A heavy metal pollution-resistant catalyst and its preparation method

Abstract

A heavy metal pollution-resistant catalyst and its preparation method. The catalyst comprises, on a dry basis, 10-70% by weight of a cracking-active component, 1-20% by weight of a zirconium oxide binder, 1-20% by weight of a silica sol binder, 0-50% of an alumina-based binder, and 10-70% by weight of clay. The catalyst preparation method comprises slurrying the cracking-active component, binder, and clay, followed by spray drying. The catalyst is used in heavy oil catalytic cracking reactions and exhibits excellent resistance to metal pollution while achieving a high heavy oil conversion rate.

Description

Technical Field

[0001] The present invention relates to a metal pollution-resistant cracking catalyst and a preparation method thereof. Background Art

[0002] As catalytic cracking feedstocks become increasingly heavier, the heavy metal content in these feedstocks increases, requiring cracking catalysts with high heavy oil cracking capacity and resistance to heavy metal contamination. Heavy metal contamination of Y molecular sieve, the primary active component of cracking catalysts primarily used to produce light oil products, can affect its thermal and hydrothermal stability, altering the distribution of acidic active sites. This can lead to a poor product distribution and reduced conversion activity. Furthermore, the use of Y molecular sieve alone in catalytic cracking reactions is subject to numerous limitations due to difficulties in meeting certain performance requirements, such as abrasion resistance and selectivity. Therefore, catalytic cracking catalysts often include a matrix to modify the catalyst's properties. The matrix of a catalytic cracking catalyst typically contains a binder to bond the various component particles together. To process feedstocks containing heavy metals, the matrix component of the catalyst is desired to have a strong ability to capture heavy metal components and crack heavy oil macromolecules. Currently, catalytic cracking catalysts mostly use alumina sols and peptized pseudo-boehmite as binders, resulting in low matrix activity, poor selectivity, and difficulty in increasing strength. Some studies have used silica sol binders, but these still suffer from low activity and poor resistance to metal contamination. Adding metal oxides or non-metallic compounds to the catalyst matrix can enhance certain physicochemical properties, but these components often lack adhesive properties and can even compromise product strength.

[0003] Zirconium precursors are highly acidic and can easily destroy active components in the catalyst if added directly to it. Therefore, existing research has also investigated the method of preparing zirconium into zirconium sol and adding it to the catalyst. However, the zirconium sol prepared by existing technology has limited improvement in its ability to resist heavy metal pollution when used as a cracking catalyst matrix. Summary of the Invention

[0004] The inventors of the present invention unexpectedly discovered during research that the co-introduction of appropriate zirconium sol and silica sol into a catalytic cracking catalyst will not destroy the molecular sieve and can effectively improve the metal resistance of the catalyst.

[0005] The technical problem to be solved by the present invention is to provide a catalytic cracking catalyst resistant to metal pollution, wherein the catalytic cracking catalyst contains zirconium sol and silica sol binders.

[0006] The present invention provides a catalytic cracking catalyst resistant to metal contamination, which comprises, on a dry basis, 10-70 wt% of a cracking active component, 1-20 wt% of a zirconium oxide binder, calculated as ZrO2, 1-20 wt% of a silica sol binder, calculated as SiO2, 0-50% of an alumina-based binder, calculated as Al2O3, and 10-70 wt% of clay, calculated as a dry basis.

[0007] According to the catalytic cracking catalyst described in the above technical solution, in one embodiment, the cracking active component includes 70-100 weight % such as 80 weight %-100 weight % of Y-type molecular sieve and 0-30 weight % such as 0-20 weight % of the second molecular sieve.

[0008] The catalytic cracking catalyst according to any of the above technical solutions, wherein the zirconium oxide binder is zirconium sol, the zirconium sol comprises 0.5 wt%-20 wt% ZrO2, for example, 1-18 wt% or 5-15 wt%, a stabilizer, an alkali cation and water, wherein the molar ratio of the stabilizer to Zr is 1-6, and the pH value of the zirconium sol is 1-7.

[0009] The catalytic cracking catalyst according to any of the above technical solutions, wherein the zirconium sol particles have a size between 5 nm and 15 nm, an average particle size of approximately 10 nm (approximately 10 nm refers to 10 ± 2 nm), and a concentration of greater than 90%. The concentration is the ratio of the number of particles with a particle size of approximately 10 nm in the zirconium sol sample to the total number of particles measured, and can be obtained by obtaining a zirconium sol sample image through TEM and computer image analysis. The particle size refers to the diameter of the largest circumscribed circle in the particle projection diagram, and the average particle size is the arithmetic mean of the sample particle sizes.

[0010] The catalytic cracking catalyst according to any of the above technical solutions, wherein the zirconium sol is dried at 100°C for 6 hours and calcined at 600°C for 2-6 hours for heat treatment, and the resulting product has monoclinic and tetragonal phases coexisting, and the ratio of the monoclinic phase to the tetragonal phase is preferably 0.05-0.6:1; and / or the zirconium sol is dried at 100°C for 6 hours and calcined at 800°C for 2-6 hours for heat treatment, and ZrO2 in the resulting product exists in the tetragonal phase.

[0011] According to the catalytic cracking catalyst described in any of the above technical solutions, in the zirconium sol, the stabilizer is an organic acid, and the stabilizer is preferably at least one of glycolic acid, oxalic acid, acetic acid, malonic acid, malic acid, tartaric acid, succinic acid, adipic acid, maleic acid, itaconic acid, citric acid, etc., and more preferably one or more of acetic acid, oxalic acid or citric acid.

[0012] The catalytic cracking catalyst according to any of the above technical solutions, wherein in the zirconium sol, the alkali cation is a nitrogen-containing cation, such as an ammonium ion or a nitrogen-containing cation formed by hydrolysis of a water-soluble organic base, and the water-soluble organic base is, for example, one or more of methylamine, dimethylamine, trimethylamine, methanolamine, dimethanolamine, trimethanolamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, monomethyltriethylammonium hydroxide, monomethyltriethanolammonium hydroxide, and monomethyltributylammonium hydroxide.

[0013] According to the catalytic cracking catalyst described in any of the above technical solutions, in the zirconium sol, the molar ratio of the alkali cation (also called basic cation) to Zr is preferably 1-8.

[0014] According to any of the above technical solutions, the catalytic cracking catalyst may further contain inorganic acid radicals and / or alcohols, wherein the molar ratio of the inorganic acid radicals and / or alcohols to Zr is 1-6, for example, 1-4:1. The inorganic acid radicals may be one or more of sulfate, chloride, and nitrate, and the alcohols may be one or more of methanol, ethanol, propanol, and butanol.

[0015] According to any of the above technical solutions, the pH value of the zirconium sol is preferably 1.5-5, more preferably 2-4, and even more preferably 2-3.

[0016] According to any of the above technical solutions, the catalytic cracking catalyst is an acidic silica sol. In one embodiment, the silica sol has a pH of 1.5-3.5 and a silica sol particle size of 2nm-20nm. The silica sol preferably has a pH of 1.5-3 and a silica sol particle size of 3nm-10nm. More preferably, the silica sol has a pH of 2-3 and a silica sol particle size of 3nm-5nm. The silica sol particle size refers to the maximum size of the silica sol particles and can be obtained by measuring the maximum circumscribed circle diameter of the particles in a TEM projection image.

[0017] According to the catalytic cracking catalyst described in any of the above technical solutions, the content of SiO2 in the silica sol is preferably 5% by weight to 15% by weight.

[0018] According to any of the above technical solutions, the silica sol is preferably prepared by a water glass direct acidification method, wherein the preparation method comprises rapidly adding a strong acid to water glass, and the pH value of the silica sol is preferably 1.5-3. The method for preparing the silica sol by the water glass direct acidification method can refer to the existing methods.

[0019] According to any of the above technical solutions, the catalytic cracking catalyst, wherein the alumina binder is one or more of aluminum sol, acidified boehmite, and modified boehmite. The modified boehmite is pseudo-boehmite containing metal and / or phosphorus, wherein the metal (also referred to as modified metal) is, for example, one or more alkaline earth metals, and the content of the metal and / or phosphorus, calculated as oxide, is 5-20% by weight based on the dry weight of the modified boehmite. The content of the alumina binder in the catalytic cracking catalyst is preferably 5-35% by weight, preferably 10-25% by weight. The alumina binder is preferably acidified pseudo-boehmite, and the acid-to-aluminum ratio of the acidified pseudo-boehmite is, for example, 0.1 to 0.3 molar ratio.

[0020] According to any of the above technical solutions, the catalytic cracking catalyst comprises 70 wt%-100 wt%, preferably 80 wt%-100 wt% of the Y-type molecular sieve and 0-30 wt%, preferably 0-20 wt% of the second molecular sieve.

[0021] According to any of the above technical solutions, the catalytic cracking catalyst is any one or more Y-type molecular sieves having a unit cell constant of 2.430 nm-2.480 nm and a rare earth content of 0-20 wt%, such as one or more of DASY molecular sieve, rare earth-containing DASY molecular sieve, USY molecular sieve, rare earth-containing USY molecular sieve, REY molecular sieve, and Y-type molecular sieve synthesized by in-situ crystallization of modified kaolin; the second molecular sieve is a molecular sieve having a five-membered ring structure, and the molecular sieve having a five-membered ring structure includes one or more of BEA molecular sieve, MFI molecular sieve, and mordenite, preferably one or more of BEA molecular sieve and MFI molecular sieve. The BEA molecular sieve can be obtained by crystallization without amine, or by calcining a molecular sieve prepared by a template method, such as Beta molecular sieve; the MFI molecular sieve is, for example, at least one of a rare earth-containing MFI molecular sieve, a phosphorus-containing MFI molecular sieve, and an iron-containing MFI molecular sieve. The phosphorus-containing MFI molecular sieve contains phosphorus and may further contain one or more transition metals such as Fe, Co, Ni, Zn, and Cu. The mordenite zeolite includes at least one of high-silicon mordenite and low-silicon mordenite. The mordenite zeolite includes at least one of high-silicon mordenite and low-silicon mordenite.

[0022] According to the catalytic cracking catalyst of the present invention, the clay is, for example, one or more of kaolin, montmorillonite, diatomaceous earth, halloysite, pseudo-halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite and bentonite.

[0023] A method for preparing the catalytic cracking catalyst according to any of the above technical solutions comprises:

[0024] A mixture of zirconium sol and silica sol is formed; the mixture of zirconium sol and silica sol, cracking active component, clay and optional alumina binder are formed into a slurry; and spray drying is performed. The cracking active component preferably includes a Y-type molecular sieve and an optional second molecular sieve.

[0025] In one embodiment, the method for preparing the catalytic cracking catalyst comprises the following steps:

[0026] (s1) mixing zirconium sol and silica sol, and in one embodiment, controlling the pH value of the mixture to be 2.5-3.5;

[0027] (s2) preparing clay slurry;

[0028] (s3) preparing a molecular sieve slurry; wherein the multiple molecular sieves can be in the same slurry or in different slurries, for example, the Y molecular sieve and the second molecular sieve each form a slurry;

[0029] (s4) mixing the clay slurry, the molecular sieve slurry, the mixture obtained in step (s1), and an alumina binder;

[0030] (s5) The slurry obtained in step (s4) is uniformly dispersed and spray-dried.

[0031] The catalytic cracking catalyst provided by the present invention has at least one of the following advantages, and preferably has multiple advantages or all of the advantages:

[0032] (1) The catalytic cracking catalyst provided by the present invention has good wear resistance.

[0033] (2) The catalytic cracking catalyst provided by the present invention has good heavy oil cracking activity and gasoline selectivity.

[0034] (3) The catalytic cracking catalyst provided by the present invention is used for hydrocarbon oil conversion and can achieve a higher conversion rate and gasoline yield under the condition of metal contamination.

[0035] (4) The catalytic cracking catalyst provided by the present invention can achieve a higher conversion rate and a higher gasoline yield by using a modified NSY molecular sieve.

[0036] The present invention provides a method for preparing a catalytic cracking catalyst. This method introduces zirconium in the form of a sol, preventing damage to the molecular sieve. Simultaneously, the introduction of silica sol improves the catalyst's resistance to metal contamination through the synergistic effect of zirconium and silicon. The catalyst preparation method can produce a catalytic cracking catalyst with excellent wear resistance. DETAILED DESCRIPTION

[0037] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0038] The catalytic cracking catalyst of the present invention comprises, on a dry basis, 10-70 weight percent of a cracking active component, e.g., 20-60 weight percent, 25-55 weight percent, or 30-400 weight percent of the cracking active component. The cracking active component comprises 70-100 weight percent, e.g., 80-100 weight percent, of a Y-type molecular sieve and 0-30 weight percent, e.g., 0-20 weight percent, of a second molecular sieve.

[0039] The catalytic cracking catalyst of the present invention comprises, on a dry basis, 0-50% alumina-based binder in terms of Al2O3. Preferably, it comprises 5% to 30% by weight, for example 10% to 25% by weight, of an aluminum-based binder in terms of Al2O3. The aluminum-based binder is preferably acidified pseudo-boehmite (abbreviated as acidified boehmite) and / or aluminum sol. In one embodiment, the catalytic cracking catalyst comprises 5% to 25% by weight, for example 10% to 20% by weight, of acidified pseudo-boehmite in terms of Al2O3 and 0-15% by weight, for example 0-10% by weight, of aluminum sol. In one embodiment, the acid-to-aluminum ratio (acid to pseudo-boehmite in terms of Al2O3) of the acidified pseudo-boehmite is a molar ratio of 0.15-0.3:1.

[0040] The catalytic cracking catalyst of the present invention comprises 10-70 wt% clay on a dry basis. In one embodiment, the clay content is 15-50 wt%, such as 20-45 wt%.

[0041] The catalytic cracking catalyst of the present invention comprises, on a dry basis, 1-20 wt% zirconium oxide binder as ZrO2, for example, 3-20 wt% or 5-20 wt% zirconium sol as ZrO2.

[0042] The catalytic cracking catalyst of the present invention comprises 1-20 wt% of silica sol binder calculated as SiO2 on a dry basis, for example, 3 wt%-20 wt% or 5 wt%-15 wt% of zirconium sol calculated as SiO2.

[0043] According to the catalytic cracking catalyst of the present invention, in one embodiment, the total content of the zirconium sol and the silica sol is 5-30 weight %, for example, 10-25 weight %, and the weight ratio of the zirconium sol to the silica sol is preferably 0.2-5:1 and more preferably 0.3-4:1, wherein the zirconium sol is calculated as ZrO2 and the silica sol is calculated as SiO2.

[0044] According to the catalytic cracking catalyst of the present invention, preferably, the Y-type molecular sieve is a modified NSY-type molecular sieve obtained by modifying NSY molecular sieve synthesized by in-situ crystallization of kaolin, wherein the sodium oxide content is less than 2% by weight, and the modification treatment includes ultrastabilization treatment and / or ion exchange treatment.

[0045] The modified NSY molecular sieve is obtained by subjecting an NSY molecular sieve synthesized by in-situ crystallization of kaolin (hereinafter referred to as the in-situ crystallized NSY molecular sieve) to a modification treatment. The modification treatment, such as ion exchange and / or ultrastabilization treatment, reduces the sodium oxide content in the NSY molecular sieve synthesized by in-situ crystallization of kaolin to below 2% by weight.

[0046] In a preferred embodiment, the NSY molecular sieve synthesized by in-situ crystallization of kaolin is measured by an X-ray diffraction method, and the ratio of the crystallinity by the peak height method to the peak area method is K1, K1 = 0.76 to 0.89, and the crystallinity by the peak height method is preferably ≥60%; the silicon-aluminum ratio measured by the unit cell constant a0 is 5.0 to 5.5, and the ratio to the silicon-aluminum ratio measured by the chemical method is K2, K2 = 0.87 to 0.93, and the silicon-aluminum ratio is the molar ratio of silicon oxide to aluminum oxide.

[0047] According to common sense of crystallization, the difference between the crystallinity measured by the peak height method and the crystallinity measured by the peak area method is related to the size of the crystal grains. The Y-type molecular sieve composite material of the present invention (hereinafter referred to as the composite material) sets the crystallite coefficient K1, K1 = S 峰高 / S 峰面积 , which is the ratio of the crystallinity measured by the peak height method to the crystallinity measured by the peak area method. The K1 value indicates the size of the crystallites; a larger K1 value indicates a larger crystallite size. The molar ratio of silicon oxide to aluminum oxide calculated from the unit cell constant a0 represents the framework silicon-aluminum ratio of the molecular sieve, while the molar ratio of silicon oxide to aluminum oxide determined by chemical methods represents the overall silicon-aluminum ratio of the composite material. The NSY molecular sieve synthesized by in-situ crystallization of kaolin described herein has a framework silicon-aluminum ratio of 5.0 to 5.5, preferably 5.2 to 5.5, as determined by the unit cell constant a0. The overall silicon-aluminum ratio determined by chemical methods represents the macroscopic silicon-aluminum ratio of the entire material. Both the framework silicon-aluminum ratio and the overall silicon-aluminum ratio are related to the framework integrity and purity of the molecular sieve in the composite material. The NSY molecular sieve synthesized by in-situ crystallization of kaolin described herein is obtained by crystallization of metakaolin, wherein a portion of the metakaolin is an intermediate in the process of crystallization toward a Y-type molecular sieve. Therefore, the intermediate system coefficient K2 is set as K2 = framework silicon-aluminum ratio / overall silicon-aluminum ratio. The size of the K2 value indicates the degree of composite material. The smaller the K2 value, the more intermediates it contains. The preferred K2 is 0.87-0.92, and more preferably 0.88-0.90.

[0048] According to the heavy oil cracking catalyst of the present invention, in one embodiment, the K1 of the NSY molecular sieve synthesized by in-situ crystallization of ridge clay is 0.80-0.89.

[0049] According to the heavy oil cracking catalyst of the present invention, in one embodiment, the K1 of the NSY molecular sieve synthesized by in-situ crystallization of ridge clay is 0.80-0.85.

[0050] According to the heavy oil cracking catalyst of the present invention, in one embodiment, the K2 of the NSY molecular sieve synthesized by in-situ crystallization of ridge clay is 0.87 to 0.92.

[0051] According to the heavy oil cracking catalyst of the present invention, in one embodiment, the K2 of the NSY molecular sieve synthesized by in-situ crystallization of ridge clay is 0.88-0.90.

[0052] Preferably, the NSY molecular sieve (also called Y-type molecular sieve composite material) synthesized by in-situ crystallization of kaolin described in the present invention has K2=0.87-0.91 and K1=0.77-0.88, for example, K1=0.81-0.88 or K1=0.86-0.88.

[0053] According to the heavy oil cracking catalyst of the present invention, preferably, the NSY molecular sieve synthesized by in-situ crystallization of kaolin has spherical particles of 5 to 20 microns, and a crystallinity of ≥60% as measured by the peak height method, i.e., the weight percentage of the NaY molecular sieve is at least 60%. Preferably, the crystallinity as measured by the peak height method is greater than 75%, and more preferably ≥80%.

[0054] In the present invention, pores with a diameter greater than 0.8 nm are defined as medium and macropores. The NSY molecular sieve synthesized by in-situ crystallization of kaolin described in the present invention has a suitable medium and macropore ratio, wherein the macropore ratio is 10-20%.

[0055] According to the heavy oil cracking catalyst of the present invention, in one embodiment, the preparation method of the NSY molecular sieve synthesized by in-situ crystallization of kaolin comprises the following steps:

[0056] a) calcining and dehydrating kaolin at 500-900° C. to convert it into metakaolin, and crushing it into metakaolin powder with a particle size of less than 10 μm;

[0057] b) adding a directing agent, sodium silicate, sodium hydroxide solution and water to the metakaolin powder to prepare a reaction raw material A, wherein the weight ratio of the directing agent to the metakaolin is 0.01 to 1.0, and the ratio of the reaction raw material A is (1 to 2.5) Na2O:Al2O3:(4 to 9)SiO2:(40 to 100)H2O in a molar ratio;

[0058] c) crystallizing the reaction raw material A at 88-98° C. under stirring for 1-70 hours, and then adding a second silicon source to obtain the reaction raw material B, wherein the second silicon source accounts for 0.1-10% by weight of the total silicon feed, calculated as silicon oxide;

[0059] d) crystallizing the reaction material B at 88-98° C. under stirring and recovering the product.

[0060] According to the heavy oil cracking catalyst of the present invention, the modified NSY molecular sieve contains rare earth, and the rare earth content in the modified NSY molecular sieve is 10% to 20% by weight in terms of RE2O3.

[0061] According to the catalytic cracking catalyst of the present invention, in a preferred embodiment, the Y-type molecular sieve comprises a modified NSY molecular sieve, wherein the modified NSY molecular sieve is an NSY molecular sieve synthesized by in-situ crystallization of kaolin, modified to obtain a sodium oxide content of no more than 2.0%. The modified NSY molecular sieve can be treated by any method capable of reducing the sodium content of the NSY molecular sieve synthesized by in-situ crystallization of kaolin to a sodium oxide content of no more than 2% by weight, such as by ion exchange. The ion exchange can be performed using ammonium salt and / or rare earth salt solutions, and the present invention does not have any special requirements.

[0062] According to the method for preparing a catalytic cracking catalyst provided by the present invention, the method for preparing the modified NSY molecular sieve comprises the following steps:

[0063] (1) calcining kaolin at 500-900°C to dehydrate it and convert it into metakaolin, which is then crushed to produce metakaolin powder with a particle size of less than 10 μm;

[0064] (2) adding sodium silicate, a directing agent, a sodium hydroxide solution, and water to metakaolin powder to prepare a reaction raw material A having a molar ratio of (1-2.5) Na2O:Al2O3:(4-9)SiO2:(40-100)H2O, wherein the weight ratio of the directing agent to the metakaolin is 0.01-1.0;

[0065] (3) crystallizing the reaction raw material A at 88-98° C. under stirring, and adding a second silicon source after the crystallization time reaches 1-70 hours to obtain the reaction raw material B, wherein the second silicon source accounts for 0.1% to 10% by weight of the total silicon feed, calculated as silicon oxide;

[0066] (4) crystallizing the reaction raw material B at 88-98° C. under stirring and recovering the NSY molecular sieve synthesized by in-situ crystallization of kaolin;

[0067] (5) The NSY molecular sieve synthesized by in-situ crystallization of kaolin is subjected to ion exchange and / or ultra-stabilization treatment.

[0068] According to the present invention, the method for preparing a catalytic cracking catalyst comprises synthesizing a directing agent according to conventional methods, such as those described in USP 3574538, USP 3671191, USP 3639099, USP 4166099, and EUP 0435625. The directing agent has a molar composition of (10-17) SiO2: (0.7-1.3) Al2O3: (11-18) Na2O: (200-350) H2O. During synthesis, the raw materials are aged at 4-35°C, preferably 4-20°C, to obtain the directing agent.

[0069] According to the present invention, in the preparation method of the modified NSY molecular sieve, the second silicon source can be a solid silicon source and / or a liquid silicon source. The sodium content of the second silicon source, calculated as Na2O, is 0.01% to 10% by weight, preferably less than 1% by weight. For cost control, the preferred second silicon source is solid silica gel. The solid silica gel is included in the overall synthesis ratio and can have varying pore sizes. Based on pore size, there are fine-pore silica gel, coarse-pore silica gel, and mesoporous silica gel, which lies between the two. Silica gel with an average pore size of 1.5 to 2.0 nm or less is conventionally referred to as fine-porous silica gel (e.g., Type A solid silica gel from the Qingdao Ocean Chemical Group Special Silica Gel Factory), and silica gel with an average pore size of 4.0 to 5.0 nm or greater is referred to as coarse-porous silica gel (e.g., Type C solid silica gel from the Qingdao Ocean Chemical Group Special Silica Gel Factory). Furthermore, silica gel with an average pore size of 10.0 nm or greater is referred to as extra-coarse-porous silica gel, and silica gel with an average pore size of 0.8 nm or less is referred to as extra-fine-porous silica gel (e.g., Type B solid silica gel from the Qingdao Ocean Chemical Group Special Silica Gel Factory). The second silicon source may also be liquid silica gel. When liquid silica gel is used as the second silicon source, it preferably has a SiO2 content of at least 30% by weight.

[0070] According to the method for preparing a heavy oil cracking catalyst of the present invention, in the method for preparing the modified NSY molecular sieve, the second silicon source accounts for 4 wt% to 10 wt% of the total silicon feed, calculated as silicon oxide.

[0071] According to the preparation method of the catalytic cracking catalyst provided by the present invention, in the preparation method of the modified NSY molecular sieve, sodium silicate and the second silicon source are added to the synthesis preparation system in different processes, and in particular, the second silicon source is added during the crystal growth period. The present invention combines the means of adding different silicon sources at different stages of the crystallization process to control the synthesis ratio technology with kaolin in-situ crystallization synthesis technology (using natural minerals as the main aluminum source and silicon source), changes the crystal growth environment by the silicon source, and adopts two completely different material ratios in the crystal nucleation period and the crystal growth period. In the crystal nucleation period, the method of the present invention adopts a larger sodium-silicon ratio (Na2O / SiO2) in the material, which is conducive to the rapid nucleation of the Y-type molecular sieve, and in the crystal growth period, a low-sodium or sodium-free silicon source is added to increase the silicon-aluminum ratio (SiO2 / Al2O3) in the synthetic material while reducing the sodium-silicon ratio (Na2O / SiO2) in the material. Under the premise of shortening the crystallization time, it is conducive to the improvement of the product silicon-aluminum ratio, and the skeleton silicon-aluminum ratio is increased to 5.0-5.5.

[0072] According to the method for preparing a catalytic cracking catalyst provided by the present invention, wherein the modified NSY molecular sieve is prepared by crystallizing under stirring to obtain a multi-level pore Y-type molecular sieve composite material product containing certain medium and large pores, the crystallization stirring speed can be, but is not limited to, 50 to 1000 rpm, preferably 300 to 500 rpm, for 16 to 48 hours, preferably 24 to 32 hours. The drying temperature of the crystallized zeolite is 100 to 120°C.

[0073] According to the method for preparing a catalytic cracking catalyst provided by the present invention, in step (4) of preparing the modified NSY molecular sieve, the product is recovered after crystallization to obtain an NSY molecular sieve synthesized by in-situ crystallization of kaolin. The recovery generally includes a filtration step and, optionally, may also include one or more steps of washing, drying, and calcining.

[0074] According to the method for preparing a catalytic cracking catalyst provided by the present invention, in the preparation step (5) of the modified NSY molecular sieve, the NSY molecular sieve synthesized by in-situ crystallization of kaolin is subjected to a modification treatment including ion exchange and / or ultrastabilization treatment. Preferably, the ion exchange is ammonium ion exchange and / or rare earth ion exchange.

[0075] According to the method for preparing a heavy oil cracking catalyst of the present invention, in one embodiment, the step (5) includes ion exchange, the ion exchange includes rare earth ion exchange, and the rare earth content in the modified NSY molecular sieve obtained in step (5) is 10% to 20% by weight in terms of RE2O3, and the sodium oxide content is less than 2% by weight.

[0076] In one embodiment, the ion exchange comprises mixing the NSY molecular sieve synthesized by in-situ crystallization of kaolin with an exchange solution and stirring at 20-90°C for 10-120 minutes. This process can be performed one or more times, and the exchange solution for each exchange can contain ammonium ions, rare earth ions, or both. Preferably, the ammonium salt concentration in the exchange solution is 5-700 g / L, for example, 5-100 g / L, and / or the rare earth salt concentration, calculated as RE2O3, is 5-400 g / L, for example, 5-200 g / L. The ammonium salt may be one or more of ammonium chloride, ammonium nitrate, and ammonium sulfate. The rare earth salt may be one or more of rare earth chloride and rare earth nitrate. The rare earth may include one or more of the lanthanide rare earths and actinide rare earths, for example, one or more of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, TB, Dy, Ho, Er, Tm, Yb, and Lu.

[0077] In one embodiment, the ion exchange product obtained in step (5) of preparing the modified NSY molecular sieve is further calcined.

[0078] According to the preparation of the catalytic cracking catalyst provided by the present invention, the modification treatment in the preparation step (5) of the modified NSY molecular sieve may also include an ultrastabilization process, and the ultrastabilization process may be performed before or after the ion exchange, or the ion exchange process and the ultrastabilization process may be performed multiple times. The ultrastabilization process may be, for example, gas-phase ultrastabilization and / or hydrothermal ultrastabilization. The methods for gas-phase ultrastabilization and hydrothermal ultrastabilization may refer to the gas-phase ultrastabilization method and the hydrothermal ultrastabilization method known in the art.

[0079] According to the preparation method of the catalytic cracking catalyst provided by the present invention, the NSY molecular sieve synthesized by in-situ crystallization of kaolin may further include one or more steps of filtration, washing, drying and calcination after ion exchange and / or ultrastabilization treatment. These steps can refer to the filtration, washing, drying and calcination methods well known to those skilled in the art.

[0080] According to the method for preparing a catalytic cracking catalyst provided by the present invention, the zirconium sol can be prepared by a method comprising the following steps:

[0081] (A) preparing a zirconium source solution, wherein the concentration of the zirconium source solution is 0.5% to 20% by mass, for example, 1 to 18% by mass or 5 to 15% by mass, calculated as ZrO2; the zirconium source solution can be prepared at room temperature, which can be 15-40°C;

[0082] (B) adding a stabilizer to the zirconium source solution, stirring at room temperature to 90° C. for 0.5-3 hours to allow the solution to fully react, thereby obtaining a first mixed solution; wherein the molar ratio of the stabilizer to the zirconium is 1-6:

[0083] (C) adding alkali solution to the first mixed solution at room temperature to 50° C. to obtain zirconium sol, wherein the amount of alkali solution is such that the pH value of the zirconium sol is 1 to 7.

[0084] In the zirconium sol preparation method, alkali solution is slowly added to the first mixed solution to obtain a clear and transparent zirconium sol. The slowly adding can be, for example, dropwise addition, or a certain alkali solution addition rate can be controlled, for example, the alkali solution addition rate is 0.05ml~50ml alkali solution / minute / L first mixed solution, for example, 0.1~30ml alkali solution / minute / L first mixed solution or 1~35ml alkali solution / minute / L first mixed solution or 0.05ml~10ml / minute / L first mixed solution or 0.1ml~5ml / minute / L first mixed solution. In one embodiment, alkali solution is slowly added to the first mixed solution by a pump, for example, a peristaltic pump. Preferably, the amount of alkali solution added makes the pH value of the zirconium sol 1.5~5, for example 2-4, and more preferably 2~3.

[0085] In the zirconium sol preparation method, the zirconium source is one or more inorganic zirconium salts or organic zirconium salts, such as one or more of zirconium tetrachloride, zirconium oxychloride, zirconium acetate, zirconium nitrate, zirconium oxynitrate, zirconium oxysulfate and zirconium oxycarbonate; the organic zirconium salt is one or more of zirconium n-propoxide, zirconium isopropoxide, zirconium ethanol and zirconium butoxide.

[0086] In the zirconium sol preparation method, the stabilizer is an organic acid that can form a coordination polymer with zirconium. The stabilizer is, for example, at least one of glycolic acid, acetic acid, oxalic acid, malonic acid, malic acid, tartaric acid, succinic acid, adipic acid, maleic acid, itaconic acid, citric acid, etc., more preferably one or more of acetic acid, oxalic acid or citric acid.

[0087] In the zirconium sol preparation method, the alkali solution can be selected from ammonia water or an aqueous solution of a water-soluble organic base, and the water-soluble organic base is, for example, one or more of methylamine, dimethylamine, trimethylamine, methanolamine, dimethanolamine, trimethanolamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, monomethyltriethylammonium hydroxide, monomethyltriethanolammonium hydroxide, and monomethyltributylammonium hydroxide.

[0088] In the method for preparing a catalytic cracking catalyst provided herein, the product obtained by spray drying can be calcined and / or washed. The methods of spray drying, calcining, and washing are well known to those skilled in the art and are not particularly required by the present invention. For example, the calcination temperature can be 350-550°C, and the calcination time can be 0.5-4 hours. The washing can be performed, for example, with a 0.5-10 wt% ammonium salt solution. The ammonium salt can be, for example, one or more of ammonium nitrate, ammonium sulfate, and ammonium chloride.

[0089] The present invention will be described in detail below through examples.

[0090] The elemental content of the catalyst was determined by XRF, while the specific surface area and pore volume were determined using low-temperature nitrogen adsorption-desorption. The catalyst wear index was determined using RIPP 28-90 and RIPP 29-90 methods, respectively, as described in "Analytical Methods in Petrochemical Engineering, RIPP Test Method" (edited by Yang Cuiding, Science Press, 1990).

[0091] The specifications of the raw materials used in the catalyst preparation example are as follows:

[0092] Pseudoboehmite: purchased from Shandong Aluminum Company, solid content 65 wt%;

[0093] Zirconium oxychloride: purchased from Aldrich, analytical grade, 98.5%;

[0094] Kaolin: solid content 75% by weight, produced by China Kaolin Co., Ltd. (Suzhou);

[0095] ZSP-3 molecular sieve: product of Sinopec Catalyst Qilu Branch, with a P2O5 content of 3.02 wt%;

[0096] REY molecular sieve: a product of Sinopec Catalyst Qilu Branch, with a rare earth content (calculated as RE2O3) of 16% by weight;

[0097] SOY-8 molecular sieve: Qilu Catalyst Branch, rare earth content (calculated as RE2O3) is 8% by weight.

[0098] Aluminum sol: produced by Shandong Aluminum Plant, solid content 25% by weight.

[0099] Glacial acetic acid: Sinopharm Group, analytical grade, 99 wt%.

[0100] Ammonia: Sinopharm Group, analytical grade, 28 wt%.

[0101] Oxalic acid: Sinopharm Group, analytical grade, 99% by weight

[0102] Isopropyl alcohol: Sinopharm Group, analytical grade, 99% by weight

[0103] Triethanolamine: Sinopharm Group, analytical grade, 99% by weight

[0104] Water glass: Qilu Catalyst Branch, SiO2 250g / L.

[0105] Hydrochloric acid: Sinopharm Group, analytical grade, 36% by weight

[0106] In the molecular sieve preparation examples and comparative examples, the directing agent was prepared by slowly adding 120 kg of sodium metaaluminate solution (containing 3.15 wt% Al2O3 and 21.1 wt% Na2O) to 250 kg of sodium silicate solution (containing 20.05 wt% SiO2 and 6.41 wt% Na2O) at 30°C with rapid stirring. The mixture was stirred for 1 hour and aged at 20°C for 48 hours to obtain the directing agent. The directing agent composition was 16 Na2O: Al2O3: 15 SiO2: 320 H2O.

[0107] Zirconium Sol Preparation Example 1

[0108] Add 130 g of deionized water to a beaker, then add 125 g of zirconium oxychloride, stir for 10 min, add 93 g of acetic acid, and stir for 30 min to obtain a mixed solution; then use a peristaltic pump to slowly add ammonia water to the above solution, control the pump speed (i.e., feeding rate) at 5 ml / min, and control the pH value to 2.5 to obtain a clear and transparent zirconium sol A1.

[0109] Zirconium Sol Preparation Example 2

[0110] Add 130 g of deionized water to a beaker, then add 125 g of zirconium oxychloride, stir for 10 min, add 70 g of oxalic acid, and stir for 30 min to obtain a mixed solution; then slowly add ammonia water to the above solution using a pump at a pump speed of 5 ml of ammonia water / min and control the pH value to 2.5 to obtain a clear and transparent zirconium sol A2.

[0111] Zirconium Sol Preparation Example 3

[0112] Add 170 g of deionized water to a beaker, then add 176 g of zirconium isopropoxide, stir for 10 min, add 70 g of oxalic acid, and stir for 30 min to obtain a mixed solution; then slowly add triethanolamine to the above solution using a pump at a pump speed of 5 ml / min and control the pH to 2.5 to obtain a clear and transparent zirconium sol A3.

[0113] Comparative Example 1 for Preparation of Zirconium Sol

[0114] Add 130 g of deionized water to the beaker, then add 125 g of zirconium oxychloride, stir for 10 min, and then slowly add ammonia water to the above solution using a peristaltic pump with the pump speed controlled at 5 ml / min to generate a precipitate suspension with a pH of 1.2 to obtain product D1.

[0115] Comparative Example 2 for Preparation of Zirconium Sol

[0116] 35.38 g of ZrOCl2·8H2O was added to a beaker, and 9.77 g of a 45 wt% sodium hydroxide solution was added according to a molar ratio of Zr to sodium hydroxide of 1:1. The mixture was then stirred at 60°C for 60 min to obtain the first contact product after the reaction. The mixture was then heated at 40°C according to a Zr:H + =1:1.5 ratio, add 19.41g of hydrochloric acid with a concentration of 31% by weight, and then stir at a temperature of 40°C for 60min to obtain a second contact material, and then heat at a temperature of 40°C according to the Zr:H + =1:1.5 ratio, 19.41 g of hydrochloric acid with a concentration of 31 wt % (wt % means weight %) was added to the second contact material, and stirred at 40° C. for 60 min to obtain zirconium sol D2.

[0117] Comparative Example 3 of Zirconium Sol Preparation

[0118] Zirconium sol D1 was prepared according to the preparation method of Comparative Example 1, dried at 120° C. for 12 h, and then calcined at 600° C. for 4 h to obtain zirconium oxide powder D3.

[0119] The properties of the zirconium sols prepared in Examples 1-3 of Zirconium Sol Preparation and Comparative Examples 1-3 of Zirconium Sol Preparation are shown in Table 1.

[0120] Table 1

[0121] Zirconium sol preparation example number 1 2 3 Comparative Example 1 Comparative Example 2 Zirconium sol number A1 A2 A3 D1 D2 <![CDATA[ZrO2, wt%]]> 10.8 11.9 11.3 13.4 16.3 pH 2.5 2.5 2.5 1.2 2.5 Molar ratio of alkali cation to Zr 2 1.67 1.74 0.6 1 Stabilizer to Zr molar ratio 4 4 4 0 0 Average particle size, nm 10 9.8 9.7 Particle size range, nm 8-10 8-10 8-10 Concentration, % 95 93 92 Ratio of monoclinic to tetragonal phase* 0.4:1 0.35:1 0.3:1

[0122] * Sample dried at 100°C for 6 hours and calcined at 600°C for 4 hours. D1 is a suspension.

[0123] Catalyst Preparation Examples 1-5

[0124] The catalytic cracking catalyst was prepared according to the following method. The catalyst formulation is shown in Table 2:

[0125] (1) Preparation of Acidic Silica Sol: 25 g of water glass was diluted with 75 g of water and stirred for 10 min. 5 g of hydrochloric acid was quickly added and stirred for 10 min to obtain a clear, transparent silica sol with a SiO2 content of 5 wt% and a pH of 2.5. This was designated as S1. The silica sol particles were 4 nm in size.

[0126] (2) Catalyst preparation: First, kaolin was beaten to prepare a kaolin slurry with a solid content of 20 wt%. SOY molecular sieve and ZSP-3 molecular sieve were taken and beaten with water separately. The mixture was dispersed with a homogenizer to obtain SOY molecular sieve slurry and ZSP-3 molecular sieve slurry with a solid content of 35 wt%. The kaolin slurry, SOY molecular sieve slurry and ZSP-3 molecular sieve slurry were mixed and stirred, and then acidified boehmite (pseudo-boehmite acidified with hydrochloric acid, with an acid-aluminum ratio (HCl:pseudo-boehmite in terms of Al2O3)) with a solid content of 10 wt% was added. The method comprises the following steps: preparing a first slurry by stirring for 10 minutes; mixing zirconium sol and the acidic silica sol S1 (pH 2.5), adding the mixed solution to the first slurry, and stirring for 30 minutes to obtain a second slurry; spray-drying the second slurry to obtain catalyst microspheres, calcining the obtained catalyst microspheres at 500° C. for 2 hours, and then washing with an ammonium sulfate solution (ammonium sulfate accounting for 6% of the dry weight of the catalyst in each washing) until the sodium oxide in the catalyst is less than 0.2% by weight, to obtain a catalytic cracking catalyst.

[0127] Table 2

[0128] catalyst C1 C2 C3 C4 C5 DB1 DB2 DB3 DB4 DB5 DB6 Kaolin 30 30 30 30 40 40 40 40 40 40 40 SOY-8 30 26 22 25 20 20 20 20 20 20 20 ZSP-3 0 4 8 5 5 5 5 5 5 5 5 Aluminite 20 10 20 10 20 30 25 25 20 20 20 Zirconium sol A1 A2 A3 A1 A2 A2 D1 D2 D3 Zirconium sol 5 10 15 20 5 5 5 5 5 Acidic silica sol 15 10 5 5 5 5 5 5 5 Aluminum sol 10 5 5 5 5 5 5 5 5

[0129] The proportions in Table 2 and Table B2 are in parts by weight, with kaolin and molecular sieves being calculated on a dry basis, zirconium sol as ZrO2, silica sol as SiO2, and aluminum sol and aluminum oxide as Al2O3. D1 is a suspension, and D3 is a powder.

[0130] Catalyst Preparation Comparative Examples 1-6

[0131] A comparative catalyst was prepared according to the method of Catalyst Preparation Example 1. The catalyst formula is shown in Table 2.

[0132] Catalyst evaluation:

[0133] The catalyst was deactivated by aging at 800°C with 100% steam for 15 hours. The catalyst was evaluated on a fixed fluidized bed micro-reactor ACE reactor using a hydro-reformed oil as the feedstock (composition and properties are shown in Table 3). The evaluation conditions were: reaction temperature of 500°C, catalyst-to-oil ratio (weight ratio) of 6, and WHSV of 16h. -1 The results are listed in Table 4.

[0134] Among them, conversion rate = gasoline yield + liquefied gas yield + dry gas yield + coke yield

[0135] Table 3

[0136] project crude oil <![CDATA[Density (20 °C), g / cm 3 > 0.9334 Refractive index (70℃) 1.5061 Four components, m% saturated hydrocarbons 55 Aromatics 30.4 colloid 14.6 Asphaltene <0.1 Freezing point, ℃ 34 Metal content, ppm Ca 3.9 Fe 1.1 Mg 3.3 Na 0.7 Ni 86.88 Pb 11.94 V 0.7 C m% 1.77 H m% 55 S m% 30.4 Residual carbon m% 14.6 H m% 11.94

[0137]

[0138]

[0139] Molecular sieve preparation example 1

[0140] To 100 kg of crushed metakaolin powder, 400 kg of sodium silicate solution (containing 20.05 wt% SiO2 and 6.41 wt% Na2O), 60 kg of a directing agent, and 100 kg of a 5 wt% sodium hydroxide solution were added with stirring. The mixture was heated to 95°C and stirred. After 8 hours, 10 kg of solid silica gel (Type A, from Qingdao Ocean Chemical Group Special Silica Gel Factory) was added. The mixture was then crystallized for 12 hours. The stirring speed during the addition and crystallization was 400 rpm. After completion of the crystallization, the crystallization tank was quenched, filtered, and washed with water until the washing liquid had a pH of less than 10. The mixture was then dried at 120°C for 2 hours to obtain zeolite material Y-1. Y-1 was measured by X-ray diffraction. The crystallinity determined by the peak height method, the K1 value of the ratio of the crystallinity determined by the peak height method to the crystallinity determined by the peak area method, the silicon-aluminum ratio determined by the unit cell constant a0, the K2 value of the ratio of the silicon-aluminum ratio determined by the unit cell constant a0 to the silicon-aluminum ratio determined by the chemical method, and the medium and macroporosity are shown in Table B1.

[0141] Molecular sieve preparation example 2

[0142] According to the method of molecular sieve preparation Example 1, 100 kg of crushed metakaolin powder was stirred and added with 380 kg of sodium silicate solution (containing 20.05% by weight SiO2 and 6.41% by weight Na2O), 60 kg of directing agent, and 100 kg of 5% by weight sodium hydroxide solution. The mixture was heated to 93°C and stirred constantly. After 8 hours, 15 kg of solid silica gel (Type A, from Qingdao Ocean Chemical Group Special Silica Gel Factory) was added and crystallized for 14 hours. The stirring speed during the addition and crystallization was 400 rpm. After crystallization, the crystallization tank was quenched, filtered, and washed with water until the washing liquid had a pH of less than 10. The mixture was dried at 120°C for 2 hours to obtain zeolite material Y-2. Y-2 was measured by X-ray diffraction. The crystallinity determined by the peak height method, the K1 value of the ratio of the crystallinity determined by the peak height method to the crystallinity determined by the peak area method, the silicon-aluminum ratio determined by the unit cell constant a0, the K2 value of the ratio of the silicon-aluminum ratio determined by the unit cell constant a0 to the silicon-aluminum ratio determined by the chemical method, and the medium and macroporosity are shown in Table B1.

[0143] Molecular sieve preparation example 3

[0144] Following the method of Molecular Sieve Preparation Example 1, 100 kg of crushed metakaolin powder was stirred and added with 360 kg of sodium silicate solution (containing 20.05 wt% SiO2 and 6.41 wt% Na2O), 60 kg of a directing agent, and 100 kg of a 5 wt% sodium hydroxide solution. The mixture was heated to 95°C and stirred constantly. After 8 hours, 20 kg of solid silica gel (Type A, from Qingdao Ocean Chemical Group Special Silica Gel Factory) was added. The mixture was then crystallized for 16 hours. The stirring speed during the addition and crystallization was 400 rpm. After completion of the crystallization, the crystallization tank was quenched, filtered, and washed with water until the washing liquid had a pH of less than 10. The mixture was then dried at 120°C for 2 hours to obtain zeolite material Y-3. Y-3 was measured by X-ray diffraction. The crystallinity determined by the peak height method, the K1 value of the ratio of the crystallinity determined by the peak height method to the crystallinity determined by the peak area method, the silicon-aluminum ratio determined by the unit cell constant a0, the K2 value of the ratio of the silicon-aluminum ratio determined by the unit cell constant a0 to the silicon-aluminum ratio determined by the chemical method, and the medium and macroporosity are shown in Table B1.

[0145] Molecular sieve preparation comparative example 1

[0146] This comparative example illustrates the situation where two silicon sources are added to the reaction system at one time.

[0147] According to the method of Molecular Sieve Preparation Example 1, 100 kg of crushed metakaolin powder was stirred with 400 kg of sodium silicate solution (containing 20.05 wt% SiO2 and 6.41 wt% Na2O), 60 kg of a directing agent, 105 kg of a 5 wt% sodium hydroxide solution, and 10 kg of solid silica gel (Type A, from Qingdao Ocean Chemical Group Special Silica Gel Factory). The mixture was heated to 94°C and stirred for 24 hours. The stirring speed during addition and crystallization was 400 rpm. After crystallization, the crystallization tank was quenched, filtered, and washed with water until the washing liquid had a pH of less than 10. The mixture was then dried at 120°C for 2 hours to obtain zeolite material DY-1. DY-1 was measured using X-ray diffraction. The crystallinity measured by the peak height method, the K1 value (the ratio of the crystallinity measured by the peak height method to the crystallinity measured by the peak area method), the silicon-aluminum ratio measured by the unit cell constant a0, the K2 value (the ratio of the silicon-aluminum ratio measured by the unit cell constant a0 to the silicon-aluminum ratio measured by the chemical method), and the macroporosity are shown in Table B1. DY-1 has low crystallinity and contains impurities.

[0148] Molecular sieve preparation comparative example 2

[0149] This comparative example illustrates the case where no second silicon source is added.

[0150] According to the method of Molecular Sieve Preparation Example 1, 100 kg of crushed metakaolin powder was stirred and added with 400 kg of sodium silicate solution (containing 20.05 wt% SiO2 and 6.41 wt% Na2O), 60 kg of directing agent, and 100 kg of 5 wt% sodium hydroxide solution. The mixture was heated to 94°C with constant stirring and crystallization for 24 hours. The stirring speed during addition and crystallization was 400 rpm. After crystallization, the crystallization tank was quenched, filtered, and washed with water until the washing liquid had a pH of less than 10. The mixture was dried at 120°C for 2 hours to obtain zeolite DY-2. X-ray diffraction measurements of DY-2 showed the crystallinity by the peak height method, the K1 value (the ratio of the crystallinity by the peak height method to the crystallinity by the peak area method), the silicon-aluminum ratio determined by the unit cell constant a0, the K2 value (the ratio of the silicon-aluminum ratio determined by the unit cell constant a0 to the silicon-aluminum ratio determined by the chemical method), and the meso-macroporosity, as shown in Table B1. The crystallinity of DY-2 is not bad, but the silicon-aluminum ratio is low.

[0151] Table B1

[0152]

[0153] Catalyst Preparation Example B1

[0154] (1) Preparation of silica sol: 25 g of water glass was diluted with 75 g of water, stirred for 10 min, and 5 g of hydrochloric acid was quickly added and stirred for 10 min to obtain clear and transparent zirconium sol S1.

[0155] (2) Preparation of modified NSY molecular sieve: zeolite material Y-1 was added to deionized water and slurried to obtain a molecular sieve slurry with a solid content of 10 wt%; lanthanum chloride was added to water and slurried to form a lanthanum chloride solution with a La2O3 concentration of 5 wt%; the lanthanum chloride solution was added to the molecular sieve slurry, and the weight ratio of lanthanum chloride (calculated as La2O3) to molecular sieve (calculated on a dry basis) was 1:6; stirred at 70°C for 1 hour, filtered, washed, dried at 150°C for 8 hours, calcined at 500°C for 4 hours, and washed with ammonium sulfate at a dry basis of 10 wt% of the molecular sieve (ammonium sulfate solution concentration of 2 wt%) to reduce the sodium oxide in the molecular sieve to less than 2 wt%, to obtain a modified NSY molecular sieve containing rare earth.

[0156] (3) Catalyst preparation: The catalyst formula is shown in Table B2. First, kaolin is slurried with water to obtain a kaolin slurry with a solid content of 20 wt%. Then, a modified NSY molecular sieve containing rare earth is slurried with water and dispersed with a homogenizer to obtain a modified NSY molecular sieve slurry with a solid content of 35 wt%. The kaolin slurry and the modified NSY molecular sieve slurry are mixed and stirred, and then an acidified aluminum ore with a solid content of 10 wt% is added (wherein the acidified aluminum ore, HCl and aluminum ore calculated as Al2O3 are added). The mixture was stirred for 10 min, and finally a mixture of silica sol S1 and zirconium sol A1 was added and stirred for 30 min to obtain a catalyst slurry. The catalyst slurry was spray-dried, and the obtained catalyst microspheres were calcined at 500°C for 2 hours, and then washed with a 2% by weight ammonium sulfate solution, wherein the weight ratio of the ammonium sulfate solution to the catalyst microspheres on a dry basis was 10:1, the washing temperature was 60°C, the washing time was 30 minutes, and the mixture was dried to obtain a catalytic cracking catalyst BC1.

[0157] Catalyst Preparation Examples B2-B5

[0158] Catalyst Preparation Example 1 was used to prepare the catalyst, and the catalyst formulation is shown in Table B2. ZSP-3 molecular sieve was slurried with water to form a ZSP-3 molecular sieve slurry having a solids content of 35 wt %. This slurry was then mixed with a kaolin slurry and a modified NSY molecular sieve slurry, and then mixed with a mixture of zirconium sol and silica sol.

[0159] Comparative Examples B1-B5 of Catalyst Preparation

[0160] The catalyst was prepared according to the method of Catalyst Preparation Example B1, and the catalyst formula is shown in Table B2.

[0161] Catalyst evaluation:

[0162] The catalyst was deactivated by aging at 800°C with 100% steam for 15 hours. The catalyst was evaluated on a fixed fluidized bed microreactor ACE. The feed oil was a hydro-reformed oil (composition and physical properties are shown in Table 3). The evaluation conditions were: reaction temperature 500°C, catalyst-to-oil ratio (weight) 6, and WHSV = 16h. -1 The results are listed in Table B3.

[0163] Among them, conversion rate = gasoline yield + liquefied gas yield + dry gas yield + coke yield

[0164] Table B2

[0165]

[0166] Table B3

[0167] catalyst BC1 BC2 BC3 BC4 BC5 BDB1 BDB2 BDB3 BDB4 BDB5 active 76 75 77 75 77 70 72 68 67 71 Product distribution / weight % dry gas 1.61 2.07 2.38 2.17 2.42 1.91 1.95 1.48 1.43 1.86 Liquefied gas 14.23 15.19 16.01 15.79 15.41 15.22 15.28 14.31 14.25 15.17 <![CDATA[C5 + Gasoline]]> 52.13 51.06 51.87 50.28 51.92 46.11 47.27 47.76 46.55 47.22 circulating oil 15.61 15.71 14.34 15.84 14.01 19.23 18.71 19.03 19.74 18.03 Oil slurry 9.83 9.73 8.84 9.54 9.91 11.17 10.36 11.01 11.81 11.25 coke 6.59 6.24 6.56 6.38 6.33 6.36 6.43 6.41 6.22 6.47 Conversion rate 74.56 74.56 76.82 74.62 76.08 69.6 70.93 69.96 68.45 70.72 Coke selectivity 8.84 8.37 8.54 8.55 8.32 9.14 9.07 9.16 9.09 9.15 Coke Factor 2.25 2.13 1.98 2.17 1.99 2.78 2.64 2.75 2.87 2.68

[0168] Coke factor (also called coke generation factor) = coke yield × (1-conversion rate) / conversion rate × 100.

[0169] The results in Table B3 show that the catalytic cracking catalyst provided by the present invention further improves the conversion rate and gasoline yield in the catalytic cracking reaction. Compared with Table 4, it can be seen that the use of modified NSY molecular sieves achieves higher gasoline yield, higher conversion rate, and lower coke selectivity.

[0170] The catalyst was impregnated using the Michael method to contaminate heavy metals at 1000 μg / g nickel and 3000 μg / g vanadium. The contaminated catalyst was aged at 780°C in 100% steam for 4 hours and then evaluated on an ACE apparatus using the same reaction conditions as above. The results are shown in Table B4.

[0171] Table B4

[0172]

[0173] As shown in Table B4, compared with the catalyst provided in the comparative example, the cracking catalyst provided by the present invention exhibits stronger heavy oil cracking ability, higher activity, higher conversion rate, and higher gasoline yield after metal contamination, indicating its strong resistance to metal contamination. A comparison with Table 5 shows that when the modified NSY molecular sieve is used, the catalyst exhibits higher gasoline yield and higher conversion rate after metal contamination.

Claims

1. A catalytic cracking catalyst resistant to metal contamination, comprising, based on the dry weight of the catalytic cracking catalyst: 10-70 wt% of a cracking active component, 1-20 wt% of a zirconium oxide binder, 1-20 wt% of a silica sol binder, 0-50% of an alumina-based binder, and 10-70 wt% of clay; The zirconium oxide binder is a zirconium sol, which comprises 0.5 wt%-20 wt% ZrO2, a stabilizer, an alkali cation and water, wherein the molar ratio of the stabilizer to Zr is 1-6, and the pH value of the zirconium sol is 1.5-5; the zirconium sol is dried at 100 ° C for 6 hours and calcined at 600 ° C for 2-6 hours for heat treatment, and the resulting product has monoclinic and tetragonal phases coexisting; and / or the zirconium sol is dried at 100 ° C for 6 hours and calcined at 800 ° C for 2-6 hours for heat treatment, and the ZrO2 in the resulting product exists in the tetragonal phase; the alkali cation is an ammonium ion or a nitrogen-containing cation formed by hydrolysis of a water-soluble organic base, and in the zirconium sol, the molar ratio of the alkali cation to Zr is 1-8; the stabilizer is one or more of glycolic acid, oxalic acid, acetic acid, malonic acid, malic acid, tartaric acid, succinic acid, adipic acid, maleic acid, itaconic acid, and citric acid; The pH value of the silica sol is 1.5-3.5, and the size of the silica sol particles is 2nm-20nm; the content of SiO2 in the silica sol is 5wt%-15wt%.

2. The catalytic cracking catalyst according to claim 1, characterized in that The zirconium sol includes 5-15 wt % of ZrO 2 .

3. The catalytic cracking catalyst according to claim 1, characterized in that The zirconium sol particles have a size between 5nm and 15nm, an average particle size of 10±2nm, and a concentration of more than 90%.

4. The catalytic cracking catalyst according to claim 1, characterized in that The zirconium sol is dried at 100° C. for 6 hours and calcined at 600° C. for 2-6 hours for heat treatment. The obtained product has coexistence of monoclinic phase and tetragonal phase, and the ratio of monoclinic phase to tetragonal phase is 0.05-0.6:

1.

5. The catalytic cracking catalyst according to claim 1, characterized in that In the zirconium sol, the water-soluble organic base is one or more of methylamine, dimethylamine, trimethylamine, methanolamine, dimethanolamine, trimethanolamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, monomethyltriethylammonium hydroxide, monomethyltriethanolammonium hydroxide, and monomethyltributylammonium hydroxide.

6. The catalytic cracking catalyst according to claim 1, characterized in that In the zirconium sol, the molar ratio of the alkali cation to Zr is 1-2.

7. The catalytic cracking catalyst according to claim 1, characterized in that The zirconium sol further contains inorganic acid radicals and / or alcohols, and the molar ratio of the inorganic acid radicals and / or alcohols to Zr is 1-6; the inorganic acid radicals are one or more of sulfate, chloride, and nitrate; and the alcohol is one or more of methanol, ethanol, propanol, and butanol.

8. The catalytic cracking catalyst according to claim 1, characterized in that The pH value of the zirconium sol is 2-3.

9. The catalytic cracking catalyst according to claim 1, characterized in that The silica sol is prepared by a water glass direct acidification method, and the pH value of the silica sol is 1.5-3.

10. The catalytic cracking catalyst according to claim 1, characterized in that The alumina binder is one or more of aluminum sol, acidified aluminum stone, phosphorus and / or metal-modified aluminum stone.

11. The catalytic cracking catalyst according to claim 1, characterized in that The cracking active component includes 70% to 100% by weight of a Y-type molecular sieve and 0-30% by weight of a second molecular sieve; the unit cell constant of the Y-type molecular sieve is 2.430 nm to 2.480 nm, and the rare earth content calculated as RE2O3 is 0-20% by weight; the second molecular sieve is a molecular sieve having a five-membered ring structure; and the clay is one or more of kaolin, montmorillonite, diatomaceous earth, halloysite, pseudo-halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite and bentonite.

12. The catalytic cracking catalyst according to claim 11, characterized in that The Y-type molecular sieve is a modified NSY-type molecular sieve obtained by modifying the NSY molecular sieve synthesized by in-situ crystallization of kaolin, and its sodium oxide content is less than 2% by weight. The modification treatment includes ultrastabilization treatment and / or ion exchange treatment.

13. The catalytic cracking catalyst according to claim 12, wherein: The NSY molecular sieve synthesized by in-situ crystallization of kaolin is measured by X-ray diffraction method, and the crystallinity measured by the peak height method is ≥60%, and the ratio of the crystallinity to the peak area method is K1, K1=0.76-0.89; the silicon-aluminum ratio measured by the unit cell constant a0 is 5.0-5.5, and the ratio to the silicon-aluminum ratio measured by the chemical method is K2, K2=0.87-0.93, and the silicon-aluminum ratio is the molar ratio of silicon oxide to aluminum oxide.

14. The catalytic cracking catalyst according to claim 13, wherein The crystallinity determined by the peak height method is ≥80%.

15. The catalytic cracking catalyst according to claim 13, wherein The NSY molecular sieve synthesized by in-situ crystallization of kaolin has K1=0.77-0.88 and K2=0.87-0.

91.

16. The catalytic cracking catalyst according to claim 13, wherein The large mesopore ratio of the NSY molecular sieve synthesized by in-situ crystallization of kaolin is 10-20%.

17. The catalytic cracking catalyst according to claim 13, wherein The NSY molecular sieve synthesized by in-situ crystallization of kaolin has a silicon-aluminum ratio of 5.2-5.5 as measured by the unit cell constant a0.

18. The catalytic cracking catalyst according to claim 13, wherein In the preparation process of the catalytic cracking catalyst, the zirconium oxide binder and the silica sol binder are first mixed, and then mixed with the cracking active component, clay and alumina-based binder.

19. The catalytic cracking catalyst according to claim 13, wherein The modified NSY molecular sieve contains rare earth, and the rare earth content of the modified NSY molecular sieve is 10% by weight to 20% by weight calculated as RE2O3.

20. A method for preparing the catalytic cracking catalyst according to any one of claims 1 to 19, comprising: forming a mixture of zirconium sol and silica sol; forming a slurry of the mixture of zirconium sol and silica sol, a cracking active component, clay and an optional alumina binder; Spray drying; the cracking active component includes a Y-type molecular sieve and an optional second molecular sieve.

21. The method for preparing a catalytic cracking catalyst according to claim 20, characterized in that: The following steps are involved: (s1) mixing zirconium sol and silica sol, and controlling the pH value of the mixture to be 2.5-3.5; (s2) preparing clay slurry; (s3) preparing a molecular sieve slurry; (s4) mixing the clay slurry, the molecular sieve slurry, the mixture obtained in step (s1), and an alumina binder; (s5) The slurry obtained in step (s4) is uniformly dispersed and spray-dried.

22. The method for preparing a catalytic cracking catalyst according to claim 20 or 21, characterized in that: The preparation method of the zirconium sol comprises the following steps: (1) preparing a zirconium source solution, wherein the concentration of the zirconium source solution is 0.5 wt % to 20 wt % based on ZrO 2 ; (2) adding a stabilizer to the zirconium source solution and stirring at room temperature to 90° C. for 0.5-3 hours to obtain a first mixed solution; wherein the molar ratio of the stabilizer to the zirconium is 1-6; (3) adding alkali solution to the first mixed solution at room temperature to 50° C. to obtain zirconium sol, wherein the amount of alkali solution is such that the pH value of the zirconium sol is 1-7.

23. The method for preparing a catalytic cracking catalyst according to claim 22, characterized in that: In the zirconium sol preparation method, alkali solution is slowly added to the first mixed solution to obtain a clear and transparent zirconium sol; the slow addition is dropwise addition or the alkali solution addition rate is controlled to be 0.05 ml-50 ml alkali solution / minute / L of the first mixed solution; the amount of alkali solution added is such that the pH value of the zirconium sol is 1.5-5.

24. The method for preparing a catalytic cracking catalyst according to claim 22, characterized in that: The zirconium source is one or more of an inorganic zirconium salt or an organic zirconium salt. The inorganic zirconium salt is one or more of zirconium tetrachloride, zirconium oxychloride, zirconium acetate, zirconium nitrate, zirconium oxynitrate, zirconium oxysulfate and zirconium oxycarbonate. The organic zirconium salt is one or more of zirconium n-propoxide, zirconium isopropoxide, zirconium ethanol and zirconium butoxide.

25. The method for preparing a catalytic cracking catalyst according to claim 22, wherein: The stabilizer is one or more of glycolic acid, acetic acid, oxalic acid, malonic acid, malic acid, tartaric acid, succinic acid, adipic acid, maleic acid, itaconic acid, and citric acid.

26. The method for preparing a catalytic cracking catalyst according to claim 22, wherein: The alkali solution is selected from ammonia water or an aqueous solution of a water-soluble organic base, and the water-soluble organic base is one or more of methylamine, dimethylamine, trimethylamine, methanolamine, dimethanolamine, trimethanolamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, monomethyltriethylammonium hydroxide, monomethyltriethanolammonium hydroxide, and monomethyltributylammonium hydroxide.

27. The method for preparing a catalytic cracking catalyst according to claim 20, wherein: The Y-type molecular sieve includes a modified NSY molecular sieve, and the preparation method of the modified NSY molecular sieve includes the following steps: (1) calcining and dehydrating kaolin at 500-900°C to convert it into metakaolin, which is then crushed to produce metakaolin powder with a particle size of less than 10 microns; (2) adding sodium silicate, a directing agent, a sodium hydroxide solution and water to metakaolin powder to prepare a reaction raw material A having a molar ratio of (1-2.5) Na2O:Al2O3:(4-9)SiO2:(40-100)H2O, wherein the weight ratio of the directing agent to the metakaolin is 0.01-1.0; (3) crystallizing the reaction material A at 88-98° C. under stirring, and adding a second silicon source after the crystallization time reaches 1-70 hours to obtain the reaction material B, wherein the second silicon source accounts for 0.1% to 10% by weight of the total silicon feed, calculated as silicon oxide; (4) crystallizing the reaction material B at 88-98°C under stirring and recovering the product to obtain NSY molecular sieve synthesized by in-situ crystallization of kaolin; (5) recovering the NSY molecular sieve synthesized by in-situ crystallization of the kaolin and subjecting it to ion exchange and / or ultra-stabilization treatment.

28. The method for preparing a catalytic cracking catalyst according to claim 27, wherein: The molar composition of the directing agent is: (10-17) SiO2: (0.7-1.3) Al2O3: (11-18) Na2O: (200-350) H2O.

29. The method for preparing a catalytic cracking catalyst according to claim 27, wherein: The sodium content of the second silicon source is less than 1% by weight as Na2O, all calculated as silicon oxide, and the second silicon source accounts for 4-10% by weight of the total silicon feed.

30. The method for preparing a catalytic cracking catalyst according to claim 27 or 29, wherein: In the preparation method of the modified NSY molecular sieve, the second silicon source is solid silica gel and / or liquid silica gel; wherein, the average pore diameter of the solid silica gel is 1.5-2.0 nm, or the average pore diameter of the solid silica gel is 4.0-5.0 nm, or the average pore diameter of the solid silica gel is above 10.0 nm, or the average pore diameter of the solid silica gel is below 0.8 nm, and the weight content of SiO2 in the liquid silica gel is 1-30%.

31. The method for preparing a catalytic cracking catalyst according to claim 27, wherein: The ion exchange in step (5) is ammonium ion exchange and / or rare earth ion exchange.

32. The method for preparing a catalytic cracking catalyst according to claim 27 or 31, wherein: The ion exchange includes rare earth ion exchange. The rare earth content in the modified NSY molecular sieve obtained in step (5) is 10% to 20% by weight in terms of RE2O3, and the sodium oxide content is less than 2% by weight.

33. The method for preparing a catalytic cracking catalyst according to claim 22, wherein: The concentration of the zirconium source solution is 5-15% by weight calculated as ZrO2.

34. The method for preparing a catalytic cracking catalyst according to claim 23, wherein: The amount of alkali solution added is such that the pH value of the zirconium sol is 2-3.

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