A silica-alumina material, its preparation and a low-fouling, high-activity heavy oil conversion catalytic cracking catalyst

Abstract

The present invention belongs to the technical field of catalytic materials and relates to a silicon-aluminum material, its preparation and a low-coking, high-activity heavy oil conversion catalytic cracking catalyst. The silicon-aluminum material has an anhydrous weight chemical formula of (0-1)Na2O·(15-50)Al2O3·(85-50)SiO2, a most probable pore diameter of 10-100 nm, and a specific surface area of ​​150-600 m 2 / g, a pore volume of 0.5-1.5 ml / g, and a pore volume of pores with a pore diameter greater than 10 nm accounting for 70%-98% of the total pore volume. Its preparation method comprises the steps of adding an alkaline silicon source to an acidic aluminum source, contacting with a base, and washing. The low-coking, high-activity heavy oil conversion catalytic cracking catalyst contains the aforementioned silicon-aluminum material and an in-situ crystallized Y-type molecular sieve. The catalytic cracking catalyst has good coke selectivity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of catalytic materials, and relates to a catalytic material, a preparation method and an application method thereof, and a low-coke catalytic cracking catalyst and a preparation method thereof BACKGROUND

[0002] Catalytic cracking (FCC) is an important secondary processing process of crude oil and plays an important role in the oil refining industry. In the catalytic cracking process, heavy distillate such as vacuum distillate or heavier component of residual oil is reacted in the presence of a catalyst to be converted into liquefied gas, gasoline, diesel and other high-value-added products, and a catalytic material with high cracking activity is usually required in this process. Y-type zeolite is widely used in catalytic cracking reaction due to its excellent shape-selective catalytic performance and high cracking reaction activity. Y-type zeolite is obtained by two technologies: one technology is to first synthesize Y-type zeolite by using an alkaline silica-alumina gel, and then mix the Y-type zeolite with a matrix to spray dry microspherical catalysts. The Y-type zeolite synthesized by the alkaline silica-alumina gel has the characteristics of high molecular sieve content and high silicon-aluminum ratio, and can have various reaction characteristics by using different modification methods. The other technology is an in-situ crystallization technology, which first forms microspheres and then crystallizes the microspheres to generate molecular sieves, directly obtaining catalyst microspheres containing active components-molecular sieves and non-molecular sieve components. The catalyst synthesized by the in-situ crystallization technology has the characteristics of strong resistance to heavy metal pollution, high activity index, good hydrothermal stability and structural stability.

[0003] Bao Xiaojun CN103043680A provides all silicon and aluminum sources for synthesizing molecular sieves by using natural kaolin minerals and natural diatomite minerals, and uses them as a matrix for growing molecular sieves to form crystal products by in-situ crystallization. In the composite material, the mass percentage of NaY molecular sieves is 25% to 50%, and the silicon-aluminum ratio of the NaY molecular sieves is 3 to 5.5.

[0004] Zheng Shuqin (Synthesis of multi-level pore catalytic material by hydrothermal crystallization of Si-Al gel and kaolin, Petroleum Science and Technology (Petroleum Processing), V30 (1), 32-37) reported the synthesis of multi-level pore catalytic material by hydrothermal synthesis of Si-Al gel and kaolin. The method is to prepare Si-Al gel by using water glass and sodium metaaluminate as silicon and aluminum sources respectively, and then spray the Si-Al gel and kaolin into balls, and then synthesize them.

[0005] The above disclosed catalysts of in-situ crystallized Y-type molecular sieves have an undesirable coke selectivity for heavy oil conversion.

[0006] For the catalytic cracking of heavier oil, due to the large amount of hydrocarbon macromolecules contained in the heavy oil, these macromolecules are not easy to enter the interior of the molecular sieve, and sometimes the conversion effect is not ideal. For this reason, some studies use mesoporous materials to pre-crack macromolecules. Amorphous silicon aluminum has been extensively studied due to its unique acidity. Compared with molecular sieves, its significant feature is the non-crystalline structure and large pore size. Silicon aluminum materials exhibit good macromolecular cracking performance in catalytic cracking reactions, which is beneficial to improve the conversion rate of raw oil and reduce the yield of heavy oil.

[0007] CN104549540B discloses a preparation method of a macroporous amorphous silicon aluminum carrier, which comprises the following steps: (1) mixing an acidic aluminum salt solution and a sodium aluminate solution to prepare an aluminum sol; (2) adding a sodium silicate solution to the aluminum sol obtained in step (1); (3) performing aging treatment on the material of step (2); (4) filtering and washing the material obtained in step (3); and (5) drying the material obtained in step (4) at a drying temperature of 100-150 DEG C for 1-20 hours, and then calcining to obtain the macroporous amorphous silicon aluminum material. The method can not only prepare high-quality amorphous silicon aluminum with uniform silicon aluminum distribution, high silica content, large pore volume and specific surface area, but also can reduce the preparation cost of the amorphous silicon aluminum by using inexpensive inorganic salts as raw materials and without adding pore adjusting agents.

[0008] CN1261217C discloses a mesoporous silicon aluminum material having a pseudo-boehmite phase structure, and an anhydrous chemical expression of the material in terms of oxide weight is (0-0.3)Na2O·(40-90)Al2O3·(10-60)SiO2. The specific surface area of the material is 200-400 m 2 / g, the pore volume is 0.5-2.0 ml / g, and the average pore diameter is 8-20 nm, and the most probable pore diameter is 5-15 nm. The material is prepared by neutralizing an aluminum source with an alkali solution to form a gel, then adding a silicon source and aging, and finally performing ion exchange, drying and calcination. The material has a concentrated mesopore distribution, retains the mesopore structure characteristics of aluminum oxide, and has good hydrothermal stability.

[0009] Although the silicon aluminum materials in the above documents have achieved good results in applications, however, they have poor coke formation performance when used in a catalytic cracking catalyst containing in-situ crystallized Y-type molecular sieves. SUMMARY

[0010] The first technical problem to be solved by the present application is to provide a new type of silicon aluminum material for solving the problem of high coke formation of a catalytic cracking catalyst containing in-situ crystallized Y-type molecular sieves in the prior art. The second technical problem to be solved by the present application is to provide a preparation method of the silicon aluminum material.

[0011] The third technical problem to be solved by the present invention is to provide a catalytic cracking catalyst having higher conversion activity and lower coking tendency.

[0012] The fourth technical problem to be solved by the present invention is to provide a method for preparing the catalytic cracking catalyst.

[0013] The fifth technical problem to be solved by the present invention is to provide an application method of the catalytic cracking catalyst.

[0014] The first aspect of the present invention provides a silicon-aluminum material, wherein the anhydrous chemical formula of the silicon-aluminum material is (0-1)Na2O·(15-50)Al2O3·(50-85)SiO2, and the specific surface area is 150-600m 2 / g, the pore volume is 0.5-1.5ml / g, the pore volume of pores with a pore diameter greater than 10nm accounts for 70%-98% of the total pore volume; the most probable pore diameter of the silicon-aluminum material is 10-100nm.

[0015] The pore size mentioned in the present invention refers to the diameter of the pores. The specific surface area, total pore volume, i.e., pore volume, and pore size distribution of the silicon-aluminum material can be measured by a low-temperature nitrogen adsorption capacity method. The specific surface area can be calculated using the BET equation, and the pore size distribution can be calculated using the BJH formula.

[0016] A second aspect of the present invention provides a method for preparing a silicon-aluminum material, comprising the following steps:

[0017] (1) gradually adding an alkaline silicon source to an acidic aluminum source at room temperature to 95°C in a weight ratio of SiO2:Al2O3 = (50-85): (50-15);

[0018] (2) After all the alkaline silicon source is added to the acidic aluminum source, an alkaline solution is added until the slurry has a pH of 8-10.5, and then aged at 50-95° C. for 1-10 hours to obtain a solid precipitate;

[0019] (3) The obtained solid precipitate is contacted with a solution containing ammonium salt and / or acid, and filtered to obtain a silicon-aluminum material with a sodium content of less than 1%.

[0020] In a third aspect, the present invention provides a catalytic cracking catalyst comprising 10-70 wt% of a cracking active component, 1-20 wt% of the silicon-aluminum material provided by the present invention or the silicon-aluminum material obtained by the method for preparing the silicon-aluminum material provided by the present invention, 10-60 wt% of a binder, and 10-70 wt% of clay; wherein the cracking active component comprises 25-100 wt% of a first Y-type molecular sieve and 0-75 wt% of a second molecular sieve; and the first Y-type molecular sieve is an in-situ crystallized Y molecular sieve having a sodium oxide content of less than 2 wt%.

[0021] The Y zeolite synthesized in-situ crystallization of kaolin with sodium oxide content less than 2wt% can be obtained by treating Y zeolite synthesized in-situ crystallization of kaolin to reduce the sodium content, also known as modified Y zeolite synthesized in-situ crystallization of kaolin, which can also contain modified metal elements. Preferably, the Y zeolite synthesized in-situ crystallization of kaolin with sodium oxide content less than 2wt% also contains rare earth elements, wherein the content of rare earth elements is preferably 10wt%-20wt% in terms of RE2O3. The treatment to reduce the sodium content is, for example, ion exchange, such as ammonium ion exchange and / or rare earth ion exchange.

[0022] In a fourth aspect of the present application, a preparation method of a catalytic cracking catalyst is provided, comprising forming a slurry of clay, a silicon-aluminum material, a cracking active component, and a binder, and spray drying; wherein the silicon-aluminum material is the silicon-aluminum material provided in the first aspect of the present application or the silicon-aluminum material prepared by the preparation method provided in the second aspect of the present application, the cracking active component comprises a first Y zeolite and optionally a second zeolite; the first Y zeolite is a Y zeolite synthesized in-situ crystallization of kaolin with sodium oxide content less than 2wt%

[0023] The silicon-aluminum material provided by the present application has an alumina content not exceeding the silica content, a higher average pore size, a higher pore volume, and a higher specific surface area. In combination with the Y zeolite synthesized in-situ crystallization of kaolin, it can have higher conversion activity and lower coke selectivity.

[0024] The catalytic cracking catalyst provided by the present application has the advantages of high conversion activity and low coke selectivity when used for heavy oil catalytic conversion, and preferably has higher gasoline yield. DETAILED DESCRIPTION

[0025] The following detailed description and examples are provided to further illustrate the present application. It will be understood that the detailed description and examples described herein are provided by way of illustration only and not by way of limitation.

[0026] According to the silicon-aluminum material provided by the present application, the proportion of pores with a pore size greater than 10nm in the silicon-aluminum material is 70%-98%, for example, 70%-90% or 75%-85%.

[0027] Preferably, the silicon-aluminum material provided by the present application contains pseudoboehmite grains, and the average size of the pseudoboehmite grains is preferably 1.5nm-3.5nm. The size of the pseudoboehmite grains can be measured by TEM, and the size refers to the size of the widest part of the grain, which can be obtained by measuring the diameter of the largest circumscribed circle of the grain projection surface. The average size is the average of the sizes of multiple grains.

[0028] According to the present application, the pore volume of the silica-alumina material is preferably 0.8-1.5 ml / g.

[0029] According to the present application, the silica-alumina material has a pore diameter of 10-100 nm, for example 15-80 nm or 20-60 nm or 25-35 nm.

[0030] According to the present application, the silica-alumina material has a specific surface area of preferably 280-450 m 2 / g.

[0031] According to the present application, the silica-alumina material has a SiO2:Al2O3 weight ratio of preferably 2-4:1.

[0032] According to the present application, the silica-alumina material is prepared by gradually adding a basic silicon source to an acidic aluminum source, which can be carried out under stirring. The gradual addition can be, for example, dropwise addition, or controlled addition time, for example, the addition time is controlled to be more than 10 minutes, for example, 10-50 minutes.

[0033] In the preparation method of the silica-alumina material of the present application, the acidic aluminum source is selected from aluminum sulfate, aluminum chloride, aluminum sol, acidic hydrolysis product of metal alkoxide of aluminum, i.e. the product of hydrolysis of metal alkoxide under acidic conditions, and the metal alkoxide is, for example, one or more of aluminum alcoholate, isopropyl alcoholate, sec-butyl alcoholate, triethyl alcoholate, etc.

[0034] In the preparation method of the silica-alumina material of the present application, the basic silicon source is selected from basic silicon sol, water glass, sodium silicate, basic hydrolysis product of silicon ester, i.e. the product of hydrolysis of silicon ester under basic conditions, and the silicon ester is, for example, one or more of methyl orthosilicate, tetraethyl silicate, isopropyl orthosilicate, butyl orthosilicate, etc.

[0035] In the preparation method of the silica-alumina material of the present application, the base in the alkali solution in step (2) can be one or more of ammonia, sodium hydroxide, potassium hydroxide, sodium aluminate. The alkali solution is, for example, one or more of ammonia, sodium hydroxide solution, potassium hydroxide solution, sodium aluminate solution. The SiO2:Al2O3 weight ratio of 50-85:50-15 in step (1) means that the raw materials are added according to the SiO2:Al2O3 ratio of 50-85:50-15 of the obtained silica-alumina material, and when the alkali solution is sodium aluminate, the aluminum in the above ratio includes the aluminum introduced by sodium aluminate and the acidic aluminum source.

[0036] If the step (2) is to add the alkali solution containing aluminum, preferably, the amounts of the basic silicon source, the acidic aluminum source and the alkali solution containing aluminum are such that the SiO2:Al2O3 ratio in the obtained silicon-aluminum material is (50-85):(15-50) by weight. Due to the introduction of the basic aluminum source, the amount of the acidic aluminum source is correspondingly reduced. Preferably, the SiO2:Al2O3 ratio in the obtained silicon-aluminum material is (60-85):(15-40) or (65-80):(35-20) or (70-80):(30-20) by weight.

[0037] In the method for preparing the silicon-aluminum material, after the aging is completed in the step (2), the solid precipitate can be obtained by filtration, optionally followed by drying.

[0038] In the method for preparing the silicon-aluminum material, in the step (3), the solid precipitate is contacted with a solution containing an ammonium salt and / or an acid to perform ion exchange to remove sodium ions therefrom. In one embodiment, the solid precipitate is contacted with an ammonium salt to perform the exchange, and the contacting is performed at room temperature to 100°C, for example, 60-95°C, for a time period of 0.5 hour or more, for example, 0.5-2 hours or more, and the weight ratio of the dry basis of the solid precipitate:ammonium salt:H2O is 1:(0.05-0.1):(5-30). The contacting and exchanging process can be performed once or more, for example, 1-3 times, and the contacting time is preferably 0.5-1 hour each time, until the sodium oxide content in the solid precipitate is less than 1% by weight. The ammonium salt can be selected from one or more of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium carbonate and ammonium bicarbonate. The room temperature can be 15-40°C.

[0039] In the method for preparing the silicon-aluminum material, in one embodiment, in the step (3), the solid precipitate is contacted with an acid solution to perform the exchange, and the contacting is performed at room temperature to 100°C, for example, 60-95°C, for a time period of at least 0.5 hour, for example, 0.5-2 hours or 0.5-1 hour, and the weight ratio of the dry basis of the solid precipitate:acid:H2O is 1:(0.03-0.3):(5-30). The contacting and exchanging process can be performed once or more, for example, 1-3 times, and the contacting time is preferably 0.5-1 hour each time. The acid can be selected from one or more of sulfuric acid, hydrochloric acid or nitric acid.

[0040] The catalytic cracking catalyst provided by the present application comprises: 10-70 wt%, for example 20-60 wt% or 25-65 wt% of a cracking active component, 1-20 wt%, for example 5-20 wt% of the silicon-aluminum material provided by the present application, 10-60 wt%, for example 20-45 wt% of a binder, and 10-70 wt%, for example 20-60 wt% or 25-55 wt% of clay, wherein the cracking active component comprises 25-100 wt%, for example 60-100 wt% of a first Y-type molecular sieve and 0-75 wt%, for example 0-40 wt% of a second molecular sieve.

[0041] The catalytic cracking catalyst provided by the present application can further comprise a second molecular sieve, which is preferably an octagonal zeolite and / or a molecular sieve with a five-membered ring structure. The octagonal zeolite is for example one or more of HY, REY, REHY, USY, REUSY, DASY and REDASY. The molecular sieve with a five-membered ring structure is for example one or more of a BEA structure molecular sieve, an MFI structure molecular sieve and mordenite, preferably one or more of a BEA structure molecular sieve and an MFI structure molecular sieve. The BEA structure molecular sieve can be obtained by crystallization without amine or by calcining a molecular sieve prepared by a template method, for example, the BEA structure molecular sieve is for example a β molecular sieve; the MFI structure molecular sieve is for example at least one of a rare earth-containing MFI structure molecular sieve, a phosphorus-containing MFI structure molecular sieve, an iron-containing MFI structure molecular sieve and a phosphorus and transition metal-containing MFI structure molecular sieve; and the mordenite is for example at least one of a high-silicon mordenite and a low-silicon mordenite.

[0042] The catalytic cracking catalyst provided by the present application comprises clay, which can be one or more of kaolin, montmorillonite, diatomite, halloysite, metahalloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite and bentonite.

[0043] The catalytic cracking catalyst provided by the present application comprises a binder, which can be one or more of a silica sol, an aluminum sol, an aluminum oxide stone (pseudoboehmite, referred to as aluminum stone in the present application) and a metal-modified aluminum stone.

[0044] The catalytic cracking catalyst provided by the present application contains a first Y-type molecular sieve, the first Y-type molecular sieve is a Y molecular sieve synthesized by in-situ crystallization of kaolin with a sodium oxide content less than 2% by weight, the sodium oxide content of the Y molecular sieve is not more than 2% by weight, the Y-type molecular sieve synthesized by in-situ crystallization of kaolin can be obtained by treating the Y-type molecular sieve synthesized by in-situ crystallization of kaolin to reduce the sodium oxide content, and the Y-type molecular sieve synthesized by in-situ crystallization of kaolin is also referred to as the Y-type molecular sieve synthesized by in-situ crystallization of kaolin in the present application. Preferably, the Y molecular sieve synthesized by in-situ crystallization of kaolin with a sodium oxide content less than 2% by weight contains rare earth, and the content of the rare earth is not more than 20% by weight in terms of RE2O3; more preferably, the content of the rare earth in the Y molecular sieve synthesized by in-situ crystallization of kaolin with a sodium oxide content less than 2% by weight is 10%-20% by weight in terms of RE2O3. In one embodiment, the crystallinity of the Y molecular sieve synthesized by in-situ crystallization of kaolin is ≥60%, for example, ≥70% measured by the peak height method of X-ray diffraction.

[0045] The catalytic cracking catalyst provided by the present application contains a first Y-type molecular sieve, the first Y-type molecular sieve is a Y-type molecular sieve synthesized by in-situ crystallization of kaolin with a sodium oxide content less than 2% by weight, the sodium oxide content of the Y molecular sieve is not more than 2% by weight, the Y-type molecular sieve synthesized by in-situ crystallization of kaolin can be obtained by treating the Y-type molecular sieve synthesized by in-situ crystallization of kaolin to reduce the sodium oxide content, and the Y-type molecular sieve synthesized by in-situ crystallization of kaolin is also referred to as the Y-type molecular sieve synthesized by in-situ crystallization of kaolin in the present application. Preferably, the Y molecular sieve synthesized by in-situ crystallization of kaolin with a sodium oxide content less than 2% by weight contains rare earth, and the content of the rare earth is not more than 20% by weight in terms of RE2O3; more preferably, the content of the rare earth in the Y molecular sieve synthesized by in-situ crystallization of kaolin with a sodium oxide content less than 2% by weight is 10%-20% by weight in terms of RE2O3. In one embodiment, the crystallinity of the Y molecular sieve synthesized by in-situ crystallization of kaolin is ≥60%, for example, ≥70% measured by the peak height method of X-ray diffraction.

[0046] The Y-type molecular sieve synthesized by in-situ crystallization of kaolin is a Y-type molecular sieve composite material. The crystallinity of the Y-type molecular sieve synthesized by in-situ crystallization of kaolin (or the Y-type molecular sieve composite material) measured by the peak height method of X-ray diffraction is ≥60%, and the ratio of the crystallinity measured by the peak area method is K1, K1=0.76-0.89; the silicon-aluminum ratio determined by the unit cell constant a0 is 5.0-5.5, and the ratio of the silicon-aluminum ratio determined by the chemical method is K2, K2=0.87-0.93, for example, K2=0.87-0.90, and the silicon-aluminum ratio is the molar ratio of silicon oxide to aluminum oxide.

[0047] The Y-type molecular sieve synthesized by in-situ crystallization of kaolin provided by the present application has a similar sphere with a size of 5-20 microns, the crystallinity measured by the peak height method is ≥60%, that is, the mass percentage of the NaY molecular sieve is at least 60%. Preferably, the crystallinity measured by the peak height method is greater than 75%, and more preferably, ≥80%.

[0048] According to the knowledge of crystal crystallization, the difference between the crystallinity measured by the peak height method and the crystallinity measured by the peak area method is related to the size of the crystal grain. The Y-type molecular sieve composite material (referred to as the composite material) provided by the present application sets the crystal grain coefficient K1, K1=S 峰高 / S 峰面积The ratio of the crystallinity by the peak height method to the crystallinity by the peak area method. The value of K1 indicates the size of the crystal grain, and the larger the value of K1, the larger the size of the crystal grain. Preferably, K1 is 0.80-0.89, more preferably 0.80-0.85.

[0049] The molar ratio of silicon oxide to aluminum oxide calculated from the unit cell constant a0 is the framework silica alumina ratio of the molecular sieve, and the molar ratio of silicon oxide to aluminum oxide determined by the chemical method is the overall silica alumina ratio of the composite material. The NSY molecular sieve synthesized by in-situ crystallization of the kaolin according to the present application has a framework silica alumina ratio of 5.0-5.5, preferably 5.2-5.5, as determined by the unit cell constant a0, and an overall silica alumina ratio of the entire material as determined by the chemical method. The two values of the framework silica alumina ratio and the overall silica alumina ratio are related to the framework integrity and purity of the molecular sieve in the composite material. The NSY molecular sieve synthesized by in-situ crystallization of the kaolin according to the present application is obtained by metacrystallization of the metakaolin, and a portion of the metakaolin is in the intermediate state of metacrystallization to Y-type molecular sieve. Therefore, the intermediate system number K2 is defined as K2 = framework silica alumina ratio / overall silica alumina ratio. The value of K2 indicates the degree of compounding of the composite material, and the smaller the value of K2, the more intermediate bodies are contained. Preferably, K2 is 0.87-0.92, more preferably 0.88-0.90.

[0050] Preferably, the NSY molecular sieve (also referred to as Y-type molecular sieve composite material) synthesized by in-situ crystallization of the kaolin according to the present application has K1 = 0.77-0.88, for example K1 = 0.81-0.88 or K1 = 0.86-0.88 and K2 = 0.87-0.91.

[0051] In the present application, the pores with a diameter greater than 0.8 nm are defined as mesopores. The NSY molecular sieve synthesized by in-situ crystallization of the kaolin according to the present application has a suitable mesopore rate, wherein the mesopore rate is 10-20%.

[0052] In one embodiment, the NSY molecular sieve synthesized by in-situ crystallization of the kaolin has a silica alumina ratio of 5.2-5.5 as determined by the unit cell constant a0.

[0053] The NSY molecular sieve synthesized by in-situ crystallization of kaolin is a Y-type molecular sieve composite material, and a preparation method thereof comprises the following steps: (1) calcining and dehydrating kaolin at 500-900 DEG C to convert it into metakaolin, crushing the metakaolin to prepare metakaolin powder with a particle size of less than 10 microns; (2) adding sodium silicate, a directing agent, a sodium hydroxide solution and water into the metakaolin powder to prepare reaction raw material A with a molar ratio of (1-2.5) Na2O:Al2O3:(4-9) SiO2:(40-100) H2O, wherein the mass ratio of the directing agent to the metakaolin is 0.01-1.0; (3) crystallizing the reaction raw material A at 88-98 DEG C under stirring, and supplementing a second silicon source to obtain reaction raw material B after the crystallization time reaches 1-70 h, wherein the second silicon source accounts for 0.1-10 wt% of the total amount of silicon in the raw material; and (4) crystallizing the reaction raw material B at 88-98 DEG C under stirring and recovering the product.

[0054] In the preparation method of the NSY molecular sieve synthesized by in-situ crystallization of kaolin, the directing agent can be synthesized according to conventional methods, such as the preparation methods in USP3574538, USP3639099, USP3671191, USP4166099 and EUP0435625. The molar composition of the directing agent is (10-17) SiO2:(0.7-1.3) Al2O3:(11-18) Na2O:(200-350) H2O. The raw material is aged at 4-35 DEG C, preferably 4-20 DEG C, to obtain the directing agent during synthesis.

[0055] In the preparation method of the NSY molecular sieve synthesized by in-situ crystallization of kaolin, the sodium content in the second silicon source is 0.01 wt%-10 wt%, preferably <1 wt%, as Na2O. Preferably, the second silicon source is solid silica gel from the perspective of cost control. The solid silica gel is included in the total synthesis ratio, and the solid silica gel used can be solid silica gel with different pore sizes. The silica gel is classified according to the pore size, and the silica gel with an average pore size of less than 1.5-2.0 nm is referred to as fine pore silica gel (for example, A-type solid silica gel from Qingdao Haigang Special Silica Gel Factory), and the silica gel with an average pore size of more than 4.0-5.0 nm is referred to as coarse pore silica gel (for example, C-type solid silica gel from Qingdao Haigang Special Silica Gel Factory); in addition, the silica gel with an average pore size of more than 10.0 nm is referred to as extra coarse pore silica gel, and the silica gel with an average pore size of less than 0.8 nm is referred to as extra fine pore silica gel (for example, B-type solid silica gel from Qingdao Haigang Special Silica Gel Factory). The second silicon source can also be liquid silica gel, and the SiO2 mass content in the liquid silica gel is preferably at least 30%.

[0056] The preparation method of the NSY molecular sieve synthesized by in-situ crystallization of kaolin clay, the multi-level pore Y-type molecular sieve composite material product is obtained by crystallization under stirring, the crystallization stirring speed can be but is not limited to 50-1000 rpm, preferably 300-500 rpm, and the time is 16-48 hours, preferably 24-32 hours. The drying temperature of the zeolite after crystallization is 100-120°C.

[0057] In the preparation method of the NSY molecular sieve synthesized by in-situ crystallization of kaolin clay, the second silicon source accounts for 0.1-10 wt% of the total amount of silicon in the raw material, preferably 4-10 wt%.

[0058] In the preparation method of the catalytic cracking catalyst, the preparation method of the NSY molecular sieve synthesized by in-situ crystallization of kaolin clay, the sodium silicate and the second silicon source are added to the synthesis preparation system at different stages, and in particular, the second silicon source is added at the crystal growth stage. The present application combines the synthesis ratio control technology and the in-situ crystallization technology of kaolin clay (using natural minerals as the main aluminum and silicon sources) by adding different silicon sources at different stages of the crystallization process, changes the crystal growth environment through the silicon source, and uses two completely different material ratios at the crystal nucleation stage and the crystal growth stage. In the present application, a larger sodium-silicon ratio (Na2O / SiO2) is used in the material at the crystal nucleation stage, which is beneficial to the rapid nucleation of the Y-type molecular sieve, and a low-sodium or sodium-free silicon source is added at the crystal growth stage, which increases the silicon-aluminum ratio (SiO2 / A12O3) of the synthesis material and reduces the sodium-silicon ratio (Na2O / SiO2) of the material. Under the premise of shortening the crystallization time, it is beneficial to improve the silicon-aluminum ratio of the product, and the framework silicon-aluminum ratio is increased to 5.0-5.5.

[0059] In step (4) of the preparation of the NSY molecular sieve synthesized by in-situ crystallization of kaolin clay, the product is recovered after crystallization to obtain the NSY molecular sieve synthesized by in-situ crystallization of kaolin clay. The recovery generally includes a filtration step, and optionally, one or more processes of washing, drying, and calcination.

[0060] The modified NSY molecular sieve can be obtained by modifying the NSY molecular sieve synthesized by in-situ crystallization of kaolin clay, such as ion exchange. The modification process reduces the sodium oxide content in the NSY molecular sieve synthesized by in-situ crystallization of kaolin clay to below 2 wt%.

[0061] The NSY zeolite synthesized by in-situ crystallization of kaolin can be treated by any method capable of reducing the sodium oxide content therein to not more than 2 wt% to obtain a modified NSY zeolite. The sodium oxide content can be reduced by ion exchange. The ion exchange can be carried out using an ammonium salt and / or a rare earth salt solution. The ion exchange can be carried out according to known methods for ammonium exchange and rare earth exchange of zeolites. The present application does not have any special requirements. Preferably, the ion exchange is carried out so that the rare earth content of the modified NSY zeolite obtained is 10 wt% to 20 wt% as RE2O3 and the sodium oxide content is less than 2 wt%. In one embodiment, the NSY zeolite synthesized by in-situ crystallization of kaolin is mixed with an exchange solution and stirred at 20 to 90°C for 10 to 120 minutes. The process can be carried out once or multiple times. Each exchange solution can contain ammonium ions, rare earth ions or both ammonium ions and rare earth ions. Preferably, the concentration of the ammonium salt in the exchange solution is 5 to 700 g / L and / or the concentration of the rare earth salt in the exchange solution is 5 to 400 g / L as RE2O3. The ammonium salt can be one or more of ammonium chloride, ammonium nitrate and ammonium sulfate. The rare earth can include one or more of lanthanide rare earths and actinide rare earths, for example, one or more of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. The rare earth salt can be one or more of a rare earth chloride and a rare earth nitrate.

[0062] The NSY zeolite synthesized by in-situ crystallization of kaolin can be treated by any method capable of reducing the sodium oxide content therein to not more than 2 wt% to obtain a modified NSY zeolite. The sodium oxide content can be reduced by ion exchange. The ion exchange can be carried out using an ammonium salt and / or a rare earth salt solution. The ion exchange can be carried out according to known methods for ammonium exchange and rare earth exchange of zeolites. The present application does not have any special requirements. Preferably, the ion exchange is carried out so that the rare earth content of the modified NSY zeolite obtained is 10 wt% to 20 wt% as RE2O3 and the sodium oxide content is less than 2 wt%. In one embodiment, the NSY zeolite synthesized by in-situ crystallization of kaolin is mixed with an exchange solution and stirred at 20 to 90°C for 10 to 120 minutes. The process can be carried out once or multiple times. Each exchange solution can contain ammonium ions, rare earth ions or both ammonium ions and rare earth ions. Preferably, the concentration of the ammonium salt in the exchange solution is 5 to 700 g / L and / or the concentration of the rare earth salt in the exchange solution is 5 to 400 g / L as RE2O3. The ammonium salt can be one or more of ammonium chloride, ammonium nitrate and ammonium sulfate. The rare earth can include one or more of lanthanide rare earths and actinide rare earths, for example, one or more of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. The rare earth salt can be one or more of a rare earth chloride and a rare earth nitrate.

[0063] In one preferred embodiment, the modified NSY zeolite contains rare earth (the modified NSY zeolite containing rare earth is also referred to as NSY zeolite containing rare earth), the rare earth content of which is preferably 10 wt% to 20 wt% as RE2O3 and the sodium oxide content is less than 2 wt%. When the rare earth content of the modified NSY zeolite is within this range, the catalytic cracking catalyst has higher heavy oil conversion activity.

[0064] The present application provides a method for preparing a catalytic cracking catalyst. The method comprises forming a slurry of clay, silica-alumina material, cracking active component, water and binder. The clay, silica-alumina material, cracking active component, water and binder can be mixed and slurried. The slurry can be spray dried to obtain catalyst microspheres. The catalyst microspheres can be further calcined. The spray drying and calcination can be carried out according to known methods for spray drying and calcination of catalytic cracking catalysts. The calcined catalyst microspheres can be washed.

[0065] The application will be further described by examples.

[0066] The specifications of raw materials used in catalyst preparation examples are as follows:

[0067] Pseudo boehmite: commercially available from Shandong Aluminum Company, solid content 75% by weight;

[0068] Kaolin: solid content 75% by weight, produced by China Kaolin Co., Ltd. (Suzhou);

[0069] REY molecular sieve: product of Sinopec Qilu Catalyst Branch, rare earth content 17.6% by weight;

[0070] Beta molecular sieve: Qilu Catalyst Branch, silicon-aluminum ratio (molar ratio of SiO2:Al2O3) 25.

[0071] Aluminum sol: produced by Shandong Aluminum Plant, solid content 23% by weight.

[0072] Element content in catalyst and molecular sieve is determined by XRF method.

[0073] The average size of crystal grains is determined by randomly measuring the size of 50 crystal grains and taking the arithmetic average.

[0074] The content of NaY zeolite in composite material in examples is determined according to RIPP146-90 standard method (RIPP standard method is described in Petroleum and Chemical Industry Analysis Method (RIPP Test Method), edited by Yang Cuiding et al., published by Science Press in 1990, same below).

[0075] The lattice constant a0 is determined according to RIPP145-90 standard method. The framework silicon-aluminum ratio is calculated from the lattice constant a0 according to the following formula: SiO2 / Al2O3 (molar ratio) = 2x(25.858-a0) / (a0-24.191).

[0076] The specific surface area is determined by nitrogen adsorption method (GB / T5816-1995); the pore volume is determined by nitrogen adsorption method (RIPP151-90). The pores with a diameter greater than 0.8 nm are defined as mesopores and macropores, and the calculation formula of mesopore and macropore rate is (V 总孔 -V 微孔 ) / V 总孔 x 100%.

[0077] Preparation of the directing agent in the examples and comparative examples of the molecular sieve: 250 kg of sodium silicate solution (containing 20.05 wt% of SiO2, 6.41 wt% of Na2O) was slowly added to 120 kg of sodium aluminate solution (containing 3.15 wt% of Al2O3, 21.1 wt% of Na2O) under rapid stirring at 30°C, and stirring was continued for 1 hour. The mixture was aged at 20°C for 48 hours to obtain the directing agent. The composition of the directing agent was 16Na2O:Al2O3:15SiO2:320H2O.

[0078] Example 1 of the preparation of the silicon-aluminum material

[0079] At room temperature (25°C), the water glass solution (SiO2concentration 250 g / L) was added dropwise to the aluminum sulfate solution (aluminum sulfate solution Al2O3concentration 90 g / L) under stirring according to the weight ratio of SiO2:Al2O3=75:25. After the addition was completed, sodium hydroxide solution (concentration 300 g / L) was added, and the slurry pH value was adjusted to 10. The mixture was aged at 50°C for 6 hours. The obtained solid precipitate was dried at 120°C for 6 hours, and then washed with ammonium chloride solution (concentration 50 g / L) and filtered to obtain the silicon-aluminum material B1 with a sodium content of less than 1%. The elemental analysis chemical weight composition was 0.2Na2O·25Al2O3·74.8SiO2; the specific surface area was 324 m 2 / g, the pore volume was 1.26 cm 3 / g, and the proportion of the pore size greater than 10 nm was 82%. The average size of the pseudo-boehmite grains in the material was 2.2 nm, and the average pore size was 33.2 nm.

[0080] Example 2 of the preparation of the silicon-aluminum material

[0081] At 50°C, the water glass solution (SiO2concentration 250 g / L) was added dropwise to the aluminum sulfate solution (aluminum sulfate solution Al2O3concentration 90 g / L) under stirring according to the weight ratio of SiO2:Al2O3=60:30. After the addition was completed, sodium hydroxide solution (concentration 300 g / L) was added, and the slurry pH value was adjusted to 9.5. The mixture was aged at 70°C for 8 hours. The obtained solid precipitate was dried at 120°C for 6 hours, and then washed with ammonium chloride solution and filtered to obtain the silicon-aluminum material B2 with a sodium content of less than 1 wt%. The elemental analysis chemical weight composition was 0.1Na2O·25.2Al2O3·59.7SiO2; the specific surface area was 331 m 2 / g, the pore volume was 1.30 cm 3 / g, and the proportion of the pore size greater than 10 nm was 75%. The average size of the pseudo-boehmite grains in the material was 2.8 nm, and the average pore size was 26.4 nm.

[0082] Comparative Example 1 of the silicon-aluminum material

[0083] ](1) Al2(SO4)3 solution with a concentration of 90 g Al2O3 / L and NaAlO2 solution with a concentration of 102 g Al2O3 / L and a caustic ratio of 2.5 are used as raw materials, mixed and gelled in a parallel flow mode under vigorous stirring, the temperature of the system is controlled at 40℃, the pH value of the system is 9.0, and the metering gelling slurry is collected; (2) under stirring, water glass with a concentration of 60 g SiO2 / L is added into the gelling slurry according to a weight ratio of SiO2:Al2O3 = 1:2, the temperature is raised to 60℃, and the first solid precipitate is obtained after aging for 3 hours; (3) the first solid precipitate is added with NH4Cl and deionized water according to a weight ratio of the precipitate dry base:ammonium salt:H2O = 1:0.5:12, the precipitate is ion exchanged to remove sodium ions at 60℃, the exchange is repeated once, each time for 0.5 hours, until the sodium oxide content is less than 0.3%, and the second solid precipitate is obtained; (4) then the obtained second solid precipitate is mixed with water according to a weight ratio of the precipitate dry base:H2O = 1:8, and phosphoric acid and magnesium nitrate are added according to a weight ratio of P2O5:MgO:material dry base = 0.033:0.022:1, and then the reaction is carried out at 80℃ for 1 hour, after filtration and water washing, the high-cracking-activity mesoporous material provided by the present application is obtained after drying at 120℃ for 10 hours, and is recorded as DD-1. DD has a pseudo-boehmite structure, and the elemental analysis chemical composition is 0.12Na2O·65.1Al2O3·28.2SiO2·3.2P2O5·2.1MgO; the specific surface area is 391 m 2 / g, the pore volume is 0.97 cm 3 / g, and the average pore diameter is 9.9 nm.

[0084] Silicon-aluminum material comparative example 2

[0085] (1) Al2(SO4)3 solution with a concentration of 90 g Al2O3 / L and ammonia water with a concentration of 25 wt.% were used as raw materials, and the Al2(SO4)3 solution and the ammonia water were mixed into gel under the condition of co-current gelation and intense stirring, the temperature of the system was controlled at 40 °C, the pH value of the system was 9.5, and the metering gel slurry was collected; (2) under stirring, water glass with a concentration of 102 g SiO2 / L was added into the gel slurry according to the weight ratio of SiO2:Al2O3=1:2.6, the temperature was increased to 70 °C, and the first solid precipitate was obtained after aging for 2 hours; (3) the first solid precipitate was ion exchanged to remove sodium ions at 60 °C according to the weight ratio of the solid precipitate dry base:ammonium salt:H2O=1:0.8:15, and the sodium oxide was washed to 0.3%, and the second solid precipitate was obtained; (4) the second solid precipitate was reslurried by adding water, mixed with phosphoric acid according to the weight ratio of P2O5:second solid precipitate dry base=0.05:1, the temperature was increased to 60 °C, and stirring was performed for 1 hour, and the comparative material was obtained after filtration and drying at 120 °C for 10 hours. It is denoted as DD-2. DD-2 has a pseudo-boehmite structure, and the elemental analysis chemical composition is 0.12Na2O·62.5Al2O3·31.7SiO2·5.0P2O5; the specific surface area is 413 m2 / g, the pore volume is 0.97 cm3 / g, and the average pore diameter is 9.4 nm. 2 / g, pore volume 0.97 cm 3 / g, average pore diameter 9.4 nm.

[0086] Molecular sieve preparation example 1

[0087] 100 kg of crushed metakaolin powder was added into 400 kg of sodium silicate solution (containing 20.05 wt.% of SiO2 and 6.41 wt.% of Na2O), 60 kg of directing agent and 100 kg of sodium hydroxide solution with a concentration of 5 wt.% under stirring. The temperature was increased to 95 °C, and constant temperature stirring was performed, 10 kg of solid silica gel (A type from Qingdao Marine Chemical Group Special Silica Gel Factory) was added after 8 hours, and recrystallization was performed for 12 hours. The stirring speed was 400 rpm during the addition and crystallization. After the crystallization was completed, the crystallization tank was rapidly cooled, filtered, and washed with water until the pH value of the washing liquid was less than 10. Drying was performed at 120 °C for 2 hours, and zeolite material Y-1 was obtained. The crystallinity by peak height method, K1 value of the ratio of the crystallinity by peak height method to the crystallinity by peak area method, silicon-aluminum ratio determined by unit cell constant a0, K2 value of the ratio of the silicon-aluminum ratio determined by unit cell constant a0 to the silicon-aluminum ratio determined by chemical method, and mesopore rate of Y-1 were measured by X-ray diffraction method and are shown in Table 1.

[0088] Molecular sieve preparation example 2

[0089] The procedure of Example 1 was followed using 100 kg of the pulverized metakaolin powder, 360 kg of the sodium silicate solution (containing 20.05 wt% of SiO2, 6.41 wt% of Na2O), 60 kg of the directing agent, and 100 kg of the 5 wt% sodium hydroxide solution. The temperature was raised to 95°C and the mixture was stirred at this temperature. After 8 hours, 20 kg of the solid silica gel (A type from Qingdao Marine Chemical Group Co., Ltd.) was added and the crystallization was continued for 16 hours. The stirring speed was 400 rpm during the addition of the silica gel and the crystallization. After the crystallization, the crystallization tank was rapidly cooled, filtered, and washed with water until the pH of the washing solution was less than 10. The product was dried at 120°C for 2 hours to obtain the zeolitic material Y-3. The Y-3 was measured by the X-ray diffraction method, and the crystallinity by the peak height method, the K1 value of the ratio of the crystallinity by the peak height method to the crystallinity by the peak area method, the Si / Al ratio determined by the unit cell constant a0, the K2 value of the ratio of the Si / Al ratio determined by the unit cell constant a0 to the Si / Al ratio determined by the chemical method, and the meso-macropore volume are shown in Table 1.

[0090] Molecular sieve preparation example 3

[0091] The procedure of Example 1 was followed using 100 kg of the pulverized metakaolin powder, 360 kg of the sodium silicate solution (containing 20.05 wt% of SiO2, 6.41 wt% of Na2O), 60 kg of the directing agent, and 100 kg of the 5 wt% sodium hydroxide solution. The temperature was raised to 95°C and the mixture was stirred at this temperature. After 8 hours, 20 kg of the solid silica gel (A type from Qingdao Marine Chemical Group Co., Ltd.) was added and the crystallization was continued for 16 hours. The stirring speed was 400 rpm during the addition of the silica gel and the crystallization. After the crystallization, the crystallization tank was rapidly cooled, filtered, and washed with water until the pH of the washing solution was less than 10. The product was dried at 120°C for 2 hours to obtain the zeolitic material Y-3. The Y-3 was measured by the X-ray diffraction method, and the crystallinity by the peak height method, the K1 value of the ratio of the crystallinity by the peak height method to the crystallinity by the peak area method, the Si / Al ratio determined by the unit cell constant a0, the K2 value of the ratio of the Si / Al ratio determined by the unit cell constant a0 to the Si / Al ratio determined by the chemical method, and the meso-macropore volume are shown in Table 1.

[0092] Molecular sieve preparation comparative example 1

[0093] This comparative example illustrates the case where two kinds of silica sources are added to the reaction system at one time.

[0094] The 100 kg of the pulverized metakaolin powder was added into 400 kg of sodium silicate solution (containing 20.05 wt% of SiO2 and 6.41 wt% of Na2O), 60 kg of directing agent, 105 kg of 5 wt% sodium hydroxide solution and 10 kg of solid silica gel (A type from Qingdao Marine Chemical Group Co., Ltd.) under stirring according to the method of Example 1. The temperature was raised to 94°C and kept constant for 24 hours of crystallization. The stirring speed was 400 rpm during the feeding and crystallization. After the crystallization, the crystallization tank was rapidly cooled, filtered and washed with water until the pH of the washing liquid was less than 10. The zeolite material DY-1 was obtained by drying at 120°C for 2 hours. The crystallinity by peak height method, the K1 value of the ratio of the crystallinity by peak height method to the crystallinity by peak area method, the Si / Al ratio determined by the unit cell constant a0, the K2 value of the ratio of the Si / Al ratio determined by the unit cell constant a0 to the Si / Al ratio determined by chemical method and the meso-macropore ratio of DY-1 were shown in Table 1. DY-1 had low crystallinity and contained impurity crystals.

[0095] Preparation of molecular sieve Comparative Example 2

[0096] This comparative example illustrates the case without adding the second silicon source.

[0097] The 100 kg of the pulverized metakaolin powder was added into 400 kg of sodium silicate solution (containing 20.05 wt% of SiO2 and 6.41 wt% of Na2O), 60 kg of directing agent, 105 kg of 5 wt% sodium hydroxide solution and 10 kg of solid silica gel (A type from Qingdao Marine Chemical Group Co., Ltd.) under stirring according to the method of Example 1. The temperature was raised to 94°C and kept constant for 24 hours of crystallization. The stirring speed was 400 rpm during the feeding and crystallization. After the crystallization, the crystallization tank was rapidly cooled, filtered and washed with water until the pH of the washing liquid was less than 10. The zeolite material DY-1 was obtained by drying at 120°C for 2 hours. The crystallinity by peak height method, the K1 value of the ratio of the crystallinity by peak height method to the crystallinity by peak area method, the Si / Al ratio determined by the unit cell constant a0, the K2 value of the ratio of the Si / Al ratio determined by the unit cell constant a0 to the Si / Al ratio determined by chemical method and the meso-macropore ratio of DY-1 were shown in Table 1. DY-1 had low crystallinity and contained impurity crystals.

[0098] Table 1

[0099]

[0100] Preparation of catalyst Example 1

[0101] (1) Preparation of modified NSY molecular sieve: The zeolite material Y-1 was slurried in deionized water to obtain a molecular sieve slurry with a solid content of 10 wt%; a lanthanum chloride solution was added to the molecular sieve slurry, and the weight ratio of the lanthanum chloride to the molecular sieve on a dry basis was 1:6 in terms of La2O3; the mixture was stirred at 70°C for 1 h, filtered, washed, dried at 150°C for 8 h and calcined at 500°C for 4 h to obtain a modified NSY molecular sieve containing rare earth.

[0102] (2) Catalyst preparation: According to the catalyst formulation in Table 2, kaolin was first slurried to obtain a kaolin slurry with a solid content of 20% by weight; the modified NSY molecular sieve containing rare earth was slurried with water, and dispersed by a homogenizer to obtain a modified NSY molecular sieve slurry with a solid content of 35% by weight; the kaolin slurry and the modified NSY molecular sieve slurry were mixed and stirred, then the silicon-aluminum material was added, and then the acidified alumina stone with a solid content of 10% by weight was added, wherein the mass ratio of HCl to pseudo-boehmite calculated as Al2O3 in the acidified alumina stone was 0.2, and stirred for 10 min, and then the aluminum sol was added, and stirred for 30 min. The catalyst slurry was spray dried to obtain catalyst microspheres, which were calcined at 500°C for 2 hours, and then washed with an ammonium sulfate solution with a concentration of 2% by weight of ammonium sulfate, and the weight ratio of the ammonium sulfate solution to the catalyst microspheres on a dry basis was 10:1, to obtain a catalytic cracking catalyst C1.

[0103] Table 2

[0104]

[0105] In Table 2, the ratio of each component is the weight percentage on a dry basis. The rare earth content in the modified NSY molecular sieve is calculated as RE2O3. The modified NSY corresponding to C7, DB3 and DB5 refers to the modified Y molecular sieve obtained by modifying the respective zeolite material.

[0106] Catalyst preparation examples 2-7

[0107] Y-1 to Y-3 and DY-2 were modified by the method of catalyst preparation example 1, respectively, and then catalysts C2 to C7 were prepared by the method of step (2) of catalyst preparation example 1, wherein the second molecular sieve was formed into a second molecular sieve slurry with a solid content of 35% by weight, which was mixed with the modified NSY molecular sieve slurry and the kaolin slurry, then the silicon-aluminum material was added, and then the acidified alumina stone and the aluminum sol were added. The catalyst formulation is shown in Table 2.

[0108] Catalyst preparation comparative examples 1-5

[0109] Catalysts DB1 to DB5 were prepared by the method of catalyst preparation example 1, and the catalyst formulation is shown in Table 1.

[0110] Catalyst evaluation:

[0111] The catalysts were deactivated by aging at 800°C with 100% steam for 17 hours. The evaluation was carried out on a fixed fluidized bed microreactor ACE, and the raw oil was a hydro-upgraded oil (composition and properties are shown in Table 3), and the evaluation conditions were: reaction temperature was 520°C, catalyst to oil ratio (weight ratio) was 4, and WHSV = 16 h -1 . The results are shown in Table 4.

[0112] wherein conversion = gasoline yield + LPG yield + dry gas yield + coke yield

[0113] Coke selectivity = coke yield / conversion x 100

[0114] Coke formation factor = coke yield x (1 - conversion) / conversion x 100

[0115] Table 3

[0116] Item Feed oil Density (20°C), g / cm 3 ]] 0.9334 Refractive index (70°C) 1.5061 Four components, m% Saturated hydrocarbon 45.6 Aromatic hydrocarbon 40 Gum 14.4 Asphaltene <0.1 Freezing point, °C 34 Metal content, ppm Ca 3.9 Fe 1.1 Mg <0.1 Na 0.9 Ni 3.1 Pb <0.1 V 0.5 C m% 86.88 H m% 11.94 S m% 0.7 Carbon residue m% 1.77

[0117]

Claims

1. A catalytic cracking catalyst comprising 10% to 70% by weight of a cracking active component, 1% to 20% by weight of a silicon-aluminum material, 10% to 60% by weight of a binder, and 10% to 70% by weight of clay; wherein: The cracking active component comprises 25% to 100% by weight of a first Y-type molecular sieve and 0% to 75% by weight of a second molecular sieve; the first Y-type molecular sieve is an in-situ crystallized Y molecular sieve having a sodium oxide content of less than 2% by weight; The silicon-aluminum material has an anhydrous weight chemical formula of (0-1) Na2O·(15-50) Al2O3·(85-50) SiO2, a most probable pore size of 10-100 nm, and a specific surface area of ​​150-600 m 2 / g, pore volume is 0.5-1.5ml / g, and the pore volume of pores with a pore diameter greater than 10nm accounts for 70%-98% of the total pore volume; The in-situ crystallized Y molecular sieve with a sodium oxide content of less than 2% by weight is a modified NSY molecular sieve. The modified NSY molecular sieve is an NSY molecular sieve synthesized by in-situ crystallization of kaolin, which is obtained by reducing the sodium content and / or introducing rare earth treatment. The sodium oxide content of the modified NSY molecular sieve is less than 2% by weight. The NSY molecular sieve synthesized by in-situ crystallization of kaolin is measured by an X-ray diffraction method, and the crystallinity of the NSY molecular sieve by the peak height method is ≥60%, and the ratio to the crystallinity by the peak area method is K1, K1=0.76~0.89; the silicon-aluminum ratio determined by the unit cell constant a0 is 5.0~5.5, and the ratio to the silicon-aluminum ratio determined by the chemical method is K2, K2=0.87~0.93, and the silicon-aluminum ratios are all molar ratios of silicon oxide to aluminum oxide.

2. The catalytic cracking catalyst according to claim 1, wherein The silicon-aluminum material contains pseudo-boehmite grains, and the average size of the pseudo-boehmite grains is 1.5nm-3.5nm.

3. The catalytic cracking catalyst according to claim 1, wherein The pore volume of the silicon-aluminum material is 0.8-1.5 ml / g.

4. The catalytic cracking catalyst according to claim 1, wherein The specific surface area of ​​the silicon-aluminum material is 280-450m 2 / g.

5. The catalytic cracking catalyst according to claim 1, wherein The weight ratio of SiO2:Al2O3 in the silicon-aluminum material is 2-4:

1.

6. The catalytic cracking catalyst according to claim 1, wherein The method for preparing the silicon-aluminum material comprises the following steps: At room temperature to 95°C, gradually add the alkaline silicon source to the acidic aluminum source in a weight ratio of SiO2:Al2O3 = (50-85): (50-15); After all the alkaline silicon source is added to the acidic aluminum source, an alkaline solution is added until the slurry pH value reaches 8-10.5, and then aged at 50-95° C. for 1-10 hours to obtain a solid precipitate; The solid precipitate is contacted with a solution containing an ammonium salt and / or an acid, and filtered to obtain a silicon-aluminum material having a sodium content of less than 1 wt% in terms of Na2O, wherein the solid precipitate is dried or not dried before contacting with the solution containing an ammonium salt and / or an acid.

7. The catalytic cracking catalyst according to claim 6, wherein In the method for preparing the silicon-aluminum material, the acidic aluminum source is selected from aluminum sulfate, aluminum chloride, aluminum sol, and acidic hydrolysis products of aluminum metal alkoxides, and the aluminum metal alkoxide is one or more of aluminum isopropoxide, aluminum sec-butoxide, and aluminum triethanolate.

8. The catalytic cracking catalyst according to claim 6, wherein In the method for preparing the silicon-aluminum material, the alkaline silicon source is selected from alkaline silica sol, water glass, sodium silicate, and alkaline hydrolysis products of silicon ester.

9. The catalytic cracking catalyst according to claim 6, wherein In the method for preparing the silicon-aluminum material, the alkaline solution is one or more of ammonia water, sodium hydroxide solution, potassium hydroxide solution, and sodium metaaluminate solution.

10. The catalytic cracking catalyst according to claim 6, wherein In the method for preparing the silicon-aluminum material, the process of contacting the solid precipitate with a solution containing an ammonium salt and / or an acid comprises: contacting the obtained solid precipitate with an ammonium salt solution at room temperature to 100°C according to a weight ratio of solid precipitate dry basis: ammonium salt: H2O = 1: (0.05-0.1): (5-30).

11. The catalytic cracking catalyst according to claim 6 or 10, wherein In the method for preparing the silicon-aluminum material, the ammonium salt is selected from one or more of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium carbonate and ammonium bicarbonate.

12. The catalytic cracking catalyst according to claim 6, wherein In the method for preparing the silicon-aluminum material, the solution containing ammonium salt and / or acid is an acid solution, and the solid precipitate is contacted with the solution containing ammonium salt and / or acid by a weight ratio of solid precipitate dry basis: acid: H2O = 1: (0.03-0.3): (5-30) at room temperature to 100°C for at least 0.5 hour.

13. The catalytic cracking catalyst according to claim 6 or 12, wherein In the method for preparing the silicon-aluminum material, the acid is one or more of sulfuric acid, hydrochloric acid or nitric acid.

14. The catalytic cracking catalyst according to claim 6, wherein In the method for preparing the silicon-aluminum material, the process of contacting with the solution containing ammonium salt and / or acid is carried out once or multiple times, with each contact lasting 0.5-1 hour, until the sodium oxide content in the solid precipitate is less than 1% by weight.

15. The catalytic cracking catalyst according to claim 8, wherein In the method for preparing the silicon-aluminum material, the silicone grease is one or more of methyl orthosilicate, tetraethyl orthosilicate, isopropyl orthosilicate, and butyl orthosilicate.

16. The catalytic cracking catalyst according to claim 12, wherein In the method for preparing the silicon-aluminum material, the solid precipitate is contacted with the acid solution at room temperature to 100° C. for 0.5-2 hours.

17. The catalytic cracking catalyst according to claim 1, wherein The Y molecular sieve synthesized by in-situ crystallization of kaolin with a sodium oxide content of less than 2% by weight contains rare earth, wherein the rare earth content is 10% to 20% by weight calculated as RE2O3.

18. The catalytic cracking catalyst according to claim 1, wherein The crystallinity determined by the peak height method is ≥80%.

19. The catalytic cracking catalyst according to claim 1, wherein The K1=0.77-0.88, and K2=0.87-0.

91.

20. The catalytic cracking catalyst according to claim 1 or 19, wherein The K1 is 0.80-0.

89.

21. The catalytic cracking catalyst according to claim 20, wherein The K2=0.87-0.

92.

22. The catalytic cracking catalyst according to claim 18, wherein The large mesopore ratio of the NSY molecular sieve synthesized by in-situ crystallization of kaolin is 10-20%.

23. The catalytic cracking catalyst according to claim 18, wherein The silicon-aluminum ratio measured by the unit cell constant a0 is 5.2-5.

5.

24. The catalytic cracking catalyst according to claim 21, wherein The K1=0.80-0.85, and the K2=0.88-0.

90.

25. The catalytic cracking catalyst according to claim 1, wherein The preparation method of the NSY molecular sieve synthesized by in-situ crystallization of kaolin comprises the following steps: (1) calcining and dehydrating kaolin at 500-900°C to convert it into metakaolin, which is then crushed to produce metakaolin powder with a particle size of less than 10 microns; (2) adding a directing agent, sodium silicate, sodium hydroxide solution and water to the metakaolin powder to prepare a reaction raw material A, wherein the mass ratio of the directing agent to the metakaolin is 0.01-1.0, and the molar ratio of the reaction raw material A is (1-2.5) Na2O:Al2O3:(4-9)SiO2:(40-100)H2O; (3) crystallizing the reaction material A at 88-98° C. under stirring for 1-70 h, and then adding a second silicon source to obtain the reaction material B, wherein the second silicon source accounts for 0.1-10% by weight of the total silicon feed, calculated as silicon oxide; (4) The reaction material B is crystallized under stirring at 88-98°C and the product is recovered.

26. The catalytic cracking catalyst according to claim 1, wherein The second molecular sieve is selected from faujasite and / or a molecular sieve having a five-membered ring structure, the faujasite is one or more of HY, REY, REHY, USY, REUSY, DASY and REDASY, and the molecular sieve having a five-membered ring structure includes one or more of BEA structure molecular sieve, MFI structure molecular sieve and mordenite; the binder is selected from one or more of silica sol, alumina sol, acidified aluminum stone and metal-modified aluminum stone; the clay is one or more of kaolin, montmorillonite, diatomaceous earth, halloysite, pseudo-halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite and bentonite.

27. The method for preparing the catalytic cracking catalyst according to any one of claims 1 to 26, characterized in that: The following steps are involved: Clay, silicon-alumina material, cracking active component and binder are formed into a slurry and spray-dried; the cracking active component includes a first Y-type molecular sieve and an optional second molecular sieve; the first Y-type molecular sieve is an in-situ crystallized Y molecular sieve with a sodium oxide content of less than 2% by weight.

28. The method for preparing a catalytic cracking catalyst according to claim 27, wherein: The first Y-type molecular sieve is a modified NSY molecular sieve, and the preparation method of the modified NSY molecular sieve comprises the following steps: (1) calcining and dehydrating kaolin at 500-900°C to convert it into metakaolin, which is then crushed to produce metakaolin powder with a particle size of less than 10 microns; (2) Sodium silicate, a directing agent, a sodium hydroxide solution, and water are added to the metakaolin powder to prepare a reaction raw material A with a ratio of (1-2.5) Na2O:Al2O3:(4-9)SiO2:(40-100)H2O, wherein the mass ratio of the directing agent to the metakaolin is 0.01-1.0; (3) crystallizing the reaction material A at 88-98° C. under stirring, and adding a second silicon source after the crystallization time reaches 1-70 hours to obtain the reaction material B, wherein the second silicon source accounts for 0.1% to 10% by weight of the total silicon feed, calculated as silicon oxide; (4) crystallizing the reaction material B at 88-98°C under stirring and recovering the product; (5) The recovered product is subjected to ion exchange.

29. The method for preparing a catalytic cracking catalyst according to claim 28, wherein: The molar composition of the directing agent is: (10-17) SiO2: (0.7-1.3) Al2O3: (11-18) Na2O: (200-350) H2O.

30. The method for preparing a catalytic cracking catalyst according to claim 28, wherein: The sodium content of the second silicon source is less than 1% by weight as calculated as Na2O.

31. The method for preparing a catalytic cracking catalyst according to claim 28 or 30, wherein: The second silicon source is solid silica gel and / or liquid silica gel.

32. The method for preparing a catalytic cracking catalyst according to claim 31, wherein: The average pore diameter of the solid silica gel is less than 0.8 nm, or the average pore diameter of the solid silica gel is 1.5-2.0 nm, or the average pore diameter of the solid silica gel is 4.0-5.0 nm, or the average pore diameter of the solid silica gel is greater than 10.0 nm; the mass content of SiO2 in the liquid silica gel is 1%-30%.

33. The method for preparing a catalytic cracking catalyst according to claim 28, wherein: Calculated as silicon oxide, the second silicon source accounts for 4 wt% to 10 wt% of the total silicon input.

34. The method for preparing a catalytic cracking catalyst according to claim 28, wherein: The ion exchange in step (5) is ammonium ion exchange and / or rare earth ion exchange.

35. The method for preparing a catalytic cracking catalyst according to claim 28 or 34, wherein: The ion exchange includes rare earth ion exchange. The rare earth content in the modified NSY molecular sieve obtained in step (5) is 10% to 20% by weight in terms of RE2O3, and the sodium oxide content is less than 2% by weight.

36. The method for preparing a catalytic cracking catalyst according to claim 28, wherein: The ion exchange product obtained in step (5) is further calcined.

37. A catalytic cracking catalyst obtained by the preparation method of the catalytic cracking catalyst according to any one of claims 27 to 36.

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