CN106890675B

CN106890675B - Preparation method of rare earth-containing catalytic cracking catalyst

Info

Publication number: CN106890675B
Application number: CN201510958985.3A
Authority: CN
Inventors: 高雄厚; 孙书红; 王栋; 黄校亮; 郑云锋; 范振宇; 刘明霞
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2015-12-18
Filing date: 2015-12-18
Publication date: 2020-02-14
Anticipated expiration: 2035-12-18
Also published as: CN106890675A

Abstract

A preparation method of a catalytic cracking catalyst containing rare earth. The preparation method comprises the following steps: (1) synthesizing catalyst precursor microspheres by a semisynthesis method or a total synthesis method; (2) dissolving a compound containing IIIB metal ions in the periodic table of elements in water or acid to form a solution, mixing the solution with (a) an organic complexing agent and/or a dispersing agent and (B) a precipitating agent, and stirring for at least 10 minutes at the temperature of 5-100 ℃ to form a precipitate containing IIIB elements; (3) mixing the obtained precipitate containing the IIIB element with catalyst precursor microspheres, stirring at the temperature of 5-100 ℃ for at least 10 minutes, filtering, and drying to prepare a catalytic cracking catalyst containing the IIIB element precipitate; wherein the weight ratio of IIIB element to catalyst dry base is 0.002-0.06: 1. The catalyst prepared by the method has good heavy metal resistance.

Description

Preparation method of rare earth-containing catalytic cracking catalyst

Technical Field

The invention relates to a preparation method of an oil refining catalyst, in particular to a preparation method of a catalytic cracking catalyst.

Background

The heavy oil and the inferior oil degree of the crude oil are increasingly aggravated, and the high-efficiency processing of the heavy oil and the blending of the residual oil become urgent requirements for improving the processing capacity and obtaining higher profits of oil refining enterprises. The catalytic cracking is the most important process for processing heavy oil, and has the significant advantages of high heavy oil conversion efficiency, good product quality, non-hydrogenation, low operating pressure and the like, so that the catalytic cracking plays a significant role in the process for processing heavy oil in a refinery, and is a main source of profit of the refinery. According to statistics, the current catalytic cracking unit around the world has about 420 sets, the maximum scale of a single set of catalytic cracking unit reaches 1000 ten thousand tons/year, the total processing capacity is about 7.37 hundred million tons, and the catalytic cracking unit is the first of secondary processing.

Heavy oil and residual oil contain colloid, asphaltene and other macromolecular compounds which are easy to generate coke, and also contain heavy metals of nickel, vanadium and the like, so that the content of nickel and vanadium on the catalytic cracking equilibrium catalyst is more common at 10000 mug/g, but severe pollution as high as 15000 mug/g is not rare, and vanadium seriously damages the structure of an active component molecular sieve in the catalyst under the catalytic cracking high-temperature hydrothermal environment, so that the activity of the catalyst is reduced, and the distribution of catalytic cracking products is poor. Therefore, there is a need to develop a molecular sieve catalyst with excellent activity, hydrothermal stability and resistance to heavy metal contamination to meet the strict requirements of heavy oil and residue cracking on catalyst performance.

In order to improve the activity and stability of the catalyst, the prior art generally adopts rare earth or phosphorus modified molecular sieve or catalytic cracking catalyst, for example, Chinese patent CN 1111136C discloses a preparation method of Y-type molecular sieve containing phosphorus and rare earth, which comprises the steps of firstly exchanging NaY molecular sieve with ammonium ions and rare earth ions, roasting, and then reacting with phosphorus compound to combine 1-10 wt% of P₂O₅And then roasting to obtain the catalyst. Chinese patent CN 1209288C discloses a process for preparing faujasite containing phosphorus and rare earth, which comprises the steps of first carrying out primary exchange reaction of faujasite with ammonium compound and phosphorus compound, then introducing rare earth solution into the exchange slurry for further reaction, filtering, washing and roasting. The catalyst containing said zeolite has high activity stability, high gasoline yield, low coke yield, and high heavy oil cracking and heavy metal pollution resistance.

The rare earth is introduced into the catalyst in a mode of basically comprising 3 types:

firstly, the rare earth modified molecular sieve is used for preparing the catalyst, such as Chinese patent CN1169717C discloses a method for modifying Y zeolite with rare-earth ions, which uses NaY molecular sieve as raw material, and includes ammonium exchange, hydrothermal treatment and H-contained⁺、NH₄ ⁺And RE³⁺After the solution is treated, the modified molecular sieve product is obtained by washing, drying and roasting. Chinese patent CN 1026225C discloses a preparation method of a rare earth Y molecular sieve, which is obtained by carrying out ion exchange on a NaY molecular sieve and rare earth ions in an aqueous solution, filtering, and roasting a filter cake in flowing water vapor. Chinese patent CN1069553C discloses a method for preparing rare earth Y-type molecular sieve, which comprises the steps of carrying out ion exchange on NaY molecular sieve and rare earth ions, filtering, roasting a filter cake, circularly returning 1-40% of roasted products to next batch of rare earth exchange slurry to continue the operation, and continuously carrying out the steps by using the rest of the products as REY molecular sieve products for preparing catalysts. Chinese patent No. 103058217A discloses a method for preparing rare earth-containing Y molecular sieve, which uses NaY molecular sieve as raw material, firstly carries out ammonium exchange, then carries out hydrothermal treatment, and then contains H⁺、NH₄ ⁺、RE³⁺And treating the mixed solution with an organic solvent, separating mother liquor, and roasting a filter cake to obtain a modified molecular sieve product. Chinese patent CN 1159101C discloses a method for preparing ultrastable Y zeolite containing rare earth, which comprises mixing ultrastable Y zeolite with 3-5 wt% of sodium oxide with a rare earth compound solution to obtain a slurry, and subjecting the slurry to a shear stress of at least 10 kg/cm²And grinding for at least 1 minute under the condition of (1) to obtain the modified molecular sieve product. The zeolite prepared by the method has high hydrothermal stability, sodium resistance and heavy metal pollution resistance. CN99105792.9 discloses a rare earth-containing molecular sieve and a preparation method thereof, wherein the preparation method comprises the steps of contacting a rare earth type molecular sieve containing 0.1-40 wt% of rare earth and a solution containing at least one substance in the formula (I) and at least one substance in the formula (II) at 25-120 ℃ for at least 0.1 hour; the reagent (I) comprises inorganic acid, inorganic base, organic acid or a reagent capable of forming a complex with aluminum, and the reagent (II) comprises soluble ammonium salt, organic acid salt, amine, alcohol,Aldehydes, ketones; the pH value of the solution is 3-12. The method is characterized in that rare earth is loaded on a molecular sieve firstly and then is treated with at least one substance in the (I) and at least one substance in the (II), and the purpose is to obtain a framework rare earth molecular sieve, wherein the rare earth exists on the framework of the molecular sieve and replaces part of cations on the framework of the molecular sieve. CN200510114495.1 discloses a method for increasing the rare earth content of ultrastable Y-type zeolite, which comprises the following steps: and (2) fully mixing the ultrastable Y-type zeolite and an acid solution with the concentration of 0.01-2N according to the liquid-solid ratio of 4-20 at the temperature range of 20-100 ℃, treating for 10-300 minutes, washing and filtering, adding a rare earth salt solution for rare earth ion exchange, and washing, filtering and drying after exchange to obtain the rare earth ultrastable Y-type zeolite with smooth pore passages and obviously improved rare earth content. The method comprises the steps of firstly cleaning a Y-type zeolite pore channel by using an acid solution, and carrying out rare earth exchange on a zeolite molecular sieve after filtering, wherein the purpose is to improve the rare earth content in the molecular sieve, and the rare earth exists on a framework of the molecular sieve and replaces part of cations on the framework of the molecular sieve. For example, CN200610087535.2 discloses a preparation method of REY molecular sieve, which comprises contacting NaY molecular sieve with an aqueous solution containing rare earth ions for exchange, contacting with an external precipitant to precipitate a part of rare earth on the molecular sieve, performing hydrothermal treatment, and finally contacting with an ammonium salt aqueous solution, wherein the precipitant is a soluble carbonate aqueous solution or an alkaline aqueous solution. The essence of the preparation method is that Na in the NaY molecular sieve is removed by rare earth exchange and ammonium salt exchange⁺Content, simultaneously introducing rare earth ions; the preparation method comprises the steps of firstly carrying out rare earth exchange on a molecular sieve, then adopting an external precipitator to deposit partial rare earth on the molecular sieve, then filtering and washing the molecular sieve, and carrying out hydrothermal treatment and ammonium exchange on a filter cake. During the preparation process, the RE is loaded onto the molecular sieve in ion exchange mode and partial RE not exchanged onto the molecular sieve is precipitated with precipitant, so that the RE-containing Y-type molecular sieve prepared with the precipitation process has RE precipitate containing independent phase RE, and the RE precipitate has relatively large size and is not favorable to homogeneous dispersion on the surface of the molecular sieve and homogeneous dispersion on the surface of the molecular sieveHeavy metals are effectively contacted and timely trapped, so that the heavy metal pollution resistance is insufficient. Meanwhile, as the raw material is NaY, the utilization rate of the rare earth is greatly reduced in the processes of filtration, washing, hydrothermal treatment and ammonium exchange sodium reduction after rare earth exchange. Chinese patent CN02103909.7 discloses a method for preparing a novel rare earth ultrastable Y molecular sieve containing vanadium-resistant components for catalytic cracking of heavy oil, which takes NaY type molecular sieve as raw material, the chemical dealumination complexing agent contains oxalic acid or oxalate and the mixture thereof, meanwhile, rare earth ions are introduced at the later stage of the chemical dealumination reaction to form rare earth precipitates, and then the purposes of ultrastabilization and introduction of rare earth ions and independent phase rare earth oxide can be realized through hydrothermal treatment. The method comprises the steps of firstly treating a molecular sieve by using a chemical dealumination complexing agent (oxalic acid and/or oxalate) to dealuminate the molecular sieve, and then forming rare earth precipitate containing rare earth oxalate by using rare earth and the complexing agent.

Secondly, rare earth is added in the gelling process of the conventional semi-synthetic catalytic cracking catalyst, for example, chinese patent CN1291787C discloses a hydrocarbon cracking catalyst containing a molecular sieve and a preparation method thereof, the catalyst contains the molecular sieve, a heat-resistant inorganic oxide matrix, clay and a metal component, the metal component exists basically in a reduction valence state, and is selected from one or more of IIIA non-aluminum metals, IVA metals, VA metals, IB metals, IIB metals, VB metals, VIB metals, VIIB metals and VIII non-noble metals in the periodic table of elements, the catalyst also contains rare earth metals existing outside the pore channels of the molecular sieve, the molecular sieve is selected from Y-type zeolite or a mixture of Y-type zeolite and at least one of zeolite having an MFI structure and β zeolite, the content of the molecular sieve is 1-90 wt%, the content of the heat-resistant inorganic oxide is 2-80 wt%, the content of the clay is 2-80 wt%, the content of the rare earth metals existing outside the pore channels of the molecular sieve is 0.1-10 wt%, the content of the metal component is 0.1-30 wt%, the catalyst has a higher catalytic cracking activity of heavy oil cracking catalyst, and the heavy oil cracking catalyst also contains a heavy oil with a higher selectivity of the heavy oil and a heavy oil cracking resistant additive.

Thirdly, rare earth is introduced into catalyst microspheres, for example, chinese patent CN1179734A discloses a method for in-situ preparation of an improved zeolite catalyst for fluid catalytic cracking, which comprises spray-drying a mixture of hydrous kaolin, gibbsite and spinel kaolin which is substantially free of metakaolin, calcining the resultant microspheres to convert hydrous kaolin into metakaolin and gibbsite into transition alumina, reacting the microspheres consisting of a mixture of spinel kaolin, transition alumina and metakaolin with a seeded alkaline sodium silicate solution to obtain microspheres containing Y-type molecular sieves, and then carrying out ion exchange sodium reduction treatment with ammonium, rare earth and the like to obtain the catalyst of the invention. Chinese patent CN1179734A discloses a method for preparing a high-activity fluid catalytic cracking catalyst, which is characterized in that kaolin is used as a main raw material to prepare the high-activity catalytic cracking catalyst by an in-situ crystallization technology, the preparation process comprises the steps of spray drying and molding kaolin, solid crystal seeds, an auxiliary agent, an organic dispersant, a bonding agent and the like to obtain kaolin microspheres a, roasting at a high temperature to obtain metakaolin microspheres, and then carrying out a crystallization reaction with sodium silicate, sodium hydroxide and the like to obtain crystallized microspheres with the NaY zeolite content of 20-70% and the zeolite silica-alumina ratio of 4.0-6.0. Then is subjected to primary roasting and NH₄ ⁺、RE³ ⁺And exchanging for the third time to obtain a catalyst product. The catalyst has the characteristics of strong heavy metal resistance, high cracking activity, good activity stability, low cost and the like.

Compared with 3 modes of introducing rare earth in the catalytic cracking catalyst, the rare earth is introduced in the form of ion exchange modified molecular sieve, so that the activity of the catalyst can be improved, but the heavy metal pollution resistance of the catalyst is insufficient; although the Y molecular sieve prepared by a rare earth precipitation method added with a precipitator improves the heavy metal pollution resistance of the molecular sieve catalyst, the heavy metal pollution resistance effect is relatively poor because the rare earth precipitates have large particles and are not uniformly distributed in the molecular sieve; rare earth is introduced into the catalyst in a mode of mixing and molding components such as a molecular sieve, a matrix, rare earth and the like (a preparation mode of a semi-synthetic catalyst), although the stability and the heavy metal resistance of the catalyst can be improved, the rare earth is easier to migrate onto the molecular sieve through ion exchange and plays a role in exchanging the rare earth, so that the heavy metal resistance of the catalyst is relatively poor, or the rare earth is unevenly distributed in the catalyst (such as the rare earth is added in an oxide form) and is buried in the matrix of the catalyst, so that the heavy metal resistance of the catalyst is insufficient; the rare earth is introduced after the catalyst microsphere is formed, generally, an in-situ crystallization type catalyst synthesized by kaolin spray microsphere through high-temperature roasting and in-situ crystallization is taken as a main material, the rare earth is introduced in an ion exchange mode or a precipitation mode, wherein the rare earth introduced in the ion exchange mode improves the activity of the catalyst, but the heavy metal resistance of the catalyst is insufficient, the rare earth introduced in the precipitation mode does not relate to the reduction of the granularity of the precipitated rare earth in the prior art, and is not beneficial to the effective contact of the precipitated rare earth and the heavy metal and the timely capture of the heavy metal, so the heavy metal resistance of the precipitated rare earth modified in-situ crystallization type catalyst also needs to be further.

In the catalytic cracking process, heavy metals such as nickel and vanadium in the raw oil are continuously deposited on the catalyst, wherein the vanadium deposited on the catalyst forms vanadic acid in the aerobic, high-temperature and water vapor environment of a regenerator, and the structure of an active component, namely a molecular sieve, in the catalyst is damaged, so that the collapse of the crystal structure of the molecular sieve and the inactivation of the molecular sieve are caused. The heavy metal nickel deposited on the catalyst can be used as a dehydrogenation active center to participate in the reaction process, so that the selectivity of the catalytic cracking reaction is poor, and more coke and dry gas are generated. Therefore, nickel, vanadium, etc. need to be captured and passivated in time to be converted into stable and inert compounds, thereby achieving the purpose of improving the heavy metal pollution resistance of the molecular sieve. It has been found that rare earth ions are ion exchanged with cations such as sodium of the molecular sieve and migrate into the molecular sieve to play a role in improving the activity and stability of the molecular sieve, but once the ion exchanged rare earth is contacted with vanadium, the ion exchanged rare earth is easy to be separated from the framework structure of the molecular sieve to form rare earth vanadate, and the structural stability of the molecular sieve is rather poor; the rare earth existing in an independent phase form can be used for trapping heavy metals in the catalytic cracking reaction process due to different existing positions and existing states, and plays a role in resisting the heavy metals. Therefore, the rare earth molecular sieve prepared by rare earth ion exchange does not contain independent phase rare earth, and has insufficient capability of resisting heavy metal pollution.

Even if the rare earth precipitate is formed and contains independent phase rare earth, the rare earth precipitate has larger particles, is not beneficial to uniformly dispersing on the surface of the molecular sieve and effectively contacting with heavy metal and timely trapping the heavy metal. Therefore, in order to satisfy the requirements of molecular sieve catalysts for activity stability and resistance to heavy metal contamination, new catalyst preparation techniques having excellent activity stability and resistance to heavy metal contamination are required in spite of recent molecular sieve catalyst preparation techniques.

Disclosure of Invention

The invention aims to provide a preparation method of a rare earth-containing catalytic cracking catalyst, and the catalyst prepared by the method has good heavy metal pollution resistance, and simultaneously has good activity and stability.

The invention discloses a preparation method of a rare earth-containing catalytic cracking catalyst, which comprises the following steps:

(1) synthesizing catalyst precursor microspheres by a semisynthesis method or a total synthesis method;

(2) dissolving a compound containing IIIB metal ions in the periodic table in water or acid to form a solution containing IIIB metal ions, mixing the solution with (a) an organic complexing agent and/or a dispersing agent and (B) a precipitating agent, stirring at 5-100 ℃ for at least 10 minutes to form a precipitate containing IIIB metal ions, wherein the molar ratio of the organic complexing agent to the IIIB metal ions is 0.3-10: 1, preferably 0.5-6: 1, more preferably 1.0-4: 1, and the molar ratio of the dispersing agent to the IIIB metal ions is 0.2-16: 1, preferably 1-11: 1, more preferably 2-7: 1;

(3) mixing the obtained precipitate containing the IIIB element with catalyst precursor microspheres, stirring at the temperature of 5-100 ℃ for at least 10 minutes, filtering, and drying to prepare a catalytic cracking catalyst containing the IIIB element precipitate; wherein the weight ratio of the IIIB element to the catalyst dry basis calculated by oxide is 0.002-0.06: 1, preferably 0.004-0.03: 1, and more preferably 0.006-0.015: 1.

The invention discloses a preparation method of a rare earth-containing catalytic cracking catalyst, wherein step (2) is the preparation of a precipitate containing IIIB element, and in the mixing process of the solution containing IIIB metal ions in the periodic table of elements, an organic complexing agent and/or a dispersing agent and a precipitating agent, the adding sequence and the adding times of the solution containing IIIB metal ions in the periodic table of elements, the organic complexing agent and/or the dispersing agent and the precipitating agent are not particularly limited. The method can be realized by one of the following modes: in the mode 1, after uniformly mixing a solution containing IIIB metal ions in a periodic table of elements with an organic complexing agent and/or a dispersing agent, adding a precipitating agent, and stirring for at least 10 minutes to form a precipitate containing IIIB elements; mode 2, uniformly mixing a precipitator with an organic complexing agent and/or a dispersing agent, then adding a solution of a compound containing IIIB metal ions in the periodic table of elements, and stirring for at least 10 minutes to form a precipitate containing IIIB elements; mode 3, mixing a precipitator with a solution of a compound containing IIIB metal ions in the periodic table of elements, adding an organic complexing agent and/or a dispersing agent, and stirring for at least 10 minutes to form a precipitate containing IIIB elements; mode 4, the solution containing the IIIB metal ions in the periodic table of the elements, the organic complexing agent and/or the dispersant and the precipitator are added and mixed simultaneously, and stirred for at least 10 minutes to form the precipitate containing the IIIB elements. Among these forms of the precipitate, the particle size of the precipitate formed in the forms 1 and 2 is the smallest, and the most preferable form is. The organic complexing agent and/or the dispersing agent play a role in dispersing, and the main role of the organic complexing agent and/or the dispersing agent is to reduce the particle size of IIIB element precipitates in the periodic table of elements; the precipitant is mainly used for precipitating IIIB elements in the periodic table. The organic complexing agent and the precipitating agent can be directly used or dissolved in water to form a solution for use.

The invention discloses a preparation method of a rare earth-containing catalytic cracking catalyst, wherein the catalyst precursor microsphere is synthesized by a semisynthesis method or a total synthesis method, and the catalyst precursor microsphere or the catalytic cracking catalyst is synthesized by a semisynthesis method used in the prior art, namely: mixing the components of a catalytic cracking catalyst containing a molecular sieve, a matrix and a binder to form mixed slurry, and performing spray drying to form catalyst precursor microspheres; the catalyst precursor microsphere or the catalytic cracking catalyst is synthesized by the total synthesis method used in the prior art, namely: the in-situ crystallization type catalytic cracking catalyst which takes kaolin as a raw material and contains a matrix and a molecular sieve is synthesized by hydrothermal crystallization. Whether semi-synthetic or total synthetic methods are known to the person skilled in the art, for example CN02155601.6, CN00105235.7, CN200910092838.7, CN201110419922.2, CN02103907.0, CN03156915.3, CN1334318, CN200810102244.5 are described in detail.

In particular, the semisynthetic methods common to the prior art include: mixing the components including the molecular sieve, the matrix and the binder, gelling, and then carrying out spray drying, curing and washing to obtain the catalyst precursor particles. The total synthesis method comprises the steps of spray forming clay slurry into spray microspheres, roasting the spray microspheres into roasted microspheres, mixing sodium silicate, a guiding agent, the roasted microspheres and water, carrying out hydrothermal crystallization on the mixed system under an alkaline condition to synthesize zeolite by clay in situ crystallization, and carrying out repeated ion exchange, sodium reduction and roasting to obtain catalyst precursor particles.

The preparation method of the catalytic cracking catalyst disclosed by the invention is characterized in that the catalyst precursor microsphere is synthesized by a semisynthesis method or a total synthesis method, and Na in the catalyst precursor microsphere is synthesized by the semisynthesis method₂The content of O is preferably not more than 0.4 percent by mass, and Na in the catalyst precursor microspheres is synthesized by adopting a total synthesis method₂The content of O is preferably not more than 0.7% by mass when the content of the catalyst precursor microspheres satisfies Na₂The catalyst precursor microspheres can be mixed with the IIIB element-containing precipitate without any treatment to prepare the catalyst of the invention.

For the catalyst precursor microspheres synthesized by the semi-synthesis method, when the catalyst precursor microspheres are low-sodium-content catalyst precursor microspheres, namely Na₂The mass content of O is not more than 0.4 percentThe catalyst precursor microspheres can be mixed with the IIIB element-containing precipitate without any treatment to prepare the catalyst of the invention; when the procatalyst microspheres are high sodium content procatalyst microspheres, i.e., Na₂The mass content of O is more than 0.4 percent, the catalyst precursor microspheres need to be treated in two ways: firstly, the catalyst precursor microspheres are subjected to sodium reduction treatment in step (1), which is well known to those skilled in the art, and the most common method for sodium reduction is water washing and ion exchange; and secondly, mixing the precipitate containing the IIIB element with catalyst precursor microspheres in the step (3), preparing the catalytic cracking catalyst containing the IIIB element precipitate, and then performing sodium reduction treatment.

The invention discloses a preparation method of a catalytic cracking catalyst, which is characterized in that Na is used as a catalyst precursor microsphere synthesized by a total synthesis method₂The mass content of O is not more than 0.7 percent. When the sodium content is higher than this value, it is necessary to lower the sodium by an ion exchange method in step (1), which is well known to those skilled in the art, and the most commonly used means are water washing, ammonium ion exchange, which are disclosed in CN03156915.3, CN1334318, CN 200810102244.5.

The IIIB element is selected from one or more of scandium, yttrium and lanthanide rare earth elements. The lanthanide rare earth includes one or more of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and may be, for example, a mixture of various rare earth elements, or a single rare earth of high purity, commonly lanthanum-rich rare earth, cerium-rich rare earth, pure lanthanum, or pure cerium. The IIIB element-containing compound is selected from one or more of water-or acid-soluble IIIB element halides, nitrates, sulfates, oxides, hydroxides. The weight ratio of the IIIB element to the dry base of the catalyst calculated by oxide is 0.002-0.06: 1.

The invention discloses a preparation method of a rare earth-containing catalytic cracking catalyst, wherein a precipitator can chemically react with IIIB group metal ions in a system in a chemical precipitation reaction and enable a product to be in a bodyIs a sparingly soluble or insoluble substance. The type and amount of precipitating agent added is therefore well known to those skilled in the art and is capable of providing or generating hydroxide ions (OH)^-) Carbonate ion (CO)₃ ^2-) Bicarbonate ion (HCO)₃ ^-) Phosphate radical ion (PO)₄ ^3-) Hydrogen phosphate ion (HPO)₄ ^2-) Dihydrogen phosphate ion (H)₂PO₄ ^-) Oxalate ion (C)₂O₄ ^2-) The compound (b) can be used as the precipitant, and the addition amount of the compound (b) can meet the molar ratio of substances in the precipitation reaction.

In the preparation method of the rare earth-containing catalytic cracking catalyst, the precipitator is preferably one or more of oxalic acid, ammonium oxalate, ammonium carbonate, ammonium bicarbonate, carbon dioxide, ammonia water, phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate and urea. The adding amount of the ammonia water is determined according to the pH value of the molecular sieve slurry, so that the pH value of the molecular sieve slurry is kept within the range of 6.5-9.0; the addition amount of oxalic acid, ammonium oxalate, ammonium carbonate, ammonium hydrogen carbonate, carbon dioxide, phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate, urea is determined according to the addition amount of the IIIB element compound, so that the above-mentioned precipitant: the weight ratio of the IIIB element compound (calculated by oxide) is 0.3-5.

The preparation method of the rare earth-containing catalytic cracking catalyst disclosed by the invention is characterized in that the organic complexing agent is selected from formic acid, acetic acid, adipic acid, citric acid, tartaric acid, benzoic acid, ethylene diamine tetraacetic acid, salicylic acid and salts of the above acids, and one or more of acetylacetone, diethanolamine and triethanolamine, and preferably one or more of citric acid, ammonium citrate, ammonium dihydrogen citrate, diammonium hydrogen citrate and EDTA (ethylene diamine tetraacetic acid). The molar ratio of the organic complexing agent to the metal ions is 0.3-10: 1.

The dispersant is known by the technical personnel in the field, is a surfactant with two opposite properties of lipophilicity and hydrophily in a molecule, can uniformly disperse solid particles of precipitates containing IIIB elements which are difficult to dissolve in liquid, can prevent the solid particles from settling and coagulating to form substances required by stable suspension, has the main function of reducing the interfacial tension between liquid-liquid and solid-liquid, and can also be used as the dispersant; and the dispersant does not react with the group IIIB metal ions to form a precipitate. The dispersing agent is selected from one or more of monohydric alcohol or dihydric alcohol with the carbon atom number of 2-8, polyethylene glycol, cellulose derivatives, polyacrylamide and derivatives thereof, and guar gum. The molar ratio of the dispersing agent to the metal ions is 0.2-16: 1.

In the preparation method of the rare earth-containing catalytic cracking catalyst disclosed by the invention, the cellulose derivatives are typically sodium hydroxymethyl cellulose, methyl hydroxyethyl cellulose and hydroxypropyl methyl cellulose.

In the preparation method of the rare earth-containing catalytic cracking catalyst disclosed by the invention, the monohydric alcohol or dihydric alcohol with 2-8 carbon atoms is known to those skilled in the chemical field, for example: the monohydric alcohol or polyhydric alcohol with carbon number of 2 is ethanol or ethylene glycol, and the monohydric alcohol or dihydric alcohol with carbon number of 3 is isopropanol, n-propanol, 1, 3-dipropanol, 1, 2-dipropanol. In the invention, monohydric alcohol or dihydric alcohol with 2-5 carbon atoms is preferably selected; more preferably one or more of ethanol, ethylene glycol, isopropanol, butanol, methyl pentanol.

The invention discloses a preparation method of a rare earth-containing catalytic cracking catalyst, wherein a semisynthetic method is adopted to synthesize a catalyst precursor microsphere, and the catalyst precursor microsphere is prepared by mixing all components of the catalytic cracking catalyst containing a molecular sieve, a matrix and a binder to form mixed slurry, and spray drying the mixed slurry to form the catalyst precursor microsphere₄Y, REY, phosphorus-containing Y molecular sieve. The content of the molecular sieve sodium oxide is not higher than 2 percent (weight). The technique for reducing the content of sodium oxide in molecular sieve is well known to those skilled in the artThe catalyst is prepared by performing ion exchange sodium reduction treatment on ammonium salt, wherein the ammonium salt is selected from one or more of ammonium sulfate, ammonium bisulfate, ammonium nitrate, ammonium chloride, ammonium carbonate and ammonium bicarbonate, the ammonium salt is mainly used for exchanging sodium on a molecular sieve, so that the exchanged molecular sieve has acid catalytic activity, the matrix is a component of the catalyst except for an active component molecular sieve and a binder, and commonly comprises one or more of clay, alumina, silica, alumina-silica, amorphous silica-alumina, titanium oxide, zirconium oxide and other inorganic oxides, the clay is selected from one or more of metakaolin, halloysite, montmorillonite, kieselguhr, sepiolite, halloysite, hydrotalcite, bentonite, acidified or alkali-soluble kaolin/halloysite, the inorganic oxides except for the clay are alumina, silica, amorphous silica-alumina, titanium oxide, zirconium oxide or a mixture thereof, the alumina is selected from alumina and/or hydrated alumina in various forms, such as gamma-alumina, η -alumina, Boehmite, alumina, or a modified alumina, and/or a binder, wherein the modified alumina is selected from one or alumina, silica, alumina, Boehmite, alumina, silica, Boehmite, alumina, silica, alumina, silica, alumina, silica, alumina, silica.

The preparation method of the rare earth-containing catalytic cracking catalyst disclosed by the invention is characterized in that a semisynthesis method is adopted to synthesize the catalyst precursor microsphere, the catalyst precursor microsphere can also comprise components of group IIA, VA, VIA, IB, IIB, IVB, VB, VIIB and VIII compounds in a periodic table of elements, such as magnesium, calcium, zinc, manganese, phosphorus and other components, the content of the components is 0.5-25% (calculated by oxides), and the specific content range is related to different elements.

The preparation method of the catalytic cracking catalyst containing the rare earth achieves the purpose of adjusting the distribution state of the IIIB element in the catalyst by controlling the adding amount of the IIIB element compound in the periodic table of the elements and controlling the adding amount and adding sequence of the precipitator, the organic complexing agent and/or the dispersing agent. The ratio of IIIB elements in ionic form and in independent phase form can be adjusted according to the actual requirements on the activity, stability and resistance to heavy metal contamination of the catalyst, as long as the weight ratio of IIIB element in terms of oxide to the dry base of the catalyst is in the range of 0.002-0.06: 1.

The invention discloses a preparation method of a rare earth-containing catalytic cracking catalyst, which is characterized in that an organic complexing agent and/or a dispersing agent is selected to provide a proper reaction environment for IIIB elements in a periodic table to deposit on the catalyst, so that ultrafine particles of the IIIB elements in the periodic table are formed, the granularity of IIIB element precipitates is reduced, the outer surface and the dispersion degree of the precipitates are increased, the IIIB elements in the periodic table are more uniformly deposited on the catalyst, and the IIIB elements in the periodic table exist in an independent phase or a mixed phase form of an independent phase/exchange ions, namely the IIIB elements exist in the catalyst in an independent phase or a mixed phase form of an independent phase/exchange ions. The catalyst prepared by the invention is more beneficial to timely and effectively contacting the polluted heavy metal with the polluted heavy metal passivator (IIIB element precipitate), and avoids the uneven distribution of the catalyst microsphere passivator and the local arrangement of the passivator on the microsphere, thereby achieving the purpose of effectively trapping the heavy metal.

The catalyst prepared by the invention is suitable for heavy oil catalytic cracking, and is particularly suitable for heavy oil catalytic cracking with high content of heavy metal vanadium. Such as one or more of atmospheric residue, vacuum gas oil, atmospheric gas oil, deasphalted oil, and coker gas oil.

Detailed Description

The present invention will be further described with reference to examples, but the present invention is not limited to these examples.

Analytical test methods used in the examples

1. Granularity: and analyzing by a laser particle analyzer method.

2. Determination of the activity of the catalyst: the evaluation was carried out on a CSA-B type catalyst evaluation apparatus manufactured by Huayang corporation. The catalyst is aged for 6 hours or 17 hours at 800 ℃ under the condition of 100 percent of water vapor, and then the activity of the catalyst is measured by using Hongkong light diesel oil as a raw material, wherein the reaction temperature is 460 ℃, the reaction time is 70s, the catalyst loading is 5.0g, and the catalyst-oil ratio is 3.2.

(II) specification of raw materials used in example

NaY molecular sieves, REUSY molecular sieves (rare earth ion exchange molecular sieves, RE)₂O₃Content 4.02%, Na₂O content 1.24%), NH₄Y molecular sieve (Na)₂O content of 1.68%, once hydrothermal roasting), ZSM-5 molecular sieve (Na)₂0.10% of O content, 14.6% of kaolin (ignition), 15.4% of diatomite (ignition), 19.4% of alumina sol (ignition containing alumina), 31.8% of pseudo-boehmite (ignition), 18% of ammonia water and rare earth nitrate (RE) in concentration₂O₃230.5 g/L): all are industrial products, and are collected from catalyst factories of petrochemical companies in Lanzhou.

2. Ammonium sulfate, ammonium chloride, citric acid, ammonium citrate, ethylene glycol, ethanol, methylhydroxyethylcellulose, ammonium oxalate, ethylenediaminetetraacetic acid, urea, lanthanum nitrate: all are chemical reagents.

3. Hydrochloric acid: concentration 36%, chemical agent.

Example 1

2g of citric acid, 2.48mL of rare earth nitrate and 75mL of deionized water were mixed to form a homogeneous solution, and 2g of ammonium oxalate was added and stirred for 15 minutes to form a rare earth-containing precipitate slurry CD-1.

Example 2

2g of ethanol, 2.48mL of rare earth nitrate and 75mL of deionized water were mixed to form a homogeneous solution, and 2g of ammonium oxalate was added and stirred for 15 minutes to form a rare earth-containing precipitate slurry CD-2.

Comparative example 1

Mixing 2.48mL of rare earth nitrate and 75mL of deionized water to form a uniform solution, adding 2g of ammonium oxalate, and stirring for 15 minutes to form precipitate slurry DCD-1 containing rare earth

The rare earth-containing precipitate slurries CD-1, CD-2 and DCD-1 prepared in examples 1 and 2 and comparative example 1 were each tested for particle size of the rare earth precipitate and the results are shown in Table 1.

TABLE 1 particle size of rare earth precipitates

The results in Table 1 show that the rare earth-containing precipitates CD-1 and CD-2 prepared in examples 1 and 2 have smaller particle sizes than the rare earth-containing precipitate DCD-1 prepared in comparative example 1, and the organic complexing agent and the dispersant of the present invention are effective in reducing the particle sizes of the precipitates formed by the reaction of the rare earth and the precipitant.

Example 3

(1) Preparing a rare earth ion exchange molecular sieve: (a) adding 1000g of NaY molecular sieve (dry basis) into 7L of deionized water, adding 300g of ammonium chloride and 165mL of rare earth nitrate under the stirring state, adjusting the pH value of the slurry to 3.82 by using hydrochloric acid, stirring for 1h at 80 ℃, then filtering and washing, and carrying out hydrothermal roasting on a filter cake in a roasting furnace under the atmosphere of 100% water vapor at the roasting temperature of 600 ℃ for 2 h. (b) Mixing the molecular sieve obtained in the step (a), ammonium sulfate and water according to the weight ratio of the molecular sieve (dry basis): ammonium salt: water 1: 0.3: 5 to form slurry, stirring the slurry for 1 hour at the temperature of 75 ℃ and the pH value of 3.5, filtering and washing the slurry, and carrying out hydrothermal roasting on a filter cake in a roasting furnace in the atmosphere of 100 percent of water vapor at the roasting temperature of 620 ℃ for 2 hours to obtain the rare earth ion exchange molecular sieve Z-1.

800g (dry basis) of rare earth ion exchange molecular sieve Z-1 is added into 1.2L of deionized water, and the molecular sieve slurry Z-1J is obtained after sanding treatment. Mixing 619g of alumina sol, 1246g of kaolin and 1.3L of water, pulping, then adding molecular sieve slurry Z-1J, continuously stirring for 30min, homogenizing, spray-drying, forming, roasting, mixing the roasted microspheres with deionized water and ammonium chloride, wherein the roasted microspheres are as follows: water: the weight ratio of ammonium chloride is 1: 6: 0.003, stirring for 30 minutes at the temperature of 80 ℃, filtering and drying to prepare the catalyst precursor microsphere synthesized by the semi-synthesis method.

(2) 16g of citric acid, 4g of ethylene glycol, 52mL of rare earth nitrate and 0.8L of deionized water were mixed to form a uniform solution, 40g of ammonium oxalate was added, and stirring was carried out for 15 minutes to form a rare earth-containing precipitate slurry.

(3) And (3) mixing 3L of deionized water, the catalyst precursor microspheres prepared in the step (1) and the precipitate slurry formed in the step (2), stirring for 20 minutes at the temperature of 20 ℃, filtering and drying to obtain the catalyst C-1.

Comparative example 2

(1) Preparing a rare earth ion exchange molecular sieve: (a) adding 1000g of NaY molecular sieve (dry basis) into 7L of deionized water, adding 300g of ammonium chloride and 165mL of rare earth nitrate under the stirring state, adjusting the pH value of the slurry to 3.82 by using hydrochloric acid, stirring for 1h at 80 ℃, then filtering and washing, and carrying out hydrothermal roasting on a filter cake in a roasting furnace under the atmosphere of 100% water vapor at the roasting temperature of 600 ℃ for 2 h. (b) Mixing the molecular sieve obtained in the step (a), ammonium sulfate and water according to the weight ratio of the molecular sieve (dry basis): ammonium salt: water 1: 0.3: 5 to form slurry, stirring the slurry for 1 hour at the temperature of 75 ℃ and the pH value of 3.5, filtering and washing the slurry, and carrying out hydrothermal roasting on a filter cake in a roasting furnace in the atmosphere of 100 percent of water vapor at the roasting temperature of 620 ℃ for 2 hours to obtain the rare earth ion exchange molecular sieve DZ-1.

800g (dry basis) of rare earth ion exchange molecular sieve DZ-1 is added into 1.2L of deionized water, and the molecular sieve slurry DZ-1J is obtained after sanding treatment. Mixing 619g of alumina sol, 1246g of kaolin and 1.3L of water, pulping, then adding molecular sieve slurry DZ-1J, continuously stirring for 30min, homogenizing, spray-drying, forming, roasting, mixing the roasted microspheres with deionized water and ammonium chloride, wherein the roasted microspheres are as follows: water: the weight ratio of ammonium chloride is 1: 6: 0.003, stirring for 30 minutes at the temperature of 80 ℃, filtering and drying to prepare the catalyst precursor microsphere synthesized by the semi-synthesis method.

(2) And (2) mixing the catalyst precursor microspheres prepared in the step (1) with 3.8L of deionized water, stirring for 20 minutes at the temperature of 20 ℃, filtering and drying to obtain the comparative catalyst DC-1.

Comparative example 3

(1) Preparing a rare earth ion exchange molecular sieve: (a) adding 1000g of NaY molecular sieve (dry basis) into 7L of deionized water, adding 300g of ammonium chloride and 217mL of rare earth nitrate under the stirring state, adjusting the pH value of the slurry to 3.82 by using hydrochloric acid, stirring for 1h at 80 ℃, adding 40g of ammonium oxalate, stirring for 15min, filtering, washing, and carrying out hydrothermal roasting on a filter cake in a roasting furnace under the atmosphere of 100% water vapor at the roasting temperature of 600 ℃ for 2 h. (b) Mixing the molecular sieve obtained in the step (a), ammonium sulfate and water according to the weight ratio of the molecular sieve (dry basis): ammonium salt: water 1: 0.3: 5 to form slurry, stirring the slurry for 1 hour at the temperature of 75 ℃ and the pH value of 3.5, filtering and washing the slurry, and carrying out hydrothermal roasting on a filter cake in a roasting furnace in the atmosphere of 100 percent of water vapor at the roasting temperature of 620 ℃ for 2 hours to obtain the rare earth ion exchange molecular sieve DZ-2.

800g (dry basis) of rare earth ion exchange molecular sieve DZ-2 is added into 1.2L of deionized water, and the molecular sieve slurry DZ-2J is obtained after sanding treatment. Mixing 619g of alumina sol, 1246g of kaolin and 1.3L of water, pulping, then adding molecular sieve slurry DZ-2J, continuously stirring for 30min, homogenizing, spray-drying, forming, roasting, mixing the roasted microspheres with deionized water and ammonium chloride, wherein the roasted microspheres are as follows: water: the weight ratio of ammonium chloride is 1: 6: 0.003, stirring for 30 minutes at the temperature of 80 ℃, filtering and drying to prepare the catalyst precursor microsphere synthesized by the semi-synthesis method.

(2) And (2) mixing the catalyst precursor microspheres prepared in the step (1) with 3.8L of deionized water, stirring for 20 minutes at the temperature of 20 ℃, filtering and drying to obtain the comparative catalyst DC-2.

Comparative example 4

(1) 52mL of rare earth nitrate and 0.8L of deionized water were mixed to form a homogeneous solution, and then 40g of ammonium oxalate was added and stirred for 15 minutes to form a rare earth-containing precipitate slurry.

(2) Preparing a rare earth ion exchange molecular sieve: (a) adding 1000g of NaY molecular sieve (dry basis) into 7L of deionized water, adding 300g of ammonium chloride and 165mL of rare earth nitrate under the stirring state, adjusting the pH value of the slurry to 3.82 by using hydrochloric acid, stirring for 1h at 80 ℃, then filtering and washing, and carrying out hydrothermal roasting on a filter cake in a roasting furnace under the atmosphere of 100% water vapor at the roasting temperature of 600 ℃ for 2 h. (b) Mixing the molecular sieve obtained in the step (a), ammonium sulfate and water according to the weight ratio of the molecular sieve (dry basis): ammonium salt: water 1: 0.3: 5 to form slurry, stirring the slurry for 1 hour at the temperature of 75 ℃ and the pH value of 3.5, filtering and washing the slurry, and carrying out hydrothermal roasting on a filter cake in a roasting furnace in the atmosphere of 100 percent of water vapor at the roasting temperature of 620 ℃ for 2 hours to obtain the rare earth ion exchange molecular sieve DZ-3.

800g (dry basis) of rare earth ion exchange molecular sieve DZ-3 is added into 1.2L of deionized water, and the molecular sieve slurry DZ-3J is obtained after sanding treatment. Mixing 619g of alumina sol, 1246g of kaolin and 1.3L of water, pulping, then adding molecular sieve slurry DZ-3J and the precipitate slurry formed in the step (1), continuously stirring for 30min, homogenizing, spray drying, forming, roasting, mixing the roasted microspheres with deionized water and ammonium chloride, wherein the roasted microspheres are as follows: water: the weight ratio of ammonium chloride is 1: 6: 0.003, stirring for 30 minutes at the temperature of 80 ℃, filtering and drying to prepare the catalyst precursor microsphere synthesized by the semi-synthesis method.

(3) And (3) mixing the catalyst precursor microspheres prepared in the step (2) with 3.8L of deionized water, stirring for 20 minutes at the temperature of 20 ℃, filtering and drying to obtain the comparative catalyst DC-3.

Example 4

(1) 588g (dry basis) of REUSY molecular sieve, 12g (dry basis) of ZSM-5 molecular sieve and water are mixed according to the weight ratio of the molecular sieve to the molecular sieve: water 1: 2 to form a molecular sieve slurry Z-2J. Mixing 619g of alumina sol, 1513g of diatomite and 1.6L of water, pulping, adding molecular sieve slurry Z-2J, continuously stirring for 30min, homogenizing, spray-drying, forming, roasting, mixing the roasted microspheres with deionized water and ammonium chloride to enable the microspheres to: water: the weight ratio of ammonium chloride is 1: 6: 0.003, stirring for 20 minutes at the temperature of 15 ℃, and filtering to prepare the catalyst precursor microsphere synthesized by the semi-synthesis method.

(2) 82g of ethylenediamine tetraacetic acid and 78mL of rare earth nitrate were added to 0.6L of deionized water to form a solution, ammonia was added to adjust the pH of the mixed slurry to 8.8, 17g of ethanol was added thereto, and the mixture was stirred at room temperature (25 ℃ C.) for 30 minutes to form a slurry containing a rare earth precipitate.

(3) And (3) mixing the catalyst precursor microspheres obtained in the step (1) with 3L of deionized water, adding the precipitate slurry formed in the step (2), stirring for 30 minutes at room temperature (25 ℃), filtering, and drying to obtain the catalyst C-2.

Comparative example 5

(1) The preparation method of the rare earth-containing molecular sieve disclosed in Chinese patent CN99105792.9 comprises the following steps: 798g (dry basis) of REUSY molecular sieve, 16g (dry basis) of ZSM-5 molecular sieve and water are mixed according to the weight ratio of the molecular sieve (dry basis): water 1: 3 to form molecular sieve slurry, adding 110g of ethylenediamine tetraacetic acid, adjusting the pH value of the molecular sieve slurry to 8.8 by using ammonia water, adding 23g of ethanol, and stirring for 30 minutes at room temperature (25 ℃). Filtering, washing, and drying the filter cake at 200 ℃. To obtain the comparative molecular sieve DZ-4.

600g (dry basis) of molecular sieve DZ-4 was added to 1.2L of deionized water to obtain molecular sieve slurry DZ-4J. Mixing 619g of alumina sol, 1513g of diatomite and 1.6L of water, pulping, adding molecular sieve slurry DZ-4J, continuously stirring for 30min, homogenizing, spray-drying, molding, roasting, mixing the roasted microspheres with deionized water and ammonium chloride to ensure that the microspheres: water: the weight ratio of ammonium chloride is 1: 6: 0.003, stirring for 20 minutes at the temperature of 15 ℃, and filtering to prepare the catalyst precursor microsphere synthesized by the semi-synthesis method.

(2) And (2) mixing the catalyst precursor microspheres obtained in the step (1) with 3.6L of deionized water, stirring for 30 minutes at room temperature (25 ℃), filtering, and drying to obtain a comparative catalyst DC-4.

Example 5

(1) 600g (dry basis) NH₄And adding the Y molecular sieve into 1.2L of deionized water, and performing sanding treatment to obtain molecular sieve slurry Z-3J. Mixing and pulping 1054g of kaolin, 587g of pseudo-boehmite and 1.4L of water, adding 60mL of hydrochloric acid, stirring for 1 hour, then adding molecular sieve slurry Z-3J, stirring for 15min, then adding 515g of alumina sol, continuing stirring for 30min to form gel, homogenizing, spray drying, forming, roasting, mixing the roasted microspheres with deionized water and ammonium chloride to enable the microspheres to: water: the weight ratio of ammonium chloride is 1: 5: 0.002, stirring at 55 deg.C for 30min, filtering, and making into semi-syntheticThe catalyst precursor microsphere synthesized by the method.

(2) Adding 155g of urea and 85g of lanthanum nitrate into 0.8L of deionized water, stirring, adjusting the pH value of the system to be within the range of 6.5-9.0 by using ammonia water, adding 14g of ethylene glycol, and continuously stirring for 1.5 hours at room temperature (25 ℃) to form slurry containing rare earth precipitates.

(3) And (2) mixing the catalyst precursor microspheres obtained in the step (1) with 2.5L of deionized water, adding the precipitate slurry formed in the step (2), stirring for 1.5 hours at room temperature (25 ℃), filtering and drying to obtain the catalyst C-3.

Comparative example 6

(1) Adding 85g of lanthanum nitrate into 0.8L of deionized water, stirring, adjusting the pH value of the system to be 6.5-9.0 by using ammonia water, and continuously stirring for 1.5 hours at room temperature (25 ℃) to form slurry containing rare earth precipitates.

(2) Adding 600g (dry basis) of NH₄And (2) adding the Y molecular sieve into 1.2L of deionized water, performing sanding treatment to obtain molecular sieve slurry, adding the precipitate slurry formed in the step (1), and stirring at room temperature (25 ℃) for 15 minutes to obtain molecular sieve slurry DZ-5J. Mixing and pulping 1054g of kaolin, 587g of pseudo-boehmite and 1.4L of water, adding 60mL of hydrochloric acid, stirring for 1 hour, then adding molecular sieve slurry DZ-5J, stirring for 15min, then adding 515g of alumina sol, continuing stirring for 30min to form gel, homogenizing, spray drying, forming, roasting, mixing the roasted microspheres with deionized water and ammonium chloride to obtain the microspheres: water: the weight ratio of ammonium chloride is 1: 5: 0.002, stirring for 30 minutes at the temperature of 55 ℃, filtering, and preparing the catalyst precursor microsphere synthesized by the semi-synthesis method.

(3) And (3) mixing the catalyst precursor microspheres obtained in the step (2) with 3.3L of deionized water, stirring for 1.5 hours at room temperature (25 ℃), filtering, and drying to obtain a comparative catalyst DC-5.

Example 6

(1) The preparation method of the in-situ crystallization type catalytic cracking catalyst disclosed in the embodiment 8 of the Chinese patent CN200810102244.5 comprises the following steps:

adding water into 20Kg (dry basis) of kaolin to prepare slurry with the solid content of 35%, and adding 3% of auxiliary agent in total of sodium pyrophosphate and sodium hydroxideAnd spray forming to obtain 15Kg of sprayed soil balls. The sprayed soil balls are respectively roasted in a muffle furnace at 980 ℃ for 2 hours to obtain roasted soil balls A1, and roasted at 750 ℃ for 3.5 hours to obtain roasted soil balls B1. Sodium silicate (containing 19.84% SiO) was sequentially added under stirring₂6.98% of Na₂O)750g, mother liquor from a gel-process NaY synthesis (using the method of example 3 in US 3639099) (8.04% SiO)₂，0.67％Al₂O₃，4.29％Na₂O60: 5: 32)300g, sodium hydroxide 11.2g, directing agent (containing 11.65% SiO₂1.32% of Al₂O₃12.89% of Na₂O)96g, deionized water 200g, 260gA1 and 140gB1 are put into a stainless steel reactor, heated to 90 ℃ and crystallized at constant temperature for 20 hours. And after crystallization is finished, filtering to remove mother liquor, washing and drying a filter cake to obtain an in-situ crystallization product. The in-situ crystallized product contained 31% Y-type zeolite with a Si/Al ratio (mole ratio) of 4.5 as determined by X-ray diffraction method. Adding 500g of crystallized product, ammonium sulfate and deionized water into a stainless steel kettle under stirring, wherein the ammonium sulfate/crystallized product is 0.38, exchanging for 1.5 hours under the conditions that the pH value is 3.0-3.5 and the temperature is 90 ℃, filtering to remove filtrate, washing filter cakes with deionized water, and drying to obtain a first-handed material; roasting the first-handed material for 2 hours at 560 ℃ and with the steam introduction amount of 45 percent to obtain a first-roasted material; exchanging the primary baked material with rare earth chloride once, wherein the exchange conditions are as follows: the rare earth/one-baking material is 0.05, the pH value is 3.5-4.2, the temperature is 90 ℃, the time is 1 hour, and the exchanged material is filtered, washed and dried to obtain a secondary exchange material; roasting the secondary cross-linked material for 2 hours at 670 ℃ under the condition that the water vapor introduction amount is 100 percent to obtain a secondary roasted material; exchanging the secondary baked material with ammonium chloride, wherein the ammonium chloride/secondary baked material is 0.45, the pH value is 3.8-4.5, introducing diammonium hydrogen phosphate into the exchange solution after 0.5 hour of exchange, adding phosphorus/secondary baked material in the proportion of 0.03, the pH value is 4.0-4.8, exchanging for 0.5 hour, filtering, washing and drying the exchange product to obtain Na₂Catalyst precursor microsphere YW-1 with O content of 0.77%, RE content of 2.95% and P content of 2.13%.

(2) To 0.2L of deionized water were added 13.8mL of rare earth nitrate, 3.3g of ammonium citrate, and 0.6g of methylhydroxyethyl cellulose, and the mixture was stirred at 25 ℃ for 15 minutes, followed by addition of 12.8g of ammonium oxalate and further stirring for 15 minutes to form a slurry containing a rare earth precipitate.

(3) Adding 400g of catalyst precursor microsphere YW-1 prepared in the step (1) into 0.8L of deionized water, adding the slurry containing the rare earth precipitate formed in the step (2) in a stirring state, stirring for 15 minutes at the temperature of 25 ℃, filtering, washing and drying to obtain the catalyst C-4.

Comparative example 7

(1) The catalyst precursor microsphere YW-1 is prepared according to the preparation method of the in-situ crystallization type catalytic cracking catalyst disclosed in embodiment 8 of Chinese patent CN 200810102244.5.

(2) And (2) adding 400g of the catalyst precursor microsphere YW-1 prepared in the step (1) into 1L of deionized water, stirring for 15 minutes at the temperature of 25 ℃, filtering, washing and drying to obtain the comparative catalyst DC-6.

In order to examine the cracking activity and hydrothermal stability of the catalyst, the activity of the catalyst after 17h of steam aging was tested using catalysts C-1 to C-4 prepared in examples 3 to 6 and comparative catalysts DC-1 to DC-6 prepared in comparative examples 2 to 7, respectively, and the test results are shown in Table 2.

In order to examine the heavy metal pollution resistance of the catalyst, the catalyst is respectively soaked in 5000 mug/g V and 3000 mug/g Ni (relative to the catalyst) by an equal-volume soaking method, the catalyst polluted by vanadium and nickel is treated for 6 hours under the conditions of 800 ℃ and 100% water vapor, the activity of the catalyst polluted by vanadium and nickel after 6 hours of water vapor aging is tested, and the test results are listed in Table 2.

In table 2, the activity retention R1 is used to characterize the resistance of the catalyst to heavy metal contamination. The activity retention rate R1 is defined as vanadium and nickel pollution 6h water vapor aging activity/17 h water vapor aging activity multiplied by 100%.

The results in Table 2 show that compared with comparative catalysts DC-1 to DC-6 prepared in comparative examples 2 to 7, the catalysts C-1 to C-4 prepared in examples 3 to 6 of the present invention have improved activity retention rate R1, which indicates that the modified molecular sieve catalyst of the present invention has stronger vanadium and nickel pollution resistance. TABLE 2 catalyst Activity and heavy metal resistance

Compared with the catalyst DC-1 prepared by adopting the comparative example 2, the catalyst C-1 prepared by the embodiment 3 of the invention has the activity for 17h which is obviously higher than that of the comparative catalyst DC-1 by 2 percent; the activity of the catalyst C-1 prepared in the embodiment 3 of the invention after 6h of water vapor aging of the vanadium and nickel polluted catalyst is obviously higher than that of the comparative catalyst (DC-1) by 7 percentage points, and the activity retention rate R1 is improved by 11 percentage points, which shows that the catalyst containing the precipitated rare earth has higher activity stability and vanadium and nickel pollution resistance. Compared with the catalyst DC-2 prepared by the comparative example 3, the catalyst C-1 prepared by the example 3 of the invention has the activity of 17h equivalent to that of the comparative catalyst DC-2, but the activity of the catalyst polluted by vanadium and nickel after 6h of water vapor aging is obviously higher than that of the comparative catalyst (DC-2) by 3 percentage points, and the activity retention rate R1 is improved by 6 percentage points, which shows that the catalyst prepared by the organic complexing agent and the dispersing agent and used for precipitating rare earth has higher vanadium and nickel pollution resistance. Compared with the catalyst DC-3 prepared by using the comparative example 4, the catalyst C-1 prepared by using the invention in the example 3 has the activity of 1 percentage point higher than that of the comparative catalyst in 17 h; the activity of the vanadium and nickel polluted catalyst after 6h of water vapor aging is obviously higher than that of a comparative catalyst (DC-3) by 4 percent, and the activity retention rate R1 is improved by 7 percent, which shows that the catalyst for preparing the precipitated rare earth by adopting the organic complexing agent and the dispersing agent has higher activity stability and vanadium and nickel pollution resistance.

Compared with the catalyst DC-4 prepared by adopting the comparative example 5, the catalyst C-2 prepared by the invention in the example 4 has the activity of 4 percentage points after 17 hours; the activity of the vanadium and nickel polluted catalyst after 6h of water vapor aging is obviously higher than that of a comparative catalyst (DC-4) by 12 percent, and the activity retention rate R1 is improved by 16 percent, which shows that the catalyst containing the precipitated rare earth has higher activity stability and vanadium and nickel pollution resistance.

Compared with the catalyst DC-5 prepared by adopting the comparative example 6, the activity of the catalyst C-3 prepared by the invention in the example 5 after 6h of water vapor aging is obviously higher than that of the comparative catalyst (DC-5) after being polluted by vanadium and nickel, and the activity retention rate R1 is improved by 10 percent, which shows that the catalyst containing the precipitated rare earth has higher vanadium and nickel pollution resistance.

Compared with the catalyst DC-6 prepared by the comparative example 7, the catalyst C-4 prepared by the invention in the example 6 has the activity of 3 percentage points higher than that of the comparative catalyst DC-6 in 17 h; the activity of the vanadium and nickel polluted catalyst after 6h of water vapor aging is 9 percent higher than that of a comparative catalyst (DC-6), and the activity retention rate R1 is improved by 9 percent, which shows that the catalyst containing the precipitated rare earth prepared by the invention has higher activity stability and vanadium and nickel pollution resistance.

The present invention is capable of other embodiments, and various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A preparation method of a rare earth-containing catalytic cracking catalyst is characterized by comprising the following steps:

(2) dissolving a compound containing IIIB metal ions in the periodic table of elements in water or acid to form a solution, mixing the solution with (a) an organic complexing agent and a dispersing agent, (B) a precipitating agent, stirring for at least 10 minutes at the temperature of 5-100 ℃ to form a precipitate containing IIIB elements, wherein the molar ratio of the organic complexing agent to the IIIB metal ions is 0.3-10: 1, and the molar ratio of the dispersing agent to the IIIB metal ions is 0.2-16: 1; the organic complexing agent is selected from formic acid, acetic acid, adipic acid, citric acid, tartaric acid, benzoic acid, ethylene diamine tetraacetic acid, salicylic acid and salts of the above acids, and one or more of acetylacetone, diethanolamine and triethanolamine; the dispersing agent is selected from one or more of monohydric alcohol or dihydric alcohol with 2-8 carbon atoms, polyethylene glycol, cellulose derivatives, polyacrylamide and derivatives thereof, and guar gum;

(3) mixing the obtained precipitate containing the IIIB element with catalyst precursor microspheres, stirring at the temperature of 5-100 ℃ for at least 10 minutes, filtering, and drying to prepare a catalytic cracking catalyst containing the IIIB element precipitate; wherein the weight ratio of IIIB element to catalyst dry base is 0.002-0.06: 1.

2. The preparation method according to claim 1, wherein the molar ratio of the organic complexing agent to the IIIB metal ions is 0.5-6: 1.

3. The preparation method according to claim 1, wherein the molar ratio of the dispersing agent to the IIIB metal ion is 1-11: 1.

4. The preparation method according to claim 1, wherein the molar ratio of the organic complexing agent to the IIIB metal ions is 0.5-6: 1; the molar ratio of the dispersing agent to the metal ions is 1-11: 1.

5. The method according to claim 1, wherein the weight ratio of IIIB element to the dry catalyst basis in terms of oxide is 0.004 to 0.03: 1.

6. The method according to any one of claims 1 to 5, wherein the step (2) of dissolving the compound containing the IIIB metal ion of the periodic Table in water or an acid to form a solution is carried out by mixing (a) an organic complexing agent and a dispersing agent, (B) a precipitating agent by one of the following methods: in the mode 1, after uniformly mixing a solution containing IIIB metal ions in a periodic table of elements with an organic complexing agent and a dispersing agent, adding a precipitator, and stirring for at least 10 minutes to form a precipitate containing IIIB elements; mode 2, uniformly mixing a precipitator with an organic complexing agent and a dispersing agent, then adding a solution of a compound containing IIIB metal ions in the periodic table of elements, and stirring for at least 10 minutes to form a precipitate containing IIIB elements; mode 3, mixing a precipitator with a solution of a compound containing IIIB metal ions in the periodic table of elements, adding an organic complexing agent and a dispersing agent, and stirring for at least 10 minutes to form a precipitate containing IIIB elements; mode 4, the solution containing the IIIB metal ions in the periodic table of the elements, the organic complexing agent, the dispersing agent and the precipitating agent are added and mixed simultaneously, and stirred for at least 10 minutes to form the precipitate containing the IIIB elements.

7. The method according to any one of claims 1 to 5, wherein the catalyst precursor microspheres are prepared by semisynthetic synthesis of Na in the catalyst precursor microspheres₂The mass content of O is not more than 0.4 percent, and Na in the catalyst precursor microsphere is synthesized by adopting a total synthesis method₂The mass content of O is not more than 0.7 percent.

8. The method according to any one of claims 1 to 5, wherein the synthesis of Na in the microspheres of the catalyst precursor by the semisynthetic method is performed₂The mass content of O is more than 0.4 percent, and the catalyst precursor microspheres are subjected to sodium reduction treatment in a way selected from one of the following ways: in the method 1, the catalyst precursor microspheres are subjected to sodium reduction treatment in the step (1); and 2, mixing the precipitate containing the IIIB element with catalyst precursor microspheres in the step (3), preparing the catalytic cracking catalyst containing the IIIB element precipitate, and then performing sodium reduction treatment.

9. The method according to any one of claims 1 to 5, wherein Na is added to the microspheres of the catalyst precursor synthesized by the total synthesis method₂The mass content of O is more than 0.7 percent, and the catalyst precursor microspheres are subjected to sodium reduction treatment in the step (1).

10. The method according to any one of claims 1 to 5, wherein the precipitating agent is a compound capable of providing or generating hydroxide ions, carbonate ions, bicarbonate ions, phosphate ions, hydrogen phosphate ions, dihydrogen phosphate ions, or oxalate ions.

11. The method according to claim 10, wherein the precipitating agent is selected from one or more of oxalic acid, ammonium oxalate, ammonium carbonate, ammonium bicarbonate, carbon dioxide, ammonia water, phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate, and urea.

12. The preparation method of claim 11, wherein the pH value of the molecular sieve slurry after the ammonia water is added is 6.5-9.0; the adding amount of oxalic acid, ammonium oxalate, ammonium carbonate, ammonium bicarbonate, carbon dioxide, phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate and urea meets the condition that the weight ratio of the precipitating agent to the IIIB element compound counted by oxide is 0.3-5.

13. The method according to any one of claims 1 to 5, wherein the cellulose derivative is sodium hydroxymethylcellulose, methylhydroxyethylcellulose, hydroxypropylmethylcellulose; the monohydric alcohol or dihydric alcohol with 2-8 carbon atoms is ethanol or ethylene glycol, and the monohydric alcohol or dihydric alcohol with 3 carbon atoms is isopropanol, n-propanol, 1, 3-dipropanol or 1, 2-dipropanol.

14. The method according to any one of claims 1 to 5, wherein the IIIB element is one or more selected from scandium, yttrium, and lanthanides.

15. The preparation method according to claim 2, wherein the molar ratio of the organic complexing agent to the IIIB metal ions is 1.0-4: 1.

16. The preparation method according to claim 3, wherein the molar ratio of the dispersing agent to the IIIB metal ions is 2 to 7: 1.

17. The method according to claim 5, wherein the weight ratio of the IIIB element to the catalyst on a dry basis in terms of oxide is 0.006 to 0.015: 1.