CN110833855A

CN110833855A - Catalytic cracking catalyst, preparation method and application thereof

Info

Publication number: CN110833855A
Application number: CN201810942081.5A
Authority: CN
Inventors: 周灵萍; 许明德; 袁帅; 沙昊; 姜秋桥; 陈振宇; 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: 2020-02-25
Anticipated expiration: 2038-08-17
Also published as: CN110833855B

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; taking the dry weight of the modified Y-type molecular sieve as a reference, the content of rare earth elements of the modified Y-type molecular sieve calculated by oxides is 4-11 wt%, and P is used₂O₅The content of phosphorus is 0.05-10 wt%, the content of sodium oxide is 0.1-0.7 wt%, the content of active element oxide is 0.1-5 wt%, and the active element is 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 15-30% 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 proportion of non-framework aluminum content in the total aluminum content is not higher than 20%, and the ratio of B acid content to L acid content in the strong acid content of the modified Y-type molecular sieve is not lower than 3.5.When the catalyst is used for hydrogenating LCO, the LCO conversion efficiency is high, the coke selectivity is low, the gasoline yield is high, and the BTX is rich.

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 hydrothermal method is mainly adopted for industrially preparing the high-silicon Y-type zeolite. The rare earth-containing high-silicon Y-type zeolite can be prepared by carrying out rare earth ion exchange and high-temperature roasting on NaY zeolite for multiple times, which is the most conventional method for preparing the high-silicon Y-type zeolite, but the defect of preparing the rare earth high-silicon Y-type zeolite by a hydrothermal method is 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; while the production of extra-framework aluminum is beneficial for improving the stability of the zeolite and forming new acid centers, the excess extra-framework aluminum reduces the selectivity of the zeolite; in addition, many dealuminization cavities in the zeolite cannot be timely supplemented by silicon migrated from the framework, so that lattice defects of the zeolite are often caused, and the crystal retention of the zeolite is low; therefore, the thermal and hydrothermal stability of the rare earth-containing high-silicon Y-type zeolite prepared by the hydrothermal method is poor, which is shown in that the lattice collapse temperature is low, and the crystallinity retention rate and the specific surface area retention rate are low after hydrothermal aging.

In U.S. Pat. Nos. 4,849,287 and 4,4429053, NaY zeolite is exchanged with rare earth ions and then treated with water vapor, in the method, the aluminum removal of zeolite is difficult in the water vapor treatment process due to the shielding effect and support of the rare earth ions, the unit cell parameters of zeolite before the water vapor 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 high (593-733 ℃).

In the processes provided in US5340957 and US5206194, SiO of NaY zeolite is used as the starting material₂/Al₂O₃The ratio is 6.0, which is also a rare earth exchange of NaY followed by hydrothermal treatment, with the same disadvantages of the aforementioned US4584287 and US 4429053.

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 SiCl under the protection of nitrogen₄Reacting with anhydrous NaY zeolite at a certain temperature. Fully utilizes SiCl in the whole reaction process₄The supplied foreign Si source completes dealuminization and silicon supplement reaction at one time through isomorphous substitution. But gas phase ultrastable molecular sieves do not have secondary pores. 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, the existing gas-phase ultrastable molecular sieve still has the problem of low activity when used for heavy oil cracking, can not meet the processing requirements of heavy oil and poor oil, and can directly meet the requirements of heavy oil and poor oilAffecting the product distribution and economic benefits of the catalytic cracking unit.

In order to make the molecular sieve meet the requirements of processing heavy oil and poor oil at present, the prior art carries out ion exchange modification and surface modification of rare earth, phosphorus and the like on the Y-type molecular sieve.

CN1330981A discloses a phosphorus-containing Y-type zeolite and a preparation method thereof. The said P-containing Y-type zeolite contains P, a Si component and rare-earth component, and the Si component is loaded by impregnating zeolite with solution of Si compound and is SiO₂The content of the silicon component is 1-15 wt% calculated by P₂O₅The content of the phosphorus component is 0.1-15 wt%, and the content of the rare earth component is 0.2-15 wt% calculated by rare earth oxide. The molecular sieve is obtained by co-soaking rare earth-containing Y-type zeolite and a solution containing silicon and phosphorus, drying and then carrying out hydrothermal roasting at the temperature of 550-850 ℃. The phosphorus-containing Y-type zeolite has high crystallinity after hydrothermal treatment and good catalytic performance, and the cracking catalyst containing the Y-type zeolite has strong heavy oil conversion capacity and good product distribution.

CN1353086A discloses a method for preparing a Y-shaped molecular sieve containing phosphorus and rare earth, and the obtained Y-shaped molecular sieve can remarkably reduce the olefin content of FCC gasoline and simultaneously can keep good coke selectivity. The method comprises the steps of firstly carrying out mixed exchange on a NaY molecular sieve by using ammonium ions and rare earth ions, carrying out hydrothermal roasting, and then carrying out reaction and combination on the NaY molecular sieve and a phosphorus compound by 0.2-10 wt% (by P)₂O₅Calculated), and then carrying out hydrothermal roasting.

CN1506161 discloses an active component of a rare earth ultrastable Y molecular sieve, wherein the modified molecular sieve contains 8-25 wt% of rare earth oxide and 0.1-3.0 wt% of phosphorus; 0.3 to 2.5 wt% of sodium oxide, 30 to 55% of crystallinity and 2.455 to 2.472nm of unit cell constant. The molecular sieve is prepared by using NaY zeolite as a raw material, performing rare earth exchange and first roasting to obtain 'once-exchanged once-roasted' rare earth NaY, reacting with rare earth, phosphorus-containing substances and ammonium salt, and performing second roasting treatment to obtain modified Y zeolite modified by phosphorus and rare earth. The coke yield of the modified molecular sieve is moderate. The molecular sieve prepared by the method has high rare earth content and large unit cell constant, so that the selectivity of the molecular sieve coke is influenced.

CN1317547A discloses a phosphorus and rare earth compound modified Y zeolite and a preparation method thereof, the molecular sieve is prepared by mixing and exchanging NaY zeolite with rare earth and ammonium salt, then carrying out hydrothermal roasting treatment, reacting with phosphorus compound, and then carrying out secondary roasting treatment, wherein RE is RE₂O₃The weight ratio of the ammonium salt to the Y zeolite is 0.02-0.18, the weight ratio of the ammonium salt to the Y zeolite is 0.1-1.0, the weight ratio of the P to the Y zeolite is 0.003-0.05, the roasting temperature is 250-750 ℃, the water vapor condition is 5-100%, and the time is 0.2-3.5 h.

CN02103910.0 provides a method for preparing 'one-exchange one-baking' modified faujasite, which is obtained by carrying out primary exchange reaction on faujasite, a phosphorus compound and an ammonium compound, then introducing a rare earth solution into the exchange slurry for further reaction, and carrying out filtration, washing and water vapor roasting treatment. The catalyst prepared by using the zeolite as an active component has low cracking activity and low heavy oil conversion rate.

However, the existing ultrastable Y-type molecular sieve containing phosphorus and rare earth has low heavy oil cracking activity and poor coke selectivity.

Disclosure of Invention

It is an object of the present disclosure to provide a catalytic cracking catalyst having higher LCO conversion efficiency, better coke selectivity and higher BTX-rich gasoline yield, as well as a method for preparing and using the same.

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-shaped molecular sieve, the content of rare earth elements of the modified Y-shaped molecular sieve calculated by oxides is 4-11 wt%, and P is used₂O₅The content of phosphorus is 0.05-10 wt%, the content of sodium oxide is 0.1-0.7 wt%, the content of active element oxide is 0.1-5 wt%, and the active element is gallium and/or boron; the modified Y-type moleculeThe total pore volume of the 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 15-30% 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 3.5.

Optionally, the pore volume of secondary pores with the pore diameter of 2-100 nm of the modified Y-type molecular sieve accounts for 20-30% 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 7-14.

Optionally, the modified Y-type molecular sieve has a lattice collapse temperature of 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 3.6-5; 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 35% or more as determined by XRD after aging with 100% steam at 800 deg.C for 17 h.

Optionally, on the basis of the dry weight of the modified Y-type molecular sieve, the content of rare earth elements in the modified Y-type molecular sieve calculated by oxides is 4.5-10 wt%, and the content is P₂O₅The phosphorus content is 0.1-6 wt%, and the sodium oxide content is 0.3-0.7 wt%; the unit cell constant of the modified Y-type molecular sieve is 2.440-2.453 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, 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 selected from 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) contacting a NaY molecular sieve with rare earth salt for ion exchange reaction, filtering and washing for the first time to obtain the molecular sieve after ion exchange, wherein the sodium oxide content of the molecular sieve after ion exchange is not more than 9.5 percent by weight based on the dry weight of the molecular sieve after ion exchange;

(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% of water vapor to obtain a molecular sieve modified by moderating hydrothermal superstability;

(3) molecular sieves and SiCl for ultrastable modification of said mild water₄Performing contact reaction, and obtaining the gas-phase ultra-stable modified molecular sieve after second washing and second filtering;

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

the method also comprises the step of carrying out phosphorus modification treatment on the molecular sieve subjected to mild hydrothermal superstable modification and/or the molecular sieve subjected to gas-phase superstable modification by adopting a phosphorus compound.

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 4.5-13 wt% calculated by oxide, and the sodium oxide content is 5.5-9.5 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% 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 (6-15): 1.

optionally, the phosphorus compound is phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate, or diammonium hydrogen phosphate, or a combination of two or three or four thereof; the phosphorus modification treatment comprises: contacting the molecular sieve modified by the moderated hydrothermal hyperstabilization and/or the gas-phase hyperstabilization with an exchange solution containing a phosphorus compound, carrying out exchange reaction for 10-100 min at 15-100 ℃, filtering and washing, thus obtaining the modified molecular sieveP in the exchange liquid₂O₅The weight ratio of the phosphorus to the water in the exchange liquid to the molecular sieve is (0.0005-0.10): (2-5): 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 (0.005-0.045): (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 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.

alternatively, in the step (4), the conditions of the second calcination 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 500-610 ℃, and the weight hourly space velocity is 2-16 h^-1The weight ratio of the components is 3-10.

According to the technical scheme, the method for preparing the catalytic cracking catalyst provided by the disclosure can be used for preparing the high-silicon Y-type molecular sieve containing phosphorus, rare earth and gallium and having a certain secondary pore structure and high crystallinity, high thermal stability and high hydrothermal stability by performing rare earth exchange, hydrothermal superstability treatment and gas phase superstability treatment on the Y-type molecular sieve, cleaning pore channels of the molecular sieve by combining phosphorus modification treatment and performing impregnation modification by adopting active elements, and the prepared molecular sieve has uniform aluminum distribution and less non-framework aluminum content. The catalytic cracking catalyst of the present disclosure having the above-described modified Y-type molecular sieve as an active component is useful for processing hydrogenated LCO while having high LCO conversion efficiency and lower coke selectivity, and has higher and BTX-rich gasoline yield.

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;

on the basis of the dry weight of the modified Y-shaped molecular sieve, the content of rare earth elements of the modified Y-shaped molecular sieve calculated by oxides is 4-11 wt%, and P is used₂O₅Content of phosphorus inThe content of the active element is 0.05-10 wt%, the content of sodium oxide is 0.1-0.7 wt%, the content of the active element oxide is 0.1-5 wt%, and the active element is 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 15-30% 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 3.5.

The catalytic cracking catalyst disclosed by the invention contains the modified Y-type molecular sieve with high crystallinity, secondary pore structure and high thermal and hydrothermal stability, and has high LCO conversion efficiency, lower coke selectivity and higher gasoline yield rich in BTX when being used for processing hydrogenated LCO.

In the catalytic cracking catalyst provided by the disclosure, the modified Y-type molecular sieve contains rare earth elements, and the content of the rare earth elements in the modified Y-type molecular sieve calculated by oxides can be 4-11 wt%, preferably 4.5-10 wt%, based on the dry weight of the modified Y-type molecular sieve. The rare earth element may include La, Ce, Pr, or Nd, or a combination of two, three, or four of them, and further, the rare earth element may include other rare earth elements besides La, Ce, Pr, and Nd.

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 one 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 one embodiment, the active elements are gallium and boron, the total content of gallium oxide and boron oxide is 0.5 to 5 wt%, preferably 1 to 3 wt%, the content of gallium oxide is 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 disclosure, the modified Y-type molecular sieve contains modified element phosphorus to further improve the coke selectivity of the molecular sieve, and P is based on the dry weight of the molecular sieve₂O₅(i.e. with P)₂O₅The phosphorus content) is 0.05 to 10 wt%, for example, 0.1 to 6 wt%, preferably 0.1 to 5 wt%.

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%, for example, 0.35 to 0.60 wt% or 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, sodium oxide, phosphorus and active element in the modified Y-type molecular sieve can be respectively measured by adopting an X-ray fluorescence spectrometry.

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 preferably 0.35-0.39 mL/g, and more preferably 0.36-0.375 mL/g; the pore volume of the secondary pores with the pore diameter of 2-100 nm accounts for 15-30% of the total pore volume, and the pore volume is preferably 20-30%. In the present disclosure, the total pore volume of the molecular sieve may be determined from the adsorption isotherm according to RIPP 151-90 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 600-670 m²A/g, for example, of 610 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 determined according toMeasured according to the ASTM D4222-98 standard method.

In the catalytic cracking catalyst provided by the present disclosure, the unit cell constant of the modified Y-type molecular sieve may be 2.440nm to 2.455nm, for example, 2.440nm to 2.453 nm. The lattice collapse temperature of the modified Y-type molecular sieve is 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 not less than 60%, preferably 60 to 70%, for example 60 to 66%. The modified Y-type molecular sieve disclosed by the invention has higher hydrothermal aging resistance, and after the modification 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 35%, for example, 38-48% or 35-45%. 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 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

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 present disclosureThe 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 3.2 to 6, 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 3.2 to 5.6, for example, 3.3 to 5.5; when the active element is boron, 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 3.5-6, for example, 3.6-5.5 or 3.5-5 or 3.5-4.6 or 3.8-5.6; 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 3.5-5.5, for example 3.6-5.4. 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 content of the rare earth element in the modified Y-type molecular sieve calculated by oxide may be 4.5 to 10 wt%, the content of sodium oxide may be 0.3 to 0.7 wt%, and the content of phosphorus is P₂O₅0.1-6 wt% and 0.1-3 wt% of gallium oxide; the unit cell constant of the modified Y-type molecular sieve can be 2.440-2.453 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 another embodiment of the present disclosure, the modified Y-type molecular sieve may have a rare earth element content in terms of oxide, based on the dry weight of the modified Y-type molecular sieve4.5 to 10 wt%, sodium oxide 0.3 to 0.7 wt%, and phosphorus P₂O₅0.1-6 wt% and 0.5-5 wt% of boron oxide; the unit cell constant of the modified Y-type molecular sieve can be 2.440-2.453 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 contain other molecular sieves than the modified Y-type molecular sieve, such as 0 to 40 wt%, such as 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 sieves are selected from the molecular sieves used in the catalytic cracking catalyst, such as zeolite with MFI structure, zeolite Beta, other Y-type zeolite or non-zeolite molecular sieve, or a combination comprising two or three or four thereof, preferably, the other Y-type zeolite is not more than 40 wt%, such as 1 to 40 wt% or 0 to 20 wt% based on a dry basis, the other Y-type zeolite, such as REY, REHY, DASY, SOY or PSRY, or a combination comprising two or three or four thereof, the MFI-structure zeolite, such as HZSM-5, ZRP or ZRP, or a combination comprising two or three or four thereof, the Beta zeolite, such as H β, the non-zeolite, such as aluminum molecular sieve (silicoaluminophosphate molecular sieve) or a silicoaluminophosphate molecular sieve (SAPO molecular sieve).

In the catalytic cracking catalyst for the high-yield aromatic-hydrocarbon-rich gasoline provided by the disclosure, the content of the modified Y-type molecular sieve is 10-50 wt%, preferably 15-45 wt%, for example 25-40 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.

The present invention provides a catalytic cracking catalyst for the high yield of aromatic hydrocarbon-rich gasoline, wherein the content of the alumina binder is 10-40 wt%, for example 20-35 wt%, and the alumina binder is selected from one or more of various forms of alumina, hydrated alumina and alumina sol commonly used in cracking catalysts, for example, selected from gamma-alumina, η -alumina, theta-alumina, chi-alumina, pseudoboehmite (pseudoboehmite), diaspore (Boehmite), Gibbsite (Gibbsite), bayer (bayer) or alumina sol, or a combination comprising two or three or four of them, preferably pseudoboehmite and alumina sol, for example, the catalytic cracking catalyst contains 2-15 wt%, preferably 3-10 wt% of alumina sol, 10-30 wt%, preferably 15-25 wt% of pseudoboehmite in terms of alumina.

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, drying are prior art, and the disclosure has no special requirements.

The preparation method provided by the disclosure can be used for preparing the catalytic cracking catalyst rich in aromatic gasoline in high yield, the catalytic cracking catalyst contains the high-silicon Y-shaped molecular sieve which is high in crystallinity, high in thermal stability and high in hydrothermal stability and contains phosphorus, rare earth and gallium and 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 is used for processing hydrogenated LCO and has high LCO conversion efficiency, low coke selectivity and higher gasoline yield rich in BTX.

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).

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 may be any kind of rare earth, and the kind and composition thereof are not particularly limited, for example, one or more of La, Ce, Pr, Nd and misch metal, and preferably, the misch metal contains one or more of La, Ce, Pr and Nd, or further contains at least one of rare earth other than La, Ce, Pr and Nd. The washing in step (1) is intended to wash out exchanged sodium ions, and for example, deionized water or decationized water may be used for washing. Preferably, the rare earth content of the ion-exchanged molecular sieve obtained in the step (1) is RE₂O₃The amount of the sodium oxide is 4.5 to 13 wt%, for example 5.5 to 13 wt%, or 5.5 to 12 wt%, or 4.5 to 11.5 wt%, the content of the sodium oxide is not more than 9.5 wt%, for example 5.5 to 9.5 wt%, or 5.5 to 8.5 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 for hydrothermal superstable treatment, 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. Preferably, the calcined molecular sieve is also dried in step (2) so that the water content in the molecular sieve modified to moderate hydrothermal superstability is preferably not more than 1 wt.%. The solid content of the molecular sieve subjected to mild hydrothermal superstable modification in the step (2) is preferably not less than 99 weight percent.

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 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 (calculated on a dry basis) obtained in the step (2) to the modified molecular sieve (calculated on a dry basis) 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 0.5-4 h; the step (3) may or may not be subjected to a second washing and a second filtration, and the second filtration may or may not be followed by drying, and the second washing may be carried out by a conventional washing method, and may be washed 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 ℃; E)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.

The preparation method of the catalytic cracking catalyst provided by the disclosure further comprises the step of carrying out phosphorus modification treatment on the molecular sieve by adopting a phosphorus-containing compound, wherein the phosphorus modification treatment on the molecular sieve by the phosphorus compound can be carried out by contacting once or contacting for multiple times so as to introduce required amount of phosphorus into the molecular sieve. The phosphorus modification treatment can be carried out before and/or after the gas phase superstabilization modification step, for example: the method can comprise the step of carrying out phosphorus modification treatment on the molecular sieve which is subjected to mild hydrothermal superstability modification and has a reduced unit cell constant and is obtained in the step (2), or the step of carrying out phosphorus modification treatment on the molecular sieve which is subjected to gas phase superstability modification and is obtained in the step (3), or the step of carrying out phosphorus modification treatment on the molecular sieve which is subjected to mild hydrothermal superstability modification and is obtained in the step (2) and the molecular sieve which is subjected to gas phase superstability modification and is obtained in the step (3) respectively. Wherein, in the embodiment that the method disclosed by the invention comprises the step of carrying out phosphorus modification treatment on the molecular sieve with the reduced unit cell constant and the modified molecular sieve with the reduced hydrothermal instability obtained in the step (2), the molecular sieve with the modified hydrothermal instability obtained in the step (3) is mixed with SiCl₄The contact reaction refers to the molecular sieve and SiCl which are modified by the moderating hydrothermal superstable after the phosphorus modification treatment₄Carrying out contact reaction; in the embodiment of the method disclosed by the invention, which comprises the step of performing phosphorus modification treatment on the gas-phase super-stable modified molecular sieve obtained in the step (3), the step of contacting the gas-phase super-stable modified molecular sieve with the solution containing the active element in the step (4) refers to a contact reaction of the gas-phase super-stable modified molecular sieve subjected to the phosphorus modification treatment with the solution containing the active element; in the embodiment of the method disclosed by the invention, which comprises the step of respectively carrying out phosphorus modification treatment on the molecular sieve subjected to mild hydrothermal superstable modification in the step (2) and the molecular sieve subjected to gas phase superstable modification in the step (3), the molecular sieve subjected to mild hydrothermal superstable modification in the step (3) and SiCl are subjected to phosphorus modification treatment₄The contact reaction refers to the molecular sieve and SiCl which are modified by the moderating hydrothermal superstable after the phosphorus modification treatment₄Contact reaction of the gas phase super-stable modified molecular sieve in the step (4) with the catalystThe solution contact of the elements refers to the contact reaction of the gas phase ultra-stable modified molecular sieve after the phosphorus modification treatment and the solution containing the active elements.

In the preparation method of the catalytic cracking catalyst provided by the present disclosure, a phosphorus compound may be adopted to perform phosphorus modification treatment to introduce phosphorus into the molecular sieve, where the phosphorus modification treatment generally includes contacting the molecular sieve subjected to mild hydrothermal superstable modification in step (2) and/or the molecular sieve subjected to gas phase superstable modification in step (3) with an exchange liquid, where the exchange liquid contains a phosphorus compound, and the contacting is generally performed at 15-100 ℃, preferably 30-95 ℃, for 10-100 min, and then filtering and washing are performed. Wherein the exchange liquid is P₂O₅The weight ratio of the phosphorus to the water in the exchange liquid to the molecular sieve is (0.0005-0.10): (2-5): 1, namely the weight ratio of water in the exchange liquid to the molecular sieve is (2-5): 1, preferably (3-4): 1, phosphorus (as P)₂O₅Calculated) and the weight ratio of the molecular sieve to the molecular sieve is (0.0005-0.10): 1, preferably (0.001 to 0.05): 1. the phosphorus compound can be one or more of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate and diammonium hydrogen phosphate. The washing is performed by using water with the weight 5-15 times of that of the molecular sieve, such as decationized water or deionized water.

In one embodiment, the phosphorus modification treatment conditions are: adding the Y-type molecular sieve powder sample with the reduced unit cell constant into an exchange solution containing a phosphorus compound, carrying out exchange reaction for 10-100 min at the temperature of 15-100 ℃, filtering and washing; wherein the weight ratio of water to the molecular sieve in the exchange liquid is (2-5): 1, preferably (3-4): 1, phosphorus (as P)₂O₅Calculated) and the weight ratio of the molecular sieve to the molecular sieve is (0.0005-0.10): 1, preferably (0.001 to 0.05): 1.

further, in order to ensure the effect of gas phase ultra-stable modification, the molecular sieve may be dried before step (3) to reduce the water content in the molecular sieve, so that the molecular sieve is used for reacting with SiCl in step (3)₄The contacted molecular sieve has a water content of no more than 1 wt.%. For example, in embodiments where the phosphorus modification treatment is performed prior to the gas phase superstable modification step, the phosphorus-containing molecular sieve obtained after the phosphorus modification treatment may be modified hydrothermally and superstableDrying to make water content in the phosphorus-containing molecular sieve modified by moderate hydrothermal superstability not exceed 1 wt%, and mixing with SiCl₄Carrying out contact reaction; in embodiments where the phosphorus modification treatment is performed after the gas phase ultrastable modification step, the molecular sieve modified by moderating the hydrothermal ultrastable modification obtained in step (2) may be dried so that the water content in the molecular sieve modified by moderating the hydrothermal ultrastable modification does not exceed 1 wt%, and then mixed with SiCl₄And (4) contact reaction. The drying is, for example, baking drying in a rotary baking furnace or a muffle furnace.

In the preparation method of the catalytic cracking catalyst provided by the present disclosure, the molecular sieve may be contacted with a solution containing an active element, and exchange and/or impregnation treatment is performed to load the active element on the modified Y-type molecular sieve, and in order to facilitate improvement of the exchange and/or impregnation treatment effect, the solution containing the active element is 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 of them; 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, the phase ultrastable molecular sieve may be added to Ga (NO) under stirring₃)₃The solution of (2) is dipped with the gallium component, stirred uniformly and then kept stand for 24-36 h at 15-40 ℃, preferably kept stand at room temperature. Then the molecular sieve containing gas phase super-stable modification is mixed with Ga (NO)₃)₃The slurry is stirred for 20min to mix uniformly and is dried and then is roasted again, 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, the slurry is transferred to a rotary evaporator to be heated in water bath and subjected to 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 480 ℃Roasting at 580 ℃ for 2.2-4.5 h.

Wherein the aqueous solution of gallium salt may be Ga (NO)₃)₃Aqueous solution, Ga₂(SO₄)₃Aqueous solutions or GaCl₃Aqueous solution, or a combination of two or three thereof, 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 an aqueous solution of boron compound, that is, the solution containing active elements is an aqueous solution of 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 85-95 ℃, then adding the boron compound, stirring and mixing for 1h, then filtering, drying the filtered sample, and performing second roasting, wherein the drying can be any drying method, such as flash drying, drying and air flow drying, in one mode, the drying method is drying for 5-10 h at 120-140 ℃, then performing second roasting, and the second roasting condition is preferably roasting for 1-4 h at 350-600 ℃; 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): 100 boric acid is added in an amount of B₂O₃Preferably B₂O₃: the molecular sieve is (0.5-4.5): 100, preferably (0.8-4.2): 100.

in a third embodiment of the present invention,in the 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 may include: 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, 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; the ion exchange is carried out for 30-120 min under the conditions of stirring and the temperature of 15-95 ℃, preferably 65-95 ℃;

(2) roasting the rare earth-containing Y-type molecular sieve with the conventional unit cell size and the reduced sodium oxide content 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 moderated hydrothermal superstable modified molecular sieve with the water content of 1 wt%, wherein the unit cell constant of the moderated hydrothermal superstable modified molecular sieve is reduced to 2.450-2.462 nm;

(3) adding the molecular sieve with the reduced unit cell constant and modified by the mild hydrothermal superstability into an exchange solution containing a phosphorus compound, carrying out exchange reaction for 10-100 min at 15-100 ℃, filtering and washing; wherein the weight ratio of water to molecular sieve in the exchange liquid is 2-5, preferably 3-4, phosphorus (as P)₂O₅Calculated) to the molecular sieve in a weight ratio of 0.0005 to 0.10, preferably 0.001 to 0.05, and drying to obtain a phosphorus-containing Y-type molecular sieve with a reduced unit cell constant and a water content of less than 1 wt%;

(4) mixing the phosphorus-containing Y-type molecular sieve with SiCl vaporized by heating, wherein the water content of the Y-type molecular sieve is less than 1 wt%₄Gas contact of SiCl₄: weight ratio of the Y-type molecular sieve with reduced unit cell constant and water content of less than 1 wt% (on 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 the gas-phase ultra-stable modified molecular sieve.

(5) Adding the gas-phase ultra-stable modified molecular sieve obtained in the step (4) into Ga (NO) while stirring₃)₃Is impregnated with a gallium component and the modified Y molecular sieve is mixed with a 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 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 2-5 h at 450-600 ℃.

In the preparation method of the catalytic cracking catalyst provided by the present disclosure, another embodiment of preparing the modified Y-type molecular sieve comprises the following steps:

(5) Adding the gas-phase ultra-stable modified molecular sieve obtained in the step (4) 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, is 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 molecular sieve for 1 hour at a ratio of 0.5-4.5: 100, 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 a modified Y-type molecular sieve comprises the steps of:

(5) Adding the gas-phase ultra-stable modified molecular sieve obtained in the step (4) 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 in the catalytic cracking catalyst of the present disclosure may be 20 to 55 wt% or 30 to 50 wt% on a dry basis.

In the preparation method provided by the disclosure, the alumina binder can be selected from one or more of various forms of alumina, hydrated alumina and alumina sol commonly used in cracking catalysts, for example, one or more of gamma-alumina, η -alumina, theta-alumina, chi-alumina, pseudoboehmite (pseudoboehmite), diaspore (Boehmite), Gibbsite (Gibbsite), Bayerite (bayer) or alumina sol, preferably pseudoboehmite and/or alumina sol, the alumina binder can be used in an amount conventional in the art, preferably, the alumina binder can be used in an amount of 10 to 40 wt%, for example, 20 to 35 wt%, based on alumina, in the catalytic cracking catalyst, the alumina binder can be used in an amount of pseudo Boehmite and alumina sol, and the catalytic cracking catalyst contains 2 to 15 wt%, preferably, 3 to 15 wt%, based on alumina, and the pseudo Boehmite and the alumina sol can be used in an amount of 10 to 30 wt%, based on alumina.

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 ℃): 0.850E &0.920g/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

Wherein, a₀Is a unit cell constant in

The total Si/Al ratio of zeolite is calculated according to Si and Al element contents measured by X-ray fluorescence spectrometry, and the ratio of skeleton Al to total Al can be calculated by the skeleton Si/Al ratio measured by XRD method and the total Si/Al ratio measured by XRF method, and further calculatedCalculating the ratio of non-framework Al to total Al. The lattice collapse temperature was determined by Differential Thermal Analysis (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 RIPP 151-90 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)₂O₃Calculated as 319g/L), stirring, heating to 90-95 ℃ and keepingHolding for 1h, filtering, washing, drying filter cake at 120 deg.C to obtain crystal cell constant of 2.471nm, sodium oxide content of 7.0 wt%, and RE₂O₃Metering a Y-type molecular sieve with the rare earth content of 8.8 wt%, roasting for 6 hours at 390 ℃ in an atmosphere containing 50 vol% of water vapor and 50 vol% of air to obtain the Y-type molecular sieve with the unit cell constant of 2.455nm, cooling, adding the molecular sieve into 6L of solution dissolved with 35g of phosphoric acid, heating to 90 ℃, carrying out phosphorus modification treatment for 30min, filtering and washing the molecular sieve, drying a filter cake to ensure that the water content is lower than 1 wt%, and then carrying out SiCl treatment₄: 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 taken and added into 8146g of decationized water, 210ml of hydrochloric acid with the concentration of 36% is added under the stirring state, dispersed kaolin slurry is added after acidification is carried out for 60min, then 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. The obtained SC1 catalyst contains 30 wt% of SZ1 molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% 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 RE₂O₃Measuring a Y-type molecular sieve with the rare earth content of 11.3 wt%, roasting for 5.5 hours at the temperature of 450 ℃ and under the condition of 80% water vapor to obtain the Y-type molecular sieve with the unit cell constant of 2.461nm, cooling, adding the molecular sieve into 6L of solution dissolved with 268g of ammonium phosphate, heating to 60 ℃, carrying out phosphorus modification treatment for 50min, filtering and washing the molecular sieve, drying a filter cake until the water content is lower than 1 wt%, and then carrying out SiCl treatment₄: 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 crystallinity of the zeolite before and after aging of SZ2 was analyzed by XRD after aging of SZ2 in the exposed state at 800 deg.C for 17h with 100% steamThe relative crystallinity retention after aging was calculated and the results are shown in table 2.

Preparation of a catalytic cracking catalyst with reference to the preparation method of example 1: forming slurry from an SZ2 molecular sieve, kaolin, water, a pseudo-boehmite binder and an aluminum sol by a conventional preparation method of a catalytic cracking catalyst, and preparing a microspherical catalyst by spray drying, wherein the prepared catalytic cracking catalyst is marked as SC 2. 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.

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 RE₂O₃Metering a Y-type molecular sieve with the rare earth content of 8.5 wt%, roasting for 5 hours at the temperature of 470 ℃ and under 70 vol% of water vapor to obtain the Y-type molecular sieve with the unit cell constant of 2.458nm, cooling, adding the molecular sieve into 6L of solution dissolved with 95g of diammonium hydrogen phosphate, heating to 40 ℃, carrying out phosphorus modification treatment for 80min, filtering and washing the molecular sieve, drying a filter cake to ensure that the water content is lower than 1 wt%, and then carrying out SiCl treatment₄: y-type zeolite 0.4: 1, by weight, introducing SiCl vaporized by heating₄Gas, at 500 ℃ for 1h, then washed with 20L of decationized water, 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)₃Stirring the slurry for 20min to mix well, transferring the slurry to a rotary evaporator for water bath heating and rotary evaporation, and putting the evaporated material into a muffleAnd roasting in a furnace at 600 ℃ for 2h to obtain the modified Y-type molecular sieve which is 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.

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 taken and added into 8146g of decationized water, 210ml of chemically pure hydrochloric acid is added under the stirring state, dispersed kaolin slurry is added after acidification is carried out for 60min, then 1500g (dry basis) of ground SZ-3 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 3. 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.

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%, RE₂O₃Metering a Y-type molecular sieve with the rare earth content of 8.8 wt%, roasting for 5 hours at 365 ℃ in an atmosphere containing 30 vol% of water vapor and 70 vol% of air to obtain the Y-type molecular sieve with the unit cell constant of 2.455nm, cooling, adding the molecular sieve into 6L of solution dissolved with 234g of phosphoric acid, heating to 120 ℃, carrying out phosphorus modification treatment for 5min, filtering and washing the molecular sieve, drying a filter cake to ensure that the water content is lower than 1 wt%, and then carrying out SiCl treatment₄: y-type molecular sieve (dry basis) ═ 0.2: 1, by weight, introducing SiCl vaporized by heating₄Reacting gas at 250 deg.C for 2h, washing with 20L decationized water, filtering, and stirring the filter cakeThe mixture was added to 4000mL of 71.33gGa (NO) dissolved in the solution₃)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.

Preparation of a catalytic cracking catalyst with reference to the preparation method of example 1: forming slurry from an SZ4 molecular sieve, kaolin, water, a pseudo-boehmite binder and an aluminum sol by a conventional preparation method of a catalytic cracking catalyst, and preparing a microspherical catalyst by spray drying, wherein the prepared catalytic cracking catalyst is marked as SC 4. 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.

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%, RE₂O₃Metering a Y-type molecular sieve with the rare earth content of 8.8 wt%, roasting for 6 hours at 390 ℃ in an atmosphere containing 50 vol% of water vapor and 50 vol% of air to obtain the Y-type molecular sieve with the unit cell constant of 2.455nm, cooling, adding the molecular sieve into 6L of solution dissolved with 35g of phosphoric acid, heating to 90 ℃, carrying out phosphorus modification treatment for 30min, filtering and washing the molecular sieve, and carrying out filter cake treatmentDrying to a water content of less than 1% by weight, and then drying in accordance with SiCl₄: y-type molecular sieve (dry basis) ═ 0.5: 1, by weight, introducing SiCl vaporized by heating₄Reacting gas at 400 ℃ for 2h, washing with 20L of decationized water, filtering, adding the filter cake to an exchange tank, adding 5L of chemical water, heating the molecular sieve slurry to 65 ℃, adding 12.46g of boric acid, stirring for 1h, filtering, and adding the filter cake to 4000mL of a solution containing 42.8gGa (NO: 8) 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, 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, the physicochemical properties of which are shown in Table 1-1, aging SZ5 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 SZ5 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.

Preparation of a catalytic cracking catalyst with reference to the preparation method of example 1: forming slurry from an SZ5 molecular sieve, kaolin, water, a pseudo-boehmite binder and an aluminum sol by a conventional preparation method of a catalytic cracking catalyst, and preparing a microspherical catalyst by spray drying, wherein the prepared catalytic cracking catalyst is marked as SC 5. 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.

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 cakes at 120 ℃,the resulting material had a cell constant of 2.471nm, a sodium oxide content of 7.0 wt.%, and RE₂O₃Metering a Y-type molecular sieve with the rare earth content of 8.8 wt%, roasting for 6 hours at 390 ℃ in an atmosphere containing 50 vol% of water vapor and 50 vol% of air to obtain the Y-type molecular sieve with the unit cell constant of 2.455nm, cooling, adding the molecular sieve into 6L of solution dissolved with 35g of phosphoric acid, heating to 90 ℃, carrying out phosphorus modification treatment for 30min, filtering and washing the molecular sieve, drying a filter cake to ensure that the water content is lower than 1 wt%, and then carrying out SiCl treatment₄: y-type molecular sieve (dry basis) ═ 0.5: 1, by weight, introducing SiCl vaporized by heating₄Gas, at a temperature of 400 ℃, for 2h, after which it was washed with 20L of decationized water, then filtered, then the filter cake was added to the exchange tank, 5L of chemical water was added and the molecular sieve slurry was then warmed to 65 ℃, followed by the addition of 17.8g of boric acid (B)₂O₃: the molecular sieve is 1:100), stirring for 1 hour, filtering, drying a filtered sample at 130 ℃ for 5 hours, then roasting for 2.5 hours under the roasting condition of 400 ℃, obtaining the modified Y-type molecular sieve, marked as SZ6, the physicochemical properties of which are shown in Table 1-1, aging SZ6 in a naked state for 17 hours at 800 ℃, 1atm and 100% water vapor, analyzing the relative crystallinity of the molecular sieve before and after aging of SZ6 by using an XRD method, and calculating the retention rate of the relative crystallinity 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 taken and added into 8146g of decationized water, 210ml of hydrochloric acid with the concentration of 36% is added under the stirring state, dispersed kaolin slurry is added after acidification is carried out for 60min, then 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. 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.

Example 7

Taking 2000g NaY molecular sieve (in dry basis)Meter) was added to 25L of the decationized aqueous solution, stirred to mix well, and 800mL of RECl was 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 RE₂O₃Measuring a Y-type molecular sieve with the rare earth content of 11.3 wt%, roasting for 5.5 hours at the temperature of 450 ℃ and under the condition of 80% water vapor to obtain the Y-type molecular sieve with the unit cell constant of 2.461nm, cooling, adding the molecular sieve into 6L of solution dissolved with 268g of ammonium phosphate, heating to 60 ℃, carrying out phosphorus modification treatment for 50min, filtering and washing the molecular sieve, drying a filter cake until the water content is lower than 1 wt%, and then carrying out SiCl treatment₄: 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, then the filter cake was added to the exchange tank, 6L of chemical water was added and the molecular sieve slurry was warmed to 80 ℃ and then 32g of boric acid (B) was added₂O₃: molecular sieve 1.8:100), stirring for 1h, filtering, drying the filtered sample at 130 ℃ for 5h, then roasting, and roasting at 380 ℃ for 3.5h to obtain the modified Y-type molecular sieve, which is recorded 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 crystallinity retention rate after aging is calculated.

Preparation of a catalytic cracking catalyst with reference to the preparation method of example 1: forming slurry from an SZ7 molecular sieve, kaolin, water, a pseudo-boehmite binder and an aluminum sol by a conventional preparation method of a catalytic cracking catalyst, and preparing a microspherical catalyst by spray drying, wherein the prepared catalytic cracking catalyst is marked as SC 7. 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.

Example 8

Adding 2000g NaY molecular sieve (dry basis) into 22L of decationizingThe ionic water solution is stirred to be evenly mixed, and 570mL of RECl is 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 RE₂O₃Metering a Y-type molecular sieve with the rare earth content of 8.5 wt%, roasting for 5 hours at the temperature of 470 ℃ and under 70 vol% of water vapor to obtain the Y-type molecular sieve with the unit cell constant of 2.458nm, cooling, adding the molecular sieve into 6L of solution dissolved with 95g of diammonium hydrogen phosphate, heating to 40 ℃, carrying out phosphorus modification treatment for 80min, filtering and washing the molecular sieve, drying a filter cake to ensure that the water content is lower than 1 wt%, and then carrying out SiCl treatment₄: y-type zeolite 0.4: 1, by weight, introducing SiCl vaporized by heating₄Reacting gas at 500 ℃ for 1h, washing 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 ℃, and adding 71.2g of boric acid (B)₂O₃: molecular sieve 4:100), stirring for 1h, filtering, drying the filtered sample at 130 ℃ for 5h, then roasting at 500 ℃ for 2h to obtain the modified Y-type molecular sieve, which is recorded 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 under 100% steam for 17h, and the retention rate of relative crystallinity after aging is calculated.

Preparation of a catalytic cracking catalyst with reference to the preparation method of example 1: forming slurry from an SZ8 molecular sieve, kaolin, water, a pseudo-boehmite binder and an aluminum sol by a conventional preparation method of a catalytic cracking catalyst, and preparing a microspherical catalyst by spray drying, wherein the prepared catalytic cracking catalyst is marked as SC 8. 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.

Comparative example 1

Adding 2000g NaY molecular sieve (dry basis) into 20L of decationized water solutionStirring in the solution 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 weight percent of DZ1 molecular sieve, 42 weight percent of kaolin, 25 weight percent of pseudo-boehmite and 3 weight percent of alumina sol.

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 ℃ for 1h, filtering, washing, and drying a filter cake at 120 ℃ to obtain a Y-type molecular sieve with a unit cell constant of 2.470nm and a sodium oxide content 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)₂O₃Measuring the concentration of rare earth solutionThe degree is as follows: 319g/L) and 900g (NH)₄)₂SO₄Stirring, heating to 90-95 deg.C for 1h, filtering, washing filter cake, and drying at 120 deg.C to obtain crystal cell with constant of 2.456nm, sodium oxide content of 1.5 wt%, and RE₂O₃And (3) calculating the Y-shaped molecular sieve with the rare earth content of 2.7 weight percent, and then performing second hydrothermal modification treatment (roasting for 5 hours at the temperature of 650 ℃ under 100 percent of water vapor) to obtain the rare earth-containing hydrothermal ultrastable Y-shaped molecular sieve which is subjected to twice ion exchange and twice hydrothermal ultrastable, 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

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 RE₂O₃Measuring Y-type molecular sieve with rare earth content of 8.5 wt%, adding molecular sieve into 6L solution dissolved with 95g diammonium hydrogen phosphate, heating to 40 deg.C, performing phosphorus modification treatment for 80min, filtering and washing molecular sieve, drying filter cake to water content lower than 1 wt%, and adding SiCl₄: y-type zeolite 0.4: 1, by weight, introducing SiCl vaporized by heating₄Reacting the gas at 580 deg.C for 1.5h, washing with 20L decationized waterAnd then filtered to obtain a modified Y-type molecular sieve, which is recorded as DZ 3. The physicochemical properties are shown in Table 1-2, 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 DZ3 in naked state at 800 deg.C and 100% water vapor for 17h, and the relative crystal retention 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 weight percent of DZ3 molecular sieve, 42 weight percent of kaolin, 25 weight percent of pseudo-boehmite and 3 weight percent of alumina sol.

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 the unit cell constant of 2.455nm, cooling, adding the molecular sieve into 6L of solution dissolved with 35g of phosphoric acid, heating to 90 ℃, carrying out phosphorus modification treatment for 30min, then filtering and washing the molecular sieve, drying a filter cake to ensure that the water content is lower than 1 wt%, and then carrying out SiCl-based treatment₄: 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, then filtered and the filter cake dried at 120 ℃ to give a modified Y molecular sieve, noted as DZ 4. The physicochemical properties are shown in 1-2, after the DZ4 is aged for 17h at 800 ℃ under 100% steam in a naked state, the crystallinity of the zeolite before and after the aging of DZ4 is analyzed by an XRD method, and the relative crystallization after the aging is calculatedThe results of the degree retention are shown in Table 2.

DZ4 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 DC4 (refer to the preparation method of example 1). Wherein, the obtained DC4 catalyst contains 30 weight percent of DZ4 molecular sieve, 42 weight percent of kaolin, 25 weight percent of pseudo-boehmite and 3 weight percent of alumina sol.

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%, RE₂O₃Metering a Y-type molecular sieve with the rare earth content of 8.8 wt%, roasting for 6 hours at 390 ℃ in an atmosphere containing 50 vol% of water vapor and 50 vol% of air to obtain the Y-type molecular sieve with the unit cell constant of 2.455nm, cooling, adding the molecular sieve into 6L of solution dissolved with 35g of phosphoric acid, heating to 90 ℃, carrying out phosphorus modification treatment for 30min, filtering and washing the molecular sieve, drying a filter cake to ensure that the water content is lower than 1 wt%, and then carrying out SiCl treatment₄: y-type molecular sieve (dry basis) ═ 0.5: 1, by weight, introducing SiCl vaporized by heating₄Gas, at a temperature of 400 ℃, for 2h, after which it is washed with 20L of decationized water, then filtered, and the filter cake is added while stirring to 4000mL of 491gGa (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 well, transferring the slurry to a rotary evaporator for water bath heating and rotary evaporation, and putting the evaporated material into a muffle furnace for 5minRoasting at 50 ℃ for 2.5h to obtain the modified Y-type molecular sieve, which is marked as SZ6, and the physicochemical properties of the modified Y-type molecular sieve are shown in Table 1-2, aging SZ6 at 800 ℃, 1atm and 100% water vapor for 17h in a naked state, analyzing the relative crystallinity of the molecular sieve before and after the aging of SZ6 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.

DZ5 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 DC5 (refer to the preparation method of example 1). Wherein, the obtained DC5 catalyst contains 30 weight percent of DZ5 molecular sieve, 42 weight percent of kaolin, 25 weight percent of pseudo-boehmite and 3 weight percent of alumina sol.

Comparative 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 a Y-type molecular sieve with the rare earth content of 8.8 wt%, roasting for 6 hours at 390 ℃ in an atmosphere containing 50 vol% of water vapor and 50 vol% of air to obtain the Y-type molecular sieve with the unit cell constant of 2.455nm, filtering and washing the molecular sieve, drying a filter cake until the water content is lower than 1 wt%, and then calculating 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)₃The slurry is stirred 20 moreAnd (2) uniformly mixing the materials in min, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation, then placing the evaporated material into a muffle furnace to bake for 2.5 hours at 550 ℃ to obtain the modified Y-type molecular sieve, marked as DZ6, the physicochemical properties of which are shown in tables 1-2, aging DZ6 in a naked state for 17 hours at 800 ℃, 1atm and 100% water vapor, analyzing the relative crystallinity of the molecular sieve before and after aging DZ6 by using an XRD method, and calculating the retention rate of the relative crystallinity after aging, wherein the results are shown in table 2.

DZ6 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 DC6 (refer to the preparation method of example 1). Wherein, the obtained DC6 catalyst contains 30 weight percent of DZ6 molecular sieve, 42 weight percent of kaolin, 25 weight percent of pseudo-boehmite and 3 weight percent of alumina sol.

Comparative example 7

This comparative example employed the conventional FCC catalyst of CN104560187a example 1, designated catalyst DC 7.

Test examples 1 to 8

The catalytic cracking reaction performance of the catalytic cracking catalysts SC 1-SC 8 prepared by the methods provided in examples 1-8 was tested.

Cracking performance evaluation conditions for processing hydrogenated LCO: the SC 1-SC 8 catalyst is aged for 12h at 800 ℃ by 100 percent water vapor, and then is evaluated on an ACE (fixed fluidized bed) device, the raw oil is SJZHLCO (hydrogenated LCO) (the properties are shown in Table 4), and the reaction temperature is 500 ℃. 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 7

The catalytic cracking reaction performances of the catalytic cracking catalysts DC 1-DC 6 prepared by the methods provided by comparative examples 1-6 and the conventional FCC catalyst DC7 of comparative example 7 were tested.

The catalysts DC 1-DC 7 were first aged at 800 deg.C for 12h with 100% steam, then evaluated on an ACE (fixed fluidized bed) apparatus, the feed oil was SJZHLCO (hydrogenated LCO) (properties are shown in Table 3), the reaction temperature was 500 deg.C, and the results are shown in tables 4-2, respectively. 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 a comparison of tables 1-1 and tables 1-2, the catalytic cracking catalyst provided by the present disclosure contains the modified Y-type molecular sieve with high stability, and has 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

Table 2 shows that the modified Y-type molecular sieve contained in the catalytic cracking catalyst provided by the present invention has a high relative crystallinity retention rate after the molecular sieve sample is aged under severe conditions of 800 ℃ and 17 hours in an exposed state, which indicates that the modified Y-type molecular sieve provided by the present invention has high hydrothermal stability.

TABLE 3 Properties of hydrogenated LCO (SJZHLCO)

Item	Numerical value
		Carbon content/%)	88.91
Content of hydrogen/%)	11.01
		Density/(kg/m) at 20 DEG C³)	910.7
Mass spectral hydrocarbon mass composition/%)
		Alkane hydrocarbons	10.1
Total cycloalkanes	16.9
		Total monocyclic aromatic hydrocarbons	60.3
Total bicyclic aromatic hydrocarbons	11.5
		Tricyclic aromatic hydrocarbons	1.2
Total aromatic hydrocarbons	73
		Glue	0
Total weight of	100
		Nitrogen content/mg/L	0.9
Sulfur content/mg/L	49

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 significantly lower coke selectivity, higher LCO conversion, and significantly higher gasoline yield, and the yield of BTX (benzene + toluene + xylene) in gasoline is significantly improved, and the coke selectivity is also better.

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-shaped molecular sieve, the content of rare earth elements of the modified Y-shaped molecular sieve calculated by oxides is 4-11 wt%, and P is used₂O₅The content of phosphorus is 0.05-10 wt%, the content of sodium oxide is 0.1-0.7 wt%, the content of active element oxide is 0.1-5 wt%, and the active element is 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 15-30% 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 3.5.

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 20 to 30% of the total pore volume.

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 n (SiO)₂)/n(Al₂O₃) And the framework silicon-aluminum ratio of the modified Y-type molecular sieve is 7-14.

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 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 3.6-5; 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.

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 35% or more as determined by XRD after 17h aging with 100% steam at 800 ℃.

8. The catalytic cracking catalyst of any one of claims 1 to 7, wherein the modified Y-type molecular sieve contains 4.5 to 10 wt% of rare earth element(s) in terms of oxide(s) based on the dry weight of the modified Y-type molecular sieve₂O₅The phosphorus content is 0.1-6 wt%, and the sodium oxide content is 0.3-0.7 wt%; the unit cell constant of the modified Y-type molecular sieve is 2.440-2.453 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;

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 or four of them.

10. A method of making the catalytic cracking catalyst sieve of any of claims 1-9, characterized in that the method 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 4.5 to 13 wt% calculated as oxide, and a sodium oxide content of 5.5 to 9.5 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% 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 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 (6-15): 1.

17. the method of claim 10, wherein the phosphorus compound is phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate, or diammonium hydrogen phosphate, or a combination of two or three or four thereof; the phosphorus modification treatment comprises: contacting the molecular sieve modified by the moderating hydrothermal hyperstability and/or the molecular sieve modified by the gas phase hyperstability with an exchange solution containing a phosphorus compound, carrying out exchange reaction for 10-100 min at 15-100 ℃, filtering and washing, wherein P is added into the exchange solution₂O₅The weight ratio of the phosphorus to the water in the exchange liquid to the molecular sieve is (0.0005-0.10): (2-5): 1.

18. 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;

19. 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.

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

21. 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.