic acid ligand solution, wherein the molar concentration of the hydroxyethylidene diphosphonic acid is 0.6 mol / L, the concentration of the organic acid in the solution is 20%, and the concentration of methanol is 10%.

[0105] S2: Add neodymium sulfate and zinc sulfate to the propionic acid solution. Once completely dissolved, add the methanol solution and mix thoroughly to obtain a mixed metal center ligand precursor solution. The concentration of propionic acid in the precursor solution is 20%, the concentration of methanol is 10%, and the molar concentration of the mixed metal in the precursor solution is 0.2 mol / L.

[0106] S3: The hydroxyethylidene diphosphonic acid ligand solution obtained in S1 and the metal center ligand precursor solution obtained in S2 are added into a high shear dispersing emulsifier in a volume ratio of 1:1. The temperature is maintained at 40°C. Ammonia water is added to adjust the pH value of the system to 7. The reaction is carried out for 40 minutes to obtain a multi-metal complex chelating modifier solution.

[0107] Preparation of adhesive:

[0108] The organic phosphonic acid was diluted with deionized water to a concentration of 60%, and then aluminum hydroxide was added in proportion and stirred at 60°C until completely dissolved. The pH value of the system was adjusted to 2.0. The mixed solution was then added to a high shear emulsifier and the reaction temperature was maintained at 60°C for a rapid reaction for 10 minutes. The previously prepared binder modifier was added in proportion and the reaction was continued at 60°C for 5 minutes to obtain a binder.

[0109] Preparation of catalytic cracking catalyst:

[0110] At room temperature, the matrix slurry is added to a high-shear emulsifier, and after homogenization, the pre-mixed molecular sieve slurry is added to obtain a mixed slurry of the zeolite molecular sieve and the matrix. The above-mentioned binder and the mixed slurry of the zeolite molecular sieve and the matrix are added to the high-shear emulsifier, and immediately discharged after high-speed emulsification for 2 minutes, and spray-molded and dried. The spray molding conditions are as follows: the spray tower furnace temperature is controlled at 580°C, and the spray exhaust temperature is controlled at 160°C. After the obtained material is calcined at 450°C for 1 hour, it is ion-exchanged with an ammonium nitrate salt solution with a pH value of 3.0-3.5 for 0.3 hour to obtain a catalytic cracking catalyst.

[0111] The physical and chemical properties and catalytic performance of the catalyst are shown in Table 2.

[0112] Example 4

[0113] The catalytic cracking catalyst provided in this embodiment, based on the total weight of the catalytic cracking catalyst on a dry basis as 100%, based on the solid content of the catalytic cracking catalyst slurry being 60wt%, has a ReY molecular sieve content of 30wt%, a ZSM-5 molecular sieve content of 5%, boehmite as a γ-alumina precursor, and a boehmite content of 5.6% (peptization index of 30%); a halloysite content of 39.4wt%, and a binder content of 20wt%.

[0114] The binder has a phosphorus / aluminum molar ratio of 8:1, the phosphorus-containing compound is phosphorus pentoxide, and the aluminum-containing compound is sodium metaaluminate. The binder contains a binder modifier at a content of 3.0 wt% (based on 100% total dry mass of the catalyst). The multidentate chelating ligand in the binder modifier is a tetradentate chelating ligand hexamethylenediaminetetramethylenephosphonic acid, the organic acid is benzoic acid, the alcohol is 1-propanol, the transition metal ion compound is nickel nitrate, the rare earth metal ion compound is neodymium sulfate, and the molar ratio of nickel ion to neodymium ion is 1:5.

[0115] The preparation method of the above-mentioned catalytic cracking catalyst is as follows:

[0116] Preparation of matrix slurry:

[0117] Boehmite (peptization index of 30%), shaleite and deionized water were mixed and homogenized, and then a small amount of hydrochloric acid was slowly added. The slurry temperature was raised and maintained at about 60° C. to perform acidification and peptization to prepare a matrix slurry.

[0118] Preparation of binder modifier:

[0119] S1: mixing a tetradentate chelating ligand hexamethylenediaminetetramethylenephosphonic acid with a benzoic acid solution to prepare a benzoic acid solution of a hexamethylenediaminetetramethylenephosphonic acid multidentate chelating ligand; after uniform mixing, adding an ethanol solution to prepare a hexamethylenediaminetetramethylenephosphonic acid ligand solution; wherein the molar concentration of the hexamethylenediaminetetramethylenephosphonic acid is 0.6 mol / L, the concentration of the organic acid in the solution is 20%, and the concentration of the ethanol is 10%.

[0120] S2: Add nickel nitrate and neodymium sulfate to the benzoic acid solution. After complete dissolution, add the 1-propanol solution and mix thoroughly to obtain a mixed metal-centered ligand precursor solution. The concentration of benzoic acid in the precursor solution is 20%, the concentration of 1-propanol is 10%, and the molar concentration of the mixed metals in the precursor solution is 0.2 mol / L. S3: Add the hexamethylenediaminetetramethylenephosphonic acid ligand solution obtained in S1 and the metal-centered ligand precursor solution obtained in S2 to a high-shear dispersing emulsifier in a volume ratio of 1:1. Maintain the temperature at 40°C, add ammonia water to adjust the pH of the system to 7, and react for 40 minutes to obtain a multi-metal complex chelating modifier solution.

[0121] Preparation of the binder: Phosphorus pentoxide is slurried and mixed evenly with deionized water, and stirred at 80°C until completely dissolved, and the pH is adjusted to 1.5 with hydrochloric acid. Then, sodium aluminate is added in proportion and stirred until completely dissolved. The mixed solution is added to a high shear emulsifier and the reaction temperature is maintained at 80°C for rapid reaction for 10 minutes. Then, the previously prepared binder modifier is added in proportion and the reaction is continued at 80°C for 5 minutes to obtain the binder.

[0122] Preparation of catalytic cracking catalyst:

[0123] At room temperature, the matrix slurry is added to a high-shear emulsifier, and after homogenization, the pre-mixed molecular sieve slurry is added to obtain a mixed slurry of the zeolite molecular sieve and the matrix. The above-mentioned binder and the mixed slurry of the zeolite molecular sieve and the matrix are added to the high-shear emulsifier, and immediately discharged after high-speed emulsification for 4 minutes, and spray-molded and dried. The spray molding conditions are as follows: the spray tower furnace temperature is controlled at 580°C, and the spray exhaust temperature is controlled at 160°C. After the obtained material is calcined at 450°C for 1 hour, ion exchange is carried out with an ammonium carbonate solution with a pH value of 3.0-3.5 for 0.3 hour to obtain a catalytic cracking catalyst.

[0124] The physical and chemical properties and catalytic performance of the catalyst are shown in Table 2.

[0125] Example 5

[0126] The catalytic cracking catalyst provided in this embodiment, based on the total weight of the catalytic cracking catalyst on a dry basis as 100%, based on the solid content of the catalytic cracking catalyst slurry being 45wt%, has a content of ultra-stable Y molecular sieve of 42wt%, a γ-alumina precursor being pseudo-boehmite, a content of pseudo-boehmite of 6.7% (peptization index of 25%), a content of montmorillonite of 33.3%, and a content of a binder of 18wt%.

[0127] The binder has a phosphorus / aluminum molar ratio of 6:1, the phosphorus-containing compounds are sodium phosphate and phosphoric acid, and the aluminum-containing compound is aluminum isopropoxide. The binder contains a binder modifier at a content of 2.7 wt% (based on 100% total dry mass of the catalyst). The multidentate chelating ligand in the binder modifier is an octadentate chelating ligand, diethylenetriamine penta (methylene phosphonic acid), the organic acid is lactic acid, the alcohol is ethanol, the transition metal ion compound is cobalt chloride, the rare earth metal ion compound is samarium chloride, and the molar ratio of cobalt ion to samarium ion is 1:8.

[0128] The preparation method of the above-mentioned catalytic cracking catalyst is as follows:

[0129] Preparation of matrix slurry:

[0130] Montmorillonite, pseudo-boehmite (peptization index of 25%) and deionized water were mixed and homogenized, and then a small amount of hydrochloric acid was slowly added. The slurry temperature was raised and maintained at about 50° C. to perform acidification and peptization to prepare a matrix slurry.

[0131] Preparation of binder modifier:

[0132] S1: Mixing the octadentate chelating ligand diethylenetriamine penta(methylenephosphonic acid) with a lactic acid solution to prepare a lactic acid solution of a diethylenetriamine penta(methylenephosphonic acid) multidentate chelating ligand. After uniform mixing, adding an ethanol solution to prepare a diethylenetriamine penta(methylenephosphonic acid) ligand solution. The molar concentration of the diethylenetriamine penta(methylenephosphonic acid) is 0.6 mol / L, the concentration of the organic acid in the solution is 20%, and the concentration of the ethanol is 10%.

[0133] S2: Add samarium chloride and cobalt chloride to the lactic acid solution. After they are completely dissolved, add ethanol solution and mix well to obtain a mixed metal center ligand precursor solution. The concentration of lactic acid in the precursor solution is 20%, the concentration of ethanol is 10%, and the molar concentration of the mixed metal in the precursor solution is 0.15 mol / L.

[0134] S3: Add the diethylenetriamine penta (methylene phosphonic acid) ligand solution obtained in S1 and the metal center ligand precursor solution obtained in S2 into a high shear dispersing emulsifier in a volume ratio of 1:1. Maintain the temperature at 40°C, add ammonia water to adjust the pH value of the system to 7, and react for 40 minutes to obtain a multi-metal composite chelating modifier solution.

[0135] Preparation of adhesive:

[0136] Sodium phosphate was mixed with deionized water and stirred at 80°C until completely dissolved. The pH value of the system was then adjusted to 3 with phosphoric acid (85% concentration). Aluminum isopropoxide was then added in proportion and stirred until completely dissolved. The mixed solution was then added to a high shear emulsifier and rapidly reacted at 80°C for 10 minutes. A binder modifier was then added in proportion and the reaction was continued at 80°C for 5 minutes to obtain a binder.

[0137] Preparation of catalytic cracking catalyst: At room temperature, the matrix slurry is added to a high-shear emulsifier, and after homogenization, the pre-mixed molecular sieve slurry is added to obtain a mixed slurry of zeolite molecular sieve and matrix. The above-mentioned binder and the mixed slurry of zeolite molecular sieve and matrix are added to the high-shear emulsifier, and after high-speed emulsification for 2 minutes, the mixture is immediately discharged and spray-formed and dried. The spray forming conditions are as follows: the spray tower furnace temperature is controlled at 580°C and the spray exhaust temperature is controlled at 160°C. The obtained material is calcined at 450°C for 1 hour, and then ion-exchanged with an ammonium bicarbonate salt solution with a pH value of 3.0-3.5 for 0.3 hour to obtain a catalytic cracking catalyst.

[0138] The physical and chemical properties and catalytic performance of the catalyst are shown in Table 2.

[0139] Comparative Example 1

[0140] The contents of the components and raw materials of the catalytic cracking catalyst provided in this comparative example are the same as those in Example 5. The only difference from Example 5 is that the binder in this comparative example is aluminum sol commonly used in the industry.

[0141] Preparation of catalytic cracking catalyst: At room temperature, the matrix slurry is added to a high-shear emulsifier, and after homogenization, the pre-mixed molecular sieve slurry is added to obtain a mixed slurry of zeolite molecular sieve and matrix. Aluminum sol and the mixed slurry of zeolite molecular sieve and matrix are added to the high-shear emulsifier, and after high-speed emulsification for 2 minutes, they are immediately discharged and spray-formed and dried. The spray forming conditions are as follows: the spray tower furnace temperature is controlled at 580°C and the spray exhaust temperature is controlled at 160°C. The obtained material is calcined at 450°C for 1 hour, and then ion exchange is carried out with an ammonium chloride solution with a pH value of 3.0-3.5 for 0.3 hour to obtain a catalytic cracking catalyst.

[0142] The physical and chemical properties and catalytic performance of the catalyst are shown in Table 2.

[0143] Comparative Example 2

[0144] The contents of the raw materials in the catalytic cracking catalyst provided in this comparative example and the preparation method of the catalyst are the same as those in Example 5. The only difference from Example 5 is that in this comparative example, pseudo-boehmite with a peptization index of 99% is used instead of the pseudo-boehmite with a peptization solubility of 25% in Example 5, and the binder does not contain a binder modifier.

[0145] Specifically, the preparation method of the binder in this comparative example is as follows: sodium phosphate is mixed with deionized water, stirred at 80°C until completely dissolved, then the pH value of the system is adjusted to 3 with phosphoric acid (concentration 85%), and then aluminum isopropoxide is added in proportion and stirred until completely dissolved. Then, the mixed solution is added to a high shear emulsifier and the reaction temperature is maintained at 80°C for 10 minutes to obtain the binder.

[0146] The physical and chemical properties and catalytic performance of the catalyst are shown in Table 2.

[0147] Comparative Example 3

[0148] The contents and preparation methods of the components in the catalytic cracking catalyst provided in this comparative example are the same as those in Example 5. The only difference from Example 5 is that a mixed solution of cobalt chloride and samarium chloride is used in the binder of this comparative example to replace the binder modifier prepared by the octadentate chelating ligand diethylenetriamine penta (methylene phosphonic acid), lactic acid, ethanol, cobalt chloride and samarium chloride in Example 5.

[0149] Preparation of the binder in this comparative example: Sodium phosphate was mixed with deionized water and stirred at 80°C until completely dissolved, and then the pH value of the system was adjusted to 3 with phosphoric acid (concentration 85%), and then aluminum isopropoxide was added in proportion and stirred until completely dissolved. The mixed solution was then added to a high shear emulsifier and the reaction temperature was maintained at 80°C for a rapid reaction for 10 minutes. A mixed aqueous solution of cobalt chloride and samarium chloride was added in proportion, wherein the molar concentration of the mixed metal of cobalt chloride and samarium chloride was 0.15 mol / L, and the molar ratio of cobalt ions to samarium ions was 1:8. The reaction was continued at 80°C for 5 minutes to obtain the binder.

[0150] The physical and chemical properties and catalytic performance of the catalyst are shown in Table 2.

[0151] Comparative Example 4

[0152] The contents of the components and the preparation method of the catalytic cracking catalyst provided in this comparative example are the same as those in Example 5. The only difference from Example 5 is that the binder and catalyst were prepared in a conventional reactor instead of using a high shear emulsifier. The specific process is as follows:

[0153] Preparation of matrix slurry: same as in Example 5;

[0154] Preparation of binder modifier: Same as Example 5;

[0155] Preparation of the binder: Sodium phosphate is mixed with deionized water and stirred at 80°C until completely dissolved. Then, the pH value of the system is adjusted to 3 with phosphoric acid (concentration 85%). Then, aluminum isopropoxide is added in proportion and stirred until completely dissolved. Then, the mixed solution is added to a stirred reactor and the reaction temperature is maintained at 80°C for a rapid reaction for 10 minutes. Then, a binder modifier is added in proportion and the reaction is continued at 80°C for 5 minutes to obtain the binder.

[0156] Preparation of catalytic cracking catalyst: at room temperature, add the matrix slurry into a high shear emulsifier, homogenize until uniform, then add the pre-mixed molecular sieve slurry to obtain a mixed slurry of zeolite molecular sieve and matrix, add the above-mentioned binder and the mixed slurry of zeolite molecular sieve and matrix into a stirred reactor, stir and emulsify for 2 minutes, and immediately discharge and spray-form and dry. The spray forming conditions are as follows: the spray tower furnace temperature is controlled at 580°C, and the spray tail gas temperature is controlled at 160°C. After the obtained material is roasted at 450°C for 1 hour, it is ion-exchanged with an ammonium bicarbonate salt solution with a pH value of 3.0-3.5 for 0.3 hour to obtain a catalytic cracking catalyst.

[0157] The physical and chemical properties and catalytic performance of the catalyst are shown in Table 2.

[0158] Comparative Example 5

[0159] The contents of the components and the preparation method of the catalytic cracking catalyst provided in this comparative example are the same as those in Example 5. The only difference from Example 5 is that in this comparative example, the binder modifier is added to the molecular sieve slurry instead of being added to the binder to modify the binder. The specific process is as follows:

[0160] Preparation of the binder: Sodium phosphate was mixed with deionized water and stirred at 80°C until completely dissolved. Phosphoric acid (85%) was added to adjust the pH value of the system to 3. Aluminum isopropoxide was then added in proportion and stirred until completely dissolved. The mixture was then added to a high shear emulsifier and reacted rapidly at 80°C for 10 minutes to obtain the binder.

[0161] The preparation of the binder modifier is the same as in Example 5.

[0162] Preparation of catalytic cracking catalyst:

[0163] S1: Mix montmorillonite, pseudo-boehmite (peptization index is 25%) and deionized water, homogenize them, slowly add a small amount of hydrochloric acid, heat and maintain the slurry temperature at about 50°C, acidify and peptize, and prepare a matrix slurry.

[0164] S2: Mix the ultra-stable Y-type molecular sieve with deionized water, add the prepared binder modifier after mixing evenly, react for 30 minutes, add it to a high-speed high-shear emulsifier, mix it with the binder and the matrix slurry prepared in S1, and then spray-form and dry it. The spray-forming conditions are as follows: the spray tower furnace temperature is controlled at 580°C, and the spray exhaust temperature is controlled at 160°C. After the obtained material is calcined at 450°C for 1 hour, it is ion-exchanged with an ammonium bicarbonate salt solution with a pH value of 3.0-3.5 for 0.3 hour to obtain a catalytic cracking catalyst.

[0165] Comparative Example 6

[0166] The contents of the components and the preparation method of the catalytic cracking catalyst provided in this comparative example are the same as those in Example 5. The only difference from Example 5 is that the binder modifiers in this comparative example are copper chelated with ethylenediaminetetraacetic acid and lanthanum chelated with hydroxyethylethylenediaminetriacetic acid, rather than in situ synthesized multi-metal complex metal chelates. Since cobalt and samarium metal chelates are not commercially available, copper and lanthanum metal chelates are used instead. The specific process is as follows:

[0167] Preparation of the binder: Sodium phosphate is mixed with deionized water, stirred at 80° C. until completely dissolved, then the system is adjusted to a pH of 3 with phosphoric acid (concentration 85%), aluminum isopropoxide is added in proportion, stirred until completely dissolved, then the mixed solution is added to a high shear emulsifier, and the reaction temperature is maintained at 80° C. After rapid reaction for 10 minutes, a mixed solution of copper chelated with ethylenediaminetetraacetic acid and lanthanum chelated with hydroxyethylethylenediaminetriacetic acid is added in proportion, with a molar ratio of copper ions to lanthanum ions of 3.5:1, and the reaction is continued at 80° C. for 5 minutes to obtain the binder.

[0168] Preparation of catalytic cracking catalyst: At room temperature, the matrix slurry is added to a high-shear emulsifier, and after homogenization, the pre-mixed molecular sieve slurry is added to obtain a mixed slurry of zeolite molecular sieve and matrix. The above-mentioned binder and the mixed slurry of zeolite molecular sieve and matrix are added to the high-shear emulsifier, and after high-speed emulsification for 2 minutes, the mixture is immediately discharged and spray-formed and dried. The spray forming conditions are as follows: the spray tower furnace temperature is controlled at 580°C and the spray exhaust temperature is controlled at 160°C. The obtained material is calcined at 450°C for 1 hour, and then ion-exchanged with an ammonium bicarbonate salt solution with a pH value of 3.0-3.5 for 0.3 hour to obtain a catalytic cracking catalyst.

[0169] The parameters in the above embodiments are specifically shown in Table 1.

[0170] Table 1 Components and contents of catalysts in various examples

[0171]

[0172]

[0173] Note: M / N represents the molar ratio of transition metal ions to rare earth metal ions, and P / Al represents the molar ratio of phosphorus in the phosphorus-containing compound to aluminum in the aluminum-containing compound in the binder. Except for the solid content, the content of each component in the table is calculated based on the total dry weight of the catalytic cracking catalyst as 100%.

[0174] The catalysts prepared in the above examples and comparative examples were characterized and evaluated for their physical and chemical properties and reaction performance. The results are listed in Table 2.

[0175] Table 2 Comparison of physical and chemical properties of catalysts

[0176]

[0177]

[0178] Data Analysis:

[0179] From the data in the above table, it can be seen that Comparative Example 1 and Example 5 have the same molecular sieve and matrix content. The catalyst prepared by the formulation and method of the present invention has a low wear index, a larger pore volume, a smaller thermal collapse rate, and exhibits better anti-wear performance at high temperatures. At the same time, it has a higher micro-reaction activity, indicating that it has better reaction performance.

[0180] Comparison of Example 5 with Comparative Example 2 shows that the catalyst prepared using pseudo-boehmite with a peptization index of 25% has a higher pore volume, specific surface area and lower thermal collapse rate, as well as better anti-wear performance, compared with the catalyst prepared using only aluminum phosphate binder (without multimetal chelate).

[0181] Comparison between Comparative Example 3 and Example 5 shows that adding the same amount of transition metal and rare earth metal chelates to the aluminum phosphate binder can significantly improve the wear index, pore volume and thermal collapse rate of the catalyst, while using the same amount of transition metal and rare earth metal inorganic salts has no effect on improving the bonding performance and pore volume of the binder.

[0182] Comparison between Comparative Example 4 and Example 5 shows that, under the same formulation, the catalyst prepared using the high-efficiency shear emulsifier of the present invention is beneficial to the emulsification of the γ-alumina precursor and the dispersion of the metal chelate, and the prepared catalyst has better strength, specific surface area, thermal collapse index and micro-reactivity.

[0183] Comparison between Comparative Example 5 and Example 5 shows that adding the multi-metal chelate to the slurry of the molecular sieve and the matrix greatly weakens the modification effect of the binder.

[0184] Comparison between Comparative Example 6 and Example 5 shows that the catalyst prepared by in-situ preparation of multi-metal chelates has a richer source of raw materials and has better improvements in binder and reactivity.

[0185] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims of the present invention.

Claims

1. A catalytic cracking catalyst with high thermal wear resistance, characterized in that: The raw materials of the catalytic cracking catalyst include zeolite molecular sieve, matrix and binder, wherein the matrix is ​​composed of a γ-alumina precursor with a peptization index of ≤50% and clay, and the binder includes a phosphorus-containing compound, an aluminum-containing compound and a binder modifier; The binder modifier comprises a multidentate chelating ligand, a metal center ligand, an alcohol and an organic acid, wherein the metal center ligand contains at least two metal ions; The catalytic cracking catalyst is prepared in a high shear emulsifier; The metal ions in the metal center ligand are selected from rare earth metal ions and transition metal ions; The molar ratio of the transition metal ion to the rare earth metal ion is 1:5-10; the molar ratio of the multidentate chelating ligand to the metal ion in the metal center ligand is 2-5:1; Based on the total mass of the catalytic cracking catalyst on a dry basis as 100%, the content of the binder modifier is 1% to 3%; Based on the total dry weight of the catalytic cracking catalyst as 100%, the content of the zeolite molecular sieve is 25wt%-60wt%, the content of the matrix is ​​30wt%-50wt%; the content of the binder is 10wt%-25wt%, and the solid content of the catalytic cracking catalyst is 35wt%-60wt%.

2. The catalytic cracking catalyst with high thermal wear resistance according to claim 1, characterized in that: The multidentate chelate ligand is a bidentate chelate ligand having at least two coordinating atoms, and the coordinating atoms are P, O or N, O.

3. The catalytic cracking catalyst with high thermal wear resistance according to claim 1, characterized in that: The rare earth metal ions are selected from light rare earth metal ions.

4. The catalytic cracking catalyst with high thermal wear resistance according to claim 2, characterized in that: The multidentate chelating ligand is selected from any one of aminotris(methylene)phosphonic acid, hydroxyethylidene diphosphonic acid, ethylenediaminetetra(methylene)phosphonic acid, diethylenetriaminepenta(methylene)phosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, 2-hydroxyphosphonoacetic acid, bis(1,6-hexamethylenetriaminepenta(methylene)phosphonic acid), hexamethylenediaminetetra(methylene)phosphonic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid and 1,2-ethylenediamine.

5. The catalytic cracking catalyst with high thermal wear resistance according to claim 1, characterized in that: The organic acid is one or more of benzoic acid, lactic acid, propionic acid, formic acid, acetic acid, sorbic acid and malic acid; The alcohol is selected from C1~C3 monohydric alcohol.

6. The catalytic cracking catalyst with high thermal wear resistance according to claim 5, characterized in that: The alcohol is selected from one or more of methanol, ethanol and propanol.

7. The catalytic cracking catalyst with high thermal wear resistance according to claim 1, characterized in that: The molar ratio of phosphorus in the phosphorus-containing compound to aluminum in the aluminum-containing compound is 4 to 10:1; and / or The peptization index of the γ-alumina precursor is 20% to 30%; and / or The mass ratio of the γ-alumina precursor to the clay is 1:1-9.

8. The catalytic cracking catalyst with high thermal wear resistance according to claim 1, characterized in that: Based on the total dry weight of the catalytic cracking catalyst as 100%, the content of the zeolite molecular sieve is 35wt% to 50wt%.

9. The catalytic cracking catalyst with high thermal wear resistance according to claim 7, characterized in that: The molar ratio of the phosphorus element in the phosphorus-containing compound to the aluminum element in the aluminum-containing compound is 5-8:

1.

10. The catalytic cracking catalyst with high thermal wear resistance according to claim 7, characterized in that: The XRD spectrum of the γ-alumina precursor shows characteristic peaks at 2θ of 14±1°, 28±1°, 38±1°, and 49±1°.

11. The catalytic cracking catalyst with high thermal wear resistance according to claim 7, characterized in that: The mass ratio of the γ-alumina precursor to the clay is 1:3-7.

12. The catalytic cracking catalyst with high thermal wear resistance according to claim 8, characterized in that: Based on the total dry weight of the catalytic cracking catalyst as 100%, the content of the binder is 15wt% to 20wt%.

13. The catalytic cracking catalyst with high thermal wear resistance according to claim 8, characterized in that: Based on the total dry weight of the catalytic cracking catalyst as 100%, the solid content of the catalytic cracking catalyst is 40wt% to 50wt%.

14. A method for preparing a catalytic cracking catalyst having high thermal wear resistance according to any one of claims 1 to 13, characterized in that: The steps include: The mixed slurry of the zeolite molecular sieve and the matrix is ​​mixed evenly with the binder in a high shear emulsifier within 3 minutes, spray-formed and dried, calcined, and ion-exchanged to obtain the catalytic cracking catalyst with high thermal wear resistance.

15. The preparation method according to claim 14, wherein The preparation of the binder comprises the following steps: adding alcohol to the organic acid solution of the multi-dentate chelating ligand and mixing the mixture to obtain a multi-dentate chelating ligand solution; Adding alcohol to the organic acid solution of the metal center ligand and mixing well to obtain a metal center ligand solution; Adding the multi-dentate chelating ligand solution and the metal center ligand solution into a high shear dispersing emulsifier, and adjusting the pH value of the system to 5-8; obtaining a binder modifier solution; After heating an aqueous solution of a phosphorus-containing compound with a pH value of ≤5, an aluminum-containing compound is added and mixed, and then the mixed solution is added to a high shear emulsifier for reaction, and then the binder modifier solution is added to continue the reaction. After the reaction is completed, the binder is obtained.

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