Kaolin slurry and preparation method thereof, and novel catalytic cracking catalyst and preparation method thereof

Abstract

The invention belongs to the technical field of catalytic cracking, and provides kaolin slurry and a preparation method thereof as well as a novel catalytic cracking catalyst and a preparation method thereof, the kaolin slurry contains kaolin clay and alumina sol in a weight ratio of (90-98): (2-10), and the solid content is 35-50wt%. The catalytic cracking catalyst comprises kaolin introduced by the kaolin slurry, alumina sol, pseudo-boehmite and a second molecular sieve. The catalytic cracking catalyst has higher gasoline yield. The preparation method is low in cost and can realize continuous preparation.

Description

Technical Field

[0001] This invention belongs to the field of catalytic cracking technology, and relates to a novel catalytic cracking catalyst and its preparation process, as well as a method for dispersing high solids content slurry. Technical Background

[0002] Catalytic cracking (FCC) catalysts are microspheres, typically composed of a support and an active component. Molecular sieves are commonly used active components in catalytic cracking catalysts, and can be one or more of Y-type, MFI-type, or β-type molecular sieves. Common supports include kaolin and binders that act as binders, such as pseudoboehmite or alumina sol binders. The stability of the support is crucial for ensuring the stability of the catalyst quality.

[0003] A common method for preparing catalytic cracking catalysts involves preparing unmodified kaolin (raw clay) into a kaolin slurry, mixing it with a molecular sieve slurry and a binder, and then spray-drying the mixture. Typically, the kaolin slurry is prepared by mixing kaolin with water in a stirred tank and stirring to disperse the kaolin into fine particles; this process is also known as kaolin pulping. This method requires no modification of the kaolin, is simple, and produces minimal pollution, making it widely used. However, the particle size and impurities of the kaolin in the slurry significantly affect the catalyst's attrition index, its compatibility with the molecular sieve and binder, its cost and cracking performance, and parameters such as catalyst sieving. Furthermore, it influences the wear of the slurry filtration screen and the nozzles during the molding process.

[0004] However, unmodified kaolin used in the preparation of catalytic cracking catalysts presents the following problems during slurry preparation: the slurry concentration of kaolin is difficult to increase; otherwise, it is prone to poor dispersion, resulting in large kaolin particles and numerous impurities in the slurry, which easily settle and stratify, affecting the physicochemical properties of the catalyst. To improve the dispersibility of kaolin, one method is to use dispersants or additives during the kaolin slurry preparation process. However, the use of both inorganic and organic additives not only increases the preparation cost of the catalyst but may also adversely affect its performance, even causing environmental problems such as increased secondary pollution and carbon emissions. Furthermore, the dispersed particles remain relatively large, making them prone to stratification after prolonged storage. This results in the synthesized colloids used in the preparation of catalytic cracking catalysts having high viscosity, encapsulating kaolin particles and impurities, leading to poor colloid flowability, difficulty in spraying, and high wear frequency of the vibrating screen. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a new kaolin-containing slurry that can have high stability when the solid content is high, and the slurry does not exhibit solid-liquid separation after being left to stand for at least 24 hours.

[0006] The second technical problem to be solved by the present invention is to provide a method for preparing the kaolin-containing slurry, which does not require a dispersant, obtains a kaolin-containing slurry with high solid content and good dispersion, reduces the impurity content in the kaolin slurry, and facilitates transportation.

[0007] The third technical problem to be solved by the present invention is to provide a catalytic cracking catalyst containing solid particles in the kaolin-containing slurry.

[0008] The fourth technical problem to be solved by this invention is to provide a method for preparing the catalytic cracking catalyst, which facilitates the transportation of various raw materials, yields a catalyst slurry (catalyst colloid) with a high solids content, and eliminates the need for additional dispersants. The resulting catalytic cracking catalyst exhibits better gasoline yield and conversion rates than catalytic cracking catalysts obtained by existing methods.

[0009] The fifth technical problem to be solved by the present invention is to provide a method for applying the catalytic cracking catalyst.

[0010] In a first aspect, the present invention provides a kaolin-containing slurry (hereinafter referred to as kaolin slurry) containing solid particles and aluminum sol, wherein the solid particles comprise kaolin clay, and the weight ratio of the solid particles on a dry basis to the aluminum sol (referred to as the first aluminum sol) on an alumina basis is 90-98:2-10, and the solid content of the kaolin-containing slurry is 35-50% by weight.

[0011] The viscosity of the kaolin-containing slurry does not exceed 1000 mPa·s and / or the impurity content does not exceed 0.5% by weight, for example, 0.01 to 0.4% by weight, preferably not exceeding 0.1% by weight. The impurity content is the percentage of the weight of the solid product obtained after filtering the kaolin slurry through a 200-mesh sieve, rinsing it with water, collecting the material that does not pass through the sieve, drying it, and calcining it at 800°C for 1 hour, relative to the weight of the dry basis material in the slurry. The dry basis refers to the solid product obtained by calcining the material at 800°C for 1 hour.

[0012] The kaolin-containing slurry was measured by laser particle size distribution, and the particle size distribution of its solid particles was as follows: D(50) was ≤6 μm, for example, 1-6, 1.5-5, 1.5-3.5, 2-3 μm, or 4-5 μm. D(90) was not more than 20 μm, for example, 3-20 μm, not more than 10 μm, 3-10 μm, 7-10 μm, 15-18 μm, or 8-16.5 μm.

[0013] Where D(50), or DV(0.5), means that the total volume of particles with a diameter smaller than this value accounts for 50% of the total volume of all particles. D(90), or DV(0.9), means that the total volume of particles with a diameter smaller than this value accounts for 90% of the total volume of all particles.

[0014] In one embodiment, the solid particles are kaolin clay, wherein the weight ratio of kaolin clay to alumina sol (based on a dry basis) is 90-98:2-10. The particle size distribution of the kaolin-containing slurry, measured by laser particle size distribution method, is as follows: D(50) ≤ 4 μm, for example 1.5-3.5 or 2-3 μm; D(90) not exceeding 10 μm, for example 7-10 μm. For laser particle size distribution measurement, refer to NB / SH / T0951-2017 Determination of Particle Size Distribution of Catalytic Cracking Catalysts - Laser Scattering Method.

[0015] In one embodiment, the solid particles are kaolin clay and fine powder of catalytic cracking catalyst; in the kaolin-containing slurry (referred to as the second kaolin-containing slurry), the weight ratio of kaolin clay (dry basis), alumina sol (calculated as alumina), and fine powder of catalytic cracking catalyst (dry basis) is 90-98:2-10:3-10, and the solid content of the kaolin-containing slurry is 35-50% by weight; the average particle size of the fine powder of catalytic cracking catalyst does not exceed 6 micrometers; the particle size distribution of the kaolin-containing slurry is: D(50) ≤6μm, for example 4-5μm; D(90) not exceeding 20μm, for example 15-18μm, and the particle size of the fine powder of catalytic cracking catalyst is measured by laser particle size distribution method; the particle size distribution of the solid particles is as specified in NB / SH / T 0951-2017.

[0016] In one embodiment, the solid particles are kaolin clay, fine powder of catalytic cracking catalyst, and molecular sieve; in the kaolin-containing slurry, the weight ratio of kaolin clay (dry basis), alumina sol (calculated as alumina), fine powder of catalytic cracking catalyst (dry basis), and molecular sieve (dry basis) is 40-65:2-10:3-10:30-40, and the solid content of the kaolin-containing slurry is 35-50% by weight; the average particle size of the fine powder of catalytic cracking catalyst does not exceed 6 micrometers, and the particle size distribution of the kaolin-containing slurry is: D50 is ≤6μm, for example 4-5μm; D(90) is not more than 20μm, for example 15-18μm. The particle size of the fine powder and slurry is measured by laser particle size distribution method (see NB / SH / T 0951-2017).

[0017] A second aspect of the present invention provides a method for preparing the kaolin-containing slurry, comprising:

[0018] A mixture of solid material including kaolin clay and a first aluminum sol and water is formed and pulped, and optionally filtered; in one embodiment, the pulping time is 2 to 5 hours; the pulping temperature can be 15-50°C, for example 20 to 40°C; the pH value of the kaolin-containing slurry is preferably 3 to 5.

[0019] The first aluminum sol has the following characteristics: Al content of 11-12% by weight, aluminum-chlorine ratio greater than 1.25, and pH value less than 4.

[0020] The aluminum sol is preferably obtained by reacting metallic aluminum particles with hydrochloric acid.

[0021] According to the present invention, the kaolin clay is well known to those skilled in the art, and commonly used types of kaolin can be used in the present invention. Preferably, the kaolin clay is one or more of the following: kaolin (with kaolinite as the main component, typically exceeding 50% by weight), hydrous kaolin (with halloysite as the main component, typically exceeding 50% by weight), quasi-haloysite, and bentonite. Preferably, the kaolin clay is kaolin (with kaolinite as the main component) and / or halloysite.

[0022] Preferably, the kaolin is kaolin with a flaky or tubular structure, having an alumina content greater than 36% by weight, an iron oxide content less than 3% by weight, an α-SiO2 quartz sand content less than 5% by weight, and a specific surface area greater than 20 m². 2 / g.

[0023] Preferably, the filtration is performed using a filter medium with a mesh size of 100 mesh or more but not exceeding 200 mesh, such as a 100-200 mesh sieve.

[0024] A third aspect of the present invention provides a catalytic cracking catalyst comprising kaolin clay, a first alumina sol, boehmite, and a molecular sieve introduced from the kaolin-containing slurry, wherein the molecular sieve may be a first molecular sieve and / or a second molecular sieve, the first molecular sieve being a molecular sieve added during the preparation of the kaolin-containing slurry, and the second molecular sieve being a molecular sieve not added during the preparation of the kaolin-containing slurry, for example, a molecular sieve added during the preparation of the catalytic cracking catalyst colloid (or catalyst slurry).

[0025] In one embodiment, the catalyst is prepared from raw materials including the kaolin-containing slurry, an optional second alumina sol, boehmite, and an optional second molecular sieve (referred to as a molecular sieve not added to the kaolin slurry). Wherein, when the kaolin-containing slurry does not contain a molecular sieve, the second molecular sieve (i.e., the molecular sieve not added to the kaolin slurry) is added.

[0026] The total weight of all components in the catalytic cracking catalyst is 100 parts by weight, wherein, on a dry basis, kaolin clay comprises 35-50 parts by weight, fine catalytic cracking catalyst powder comprises 0-10 parts by weight, on a dry basis, molecular sieve comprises 25-35 parts by weight, on a dry basis, a first alumina sol comprises 0.5-6 parts by weight, a second alumina sol comprises 0-15 parts by weight (e.g., 6-10 parts by weight, 4.5-14 parts by weight, or 0-10 parts by weight), and boehmite comprises 15-20 parts by weight, on alumina. The molecular sieve includes a molecular sieve in the kaolin slurry (referred to as the first molecular sieve) and a second molecular sieve. The first and second molecular sieves can be the same molecular sieve or different molecular sieves.

[0027] Preferably, the total amount of the first aluminum sol and the second aluminum sol is 5 to 20 parts by weight, for example, 7 to 12 parts by weight.

[0028] According to the catalytic cracking catalyst of the present invention, all types of molecular sieves used in catalytic cracking reactions in the art can be used in the present invention. Preferably, for example, the molecular sieve is at least one of Y zeolite, ZSM-5 zeolite and β-type zeolite; the Y zeolite is preferably one or more of REY, REHY, REUSY, USY, Y zeolite modified with different silicon-to-aluminum ratios prepared by gas-phase chemical method (SiCl4 de-Al and Si-replenishment method), liquid-phase chemical method ((NH4)2SiF6 aluminum extraction and silicon-replenishment method) and other methods, or mixtures thereof; the ZSM-5 zeolite is, for example, a high silicon-to-aluminum ratio ZSM-5 zeolite, whose silicon-to-aluminum ratio (SiO2 / Al2O3 molar ratio) is, for example, 20 to 40; it can be hydrogen-form ZSM-5 zeolite, or ZSM-5 zeolite containing phosphorus and / or transition metals such as Fe, Co, Ni, Zn, RE, or one or more of them; the β zeolite is preferably a high silicon-to-aluminum ratio β zeolite.

[0029] According to the present invention, the molecular sieve can be introduced into the kaolin-containing slurry and / or added during the process of preparing the catalyst slurry (the molecular sieve not introduced during the kaolin slurry beating process). The molecular sieve introduced into the kaolin-containing slurry (i.e., introduced during the kaolin slurry beating process) is called the first molecular sieve. The molecular sieve not introduced during the kaolin slurry beating process is called the second molecular sieve.

[0030] According to the catalytic cracking catalyst of the present invention, based on the total dry weight of the catalytic cracking catalyst, the catalyst comprises: 45-55 wt% Al2O3, 30-40 wt% SiO2, 0-5 wt% Re2O3, 0.1-0.5 wt% Na2O, and 0-1 wt% SO4. 2- 0.3-0.5% by weight of Fe2O3 and 0.3-0.8% by weight of Cl -Preferably, by XRD (X-ray diffraction spectroscopy) analysis, the catalyst has characteristic peaks of Y-type molecular sieve and / or characteristic peaks of ZSM-5 molecular sieve and / or characteristic peaks of β molecular sieve.

[0031] According to one embodiment of the catalytic cracking catalyst of the present invention, the ratio of the crystallinity of the catalytic cracking catalyst to the crystallinity of pure Y-type molecular sieve is 15-25. The crystallinity is analyzed by XRD method.

[0032] A fourth aspect of the present invention provides a method for preparing the catalytic cracking catalyst of the present invention, comprising: mixing a raw material including the kaolin-containing slurry provided by the present invention, an optional second molecular sieve, an optional second alumina sol, and boehmite with water to form a slurry, the slurry also referred to as a catalyst colloid or catalyst slurry, and spray drying the mixture. In one embodiment, the solid content of the catalyst colloid is 20–45% by weight, for example 22–42% by weight or 25–38% by weight.

[0033] According to the method for preparing the catalytic cracking catalyst of the present invention, the pseudoboehmite undergoes one or more acidification processes. In one embodiment, the pseudoboehmite undergoes two acidification processes, wherein the acid-to-aluminum ratio in the first acidification is 0.01–0.1:1, and the acid-to-aluminum ratio in the second acidification is 0.05–0.1:1; wherein the acid-to-aluminum ratio is the weight ratio of the acid added (converted to an acid concentration of 36% by weight) to the pseudoboehmite (calculated as alumina), and the acid is preferably hydrochloric acid. In one embodiment, the first acidification is performed on the pseudoboehmite alone, i.e., acid is added to the pseudoboehmite slurry for acidification; the second acidification can be performed by adding acid to the slurry formed after mixing the pseudoboehmite with other components. Using two acidification processes can improve the continuity of catalyst production, increase the mixing speed, make the colloid more uniform, thus reducing nozzle clogging and ensuring more stable quality of the prepared catalyst. In one embodiment, the first acidification may be omitted, and the second acidification may be performed instead. In one implementation, only the first acidification may be performed, without the second acidification.

[0034] According to the preparation method of the catalytic cracking catalyst of the present invention, a first embodiment includes the following steps:

[0035] (1) Solid boehmite, acidic water and a first acid are mixed and stirred to obtain a boehmite slurry; the viscosity of the boehmite slurry is preferably less than 100,000 mPa·s, preferably less than 50,000 mPa·s; the solid content of the boehmite slurry is preferably 8-12% by weight; in one embodiment, the dry weight ratio of the first acid (based on the added acid solution) to the boehmite is 0.01-0.1; the stirring time after mixing the solid boehmite, acidic water and the first acid is preferably 1-2 hours, for example, the boehmite is mixed with water and pulped, then the first acid is added and stirred to obtain the boehmite slurry;

[0036] (2) The molecular sieve (referred to as the second molecular sieve) is preferably a molecular sieve slurry, the kaolin slurry of the present invention is preferably a slurry obtained after being filtered through a filter screen with a mesh size of more than 100 mesh, for example, 100 to 200 mesh, the pseudoboehmite slurry, and optionally the second aluminum sol are mixed and stirred for 10 to 60 minutes to obtain the first catalyst colloid (2); the solid content of the molecular sieve slurry is preferably 30 to 50% by weight; the solid content of the first catalyst colloid is preferably 20 to 45% by weight;

[0037] (3) The second acid is added to the slurry (2) obtained in step (2), and the mixture is stirred for 1-3 hours. It is then spray-dried and shaped, and optionally calcined, washed, and dried to obtain the finished catalyst. The weight ratio of the second acid (based on the weight of the added acid solution) to boehmite is 0.05-0.1 (dry basis).

[0038] In this first embodiment, the boehmite is weakly acidified with a first acid to avoid insufficient acidification leading to slurry stratification (a stratified boehmite slurry, when added to the catalyst preparation slurry, easily causes uneven distribution of the boehmite), and also to avoid over-acidification causing excessive viscosity of the boehmite slurry, which would make transportation difficult. A second acid is then used for complete acidification to obtain a suitable colloid that meets the requirements for catalytic cracking catalyst preparation.

[0039] According to the second embodiment of the preparation method of the catalytic cracking catalyst of the present invention, the method includes the following steps:

[0040] (S1) Molecular sieve (second molecular sieve) preferably molecular sieve slurry, pseudoboehmite, the kaolin-containing slurry obtained in this invention (preferably filtered through a filter with a mesh size of 100 mesh or higher), and optionally a second aluminum sol are mixed and stirred, preferably for 10-60 minutes, to obtain the slurry;

[0041] (S2) The third acid is added to the slurry obtained by (S1), and the mixture is stirred for 1-3 hours. The mixture is then spray-dried, calcined, washed, and dried to obtain the finished catalyst. The weight ratio of the third acid (based on the weight of the added acid solution) to boehmite is 0.1-0.2 (dry basis). The third acid is preferably hydrochloric acid.

[0042] According to the preparation method of the catalytic cracking catalyst of the present invention, a third embodiment includes the following steps:

[0043] (S1') Molecular sieve (second molecular sieve) preferably molecular sieve slurry, pseudoboehmite, the kaolin-containing slurry (second kaolin-containing slurry) containing catalyst fine powder of the present invention (preferably filtered through a filter screen with a mesh size of more than 100 mesh), and optionally a second alumina sol are mixed and stirred, for example, for 10-60 minutes to obtain a slurry;

[0044] (S2') The slurry obtained by adding the fourth acid, such as hydrochloric acid, to (S1') is stirred for 1-3 hours, spray-dried, calcined, washed, and dried to obtain the finished catalyst; the weight ratio of the fourth acid (based on the added acid solution) to boehmite is 0.1-0.2 (dry basis).

[0045] According to the preparation method of the catalytic cracking catalyst of the present invention, the fourth embodiment includes the following steps:

[0046] (S1”) Solid kaolin clay, first alumina sol, water, catalyst fine powder slurry, and molecular sieve (first molecular sieve), preferably molecular sieve slurry, are mixed and stirred for 2-5 hours to obtain a third kaolin-containing slurry with a solid content of 35-50% by weight. The weight ratio of solid kaolin, first alumina sol (calculated as alumina), catalyst fine powder slurry, and molecular sieve (calculated as dry basis) is 40-65:2-10:3-10:30-40.

[0047] (S2”) Mix the pseudoboehmite, the third kaolin-containing slurry (after filtering through a filter with a mesh size of 100 mesh or higher), and the optional second aluminum sol, and stir for, for example, 10-60 minutes to obtain the slurry;

[0048] (S3”) The fifth acid is added to the slurry obtained by (S2”), stirred for example for 1-3 hours, spray dried, calcined, washed, and dried to obtain the finished catalyst; the weight ratio of the fifth acid (based on the added acid solution) to boehmite is 0.1-0.2, preferably 0.12-0.15.

[0049] According to the present invention, the first, second, third, fourth, and fifth acids are used to acidify boehmite. The terms "first," "second," "third," "fourth," and "fifth" are used to distinguish the acids added in each step and are not intended to limit the types of acids; they can be the same acid or different acids. Each of the first, second, third, fourth, and fifth acids is preferably an acid solution with a concentration of 10-36% by weight. For example, each of the first, second, third, fourth, and fifth acids can be one or more of hydrochloric acid and nitric acid, preferably hydrochloric acid. In one embodiment, each of the first, second, third, fourth, and fifth acids is hydrochloric acid, wherein the HCl weight fraction of the hydrochloric acid is 31-36%, for example, 31%, 32%, 33%, 34%, 35%, or 36%. The HNO3 weight fraction of the nitric acid is 5-15%, for example, 5%, 6%, 7%, 8%, 9%, or 10%. The addition of the second, third, fourth, and fifth acids is to completely acidify the resulting slurry, achieving the most suitable colloid (or slurry) to meet the requirements for catalytic cracking catalyst preparation; typically, the viscosity of the colloid is greater than 100,000 mPa·s, for example, 100,000 to 200,000 mPa·s.

[0050] The viscosity of the slurry or colloid was measured using a rotational viscometer (Shanghai Hengping Scientific Instruments Co., Ltd., NDJ-1 type rotational viscometer).

[0051] The preparation method of the catalytic cracking catalyst according to the present invention, after spray drying, may optionally further include one or more of the following steps: calcination, washing, filtration, and drying, wherein preferably, the washing, filtration, and drying are performed after calcination.

[0052] A fifth aspect of this invention provides a method for catalytic cracking of hydrocarbon oil, comprising the step of contacting hydrocarbon oil with a catalytic cracking catalyst provided by this invention. The contact reaction can refer to existing technologies. For example, the reaction temperature is 480-520°C, the reaction time is 0.2-10 seconds, the reaction can be carried out in a fluidized bed or riser reactor, and the catalyst-to-oil ratio can be 3-12, for example, 4-8 by weight.

[0053] The present invention has the following effects:

[0054] The kaolin-containing slurry provided by this invention contains an appropriate amount of aluminum sol. While maintaining a high solid content, the kaolin-containing slurry exhibits small particle size, low impurity content (few large particles), fine kaolin particles, and low viscosity. This kaolin-containing slurry demonstrates good kaolin dispersibility and high uniformity, allowing it to be stored for 24 hours or more without stratification. The slurry exhibits good fluidity, stable performance, and ease of filtration (avoiding frequent clogging of filter screens or filtration systems). Therefore, this kaolin-containing slurry can be used in the preparation of catalytic cracking catalysts, reducing the amount of binder and molecular sieves required, thereby lowering catalyst preparation costs while maintaining catalyst quality and stability.

[0055] The method for preparing kaolin slurry provided by this invention has a simple process. It involves slurrying raw kaolin clay with a specific aluminum sol dispersion. The kaolin-containing aluminum sol in the slurry reacts with the kaolin surface to modulate it, forming a specific kaolin-aluminum sol structure. No prior modification of the kaolin is required, nor are additional dispersants or additives needed. Using aluminum sol, which can be used as a component of a catalytic cracking catalyst, for slurrying avoids introducing other components during catalyst preparation. This method yields a kaolin slurry with high solids content, fine kaolin particle size, uniform particle size distribution, low impurity content, and low viscosity. It solves the problems of existing high-solids-content kaolin slurries, where the kaolin is difficult to simultaneously achieve fine particle size, high impurity content, poor uniformity, and difficulty in impurity separation. The resulting kaolin slurry exhibits good dispersion, low viscosity, good fluidity, convenient transportation, and easy impurity separation through filter vibration. It does not stratify during long-term storage, demonstrating unexpected and beneficial technical effects. This may be due to the specific bonding structure formed between the aluminum sol and the kaolin.

[0056] The catalytic cracking catalyst provided by this invention, containing the first aluminum sol-modified kaolin, can achieve a higher gasoline yield when used for the catalytic cracking of hydrocarbon oils such as heavy oil, under the same composition. Preferably, it can achieve a higher conversion rate.

[0057] The catalytic cracking catalyst preparation method provided by this invention is simple and easy to industrialize. The catalyst slurry (or catalyst colloid) obtained by this method is of stable quality, fine in texture, and free of excessive impurities. It is easy to filter, less prone to clogging of the spray drying nozzles and the colloid filter screen, reducing wear on the filter screen material and spray drying nozzles, thus reducing manual labor intensity and increasing automation. It can reduce the amount of binder and molecular sieve added, eliminating the need for additional kaolin dispersants or additives, lowering catalyst preparation costs, maintaining catalyst quality and performance stability, thereby increasing the solid content of the catalyst colloid (i.e., the slurry before spray drying), effectively improving the continuity of catalyst quality, enhancing the stability of the catalyst preparation process, reducing catalyst gelation time, increasing catalyst yield per unit time, and reducing catalyst energy consumption.

[0058] The catalytic cracking method provided by this invention can improve the gasoline yield and / or conversion rate of hydrocarbon oil, especially heavy oil, through catalytic cracking. Detailed Implementation

[0059] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0060] The present invention provides a method for preparing a catalytic cracking catalyst, Scheme 1, which includes:

[0061] (1): Solid kaolin and alumina sol (first alumina sol) and water, such as acidic water, are mixed, preferably stirred for 2-5 hours, and preferably filtered through a filter screen with a mesh size of 100 mesh or higher, such as 100-200 mesh, to obtain kaolin slurry one;

[0062] (2): Solid boehmite, acidic water and hydrochloric acid are mixed and stirred for 1-2 hours to obtain boehmite slurry, which is called slurry two;

[0063] (3): Molecular sieve, kaolin slurry one, pseudoboehmite slurry one, and alumina sol (second alumina sol) are mixed, preferably stirred for 10-60 min; to obtain slurry three.

[0064] (4): Add hydrochloric acid to slurry three, stir for 1-3 hours to obtain catalyst slurry, spray dry to form, calcine, wash, dry to obtain finished catalyst.

[0065] According to the present invention, the acidic water is also called decationized water, and its pH value is usually 3-5.

[0066] According to the preparation method of the catalytic cracking catalyst provided by the present invention, in step (1) of Scheme 1, the dry weight ratio of solid kaolin and alumina sol (calculated as alumina) is 90-98:2-10, and the solid content of the slurry is 35-50% by weight.

[0067] According to the preparation method of the catalytic cracking catalyst provided by the present invention, in step (2) of Scheme 1, the solid content of the slurry can be 8-12% by weight. The dry weight ratio of hydrochloric acid (calculated as 36% by weight hydrochloric acid) to boehmite is 0.01-0.1. Preferably, the weight fraction of HCl in the hydrochloric acid is 31-36%, for example, 31%, 32%, 33%, 34%, 35%, or 36%. The viscosity of the boehmite slurry obtained after acidification is less than 100,000 centipoise, preferably less than 50,000 centipoise. This slurry is defined as a weakly acidified slurry, which can avoid the stratification phenomenon of unacidified boehmite, resulting in uneven distribution in the catalyst, and also avoid the excessive viscosity of over-acidified boehmite, which is difficult to transport.

[0068] According to the preparation method of the catalytic cracking catalyst provided by the present invention, in step (4) of Scheme 1, the dry weight ratio of hydrochloric acid (converted to 36% by weight hydrochloric acid) to boehmite is 0.05-0.1. Preferably, the weight ratio of the sum of the acids in step (2) and step (4) (converted to 36% by weight hydrochloric acid) to boehmite on a dry basis is 0.1-0.2. The acid added in this step completely acidifies the mixed slurry (3) to achieve the most suitable colloid, thereby meeting the requirements for the preparation of the catalytic cracking catalyst.

[0069] According to the preparation method of the catalytic cracking catalyst provided by the present invention, Scheme 2, the method includes:

[0070] (1): Solid kaolin, aluminum sol, and acidic water are mixed and stirred for 2-5 hours; preferably filtered through a filter screen of 100 mesh or higher, such as 100-200 mesh, to obtain a slurry containing kaolin.

[0071] (2): Molecular sieve, pseudoboehmite, kaolin-containing slurry II, and aluminum sol are mixed and stirred for 10-60 min to obtain slurry V;

[0072] (3): Add hydrochloric acid to slurry five and stir for 1-3 hours to obtain catalyst slurry. Spray dry to form, calcine, wash and dry to obtain finished catalyst.

[0073] According to the preparation method of the catalytic cracking catalyst provided by the present invention, in Scheme 2, the dry weight ratio of solid kaolin and alumina sol (calculated as alumina) in step (1) is 90-98:2-10, and the solid content of kaolin slurry is 35-50% by weight.

[0074] The preparation method of the catalytic cracking catalyst provided by the present invention, in Scheme 2, the dry weight ratio of hydrochloric acid and boehmite in step (3) is 0.1-0.2, so as to completely acidify the mixed slurry to achieve the most suitable colloid, so as to meet the preparation requirements of the catalytic cracking catalyst.

[0075] According to Scheme 2 of the method for preparing the catalytic cracking catalyst of the present invention, preferably, the solid content of the catalyst slurry is 35-45% by weight, more preferably 36-40% by weight, for example 37-38% by weight.

[0076] The preparation method of the catalytic cracking catalyst provided by the present invention, Scheme 3, includes:

[0077] (1): Solid kaolin, aluminum sol, acidic water, and catalyst powder are mixed and stirred for 2-5 hours to obtain a slurry containing kaolin. It is preferred to filter the slurry through a filter screen of 100 mesh or higher, such as 100-200 mesh. The catalyst powder can be mixed with some or all of the water to form a slurry before being mixed with other materials.

[0078] (2): Molecular sieve, pseudoboehmite, kaolin-containing slurry, and aluminum sol are mixed and stirred for 10-60 minutes to obtain slurry.

[0079] (3): Hydrochloric acid is added to slurry 6 and stirred for 1-3 hours to obtain catalyst slurry. The slurry is then spray-dried, calcined, washed, and dried to obtain the finished catalyst.

[0080] In the third embodiment of the present invention, the dry weight ratio of solid kaolin, alumina sol (calculated as alumina) and catalyst fine powder in step (1) is preferably 90-98:2-10:3-10, and the solid content of the slurry is 35-50% by weight.

[0081] In the preparation method of the catalytic cracking catalyst provided by the present invention, in Scheme 3, the dry weight ratio of hydrochloric acid (calculated as HCl concentration 36% by weight) and boehmite in step (3) is preferably 0.1-0.2. By adding hydrochloric acid to completely acidify the mixed slurry (3), a suitable colloid is obtained to meet the requirements for the preparation of the catalytic cracking catalyst.

[0082] According to the preparation method of the catalytic cracking catalyst provided by the present invention, in Scheme 3, the solid content of the catalyst slurry (catalyst colloid) is preferably 35-45% by weight, more preferably 36-40% by weight, for example 38-39% by weight.

[0083] According to the preparation method of the catalytic cracking catalyst of the present invention, Scheme 4 includes:

[0084] 1): Solid kaolin, aluminum sol, acidic water, catalyst powder, and molecular sieve slurry are mixed and stirred for 2-5 hours; preferably filtered through a filter screen of 100 mesh or higher, such as 100-200 mesh; to obtain kaolin-containing slurry IV, wherein the catalyst powder can be first mixed with some or all of the water to form a slurry, and then mixed with other materials;

[0085] (2): Mix boehmite, kaolin-containing slurry IV, and alumina sol, and stir for 10-60 minutes to obtain slurry V.

[0086] (3): Add hydrochloric acid to slurry 7 and stir for 1-3 hours to obtain catalyst slurry. Spray dry to form, calcine, wash and dry to obtain finished catalyst.

[0087] The preparation method of the catalytic cracking catalyst provided by the present invention, in Scheme 4, in step (1), the dry weight ratio of solid kaolin, alumina sol (calculated as alumina), catalyst fine powder slurry, and molecular sieve slurry is 40-65:2-10:3-10:30-40, to obtain Kaolin Slurry 4, the solid content of Kaolin Slurry 4 is 35-50% by weight; preferably, the ratio of the total weight of molecular sieve, catalyst fine powder, and kaolin on a dry basis to the total weight of alumina sol on alumina is 90-98:2-10.

[0088] The preparation method of the catalytic cracking catalyst provided by the present invention, in Scheme 4, in step (3), the dry weight ratio of hydrochloric acid (calculated as 36% hydrochloric acid) and boehmite is 0.1-0.2, preferably 0.12-0.15, so as to completely acidify the mixed slurry and obtain a suitable colloid to meet the needs of catalytic cracking catalyst preparation.

[0089] According to the preparation method of the catalytic cracking catalyst provided by the present invention, in Scheme 4, preferably, the solid content of the catalyst slurry is 35-45% by weight, more preferably 36-42% by weight, for example 40-42% by weight.

[0090] Preferably, the catalyst cracking catalyst is prepared using either Scheme 1 or Scheme 2.

[0091] According to one specific embodiment of the present invention, after spray drying, the process further includes one or more of the following steps: calcination, washing, filtering, and drying. Preferably, the washing, filtering, and drying are performed after calcination. The spray drying, calcination, washing, filtering, and drying processes are prior art, and the present invention does not have specific requirements for them, so they will not be described in detail here.

[0092] The present invention does not impose any particular limitation on the acidification process, and it can be carried out using conventional techniques in the art. The present invention allows for a wide selection of the type of acid used for acidification; for example, it can use inorganic acids commonly used in the art, including but not limited to hydrochloric acid.

[0093] The kaolin described in this invention is a clay raw material well-known to those skilled in the art. Commonly used kaolin clay varieties can be used in this invention. For this invention, the preferred kaolin clay is one or more of the following: kaolin (primarily kaolinite with a kaolinite content exceeding 50% by weight), hydrous kaolin (hydrous kaolinite content exceeding 50% by weight), halloysite, quasi-haloysite, and bentonite. For this invention, the preferred kaolin clay is kaolinite (kaolinite) and / or halloysite.

[0094] In this invention, the molecular sieve is a molecular sieve raw material well known in the art. All commonly used molecular sieve types in the art can be used in this invention. Preferably, the molecular sieve is at least one of Y zeolite, ZSM-5 zeolite, and β-type zeolite. More preferably, it is REY, REHY, REUSY, USY, Y zeolite modified with different silicon-to-aluminum ratios prepared by gas-phase chemical methods (SiCl4 de-Al and Si-replenishment method), liquid-phase chemical methods ((NH4)2SiF6 aluminum extraction and silicon replenishment method), or other methods, or mixtures thereof, as well as ZSM-5 type, β-type zeolite, or mixtures thereof containing other types of high silicon-to-aluminum ratios. The molecular sieve is preferably REY molecular sieve.

[0095] The present invention also provides a catalytic cracking catalyst prepared by the above-described method, wherein the catalyst comprises, based on the total amount of the catalytic cracking catalyst, 45-55 wt% Al₂O₃, 30-40 wt% SiO₂, 0-5 wt% Re₂O₃, 0.1-0.5 wt% Na₂O, and 0-1 wt% SO₄²⁻. 2- 0.3-0.5% by weight of Fe2O3 and 0.3-0.8% by weight of Cl - .

[0096] Preferably, the catalyst has a specific surface area of ​​250 m². 2 / g or more, preferably 260-300m 2 / g.

[0097] In this invention, unless otherwise specified, the specific surface area of ​​the catalyst is obtained by the method for testing the specific surface area of ​​petroleum refining catalysts in GB / T38691-2020.

[0098] In this invention, unless otherwise specified, the composition of the catalyst is obtained by fluorescence analysis as described in ASTM D7085-2004e1.

[0099] The catalytic cracking catalyst provided by the present invention is preferably composed of 25-35 wt% molecular sieve on a dry basis, 0.5-6 wt% first alumina sol on alumina, 0-10 wt% (e.g., 6-10 wt%) second alumina sol on alumina, 15-20 wt% boehmite on alumina, 0-10 wt% fine powder of catalytic cracking agent on a dry basis, and 35-50 wt% kaolinite clay on a dry basis.

[0100] The present invention will be described in detail below through examples. The specifications of the raw materials used in the examples and comparative examples are as follows:

[0101] Kaolin: Solid content 72 wt%, produced by China Kaolin Co., Ltd. (Suzhou). The kaolin exhibits a tubular structure, with an alumina content of 36 wt%, iron oxide 0.78 wt%, α-SiO2 quartz sand content of 1.0 wt%, and a specific surface area of ​​25 m². 2 / g. Of which, kaolinite content is 65% by weight.

[0102] Aluminum sol: Al2O3 content 22% by weight, produced by Qilu Branch of Sinopec Catalyst Co., Ltd.

[0103] Boehmite: solid content 72% by weight, Shandong Branch of Aluminum Corporation of China Limited.

[0104] The molecular sieve used in the preparation of the catalytic cracking catalyst is a Y-type molecular sieve (Y-type molecular sieve containing RE): produced by Qilu Branch of Sinopec Catalyst Co., Ltd., with a solid content of 80% by weight, a rare earth content of 7.0% by weight, and a silicon-aluminum ratio (SiO2 / Al2O3 molar ratio) of 3.2.

[0105] Catalyst fine powder: Conventional heavy oil catalyst product, alumina 50 wt%, sodium oxide 0.2 wt%, average particle size DV(0.5) 4.5, DV(0.9) 18 μm.

[0106] Acidic water (deionized water) with a pH of 3-5.

[0107] Hydrochloric acid, concentration 36% by weight.

[0108] In the examples and comparative examples, room temperature refers to 26°C.

[0109] The composition of the catalyst is determined based on the amount of each raw material fed.

[0110] Unless otherwise specified, all percentages in the following examples and comparative examples are by weight.

[0111] Analysis method:

[0112] (1) The pore volume and wear index were determined by RIPP28-90 and RIPP29-90 methods in "Analytical Methods for Petrochemicals, RIPP Test Methods" (edited by Yang Cuiding, Science Press, published in 1990).

[0113] (2) The bulk density was obtained by the apparent bulk density determination method of NB / SH / T 0954-2017 catalytic cracking catalyst.

[0114] The catalyst examples use the following uniform formulation: 35% molecular sieve, 20% bauxite, 8% alumina sol, and 37% kaolin. The contents are weight percentages, with molecular sieve and kaolin on a dry basis, and bauxite and alumina sol on alumina.

[0115] Kaolin Pulping Example 1

[0116] According to the ratio of 37 parts by weight of kaolin (dry basis) and 2 parts by weight of aluminum sol (alumina basis), kaolin, acidic water and aluminum sol were mixed in a 1m solution. 3 The mixture was stirred in a gelling tank (mixing vessel) for 120 minutes to obtain a kaolin slurry with a solid content of 42% by weight; denoted as GLJ-1. The stirring conditions and properties of the kaolin slurry are shown in Table 1.

[0117] GLJ-1, after being placed for 24 hours, did not separate into layers, showed no sedimentation, and was stable.

[0118] Example 2 of Kaolin Pulverization

[0119] Kaolin slurry was prepared according to the method in Example 1 of kaolin slurry preparation, except that slurry preparation was carried out at 50°C and the slurry was kept at 50°C for 24 hours. The slurry preparation conditions and properties are shown in Table 1 and are denoted as GLJ-2.

[0120] GLJ-2, after being placed for 24 hours, did not separate into layers, showed no sedimentation, and was stable.

[0121] Example 3 of Kaolin Pulverization

[0122] Kaolin slurry was prepared according to the method in Example 1 of kaolin slurry preparation. The slurry preparation conditions and properties are shown in Table 1 and are denoted as GLJ-3.

[0123] Kaolin Pulping Example 4

[0124] Kaolin slurry was prepared according to the method in Example 1 of kaolin slurry preparation, except that the weight ratio of kaolin to alumina sol was 37:0.8. This slurry was designated GLJ-4, and its slurry preparation conditions and properties are shown in Table 1.

[0125] Kaolin Pulping Example 5

[0126] Kaolin slurry was prepared according to the method in Example 1 of kaolin slurry preparation, except that the weight ratio of kaolin to alumina sol was 37:4, and the solid content was 48% by weight, denoted as GLJ-5. The slurry preparation conditions and properties are shown in Table 1.

[0127] Kaolin Pulping Example 6

[0128] The method of kaolin slurry preparation in Example 1 was followed by the addition of water to a gelling tank, followed by the addition of kaolin, catalytic cracking catalyst fine powder slurry, and alumina sol. The weight ratio of kaolin (on a dry basis), alumina sol (based on alumina), and catalytic cracking catalyst fine powder (on a dry basis) was 37:2:3. The solid content of the slurry was 42% by weight, resulting in a kaolin-containing slurry. This slurry was designated GLJ-6. The slurry preparation conditions and properties of this kaolin-containing slurry are shown in Table 1.

[0129] Kaolin Pulping Example 7

[0130] Following the method of Example 1 for kaolin slurry preparation, the difference is that water is added to the gelling tank, followed by kaolin, molecular sieves, fine powder of catalytic cracking catalyst, and alumina sol. The weight ratio of kaolin (on a dry basis), alumina sol (based on alumina), fine powder of catalytic cracking catalyst (on a dry basis), and molecular sieve (on a dry basis) is 34:3:3:35. The solid content of the slurry is 42% by weight, resulting in a kaolin slurry. This slurry is designated GLJ-7. The slurry preparation conditions and properties are shown in Table 1.

[0131] Kaolin Pulping Comparative Example 1

[0132] Kaolin slurry was prepared according to the method in Example 1, except that the ratio of aluminum sol to kaolin was 37:5. The slurry mixing conditions and slurry properties are shown in Table 1.

[0133] Kaolin Pulverization Comparative Example 2

[0134] Kaolin slurry was prepared according to the method in Example 1, except that the weight ratio of aluminum sol to aluminum sol (calculated as alumina) was 37:0.2. The pulping conditions and slurry properties are shown in Table 1.

[0135] Kaolin Pulping Comparative Example 3

[0136] The pulping was carried out according to the method of Example 1, except that aluminum sol was not added; instead, water was used directly for pulping, with the material added at a solid content of 42% by weight. Pulping was difficult, the slurry was too thick, and the kaolin solidified. The pulping conditions and slurry properties are shown in Table 1.

[0137] Kaolin was slurried with water, with a solid content of 20% by weight. When stirring was stopped, it separated into layers and the viscosity was greater than 200,000 mPa·s.

[0138] Kaolin Pulverization Comparison Example 4

[0139] The pulping was performed according to the method in Example 1, except that aluminum sol was not added; instead, ammonium polyacrylate dispersant was added, and acidic water was used for pulping. After standing for 12 hours, solid-liquid separation gradually occurred. The pulping conditions and pulp properties are shown in Table 1.

[0140] Table 1

[0141]

[0142] In Table 1, * indicates the weight ratio of kaolin (dry basis) to the first alumina sol (alumina basis) in the kaolin-containing slurry.

[0143] Table 1 (continued)

[0144]

[0145] Table 2

[0146]

[0147]

[0148] Note: The aluminum sol used for slurrying kaolin is called the first aluminum sol; the second aluminum sol is the aluminum sol introduced outside the kaolin-containing slurry during the preparation of the catalyst slurry.

[0149] Table 3

[0150]

[0151] Example 1

[0152] Acidic water was mixed with 20 parts by weight of pseudoboehmite (abbreviated as alumina) in a 1m solution. 3 The mixture was pulped in a gelling tank to obtain a solid content of 12% by weight. 36% by weight hydrochloric acid was added at an acid-to-aluminum ratio of 0.1 by weight, and the mixture was stirred for 60 min to obtain a pseudo-boehmite slurry, denoted as NBJ-1, in which DV(0.5) was 1.6 μm and DV(0.9) was 3.3 μm.

[0153] 35 parts by weight of molecular sieve slurry (concentration 400 g / L, dry basis), GLJ-1 kaolin slurry (used after standing for 24 hours), the NBJ-1 pseudoboehmite slurry, and 6 parts by weight of second alumina sol (based on alumina) were mixed and stirred for 10 min. Hydrochloric acid was added and acidified for 90 min at an acid-to-alumina ratio of 0.07 (36% hydrochloric acid to pseudoboehmite based on alumina) to obtain a catalyst slurry. The catalyst slurry was spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500 °C for 1 h, washed twice, each time with 8 times the dry weight of the catalyst microspheres of decationized water, and dried at 120 °C for 2 h to obtain catalytic cracking catalyst C-1. The preparation conditions and composition of the catalyst are shown in Table 2.

[0154] Example 2

[0155] A catalytic cracking catalyst was prepared according to Example 1. Molecular sieve slurry, kaolin slurry GLJ-1, pseudoboehmite slurry NBJ-1, and a second alumina sol were mixed and stirred for 90 min. Hydrochloric acid was added and acidified for 180 min at an acid-to-alumina ratio of 0.07. The catalyst slurry was then spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500℃ for 1 h, washed twice, each time with 8 times the dry weight of the catalyst microspheres of decationized water, and dried at 120℃ for 2 h to obtain catalytic cracking catalyst C-2. The preparation conditions and composition of the catalyst are shown in Table 2.

[0156] Example 3

[0157] Following the method described in Example 1, molecular sieve slurry GLJ-1, kaolin slurry, pseudoboehmite slurry NBJ-1, and second alumina sol were mixed for 10 min, acidified with hydrochloric acid for 90 min (acid-to-alumina ratio 0.02), and the catalyst slurry was spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500℃ for 1 h, washed twice (each wash with 8 times the dry weight of the catalyst microspheres of decationized water), and dried at 120℃ for 2 h to obtain catalytic cracking catalyst C-3. The preparation conditions and composition of the catalyst are shown in Table 2.

[0158] Example 4

[0159] REY molecular sieve slurry (concentration 400 g / L), kaolin slurry GLJ-2, pseudoboehmite dry powder, and second alumina sol were mixed and stirred for 10 min. Then, hydrochloric acid was added and acidified for 90 min at an acid-to-alumina ratio of 0.20 to obtain a catalyst slurry with a total solid content of 36% by weight. The catalyst slurry was spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500 °C for 1 h, washed twice, each time with 8 times the dry weight of the catalyst microspheres of decationized water, and dried at 120 °C for 2 h to obtain catalytic cracking catalyst C-4. The preparation conditions and composition of the catalyst are shown in Table 2.

[0160] Example 5

[0161] Molecular sieve, kaolin slurry GLJ-1 prepared in Example 1, boehmite NBJ-1, and second alumina sol were mixed for 10 min, acidified with hydrochloric acid for 90 min, with an acid-to-alumina ratio of 0.10 and a total colloidal solids content of 38%. The catalyst slurry was spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500℃ for 1 h, washed twice, each time with 8 times the dry weight of the catalyst microspheres of decationized water, and dried at 120℃ for 2 h to obtain catalytic cracking catalyst C-5. The preparation conditions and composition of the catalyst are shown in Table 2.

[0162] Example 6

[0163] Molecular sieve slurry, kaolin slurry GLJ-3, pseudoboehmite dry powder, and second alumina sol were mixed for 10 min, acidified with hydrochloric acid for 90 min, with an acid-to-alumina ratio of 0.20, to obtain a catalyst slurry (also known as catalyst colloid) with a total solid content of 36% by weight. The catalyst slurry was spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500℃ for 1 h, washed twice, each time with 8 times the dry weight of the catalyst microspheres of decationized water, and dried at 120℃ for 2 h to obtain catalytic cracking catalyst C-6. The composition and properties of the catalyst are shown in Table 2.

[0164] Example 7

[0165] The catalyst was prepared according to the method of Example 1, except that the kaolin-containing slurry GLJ-4 prepared in Example 4 was used. The preparation conditions and composition of the catalyst are shown in Table 2.

[0166] Example 8

[0167] The catalyst was prepared according to the method of Example 1, except that a kaolin-containing slurry GLJ-5 was prepared in Example 5 using kaolin slurry. The preparation conditions and composition of the catalyst are shown in Table 2.

[0168] Example 9

[0169] The catalyst was prepared according to the method of Example 1, except that GLJ-6, a kaolin-containing slurry prepared in Example 6, was used instead of GLJ-1. The preparation conditions and composition of the catalyst are shown in Table 2.

[0170] Example 10

[0171] 75 parts by weight (dry basis) of GLJ-7 kaolin-containing slurry, 20 parts by weight (alumina basis) of NBJ-1 slurry, and 5 parts by weight (alumina basis) of second alumina sol were mixed. 36% by weight hydrochloric acid was added, resulting in an acid-to-alumina ratio of 0.1 by weight. The mixture was stirred for 10 min, then acidified with hydrochloric acid for 90 min, resulting in an acid-to-alumina ratio of 0.07 (36% by weight hydrochloric acid to boehmite based on alumina). The resulting catalyst slurry was spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500℃ for 1 h, washed twice, each time with 8 times the dry weight of the catalyst microspheres of decationized water, and dried at 120℃ for 2 h to obtain catalytic cracking catalyst C-10. The preparation conditions and formulation of the catalyst are shown in Table 2.

[0172] Example 11

[0173] Using the kaolin slurry and pseudoboehmite slurry from Example 1, the molecular sieve slurry, kaolin slurry, and pseudoboehmite slurry were mixed for 90 min, acidified with hydrochloric acid for 90 min (acid-to-aluminum ratio 0.07), and the catalyst slurry was spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500℃ for 1 h, washed twice, each time with 8 times the dry weight of the catalyst microspheres of decationized water, and dried at 120℃ for 2 h to obtain catalytic cracking catalyst C-11. The catalyst formulation and preparation conditions are shown in Table 3.

[0174] Example 12

[0175] Molecular sieves, the kaolin-containing slurry used in Example 1, boehmite, and the second alumina sol were mixed for 120 min, acidified with hydrochloric acid for 300 min, with an acid-to-alumina ratio of 0.25, and the total solid content of the catalyst slurry was 36% by weight. The catalyst slurry was then spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500℃ for 1 h, washed twice, each time with 8 times the dry weight of the catalyst microspheres of decationized water, and dried at 120℃ for 2 h to obtain catalytic cracking catalyst C-12. The catalyst composition and preparation conditions are shown in Table 3.

[0176] Comparative Example 1

[0177] Acidic water, molecular sieves, kaolin, and alumina sol were added to a gelling reactor and stirred for 2 hours. Then, alumina was added and stirred for 40 minutes. Finally, hydrochloric acid was added for acidification (36% hydrochloric acid to boehmite by weight of 0.2, calculated as alumina) for 60 minutes. The catalyst slurry was spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500℃ for 1 hour, washed twice, each time with 8 times the dry weight of the catalyst microspheres of decationized water, and dried at 120℃ for 2 hours to obtain catalytic cracking catalyst D-1. The catalyst formulation is shown in Table 3.

[0178] Comparative Example 2

[0179] The catalyst was prepared using the method of Example 1, except that DGLJ-2 was prepared by slurry preparation of kaolin clay as in Comparative Example 2. The resulting catalyst is denoted as D-2.

[0180] Comparative Example 3

[0181] Molecular sieves were slurried with kaolin and acidic water to obtain a slurry with a solid content of 32% by weight. The mixture was stirred for 120 min to obtain a molecular sieve + kaolin slurry. A pseudoboehmite + alumina sol slurry was slurried in a gelling tank to obtain a solid content of 25% by weight. Hydrochloric acid was added for acidification at an acid-to-alumina ratio of 0.025, and the mixture was stirred for 60 min to obtain a pseudoboehmite slurry. The molecular sieve + kaolin slurry and the pseudoboehmite slurry were mixed and stirred for 30 min. Hydrochloric acid was added, and the mixture was acidified for 90 min at an acid-to-alumina ratio of 0.2. The mixture was then spray-dried to obtain catalyst microspheres. The obtained catalyst microspheres were calcined at 500℃ for 1 h, washed twice, each time with 8 times the dry weight of the catalyst microspheres of decationized water, and dried at 120℃ for 2 h to obtain catalytic cracking catalyst D-3. The catalyst formulation is shown in Table 3.

[0182] Comparative Example 4

[0183] The catalyst was prepared using the method of Example 1, except that DGLJ-4 was prepared by slurry preparation of kaolin clay as in Comparative Example 4. The comparative catalyst D-4 was obtained. Its formulation is shown in Table 3.

[0184] Comparative Example 5

[0185] Kaolin, alumina sol, and water were mixed and stirred for 1 hour to prepare a slurry with a solid content of 31% by weight. Boehmite was added and stirred for 40 minutes. Molecular sieve slurry was added and stirred for 30 minutes. Silica sol (silicon oxide content 30% by weight) was added and stirred for 30 minutes. The mixture was then spray-dried, calcined at 200℃ for 30 minutes, washed twice, each time with 5 times the dry weight of the catalyst microspheres of decationized water, and dried at 120℃ for 2 hours to prepare catalyst D-5. The formulation is shown in Table 3.

[0186] The physicochemical properties of catalysts C-1 to 12 prepared in the examples and catalysts prepared in the comparative examples are shown in Table 4.

[0187] Table 4 Properties of the catalyst

[0188]

[0189] Test case

[0190] This test example is used to evaluate the performance of the catalytic cracking catalyst provided above.

[0191] The catalyst was subjected to aging and deactivation treatment at 800℃ and 100% (v / v) water vapor for 12 hours. The catalyst loading was 9g, and the reaction feedstock was Wuhunsan feedstock oil, which is shown in Table 5. The reaction temperature was 500℃, and the catalyst-to-oil ratio (by weight) was 6. The measured catalyst performance parameters are listed in Tables 6 and 7.

[0192] Wherein, conversion rate = gasoline yield + liquefied petroleum gas yield + dry gas yield + coke yield;

[0193] Light oil yield = Gasoline yield + Diesel yield;

[0194] Liquid yield = LPG yield + gasoline yield + diesel yield;

[0195] Coke selectivity = Coke yield / Conversion rate;

[0196] Table 5

[0197]

[0198] Table 6

[0199]

[0200] Table 7

[0201]

[0202] As can be seen from Tables 6 and 7, the catalytic cracking catalyst prepared by the method provided in this invention has better heavy oil cracking performance than the catalytic cracking catalyst prepared by the prior art, with higher conversion rate and gasoline yield, and the prepared catalyst has more stable performance.

Claims

1. A slurry containing kaolin, characterized in that, The slurry contains solid particles and aluminum sol, referred to as the first aluminum sol. The solid particles comprise kaolin clay, wherein the weight ratio of the solid particles (dry basis) to the aluminum sol (alumina basis) is 90-98:2-10, and the solid content of the kaolin-containing slurry is 35-50% by weight.

2. The kaolin-containing slurry according to claim 1, characterized in that, The viscosity of the kaolin-containing slurry does not exceed 1000 mPa·s and / or the impurity content does not exceed 0.5% by weight.

3. The kaolin-containing slurry according to claim 1, characterized in that, The solid particles are kaolin clay, wherein the weight ratio of kaolin clay to aluminum sol on a dry basis is 90-98:2-10. The particle size distribution of the solid particles in the kaolin-containing slurry is measured by laser particle size distribution method as follows: D(50) is ≤4μm, for example 1.5~3.5; D(90) is not more than 10μm, for example 7~10μm.

4. The kaolin-containing slurry according to claim 1, characterized in that, The solid particles are kaolin clay and fine powder of catalytic cracking catalyst; in the kaolin-containing slurry, the weight ratio of kaolin clay (dry basis), alumina sol (calculated as alumina), and fine powder of catalytic cracking catalyst (dry basis) is 90-98:2-10:3-10, and the solid content of the kaolin-containing slurry is 35-50% by weight; the average particle size of the fine powder of catalytic cracking catalyst does not exceed 6 micrometers; the particle size distribution of the kaolin-containing slurry is: D50 is ≤6μm, for example 4-5μm; D(90) is not more than 20μm, for example 15-18μm.

5. The kaolin-containing slurry according to claim 1, characterized in that, The solid particles are kaolin clay, fine powder of catalytic cracking catalyst, and molecular sieve; in the kaolin-containing slurry, the weight ratio of kaolin clay (dry basis), alumina sol (calculated as alumina), fine powder of catalytic cracking catalyst (dry basis), and molecular sieve (dry basis) is 40-65:2-10:3-10:30-40, and the solid content of the kaolin-containing slurry is 35-50% by weight; the average particle size of the fine powder of catalytic cracking catalyst does not exceed 6 micrometers; the particle size distribution of the kaolin-containing slurry is: D(50) is ≤6μm, for example 4-5μm; D(90) is not more than 20μm, for example 15-18μm.

6. A method for preparing the kaolin-containing slurry according to any one of claims 1-5, comprising: A mixture of solid material including kaolin clay and a first aluminum sol and water is formed and pulped, and optionally filtered; in one embodiment, the pulping time is 2 to 5 hours; the pH value of the kaolin-containing slurry is preferably 3 to 5.

7. The method for preparing kaolin-containing slurry according to claim 6, characterized in that, The first aluminum sol has the following characteristics: Al content is 11-12% by weight, aluminum-chlorine ratio is greater than 1.25, and pH value is less than 4; Preferably, the aluminum sol is obtained by reacting metallic aluminum particles with hydrochloric acid; Preferably, the kaolin clay is one or more of kaolin, hydrous kaolin, quasi-halolite, and bentonite; Preferably, the kaolin is kaolin with a flaky or tubular structure, having an alumina content greater than 36% by weight, an iron oxide content less than 3% by weight, an α-SiO2 quartz sand content less than 5% by weight, and a specific surface area greater than 20 m². 2 / g; Preferably, the filtration is performed using a filter medium with a mesh size of 100 mesh or higher, such as a sieve with a mesh size of 100-200 mesh.

8. A catalytic cracking catalyst comprising kaolin clay introduced from the kaolin-containing slurry of claim 1, a first alumina sol, boehmite, a molecular sieve, optionally a second alumina sol, and optionally fine powder of the catalytic cracking catalyst.

9. The catalytic cracking catalyst according to claim 8 is prepared from a raw material comprising the kaolin-containing slurry according to any one of claims 1 to 5, optionally a second alumina sol, pseudoboehmite, and optionally a second molecular sieve.

10. The catalytic cracking catalyst according to claim 8 or 9, characterized in that, The total weight of each component in the catalytic cracking catalyst is 100 parts by weight, wherein the kaolin clay (dry basis) is 35-50 parts by weight, the fine powder of the catalytic cracking catalyst (dry basis) is 0-10 parts by weight, the molecular sieve (dry basis) is 25-35 parts by weight, the first alumina sol (alumina) is 0.5-6 parts by weight, the second alumina sol (alumina) is 0-15 parts by weight (e.g., 6-10 parts by weight), and the pseudoboehmite (alumina) is 15-20 parts by weight. Preferably, the total amount of the first aluminum sol and the second aluminum sol is 5 to 20 parts by weight, for example, 7 to 12 parts by weight; The molecular sieve includes a first molecular sieve and / or a second molecular sieve; the first molecular sieve is a molecular sieve added during the preparation of the kaolin-containing slurry, and the second molecular sieve is a molecular sieve added outside the preparation process of the kaolin-containing slurry. The molecular sieve is, for example, at least one of Y zeolite, ZSM-5 zeolite, and β-type zeolite.

11. The catalytic cracking catalyst according to claim 8, 9 or 10, characterized in that, Based on the total dry weight of the catalytic cracking catalyst, the catalyst comprises: 45-55 wt% Al₂O₃, 30-40 wt% SiO₂, 0-5 wt% Re₂O₃, 0.1-0.5 wt% Na₂O, and 0-1 wt% SO₄²⁻. 2- 0.3-0.5% by weight of Fe2O3 and 0.3-0.8% by weight of Cl - Preferably, by XRD analysis, the catalyst has characteristic peaks of Y-type molecular sieve and / or ZSM-5 molecular sieve and / or β molecular sieve.

12. The catalytic cracking catalyst according to claim 11, characterized in that, XRD analysis showed that the crystallinity of the catalytic cracking catalyst was 15–25 times that of the pure Y-type molecular sieve.

13. A method for preparing the catalytic cracking catalyst according to any one of claims 8 to 12, comprising: The catalyst slurry is formed by mixing raw materials including the kaolin-containing slurry according to any one of claims 1 to 5 or the kaolin-containing slurry obtained by the method according to any one of claims 6 to 7, an optional second molecular sieve, an optional second alumina sol, and boehmite with water, followed by spray drying. In one embodiment, the solid content of the catalyst slurry is 20 to 45% by weight.

14. The method for preparing the catalytic cracking catalyst according to claim 13, characterized in that, Given any one of the following four schemes, Option 1 includes the following steps: (1) Solid boehmite, acidic water and a first acid are mixed and stirred to obtain a boehmite slurry; the viscosity of the boehmite slurry is less than 100,000 mPa·s; the solid content of the boehmite slurry is preferably 8-12% by weight; in one embodiment, the weight ratio of the first acid to the boehmite dry basis is 0.01-0.1 based on the added acid solution. (2) Molecular sieve slurry, preferably the kaolin-containing slurry of claim 1, 2 or 3 obtained by filtering through a sieve with a mesh size of 100 mesh or higher, the pseudoboehmite slurry, and optionally a second aluminum sol are mixed and stirred for 10-60 min to obtain a first catalyst slurry (or first catalyst colloid); the solid content of the molecular sieve slurry is preferably 30-50% by weight; the solid content of the first catalyst slurry is preferably 20-45% by weight. (3) The second acid is added to the slurry (2) obtained in step (2), and stirred for 1-3 hours. It is then spray-dried and shaped, and optionally calcined, washed, and dried to obtain the finished catalyst. The weight ratio of the second acid to the dry basis of boehmite is 0.05-0.1 based on the weight of the added acid solution. Option 2 includes the following steps: (S1) Molecular sieve, pseudoboehmite, the kaolin slurry contained in claim 1, 2 or 3 is preferably a kaolin-containing slurry filtered through a 100-mesh filter, and optionally a second aluminum sol are mixed, and stirred, preferably for 10-60 minutes, to obtain the slurry; (S2) The third acid is added to the slurry obtained by (S1), and the mixture is stirred for 1-3 hours. The mixture is then spray-dried, calcined, washed, and dried to obtain the finished catalyst. The weight ratio of the third acid to the dry basis of boehmite is 0.1-0.2 based on the weight of the added acid solution. The third acid is preferably hydrochloric acid. Option 3 includes the following steps: (S1') Molecular sieve, pseudoboehmite, and the kaolin-containing slurry of claim 4 are preferably filtered through a 100-mesh filter and then optionally mixed with a second aluminum sol, and stirred for, for example, for 10-60 minutes to obtain the slurry; (S2') The fourth acid, such as hydrochloric acid, is added to the slurry obtained by (S1'), stirred for 1-3 hours, spray-dried, calcined, washed, and dried to obtain the finished catalyst; the fourth acid is 0.1-0.2 by weight of the acid solution added and the boehmite (dry basis). Option 4 includes the following steps: (S1”) Kaolin clay, first alumina sol, water, catalyst fine powder slurry, and molecular sieve are mixed and stirred, preferably for 2-5 hours, to obtain a third kaolin-containing slurry with a solid content of 35-50% by weight, wherein the weight ratio of solid kaolin, first alumina sol, catalyst fine powder slurry, and molecular sieve on a dry basis is 40-65:2-10:3-10:30-40. (S2”) The pseudoboehmite, the kaolin-containing slurry of claim 5 or the third kaolin-containing slurry are preferably filtered through a filter screen with a mesh size of 100 mesh or higher, and then mixed with the second aluminum sol and stirred for, for example, for 10-60 minutes to obtain the slurry; (S3”) The fifth acid is added to the slurry obtained by (S2”), stirred for example for 1-3 hours, spray dried, calcined, washed, and dried to obtain the finished catalyst; the weight ratio of the added acid solution to the dry basis of boehmite is 0.1-0.2, preferably 0.12-0.15; The first acid, second acid, third acid, fourth acid, and fifth acid are each preferably acid solutions with a concentration of 10-36% by weight. The first acid, second acid, third acid, fourth acid, and fifth acid may each be, for example, one or more of hydrochloric acid and nitric acid, preferably hydrochloric acid. In one embodiment, the first acid, the second acid, the third acid, the fourth acid, and the fifth acid are each hydrochloric acid, wherein the hydrochloric acid contains 31-36% HCl by weight.

15. The method for preparing the catalytic cracking catalyst according to claim 13 or 14, characterized in that, The pseudoboehmite undergoes two acidification processes. The acid-to-aluminum ratio in the first acidification is 0.01–0.1:1, and the acid-to-aluminum ratio in the second acidification is 0.05–0.1:

1. The acid-to-aluminum ratio is the weight ratio of the acid added (converted to an acid concentration of 36% by weight) to the pseudoboehmite (calculated as alumina). In one embodiment, the first acidification is performed on the pseudoboehmite alone, and the second acidification can be performed by adding acid to the slurry formed after the pseudoboehmite is mixed with other components.

16. A method for catalytic cracking of hydrocarbon oil, comprising the step of contacting and reacting hydrocarbon oil with the catalytic cracking catalyst according to any one of claims 8 to 12 or the catalytic cracking catalyst obtained according to any one of claims 13 to 15.

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