CN101451074B - Catalyst for heavy oil catalytic cracking and preparation method thereof - Google Patents

Abstract

The invention provides a catalyst for catalytic cracking of heavy oil and a preparation method thereof, wherein the catalyst comprises an effective amount of REY molecular sieve and a matrix, and is characterized in that the preparation method of the REY molecular sieve comprises contacting NaY molecular sieve with an aqueous solution containing rare earth ions or with After the aqueous solution containing rare earth ions is in contact with the solution or colloid containing aluminum ions, it is contacted with an external precipitant to precipitate part of the rare earth on the molecular sieve, then undergoes hydrothermal treatment, and finally contacts with an aqueous ammonium salt solution, and the matrix contains a transition metal oxide Modified hydrated alumina; the catalyst is prepared by beating REY molecular sieve and matrix and spray drying. The catalyst of the invention is used for heavy oil cracking, has strong heavy oil cracking ability, high gasoline yield, low sulfur content in gasoline and strong vanadium pollution resistance.

Description

A kind of heavy oil catalytic cracking catalyst and preparation method thereof

technical field

The invention relates to a hydrocarbon oil catalytic cracking catalyst and a preparation method thereof.

Background technique

In recent years, due to environmental protection considerations, the requirements for fuel oil have been increasing worldwide. Taking China as an example, GB 17930-2006 implemented on December 6, 2006 stipulates that the sulfur content of motor gasoline (II) is not more than 500ppm (mass fraction), the olefin content is not more than 35v%, and the sulfur content of motor gasoline (III) The sulfur content is not greater than 150ppm (mass fraction), and the olefin content is not greater than 30v%. More than 75% of the blending group and olefins in my country's finished gasoline come from catalytic cracking units, and Chinese refineries are processing more and more Middle Eastern crude oil with high sulfur content. Therefore, reducing the sulfur content and olefin content in FCC gasoline is beneficial to production cleanliness Gasoline is critical.

Due to limited resources, the feedstock for catalytic cracking has changed from traditional vacuum distillate oil to blended residue or pure residue, and it is required to produce as much gasoline as possible. Residual oil not only contains colloid and asphaltene and other macromolecular compounds that are prone to coke, but also contains more heavy metals (such as nickel, vanadium, etc.), sulfur, nitrogen and other elements. In the cracking reaction, metals such as nickel and vanadium are deposited on the catalyst, which reduces the activity of the catalyst, especially vanadium, which has a high oxidation state and has strong mobility in a high-temperature hydrothermal environment, and it is easier to destroy the structure of the molecular sieve in the catalyst, making the catalyst Consumption increases, and operating costs increase significantly. The increase of sulfur content in raw materials will lead to the increase of sulfur content in cracked gasoline.

One way to reduce the sulfur content in catalytic cracking gasoline is to use cracking catalysts or additives with desulfurization function in the catalytic cracking process.

CN 1049678C discloses a catalytic cracking catalyst composition comprising (a) a molecular sieve dispersed in an inorganic oxide matrix, (b) 1-50% by weight of an alumina-containing Lewis acid component, the The composition consists essentially of 1-50% by weight of a Lewis acid expressed as an oxide selected from the group consisting of nickel, copper, zinc, silver, cadmium, based on the total weight of the Lewis acid and aluminum oxide in the composition , indium, tin, mercury, thallium, lead, bismuth, boron, aluminum (except Al ₂ O) and gallium elements and compounds, and the Lewis acid is supported on alumina. The Lewis-acid-containing alumina component is obtained by combining an alumina matrix which has Lewis acid properties and has a surface area of about 30-400m ² /g with/with a material selected from Ni, Cu, Zn, Ag, Cd, In, Sn , Hg, Tl, Pb, Bi, B, Al (not Al ₂ O ₃ ), Ca and mixtures thereof, the "second" component reaction/impregnation of a group of elements/compounds is prepared by reacting/impregnating or by combining alumina and Preparation by Co-precipitation of Key Lewis Acid Components.

CN1281887A provides a gasoline desulfurization catalyst for FCC process, the molecular sieve of which contains oxidized metal components (preferably vanadium) and rare earth components (preferably cerium) to improve the cracking activity of the catalyst. In order to be effective for desulfurization, the metal exists inside the pore structure of the molecular sieve. In order to avoid excessive coke and hydrogen during the cracking process, the added metal should not have significant hydrogenation activity. Therefore, vanadium, zinc, iron, cobalt and gallium are desirable components, with vanadium being the preferred metal component. MAT evaluation shows that vanadium-exchanged molecular sieves are very effective for gasoline desulfurization. Adding 10% of V/ZSM-5, V/MCM-49, V/β and V/USY to the benchmark agent, it is observed that the sulfur content of gasoline is reduced by 10%, 17%, 41%, and 75%.

The sulfur reduction catalyst described in CN1261618A contains a porous molecular sieve, the molecular sieve contains a first metal component and a second metal component, the first metal component is located inside the pore structure of the molecular sieve and its oxidation state is greater than zero, and the second metal component includes At least one rare earth element located inside the pore structure of the molecular sieve. The first metal component is selected from the metals of the fourth period of the periodic table and the metals of groups IIB, VB, IIIA, and VIII, especially vanadium, zinc, iron, and gallium. The amount of the metal component in the catalyst is 0.2-5% by weight.

WO 01/21732 A1 discloses a process for reducing the sulfur content of cracked petroleum fractions, which comprises catalytically cracking petroleum fractions at elevated temperatures and in the presence of a cracking catalyst and an additive to reduce the sulfur content of the product to obtain Liquid cracking products with lower sulfur content. Wherein, the additive for reducing the sulfur content of the product contains a vanadium-containing non-molecular sieve carrier, and the non-molecular sieve carrier can be an organic or inorganic carrier, and the preferred carrier is an amorphous or subcrystalline inorganic oxide, such as alumina, silicon oxide , clay or their mixtures.

CN1552802A provides a cracking aid with desulfurization effect and its preparation method. The aid contains a heat-resistant inorganic oxide, clay and a metal component, with or without molecular sieve, based on the total amount of the aid , the content of heat-resistant inorganic oxide is 2-68% by weight, the content of clay is 30-80% by weight, the content of molecular sieve is 0-40% by weight, based on the metal oxide in the highest valence state, the metal component The content is 0.1-30% by weight, and the metal component exists in a reduced valence state, which is selected from the group IIIA non-aluminum metals, IVA group metals, VA group metals, IB group metals, IIB group metals, VB group One or more of metals, VIB group metals, VIIB group metals, and VIII group non-noble metals. The additive has higher desulfurization activity, and the catalyst mixture containing the additive and cracking catalyst has higher cracking activity.

The key to reducing the olefin content of FCC gasoline and increasing gasoline yield is to increase the activity of the FCC balancer and increase the hydrogen transfer capacity of the catalyst to saturate the olefins in gasoline while maintaining good coke selectivity (He, MY, Catal .Today, 73(1-2), 49-55, 2002) and higher activity. This requires catalysts with high hydrothermal activity stability. Increasing the rare earth content of molecular sieves helps to stabilize the structure of molecular sieves.

The REY molecular sieve prepared after rare earth exchange is a highly active component of catalytic cracking catalyst. The rare earth ions in the REY molecular sieve migrate into the sodalite cage and form a multi-nuclear cation structure with oxygen bridges, which increases the stability of the acid center of the molecular sieve in a high-temperature hydrothermal environment, and improves the cracking activity and activity stability of the molecular sieve catalyst. Thereby improving the heavy oil conversion activity and selectivity of the catalyst. However, when the NaY molecular sieve and the aqueous solution of the rare earth salt are ion-exchanged at normal temperature and pressure, the hydrated rare earth ions with a diameter of about 0.4 nm are difficult to enter the sodalite cage through the six-membered ring window of the Y molecular sieve (0.26 nm in diameter). Therefore, during the preparation of REY molecular sieves, the hydration layer around the rare earth ions must be removed by roasting, so that the rare earth ions can enter the sodalite cages, and the sodium ions in these cages also migrate out to the supercages by means of the roasting process. , to create conditions for further ion exchange (USP3402996). In order to promote the migration of rare earth ions into the sodalite cage, high temperature roasting is usually used. However, an excessively high calcination temperature not only requires high materials for the calcination equipment, but also the rare earth ions already in the sodalite cage tend to return to the large cage (Zeolites, 6(4), 235, 1986). On the other hand, it is generally believed that a sufficiently high rare earth content in REY molecular sieves is a necessary condition for molecular sieves to have high thermal and hydrothermal stability (USP3140249, USP3140250, USP3140251, USP3140252, USP3140253).

In order to further improve the catalytic performance of REY zeolite, many modification methods have been proposed in relevant patent documents.

CN1449306 discloses a molecular sieve catalyst with enhanced Lewis acidity and a preparation method thereof. The catalyst component molecular sieve effectively adds organometallic compounds that promote dehydrogenation and increase Lewis acidity. This compound is in the non-framework part of the molecular sieve, preferably aluminum acetylacetonate. These non-framework components do not affect zeolite cell shrinkage, but increase activity.

US5037531 discloses a catalyst for catalytic cracking, which contains framework dealuminated Y zeolite components exchanged by aluminum and rare earth, and has good gasoline selectivity.

CN1142019C discloses a phosphorus-containing hydrocarbon cracking catalyst and its preparation. The catalyst is mixed with molecular sieve treated with phosphorus-containing solution, clay and double aluminum binder, roasted or spray-dried at 500°C, and then treated with phosphorus-containing solution get. The catalyst can reduce the olefin content of product gasoline fraction to 20-26% by weight.

CN1353086A discloses a preparation method of Y-type molecular sieve containing phosphorus and rare earth, the method comprises first mixing and exchanging NaY molecular sieve with ammonium ion and rare earth ion and hydrothermal roasting, then reacting it with phosphorus compound and combining it with 0.2-10 wt. % (calculated as P ₂ O ₅ ) of phosphorus, and then hydrothermally roasted. The Y-type molecular sieve obtained by the method of the invention can significantly reduce the olefin content of the FCC gasoline, while maintaining good coke selectivity.

CN1330981A discloses a phosphorus-containing Y zeolite and its preparation method. The phosphorus-containing Y zeolite contains phosphorus, and also contains a silicon component and a rare earth component. The silicon component is loaded by impregnating the zeolite with a silicon compound solution. In terms of SiO ₂ , the content of the silicon component is The content of the phosphorus component is 1-15 wt%, calculated as P ₂ O ₅ , the content of the phosphorus component is 0.1-15 wt%, and calculated as the rare earth oxide, the content of the rare earth component is 0.2-15 wt%. The preparation method is that the Y zeolite containing rare earth is co-impregnated with the solution containing silicon and phosphorus, and after being dried, it is hydrothermally roasted at 550-850°C. The phosphorus-containing zeolite has higher crystallinity after hydrothermal treatment and has better catalytic performance, and the cracking catalyst containing the phosphorus-containing Y zeolite has stronger heavy oil conversion ability and better product distribution.

CN1325940A discloses a phosphorus-containing hydrocarbon cracking catalyst and its preparation. The catalyst is composed of 10-60% by weight of Y-type molecular sieve or Y-type molecular sieve and MFI structure molecular sieve and/or β molecular sieve, 0-75% by weight of clay, 10-60% by weight of two kinds of alumina, and _P2 0.1-7.0 wt% phosphorus _{as O5} and 0-20 wt% rare earth as _RE2O3 . The catalyst is to mix the molecular sieve treated with the phosphorus-containing solution with or without the molecular sieve not treated with the phosphorus solution, and then mix it with clay and double aluminum binder, roast or spray dry at 500°C, and then treat it with the phosphorus-containing solution get. The catalyst can reduce the olefin content in the product gasoline fraction to 20-26% by weight.

，磷含量占0.2-3％(以P计)。和常规催化剂相比，在保证其他产品分布和汽油辛烷值基本不变的前提下，能明显降低汽油的烯烃含量。CN1317547A discloses a FCC catalyst for reducing the olefin content of gasoline and its preparation method. The catalyst is composed of zeolite-type active components, amorphous silica-alumina oxide and kaolin, wherein the active components are 0.5-5% (accounting for the weight percentage of FCC catalyst, the same below) ZSM-5, 0.5-15% rare earth Y zeolite , 20-40% phosphorus and rare earth composite modified super stable Y zeolite composition. Phosphorus and rare earth compound modified Y zeolite is made of NaY zeolite mixed with rare earth and ammonium salt, after hydrothermal roasting treatment, it reacts with phosphorus compound, and then performs second roasting treatment. Wherein, the weight ratio of RE ₂ O ₃ /Y zeolite is 0.02-0.18, the weight ratio of ammonium salt/Y zeolite is 0.1-1.0, the weight ratio of P/Y zeolite is 0.003-0.05, and the roasting temperature is 250-750°C. The water vapor condition is 5-100%, and the time is 0.2-3.5 hours. The rare earth content on the obtained PREY zeolite accounts for 2-12%, and the unit cell constant is 24.45-24.46

, the phosphorus content accounts for 0.2-3% (calculated as P). Compared with conventional catalysts, it can significantly reduce the olefin content of gasoline under the premise of ensuring the distribution of other products and the octane number of gasoline are basically unchanged.

CN1284403A discloses an improved rare earth Y zeolite and its preparation. The relative crystallinity of the zeolite is 65-85%, and the percentage of the secondary pore volume to the total pore volume is 20-80%. It is prepared by impregnating a rare earth Y zeolite with a Na ₂ O content of 2.5-8% by weight with a silicon-containing solution and then drying, so that the rare earth Y zeolite contains 1-15% by weight of impregnated silicon (calculated as SiO ₂ ) , and then hydrothermally calcining the obtained silicon-impregnated rare earth Y zeolite at 500-850° C. for 0.5-30 hours in a steam atmosphere. The zeolite has relatively high conversion capacity of heavy oil and is suitable for processing residual oil raw materials.

CN1217231A discloses a phosphorus-containing faujasite hydrocarbon cracking catalyst and a preparation method thereof. The catalyst contains 10-60% by weight of faujasite, 0.01-1.5% by weight of phosphorus, 0.1-40% by weight of rare earth oxide, 10-60% by weight of aluminum binder (calculated as alumina), and 0-75% by weight of clay , the aluminum binder comes from pseudo-boehmite and aluminum sol respectively. The phosphorus-containing faujasite is prepared by uniformly mixing the faujasite and the phosphorus-containing compound aqueous solution, standing still for 0-8 hours, drying, and roasting at 450-600° C. for more than 0.5 hours.

CN1053808A discloses a preparation method of rare earth Y molecular sieve, which is to perform ion exchange between NaY molecular sieve and rare earth ions in aqueous solution, and then roast at 450-600°C and 100% steam for 1-3 hours. This method simplifies the preparation process, reduces the amount of rare earths and production costs, and the molecular sieve prepared by this method can be reverse-exchanged with less rare earths during further ammonium exchange, and has higher hydrothermal structural stability and higher cracking activity. stability.

The conventional rare earth liquid phase ion exchange is used in the preparation of the above improved REY molecular sieve, and the utilization rate of the rare earth is low.

CN1436728A discloses a preparation method of rare earth ultra-stable Y molecular sieve, which uses NaY type molecular sieve as raw material, and the chemical dealumination complexing agent contains oxalic acid or oxalate and its mixture, and at the same time, rare earth ions are introduced in the later stage of chemical dealumination reaction, The formation of rare earth precipitation, and then through hydrothermal treatment, can achieve the purpose of ultra-stabilization and the introduction of rare earth ions and independent phase oxidation of rare earth. The precipitated rare earth precursors formed include rare earth oxalates. Compared with conventional REY, REHY or REUSY, the molecular sieve has a simple preparation process, high rare earth utilization rate, and has the characteristics of uniform aluminum distribution, developed secondary pores, good hydrothermal stability, high activity, and strong vanadium pollution resistance.

CN86107531A and CN86107598A disclose molecular sieves containing rare earth oxides and their preparation methods. The rare earths of the molecular sieve all exist in the state of RE ₂ O ₃ or RE(OH) ₃ , and the exchangeable cation positions are occupied by H ⁺ , NH ₄ ⁺ or Na ⁺ . The cracking catalyst prepared by the molecular sieve can effectively reduce the hydrogen transfer reaction, significantly weaken the unit cell shrinkage phenomenon in the heat and hydrothermal aging process, and has the performance of anti-sodium and heavy metal pollution.

Contents of the invention

One of the technical problems to be solved by the present invention is to provide a new cracking catalyst, which has strong heavy oil cracking ability and vanadium pollution resistance, and can reduce the sulfur content of cracked gasoline; the second technical problem to be solved by the present invention is The invention provides a preparation method of the above-mentioned cracking catalyst.

The invention provides a catalyst for catalytic cracking, comprising an effective amount of REY molecular sieve and substrate, characterized in that the preparation method of the REY molecular sieve comprises contacting NaY molecular sieve with an aqueous solution containing rare earth ions or with an aqueous solution containing rare earth ions and an aluminum-containing After the ion solution or colloid is in contact, contact with an external precipitant to precipitate part of the rare earth on the molecular sieve, then perform hydrothermal treatment, and finally contact with an ammonium salt aqueous solution, wherein the precipitant is an alkaline aqueous solution; the matrix contains a Modified hydrated alumina, the modified hydrated alumina has a pseudoboehmite structure, contains 50-99.5% by weight of alumina, and 0.5-50% by weight of transition metal oxides, and the transition metals are zinc and copper , cobalt, iron, titanium, vanadium, chromium, manganese, molybdenum, zirconium in one or more.

The present invention also provides a kind of preparation method of above-mentioned catalyst, comprises the following steps:

(a) Preparation of rare earth Y molecular sieve: NaY molecular sieve is contacted with an aqueous solution containing rare earth ions or after being contacted with an aqueous solution containing rare earth ions and a solution or colloid containing aluminum ions, and then contacted with an additional precipitant to precipitate part of the rare earth on the molecular sieve, and then Carrying out hydrothermal treatment, and finally contacting with an ammonium salt aqueous solution, wherein the precipitating agent is an alkaline aqueous solution;

(b) preparing modified hydrated alumina;

(c) Mix REY molecular sieve, modified alumina and other matrix components, make a slurry, and spray dry.

In the catalyst provided by the present invention, the REY molecular sieve used is by introducing precipitated rare earth or introducing precipitated rare earth and external aluminum during the modification process of NaY molecular sieve, so that the catalyst has good hydrothermal stability when it contacts with vanadium oxide; The modified hydrated alumina contained in the preparation method is different from the prior art, has the advantage of large average pore size, helps to improve the heavy oil conversion capacity of the catalyst, and reduces the sulfur content of cracked gasoline. The method for preparing the catalyst of the present invention has a short process for preparing the REY molecular sieve, and the preparation process is simple and easy. The catalyst provided by the invention is used for catalytic cracking of heavy oil, has strong cracking ability, strong resistance to heavy metals, especially vanadium pollution, high gasoline yield, and low sulfur content in gasoline products. For example, according to the method provided by the present invention, REY molecular sieve containing 18.2% by weight of rare earth oxide is prepared, and then the molecular sieve is mixed with REHY molecular sieve, ZRP molecular sieve, modified hydrated alumina containing Zn, V and RE, aluminum sol, kaolin by 15: The catalyst was prepared in a weight ratio of 14:5:12:11:43, aged at 800°C/100% steam/8 hours, on a small fixed fluidized bed, using heavy oil with a specific gravity of 0.9177 as raw material, at a temperature of 500°C , the agent oil weight ratio is evaluated under the condition of 6, the heavy oil yield is 9.18% by weight, the gasoline yield is 45.04% by weight, and the sulfur content in gasoline is 535mg/l. The reaction was carried out under the conditions, the yield of heavy oil was 10.32% by weight, and the yield of gasoline was 43.31% by weight. And the molecular sieve in the catalyzer is replaced with the REY molecular sieve containing rare earth oxide 18.5% by weight prepared according to the existing two-according and double-calcined method, and the aluminum oxide containing Zn, V and RE is prepared according to the existing method with the same amount The Zn-containing alumina replaces, when not polluted by vanadium, evaluates under the same conditions, the heavy oil yield is 12.21% by weight, the gasoline yield is 41.98% by weight, and the sulfur content in gasoline is 732mg/l; After 2000ppm (mass ) after vanadium pollution, evaluated under the same conditions, the heavy oil yield was 14.38% by weight, and the gasoline yield was 39.23% by weight.

Detailed ways

According to catalyst provided by the present invention, described REY molecular sieve preparation method comprises the following steps:

(1) Contact NaY molecular sieve with a silicon-aluminum ratio ≥ 4.5 with an aqueous solution containing rare earth ions or with an aqueous solution containing rare earth ions and an aqueous solution containing aluminum ions, wherein, in terms of rare earth oxides, the ratio of rare earth ions to molecular sieve solids is preferred 0.12-0.30, more preferably 0.13-0.20, based on alumina, the ratio of aluminum ions to molecular sieve solids is 0-0.1, preferably 0-0.05, the liquid-solid ratio is 4-20, preferably 8-15, and the reaction temperature is 60- 95°C, preferably 70-80°C, the reaction time is 10-120min, the ratio is a weight ratio, adding an alkaline aqueous solution to the reaction slurry, filtering and washing to obtain a filter cake product;

(2) performing hydrothermal treatment on the filter cake product obtained in step (1), the condition is that the temperature is 450-800°C, the time is 0.5-4h, and the ambient atmosphere is a water vapor atmosphere with a water content of 10-100% by volume;

(3) The hydrothermally treated product of step (2) is contacted with an aqueous solution containing ammonium ions, filtered and washed, wherein the ratio of ammonium salt to molecular sieve solid is 0.1-1.0, the liquid-solid ratio is 4-20, and the reaction temperature is 60 -95°C, the reaction time is 30-120min, wherein the ratio is a weight ratio.

According to the catalyst provided by the present invention, in the step (1) of preparing REY molecular sieve, the described rare earth ion solution is an aqueous solution of chloride or nitrate containing one or more of lanthanum, cerium, praseodymium, and neodymium ions , wherein the more preferred rare earth ion solution is a lanthanum-rich rare earth salt solution.

The aluminum-containing ion solution described in step (1) is an aqueous solution or sodium aluminate solution of chloride, sulfate or nitrate of aluminum, and the colloid is aluminum sol or acidified pseudo-boehmite, preferably aluminum Sol.

According to the catalyst provided by the present invention, the precipitating agent is an alkaline aqueous solution, and the alkaline aqueous solution is a soluble carbonate aqueous solution or an alkaline aqueous solution without carbonate, when the precipitating agent is a soluble carbonate aqueous solution , in terms of carbonate, the ratio of the precipitant to the rare earth oxide is 0.1-1.5, more preferably 0.3-0.7; when the precipitant is an alkaline aqueous solution without carbonate, the amount of the precipitant is controlled until the pH value of the molecular sieve slurry is 6-10, preferably controlling the amount of precipitating agent added until the pH value of the molecular sieve slurry is 7-9. Then filter and wash to obtain the filter cake product. Described soluble carbonate is selected from ammonium bicarbonate, ammonium carbonate, sodium carbonate or sodium bicarbonate, wherein preferred ammonium bicarbonate; Described alkaline aqueous solution not containing carbonate is ammonia solution, water glass solution or Alkaline molecular sieve synthesis mother liquor, wherein ammonia solution is preferred.

According to the catalyst provided by the present invention, in the step (2) of the preparation of the REY molecular sieve, the preferred hydrothermal treatment conditions are a temperature of 580-700° C., and the ambient atmosphere is a water vapor atmosphere with a water content of 100% by volume.

According to the catalyst provided by the present invention, in the REY molecular sieve preparation step (3), the ratio of the ammonium salt to the molecular sieve solid is preferably 0.3-0.6, and the liquid-solid ratio is preferably 8-15. The ammonium salt is selected from one or more of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium oxalate and ammonium carbonate.

According to the catalyst provided by the present invention, the solution containing ammonium ions described in the preparation step (3) of REY molecular sieve also contains phosphate ions, and the ratio of phosphate ions to molecular sieve solids is no more than 0.07 (weight ratio), preferably no more than 0.04. The phosphate ion is derived from phosphorus-containing compounds, such as one or more of ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, phosphoric acid, aluminum phosphate and sodium phosphate.

In the catalyst provided by the present invention, the preparation method of the REY molecular sieve used is characterized in that the rare earth or the rare earth and the external aluminum are partially precipitated on the Y molecular sieve at the same time, and then hydrothermally roasted. After hydrothermal calcination, the rare earths on the molecular sieve exist in two forms, part of the rare earths enters the molecular sieve cage in the ion state, and the other part of the rare earths is dispersed on the surface of the molecular sieve as the oxidized rare earth phase. The preparation method is simple and easy, has high rare earth utilization rate, shortens the preparation process of molecular sieves, and saves production costs.

According to the catalyst provided by the present invention, it contains modified hydrated alumina, based on the weight of modified hydrated alumina, the modified hydrated alumina preferably contains 60-90% by weight of alumina, 10-40% by weight of transition Metal oxide. The modified hydrated alumina can be prepared according to the method described in CN200610089022.5, including the following steps:

(A) Pseudo-boehmite is mixed under stirring with water and acid sufficient to make it slurry, wherein the acid is used in an amount such that the weight ratio of the acid to the alumina in the pseudo-boehmite is 0.01-0.5;

(B) Aging the mixed slurry obtained in step (A) at room temperature-90°C, preferably room temperature-80°C, for 0-24 hours, preferably 0.5-4 hours;

(C) mixing the product obtained in step (B) with a compound containing a transition metal element. The transition metal compound is an oxide or an oxide precursor of a transition metal.

According to the catalyst provided by the present invention, based on the weight of the catalyst, it contains 10-50% by weight of REY molecular sieve on a dry basis, and 50-90% by weight of a substrate, the substrate comprising the modified hydrated alumina, Inorganic oxide binders and clays may also be included. Based on the weight of the catalyst, in the catalyst, the content of the modified alumina hydrate in terms of oxides is 10-70% by weight, and the content of the inorganic oxide binder is 0-40% by weight, preferably 10-40% by weight. % by weight, based on dry basis, the content of clay is 0-70% by weight, preferably 10-70% by weight. The clay is selected from one or more clays commonly used as cracking catalyst components, such as kaolin, halloysite, montmorillonite, diatomaceous earth, halloysite, saponite, retortite, sea foam One or more of stone, attapulgite, hydrotalcite, and bentonite. Described inorganic oxide binding agent is one or more in the commonly used inorganic oxide binding agent of catalytic cracking catalyst, preferably alumina binding agent, and described alumina binding agent is selected from cracking catalyst usually used One or more of various forms of alumina, hydrated alumina and aluminum sol. For example, selected from γ-alumina, η-alumina, θ-alumina, χ-alumina, pseudoboemite (Pseudoboemite), gibbsite (Boehmite), gibbsite (Gibbsite) or Bayer One or more of Bayerite, preferably pseudo-boehmite and/or aluminum sol.

The catalyst provided by the present invention may also contain other molecular sieves, and the other molecular sieves are one or more of other types of Y-type zeolites, zeolites with MFI structure, Beta zeolites, and non-zeolite molecular sieves commonly used in catalytic cracking catalysts. Based on the weight of the catalyst, the content of other molecular sieves is not more than 50% by weight. The other types of Y-type zeolites mentioned are, for example, REY, REHY, USY, REUSY, and DASY. The non-zeolite molecular sieves are, for example, TS-1 molecular sieves, SAPO-17 molecular sieves, SAPO-34 molecular sieves, and SAPO-37 molecular sieves.

According to the catalyst preparation method provided by the present invention, the mixing of REY molecular sieve, modified hydrated alumina and other matrix components, beating, and spray drying can be carried out according to the existing catalyst preparation method. The present invention has no special requirements, for example, according to the patent The method described in CN1098130A, CN1362472A, CN1727442A, CN1132898C, CN1727445A. The catalyst obtained by spray drying can also be washed and dried, which is well known to those skilled in the art.

The catalyst of the invention can be used for catalytic cracking of heavy oil, especially for catalytic cracking of heavy oil containing vanadium. The heavy oil is one or more of atmospheric residue, vacuum residue, vacuum gas oil, atmospheric gas oil, straight-run gas oil, propane light/heavy deasphalted oil and coker gas oil.

The following examples will further illustrate the present invention, but do not limit the present invention thereby.

In Examples and Comparative Examples:

The hydrothermal ultra-stable Y zeolite DASY0.0, DASY2.0, REHY and ZRP molecular sieves were provided by Sinopec Catalyst Qilu Branch. The properties are shown in Table 1. The aluminum sol was provided by Sinopec Catalyst Qilu Branch. Bauxite is provided by Shandong Aluminum Plant.

In the physical and chemical data of the samples obtained in Examples and Comparative Examples, the contents of _P2O5 , _RE2O3 and _Na2O were determined by X-ray fluorescence spectroscopy; the _unit cell constants were determined by X-ray diffraction ( _XRD ) using RIPP145-90 Standard method (see "Petrochemical Analysis Method (RIPP Test Method)", edited by Yang Cuiding et al., Science Press, 1990 edition) for determination.

Example 1

This example illustrates the catalyst provided by the invention and its preparation method.

(1) Take 1500 grams of NaY molecular sieves (dry basis weight, produced by Qilu Catalyst Factory, the same below), after beating with 12 liters of deionized water, add a mixed _RECl solution with a concentration of 231g/l (calculated as RE ₂ O ₃ ) (provided by Qilu Catalyst Factory _, wherein _La2O3 accounts for 52.5% by weight, _CeO2 accounts for 46.5% by weight, _Pr2O5 accounts for 0.6% by weight, _Nd2O3 accounts for _0.4 % by weight _, the same below) 1059 milliliters, at 80 ℃ Exchange for 0.5 hour, then add 150 grams of ammonium bicarbonate (chemically pure, produced by Tianjin Nankai Chemical Factory, the same below), stir at 80°C for 0.5 hour, filter and rinse, then filter cake at 650°C, 100% steam atmosphere Medium roasting for 2 hours to obtain molecular sieve dry powder. Take 1500 grams of this molecular sieve dry powder (dry basis weight), beat with 12 liters of deionized water, add 1500 grams of ammonium chloride (chemically pure, produced by Tianjin Dengfeng Chemical Reagent Factory, the same below), and exchange at 85 ° C for 0.5 hours , filtered and rinsed, and the filter cake was dried to obtain a molecular sieve, denoted as V-1, and its properties are shown in Table 1.

(2) Mix 1000 grams of pseudoboehmite (produced by Shandong Aluminum Factory, alumina content 60% by weight), 4000 grams of deionized water and 120 grams of hydrochloric acid (concentration 36%, produced by Beijing Chemical Plant, analytically pure) under stirring (wherein the weight ratio of acid to alumina is 0.2), beating, aging for 4 hours at 50°C, and then mixing with 666 grams of ZnCl ₂ (produced by Beijing Shuanghuan Reagent Factory, analytically pure) to obtain zinc-containing pseudo-boehmite Structure of modified hydrated alumina A-1.

(3) The molecular sieve V-1 obtained in (1), the modified hydrated alumina A-1 obtained in (2), aluminum sol, kaolin are mixed with deionized water in a weight ratio of 37:34:11:18 (wherein , molecular sieve and kaolin are calculated on a dry basis, modified hydrated alumina is calculated as an oxide, and aluminum sol is calculated as an alumina, the same below), beating, the solid content of the slurry is 15% by weight, spray-dried at a temperature of 280 ° C, The catalyst was washed three times with decationized water, the ratio of each wash water to the molecular sieve in the catalyst was 10:1 (weight ratio), and dried to obtain the catalyst C1 provided by the present invention.

Example 2

This example illustrates the catalyst provided by the invention and its preparation method.

(1) The preparation method of molecular sieve V-1 is the same as that in Example 1.

(2) Mix 1150 grams of pseudo-boehmite (produced by Shandong Aluminum Factory, alumina content 60%), 6000 grams of deionized water and 83 grams of hydrochloric acid (concentration 36%, produced by Beijing Chemical Plant, analytically pure) under stirring (the weight ratio of acid to alumina is 0.12), aging at 80°C for 1 hour, adding 154 grams of ZnO and 158 grams of TiO ₂ (both ZnO and TiO ₂ are produced by Beijing Shuanghuan Reagent Factory, analytically pure) under stirring to obtain zinc-containing and titanium modified hydrated alumina A-2 with a pseudo-boehmite structure.

(3) Molecular sieve V-1 obtained in (1), DASY0.0 ultrastable molecular sieve, modified alumina hydrate A-2 obtained in (2), aluminum sol, kaolin according to the ratio of 20:17:27:11:25 The weight ratio is mixed with deionized water, beaten, the solid content of the slurry is 15% by weight, spray-dried at a temperature of 280° C., washed (same as Example 1), and dried to obtain the catalyst C2 provided by the present invention.

Example 3

This example illustrates the catalyst provided by the invention and its preparation method.

(1) Get 1000 grams _of NaY molecular sieves, after beating with 10 liters of deionized water, add 620 milliliters of RECl solution with a concentration of 231g/l (in terms of RE ₂ O ₃ ), then add aluminum sol (produced by Qilu Catalyst Factory, Al ₂ O ₃ accounted for 22%) 240 grams, exchanged at 90 ° C for 1 hour, then added 75 grams of ammonium bicarbonate, stirred at a constant temperature for 0.3 hours, filtered and rinsed, and then roasted the filter cake at 620 ° C, 100% water vapor atmosphere After 2 hours, a molecular sieve dry powder was obtained. Take 1000 grams of this molecular sieve dry powder (dry basis weight), beat it with 10 liters of deionized water, add 500 grams of ammonium sulfate (analytical pure, produced by Beijing Yili Fine Chemicals Co., Ltd., the same below), and exchange at 70 ° C for 1.5 hours , filter and rinse, and dry the filter cake to obtain a molecular sieve, denoted as V-2, whose properties are shown in Table 1.

(2) 1027 grams of pseudo-boehmite (produced by Shandong Aluminum Factory, alumina content 60%), 6000 grams of deionized water and 123 grams of hydrochloric acid (concentration 36%, produced by Beijing Chemical Plant, analytically pure) were mixed under stirring (by weight, the weight ratio of acid to alumina is 0.2), aged at 60°C for 2 hours, and then mixed with 287 g of ZnO, 340 g of Co(NO ₃ ) ₂ ·6H ₂ O(ZnO and Co(NO ₃ ) ₂ · 6H ₂ O (all produced by Beijing Shuanghuan Reagent Factory, analytically pure) was mixed to obtain modified hydrated alumina A-3 with pseudo-boehmite structure containing zinc and cobalt.

(3) The molecular sieve V-1 obtained in (1), DASY2.0 ultra-stable molecular sieve, the modified hydrated alumina A-3 obtained in (2), aluminum sol (calculated as oxide), and kaolin were mixed in a ratio of 20:17 : The weight ratio of 27: 11: 25 is mixed with deionized water, beating, and the solid content of the slurry is 15% by weight, spray-dried at a temperature of 280° C., and washed (with embodiment 1), and dried to obtain this Catalyst C3 provided by the invention.

Example 4

This example illustrates the catalyst provided by the invention and its preparation method.

(1) Take 1000 grams of NaY molecular sieves, beat with 10 liters of deionized water, add 580 ml of RECl ₃ solution with a concentration of 231g/l (calculated as RE ₂ O ₃ ), exchange at 90°C for 1 hour, and then add bicarbonate 75 grams of ammonium, stirred at constant temperature for 1 hour, filtered and rinsed, and then the filter cake was roasted at 620° C. in a 100% water vapor atmosphere for 2 hours to obtain dry molecular sieve powder. Get 1000 grams (dry weight) of this molecular sieve dry powder, after beating with 10 liters of deionized water, add 500 grams of ammonium chloride solid, add ammonium dihydrogen phosphate (analytical pure, produced by Beijing Yili Fine Chemicals Co., Ltd., the same below). ) 40.5 g, exchanged at 75°C for 1 hour, filtered and rinsed, and dried the filter cake to obtain a molecular sieve, denoted as V-3, and its properties are shown in Table 1.

(2) According to the method of Example 3, the modified hydrated alumina A-3 containing zinc and cobalt and having a pseudo-boehmite structure was prepared.

(3) The molecular sieve V-3 obtained in (1), DASY0.0 ultrastable molecular sieve, the modified hydrated alumina A-3 obtained in (2), aluminum sol, kaolin according to the ratio of 19:15:19:9:38 The weight ratio is mixed with deionized water, beaten, the solid content of the slurry is 15% by weight, spray-dried at a temperature of 280 ° C, and washed (same as Example 1), and dried to obtain the catalyst C4 provided by the present invention.

Example 5

This example illustrates the catalyst provided by the invention and its preparation method.

(1) Get 1000 grams of NaY molecular sieves, after beating with 10 liters of deionized water, add 706 milliliters of RECl solution with a concentration of 231g/l (in terms of RE ₂ O ₃ ), then add aluminum sulfate (analytical pure, Tianjin Chemical Industry Co., _Ltd. Reagent No. 3 Factory) 240 grams, exchanged at 90 ° C for 1 hour, then added 75 grams of ammonium bicarbonate, stirred at constant temperature for 0.25 hours, filtered and rinsed, and then roasted the filter cake at 600 ° C, 100% water vapor atmosphere for 2 hours , to obtain molecular sieve dry powder. Take 1000 grams of this molecular sieve dry powder (dry basis weight), beat it with 10 liters of deionized water, add 500 grams of ammonium nitrate (analytical grade, produced by Beijing Yili Fine Chemical Co., Ltd., the same below), and exchange at 75 ° C for 1 hour , filter and rinse, and dry the filter cake to obtain a molecular sieve, denoted as V-4, whose properties are shown in Table 1.

(2) 1200 grams of pseudo-boehmite (produced by Shandong Aluminum Factory, alumina content 60%), 5000 grams of deionized water and 130 grams (by weight, the weight ratio of acid and alumina is 0.18) hydrochloric acid ( Concentration 36% by weight, produced by Beijing Chemical Plant, analytically pure) mixed under stirring, aging at 60°C for 2 hours, and 483 grams of Zn(NO ₃ ) ₂ 6H ₂ O (produced by Beijing Shuanghuan Reagent Factory, analytically pure), 51 gram of V ₂ O ₅ (produced by Beijing Shuanghuan Reagent Factory, analytically pure) and 285 milliliters of rare earth chloride aqueous solution (produced by Inner Mongolia Baotou Rare Earth Factory, wherein, the mass content of rare earth oxide is 337 g/liter) are mixed, beaten to obtain zinc, vanadium-containing and rare earth modified hydrated alumina A-4 with a pseudo-boehmite structure.

(3) The molecular sieve V-4 obtained in (1), DASY0.0 ultra-stable molecular sieve, ZRP molecular sieve, the modified hydrated alumina A-4 obtained in (2), aluminum sol, kaolin according to the ratio of 19:10:5:12 : The weight ratio of 10: 44 is mixed with deionized water, beating, and the solid content of the slurry is 15% by weight, spray-dried at a temperature of 280° C., and washed (with embodiment 1), and dried to obtain the present invention. Catalyst C5.

Example 6

This example illustrates the catalyst provided by the invention and its preparation method.

(1) Take 1000 grams of NaY molecular sieves, beat with 10 liters of deionized water, add 730 ml of RECl ₃ solution with a concentration of 231 g/l (calculated as RE ₂ O ₃ ), exchange at 70°C for 1 hour, and slowly add 25% Adjust the pH value of the molecular sieve slurry to 8.0 with an aqueous ammonia solution (analytically pure, produced by Beijing Chemical Plant), stir at a constant temperature for 0.25 hours, filter and rinse, and then roast the filter cake at 600°C in a 100% steam atmosphere for 2 hours to obtain a molecular sieve dry powder . Take 1000 grams of this molecular sieve dry powder (dry basis weight), beat it with 10 liters of deionized water, add 500 grams of ammonium nitrate solid, exchange at 75 ° C for 1 hour, filter and rinse, and dry the filter cake to obtain a molecular sieve, which is recorded as V -5, see Table 1 for properties.

(2) The modified alumina hydrate A-4 containing zinc, vanadium and rare earth and having a pseudo-boehmite structure was prepared according to the method in Example 5.

(3) The molecular sieve V-5, REHY molecular sieve, ZRP molecular sieve obtained in (1), the modified hydrated alumina A-4 obtained in (2), aluminum sol, kaolin according to 15:14:5:12:11:43 The weight ratio is mixed with deionized water, beating, the solid content of the slurry is 15% by weight, spray-dried at a temperature of 280° C., and washed (same as Example 1), and dried to obtain catalyst C6 provided by the invention.

Comparative example 1

(1) Molecular sieves were prepared according to the method in CN1353086A.

Take 1 000 grams of NaY molecular sieves, beat with 8 liters of deionized water, add 2000 ml of RECl ₃ solution with a concentration of 100 g/l (calculated as RE ₂ O ₃ ), exchange at 90° C. for 1 hour, filter and rinse, and then The filter cake was calcined at 570° C. for 2 hours in a 100% water vapor atmosphere to obtain REY molecular sieves. Dissolve 4.4 g (NH ₄ ) ₃ PO ₄ (chemically pure, produced by Beijing Hongxing Chemical Factory) with 145 ml of deionized water, and impregnate 100 g of REY molecular sieve (calculated on a dry basis). After drying the impregnated sample, put it into a muffle furnace, and bake it at 600°C for 1 hour to obtain a phosphorus-containing REY molecular sieve, which is denoted as DB1, and its properties are shown in Table 1.

(2) The modified hydrated alumina A-3 containing zinc and cobalt and having a pseudo-boehmite structure was prepared according to the method in Example 3.

(3) Molecular sieve DB1, DASY0.0 ultrastable molecular sieve obtained by (1), modified hydrated alumina A-3, aluminum sol, kaolin obtained by (2) are mixed with the weight ratio of 19:15:19:9:38 Mixed with deionized water, beating, the solid content of the slurry was 15% by weight, spray-dried at a temperature of 280° C., and washed (same as Example 1), and dried to obtain a comparative catalyst, which was recorded as DC1.

Comparative example 2

(1) Molecular sieves were prepared according to the method in CN1053808A.

Take 1000 grams of NaY molecular sieves, beat with 10 liters of deionized water, add 1250 ml of RECl ₃ solution with a concentration of 157 g/l (calculated as RE ₂ O ₃ ), exchange at 85° C. for 1 hour, filter and rinse, and then dry The dry filter cake was calcined at 600° C. for 2 hours in a 100% water vapor atmosphere to obtain dry molecular sieve powder. That is to get the REY molecular sieve in CN1053808A, which is recorded as DB2, and its properties are shown in Table 1.

(2) According to the method of Example 3, the modified hydrated alumina A-3 containing zinc and cobalt and having a pseudo-boehmite structure was prepared.

(3) The molecular sieve DB2 obtained in (1), DASY2.0 ultrastable molecular sieve, the modified hydrated alumina A-3 obtained in (2), aluminum sol, kaolin according to the weight ratio of 20:17:27:11:25 Mixed with deionized water, beaten, the solid content of the slurry was 15% by weight, spray-dried at a temperature of 280° C., washed (same as Example 1), and dried to obtain a comparative catalyst, which was designated as DC2.

Comparative example 3

(1) Preparation of conventional diacrylic REY molecular sieves.

Take 1000 grams _of NaY molecular sieves, beat with 10 liters of deionized water, add 1250 milliliters of RECl solution with a concentration of 157 g/l (calculated as RE ₂ O ₃ ), exchange at 85° C. for 1 hour, filter and rinse, and then filter The cake was calcined in an air atmosphere at 600° C. for 2 hours to obtain a molecular sieve dry powder. Take 1000 g of this molecular sieve dry powder (dry basis weight), beat it with 8 liters of deionized water, add 900 ml of RECl solution with a concentration of 157 g/l (calculated as RE ₂ O ₃ ), exchange it at 85° C. for 0.75 hours, _and filter Rinse and dry the filter cake to obtain REY molecular sieve, which is denoted as DB3, and its properties are shown in Table 1.

(2) Take 1000 grams of γ-alumina (produced by Shandong Aluminum Factory, specific surface area 297m ² /g), and mix it with 1000g water and 49.4g Zn(NO ₃ ) ₂ ·6H ₂ O at a temperature of 100°C. The solutions were mixed, impregnated for 18 hours to make the zinc oxide content 12%, and then calcined at 815° C. for 4 hours to obtain zinc-containing aluminum oxide.

(3) Molecular sieve DB3, REHY molecular sieve, ZRP molecular sieve obtained in (1), modified alumina, aluminum sol and kaolin obtained in (2) are mixed with deionized Mixed with water, beating, the solid content of the slurry is 15% by weight, spray-dried at a temperature of 280° C., washed (same as Example 1), and dried to obtain catalyst DC3.

Example 7-12

This example illustrates the cracking reaction performance of the catalyst provided by the present invention.

The evaluation device is a small fixed fluidized bed (manufactured by U.S. xytel company). The properties of the raw oil are shown in Table 3. The reaction temperature is 500°C, the weight ratio of agent to oil is 6, and the catalysts are aged at 800°C/100% steam/8 hours. The evaluation results are shown in Table 4.

Comparative example 4-6

This example illustrates the reactivity of the catalysts DC1-DC3 provided in the comparative examples.

The evaluation conditions are the same as in Example 7, and the evaluation results are shown in Table 4.

It can be seen from Table 4 that the catalyst of the present invention has strong heavy oil conversion ability, high gasoline yield, and low sulfur content in gasoline fractions.

Examples 13-18

This example investigates the anti-metal pollution performance of the catalyst of the present invention

Dissolve 10.1 g of vanadium naphthenate with a vanadium content of 1.98% by weight in 30 ml of kerosene; respectively take 100 g of the catalysts prepared in Examples 1-6, impregnate with the above solution, dry at 220° C. for 2 hours, and then roast at 650° C. for 3 hours , to obtain a catalyst with a metal vanadium content of 2000ppm (mass content), denoted as WC-1-WC-6, the catalyst was aged at 800°C/100% steam/4 hours, evaluated on a small fixed fluidized bed, and other reactions The conditions are the same as in Example 7, and the evaluation results are shown in Table 5.

Comparative example 7-9

This comparative example examines the anti-metal pollution performance of the catalysts prepared in Comparative Examples 1-3. Get 100g of the catalyst in Comparative Examples 1-3 respectively, and carry out metal pollution to the catalyst according to the method in Example 13, so that the content of metal vanadium on the catalyst is 2000ppm, which is recorded as WDC-1-WDC-3, and the catalyst is heated through 800°C/100% water Steam/8 hours of aging, evaluated on a small fixed fluidized bed, other reaction conditions are the same as in Example 8, and the evaluation results are shown in Table 5.

It can be seen from the data in Table 5 that the catalyst of the present invention is polluted by metal vanadium and subjected to hydrothermal treatment under harsh conditions, and is used for heavy oil cracking. It has high conversion capacity of heavy oil and gasoline yield, and the sulfur content in gasoline is low.

Table 1

Molecular Sieve Number V-1 V-2 V-3 V-4 V-5 DB 1 DB2 DB3 RE ₂ O ₃ , wt% 17.5 14.3 15.3 16.9 18.2 14.6 13.3 18.5 P ₂ O ₅ , weight % 0 0 2.4 0 0 2.1 0 0 Na ₂ O, weight % 1.0 0.9 1.0 0.9 1.0 3.8 4.2 1.9 unit cell constant ( ) 24.62 24.66 24.64 24.66 24.65 24.64 24.66 24.69

Table 2

raw material DASY-0.0 DASY-2.0 REHY ZRP Element content, weight % RE ₂ O ₃ / 2.5 7.0 / Na ₂ O 1.3 1.5 4.2 0.2 Al ₂ O ₃ 20.5 20.2 21.7 1.6 Cell constant, nm 2.445 2.448 2.460 / Crystallinity, % 79.2 67.7 57.3 95

table 3

Density (20℃), g/ ^cm3 0.9177 Viscosity(100℃)mm ² /s 13.05 Four components, m% saturated aromatic hydrocarbon colloid asphaltenes 57.625.216.90.3 Metal content, ppmCaFeNaNiV 5.99.30.911.32.0 C m%H m%S m%N m% 86.812.310.540.32 Carbon residue m% 4.06 Distillation range, °C Initial boiling point 10% 30% 50% 70% 76% 269352411452522550

Table 4

Example number 7 8 9 10 11 12 Comparative example 4 Comparative example 5 Comparative example 6 Catalyst C-1 C-2 C-3 C-4 C-5 C-6 DC-1 DC-2 DC-3 Material balance, weight % dry gas 1.32 1.3 1.29 1.25 1.37 1.35 1.31 1.27 1.21 Liquefied petroleum gas 18.7 18.51 18.02 18.53 20.23 20.79 17.22 17.71 18.25 gasoline 48 47.97 47.31 46.35 45.52 45.04 44.78 44.12 41.98 diesel fuel 16.38 16.7 17.28 17.07 16.34 16.19 17.85 18.73 18.48 Heavy oil 7.94 8.39 8.83 9.82 9.29 9.18 10.93 11.25 12.21 coke 7.66 7.13 7.27 6.98 7.25 7.45 7.91 6.92 7.87 Conversion rate, % by weight 75.68 74.91 73.89 73.11 74.37 74.63 71.22 70.02 69.31 S content in gasoline, ng/μl 568 592 534 492 543 535 704 679 732

table 5

Example number 13 14 15 16 17 18 Comparative example 7 Comparative example 8 Comparative example 9 catalyst WC-1 WC-2 WC-3 WC-4 WC-5 WC-6 WDC-1 WDC-2 WDC-3 Material balance, weight % dry gas 1.32 1.36 1.31 1.35 1.41 1.37 1.3 1.26 1.27 Liquefied gas 17.3 17.13 17.01 17.15 18.91 19.14 14.85 14.92 15.98 gasoline 45.8 45.55 45.49 45.13 43.67 43.31 43.04 41.96 39.23 diesel fuel 18.48 18.46 18.89 18.88 17.84 18.04 19.53 20.55 20.91 heavy oil 9.09 9.72 9.46 10.05 10.42 10.32 13.13 13.47 14.38 coke 8.01 7.78 7.84 7.44 7.75 7.82 8.15 7.84 8.23 Conversion, % by weight 72.43 71.82 71.65 71.07 71.74 71.64 67.34 65.98 64.71 S content in gasoline, ng/μl 472 513 456 425 477 442 663 646 685

Claims (19)

1. a catalyst for catalytic cracking, comprising effective amount of REY molecular sieve and substrate, characterized in that, the preparation method of said REY molecular sieve comprises NaY molecular sieve is contacted with the aqueous solution containing rare earth ion or with the aqueous solution containing rare earth ion and aluminum ion After being in contact with the solution or colloid, contact with an external precipitant to precipitate part of the rare earth on the molecular sieve, then perform hydrothermal treatment, and finally contact with an ammonium salt aqueous solution, wherein the precipitant is an alkaline aqueous solution; the matrix contains a modified The modified hydrated alumina has a pseudo-boehmite structure and contains 50-99.5% by weight of alumina and 0.5-50% by weight of transition metal oxides, and the transition metals are zinc, copper, One or more of cobalt, iron, titanium, vanadium, chromium, manganese, molybdenum, zirconium, the catalyst contains 10-50% by weight of REY type molecular sieve and 50-90% by weight of matrix on a dry basis; The preparation method of described REY molecular sieve comprises the following steps: (1) Contact NaY molecular sieve with a silicon-aluminum ratio ≥ 4.5 with an aqueous solution containing rare earth ions or with an aqueous solution containing rare earth ions and a solution or colloid containing aluminum ions, wherein, in terms of rare earth oxides, the ratio of rare earth ions to molecular sieve solids is The ratio is 0.12-0.30, based on alumina, the ratio of aluminum ion to molecular sieve solid is 0-0.1, the liquid-solid ratio is 4-20, the reaction temperature is 60-95°C, and the reaction time is 10-120min. Add alkaline solution in, then filter, wash to obtain filter cake product, described ratio is weight ratio; (2) performing hydrothermal treatment on the filter cake product obtained in step (1), the condition is that the temperature is 450-800°C, the time is 0.5-4h, and the ambient atmosphere is a water vapor atmosphere with a water content of 10-100% by volume; (3) The hydrothermally treated product of step (2) is contacted with an aqueous solution containing ammonium ions, filtered and washed, wherein the ratio of ammonium salt to molecular sieve solid is 0.1-1.0, the liquid-solid ratio is 4-20, and the temperature is 60- 95°C, the contact time is 30-120min, wherein the ratio is a weight ratio. 2. according to the described catalyst of claim 1, it is characterized in that, the ratio of rare earth ion described in step (1) and molecular sieve solid is 0.13-0.20, and the ratio of aluminum ion and molecular sieve solid is 0-0.05, and liquid-solid ratio 8-15, and the reaction temperature is 70-80°C. 3. according to the described catalyst of claim 1, it is characterized in that, the rare earth ion solution described in step (1) is the chloride or the nitrate that comprise one or more of lanthanum, cerium, praseodymium, neodymium ion of aqueous solution. 4. according to the described catalyst of claim 3, it is characterized in that, described rare earth ion solution is the rare earth salt solution rich in lanthanum. 5. according to the described catalyst of claim 1, it is characterized in that, described aluminum-containing ion solution is the aqueous solution or the sodium aluminate solution of aluminum chloride, sulfate or nitrate, and described colloid is aluminum sol or through Acidified pseudoboehmite. 6. The catalyst according to claim 1, wherein the alkaline aqueous solution is a soluble carbonate aqueous solution or an alkaline aqueous solution without carbonate. 7. according to the described catalyst of claim 6, it is characterized in that, described soluble carbonate is selected from ammonium bicarbonate, ammonium carbonate, sodium carbonate or sodium bicarbonate; Described alkaline aqueous solution not containing carbonate Selected from ammonia solution, water glass solution or basic molecular sieve synthesis mother liquor. 8. according to the described catalyzer of claim 6, it is characterized in that, when precipitating agent is soluble carbonate aqueous solution, in carbonate radical, the ratio of precipitating agent and rare earth oxide is 0.1-1.5; When precipitating agent is not containing In the alkaline aqueous solution of carbonate, the amount of precipitating agent added is controlled until the pH value of the molecular sieve slurry is 6.0-10.0. 9. according to the described catalyst of claim 8, it is characterized in that, when precipitating agent is soluble carbonate aqueous solution, the ratio of precipitating agent and rare earth oxide is 0.3-0.7; When precipitating agent is the alkali that does not contain carbonate In the case of aqueous solution, control the amount of precipitating agent added until the pH value of the molecular sieve slurry is 7.0-9.0. 10. The catalyst according to claim 1, characterized in that in step (2), the hydrothermal treatment condition is a temperature of 580-700°C, and the ambient atmosphere is a water vapor atmosphere with a water content of 100% by volume. 11. according to the described catalyst of claim 1, it is characterized in that the ratio of ammonium salt and molecular sieve solid is 0.3-0.6 in step (3), and liquid-solid ratio is 8-15. 12. The catalyst according to claim 1, characterized in that the ammonium salt described in step (3) is selected from one or more of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium oxalate or ammonium carbonate. 13. The catalyst according to claim 1 or 11, characterized in that the ammonium ion-containing solution described in step (3) also contains phosphate ions, and the weight ratio of phosphate ions to molecular sieve solids is no more than 0.07. 14. according to the described catalyst of claim 13, it is characterized in that described phosphate ion is derived from one or more of ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, phosphoric acid, aluminum phosphate or sodium phosphate, phosphoric acid The ratio of root ion to molecular sieve solid is not more than 0.04. 15. The catalyst according to claim 1, wherein the modified alumina hydrate contains 60-90% by weight of alumina and 10-40% by weight of transition metal oxide. 16. according to the described catalyst of claim 1 or 15, it is characterized in that, described modified alumina hydrate is prepared by the method comprising the following steps: (A) Pseudo-boehmite is mixed under stirring with water and acid sufficient to make it slurry, wherein the acid is used in an amount such that the weight ratio of the acid to the alumina in the pseudo-boehmite is 0.01-0.5; (B) Aging the mixed slurry obtained in step (A) for 0-24 hours at room temperature-90°C; (C) mixing the product obtained in step (B) with a compound containing a transition metal element. 17. according to the described catalyst of claim 1, it is characterized in that, take catalyst weight as a basis, contain the REY type molecular sieve of 10-50 weight % in the described catalyst, the inorganic oxide binding agent of 0-40 weight %, 0 - 70% by weight of clay, 10-70% by weight of modified hydrated alumina. 18. according to the described catalyzer of claim 1, it is characterized in that, described catalyzer also contains and is selected from one or more molecular sieves in zeolite with MFI structure, Beta zeolite, other Y-type zeolite, non-zeolite molecular sieve, said The molecular sieve content does not exceed 50% by weight. 19. The preparation method of the described catalyst of claim 1, comprising: (a) Preparation of REY molecular sieve: after NaY molecular sieve is contacted with an aqueous solution containing rare earth ions or with an aqueous solution containing rare earth ions and a solution or colloid containing aluminum ions, it is contacted with an external precipitant to precipitate part of the rare earth on the molecular sieve, and then Hydrothermal treatment, finally contacting with an ammonium salt aqueous solution, wherein the precipitating agent is an alkaline aqueous solution; (b) preparing modified hydrated alumina; (c) mixing REY molecular sieve, modified hydrated alumina and other matrix components, beating, and spray drying; Wherein, the preparation of modified hydrated alumina described in step (b) comprises the following steps: (A) Pseudo-boehmite is mixed under stirring with water and acid sufficient to make it slurry, wherein the acid is used in an amount such that the weight ratio of the acid to the alumina in the pseudo-boehmite is 0.01-0.5; (B) Aging the mixed slurry obtained in step (A) for 0-24 hours at room temperature-90°C; (C) mixing the product obtained in step (B) with a compound containing a transition metal element.