CN110833860B

CN110833860B - Catalytic cracking catalyst, preparation method and application thereof

Info

Publication number: CN110833860B
Application number: CN201810942912.9A
Authority: CN
Inventors: 周灵萍; 姜秋桥; 陈振宇; 沙昊; 袁帅; 许明德; 张蔚琳; 田辉平
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2018-08-17
Filing date: 2018-08-17
Publication date: 2022-05-03
Anticipated expiration: 2038-08-17
Also published as: CN110833860A

Abstract

The present disclosure relates to a catalytic cracking catalyst, a preparation method and an application thereof. The catalyst contains 10-50 wt% of modified Y-type molecular sieve, 10-40 wt% of alumina binder calculated by alumina and 10-80 wt% of clay calculated by dry basis; the content of rare earth elements of the modified Y-type molecular sieve calculated by oxides is 5-12 wt%, the content of sodium oxide is 0.1-0.7 wt%, the content of active element oxides is 0.1-5 wt%, and the active elements are gallium and/or boron; the total pore volume of the modified Y-type molecular sieve is 0.33-0.39 mL/g, and the pore volume of secondary pores with the pore diameter of 2-100 nm accounts for 10-25% of the total pore volume; the unit cell constant is 2.440-2.455 nm, and the lattice collapse temperature is not lower than 1050 ℃; the non-framework aluminum content accounts for no more than 20% of the total aluminum content, and the ratio of the B acid amount to the L acid amount in the strong acid amount is no less than 3.0. The catalytic cracking catalyst contains a modified Y-type molecular sieve with high thermal and hydrothermal stability, is used for processing the catalytic cracking reaction of hydrogenated LCO, and simultaneously has high LCO conversion efficiency, lower coke selectivity and higher gasoline yield rich in BTX.

Description

Catalytic cracking catalyst, preparation method and application thereof

Technical Field

The present disclosure relates to a catalytic cracking catalyst, a preparation method and an application thereof.

Background

Light aromatic hydrocarbons such as benzene, toluene, xylene (BTX), and the like are important basic organic chemical raw materials, are widely used for producing polyesters, chemical fibers, and the like, and have been in strong demand in recent years. Light aromatic hydrocarbons such as benzene, toluene and xylene (BTX) are mainly obtained from catalytic reforming and steam cracking processes using naphtha as a raw material. Due to the shortage of naphtha raw material, the light aromatics have larger market gap.

The catalytic cracking Light Cycle Oil (LCO) is an important byproduct of catalytic cracking, is large in quantity, is rich in aromatic hydrocarbon, particularly polycyclic aromatic hydrocarbon, and belongs to poor diesel oil fraction. With the development and change of market demand and environmental protection requirement, LCO is greatly limited as a diesel blending component. The hydrocarbon composition of LCO comprises paraffin, naphthene (containing a small amount of olefin) and aromatic hydrocarbon, the hydrocarbon composition of LCO has larger difference according to different catalytic cracking raw oil and different operation severity, but the aromatic hydrocarbon is the main component of the LCO, the mass fraction is usually more than 70%, some aromatic hydrocarbon even reaches about 90%, and the rest is paraffin and naphthene. The LCO has the highest content of bicyclic aromatics, belongs to typical components of the LCO and is also a key component influencing the catalytic cracking to produce light aromatics. Under the catalytic cracking reaction condition, polycyclic aromatic hydrocarbons are difficult to open-loop crack into light aromatic hydrocarbons, and under the hydrotreating condition, the polycyclic aromatic hydrocarbons are easy to saturate into heavy monocyclic aromatic hydrocarbons such as alkylbenzene and cyclohydrocarbyl benzene (indanes, tetrahydronaphthalenes and indenes). The heavy monocyclic aromatic hydrocarbon is a potential component for producing light aromatic hydrocarbon by catalytic cracking, and can be cracked into the light aromatic hydrocarbon under the catalytic cracking condition. Therefore, LCO is a potential and cheap resource for producing light aromatics, and the production of light aromatics by a hydroprocessing-catalytic cracking technological route has important research value.

CN103923698A discloses a catalytic conversion method for producing aromatic compounds, in the method, poor quality heavy cycle oil and residual oil are subjected to hydrotreating reaction in the presence of hydrogen and hydrogenation catalysts, and reaction products are separated to obtain gas, naphtha, hydrogenated diesel oil and hydrogenated residual oil; the hydrogenated diesel oil enters a catalytic cracking device, a cracking reaction is carried out in the presence of a catalytic cracking catalyst, and a reaction product is separated to obtain dry gas, liquefied gas, catalytic gasoline rich in benzene, toluene and xylene, catalytic light diesel oil, fractions with the distillation range of 250-450 ℃ and slurry oil; wherein the distillation range of 250-450 ℃ is sent to a residual oil hydrotreater for recycling. The method makes full use of the residual oil hydrogenation condition to maximally saturate aromatic rings in the poor-quality heavy cycle oil, so that the hydrogenated diesel oil can maximally produce benzene, toluene and xylene in the catalytic cracking process.

CN104560185A discloses a catalytic conversion method for producing gasoline rich in aromatic compounds, in which catalytic cracking light cycle oil is cut to obtain light fraction and heavy fraction, wherein the heavy fraction is hydrotreated to obtain hydrogenated heavy fraction, the light fraction and the hydrogenated heavy fraction separately enter a catalytic cracking device through different nozzles in a layered manner, a cracking reaction is performed in the presence of a catalytic cracking catalyst, and a product including gasoline rich in aromatic compounds and light cycle oil is obtained by separating reaction products. The method adopts a single catalytic cracking device to process the light fraction of the light cycle oil and the hydrogenated heavy fraction and allows the light fraction and the hydrogenated heavy fraction to enter in a layering manner, so that the harsh conditions required by catalytic cracking reaction of different fractions of the light cycle oil can be optimized and met to the maximum extent, and the catalytic gasoline rich in benzene, toluene and xylene can be produced to the maximum extent.

CN104560187A discloses a catalytic conversion method for producing gasoline rich in aromatic hydrocarbons, which cuts catalytic cracking light cycle oil to obtain light fraction and heavy fraction, wherein the heavy fraction is hydrotreated to obtain hydrogenated heavy fraction, the light fraction and the hydrogenated heavy fraction separately enter different riser reactors of a catalytic cracking device respectively, and are subjected to cracking reaction in the presence of a catalytic cracking catalyst, and reaction products are separated to obtain products including gasoline rich in aromatic hydrocarbons and light cycle oil. The method adopts a single catalytic cracking device to process the light fraction and the hydrogenated heavy fraction of the light cycle oil, and can optimize and meet the harsh conditions required by the catalytic cracking reaction of different fractions of the light cycle oil to the maximum extent, thereby producing the catalytic gasoline rich in benzene, toluene and xylene to the maximum extent.

In the prior art, LCO is adopted for proper hydrogenation, most polycyclic aromatic hydrocarbons in the LCO are saturated into hydrogenated aromatic hydrocarbons containing naphthenic rings and an aromatic ring, and then cracking reaction is carried out in the presence of a catalytic cracking catalyst to produce BTX light aromatic hydrocarbons. However, the cracking performance of hydrogenated aromatics obtained by hydrogenation of LCO is inferior to that of conventional catalytic cracking raw materials, and the hydrogen transfer performance is much higher than that of general catalytic cracking raw materials, so that the conventional catalytic cracking catalyst used in the prior art cannot meet the requirements of catalytic cracking of hydrogenated LCO.

In order to better meet the requirement of catalytic cracking of hydrogenated LCO for producing BTX light aromatic hydrocarbons in high yield, the invention aims to develop a high-stability modified molecular sieve which has strong cracking capability and weaker hydrogen transfer performance simultaneously as a new active component, and further develop a catalytic cracking agent of BTX light aromatic hydrocarbons in high yield suitable for catalytic cracking of hydrogenated LCO by using the new active component, strengthen cracking reaction, control hydrogen transfer reaction, further improve the conversion efficiency of hydrogenated LCO, and furthest produce catalytic gasoline rich in benzene, toluene and xylene (BTX).

At present, the industrial preparation of the high-silicon Y-type zeolite mainly adopts a hydrothermal method, and the NaY zeolite is subjected to rare earth ion exchange for many times and high-temperature roasting for many times, so that the rare earth-containing high-silicon Y-type zeolite can be prepared, which is the most conventional method for preparing the high-silicon Y-type zeolite, but the hydrothermal method for preparing the rare earth high-silicon Y-type zeolite has the defects that: because the structure of the zeolite can be damaged by too harsh hydrothermal treatment conditions, the Y-type zeolite with high silica-alumina ratio can not be obtained; although the generation of the aluminum outside the framework is beneficial to improving the stability of the zeolite and forming a new acid center, the excessive aluminum outside the framework reduces the selectivity of the zeolite, in addition, a plurality of dealuminized cavities in the zeolite cannot be timely supplemented by the silicon migrated from the framework, the lattice defect of the zeolite is often caused, and the crystallization retention degree of the zeolite is lower, so that the thermal and hydrothermal stability of the rare earth-containing high-silicon Y-type zeolite prepared by a hydrothermal method is poorer, the crystal lattice collapse temperature is lower, the crystallinity retention rate and the specific surface area retention rate are lower after hydrothermal aging, and the selectivity is poorer.

In U.S. Pat. Nos. 4,849,287 and 4,4429053, NaY zeolite is exchanged with rare earth ions and then treated with steam, the aluminum removal of the zeolite is difficult in the steam treatment process, the unit cell parameters of the zeolite before the steam treatment are increased to 2.465-2.475 nm, the unit cell parameters after the treatment are 2.420-2.464 nm, and the temperature required for reducing the unit cell parameters is higher (593-733 ℃). The heavy oil cracking activity of zeolite is not high and coke selectivity is not good.

In the processes provided in US5340957 and US5206194, SiO of NaY zeolite is used as the starting material₂/Al₂O₃The ratio is 6.0, and this method also has the disadvantages of the aforementioned U.S. Pat. Nos. 4,84287 and 4429053, in which NaY is subjected to rare earth exchange and then to hydrothermal treatment.

Gas phase chemical processes are another important process for preparing high silica zeolites first reported by Beyer and Mankui in 1980. The gas phase chemical method generally adopts SiCl4 and anhydrous NaY zeolite under the protection of nitrogen to react at a certain temperature. U.S. Pat. Nos. 4,42737,178, U.S. Pat. No. 4,4438178, Chinese patent Nos. CN1382525A, CN1194941A and CN1683244A disclose the use of SiCl₄A process for preparing ultra-stable Y-type zeolite by gas-phase chemical dealumination. However, pore structure analysis shows that the gas phase ultrastable molecular sieve has no secondary pores.

The performance of the ultra-stable molecular sieve prepared by a hydrothermal method or a gas phase method in the prior art cannot well meet the requirement of processing a hydrogenation LCO catalytic cracking catalyst.

Disclosure of Invention

The purpose of the present disclosure is to provide a catalytic cracking catalyst, which has higher LCO conversion efficiency, better coke selectivity and higher yield of gasoline rich in aromatics, and a preparation method and application thereof.

In order to achieve the above object, the first aspect of the present disclosure provides a catalytic cracking catalyst comprising 10 to 50 wt% of a modified Y-type molecular sieve, 10 to 40 wt% of an alumina binder, and 10 to 80 wt% of clay, on a dry basis, based on the dry weight of the catalyst;

on the basis of the dry weight of the modified Y-type molecular sieve, the modified Y-type molecular sieve contains 5-12 wt% of rare earth elements, 0.1-0.7 wt% of sodium oxide and 0.1-5 wt% of active element oxides, wherein the active elements are gallium and/or boron, and the oxides are calculated by oxides; the total pore volume of the modified Y-type molecular sieve is 0.33-0.39 mL/g, and the pore volume of secondary pores with the pore diameter of 2-100 nm accounts for 10-25% of the total pore volume; the unit cell constant of the modified Y-type molecular sieve is 2.440-2.455 nm, and the lattice collapse temperature is not lower than 1050 ℃; the proportion of non-framework aluminum content of the modified Y-type molecular sieve in the total aluminum content is not higher than 20%, and the ratio of B acid content to L acid content in strong acid content of the modified Y-type molecular sieve is not lower than 3.0.

Optionally, the pore volume of secondary pores with the pore diameter of 2-100 nm of the modified Y-type molecular sieve accounts for 15-21% of the total pore volume.

Optionally, the proportion of non-framework aluminum content of the modified Y-type molecular sieve in the total aluminum content is 13-19%; with n (SiO)₂)/n(Al₂O₃) And the framework silicon-aluminum ratio of the modified Y-type molecular sieve is 7.3-14.

Optionally, the lattice collapse temperature of the modified Y-type molecular sieve is 1055-1080 ℃.

Optionally, the ratio of the B acid amount to the L acid amount in the strong acid amount of the modified Y-type molecular sieve is 3.1-5.0; the ratio of the B acid amount to the L acid amount in the strong acid amount of the modified Y-type molecular sieve is measured at 350 ℃ by adopting a pyridine adsorption infrared method.

Optionally, the relative crystallinity of the modified Y-type molecular sieve is 60-70%.

Optionally, the modified Y-type molecular sieve has a relative crystallinity retention of 38% or more as determined by XRD after aging for 17h at 800 ℃ with 100% steam.

Optionally, the modified Y-type molecular sieve is oxidized based on the dry weight of the modified Y-type molecular sieveThe content of rare earth elements is 5.5-10 wt%, and the content of sodium oxide is 0.3-0.7 wt%; the unit cell constant of the modified Y-type molecular sieve is 2.442-2.450 nm; with n (SiO)₂)/n(Al₂O₃) The framework silicon-aluminum ratio of the modified Y-type molecular sieve is 8.5-12.6; the rare earth element comprises La, Ce, Pr or Nd, or a combination of two or three or four of them;

the active element is gallium, and the content of gallium oxide is 0.1-3 wt%; or the active element is boron, and the content of boron oxide is 0.5-5 wt%; or the active elements are gallium and boron, and the total content of gallium oxide and boron oxide is 0.5-5 wt%.

Optionally, the clay is kaolin, halloysite, montmorillonite, diatomaceous earth, halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite, or bentonite, or a combination of two or three or four thereof; the alumina binder is alumina, hydrated alumina or alumina sol, or a combination of two or three or four of them.

A second aspect of the present disclosure provides a process for preparing a catalytic cracking catalyst according to the first aspect of the present disclosure, the process comprising: preparing a modified Y-type molecular sieve, forming slurry comprising the modified Y-type molecular sieve, an alumina binder, clay and water, and spray-drying to obtain the catalytic cracking catalyst;

wherein, the preparation of the modified Y-type molecular sieve comprises the following steps:

(1) the method comprises the steps of enabling a NaY molecular sieve to be in contact with rare earth salt for ion exchange reaction, carrying out first filtration and first washing to obtain an ion-exchanged molecular sieve, wherein the sodium oxide content of the ion-exchanged molecular sieve is not more than 9.0 wt% based on the dry weight of the ion-exchanged molecular sieve;

(2) performing first roasting on the ion-exchanged molecular sieve at the temperature of 350-480 ℃ for 4.5-7 h in the presence of 30-90 vol% of steam to obtain a molecular sieve modified by moderating hydrothermal superstability;

(3) molecular sieves and SiCl for ultrastable modification of said mild water₄Contact reactionCarrying out second washing and second filtering to obtain the gas-phase ultra-stable modified molecular sieve;

(4) contacting the gas-phase ultra-stable modified molecular sieve with a solution containing active elements, and drying and carrying out second roasting to obtain the modified Y-type molecular sieve; the active element is gallium and/or boron.

Optionally, the method of ion exchange reaction comprises: mixing NaY molecular sieve with water, adding rare earth salt and/or rare earth salt water solution under stirring to perform ion exchange reaction, and filtering and washing;

the conditions of the ion exchange reaction include: the temperature is 15-95 ℃, the time is 30-120 min, and the weight ratio of the NaY molecular sieve to the rare earth salt to the water is 1: (0.01-0.18): (5-15).

Optionally, the unit cell constant of the ion-exchanged molecular sieve is 2.465-2.472 nm, the rare earth content is 5.5-14 wt% calculated by oxide, and the sodium oxide content is 4-9 wt%.

Optionally, the rare earth salt is a rare earth chloride or a rare earth nitrate.

Optionally, the processing conditions of step (2) include: the first roasting is carried out for 5-6 h at 380-460 ℃ and under 40-80 vol% of water vapor.

Optionally, the unit cell constant of the molecular sieve subjected to mild hydrothermal superstability modification is 2.450-2.462 nm, and the water content of the molecular sieve subjected to mild hydrothermal superstability modification is not more than 1 wt%.

Optionally, in step (3), SiCl₄The weight ratio of the modified molecular sieve to the modified molecular sieve for moderating hydrothermal superstability is (0.1-0.7): 1, the temperature of the contact reaction is 200-650 ℃, and the reaction time is 10 min-5 h; the second washing method includes: washing with water until the pH value of a washing liquid is 2.5-5.0, the washing temperature is 30-60 ℃, and the weight ratio of the water consumption to the unwashed gas-phase ultra-stable modified molecular sieve is (5-20): 1.

optionally, the solution containing the active element is an aqueous solution of a gallium salt and/or an aqueous solution of a boron compound;

the method for contacting the gas-phase ultra-stable modified molecular sieve with the solution containing the active elements comprises the following steps: uniformly mixing the gas-phase ultrastable modified molecular sieve with an aqueous solution of gallium salt, and standing for 24-36 h at 15-40 ℃, wherein the weight ratio of gallium in the aqueous solution of gallium salt, water in the aqueous solution of gallium salt and the gas-phase ultrastable modified molecular sieve is (0.001-0.03): (2-3): 1; or may comprise, in combination with the above-mentioned,

heating the gas phase ultra-stable modified molecular sieve to 60-99 ℃, and then contacting and mixing the gas phase ultra-stable modified molecular sieve with a boron compound in an aqueous solution for 1-2 h, wherein the weight ratio of boron in the aqueous solution, water in the aqueous solution and the gas phase ultra-stable modified molecular sieve is (0.005-0.05): (2.5-5): 1, the boron compound is selected from boric acid, a borate, a metaborate or a polyborate, or a combination comprising two or three or four of them; or may comprise, in combination with the above-mentioned,

heating the gas phase superstable modified molecular sieve to 85-95 ℃, then contacting and mixing the molecular sieve with a boron compound in a first aqueous solution for 1-2 h, filtering, uniformly mixing the obtained molecular sieve material with a second aqueous solution containing gallium salt, and standing for 24-36 h at 15-40 ℃; the weight ratio of boron in the first aqueous solution calculated by oxide, water in the first aqueous solution and the gas-phase ultra-stable modified molecular sieve calculated by dry weight is (0.005-0.03): (2.5-5): 1, the weight ratio of the gallium in the second aqueous solution calculated by oxide, the water in the second aqueous solution and the molecular sieve material calculated by dry weight is (0.001-0.02): (2-3): 1.

optionally, in the step (4), the second roasting conditions include: the roasting temperature is 350-600 ℃, and the roasting time is 1-5 h.

A third aspect of the present disclosure provides the use of a catalytic cracking catalyst according to the first aspect of the present disclosure in the catalytic cracking reaction of a hydrocarbon feedstock.

A fourth aspect of the present disclosure provides a catalytic cracking process for processing hydrogenated LCO, comprising the step of contacting, under catalytic cracking conditions, the hydrogenated LCO with a catalyst as described in the first aspect; wherein, the catalytic cracking conditions comprise: the reaction temperature is 500-6The weight hourly space velocity is 2-16 h at 10 DEG C^-1The weight ratio of the components is 3-10.

According to the technical scheme, the preparation method disclosed by the invention comprises the steps of firstly carrying out rare earth exchange, hydrothermal hyperstabilization treatment and gas phase hyperstabilization treatment on the Y-type molecular sieve, and carrying out immersion modification by adopting active elements, so that the high-silicon Y-type molecular sieve with high crystallinity, high thermal stability and high hydrothermal stability and a certain secondary pore structure can be prepared, the aluminum in the molecular sieve is uniformly distributed, the non-framework aluminum content is low, and then the modified Y-type molecular sieve is adopted to prepare the catalytic cracking catalyst with high reactivity. The catalytic cracking catalyst disclosed by the invention contains the modified Y-type molecular sieve with high thermal and hydrothermal stability, has higher hydrothermal stability, is used for processing catalytic cracking of hydrogenated LCO, and simultaneously has high LCO conversion efficiency (for example, the LCO effective conversion rate is high), lower coke selectivity and higher yield of gasoline rich in aromatic hydrocarbon.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Detailed Description

The following describes in detail specific embodiments of the present disclosure. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

The first aspect of the present disclosure provides a catalytic cracking catalyst, which contains 10 to 50 wt% of a modified Y-type molecular sieve, 10 to 40 wt% of an alumina binder, and 10 to 80 wt% of clay, on a dry basis, based on the dry basis weight of the catalyst;

The catalytic cracking catalyst disclosed by the invention contains the modified Y-shaped molecular sieve with high thermal stability and hydrothermal stability, the Y-shaped molecular sieve has a certain secondary pore structure, the aluminum in the molecular sieve is uniformly distributed, the non-framework aluminum content is low, and the catalytic cracking catalyst can have high LCO conversion efficiency when being used for processing hydrogenated LCO, has lower coke selectivity and has higher yield of gasoline rich in aromatic hydrocarbon.

In the catalytic cracking catalyst provided by the present disclosure, the modified Y-type molecular sieve contains active elements gallium and/or boron, and the content of the active element oxide may be 0.1 to 5 wt% based on the dry weight of the molecular sieve, wherein preferably, in one embodiment, the active element is gallium, and the content of gallium oxide may be 0.1 to 3 wt%, and more preferably 0.5 to 2.5 wt%; in another embodiment, the active element is boron, and the content of boron oxide may be 0.5 to 5 wt%, and more preferably 1 to 4 wt%; in the third embodiment, the active elements are gallium and boron, the total content of gallium oxide and boron oxide may be 0.5 to 5 wt%, preferably 1 to 3 wt%, the content of gallium oxide may be 0.1 to 2.5 wt%, and the content of boron oxide may be 0.5 to 4 wt%. Within the preferable content range, the conversion efficiency of the modified Y-type molecular sieve for catalyzing LCO is higher, the coke selectivity is lower, and the gasoline rich in aromatic hydrocarbon can be obtained more favorably.

In the catalytic cracking catalyst provided by the present disclosure, the modified Y-type molecular sieve may contain a small amount of sodium, and the content of sodium oxide may be 0.1 to 0.7 wt%, preferably 0.3 to 0.7 wt%, more preferably 0.35 to 0.60 wt%, and further preferably 0.4 to 0.55 wt%, based on the dry weight of the molecular sieve.

In the catalytic cracking catalyst provided by the disclosure, the rare earth element, the sodium oxide and the active element in the modified Y-type molecular sieve can be respectively measured by adopting an X-ray fluorescence spectrometry method.

In the catalytic cracking catalyst provided by the disclosure, the pore structure of the modified Y-type molecular sieve can be further optimized to obtain more appropriate catalytic cracking reaction performance. The total pore volume of the modified Y-type molecular sieve is further preferably 0.36-0.375 mL/g; the pore volume proportion of the secondary pores with the pore diameter of 2-100 nm in the total pore volume is preferably 15-21%. Further, in one embodiment of the present disclosure, the micropore volume of the modified Y-type molecular sieve may be 0.25 to 0.35mL/g, preferably 0.26 to 0.32 mL/g. In the present disclosure, the total pore volume of the molecular sieve may be determined from the adsorption isotherm according to RIPP151-90 Standard method, "petrochemical analysis method (RIPP test method)," compiled by Yankee et al, scientific Press, published in 1990), and then the micropore volume of the molecular sieve may be determined from the adsorption isotherm according to the T-plot method, and the secondary pore volume may be obtained by subtracting the micropore volume from the total pore volume.

In one embodiment of the present disclosure, the specific surface area of the modified Y-type molecular sieve may be 620-670 m²A/g, for example, of 630 to 660m²(ii) in terms of/g. Wherein, the specific surface area of the modified Y-type molecular sieve refers to BET specific surface area, and the specific surface area can be measured according to the ASTM D4222-98 standard method.

In the catalytic cracking catalyst provided by the disclosure, the unit cell constant of the modified Y-type molecular sieve is further preferably 2.442-2.450 nm. The lattice collapse temperature of the modified Y-type molecular sieve can be not lower than 1055 ℃, preferably 1055-1080 ℃, and more preferably 1057-1075 ℃.

In the catalytic cracking catalyst provided by the present disclosure, the relative crystallinity of the modified Y-type molecular sieve may be 60 to 70%, preferably 60 to 66%. The modified Y-type molecular sieve disclosed by the invention has higher hydrothermal aging resistance, and after the modified Y-type molecular sieve is aged for 17 hours by 100% of water vapor at 800 ℃ under normal pressure, the retention rate of the relative crystallinity of the modified Y-type molecular sieve measured by XRD is more than 38%, for example, 38-48% or 39-45%. The normal pressure can be 1 atm.

Wherein, the lattice collapse temperature of the modified Y-type molecular sieve can be determined by a Differential Thermal Analysis (DTA) method. The unit cell constant and relative crystallinity of zeolite are determined by X-ray powder diffraction (XRD) using RIPP145-90 and RIPP146-The framework silica-alumina ratio of zeolite was calculated by the following formula, as determined by the standard 90 method (compiled by petrochemical analysis method (RIPP test method) Yangcui et al, published by scientific Press, 1990): framework SiO₂/Al₂O₃Molar ratio of 2 × (25.858-a)₀)/(a₀-24.191), wherein, a₀Is a unit cell constant in

The total silicon-aluminum ratio of the zeolite is calculated according to the content of Si and Al elements measured by an X-ray fluorescence spectrometry, and the ratio of the framework Al to the total Al can be calculated by the framework silicon-aluminum ratio measured by an XRD method and the total silicon-aluminum ratio measured by an XRF method, so that the ratio of non-framework Al to the total Al can be calculated. Wherein the relative crystallinity retention rate ═ (relative crystallinity of aged sample/relative crystallinity of fresh sample) × 100%.

In the catalytic cracking catalyst provided by the disclosure, the non-framework aluminum content of the modified Y-type molecular sieve is low, and the proportion of the non-framework aluminum content in the total aluminum content is not higher than 20%, preferably 13-19%; with n (SiO)₂)/n(Al₂O₃) The framework Si/Al ratio of the modified Y-type molecular sieve can be 7.3-14, and preferably 8.5-12.6.

In the catalytic cracking catalyst provided by the present disclosure, in order to ensure that the modified Y-type molecular sieve has a suitable surface acid center type and strength, the ratio of the amount of B acid to the amount of L acid in the strong acid amount of the modified Y-type molecular sieve is preferably 3.1 to 5.0, and further, when the active element is gallium, the ratio of the amount of B acid to the amount of L acid in the strong acid amount of the modified Y-type molecular sieve is preferably 3.1 to 4.5, for example, 3.2 to 4.3; when the active element is boron, the ratio of the B acid amount to the L acid amount in the strong acid amount of the modified Y-type molecular sieve is preferably 3.6-5.0, such as 3.7-4.3; when the active elements are gallium and boron, the ratio of the amount of the B acid to the amount of the L acid in the strong acid amount of the modified Y-type molecular sieve is preferably 3.3-4.8, for example 3.5-4.6. The ratio of the B acid amount to the L acid amount in the strong acid amount of the modified Y-type molecular sieve, namely the ratio of the strong B acid amount to the strong L acid amount, can be measured at 350 ℃ by adopting a pyridine adsorption infrared method, wherein the strong acid amount refers to the total amount of strong acid on the surface of the molecular sieve, and the strong acid refers to acid obtained by measuring at 350 ℃ by adopting the pyridine adsorption infrared method.

In a specific embodiment of the present disclosure, based on the dry weight of the modified Y-type molecular sieve, the modified Y-type molecular sieve may have a content of rare earth elements of 5.5 to 10 wt% in terms of oxide, a content of sodium oxide of 0.3 to 0.7 wt%, a content of gallium oxide of 0.1 to 3 wt% when the active element is gallium, or a content of boron oxide of 0.5 to 5 wt% when the active element is boron; the unit cell constant of the modified Y-type molecular sieve can be 2.442-2.450 nm; with n (SiO)₂)/n(Al₂O₃) And the framework silicon-aluminum ratio of the modified Y-type molecular sieve can be 8.5-12.6.

In the catalytic cracking catalyst provided by the present disclosure, the rare earth element may be of any kind, and the kind and composition thereof are not particularly limited, and in one embodiment, the rare earth element may include La, Ce, Pr, or Nd, or a combination of two or three or four of them, and may further include other rare earth elements besides La, Ce, Pr, and Nd.

The catalytic cracking catalyst provided by the present disclosure may further include other molecular sieves other than the modified Y-type molecular sieve, and the content of the other molecular sieves is, for example, 0 to 40 wt%, for example, 0 to 30 wt%, or 1 to 20 wt%, based on the weight of the catalytic cracking catalyst, on a dry basis. The other molecular sieve is selected from molecular sieves used in catalytic cracking catalysts, such as zeolites with the MFI structure, zeolites Beta, other Y-type zeolites or non-zeolitic molecular sieves, or combinations comprising two or three or four of them. Preferably, the content of the other Y-type zeolite is not more than 40 wt% on a dry basis, and may be, for example, 1 to 40 wt% or 0 to 20 wt%. Such as REY, REHY, DASY, SOY or PSRY, or combinations comprising two or three or four of them, MFI structure zeolites such as HZSM-5, ZRP or ZSP, or combinations comprising two or three or four of them, beta zeolites such as H β, non-zeolitic molecular sieves such as aluminum phosphate molecular sieves (AlPO molecular sieves) and/or silicoaluminophosphate molecular sieves (SAPO molecular sieves).

In the catalytic cracking catalyst for the high-yield aromatic-hydrocarbon-rich gasoline provided by the present disclosure, the content of the modified Y-type molecular sieve may be 10 to 50 wt%, preferably 15 to 45 wt%, for example 25 to 40 wt%, on a dry basis.

In the catalytic cracking catalyst for high yield of aromatic-rich gasoline provided by the present disclosure, the clay is selected from one or more of clays used as a component of a cracking catalyst, such as kaolin, halloysite, montmorillonite, diatomaceous earth, halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite, or bentonite, or a combination comprising two or three or four of them. These clays are well known to those of ordinary skill in the art. Preferably, the content of the clay in the catalytic cracking catalyst of the present disclosure is 20 to 55 wt% or 30 to 50 wt% on a dry basis.

In the catalytic cracking catalyst for the high-yield aromatic-hydrocarbon-rich gasoline, the content of the alumina binder can be 10-40 wt%, such as 20-35 wt% calculated by alumina. The alumina binder is selected from one or more of alumina, hydrated alumina and alumina sol in various forms commonly used in cracking catalysts. For example, the catalyst is selected from gamma-alumina, eta-alumina, theta-alumina, chi-alumina, pseudo-Boehmite (Pseudobioemite), diaspore (Boehmite), Gibbsite (Gibbsite), Bayer (Bayerite) or alumina sol, or a combination comprising two or three or four of them, preferably pseudo-Boehmite and alumina sol, for example, the catalytic cracking catalyst contains 2-15 wt% of alumina sol, preferably 3-10 wt% of alumina sol, and 10-30 wt% of alumina sol, preferably 15-25 wt% of pseudo-Boehmite.

The catalyst of the present disclosure can be prepared by the methods disclosed in patents CN1098130A and CN 1362472A. Typically comprising the steps of forming a slurry comprising the modified Y-type molecular sieve, a binder, clay and water, spray drying, optionally washing and drying. Spray drying, washing and drying are the prior art, and the invention has no special requirements.

(3) molecular sieves and SiCl for ultrastable modification of said mild water₄Carrying out contact reaction, and carrying out second washing and second filtering to obtain the gas-phase ultra-stable modified molecular sieve;

The preparation method provided by the disclosure can be used for preparing the catalytic cracking catalyst rich in aromatic gasoline in yield, the catalytic cracking catalyst contains the modified Y-type molecular sieve with high thermal and hydrothermal stability, has higher hydrothermal stability, is used for processing hydrogenation LCO catalytic cracking, has higher LCO conversion efficiency, lower coke selectivity and higher yield of the aromatic gasoline compared with the conventional catalytic cracking catalyst containing the Y-type molecular sieve.

In the preparation method of the catalytic cracking catalyst provided by the present disclosure, in step (1), the NaY molecular sieve is subjected to an ion exchange reaction with a rare earth solution to obtain a rare earth-containing Y-type molecular sieve with a conventional unit cell size and reduced sodium oxide content, and the method of the ion exchange reaction may be well known to those skilled in the art, for example, the method of the ion exchange reaction may include: mixing NaY molecular sieve with water, adding rare earth salt and/or rare earth salt water solution while stirring for ion exchange reaction, and filtering and washing.

Wherein, the water can be decationized water and/or deionized water; the NaY molecular sieve can be purchased or prepared according to the existing method, and in one embodiment, the unit cell constant of the NaY molecular sieve can be 2.465-2.472 nm, and the framework silicon-aluminum ratio (SiO)₂/Al₂O₃Molar ratio) of 4.5 to 5.2, a relative crystallinity of 85% or more, for example, 85 to 95%, and a sodium oxide content of 13.0 to 13.8% by weight. The conditions of the ion exchange reaction can be conventional in the field, and further, in order to promote the ion exchange reaction, in the ion exchange reaction between the NaY molecular sieve and the rare earth solution, the exchange temperature can be 15-95 ℃, preferably 65-95 ℃, and the exchange time can be 30-120 min, preferably 45-90 min. NaY molecular sieve (on a dry basis): rare earth salts (as RE)₂O₃Meter): h₂The weight ratio of O may be 1: (0.01-0.18): (5-15), preferably 1: (0.5-0.17): (6-14).

In one embodiment of the present disclosure, the molecular weight may be as follows NaY molecular sieve: rare earth salt: h₂The exchange between rare earth ions and sodium ions is carried out by mixing NaY molecular sieve (also called NaY zeolite), rare earth salt and water at a weight ratio of 1: 0.01-0.18: 5-15, and stirring at 15-95 deg.C, for example, 65-95 deg.C, preferably 30-120 min. Wherein mixing the NaY molecular sieve, the rare earth salt, and water may comprise slurrying the NaY molecular sieve and water, and adding to the slurry a rare earth salt and/or an aqueous solution of a rare earth salt, the rare earth salt being a solution of a rare earth salt, the rare earth salt preferably being a rare earth chloride and/or a rare earth nitrate. The rare earth can be any kind of rare earth, the kind and composition of which are not particularly limited, such as one or more of La, Ce, Pr, Nd, and mischmetal, and preferably, the mischmetal contains one or more of La, Ce, Pr, and Nd, or may further contain other rare earth elements besides La, Ce, Pr, and Nd. The washing in step (1) is intended to wash out exchanged sodium ions, and for example, deionized water orWashing with decationized water. Preferably, the rare earth content of the ion-exchanged molecular sieve obtained in the step (1) is RE₂O₃The amount of the sodium oxide is 5.5 to 14 wt%, for example, 7 to 14 wt% or 5.5 to 12 wt%, the content of the sodium oxide is 4 to 9 wt%, for example, 5.5 to 8.5 wt% or 5.5 to 7.5 wt%, and the cell constant is 2.465nm to 2.472 nm.

In the preparation method of the catalytic cracking catalyst, in the step (2), the Y-type molecular sieve containing rare earth and having a conventional unit cell size is roasted for 4.5-7 hours at the temperature of 350-480 ℃ under the atmosphere of 30-90 vol% of water vapor, preferably, the roasting temperature in the step (2) is 380-460 ℃, the roasting atmosphere is 40-80 vol% of water vapor, and the roasting time is 5-6 hours. The water vapor atmosphere may also contain other gases, such as one or more of air, helium or nitrogen. The unit cell constant of the molecular sieve modified by the moderating hydrothermal superstability obtained in the step (2) can be 2.450 nm-2.462 nm.

The 30-90 vol% steam atmosphere refers to an atmosphere containing 30-90 vol% steam and the balance air, for example, a 30 vol% steam atmosphere refers to an atmosphere containing 30 vol% steam and 70 vol% air.

In order to ensure the effect of gas phase ultra-stable modification, in one embodiment of the present disclosure, the molecular sieve may be dried before step (3) to reduce the water content in the molecular sieve, so that step (3)

The molecular sieve used in contact with SiCl4 has a water content of not more than 1 wt%, and the drying treatment is, for example, calcination drying in a rotary roaster or a muffle furnace.

In the preparation method of the catalytic cracking catalyst provided by the present disclosure, the contact reaction conditions of the step (3) can be changed within a wide range, and in order to further promote the gas phase ultra-stable treatment effect, preferably, SiCl₄The weight ratio of the modified molecular sieve to the molecular sieve (calculated on a dry basis) obtained in the step (2) for moderating the hydrothermal superstable modification can be (0.1-0.7): 1, preferably (0.2-0.6): 1, the temperature of the contact reaction can be 200-650 ℃, preferably 350-500 ℃, and the reaction time can be 10 min-5 h, preferably 0.5-E4 h; the second washing method in step (3) may be a conventional washing method, and may be a washing with water such as decationized water or deionized water, in order to remove Na remaining in the zeolite⁺，Cl^-And Al³⁺And (3) waiting for soluble byproducts, and the washing method can comprise: washing with water until the pH value of a washing liquid is 2.5-5.0, the washing temperature can be 30-60 ℃, and the weight ratio of the water consumption to the unwashed gas-phase ultra-stable modified molecular sieve can be (5-20): 1, preferably (6-15): 1. further, the washing may be such that no free Na is detectable in the washing solution after washing⁺，Cl^-And Al³⁺And (3) plasma.

In the preparation method according to the present disclosure, the exchange and/or impregnation treatment may be performed by contacting the molecular sieve with a solution containing an active element, preferably an aqueous solution of a gallium salt or an aqueous solution of a boron compound or an aqueous solution containing a gallium salt and a boron compound, or a combination of both, in order to facilitate the improvement of the effect of the exchange and/or impregnation treatment, to load the active element on the modified Y-type molecular sieve; the contact with the active element solution can be carried out once or for multiple times so as to introduce the active element with required quantity; for example:

in one embodiment, in step (4), the gas-phase ultra-stably modified molecular sieve is contacted with an aqueous solution of gallium salt, that is, the solution containing the active element is an aqueous solution of gallium salt, and the contacting method may include: and uniformly mixing the gas-phase ultra-stable modified molecular sieve with the aqueous solution of the gallium salt, and standing. For example, a gas phase ultra-stable modified molecular sieve may be added to Ga (NO) under stirring₃)₃The solution is dipped with gallium components, stirred evenly and then kept stand for 24-36 hours at room temperature. Then the molecular sieve containing gas phase super-stable modification is mixed with Ga (NO)₃)₃Stirring the slurry for 20min to mix well, drying by any drying method such as flash drying, oven drying, and air drying, or by transferring the slurry to a rotary evaporator for rotary evaporation with water bath heating, and performing second roasting by evaporating the evaporated materialAnd putting the mixture into a rotary roasting furnace to roast for 2 to 5 hours at the temperature of 450 to 600 ℃, and further preferably roasting for 2.2 to 4.5 hours at the temperature of 480 to 580 ℃.

Wherein the aqueous solution of gallium salt may be Ga (NO)₃)₃Aqueous solution, Ga₂(SO₄)₃Aqueous solutions or GaCl₃Aqueous solution, preferably Ga (NO)₃)₃An aqueous solution. The weight ratio of water in the gallium salt aqueous solution, the gallium salt aqueous solution and the gas-phase ultra-stable modified molecular sieve in terms of dry weight in the gallium salt aqueous solution can be (0.001-0.03): (2-3): 1, preferably (0.005 to 0.025): (2.2-2.6): 1.

in another embodiment, in step (4), the gas-phase ultra-stable modified molecular sieve is contacted with a boron compound solution, that is, the solution containing the active element is an aqueous solution of a boron compound, and the contacting method may include: heating the gas phase super-stable modified molecular sieve to 60-99 ℃, then contacting and mixing the gas phase super-stable modified molecular sieve with a boron compound in an aqueous solution for 1-2 h, preferably, heating the gas phase super-stable modified molecular sieve to 85-95 ℃, then contacting and mixing the gas phase super-stable modified molecular sieve with the boron compound in the aqueous solution for 1-1.5 h, for example, adding the gas phase super-stable modified molecular sieve into an exchange tank, mixing the gas phase super-stable modified molecular sieve with water to form slurry, then heating the molecular sieve slurry to 60-99 ℃, then adding the boron compound, stirring and mixing for 1h, then filtering, drying the filtered sample, and carrying out secondary roasting, wherein the drying can be any drying method, such as flash drying, drying and air flow drying, and the drying can be one method, such as drying at 120-140 ℃ for 5-10 h, and the secondary roasting condition is preferably 350-600 ℃ for 1-5 h; the boron compound may comprise a compound containing a positive boron ion, for example selected from boric acid, a borate, a metaborate or a polyborate, or from a combination of two or three or four thereof.

Wherein the liquid-solid ratio in the molecular sieve slurry, namely the weight ratio of water to the molecular sieve, can be (2.5-5): 1, preferably (2.8-4.5): 1, adding boron compound in an amount of B₂O₃Preferably B₂O₃: the molecular sieve is (0.5-5): 100, preferably (0.8-4.2): 100.

third embodiment, step(4) The gas phase ultra-stable modified molecular sieve is respectively contacted with the aqueous solution of gallium salt and the aqueous solution of boron compound, that is, the solution containing active elements is the aqueous solution of gallium salt and the aqueous solution of boron compound, and the contacting method can comprise the following steps: heating the gas phase superstable modified molecular sieve to 85-95 ℃, then contacting and mixing the molecular sieve with a boron compound in a first aqueous solution for 1-2 h, filtering, uniformly mixing the molecular sieve material with a second aqueous solution containing gallium salt, and standing for 24-36 h at 15-40 ℃. For example, the gas phase ultra-stable modified molecular sieve can be added into an exchange tank to be mixed with water to form slurry, then the temperature of the molecular sieve slurry is raised to 85-95 ℃, then the boron compound is added, namely the molecular sieve slurry is contacted with the boron compound in the first aqueous solution, the mixture is stirred and mixed for 1 hour and then filtered, and then the filter cake is added into Ga (NO) while being stirred₃)₃Is impregnated with a gallium component containing Ga (NO) in a solution (i.e., a second aqueous solution)₃)₃And stirring the slurry for 20min to uniformly mix the slurry, drying the slurry and performing second roasting, wherein the drying can be any one of drying methods, such as flash drying, drying and air flow drying, in one mode, the drying method is, for example, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation, and the second roasting can comprise roasting the evaporated material in a rotary roasting furnace at 450-600 ℃ for 2-5 h, and preferably at 480-580 ℃ for 2.2-4.5 h.

Wherein the weight ratio of boron in the first aqueous solution calculated as oxide, water in the first aqueous solution and the gas phase ultra-stable modified molecular sieve in dry weight basis may be (0.005-0.03): (2.5-5): the weight ratio of the gallium in the second aqueous solution calculated by oxide, the water in the second aqueous solution and the molecular sieve material calculated by dry weight can be (0.001-0.02): (2-3): 1.

in one embodiment of the present disclosure, preparing the modified Y-type molecular sieve may comprise the steps of:

(1) carrying out ion exchange reaction on a NaY molecular sieve (also called NaY zeolite) and a rare earth solution at 15-95 ℃ for 30-120 min, filtering and washing to obtain the molecular sieve after ion exchange, wherein the molecular sieve after ion exchange has reduced sodium oxide content, contains rare earth elements and has conventional unit cell size;

(2) roasting the ion-exchanged molecular sieve for 4.5-7 h at 350-480 ℃ in an atmosphere containing 30-90 vol% of water vapor, and drying to obtain a molecular sieve modified by the moderated hydrothermal superstability, wherein the water content of the molecular sieve is lower than 1 wt%, and the unit cell constant of the molecular sieve modified by the moderated hydrothermal superstability is reduced to 2.450-2.462 nm;

(3) mixing the molecular sieve sample modified by the mild hydrothermal superstability with SiCl vaporized by heating₄Gas contact of SiCl₄: the weight ratio of the molecular sieve for moderating hydrothermal superstable modification (calculated by dry basis) is (0.1-0.7): 1, carrying out contact reaction for 10min to 5h at the temperature of 200-650 ℃, and then washing and filtering to obtain a gas-phase ultra-stable modified molecular sieve;

(4) adding the gas-phase super-stable modified molecular sieve obtained in the step (3) into Ga (NO) while stirring₃)₃Is dipped in the solution of (A) and the gas phase ultra-stable modified molecular sieve is mixed with the solution containing Ga (NO)₃)₃The solution of (A) is stirred uniformly and then is allowed to stand at room temperature, wherein Ga (NO)₃)₃Ga (NO) contained in the solution of (1)₃)₃In an amount of Ga₂O₃The weight ratio of the molecular sieve to the molecular sieve is 0.1-3 wt%, and Ga (NO)₃)₃The weight ratio of the water added in the solution to the molecular sieve is as follows: water: soaking the molecular sieve (dry basis): 1: 2-3 for 24h, and then mixing the molecular sieve containing the modified Y molecular sieve with Ga (NO)₃)₃And stirring the slurry for 20min to uniformly mix the slurry, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation, and then putting the evaporated material into a muffle furnace to roast for 2-5 h at 450-600 ℃ to obtain the modified Y molecular sieve.

In another embodiment of the present disclosure, preparing the modified Y-type molecular sieve may comprise the steps of:

(2) roasting the ion-exchanged molecular sieve for 4.5-7 h at the temperature of 350-480 ℃ in the atmosphere containing 30-90 vol% of water vapor, and drying to obtain the molecular sieve with the water content lower than 1 wt% and modified by the moderated hydrothermal superstability, wherein the unit cell constant of the molecular sieve with the modified by the moderated hydrothermal superstability is reduced to 2.450-2.462 nm;

(3) the molecular sieve modified by the mild hydrothermal superstability and the SiCl vaporized by heating₄Gas contact of SiCl₄: the weight ratio of the molecular sieve for moderating hydrothermal superstable modification (calculated by dry basis) is (0.1-0.7): 1, carrying out contact reaction for 10min to 5h at the temperature of 200-650 ℃, and then washing and filtering to obtain a gas-phase ultra-stable modified molecular sieve;

(4) adding the gas-phase ultra-stable modified molecular sieve obtained in the step (3) into an exchange tank, and adding chemical water to ensure that the liquid-solid ratio in the molecular sieve slurry, namely the weight ratio of water to the molecular sieve, can be (2.5-5): 1, heating the molecular sieve slurry to 85-95 ℃, and then adding boric acid, wherein the amount of the boric acid added is B₂O₃Is counted as B₂O₃: and (3) stirring the gas-phase ultra-stable modified molecular sieve (0.5-4.5) for 1 hour, filtering, drying the filtered sample at 130 ℃ for 5 hours, and roasting at 350-600 ℃ for 1-4 hours to obtain the modified Y molecular sieve.

In a third embodiment of the present disclosure, preparing the modified Y-type molecular sieve may comprise the steps of:

(4) adding the gas-phase ultra-stable modified molecular sieve obtained in the step (3) into an exchange tank, and adding chemical water to ensure that the liquid-solid ratio in the molecular sieve slurry, namely the weight ratio of water to the molecular sieve, can be (2.5-5): 1, heating the molecular sieve slurry to 85-95 ℃, and then adding boric acid, wherein the amount of the boric acid added is B₂O₃Is counted as B₂O₃: stirring the gas-phase super-stable modified molecular sieve (0.5-3): 100 for 1h, filtering, and adding the filter cake into Ga (NO) while stirring₃)₃The solution of (a) is impregnated with a gallium component, and the solution is stirred uniformly and then allowed to stand at room temperature, wherein Ga (NO)₃)₃Ga (NO) contained in the solution of (1)₃)₃In an amount of Ga₂O₃The weight ratio of the molecular sieve to the molecular sieve is 0.1-2 wt%, and Ga (NO)₃)₃The weight ratio of the water added in the solution to the molecular sieve is as follows: water: and (3) soaking the molecular sieve (dry basis): 1 for 24 hours, then stirring the slurry for 20min to uniformly mix the slurry, transferring the slurry into a rotary evaporator to carry out water bath heating and rotary evaporation to dryness, and then roasting the evaporated material in a muffle furnace at 450-600 ℃ for 2-5 hours to obtain the modified Y molecular sieve.

In the preparation method of the catalytic cracking catalyst provided by the disclosure, spray drying, washing and drying are the prior art, and the method has no special requirements.

In the preparation method of the catalytic cracking catalyst provided by the present disclosure, the amount of the modified Y-type molecular sieve may be conventional in the art, and preferably, the content of the modified Y-type molecular sieve in the prepared catalyst on a dry basis may be 10 to 50 wt%, preferably 15 to 45 wt%, for example, 25 to 40 wt%.

In the preparation method provided by the present disclosure, the clay may be selected from one or more of clays used as cracking catalyst components, such as one or more of kaolin, halloysite, montmorillonite, diatomite, halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite, and bentonite. These clays are well known to those of ordinary skill in the art. The amount of the clay used may be conventional in the art, and preferably, the amount of the clay used may be 20 to 55 wt% or 30 to 50 wt% based on the dry weight of the clay in the catalytic cracking catalyst.

In the preparation method provided by the present disclosure, the alumina binder may be selected from one or more of alumina, hydrated alumina and alumina sol in various forms commonly used in cracking catalysts. For example, one or more selected from gamma-alumina, eta-alumina, theta-alumina, chi-alumina, pseudoboehmite (pseudoboehmite), diaspore (Boehmite), Gibbsite (Gibbsite), Bayerite (Bayerite) or alumina sol, preferably pseudoboehmite and/or alumina sol. The amount of the alumina binder may be conventional in the art, and preferably, the amount of the alumina binder may be 10 to 40 wt%, for example, 20 to 35 wt%, in terms of alumina, in the catalytic cracking catalyst. In one embodiment, the alumina binder comprises pseudo-boehmite and alumina sol, and the catalytic cracking catalyst comprises 2-15 wt% of alumina sol, preferably 3-10 wt% of alumina sol, and 10-30 wt% of pseudo-boehmite, preferably 15-25 wt% of alumina sol.

A third aspect of the present disclosure provides the use of a catalytic cracking catalyst according to the first aspect of the present disclosure in the catalytic cracking reaction of a hydrocarbon feedstock. In one embodiment, the catalytic cracking catalyst of the present disclosure may be used in processing a hydrocracked LCO catalytic cracking reaction.

A fourth aspect of the present disclosure is a catalytic cracking process for processing hydrogenated LCO, comprising the step of contacting the hydrogenated LCO with the catalyst described above under catalytic cracking conditions; wherein the catalytic cracking conditions may comprise: the reaction temperature is 500-610 ℃, and the weight hourly space velocity is 2-16 h^-1The agent-oil ratio is 3-10, and the agent-oil ratio is a weight ratio.

In one embodiment, the hydrogenated LCO may have the following properties: density (20 ℃): 0.850-0.920 g/cm³And H content: 10.5 to 12 wt%, S content<50 μ g/g, N content<10 μ g/g, total aromatic content: 70-85 wt% and polycyclic aromatic hydrocarbon content less than or equal to 15 wt%.

The following examples further illustrate the present disclosure, but are not intended to limit the same.

In the examples and comparative examples described below, the NaY molecular sieve (also known as NaY zeolite) was supplied by the zeuginese corporation, petrochemical catalyst ltd, china, and had a sodium oxide content of 13.5 wt% and a framework silica to alumina ratio (SiO-to-alumina ratio)₂/Al₂O₃Molar ratio) of 4.6, unit cell constant of 2.470nm, relative crystallinity of 90%; the rare earth chloride, the rare earth nitrate and the gallium nitrate are chemically pure reagents produced by Beijing chemical plants. The pseudoboehmite is an industrial product produced by Shandong aluminum factories, and the solid content is 61 percent by weight; the kaolin is kaolin specially used for a cracking catalyst produced by Suzhou China kaolin company, and the solid content is 76 percent by weight; the alumina sol was provided by the Qilu division of China petrochemical catalyst, Inc., in which the alumina content was 21 wt%.

The analysis method comprises the following steps: in each comparative example and example, the elemental content of the zeolite was determined by X-ray fluorescence spectroscopy; the unit cell constants and relative crystallinity of the zeolite were measured by X-ray powder diffraction (XRD) using RIPP145-90 and RIPP146-90 standard methods (compiled by petrochemical analysis method (RIPP test method), Yankee et al, scientific Press, published in 1990), and the framework silica-alumina ratio of the zeolite was calculated from the following formula: framework SiO₂/Al₂O₃Molar ratio of 2 × (25.858-a)₀)/(a₀-24.191), wherein, a₀Is a unit cell constant in

The total silicon-aluminum ratio of the zeolite is calculated according to the content of Si and Al elements measured by an X-ray fluorescence spectrometry, and the ratio of the framework Al to the total Al can be calculated by the framework silicon-aluminum ratio measured by an XRD method and the total silicon-aluminum ratio measured by an XRF method, so that the ratio of non-framework Al to the total Al can be calculated. Lattice collapse temperature by differential thermal analysisMeasurement by the method (DTA).

In each comparative example and example, the acid center type of the molecular sieve and its acid amount were determined by infrared analysis using pyridine adsorption. An experimental instrument: model Bruker IFS113V FT-IR (fourier transform infrared) spectrometer, usa. The experimental method for measuring the acid content at 350 ℃ by using a pyridine adsorption infrared method comprises the following steps: and (3) carrying out self-supporting tabletting on the sample, and placing the sample in an in-situ cell of an infrared spectrometer for sealing. Heating to 400 deg.C, and vacuumizing to 10 deg.C^-3And Pa, keeping the temperature for 2h, and removing gas molecules adsorbed by the sample. The temperature is reduced to room temperature, pyridine vapor with the pressure of 2.67Pa is introduced to keep the adsorption equilibrium for 30 min. Then heating to 350 ℃, and vacuumizing to 10 DEG C^-3Desorbing for 30min under Pa, reducing to room temperature for spectrography, scanning wave number range: 1400cm^-1～1700cm^-1And obtaining the pyridine absorption infrared spectrogram of the sample desorbed at 350 ℃. According to pyridine absorption infrared spectrogram of 1540cm^-1And 1450cm^-1The strength of the adsorption peak is characterized to obtain the medium-strength molecular sieve

Relative amount of acid center (B acid center) to Lewis acid center (L acid center).

In each of the comparative examples and examples, the secondary pore volume was determined as follows: the total pore volume of the molecular sieve was determined from the adsorption isotherm according to RIPP151-90 Standard method, "petrochemical analysis method (RIPP test method)," compiled by Yankee corporation, published in 1990 ", then the micropore volume of the molecular sieve was determined from the adsorption isotherm according to the T-plot method, and the secondary pore volume was obtained by subtracting the micropore volume from the total pore volume.

The chemical reagents used in the comparative examples and examples are not specifically noted, and are specified to be chemically pure.

Example 1

2000g NaY molecular sieve (dry basis) is added into 20L of decationized aqueous solution, stirred to be mixed evenly, and 600mL of RE (NO) is added₃)₃Solution (rare earth solution concentration in RE)₂O₃319g/L), stirring, heating to 90-95 ℃, keeping for 1h, then filtering, washing, drying filter cake at 120 ℃ to obtain unit cellConstant 2.471nm, sodium oxide content 7.0 wt.%, based on RE₂O₃Y-type molecular sieve with rare earth content of 8.8 wt%; then roasting for 6h at 390 ℃ in an atmosphere containing 50 vol% of water vapor and 50 vol% of air to obtain a Y-type molecular sieve with a unit cell constant of 2.455nm, and then drying to ensure that the water content is lower than 1 wt%; then according to SiCl₄: y-type molecular sieve (dry basis) ═ 0.5: 1, by weight, introducing SiCl vaporized by heating₄Gas, at 400 ℃ for 2h, after which it was washed with 20L of decationized water and then filtered, and the filter cake was added while stirring to 4000mL of 71.33gGa (NO) dissolved in it₃)₃·9H₂Soaking gallium component in O solution, and mixing the modified Y molecular sieve with Ga (NO)₃)₃The solution is stirred evenly and then stands at room temperature for 24 hours, and then the solution containing the modified Y molecular sieve and Ga (NO) is mixed₃)₃Stirring the slurry for 20min to mix uniformly, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation, then putting the evaporated material into a muffle furnace to bake for 2.5h at 550 ℃ to obtain the modified Y-type molecular sieve, marked as SZ1, the physicochemical properties of which are shown in Table 1-1, aging SZ1 in a naked state for 17h at 800 ℃, 1atm and 100% of water vapor, analyzing the relative crystallinity of the molecular sieve before and after the aging of SZ1 by using an XRD method, and calculating the retention rate of the relative crystallinity after the aging, wherein the results are shown in Table 2: relative crystallinity retention ═ relative crystallinity of aged sample/relative crystallinity of fresh sample x 100%. 714.5g of alumina sol with the alumina content of 21 wt% is added into 1565.5g of decationized water, stirring is started, 2763g of kaolin with the solid content of 76 wt% is added, and the mixture is dispersed for 60 min. 2049g of pseudo-boehmite with the alumina content of 61 wt% is added into 8146g of decationized water, 210mL of hydrochloric acid with the mass concentration of 36% is added under the stirring state, dispersed kaolin slurry is added after acidification is carried out for 60min, 1500g (dry basis) of ground SZ1 molecular sieve is added, after uniform stirring, spray drying and washing treatment are carried out, and the catalyst is obtained after drying and is marked as SC 1. Wherein the obtained SC1 catalyst contains 30 wt% of SZ1 molecular sieve and 42 wt% of kaolin,25 weight percent of pseudo-boehmite and 3 weight percent of alumina sol.

Example 2

2000g NaY molecular sieve (dry basis) is added into 25L of decationized aqueous solution, stirred to be mixed evenly, and 800mL of RECl is added₃Solutions (with RE)₂O₃The solution concentration is measured as: 319g/L), stirring, heating to 90-95 ℃, keeping for 1h, then filtering, washing, drying the filter cake at 120 ℃, and obtaining the crystal cell with the constant of 2.471nm, the content of sodium oxide of 5.5 weight percent and RE₂O₃Calculating Y-type molecular sieve with rare earth content of 11.3 wt%, calcining at 450 deg.C under 80% water vapor for 5.5h to obtain Y-type molecular sieve with unit cell constant of 2.461nm, drying to water content below 1 wt%, and adding SiCl₄: y-type zeolite 0.6: 1, by weight, introducing SiCl vaporized by heating₄The gas was reacted at 480 ℃ for 1.5h, after which it was washed with 20L of decationized water, then filtered, and the filter cake was added to 4500mL of 133.74gGa (NO) dissolved in it while stirring₃)₃·9H₂Soaking gallium component in O solution, and mixing the modified Y molecular sieve with Ga (NO)₃)₃The solution is stirred evenly and then stands at room temperature for 24 hours, and then the solution containing the modified Y molecular sieve and Ga (NO) is mixed₃)₃And stirring the slurry for 20min to mix uniformly, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation to dryness, and then putting the evaporated material into a muffle furnace to bake for 3h at 500 ℃ to obtain the modified Y-type molecular sieve recorded as SZ 2. The physicochemical properties are shown in Table 1-1, and the results are shown in Table 2, wherein the crystallinity of zeolite before and after aging of SZ2 is analyzed by XRD method after aging of SZ2 in naked state at 800 deg.C and 100% water vapor for 17h, and the relative crystallinity retention rate after aging is calculated.

Referring to the preparation method of example 1, SZ2 molecular sieve, kaolin, water, pseudo-boehmite binder, and alumina sol were slurried and spray-dried to prepare a microspherical catalyst according to a conventional preparation method of a catalytic cracking catalyst, and the prepared catalytic cracking catalyst was designated as SC 2. Wherein the obtained SC2 catalyst contains 30 wt% of SZ2 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Example 3

2000g NaY molecular sieve (dry basis) was added to 22L of decationized aqueous solution and mixed well, 570mL of RECl was added₃Solutions (with RE)₂O₃The calculated concentration of the rare earth solution is 319g/L), stirring, heating to 90-95 ℃, keeping stirring for 1h, then filtering, washing, drying a filter cake at 120 ℃, and obtaining the rare earth solution with the unit cell constant of 2.471nm, the sodium oxide content of 7.5 weight percent and the RE₂O₃Calculating Y-type molecular sieve with rare earth content of 8.5 wt%, calcining at 470 deg.C under 70 vol% steam for 5 hr to obtain Y-type molecular sieve with unit cell constant of 2.458nm, drying to water content lower than 1 wt%, and adding SiCl₄: y-type zeolite 0.4: 1, by weight, introducing SiCl vaporized by heating₄Gas, at a temperature of 500 ℃ for 1h, after which it was washed with 20L of decationized water and then filtered, and the filter cake was added while stirring to 4800mL of 178.32gGa (NO) dissolved in it₃)₃·9H₂Soaking gallium component in O solution, and mixing the modified Y molecular sieve with Ga (NO)₃)₃The solution is stirred evenly and then stands at room temperature for 24 hours, and then the solution containing the modified Y molecular sieve and Ga (NO) is mixed₃)₃And stirring the slurry for 20min to mix uniformly, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation to dryness, and then putting the evaporated material into a muffle furnace to roast for 2h at 600 ℃ to obtain the modified Y-type molecular sieve recorded as SZ 3. The physicochemical properties are shown in Table 1-1, and the results are shown in Table 2, wherein the crystallinity of zeolite before and after aging of SZ3 is analyzed by XRD method after aging of SZ3 in naked state at 800 deg.C under 100% steam for 17h, and the retention rate of relative crystallinity after aging is calculated.

Slurry is formed by using an SZ3 molecular sieve, kaolin, water, a pseudo-boehmite binder and an aluminum sol according to a conventional preparation method of a catalytic cracking catalyst, and the slurry is spray-dried to prepare a microspherical catalyst, wherein the prepared catalytic cracking catalyst is marked as SC3 (refer to the preparation method of example 1). Wherein the obtained SC3 catalyst contains 30 wt% of SZ3 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Example 4

2000g NaY molecular sieve (dry basis) is added into 20L of decationized aqueous solution, stirred to be mixed evenly, and 600mL of RE (NO) is added₃)₃Solution (rare earth solution concentration in RE)₂O₃319g/L), stirring, heating to 90-95 ℃, keeping for 1h, then filtering, washing, drying filter cake at 120 ℃, obtaining crystal cell constant of 2.471nm, sodium oxide content of 7.0 wt%, RE₂O₃Y-type molecular sieve with rare earth content of 8.8 wt%; then roasting for 5 hours at the temperature of 365 ℃ in an atmosphere containing 30 vol% of water vapor and 70 vol% of air to obtain a Y-type molecular sieve with a unit cell constant of 2.460nm, and then drying to ensure that the water content is lower than 1 wt%; then according to SiCl₄: y-type molecular sieve (dry basis) ═ 0.2: 1, by weight, introducing SiCl vaporized by heating₄Gas, at a temperature of 250 ℃, for 2h, after which it was washed with 20L of decationized water, then filtered, and the filter cake was added while stirring to 4000mL of 71.33gGa (NO) dissolved in it₃)₃·9H₂Soaking gallium component in O solution, and mixing the modified Y molecular sieve with Ga (NO)₃)₃The solution is stirred evenly and then stands at room temperature for 24 hours, and then the solution containing the modified Y molecular sieve and Ga (NO) is mixed₃)₃Stirring the slurry for 20min to mix uniformly, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation, then putting the evaporated material into a muffle furnace to bake for 2.5h at 550 ℃ to obtain the modified Y-type molecular sieve, marked as SZ4, the physicochemical properties of which are shown in Table 1-1, aging SZ4 in a naked state for 17h at 800 ℃, 1atm and 100% of water vapor, analyzing the relative crystallinity of the molecular sieve before and after the aging of SZ4 by using an XRD method, and calculating the retention rate of the relative crystallinity after the aging, wherein the result is shown in Table 2.

With reference to the preparation method of example 1, SZ4 molecular sieve, kaolin, water, pseudo-boehmite binder, and alumina sol were slurried and spray-dried to prepare a microspherical catalyst according to a conventional preparation method of a catalytic cracking catalyst, and the prepared catalytic cracking catalyst was designated as SC 4. Wherein the obtained SC4 catalyst contains 30 wt% of SZ4 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Example 5

2000g NaY molecular sieve (dry basis) is added into 20L of decationized aqueous solution, stirred to be mixed evenly, and 600mL of RE (NO) is added₃)₃Solution (rare earth solution concentration in RE)₂O₃319g/L), stirring, heating to 90-95 ℃, keeping for 1h, then filtering, washing, drying filter cake at 120 ℃, obtaining crystal cell constant of 2.471nm, sodium oxide content of 7.0 wt%, RE₂O₃Y-type molecular sieve with rare earth content of 8.8 wt%; then roasting for 6h at 390 ℃ in an atmosphere containing 50 vol% of water vapor and 50 vol% of air to obtain a Y-type molecular sieve with a unit cell constant of 2.455nm, and then drying to ensure that the water content is lower than 1 wt%; then according to SiCl₄: y-type molecular sieve (dry basis) ═ 0.5: 1, by weight, introducing SiCl vaporized by heating₄Reacting gas at 400 deg.C for 2h, washing with 20L decationized water, and filtering; the filter cake was then added to the exchange tank, 5L of chemical water was added followed by warming the molecular sieve slurry to 65 deg.C, followed by addition of 12.46g of boric acid, stirring for 1 hour, filtering, and then the filter cake was added to 4000mL of a solution of 42.8gGa (NO) while stirring₃)₃·9H₂Soaking gallium component in O solution, and mixing the modified Y molecular sieve with Ga (NO)₃)₃The solution is stirred evenly and then stands at room temperature for 24 hours, and then the solution containing the modified Y molecular sieve and Ga (NO) is mixed₃)₃Stirring the slurry for 20min to mix uniformly, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation to dryness, then putting the evaporated material into a muffle furnace to bake for 2.5h at 550 ℃ to obtain the modified Y-type molecular sieve marked as SZ5, wherein the physicochemical properties are shown in Table 1-1, aging SZ5 in a naked state for 17h at 800 ℃, 1atm and 100% of water vapor, and analyzing by using an XRD methodThe relative crystallinity of the molecular sieve before and after SZ5 aging was calculated and the retention of the relative crystallinity after aging was calculated, and the results are shown in table 2.

With reference to the preparation method of example 1, SZ5 molecular sieve, kaolin, water, pseudo-boehmite binder, and alumina sol were slurried and spray-dried to prepare a microspherical catalyst according to a conventional preparation method of a catalytic cracking catalyst, and the prepared catalytic cracking catalyst was designated as SC 5. Wherein the obtained SC5 catalyst contains 30 wt% of SZ5 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Example 6

2000g NaY molecular sieve (dry basis) is added into 20L of decationized aqueous solution, stirred to be mixed evenly, and 600mL of RE (NO) is added₃)₃Solution (rare earth solution concentration in RE)₂O₃319g/L), stirring, heating to 90-95 ℃, keeping for 1h, then filtering, washing, drying filter cake at 120 ℃, obtaining crystal cell constant of 2.471nm, sodium oxide content of 7.0 wt%, RE₂O₃Calculating Y-type molecular sieve with 8.8 wt% of rare earth, roasting at 390 deg.C in the atmosphere containing 50 vol% of water vapor and 50 vol% of air for 6h to obtain Y-type molecular sieve with unit cell constant of 2.455nm, drying to make its water content less than 1 wt%, and adding SiCl₄: y-type molecular sieve (dry basis) ═ 0.5: 1, by weight, introducing SiCl vaporized by heating₄Reacting gas at 400 ℃ for 2h, washing the gas with 20L decationized water, filtering, adding a filter cake into an exchange tank, adding 5L of chemical water, heating molecular sieve slurry to 65 ℃, adding 17.8g of boric acid, stirring for 1h, filtering, drying a filtered sample at 130 ℃ for 5h, roasting at 400 ℃ for 2.5h to obtain the modified Y-type molecular sieve, marked as SZ6, wherein the physicochemical properties of the modified Y-type molecular sieve are shown in Table 1-1, and after the exposed SZ6 is aged for 17h at 800 ℃, 1atm and 100% steam, analyzing the relative crystallinity of the molecular sieve before and after aging of SZ6 by using an XRD method, and calculating the relative crystallinity retention after aging, wherein the results are shown in Table 2.

714.5g of alumina sol with the alumina content of 21 wt% is added into 1565.5g of decationized water, stirring is started, 2763g of kaolin with the solid content of 76 wt% is added, and the mixture is dispersed for 60 min. 2049g of pseudo-boehmite with the alumina content of 61 wt% is added into 8146g of decationized water, 210mL of hydrochloric acid with the mass concentration of 36% is added under the stirring state, dispersed kaolin slurry is added after acidification is carried out for 60min, 1500g (dry basis) of ground SZ6 molecular sieve is added, after uniform stirring, spray drying and washing treatment are carried out, and the catalyst is obtained after drying and is marked as SC 6. Wherein the obtained SC6 catalyst contains 30 wt% of SZ6 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Example 7

2000g NaY molecular sieve (dry basis) is added into 25L of decationized aqueous solution, stirred to be mixed evenly, and 800mL of RECl is added₃Solutions (with RE)₂O₃The solution concentration is measured as: 319g/L), stirring, heating to 90-95 ℃, keeping for 1h, then filtering, washing, drying the filter cake at 120 ℃, and obtaining the crystal cell with the constant of 2.471nm, the content of sodium oxide of 5.5 weight percent and RE₂O₃Calculating Y-type molecular sieve with rare earth content of 11.3 wt%, calcining at 450 deg.C under 80% water vapor for 5.5h to obtain Y-type molecular sieve with unit cell constant of 2.461nm, drying to water content below 1 wt%, and adding SiCl₄: y-type zeolite 0.6: 1, by weight, introducing SiCl vaporized by heating₄Reacting gas for 1.5h at 480 ℃, then washing with 20L of decationized water, filtering, then adding a filter cake into an exchange tank, adding 6L of chemical water, then heating molecular sieve slurry to 80 ℃, then adding 32g of boric acid, stirring for 1h, filtering, drying a filtered sample at 130 ℃ for 5h, then roasting at 380 ℃ for 3.5h to obtain the modified Y-type molecular sieve, and recording as SZ 7. The physicochemical properties are shown in Table 1-1, and the results are shown in Table 2, wherein the crystallinity of zeolite before and after aging of SZ7 is analyzed by XRD method after aging of SZ7 in naked state at 800 deg.C and 100% water vapor for 17h, and the relative crystal retention after aging is calculated.

Referring to the preparation method of example 1, SZ7 molecular sieve, kaolin, water, pseudo-boehmite binder, and alumina sol were slurried and spray-dried to prepare a microspherical catalyst according to a conventional preparation method of a catalytic cracking catalyst, and the prepared catalytic cracking catalyst was designated as SC 7. Wherein the obtained SC7 catalyst contains 30 wt% of SZ7 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Example 8

2000g NaY molecular sieve (dry basis) was added to 22L of decationized aqueous solution and mixed well, 570mL of RECl was added₃Solutions (with RE)₂O₃The calculated concentration of the rare earth solution is 319g/L), stirring, heating to 90-95 ℃, keeping stirring for 1h, then filtering, washing, drying a filter cake at 120 ℃, and obtaining the rare earth solution with the unit cell constant of 2.471nm, the sodium oxide content of 7.5 weight percent and the RE₂O₃Calculating Y-type molecular sieve with rare earth content of 8.5 wt%, calcining at 470 deg.C under 70 vol% steam for 5 hr to obtain Y-type molecular sieve with unit cell constant of 2.458nm, drying to water content lower than 1 wt%, and adding SiCl₄: y-type zeolite 0.4: 1, by weight, introducing SiCl vaporized by heating₄Reacting gas for 1h at the temperature of 500 ℃, washing the gas with 20L of decationized water, filtering, adding a filter cake into an exchange tank, adding 5L of chemical water, heating molecular sieve slurry to 60-99 ℃, adding 71.2g of boric acid, stirring for 1h, filtering, drying a filtered sample at 130 ℃ for 5h, roasting at the temperature of 500 ℃ for 2h to obtain the modified Y-type molecular sieve, and recording the modified Y-type molecular sieve as SZ 8. The physicochemical properties are shown in Table 1-1, and the results are shown in Table 2, wherein the crystallinity of zeolite before and after aging of SZ8 is analyzed by XRD method after aging of SZ8 in naked state at 800 deg.C under 100% steam for 17h, and the relative crystal retention after aging is calculated.

Slurry is formed by using an SZ8 molecular sieve, kaolin, water, a pseudo-boehmite binder and an aluminum sol according to a conventional preparation method of a catalytic cracking catalyst, and the slurry is spray-dried to prepare a microspherical catalyst, wherein the prepared catalytic cracking catalyst is marked as SC8 (refer to the preparation method of example 1). Wherein the obtained SC8 catalyst contains 30 wt% of SZ8 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Comparative example 1

Adding 2000g NaY molecular sieve (dry basis) into 20L of decationized aqueous solution, stirring to mix well, adding 1000g (NH)₄)₂SO₄Stirring, heating to 90-95 deg.C, maintaining for 1h, filtering, washing, drying filter cake at 120 deg.C, performing hydrothermal modification treatment (temperature 650 deg.C, roasting with 100% water vapor for 5h), adding into 20L decationized water solution, stirring, mixing, adding 1000g (NH)₄)₂SO₄Stirring, heating to 90-95 ℃ for 1h, filtering, washing, and drying a filter cake at 120 ℃ to obtain a Y-type molecular sieve with a unit cell constant of 2.454nm and a sodium oxide content of 1.3 wt%; and then carrying out second hydrothermal modification treatment, wherein the hydrothermal treatment condition is that the temperature is 650 ℃, and the roasting is carried out for 5 hours under 100% of water vapor, so as to obtain the rare earth-free hydrothermal ultrastable Y-shaped molecular sieve which is subjected to twice ion exchange and twice hydrothermal ultrastable, and is marked as DZ 1. The physicochemical properties are shown in Table 1-2, and the results are shown in Table 2, wherein the crystallinity of the zeolite before and after aging of DZ1 is analyzed by XRD method after aging DZ1 in naked state at 800 deg.C and 100% water vapor for 17h, and the relative crystallinity retention rate after aging is calculated.

DZ1 molecular sieve, kaolin, water, pseudo-boehmite binder and alumina sol are formed into slurry according to a conventional preparation method of a catalytic cracking catalyst, the slurry is spray-dried to prepare a microspherical catalyst, and the prepared catalytic cracking catalyst is marked as DC1 (refer to the preparation method of example 1). Wherein the obtained DC1 catalyst contains 30 wt% of DZ1 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Comparative example 2

Adding 2000g NaY molecular sieve (dry basis) into 20L of decationized aqueous solution, stirring to mix well, adding 1000g (NH)₄)₂SO₄Stirring, heating to 90-95 deg.C, holding for 1 hr, filtering, washing, and drying at 120 deg.C to obtain sodium oxide with unit cell constant of 2.470nmY-type molecular sieve in an amount of 5.0 wt%; then carrying out hydrothermal modification treatment, roasting the hydrothermal modification treatment for 5h at 650 ℃ under 100% water vapor, adding the hydrothermal modification treatment into 20L of decationized aqueous solution, stirring the mixture to be uniformly mixed, and adding 200mL of RE (NO)₃)₃Solutions (with RE)₂O₃The concentration of the rare earth solution is measured as follows: 319g/L) and 900g (NH)₄)₂SO₄Stirring, heating to 90-95 deg.C, maintaining for 1h, filtering, washing, and drying filter cake at 120 deg.C to obtain crystal cell with constant of 2.456nm, sodium oxide content of 1.5 wt%, and RE₂O₃Y-type molecular sieve with 2.7 wt% of rare earth content; and then carrying out second hydrothermal modification treatment (roasting for 5 hours at 650 ℃ under 100% of water vapor) to obtain the rare earth-containing hydrothermal ultrastable Y-shaped molecular sieve which is subjected to ion exchange twice and hydrothermal ultrastable twice, and is marked as DZ 2. The physicochemical properties are shown in Table 1-2, and the results are shown in Table 2, wherein the crystallinity of the zeolite before and after aging of DZ2 is analyzed by XRD method after aging DZ2 in naked state at 800 deg.C and 100% water vapor for 17h, and the relative crystallinity retention rate after aging is calculated.

DZ2 molecular sieve, kaolin, water, pseudo-boehmite binder and alumina sol are formed into slurry according to a conventional preparation method of a catalytic cracking catalyst, the slurry is spray-dried to prepare a microspherical catalyst, and the prepared catalytic cracking catalyst is marked as DC2 (refer to the preparation method of example 1). Wherein the obtained DC2 catalyst contains 30 wt% of DZ2 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Comparative example 3

Adding 2000g NaY molecular sieve (dry basis) into 20L of decationized aqueous solution, stirring to mix well, adding 650mL of RE (NO)₃)₃Stirring the solution (319g/L), heating to 90-95 ℃ for 1h, filtering and washing to obtain the solution with the unit cell constant of 2.471nm, the sodium oxide content of 6.7 wt% and the RE content₂O₃Calculating Y-type molecular sieve with rare earth content of 9.5 wt%, gas-phase superstable modifying, drying to water content lower than 1 wt%, and adding SiCl₄: y-type zeolite 0.4: 1 by weight ratio, introducing SiC vaporized by heatingl₄The gas was reacted at 580 ℃ for 1.5h, then washed with 20L of decationized water and filtered to obtain a gas phase high silicon ultrastable Y-type molecular sieve, noted as DZ 3. The physicochemical properties are shown in Table 1-2, and the results are shown in Table 2, wherein the crystallinity of the zeolite before and after aging of DZ3 is analyzed by XRD method after aging DZ3 in naked state at 800 deg.C and 100% water vapor for 17h, and the relative crystallinity retention rate after aging is calculated.

DZ3 molecular sieve, kaolin, water, pseudo-boehmite binder and alumina sol are formed into slurry according to a conventional preparation method of a catalytic cracking catalyst, the slurry is spray-dried to prepare a microspherical catalyst, and the prepared catalytic cracking catalyst is marked as DC3 (refer to the preparation method of example 1). Wherein the obtained DC3 catalyst contains 30 wt% of DZ3 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Comparative example 4

2000g NaY molecular sieve (dry basis) is added into 20L of decationized aqueous solution, stirred to be mixed evenly, and 600mL of RE (NO) is added₃)₃Solution (rare earth solution concentration in RE)₂O₃319g/L), stirring, heating to 90-95 ℃, keeping for 1h, then filtering, washing, drying filter cake at 120 ℃, obtaining crystal cell constant of 2.471nm, sodium oxide content of 7.0 wt%, RE₂O₃Y-type molecular sieve with rare earth content of 8.8 wt%; then roasting for 6h at 390 ℃ in an atmosphere containing 50 vol% of water vapor and 50 vol% of air to obtain a Y-type molecular sieve with a unit cell constant of 2.455nm, and then drying to ensure that the water content is lower than 1 wt%; then according to SiCl₄: y-type molecular sieve (dry basis) ═ 0.5: 1, by weight, introducing SiCl vaporized by heating₄The gas was reacted at 400 ℃ for 2h, then washed with 20L of decationized water, filtered and dried to obtain a modified Y-type molecular sieve designated as DZ 4. The physicochemical properties are shown in Table 1-2, and the results are shown in Table 2, wherein the crystallinity of the zeolite before and after aging of DZ4 is analyzed by XRD method after aging DZ4 in naked state at 800 deg.C and 100% water vapor for 17h, and the relative crystallinity retention rate after aging is calculated.

With reference to the preparation method of example 1, a DZ4 molecular sieve, kaolin, water, a pseudo-boehmite binder and an alumina sol are formed into slurry according to a conventional preparation method of a catalytic cracking catalyst, and the slurry is spray-dried to prepare a microspherical catalyst, wherein the prepared catalytic cracking catalyst is designated as DC 4. Wherein the obtained DC4 catalyst contains 30 wt% of DZ4 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Comparative example 5

2000g NaY molecular sieve (dry basis) is added into 20L of decationized aqueous solution, stirred to be mixed evenly, and 600mL of RE (NO) is added₃)₃Solution (rare earth solution concentration in RE)₂O₃319g/L), stirring, heating to 90-95 ℃, keeping for 1h, then filtering, washing, drying filter cake at 120 ℃, obtaining crystal cell constant of 2.471nm, sodium oxide content of 7.0 wt%, RE₂O₃Y-type molecular sieve with rare earth content of 8.8 wt%; then roasting for 6h at 390 ℃ in an atmosphere containing 50 vol% of water vapor and 50 vol% of air to obtain a Y-type molecular sieve with a unit cell constant of 2.455nm, and then drying to ensure that the water content is lower than 1 wt%; then according to SiCl₄: y-type molecular sieve (dry basis) ═ 0.5: 1, by weight, introducing SiCl vaporized by heating₄Reacting gas at 400 deg.C for 2h, washing with 20L decationized water, and filtering; the filter cake was then added to 4000mL of 491gGa (NO) dissolved in it with stirring₃)₃·9H₂Soaking gallium component in O solution, and mixing the modified Y molecular sieve with Ga (NO)₃)₃The solution is stirred evenly and then stands at room temperature for 24 hours, and then the solution containing the modified Y molecular sieve and Ga (NO) is mixed₃)₃Stirring the slurry for 20min to mix uniformly, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation to dryness, then putting the evaporated material into a muffle furnace to bake for 2.5h at 550 ℃ to obtain the modified Y-type molecular sieve, marked as DZ5, the physicochemical properties of which are shown in Table 1-1, aging DZ5 in a naked state for 17h at 800 ℃, 1atm and 100% of water vapor, and then using the method of XRDThe relative crystallinity of the molecular sieve before and after aging of DZ5 was analyzed by the method and the retention of the relative crystallinity after aging was calculated, the results are shown in table 2.

With reference to the preparation method of example 1, a DZ5 molecular sieve, kaolin, water, a pseudo-boehmite binder and an alumina sol are formed into slurry according to a conventional preparation method of a catalytic cracking catalyst, and the slurry is spray-dried to prepare a microspherical catalyst, wherein the prepared catalytic cracking catalyst is designated as DC 5. Wherein the obtained DC5 catalyst contains 30 wt% of DZ5 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Comparative example 6

This comparative example employed the conventional FCC catalyst of CN104560187a example 1, designated catalyst DC 6.

Test examples 1 to 8

The catalytic cracking reaction performance of the catalytic cracking catalysts of examples 1 to 8 was tested.

After the SC 1-SC 8 catalysts are aged for 12 hours at 800 ℃ by 100 percent of water vapor, the catalytic cracking reaction performance of the catalysts for processing hydrogenated LCO is evaluated on a small-sized fixed fluidized bed reactor (ACE), and cracked gas and product oil are respectively collected and analyzed by gas chromatography. The catalyst loading is 9g, the reaction temperature is 500 ℃, and the weight hourly space velocity is 16h^-1The oil-to-agent ratio (weight ratio) is shown in Table 4-1, the properties of the raw oil in the ACE test are shown in Table 3, and the results are shown in Table 4-1.

Wherein LCO effective conversion/% -100-diesel yield-dry gas yield-coke yield-heavy oil yield.

Comparative examples 1 to 6

The catalytic cracking reaction performances of the catalytic cracking catalysts DC 1-DC 5 prepared by the methods provided by comparative examples 1-5 and the conventional FCC catalyst DC6 of comparative example 6 were tested.

After aging the catalysts DC 1-DC 6 for 12h at 800 ℃ with 100% water vapor, the catalytic cracking reaction performance of the catalysts for processing hydrogenated LCO is evaluated on a small fixed fluidized bed reactor (ACE), the evaluation method is shown in test example 1, the properties of the raw materials for the ACE experiment are shown in Table 3, and the results are shown in tables 4-2.

Wherein LCO effective conversion/% -100-diesel yield-dry gas yield-coke yield-heavy oil yield. TABLE 1-1

Tables 1 to 2

As can be seen from the comparison between tables 1-1 and tables 1-2, the modified Y-type molecular sieve in the catalytic cracking catalyst provided by the invention has high stability and the following advantages: the content of sodium oxide is low, the non-framework aluminum content is low when the silicon-aluminum content of the molecular sieve is high, the pore volume of 2.0-100 nm secondary pores in the molecular sieve accounts for the higher percentage of the total pore volume, the B acid/L acid (the ratio of the strong B acid content to the L acid content) is high, the crystallinity value measured when the unit cell constant of the molecular sieve is small and the rare earth content is high, and the thermal stability is high.

TABLE 2

As can be seen from Table 2, the modified Y-type molecular sieve in the catalytic cracking catalyst provided by the invention has a high relative crystal retention after being aged under severe conditions of 800 ℃ and 17 hours in an exposed molecular sieve sample, which indicates that the modified Y-type molecular sieve provided by the invention has high hydrothermal stability.

TABLE 3 Properties of hydrogenated LCO

TABLE 4-1

TABLE 4-2

As can be seen from the results listed in tables 4-1 and 4-2, the catalytic cracking catalyst provided by the present invention has very high hydrothermal stability, significantly lower coke selectivity, significantly higher gasoline yield, and significantly improved BTX (benzene + toluene + xylene) yield in gasoline.

The preferred embodiments of the present disclosure have been described in detail above, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. The catalytic cracking catalyst is characterized by comprising 10-50 wt% of modified Y-type molecular sieve, 10-40 wt% of alumina binder and 10-80 wt% of clay on a dry basis, wherein the modified Y-type molecular sieve is based on the dry basis weight of the catalyst;

on the basis of the dry weight of the modified Y-type molecular sieve, the modified Y-type molecular sieve contains 5-12 wt% of rare earth elements, 0.1-0.7 wt% of sodium oxide and 0.1-5 wt% of active element oxides, wherein the active elements are gallium and/or boron, and the oxides are calculated by oxides; the total pore volume of the modified Y-type molecular sieve is 0.33-0.39 mL/g, and the pore volume of secondary pores with the pore diameter of 2-100 nm accounts for 10-25% of the total pore volume; the unit cell constant of the modified Y-type molecular sieve is 2.440-2.455 nm, and the lattice collapse temperature is not lower than 1050 ℃; the proportion of non-framework aluminum content of the modified Y-type molecular sieve in the total aluminum content is not higher than 20%, and the ratio of B acid content to L acid content in strong acid content of the modified Y-type molecular sieve is not lower than 3.0; the ratio of the B acid amount to the L acid amount in the strong acid amount of the modified Y-type molecular sieve is measured at 350 ℃ by adopting a pyridine adsorption infrared method.

2. The catalytic cracking catalyst of claim 1, wherein the modified Y-type molecular sieve has a pore volume of secondary pores having a pore diameter of 2 to 100nm in a proportion of 15 to 21% by volume of the total pores.

3. The catalytic cracking catalyst of claim 1, wherein the non-framework aluminum content of the modified Y-type molecular sieve accounts for 13-19% of the total aluminum content; with SiO₂/Al₂O₃The framework silica-alumina ratio of the modified Y-type molecular sieve is 7.3-14.

4. The catalytic cracking catalyst of claim 1, wherein the modified Y-type molecular sieve has a lattice collapse temperature of 1055-1080 ℃.

5. The catalytic cracking catalyst of claim 1, wherein the modified Y-type molecular sieve has a ratio of the amount of B acid to the amount of L acid in the strong acid amount of 3.1-5.0.

6. The catalytic cracking catalyst of claim 1, wherein the modified Y-type molecular sieve has a relative crystallinity of 60 to 70%.

7. The catalytic cracking catalyst of claim 1, wherein the modified Y-type molecular sieve has a relative crystallinity retention of 38% or more as determined by XRD after aging with 100% steam at 800 ℃ for 17 hours.

8. The catalytic cracking catalyst of any one of claims 1 to 7, wherein the modified Y-type molecular sieve contains 5.5 to 10 wt% of rare earth elements and 0.3 to 0.7 wt% of sodium oxide in terms of oxide, based on the dry weight of the modified Y-type molecular sieve; the unit cell constant of the modified Y-type molecular sieve is 2.442-2.450 nm; with SiO₂/Al₂O₃The framework silica-alumina ratio of the modified Y-type molecular sieve is 8.5-12.6; the rare earth element comprises La, Ce, Pr or Nd, or a combination of two or three or four of them;

9. The catalytic cracking catalyst of claim 1, wherein the clay is kaolin, halloysite, montmorillonite, diatomaceous earth, halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite, or bentonite, or a combination of two or three or four thereof; the alumina binder is alumina, hydrated alumina or alumina sol, or a combination of two or three of the above.

10. A process for preparing a catalytic cracking catalyst according to any of claims 1 to 9, characterized in that it comprises: preparing a modified Y-type molecular sieve, forming slurry comprising the modified Y-type molecular sieve, an alumina binder, clay and water, and spray-drying to obtain the catalytic cracking catalyst;

11. The method of claim 10, wherein the method of ion exchange reaction comprises: mixing NaY molecular sieve with water, adding rare earth salt and/or rare earth salt water solution under stirring to perform ion exchange reaction, and filtering and washing;

12. The process of claim 10 or 11, wherein the ion exchanged molecular sieve has a unit cell constant of 2.465 to 2.472nm, a rare earth content of 5.5 to 14 wt% calculated as oxide, and a sodium oxide content of 4 to 9 wt%.

13. The method of claim 10 or 11, wherein the rare earth salt is a rare earth chloride or a rare earth nitrate.

14. The method of claim 10, wherein the processing conditions of step (2) comprise: the first roasting is carried out for 5-6 h at 380-460 ℃ and under 40-80 vol% of water vapor.

15. The method according to claim 10 or 14, wherein the molecular sieve modified by mild hydrothermal superstability has a unit cell constant of 2.450-2.462 nm, and the molecular sieve modified by mild hydrothermal superstability has a water content of not more than 1 wt%.

16. The method of claim 10, wherein in step (3), SiCl is used₄The weight ratio of the modified molecular sieve to the modified molecular sieve for moderating hydrothermal superstability is (0.1-0.7): 1, the temperature of the contact reaction is 200-650 ℃, and the reaction time is 10 min-5 h; the second washing method includes: washing with water until the pH value of a washing liquid is 2.5-5.0, the washing temperature is 30-60 ℃, and the weight ratio of the water consumption to the unwashed gas-phase ultra-stable modified molecular sieve is (5-20): 1.

17. the method according to claim 10, wherein the solution containing the active element is an aqueous solution of a gallium salt and/or an aqueous solution of a boron compound;

18. the method of claim 10, wherein in step (4), the conditions of the second firing comprise: the roasting temperature is 350-600 ℃, and the roasting time is 1-5 h.

19. Use of the catalytic cracking catalyst of any one of claims 1 to 9 in catalytic cracking reactions of hydrocarbon feedstocks.

20. A catalytic cracking process for processing hydrogenated LCO, comprising the step of contacting hydrogenated LCO with the catalyst of any one of claims 1 to 9 under catalytic cracking conditions; wherein the catalytic cracking conditions comprise: the reaction temperature is 500-610 ℃, and the weight hourly space velocity is 2-16 h^-1The agent-oil ratio is 3-10, and the agent-oil ratio is a weight ratio.