RU2804255C2 - Modified y-type molecular sieves, catalytic cracking catalyst containing them, catalyst production and application of sieves - Google Patents

Abstract

FIELD: molecular sieves and catalytic cracking.

SUBSTANCE: group of inventions relates to a modified Y-type molecular sieve, a catalytic cracking catalyst containing it, its production and their use. A modified Y-type molecular sieve is presented, having a modifying metal content of 0.5-6.3 wt.% in terms of modifying metal oxide and the sodium content is not more than 0.5 wt.% in terms of sodium oxide in terms of dry matter and based on the weight of the specified modified Y-type molecular sieve, and the specified modifying metal is magnesium and/or calcium, and the modified Y-type molecular sieve comprises aluminium and silicon, has the ratio of the content of non-lattice aluminium to the total aluminium content not more than 20% and has a ratio of silicon dioxide-alumina in the crystal lattice, calculated as the molar ratio of SiO₂/Al₂O₃ equal to 7.3-14, the total pore volume is 0.33-0.39 ml/g, the ratio of the volume of secondary pores with a pore size of 2-100 nm to the total pore volume of 10-25%, the crystal lattice constant is 2.440-2.455 nm, the temperature of destruction of the crystal lattice is not lower than 1040° C and the ratio of B acid to L acid in the total acid content is not less than 2.30, as determined by infrared spectroscopy of adsorbed pyridine at 200°C. In another embodiment, a method for producing a modified Y-type molecular sieve is provided comprising the steps of: (1) contacting a NaY type molecular sieve with a solution of a soluble magnesium salt and/or a soluble calcium salt for an ion exchange reaction to obtain Y type molecular sieve containing magnesium and/or calcium, with a reduced sodium content; (2) subjecting the Y-type molecular sieve obtained in step (1) to calcination at a temperature of 350-480°C in an atmosphere of 30-90 vol.% steam for 4.5-7 hours and optionally drying to obtain a Y-type molecular sieve with a reduced constant crystal lattice; and (3) contacting the reduced lattice constant Y-type molecular sieve with gaseous silicon tetrachloride to react at a weight ratio of SiCl₄ to reduced lattice constant Y-type molecular sieve, on a dry matter basis, from 0.1:1 to 0.7 :1 and reaction temperature 200-650°C for a reaction time of 10 minutes to 5 hours to obtain a modified molecular sieve type Y. A catalytic cracking catalyst is presented containing 10-50 wt.% in terms of dry matter of the modified molecular sieve type Y, 10-40 wt.% binder based on aluminium oxide in terms of aluminium oxide and 10-80 wt.% in terms of dry matter of clay in terms of the weight of the catalytic cracking catalyst, and the use of a modified molecular sieve type Y in the catalytic cracking of hydrocarbon oils is presented, providing for the contact of a hydrocarbon oil with a catalytic cracking catalyst containing a modified molecular sieve type Y.

EFFECT: making a modified Y-type molecular sieve, which has high crystallinity, high thermal and hydrothermal stability, a certain secondary pore structure, uniform distribution of aluminium, and less non-lattice aluminium.

15 cl, 10 tbl, 50 ex

Description

Link to related applications

This application claims priority to Chinese Patent Application No. 201810713603.4 entitled “Modified Y-Type Molecular Sieve with High Stability for Enhancing the Production of Branched Hydrocarbons and Its Production,” filed on June 29, 2018; priority according to Chinese Patent Application No. 201810714440.1 entitled “Fatalytic cracking catalyst, its preparation and use”, filed on June 29, 2018; priority according to Chinese Patent Application No. 201810715455.X entitled “Fatalytic Cracking Catalyst” filed on June 29, 2018; and priority in accordance with Chinese Patent Application No. 201810713533.2 entitled “Modified Y-Type Molecular Sieve with High Stability for Enhancing the Production of Dimethyl Branched Hydrocarbons and Its Production”, filed on June 29, 2018, which are incorporated herein by reference in their entirety .

Field of technology to which the present invention relates

The present application relates to the technical field of molecular sieves and catalytic cracking, in particular to a modified Y-type molecular sieve, a catalytic cracking catalyst containing it, its preparation and use thereof.

BACKGROUND OF THE INVENTION

Currently, high silica Y-type molecular sieves (also called Y-type zeolites) are produced commercially mainly by the hydrothermal process. The hydrothermal method is the most commonly used method for producing high silica Y type molecular sieve, in which the NaY type molecular sieve is subjected to repeated ion exchange with a rare earth element and calcined at high temperature to obtain a rare earth containing high silica Y type molecular sieve silicon However, rare earth-containing Y-type molecular sieves with high silica content produced by the hydrothermal process have the following disadvantages: since the structure of the molecular sieve may be damaged under severe hydrothermal processing conditions, producing Y-type molecular sieves with a high silica-alumina ratio may be difficult; Although creating non-lattice aluminum is beneficial for improving the stability of the molecular sieve and the formation of new acid sites, excessive amounts of non-lattice aluminum can reduce the selectivity of the molecular sieve; In addition, many dealuminated voids in the molecular sieve may not be timely supplemented with silicon migrating from the crystal lattice so that lattice defects can be created in the molecular sieve, and the retention of crystallinity of the molecular sieve is low. In addition, since conventional Y-type molecular sieves contain only rare earth elements, silicon, aluminum and some other elements, the control of their structure and performance characteristics is limited to some extent, so that the composition of the product is generally stabilized within a certain range. Consequently, rare earth-containing high silica Y-type molecular sieves prepared by the hydrothermal process exhibit poor thermal and hydrothermal stability, as reflected by their low lattice breakdown temperature, poor retention of crystallinity and specific surface area after hydrothermal aging, and poor selectivity.

In the method disclosed in US4584287 and US4429053, the NaY type molecular sieve is first ion exchanged with a rare earth element and then treated with steam, which makes dealumination of the molecular sieve by steam treatment difficult due to the shielding and supporting effect of the rare earth ion. The lattice parameter of the molecular sieve increases to 2.465-2.475 nm before steam treatment and is 2.420-2.464 nm after treatment, and the temperature required to reduce the lattice parameter is relatively high (593-733°C).

In the method disclosed in US Pat. No. 5,340,957 and US Pat. No. 5,206,194, a NaY type molecular sieve with a SiO ₂ /Al ₂ O ₃ ratio of 6.0 is used as a starting material, and NaY is also subjected to ion exchange with a rare earth element and then hydrothermal treatment. Thus, the method also has the disadvantage of the above-mentioned US patents No. 4584287 and No. 4429053.

Another method for producing high silica Y type molecular sieves is the gas phase chemical process, which is another important method for producing high silica molecular sieves first reported by Beyer and Mankui in 1980. The gas phase chemical process generally involves reaction of SiCl ₄ and anhydrous molecular sieve such as NaY in a nitrogen atmosphere at a certain temperature. The entire reaction process fully utilizes the external source of Si provided by SiCl ₄ , and the dealumination and silicon addition reaction can be completed simultaneously through isomorphic substitution. U.S. Patent No. 4273753 and No. 4438178 and Chinese Patent Applications CN1382525A, CN1194941A, CN1683244A disclose a method for producing ultra-stable Y-type molecular sieves by gas-phase chemical dealumination with SiCl _4. However, gas-phase ultra-stabilized molecular sieves are substantially free of secondary pores.

In addition, the content of branched hydrocarbons in gasoline produced using catalysts derived from conventional Y-type molecular sieves remains within a certain range and is difficult to increase. This limits the quality improvements of catalytically cracked gasoline and reduces the competitiveness of catalytically cracked product gasoline.

Huayuan Zhu et al. (Acta Petrolei Sinica (Petroleum Processing Section), 2001, 17 (6): 6-10) studied the effect of magnesium-containing modified molecular sieves on the performance of FCC catalysts and reported that Mg, Ca-containing FCC catalysts molecular sieves show high productivity for heavy oil refining, high activity for hydrogen transfer reaction and high isobutane productivity. However, the Y-type molecular sieve produced by the method disclosed herein has poor thermal and hydrothermal stability and can only be used to enhance isobutane production under certain conditions. In addition, such a Y-type molecular sieve cannot be effectively used to increase the branched hydrocarbon content of gasoline, and can hardly be used to increase the dimethyl branched hydrocarbons/monomethyl branched hydrocarbons ratio.

The performance of ultrastable molecular sieves produced by the hydrothermal process or the gas phase process known in the art cannot meet the needs for heavy oil and low grade oil processing and gasoline upgrading. In addition, when catalytic cracking catalysts based on existing Y-type molecular sieves are used for cracking heavy oil, the branched hydrocarbon content of the resulting product gasoline is relatively low.

The foregoing description is provided only as background to this application and is not in any way taken as prior art published prior to the filing date of this application.

Brief Disclosure of the Present Invention

The object of the present application is to provide a highly stable modified Y type molecular sieve, its preparation and its use, which is useful in the catalytic cracking of heavy oils and can enhance the production of branched hydrocarbons. Another object of the present application is to provide a catalytic cracking catalyst containing a modified Y-type molecular sieve, its preparation and its use, wherein when used for heavy oil catalytic cracking, the catalyst exhibits low coke selectivity, high gasoline yield and high liquefied gas yield, and the resulting product gasoline has a high content of branched hydrocarbons.

To achieve the above objectives, an aspect of the present application provides a modified Y-type molecular sieve having a modifying metal content of approximately 0.5-6.3 wt. % in terms of the oxide of the modifying metal and a sodium content of not more than approximately 0.5 wt. %, preferably approximately 0.1-0.5 wt. %, based on sodium oxide, based on dry matter, and based on the weight of the modified Y-type molecular sieve, wherein the modifying metal is magnesium and/or calcium, wherein the modified Y-type molecular sieve has a non-lattice aluminum to total aluminum content ratio of no more than than approximately 20%, total pore volume approximately 0.33-0.39 ml/g, ratio of secondary pore volume with pore size 2-100 nm to total pore volume approximately 10-25%, lattice constant approximately 2.440-2.455 nm, a crystal lattice breakdown temperature of not less than about 1040°C; and a ratio of acid B to acid L in the total acid content of not less than about 2.30, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

In another aspect, the present application provides a process for producing a modified Y-type molecular sieve, comprising the steps of:

(1) contacting the NaY type molecular sieve with a solution of a soluble magnesium salt and/or a soluble calcium salt for an ion exchange reaction to produce a Y type molecular sieve containing magnesium and/or calcium with a reduced sodium content;

(2) subjecting the Y-type molecular sieve obtained in step (1) to calcination at a temperature of about 350-480° C. in an atmosphere of about 30-90 vol.% steam for about 4.5-7 hours and optionally drying to obtain a molecular sieve Y-type sieves with reduced lattice constant; And

(3) contacting the Y-type molecular sieve obtained in step (2) with silicon tetrachloride gas to react at a weight ratio of SiCl ₄ to Y-type molecular sieve with a reduced lattice constant on a dry matter basis ranging from about 0.1: 1 to about 0.7:1 and a reaction temperature of about 200-650° C. for a reaction time of about 10 minutes to about 5 hours to produce a modified Y-type molecular sieve.

In another aspect, the present application provides a modified Y-type molecular sieve produced by a process for producing a modified Y-type molecular sieve as described above.

In yet another aspect, the present application provides a catalytic cracking catalyst containing approximately 10-50 wt. % based on dry matter of the modified molecular sieve type Y according to this application, approximately 10-40 wt. % of alumina-based binder in terms of aluminum oxide and approximately 10-80 wt. % based on clay dry matter based on the weight of the catalytic cracking catalyst.

In yet another aspect, the present application provides the use of the modified Y-type molecular sieve of the present application in the catalytic cracking of hydrocarbon oils, comprising the steps of contacting the hydrocarbon oil with a catalytic cracking catalyst containing the modified Y-type molecular sieve.

The modified Y-type molecular sieve of the present application has high thermal and hydrothermal stability and, when used as an active component in a catalytic cracking catalyst for heavy oil catalytic cracking, can provide lower coke selectivity and higher gasoline and LPG yields, as well as higher branched hydrocarbon content of the resulting gasoline compared to existing Y-type molecular sieves. When the inoculant metal content is magnesium, the resulting gasoline shows a higher monomethyl branched hydrocarbon content, and when the inoculant metal content is calcium, the resulting gasoline shows a higher dimethyl branched hydrocarbon content hydrocarbons.

In addition to being used as an active component in a catalytic cracking catalyst, the modified Y-type molecular sieve of the present application can also be used as a support in a lubricating oil isodewaxing catalyst, and when used in a lubricating oil isomerization process, the isodewaxing catalyst containing the molecular sieve as a support shows good isomerization characteristics and high stability.

The method for producing the modified Y-type molecular sieve of the present application can produce high-silica content Y-type molecular sieves with high crystallinity, high thermal stability and high hydrothermal stability and some secondary pore structure that have uniform aluminum distribution and less non-lattice aluminum content. When used for heavy oil refining, the modified Y-type molecular sieve can provide good coke selectivity, high heavy oil cracking activity, increased gasoline, LPG and total liquid yields, and increased branched hydrocarbon content in gasoline.

The catalytic cracking catalyst of the present application containing a modified Y-type molecular sieve as an active component has high thermal and hydrothermal stability, and when used for heavy oil catalytic cracking, shows high activity stability and lower coke selectivity, and can provide higher gasoline yield , liquefied gas, light oil and total liquids and higher branched hydrocarbon content in the resulting gasoline compared to existing catalytic cracking catalysts containing Y-type molecular sieves.

Detailed Disclosure of the Present Invention

The present application will now be described in more detail with reference to its embodiments, and it should be noted that the embodiments described in the present invention are presented only for the purpose of illustration and explanation of the present application, while not being limiting in any way.

Any numerical value (including the end values of numerical ranges) provided herein is not limited to the exact value stated, but should be understood to cover any value close to the specified precise value, for example, all possible values within 5% of the specified precise value. Moreover, for any numerical range provided herein, one or more new numerical ranges may be obtained by arbitrarily combining the end values of the range, the end value with a particular value represented in the range, or different particular values represented in the range. Such new numerical ranges should also be considered as specifically disclosed herein.

Unless otherwise specified, terms used herein have the same meaning as commonly understood by those skilled in the art, and if the definition of a term provided herein differs from the common understanding in the art, the definition provided herein , will prevail.

In this application, except where specifically indicated, any material or materials not specified are directly applicable to those known in the art without any modification. In addition, any embodiments described herein may be combined without limitation with one or more other embodiments described herein, and the resulting technical solution or technical idea should be considered part of the original disclosure or the original description of this application, in which case should not be construed as a new issue that has not been disclosed or provided for herein, unless it is obvious to those skilled in the art that such a combination is clearly unreasonable.

The RIPP test methods included in this application can be found in Petrochemical Analysis Methods (RIPP Test Methods), edited by Guiding YANG et al., Science Press, September 1990, First Edition, ISBN: 7-03-001894-X , pages 263-268, 412-415 and 424-426, which are incorporated herein by reference in their entirety.

All patent and non-patent documents referenced herein, including, without limitation, textbooks and journal articles, are hereby incorporated by reference in their entirety.

As used herein, the term “branched hydrocarbon(s)” refers to isoparaffins and branched alkenes. Increasing the content of branched hydrocarbons is beneficial for improving the quality of gasoline, for example, by maintaining the octane number of gasoline, while the content of aromatic hydrocarbons and olefins is reduced.

As used herein, the term "dimethyl branched hydrocarbon(s)" refers to branched hydrocarbons containing two methyl side groups on a carbon chain, while the term "monomethyl branched hydrocarbons" refers to branched hydrocarbons containing one methyl side group on a carbon chain. chains. Increasing the DMB content can improve the quality of FCC gasoline, for example, by maintaining a high octane number of gasoline while reducing the olefin and aromatic hydrocarbon content.

As used herein, the expression "Y-type molecular sieve with normal lattice constant" means that the lattice constant of the Y-type molecular sieve is in the range of the lattice constant of conventional NaY-type molecular sieve, which is preferably in the range of about 2.465 nm to about 2.472 nm.

As used herein, the term “atmospheric pressure” means a pressure of approximately 1 atm.

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

In this application, the terms “Y-type molecular sieve” and “Y-type zeolite” are used interchangeably, and the terms “NaY-type molecular sieve” and “NaY-type zeolite” are also used interchangeably.

In a first aspect, the present application provides a modified Y-type molecular sieve with a modifying metal content of approximately 0.5-6.3 wt. % in terms of the oxide of the modifying metal and a sodium content of not more than approximately 0.5 wt. %, preferably approximately 0.1-0.5 wt. % based on sodium oxide on a dry matter basis and based on the weight of the modified Y-type molecular sieve, wherein the inoculant metal is magnesium and/or calcium, wherein the modified Y-type molecular sieve has a non-lattice aluminum to total aluminum content ratio of no more than about 20%, total pore volume approximately 0.33-0.39 ml/g, ratio of secondary pore volume with pore size (i.e. pore diameter) 2-100 nm to total pore volume approximately 10-25%, lattice constant about 2.440 to 2.455 nm, a lattice breakdown temperature (also called structure breakdown temperature) of not less than about 1040° C., and a ratio of acid B to acid L in the total acid content of not less than about 2.30, as determined by infrared spectroscopy of the adsorbed pyridine at 200°C.

In some preferred embodiments, the modified Y-type molecular sieve does not have an absorption peak at a wavelength of 285-295 nm in its UV-visible light absorption spectrum.

In some preferred embodiments, the inoculant metal is magnesium, and the modified Y-type molecular sieve has a magnesium content, expressed as magnesium oxide, of about 0.5 to 4.5 wt. %, preferably approximately 0.6-4.3 wt. %, for example approximately 0.8-4.5 wt. %, approximately 1-4.5 wt. % or approximately 1.2-4.3 wt. %.

In other preferred embodiments, the modifying metal is calcium, and the modified Y-type molecular sieve has a calcium content expressed as calcium oxide of approximately 0.7 to 6.3 wt. %, preferably approximately 0.9-5.9 wt. %, for example approximately 1.5-6 wt. % or approximately 0.7-4.3 wt. %.

In a preferred embodiment, the modified Y-type molecular sieve has a sodium content expressed as sodium oxide of approximately 0.15 to 0.5 wt. %, for example approximately 0.2-0.5 wt. %, approximately 0.30-0.5 wt. %, approximately 0.35-0.48 wt. % or approximately 0.3-0.46 wt. %.

In a preferred embodiment, the modified Y-type molecular sieve of the present application is substantially free of modifying ions or elements other than magnesium and calcium, including, but not limited to, P, rare earth elements, Ga, Cr, Zn, Cu, etc. For example, each of modifying ions or elements other than magnesium and calcium is present in an amount (calculated as oxides) of less than approximately 0.1 wt. %, for example, less than about 0.05 wt. % or less than about 0.01 wt. %, based on the dry weight of the modified molecular sieve type Y.

In a preferred embodiment, the modified Y-type molecular sieve has a ratio of secondary pore volume of 2-100 nm pore size to total pore volume of about 15-21%, such as about 17-21%.

In a preferred embodiment, the modified Y-type molecular sieve has a non-lattice aluminum to total aluminum content ratio of approximately 13-19%.

In a further preferred embodiment, the modified Y-type molecular sieve is a high-silica Y-type molecular sieve that has a silica-alumina lattice ratio, based on a SiO ₂ /Al ₂ O ₃ molar ratio, of approximately 7.3- 14.0, for example, about 8.4-12.6, about 8.0-12.6, or about 8.1-12.

In a preferred embodiment, the modified Y-type molecular sieve has a lattice constant of about 2.442-2.452 nm, for example about 2.442-2.450 nm.

In a preferred embodiment, the modified Y-type molecular sieve has a lattice breakdown temperature of about 1040-1080°C, for example, about 1045-1080°C, about 1041-1055°C, about 1047-1058°C, about 1057-1075°C or approximately 1047-1065°C.

In a preferred embodiment, the modified Y-type molecular sieve has a ratio of acid B to acid L in total acid content of about 2.3-5.0, preferably about 2.4-4.2, for example about 2.4-3.5, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

In a preferred embodiment, the modified Y-type molecular sieve has a relative crystallinity retention of about 33% or greater, such as about 33-48%, about 33-45%, about 35-45%, about 36-40%, or about 39-45%, after aging at 800°C under atmospheric pressure in an atmosphere of 100% steam for 17 hours.

In a preferred embodiment, the modified Y-type molecular sieve has a relative crystallinity of not less than about 58%, for example, about 58-75%, about 58-70%, about 59-70%, about 58-68%, about 59-68% , approximately 59-64% or approximately 59-63%.

In a preferred embodiment, the modified Y-type molecular sieve has a specific surface area of about 620-670 m ² /g, for example about 630-660 m ² /g.

In a preferred embodiment, the modified Y-type molecular sieve has a total pore volume of about 0.35-0.39 ml/g, such as about 0.35-0.375 ml/g or about 0.355-0.375 ml/g.

In a preferred embodiment, the modified Y-type molecular sieve has a micropore volume of about 0.25-0.35 ml/g, for example about 0.26-0.32 ml/g.

In some particularly preferred embodiments, the inoculant metal is magnesium, and the modified Y-type molecular sieve has a magnesium content on a magnesium oxide basis of approximately 0.6 to 4.3 wt. %, preferably approximately 0.8-4.5 wt. %; sodium content approximately 0.15-0.5 wt. %, preferably approximately 0.30-0.5 wt. %, in terms of sodium oxide; a lattice constant of approximately 2.442-2.452 nm and a silica-alumina lattice ratio of approximately 8.4-12.6.

In other particularly preferred embodiments, the modifying metal is calcium, and the modified Y-type molecular sieve has a calcium content expressed as calcium oxide of approximately 0.7 to 6.3 wt. %, preferably approximately 0.9-5.9 wt. %; sodium content approximately 0.15-0.5 wt. %, preferably approximately 0.2-0.5 wt. %, in terms of sodium oxide; a lattice constant of approximately 2.442-2.452 nm and a silica-alumina lattice ratio of approximately 8.0-12.6.

In a preferred embodiment, the modified Y-type molecular sieve has an electron binding energy Ols of no more than about 532.55 eV, such as about 532.39-532.52 eV.

In a preferred embodiment, the modified Y-type molecular sieve of the present application is produced by the modified Y-type molecular sieve production process that will be described later herein.

In a second aspect, the present application provides a process for producing a modified Y-type molecular sieve, comprising the steps of:

(1) contacting the NaY type molecular sieve with a solution of a soluble magnesium salt and/or a soluble calcium salt for an ion exchange reaction to produce a Y type molecular sieve containing magnesium and/or calcium with a reduced sodium content;

(2) subjecting the Y-type molecular sieve obtained in step (1) to calcination at a temperature of about 350-480° C. in an atmosphere of about 30-90 vol.% steam for about 4.5-7 hours and optionally drying to obtain a molecular sieve Y-type sieves with reduced lattice constant; And

(3) contacting the Y-type molecular sieve obtained in step (2) with silicon tetrachloride gas to react at a weight ratio of SiCl ₄ to Y-type molecular sieve with a reduced lattice constant on a dry matter basis ranging from about 0.1: 1 to about 0.7:1 and a reaction temperature of about 200-650° C. for a reaction time of about 10 minutes to about 5 hours to produce a modified Y-type molecular sieve.

In some embodiments, the method of this application comprises the steps of:

(1) contacting the NaY type molecular sieve with a solution of a soluble magnesium salt and/or a soluble calcium salt for an ion exchange reaction, filtering, washing and optionally drying to obtain a Y type molecular sieve containing magnesium and/or calcium and having a normal lattice constant; and reduced sodium content;

(2) subjecting the Y-type molecular sieve obtained in step (1) to calcination at a temperature of about 350-480° C. in an atmosphere of about 30-90 vol.% steam for about 4.5-7 hours and optionally drying to obtain a molecular sieve Y-type sieves with reduced lattice constant;

(3) contacting the Y-type molecular sieve obtained in step (2) with silicon tetrachloride gas to react at a weight ratio of SiCl ₄ to Y-type molecular sieve with a reduced lattice constant on a dry matter basis ranging from about 0.1: 1 to about 0.7:1 and a reaction temperature of about 200-650° C. for a reaction time of about 10 minutes to about 5 hours, washing and filtering to obtain a modified Y-type molecular sieve.

In the method for producing a modified Y-type molecular sieve according to the present application, the NaY-type molecular sieve is subjected to an ion exchange reaction with a solution of a soluble magnesium salt and/or a soluble calcium salt in step (1) to obtain a Y-type molecular sieve with a normal lattice constant and a reduced sodium content . NaY type molecular sieve can be commercially available or prepared according to existing methods. In a preferred embodiment, the NaY type molecular sieve has a lattice constant of approximately 2.465-2.472 nm, a silica-alumina lattice ratio (SiO ₂ /Al ₂ O ₃ molar ratio) of approximately 4.5-5.2, a relative crystallinity of approximately 85% or more, for example about 85-95%, and a sodium content of about 13.0-13.8 wt. % in terms of sodium oxide.

In a preferred embodiment, the Y-type molecular sieve obtained in step (1) has a lattice constant of about 2.465-2.472 nm and a sodium content of no more than about 9 wt. %, for example, no more than about 8.8 wt. %, in terms of sodium oxide.

In a preferred embodiment, step (1) further comprises washing the resulting Y-type molecular sieve to wash away the exchanged sodium ions, for example with deionized water or deionized water.

In a preferred embodiment, the Y-type molecular sieve obtained in step (1) has a magnesium content of approximately 0.5-7.0 wt. % in terms of MgO, sodium content approximately 4-8.8 wt. % in terms of sodium oxide and the crystal lattice constant is approximately 2.465-2.472 nm; or

the Y-type molecular sieve obtained in step (1) has a calcium content of approximately 0.7-11 wt. % in terms of CaO, sodium content is approximately 4-8.8 wt. % in terms of sodium oxide and the crystal lattice constant is approximately 2.465-2.472 nm.

In some particularly preferred embodiments, the magnesium-containing normal-lattice-reduced-sodium Y-type molecular sieve obtained in step (1) has a magnesium content of approximately 0.6 to 6.5 wt. %, for example approximately 0.7-6.5 wt. % or approximately 0.75-6.3 wt. %, in terms of MgO; sodium content approximately 5.5-8.5 wt. % or approximately 5-7.5 wt. %, in terms of sodium oxide and the crystal lattice constant is approximately 2.465-2.472 nm; or

The calcium-containing Y-type molecular sieve with normal lattice constant and reduced sodium content obtained in step (1) has a calcium content of approximately 0.8-10 wt. %, for example approximately 4-10 wt. %, approximately 0.9-9.0 wt. %, approximately 1.5-6 wt. % or approximately 0.7-5.0 wt. %, in terms of CaO; sodium content approximately 4.5-8.5 wt. % or approximately 5-7.5 wt. % in terms of sodium oxide and the crystal lattice constant is approximately 2.465-2.472 nm.

In a preferred embodiment, in step (1), the NaY molecular sieve, soluble magnesium salt and/or calcium salt and water are mixed in a weight ratio of NaY molecular sieve: soluble magnesium salt and/or calcium salt (in terms of MgO and/or CaO ): H ₂ O approximately 1:0.005-0.28:5-15 to perform the ion exchange reaction. For example, in some further preferred embodiments, the weight ratio of NaY molecular sieve (on a dry basis): soluble magnesium salt (on a MgO basis): H ₂ O is approximately 1:0.005-0.19:5-15, for example , approximately 1:0.01-0.15:6-12 or approximately 1:0.05-0.12:6-12; in other further preferred embodiments, the weight ratio of molecular sieve type NaY (on a dry basis): soluble calcium salt (on a CaO basis): H ₂ O is about 1:0.009-0.28:5-15, for example, about 1:0.009-0.27:5-15.

In a preferred embodiment, in step (1), a NaY type molecular sieve is mixed with water, and then a soluble magnesium salt, a soluble calcium salt, a soluble calcium salt solution and/or a soluble magnesium salt solution are added with stirring to perform an ion exchange reaction;

conditions for the ion exchange reaction include: an exchange temperature of about 15-95°C, eg about 65-95°C, and an exchange time of about 30-120 minutes, eg about 45-90 minutes.

In the present application, the soluble magnesium salt may be any magnesium salt soluble in a solvent such as water, for example one or more of magnesium chloride, magnesium nitrate, magnesium sulfate, preferably magnesium chloride and/or magnesium nitrate. The soluble calcium salt may be any calcium salt soluble in a solvent such as water, preferably calcium chloride and/or calcium nitrate. The soluble magnesium salt solution and the soluble calcium salt solution are preferably aqueous solutions.

In a preferred embodiment, the calcination conditions in step (2) include: a calcination temperature of approximately 380-470°C, a calcination atmosphere of approximately 40-80% steam, and a calcination time of approximately 5-6 hours.

In a preferred embodiment, the steam atmosphere contains about 30-90 vol.%, preferably about 40-80 vol.%, steam and may also contain other gases such as one or more of air, helium or nitrogen.

In a preferred embodiment, the reduced lattice constant type Y molecular sieve obtained in step (2) has a lattice constant of approximately 2.450-2.462 nm.

In a preferred embodiment, step (2) also involves drying the calcined molecular sieve to obtain a reduced lattice constant type Y molecular sieve that has a water content of preferably no more than about 1 wt. %.

In a preferred embodiment, in step (3), the SiO14:Y molecular sieve weight ratio (on a dry basis) is about 0.3:1 to about 0.6:1, and the reaction temperature is about 350-500°C.

In a preferred embodiment, step (3) may also include washing the resulting modified Y-type molecular sieve with water. Washing can be carried out by a conventional washing method using water, such as deionized water or deionized water, to remove soluble by-products such as Na+, SG, Al3+ and the like remaining in the molecular sieve. For example, washing conditions may include: a wash water to molecular sieve weight ratio of about 5-20:1, such as about 6-15:1, a pH of about 2.5-5.0, and a wash temperature of about 30-60°C. Preferably, the washing is carried out to such an extent that no free ions such as Na ⁺ , Cl ^- and Al ³⁺ can be detected in the spent washing liquid, and usually the content of each of the Na ⁺ , Cl ^- and Al ³⁺ ions in the spent washing liquid is is no more than about 0.05 wt. %.

In a preferred embodiment, the method for producing a modified Y-type molecular sieve according to the present application comprises the steps of:

(1) subjecting the NaY type molecular sieve to an ion exchange reaction with a soluble calcium salt solution, filtration and washing to obtain a calcium-containing Y type molecular sieve with a normal lattice constant and reduced sodium content, said ion exchange being carried out under stirring at a temperature of about 15 - 95°C, preferably about 65-95°C, for about 30-120 minutes, preferably about 45-90 minutes;

(2) subjecting a calcium-containing molecular sieve of type Y with normal lattice constant and reduced sodium content to calcination at a temperature of about 350-480°C, preferably about 380-470°C, in an atmosphere containing about 30-90% by volume, preferably about 40-80 vol.%, steam for about 4.5-7 hours, preferably about 5-6 hours, and drying to obtain a Y-type molecular sieve with a reduced lattice constant and a water content of less than about 1 wt. %, and the lattice constant of the Y-type molecular sieve with reduced lattice constant is approximately 2,450-2,462 nm; And

(3) contacting a Y-type molecular sieve with a reduced lattice constant and a water content of less than about 1 wt. % with gaseous SiCl ₄ , evaporated by heating, to react at a weight ratio of SiCl ₄ to a Y-type molecular sieve with a reduced lattice constant (on a dry matter basis) of about 0.1:1 to about 0.7:1, preferably from about 0.3:1 to about 0.6:1, and a temperature of about 200-650°C, preferably about 350-500°C, for about 10 minutes to about 5 hours, washing and filtering to obtain a modified molecular Y type sieves.

In another preferred embodiment, the method for producing a modified Y-type molecular sieve according to the present application comprises the steps of:

(1) subjecting the NaY type molecular sieve to an ion exchange reaction with a solution of a soluble magnesium salt, filtration and washing to obtain a magnesium-containing Y type molecular sieve with a normal lattice constant and reduced sodium content, said ion exchange being carried out under stirring at a temperature of approximately 15 - 95°C, preferably about 65-95°C, for about 30-120 minutes, preferably about 45-90 minutes;

(2) subjecting a magnesium-containing Y-type molecular sieve of normal lattice constant and reduced sodium content to calcination at a temperature of about 350-480°C, preferably about 380-470°C, in an atmosphere containing about 30-90% by volume, preferably about 40-80 vol.%, steam for about 4.5-7 hours, preferably about 5-6 hours, and drying to obtain a Y-type molecular sieve with a reduced lattice constant and a water content of less than about 1 wt. %, and the lattice constant of the Y-type molecular sieve with reduced lattice constant is approximately 2,450-2,462 nm; And

(3) contacting a Y-type molecular sieve with a reduced lattice constant and a water content of less than about 1 wt. % with gaseous SiCl ₄ , evaporated by heating, to react at a weight ratio of SiCl ₄ to a Y-type molecular sieve with a reduced lattice constant (on a dry matter basis) of about 0.1:1 to about 0.7:1, preferably from about 0.3:1 to about 0.6:1, and a temperature of about 200-650°C, preferably about 350-500°C, for about 10 minutes to about 5 hours, washing and filtering to obtain a modified molecular Y type sieves.

In a third aspect, the present application provides a modified Y-type molecular sieve obtained by the method for producing a modified Y-type molecular sieve according to the present application.

In a fourth aspect, the present application provides a catalytic cracking catalyst containing approximately 10-50 wt. % based on dry matter of the modified molecular sieve type Y according to this application, approximately 10-40 wt. % of alumina-based binder in terms of aluminum oxide and approximately 10-80 wt. % based on clay dry matter based on the weight of the catalytic cracking catalyst.

In some embodiments, the catalytic cracking catalyst of the present application may also contain an additional molecular sieve other than a modified Y-type molecular sieve, and the additional molecular sieve may be present in an amount on a dry matter basis of approximately 0-40 weight percent. %, for example approximately 0-30 wt. % or approximately 1-20 wt. %, based on the mass of the catalyst. The additional molecular sieve may be selected from a variety of molecular sieves useful in catalytic cracking catalysts, such as one or more of MFI zeolites, beta zeolite, other Y-type zeolites, and non-zeolitic molecular sieves. Preferably, the additional Y-type molecular sieve is present in an amount on a dry matter basis of no more than about 40 weight percent. %, for example approximately 1-40 wt. % or approximately 0-20 wt. %. The optional Y-type molecular sieve may be, for example, one or more of REY, REHY, DASY, SOY and PSRY; The MFI structured zeolite may be, for example, one or more of HZSM-5, ZRP and ZSP; the beta zeolite may be, for example, an Hp zeolite; and the non-zeolite molecular sieve may be, for example, one or more of aluminophosphate molecular sieves (A1PO molecular sieves) and silicoaluminophosphate molecular sieves (SAPO molecular sieves).

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

In the catalytic cracking catalyst of the present application, the alumina binder is preferably present in an amount of about 20-35 wt. %. According to the present application, the alumina binder may be one or more selected from the group consisting of various forms of alumina, hydrated alumina and alumina sol commonly used in catalytic cracking catalysts. For example, it may be one or more selected from the group consisting of γ-alumina, η-alumina, θ-alumina, χ-alumina, pseudoboehmite, boehmite, gibbsite, bayerite and aluminum sol, preferably pseudoboehmite and sol aluminum For example, the catalytic cracking catalyst may contain approximately 2-15 wt. %, preferably approximately 3-10 wt. %, aluminum sol in terms of aluminum oxide and approximately 10-30 wt. %, preferably approximately 15-25 wt. %, pseudoboehmite in terms of aluminum oxide.

In the catalytic cracking catalyst of the present application, the clay can be selected from various clays suitable for use as a component in catalytic cracking catalysts, which are well known to those skilled in the art. For example, the clay may be one or more selected from kaolin, hydrogenated halloysite, montmorillonite, diatomite, halloysite, saponite, rector, sepiolite, attapulgite, hydrotalcite and bentonite. Preferably, the clay is present in the catalytic cracking catalyst according to the present application in an amount on a dry matter basis of approximately 20-55 wt. % or approximately 30-50 wt. %.

In a preferred embodiment, the catalytic cracking catalyst according to the present application contains approximately 25-40 wt. % based on dry matter of the modified molecular sieve type Y, approximately 20-35 wt. % of alumina-based binder in terms of aluminum oxide and approximately 30-50 wt. % in terms of clay dry matter.

First embodiment of a catalytic cracking catalyst according to the present application

In the first embodiment of the catalytic cracking catalyst according to the present application, the modifying metal in the modified molecular sieve is magnesium, the modified molecular sieve has a magnesium content of about 0.5 to 4.5 mass. % in terms of magnesium oxide, sodium content is not more than approximately 0.5 wt. % in terms of sodium oxide, total pore volume approximately 0.33-0.39 ml/g, ratio of the volume of secondary pores with a pore size of 2-100 nm to the total pore volume approximately 10-25%, lattice constant approximately 2.440-2.455 nm, lattice silica-alumina ratio (SiCh/AhCh molar ratio) of approximately 7.3-14.0, ratio of non-lattice aluminum to total aluminum content of not more than approximately 20%, lattice breakdown temperature of not less than approximately 1040°C and the ratio of acid B to acid L in the total acid content is not less than about 2.30, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

Preferably, the modified Y-type molecular sieve has a magnesium content of approximately 0.8 to 4.5 wt. %, for example approximately 0.8-4.3 wt. %, approximately 1-4.5 wt. % or approximately 1.2-4.3 wt. % in terms of magnesium oxide.

Preferably, the modified Y-type molecular sieve has a sodium content of approximately 0.1-0.5 wt. %, for example approximately 0.15-0.5 wt. %, approximately 0.2-0.48 wt. %, approximately 0.30-0.5 wt. % or approximately 0.35-0.48 wt. % in terms of sodium oxide.

Preferably, the modified Y-type molecular sieve has a total pore volume of about 0.35-0.39 ml/g, such as about 0.355-0.375 ml/g.

Preferably, the modified Y-type molecular sieve has a secondary pore volume of 2-100 nm pore size to total pore volume ratio of about 15-21%, preferably about 17-21%.

Preferably, the modified Y-type molecular sieve has a silica-alumina lattice ratio (SiO ₂ /Al ₂ O ₃ mole ratio) of about 8.4 to 12.6.

Preferably, the modified Y-type molecular sieve has a non-lattice aluminum to total aluminum content ratio of approximately 13-19%.

Preferably, the modified Y-type molecular sieve has a lattice breakdown temperature of about 1040-1080°C, for example, about 1045-1080°C, about 1041-1055°C, about 1047-1058°C, about 1057-1075°C, or about 1047 -1065С.

Preferably, the modified Y-type molecular sieve has a ratio of acid B to acid L in total acid content of about 2.3-5.0, preferably about 2.4-4.2, for example about 2.4-3.5, as determined by using infrared spectroscopy of adsorbed pyridine at 200°C.

Preferably, the modified Y-type molecular sieve has a lattice constant of approximately 2.442-2.452 nm.

Preferably, the modified Y-type molecular sieve has a crystallinity retention of greater than about 33%, such as about 33-48%, about 33-45%, about 36-40%, or about 39-45%, after aging at 800° C. under atmospheric pressure in an atmosphere of 100 vol.% steam for 17 hours.

Preferably, the modified Y-type molecular sieve has a relative crystallinity of at least about 58%, such as about 58-70%, about 59-68%, or about 59-64%.

Preferably, the modified Y-type molecular sieve has a specific surface area of about 620-670 m2/g, for example about 630-660 ^m2 /g.

Preferably, the modified Y-type molecular sieve has a micropore volume of about 0.25-0.35 ml/g, for example about 0.26-0.32 ml/g.

Preferably, the modified Y-type molecular sieve does not have an absorption peak at a wavelength of 285-295 nm in its UV-visible light absorption spectrum.

Preferably, the modified Y-type molecular sieve has an electron binding energy Ols of no more than about 532.55 eV, such as about 532.39-532.52 eV.

Second embodiment of the catalytic cracking catalyst of the present application

In the second embodiment of the catalytic cracking catalyst according to the present application, the modifying metal in the modified molecular sieve is calcium, the modified Y-type molecular sieve has a calcium content of approximately 0.7 to 6.3 mass. % in terms of calcium oxide, sodium content is not more than approximately 0.5 wt. % in terms of sodium oxide, total pore volume approximately 0.33-0.39 ml/g, ratio of the volume of secondary pores with a pore size of 2-100 nm to the total pore volume approximately 10-25%, lattice constant approximately 2.440-2.455 nm, silica-alumina lattice ratio (SiO ₂ /Al ₂ O ₃ molar ratio) of approximately 7.3-14.0, ratio of non-lattice aluminum to total aluminum content of not more than approximately 20%, lattice breakdown temperature not less than about 1040°C and the ratio of acid B to acid L in the total acid content is not less than about 2.30, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

Preferably, the modified Y-type molecular sieve has a calcium content of approximately 0.9-5.9 wt. %, for example, approximately 1.5-6.0 wt. % or approximately 0.7-4.3 wt. %, in terms of calcium oxide.

Preferably, the modified Y-type molecular sieve has a sodium content of approximately 0.1-0.5 wt. %, for example approximately 0.15-0.5 wt. %, approximately 0.20-0.5 wt. % or approximately 0.3-0.46 wt. %, in terms of sodium oxide.

Preferably, the modified Y-type molecular sieve has a total pore volume of about 0.35-0.39 ml/g, such as about 0.35-0.375 ml/g.

Preferably, the modified Y-type molecular sieve has a ratio of secondary pore volume of 2.0-100 nm pore size to total pore volume of about 15-21%, such as about 17-21%.

Preferably, the modified Y-type molecular sieve has a lattice breakdown temperature of about 1040-1080°C or about 1041-1055°C.

Preferably, the modified Y-type molecular sieve has a ratio of acid B to acid L in total acid content of about 2.3-5.0, preferably about 2.4-4.2, for example about 2.4-3.5, as determined by using infrared spectroscopy of adsorbed pyridine at 200°C.

Preferably, the modified Y-type molecular sieve has a lattice constant of approximately 2.442-2.452 nm.

Preferably, the modified Y-type molecular sieve has a silica-alumina lattice ratio (SiO ₂ /Al ₂ O ₃ molar ratio) of about 8.0-12.6 or about 8.1-12.

Preferably, the modified Y-type molecular sieve has a non-lattice aluminum to total aluminum content ratio of approximately 13-19%.

Preferably, the modified Y-type molecular sieve is characterized by retaining crystallinity of greater than about 33%, such as about 36-40%, about 39-45%, or about 35-45%, after aging at 800° C. under atmospheric pressure in a 100 vol.% atmosphere. couple for 17 hours.

Preferably, the modified Y-type molecular sieve has a relative crystallinity of at least about 58%, such as about 58-75%, about 58-68%, about 59-70%, or about 59-63%.

Preferably, the modified Y-type molecular sieve has a specific surface area of about 620-670 m2/g, for example about 630-660 ^m2 /g.

Preferably, the modified Y-type molecular sieve has a micropore volume of about 0.25-0.35 ml/g, for example about 0.26-0.32 ml/g.

In a fifth aspect, the present application provides a method for producing a catalytic cracking catalyst comprising the steps of: providing a modified Y-type molecular sieve according to the present application, forming a slurry containing the modified Y-type molecular sieve, an alumina binder, clay and water, and spray drying.

In a sixth aspect, the present application provides the use of the modified Y-type molecular sieve of the present application in the catalytic cracking of hydrocarbon oils by contacting the hydrocarbon oil with a catalytic cracking catalyst containing the modified Y-type molecular sieve of the present application.

In a seventh aspect, the present application provides a catalytic cracking process comprising the step of contacting a heavy oil feedstock with a catalytic cracking catalyst of the present application to react under conditions for cracking the heavy oil in a fluidized bed of the catalyst.

In the catalytic cracking process of the present application, the heavy oil may be any heavy hydrocarbon oil feedstock known in the art, such as one or more of vacuum gas oil, fuel oil, tar, and deasphalted heavy oil.

In the catalytic cracking process of the present application, the reaction conditions for fluidized-bed cracking of heavy oil may be those generally used in the art and may, for example, include: reaction temperature of about 480-530° C., reaction time of about 1-10 seconds and a catalyst to oil weight ratio of from about 3:1 to about 20:1.

The catalytic cracking process of the present application has a high productivity in processing heavy oil and can provide high yield of liquefied gas, light oil, total liquid and gasoline, high content of dimethyl-branched hydrocarbons, high ratio of dimethyl-branched hydrocarbons to monomethyl-branched hydrocarbons in the resulting gasoline and high selectivity to coke.

In some preferred embodiments, the present application provides the following technical solutions.

A1. A modified Y-type molecular sieve having a modifying metal content of approximately 0.5-6.3 wt. % based on the oxide of the modifying metal and the sodium content is not more than approximately 0.5 wt. %, preferably approximately 0.1-0.5 wt. %, based on sodium oxide on a dry matter basis and based on the weight of said modified Y-type molecular sieve, wherein said modifying metal is magnesium and/or calcium; the ratio of non-lattice aluminum to the total aluminum content is not more than approximately 20%, the total pore volume is approximately 0.33-0.39 ml/g, the ratio of the volume of secondary pores with a pore size of 2-100 nm to the total pore volume is approximately 10-25%, a lattice constant of approximately 2.440-2.455 nm, a lattice breakdown temperature of not less than about 1040° C., and a ratio of acid B to acid L in the total acid content of not less than about 2.30, as determined by infrared spectroscopy of adsorbed pyridine at 200° C, preferably, the modified Y-type molecular sieve does not have an absorption peak at a wavelength of 285-295 nm in its UV-visible light absorption spectrum.

A2. The modified Y-type molecular sieve according to claim A1, having a ratio of secondary pore volume with a pore size of 2-100 nm to total pore volume of approximately 15-21%, preferably approximately 17-21%.

A3. Modified molecular sieve type Y according to claims. A1 or A2 having a non-lattice aluminum to total aluminum content ratio of approximately 13-19% and a silica-alumina lattice ratio of approximately 7.3-14, calculated as the Si02/Al203 molar ratio.

A4. The modified Y-type molecular sieve of any one of the preceding claims, having a lattice breakdown temperature of about 1040-1080°C, for example about 1045-1080°C.

A5. The modified Y-type molecular sieve of any one of the preceding claims, having a ratio of acid B to acid L in a total acid content of about 2.3-5.0, preferably about 2.4-4.2, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

A6. The modified Y-type molecular sieve of any one of the preceding claims, wherein the modified Y-type molecular sieve is characterized by maintaining a relative crystallinity of about 33% or more, such as about 33-45%, after aging at 800° C. under atmospheric pressure in an atmosphere of 100% steam in for 17 hours.

A7. The modified Y-type molecular sieve of any one of the preceding claims, having a relative crystallinity of about 58-75%, for example about 58-70%.

A8. The modified Y-type molecular sieve of any one of the preceding claims, wherein the modifying metal is magnesium, and the modified Y-type molecular sieve has a magnesium content of about 0.5 to 4.5 wt. %, for example approximately 0.6-4.3 wt. %, in terms of magnesium oxide, sodium content is approximately 0.2-0.5 wt. % in terms of sodium oxide, a lattice constant of approximately 2.442-2.452 nm and a silica-alumina lattice ratio calculated as the SiO ₂ /Al ₂ O ₃ molar ratio of approximately 8.4-12.6; or

the modifying metal is calcium, and the modified Y-type molecular sieve has a calcium content of approximately 0.7 to 6.3 mass. %, preferably approximately 0.9-5.9 wt. %, for example approximately 1.5-6 wt. %, in terms of calcium oxide, sodium content is not more than approximately 0.5 wt. %, preferably approximately 0.2-0.5 wt. %, based on sodium oxide, a lattice constant of approximately 2.442-2.452 nm and a silica-alumina lattice ratio, calculated as the SiO ₂ /Al ₂ O ₃ molar ratio, of approximately 8.0-12.6.

A9. The modified Y-type molecular sieve of any one of the preceding claims, wherein the modified Y-type molecular sieve has an electron binding energy Ols of no more than about 532.55 eV, such as about 532.39-532.52 eV.

A10. A method for producing a modified Y-type molecular sieve, comprising the steps of:

(1) contacting the NaY type molecular sieve with a solution of a soluble magnesium salt and/or a soluble calcium salt for an ion exchange reaction to produce a Y type molecular sieve containing magnesium and/or calcium with a reduced sodium content;

(2) subjecting the Y-type molecular sieve obtained in step (1) to calcination at a temperature of about 350-480° C. in an atmosphere of about 30-90 vol.% steam for about 4.5-7 hours and optionally drying to obtain a molecular sieve Y-type sieves with reduced lattice constant; And

(3) contacting the Y-type molecular sieve obtained in step (2) with silicon tetrachloride gas to react at a weight ratio of SiCl ₄ to Y-type molecular sieve of a reduced lattice constant on a dry matter basis from about 0.1:1 to about 0.7:1 and a reaction temperature of about 200-650° C. for a reaction time of about 10 minutes to about 5 hours to produce a modified Y-type molecular sieve.

A11. The method of claim A10, wherein the Y-type molecular sieve obtained in step (1) has a lattice constant of about 2.465-2.472 nm and a sodium content of no more than about 8.8 wt. % in terms of sodium oxide.

A12. Method according to paragraphs. A10 or A11, in which the Y-type molecular sieve obtained in step (1) has a magnesium content in terms of MgO of approximately 0.5-7.0 wt. %, sodium content in terms of sodium oxide is approximately 4-8.8 wt. %, for example approximately 5.5-8.5 wt. %, and the lattice constant is approximately 2.465-2.472 nm; or

the Y-type molecular sieve obtained in step (1) has a calcium content in terms of CaO of approximately 0.8-10 wt. %, sodium content approximately 4-8.8 wt. %, for example approximately 5-7.5 wt. %, in terms of sodium oxide and the crystal lattice constant is approximately 2.465-2.472 nm.

A13. The method according to any one of paragraphs. A10-A12, wherein in step (1), NaY molecular sieve, soluble magnesium salt and/or calcium salt and water are mixed with a mass ratio of NaY molecular sieve: soluble magnesium salt and/or calcium salt: H ₂ O of approximately 1:0.005 -0.28:5-15 for ion exchange.

A14. The method according to any one of paragraphs. A11 to A13, wherein in step (1), a NaY type molecular sieve is mixed with water, and then a soluble magnesium salt, a soluble calcium salt, a soluble calcium salt solution and/or a soluble magnesium salt solution are added with stirring to perform an ion exchange reaction;

conditions for the ion exchange reaction include: an exchange temperature of approximately 15-95°C and an exchange time of approximately 30-120 minutes;

preferably the soluble magnesium salt is magnesium chloride and/or magnesium nitrate, and/or

preferably the soluble calcium salt is calcium chloride and/or calcium nitrate.

A15. The method according to any one of paragraphs. A10-A14, in which in step (2) the calcination temperature is approximately 380-470°C, the calcination atmosphere is an atmosphere of approximately 40-80% steam, and the calcination time is approximately 5-6 hours.

A16. The method according to any one of paragraphs. A10-A15, in which the Y-type molecular sieve with reduced lattice constant obtained in step (2) has a lattice constant of about 2,450-2,462 nm and a water content of not more than about 1 mass. %.

A17. The method according to any one of paragraphs. A10-A16, wherein step (3) further comprises washing the resulting modified Y-type molecular sieve with water under washing conditions which include: a molecular sieve:WO ratio of about 1:5-20, a pH of about 2.5-5.0, and a temperature washing approximately 30-60°C.

A18. A modified Y-type molecular sieve obtained by the method according to any one of paragraphs. A10-A17.

A19. A catalytic cracking catalyst containing approximately 10-50 wt. % based on dry matter of the modified molecular sieve type Y, approximately 10-40 wt. % in terms of aluminum oxide binder based on aluminum oxide and approximately 10-80 wt. % in terms of clay dry matter; wherein the modified Y-type molecular sieve is a modified Y-type molecular sieve according to any one of claims. A1-A9 and A18.

A20. The use of a modified Y-type molecular sieve according to any one of paragraphs. A1-A9 and A18 in the catalytic cracking of hydrocarbon oils, comprising the step of contacting the hydrocarbon oil with a catalytic cracking catalyst containing a modified Y-type molecular sieve according to any one of paragraphs. A1-A9 and A18.

IN 1. A modified Y-type molecular sieve having a magnesium oxide content of approximately 0.5-4.5 wt. %, sodium oxide content approximately 0.1-0.5 wt. %, total pore volume 0.33-0.39 ml/g, ratio of secondary pore volume with pore size 2-100 nm to total pore volume approximately 10-25%, lattice constant approximately 2.440-2.455 nm, ratio of non-lattice aluminum content to the total aluminum content of not more than about 20%, a lattice breakdown temperature of not less than about 1040° C., and a ratio of acid B to acid L in the total acid content of not less than about 2.30, as determined by infrared spectroscopy of adsorbed pyridine at 200°C; wherein the molecular sieve does not have an absorption peak at a wavelength of 285-295 nm in its UV-visible light absorption spectrum obtained by UV-visible spectrum analysis.

AT 2. The modified Y-type molecular sieve of claim B1, wherein the modified Y-type molecular sieve has a secondary pore volume ratio of 2-100 nm pore size to total pore volume of approximately 15-21%.

AT 3. The modified Y-type molecular sieve of claim B1, wherein the modified Y-type molecular sieve has a non-lattice aluminum to total aluminum content ratio of approximately 13-19% and a backbone silica-alumina ratio of approximately 7.3-14, calculated as a mole ratio SiO ₂ /Al ₂ O ₃ .

AT 4. The modified Y-type molecular sieve according to claim B1, wherein the modified Y-type molecular sieve has a lattice breakdown temperature of approximately 1045-1080°C.

AT 5. The modified molecular sieve of type Y according to claim B1, wherein the modified molecular sieve of type Y has a ratio of acid B to acid L in a total acid content of approximately 2.4-4.2, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

AT 6. The modified Y-type molecular sieve of claim B1, wherein the modified Y-type molecular sieve is characterized by maintaining a relative crystallinity of about 33% or more, such as about 33-45%, after aging at 800° C. under atmospheric pressure in an atmosphere of 100% steam for 17 o'clock.

AT 7. The modified Y-type molecular sieve of claim B1, wherein the modified Y-type molecular sieve has a relative crystallinity of approximately 58-70%.

AT 8. Modified Y-type molecular sieve according to any one of paragraphs. B1-B7, wherein the modified Y-type molecular sieve has a magnesium oxide content of approximately 0.6-4.3 wt. %, sodium oxide content approximately 0.2-0.5 wt. %, a lattice constant of approximately 2.442-2.450 nm and a silica-alumina lattice ratio of approximately 8.4-12.6.

AT 9. A method for producing a modified Y-type molecular sieve, comprising the steps of:

(1) contacting the NaY molecular sieve with a soluble magnesium salt solution for an ion exchange reaction, filtration, washing, and optionally drying to produce a magnesium-containing Y-type molecular sieve with a normal lattice constant and reduced sodium oxide content;

(2) subjecting the above Y-type magnesium-containing molecular sieve of normal lattice constant and reduced sodium oxide content to calcination at a temperature of about 350-480° C. in an atmosphere of about 30-90 vol.% steam for about 4.5-7 hours, optionally drying to obtain a Y-type molecular sieve with a reduced lattice constant; And

(3) contacting the reduced lattice constant type Y molecular sieve with gaseous silicon tetrachloride to react at a weight ratio of SiCl ₄ to reduced lattice constant type Y molecular sieve on a dry matter basis of about 0.1:1 to about 0.7 :1 and a reaction temperature of about 200-650° C. for a reaction time of about 10 minutes to about 5 hours, washing and filtering to obtain a modified Y-type molecular sieve.

AT 10 O'CLOCK. The method according to claim B9, wherein the magnesium-containing Y-type molecular sieve with normal lattice constant and reduced sodium oxide content obtained in step (1) has a lattice constant of approximately 2.465-2.472 nm and a sodium oxide content of not more than 8, 8 wt. %.

AT 11. The method according to claim B9, wherein in step (1) the magnesium-containing Y-type molecular sieve with normal lattice constant and reduced sodium oxide content has a magnesium content of approximately 0.6-5.5 wt. % in terms of MgO, sodium oxide content is approximately 4-8.8 wt. %, for example approximately 5.5-8.5 wt. %, and a lattice constant of approximately 2.465-2.472 nm.

AT 12. The method according to claim B9, wherein step (1) of contacting the NaY type molecular sieve with a soluble magnesium salt solution for an ion exchange reaction is carried out by mixing the NaY type molecular sieve, the soluble magnesium salt and water at a mass ratio of NaY type molecular sieve: soluble magnesium salt : ШО approximately 1:0.005-0.19:5-15 and stirring.

B13. The method according to claim B10 or B12, wherein step (1) of contacting the NaY type molecular sieve with a solution of soluble magnesium salts for an ion exchange reaction involves: mixing the NaY type molecular sieve with water, adding a magnesium salt and/or a magnesium salt solution while stirring to ion exchange reactions, filtration and washing; conditions for the ion exchange reaction include: an exchange temperature of approximately 15-95° C. and an exchange time of approximately 30-120 minutes, the soluble magnesium salt solution being an aqueous solution of soluble magnesium salt; and the soluble magnesium salt is preferably magnesium chloride and/or magnesium nitrate.

B14. The method according to claim B9, wherein in step (2) the firing temperature is approximately 380-460°C, the firing atmosphere is an atmosphere of approximately 40-80% steam, and the firing time is approximately 5-6 hours.

B15. The method of claim B9, wherein the Y-type molecular sieve with reduced lattice constant obtained in step (2) has a lattice constant of about 2,450-2,462 nm and a water content of not more than about 1 wt. %.

B16. The method of claim B9, wherein the washing of step (3) is carried out by washing with water under conditions including a molecular sieve:WO ratio of approximately 1:6-15, a pH of approximately 2.5-5.0 and a washing temperature of approximately 30-60° WITH.

C1. Catalytic cracking catalyst containing 10-50 wt. % based on dry matter of modified molecular sieve type Y, 10-40 wt. % of alumina-based binder in terms of aluminum oxide and 10-80 wt. % in terms of clay dry matter; wherein the modified Y-type molecular sieve has a magnesium oxide content of approximately 0.5-4.5 wt. %, sodium oxide content approximately 0.1-0.5 wt. %, total pore volume 0.33-0.39 ml/g, ratio of secondary pore volume with pore size 2-100 nm to total pore volume approximately 10-25%, lattice constant approximately 2.440-2.455 nm, ratio of non-lattice aluminum content to the total aluminum content of not more than about 20%, a lattice breakdown temperature of not less than about 1040° C., and a ratio of acid B to acid L in the total acid content of not less than about 2.30, as determined by infrared spectroscopy of adsorbed pyridine at 200°C; wherein the molecular sieve does not have an absorption peak at a wavelength of 285-295 nm in its UV-visible light absorption spectrum obtained by UV-visible spectrum analysis.

C2. The catalytic cracking catalyst according to claim C1, wherein the modified Y-type molecular sieve has a ratio of secondary pore volume with a pore size of 2-100 nm to the total pore volume of approximately 15-21%, a ratio of non-lattice aluminum content to total aluminum content of approximately 13-19% , the ratio of silicon dioxide-alumina in the crystal lattice is approximately 7.3-14, which is calculated as the molar ratio of SiO ₂ /Al ₂ O ₃ , the temperature of destruction of the crystal lattice is 1045-1080 ° C and the ratio of acid B to acid L in the total acid content approximately 2.4-4.2, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

C3. The catalytic cracking catalyst of claim C1, wherein the modified Y-type molecular sieve is characterized by maintaining a relative crystallinity of about 33% or more, such as about 33-45%, after severe aging at 800° C. under atmospheric pressure in an atmosphere of 100% steam for 17 o'clock.

C4. The catalytic cracking catalyst according to claim C1, wherein the modified Y-type molecular sieve has a relative crystallinity of approximately 58-70%.

C5. Catalytic cracking catalyst according to any one of paragraphs. C1-C4, in which the modified Y-type molecular sieve has a magnesium oxide content of approximately 0.6-4.3 wt. %, sodium oxide content approximately 0.2-0.5 wt. %, a lattice constant of approximately 2.442-2.450 nm and a silica-alumina lattice ratio of approximately 8.4-12.6.

C6. A method of producing a catalytic cracking catalyst, comprising the steps of preparing a modified Y-type molecular sieve, forming a slurry containing the modified Y-type molecular sieve, an alumina binder, clay and water, and spray drying, wherein the modified Y-type molecular sieve is produced by a method comprising the steps of: :

(1) contacting the NaY molecular sieve with a soluble magnesium salt solution for an ion exchange reaction, filtration, washing, and optionally drying to produce a magnesium-containing Y-type molecular sieve with a normal lattice constant and reduced sodium oxide content;

(2) subjecting the above Y-type magnesium-containing molecular sieve of normal lattice constant and reduced sodium oxide content to calcination at a temperature of about 350-480° C. in an atmosphere of about 30-90 vol.% steam for about 4.5-7 hours, optionally drying to obtain a Y-type molecular sieve with a reduced lattice constant;

(3) contacting the reduced lattice constant type Y molecular sieve with gaseous silicon tetrachloride to react at a weight ratio of SiCl ₄ to reduced lattice constant type Y molecular sieve on a dry matter basis of from about 0.1:1 to about 0, 7:1 and a reaction temperature of about 200-650° C. for a reaction time of about 10 minutes to about 5 hours, washing and filtering to obtain a modified Y-type molecular sieve.

C7. The method according to claim C6, wherein the magnesium-containing Y-type molecular sieve with normal lattice constant and reduced sodium oxide content obtained in step (1) has a lattice constant of approximately 2.465-2.472 nm and a sodium oxide content of not more than 8, 8 wt. %; the reduced lattice constant type Y molecular sieve obtained in step (2) has a lattice constant of about 2,450-2,462 nm and a water content of no more than about 1 wt. %.

C8. The method according to claim C7, wherein in step (1) the magnesium-containing Y-type molecular sieve with normal lattice constant and reduced sodium oxide content has a magnesium content of approximately 0.6-5.5 wt. % in terms of MgO, sodium oxide content is approximately 4-8.8 wt. %, for example approximately 5.5-8.5 wt. %, and a lattice constant of approximately 2.465-2.472 nm.

C9. The method according to claim C6, wherein step (1) of contacting the NaY type molecular sieve with a solution of soluble magnesium salts for an ion exchange reaction is carried out by mixing the NaY type molecular sieve, soluble magnesium salt and water at a mass ratio of NaY type molecular sieve: soluble magnesium salt : ШО approximately 1:0.005-0.19:5-15 and stirring.

C10. Method according to paragraphs. C6 or C9, in which step (1) of contacting the NaY type molecular sieve with a solution of soluble magnesium salts for an ion exchange reaction involves: mixing the NaY type molecular sieve with water, adding a soluble magnesium salt and/or a soluble magnesium salt solution while stirring to carry out the reaction ion exchange, filtration and washing; conditions for the ion exchange reaction include: an exchange temperature of about 15-95° C. and an exchange time of about 30-120 minutes, the soluble magnesium salt being preferably magnesium chloride and/or magnesium nitrate.

C11. The method according to claim C6, wherein in step (2) the firing temperature is approximately 380-460°C, the firing atmosphere is an atmosphere of approximately 40-80% steam, and the firing time is approximately 5-6 hours.

C12. The method of claim C6, wherein the washing of step (3) is carried out by washing with water under conditions including a molecular sieve:WO ratio of about 1:6-15, a pH of about 2.5-5.0 and a washing temperature of about 30-60° WITH.

C13. A catalytic cracking method comprising the step of contacting heavy oil with a catalytic cracking catalyst under FCC conditions, wherein the catalytic cracking catalyst is a catalytic cracking catalyst according to any one of claims. C1-C5; and FCC conditions include, for example: reaction temperature of approximately 480-530°C, reaction time of 1-10 seconds, catalyst to oil weight ratio of 3-20:1.

D1. A modified Y-type molecular sieve having a calcium oxide content of approximately 0.7-6.3 wt. %, sodium oxide content approximately 0.1-0.5 wt. %, total pore volume 0.33-0.39 ml/g, ratio of secondary pore volume with pore size 2-100 nm to total pore volume approximately 10-25%, lattice constant approximately 2.440-2.455 nm, ratio of non-lattice aluminum content to a total aluminum content of not more than about 20%, a lattice breakdown temperature of not less than about 1040° C., and a ratio of acid B to acid L in the total acid content of not less than about 2.30, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

D2. The modified Y-type molecular sieve of claim D1, wherein the modified Y-type molecular sieve has a secondary pore volume ratio of 2-100 nm pore size to total pore volume of approximately 15-21%.

D3. The modified Y-type molecular sieve according to claim D1, wherein the modified Y-type molecular sieve has a lattice breakdown temperature of approximately 1040-1080°C, for example 1040-1055°C.

D4. Modified molecular sieve type Y according to item D1, with a ratio of acid B to acid L in the total acid content of approximately 2.4-4.2, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

D5. The modified Y-type molecular sieve of claim D1, wherein the modified Y-type molecular sieve has a non-lattice aluminum to total aluminum content ratio of approximately 13-19% and a silica-alumina lattice ratio of approximately 7.3-14, calculated as molar SiO ₂ /Al ₂ O ₃ ratio.

D6. The modified Y-type molecular sieve of claim D1, wherein the modified Y-type molecular sieve is characterized by maintaining a relative crystallinity of about 33% or more, such as about 33-45%, after aging at 800° C. under atmospheric pressure in an atmosphere of 100% steam for 17 o'clock.

D7. The modified Y-type molecular sieve of claim D1, wherein the modified Y-type molecular sieve has a relative crystallinity of approximately 58-75%.

D8. Modified Y-type molecular sieve according to any one of paragraphs. D1-D7, wherein the modified Y-type molecular sieve has a calcium oxide content of approximately 0.9-5.9 wt. %, for example, 1.5-6 wt. %, sodium oxide content approximately 0.2-0.5 wt. %, a lattice constant of approximately 2.442-2.452 nm and a silica-alumina lattice ratio of approximately 8.5-12.6.

D9. A method for producing a modified Y-type molecular sieve, comprising the steps of:

(1) contacting the NaY molecular sieve with a soluble calcium salt solution for an ion exchange reaction, filtering, washing, and optionally drying to produce a calcium-containing Y-type molecular sieve with a normal lattice constant and reduced sodium oxide content;

(2) subjecting a calcium-containing Y-type molecular sieve of normal lattice constant and reduced sodium oxide content to calcination at a temperature of about 350-480° C. in an atmosphere of about 30-90 vol.% steam for about 4.5-7 hours, optionally drying to obtain a Y-type molecular sieve with a reduced lattice constant;

(3) contacting the reduced lattice constant type Y molecular sieve with gaseous silicon tetrachloride to react at a weight ratio of SiCl ₄ to reduced lattice constant type Y molecular sieve on a dry matter basis of from about 0.1:1 to about 0, 7:1 and a reaction temperature of about 200-650° C. for a reaction time of about 10 minutes to about 5 hours, washing and filtering to obtain a modified Y-type molecular sieve.

D10. The method according to claim D9, wherein the calcium-containing Y-type molecular sieve with normal lattice constant and reduced sodium oxide content obtained in step (1) has a lattice constant of approximately 2.465-2.472 nm and a sodium oxide content of not more than 8, 8 wt. %.

D11. The method according to claim D9, wherein in step (1) the calcium-containing molecular sieve of type Y with normal lattice constant and reduced sodium oxide content has a calcium content of approximately 0.8-10 wt. % in terms of CaO, sodium oxide content is approximately 4-8.8 wt. %, for example approximately 5-7.5 wt. %, and a lattice constant of approximately 2.465-2.472 nm.

D12. The method according to claim D9, wherein step (1) of contacting the NaY type molecular sieve with the soluble calcium salt solution for ion exchange is carried out by mixing the NaY type molecular sieve, the soluble calcium salt and water at a mass ratio of NaY type molecular sieve:soluble calcium salt: H2O 1:0.009-0.28:5-15 and stirring, wherein the soluble calcium salt can be, for example, calcium chloride and/or calcium nitrate.

D13. Method according to paragraphs. D9 or D12, in which step (1) of contacting the NaY type molecular sieve with a soluble calcium salt solution for an ion exchange reaction involves: mixing the NaY type molecular sieve with water, adding a soluble calcium salt and/or a soluble calcium salt solution while stirring to carry out the reaction ion exchange, filtration and washing; conditions for the ion exchange reaction include: an exchange temperature of approximately 15-95°C and an exchange time of approximately 30-120 minutes.

D14. The method according to claim D9, wherein in step (2) the firing temperature is approximately 380-460°C, the firing atmosphere is an atmosphere of approximately 40-80% steam, and the firing time is approximately 5-6 hours.

D15. The method of claim D9, wherein the Y-type molecular sieve with reduced lattice constant obtained in step (2) has a lattice constant of about 2,450-2,462 nm and a water content of not more than about 1 wt. %.

D16. The method of claim D9, wherein the washing of step (3) is carried out by washing with water under conditions including a molecular sieve:H ₂ O ratio of about 1:6-15, a pH of about 2.5-5.0 and a washing temperature of about 30- 60°C.

E1. Catalytic cracking catalyst containing 10-50 wt. % based on dry matter of modified molecular sieve type Y, 10-40 wt. % of alumina-based binder in terms of aluminum oxide and 10-80 wt. % in terms of clay dry matter; wherein the modified Y-type molecular sieve has a calcium oxide content of approximately 0.7-6.3 wt. %, sodium oxide content approximately 0.1-0.5 wt. %, total pore volume 0.33-0.39 ml/g, ratio of secondary pore volume with pore size 2-100 nm to total pore volume approximately 10-25%, lattice constant approximately 2.440-2.455 nm, ratio of non-lattice aluminum content to the total aluminum content of not more than about 20%, a lattice breakdown temperature of not less than about 1040° C., and a ratio of acid B to acid L in the total acid content of not less than about 2.30, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

E2. The catalytic cracking catalyst according to claim E1, wherein the modified Y-type molecular sieve has a ratio of secondary pore volume with a pore size of 2-100 nm to the total pore volume of approximately 15-21%, a ratio of non-lattice aluminum content to total aluminum content of approximately 13-19% , the ratio of silicon dioxide-alumina in the crystal lattice is approximately 7.3-14, which is calculated as the molar ratio of SiO ₂ /Al ₂ O ₃ , the temperature of destruction of the crystal lattice is 1045-1080 ° C and the ratio of acid B to acid L in the total acid content approximately 2.4-4.2, as determined by infrared spectroscopy of adsorbed pyridine at 200°C.

E3. Catalytic cracking catalyst according to claims. E1 or E2, wherein the modified Y-type molecular sieve is characterized by retaining a relative crystallinity of about 33% or more, for example about 33-45%, after severe aging at 800C under atmospheric pressure in an atmosphere of 100% steam for 17 hours.

E4. Catalytic cracking catalyst according to claims. El, E2 or E3, in which the modified Y-type molecular sieve has a relative crystallinity of approximately 58-75%.

E5. Catalytic cracking catalyst according to any one of paragraphs. E1-E4, in which the modified Y-type molecular sieve has a calcium oxide content of approximately 0.9-5.9 wt. %, sodium oxide content approximately 0.2-0.5 wt. %, a lattice constant of approximately 2.442-2.450 nm and a silica-alumina lattice ratio of approximately 8.5-12.6.

E6. A method of producing a catalytic cracking catalyst, comprising the steps of preparing a modified Y-type molecular sieve, forming a slurry containing the modified Y-type molecular sieve, an alumina binder, clay and water, and spray drying, wherein the modified Y-type molecular sieve is produced by a method comprising the steps of: :

(1) contacting the NaY molecular sieve with a soluble calcium salt solution for an ion exchange reaction, filtering, washing, and optionally drying to produce a calcium-containing Y-type molecular sieve with a normal lattice constant and reduced sodium oxide content;

(2) subjecting a calcium-containing Y-type molecular sieve of normal lattice constant and reduced sodium oxide content to calcination at a temperature of about 350-480° C. in an atmosphere of about 30-90 vol.% steam for about 4.5-7 hours, optionally drying to obtain a Y-type molecular sieve with a reduced lattice constant;

(3) contacting the reduced lattice constant type Y molecular sieve with gaseous silicon tetrachloride to react at a weight ratio of SiCU to reduced lattice constant type Y molecular sieve on a dry matter basis of from about 0.1:1 to about 0.7 :1 and a reaction temperature of about 200-650° C. for a reaction time of about 10 minutes to about 5 hours, washing and filtering to obtain a modified Y-type molecular sieve.

E7. The method according to claim E6, wherein the calcium-containing Y-type molecular sieve with normal lattice constant and reduced sodium oxide content obtained in step (1) has a lattice constant of approximately 2.465-2.472 nm and a sodium oxide content of not more than 8, 8 wt. %; the reduced lattice constant type Y molecular sieve obtained in step (2) has a lattice constant of about 2,450-2,462 nm and a water content of no more than about 1 wt. %.

E8. The method according to claim E7, in which in step (1) the calcium-containing molecular sieve of type Y with normal lattice constant and reduced sodium oxide content has a calcium content of approximately 0.8-10 wt. % in terms of CaO, sodium oxide content is approximately 4-8.8 wt. %, for example approximately 5-7.5 wt. %, and a lattice constant of approximately 2.465-2.472 nm.

E9. The method according to claim E6, wherein step (1) of contacting the NaY type molecular sieve with a soluble calcium salt solution for an ion exchange reaction is carried out by mixing the NaY type molecular sieve, the soluble calcium salt and water at a mass ratio of NaY type molecular sieve:soluble calcium salt : H ₂ O 1: 0.009-0.28: 5-15 and stirring.

E10. Method according to paragraphs. E6 or E9, in which step (1) of contacting the NaY type molecular sieve with a soluble calcium salt solution for an ion exchange reaction involves: mixing the NaY type molecular sieve with water, adding a soluble calcium salt and/or a soluble calcium salt solution while stirring to carry out the reaction ion exchange, filtration and washing; conditions for the ion exchange reaction include: an exchange temperature of about 15-95° C. and an exchange time of about 30-120 minutes, the soluble calcium salt being preferably calcium chloride and/or calcium nitrate.

E11. The method according to claim E6, wherein in step (2) the firing temperature is approximately 380-460°C, the firing atmosphere is an atmosphere of approximately 40-80% steam, and the firing time is approximately 5-6 hours.

E12. The method of claim E6, wherein the washing of step (3) is carried out by washing with water under conditions including a molecular sieve:WO ratio of about 1:6-15, a pH of about 2.5-5.0 and a washing temperature of about 30-60° WITH.

E13. A catalytic cracking method comprising the step of contacting heavy oil with a catalytic cracking catalyst under FCC conditions, wherein the catalytic cracking catalyst is a catalytic cracking catalyst according to any one of claims. E1-E5; FCC conditions include, for example, a reaction temperature of approximately 480-530°C, a reaction time of 1-10 seconds, and a catalyst to oil weight ratio of 3-20:1.

Examples

The present application will be further illustrated by the following examples, without limiting the present application, however.

Raw Materials: In the following examples and comparative examples, NaY type molecular sieves are supplied by Qilu Branch of Sinopec Catalyst Co., Ltd., whose sodium content is 13.5 mass. % based on sodium oxide, the silica-alumina lattice ratio (SiO ₂ /Al ₂ O ₃ molar ratio) is 4.6, the lattice constant is 2.470 nm, and the relative crystallinity is 90%; Magnesium chloride and magnesium nitrate are chemically pure reagents produced by Sinopharm Chemical Reagent Co., Ltd. (Hushi); Calcium chloride and calcium nitrate are chemically pure reagents produced by Sinopharm Chemical Reagent Co., Ltd. (Hushi); pseudoboehmite is an industrial product produced by Shandong Aluminum Smelter, with a solid content of 61 wt. %; kaolin is a specialty kaolin for cracking catalysts manufactured by China Kaolin Clay Co., Ltd., of Suzhou, with a solids content of 76 wt. %; aluminum sol is supplied by Qilu Division of Sinopec Catalyst Co., Ltd., with an aluminum oxide content of 21 wt. %.

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

Analytical Method: In each of the comparative examples and examples, the element content of the molecular sieve was determined using X-ray fluorescence spectrometry; The lattice constant and relative crystallinity of the molecular sieve were determined using X-ray powder diffractometry (XRD) according to the standard method RIPP 145-90, RIPP 146-90 (see "Petrochemical Analysis Methods (RIPP Test Methods)", edited by Cuiding YANG et al. , Science Press, September 1990, First Edition, pp. 412-415), the silica-alumina ratio in the molecular sieve lattice was calculated according to the following equation:

where a ₀ refers to the lattice constant, the unit of which is nm.

The total silica-alumina ratio of the molecular sieve was calculated based on the Si and Al elemental contents determined by X-ray fluorescence spectrometry. The ratio of lattice Al content to total Al content was calculated based on the lattice silica-alumina ratio determined by XRD and the total silica-alumina ratio determined by XRF, and then the ratio of non-lattice Al content to total Al content. The lattice failure temperature was determined using differential thermal analysis (DTA).

In each of the comparative examples and examples, the type of acid site of the molecular sieve and the acid content thereof were determined by infrared spectroscopy of adsorbed pyridine. The instrument was an IFS113V FT-IR (Fourier transform infrared) spectrometer from Bruker Company, USA. The method for determining the acid content using infrared spectroscopy of adsorbed pyridine at 200°C was as follows: a self-supporting sample plate was placed in the in-situ cell of the infrared spectrometer and sealed; the sample was heated to a temperature of 400°C, evacuated to 10 ^-3 Pa and kept at the temperature for 2 hours to remove gas molecules adsorbed 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 these conditions for 30 minutes to achieve adsorption equilibrium; then the sample was heated to a temperature of 200°C and vacuumed to 10 ^-3 Pa for desorption for 30 minutes; After this, the sample was cooled to room temperature and subjected to spectral analysis in the scanning wavenumber range from 1400 cm ^-1 to 1700 cm ^-1 , and an infrared spectrum of pyridine adsorption of the sample desorbed at 200°C was obtained. The relative amounts of all Brønsted acid sites (B acid sites) and Lewis acid sites (L acid sites) in the molecular sieve were obtained based on the intensities of the characteristic absorption peaks at 1540 cm ^-1 and 1450 cm ^-1 in the infrared light spectrum of the adsorbed pyridine.

UV-vis absorption spectrum analysis was performed using an Agilent Cary300 Multifunction UV-Vis Spectrophotometer (with a diffuse reflectance ball photometer device). The instrument specification was as follows: wavelength range is 190-1100 nm, wavelength accuracy is +/-0.1 nm, wavelength repeatability is +/-0.1 nm, baseline stability is 0.0003/h, diffuse light is less than 0.02%, the photometer accuracy is +/-0.003, and the wavelength interval is 3 nm.

In each of the comparative examples and examples, the secondary pore volume was determined as follows: according to the standard method RIPP 151-90 (see "Petrochemical Analysis Methods (RIPP Test Methods)", Guiding YANG et al., Science Press, September 1990, First Edition, pp. 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 secondary pore volume was obtained by subtracting the micropore volume from the total pore volume.

In each of the Comparative Examples and Examples, the electron binding energy Ols of the molecular sieve was determined as follows: The XPS test was performed on an ESCALab 250 X-ray photoelectron spectrometer from Thermo Fisher. The excitation source was a monochromatic A1 Kα x-ray beam with an energy of 1486.6 eV and a power of 150 W. The penetration energy for narrow scans was 30 eV. The base vacuum at the time of analysis was approximately 6.5×10 ^-10 mbar. The binding energy was calibrated according to the Cls peak (284.8 eV) of the alkyl carbon or contaminated carbon. The processing software was Avantage 5.952, originally installed in the instrument. The binding energy value was determined based on the obtained XPS data.

Example 1

2000 g of NaY type molecular sieve (in terms of dry matter) was added to 20 l of cation-free water and mixed evenly with stirring, 492 ml of Mg(NCh)2 solution (with a concentration of 248 g/l in terms of MgO) was added and the mixture stirred, heated to a temperature of 90-95°C and kept for 1 hour. The mixture was then filtered and washed, and the filter cake was dried at 120°C to obtain a Y-type molecular sieve with a lattice constant of 2.471 nm, sodium content of 6.6 wt. % in terms of sodium oxide and magnesium content of 5.7 wt. % in terms of MgO. The resulting product was then calcined at 390°C in an atmosphere containing 50 vol.% steam and 50 vol.% air for 6 hours to obtain a Y-type molecular sieve with a lattice constant of 2.455 nm, and then dried to obtain a water content of less than 1 wt. %. After this, gaseous SiCl ₄ evaporated by heating was introduced at a mass ratio of SiCl ₄ : molecular sieve type Y (in terms of dry matter) of 0.5: 1, reacted at 400 ° C for 2 hours, then washed with 20 l cation-free water and filtered to obtain a modified Y type molecular sieve of the present application, designated SZ1, the physicochemical properties of which are shown in Table 1.

After aging SZ1 in an unprotected state at 800° C. under atmospheric pressure in an atmosphere of 100% steam for 17 hours (i.e., aged in an atmosphere of 100% steam for 17 hours), the relative crystallinity of the molecular sieve SZ1 before aging was analyzed by XRD and after it and calculated the retention of relative crystallinity after aging. The results are shown in Table 2, in which:

714.5 g of aluminum oxide sol with an aluminum oxide content of 21 wt. % was added to 1565.5 g of water purified from cations, stirring began and 2763 g of kaolin with a solids content of 76 wt. % was added and dispersed for 60 minutes. 2049 g of pseudoboehmite with an aluminum oxide content of 61 wt. % was added to 8146 g of cation-free water, 210 ml of hydrochloric acid with a mass concentration of 36% was added with stirring and a suspension of dispersed kaolin was added after 60 minutes of acidification. Then, 1500 g (on a dry basis) of ground molecular sieve SZ1 was added, mixed uniformly with stirring, then spray dried, washed and dried to obtain a catalyst designated as SC1. The resulting catalyst SC1 contained, in terms of dry matter, 30 wt. % molecular sieve SZ1, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Example 2

2000 g of molecular sieve NaY type (in terms of dry matter) was added to 25 l of water purified from cations and evenly with stirring, 524 ml of MgCh solution (with a concentration of 248 g/l in terms of MgO) was added and the mixture was stirred, heated to temperature 90-95°C and kept for 1 hour. The mixture was then filtered and washed, and the filter cake was dried at 120°C to obtain a Y-type molecular sieve with a lattice constant of 2.471 nm, sodium content of 5.2 wt. % in terms of sodium oxide and magnesium content of 6.2 wt. % in terms of MgO. The resulting product was then calcined at 450°C in an 80% steam atmosphere for 5.5 hours to obtain a Y-type molecular sieve with a lattice constant of 2.461 nm, and then dried to obtain a water content of less than 1 mass. %. After this, gaseous SiCl ₄ , evaporated by heating, was introduced at a mass ratio of SiCl ₄ : molecular sieve type Y 0.6:1, reacted at 480°C for 1.5 hours, then washed with 20 l of cation-free water and filtered to obtain a modified Y type molecular sieve designated as SZ2, the physicochemical properties of which are shown in Table 1.

After aging SZ1 in an unprotected state at 800°C under atmospheric pressure in a 100% steam atmosphere, the crystallinity of the molecular sieve SZ2 before and after aging was analyzed by XRD, and the retention of relative crystallinity after aging was calculated. The results are presented in Table 2.

The microspherical catalyst, designated SC2, was prepared as described in Example 1 by forming a slurry of molecular sieve SZ2, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts. The resulting catalyst SC2 contained, in terms of dry matter, 30 wt. % molecular sieve SZ2, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Example 3

2000 g of molecular sieve of the NaY type (in terms of dry matter) were added to 22 l of water purified from cations and mixed evenly with stirring, 306 ml of MgCl ₂ solution (with a concentration of 248 g/l in terms of MgO) was added and the mixture was stirred, heated to a temperature of 90-95°C and kept for 1 hour with stirring. The mixture was then filtered and washed, and the filter cake was dried at 120°C to obtain a Y-type molecular sieve with a lattice constant of 2.471 nm, sodium content of 7.2 wt. % in terms of sodium oxide and magnesium content of 3.4 wt. % in terms of MgO. The resulting product was then calcined at 470° C. in an atmosphere of 70 vol.% steam for 5 hours to obtain a Y-type molecular sieve with a lattice constant of 2.458 nm, and then dried to obtain a water content of less than 1 mass. %. After this, gaseous SiCl ₄ , evaporated by heating, was introduced at a mass ratio of SiCl _4: Y type molecular sieve of 0.4:1, reacted at 500°C for 1 hour, then washed with 20 L of cation-free water and filtered to obtain a modified Y-type molecular sieve designated as SZ3, the physicochemical properties of which are shown in Table 1.

After aging SZ3 in an unprotected state at 800°C under atmospheric pressure in a 100% steam atmosphere, the crystallinity of the SZ3 molecular sieve before and after aging was analyzed by XRD, and the retention of relative crystallinity after aging was calculated. The results are presented in Table 2.

The microspherical catalyst, designated SC3, was prepared by forming a slurry of SZ3 molecular sieve, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example 1). The resulting catalyst SC3 contained, in terms of dry matter, 30 wt. % molecular sieve SZ3, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Example 4

The microspherical catalyst, designated SC4, was prepared by forming a slurry of molecular sieve SZ2, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example 1). The resulting SC4 catalyst contained, in terms of dry matter, 25 wt. % molecular sieve SZ2, 47 wt. % kaolin, 24 wt. % pseudoboehmite and 4 wt. % aluminum oxide sol.

Example 5

The microspherical catalyst, designated SC5, was prepared by forming a slurry of molecular sieve SZ2, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example 1). The resulting SC5 catalyst contained, in terms of dry matter, 40 wt. % molecular sieve SZ2, 30 wt. % kaolin, 20 wt. % pseudoboehmite and 10 wt. % aluminum oxide sol.

Comparative example 1

2000 g of molecular sieve of the NaY type (in terms of dry matter) were added to 20 l of water purified from cations, mixed evenly with stirring, 1000 g of (NH ₄ ) ₂ SO ₄ were added and the mixture was stirred, heated to a temperature of 90-95 ° C and kept for 1 hour. Then, after filtration and washing, the filter cake was dried at 120C, and then subjected to hydrothermal treatment by firing at 650C in an atmosphere of 100% steam for 5 hours. Then the resulting product was added to 20 liters of water purified from cations, mixed evenly with stirring, 1000 g of (NH ₄ ) ₂ SO ₄ was added and the mixture was stirred, heated to a temperature of 90-95°C and kept for 1 hour. Then, after filtration and washing, the filter cake was dried at 120°C and then subjected to a second hydrothermal treatment by firing at 650°C in a 100% steam atmosphere for 5 hours to obtain a hydrothermally superstabilized magnesium-free Y-type molecular sieve, which was subjected to two ion exchange stages and two hydrothermal superstabilization stages, designated DZ1, the physicochemical properties of which are shown in Table 1.

After aging DZ1 in an unprotected state at 800° C. under atmospheric pressure in a 100% steam atmosphere, the crystallinity of the DZ1 molecular sieve before and after aging was analyzed by XRD, and the relative crystallinity retention after aging was calculated. The results are presented in Table 2.

The microspherical catalyst, designated DC1, was prepared by forming a slurry of molecular sieve DZ1, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example 1). The resulting catalyst DC1 contained, in terms of dry matter, 30 wt. % molecular sieve DZ1, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Comparative example 2

2000 g of molecular sieve of the NaY type (in terms of dry matter) were added to 20 l of water purified from cations, mixed evenly with stirring, 1000 g of (NH ₄ ) ₂ SO ₄ were added and the mixture was stirred, heated to a temperature of 90-95 ° C and kept for 1 hour. Then, after filtration and washing, the filter cake was dried at 120°C and then subjected to hydrothermal treatment by firing at 650°C in an atmosphere of 100% steam for 5 hours. Then the resulting product was added to 20 l of water purified from cations, mixed evenly with stirring, 290 ml of Mg(NO ₃ ) ₂ solution (with a concentration of 248 g/l in terms of MgO) and 900 g of (NH ₄ ) ₂ SO ₄ and the mixture was stirred, heated to a temperature of 90-95°C and kept for 1 hour. Then, after filtration and washing, the filter cake was dried at 120°C, and then subjected to a second hydrothermal treatment by calcination at 650°C in a 100% steam atmosphere for 5 hours to obtain a hydrothermally superstabilized rare earth element-containing Y-type molecular sieve, which was subjected to two stages ion exchange and two stages of hydrothermal superstabilization, designated DZ2, the physicochemical properties of which are shown in Table 1.

After aging DZ2 in an unprotected state at 800° C. under atmospheric pressure in a 100% steam atmosphere, the crystallinity of the DZ2 molecular sieve before and after aging was analyzed by XRD, and the retention of relative crystallinity after aging was calculated. The results are presented in Table 2.

The microspherical catalyst, designated DC2, was prepared by forming a slurry of molecular sieve DZ2, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example 1). The resulting catalyst DC2 contained, in terms of dry matter, 30 wt. % molecular sieve DZ2, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Comparative example 3

2000 g of NaY molecular sieve (in terms of dry matter) was added to 20 l of cation-free water and mixed evenly with stirring, 347 ml of Mg(NO ₃ ) ₂ solution (with a concentration of 248 g/l in terms of MgO) was added and the mixture was stirred, heated to a temperature of 90-95°C and kept for 1 hour. The mixture was then filtered, washed and dried to obtain a water content of less than 1 wt. %. The resulting product was then subjected to gas-phase superstabilization by introducing heat-evaporated SiCl ₄ gas at a weight ratio of SiCl ₄ : Y-type molecular sieve of 0.4:1 and reacted at 580° C. for 1.5 hours. The resulting product was washed with 20 L of decationized water and filtered to obtain a gas-phase ultra-stabilized high silica Y type molecular sieve designated DZ3, the physicochemical properties of which are shown in Table 1.

After aging DZ3 in an unprotected state at 800° C. under atmospheric pressure in a 100% steam atmosphere, the crystallinity of the DZ3 molecular sieve before and after aging was analyzed by XRD, and the retention of relative crystallinity after aging was calculated. The results are presented in Table 2.

The microspherical catalyst, designated DC3, was prepared by forming a slurry of DZ3 molecular sieve, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example 1). The resulting catalyst DC3 contained, in terms of dry matter, 30 wt. % molecular sieve DZ3, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Reference Example 1

2000 g of molecular sieve of the NaY type (in terms of dry matter) were added to 20 l of water purified from cations, mixed evenly with stirring, 600 ml of RE(NO ₃ ) ₃ solution (with a concentration of 319 g/l in terms of RE ₂ O) was added ₃ ) and the mixture was stirred, heated to a temperature of 90-95°C and kept for 1 hour. Then, after filtration and washing, the filter cake was dried at 120°C to obtain a Y-type molecular sieve with a lattice constant of 2.471 nm, sodium content of 7.0 wt. % in terms of sodium oxide and a rare earth element content of 8.8 wt. % in terms of RE ₂ O. The resulting product was then calcined at 390°C in an atmosphere containing 50 vol.% steam and 50 vol.% air for 6 hours to obtain a Y-type molecular sieve with a lattice constant of 2.455 nm, and then dried to obtain a water content of less than 1 wt. %. After this, gaseous SiCl ₄ , evaporated by heating, was introduced at a mass ratio of SiCl ₄ : molecular sieve type Y (in terms of dry matter) of 0.5: 1, reacted at 400 ° C for 2 hours, then washed with 20 l water purified from cations and filtered. A sample of molecular sieve filter cake was added to a solution containing magnesium chloride where the weight ratio of water to molecular sieve was 2.5 and the weight ratio of magnesium (expressed as magnesium oxide) to molecular sieve was 0.01. The mixture was stirred at 25°C for 40 minutes, then ammonia water was added and the pH was adjusted to 8.5. The resulting product was uniformly mixed with stirring, filtered and washed with deionized water. Thereafter, the filter cake was dried and then calcined at 550° C. for 2 hours to obtain a magnesium-containing modified Y-type molecular sieve designated as SZB1, the physicochemical properties of which are shown in Table 1.

The reference catalyst, designated SCB1, was prepared using SZB1 following the procedure described in Example 1 for catalyst preparation.

From Table 1, it can be seen that the very stable modified Y type molecular sieve of the present application has the following advantages: low sodium content, relatively low non-lattice aluminum content with a relatively high silica-alumina ratio, relatively high secondary pore volume ratio with pore size 2, 0-100 nm to total pore volume, a relatively high acid B/acid L ratio (the ratio of the total acid B content to the acid L content), relatively high crystallinity, determined at a relatively small lattice constant and a certain magnesium content of the molecular sieve, and high thermal stability.

From Table 2, it can be seen that the modified Y type molecular sieve of the present application shows relatively high retention of relative crystallinity after aging in an unprotected state at a severe condition of 800° C. for 17 hours, indicating that the modified Y type molecular sieve of the present application has high hydrothermal stability .

Examples 6-10

The catalysts SCI, SC2, SC3, SC4 and SC5 obtained in examples 1-5, respectively, were aged at 800°C in an atmosphere of 100% steam for 4 or 17 hours, and then the microactivity of the light oil catalysts was assessed. The results are presented in Table 3.

Microactivity assessment for light oil

The light oil microactivity of each catalyst was assessed according to the standard RIPP 92-90 method (see "Petrochemical Analysis Methods (RIPP Test Methods)", edited by Cuiding YANG et al., Science Press, September 1990, First Edition, pp. 263-268 ) in which the catalyst loading was 5.0 g, the reaction temperature was 460°C, and the feed oil was Dagang light diesel fuel with a boiling range of 235-337°C. The product composition was analyzed by gas chromatography and microactivity for light oil was calculated based on the product composition.

Microactivity for light oil (MA) = (gasoline production below 216°C + gas production + coke production) / total amount of raw materials × 100%.

Comparative examples 4-6

Catalysts DC1, DC2 and DC3 obtained in comparative examples 1-3, respectively, were aged at 800°C in an atmosphere of 100% steam for 4 or 17 hours, and then the microactivity of the light oil catalysts was assessed according to the method described in examples 4- 6. The results are presented in Table 3.

Examples 11-15

Examples 11-15 show the performance characteristics for catalytic cracking of catalysts containing a modified Y-type molecular sieve according to the present application.

Catalysts SC1, SC2, SC3, SC4 and SC5 were aged at 800° C. under atmospheric pressure in a 100% steam atmosphere and their performance for catalytic cracking was evaluated in a small fixed fluidized bed reactor (ACE). The cracking gas and product oils were collected separately and analyzed by gas chromatography. The catalyst loading was 9 g, the reaction temperature was 500°C, the average hourly feed rate was 16 h ^-1 , and the mass ratio of catalyst to oil was shown in Table 5. The properties of the feedstock used in the ACE test are shown in Table 4, and the results are shown in Table 5.

Branched hydrocarbon content in gasoline (wt.%) = isoparaffin content in gasoline (wt. %) + branched alkene content in gasoline (wt. %).

Comparative Examples 7-9

Comparative Examples 7-9 show the catalytic cracking performance of catalysts containing the ultrastable Y-type molecular sieve obtained in Comparative Examples 1-3.

Catalysts DC1, DC2 and DC3 were aged at 800° C. under atmospheric pressure under a 100% steam atmosphere and their catalytic cracking performance was evaluated in a small fixed fluidized bed (ACE) reactor according to the method described in Example 11. Crude Oil Properties , used in the ACE test are shown in Table 4, and the results are shown in Table 5.

Reference example 2

SZB1 was evaluated according to the method described in Examples 11-15, and the results are shown in Table 5.

From the results shown in Tables 3 and 5, it can be seen that the catalytic cracking catalyst obtained using the molecular sieve of the present application as the active component shows very strong hydrothermal stability, significantly lower selectivity to coke and significantly higher liquid yield, yield light oil and gasoline yield, and the branched hydrocarbon content of gasoline is also significantly higher, and the monomethyl branched hydrocarbon content is high.

Example B1

2000 g of NaY molecular sieve (in terms of dry matter) was added to 20 l of water purified from cations and mixed evenly with stirring, 689 ml of Ca(NO ₃ ) ₂ solution (with a concentration of 248 g/l in terms of CaO) was added and the mixture was stirred, heated to a temperature of 90-95°C and kept for 1 hour. The mixture was then filtered and washed, and the filter cake was dried at 120°C to obtain a Y-type molecular sieve with a lattice constant of 2.471 nm, sodium content of 6.6 wt. % in terms of sodium oxide and calcium content of 9.8 wt. % in terms of CaO. The resulting product was then calcined at 390°C in an atmosphere containing 50 vol.% steam and 50 vol.% air for 6 hours to obtain a Y-type molecular sieve with a lattice constant of 2.454 nm, and then dried to obtain a water content of less than 1 wt. %. After this, gaseous SiCl ₄ , evaporated by heating, was introduced at a mass ratio of SiCl ₄ : molecular sieve type Y 0.5:1, reacted at 400°C for 2 hours, then washed with 20 l of cation-free water and filtered with by obtaining a modified Y type molecular sieve of the present application, designated BSZ1, the physicochemical properties of which are shown in Table B1.

After aging BSZ1 in an unprotected state at 800°C under atmospheric pressure in an atmosphere of 100% steam for 17 hours, the relative crystallinity of the BSZ1 molecular sieve before and after aging was analyzed by XRD, and the retention of relative crystallinity after aging was calculated. The results are shown in Table B2.

714.5 g of aluminum oxide sol with an aluminum oxide content of 21 wt. % was added to 1565.5 g of cation-free water, stirring began, and 2763 g of kaolin with a solids content of 76 wt. % was added and dispersed for 60 minutes. 2049 g of pseudoboehmite with an aluminum oxide content of 61 wt. % was added to 8146 g of cation-free water, 210 ml of hydrochloric acid with a mass concentration of 36% was added with stirring and a suspension of dispersed kaolin was added after 60 minutes of acidification. Then, 1500 g (on a dry basis) of ground molecular sieve BSZ1 was added, mixed uniformly with stirring, then spray dried, washed and dried to obtain a catalyst designated as BSC1. The resulting catalyst BSC1 contained, in terms of dry matter, 30 wt. % molecular sieve BSZ1, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Example B2

2000 g of molecular sieve of the NaY type (in terms of dry matter) were added to 25 l of water purified from cations and evenly with stirring, 734 ml of CaCl ₂ solution (with a concentration of 248 g/l in terms of CaO) was added and the mixture was stirred, heated to temperature 90-95°C and kept for 1 hour. The mixture was then filtered and washed, and the filter cake was dried at 120°C to obtain a Y-type molecular sieve with a lattice constant of 2.471 nm, sodium content of 5.2 wt. % in terms of sodium oxide and calcium content of 8.7 wt. % in terms of CaO. The resulting product was then calcined at 450°C in an 80% steam atmosphere for 5.5 hours to obtain a Y-type molecular sieve with a lattice constant of 2.460 nm, and then dried to obtain a water content of less than 1 wt. %. Thereafter, the SiCU gas, evaporated by heating, was introduced at a weight ratio of SiCl ₄ : Y type molecular sieve of 0.6:1, reacted at 480°C for 1.5 hours, then washed with 20 L of cation-free water and filtered to obtain a modified Y-type molecular sieve designated BSZ2, the physicochemical properties of which are shown in Table B1.

After aging BSZ2 in an unprotected state at 800°C under atmospheric pressure in an atmosphere of 100% steam (aging in 100% steam for 17 hours means aged in an atmosphere of 100% steam for 17 hours), the crystallinity of the BSZ2 molecular sieve before and after aging was analyzed using XRD and the retention of relative crystallinity after aging was calculated. The results are shown in Table B2.

The microspherical catalyst, designated BSC2, was prepared as described in Example B1 by forming a slurry of molecular sieve BSZ2, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts. The resulting BSC2 catalyst contained, in terms of dry matter, 30 wt. % molecular sieve BSZ2, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Example B3

2000 g of molecular sieve of the NaY type (in terms of dry matter) were added to 22 l of water purified from cations and mixed evenly with stirring, 428 ml of CaCl ₂ solution (with a concentration of 248 g/l in terms of CaO) was added and the mixture was stirred and heated to a temperature of 90-95°C and kept for 1 hour with stirring. The mixture was then filtered and washed, and the filter cake was dried at 120°C to obtain a Y-type molecular sieve with a lattice constant of 2.471 nm, sodium content of 7.2 wt. % in terms of sodium oxide and calcium content of 4.8 wt. % in terms of CaO. The resulting product was then calcined at 470° C. in an atmosphere of 70 vol.% steam for 5 hours to obtain a Y-type molecular sieve with a lattice constant of 2.457 nm, and then dried to obtain a water content of less than 1 mass. %. After this, gaseous SiCl ₄ , evaporated by heating, was introduced at a mass ratio of SiCl ₄ : molecular sieve type Y 0.4:1, reacted at 500°C for 1 hour, then washed with 20 l of cation-free water and filtered with by obtaining a modified Y-type molecular sieve designated as BSZ3, the physicochemical properties of which are shown in Table B1.

After aging BSZ3 in an unprotected state at 800° C. under atmospheric pressure in an atmosphere of 100% steam, the crystallinity of the BSZ3 molecular sieve before and after aging was analyzed by XRD, and the retention of relative crystallinity after aging was calculated. The results are shown in Table B2.

The microspherical catalyst, designated BSC3, was prepared by forming a slurry of BSZ3 molecular sieve, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example B1). The resulting BSC3 catalyst contained, in terms of dry matter, 30 wt. % molecular sieve BSZ3, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Example B4

The microspherical catalyst, designated BSC4, was prepared by forming a slurry of BSZ2 molecular sieve, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example B1). The resulting BSC4 catalyst contained, in terms of dry matter, 25 wt. % molecular sieve BSZ2, 47 wt. % kaolin, 24 wt. % pseudoboehmite and 4 wt. % aluminum oxide sol.

Example B5

The microspherical catalyst, designated BSC5, was prepared by forming a slurry of BSZ2 molecular sieve, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example B1). The resulting BSC5 catalyst contained, in terms of dry matter, 40 wt. % molecular sieve BSZ2, 30 wt. % kaolin, 20 wt. % pseudoboehmite and 10 wt. % aluminum oxide sol.

Comparative example B1

2000 g of molecular sieve of the NaY type (in terms of dry matter) were added to 20 l of water purified from cations, mixed evenly with stirring, 1000 g of (NH ₄ ) ₂ SO ₄ were added and the mixture was stirred, heated to a temperature of 90-95 ° C and kept for 1 hour. Then, after filtration and washing, the filter cake was dried at 120°C and then subjected to hydrothermal treatment by firing at 650°C in an atmosphere of 100% steam for 5 hours. Then the resulting product was added to 20 liters of water purified from cations, mixed evenly with stirring, 1000 g of (NH ₄ ) ₂ SO ₄ was added and the mixture was stirred, heated to a temperature of 90-95°C and kept for 1 hour. Then, after filtration and washing, the filter cake was dried at 120°C, and then subjected to a second hydrothermal treatment by firing at 650°C in a 100% steam atmosphere for 5 hours to obtain a hydrothermally superstabilized calcium-free Y-type molecular sieve, which was subjected to two ion exchange steps and two hydrothermal overstabilization steps, designated BDZ1, the physicochemical properties of which are shown in Table B1.

After aging BDZ1 in an unprotected state at 800° C. under atmospheric pressure in an atmosphere of 100% steam, the crystallinity of the BDZ1 molecular sieve before and after aging was analyzed by XRD, and the retention of relative crystallinity after aging was calculated. The results are shown in Table B2.

The microspherical catalyst, designated BDC1, was prepared by forming a slurry of molecular sieve BDZ1, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional method for preparing catalytic cracking catalysts (as described in Example B1). The resulting catalyst BDC1 contained, in terms of dry matter, 30 wt. % molecular sieve BDZ1, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Comparative example B2

2000 g of molecular sieve of the NaY type (in terms of dry matter) were added to 20 l of water purified from cations, mixed evenly with stirring, 1000 g of (NH ₄ ) ₂ SO ₄ were added and the mixture was stirred, heated to a temperature of 90-95 ° C and kept for 1 hour. Then, after filtration and washing, the filter cake was dried at 120°C and then subjected to hydrothermal treatment by firing at 650°C in an atmosphere of 100% steam for 5 hours. Then the resulting product was added to 20 l of water purified from cations, mixed evenly with stirring, 406 ml of Ca(NO ₃ ) ₂ solution (with a concentration of 248 g/l in terms of CaO) and 900 g of (NH ₄ ) ₂ SO ₄ and the mixture was stirred, heated to a temperature of 90-95°C and kept for 1 hour. Then, after filtration and washing, the filter cake was dried at 120°C and then subjected to a second hydrothermal treatment by firing at 650°C under 100% steam atmosphere for 5 hours to obtain a hydrothermally superstabilized calcium-containing Y-type molecular sieve, which was subjected to two stages of ionic exchange and two stages of hydrothermal superstabilization, designated as BDZ2, the physicochemical properties of which are shown in Table B1.

After aging BDZ2 in an unprotected state at 800° C. under atmospheric pressure in an atmosphere of 100% steam, the crystallinity of the BDZ2 molecular sieve before and after aging was analyzed by XRD, and the relative crystallinity retention after aging was calculated. The results are shown in Table B2.

The microspherical catalyst, designated BDC2, was prepared by forming a slurry of molecular sieve BDZ2, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example B1). The resulting BDC2 catalyst contained, in terms of dry matter, 30 wt. % molecular sieve BDZ2, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

Comparative Example B3

2000 g of NaY molecular sieve (in terms of dry matter) was added to 20 l of water purified from cations and mixed evenly with stirring, 486 ml of Ca(NO ₃ ) ₂ solution (with a concentration of 248 g/l in terms of CaO) was added and the mixture was stirred, heated to a temperature of 90-95°C and kept for 1 hour. The mixture was then filtered, washed and dried to obtain a water content of less than 1 wt. %. The resulting product was then subjected to gas-phase superstabilization by introducing heat-evaporated SiCl ₄ gas at a weight ratio of SiCl ₄ : Y-type molecular sieve of 0.4:1 and reacted at 580° C. for 1.5 hours. The resulting product was washed with 20 L of decationized water and filtered to obtain a gas-phase ultra-stabilized high silica Y type molecular sieve designated as BDZ3, the physicochemical properties of which are shown in Table B1.

After aging BDZ3 in an unprotected state at 800° C. under atmospheric pressure in an atmosphere of 100% steam, the crystallinity of the BDZ3 molecular sieve before and after aging was analyzed by XRD, and the retention of relative crystallinity after aging was calculated. The results are shown in Table B2.

The microspherical catalyst, designated BDC3, was prepared by forming a slurry of BDZ3 molecular sieve, kaolin, water, pseudoboehmite binder and alumina sol and spray drying according to a conventional process for preparing catalytic cracking catalysts (as described in Example B1). The resulting BDC3 catalyst contained, in terms of dry matter, 30 wt. % molecular sieve BDZ3, 42 wt. % kaolin, 25 wt. % pseudoboehmite and 3 wt. % aluminum oxide sol.

From Table B1, it can be seen that the modified Y type molecular sieve of the present application has the following advantages: low sodium content, relatively low non-lattice aluminum content with a relatively high silica-alumina ratio, relatively high secondary pore volume ratio with a pore size of 2.0- 100 nm to the total pore volume, a relatively high acid B/acid L ratio (the ratio of the total acid B content to the acid L content), relatively high crystallinity, determined at a relatively small lattice constant and a certain magnesium content of the molecular sieve, and high thermal stability.

From Table B2, it can be seen that the modified Y-type molecular sieve of the present application shows relatively high retention of relative crystallinity after aging in an unprotected state at a severe condition of 800°C for 17 hours, indicating that the modified Y-type molecular sieve of the present application has high hydrothermal stability .

Examples Vb-VYu

The catalysts BSC1, BSC2, BSC3, BSC4 and BSC5 obtained in examples B1-B5, respectively, were aged at 800°C in an atmosphere of 100% steam for 4 or 17 hours, and then the microactivity of the light oil catalysts was evaluated. The results are shown in Table 3.

Microactivity assessment for light oil

The light oil microactivity of each catalyst was assessed according to the standard RIPP 92-90 method (see "Petrochemical Analysis Methods (RIPP Test Methods)", edited by Cuiding YANG et al., Science Press, September 1990, First Edition, pp. 263-268 ) in which the catalyst loading was 5.0 g, the reaction temperature was 460°C, and the feed oil was Dagang light diesel fuel with a boiling range of 235-337°C. The product composition was analyzed by gas chromatography and microactivity for light oil was calculated based on the product composition.

Microactivity for light oil (MA) = (gasoline production below 216°C + gas production + coke production) / total amount of raw materials × 100%.

Comparative examples B4-B6

Catalysts BDC1, BDC2 and BDC3 obtained in comparative examples B1-B3, respectively, were aged at 800°C in an atmosphere of 100% steam for 4 or 17 hours, and then the microactivity of the light oil catalysts was assessed according to the method described in example B6. The results are shown in Table B3.

Examples B11-B15

Examples B11-B15 show the performance characteristics for catalytic cracking of catalysts containing a modified Y-type molecular sieve according to the present application.

Catalysts BSC1, BSC2, BSC3, BSC4 and BSC5 were aged at 800° C. under atmospheric pressure in a 100% steam atmosphere and their catalytic cracking performance was evaluated in a small fixed-bed fluidized bed (ACE) reactor. The cracking gas and product oils were collected separately and analyzed by gas chromatography. The catalyst loading was 9 g, the reaction temperature was 500° C., the average hourly feed rate was 16 h ^-1 , and the mass ratio of catalyst to oil was shown in Table B5. The properties of the crude oil used in the ACE test are shown in Table B4 and the results are shown in Table B5.

Gasoline branched hydrocarbon content (wt.%)=gasoline isoparaffin content (wt.%)+gasoline branched alkene content (wt.%) Dimethyl-branched hydrocarbon content (wt.%)=dimethyl isoparaffin content (wt.%) +content of dimethyl-branched alkene (wt.%)

Comparative examples B7-B9

Comparative Examples B7-B9 show the catalytic cracking performance of catalysts containing the ultrastable Y-type molecular sieve obtained in Comparative Examples B1-B3.

Catalysts BDC1, BDC2 and BDC3 were aged at 800° C. under atmospheric pressure under a 100% steam atmosphere and their catalytic cracking performance was evaluated in a small fixed bed reactor (ACE) according to the method described in Example BH. The properties of the crude oil used in the ACE test are shown in Table B4 and the results are shown in Table B5.

From the results shown in Tables B3 and B5, it can be seen that the catalytic cracking catalyst obtained using the molecular sieve of the present application as the active component shows very strong hydrothermal stability, significantly lower selectivity to coke and significantly higher liquid yield, yield light oil and gasoline yield, the content of branched hydrocarbon and dimethyl branched hydrocarbon in gasoline is also significantly higher, and the ratio of dimethyl branched hydrocarbon content/monomethyl branched hydrocarbon content in gasoline is also increased.

In the description above, the idea of the present application has been described with reference to embodiments. However, those skilled in the art will appreciate that various modifications and changes may be made without departing from the scope of the present invention as defined in the appended claims. Accordingly, the description and figures are to be considered as illustrative and not limiting, and all such modifications and changes are intended to be embraced by the present invention.

It should be understood that some of the features described individually in multiple embodiments for the sake of clarity may also be provided in combination in a single embodiment. In contrast, many different features that are described in one embodiment for brevity may also be provided individually or in any subcombination in different embodiments.

Claims (28)

1. Modified Y-type molecular sieve having a modifying metal content of 0.5-6.3 wt. % in terms of the oxide of the modifying metal and the sodium content is not more than 0.5 wt. % based on sodium oxide on a dry matter basis and based on the weight of said modified Y-type molecular sieve, wherein said modifying metal is magnesium and/or calcium, wherein the modified Y-type molecular sieve contains aluminum and silicon, has a ratio of non-lattice aluminum to total aluminum content is not more than 20% and has a silicon dioxide-aluminum oxide ratio in the crystal lattice, calculated as the SiO ₂ /Al ₂ O ₃ molar ratio of 7.3-14, total pore volume 0.33-0.39 ml /g, the ratio of the volume of secondary pores with a pore size of 2-100 nm to the total pore volume is 10-25%, the crystal lattice constant is 2.440-2.455 nm, the destruction temperature of the crystal lattice is not lower than 1040°C and the ratio of B acid to L acid in general acid content of at least 2.30, as determined by infrared spectroscopy of adsorbed pyridine at 200°C. 2. The modified Y-type molecular sieve according to claim 1, wherein the modified Y-type molecular sieve has a ratio of secondary pore volume with a pore size of 2-100 nm to the total pore volume of 15-21%, preferably 17-21%; and/or The modified Y-type molecular sieve has a non-lattice aluminum to total aluminum content ratio of 13-19%. 3. The modified Y-type molecular sieve according to any one of the preceding paragraphs, wherein the modified Y-type molecular sieve has a lattice breakdown temperature of 1040-1080°C, for example 1045-1080°C; and/or preferably the modified Y type molecular sieve has an acid B to acid L ratio of total acid content of 2.3-5.0, more preferably 2.4-4.2, as determined by infrared spectroscopy of adsorbed pyridine at 200°C. 4. The modified Y-type molecular sieve according to any one of the preceding claims, wherein the modified Y-type molecular sieve is characterized by maintaining a relative crystallinity of 33% or more, such as 33-45%, after aging at 800° C. under atmospheric pressure in an atmosphere of 100 vol.% steam within 17 hours; and/or preferably the modified Y-type molecular sieve has a relative crystallinity of 58-75%, for example 58-70%. 5. The modified Y-type molecular sieve according to any one of the preceding claims, wherein the modifying metal is magnesium, and the modified Y-type molecular sieve has a magnesium content of 0.5 to 4.5 mass. %, for example, 0.6-4.3 wt. %, in terms of magnesium oxide, sodium content 0.2-0.5 wt. % in terms of sodium oxide, lattice constant of 2.442-2.452 nm and silicon dioxide-aluminum oxide ratio in the crystal lattice of 8.4-12.6, calculated as the molar ratio of SiO ₂ /Al ₂ O ₃ ; or the modifying metal is calcium, and the modified Y-type molecular sieve has a calcium content of 0.7-6.3 mass. %, preferably 0.9-5.9 wt. %, for example 1.5-6 wt. %, in terms of calcium oxide, sodium content 0.2-0.5 wt. % in terms of sodium oxide, lattice constant of 2.442-2.452 nm and silicon dioxide-aluminum oxide ratio in the crystal lattice of 8.0-12.6, calculated as the molar ratio of SiO ₂ /Al ₂ O ₃ . 6. The modified Y-type molecular sieve according to any one of the preceding claims, wherein the modified Y-type molecular sieve has an electron binding energy Ols of not more than 532.55 eV, for example 532.39-532.52 eV. 7. A method for producing a modified molecular sieve of type Y according to claim 1, comprising the steps: (1) contacting the NaY type molecular sieve with a solution of a soluble magnesium salt and/or a soluble calcium salt for an ion exchange reaction to produce a Y type molecular sieve containing magnesium and/or calcium with a reduced sodium content; (2) subjecting the Y-type molecular sieve obtained in step (1) to baking at a temperature of 350-480°C in an atmosphere of 30-90 vol.% steam for 4.5-7 hours and optionally drying to obtain a Y-type molecular sieve with a reduced crystal lattice constant; And (3) contacting the reduced lattice constant type Y molecular sieve with gaseous silicon tetrachloride to react at a weight ratio of SiCl ₄ to reduced lattice constant type Y molecular sieve on a dry matter basis of 0.1:1 to 0.7: 1 and a reaction temperature of 200-650°C for a reaction time of 10 minutes to 5 hours to obtain a modified Y-type molecular sieve. 8. The method according to claim 7, in which the Y-type molecular sieve obtained in step (1) has a lattice constant of 2.465-2.472 nm, a sodium content of no more than 8.8 wt. % in terms of sodium oxide; preferably, the Y-type molecular sieve obtained in step (1) has a magnesium content of 0.5 to 7.0 wt. % in terms of MgO, sodium content 4-8.8 wt. %, for example 5.5-8.5 wt. %, in terms of sodium oxide and crystal lattice constant 2.465-2.472 nm; or preferably, the Y-type molecular sieve obtained in step (1) has a calcium content of 0.8-10 wt. % in terms of CaO, sodium content 4-8.8 wt. %, for example 5-7.5 wt. %, in terms of sodium oxide and crystal lattice constant 2.465-2.472 nm. 9. The method according to claim 7 or 8, in which in step (1) the NaY type molecular sieve, soluble magnesium salt and/or calcium salt and water are mixed with a mass ratio of NaY type molecular sieve: soluble magnesium salt and/or calcium salt: H ₂ O 1:0.005-0.28:5-15 for ion exchange. 10. Method according to any one of paragraphs. 7-9, wherein step (1) further comprises mixing the NaY type molecular sieve with water and adding soluble magnesium salt, soluble calcium salt, soluble calcium salt solution and/or soluble magnesium salt thereto while stirring to perform an ion exchange reaction; conditions for the ion exchange reaction include: exchange temperature 15-95°C and exchange time 30-120 minutes; preferably the soluble magnesium salt is magnesium chloride and/or magnesium nitrate, and/or preferably the soluble calcium salt is calcium chloride and/or calcium nitrate. 11. Method according to any one of paragraphs. 7-10, in which in step (2), the firing temperature is 380-470°C, the firing atmosphere is an atmosphere of 40-80% steam, and the firing time is 5-6 hours; preferably, the Y-type molecular sieve with reduced lattice constant obtained in step (2) has a lattice constant of 2.450-2.462 nm and a water content of not more than 1 mass. %. 12. Method according to any one of paragraphs. 7-11, wherein step (3) further comprises washing the resulting modified Y-type molecular sieve with water under conditions including: molecular sieve:H ₂ O ratio 1:5-20, pH 2.5-5.0 and washing temperature 30 -60°C. 13. Modified molecular sieve type Y, obtained by the method according to any one of paragraphs. 7-12. 14. Catalytic cracking catalyst containing 10-50 wt. % based on dry matter of modified molecular sieve type Y, 10-40 wt. % of alumina-based binder in terms of aluminum oxide and 10-80 wt. % in terms of dry matter of clay in terms of the weight of the catalytic cracking catalyst; wherein the modified Y-type molecular sieve is a modified Y-type molecular sieve according to any one of claims. 1-6 and 13. 15. Use of a modified Y-type molecular sieve according to any one of paragraphs. 1-6 and 13 for the catalytic cracking of hydrocarbon oils, providing for contact of the hydrocarbon oil with a catalytic cracking catalyst containing a modified Y-type molecular sieve according to any one of paragraphs. 1-6 and 13.