CN110833853A

CN110833853A - Modified Y-type molecular sieve and preparation method thereof

Info

Publication number: CN110833853A
Application number: CN201810942058.6A
Authority: CN
Inventors: 周灵萍; 沙昊; 许明德; 袁帅; 姜秋桥; 张蔚琳; 陈振宇; 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: CN110833853B

Abstract

The invention relates to a modified Y-type molecular sieve and a preparation method thereof, wherein the dry weight of the modified Y-type molecular sieve is taken as a reference, the content of rare earth elements of the modified Y-type molecular sieve calculated by oxides is 4-11 wt%, and the content of the rare earth elements is P₂O₅The content of phosphorus is 0.05-10 wt%, the content of sodium oxide is 0.1-0.7 wt%, the content of gallium oxide is 0.1-2.5 wt%, and the content of zirconium oxide is 0.1-2.5 wt%; 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. The modified Y-type molecular sieve disclosed by the invention has high crystallinity, high thermal and hydrothermal stability, and a secondary pore structure, and has the advantages of high LCO conversion efficiency and low coke selectivity when being used for processing hydrogenated LCOHigh yield of gasoline rich in BTX aromatic hydrocarbon, high yield of propylene and high concentration of propylene in liquefied gas.

Description

Modified Y-type molecular sieve and preparation method thereof

Technical Field

The present disclosure relates to a modified Y-type molecular sieve and a preparation method thereof.

Background

Light aromatic hydrocarbons such as benzene, toluene, and xylene (BTX) are important basic organic chemical raw materials, and are widely used for producing polyesters, chemical fibers, and the like, and there is a 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 apparatus 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 a reaction product. 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 hydrogenated 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 carry out cracking reaction in the presence of a catalytic cracking catalyst, and the products of the reaction 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 of the light cycle oil and the hydrogenated heavy fraction, 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 toluene to the maximum extent.

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

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, which is suitable for catalytic cracking of hydrogenated LCO, by using the new active component, so as to 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 toluene (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 the hydrothermal method for preparing the rare earth high-silicon Y-type zeolite is that: because the structure of the zeolite can be damaged by too harsh hydrothermal treatment conditions, 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, a plurality of dealumination 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 crystallization retention degree 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 ultra-stable molecular sieve still has the problem of low activity when used for heavy oil cracking, and can not meet the requirement of heavy oil crackingThe processing requirements of the quality and low quality oils directly affect the product distribution and economic efficiency 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 comprises NaY zeolite, rare earth and ammonium salt mixed exchange, hydrothermal roasting treatment, reaction with phosphorus compound, and 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 selection.

Disclosure of Invention

The purpose of the present disclosure is to provide a modified Y-type molecular sieve, which has higher LCO conversion efficiency, better coke selectivity and higher yield of gasoline rich in aromatics, and a preparation method and application thereof.

In order to achieve the above purpose, the first aspect of the present disclosure provides a modified Y-type molecular sieve, wherein the content of rare earth elements in the modified Y-type molecular sieve calculated by oxides is 4 to 11 wt%, and P is calculated as P, based on the dry weight of the modified Y-type molecular sieve₂O₅The content of phosphorus is 0.05-10 wt%, the content of sodium oxide is 0.1-0.7 wt%, the content of gallium oxide is 0.1-2.5 wt%, and the content of zirconium oxide is 0.1-2.5 wt%; 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 2.440-2.455nm, and the lattice collapse temperature is not lower than 1050 ℃; the proportion of the non-skeleton aluminum content of the modified Y-type molecular sieve in the total aluminum content is not higher than 20%, and the ratio of the B acid content to the L acid content in the 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, after aging for 17h at 800 ℃ by 100% water vapor, the modified Y-type molecular sieve has a relative crystallinity retention rate of over 35% as determined by XRD.

Optionally, the content of rare earth elements in the modified Y-type molecular sieve calculated by oxides is 4.5-10 wt% based on the dry weight of the modified Y-type molecular sieve, and the content is P₂O₅The phosphorus content is 0.5-5 wt%, the sodium oxide content is 0.3-0.7 wt%, the gallium oxide content is 0.2-2 wt%, and the zirconium oxide content is 0.5-2 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 thereof.

A second aspect of the present disclosure provides a process for preparing a modified Y-type molecular sieve according to the first aspect of the present disclosure, the process comprising the steps of:

(1) contacting a NaY molecular sieve with a rare earth salt for ion exchange reaction, filtering and washing for the first time to obtain an ion-exchanged molecular sieve, wherein the sodium oxide content of the ion-exchanged molecular sieve is not more than 9.5 weight percent based on the dry weight of the ion-exchanged molecular sieve;

(2) performing first roasting on the ion-exchanged molecular sieve at the temperature of 350-480 ℃ for 4.5-7 h in the presence of 30-90% by volume 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 gallium and zirconium in a solution, and performing first drying and second roasting to obtain the modified Y-type molecular sieve;

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 the NaY molecular sieve with water, adding rare earth salt and/or a rare earth salt water solution under stirring for carrying out 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% in terms of 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 vol% of water vapor.

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

Optionally, in step (3), SiCl₄The weight ratio of the modified molecular sieve to the modified molecular sieve for moderating hydrothermal superstability is (0.1-0.7): 1, the temperature of the contact reaction is 200-650 ℃, and the reaction time is 10 min-5 h; the second washing method includes: washing with water until the pH value of a washing liquid is 2.5-5.0, the washing temperature is 30-60 ℃, and the weight ratio of the water consumption to the unwashed gas-phase ultra-stable modified molecular sieve is (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 subjected to mild hydrothermal ultrastable modification and/or the molecular sieve subjected to gas phase ultrastable modification with an exchange liquid 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 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 method of contacting of step (4) comprises: uniformly mixing the gas-phase ultra-stable modified molecular sieve with an aqueous solution containing a gallium salt and a zirconium salt, and then standing for 24-36 h at 15-40 ℃, wherein the weight ratio of gallium in terms of oxides, zirconium in terms of oxides and the gas-phase ultra-stable modified molecular sieve in terms of dry weight in the aqueous solution containing the gallium salt and the zirconium salt is (0.001-0.025): (0.001-0.025): 1, the weight ratio of water in the aqueous solution to the gas-phase ultra-stable modified molecular sieve is (2-3): 1.

alternatively, in the step (4), the conditions of the second calcination include: the roasting temperature is 450-600 ℃, and the roasting time is 2-5 h.

According to the technical scheme, the modified Y-type molecular sieve preparation method provided by the disclosure can be used for preparing the high-silicon Y-type molecular sieve containing phosphorus, rare earth and gallium with high crystallinity, high thermal stability and high hydrothermal stability and a certain secondary pore structure by performing rare earth exchange, hydrothermal hyperstable treatment and gas phase hyperstable 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 gallium and zirconium, and the prepared molecular sieve has uniform aluminum distribution and less non-framework aluminum content. The catalytic cracking catalyst taking the modified Y-type molecular sieve as the active component is used for processing hydrogenated LCO, has high LCO conversion efficiency and lower coke selectivity, has higher gasoline yield rich in BTX aromatic hydrocarbon, and has high propylene 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, and are not intended to limit the present disclosure.

The first aspect of the disclosure provides a modified Y-type molecular sieve, wherein the modified Y-type molecular sieve comprises, based on the dry weight of the modified Y-type molecular sieve, 4-11 wt% of rare earth elements in terms of oxides, and P₂O₅The content of phosphorus is 0.05-10 wt%, the content of sodium oxide is 0.1-0.7 wt%, the content of gallium oxide is 0.1-2.5 wt%, and the content of zirconium oxide is 0.1-2.5 wt%; 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 modified Y-type molecular sieve disclosed by the invention contains phosphorus, rare earth, gallium and zirconium modified components, has high crystallinity, a secondary pore structure and high thermal and hydrothermal stability, has high LCO conversion efficiency when being used for processing hydrogenated LCO, has lower coke selectivity, and has higher gasoline yield and high propylene yield, and the BTX aromatic hydrocarbon is rich in the gasoline.

The modified Y-type molecular sieve disclosed by the invention 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%, and preferably 4.5-10 wt% on the basis of the dry weight of the modified Y-type molecular sieve. The rare earth elements may include La, Ce, Pr, or Nd, or a combination of two, three, or four of them, and further, the rare earth elements may include other rare earth elements besides La, Ce, Pr, and Nd.

The modified Y-type molecular sieve disclosed by the invention contains active elements of gallium and zirconium, wherein the content of gallium oxide can be 0.1-2.5 wt%, preferably 0.2-2.0 wt% or 0.3-1.8 wt%, and the content of zirconium oxide can be 0.1-2.5 wt%, preferably 0.2-2.0 wt% or 0.5-2 wt%, based on the dry weight of the molecular sieve. Within the preferable content range, the conversion efficiency of LCO catalyzed by the modified Y-type molecular sieve is higher, the coke selectivity is lower, and the BTX aromatic hydrocarbon-rich gasoline and propylene with higher yield can be obtained more favorably.

The modified Y-type molecular sieve disclosed by the invention 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%.

According to the present disclosure, the modified Y-type molecular sieve may contain a small amount of sodium, and the amount 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.

According to the present disclosure, the contents of rare earth elements, sodium oxide, phosphorus and active elements gallium and zirconium in the modified Y-type molecular sieve can be determined by X-ray fluorescence spectrometry, respectively.

According to the disclosure, the pore structure of the modified Y-type molecular sieve can be further optimized to achieve more suitable 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 this disclosure, the total pore volume of the molecular sieve can be determined from the adsorption isotherm according to RIPP 151-90 Standard method, "petrochemical analysis method (RIPP test method)," compiled in Yanggui et al, scientific Press, published in 1990), and then the micropore volume of the molecular sieve is determined from the adsorption isotherm according to the T-plot method, and the secondary pore volume is 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 measured according to the ASTM D4222-98 standard method.

According to the present disclosure, the unit cell constant of the modified Y-type molecular sieve may be 2.440-2.455 nm, for example, 2.440-2.453 nm. The lattice collapse temperature of the modified Y-type molecular sieve is preferably 1055-1080 ℃, and more preferably 1057-1075 ℃.

According to 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 water-heat 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 a is₀Is a unit cell constant, a unit bit is

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 x 100%.

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

According to the 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 3.6-5.0, for example, 3.7-4.3. 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 P₂O₅0.5 to 5 wt.%, gallium oxide may be contained in an amount of 0.1 to 2.5 wt.%, for example 0.2 to 2 wt.% or 0.3 to 1.8 wt.%, zirconium oxide may be contained in an amount of 0.1 to 2.5 wt.%, for example 0.5 to 2.0 wt.% or 0.2 to 2 wt.%; the cell constant of the modified Y-type molecular sieve can be 2.440-2.453 nm; with n (SiO)₂)/n(Al₂O₃) Meter, the modified Y typeThe framework silicon-aluminum ratio of the sub-sieve can be 8.5-12.6.

According to 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 thereof, and may further include other rare earth elements other than La, Ce, Pr, and Nd.

The preparation method disclosed by the invention can be used for preparing the high-silicon Y-shaped molecular sieve which has high crystallinity, high thermal stability and high hydrothermal stability and has a certain secondary pore structure and contains phosphorus, rare earth, gallium and zirconium, the molecular sieve has uniform aluminum distribution and less non-framework aluminum content, and the modified Y-shaped molecular sieve is used for processing hydrogenated LCO and has high LCO conversion efficiency, lower coke selectivity, higher gasoline yield rich in BTX aromatic hydrocarbon and high propylene yield.

In the preparation method of the modified Y-type molecular sieve 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 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, further, in order to promote the ion exchange reaction, in the ion exchange reaction of 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, the mixing NaY molecular sieve, rare earth salt and water may comprise slurrying NaY molecular sieve and water, and then adding a rare earth salt and/or an aqueous solution of a rare earth salt to the slurry, wherein the rare earth salt is preferably a rare earth chloride and/or a rare earth nitrate solution. 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 mischmetal, preferably, the mischmetal contains one or more of La, Ce, Pr and Nd, or further contains rare earth other than La, Ce, Pr and NdAt least one of them. The washing in step (1) is intended to wash out the 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 modified Y-type molecular sieve, in the step (2), the Y-type molecular sieve with the conventional unit cell size containing rare earth is roasted for 4.5-7 hours at the temperature of 350-480 ℃ in 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 slow-release hydrothermal superstable modification in the step (2) is preferably not less than 99 wt%.

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

In the preparation method of the modified Y-type molecular sieve provided by the disclosure, the contact reaction conditions of the step (3) can be changed in a large range, and in order to further promote the gas phase superstable treatment effect, SiCl is preferably used₄The weight ratio of the modified molecular sieve with the mild hydrothermal superstability (calculated on a dry basis) obtained in the step (2) can be (0.1-0.7): 1, preferably (0.3-0.6): 1, the temperature of the contact reaction can be 200-650 ℃, preferably 350-500 ℃, and the reaction time can be 10 min-500%5h, 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, wherein the washing method comprises the following steps: washing with water until the pH value of a washing liquid is 2.5-5.0, the washing temperature can be 30-60 ℃, and the weight ratio of the water consumption to the unwashed gas-phase ultra-stable modified molecular sieve can be (5-20): 1, preferably (6-15): 1. furthermore, the washing can ensure that free Na can not be detected in the washing liquid after washing⁺，Cl^-And Al³⁺And (3) plasma.

The preparation method of the modified Y-type molecular sieve 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-containing 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 of the present disclosure comprises the step of carrying out phosphorus modification treatment on the molecular sieve with reduced unit cell constant and modified by the mild hydrothermal superstability obtained in the step (2), the molecular sieve with modified by the mild hydrothermal superstability and SiCl obtained in the step (3) are 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 comprising the step of subjecting the gas phase ultra-stably modified molecular sieve obtained in the step (3) to a phosphorus modification treatment, the gas phase ultra-stably modified molecular sieve is subjected to a phosphorus modification treatment in the step (4)The contact of gallium and zirconium means that the gas phase ultra-stable modified molecular sieve after the phosphorus modification treatment is contacted with gallium and zirconium in a solution; 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 ultrastable modification in the step (2) and the molecular sieve subjected to gas phase ultrastable modification in the step (3), the molecular sieve subjected to mild hydrothermal ultrastable 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 treatment₄And (4) performing contact reaction, wherein the step of contacting the gas-phase ultra-stable modified molecular sieve with gallium and zirconium in the solution in step (4) means that the gas-phase ultra-stable modified molecular sieve subjected to phosphorus modification treatment is contacted with gallium and zirconium in the solution.

According to the present disclosure, a phosphorus compound may be used for phosphorus modification treatment to introduce phosphorus into the molecular sieve, 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, the exchange liquid contains a phosphorus compound, the contacting is generally carried out at 15-100 ℃, preferably 30-95 ℃, for 10-100 min, and then filtering and washing are carried out. 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 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 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 carried out prior to the gas phase superstable modification step, the phosphorus-containing molecular sieve that has been subjected to the phosphorus modification treatment may be dried to a water content of not more than 1 wt% and then reacted with SiCl₄Carrying out contact reaction; in embodiments where the phosphorus modification treatment is carried out after the gas phase superstable modification step, the molecular sieve modified by moderating the hydrothermal superstable modification obtained in step (2) may be dried so that the water content in the molecular sieve modified by moderating the hydrothermal superstable modification does not exceed 1% by weight, and then mixed with SiCl₄Contact reaction, and the drying treatment is, for example, baking and drying in a rotary baking furnace or a muffle furnace.

In the preparation method according to the present disclosure, the molecular sieve may be contacted with gallium element and zirconium element in solution to perform exchange and/or impregnation treatment, so as to load the active elements gallium and zirconium on the modified Y-type molecular sieve, and the contact with the active elements gallium and zirconium in solution may be performed once or multiple times, so as to introduce the required amount of active elements; to facilitate increasing the effectiveness of the gallium and zirconium modification treatment, in one embodiment of the present disclosure, the molecular sieve may be contacted with a gallium salt and a zirconium salt in solution. Wherein the molecular sieve is contacted with the gallium salt and the zirconium salt simultaneously. In particular, the amount of the solvent to be used,

in one embodiment, the molecular sieve is contacted with the gallium salt and the zirconium salt simultaneously, i.e., the contacting method of step (4) may comprise: and uniformly mixing the gas-phase ultra-stable modified molecular sieve with an aqueous solution containing gallium salt and zirconium salt, and standing. For example, the phase ultrastable molecular sieve may be added to a Ga (NO) -containing molecular sieve in a stirred state₃)₃And Zr (NO)₃)₄By immersing the gallium and zirconium components in the solution of (1), and stirringStanding for 24-36 h at 15-40 ℃ after the mixture is uniform, and preferably standing at room temperature. Then mixing the gas-phase containing ultra-stable modified molecular sieve with the gas-phase containing Ga (NO)₃)₃And Zr (NO)₃)₄And stirring the slurry for 20min to uniformly mix the slurry, and drying and roasting the slurry for the second time, wherein the drying can be any one of drying methods, such as flash drying, drying and air flow drying, and the drying method comprises the following steps of 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 480-580 ℃ for 2.2-4.5 h.

Wherein the gallium salt may be Ga (NO)₃)₃、Ga₂(SO₄)₃Or GaCl₃Or a combination of two or three thereof, preferably Ga (NO)₃)₃The zirconium salt may be Zr (NO)₃)₄、Zr(SO₄)₂Or ZrCl₄Or a combination of two or three thereof, preferably Zr (NO)₃)₄. The weight ratio of the gallium calculated by oxide, the zirconium calculated by oxide and the gas-phase ultra-stable modified molecular sieve calculated by dry weight in the water solution containing the gallium salt and the zirconium salt can be (0.001-0.025): (0.001-0.025): 1, preferably (0.002 to 0.02): (0.002-0.02): 1; the weight ratio of water in the water solution containing the gallium salt and the zirconium salt to the gas-phase ultra-stable modified molecular sieve based on the dry weight can be (2-3): 1, preferably (2.2-2.6): 1.

in another embodiment, the molecular sieve may be contacted with the gallium salt and the zirconium salt in steps, such as contacting the molecular sieve with an aqueous solution comprising the gallium salt and then with an aqueous solution comprising the zirconium salt; alternatively, the molecular sieve is contacted with the aqueous solution containing the zirconium salt before the aqueous solution containing the gallium salt, and the contacting conditions such as temperature, time and concentration of gallium and zirconium may be the same as described above.

In one embodiment of the present disclosure, a method of preparing a modified Y-type molecular sieve comprises 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, wherein the water content is 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)₃And Zr (NO)₃)₄The modified Y molecular sieve is mixed with Ga (NO) containing₃)₃The solution of (A) is stirred uniformly and then is allowed to stand at room temperature, wherein Ga (NO)₃)₃And Zr (NO)₃)₄Ga (NO) contained in the mixed solution of (1)₃)₃In an amount of Ga₂O₃The weight ratio of Zr (NO) to the molecular sieve is 0.1-2.5 wt%, and Zr (NO) is contained in the mixed solution₃)₄In an amount of ZrO₂The weight ratio of the molecular sieve to the molecular sieve is 0.1-2.5 wt%, and Ga (NO)₃)₃And Zr (NO)₃)₄The weight ratio of the water added in the mixed solution to the gas phase ultra-stable modified molecular sieve is as follows: water: soaking the molecular sieve (dry basis): 1: 2-3 for 24h, and then mixing the modified Y-containing molecular sieve with Ga (NO)₃)₃And Zr (NO)₃)₄And stirring the mixed slurry for 20min to uniformly mix the slurry, 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 ℃.

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, the gallium nitrate and the zirconium nitrate are chemically pure reagents produced by Beijing chemical plants. The boehmite 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 Chinese 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 "analytical methods in petrochemical industry" (RIPP test method), Yangcui et al, published by scientific publishers, 1990), and the framework silica-alumina ratio of the zeolite was calculated by the following formula: framework SiO₂/Al₂O₃Molar ratio of 2 × (25.858-a)₀)/(a₀-24.191)。Wherein, a₀Is a unit cell constant in

The total silicon-aluminum ratio of the zeolite is calculated according to the content of Si and Al elements measured by an X-ray fluorescence spectrometry, and the ratio of the framework Al to the total Al can be calculated by the framework silicon-aluminum ratio measured by an XRD method and the total silicon-aluminum ratio measured by an XRF method, so that the ratio of non-framework Al to the total Al can be calculated. 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 1450 cm^-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)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 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 a solution of 36.67gGa (NO)₃)₃·9H₂O and 128.94gZr (NO)₃)₄·5H₂Impregnating the solution of O with gallium component and zirconium component, and mixing the modified Y molecular sieve with the solution containing Ga (NO)₃)₃And Zr (NO)₃)₄The mixed solution is stirred uniformly and then stands at room temperature for 24 hours, and then the modified Y molecular sieve and Ga (NO) are mixed₃)₃And Zr (NO)₃)₄Stirring the mixed slurry for 20min to mix uniformly, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation to dryness, then putting the evaporated material into a muffle furnace to bake for 2.5h at 550 ℃ to obtain the modified Y-type molecular sieve, marked as SZ1, the physicochemical properties of which are shown in Table 1, aging SZ1 in a naked state for 17h by 800 ℃, 1atm and 100% of water vapor, and analyzing the molecular sieve before and after the aging of SZ1 by using an XRD methodRelative crystallinity and relative crystallinity retention after aging was calculated and the results are shown in table 2, where: relative crystallinity retention ═ relative crystallinity of aged sample/relative crystallinity of fresh sample x 100%.

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 5.5h at the temperature of 450 ℃ and under 80% of 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 to ensure that the water content is lower than 1 wt%, and then carrying out SiCl treatment according to the method₄: 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 74.41gGa (NO) dissolved in it while stirring₃)₃·9H₂O and 71.63gZr (NO)₃)₄·5H₂Impregnating the solution of O with gallium component and zirconium component, and mixing the modified Y molecular sieve with the solution containing Ga (NO)₃)₃And Zr (NO)₃)₄The mixed solution is stirred uniformly and then stands at room temperature for 24 hours, and then the modified Y molecular sieve and Ga (NO) are mixed₃)₃And Zr (NO)₃)₄And stirring the mixed slurry for 20min to uniformly mix the slurry, 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, after SZ2 is aged for 17h at 800 ℃ and 100% steam in an exposed state,the crystallinity of the zeolite before and after aging of SZ2 was analyzed by XRD and the relative crystallinity retention after aging was calculated, and the results are shown in table 2.

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-based 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 110.03gGa (NO) dissolved in it₃)₃·9H₂O and 43.1gZr (NO)₃)₄·5H₂Soaking gallium component and zirconium component in O solution, and mixing the modified Y molecular sieve with Ga (NO)₃)₃And Zr (NO)₃)₄The mixed solution is stirred uniformly and then stands at room temperature for 24 hours, and then the modified Y molecular sieve and Ga (NO) are mixed₃)₃And Zr (NO)₃)₄And stirring the mixed slurry for 20min to uniformly mix the slurry, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation to dryness, and then putting the evaporated material into a muffle furnace to roast for 2h at 600 ℃ to obtain the modified Y-type molecular sieve recorded as SZ 3. The physicochemical properties are shown in Table 1, and the crystal of zeolite before and after aging of SZ3 was analyzed by XRD after aging of SZ3 in bare 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.

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 Y-type molecular sieve with rare earth content of 8.8 wt%, calcining at 365 deg.C in atmosphere of 30 vol% steam and 70 vol% air for 4.5 hr to obtain Y-type molecular sieve with unit cell constant of 2.460nm, cooling, and directly adding molecular sieve cake into phosphoric acid-containing exchange liquid in such amount that phosphorus (in the form of P) is added₂O₅Calculated) to molecular sieve weight ratio of 0.055: 1, and the weight ratio of water to molecular sieve is 2.5, carrying out exchange reaction at 50 ℃ for 20min, filtering and washing the molecular sieve, drying the filter cake to make the water content lower than 1 wt%, and then carrying out SiCl₄: y-type molecular sieve (dry basis) ═ 0.2: 1, by weight, introducing SiCl vaporized by heating₄Gas, reaction temperature 250 ℃, after which it was washed with 20L of decationized water, then filtered, and the filter cake was added while stirring to 4000mL of solution containing 36.67gGa (NO)₃)₃·9H₂O and 128.94gZr (NO)₃)₄·5H₂Impregnating the solution of O with gallium component and zirconium component, and mixing the modified Y molecular sieve with the solution containing Ga (NO)₃)₃And Zr (NO)₃)₄The mixed solution is stirred uniformly and then stands at room temperature for 24 hours, and then the modified Y molecular sieve and Ga (NO) are mixed₃)₃And Zr (NO)₃)₄Stirring the mixed slurry for 20min to mix the slurry evenly, transferring the slurry into a rotary evaporator to carry out water bath heating and rotary evaporation to dryness, putting the evaporated material into a muffle furnace to roast the material at 550 ℃ for 2.5h to obtain the modified Y-type molecular sieve, marked as SZ4, materializing the modified Y-type molecular sieveThe properties are shown in Table 1, and the results are shown in Table 2, wherein the relative crystallinity of the molecular sieve before and after aging of SZ4 in a naked state is analyzed by XRD method after aging for 17h at 800 ℃, 1atm and 100% water vapor, and the retention rate of the relative crystallinity after aging is calculated.

Comparative example 1

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

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)₂O₃The concentration of the rare earth solution is measured as follows: 319g/L) and 900g (NH)₄)₂SO₄Stirring, heating to 90-95 ℃, keeping for 1h, then filtering, washing, and drying a filter cake at 120 ℃; and then carrying out second hydrothermal modification treatment (baking for 5 hours at 650 ℃ under 100 percent of water vapor) to obtain the rare earth-containing hydrothermal ultrastable Y-shaped molecular sieve which is subjected to ion exchange twice and hydrothermal ultrastable twice, and is marked as DZ 2. The physicochemical properties are shown in Table 1, 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.

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 a Y-type molecular sieve with the rare earth content of 8.5 wt%, 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, drying the filter cake until the water content is lower than 1 wt%, and then carrying out SiCl-based treatment₄: y-type zeolite 0.4: 1, by weight, introducing SiCl vaporized by heating₄The gas was reacted at 580 deg.C for 1.5h, then washed with 20L of decationized water and filtered to give a modified Y-type molecular sieve, noted as DZ 3. The physicochemical properties are shown in Table 1, and the results are shown in Table 2, wherein the crystallinity of the zeolite before and after aging of SZ3 is analyzed by XRD method after aging DZ3 in a naked state for 17h at 800 ℃ by 100% of water vapor, and the relative crystallinity retention rate after aging is calculated.

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 DZ 4. The physicochemical properties are shown in table 1, and the results are shown in table 2, wherein the crystallinity of the zeolite before and after aging of DZ4 is analyzed by XRD method after aging DZ4 in a naked state for 17h at 800 ℃ by 100% of water vapor, and the relative crystallinity retention rate after aging is calculated.

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 meter)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 267.5gGa (NO) dissolved in it₃)₃·9H₂O and 195.51gZr (NO)₃)₄·5H₂Soaking gallium component and zirconium component in mixed solution of O, and mixing the modified Y molecular sieve with Ga (NO)₃)₃And Zr (NO)₃)₄Stirring the mixed solution uniformly, standing at room temperature for 24h, and then mixing the solution containing the modified Y molecular sieve and Ga (NO)₃)₃And Zr (NO)₃)₄And stirring the mixed slurry for 20min to uniformly mix the slurry, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation, 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 SZ6, wherein the physical and chemical properties of the modified Y-type molecular sieve are shown in Table 1, and after the exposed SZ6 is aged for 17h by 800 ℃, 1atm and 100% water vapor, analyzing the relative crystallinity of the molecular sieve before and after the aging of the 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.

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%, 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, filtering and washing the molecular sieve, drying a filter cake until the water content is lower than 1 wt%, and then weighing SiCl₄: y-type molecular sieve (dry basis) ═ 0.5: 1, by weight, introducing SiCl vaporized by heating₄Gas, at a temperature of 400 ℃, is reactedAfter 2h, it was washed with 20L of decationized water, then filtered, and the filter cake was added to 4000mL of 36.67gGa (NO) dissolved in it while stirring₃)₃·9H₂O and 128.94gZr (NO)₃)₄·5H₂Impregnating the solution of O with gallium component and zirconium component, and mixing the modified Y molecular sieve with the solution containing Ga (NO)₃)₃And Zr (NO)₃)₄The mixed solution is stirred evenly and then stands at room temperature for 24 hours, and then the modified Y molecular sieve and Ga (NO) are mixed₃)₃And Zr (NO)₃)₄Stirring the mixed slurry for 20min to mix uniformly, transferring the slurry into a rotary evaporator to perform water bath heating and rotary evaporation to dryness, then putting the evaporated material into a muffle furnace to bake for 2.5h at 550 ℃ to obtain the modified Y-type molecular sieve, marked as DZ6, the physicochemical properties of which are shown in Table 1, aging DZ6 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 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.

Comparative example 7

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 40 deg.CAfter 2 hours at 0 ℃ and washing with 20L of decationized water, the mixture was filtered, and the filter cake was added to 4000mL of a solution containing 60.88gZr (NO) while stirring₃)₄·5H₂Impregnating the zirconium component in the solution of O, and mixing the modified Y molecular sieve with Zr (NO)₃)₄The solution is stirred evenly and then stands at room temperature for 24 hours, and then the modified Y molecular sieve and Zr (NO) are added₃)₄Stirring 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 DZ7, the physicochemical properties of which are shown in Table 1, aging DZ7 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 aging DZ7 by using an XRD method, and calculating the retention rate of the relative crystallinity after aging, wherein the results are shown in Table 2.

Comparative example 8

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 to 4000m while stirringDissolved 71.33gGa (NO) of L₃)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 DZ8, the physicochemical properties of which are shown in Table 1, aging DZ8 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 aging DZ8 by using an XRD method, and calculating the retention rate of the relative crystallinity after aging, wherein the results are shown in Table 2.

Comparative example 9

This comparative example uses the conventional FCC catalyst of CN104560187A example 1, designated catalyst DC9, and was evaluated for its light oil microreflection activity, the results of which are set forth in Table 3.

Test examples 1 to 4

The catalytic cracking reaction performance of the modified Y-type molecular sieves of examples 1-4 was tested.

The modified Y-type molecular sieves SZ 1-SZ 4 prepared in examples 1-4 are prepared into catalysts, and the catalysts are numbered as follows: SC 1-SC 4.

The preparation method of the catalyst comprises the following steps:

the modified Y-type 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, and the slurry is sprayed and dried to prepare the microspherical catalyst, wherein the obtained catalyst contains 30 wt% of the modified Y-type molecular sieve, 42 wt% of kaolin, 25 wt% of pseudo-boehmite and 3 wt% of alumina sol on a dry basis.

Evaluating the cracking performance of the catalyst for processing hydrogenated LCO, and evaluating the conditions as follows: the catalyst was first aged at 800 ℃ for 12h with 100% steam and then evaluated on an ACE (fixed fluidized bed) unit with a feed oil of SJZHLCO (hydrogenated LCO) (properties see table 3) and a reaction temperature of 500 ℃. The results are shown in Table 4.

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

Comparative examples 1 to 9

The ultra-stable Y-type zeolite prepared by the method provided by comparative examples 1-8 and the conventional FCC catalyst DC9 of comparative example 9 were tested for catalytic cracking reaction performance.

Respectively mixing the ultrastable Y-type molecular sieves DZ 1-DZ 8 prepared in comparative examples 1-8 with pseudo-boehmite, kaolin, water and alumina sol according to the preparation method of the catalyst in test example 1, and spray-drying to prepare the microspherical catalyst, wherein the composition of each catalyst is the same as that in test example 1, and the catalyst numbers are as follows: DC 1-DC 8.

After aging the catalysts DC 1-DC 9 for 12h at 800 ℃ with 100% water vapor, the catalytic cracking reaction performance of the catalysts for processing hydrogenated LCO is evaluated on a small-sized fixed fluidized bed reactor (ACE), the evaluation method is shown in test example 1, the properties of raw materials for ACE experiments are shown in Table 3, and the results are respectively shown in Table 4. Wherein LCO effective conversion/% -100-diesel yield-dry gas yield-coke yield-heavy oil yield.

TABLE 1

As can be seen from table 1, the modified Y-type molecular sieve with high stability provided by the present disclosure 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

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

TABLE 3 Properties of hydrogenated LCO (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

As can be seen from the results listed in table 4, the catalytic cracking catalyst prepared by using the molecular sieve provided by the present invention as an active component has significantly lower coke selectivity, higher LCO conversion rate, and significantly higher gasoline yield, and further, the yield of BTX (benzene + toluene + xylene) in gasoline is significantly increased, the propylene yield is high, and the propylene concentration in liquefied gas is high.

The preferred embodiments of the present disclosure have been described above in detail, 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 are within the protective 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 modified Y-type molecular sieve is characterized in that the modified Y-type molecular sieve takes 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 taken as₂O₅The content of phosphorus is 0.05-10 wt%, the content of sodium oxide is 0.1-0.7 wt%, the content of gallium oxide is 0.1-2.5 wt%, and the content of zirconium oxide is 0.1-2.5 wt%; 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 modified Y-type molecular sieve of claim 1, wherein the modified Y-type molecular sieve has a pore volume of secondary pores with a pore diameter of 2-100 nm accounting for 20-30% of the total pore volume.

3. The modified Y-type molecular sieve of claim 1, wherein the modificationThe non-framework aluminum content of the Y-shaped 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 modified Y-type molecular sieve of claim 1, wherein the modified Y-type molecular sieve has a lattice collapse temperature of 1055-1080 ℃.

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

7. The modified Y molecular sieve of claim 1, wherein the modified Y molecular sieve has a relative crystallinity retention of 35% or greater as measured by XRD after aging with 100% steam at 800 ℃ for 17 hours.

8. The modified Y-type molecular sieve 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 sieve, calculated as P₂O₅The phosphorus content is 0.5-5 wt%, the sodium oxide content is 0.3-0.7 wt%, the gallium oxide content is 0.2-2 wt%, and the zirconium oxide content is 0.5-2 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 thereof.

9. A method for preparing the modified Y-type molecular sieve of any one of claims 1 to 8, characterized in that the method 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 vol% of steam to obtain a molecular sieve modified by moderating hydrothermal superstability;

10. The method of claim 9, 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;

11. The process of claim 9 or 10, 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%.

12. The method of claim 9 or 10, wherein the rare earth salt is a rare earth chloride or a rare earth nitrate.

13. The method of claim 9, wherein the processing conditions of step (2) comprise: the first roasting is carried out for 5-6 h at 380-460 ℃ and under 40-80 vol% of water vapor.

14. The method according to claim 9 or 13, 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%.

15. The method of claim 9, wherein in step (3), SiCl is used₄The weight ratio of the modified molecular sieve to the modified molecular sieve for moderating hydrothermal superstability is (0.1-0.7): 1, the temperature of the contact reaction is 200-650 ℃, and the reaction time is 10 min-5 h; the second washing method includes: washing with water until the pH value of a washing liquid is 2.5-5.0, the washing temperature is 30-60 ℃, and the weight ratio of the water consumption to the unwashed gas-phase ultra-stable modified molecular sieve is (6-15): 1.

16. the method of claim 9, 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.

17. the method of claim 9, wherein the contacting of step (4) comprises: uniformly mixing the gas-phase ultra-stable modified molecular sieve with an aqueous solution containing a gallium salt and a zirconium salt, and then standing for 24-36 h at 15-40 ℃, wherein the weight ratio of gallium in terms of oxides, zirconium in terms of oxides and the gas-phase ultra-stable modified molecular sieve in terms of dry weight in the aqueous solution containing the gallium salt and the zirconium salt is (0.001-0.025): (0.001-0.025): 1, the weight ratio of water in the aqueous solution to the gas-phase ultra-stable modified molecular sieve is (2-3): 1.

18. the method of claim 9, wherein in step (4), the conditions of the second firing comprise: the roasting temperature is 450-600 ℃, and the roasting time is 2-5 h.