Anti-vanadium poisoning catalytic cracking catalyst and preparation method therefor and use thereof

Abstract

The present invention belongs to the technical field of catalytic cracking, and relates to an anti-vanadium poisoning catalytic cracking catalyst and a preparation method therefor and the use thereof. The catalytic cracking catalyst comprises a rare earth metal-modified molecular sieve and a matrix material. The matrix material comprises a modified metal oxide and a silicon- and / or aluminum-containing material. The ratio of the concentration of the rare earth metal on the outer surface of the rare earth metal-modified molecular sieve to the average concentration of the rare earth metal of the rare earth metal-modified molecular sieve is 1.3-4.5. The ratio of the concentration of the modified metal oxide on the outer surface of the catalytic cracking catalyst to the average concentration of the modified metal oxide of the catalytic cracking catalyst is 1.3-4.5. The modified metal in the modified metal oxide is selected from at least one of an alkaline earth metal and a rare earth metal. The anti-vanadium poisoning catalytic cracking catalyst of the present invention has a good resistance to heavy metal vanadium contamination and when used in a catalytic cracking process of a high-vanadium raw oil, achieves a high conversion rate of the raw oil and a higher yield of low-carbon olefins.

Description

A vanadium-poisoning-resistant catalytic cracking catalyst, its preparation method and application Technical Field

[0001] This invention relates to a vanadium-resistant catalytic cracking catalyst, its preparation method, and its application. Background Technology

[0002] As domestic refined oil consumption enters a stable period, the supply-side structure of the refining industry faces adjustment, with "oil conversion" becoming an important direction for product structure adjustment. In 2019, China's dependence on imported crude oil exceeded 70%, surpassing the national energy security red line. Some imported crude oils have high vanadium content; in catalytic cracking units, after blending a certain proportion of high-vanadium oil residue, the yield of dienes decreases significantly, while the coke yield increases, and catalyst consumption increases significantly.

[0003] Existing technologies for vanadium-resistant catalysts generally involve adding a vanadium-resistant matrix during the molding process, designing a metal coating on the support, or preparing vanadium-resistant additives. All of these methods exhibit some resistance to heavy metals. CN1223403C discloses a novel matrix-type heavy metal-resistant FCC catalyst and its preparation method. This catalyst contains 20-80 m% clay, 5-40 m% binder, 1-25 m% metal trapping components (such as rare earth oxalate), 0-30 m% other oxides (such as activated alumina), and 5-40 m% of octahedral zeolite, ZSM-5 zeolite, β-zeolite, or mixtures thereof, with a cell constant of 2.432-2.472 nm. This catalyst exhibits excellent heavy metal resistance and is suitable as a catalyst for cracking heavy oils with high V and other content.

[0004] However, existing vanadium-resistant technologies mainly revolve around catalytic cracking, while catalytic cracking processes are more demanding than catalytic cracking, requiring the production of more ethylene and propylene. Existing vanadium-resistant technologies cannot effectively solve the problem of vanadium poisoning in catalytic cracking catalysts, and currently there are no catalysts with good vanadium resistance developed for catalytic cracking. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a vanadium-resistant catalytic cracking catalyst, its preparation method and application. The vanadium-resistant catalytic cracking catalyst has good resistance to heavy metal vanadium pollution and achieves high ethylene and propylene yields when used in the catalytic cracking process of high vanadium feedstock oil.

[0006] Therefore, this application provides a catalytic cracking catalyst comprising a rare earth metal modified molecular sieve and a matrix material, wherein the matrix material includes modified metal oxides and silicon and / or aluminum-containing materials, wherein the ratio of the rare earth metal concentration on the outer surface of the rare earth metal modified molecular sieve to the average rare earth metal concentration of the rare earth metal modified molecular sieve is 1.3 to 4.5; the ratio of the modified metal oxide concentration on the outer surface of the catalytic cracking catalyst to the average modified metal oxide concentration of the catalytic cracking catalyst is 1.3 to 4.5, and the modified metal in the modified metal oxide is selected from at least one of alkaline earth metals and rare earth metals.

[0007] The present invention also provides a method for preparing the vanadium poisoning-resistant catalytic cracking catalyst, comprising the following steps:

[0008] S1. Mix molecular sieve with water to obtain slurry A, and filter to obtain filter cake A;

[0009] S2. Contact filter cake A with an alkaline solution and filter to obtain filter cake B;

[0010] S3. Rare earth metal modified molecular sieves are obtained by modifying filter cake B with rare earth metal salt solution A.

[0011] S4. Mix rare earth metal modified molecular sieves, silicon- and / or aluminum-containing materials with water to obtain slurry B, and dry to obtain particles A;

[0012] S6. Mix particles A with water to obtain slurry C, and filter to obtain filter cake C;

[0013] S7. Contact filter cake C with alkaline solution and filter to obtain filter cake D;

[0014] S8. The filter cake D is modified using a modified metal salt solution B to obtain the catalytic cracking catalyst.

[0015] The modified metal is selected from at least one of alkaline earth metals and rare earth metals.

[0016] Compared with the prior art, the catalytic cracking catalyst provided by the present invention has one or more of the following beneficial effects, preferably all of them:

[0017] 1. The vanadium-poisoning-resistant catalytic cracking catalyst of the present invention employs rare earth metals on the outer surface of the molecular sieve and modified metals on the outer surface of the catalyst material. These rare earth metals can form stable compounds with vanadium on the outer surfaces of the molecular sieve and catalyst, greatly inhibiting the corrosive effect of vanadium on the molecular sieve. This multi-layered synergistic protection of the active centers of the molecular sieve improves the conversion capacity of heavy oil and increases the yield of ethylene and propylene. Preferably, it exhibits higher conversion rates and / or higher liquefied petroleum gas (LPG) yields.

[0018] 2. The vanadium poisoning-resistant catalytic cracking catalyst of the present invention adopts a method of precise precipitation of rare earth elements on the outer surface of molecular sieve. The content of rare earth elements precipitated on the outer surface of molecular sieve is relatively high. In preferred cases, it can form a stable compound with vanadium on the outer surface, which greatly inhibits the erosion effect of vanadium on molecular sieve, protects the active center of molecular sieve, and improves the conversion capacity of heavy oil and the yield of ethylene and propylene.

[0019] 3. In the preferred embodiment, the matrix material of the vanadium poisoning catalytic cracking catalyst of the present invention uses silica sol, which can increase a portion of silicon dioxide in the matrix, weaken the corrosive effect of vanadium acid on the catalyst, thereby playing an anti-vanadium role and effectively inhibiting the corrosion of the catalyst by vanadium acid.

[0020] 4. The method for preparing a vanadium-poisoning-resistant catalytic cracking catalyst provided by this invention can yield a catalyst containing rare earth elements on the outer surface of a molecular sieve and alkaline earth metals or rare earth metals on the outer surface of catalyst particles. By separately placing the outer surfaces of the catalyst and the molecular sieve in an alkaline environment and then adding rare earth elements, the rare earth elements are directly and uniformly precipitated on the surfaces of the catalyst and the molecular sieve, avoiding direct precipitation of rare earth elements in the alkaline liquid. This allows the rare earth elements on the outer surfaces of the catalyst and the molecular sieve to form stable compounds with vanadium. Furthermore, the prepared catalyst can reduce the formation of large-particle rare earth oxides and alkaline earth metal oxides, resulting in more metal oxides on the surface, which is beneficial for forming stable compounds with vanadium on the outer surface. The prepared catalyst exhibits better propylene and ethylene yields in heavy oil cracking and improves liquefied gas yield.

[0021] 5. The preparation method of the vanadium-resistant catalytic cracking catalyst provided by this invention is particularly suitable for the industrial preparation of catalytic cracking catalysts. The method can be implemented with only minor modifications to the existing industrial preparation process for catalytic cracking catalysts, without requiring major alterations to the existing preparation procedures.

[0022] 6. The catalytic cracking catalyst provided by the present invention is particularly suitable for the catalytic cracking of vanadium-containing heavy oil to produce low-carbon olefins. Detailed Implementation

[0023] The present application will be further described in detail below through embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0024] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0025] Any specific numerical values ​​disclosed herein (including the endpoints of numerical ranges) are not limited to their exact values, but should be understood to also include values ​​close to the exact value, such as all possible values ​​within ±5% of the exact value. Furthermore, with respect to the disclosed numerical ranges, one or more new numerical ranges can be obtained by arbitrarily combining the endpoint values ​​of the range, the endpoint values ​​with specific point values ​​within the range, and the specific point values ​​themselves; these new numerical ranges should also be considered as specifically disclosed herein.

[0026] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0027] Although the terms first, second, third, etc., may be used herein to describe various steps, elements, components, regions, layers, and / or sections, these steps, elements, components, regions, layers, and / or sections should not be limited by these terms unless otherwise specified. These terms may be used only to distinguish one step, element, component, region, layer, or section from another. Unless clearly indicated by the context, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first step, element, component, region, layer, or section discussed below may be referred to as the second step, element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0028] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a," "an," and "the" as used herein are intended to include the plural forms as well. The terms "comprising," "including," "containing," and "having" are inclusive and thus describe the presence of the stated features, elements, compositions, steps, integers, operations, and / or components, but do not exclude the presence or inclusion of one or more other features, integers, steps, operations, elements, components, and / or sets thereof. Although the open-ended term "comprising" should be understood as a non-limiting term used to describe and claim the various embodiments described herein, in some respects it may instead be understood as a more restrictive and limiting term, such as "consisting of" or "essentially composed of." Thus, for any given embodiment describing a composition, material, component, element, feature, integer, operation, and / or process step, this disclosure also particularly includes embodiments consisting of or substantially consisting of such compositions, materials, components, elements, features, integers, operations, and / or process steps. In the case of "consisting of," the alternative embodiments exclude any additional compositions, materials, components, elements, features, integers, operations, and / or process steps. In the case of "essentially composed of," any additional compositions, materials, components, elements, features, integers, operations, and / or process steps that substantially affect the essential and novel characteristics are excluded from such embodiments. However, any compositions, materials, components, elements, features, integers, operations, and / or process steps that do not substantially affect the essential and novel characteristics may be included in the embodiments.

[0029] Any methods, procedures, and operations described herein should not be construed as necessarily requiring them to be performed in the specific order discussed or shown, unless explicitly stated otherwise. It should also be understood that additional or alternative steps may be used unless otherwise stated.

[0030] The above description of the embodiments is provided for illustration and description purposes. It is not intended to be exhaustive or limiting of this disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable and applicable to the selected embodiment where applicable, even if not explicitly shown or described. It can also be changed in many ways. Such changes should not be considered as departing from this disclosure, and all such modifications are intended to be included within the scope of this disclosure.

[0031] In this application, except where expressly stated, any matters or issues not mentioned herein shall be directly applicable to those known in the art without any modification. Furthermore, any implementation described herein may be freely combined with one or more other implementations described herein, and the resulting technical solutions or concepts shall be considered part of the original disclosure or original record of this application, and should not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art consider the combination to be clearly unreasonable.

[0032] Unless otherwise stated, the terms used herein have the same meaning as commonly understood by those skilled in the art, and if a term is defined herein and its definition differs from the common understanding in the art, the definition herein shall prevail.

[0033] First aspect

[0034] A first aspect of the present invention provides a catalytic cracking catalyst comprising a rare earth metal modified molecular sieve and a matrix material, the matrix material comprising modified metal oxides and silicon and / or aluminum-containing materials, wherein the ratio of the rare earth metal concentration on the outer surface of the rare earth metal modified molecular sieve to the average rare earth metal concentration of the rare earth metal modified molecular sieve is 1.3 to 4.5; the ratio of the modified metal oxide concentration on the outer surface of the catalytic cracking catalyst to the average modified metal oxide concentration of the catalytic cracking catalyst is 1.3 to 4.5, and the modified metal in the modified metal oxide is selected from at least one of alkaline earth metals and rare earth metals.

[0035] In some advantageous aspects of the invention, the rare earth metal concentration on the outer surface of the rare earth metal modified molecular sieve is higher than the average rare earth metal concentration of the rare earth metal modified molecular sieve. In the context of this invention, the rare earth metal concentration on the outer surface of the rare earth metal modified molecular sieve refers to the rare earth metal concentration within a 5 nm range on the molecular sieve surface. In the context of this invention, the average rare earth metal concentration of the rare earth metal modified molecular sieve is the overall rare earth metal concentration of the rare earth metal modified molecular sieve. This means that the modified rare earth metals are enriched on the outer surface of the molecular sieve. The ratio of the rare earth metal concentration on the outer surface of the rare earth metal modified molecular sieve to the average rare earth metal concentration of the rare earth metal modified molecular sieve is, for example, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, and any two of these values, preferably 1.35 to 3.5, more preferably 1.4 to 2.5.

[0036] In some advantageous embodiments of the invention, the concentration of modified metal oxides on the outer surface of the catalytic cracking catalyst is higher than the average concentration of modified metal oxides on the catalytic cracking catalyst. In the context of this invention, the concentration of modified metal oxides on the outer surface of the catalytic cracking catalyst refers to the concentration of modified metals within a 5 nm range on the surface of the catalytic cracking catalyst. In the context of this invention, the average concentration of modified metal oxides on the catalytic cracking catalyst is the same as the overall concentration of modified metal oxides on the catalytic cracking catalyst. This means that modified metal oxides are enriched on the outer surface of the catalytic cracking catalyst.

[0037] According to the present invention, the rare earth elements in the rare earth metal modified molecular sieve may include exchangeable rare earth elements and non-exchangeable rare earth elements (or precipitated rare earth elements, modified rare earth elements). Exchangeable rare earth elements are well known in the art and will not be described in detail here. Exchangeable rare earth elements are introduced into the molecular sieve, for example, through ion exchange. In one embodiment, the exchangeable rare earth elements in the rare earth metal modified molecular sieve are 0-3 wt% of the rare earth metal modified molecular sieve, and the precipitated rare earth elements are 0.5-8 wt%, for example, 1-5 wt%. The content of rare earth elements is calculated as RE₂O₃. RE represents rare earth elements.

[0038] The ratio of the concentration of modified rare earth metals on the outer surface of the rare earth metal modified molecular sieve to the average concentration of modified rare earth metals in the rare earth metal modified molecular sieve is, for example, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, and any two of these values, preferably 1.35 to 3.5, more preferably 1.4 to 2.5. The surface rare earth element content is measured by XPS and is the concentration of rare earth metal elements in the region within 5 nm of the surface of the molecular sieve particles; the total precipitated rare earth element content is the content or concentration of precipitated rare earth metal elements (e.g., rare earth introduced by rinsing) in the whole rare earth metal modified molecular sieve, which can be measured by chemical method or XRF method.

[0039] In some advantageous embodiments of the invention, the content of the rare earth metal modified molecular sieve in the catalytic cracking catalyst is 20-60 wt%, based on the dry weight of the catalytic cracking catalyst, for example, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, and any two of these values, preferably 25-50 wt%. In some advantageous embodiments of the invention, the content of the modified metal oxide is 0.1-8 wt%, based on the dry weight of the catalytic cracking catalyst, for example, 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, and any two of these values. In some advantageous embodiments of the invention, when the modified metal is an alkaline earth metal, the content of the alkaline earth metal oxide, based on the dry weight of the catalytic cracking catalyst, is 0.1-5 wt%, for example, 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, and any two of these values. The content of the alkaline earth metal oxide in the catalyst is preferably 0.5-5 wt%, for example, 2-5 wt%. The alkaline earth metal oxide is, for example, an alkaline earth metal oxide introduced by a leaching method. The alkaline earth metal content on the outer surface of the catalyst is obtained by measuring the concentration of alkaline earth metal elements within 5 nm of the outer surface of the catalyst particles using XPS. The total alkaline earth metal element content of the catalyst is measured by a chemical method or XRF method. The total alkaline earth metal element content is, for example, an alkaline earth metal element introduced by a leaching method.

[0040] In some advantageous embodiments of the invention, when the modified metal is a rare earth metal, the content of the rare earth metal oxide, calculated as RE2O3, is 0.5-8 wt% based on the dry weight of the catalytic cracking catalyst, for example, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, and any two of these values. The modified metal constitutes the first barrier against vanadium poisoning in the catalytic cracking catalyst, combining with vanadium during the catalytic cracking of vanadium-containing heavy oil to form high-melting-point compounds, which helps to suppress the erosion of the catalyst interior by vanadium.

[0041] In some advantageous embodiments of the invention, the silicon and / or aluminum content is 35-80 wt% based on the dry weight of the catalytic cracking catalyst, for example, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, and any two of these values, preferably 45-75 wt%.

[0042] In the context of this invention, rare earth metals include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Hf), and yttrium (Y).

[0043] In some advantageous embodiments of the invention, the content of modified rare earth metal oxides in the rare earth metal modified molecular sieve, calculated as RE2O3, accounts for 0.5-8 wt% of the total weight of the rare earth metal modified molecular sieve, for example, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, and any two of these values. The modified rare earth metals in the molecular sieve constitute a second barrier against vanadium poisoning in the catalytic cracking catalyst. During the catalytic cracking of vanadium-containing heavy oil, they combine with vanadium to form high-melting-point compounds, which helps to inhibit the erosion of the active sites inside the molecular sieve by vanadium.

[0044] In some advantageous embodiments of the invention, the modified rare earth metal element in the rare earth metal modified molecular sieve includes one or more of cerium, lanthanum, or yttrium. Cerium is most preferably used as the modified rare earth metal element. High-valence vanadium has a low melting point and is more mobile at high temperatures, making it more likely to attack the active sites of the catalyst, resulting in a stronger poisoning effect. In addition to forming high-melting-point rare earth vanadate salts with vanadate like other rare earths, cerium also lowers the valence state of vanadium through valence changes, increasing the content of low-valence vanadium oxides, reducing the mobility of vanadium at high temperatures, and further improving vanadium resistance.

[0045] In some advantageous embodiments of the present invention, the molecular sieve in the rare earth metal modified molecular sieve includes Y-type molecular sieves and ZSM-5 type molecular sieves. Y-type molecular sieves and ZSM-5 type molecular sieves are well known in the art. The Y-type molecular sieves and ZSM-5 type molecular sieves before rare earth metal modification may themselves contain rare earth metals. These rare earth metals are mostly present in the framework of the molecular sieve and are not included in the calculation of modified rare earth metal oxides. In the vanadium poisoning catalytic cracking catalyst according to the present invention, the molecular sieve can be a commonly used molecular sieve in catalytic cracking catalysts. For example, the Y-type molecular sieve can be an ultrastable Y-type molecular sieve, a hydrogen-type ultrastable Y-type molecular sieve, and / or an ultrastable Y-type molecular sieve containing exchangeable rare earth elements. The ultrastable Y-type molecular sieve can be one or more of DASY molecular sieve (hydrothermal ultrastable Y-type molecular sieve) and USY molecular sieve (gas-phase ultrastable Y-type molecular sieve); the ZSM-5 molecular sieve can be a hydrogen-type ZSM-5 molecular sieve and / or a phosphorus-containing ZSM-5 molecular sieve (phosphorus-modified ZSM-5 molecular sieve).

[0046] In some advantageous embodiments of the invention, the weight ratio of the Y-type molecular sieve to the ZSM-5 type molecular sieve is 0.5:1 to 3:1, for example 1:1, 1.5:1, 2:1, 2.5:1 and 3:1 and any two of these values, preferably 1:1 to 2:1.

[0047] In some advantageous embodiments of the present invention, the alkaline earth metal in the modified metal oxide of the matrix material of the catalytic cracking catalyst is selected from one or more of magnesium, barium, and strontium. In some advantageous embodiments of the present invention, the rare earth metal in the modified metal oxide of the matrix material of the catalytic cracking catalyst is selected from one or more of cerium, lanthanum, and yttrium.

[0048] In some advantageous embodiments of the invention, the matrix material, comprising silicon and / or aluminum, is derived, for example, from one or more of kaolin, alumina support, silica support, and silica-alumina support. The alumina support is not particularly limited, but is preferably selected from one or more of alumina sol, boehmite, gibbsite, hydrated alumina, and activated alumina. The boehmite is, for example, acidified boehmite. The silica support is not particularly limited, including but not limited to solid silica gel, silica gel, silica sol, tetraethyl orthosilicate, silica, etc., preferably silica sol, which includes, for example, one or more of neutral silica sol, acidic silica sol, or alkaline silica sol. The silica-alumina support is, for example, one or more of mesoporous aluminosilicate materials, aluminosilicate gels, aluminosilicate sols, and solid aluminosilicate materials having a boehmite structure. In some advantageous embodiments of the invention, the catalytic cracking catalyst comprises 0-35 wt% of a silica support, such as 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, and any two of these values, preferably 0-35 wt% of silica sol, such as 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, and any two of these values. Surprisingly, a significant amount of silica support has been found to help prevent vanadium from penetrating into the molecular sieve, which is beneficial for the high diene yield and long-term operation of the catalytic cracking catalyst of the present invention.

[0049] In some advantageous embodiments of the invention, the catalytic cracking catalyst comprises 25-50 wt% molecular sieve, 5-30 wt% boehmite, 3-20 wt% aluminum sol, 10-35 wt% silica sol, 10-40 wt% kaolin and 0.1-5 wt% modified metal oxide.

[0050] Second aspect

[0051] A second aspect of the present invention provides a method for preparing a catalytic cracking catalyst, comprising the following steps:

[0052] S1. Mix molecular sieve with water to obtain slurry A, and filter to obtain filter cake A;

[0053] S2. Contact the filter cake with an alkaline solution (called the first alkaline solution) and filter to obtain filter cake B;

[0054] S3. Rare earth metal modified molecular sieves are obtained by modifying filter cake B with rare earth metal salt solution A.

[0055] S4. Mix rare earth metal modified molecular sieves, silicon- and / or aluminum-containing materials with water to obtain slurry B, and dry to obtain particles A;

[0056] S6. Mix particles A with water to obtain slurry C, and filter to obtain filter cake C;

[0057] S7. Contact the filter cake with an alkaline solution (called the second alkaline solution) and filter to obtain filter cake D;

[0058] S8. The filter cake D is modified using a modified metal salt solution B to obtain the catalytic cracking catalyst.

[0059] The modified metal is selected from at least one of alkaline earth metals and rare earth metals.

[0060] According to some preferred embodiments of the present invention, in step S1 of the method for preparing the catalytic cracking catalyst, the molecular sieve includes a Y-type molecular sieve and a ZSM-5 type molecular sieve. In some preferred embodiments of the present invention, the mass ratio of the Y-type molecular sieve to the ZSM-5 type molecular sieve is 0.5:1-3:1, for example 1:1, 1.5:1, 2:1, 2.5:1, and 3:1, and any two of these values, preferably 1:1-2:1. The mixing ratio of the molecular sieve and water in step S1 is not particularly limited, as long as sufficient mixing is achieved to obtain a slurry. The weight ratio of the molecular sieve to water is, for example, 1:2-10, or 1:2-5. The filtration in step S1 is, for example, vacuum filtration, or suction filtration.

[0061] According to the method for preparing the vanadium poisoning-resistant catalytic cracking catalyst of the present invention, in steps S1, S2, S3, S6, S7, and S8, the filtration is preferably suction filtration (i.e., vacuum filtration). Typically, filtration is performed simultaneously with rinsing to allow the rinsing liquid to pass through the filter cake. After rinsing, filtration continues until no liquid drips from the filter cake. Using suction filtration helps minimize the contact time between the solid and liquid, avoiding prolonged soaking that could lead to structural damage to the molecular sieve and catalyst, and the dissolution of active ingredients.

[0062] According to some embodiments of the present invention, in step S2 of the method for preparing the catalytic cracking catalyst, the alkaline solution (referred to as the first alkaline solution) is an ammonia solution and / or an ammonium carbonate solution. The pH of the alkaline solution is 8-10, for example 8-9 or 9-10; the weight ratio of the alkaline solution (first alkaline solution) to the filter cake A on a dry basis is 0.5:1-3:1, for example 1:1, 1.5:1, 2:1, 2.5:1, and 3:1, and any two of these values. The filtration in step S2 is, for example, vacuum filtration, or suction filtration. The contact in step S2 is preferably a washing of the filter cake A with the alkaline solution.

[0063] According to some embodiments of the present invention, in step S3 of the method for preparing a catalytic cracking catalyst, the concentration of the rare earth metal salt in the rare earth metal salt solution A is 10-30 wt%, for example, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, and any two of these values. The rare earth salt is, for example, a rare earth chloride salt or a rare earth nitrate.

[0064] Preferably, in step S3, the modification includes rinsing the filter cake A with a rare earth metal salt solution (referred to as a second rinsing), drying, and calcining. The rinsing, drying, and calcining can be performed in a manner well known to those skilled in the art. There are no particular limitations on the drying method, as long as it substantially removes the moisture from the filter cake A. For example, the drying temperature is 100-150°C, and the drying time is 2-12 hours; the calcining temperature is 400-600°C, and the calcining time is 1-6 hours. There are no special requirements for the calcining atmosphere, such as air or an oxygen-containing gas atmosphere. Filtration can be performed between the rinsing and drying in step S3, such as vacuum filtration or suction filtration.

[0065] The rare earth metals introduced in step S3 (also known as leached rare earths, precipitated rare earths, or modified rare earths) constitute 0.5-8% of the dry weight of the molecular sieve, calculated as RE2O3. As mentioned earlier regarding catalysts, the rare earth metals introduced here do not include any rare earth metals (exchangeable rare earths) that may already exist in the molecular sieve itself.

[0066] In some preferred embodiments, in step S4 of the catalytic cracking catalyst preparation method, the weight ratio of the rare earth metal modified molecular sieve to the silicon- and / or aluminum-containing material is 1:4-2:1, preferably 1:3-1:1. The silicon- and / or aluminum-containing material is described above in the corresponding description for the catalyst. The drying can be carried out using various techniques well known to those skilled in the art, such as spray drying.

[0067] According to some embodiments of the present invention, the silicon- and / or aluminum-containing material comprises one or more, for example, two or three, selected from kaolin, silica sol, and alumina carrier material, preferably including silica sol. The alumina carrier material is, for example, one or more selected from hydrated alumina, alumina sol, and activated alumina; the hydrated alumina is, for example, one or more selected from alumina trihydrate, boehmite, and boehmite, preferably boehmite, and more preferably, the boehmite is acidified to form acidified boehmite; the activated alumina is, for example, one or more selected from γ-alumina, η-alumina, and κ-alumina. The acid used for acidification is, for example, hydrochloric acid, and the acid-aluminum ratio (weight ratio of hydrochloric acid (based on 37wt% HCl concentration) to boehmite (based on Al2O3)) in the acidified boehmite acidification process is 0.15-0.22:1.

[0068] According to some embodiments of the present invention, step S5 exists between steps S4 and S6 in the method for preparing the catalytic cracking catalyst.

[0069] S5. Selectively roast particle A to obtain particle B, mix it with ammonium salt and water for ammonium exchange, dry it, and roast it a second time to obtain particle C.

[0070] According to some preferred embodiments, in step S5, particles A, ammonium salt, and water are mixed in a weight ratio of 1:(0.2-2):(5-18) for ammonium exchange. The conditions for ammonium exchange include a temperature of 50-100°C and a time of 0.5-2 hours. The ammonium salt is selected from one or more of ammonium chloride, ammonium sulfate, and ammonium nitrate. The ammonium exchange can be performed once or multiple times. Preferably, the sodium oxide content in the rare earth metal modified molecular sieve does not exceed 0.1% by weight.

[0071] Preferably, in step S5, the drying temperature is 100-150°C, and the drying time is 2-12 hours. Preferably, the temperatures of the first and second roastings are each independently 400-600°C, the roasting times are each independently 1-6 hours, and the roasting atmosphere is each independently air or an oxygen-containing gas. The roasting can be performed once or multiple times, for example, twice, wherein the first roasting occurs before ammonium exchange, and the second roasting occurs after ammonia exchange. The conditions for the first and second roastings can be the same or different.

[0072] The mixing ratio of molecular sieve and water in step S6 is not particularly limited, as long as sufficient mixing is achieved to obtain a slurry. The weight ratio of molecular sieve to water is, for example, 1:2-10 or 1:2-5. The filtration in step S6 is, for example, vacuum filtration or suction filtration.

[0073] According to some preferred embodiments, in step S7 of the catalytic cracking catalyst preparation method, the alkaline solution (second alkaline solution) is an ammonia and / or ammonium carbonate solution, and the pH value of the alkaline solution (second alkaline solution) is 8-10, for example 8-9 or 9-10; the weight ratio of the alkaline solution to the filter cake C on a dry basis is 0.5:1-3:1, for example 1:1, 1.5:1, 2:1, 2.5:1 and 3:1, and any two of these values. The contact in step S7 is preferably performed by rinsing the filter cake C with the alkaline solution.

[0074] According to some preferred embodiments, in step S8 of the method for preparing the catalytic cracking catalyst, the concentration of the modified metal salt in the modified metal salt solution B is 15-35 wt%. Preferably, in step S8, the modification includes rinsing the filter cake D with the modified metal salt solution (referred to as the fourth rinsing), drying, and calcining. Filtration may be performed between the rinsing and drying, such as vacuum filtration or suction filtration. When the modified metal is an alkaline earth metal, exemplary salts of the alkaline earth metal include, but are not limited to, magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium phosphate, barium chloride, barium nitrate, strontium chloride, and strontium nitrate. When the modified metal is a rare earth metal, the salt of the rare earth metal may include nitrates, sulfates, phosphates and hydrochlorides, including but not limited to cerium chloride (CeCl2), cerium chloride (CeCl3), lanthanum chloride (LaCl3), europium nitrate (Eu(NO3)3), yttrium nitrate (Y(NO3)3), praseodymium sulfate (Pr2(SO4)3), and neodymium sulfate (Nd2(SO4)3).

[0075] Preferably, in step S8, the drying temperature is 100-150℃; the calcination temperature is 400-600℃, the calcination time is 1-6 hours, and the calcination atmosphere is air or oxygen-containing gas.

[0076] According to some preferred embodiments, in the method for preparing catalytic cracking catalyst, the modified metal introduced by step S8 accounts for 0.1-8 wt% of the dry weight of the catalyst, for example, 2-8 wt%, based on the oxide of the modified metal.

[0077] Preferably, when the modified metal is an alkaline earth metal, the alkaline earth metal introduced in step S8 (referred to as the leached alkaline earth metal, modified alkaline earth metal) accounts for 0.1-5 wt% of the dry weight of the catalyst, based on the oxides of the alkaline earth metal.

[0078] Preferably, when the modified metal is a rare earth metal, the rare earth metal introduced by step S8 accounts for 0.5-8 wt% of the dry weight of the catalyst, for example, 0.5-5 wt%, based on RE2O3.

[0079] In this invention, the rinsing can be performed in a vacuum filtration device, such as a vacuum filtration flask, a belt vacuum filter, or a rotary drum vacuum filter.

[0080] Third aspect

[0081] A third aspect of the present invention provides a catalytic cracking catalyst prepared according to the method of the second aspect.

[0082] Fourth aspect

[0083] The fourth aspect of the present invention provides the application of the catalytic cracking catalyst according to the first or third aspect in the catalytic cracking of vanadium-containing feedstock oil.

[0084] The reaction conditions for the catalytic cracking include: a reaction temperature of 560-620℃, for example 570℃, 580℃, 590℃, or 600℃; an agent-to-oil ratio of 4-30 (by weight), for example 6-10 (by weight); and a reaction time of 0.5-6 seconds, for example 1-3 seconds.

[0085] Example

[0086] The specific embodiments of the present invention are provided to further illustrate the invention and are not intended to limit the possible embodiments of the present invention. The content of the present invention is not limited to the specific embodiments.

[0087] Unless otherwise specified, all raw materials used in the following examples and comparative examples were commercially available, wherein:

[0088] Y-type molecular sieve, DASY2.0 produced by Qilu Branch of Sinopec Catalyst Co., Ltd., has a rare earth content of 2wt% as RE2O3.

[0089] ZSM-5 molecular sieve, RMPZ-3 produced by Qilu Branch of Sinopec Catalyst Co., Ltd., has a silicon-to-aluminum ratio (SiO2 / Al2O3 molar ratio) of 25.

[0090] Aluminum sol, a product of Sinopec Catalyst Qilu Branch, with an Al2O3 content of 22wt%.

[0091] Silica sol, SiO2 content 16wt%, product of Beijing Chemical Plant, pH value 2.5.

[0092] Boehmite, a product of Shandong Aluminum Company, with an alumina content of 65 wt%.

[0093] Kaolin, solid content 75wt%, industrial product of China Kaolin Company.

[0094] In the absence of rare earth metals in the unmodified molecular sieve, the content of modified rare earth metals is the rare earth metal content calculated as RE2O3 divided by the weight of the modified molecular sieve (dry basis).

[0095] When rare earth metals are present in the unmodified molecular sieve, the content of modified rare earth metals is calculated according to the following formula:

[0096] (Total weight of RE2O3 in the modified molecular sieve - Weight of RE2O3 in the unmodified molecular sieve) ÷ Weight of the modified molecular sieve (dry basis)

[0097] When the type of rare earth metal used in the modified molecular sieve is different from the type of rare earth metal contained in the unmodified molecular sieve, the content of the modified rare earth metal can also be calculated as the content of the modified rare earth metal based on RE2O3 divided by the weight of the modified molecular sieve (dry basis).

[0098] Example 1:

[0099] 1) Mix 38g of molecular sieve (on a dry basis, the same below) with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 2:1, and filter the resulting slurry to obtain filter cake.

[0100] 2) Prepare 35g of an alkaline solution with ammonia water to a pH of 9 and rinse the filter cake while vacuum filtering until it is dry;

[0101] 3) Use 4.33g of cerium chloride to prepare a rare earth metal salt solution with a concentration of 15wt% (calculated as CeO2) to wash the filter cake, dry it at 120℃ for 8h, and calcine it at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0102] 4) Rare earth metal modified molecular sieve, boehmite, alumina sol, silica sol, and kaolin are mixed with water in a weight ratio of 40:20:10:10:20, and hydrochloric acid is added to form a slurry with a solid content of 22 wt%. In the above ratio, the modified molecular sieve and kaolin are calculated on a dry basis, the boehmite and alumina sol are calculated on alumina, and the silica sol is calculated on silicon oxide. The ratio of hydrochloric acid to boehmite is 0.2 by mass, where the hydrochloric acid is calculated as 37 wt% HCl and the boehmite is calculated as Al2O3. The slurry is spray-dried to obtain a shaped solid, and then calcined at 550℃ for 2 hours.

[0103] 5) Solid molding: Ammonium chloride and deionized water were mixed evenly at a mass ratio of 1:0.5:10, subjected to a second ammonium exchange, filtered, washed, dried, and calcined at 550℃ for 2 hours to obtain granules C;

[0104] 6) Mix 30g of granules C with 500ml of water, and filter the resulting slurry to obtain filter cake C;

[0105] 7) Prepare 40g of an alkaline solution with ammonia water to a pH of 9, and use it to filter the filter cake while rinsing it to obtain filter cake D;

[0106] 8) The filter cake D was washed with a 15wt% alkaline earth metal salt solution prepared with 3.73g of magnesium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0107] Example 2:

[0108] 1) Mix 38.8g of molecular sieve with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 1:1, and filter the resulting slurry to obtain filter cake.

[0109] 2) Prepare 35g of an alkaline solution with ammonia water to a pH of 9 and rinse the filter cake while vacuum filtering until it is dry;

[0110] 3) Use 2.60g of cerium chloride to prepare a rare earth metal salt solution with a concentration of 15wt% (calculated as CeO2) to wash the filter cake, dry it at 120℃ for 8h, and calcine it at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0111] 4) Rare earth metal modified molecular sieve, boehmite, alumina sol, silica sol, and kaolin were mixed with water in a weight ratio of 40:20:10:10:20, and hydrochloric acid was added to form a slurry with a solid content of 22 wt%. The modified molecular sieve and kaolin were calculated on a dry basis, the boehmite and alumina sol were calculated on alumina, and the silica sol was calculated on silica. The ratio of hydrochloric acid to boehmite was 0.2 by mass, where the hydrochloric acid was calculated as HCl concentration 37 wt% and the boehmite was calculated as Al2O3. The slurry was spray-dried to obtain a shaped solid, and then calcined at 550℃ for 2 hours.

[0112] 5) Solid molding: Ammonium chloride and deionized water were mixed evenly at a mass ratio of 1:0.5:10, subjected to a second ammonium exchange, filtered, washed, dried, and calcined at 550℃ for 2 hours to obtain granules C;

[0113] 6) Mix 30g of granules C with 500ml of water, and filter the resulting slurry to obtain filter cake C;

[0114] 7) Prepare 40g of an alkaline solution with ammonia water to a pH of 9, and use it to filter the filter cake while rinsing it to obtain filter cake D;

[0115] 8) The filter cake D was washed with a 15wt% alkaline earth metal salt solution prepared with 3.73g of magnesium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0116] Example 3:

[0117] 1) Mix 39.6g of molecular sieve with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 2:1. Filter the resulting slurry to obtain filter cake.

[0118] 2) Prepare 35g of an alkaline solution with ammonia water to a pH of 9 and rinse the filter cake while vacuum filtering until it is dry;

[0119] 3) Use 0.87g of cerium chloride to prepare a rare earth metal salt solution with a cerium oxide (calculated as CeO2) concentration of 15wt% to wash the filter cake, dry it at 120℃ for 8h, and calcine it at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0120] 4) Rare earth metal modified molecular sieve, boehmite, alumina sol, silica sol, and kaolin were mixed with water in a weight ratio of 40:20:10:10:20, and hydrochloric acid was added to form a slurry with a solid content of 22 wt%. The modified molecular sieve and kaolin were calculated on a dry basis, the boehmite and alumina sol were calculated on alumina, and the silica sol was calculated on silica. The ratio of hydrochloric acid to boehmite was 0.2 by mass, where the hydrochloric acid was calculated as 37% HCl and the boehmite was calculated as Al2O3. The slurry was spray-dried to obtain a shaped solid, and then calcined at 550℃ for 2 hours.

[0121] 5) Solid molding: Ammonium chloride and deionized water were mixed evenly at a mass ratio of 1:0.5:10, subjected to a second ammonium exchange, filtered, washed, dried, and calcined at 550℃ for 2 hours to obtain granules C;

[0122] 6) Mix 30g of granules C with 500ml of water, and filter the resulting slurry to obtain filter cake C;

[0123] 7) Prepare 40g of an alkaline solution with ammonia water to a pH of 9, and use it to filter the filter cake while rinsing it to obtain filter cake D;

[0124] 8) The filter cake D was washed with a 15wt% alkaline earth metal salt solution prepared with 3.73g of magnesium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0125] Example 4:

[0126] 1) Mix 39.6g of molecular sieve with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 1:1, and filter the resulting slurry to obtain filter cake.

[0127] 2) Prepare 100ml of an alkaline solution with ammonia water to a pH of 8, and rinse the filter cake while filtering it through a vacuum tube.

[0128] 3) The filter cake was washed with a rare earth metal salt solution with a cerium oxide concentration of 15wt% prepared by 0.87g cerium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0129] 4) Rare earth metal modified molecular sieve, boehmite, alumina sol, silica sol, kaolin, water, and hydrochloric acid are mixed and pulped to form a slurry. The weight ratio of rare earth metal modified molecular sieve (dry basis), boehmite (alumina basis), alumina sol (alumina basis), silica sol (silicon oxide basis), and kaolin (dry basis) is 40:20:10:10:20; the weight ratio of hydrochloric acid to boehmite is 0.2, where hydrochloric acid is calculated as 37wt% HCl and boehmite is calculated as Al2O3. The slurry is then spray-dried to prepare a shaped solid.

[0130] 5) Solid molding: Ammonium chloride and deionized water are mixed evenly at a mass ratio of 1:0.5:10, subjected to ammonium exchange, filtered, washed, dried, and calcined at 550℃ for 2 hours to obtain solid particles;

[0131] 6) Mix 30g of the solid particles obtained in step 5) with 500ml of water to obtain a slurry, and filter it to obtain a filter cake;

[0132] 7) Prepare 200ml of an alkaline solution with ammonia water to pH 8, and use it to filter and wash the filter cake while vacuum filtering to obtain the filter cake;

[0133] 8) The filter cake was washed with a 15wt% alkaline earth metal salt solution prepared with 1.45g magnesium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0134] Example 5:

[0135] 1) Mix 39.8g of molecular sieve with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 2:1. Filter the resulting slurry to obtain filter cake.

[0136] 2) Prepare 35g of an alkaline solution with ammonia water to a pH of 9 and rinse the filter cake while vacuum filtering until it is dry;

[0137] 3) The filter cake was washed with a rare earth metal salt solution of 15wt% lanthanum oxide (calculated as La2O3) prepared by 0.53g lanthanum nitrate, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0138] 4) Rare earth metal modified molecular sieve, boehmite, alumina sol, silica sol, and kaolin were mixed with water in a weight ratio of 40:20:10:10:20, and hydrochloric acid was added to form a slurry with a solid content of 22 wt%. The modified molecular sieve and kaolin were calculated on a dry basis, the boehmite and alumina sol were calculated on alumina, and the silica sol was calculated on silica. The ratio of hydrochloric acid to boehmite was 0.2 by mass, where the hydrochloric acid was calculated as 37% HCl and the boehmite was calculated as Al2O3. The slurry was spray-dried to obtain a shaped solid, and then calcined at 550℃ for 2 hours.

[0139] 5) Solid molding: Ammonium chloride and deionized water were mixed evenly at a mass ratio of 1:0.5:10, subjected to a second ammonium exchange, filtered, washed, dried, and calcined at 550℃ for 2 hours to obtain granules C;

[0140] 6) Mix 30g of granules C with 500ml of water, and filter the resulting slurry to obtain filter cake C;

[0141] 7) Prepare 40g of an alkaline solution with ammonia water to a pH of 9, and use it to filter the filter cake while rinsing it to obtain filter cake D;

[0142] 8) The filter cake D was washed with a 15wt% alkaline earth metal salt solution prepared with 0.07g magnesium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0143] Example 6

[0144] 1) Mix 39.8g of molecular sieve with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 2:1. Filter the resulting slurry to obtain filter cake.

[0145] 2) Prepare 35g of an alkaline solution with ammonia water to a pH of 9 and rinse the filter cake while vacuum filtering until it is dry;

[0146] 3) A rare earth metal salt solution with a concentration of 15wt% yttrium oxide (calculated as Y2O3) was prepared using 1.36g of yttrium nitrate to wash the filter cake, dried it at 120℃ for 8h, and calcined it at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0147] 4) Rare earth metal modified molecular sieve, boehmite, alumina sol, silica sol, and kaolin were mixed with water in a weight ratio of 40:20:10:10:20, and hydrochloric acid was added to form a slurry with a solid content of 22 wt%. The modified molecular sieve and kaolin were calculated on a dry basis, the boehmite and alumina sol were calculated on alumina, and the silica sol was calculated on silica. The ratio of hydrochloric acid to boehmite was 0.2 by mass, where the hydrochloric acid was calculated as 37% HCl and the boehmite was calculated as Al2O3. The slurry was spray-dried to obtain a shaped solid, and then calcined at 550℃ for 2 hours.

[0148] 5) Solid molding: Ammonium chloride and deionized water were mixed evenly at a mass ratio of 1:0.5:10, subjected to a second ammonium exchange, filtered, washed, dried, and calcined at 550℃ for 2 hours to obtain granules C;

[0149] 6) Mix 30g of granules C with 500ml of water, and filter the resulting slurry to obtain filter cake C;

[0150] 7) Prepare 40g of an alkaline solution with ammonia water to a pH of 9, and use it to filter the filter cake while rinsing it to obtain filter cake D;

[0151] 8) The filter cake D was washed with a 15wt% alkaline earth metal salt solution prepared with 0.72g magnesium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0152] Comparative Example 1

[0153] 1) The weight ratio of Y-type molecular sieve (dry basis), ZSM-5 type molecular sieve (dry basis), boehmite (Al2O3), alumina sol (Al2O3), silica sol (SiO2), and kaolin is 20:20:20:10:10:20. The above materials are mixed with water and hydrochloric acid to prepare a slurry with a solid content of 22wt%. The ratio of hydrochloric acid to boehmite is 0.2, where hydrochloric acid is calculated as HCl concentration of 37% by weight, and boehmite is calculated as Al2O3. The slurry is then spray-dried to prepare a molding.

[0154] 2) Solid molding: Ammonium chloride and deionized water were mixed evenly at a mass ratio of 1:0.5:10, subjected to ammonium exchange, filtered, washed, dried, and calcined at 550℃ for 2 hours to obtain the catalytic cracking catalyst.

[0155] Comparative Example 2

[0156] The catalyst was prepared according to the method in Example 4, except that in the preparation of the modified molecular sieve, the rare earth salt solution was first mixed with the molecular sieve, and then the ammonia solution was added to precipitate the sieve. The catalyst was then prepared according to the methods in steps 4-8.

[0157] Comparative Example 3

[0158] The catalyst was prepared according to the method of Comparative Example 2, except that in step 6), the particles obtained in step 5) were mixed with an alkaline earth metal salt solution and then ammonia was added to precipitate.

[0159] Comparative Example 4

[0160] Unlike Example 4, in step 1), the mixture was not first mixed with water, but directly mixed with the alkaline solution. In step 6), the mixture was not first mixed with water, but directly mixed with the alkaline solution.

[0161] Comparative Example 5

[0162] The method is the same as in Comparative Example 1, except that the rare earth salt and alkaline earth metal salt are added during the pulping process.

[0163] Test case

[0164] The finished catalytic cracking catalyst particles, as well as the catalysts prepared in the examples and comparative examples, were subjected to cyclic fouling (with V deposition) experiments in a cyclic aging unit. The V content on the catalyst mixture after cyclic fouling is shown in Tables 3 to 6. The steps of the cyclic fouling experiment included: introducing heavy metal V into the catalyst mixture using the Michell impregnation method, and then loading the catalyst with introduced heavy metal into a small fixed fluidized bed, where it was treated according to the following steps in the small fixed fluidized bed unit:

[0165] (a) Heating to 600°C at a heating rate of 20°C / min under a nitrogen atmosphere;

[0166] (b) Heat to 780°C at a heating rate of 1.5°C / min, and then maintain the temperature at 780°C. During the temperature maintenance process, change the treatment atmosphere according to the following steps.

[0167] (i) Treat for 10 minutes in an atmosphere containing 40% by volume nitrogen (in which the nitrogen contains 5% by volume propylene) and 60% by volume water vapor.

[0168] (ii) Treat for 10 minutes in an atmosphere containing 40% by volume nitrogen (pure nitrogen, propylene-free) and 60% by volume water vapor.

[0169] (iii) Treat for 10 minutes in an atmosphere containing 40% by volume air (containing 4000ppm SO2) and 60% by volume water vapor.

[0170] (iv) Treat the catalyst mixture with an atmosphere containing 40% nitrogen and 60% water vapor for 10 minutes; then repeat steps (i)-(iv) in the above order once each, and then repeat step (i) to end the cycle contamination step; then carry out the aging step: the catalyst mixture after cycle contamination is aged at 800°C in an atmosphere containing 100% water vapor for 4 hours; then examine the catalytic performance of the catalyst mixture after cycle contamination-aging on the ACE unit; wherein, the high vanadium feedstock oil (physicochemical properties are shown in Table 2) enters at the bottom of the reactor and contacts the catalyst mixture, and the specific evaluation conditions and results are shown in Table 3.

[0171] The conversion rate is calculated as follows: gasoline yield + liquefied petroleum gas yield + dry gas yield + coke yield.

[0172] Table 1

[0173] In Table 1, the content on the outer surface refers to the metal element content within a 5 nm range from the outer surface of the particles, measured by XPS. The total rare earth element content and the total alkaline earth element content were measured by XRF.

[0174] Table 2

[0175] Table 3

[0176] As shown in Table 3, the catalytic cracking catalyst provided by this invention has higher yields of propylene and ethylene, higher yield of liquefied petroleum gas, and better resistance to V pollution.

[0177] Example 7:

[0178] 1) Mix 36.8g of molecular sieve (on a dry basis) with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 2:1. Filter the resulting slurry to obtain a filter cake.

[0179] 2) Prepare 100ml of an alkaline solution with ammonia water to a pH of 9 and rinse the filter cake while filtering it through a vacuum tube;

[0180] 3) The filter cake was washed with a rare earth metal salt solution with a concentration of 15wt% (calculated as CeO2) prepared by 6.93g of cerium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0181] 4) A slurry is formed by mixing rare earth metal modified molecular sieve, boehmite, alumina sol, kaolin, hydrochloric acid, and water. The solid content of the slurry is 22 wt%. The weight ratio of rare earth metal modified molecular sieve (on a dry basis), boehmite (on alumina), alumina sol (on alumina), and kaolin (on a dry basis) is 40:20:20:20. The mass ratio of hydrochloric acid to boehmite is 0.2, where the hydrochloric acid is HCl with a concentration of 37 wt%, and the boehmite is Al2O3. The slurry is then spray-dried to prepare shaped solids (particles A).

[0182] 5) Solid molding: Ammonium chloride and deionized water are mixed evenly at a mass ratio of 1:0.5:10, and subjected to two ammonium exchange processes. The temperature of each ammonium exchange is 60℃ and the exchange time is 0.5h. After filtration, washing, drying, and calcination at 550℃ for 2h, solid particles are obtained.

[0183] 6) Mix 30g of solid particles with 500ml of water, and filter the resulting slurry to obtain filter cake C;

[0184] 7) Prepare 200 ml of an alkaline solution with ammonia water to pH 9, and wash filter cake C while filtering it with vacuum to obtain filter cake D;

[0185] 8) Filter cake D was washed with a rare earth metal salt solution with a concentration of 15wt% (calculated as CeO2) prepared by 3.42g of cerium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0186] Example 8:

[0187] 1) Mix 38.4g of molecular sieve with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 1:1. Filter the resulting slurry to obtain filter cake A.

[0188] 2) Prepare 100 ml of an alkaline solution with ammonia water to pH 9, and wash the filter cake while filtering it to obtain filter cake B;

[0189] 3) Use 3.46g of cerium chloride to prepare a rare earth metal salt solution with a concentration of 15wt% based on CeO2 to wash filter cake B, dry at 120℃ for 8h, and calcine at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0190] 4) A slurry is formed by mixing rare earth metal modified molecular sieve, boehmite, alumina sol, kaolin, hydrochloric acid, and water, with a solid content of 22%. The weight ratio of rare earth metal modified molecular sieve (dry basis), boehmite (alumina), alumina sol (alumina), and kaolin (dry basis) is 40:20:20:20, and the mass ratio of hydrochloric acid to boehmite is 0.2. The hydrochloric acid is calculated as HCl with a concentration of 37wt%, and the boehmite is calculated as Al2O3. The slurry is then spray-dried to prepare shaped solids (particles A).

[0191] 5) Solid Molding: Ammonium chloride and deionized water were mixed evenly at a mass ratio of 1:0.5:10, subjected to secondary ammonium exchange, filtered, washed, dried, and calcined at 550℃ for 2 hours to obtain solid particles C.

[0192] 6) Mix 30g of solid particles C with 500ml of water, and filter the resulting slurry to obtain filter cake C;

[0193] 7) Prepare 200 ml of an alkaline solution with ammonia water to pH 9, and wash filter cake C while filtering it to obtain filter cake D;

[0194] 8) Filter cake D was washed with a rare earth metal salt solution with a concentration of 15wt% (calculated as CeO2) prepared by 3.42g of cerium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0195] Example 9:

[0196] 1) Mix 38.4g of molecular sieve with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 1:1. Filter the resulting slurry to obtain filter cake A.

[0197] 2) Prepare 100ml of an alkaline solution with ammonia water to a pH of 9, and wash the filter cake while filtering it to obtain filter cake B;

[0198] 3) Use 3.46g of cerium chloride to prepare a rare earth metal salt solution with a concentration of 15wt% based on CeO2 to wash filter cake B, dry at 120℃ for 8h, and calcine at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0199] 4) A slurry is formed by mixing rare earth metal modified molecular sieve, boehmite, silica sol, kaolin, hydrochloric acid, and water, with a solid content of 22 wt%. The weight ratio of rare earth metal modified molecular sieve (on a dry basis), boehmite (on alumina), silica sol (on alumina), and kaolin (on a dry basis) is 40:10:30:20, and the mass ratio of hydrochloric acid to boehmite is 0.2. The hydrochloric acid is calculated as HCl with a concentration of 37 wt%, and the boehmite is calculated as Al2O3. The slurry is then spray-dried to prepare shaped solids (particles A).

[0200] 5) Solid molding: Ammonium chloride and deionized water are mixed evenly at a mass ratio of 1:0.5:10, and ammonium exchange is performed at a temperature of 60℃ for 0.5h. After filtration, the above ammonium exchange is performed again, followed by filtration, washing, drying, and calcination at 550℃ for 2h to obtain solid particles C.

[0201] 6) Mix 30g of solid particles C with 500ml of water to obtain a slurry, and filter it to obtain filter cake C;

[0202] 7) Prepare 200 ml of an alkaline solution with ammonia water to pH 9, and wash the filter cake while filtering it through a vacuum tube to obtain filter cake D;

[0203] 8) The filter cake D was washed with a rare earth metal salt solution with a concentration of 15wt% based on CeO2 prepared by 0.33g cerium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0204] Example 10:

[0205] 1) Mix 38.4g of molecular sieve with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 1:1. Filter the resulting slurry to obtain filter cake A.

[0206] 2) Prepare 100ml of an alkaline solution with ammonia water to pH 8, and wash filter cake A while filtering it to obtain filter cake B;

[0207] 3) Use 3.46g of cerium chloride to prepare a rare earth metal salt solution with a concentration of 15wt% based on CeO2 to wash filter cake B, dry at 120℃ for 8h, and calcine at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0208] 4) A slurry is formed by mixing rare earth metal modified molecular sieve, boehmite, alumina sol, kaolin, hydrochloric acid, and water, with a solid content of 22 wt%. The weight ratio of rare earth metal modified molecular sieve (dry basis), boehmite (alumina), alumina sol (alumina), and kaolin (dry basis) is 40:20:20:20, and the mass ratio of hydrochloric acid to boehmite is 0.2. The hydrochloric acid is calculated as HCl with a concentration of 37 wt%, and the boehmite is calculated as Al2O3. The slurry is then spray-dried to prepare shaped solids (particles A).

[0209] 5) Particle A undergoes a second ammonium exchange; for each exchange, particle A, ammonium chloride, and deionized water are mixed evenly at a mass ratio of 1:0.5:10, exchanged at 60℃ for 0.5h, filtered, washed, dried, and calcined at 550℃ for 2h to obtain particle C;

[0210] 6) Mix 30g of granules C with 500ml of water to obtain a slurry, and filter it to obtain filter cake C;

[0211] 7) Prepare 200 ml of an alkaline solution with ammonia water at pH 8 and wash filter cake C while filtering it through a vacuum tube to obtain filter cake D;

[0212] 8) The filter cake D was washed with a rare earth metal salt solution with a concentration of 15wt% based on CeO2 prepared by 0.33g cerium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0213] Example 11:

[0214] 1) Mix 38.8g of molecular sieve with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 1:1. Filter the resulting slurry to obtain filter cake A.

[0215] 2) Prepare 100ml of an alkaline solution with ammonia water to a pH of 9, and wash the filter cake while filtering it to obtain filter cake B;

[0216] 3) Filter cake B was washed with a rare earth metal salt solution with a concentration of 15wt% based on La2O3 prepared by 3.19g of lanthanum nitrate, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0217] 4) A slurry is formed by mixing rare earth metal modified molecular sieve, boehmite, silica sol, kaolin, hydrochloric acid, and water, with a solid content of 22 wt%. The weight ratio of rare earth metal modified molecular sieve (on a dry basis), boehmite (on alumina), silica sol (on alumina), and kaolin (on a dry basis) is 40:10:30:20, and the mass ratio of hydrochloric acid to boehmite is 0.2. The hydrochloric acid is calculated as HCl with a concentration of 37 wt%, and the boehmite is calculated as Al2O3. The slurry is then spray-dried to prepare shaped solids (particles A).

[0218] 5) Solid molding: Ammonium chloride and deionized water are mixed evenly at a mass ratio of 1:0.5:10, and ammonium exchange is performed at a temperature of 60℃ for 0.5h. After filtration, the above ammonium exchange is performed again, followed by filtration, washing, drying, and calcination at 550℃ for 2h to obtain solid particles C.

[0219] 6) Mix 30g of solid particles C with 500ml of water to obtain a slurry, and filter it to obtain filter cake C;

[0220] 7) Prepare 200 ml of an alkaline solution with ammonia water to pH 9, and wash the filter cake while filtering it through a vacuum tube to obtain filter cake D;

[0221] 8) The filter cake D was washed with a rare earth metal salt solution with a concentration of 15wt% (calculated as CeO2) prepared by 0.66g of cerium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0222] Example 12

[0223] 1) Mix 39.6g of molecular sieve with 200ml of water, wherein the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 1:1. Filter the resulting slurry to obtain filter cake A.

[0224] 2) Prepare 100ml of an alkaline solution with ammonia water to a pH of 9, and wash the filter cake while filtering it to obtain filter cake B;

[0225] 3) Filter cake B was washed with a rare earth metal salt solution with a concentration of 15wt% based on Y2O3 prepared by 1.36g of yttrium nitrate, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain rare earth metal modified molecular sieve.

[0226] 4) A slurry is formed by mixing rare earth metal modified molecular sieve, boehmite, silica sol, kaolin, hydrochloric acid, and water, with a solid content of 22 wt%. The weight ratio of rare earth metal modified molecular sieve (on a dry basis), boehmite (on alumina), silica sol (on alumina), and kaolin (on a dry basis) is 40:10:30:20, and the mass ratio of hydrochloric acid to boehmite is 0.2. The hydrochloric acid is calculated as HCl with a concentration of 37 wt%, and the boehmite is calculated as Al2O3. The slurry is then spray-dried to prepare shaped solids (particles A).

[0227] 5) Solid molding: Ammonium chloride and deionized water are mixed evenly at a mass ratio of 1:0.5:10, and ammonium exchange is performed at a temperature of 60℃ for 0.5h. After filtration, the above ammonium exchange is performed again, followed by filtration, washing, drying, and calcination at 550℃ for 2h to obtain solid particles C.

[0228] 6) Mix 30g of solid particles C with 500ml of water to obtain a slurry, and filter it to obtain filter cake C;

[0229] 7) Prepare 200 ml of an alkaline solution with ammonia water to pH 9, and wash the filter cake while filtering it through a vacuum tube to obtain filter cake D;

[0230] 8) Filter cake D was washed with a rare earth metal salt solution with a concentration of 15wt% based on CeO2 prepared by 1.33g of cerium chloride, dried at 120℃ for 8h, and calcined at 550℃ for 4h to obtain the catalytic cracking catalyst.

[0231] The physicochemical properties and composition of the catalytic cracking catalysts obtained in Examples 7-12 are shown in Table 4.

[0232] Table 4 Physicochemical properties of catalytic cracking catalysts

[0233] Comparative Example 6:

[0234] 1) Molecular sieves, boehmite, alumina sol, kaolin, hydrochloric acid, and water are mixed to form a slurry with a solid content of 22 wt%. The weight ratio of Y-type molecular sieve (dry basis), ZSM-5 type molecular sieve (dry basis), boehmite (alumina), alumina sol (alumina), silica sol, and kaolin (dry basis) is 20:20:20:10:10:20. The ratio of hydrochloric acid to boehmite is 0.2 by mass, where hydrochloric acid is calculated as 37 wt% HCl and boehmite as Al2O3. The slurry is then spray-dried to prepare a shaped solid.

[0235] 2) Solid molding: Ammonium chloride and deionized water are mixed evenly at a mass ratio of 1:0.5:10, subjected to secondary ammonium exchange, filtered, washed, dried, and calcined at 550℃ for 2 hours to obtain the catalytic cracking catalyst.

[0236] Comparative Example 7

[0237] The catalytic cracking catalyst was prepared according to the method in Example 7, except that the rare earth metal modified molecular sieve was prepared by mixing the molecular sieve with rare earth, then adding ammonia water to precipitate it, drying it, and then calcining it at 550°C for 4 hours.

[0238] Comparative Example 8

[0239] The catalytic cracking catalyst was prepared according to the method of Example 7, except that the rare earth salt described in step 8) was added in step 4), and after calcination at 550°C, ammonium exchange in step 5) was performed, but steps 6) to 8) were not performed.

[0240] Comparative Example 9

[0241] The catalytic cracking catalyst was prepared according to the method in Example 7, except that the molecular sieve was not modified with rare earth metals.

[0242] Comparative Example 10

[0243] The catalyst was prepared according to the method of Example 7, except that steps 6 and 7 were not performed.

[0244] The physicochemical properties and composition of the catalytic cracking catalysts obtained in Comparative Examples 6–10 are shown in Table 5.

[0245] Table 5

[0246] Test case

[0247] The catalysts prepared in the examples and comparative examples underwent cyclic contamination (with V deposition) experiments in a cyclic aging apparatus. The theoretical V loading on the catalyst mixture after cyclic contamination is shown in Tables 7 and 8. The cyclic contamination experiment included: introducing heavy metal V into the catalyst mixture using the Michell impregnation method, then loading the catalyst mixture with introduced heavy metal V into a small fixed fluidized bed, and processing it in the small fixed fluidized bed apparatus according to the following steps:

[0248] (a) Heating to 600°C at a heating rate of 20°C / min under a nitrogen atmosphere;

[0249] (b) Heat to 780°C at a heating rate of 1.5°C / min, and then maintain the temperature at 780°C. During the temperature maintenance process, change the treatment atmosphere according to the following steps.

[0250] (i) Treat for 10 minutes in an atmosphere containing 40% by volume nitrogen (in which the nitrogen contains 5% by volume propylene) and 60% by volume water vapor.

[0251] (ii) Treat for 10 minutes in an atmosphere containing 40% by volume nitrogen (pure nitrogen, propylene-free) and 60% by volume water vapor.

[0252] (iii) Treat for 10 minutes in an atmosphere containing 40% by volume air (containing 4000ppm SO2) and 60% by volume water vapor.

[0253] (iv) Treat the catalyst mixture in an atmosphere containing 40% by volume nitrogen and 60% by volume water vapor for 10 minutes; then repeat steps (i) to (iv) in the aforementioned order once each, and then repeat step (i) to end the cycle contamination step; then perform the aging step: the cycle contaminated catalyst mixture is aged at 800°C in an atmosphere containing 100% by volume water vapor for 4 hours; then examine the catalytic performance of the cycle contamination-aging catalyst mixture on the ACE unit; wherein, high vanadium feedstock oil (physicochemical properties are shown in Table 6) enters at the bottom of the reactor and contacts the catalyst mixture, and the specific evaluation conditions and results are shown in Tables 7 and 8. The reaction temperature is 580°C, and the catalyst-to-oil ratio is 10 by weight.

[0254] The conversion rate is calculated as follows: gasoline yield + liquefied petroleum gas yield + dry gas yield + coke yield.

[0255] Table 6

[0256] Table 7

[0257] Table 8

[0258] As can be seen from Tables 7 and 8, the vanadium poisoning resistant catalyst provided by the present invention has better ethylene and propylene yields under vanadium contamination conditions.

Claims

1. A catalytic cracking catalyst, characterized in that, The catalytic cracking catalyst contains rare earth metal modified molecular sieves and a matrix material, wherein the matrix material includes modified metal oxides and silicon- and / or aluminum-containing materials. The ratio of the concentration of modified rare earth metals on the outer surface of the rare earth metal modified molecular sieve to the average concentration of modified rare earth metals in the rare earth metal modified molecular sieve is 1.3 to 4.5, preferably 1.35 to 3.5, and more preferably 1.4 to 2.5; the ratio of the concentration of modified metal oxides on the outer surface of the catalytic cracking catalyst to the average concentration of modified metal oxides in the catalytic cracking catalyst is 1.3 to 4.5, preferably 1.35 to 3.5, and more preferably 1.4 to 2.5, wherein the modified metal in the modified metal oxide is selected from at least one of alkaline earth metals and rare earth metals.

2. The catalytic cracking catalyst according to claim 1, characterized in that, Based on the dry weight of the catalytic cracking catalyst, the content of the rare earth metal modified molecular sieve in the catalytic cracking catalyst is 20-60 wt%, preferably 25-50 wt%, the content of the modified metal oxide component is 0.1-8 wt%, and the content of the silicon and / or aluminum-containing material is 35-80 wt%, preferably 45-75 wt%. Preferably, when the modified metal is an alkaline earth metal, the content of the alkaline earth metal oxide is 0.1-5 wt% based on the dry weight of the catalytic cracking catalyst. Preferably, when the modified metal is a rare earth metal, the content of the rare earth metal oxide, calculated as RE2O3, is 0.5-8 wt% based on the dry weight of the catalytic cracking catalyst.

3. The catalytic cracking catalyst according to claim 1 or 2, characterized in that, The modified rare earth metal oxide content in the rare earth metal modified molecular sieve, calculated as RE2O3, accounts for 0.5-8 wt% of the total weight of the rare earth metal modified molecular sieve.

4. The catalytic cracking catalyst according to any one of claims 1-3, characterized in that, The rare earth metal modified molecular sieve has at least one of the following characteristics: The modified rare earth metal elements in the rare earth metal modified molecular sieve include one or more of cerium, lanthanum, or yttrium. The rare earth metal modified molecular sieves include Y-type molecular sieves and ZSM-5 type molecular sieves; The weight ratio of the Y-type molecular sieve to the ZSM-5 type molecular sieve is 0.5:1-3:1, preferably 1:1-2:

1.

5. The catalytic cracking catalyst according to any one of claims 1-4, characterized in that, The catalytic cracking catalyst has at least one of the following characteristics: In the matrix material, the alkaline earth metal in the modified metal oxide is selected from one or more of magnesium, barium, and strontium; In the matrix material, the rare earth metal in the modified metal oxide is selected from one or more of cerium, lanthanum, and yttrium; In the matrix material, the silicon- and / or aluminum-containing material is selected from one or more of kaolin, alumina support, silica support, and silica-alumina support; the alumina support is preferably selected from one or more of alumina sol, boehmite, hydrated alumina, and activated alumina; the silica support is preferably silica sol, which includes, for example, one or more of neutral silica sol, acidic silica sol, or alkaline silica sol. Based on the dry weight of the catalytic cracking catalyst, the catalytic cracking catalyst comprises 25-50 wt% molecular sieve, 5-30 wt% boehmite, 0-20 wt% aluminum sol, preferably 3-20 wt% aluminum sol, 0-35 wt% silica sol, preferably 10-35 wt% silica sol, 10-40 wt% kaolin, and 0.1-5 wt% modified metal oxide.

6. The catalytic cracking catalyst according to any one of claims 1-5, characterized in that, Based on the dry weight of the catalytic cracking catalyst, the catalytic cracking catalyst contains 10-35 wt% silica support.

7. A method for preparing a catalytic cracking catalyst, characterized in that, Includes the following steps: S1. Mix molecular sieve with water to obtain slurry A, and filter to obtain filter cake A; S2. Contact filter cake A with an alkaline solution and filter to obtain filter cake B; S3. Rare earth metal modified molecular sieves are obtained by modifying filter cake B with rare earth metal salt solution A. S4. Mix rare earth metal modified molecular sieves, silicon- and / or aluminum-containing materials with water to obtain slurry B, and dry to obtain particles A; S6. Mix particles A with water to obtain slurry C, and filter to obtain filter cake C; S7. Contact filter cake C with alkaline solution and filter to obtain filter cake D; S8. The filter cake D is modified using a modified metal salt solution B to obtain the catalytic cracking catalyst. The modified metal is selected from at least one of alkaline earth metals and rare earth metals.

8. The method for preparing the catalytic cracking catalyst according to claim 7, characterized in that, In step S1, the molecular sieve includes Y-type molecular sieve and ZSM-5 type molecular sieve. Preferably, the mass ratio of Y-type molecular sieve to ZSM-5 type molecular sieve is 1:1-2:

1.

9. The method for preparing the catalytic cracking catalyst according to claim 7 or 8, characterized in that, In step S2, at least one of the following characteristics is satisfied: The alkaline solution is an ammonia solution and / or an ammonium carbonate solution, and the pH value of the alkaline solution is 8-10, for example 8-9 or 9-10; The weight ratio of alkaline solution to filter cake A on a dry basis is 0.5:1-3:1; The contact involves rinsing filter cake A with an alkaline solution.

10. The method for preparing the catalytic cracking catalyst according to any one of claims 7-9, characterized in that, In step S3, the concentration of rare earth metal salt in the rare earth metal salt solution A is 10-30 wt%. Preferably, in step S3, the modification includes rinsing, drying, and calcining the filter cake A with a rare earth metal salt solution. The drying temperature is 100-150℃, and the drying time is 2-12 hours; the calcination temperature is 400-600℃, and the calcination time is 1-6 hours. The rare earth metals introduced in step S3 are 0.5-8 wt% of the dry weight of the molecular sieve, calculated as RE2O3.

11. The method for preparing the catalytic cracking catalyst according to any one of claims 7-10, characterized in that, In step S4, the weight ratio of rare earth metal modified molecular sieve to silicon and / or aluminum-containing materials is 1:4-2:1, preferably 1:3-1:1; Preferably, the drying is carried out by spray drying.

12. The method for preparing the catalytic cracking catalyst according to any one of claims 7-11, characterized in that, Step S5 exists between steps S4 and S6. S5. Selectively roast particle A to obtain particle B, mix it with ammonium salt and water for ammonium exchange, dry it, and roast it a second time to obtain particle C. Preferably, in step S5, particles A, ammonium salt, and water are mixed in a weight ratio of 1:(0.2-2):(5-18) for ammonium exchange, wherein the conditions for ammonium exchange include a temperature of 50-100°C and a time of 0.5-2 hours; the ammonium salt is selected from one or more of ammonium chloride, ammonium sulfate, and ammonium nitrate. Preferably, in step S5, the drying temperature is 100-150℃ and the drying time is 2-12 hours; the temperature of the first roasting and the second roasting are each independently 400-600℃, the roasting time is each independently 1-6 hours, and the roasting atmosphere is each independently air or oxygen-containing gas.

13. The method for preparing the catalytic cracking catalyst according to any one of claims 7-12, characterized in that, In step S7, at least one of the following characteristics is satisfied: The alkaline solution is an ammonia solution and / or an ammonium carbonate solution, and the pH value of the alkaline solution is 8-9 or 9-10; The weight ratio of alkaline solution to filter cake C on a dry basis is 0.5:1-3:1; The contact involves rinsing the filter cake C with an alkaline solution.

14. The method for preparing the catalytic cracking catalyst according to any one of claims 7-13, characterized in that, In step S8, the concentration of the modified metal salt in the modified metal salt solution B is 15-35 wt%. Preferably, in step S8, the modification includes rinsing, drying, and calcining the filter cake D using a modified metal salt solution. Preferably, in step S8, the drying temperature is 100-150℃; the calcination temperature is 400-600℃, the calcination time is 1-6 hours, and the calcination atmosphere is air or oxygen-containing gas.

15. The method for preparing the catalytic cracking catalyst according to any one of claims 7-14, characterized in that, The modified metal introduced in step S8 accounts for 0.1-8 wt% of the dry weight of the catalyst, based on the oxide of the modified metal. Wherein, if the modified metal is an alkaline earth metal, the alkaline earth metal introduced in step S8 accounts for 0.1-5 wt% of the dry weight of the catalyst, based on the oxide of the alkaline earth metal. Wherein, if the modified metal is a rare earth metal, the rare earth metal introduced in step S8 accounts for 0.5-8 wt% of the dry weight of the catalyst, based on Re2O3.

16. A catalytic cracking catalyst prepared by any one of claims 7-15.

17. The application of the catalytic cracking catalyst according to any one of claims 1 to 6 or claim 16 in the catalytic cracking of vanadium-containing feedstock oil.

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