RU2799029C2 - Modified y-type molecular sieves containing catalytic cracking catalyst, their production and application - Google Patents

Abstract

FIELD: molecular sieves; catalytic cracking.

SUBSTANCE: invention relates to a modified Y-type molecular sieve for catalytic cracking of a hydrocarbon feedstock having a rare earth content of from about 4 to about 11% by weight based on oxide, phosphorus content of from about 0.05 to about 10% by weight based on P₂O₅, sodium content of not more than about 0.5% by weight based on sodium oxide and an active element content of from about 0.1 to about 5% by weight based on oxide, the active element being gallium and/or boron, in relation to the weight of the modified molecular sieve type Y in terms of dry matter; wherein the modified Y-type molecular sieve has a total pore volume of about 0.36 ml/g to about 0.48 ml/g, a percentage of secondary pore volume having a pore size of 2 to 100 nm, and a total pore volume of about 20% to about 40%; lattice parameter from about 2.440 nm to about 2.455 nm, lattice break temperature not less than about 1060°C, a percentage of non-framework aluminium to total aluminium of not more than about 10%, and a ratio of Bronsted acid to Lewis acid in the strong acids contained in the modified Y-type molecular sieve of not less than about 3.5. A method for obtaining the above molecular sieve, a catalyst based on it, and catalytic cracking of hydrocarbons in the presence of a modified molecular sieve are described.

EFFECT: use of the proposed molecular sieve increases the conversion factor of hydrogenated LCO, reduces the selectivity to coke, increases the yield of catalytic gasoline enriched in benzene, toluene and xylene.

16 cl, 4 tbl, 13 ex

Description

Cross-reference to related applications

The present application claims the priority of Patent Application No. 201810942883.6 filed on August 17, 2018 with the PRC Patent Office, entitled "Modified Y-Type Molecular Sieve, Its Preparation and Use"; and Priority Patent Application No. 201810940965.7, filed on August 17, 2018 with the PRC Patent Office, entitled "Catalyst Cracking Catalyst, Its Preparation and Use", which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD OF THE INVENTION

The present application relates to the field of molecular sieves and catalytic cracking and, in particular, to a modified molecular sieve of type Y containing a catalyst for catalytic cracking, their production and use.

State of the art of the present invention

Light aromatic compounds such as benzene, toluene and xylene (BTX) are important basic organic chemical raw materials that are widely used in the production of polyesters, chemical fibers, etc., and have been in great demand in recent years. Light aromatics such as benzene, toluene and xylene (BTX) are produced mainly in catalytic reforming and steam cracking processes using naphtha as a feedstock. Due to the shortage of naphtha, which is the starting material, there is a shortage of light aromatic compounds on the market.

Light cycle oil (LCO) produced by catalytic cracking is an important by-product of catalytic cracking. It is produced in large quantities and has a high content of aromatic compounds, in particular polycyclic aromatic compounds, and is a low-grade diesel fuel cut. With the development of environmental protection requirements affecting the market demand, the use of LCO as a blended diesel fuel component is largely limited. The hydrocarbon composition of LCO includes paraffins, naphthenes (including small amounts of olefins) and aromatics. The hydrocarbon composition of LCO can vary significantly due to differences in feed materials and the severity of catalytic cracking process conditions. The main component of LCO are aromatic compounds, the mass fraction of which can be more than 70% or even approximately 90%, and the rest of the mass is made up of paraffins and naphthenes.

Bicyclic aromatics, as the component present in the highest content in the composition of LCO, are a typical component of LCO and the main component influencing the production of light aromatics through catalytic cracking. Under catalytic cracking conditions, polycyclic aromatic compounds are not readily converted to light aromatic compounds in a ring-opening cracking process. Under hydrogenation conditions, polycyclic aromatic compounds are more easily saturated to heavy monocyclic aromatic compounds such as alkylbenzenes and cycloalkylbenzenes (eg, indanes, tetrahydronaphthalenes, and indenes). Such heavy monocyclic aromatics are potential components for the production of light aromatics by catalytic cracking and can be converted to light aromatics under catalytic cracking conditions. Thus, LCO is a promising and cheap source for obtaining light aromatic compounds. Obtaining light aromatic compounds using the technology of hydrogenation and catalytic cracking is of great scientific importance.

In the prior art (see PRC Patent Application Nos. CN103923698A, CN104560185A, and CN104560187A), LCO was first subjected to mild hydrogenation in which most polycyclic aromatic compounds were saturated to give hydrogenated aromatic compounds containing a cycloalkane ring and an aromatic ring, and then reacted cracking in the presence of a catalytic cracking catalyst to give light BTX aromatics. However, hydrogenated aromatics produced by LCO hydrogenation are less suitable for cracking but have a significantly higher hydrogen transfer capacity than conventional catalytic cracking feedstocks. Thus, conventional catalytic cracking catalysts used in the prior art cannot meet the requirements for catalytically cracking hydrogenated LCOs.

Since its first application in the 1960s, Y-type molecular sieves have become the main active ingredient in fluid catalyzed cracking (FCC) catalysts. However, as the density of the crude oil in the FCC feedstock increases, the content of polycyclic compounds increases significantly, while their ability to diffuse into the pores of the molecular sieves decreases significantly. When catalysts containing Y-type molecular sieve as the main active component are directly used for the processing of heavy fractions such as oil residues, the availability of catalyst active sites becomes a major obstacle to the cracking of polycyclic compounds contained in these fractions, since the Y-type molecular sieves used in as the main active component, have a pore size of only 0.74 nm. The pore structure of molecular sieves is directly related to cracking performance, in particular for residue cracking catalysts. The secondary pores of the molecular sieves can increase the accessibility of the active sites of the catalysts to macromolecules of oil residues, and as a result, the suitability of these catalysts for cracking oil residues is improved.

The hydrothermal dealumination process is one of the most widely used methods for producing ultra-stable molecular sieves in the industry. According to this method, the NaY molecular sieve is first subjected to ion exchange with an aqueous solution containing ammonium ions to reduce the content of sodium ions in the molecular sieve, and then the molecular sieve exchanged with ammonium ions is calcined at a temperature of 600 to 825°C in a steam atmosphere to providing ultra-stabilization. This process is economical and easy to implement in industrial large-scale production, and the resulting ultra-stable Y-type molecular sieve is enriched in secondary pores, but there is a significant decrease in the degree of crystallinity of the Y-type ultra-stable molecular sieve.

The production of ultra-stable Y-type molecular sieves currently used in the industry is generally based on an improvement of the aforementioned hydrothermal calcination process. A method including two ion exchange steps and two calcination steps can be adopted, which is designed to solve the problem of a significant decrease in the degree of crystallinity occurring in severe calcination by performing calcining in separate stages under more moderate conditions. The ultra-stable Y-type molecular sieve obtained in this way may contain a certain amount of secondary pores, but the content of secondary pores having a relatively large pore size is low relative to the total number of secondary pores. In addition, the specific surface area and degree of crystallinity of ultrastable molecular sieves also need to be further improved.

In order to better meet the requirement of obtaining a higher yield of BTX light aromatics by catalytically cracking hydrogenated LCOs, the object of the present application is to develop a highly stable modified molecular sieve exhibiting high activity in the cracking reaction and relatively reduced hydrogen transfer capacity as a new active component. , and to develop a catalytic cracking catalyst suitable for catalytic cracking of hydrogenated LCO to obtain a higher yield of BTX light aromatics based on this new active component, so as to accelerate the cracking reaction, control the hydrogen transfer reaction, further improve the conversion rate of hydrogenated LCO and maximize the yield of catalytic gasolines enriched in benzene, toluene and xylene (BTX).

Brief summary of the present invention

The object of the present application is to provide a modified Y-type molecular sieve containing its catalytic cracking catalyst, their preparation and use, so that catalytic cracking catalysts obtained by using a modified Y-type molecular sieve as an active component exhibit an increased coefficient conversion of hydrogenated LCOs, reduced coke selectivity, and increased yield of BTX-enriched gasoline.

To solve the above problem, according to an aspect of the present application, a modified Y-type molecular sieve is provided having a content of rare earth elements from about 4% to about 11% by weight in terms of oxide, a phosphorus content from about 0.05% to about 10% by weight in terms of P ₂ O ₅ , the sodium content is not more than about 0.5% by weight in terms of sodium oxide and the content of the active element is from about 0.1% to about 5% by weight in terms of oxide, while the active element represents gallium and/or boron, in relation to the weight of the modified molecular sieve type Y in terms of dry matter; wherein the modified Y-type molecular sieve has a total pore volume of about 0.36 ml/g to about 0.48 ml/g, a percentage of secondary pore volume having a pore size of 2 to 100 nm, and a total pore volume of about 20% to about 40%; a lattice parameter of from about 2.440 nm to about 2.455 nm, a lattice break point of not less than about 1060° C., a percentage of non-framework aluminum to a total aluminum content of not more than about 10%, and a ratio of Bronsted acid to Lewis acid in strong acids contained in the modified molecular sieve type Y, not less than about 3.5.

According to another aspect, the present application provides a method for producing a modified type Y molecular sieve, comprising the following steps:

(1) contacting a NaY molecular sieve with a rare earth salt solution for an ion exchange reaction and obtaining an ion exchanged molecular sieve;

(2) subjecting the ion-exchanged molecular sieve to roasting at a temperature of from about 350° C. to about 480° C. in an atmosphere containing from about 30 vol.% to about 90 vol.% steam, for from about 4.5 hours to approximately 7 hours to obtain a molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment;

(3) subjecting a molecular sieve subjected to a mild hydrothermal ultrastabilization treatment to gas phase ultrastabilization by contacting and reacting with SiCl ₄ gas to obtain a gas phase ultrastabilized molecular sieve;

(4) subjecting the gas-phase ultra-stabilized molecular sieve to an acid treatment by contacting with an acid solution to obtain an acid-treated molecular sieve;

(5) subjecting the acid-treated molecular sieve to be modified with phosphorus by contacting with a phosphorus compound to obtain a phosphorus-modified molecular sieve; And

(6) subjecting the phosphorus-modified molecular sieve to a modification treatment by contacting with a solution containing an active element and then calcining to obtain a Y-type modified molecular sieve,

wherein the active element is gallium and/or boron.

According to a further aspect, the present application provides a catalytic cracking catalyst comprising from about 10% to about 50% by weight of a modified Y-type molecular sieve, from about 10% to about 40% by weight of an alumina binder based on alumina, and from about 10% to about 80% by weight of clay, on a dry basis, based on the weight of catalyst, on a dry basis, wherein the modified Y-type molecular sieve is the modified Y-type molecular sieve of the present application or the modified Y-type molecular sieve obtained by the method according to the present application.

According to a further aspect, the present application provides the use of a modified Y type molecular sieve according to the present application in the catalytic cracking of a hydrocarbon feedstock, in particular a hydrogenated light cycle oil, comprising contacting the hydrocarbon feedstock with a catalytic cracking catalyst containing a modified Y type molecular sieve, under catalytic cracking conditions.

The method for producing a modified Y-type molecular sieve of the present application can be used to obtain a Y-type molecular sieve having a high silica content and enriched in secondary pores and exhibiting a high degree of crystallinity, high thermal stability and high hydrothermal stability, by affecting the molecular Y-type sieve of ion exchange with rare earth ions, hydrothermal ultra-stabilization treatment and gas-phase ultra-stabilization treatment, combined with acid treatment used to clean the pores of the molecular sieve, and modifications by the active element and phosphorus, so that the degree of superstability of the molecular sieve can be significantly increased while maintaining its high degree of crystallinity. The resulting molecular sieve has a uniform distribution of aluminum, a low content of non-framework aluminum and non-clogged secondary pores.

The modified Y-type molecular sieve according to the present application can be used as an active component of catalytic cracking catalysts for the catalytic cracking of hydrogenated LCOs. When used to process hydrogenated LCO, catalytic cracking catalysts made by using molecular sieve as an active component exhibit high LCO conversion, reduced coke selectivity, and increased yield of BTX-enriched gasoline.

Other characteristics and advantages of the present application will be described in detail later in this document.

Detailed disclosure of the present invention

Hereinafter, the present application will be described in detail with reference to the respective embodiments. It should be understood that the embodiments described herein are merely illustrative and not restrictive.

Any numerical value (including the end values of numerical ranges) as provided herein is not limited to the exact value indicated, but should be construed as including any value in the vicinity of the aforementioned exact value, such as any possible value within ±5% of the aforementioned exact value. In addition, for any numerical range provided herein, one or more new numerical ranges can be obtained by arbitrary combination of end values of the given range, an end value with a particular value present within the given range, or various particular values present within the given range. Such new numerical ranges should also be considered as specifically described herein.

Unless otherwise indicated, all terms used herein have the meanings commonly understood by those skilled in the art, and if the definition of a term provided herein differs from the usual understanding in the art, then the definition presented in this document.

In this application, unless otherwise specified in a specific way, any unmentioned subject or subjects should be considered as directly applicable to what is known in the art, without any change. In addition, any of the embodiments that are described herein may be freely combined with one or more of the other embodiments that are described herein, and the resulting solution or technical idea should be considered as part of the original disclosure. or the original description of the present application, nor should it be considered as new subject matter that has not been described or contemplated herein, unless it is obvious to those skilled in the art that such a combination is wholly unreasonable.

The test methods of RIPP (Sinopec Petroleum Refining Research Institute) presented in this application can be found in "Petrochemical Analysis Methods (RIPP Test Methods)", Ed. Cuiding YANG et al., Science Press, September 1990, first edition, ISBN: 7-03-001894-X, pages 412-415 and 424-426, which is incorporated herein by reference in its entirety.

All patent and non-patent documents referenced herein, including, but not limited to, tutorials and journal articles, are incorporated herein by reference in their entirety.

As used herein, the terms "Y-type molecular sieve" and "Y-type zeolite" are used interchangeably, and the terms "NaY molecular sieve" and "NaY zeolite" are also used interchangeably.

As used herein, the term "secondary pores" means pores present in a molecular sieve having a pore size (ie, pore diameter) of 2 nm to 100 nm.

As used herein, the term "inorganic acid having a medium or higher strength" refers to an inorganic acid having a strength not less than HNO ₂ (nitrous acid), including, but not limited to, HClO ₄ (perchloric acid), HI (hydroiodic acid), HBr (hydrobromic acid), HCl (hydrochloric acid), HNO ₃ (nitric acid), H ₂ SeO ₄ (selenic acid), H ₂ SO ₄ (sulfuric acid), HClO ₃ (chloric acid), H ₂ SO ₃ (sulphurous acid), H ₃ PO ₃ (phosphorous acid), HNO ₂ (nitrous acid), etc.

As used herein, the terms "rare earth element solution" and "rare earth element salt solution" are used interchangeably and preferably refer to an aqueous rare earth salt solution.

As used herein, "a Y-type molecular sieve having a normal lattice parameter" means that the lattice parameter of the Y-type molecular sieve is within the lattice parameter range of conventional NaY molecular sieves, which is preferably a range of about 2.465 nm to approximately 2.472 nm.

As used herein, the term "atmospheric pressure" means a pressure of approximately 1 atmosphere.

As used herein, the weight of a material on a dry matter basis means the weight of the solid product obtained after the material is calcined at 800° C. for 1 hour.

In a first aspect, the present application provides a modified Y-type molecular sieve having a rare earth content of from about 4% to about 11% by weight based on oxide, a phosphorus content of from about 0.05% to about 10% by weight based on P2O5 , the sodium content is not more than about 0.5% by weight in terms of sodium oxide and the content of the active element is from about 0.1% to about 5% by weight in terms of oxide, while the active element is gallium and/or boron , relative to the weight of the modified molecular sieve type Y in terms of dry matter; wherein the modified Y type molecular sieve has a total pore volume of about 0.36 ml/g to about 0.48 ml/g, a percentage of secondary pore volume having a pore size of 2 to 100 nm and a total pore volume of about 20 % to about 40%; a lattice parameter of about 2.440 nm to about 2.455 nm, a lattice break point of at least about 1060° C., a percentage of non-framework aluminum to a total aluminum content of not more than about 10%, and a ratio of Bronsted acid to Lewis acid in strong acids contained in the modified molecular sieve type Y, not less than about 3.5.

The modified Y-type molecular sieve according to the present application has a high degree of superstability, a high degree of crystallinity, a uniform distribution of aluminum, a low content of non-framework aluminum, and non-clogged secondary pores. The modified Y-type molecular sieve exhibits high LCO conversion, reduced coke selectivity, and increased yield of BTX-enriched gasoline when used in the processing of hydrogenated LCO.

The modified Y type molecular sieve of the present application contains rare earth elements, and the modified Y type molecular sieve may have a rare earth content of from about 4% to about 11% by weight, preferably from about 4.5% to about 10% by weight, for example, from 5 to 9% by weight in relation to the weight of the modified molecular sieve type Y in terms of dry matter.

According to the present application, the type and composition of the rare earth elements are not limited in a certain way. Preferably the rare earth elements may be La, Ce, Pr or Nd, or a combination of two, three or four of these elements; optional rare earth elements may further contain a rare earth element other than La, Ce, Pr and Nd.

The modified Y-type molecular sieve of the present application contains gallium and/or boron as an active element, and the molecular sieve may have an active element content in terms of oxide (also referred to herein as an active element oxide content) of about 0.1 to 5 % by weight based on the weight of the molecular sieve, on a dry basis. According to a preferred embodiment, the active element is gallium and the gallium content in terms of gallium oxide (also referred to herein as gallium oxide content) can be from about 0.1 to 3% by weight, more preferably from about 0.5 to 2 .5% by weight; according to another preferred embodiment, the active element is boron, and the boron content in terms of boron oxide (also referred to herein as boron oxide content) can be from about 0.5 to 5% by weight, more preferably from about 1 to 4% by weight; according to a further preferred embodiment, the active element is gallium and boron, and the total content of gallium and boron in terms of gallium oxide and boron oxide is approximately 0.5 to 5% by mass, preferably 1 to 3% by mass, and the content gallium in terms of gallium oxide can be from about 0.1 to 2.5% by weight, and the content of boron in terms of boron oxide can be from about 0.5 to 4% by weight. Within the above preferred ranges, the modified Y-type molecular sieve exhibits an increased LCO catalytic conversion ratio and reduced coke selectivity, and is more favorable for the production of aromatic-enriched gasoline.

The modified Y-type molecular sieve of the present application contains phosphorus as a modifying element to further improve the molecular sieve coke selectivity, and the phosphorus content in terms of P ₂ O ₅ (also referred to herein as the P ₂ O ₅ content) is from about 0.05% to about 10% by weight, for example, from about 0.1 to 6% by weight, preferably from about 0.3 to 4% by weight or from 1 to 4% by weight relative to the weight of the molecular sieves in terms of dry matter.

According to some embodiments of the present application, the modified Y-type molecular sieve may further contain a small amount of sodium, and the sodium content in terms of sodium oxide (also referred to herein as sodium oxide content) may be from about 0.05 to 0.5% by weight. by weight, for example, from about 0.1 to 0.4% by weight, or from about 0.05 to 0.3% by weight, based on the weight of the molecular sieve, on a dry basis.

According to the present application, the content of rare earth elements, sodium and active element in the modified Y-type molecular sieve can be appropriately determined by X-ray fluorescence spectrometry.

According to the present application, the pore structure of the modified Y-type molecular sieve can be further optimized to achieve more desirable catalytic cracking reaction performance. The total pore volume of the modified Y-type molecular sieve may preferably be from about 0.36 ml/g to about 0.48 ml/g, more preferably from about 0.38 to 0.42, or from 0.4 to 0.48 ml/g ; the percentage of pore volume of secondary pores having a pore size of 2 to 100 nm and the total pore volume may be from about 20% to about 40%, preferably from about 28 to 38%, for example, from about 25 to 35%. For example, the pore volume of secondary pores having a pore size of 2 to 100 nm may be from about 0.08 to 0.18 ml/g, preferably from about 0.10 to 0.16 ml/g. According to the present application, the pore volume secondary pores can be determined using the standard RIPP method 151-90 (see "Petrochemical Analysis Methods (RIPP Test Methods)" ed. by Guiding YANG et al., Science Press, September 1990, pages 424-426) as follows : Determine the total pore volume of the molecular sieve based on the adsorption isotherm, then determine the micropore volume of the molecular sieve based on the adsorption isotherm using the T (adsorption film thickness) plot method, and subtract the micropore volume from the total pore volume to obtain the pore volume for secondary pores.

The modified Y-type molecular sieve proposed in the present application is a rare-earth-modified super-stable Y-type molecular sieve enriched in secondary pores, and the secondary pores of the molecular sieve having a pore size of 2 to 100 nm present a two-probability pore size distribution in which the most likely pore size for secondary pores having a relatively smaller pore size is about 2 to 5 nm, and the most likely pore size for secondary pores having a relatively larger pore size is about 6 to 20 nm, preferably about 8 to 18 nm. Preferably, the percentage of the pore volume of the secondary pores having a pore size of 2 to 100 nm and the total pore volume may be about 28 to 38%, or about 25 to 35%.

According to a preferred embodiment of the present application, the modified Y-type molecular sieve may have a specific surface area of about 600 to 670 m ² /g, for example, from about 610 to 670 m ² /g or from 640 to 670 m ² /g or from 646 to 667 m ² /g. The specific surface area of the modified molecular sieve type Y means the Brunauer-Emmett-Teller (BET) specific surface area, which can be measured in accordance with the standard method ASTM D4222-98.

According to the present application, the modified Y-type molecular sieve preferably has a crystal lattice parameter of from about 2.440 nm to about 2.455 nm, for example, from about 2.442 to 2.453 nm or from 2.442 to 2.451 nm or from 2.441 to 2.453 nm.

According to the present application, the modified Y-type molecular sieve may preferably have a crystal breakdown temperature of from about 1065°C to about 1085°C, more preferably from about 1065 to 1083°C.

According to the present application, the modified Y-type molecular sieve may have a relative degree of crystallinity of at least about 70%, such as from about 70% to about 80%, preferably from about 70 to 76%. The modified Y-type molecular sieve of the present application has a high resistance to hydrothermal aging, and the modified Y-type molecular sieve exhibits a retention of a relative degree of crystallinity of about 38% or more, for example, about 38 to 60%, or about 50 to 60%, or about 46 to 58% as determined by X-ray diffraction analysis (XRD) after aging at 800°C under normal pressure conditions in an atmosphere of 100% steam for 17 hours.

According to the present application, the fracture temperature of the crystal lattice of the modified molecular sieve type Y can be determined by the method of differential thermal analysis (DTA). The crystal lattice parameter and the relative degree of crystallinity of a molecular sieve can be determined by X-ray diffraction analysis (XRD) of a powder according to the standard methods RIPP 145-90 and RIPP 146-90 (see "Petrochemical Analysis Methods (RIPP Test Methods)", Ed. Cuiding YANG et al., Science Press, September 1990, pages 412-415).

According to the present application, the ratio of silica to alumina in the Y-type modified molecular sieve framework is calculated using the following equation:

molar ratio of SiO ₂ /Al ₂ O ₃ in the frame = (2.5858-a ₀ ) × 2 / (a ₀ -2.4191),

in which a ₀ means the parameter of the crystal lattice, the unit of which is the nanometer.

According to the present application, the total ratio of silica and alumina of the modified Y-type molecular sieve can be calculated based on the content of Si and Al elements determined by X-ray fluorescence spectrometry (XRF), and the percentage ratio of framework Al content and total Al content can be calculated based on the ratio of silicon dioxide and alumina in the frame, determined by XRD, and the total ratio of silicon dioxide and alumina, determined by XPS, and as a result, the percentage of non-framework Al content and total Al content can be calculated.

According to the present application, the retention of the relative degree of crystallinity of the modified molecular sieve type Y=(relative crystallinity of the aged sample/relative crystallinity of the fresh sample) × 100%.

The modified Y-type molecular sieve according to the present application has a low non-framework aluminum content, the percentage of non-framework aluminum and total aluminum content is not more than about 10%, more preferably from about 5% to about 9.5%, or from about 6 to 9.5% and the ratio of silicon dioxide and alumina in the framework in terms of nSiO ₂ /n(Al ₂ O ₃ ) (i.e. the molar ratio of SiO ₂ /Al ₂ O ₃ ) from about 7 to about 14, preferably from about 8.5 to 12.6, or from 9.2 to 11.4, or from 7.6 to 12.6.

According to the present application, in order to obtain a modified Y-type molecular sieve that has a desired type and strength of surface acid sites, the ratio of Brønsted acid and Lewis acid in the composition of strong acids contained in the modified Y-type molecular sieve is preferably about 3.5 to 6 ,5. In certain preferred embodiments, when the active element is gallium, the ratio of Brønsted acid to Lewis acid in the composition of the strong acids contained in the modified Y-type molecular sieve is at least about 3.5, preferably from 3.5 to 6.5 , for example, from about 3.5 to 5.8 or from 3.5 to 4.8; when the active element is boron, the ratio of the Bronsted acid to the Lewis acid in the composition of the strong acids contained in the modified Y-type molecular sieve is not less than about 3.5, preferably from about 3.5 to 6.5, or from 3.5 up to 4.8; and when the active element is gallium and boron, the ratio of the Brønsted acid to the Lewis acid in the composition of the strong acids contained in the modified Y-type molecular sieve is preferably about 3.5 to 5.6, for example, about 3.7 to 5 ,4. The ratio of the Bronsted acid to the Lewis acid of the strong acids contained in the modified Y-type molecular sieve, which is the ratio of the strong Bronsted acid to the strong Lewis acid content, can be determined by pyridine adsorption infrared spectroscopy at 350°C, where the strong acid content means the total content of strong acid on the surface of the molecular sieve, and strong acid means the acid determined by the method of infrared spectroscopy with pyridine adsorption at 350°C.

According to a preferred embodiment of the present application, the modified Y-type molecular sieve has a rare earth content of about 4.5 to 10% by weight based on oxide, a phosphorus content of about 0.1 to 6% by weight based on P ₂ O ₅ and the content of sodium oxide from about 0.05 to 3% by weight, relative to the weight of the modified molecular sieve type Y in terms of dry matter; the modified Y-type molecular sieve may have a lattice parameter of about 2.442 to 2.451 nm; and the ratio of silicon dioxide and alumina in the frame from about 8.5 to 12.6 in terms of nSiO ₂ /n(Al ₂ O ₃ ); and the modified Y-type molecular sieve may have a gallium content in terms of gallium oxide of about 0.1 to 3% by weight in the case where the active element is gallium; the content of boron in terms of boron oxide from about 0.5 to 5% by weight in the case where the active element is boron; or the total content of gallium and boron in terms of gallium oxide and boron oxide from about 0.5 to 5% by weight in the case where the active element is gallium and boron.

According to the second aspect, the present application provides a method for producing a modified Y-type molecular sieve, comprising the following steps:

(1) contacting a NaY molecular sieve with a rare earth salt solution for an ion exchange reaction and obtaining an ion exchanged molecular sieve;

(2) subjecting the ion-exchanged molecular sieve to roasting at a temperature of from about 350° C. to about 480° C. in an atmosphere containing from about 30 vol.% to about 90 vol.% steam, for from about 4.5 hours to approximately 7 hours to obtain a molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment;

(3) subjecting a molecular sieve subjected to a mild hydrothermal ultrastabilization treatment to gas phase ultrastabilization by contacting and reacting with SiCl ₄ gas to obtain a gas phase ultrastabilized molecular sieve;

(4) subjecting the gas-phase ultra-stabilized molecular sieve to an acid treatment by contacting with an acid solution to obtain an acid-treated molecular sieve;

(5) subjecting the acid-treated molecular sieve to be modified with phosphorus by contacting with a phosphorus compound to obtain a phosphorus-modified molecular sieve; And

(6) subjecting the phosphorus-modified molecular sieve to a modification treatment by contacting with a solution containing an active element and then calcining to obtain a Y-type modified molecular sieve,

wherein the active element is gallium and/or boron.

According to a specific embodiment, the method according to the present application includes the following steps:

(1) contacting a NaY molecular sieve with a salt of a rare earth element for an ion exchange reaction, filtering, and performing a first washing to obtain an ion exchanged molecular sieve having a sodium oxide content of not more than 9.5% by mass relative to the mass of the ion exchanged molecular sieve in terms of dry matter;

(2) exposing the ion-exchanged molecular sieve to a first calcination at a temperature of from about 350° C. to about 480° C. in an atmosphere containing from about 30 vol% to about 90 vol% steam for about 4.5 hours up to about 7 hours to obtain a molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment;

(3) contacting and reacting a moderate hydrothermal ultra-stabilized molecular sieve with SiCl ₄ gas, optionally performing a second washing and a second filtration to obtain a gas-phase ultra-stabilized molecular sieve;

(4) subjecting the gas-phase ultra-stabilized molecular sieve to an acid treatment by contacting with an acid solution to obtain an acid-treated molecular sieve;

(5) subjecting a phosphorus modification to an acid-treated molecular sieve using a phosphorus compound to obtain a phosphorus-modified molecular sieve; And

(6) subjecting the modified phosphorus-modified molecular sieve to a modification treatment by contacting a solution containing an active element, drying, and then a second calcination to obtain a modified Y-type molecular sieve, wherein the active element is gallium and/or boron.

The method of the present application can be used to obtain a high-silica Y-type molecular sieve rich in secondary pores with a high degree of crystallinity, high thermal stability and high hydrothermal stability, and it can also significantly improve the degree of superstability of the molecular sieve while maintaining high degree of crystallinity. The resulting molecular sieve has a uniform distribution of aluminum, a low content of non-framework aluminum and non-clogged secondary pores. The modified Y-type molecular sieve exhibits high LCO conversion, reduced coke selectivity, and increased yield of aromatic-rich gasoline when used in the processing of hydrogenated LCO.

In the method for producing a modified Y-type molecular sieve of the present application, in step (1), the NaY molecular sieve is subjected to an ion-exchange reaction with a rare earth salt solution to obtain a rare-earth modified Y-type molecular sieve having a normal lattice parameter and a reduced content of sodium oxide. . The ion exchange reaction can be carried out in accordance with a method that is well known to those skilled in the art. For example, the ion exchange reaction can be carried out by mixing a NaY molecular sieve with water, adding a rare earth salt and/or an aqueous solution of a rare earth salt under stirring conditions to carry out the ion exchange reaction, and then filtering and washing.

According to a preferred embodiment, in step (1), the water used may be deionized water; and the NaY molecular sieve may be commercially available or prepared according to existing methods. In a preferred embodiment, the NaY molecular sieve may have a lattice parameter of about 2.465 nm to about 2.472 nm, a silica to alumina ratio (i.e., a SiO ₂ /Al ₂ O ₃ molar ratio) in the framework of about 4.5 to 5.2, and a relative degree of crystallinity of about 85% or more, such as about 85 to 95%, and a sodium oxide content of about 13.0 to 13.8% by weight.

According to the present application, the ion exchange reaction can be carried out under conditions conventionally used in the art. Preferably, to promote the ion exchange reaction, the ion exchange reaction of the NaY molecular sieve with the rare earth salt solution can be carried out at a temperature of from about 15°C to about 95°C, preferably from about 65 to 95°C; over a period of from about 30 minutes to about 120 minutes, preferably from about 45 to 90 minutes; with a weight ratio of NaY molecular sieve (in terms of dry matter), salt of a rare earth element (in terms of RE ₂ O ₃ ) and water of approximately 1: (0.01-0.18): (5-20), preferably approximately 1: (0.5-0.17):(6-14).

According to an embodiment of the present application, ion exchange between rare earth ions and sodium ions can be carried out by mixing NaY molecular sieve and rare earth salt with water at a weight ratio of NaY molecular sieve, rare earth salt and water of about 1:(0.01- 0.18): (5-20), and stirring at a temperature of from about 15 to 95°C, for example, from about 65 to 95°C, preferably for from about 30 minutes to about 120 minutes. In particular, mixing the NaY molecular sieve, the rare earth salt and water may include forming a slurry of the NaY molecular sieve and water, and then adding the rare earth salt and/or an aqueous solution of the rare earth salt to the slurry. The rare earth salt is preferably rare earth chloride and/or rare earth nitrate. The rare earth element may be any type of rare earth element, and its type and composition are not particularly limited. For example, the rare earth element may be one or more of La, Ce, Pr, Nd, or a mixture of rare earth elements. Preferably, the mixture of rare earth elements contains one or more of La, Ce, Pr, and Nd, or it may additionally contain at least one of rare earth elements other than La, Ce, Pr, and Nd.

According to the present application, the washing in step (1) is intended to wash out the sodium ions released as a result of the exchange by using deionized water. Preferably, the resulting ion exchanged molecular sieve in step (1) may have a rare earth content in terms of RE ₂ O ₃ from about 4.5% to about 13% by weight, for example, from about 5.5 to 13% by weight or from 5.5 to 12% by weight, a sodium oxide content of not more than about 9.5% by weight, for example, from about 5.5 to 9.5% by weight, and a crystal lattice parameter from about 2.465 nm to about 2.472 nm.

According to the method for producing a modified Y-type molecular sieve as provided herein, in step (2), a rare-earth-modified Y-type molecular sieve having a normal lattice parameter is calcined at a temperature of from about 350°C to about 480°C in an atmosphere of containing from about 30 vol.% to about 90 vol.% steam, for from about 4.5 hours to about 7 hours. Preferably, the calcination in step (2) is carried out at a temperature of from about 380°C to about 460°C, in a calcination atmosphere containing from about 40 vol.% to about 80 vol.% steam, and for a period of from about 5 hours to about 6 hours. Optionally, the vapor atmosphere may further contain other gases, such as one or more of air, helium, or nitrogen. Preferably, the molecular sieve obtained in step (2) subjected to a mild hydrothermal ultrastabilization treatment may have a crystal lattice parameter of from about 2.450 nm to about 2.462 nm, and more preferably a solids content of at least about 99% by weight.

As used herein, an atmosphere containing 30 to 90 vol.% steam means an atmosphere in which steam is present in an amount of from about 30 to 90% by volume, and the remainder is one or more gases selected from the group consisting of air. , helium or nitrogen. For example, an atmosphere containing 30 vol.% steam may be an atmosphere containing 30 vol.% steam and 70 vol.% air.

In order to achieve the effect of ultra-stabilization treatment in the gas phase, according to an embodiment of the present application, the molecular sieve can be dried before step (3) to reduce the water content of the molecular sieve, so that the molecular sieve to be brought into contact with SiCl ₄ in the step ( 3) has a water content of not more than 1% by weight. Drying can be, for example, drying and firing in a kiln or muffle furnace.

According to the method for producing a modified molecular sieve type Y, which is proposed in this application, the conditions of introduction into contact and reaction in stage (3) can vary within a wide range. In order to further enhance the effect of ultra-stabilization treatment in the gas phase, preferably, the weight ratio of SiCl ₄ and modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment (in terms of dry matter) obtained in stage (2) may be approximately (0.1-0. 7): 1, preferably approximately (0.2-0.6): 1; the reaction temperature may be from about 200°C to about 650°C, preferably from about 350 to 500°C; and the reaction time may be from about 10 minutes to about 5 hours, preferably from about 0.5 to 4 hours. In step (3), a second rinsing and a second filtration may optionally be performed, and drying may optionally be performed after the second filtration. The second wash may be carried out by the conventional washing method, and it may be carried out using deionized water. Its purpose is to remove soluble by-products such as Na ⁺ , Cl ^- and Al ³⁺ that remain in the molecular sieve. Washing can be carried out under the following conditions: the temperature is from about 30°C to about 60°C, the weight ratio of water and ultra-stabilized in the gas phase molecular sieve before washing is about (5-20): 1, preferably about (6-15) :1, and the pH of the spent washing liquid is from about 2.5 to about 5.0. In addition, washing can be carried out to such an extent that no free ions such as Na ⁺ , Cl ^- and Al ³⁺ can be found in the spent washing liquid.

According to the method for producing a modified Y-type molecular sieve, which is proposed in the present application, in step (4), the gas-phase ultra-stabilized molecular sieve obtained in step (3) is contacted and reacted with a channel cleaning acid solution to make secondary pores unobstructed, which is also referred to herein as channel clearing. According to an embodiment of the present application, contacting and reacting the gas-phase ultra-stabilized molecular sieve obtained in step (3) with an acid solution comprises mixing the gas-phase ultra-stabilized molecular sieve with the acid solution and reacting for a period of time, followed by separating the molecular sieve from the acid solution after the reaction, for example, by filtration, and then optionally washing and optionally drying to obtain a modified Y-type molecular sieve proposed in this application. The gas-phase ultra-stabilized molecular sieve can be acid-treated by contacting an acid solution at a temperature of about 60 to 100°C, preferably about 80 to 99°C, more preferably about 88 to 98°C; over a period of about 1 to 4 hours, preferably about 1 to 3 hours. The acid solution may contain an organic acid and/or an inorganic acid, and the weight ratio of the acid in the acid solution, water in the acid solution, and gas-phase ultra-stabilized molecular sieve, on a dry basis, may be approximately (0.001-0.15):(5- 20):1, preferably about (0.002-0.1):(8-15):1 or (0.01-0.05):(8-15):1. Optionally, step (4) may further include washing the resulting acid-treated molecular sieve for the purpose of removing soluble by-products such as Na ⁺ , Cl ^- and Al ³⁺ that remain in the molecular sieve. Washing can be carried out in the same or different way compared to step (3), and it can be carried out, for example, under the following conditions: the temperature is about 30°C to about 60°C, the weight ratio of water and acid-treated molecular sieve to washing is about (5-20):1, preferably about (6-15):1, and the pH of the spent washing liquid is from about 2.5 to about 5.0. In addition, washing can be carried out to such an extent that no free ions such as Na ⁺ , Cl ^- and Al ³⁺ can be found in the spent washing liquid.

According to a preferred embodiment, the acid in acid solution (acid in aqueous solution) is at least one organic acid and at least one inorganic acid having a medium or higher strength. The organic acid may be oxalic acid, malonic acid, succinic acid, methyl succinic acid, malic acid, tartaric acid, citric acid or salicylic acid, or a combination of two, three or four of these compounds. The inorganic acid having a medium or higher strength may be phosphoric acid, hydrochloric acid, nitric acid, or sulfuric acid, or a combination of two, three, or four of these compounds. The introduction into contact can be carried out at a temperature, preferably from about 80°C to about 99°C, for example, from about 85 to 98°C, for a period of about 60 minutes or more, such as from about 60 to 240 minutes or 90 to 180 minutes. The weight ratio of organic acid and molecular sieve is preferably approximately (0.02-0.05):1; the weight ratio of the inorganic acid having a medium or higher strength and the molecular sieve is preferably about (0.01-0.06):1, for example, about (0.02)-0.05):1, and the weight ratio of water and the molecular sieve is preferably about (5-20):1, for example, about (8-15):1.

According to certain preferred embodiments, the acid treatment in step (4), also referred to as channel cleaning, is carried out in two steps, in which the gas-phase ultra-stabilized molecular sieve is first contacted with an inorganic acid, preferably an inorganic acid having a medium or higher strength. , wherein the weight ratio of the inorganic acid having a medium or higher strength and the molecular sieve may be about (0.01-0.05):1, for example, about (0.02-0.05):1, and the weight ratio water and molecular sieve is preferably about (5-20):1, for example, about (8-15):1, the reaction temperature is about 80 to 99°C, preferably 90 to 98°C, and the reaction time is from about 60 minutes to about 120 minutes; and then the resulting molecular sieve is brought into a second contact with an organic acid, wherein the weight ratio of organic acid to molecular sieve may be about (0.02-0.10):1, for example, about (0.05-0.08) :1, the weight ratio of water and molecular sieve is preferably about (5-20):1, for example, about (8-15):1, the reaction temperature is about 80 to 99°C, preferably from 90 to 98°C, and the reaction time is from about 60 minutes to about 120 minutes, and the weight ratio is calculated in relation to the weight of the molecular sieve in terms of dry matter.

The method for producing a modified Y-type molecular sieve of the present application further includes subjecting the phosphorus modification in step (5) to the acid-treated molecular sieve obtained in step (4). Phosphorus modification can be carried out using a phosphorus compound to incorporate the phosphorus into the molecular sieve, and phosphorus modification typically involves contacting the acid-treated molecular sieve with a solution containing the phosphorus compound, typically at a temperature of from about 15°C to about 100°C. , preferably from about 30 to 95°C for about 10 to 100 minutes, then filtering and washing, and the mass ratio of phosphorus in solution in terms of P ₂ O ₅ , water in solution and molecular sieve is approximately (0.0005- 0.10):(2-5):1, i.e. the weight ratio of water in solution and molecular sieve is approximately (2-5):1, preferably approximately (3-4):1, and the mass ratio of phosphorus (in terms of per P ₂ O ₅ ) and the molecular sieve is approximately (0.0005-0.10):1, preferably approximately (0.001-0.06):1. The phosphorus compound may be one or more selected from the group consisting of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate and ammonium hydrogen phosphate. Washing can be carried out, for example, by washing with deionized water in an amount greater than about 5-15 times the weight of the molecular sieve.

According to a preferred embodiment, modification with phosphorus can be carried out by adding an acid-treated molecular sieve to a solution containing a phosphorus compound, reacting at a temperature of from about 15°C to about 100°C for about 10 to 100 minutes, filtering and washing; moreover, the mass ratio of water in solution and molecular sieve is approximately (2-5):1, preferably approximately (3-4):1, and the mass ratio of phosphorus (in terms of P ₂ O ₅ ) and molecular sieve is approximately (0, 0005-0.10):1, preferably approximately (0.001-0.06):1.

In the method according to the present application, the phosphorus-modified molecular sieve can be subjected to an exchange and/or immersion treatment by contacting with a solution containing an active element in step (6) to apply the active element to the Y-type modified molecular sieve. To enhance the effect of the exchange and/or immersion treatment, the solution containing the active element is preferably an aqueous solution of a gallium salt, or an aqueous solution of a boron compound, or an aqueous solution containing a gallium salt and a boron compound, or a combination of two or three of these solutions. The introduction into contact with the solution containing the active element can be carried out one or more times to introduce the required amount of the active element.

Optionally, the second calcination in step (6) may be carried out under the following conditions: the calcination temperature is about 350 to 600° C., and the calcination time is about 1 to 5 hours.

According to a preferred embodiment, in step (6), the solution containing the active element is an aqueous solution of a gallium salt, and the phosphorus-modified molecular sieve is contacted with an aqueous solution of a gallium salt, and the contact can be carried out by homogeneously mixing the phosphorus-modified molecular sieve with an aqueous gallium salt solution and keeping at a temperature of from about 15°C to about 40°C for from about 24 hours to about 36 hours. For example, a phosphorus-modified molecular sieve can be added to the Ga(NO ₃ ) ₃ solution under stirring conditions to impregnate it with the gallium component, uniformly mixed, and left to stand at room temperature for about 24 hours to about 36 hours; thereafter, the slurry of the phosphorus-modified molecular sieve and Ga(NO ₃ ) ₃ is uniformly mixed by additional stirring for 20 minutes, dried, and then subjected to a second calcination. Drying can be carried out by any drying method such as spray drying, oven drying and air drying. According to a preferred embodiment, the drying may be carried out, for example, by transferring the suspension to a rotary evaporator and evaporating to dryness during a hot-rotation process in a water bath. Preferably, the second calcination may include placing the dried material in a kiln drum and calcining at a temperature of about 450 to 600°C for about 2 to 5 hours, preferably at a temperature of about 480 to 580°C for about from 2.2 to 4.5 hours.

Preferably, the aqueous solution of the gallium salt may be an aqueous solution of Ga(NO ₃ ) ₃ , an aqueous solution of Ga ₂ (SO ₄ ) ₃ or an aqueous solution of GaCl ₃ , preferably an aqueous solution of Ga(NO ₃ ) ₃ . Preferably, the weight ratio of gallium in an aqueous solution of gallium salt in terms of oxide, water in an aqueous solution of gallium salt and phosphorus-modified molecular sieve in terms of dry matter can be approximately (0.001-0.03):(2-3):1, preferably approximately (0.005-0.025):(2.2-2.6):1.

According to another preferred embodiment, in step (6), the solution containing the active element is an aqueous solution of a boron compound, and the phosphorus-modified molecular sieve is brought into contact with the aqueous solution of the boron compound, wherein the contacting can be carried out by heating the phosphorus-modified molecular sieve at a temperature of 60 to 99°C and then contacting and stirring it with a boron compound in an aqueous solution for 1 to 2 hours. Preferably, the phosphorus-modified molecular sieve is heated at 85 to 95° C. and then contacted and stirred with the boron compound in aqueous solution for 1 to 1.5 hours. For example, a phosphorus-modified molecular sieve can be added to the exchange tank and mixed with water to form a slurry, and then the molecular sieve slurry is heated at a temperature of 85 to 95°C, followed by the addition of a boron compound such as boric acid, mixed under stirring conditions in for 1 hour, filtered, and the resulting molecular sieve is dried and subjected to a second calcination. Drying can be carried out by any drying method such as spray drying, oven drying, and air drying. According to a preferred embodiment, the drying may be carried out, for example, by drying at a temperature of 120 to 140° C. for 5 to 10 hours. Preferably, the second calcination is carried out at a temperature of about 350 to 600° C. for about 1 to 4 hours. Preferably, the boron compound may be a compound containing positive boron ions, for example a compound selected from the group consisting of boric acid, borate, metaborate, polyborate, or a combination of two, three or four of these compounds.

Preferably, the liquid-to-solid ratio of the molecular sieve slurry, which is the weight ratio of water to molecular sieve, may be approximately (2.5-5):1, preferably approximately (2.8-4.5):1; and the boron compound is preferably added in such an amount, in terms of B ₂ O ₃ , that the weight ratio of B ₂ O ₃ and molecular sieve is approximately (0.5-4.5):100, preferably approximately (0.8-4, 2):100.

According to a further preferred embodiment, in step (6), the solution containing the active element is an aqueous solution of a gallium salt and an aqueous solution of a boron compound, and the phosphorus-modified molecular sieve is contacted with an aqueous solution of a gallium salt and a solution of a boron compound, respectively, wherein the contact can be carried out by heating the phosphorus-modified molecular sieve at a temperature of 85 to 95°C, contacting and mixing it with a boron compound in the first aqueous solution for 1 to 2 hours, filtering, homogeneously mixing the resulting molecular sieve material with with a second aqueous solution containing a gallium salt, and subsequent exposure at a temperature of from 15 to 40°C for 24 to 36 hours. For example, a phosphorus-modified molecular sieve can be added to the exchange tank and mixed with water to form a slurry, and then the molecular sieve slurry is heated at a temperature of 85 to 95°C, after which a boron compound is added, that is, contacting with a boron compound is carried out. in the first aqueous solution, mixed under stirring conditions for 1 hour, and then filtered; thereafter, the filter cake is added to the Ga(NO ₃ ) ₃ solution (which is the second aqueous solution) under stirring conditions to impregnate it with the gallium component, the suspension containing Ga(NO ₃ ) ₃ is evenly mixed by stirring for an additional 20 minutes, dried and then subjected to a second calcination. Drying can be carried out by any drying method such as spray drying, oven drying and air drying. According to a preferred embodiment, drying can be carried out, for example, by transferring the suspension to a rotary evaporator and evaporating to dryness during rotation while heating in a water bath. Preferably, the second calcination may include placing the dried material in a kiln drum and calcining at a temperature of about 450 to 600°C for about 2 to 5 hours, preferably at a temperature of about 480 to 580°C for about from 2.2 to 4.5 hours.

Preferably, the weight ratio of boron in the first aqueous solution in terms of oxide, water in the first aqueous solution and phosphorus-modified molecular sieve in terms of dry matter may be approximately (0.005-0.03):(2.5-5):1, and the mass ratio of gallium in the second aqueous solution in terms of oxide, water in the second aqueous solution and molecular sieve material in terms of dry matter may be approximately (0.001-0.02):(2-3):1.

According to a specific embodiment of the present application, a method for producing a modified Y-type molecular sieve includes the following steps:

(1) contacting a NaY molecular sieve with a rare earth salt solution for ion exchange reaction, filtering and washing to obtain an ion exchanged molecular sieve, wherein the ion exchanged molecular sieve has a reduced content of sodium oxide, contains a rare earth element, and has a normal crystal lattice parameter ; ion exchange is typically carried out under stirring conditions at a temperature of from about 15°C to about 95°C, preferably from about 65 to 95°C, for from about 30 minutes to about 120 minutes;

(2) subjecting the ion-exchanged molecular sieve to roasting at a temperature of about 350 to 480° C. in an atmosphere containing about 30 to 90 vol% steam for about 4.5 to 7 hours, and drying to obtaining a moderately hydrothermally ultrasetted molecular sieve having a water content of less than about 1% by weight, wherein the lattice parameter of the modified mildly hydrothermally ultrasetted molecular sieve is reduced to about 2.450 nm to about 2.462 nm;

(3) contacting the modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment with gaseous SiCl ₄ evaporated under the action of heat, and the mass ratio of SiCl ₄ and modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment (in terms of dry matter) is approximately (0.1-0.7):1, carrying out the reaction at a temperature of from about 200°C to about 650°C for about 10 minutes to about 5 hours, optional washing and optional filtering to obtain ultra-stabilized in the gas phase molecular sieve ;

(4) subjecting the gas-phase ultra-stabilized molecular sieve to an acid treatment by contacting with an acid solution, wherein the gas-phase ultra-stabilized molecular sieve is first mixed with an inorganic acid having a medium or higher strength and water, and reacted at a temperature, component from about 80 to 99°C, preferably from about 90 to 98°C, for at least about 30 minutes, for example, from about 60 to 120 minutes; then the organic acid is added, the reaction is carried out at a temperature of about 80 to 99°C, preferably about 90 to 98°C, for at least about 30 minutes, for example, about 60 to 120 minutes, filtered, optionally washed and optionally dried to obtain an acid-treated molecular sieve; and preferably the mass ratio of organic acid and ultra-stabilized in the gas phase molecular sieve in terms of dry matter is approximately (0.02-0.10): 1, the mass ratio of inorganic acid having a medium or higher strength, and ultra-stabilized in the gas phase molecular the sieve on a dry matter basis is approximately (0.01-0.05):1, and the weight ratio of water to gas-phase ultra-stabilized molecular sieve is approximately (5-20):1;

(5) adding an acid-treated molecular sieve to a solution containing a phosphorus compound, reacting at a temperature of from about 15°C to about 100°C for about 10 minutes to about 100 minutes, filtering, washing, and optionally drying to obtain a modified phosphorus molecular sieve, and the weight ratio of water in solution and molecular sieve is from about 2 to about 5, preferably from about 3 to about 4, and the weight ratio of phosphorus (in terms of P ₂ O ₅ ) and molecular sieve is from about 0.005 to about 0.10, preferably from about 0.01 to about 0.05; And

(6) adding the phosphorus-modified molecular sieve to the Ga(NO ₃ ) ₃ solution under stirring conditions to impregnate it with the gallium component, homogeneously mixing the acid-treated molecular sieve and the Ga(NO ₃ ) ₃ solution, and then keeping at room temperature, wherein the mass ratio of Ga (N03)3 contained in the Ga(NO ₃ ) ₃ solution, in terms of Ga(NO ₃ ) ₃ and phosphorus-modified molecular sieve is approximately 0.1-3:100, the mass ratio of added water in the Ga(NO ₃ ) solution ₃ and phosphorus-modified molecular sieve (in terms of dry matter) is approximately (2-3):1, and the impregnation time is approximately 24 hours, uniform mixing of the slurry containing Y-type modified molecular sieve and Ga(NO ₃ ) ₃ by additional mixing for approximately 20 minutes, transferring the mixture to a rotary evaporator, evaporating to dryness during slow and uniform rotation and heating, and then placing the dried material in a muffle furnace and calcining at a temperature of approximately 450 to 600°C for approximately 2 to 5 hours to obtain a modified type Y molecular sieve according to the present application.

According to another embodiment of the present application, a method for producing a modified Y-type molecular sieve includes the following steps:

(1) contacting a NaY molecular sieve with a rare earth salt solution for ion exchange reaction, filtering and washing to obtain an ion exchanged molecular sieve, wherein the ion exchanged molecular sieve has a reduced content of sodium oxide, contains a rare earth element, and has a normal crystal lattice parameter ; ion exchange is typically carried out under stirring conditions at a temperature of from about 15°C to about 95°C, preferably from about 65 to 95°C for from about 30 minutes to about 120 minutes;

(2) subjecting the ion-exchanged molecular sieve to roasting at a temperature of from about 350°C to about 480°C in an atmosphere containing from about 30 to 90% v/v steam for about 4.5 hours to about 7 hours, and drying to obtain a modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment and having a water content of less than about 1% by weight; wherein the lattice parameter of the modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment is from about 2.450 nm to about 2.462 nm;

(3) contacting the modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment with gaseous SiCl ₄ evaporated under the action of heat, and the mass ratio of SiCl ₄ and modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment (in terms of dry matter) is about (0.1-0.7):1, carrying out the reaction at a temperature of from about 200°C to about 650°C for from about 10 minutes to about 5 hours, optional washing and optional filtering to obtain an ultra-gas-phase molecular sieves;

(4) subjecting the gas-phase ultra-stabilized molecular sieve to an acid treatment by contacting with an acid solution, wherein the gas-phase ultra-stabilized molecular sieve is first mixed with an inorganic acid having a medium or higher strength and water, and the reaction is carried out at a temperature of from about 80 to 99°C, preferably from about 90 to 98°C, for at least about 30 minutes, for example, from about 60 minutes to about 120 minutes; then the organic acid is added, the reaction is carried out at a temperature of about 80 to 99°C, preferably about 90 to 98°C, for at least about 30 minutes, for example, about 60 to 120 minutes, filtered, optionally washed and optionally dried to obtain an acid-treated molecular sieve; and preferably the mass ratio of organic acid and molecular sieve in terms of dry matter is approximately (0.02-0.10): 1, the mass ratio of inorganic acid having a medium or higher strength, and molecular sieve in terms of dry matter is approximately (0.01-0.05):1, and the weight ratio of water and molecular sieve is approximately (5-20):1;

(5) adding an acid-treated molecular sieve to a solution containing a phosphorus compound, reacting at a temperature of from about 15°C to about 100°C for about 10 minutes to about 100 minutes, filtering, washing, and optionally drying to obtain a modified phosphorus molecular sieve, and the weight ratio of water in solution and molecular sieve is from about 2 to about 5, preferably from about 3 to about 4, and the weight ratio of phosphorus (in terms of P ₂ O ₅ ) and molecular sieve is from about 0.005 to about 0.10, preferably from about 0.01 to about 0.05; And

(6) adding the phosphorus-modified molecular sieve to the exchange tank, adding deionized water to obtain a liquid-to-solid ratio of the molecular sieve slurry, which is a weight ratio of water to molecular sieve of approximately (2.5-5:1), heating the molecular sieve slurry sieve at a temperature of from about 85°C to about 95°C, adding boric acid in such an amount in terms of B ₂ O ₃ to provide a mass ratio of B ₂ O ₃ and molecular sieve of approximately (0.5-4.5): 100, stirring for about 1 hour, filtering and exposing the filtered molecular sieve to first drying at a temperature of about 130°C for about 5 hours and then calcining at a temperature of about 350 to 600°C for approximately 1 to 4 hours.

According to a further embodiment of the present application, a method for producing a modified Y-type molecular sieve includes the following steps:

(1) exposing the NaY molecular sieve to a salt solution of a rare earth element for an ion exchange reaction, filtering and washing to obtain an ion exchanged molecular sieve, wherein the ion exchanged molecular sieve has a reduced content of sodium oxide, contains a rare earth element, and has a normal crystal lattice parameter; while the ion exchange is usually carried out under stirring conditions at a temperature of from about 15°C to about 95°C, preferably from about 65 to 95°C for from about 30 minutes to about 120 minutes;

(2) subjecting the ion-exchanged molecular sieve to roasting at a temperature of from about 350° C. to about 480° C. in an atmosphere containing from about 30 to 90 volume % steam for about 4.5 hours to about 7 hours, and drying to obtain a modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment and having a water content of less than about 1% by weight; moreover, the crystal lattice parameter of the modified molecular sieve, subjected to moderate hydrothermal ultra-stabilization treatment, is from about 2.450 nm to about 2.462 nm;

(3) contacting the modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment with gaseous SiCl ₄ evaporated under the action of heat, and the mass ratio of SiCl ₄ and modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment (in terms of dry matter) is about (0.1-0.7):1, carrying out the reaction at a temperature of from about 200°C to about 650°C for from about 10 minutes to about 5 hours, optional washing and optional filtering to obtain an ultra-gas-phase molecular sieves;

(4) subjecting the gas-phase ultra-stabilized molecular sieve to an acid treatment by contacting with an acid solution, wherein the gas-phase ultra-stabilized molecular sieve is first mixed with an inorganic acid having a medium or higher strength and water, and the reaction is carried out at a temperature of from about 80 to 99°C, preferably from about 90 to 98°C, for at least about 30 minutes, for example, from about 60 minutes to about 120 minutes, then the organic acid is added, the reaction is carried out at a temperature of about 80 to 99°C, preferably from about 90 to 98°C, for at least about 30 minutes, for example, from about 60 to 120 minutes, filtered, optionally washed and optionally dried to obtain an acid-treated molecular sieve; and preferably the mass ratio of organic acid and molecular sieve in terms of dry matter is approximately (0.02-0.10): 1, the mass ratio of inorganic acid having a medium or higher strength, and molecular sieve in terms of dry matter is approximately (0.01-0.05):1, and the weight ratio of water and molecular sieve is approximately (5-20):1;

(5) adding an acid-treated molecular sieve to a solution containing a phosphorus compound, reacting at a temperature of about 15°C to about 100°C for about 10 minutes to about 100 minutes, filtering, washing, and optionally drying to obtain a modified phosphorus molecular sieve, and the weight ratio of water in solution and molecular sieve is from about 2 to about 5, preferably from about 3 to about 4, and the weight ratio of phosphorus (in terms of P ₂ O ₅ ) and molecular sieve is from about 0.005 to about 0.10, preferably from about 0.01 to about 0.05; And

(6) adding a phosphorus-modified molecular sieve to the exchange tank, adding deionized water to obtain a liquid-to-solid ratio of the molecular sieve slurry, which is a weight ratio of water to molecular sieve of approximately (2.5-5:1), heating the molecular sieve slurry sieve to a temperature of from about 85°C to about 95°C, adding boric acid in such an amount in terms of B ₂ O ₃ to provide a mass ratio of B ₂ O ₃ and ultra-stabilized in the gas phase molecular sieve of approximately (0 ,5-3):100, stirring for about 1 hour, and then filtering, adding the filtered precipitate to the Ga(NO ₃ ) ₃ solution under stirring conditions to impregnate it with the gallium component, homogeneously stirring the solution and then keeping it at room temperature, moreover, the mass ratio of Ga(NO ₃ ) ₃ contained in the Ga(NO ₃ ) ₃ solution in terms of Ga ₂ O ₃ and the molecular sieve is approximately 0.1-2:100, the mass ratio of added water in the Ga(NO ₃ ) ₃ and molecular sieve (on a dry basis) is approximately (2-3):1, and soaking time is approximately 24 hours, uniform mixing of the suspension by additional stirring for approximately 20 minutes, transferring the mixture to a rotary evaporator, evaporation to dryness during rotation while heating in a water bath and then placing the dried material in a muffle furnace and calcining at a temperature of about 450 to 600°C for about 2 to 5 hours to obtain a modified Y-type molecular sieve according to the present application.

In a third aspect, the present application provides a catalytic cracking catalyst comprising from about 10% to about 50% by weight of a modified Y-type molecular sieve, from about 10% to about 40% by weight of an alumina binder based on alumina, and from about 10% to about 80% by weight of clay, on a dry basis, based on the weight of catalyst, on a dry basis, wherein the modified Y-type molecular sieve is the modified Y-type molecular sieve of the present application or the modified Y-type molecular sieve obtained by the method according to the present application.

The catalytic cracking catalyst of the present application exhibits high LCO conversion, reduced coke selectivity, and increased yield of BTX rich gasoline when used in the processing of hydrogenated LCO.

The catalytic cracking catalyst provided herein may further comprise an additional molecular sieve that is not a modified Y-type molecular sieve, and wherein the additional molecular sieve may be present in an amount of from about 0 to 40% by weight based on the weight of the catalyst. catalytic cracking, for example, from about 0 to 30% by weight or from about 1 to 20% by weight. The additional molecular sieve may be selected from molecular sieves commonly used in catalytic cracking catalysts, such as molecular sieves selected from the group consisting of zeolites having an MFI structure, beta zeolites, other Y-type zeolites, or non-zeolitic molecular sieves, or a combination of the two. , three or four of these materials. Preferably, the additional Y-type molecular sieve is present in an amount on a dry matter basis of not more than about 40% by weight, for example, from about 0 to 40% by weight, or from about 1 to 20% by weight. The additional Y-type molecular sieve may be, for example, REY, REHY, DASY, SOY or PSRY, or a combination of two, three or four of these materials; the zeolite having the MFI structure may be, for example, HZSM-5, ZRP or ZSP, or a combination of two, three or four of these materials; the beta zeolite may be, for example, Hβ; and the non-zeolitic molecular sieves may be, for example, aluminum phosphate-based molecular sieves (AlPO molecular sieves) and/or silicoaluminophosphate molecular sieves (SAPO molecular sieves).

In the catalytic cracking catalyst of the present application, the modified Y-type molecular sieve is present in an amount of about 10 to 50% by weight, on a dry basis, preferably from about 15 to 45% by weight, for example, from about 25 to 40% by weight.

In the catalytic cracking catalyst of the present application, the clay may be one or more clays selected from the group consisting of clays suitable for use as a component in cracking catalysts, such as kaolin, hydrated halloysite, montmorillonite, diatomite, halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite or bentonite, or a combination of two, three or four of these minerals. These clays are well known to those of ordinary skill in the art. Preferably, clay is present in the catalytic cracking catalyst of the present application in an amount of about 20 to 55% by weight, or about 30 to 50% by weight, on a dry matter basis.

In the catalytic cracking catalyst of the present application, the alumina binder is present in an amount of about 10 to 40% by weight, for example about 20 to 35% by weight, based on alumina. The alumina binder may be one or more selected from the group consisting of various forms of alumina, hydrated alumina, and alumina sol, which are commonly used in cracking catalysts. For example, the binder may be selected from the group consisting of γ-alumina, η-alumina, θ-alumina, χ-alumina, pseudoboehmite, boehmite, gibbsite, bayerite, or alumina sol, or a combination of two, three, or four of these materials, preferably pseudoboehmite and alumina sol. For example, the catalytic cracking catalyst may contain from about 2 to 15% by weight, preferably from about 3 to 10% by weight of alumina sol in terms of alumina and from about 10 to 30% by weight, preferably from about 15 to 25% by weight of pseudoboehmite in terms of aluminum oxide.

According to the fourth aspect, the present application provides a method for producing a catalytic cracking catalyst, comprising the following steps: obtaining a modified Y-type molecular sieve, forming a slurry containing a modified Y-type molecular sieve, a binder based on alumina, clay and water, spray drying, optional washing and optionally drying to obtain a catalytic cracking catalyst, wherein the aforementioned production of a modified Y-type molecular sieve includes the production of a modified Y-type molecular sieve according to the present application or the production of a modified Y-type molecular sieve by the method of the present application.

Except for the step of producing the Y-type modified molecular sieve, all of the steps of the method for producing the catalyst of the present application can be carried out according to existing methods, for example, according to the methods described in PRC Patent Application Publication Nos. CN1098130A and CN1362472A.

According to the method for producing the catalyst proposed in the present application, spray drying, washing and drying can be carried out according to the known methods of the prior art, and there are no special requirements in the present application.

According to the method for producing the catalyst proposed in the present application, the modified Y-type molecular sieve can be used in any amount conventionally used in the art. Preferably, the modified Y-type molecular sieve may be present in the resulting catalyst in an amount on a dry matter basis of from about 10 to 50% by weight, preferably from about 15 to 45% by weight, for example, from about 25 to 40% by weight.

According to the method for preparing the catalyst proposed in this application, the clay may be one or more clays selected from the group consisting of clays suitable for use as a component in cracking catalysts, such as one or more clays selected from the group consisting of kaolin, hydrated halloysite, montmorillonite, diatomite, halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite and bentonite. These clays are well known to those of ordinary skill in the art. The clay may be used in any amount conventionally used in the art. Preferably, clay is present in the resulting catalytic cracking catalyst in an amount of about 20 to 55% by weight, or about 30 to 50% by weight, on a dry matter basis.

According to the method for preparing the catalyst proposed in this application, the alumina-based binder may be one or more substances selected from the group consisting of various forms of alumina, hydrated alumina and alumina sol, which are typically used in cracking catalysts. For example, the binder may be one or more selected from the group consisting of γ-alumina, η-alumina, θ-alumina, χ-alumina, pseudoboehmite, boehmite, gibbsite, bayerite, or alumina sol, preferably pseudoboehmite and an alumina sol. The alumina binder may be used in any amount conventionally used in the art. Preferably, the alumina binder is present in the resulting catalytic cracking catalyst in an amount of about 10 to 40% by weight, based on alumina, such as about 20 to 35% by weight. In an embodiment, the alumina binder is pseudoboehmite and an alumina sol, and the resulting catalytic cracking catalyst may contain from about 2 to 15% by weight, preferably from about 3 to 10% by weight of alumina sol, based on alumina and about 10 to 30% by weight, preferably about 15 to 25% by weight of pseudoboehmite, based on alumina.

According to a fifth aspect, the present application proposes the use of a modified Y type molecular sieve according to the present application in the catalytic cracking of a hydrocarbon feedstock, in particular a hydrogenated light cycle oil, comprising contacting the hydrocarbon feedstock with a catalytic cracking catalyst containing a modified Y type molecular sieve in catalytic cracking conditions.

According to a sixth aspect, the present application provides the use of the catalytic cracking catalyst of the present application in the catalytic cracking of a hydrocarbon feed, in particular a hydrogenated light cycle oil, comprising contacting the hydrocarbon feed with a catalytic cracking catalyst under catalytic cracking conditions.

According to a seventh aspect, the present application provides a catalytic cracking process capable of processing hydrogenated light cycle oil (hydrogenated LCO) and comprising the step of contacting hydrogenated LCO under catalytic cracking conditions with a catalytic cracking catalyst according to the present application or a catalytic cracking catalyst containing a modified molecular sieve type Y according to the present application.

According to the present application, the preferred catalytic cracking conditions may include a reaction temperature from about 500°C to about 610°C, a volume of oil per unit mass of catalyst per hour from about 2 h ^-1 to about 16 h ^-1 and a mass ratio of catalyst to oil from about 3 to about 10.

According to the present application, preferably hydrogenated LCO may have the following properties: a density (at 20°C) of about 0.850 to 0.920 g/cm ³ , an H content of about 10.5 to 12% by weight, an S content of less than 50 μg/g, and a N content of less than 10 μg/g, a total aromatic content of about 70 to 85% by weight, and a polycyclic aromatic content of not more than 15% by weight.

According to certain preferred embodiments, the following technical solutions are proposed in this application:

A1. Modified Y-type molecular sieve, characterized in that the modified Y-type molecular sieve has a content of rare earth elements from about 4 to 11% by weight, a content of phosphorus in terms of P ₂ O ₅ from about 0.05% to about 10% by weight, the content of sodium oxide is not more than about 0.5% by weight and the content of active element oxide is from about 0.1 to 5% by weight, while the active element is gallium and/or boron, in relation to the weight of the modified type Y molecular sieve in terms of dry matter; the modified Y-type molecular sieve has a total pore volume of about 0.36 ml/g to about 0.48 ml/g, a percentage of secondary pore volume having a pore size of 2 to 100 nm and a total pore volume of about 20% up to about 40%; a lattice parameter of from about 2.440 nm to about 2.455 nm and a lattice break temperature of not less than about 1060°C; the percentage ratio of non-framework aluminum to the total aluminum content of the modified Y type molecular sieve is not more than about 10%; and the ratio of Bronsted acid to Lewis acid in the composition of strong acids contained in the modified Y type molecular sieve is not less than about 3.5.

A2. The modified Y type molecular sieve according to A1, wherein the percentage of the pore volume of the secondary pores having a pore size of 2 to 100 nm and the total pore volume of the modified Y type molecular sieve is about 28 to 38%.

A3. The modified Y-type molecular sieve of claim A1, wherein the modified Y-type molecular sieve has a non-framework aluminum to total aluminum content ratio of about 5% to about 9.5% and a framework silica to alumina ratio of about 7 to about 14 wt. converted to nSiO ₂ /n(Al ₂ O ₃ ).

A4. The modified Y-type molecular sieve of claim A1, wherein the modified Y-type molecular sieve has a crystal breakdown temperature of from about 1065°C to about 1085°C.

A5. The modified Y-type molecular sieve of A1, wherein the ratio of Brønsted acid to Lewis acid in the composition of the strong acids contained in the modified Y-type molecular sieve is from about 3.5 to about 6.5 as determined by pyridine adsorption infrared spectroscopy at 350 °C.

A6. The modified Y-type molecular sieve of claim A1, wherein the modified Y-type molecular sieve has a relative degree of crystallinity of from about 70% to about 80%.

A7. The modified Y-type molecular sieve of A1, wherein the modified Y-type molecular sieve exhibits a relative degree of crystallinity retention of about 38% or more as determined by XRD after aging at 800° C. in 100% steam for 17 hours.

A8. The modified Y type molecular sieve of any one of A1-A7, wherein the modified Y type molecular sieve has a rare earth content of from about 4.5% to about 10% by weight based on oxide, a phosphorus content of from about 0.1% to about 6% by weight, based on P ₂ O ₅ and a sodium oxide content of from about 0.05% to about 0.3% by weight, based on the weight of the modified Y-type molecular sieve, on a dry matter basis; and the modified Y-type molecular sieve has a lattice parameter of about 2.442 to 2.451 nm and a backbone silica to alumina ratio of about 8.5 to about 12.6, based on nSiO ₂ /n(Al ₂ O ₃ );

wherein the rare earth element is La, Ce, Pr or Nd, or a combination of two, three or four of these elements; and wherein the modified Y-type molecular sieve has a gallium oxide content of about 0.1 to 3% by weight, where the active element is gallium, or a boron oxide content of about 0.5 to 5% by weight, where the active element is boron; or a total content of gallium oxide and boron oxide from about 0.5 to 5% by weight, where the active element is gallium and boron.

A9. A method for producing a modified type Y molecular sieve according to any one of paragraphs A1-A8, characterized in that the method includes the following steps:

(1) contacting a NaY molecular sieve with a salt of a rare earth element for an ion exchange reaction, filtering, and performing a first wash to obtain an ion exchanged molecular sieve, wherein the ion exchanged molecular sieve has a sodium oxide content of not more than about 9.0% by weight in relation to the weight of the ion-exchanged molecular sieve in terms of dry matter;

(2) exposing the ion-exchanged molecular sieve to a first calcination at a temperature of from about 350° C. to about 480° C. in an atmosphere containing from about 30 vol% to about 90 vol% steam for about 4.5 hours up to about 7 hours to obtain a molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment;

(3) contacting and reacting with the SiCU a molecular sieve subjected to a moderate hydrothermal ultra-stabilization treatment, optionally performing a second washing and a second filtration to obtain a gas-phase ultra-stabilized molecular sieve;

(4) subjecting the gas-phase ultra-stabilized molecular sieve to an acid treatment by contacting with an acid solution to obtain an acid-treated molecular sieve;

(5) subjecting a phosphorus modification to an acid-treated molecular sieve using a phosphorus compound to obtain a phosphorus-modified molecular sieve; And

(6) contacting a phosphorus-modified molecular sieve with a solution containing an active element, and subjecting the resulting product to drying and a second calcination to obtain a Y-type modified molecular sieve;

wherein the active element is gallium and/or boron.

A10. The method of A9, wherein the ion exchange is carried out by mixing the NaY molecular sieve with water, adding a rare earth salt and/or an aqueous rare earth salt solution under stirring conditions to carry out the ion exchange reaction, filtering and washing;

wherein the ion exchange is carried out under the following conditions: the temperature is from about 15°C to about 95°C, the duration is from about 30 minutes to about 120 minutes, and the weight ratio of NaY molecular sieve, rare earth salt and water is about 1:(0 .01-0.18):(5-20).

A11. The method of A9 or A10, wherein the ion-exchanged molecular sieve has a lattice parameter of from about 2.465 nm to about 2.472 nm, the content of rare earth elements is from about 4.5% to about 13% by weight, based on oxide, and the content sodium oxide is approximately 4.5 to 9.5% by weight.

A12. The method of A9 or A10, wherein the rare earth salt is a rare earth chloride or a rare earth nitrate.

A13. The method according to item A9, in which stage (2) is carried out by carrying out the first roasting at a temperature of from about 380°C to about 460°C in an atmosphere containing from about 40 vol.% to about 80 vol.% steam, for from about 5 hours to approximately 6 hours.

A14. The method of A9 or A13, wherein the modified molecular sieve subjected to mild hydrothermal ultrastabilization treatment has a lattice parameter of from about 2.450 nm to about 2.462 nm and a water content of not more than about 1% by weight.

A15. The method according to item A9, in which in stage (3) the mass ratio of SiCl ₄ and modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment, in terms of dry matter, is approximately (0.1-0.7): 1, the reaction temperature is from about 200°C to about 650°C, and the reaction time is from about 10 minutes to about 5 hours; and the second wash is a wash to such an extent that no free ions such as Na ⁺ , Cl ^- and Al ³⁺ can be detected in the spent wash liquid, and the wash conditions may include a temperature of from about 30°C to about 60°C. , the mass ratio of water and gas-phase ultra-stabilized molecular sieve before washing is about (6-15):1 and the pH of the spent washing liquid is from about 2.5 to about 5.0.

A16. The method according to A10, wherein the acid treatment in step (4) is carried out under the following conditions: the acid treatment temperature is about 80 to 99°C, the acid treatment time is about 1 to 4 hours, the acid solution contains an organic acid and/or inorganic acid, and the weight ratio of acid in acid solution, water in acid solution and ultra-stabilized in the gas phase molecular sieve in terms of dry matter is approximately (0.001-0.15):(5-20):1.

A17. The method of claim A10, wherein the acid treatment in step (4) is carried out by first contacting the ultra-stabilized gas phase molecular sieve with an inorganic acid solution and then second contact with an organic acid solution,

and the first contact is carried out under the following conditions: the contact time is from about 60 minutes to about 120 minutes, the contact temperature is from about 90°C to about 98°C, and the mass ratio of inorganic acid in the inorganic acid solution, water in the inorganic acid solution and the gas-phase ultra-stabilized molecular sieve, on a dry matter basis, is approximately (0.01-0.05):(5-20):1; and the second contact is carried out under the following conditions: the contact time is from about 60 minutes to about 120 minutes, the contact temperature is from about 90°C to about 98°C, and the weight ratio of organic acid in the organic acid solution, water in the organic acid solution and ultra-stabilized in the gas phase of the molecular sieve in terms of dry matter is approximately (0.02-0.1):(5-20):1.

A18. The method of A16 or A17 wherein the organic acid is oxalic acid, malonic acid, succinic acid, methyl succinic acid, malic acid, tartaric acid, citric acid or salicylic acid, or a combination of two, three or four of these compounds; and the inorganic acid is phosphoric acid, hydrochloric acid, nitric acid or sulfuric acid, or a combination of two, three or four of these compounds.

A19. The method of claim A9, wherein the phosphorus compound is phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate or ammonium hydrogen phosphate, or a combination of two, three or four of these compounds; modification with phosphorus includes contacting an acid-treated molecular sieve with a solution containing a phosphorus compound, reacting at a temperature of from about 15°C to about 100°C for from about 10 minutes to about 100 minutes, filtering and washing, and the mass ratio of phosphorus in solution in terms of P2O5, water in solution and acid-treated molecular sieve is approximately (0.0005-0.10):(2-5):1.

A20. The method according to item A9, in which the solution containing the active element is an aqueous solution of a gallium salt and/or an aqueous solution of a boron compound;

wherein the aforementioned contacting of the phosphorus-modified molecular sieve with the solution containing the active element comprises:

homogeneous mixing of the phosphorus-modified molecular sieve with an aqueous solution of a gallium salt and subsequent holding at a temperature of about 15 to 40°C for about 24 to 36 hours, and the mass ratio of gallium in an aqueous solution of a gallium salt in terms of oxide, water in an aqueous solution gallium salt and phosphorus-modified molecular sieve on a dry matter basis is approximately (0.001-0.03):(2-3):1; or

heating the phosphorus-modified molecular sieve to a temperature of about 60 to 99°C, and then contacting and mixing with a boron compound in aqueous solution for about 1 hour to about 2 hours, wherein the weight ratio of boron in aqueous solution, in terms of oxide , water in aqueous solution and phosphorus-modified molecular sieve on a dry matter basis is approximately (0.005-0.045):(2.5-5):1, and the boron compound is selected from the group consisting of boric acid, borate, metaborate or polyborate , or a combination of two, three or four of these compounds; or

heating the phosphorus-modified molecular sieve to about 85 to 95° C., contacting and mixing with a boron compound in a first aqueous solution for about 1 hour to about 2 hours, filtering, homogeneously mixing the resulting molecular sieve material with a second aqueous a solution containing a gallium salt and then holding at a temperature of about 15 to 40° C. for about 24 hours to about 36 hours; and the mass ratio of boron in the first aqueous solution in terms of oxide, water in the first aqueous solution and phosphorus-modified molecular sieve in terms of dry matter is approximately (0.005-0.03):(2.5-5):1, mass ratio gallium in the second aqueous solution in terms of oxide, water in the second aqueous solution and molecular sieve material in terms of dry matter is approximately (0.001-0.02):(2-3):1.

A21. The method of A9, wherein in step (6), the second calcination is carried out under the following conditions: the calcination temperature is about 350 to 600°C, and the calcination time is about 1 to 5 hours.

B1. Catalytic cracking catalyst, characterized in that the catalyst contains from about 10 to 50 wt. by weight of clay in terms of dry matter in relation to the weight of the catalyst in terms of dry matter;

moreover, the modified Y-type molecular sieve has a content of rare earth elements from about 4% to about 11% by weight in terms of oxide, a phosphorus content from about 0.05% to about 10% by weight in terms of P ₂ O ₅ , the content of sodium oxide not more than about 0.5% by weight and an oxide content of the active element from about 0.1% to about 5% by weight, while the active element is gallium and/or boron, in relation to the weight of the modified type Y molecular sieve in in terms of dry matter; and the modified Y-type molecular sieve has a total pore volume of about 0.36 ml/g to about 0.48 ml/g, a percentage of secondary pore volume having a pore size of 2 to 100 nm and a total pore volume of about 20 % to about 40%; lattice parameter from about 2.440 nm to about 2.455 nm; the temperature of the destruction of the crystal lattice is not less than about 1060°C; the ratio of non-framework aluminum to the total aluminum content of the modified Y-type molecular sieve is not more than about 10%; and the ratio of Bronsted acid to Lewis acid in the composition of strong acids contained in the modified Y-type molecular sieve is not less than about 3.5.

B2. The catalytic cracking catalyst of claim B1, wherein the modified Y-type molecular sieve has a pore volume percentage of secondary pores having a pore size of 2 to 100 nm and a total pore volume of about 28 to 38%.

B3. The catalytic cracking catalyst of item B1, wherein the modified Y-type molecular sieve has a non-framework aluminum to total aluminum content ratio of about 5% to about 9.5% and a framework silica to alumina ratio of about 7 to about 14, based on on nSiO ₂ /n(Al ₂ O ₃ ).

B4. The catalytic cracking catalyst of claim B1, wherein the modified Y-type molecular sieve has a crystal breakdown temperature of from about 1065°C to about 1085°C.

B5. The catalytic cracking catalyst of item B1, wherein the ratio of the Brønsted acid to the Lewis acid in the composition of the strong acids contained in the modified Y-type molecular sieve is approximately 3.5 to 6.5 as determined by pyridine adsorption infrared spectroscopy at 350°C .

B6. The catalytic cracking catalyst of claim B1, wherein the modified Y-type molecular sieve has a relative degree of crystallinity of from about 70% to about 80%.

B7. The catalytic cracking catalyst of item B1, wherein the modified Y-type molecular sieve exhibits a relative degree of crystallinity retention of about 38% or more as determined by XRD after aging at 800°C in a 100% steam atmosphere for 17 hours.

B8. The catalytic cracking catalyst of any one of B1-B7, wherein the modified Y-type molecular sieve has a rare earth content of about 4.5 to 10% by weight based on oxide, a phosphorus content of about 0.1 to 6% by weight of calculated as P2O5 and a sodium oxide content of about 0.05 to 0.3% by weight, based on the weight of the modified Y-type molecular sieve, on a dry matter basis; and the modified Y-type molecular sieve has a lattice parameter of about 2.442 to 2.451 nm and a backbone silica to alumina ratio of about 8.5 to about 12.6, based on nSiO ₂ /n(Al ₂ O ₃ );

wherein the rare earth element is La, Ce, Pr or Nd, or a combination of two, three or four of these elements; And

wherein the modified Y-type molecular sieve has a gallium oxide content of about 0.1 to 3% by weight, where the active element is gallium, or a boron oxide content of about 0.5 to 5% by weight, where the active element is boron ; or a total content of gallium oxide and boron oxide from about 0.5 to 5% by weight, where the active element is gallium and boron.

AT 9. The catalytic cracking catalyst of claim B1, wherein the clay is kaolin, hydrated halloysite, montmorillonite, diatomite, halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite, or bentonite, or a combination of two, three, or four of these minerals; and the alumina-based binder is alumina, hydrated alumina, or alumina sol, or a combination of two, three, or four of these materials.

AT 10 O'CLOCK. A method for producing a catalytic cracking catalyst according to any one of items B1-B9, characterized in that the method includes: obtaining a modified Y-type molecular sieve, forming a slurry containing a modified Y-type molecular sieve, a binder based on alumina, clay and water, and spraying drying to obtain a catalytic cracking catalyst;

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

(1) contacting a NaY molecular sieve with a salt of a rare earth element for an ion exchange reaction, filtering, and performing a first wash to obtain an ion exchanged molecular sieve, wherein the ion exchanged molecular sieve has a sodium oxide content of not more than about 9.0% by weight in relation to the weight of the ion-exchanged molecular sieve in terms of dry matter;

(2) exposing the ion-exchanged molecular sieve to a first calcination at a temperature of from about 350° C. to about 480° C. in an atmosphere containing from about 30 vol% to about 90 vol% steam for about 4.5 hours up to about 7 hours to obtain a molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment;

(3) contacting and reacting with SiCl ₄ a molecular sieve subjected to a moderate hydrothermal ultra-stabilization treatment, optionally performing a second washing and a second filtration to obtain a gas-phase ultra-stabilized molecular sieve;

(4) subjecting the ultra-gas-phase ultra-stabilized molecular sieve to an acid treatment by contacting with an acid solution to obtain an acid-treated molecular sieve;

(5) subjecting the phosphorus-modified molecular sieve to an acid-treated molecular sieve using a phosphorus compound to produce a phosphorus-modified molecular sieve; And

(6) contacting a phosphorus-modified molecular sieve with a solution containing an active element, and subjecting the resulting product to drying and a second calcination to obtain a Y-type modified molecular sieve;

wherein the active element is gallium and/or boron.

AT 11. The method according to item B10, wherein the ion exchange is carried out by mixing a NaY molecular sieve with water, adding a rare earth salt and/or an aqueous solution of a rare earth salt under stirring conditions to carry out the ion exchange reaction, filtering and washing;

and the ion exchange is carried out under the following conditions: the temperature is from about 15°C to about 95°C, the duration is from about 30 minutes to about 120 minutes, and the weight ratio of NaY molecular sieve, rare earth salt and water is about 1:(0 .01-0.18):(5-20).

B12. The method of item B10 or B11 wherein the ion exchanged molecular sieve has a lattice parameter of about 2.465 nm to about 2.472 nm, a rare earth content of about 4.5% to about 13% by weight based on oxide, and a content of sodium oxide about 4.5 to 9.5% by weight.

B13. The method according to item B10 or B11, wherein the rare earth salt is a rare earth chloride or a rare earth nitrate.

B14. The method according to item B10, in which stage (2) is carried out by carrying out the first roasting at a temperature of from about 380°C to about 460°C in an atmosphere containing from about 40 vol.% to about 80 vol.% steam, for from about 5 hours to approximately 6 hours.

B15. The method of item B10 or B14, wherein the modified molecular sieve subjected to mild hydrothermal ultrastabilization treatment has a crystal lattice parameter of from about 2.450 nm to about 2.462 nm and a water content of not more than about 1% by weight.

B16. The method according to item B10, in which in stage (3) the mass ratio of SiCl ₄ and modified molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment, in terms of dry matter, is approximately (0.1-0.7): 1, the reaction temperature is from about 200°C to about 650°C, and the reaction time is from about 10 minutes to about 5 hours; and the second wash is a wash to such an extent that no free ions such as Na ⁺ , Cl ^- and Al ³⁺ can be detected in the spent wash liquid, and wash conditions may include a temperature of from about 30°C to about 60 ° C, the mass ratio of water and ultra-stabilized in the gas phase molecular sieve before washing about (6-15): 1 and the pH of the spent washing liquid from about 2.5 to about 5.0.

B17. The method according to item B10, wherein the acid treatment in step (4) is carried out under the following conditions: the acid treatment temperature is about 80 to 99°C, the acid treatment time is about 1 to 4 hours, the acid solution contains an organic acid and/or inorganic acid, and the weight ratio of acid in acid solution, water in acid solution and ultra-stabilized in the gas phase molecular sieve in terms of dry matter is approximately (0.001-0.15):(5-20):1.

B18. The method of claim B10, wherein the acid treatment in step (4) is carried out by first contacting the gas-phase ultra-stabilized molecular sieve with an inorganic acid solution and then second contact with an organic acid solution;

and the first contact is carried out under the following conditions: the contact time is from about 60 minutes to about 120 minutes, the contact temperature is from about 90°C to about 98°C, and the mass ratio of inorganic acid in the inorganic acid solution, water in the inorganic acid solution and the gas-phase ultra-stabilized molecular sieve, on a dry matter basis, is approximately (0.01-0.05):(5-20):1; and the second contact is carried out under the following conditions: the contact time is from about 60 minutes to about 120 minutes, the contact temperature is from about 90°C to about 98°C, and the weight ratio of organic acid in the organic acid solution, water in the organic acid solution and molecular sieve ultra-stabilized in the gas phase, on a dry matter basis, is approximately (0.02-0.1):(5-20):1.

B19. The method according to item B10 or B18, wherein the organic acid is oxalic acid, malonic acid, succinic acid, methyl succinic acid, malic acid, tartaric acid, citric acid or salicylic acid, or a combination of two, three or four of these compounds; and the inorganic acid is phosphoric acid, hydrochloric acid, nitric acid or sulfuric acid, or a combination of two, three or four of these compounds.

B20. The method of claim B10 wherein the phosphorus compound is phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate or ammonium hydrogen phosphate, or a combination of two, three or four of these compounds; modification with phosphorus includes contacting an acid-treated molecular sieve with a solution containing a phosphorus compound, reacting at a temperature of from about 15°C to about 100°C for from about 10 minutes to about 100 minutes, filtering and washing, and the mass ratio of phosphorus in solution in terms of P ₂ O ₅ , water in solution and acid-treated molecular sieve is approximately (0.0005-0.10):(2-5):1.

B21. The method according to item B10, in which the solution containing the active element is an aqueous solution of a gallium salt and/or an aqueous solution of a boron compound;

the aforementioned contacting a phosphorus-modified molecular sieve with a solution containing an active element includes:

homogeneous mixing of the phosphorus-modified molecular sieve with an aqueous solution of a gallium salt and subsequent holding at a temperature of about 15 to 40°C for about 24 to 36 hours, and the mass ratio of gallium in an aqueous solution of a gallium salt in terms of oxide, water in an aqueous solution gallium salt and phosphorus-modified molecular sieve on a dry matter basis is approximately (0.001-0.03):(2-3):1; or

heating the phosphorus-modified molecular sieve to a temperature of about 60 to 99° C., and then contacting and mixing with a boron compound in aqueous solution for about 1 hour to about 2 hours, wherein the weight ratio of boron in aqueous solution, in terms of on oxide, water in aqueous solution and phosphorus-modified molecular sieve on a dry matter basis is approximately (0.005-0.045):(2.5-5):1, and the boron compound is selected from the group consisting of boric acid, borate, metaborate or polyborate, or a combination of two, three or four of these compounds; or heating the phosphorus-modified molecular sieve to a temperature of about 85 to 95° C., contacting and mixing with a boron compound in the first aqueous solution for about 1 hour to about 2 hours, filtering, homogeneously mixing the resulting molecular material sieves with a second aqueous solution containing a gallium salt and subsequent exposure at a temperature of from about 15 to 40°C for about 24 hours to about 36 hours; moreover, the mass ratio of boron in the first aqueous solution in terms of oxide, water in the first aqueous solution and phosphorus-modified molecular sieve in terms of dry matter is approximately (0.005-0.03):(2.5-5):1, and the mass the ratio of gallium in the second aqueous solution in terms of oxide, water in the second aqueous solution and molecular sieve material in terms of dry matter is approximately (0.001-0.02):(2-3):1.

B22. The method according to item B10, wherein in step (6), the second calcination is carried out under the following conditions: the calcination temperature is about 350 to 600°C, and the calcination time is about 1 to 5 hours.

D23. The use of the catalytic cracking catalyst according to any one of items B1-B9 in the catalytic cracking of a hydrocarbon feed.

B24. A catalytic cracking process for processing hydrogenated LCO, comprising the step of contacting hydrogenated LCO with a catalyst according to any one of B1-B9 under catalytic cracking conditions; wherein the catalytic cracking conditions include a reaction temperature of from about 500° C. to about 610° C., a volume of oil per unit weight of catalyst per hour from about 2 h ^-1 to about 16 h ^-1 , and a weight ratio of catalyst to oil from about 3 to about 10 .

Examples

The present application will be further illustrated by the following examples, which, however, do not limit the present invention.

The following examples and comparative examples use NaY molecular sieves (also referred to as "NaY zeolites") supplied by Qilu Branch of Sinopec Catalyst Co., Ltd., in which the content of sodium oxide is 13.5% by mass, the ratio of silica and framework aluminum oxide (molar ratio of SiO ₂ /Al ₂ O ₃ ) is 4.6, the lattice parameter is 2.470 nm, and the relative degree of crystallinity is 90%; rare earth chloride, rare earth nitrate and gallium nitrate are chemically pure reagents produced by Beijing Aluminum Factory; pseudoboehmite is an industrial product with a solids content of 61% by mass, which is produced by the Shandong aluminum plant; Kaolin is a special kaolin for cracking catalysts with a solids content of 76% by mass, which is produced by China Kaolin Clay Co., Ltd. (Suzhou); and an alumina sol having an alumina content of 21% by mass was supplied by Qilu Branch of Sinopec Catalyst Co., Ltd.

Unless otherwise specified, the reagents used in each of the examples and comparative examples were commercially available chemically pure reagents.

Analytical Methods

In each of the Examples and Comparative Examples, the content of molecular sieve elements was determined by X-ray fluorescence spectrometry; the lattice parameter and the relative degree of crystallinity of the molecular sieve were determined by X-ray diffraction analysis (XRD) of the powder using standard methods RIPP 145-90, RIPP 146-90 (see "Petrochemical Analysis Methods (RIPP Test Methods)", Ed. Cuiding YANG and et al., Science Press, September 1990, pages 412-415).

The ratio of silica to alumina in the molecular sieve framework was calculated according to the following equation:

molar ratio of SiO ₂ /Al ₂ O ₃ in the frame = (2.5858-a ₀ ) × 2 / (a ₀ -2.4191),

in which a ₀ means the parameter of the crystal lattice, the unit of which is the nanometer.

The total ratio of silicon dioxide and alumina of the molecular sieve was calculated based on the content of the elements Si and Al, determined by X-ray fluorescence spectrometry (XRF). The percentage ratio of framework Al content and total Al content was calculated based on the ratio of silicon dioxide and aluminum oxide in the framework, determined by XRD, and the total ratio of silicon dioxide and aluminum oxide, determined by XPS, after which the percentage ratio of non-framework Al content and total Al content was calculated. .

The temperature of destruction of the crystal lattice was determined by the method of differential thermal analysis (DTA).

In each of the Examples and Comparative Examples, the type of acid sites of the molecular sieve and the content of the corresponding acid were determined by pyridine adsorption infrared spectroscopy. The instrument was an IFS113V Fourier transform infrared spectrometer from Bruker (USA). The method for determining the acid content by infrared spectroscopy with pyridine adsorption at 350° C. was carried out as follows: a sample in the form of a tablet without support was placed in situ in the cell of an infrared spectrometer and sealed; the sample was heated to a temperature of 400°C, evacuated to 10 ^-3 Pa and kept at the same temperature for 2 hours to remove the gas molecules absorbed by the sample; the sample was cooled to room temperature, pyridine vapor was introduced at a pressure of 2.67 Pa, and the sample was kept under such conditions for 30 minutes to achieve adsorption equilibrium; then the sample was heated to a temperature of 350°C and evacuated to 10 ^-3 Pa for desorption for 30 minutes; after that, the sample was cooled to room temperature, subjected to spectrographic analysis, scanning the wave number in the range from 1400 cm ^-1 to 1700 cm ^-1 and received the infrared spectrum of pyridine adsorbed by the sample and desorbed at a temperature of 350°C. The relative amount of strong Bronsted acid sites (Brensted acids) and strong Lewis acid sites (Lewis acids) in the molecular sieve was obtained from the intensity of the characteristic absorption peaks at 1540 cm ^-1 and 1450 cm ^-1 in the infrared absorption spectrum of pyridine.

In each of the Examples and Comparative Examples, the secondary pore volume determination method was the standard RIPP method 151-90 (See "Petrochemical Analysis Methods (RIPP Test Methods)" Ed. by Cuiding YANG et al., Science Press, September 1990. , pages 424-426), the total pore volume of the molecular sieve was determined based on the adsorption isotherm, and then the micropore volume of the molecular sieve was determined based on the adsorption isotherm according to the T plot method, and the pore volume for the secondary pores was obtained by subtracting the micropore volume from the total pore volume .

The following examples 1-8 relate to the production of a modified Y-type molecular sieve and a catalytic cracking catalyst according to the present application.

Example 1

2000 kg (dry mass) of NaY zeolite having a framework ratio of SiO ₂ /Al ₂ O ₃ of 4.6 and a sodium oxide content of 13.5% by mass (manufactured by Qilu Branch of Sinopec Catalyst Co., Ltd.) , was added to the primary exchange tank containing 20 m ³ water, and mixed until homogeneous at 25°C. Then, 600 L of RECl ₃ solution was added (the concentration of the rare earth element in terms of RE ₂₃ in the RECl ₃ solution was 319 g/l), stirred for 60 minutes, filtered and washed, and the filter cake was continuously sent to the spray drying oven for drying ; obtained a rare earth-modified Y-type molecular sieve having a normal lattice parameter and a reduced sodium oxide content, which had a sodium oxide content of 7.0% by mass, a lattice parameter of 2.471 nm, and a content of rare earth elements of 8.8% by mass, based on oxide. It was then sent to a calciner for modification by calcining at a controlled temperature of 390° C. in an atmosphere of 50% steam (atmosphere containing 50 vol% steam) for 6 hours; then, the molecular sieve material was introduced into a calcining and drying kiln at a controlled temperature of 500° C. in a dry air atmosphere (containing less than 1 vol% of steam) for 2.5 hours to obtain a Y-type molecular sieve having a reduced crystallinity parameter. lattice, a water content of less than 1% by weight, and a crystal lattice parameter of 2.455 nm. Thereafter, the Y-type molecular sieve material having a reduced crystal lattice parameter was directly sent to a continuous ultra-stabilization gas-phase reactor for ultra-stabilization in the gas phase. The gas-phase ultra-stabilization process of the molecular sieve in the continuous ultra-stabilization gas-phase reactor and the subsequent exhaust gas absorption process were carried out according to the method described in Example 1 of PRC Patent Application Publication No. CN 103787352 A, under the following conditions: the mass ratio of SiCl ₄ and zeolite Y was 0.5:1, the feed rate of the molecular sieve was 800 kg/h, and the reaction temperature was 400°C. The molecular sieve material obtained after the ultra-stabilization in the gas phase was separated by a gas-solid separator, sent to a secondary exchange tank containing 20 m ³ of water added in advance, and mixed until homogeneous. The weight of the molecular sieve material added to the secondary exchange tank was 2000 kg (weight on a dry matter basis). After that, 0.6 m ³ of a solution of 10 wt. % hydrochloric acid, the reaction mixture was heated to 90°C, and stirring was continued for 60 minutes; then, 140 kg of citric acid was added, and stirring was continued at 90° C. for 60 minutes, followed by filtration and washing. Thereafter, the filter cake of the molecular sieve was directly added to the solution containing ammonium phosphate, and the molecular sieve was added in such an amount that the mass ratio of phosphorus (in terms of P ₂ O ₅ ) and molecular sieve was 0.04, and the mass ratio of water and molecular sieve sieve was 2.5, and the reaction was carried out at a temperature of 50°C for 60 minutes, and then carried out by filtering and washing. After that, the filter cake was added to 4000 l of a solution containing 71.33 kg of dissolved Ga(NO ₃ ) ₃ ⋅9H ₂ O to impregnate it with a gallium component, the modified molecular sieve type Y and the solution containing Ga(NO ₃ ) ₃ were mixed until homogeneous and left to stand at room temperature to soak for 24 hours, and then a suspension containing a modified molecular sieve type Y and Ga(NO ₃ ) ₃ was further stirred for 20 minutes to obtain a homogeneous mixture. The mixture was then transferred to a rotary evaporator and evaporated to dryness with slow and uniform rotation and heating. Thereafter, the dried material was placed in a muffle furnace and calcined at 550°C for 2.5 hours to obtain a Y-type molecular sieve enriched in secondary pores and subjected to combined modification, which was designated SZ1.

Table 1-1 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the SZ1 molecular sieve.

After pure molecular sieve SZ1 was aged at a temperature of 800°C and atmospheric pressure in an atmosphere of 100 vol.% steam for 17 hours, the relative degree of crystallinity of molecular sieve SZ1 before and after aging was analyzed by X-ray diffraction analysis, and also calculated preservation of the relative degree of crystallinity after aging. The results are presented in table 2, while:

retention of relative crystallinity=(relative crystallinity of aged sample/relative crystallinity of fresh sample)×100%.

714.5 g of an alumina sol having an alumina content of 21% by mass was added to 1565.5 g of deionized water, stirring was started, and 2763 g of kaolin having a solids content of 76% by mass was added and dispersed for 60 minutes .2049 g of pseudoboehmite having an alumina content of 61% by mass was added to 8146 g of deionized water, and 210 ml of a 36% hydrochloric acid solution was added under stirring conditions. After acid treatment for 60 minutes, a slurry of dispersed kaolin was added, then 1500 g (on a dry matter basis) of finely ground molecular sieve SZ1 was added and mixed until homogeneous, followed by spray drying, washing and drying to obtain a catalyst designated SCl . SCl The catalyst thus obtained contained 30% by weight of SZl molecular sieve, 42% by weight of kaolin, 25% by weight of pseudoboehmite and 3% by weight of alumina sol.

Example 2

2000 kg (dry mass) of NaY zeolite having a framework ratio of SiO ₂ /Al ₂ O ₃ of 4.6 and a sodium oxide content of 13.5% by mass (manufactured by Qilu Branch of Sinopec Catalyst Co., Ltd.) , was added to the primary exchange tank containing 20 m ³ deionized water, and mixed until homogeneous at a temperature of 90°C. Then, 800 L of RECl ₃ solution was added (the concentration of the rare earth element in terms of RE ₂ O ₃ in the RECl ₃ solution was 319 g/l), stirred for 60 minutes, filtered and washed, and the filter cake was sent to a spray drying oven for drying; a rare earth-modified Y-type molecular sieve having a normal lattice parameter and a reduced sodium oxide content, which had a sodium oxide content of 5.5% by mass, a lattice parameter of 2.471 nm, and a rare earth content of 11.3% by mass, based on oxide. Then it was sent to a calcining furnace and subjected to calcination at a temperature (atmosphere temperature) of 450°C in an atmosphere of 80% steam for 5.5 hours; then, the molecular sieve material was introduced into a calcining and drying kiln at a controlled temperature of 500°C in a dry air atmosphere for 2 hours to obtain a Y-type molecular sieve having a reduced crystal lattice parameter, a water content of less than 1% by mass, and a parameter crystal lattice 2.461 nm. Thereafter, the Y-type molecular sieve having a reduced crystal lattice parameter was directly sent to a continuous ultra-stabilization gas-phase reactor for ultra-stabilization in the gas phase. The gas-phase ultra-stabilization process of the molecular sieve in the continuous ultra-stabilization gas-phase reactor and the subsequent exhaust gas absorption process were carried out according to the method described in Example 1 of PRC Patent Application Publication No. CN 103787352 A, under the following conditions: the mass ratio of SiCl ₄ and zeolite Y was 0.25:1, the feed rate of the molecular sieve was 800 kg/h, and the reaction temperature was 490°C. The molecular sieve material obtained after the ultra-stabilization in the gas phase was separated at the gas-solid separator and sent to a secondary exchange tank containing 20 m ³ of water added in advance and mixed until homogeneous. The weight of the molecular sieve material added to the secondary exchange tank was 2000 kg (weight on a dry matter basis). After that, 0.9 m ³ of a solution of 7 wt. % sulfuric acid, and the reaction mixture was heated to 93°C, followed by stirring for 80 minutes; then, 70 kg of citric acid and 50 kg of tartaric acid were added, and stirring was continued at 93° C. for 70 minutes, and then filtering and washing were carried out. Thereafter, the filter cake of the molecular sieve was directly added to the solution containing ammonium hydrogen phosphate, and the molecular sieve was added in such an amount that the mass ratio of phosphorus (in terms of P ₂ O ₅ ) and molecular sieve was 0.03, and the mass ratio of water and molecular sieve sieve was 3.0, and the reaction was carried out at a temperature of 60°C for 50 minutes, and then carried out by filtering and washing. After that, the filter cake was added to 4500 l of a solution containing 133.74 kg of dissolved Ga(NO ₃ ) ₃ ⋅9H ₂ O to impregnate it with a gallium component, the modified molecular sieve type Y and the solution containing Ga(NO ₃ ) ₃ were mixed until homogeneous and left to stand at room temperature to soak for 24 hours, and then a suspension containing a modified molecular sieve type Y and Ga(NO ₃ ) ₃ was further stirred for 20 minutes to obtain a homogeneous mixture. The mixture was then transferred to a rotary evaporator and evaporated to dryness with slow and uniform rotation and heating. Thereafter, the dried material was placed in a muffle furnace and calcined at a temperature of 500° C. for 3 hours to obtain a Y-type molecular sieve enriched in secondary pores and subjected to combined modification, which was designated SZ2.

Table 1-1 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the SZ2 molecular sieve.

After pure SZ2 molecular sieve was aged at 800° C. in 100 vol% steam for 17 hours, the degree of crystallinity of SZ2 molecular sieve before and after aging was analyzed by XRD, and the retention of the relative degree of crystallinity was calculated. after aging. The results are presented in table 2.

The catalytic cracking catalyst was prepared according to the method described in Example 1: SZ2 molecular sieve, kaolin, water, pseudoboehmite-based binder and alumina sol were suspended and spray dried according to the method conventionally used to prepare catalytic cracking catalyst to obtain a catalyst in the form of microspheres. The resulting catalytic cracking catalyst was designated SC2. The resulting SC2 catalyst contained 30% by weight of SZ2 molecular sieve, 42% by weight of kaolin, 25% by weight of pseudoboehmite, and 3% by weight of alumina sol.

Example 3

2000 kg (dry mass) of NaY zeolite having a framework ratio of SiO ₂ /Al ₂ O ₃ of 4.6 and a sodium oxide content of 13.5% by mass (manufactured by Qilu Branch of Sinopec Catalyst Co., Ltd.) , was added to the primary exchange tank containing 20 m ³ deionized water, and mixed until homogeneous at a temperature of 95°C. Then, 570 L of RECl ₃ solution was added (the concentration of the rare earth element in terms of RE ₂ O ₃ in the RECl ₃ solution was 319 g/l), stirred for 60 minutes, filtered and washed, and the filter cake was continuously sent to the spray drying oven for drying; obtained a rare earth-modified Y-type molecular sieve having a normal lattice parameter and a reduced sodium oxide content, which had a sodium oxide content of 7.5% by mass, a crystal lattice parameter of 2.471 nm, and a content of rare earth elements of 8.5% by mass, based on oxide. It was then sent to a hydrothermal modification calciner by calcining at a temperature of 470° C. in an atmosphere containing 70 vol% steam for 5 hours; then, the molecular sieve material was introduced into a calcining and drying kiln at a controlled temperature of 500°C in a dry air atmosphere for 1.5 hours to obtain a Y-type molecular sieve having a reduced crystal lattice parameter, a water content of less than 1% by mass and a crystal lattice parameter of 2.458 nm. Thereafter, the Y-type molecular sieve material having a reduced crystal lattice parameter was sent to a continuous ultra-stabilization gas-phase reactor for ultra-stabilization in the gas phase. The gas-phase ultra-stabilization process of a molecular sieve in a continuous ultra-stabilization gas-phase reactor and the subsequent off-gas absorption process was carried out in accordance with the method described in Example 1 of PRC Patent Application Publication No. CN 103787352 A, under the following conditions: the mass ratio of SiCl ₄ and Y-type zeolite was 0.45:1, the feed rate of the molecular sieve was 800 kg/h, and the reaction temperature was 400°C. The molecular sieve material obtained after the ultra-stabilization in the gas phase was separated at the gas-solid separator and sent to a secondary exchange tank containing 20 m ³ deionized water added in advance and mixed until homogeneous. The weight of the molecular sieve material added to the secondary exchange tank was 2000 kg (weight on a dry matter basis). After that, 1.2 m ³ of a solution of 5 wt. % nitric acid, and the reaction mixture was heated to 95°C and stirred for 90 minutes; then, 90 kg of citric acid and 40 kg of oxalic acid were added, and the mixture was stirred at 93° C. for 70 minutes, and then filtered and washed. The molecular sieve filter cake was directly added to the ammonium phosphate-containing solution, the molecular sieve being added in such an amount that the weight ratio of phosphorus (expressed as P ₂ O ₅ ) and molecular sieve was 0.015, and the weight ratio of water to molecular sieve was 2, 8, and the reaction was carried out at 70° C. for 30 minutes, and then filtering and washing were carried out. After that, the filter cake was added to 4800 l of a solution containing 178.32 kg of dissolved Ga(NO ₃ ) ₃ ⋅9H ₂ O to impregnate it with a gallium component, the modified molecular sieve type Y and the solution containing Ga(NO ₃ ) ₃ were mixed until homogeneous and left to stand at room temperature to soak for 24 hours, and then a suspension containing a modified molecular sieve type Y and Ga(NO ₃ ) ₃ was further stirred for 20 minutes to obtain a homogeneous mixture. After that, the mixture was transferred to a rotary evaporator and evaporated to dryness during slow and uniform rotation and heating. Thereafter, the dried material was placed in a muffle furnace and calcined at a temperature of 600° C. for 2 hours to obtain a Y-type molecular sieve enriched in secondary pores and subjected to combined modification, which was designated SZ3.

Table 1-1 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the SZ3 molecular sieve.

After pure SZ3 molecular sieve was aged at 800° C. in 100 vol% steam for 17 hours, the degree of crystallinity of SZ3 molecular sieve before and after aging was analyzed by XRD, and the retention of the relative degree of crystallinity was calculated. after aging. The results are presented in table 2.

The catalytic cracking catalyst was prepared according to the method described in Example 1: SZ3 molecular sieve, kaolin, water, pseudoboehmite-based binder and alumina sol were suspended and spray dried according to the method conventionally used to prepare catalytic cracking catalyst to obtain a catalyst in the form of microspheres. The resulting catalytic cracking catalyst was designated SC3. The resulting SC3 catalyst contained 30% by weight SZ3 molecular sieve, 42% by weight kaolin, 25% by weight pseudoboehmite and 3% by weight alumina sol.

Example 4

2000 kg (dry mass) of NaY zeolite having a framework ratio of SiO ₂ /Al ₂ O ₃ of 4.6 and a sodium oxide content of 13.5% by mass (manufactured by Qilu Branch of Sinopec Catalyst Co., Ltd.) , was added to the primary exchange tank containing 20 m ³ water, and mixed until homogeneous at 25°C. Then 600 l of RECl ₃ solution was added (the concentration of the rare earth element in terms of RE ₂ O ₃ in the RECl ₃ solution was 319 g/l), stirring was continued for 60 minutes, filtered, washed and the filter cake was sent to a spray drying oven for drying; obtained a rare earth-modified Y-type molecular sieve having a normal lattice parameter and a reduced sodium oxide content, which had a sodium oxide content of 7.0% by mass, a lattice parameter of 2.471 nm, and a content of rare earth elements of 8.8% by mass, based on oxide. Then it was sent to a calcining furnace and subjected to calcination at a temperature of 390°C in an atmosphere of 50% steam (atmosphere containing 50 vol.% steam) for 6 hours; then subjected to calcination at a temperature of 500° C. in a dry air atmosphere (containing less than 1 vol% steam) for 2.5 hours to obtain a Y-type molecular sieve having a reduced crystal lattice parameter, a water content of less than 1% by mass and a crystal lattice parameter of 2.455 nm. Thereafter, the Y-type molecular sieve material having a reduced crystal lattice parameter was directly sent to a continuous ultra-stabilization gas-phase reactor for ultra-stabilization in the gas phase. The gas-phase ultra-stabilization process of a molecular sieve in a continuous ultra-stabilization gas-phase reactor and the subsequent off-gas absorption process was carried out in accordance with the method described in Example 1 of PRC Patent Application Publication No. CN 103787352 A, under the following conditions: the mass ratio of SiCl ₄ and Y-type zeolite was 0.5:1, the feed rate of the molecular sieve was 800 kg/h, and the reaction temperature was 400°C. The molecular sieve material obtained after the ultra-stabilization in the gas phase was separated by a gas-solid separator, sent to a secondary exchange tank containing 20 m ³ of water added in advance, and mixed until homogeneous. The weight of the molecular sieve material added to the secondary exchange tank was 2000 kg (weight on a dry matter basis). After that was added 0.6 m ³ solution of 10 wt. % hydrochloric acid, and the reaction mixture was heated to 90° C., stirred for 60 minutes, then 140 kg of citric acid was added, and stirring was continued at 90° C. for 60 minutes, and then filtering and washing were carried out. The molecular sieve filter cake was directly added to the ammonium phosphate-containing solution, the molecular sieve being added in such an amount that the weight ratio of phosphorus (expressed as P ₂ O ₅ ) to molecular sieve was 0.04, and the weight ratio of water to molecular sieve was 2.5, and the reaction was carried out at a temperature of 50°C for 60 minutes, and then filtering and washing were carried out. After that, the filter cake was added to the exchange tank, 5 m ³ of deionized water was added, then the molecular sieve suspension was heated to 65°C, then 12.46 kg of boric acid was added, stirred for 1 hour, filtered, and then the filter cake was added to 4000 l of a solution containing 42.8 kg of dissolved Ga(NO ₃ ) ₃ ⋅9H ₂ O, under stirring conditions to impregnate it with a gallium component, a modified Y-type molecular sieve, and a solution containing Ga(NO ₃ ) ₃ were stirred until homogeneous and left to stand at room temperature to soak for 24 hours, and then a suspension containing a modified molecular sieve type Y and Ga(NO ₃ ) ₃ was further stirred for 20 minutes to obtain a homogeneous mixture. After that, the suspension was transferred to a rotary evaporator and evaporated to dryness during rotation while heating in a water bath. Thereafter, the dried material was placed in a muffle furnace and calcined at 550° C. for 2.5 hours to obtain a modified Y-type molecular sieve product designated SZ4.

Table 1-1 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the SZ4 molecular sieve.

After pure SZ4 molecular sieve was aged at a temperature of 800°C and atmospheric pressure in an atmosphere of 100 vol.% steam for 17 hours, the relative degree of crystallinity of SZ4 molecular sieve before and after aging was analyzed by XRD, and also calculated preservation of the relative degree of crystallinity after aging. The results are presented in table 2.

The catalytic cracking catalyst was prepared according to the method described in Example 1: SZ4 molecular sieve, kaolin, water, pseudoboehmite-based binder and alumina sol were suspended and spray dried according to the method conventionally used to prepare catalytic cracking catalyst to obtain a catalyst in the form of microspheres. The resulting catalytic cracking catalyst was designated SC4. The resulting SC4 catalyst contained 30% by weight SZ4 molecular sieve, 42% by weight kaolin, 25% by weight pseudoboehmite and 3% by weight alumina sol.

Example 5

2000 kg (dry mass) of NaY zeolite having a framework ratio of SiO ₄ /Al ₂ O ₃ of 4.6 and a sodium oxide content of 13.5% by mass (manufactured by Qilu Branch of Sinopec Catalyst Co., Ltd.) , was added to the primary exchange tank containing 20 m3 of water and mixed until homogeneous at 25°C. Then, 600 L of RECl ₃ solution was added (the concentration of the rare earth element in terms of RE ₂ O ₃ in the RECl ₃ solution was 319 g/l), stirred for 60 minutes, filtered and washed, and the filter cake was continuously sent to the spray drying oven for drying; obtained a rare earth-modified Y-type molecular sieve having a normal lattice parameter and a reduced sodium oxide content, which had a sodium oxide content of 7.0% by mass, a lattice parameter of 2.471 nm, and a content of rare earth elements of 8.8% by mass, based on oxide. It was then sent to a calciner for modification by calcining at a controlled temperature of 390° C. in an atmosphere of 50% steam (atmosphere containing 50 vol% steam) for 6 hours; then, the molecular sieve material was introduced into a calcining and drying kiln at a controlled temperature of 500° C. in a dry air atmosphere (containing less than 1 vol% of steam) for 2.5 hours to obtain a Y-type molecular sieve having a reduced crystallinity parameter. lattice, a water content of less than 1% by weight, and a crystal lattice parameter of 2.455 nm. Thereafter, the Y-type molecular sieve material having a reduced crystal lattice parameter was directly sent to a continuous ultra-stabilization gas-phase reactor for ultra-stabilization in the gas phase. The gas-phase ultra-stabilization process of the molecular sieve in the continuous ultra-stabilization gas-phase reactor and the subsequent exhaust gas absorption process were carried out according to the method described in Example 1 of PRC Patent Application Publication No. CN 103787352 A, under the following conditions: the mass ratio of SiCl ₄ and zeolite Y was 0.5:1, the feed rate of the molecular sieve was 800 kg/h, and the reaction temperature was 400°C. The molecular sieve material obtained after the ultra-stabilization in the gas phase was separated on a gas-solid separator, sent to a secondary exchange tank containing 20 m3 of water added in advance, and mixed until homogeneous. The weight of the molecular sieve material added to the secondary exchange tank was 2000 kg (weight on a dry matter basis). After that, 0.6 m ³ of a solution of 10 wt. % hydrochloric acid, the reaction mixture was heated to 90°C, and stirring was continued for 60 minutes; then, 140 kg of citric acid was added, and stirring was continued at 90° C. for 60 minutes, followed by filtration and washing. Thereafter, the filter cake of the molecular sieve was directly added to the solution containing ammonium phosphate, and the molecular sieve was added in such an amount that the mass ratio of phosphorus (in terms of P ₂ O ₅ ) and molecular sieve was 0.04, and the mass ratio of water and molecular sieve sieve was 2.5, and the reaction was carried out at a temperature of 50°C for 60 minutes, and then carried out by filtering and washing. After that, the filter cake was added to the exchange tank, 5000 L of deionized water was added, and then the molecular sieve suspension was heated to 65°C, and then 17.8 kg of boric acid was added (the ratio of B ₂ O ₃ and molecular sieve was 1:100), stirred for 1 hour and then filtered, and the filtered molecular sieve was first dried at 130°C for 5 hours and then calcined at 400C for 2.5 hours to obtain a Y-type molecular sieve, which was subjected to combined modification, designated SZ5.

Table 1-1 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the SZ5 molecular sieve.

After pure SZ5 molecular sieve was aged at 800°C and atmospheric pressure in 100 vol% steam for 17 hours, the relative degree of crystallinity of SZ5 molecular sieve before and after aging was analyzed by XRD and calculated preservation of the relative degree of crystallinity after aging. The results are presented in table 2, while:

retention of relative crystallinity=(relative crystallinity of aged sample/relative crystallinity of fresh sample)×100%.

714.5 g of an alumina sol having an alumina content of 21% by mass was added to 1565.5 g of deionized water, stirring was started, and 2763 g of kaolin having a solids content of 76% by mass was added and dispersed for 60 minutes .2049 g of pseudoboehmite having an alumina content of 61% by mass was added to 8146 g of deionized water, and 210 ml of a 36% hydrochloric acid solution was added under stirring conditions. After acid treatment for 60 minutes, a slurry of dispersed kaolin was added, then 1500 g (based on dry matter) of finely divided SZ5 molecular sieve was added and mixed until homogeneous, followed by spray drying, washing and drying to obtain a catalyst designated SC5 . The SC5 catalyst thus prepared contained 30% by weight of SZ5 molecular sieve, 42% by weight of kaolin, 25% by weight of pseudoboehmite and 3% by weight of alumina sol. Example 6

2000 kg (dry mass) of NaY zeolite having a framework ratio of SiO ₂ /Al ₂ O ₃ of 4.6 and a sodium oxide content of 13.5% by mass (manufactured by Qilu Branch of Sinopec Catalyst Co., Ltd.) , was added to the primary exchange tank containing 20 m ³ deionized water, and mixed until homogeneous at a temperature of 95°C. Then 570 L of RECl ₃ solution (rare earth element concentration in terms of RE ₂ O ₃ in RECl ₃ solution was 319 g/l) was added, stirred for 60 minutes, filtered and washed, and the filter cake was continuously sent to the spray drying oven for drying; obtained a rare earth-modified Y-type molecular sieve having a normal lattice parameter and a reduced sodium oxide content, which had a sodium oxide content of 7.5% by mass, a crystal lattice parameter of 2.471 nm, and a content of rare earth elements of 8.5% by mass, based on oxide. It was then sent to a hydrothermal modification calciner by calcining at a temperature of 470° C. in an atmosphere containing 70 vol% steam for 5 hours; then, the molecular sieve material was introduced into a calcining and drying kiln at a controlled temperature of 500°C in a dry air atmosphere for 1.5 hours to obtain a Y-type molecular sieve having a reduced crystal lattice parameter, a water content of less than 1% by mass and a crystal lattice parameter of 2.458 nm. Thereafter, the Y-type molecular sieve material having a reduced crystal lattice parameter was sent to a continuous ultra-stabilization gas-phase reactor for ultra-stabilization in the gas phase. The gas-phase ultra-stabilization process of a molecular sieve in a continuous ultra-stabilization gas-phase reactor and the subsequent off-gas absorption process was carried out in accordance with the method described in Example 1 of PRC Patent Application Publication No. CN 103787352 A, under the following conditions: the mass ratio of SiCl ₄ and Y-type zeolite was 0.45:1, the feed rate of the molecular sieve was 800 kg/h, and the reaction temperature was 400°C. The molecular sieve material obtained after the ultra-stabilization in the gas phase was separated at the gas-solid separator and sent to a secondary exchange tank containing 20 m ³ of water added in advance and mixed until homogeneous. The weight of the molecular sieve material added to the secondary exchange tank was 2000 kg (weight on a dry matter basis). After that, 1.2 m ³ of a solution of 5 wt. % nitric acid, and the reaction mixture was heated to 95°°C and stirred for 90 minutes; then, 90 kg of citric acid and 40 kg of oxalic acid were added, and the mixture was stirred at 93° C. for 70 minutes, and then filtered and washed. The molecular sieve filter cake was directly added to the ammonium phosphate-containing solution, the molecular sieve being added in such an amount that the weight ratio of phosphorus (expressed as P ₂ O ₅ ) and molecular sieve was 0.015, and the weight ratio of water to molecular sieve was 2, 8, and the reaction was carried out at 70° C. for 30 minutes, and then filtering and washing were carried out. After that, the filter cake was added to the exchange tank, 5000 L of deionized water was added, then the molecular sieve suspension was heated at a temperature of 60 to 99°C, and then 71.2 kg of boric acid was added (the ratio of B ₂ O ₃ and molecular sieve was 4: 100), stirred for 1 hour, and then filtered, and the filtered molecular sieve was first dried at 130°C for 5 hours, and then calcined at 500°C for 2 hours, to obtain an ultra-stable Y-type molecular sieve, which was subjected to a combined modification, designated SZ6.

Table 1-1 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the SZ6 molecular sieve.

After pure SZ6 molecular sieve was aged at 800° C. in 100 vol% steam for 17 hours, the degree of crystallinity of SZ6 molecular sieve before and after aging was analyzed by XRD, and the retention of the relative degree of crystallinity was calculated. after aging. The results are presented in table 2.

The catalytic cracking catalyst was prepared according to the method described in Example 1: SZ6 molecular sieve, kaolin, water, pseudoboehmite-based binder and alumina sol were suspended and spray dried according to the method conventionally used to prepare catalytic cracking catalyst to obtain a catalyst in the form of microspheres. The resulting catalytic cracking catalyst was designated SC6. The resulting SC6 catalyst contained 30 wt % SZ6 molecular sieve, 42 wt % kaolin, 25 wt % pseudoboehmite, and 3 wt % alumina sol.

Comparative Examples 1-6 below relate to the preparation of modified Y-type molecular sieves and catalytic cracking catalysts other than those proposed in the present application.

Comparative Example 1

2000 g of NaY molecular sieve (in terms of dry matter) was added to 20 l of deionized water, stirred until homogeneous, and 1000 g of (NH ₄ ) ₂ SO ₄ was added to the mixture, stirred and heated at a temperature of from 90 to 95 ° C in within 1 hour. The mixture was then filtered and washed, and the filter cake was dried at a temperature of 120°C, and then subjected to hydrothermal modification treatment by roasting at a temperature of 650°C in an atmosphere of 100% steam for 5 hours. The resulting product was then added to 20 L of deionized water, stirred until homogeneous, and 1000 g of (NH ₄ ) ₂ SO ₄ was added to the mixture, stirred and heated at 90 to 95° C. for 1 hour. Then, after filtering and washing, the filter cake was dried at 120°C and further subjected to a second hydrothermal modification treatment by calcining at 650°C under 100% steam for 5 hours to obtain hydrothermal ultra-stabilized Y-type molecular sieve free of rare earth elements. , and which was subjected to two stages of ion exchange and two stages of hydrothermal ultra-stabilization and is designated DZ1.

Table 1-2 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the DZ1 molecular sieve.

After pure DZ1 molecular sieve was aged at 800° C. in 100 vol% steam for 17 hours, the degree of crystallinity of DZ1 molecular sieve before and after aging was analyzed by XRD, and the retention of the relative degree of crystallinity was calculated. after aging. The results are presented in table 2.

Molecular sieve DZ1, kaolin, water, pseudoboehmite binder and alumina sol were suspended and spray dried according to the method conventionally used to prepare a catalytic cracking catalyst to obtain a microsphere-shaped catalyst designated DC1 (see the method described in Example 1). The resulting DC1 catalyst contained 30% by weight of DZ1 molecular sieve, 42% by weight of kaolin, 25% by weight of pseudoboehmite, and 3% by weight of alumina sol.

Comparative Example 2

2000 g of NaY molecular sieve (in terms of dry matter) was added to 20 l of deionized water, stirred until homogeneous, and 1000 g of (NH ₄ ) ₂ SO ₄ was added to the mixture, stirred and heated at a temperature of from 90 to 95 ° C in within 1 hour. The mixture was then filtered and washed, and the filter cake was dried at a temperature of 120°C, and then subjected to hydrothermal modification treatment by roasting at a temperature of 650C in an atmosphere of 100% steam for 5 hours. Then the resulting product was added to 20 l of deionized water, stirred until homogeneous, 200 ml of a solution of RE(NO ₃ ) ₃ (concentration was 319 g/l in terms of RE ₂ O ₃ ) and 900 g (NH ₄ ) ₂ SO ₄ , stirred and heated at a temperature of from 90 to 95°C for 1 hour. Then, after filtering and washing, the filter cake was dried at 120°C and further subjected to a second hydrothermal modification treatment by calcining at 650°C under 100% steam for 5 hours to obtain a hydrothermally ultra-stabilized Y-type molecular sieve containing a rare earth element, which was subjected to two stages of ion exchange and two stages of hydrothermal ultra-stabilization and designated DZ2.

Table 1-2 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the DZ2 molecular sieve.

After pure DZ2 molecular sieve was aged at 800° C. in 100 vol% steam for 17 hours, the degree of crystallinity of DZ2 molecular sieve before and after aging was analyzed by XRD, and the retention of the relative degree of crystallinity was calculated. after aging. The results are presented in table 2.

DZ2 molecular sieve, kaolin, water, pseudoboehmite binder, and alumina sol were suspended and spray dried according to the method conventionally used to prepare a catalytic cracking catalyst to obtain a microsphere-shaped catalyst designated DC2 (see the method described in Example 1). The resulting DC2 catalyst contained, on a dry matter basis, 30% by weight of DZ2 molecular sieve, 42% by weight of kaolin, 25% by weight of pseudoboehmite, and 3% by weight of alumina sol.

Comparative Example 3

2000 kg of NaY molecular sieve (in terms of dry matter) was added to 20 m ³ of water, stirred until homogeneous, 650 l of RE(NO ₃ ) ₃ solution were added to the mixture, mixed and heated at a temperature of from 90 to 95°C for 1 hour. Then, the mixture was filtered and washed, and the filter cake was sent to a spray calciner for calcination and drying at a controlled temperature of 500° C. under dry air for 2 hours, so that the water content was reduced to less than 1% by mass. The dried molecular sieve material was then sent to a continuous ultra-stabilization gas phase reactor for ultra-stabilization in the gas phase. The gas-phase ultra-stabilization process of the molecular sieve in the continuous ultra-stabilization gas-phase reactor and the subsequent off-gas absorption process were carried out in accordance with the method described in Example 1 of PRC Patent Application Publication No. CN103787352A under the following conditions: the mass ratio of SiCl ₄ and Y-type zeolite was 0, 4:1, the feed rate of the molecular sieve was 800 kg/h, and the reaction temperature was 580°C. The molecular sieve material obtained after the ultra-stabilization in the gas phase was separated by a gas-solid separator, sent to a secondary exchange tank containing 20 m ³ of water added in advance, and mixed until homogeneous. The weight of the molecular sieve material added to the secondary exchange tank was 2000 kg (weight on a dry matter basis). After that, 1.2 m ³ solution of 5 wt. % nitric acid, heated to a temperature of 95°C, and stirring was continued for 90 minutes; then, 90 kg of citric acid and 40 kg of oxalic acid were added, and stirring was continued at 93° C. for 70 minutes, followed by filtration and washing. Thereafter, the molecular sieve filter cake was directly added to the ammonium phosphate-containing solution, the molecular sieve being added in such an amount that the weight ratio of phosphorus (expressed as P ₂ O ₅ ) and molecular sieve was 0.015, and the weight ratio of water to molecular sieve was 2.8, and the reaction was carried out at 70° C. for 30 minutes, followed by filtration, washing and drying to obtain a molecular sieve designated DZ3.

Table 1-2 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the DZ3 molecular sieve.

After the pure DZ3 molecular sieve was aged at 800° C. in 100 vol% steam for 17 hours, the degree of crystallinity of the DZ3 molecular sieve before and after aging was analyzed by XRD, and the retention of the relative degree of crystallinity was calculated. after aging. The results are presented in table 2.

DZ3 molecular sieve, kaolin, water, pseudoboehmite binder, and alumina sol were suspended and spray dried according to the method conventionally used to prepare a catalytic cracking catalyst to obtain a microsphere-shaped catalyst designated DC3 (see the method described in Example 1). The resulting DC3 catalyst contained 30% by weight of DZ3 molecular sieve, 42% by weight of kaolin, 25% by weight of pseudoboehmite, and 3% by weight of alumina sol.

Comparative Example 4

2000 kg (dry mass) of NaY zeolite having a framework ratio of SiO ₂ /Al ₂ O ₃ of 4.6 and a sodium oxide content of 13.5% by mass (manufactured by Qilu Branch of Sinopec Catalyst Co., Ltd.) , was added to the primary exchange tank containing 20 m ³ water, and mixed until homogeneous at 25°C. Then, 600 L of RECl ₃ solution was added (the concentration of the rare earth element in terms of RE ₂ O ₃ in the RECl ₃ solution was 319 g/l), stirred for 60 minutes, filtered and washed, and the filter cake was continuously sent to the spray drying oven for drying; obtained a rare earth-modified Y-type molecular sieve having a normal lattice parameter and a reduced sodium oxide content, which had a sodium oxide content of 7.0% by mass, a lattice parameter of 2.471 nm, and a content of rare earth elements of 8.8% by mass, based on oxide. It was then sent to a calciner for modification by calcining at a controlled temperature of 390° C. in an atmosphere of 50% steam (atmosphere containing 50 vol% steam) for 6 hours; then, the molecular sieve material was introduced into a calcining and drying kiln at a controlled temperature of 500° C. in a dry air atmosphere (containing less than 1 vol% of steam) for 2.5 hours to obtain a Y-type molecular sieve having a reduced crystallinity parameter. lattice, a water content of less than 1% by weight, and a crystal lattice parameter of 2.455 nm. Thereafter, the Y-type molecular sieve material having a reduced crystal lattice parameter was directly sent to a continuous ultra-stabilization gas-phase reactor for ultra-stabilization in the gas phase. The gas-phase ultra-stabilization process of the molecular sieve in the continuous ultra-stabilization gas-phase reactor and the subsequent exhaust gas absorption process were carried out according to the method described in Example 1 of PRC Patent Application Publication No. CN 103787352 A, under the following conditions: the mass ratio of SiCl ₄ and zeolite Y was 0.5:1, the feed rate of the molecular sieve was 800 kg/h, and the reaction temperature was 400°C. The molecular sieve material obtained after the ultra-stabilization in the gas phase was separated by a gas-solid separator, sent to a secondary exchange tank containing 20 m ³ of water added in advance, and mixed until homogeneous. The weight of the molecular sieve material added to the secondary exchange tank was 2000 kg (weight on a dry matter basis). After that, 0.6 m ³ of a solution of 10 wt. % hydrochloric acid, the reaction mixture was heated to 90°C, and stirring was continued for 60 minutes; then, 140 kg of citric acid was added, and stirring was continued at 90° C. for 60 minutes, followed by filtration and washing. Thereafter, the filter cake of the molecular sieve was directly added to the solution containing ammonium phosphate, and the molecular sieve was added in such an amount that the mass ratio of phosphorus (in terms of P ₂ O ₅ ) and molecular sieve was 0.04, and the mass ratio of water and molecular sieve sieve was 2.5, and the reaction was carried out at a temperature of 50°C for 60 minutes, and then filtering and washing were carried out, and the filter cake was dried at a temperature of 120°C to obtain a modified Y-type molecular sieve, designated DZ4.

Table 1-2 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the DZ4 molecular sieve.

After the pure DZ4 molecular sieve was aged at 800° C. in 100 vol% steam for 17 hours, the degree of crystallinity of the DZ4 molecular sieve before and after aging was analyzed by XRD, and the retention of the relative degree of crystallinity after aging was calculated. . The results are presented in table 2.

DZ4 molecular sieve, kaolin, water, pseudoboehmite binder, and alumina sol were suspended and spray dried according to the method conventionally used to prepare a catalytic cracking catalyst to obtain a microsphere-shaped catalyst designated DC4 (see the method described in Example 1). The resulting DC4 catalyst contained 30% by weight of DZ4 molecular sieve, 42% by weight of kaolin, 25% by weight of pseudoboehmite, and 3% by weight of alumina sol.

Comparative Example 5

2000 kg (dry mass) of NaY zeolite having a framework ratio of SiO ₂ /Al ₂ O ₃ of 4.6 and a sodium oxide content of 13.5% by mass (manufactured by Qilu Branch of Sinopec Catalyst Co., Ltd.) , was added to the primary exchange tank containing 20 m ³ water, and mixed until homogeneous at 25°C. Then, 600 l of RECl ₃ solution were added (the concentration of the rare earth element in terms of RE ₂ O ₃ in the RECl ₃ solution was 319 g/l), stirred for 60 minutes, filtered, washed, and the filter cake was continuously sent to a spray drying oven for drying; obtained a rare earth-modified Y-type molecular sieve having a normal lattice parameter and a reduced sodium oxide content, which had a sodium oxide content of 7.0% by mass, a lattice parameter of 2.471 nm, and a content of rare earth elements of 8.8% by mass, based on oxide. It was then sent to a calciner for modification by calcining at a controlled temperature of 390° C. in an atmosphere of 50% steam (atmosphere containing 50 vol% steam) for 6 hours; then, the molecular sieve material was introduced into a calcining and drying kiln at a controlled temperature of 500° C. in a dry air atmosphere (containing less than 1 vol% of steam) for 2.5 hours to obtain a Y-type molecular sieve having a reduced crystallinity parameter. lattice, a water content of less than 1% by weight, and a crystal lattice parameter of 2.455 nm. Thereafter, the Y-type molecular sieve material having a reduced crystal lattice parameter was directly sent to a continuous ultra-stabilization gas-phase reactor for ultra-stabilization in the gas phase. The gas-phase ultra-stabilization process of the molecular sieve in the continuous ultra-stabilization gas-phase reactor and the subsequent exhaust gas absorption process were carried out according to the method described in Example 1 of PRC Patent Application Publication No. CN 103787352 A, under the following conditions: the mass ratio of SiCl ₄ and zeolite Y was 0.5:1, the feed rate of the molecular sieve was 800 kg/h, and the reaction temperature was 400°C. The molecular sieve material obtained after the ultra-stabilization in the gas phase was separated by a gas-solid separator, sent to a secondary exchange tank containing 20 m ³ of water added in advance, and mixed until homogeneous. The weight of the molecular sieve material added to the secondary exchange tank was 2000 kg (weight on a dry matter basis). After that, 0.6 m ³ of a solution of 10 wt. % hydrochloric acid, the reaction mixture was heated to 90°C, and stirring was continued for 60 minutes; then, 140 kg of citric acid was added, and stirring was continued at 90° C. for 60 minutes, followed by filtration and washing. Thereafter, the filter cake of the molecular sieve was directly added to the solution containing ammonium phosphate, and the molecular sieve was added in such an amount that the mass ratio of phosphorus (in terms of P ₂ O ₅ ) and molecular sieve was 0.04, and the mass ratio of water and molecular sieve sieve was 2.5, and the reaction was carried out at a temperature of 50°C for 60 minutes, and then carried out by filtering and washing. After that, the filter cake was added to 4000 L of a solution containing 491 kg of dissolved Ga(NO ₃ ) ₃ ⋅9H ₂ O to impregnate it with a gallium component, and the modified Y-type molecular sieve and the solution containing Ga(NO ₃ ) ₃ were stirred until homogeneous and left to stand at room temperature to soak for 24 hours, and then a suspension containing a modified molecular sieve type Y and Ga(NO ₃ ) ₃ was further stirred for 20 minutes to obtain a homogeneous mixture. After that, the mixture was transferred to a rotary evaporator and evaporated to dryness during slow and uniform rotation and heating. Thereafter, the dried material was placed in a muffle furnace and calcined at 550° C. for 2.5 hours to obtain a Y-type molecular sieve enriched in secondary pores and subjected to combined modification, which was designated DZ5.

Table 1-2 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the DZ5 molecular sieve.

After pure DZ5 molecular sieve was aged at a temperature of 800°C and atmospheric pressure in an atmosphere of 100 vol.% steam for 17 hours, the relative degree of crystallinity of the DZ5 molecular sieve before and after aging was analyzed by XRD, and also calculated preservation of the relative degree of crystallinity after aging. The results are presented in table 2.

DZ5 molecular sieve, kaolin, water, pseudoboehmite binder, and alumina sol were suspended and spray dried according to the method conventionally used to prepare a catalytic cracking catalyst to obtain a microsphere-shaped catalyst designated DC5 (see the method described in Example 1). The resulting DC5 catalyst contained 30% by weight of DZ5 molecular sieve, 42% by weight of kaolin, 25% by weight of pseudoboehmite, and 3% by weight of alumina sol.

Comparative Example 6

2000 kg (dry mass) of NaY zeolite having a framework ratio of SiO ₂ /Al ₂ O ₃ of 4.6 and a sodium oxide content of 13.5% by mass (manufactured by Qilu Branch of Sinopec Catalyst Co., Ltd.) , was added to the primary exchange tank containing 20 m ³ water, and mixed until homogeneous at 25°C. Then 600 l of RECl ₃ solution was added (the concentration of the rare earth element in terms of RE ₂ O ₃ in the RECl ₃ solution was 319 g/l), stirring was continued for 60 minutes, filtered, washed and the filter cake was sent to a spray drying oven for drying; obtained a rare earth-modified Y-type molecular sieve having a normal lattice parameter and a reduced sodium oxide content, which had a sodium oxide content of 7.0% by mass, a lattice parameter of 2.471 nm, and a content of rare earth elements of 8.8% by mass, based on oxide. Then it was sent to a calcining furnace and subjected to calcination at a temperature of 390°C in an atmosphere of 50% steam (atmosphere containing 50 vol.% steam) for 6 hours; then subjected to calcination at a temperature of 500° C. in a dry air atmosphere (containing less than 1 vol% steam) for 2.5 hours to obtain a Y-type molecular sieve having a reduced crystal lattice parameter, a water content of less than 1% by mass and a crystal lattice parameter of 2.455 nm. Thereafter, the Y-type molecular sieve material having a reduced crystal lattice parameter was directly sent to a continuous ultra-stabilization gas-phase reactor for ultra-stabilization in the gas phase. The gas-phase ultra-stabilization process of a molecular sieve in a continuous ultra-stabilization gas-phase reactor and the subsequent off-gas absorption process was carried out in accordance with the method described in Example 1 of PRC Patent Application Publication No. CN 103787352 A, under the following conditions: the mass ratio of SiCl ₄ and Y-type zeolite was 0.5:1, the feed rate of the molecular sieve was 800 kg/h, and the reaction temperature was 400°C. The molecular sieve material obtained after ultra-stabilization in the gas phase was washed with 20 m ³ of deionized water, filtered, and then the filter cake was added to 4000 L of a solution containing 71.33 kg of dissolved Ga(NO ₃ ) ₃ ⋅ 9H ₂ O to impregnate it gallium component, a modified molecular sieve type Y and a solution containing Ga(NO ₃ ) ₃ were stirred until homogeneous and left to stand at room temperature to soak for 24 hours. Then, the suspension containing the modified Y-type molecular sieve and Ga(NO ₃ ) ₃ was further stirred for 20 minutes to obtain a homogeneous mixture. The mixture was then transferred to a rotary evaporator and evaporated to dryness with slow and uniform rotation and heating. Thereafter, the dried material was placed in a muffle furnace and calcined at 550° C. for 2.5 hours to obtain a modified Y-type molecular sieve product designated DZ6.

Table 1-2 lists the composition, lattice parameter, relative degree of crystallinity, ratio of silica to alumina in the framework, lattice breakdown temperature, specific surface area, total pore volume, secondary pore volume, and percentage of secondary pore volume, having a pore size from 2 to 100 nm, and the total pore volume of the DZ6 molecular sieve.

After the pure DZ6 molecular sieve was aged at 800° C. and atmospheric pressure under 100 vol% steam for 17 hours, the relative degree of crystallinity of the DZ6 molecular sieve before and after aging was analyzed by XRD and calculated preservation of the relative degree of crystallinity after aging. The results are presented in table 2.

DZ6 molecular sieve, kaolin, water, pseudoboehmite binder, and alumina sol were suspended and spray dried according to a method conventionally used to prepare a catalytic cracking catalyst to obtain a microsphere-shaped catalyst designated DC6 (see method described in Example 1). The resulting DC5 catalyst contained 30% by weight of DZ6 molecular sieve, 42% by weight of kaolin, 25% by weight of pseudoboehmite, and 3% by weight of alumina sol.

Comparative Example 7

The conventional FCC catalyst used in Example 1 of PRC Publication No. CN 104560187 A was also used in this comparative example and was designated DC7.

Study examples 1-6

Catalytic cracking catalysts obtained in examples 1-6 were investigated, respectively, in relation to their performance characteristics for catalytic cracking.

Cracking performance for hydrogenated LCO processing was evaluated as follows: Catalysts SC1-SC6 were first aged at 800° C. in a 100 vol% steam atmosphere for 12 hours and then they were evaluated in a small fixed fluidized bed reactor to evaluate advanced oil refining (ACE); the original oil was S JZHLCO (hydrogenated LCO) (its properties are presented in table 3); and the reaction temperature was 500°C. The results are presented in Table 4-1.

LCO conversion factor /%=100 - diesel fuel yield - dry gas yield - coke yield - heavy fuel yield.

Comparative study examples 1-7

The catalytic cracking catalysts DC1-DC6 prepared by the methods proposed in Comparative Examples 1 to 6 and the conventional FCC DC7 catalyst prepared in Comparative Example 7 were examined, respectively, for their catalytic cracking performance.

Catalysts DC1-DC7 were first aged at 800° C. in 100 vol% steam for 12 hours and then evaluated using a small fixed fluidized bed (ACE) reactor for their catalytic cracking performance in the processing of hydrogenated LCO. The evaluation method is presented in Study Example 1, the properties of the starting material used in the ACE study are presented in Table 3, and the results are presented in Table 4-2.

LCO conversion factor /%=100 - diesel fuel yield - dry gas yield - coke yield - heavy fuel yield.

As can be seen in Table 1-1 and Table 1-2, the highly stable modified Y-type molecular sieve proposed in the present application has the following advantages: low sodium oxide content, relatively reduced non-framework aluminum content with a relatively high silica to alumina ratio, relatively increased percentage of pore volume of secondary pores having a pore size of 2 to 100 nm and total pore volume, relatively increased ratio of strong Brønsted acid to strong Lewis acid, relatively increased degree of crystallinity, the molecular sieve having a relatively smaller crystal lattice parameter and relatively higher content of rare earth elements and high thermal stability.

As can be seen in Table 2, after pure aging under severe conditions at 800° C. for 17 hours, the samples of the modified Y-type molecular sieve of the present application exhibit a relatively increased retention of the relative degree of crystallinity, and this shows that the modified Y-type molecular sieve proposed in the present application has a high hydrothermal stability.

As can be seen from the results presented in Tables 4-1 and 4-2, the catalytic cracking catalyst proposed in the present application exhibits high hydrothermal stability, significantly reduced coke selectivity, and significantly increased gasoline yield, and BTX (benzene+ toluene + xylene) in gasoline increases significantly.

The preferred embodiments of the present application have been described in detail above, but the present application is not limited to the specific details in the embodiments described above, and various modifications of the technical solutions of the present application can be made without deviating from the inventive concept of the present application. The present application is intended to cover all such modifications.

In addition, it should be noted that the specific technical features described herein above in specific embodiments may be combined in any suitable manner without conflict. For the sake of brevity, these potential combinations are not described individually herein. In addition, any combination of various embodiments of the present application may be made provided that it does not deviate from the idea of the present application, and such combinations should also be considered as part of the disclosure of this application.

Claims (48)

1. Modified Y-type molecular sieve for catalytic cracking of a hydrocarbon feedstock having a rare earth content of from about 4 to about 11% by weight based on oxide, a phosphorus content from about 0.05 to about 10% by weight based on P ₂ O ₅ , a sodium content of not more than about 0.5% by weight based on sodium oxide and an active element content of from about 0.1 to about 5% by weight based on oxide, the active element being gallium and/or boron , in relation to the weight of the modified molecular sieve type Y in terms of dry matter; wherein the modified Y-type molecular sieve has a total pore volume of about 0.36 ml/g to about 0.48 ml/g, a percentage of secondary pore volume having a pore size of 2 to 100 nm, and a total pore volume of about 20% to about 40%; a lattice parameter of about 2.440 nm to about 2.455 nm, a lattice break point of not less than about 1060° C., a percentage of non-framework aluminum to a total aluminum content of not more than about 10%, and a ratio of Bronsted acid to Lewis acid in strong acids contained in the modified molecular sieve type Y, not less than about 3.5. 2. The modified Y-type molecular sieve of claim 1, wherein the modified Y-type molecular sieve has one or more of the following characteristics: the percentage ratio of the pore volume of the secondary pores having a pore size of 2 to 100 nm, and the total pore volume of the modified molecular sieve type Y from about 28% to about 38%; the percentage of non-framework aluminum and total aluminum content of the modified molecular sieve type Y from about 5% to about 9.5%; the ratio of silica to alumina in the framework of the modified Y-type molecular sieve from about 7 to about 14, based on the molar ratio of SiO ₂ /(Al ₂ O ₃ ); the temperature of the destruction of the crystal lattice of the modified molecular sieve type Y from about 1065°C to about 1085°C; the ratio of Bronsted acid and Lewis acid in the composition of strong acids contained in the modified molecular sieve type Y, from about 3.5 to about 6.5 when determined by pyridine adsorption infrared spectroscopy at 350°C; the relative degree of crystallinity of the modified molecular sieve type Y from about 70% to about 80%; and/or retaining a relative degree of crystallinity of the modified Y-type molecular sieve of about 38% or more as determined by X-ray diffraction analysis (XRD) after aging at 800° C. in a 100% steam atmosphere for 17 hours. 3. A modified Y-type molecular sieve according to any one of the preceding claims, wherein the modified Y-type molecular sieve has a rare earth content of from about 4.5 to about 10% by weight based on oxide, a phosphorus content of from about 0.1 to about 6% by weight in terms of P ₂ O ₅ and a sodium content of from about 0.05 to about 0.3% by weight in terms of sodium oxide in relation to the weight of the modified molecular sieve type Y in terms of dry matter; and wherein the modified Y-type molecular sieve has a lattice parameter of about 2.442 nm to about 2.451 nm and a framework silica to alumina ratio of about 8.5 to about 12.6 based on the SiO ₂ /(Al _{2 O3} ); preferably the rare earth element is a rare earth element selected from the group consisting of La, Ce, Pr, Nd, and a combination of two, three or four of these elements; preferably the active element is gallium and the modified Y-type molecular sieve has a gallium content of from about 0.1 to about 3% by weight, based on gallium oxide; preferably the active element is boron and the modified Y-type molecular sieve has a boron content of from about 0.5 to about 5% by weight, based on boron oxide; or preferably the active element is gallium and boron, and the modified Y-type molecular sieve has a total content of gallium and boron from about 0.5 to about 5% by weight, based on gallium oxide and boron oxide. 4. A method for producing a modified Y-type molecular sieve for catalytic cracking of a hydrocarbon feedstock, comprising the following steps: (1) contacting a NaY molecular sieve with a rare earth salt solution for an ion exchange reaction and obtaining an ion exchanged molecular sieve; (2) subjecting the ion-exchanged molecular sieve to roasting at a temperature of from about 350° C. to about 480° C. in an atmosphere containing from about 30 vol.% to about 90 vol.% steam, for from about 4.5 hours to approximately 7 hours to obtain a molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment; (3) subjecting a molecular sieve subjected to a mild hydrothermal ultrastabilization treatment to gas phase ultrastabilization by contacting and reacting with SiCl ₄ gas to obtain a gas phase ultrastabilized molecular sieve; (4) subjecting the ultra-gas-phase ultra-stabilized molecular sieve to an acid treatment by contacting with an acid solution to obtain an acid-treated molecular sieve; (5) subjecting the acid-treated molecular sieve to be modified with phosphorus by contacting with a phosphorus compound to obtain a phosphorus-modified molecular sieve; And (6) subjecting the modified phosphorus-modified molecular sieve to a modification treatment by contacting with a solution containing an active element and then calcining to obtain a Y-type modified molecular sieve, wherein the active element is gallium and/or boron. 5. The method of claim 4, wherein step (1) further comprises contacting a NaY molecular sieve with a rare earth salt in an aqueous solution for an ion exchange reaction, the ion exchange reaction being carried out under the following conditions: the temperature is from about 15°C to about 95°C, the reaction time is from about 30 minutes to about 120 minutes, and the weight ratio of NaY molecular sieve, rare earth salt and water is about 1:(0.01-0.18) :(5-20), preferably, the resulting ion-exchanged molecular sieve has a sodium content of no more than about 9.5% by weight, based on the weight of the ion-exchanged molecular sieve, on a dry basis. 6. The method of claim 4 or 5, wherein the ion-exchanged molecular sieve has a lattice parameter of about 2.465 nm to about 2.472 nm, a rare earth content of about 4.5 to about 13% by weight based on oxide, and a content of sodium from about 4.5 to about 9.5% by weight, based on sodium oxide. 7. The method according to any one of paragraphs. 4-6, wherein the rare earth salt is rare earth chloride or rare earth nitrate. 8. The method according to any one of paragraphs. 4-7, wherein in step (2), the ion-exchanged molecular sieve is calcined at a temperature of from about 380° C. to about 460° C. in an atmosphere containing from about 40 vol.% to about 80 vol.% steam, for from about 5 hours to about 6 hours; preferably, the resulting mild hydrothermal ultrastabilization molecular sieve has a lattice parameter of from about 2.450 nm to about 2.462 nm and a water content of not more than about 1% by weight. 9. The method according to any one of paragraphs. 4-8, in which in stage (3) the mass ratio of SiCl ₄ and molecular sieve subjected to moderate hydrothermal ultra-stabilization treatment, in terms of dry matter, is approximately (0.1-0.7): 1, the reaction temperature is from approximately 200 °C to about 650°C, and the reaction time is from about 10 minutes to about 5 hours; preferably, step (3) further comprises washing with water the resulting ultra-gas-phase molecular sieve to such an extent that no free ions such as Na ⁺ , Cl ^- and Al ³⁺ can be detected in the spent washing liquid, and washing conditions can include a temperature of about 30° C. to about 60° C., a weight ratio of water to gas-phase ultra-stabilized molecular sieve prior to washing of about (6-15):1, and a pH of the spent washing liquid of about 2.5 to about 5.0. 10. The method according to any one of paragraphs. 4-9, wherein in step (4), the acid treatment is carried out under the following conditions: the acid treatment temperature is from about 80° C. to about 99° C., the acid treatment time is from about 1 hour to about 4 hours, the acid solution contains an organic acid and/or inorganic acid, and the weight ratio of acid in acid solution, water in acid solution and ultra-stabilized in the gas phase molecular sieve in terms of dry matter is approximately (0.001-0.15):(5-20):1; preferably the organic acid is selected from the group consisting of oxalic acid, malonic acid, succinic acid, methyl succinic acid, malic acid, tartaric acid, citric acid, salicylic acid and a combination of two, three or four of these elements; and/or preferably the inorganic acid is selected from the group consisting of phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid and a combination of two, three or four of these elements. 11. The method of claim 10, wherein the acid treatment in step (4) further comprises contacting the gas-phase ultra-stabilized molecular sieve first with an inorganic acid solution and then with an organic acid solution; wherein the contacting with the inorganic acid solution is carried out under the following conditions: the contact time is from about 60 minutes to about 120 minutes, the contact temperature is from about 90°C to about 98°C, and the mass ratio of the inorganic acid in the inorganic acid solution, water in a solution of an inorganic acid and an ultra-stabilized molecular sieve in the gas phase, on a dry matter basis, is approximately (0.01-0.05):(5-20):1; And the contacting with the organic acid solution is carried out under the following conditions: the contact time is from about 60 minutes to about 120 minutes, the contact temperature is from about 90°C to about 98°C, and the weight ratio of the organic acid in the organic acid solution, water in solution of organic acid and gas-phase ultra-stabilized molecular sieve on a dry matter basis is approximately (0.02-0.1):(5-20):1. 12. The method according to any one of paragraphs. 4-11, wherein the phosphorus compound is selected from the group consisting of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate, ammonium hydrogen phosphate, and a combination of two, three, or four of these elements; preferably, step (5) further comprises contacting and reacting the acid-treated molecular sieve with a solution containing a phosphorus compound at a temperature of from about 15° C. to about 100° C. for about 10 minutes to about 100 minutes, wherein the weight ratio of phosphorus is in a solution containing a phosphorus compound in terms of P ₂ O ₅ , water in a solution containing a phosphorus compound and an acid-treated molecular sieve is approximately (0.0005-0.10):(2-5):1. 13. The method according to any one of paragraphs. 4-12, wherein the active element-containing solution is an aqueous solution of a gallium salt and/or an aqueous solution of a boron compound; preferably, step (6) further comprises homogeneously mixing the phosphorus-modified molecular sieve with an aqueous gallium salt solution and then holding at a temperature of from about 15° C. to about 40° C. for about 24 hours to about 36 hours, wherein the weight ratio of gallium in the aqueous gallium salt solution in terms of oxide, water in an aqueous solution of gallium salt and phosphorus-modified molecular sieve in terms of dry matter is approximately (0.001-0.03): (2-3): 1; preferably the gallium salt is selected from the group consisting of Ga(NO ₃ ) ₃ , Ga ₂ (SO ₄ ) ₃ , GaCl ₃ and a combination of two or three of these elements, or preferably, step (6) further comprises heating the phosphorus-modified molecular sieve to a temperature of about 60 to 99° C. and then contacting and mixing with a boron compound in aqueous solution for about 1 hour to about 2 hours, wherein the weight ratio of boron to aqueous solution in terms of oxide, water in aqueous solution and phosphorus-modified molecular sieve in terms of dry matter is approximately (0.005-0.045): (2.5-5): 1, preferably the boron compound is selected from the group consisting of boric acid , borate, metaborate, polyborate and a combination of two, three or four of these elements; or preferably, step (6) further comprises heating the phosphorus-modified molecular sieve at about 85°C to about 95°C, contacting and mixing with the boron compound in the first aqueous solution for about 1 hour to about 2 hours, filtering, homogeneous mixing of the resulting molecular sieve material with a second aqueous solution containing a gallium salt, and then holding at a temperature of from about 15°C to about 40°C for from about 24 hours to about 36 hours; moreover, the mass ratio of boron in the first aqueous solution in terms of oxide, water in the first aqueous solution and phosphorus-modified molecular sieve in terms of dry matter is approximately (0.005-0.03):(2.5-5):1, and the mass the ratio of gallium in the second aqueous solution in terms of oxide, water in the second aqueous solution and molecular sieve material in terms of dry matter is approximately (0.001-0.02):(2-3):1. 14. The method according to any one of paragraphs. 4-13, wherein the calcination in step (6) is carried out under the following conditions: the calcination temperature is from about 350°C to about 600°C, and the calcination time is from about 1 hour to about 5 hours. 15. Catalytic cracking catalyst containing from about 10 to about 50% by weight of a modified Y-type molecular sieve, from about 10 to about 40% by weight of an alumina-based binder in terms of alumina, and from about 10 to about 80% by weight of clay in terms of dry matter relative to the mass of catalyst in terms of dry matter, and the modified molecular sieve type Y is a modified molecular sieve type Y according to any one of paragraphs. 1-3 or a modified molecular sieve type Y obtained by the method according to any one of paragraphs. 4-14. 16. The use of a modified molecular sieve type Y according to any one of paragraphs. 1-3 in the catalytic cracking of a hydrocarbon feed comprising contacting the hydrocarbon feed with a catalytic cracking catalyst containing a modified Y-type molecular sieve under catalytic cracking conditions, wherein preferably the hydrocarbon feedstock is a hydrogenated light cycle oil (LCO); and/or while preferably catalytic cracking conditions include a reaction temperature from about 500°C to about 610°C, the volume of oil per unit mass of catalyst per hour from about 2 h ^-1 to about 16 h ^-1 and the mass ratio of catalyst to oil from about 3 to approximately 10.