CN107971018B

CN107971018B - Catalytic cracking catalyst and preparation method thereof

Info

Publication number: CN107971018B
Application number: CN201610921781.7A
Authority: CN
Inventors: 王丽霞; 袁帅; 刘宇键; 田辉平; 刘俊; 周翔
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petrochemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petrochemical Corp
Priority date: 2016-10-21
Filing date: 2016-10-21
Publication date: 2019-12-27
Anticipated expiration: 2036-10-21
Also published as: CN107971018A

Abstract

The catalytic cracking catalyst comprises 5-65% of natural mineral substances, 10-60% of oxide binder and 24-75% of first molecular sieve, wherein the first molecular sieve is a sieve with the pore diameter smaller than that of the first molecular sieve

Description

Catalytic cracking catalyst and preparation method thereof

Technical Field

The invention relates to a catalytic cracking catalyst, a preparation method and application thereof.

Background

The low-carbon olefin such as ethylene, propylene, butylene and the like is an essential chemical raw material and can be used for synthesizing resin, fiber, rubber and the like. Propylene is an important raw material for manufacturing petrochemical products, which is second only to ethylene, and is mainly used for producing chemical products such as polypropylene, acrylonitrile, propylene oxide and the like. At present, propylene is mainly derived from the by-product of ethylene production by thermal cracking at home and abroad, and the second largest source of propylene is the FCC unit, which provides about 30% of the demand, and in the united states, the FCC unit provides half of the demand of propylene for petrochemical products.

In recent years, the demand for propylene has increased rapidly, and by the prediction of HIS, the global propylene consumption has increased by 2016 at an average rate of about 5% which is greater than the rate of ethylene increase by 3.4%. However, the steam cracking propylene/ethylene ratio cannot be flexibly adjusted. And the reaction temperature is up to 840-860 ℃, and the energy consumption accounts for about 40% of the energy consumption of the petrochemical industry. Thus, the large production of propylene by FCC is an effective and efficient way to meet the growing demand.

Beta molecular sieve is a high-silicon large-pore molecular sieve which was first synthesized by Mobil corporation in 1967. In 1988, Newsman and Kiggins determined the crystal structure of beta molecular sieves by modern techniques such as electron diffraction, high resolution electron microscopy and computers. The structure research shows that the Beta molecular sieve has three 12-membered ring channels which are mutually crossed, the twelve-membered ring pore diameter of one-dimensional channel which is parallel to the (001) crystal face is 0.57-0.75 nm, and the twelve-membered ring pore diameter of the other two-dimensional channel which is parallel to the (100) crystal face is 0.56-0.65 nm. Due to the unique pore structure, high acidity and good hydrothermal stability of the Beta molecular sieve, the Beta molecular sieve has wide industrial application prospect and is successfully applied to the petrochemical fields of isomerization, catalytic cracking, alkylation of aromatic hydrocarbon and the like.

The Y molecular sieve is successfully synthesized in 1964, and shows good catalytic effect in alkane catalytic conversion reaction. The Y molecular sieve has a three-dimensional twelve-membered ring channel structure, the aperture is 0.74nm, and a super cage with the diameter of 1.3nm exists in the molecular sieve. Because of the structural characteristics, the Y molecular sieve is widely applied to catalytic cracking reaction and has excellent performance. Along with the demand of products such as low-carbon olefin and the like, the Y molecular sieve is compounded with other molecular sieves, such as ZSM-5 and the like, so that the distribution of the products can be adjusted more flexibly.

CN103785460A provides a catalyst for producing low-carbon olefins and a preparation method thereof, and a catalyst system compounded by an MFI structure molecular sieve and a phosphorus modified beta molecular sieve is used for preparing propylene by catalytic cracking of naphtha, so that the yield of the low-carbon olefins is higher. The catalyst is used for heavy oil catalytic cracking, and has low activity and low yield of low-carbon olefin.

CN101837301A proposes a catalytic cracking catalyst for increasing propylene yield and a preparation method thereof, which is to mix and homogenize a shape-selective molecular sieve (ZSM-5 or beta molecular sieve) and a Y-type molecular sieve with a matrix to form slurry, spray-dry the slurry and then treat the slurry with an acid solution to obtain the catalytic cracking catalyst. The catalyst can greatly improve the yield and selectivity of propylene in the catalytic cracking liquefied gas.

However, the propylene selectivity of the cracking catalyst containing the Y-type molecular sieve and the shape-selective molecular sieve is not high.

Disclosure of Invention

One of the technical problems to be solved by the invention is to provide a fluidized bed catalytic cracking catalyst which has excellent hydrothermal stability and higher propylene selectivity, and the other aim of the invention is to provide a preparation method and an application method of the catalyst.

The invention provides a catalytic cracking catalyst, which comprises (a) 5-65% of natural mineral substances in dry basis by taking the weight of the catalyst as a reference; (b) 10% -60% of oxide; and (c) 24-75% of a first molecular sieve based on a dry basis, wherein the first molecular sieve is a Y-type molecular sieve and has a pore diameter smaller than that of the first molecular sieveThe molecular sieve or the first molecular sieve has a pore diameter smaller than that ofTwo or more of the molecular sieves of (a); the proportion of the mesoporous protonic acid in the catalytic cracking catalyst in the total acid amount is 20-70%, for example 25-65%. The total specific surface area of the catalyst is preferably greater than 240m²/g。

Preferably, the proportion of the mesopore volume of the catalytic cracking catalyst in the total pore volume is 35-60%, for example 40-60%, or 45-58%, or 35-45%. The mesoporous volume of the catalyst is 0.14-0.35ml/g, such as 0.16-0.32 ml/g, such as 0.25-0.45 ml/g, or 0.15-0.30 ml/g, or 0.25-0.40 ml/g. The mesoporous is a pore with the pore diameter of 2-100 nm.

Preferably, the total specific surface area (also called specific surface area) of the catalytic cracking catalyst is 240-350 m²Per g, for example is250～320m²/g。

The catalytic cracking catalyst provided by the invention has more mesoporous protonic acid, and the proportion of the mesoporous protonic acid in the total acid amount is 20-70%, such as 25-65%, preferably, such as 25-50% or 30-55%.

The mesoporous pore volume and the total pore volume of the catalytic cracking catalyst are measured by adopting a nitrogen adsorption BET specific surface area method; the total specific surface area of the catalyst is measured by adopting a nitrogen adsorption BET specific surface area method; the mesoporous protonic acid of the catalyst has a kinetic diameter ofThe 2, 6-di-tert-butylpyridine molecule can contact with protonic acid. Measuring the amount of mesoporous protonic acid by adopting a 2, 6-di-tert-butylpyridine adsorption infrared acidity method; total acid content adopts NH₃The TPD method is used for the measurement.

The catalytic cracking catalyst provided by the invention contains natural minerals, wherein the natural minerals are one or more of kaolin, halloysite, montmorillonite, diatomite, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite and rectorite; the oxide binder is one or more of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide and amorphous silica-alumina binder; the Y-type molecular sieve is one or more of DASY molecular sieve, rare earth-containing DASY molecular sieve, USY molecular sieve, rare earth-containing USY molecular sieve, REY molecular sieve, REHY molecular sieve and HY molecular sieve, and the pore diameter is smaller thanThe molecular sieve is at least one of MFI structure molecular sieve, IMF structure molecular sieve, BEA structure molecular sieve and ferrierite. The aperture is smaller thanThe two or more molecular sieves are two or more of MFI structure molecular sieves, IMF structure molecular sieves, BEA structure molecular sieves and ferrierite. The MFThe I-structure molecular sieve may be a sodium-type MFI-structure molecular sieve, or may be a modified MFI-structure molecular sieve obtained by modifying a sodium-type MFI-structure molecular sieve, such as a hydrogen-type MFI-structure molecular sieve, an ammonium-type MFI-structure molecular sieve, and an MFI-structure molecular sieve containing phosphorus and/or transition metals, such as one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi, and Ga. The MFI structure molecular sieve is one or more of ZSM-5, ZSP and ZRP molecular sieves, the ZSM-5 molecular sieve can be NaZSM-5 or a molecular sieve obtained by modifying NaZSM-5 molecular sieve, such as HZSM-5, ammonium ZSM-5 and ZSM-5 containing phosphorus and/or transition metal, wherein the transition metal is one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga. The molecular sieve with the IMF structure can be a sodium-type IMF structure molecular sieve, or a modified IMF structure molecular sieve obtained by modifying the IMF structure molecular sieve by various modification methods, such as an ammonium-type IMF structure molecular sieve, a hydrogen-type IMF structure molecular sieve, and one or more IMF structure molecular sieves containing phosphorus and/or transition metals, wherein the transition metals are one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga. The IMF structure molecular sieve such as IM-5 can be Na type IM-5, and can also be modified IM-5 molecular sieve obtained by modifying NaIM-5, such as IM-5 molecular sieve modified by one or more of hydrogen type IM-5, ammonium type IM-5 and phosphorus and/or transition metal, such as one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga. The molecular sieve with the BEA structure can be a sodium type BEA structure molecular sieve, or a modified BEA structure molecular sieve obtained by modifying a sodium type BEA structure molecular sieve, such as a hydrogen type BEA structure molecular sieve, an ammonium type BEA structure molecular sieve, and a BEA structure molecular sieve containing phosphorus and/or transition metals, wherein the transition metals such as one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga, and the BEA structure molecular sieve is beta molecular sieve, or sodium type beta molecular sieve, or modified beta molecular sieve obtained by modifying a sodium type beta molecular sieve, such as H beta, NH, beta molecular sieve₄Beta molecular sieve modified by one or more of beta molecular sieve, phosphorus and/or transition metal, and the transition metalSuch as one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga. The ferrierite such as Fer molecular sieve can be sodium type Fer molecular sieve, also can be modified Fer molecular sieve obtained by modifying sodium type Fer molecular sieve, such as HFer, NH₄A Fer molecular sieve modified with one or more of a Fer molecular sieve, phosphorus and/or a transition metal, such as one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga.

Preferably, the Y-type molecular sieve has a pore size smaller than that of the zeoliteThe weight ratio of the molecular sieve (b) is 1: 8-4: 0.1 or 0.3: 1-20: 1 or 0.15: 1-1: 1 or 1: 4-4: 0.1 or 0.3: 1-20: 1.

The invention also provides a preparation method of the catalytic cracking catalyst, which comprises the steps of preparing the catalyst which comprises the Y-type molecular sieve and has the aperture smaller than that of the catalystThe microsphere composition of the molecular sieve, the natural mineral and the oxide binder, which is referred to as the microsphere of the first composition, is subjected to modification treatment; the microsphere modification treatment of the first composition comprises the following steps:

a. putting the first composition microspheres into an alkaline solution for treatment, filtering and washing to obtain alkali-treated first composition microspheres;

b. and c, treating the alkali-treated first composition microspheres obtained in the step a in a composite acid solution consisting of fluosilicic acid, organic acid and inorganic acid, filtering and washing, optionally carrying out ammonium exchange sodium washing treatment, optionally filtering and optionally washing, and optionally drying to obtain the composition microspheres rich in mesopores.

c. Roasting at 400-800 deg.c for at least 0.5 hr.

In the preparation method of the catalytic cracking catalyst provided by the invention, the alkaline solution in step a comprises an alkaline compound, preferably, the alkaline compound is a strongly alkaline inorganic compound, for example, the alkaline compound is one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonium hydroxide and high-alkali sodium metaaluminate. The alkaline solution used in step a is at least one selected from the group consisting of sodium hydroxide solution, potassium hydroxide solution, lithium hydroxide solution, ammonium hydroxide solution and high-alkali sodium metaaluminate solution. The alkaline solution is an aqueous solution of an alkaline compound.

According to the preparation method of the catalytic cracking catalyst provided by the invention, in one embodiment, the alkaline solution used in the step a preferably comprises high-alkali sodium metaaluminate, preferably high-alkali sodium metaaluminate solution. Preferably, in the high-alkali sodium metaaluminate solution, Na₂O content of 270-310 g/L, Al₂O₃The content is 30-50 g/L, and the solution density is 1.25-1.45 g/mL.

According to the preparation method of the catalytic cracking catalyst provided by the invention, the treatment in the step a comprises the following steps: comprises contacting the microspheres of the first composition with an alkaline solution, wherein the alkaline solution comprises an alkaline compound, and the microspheres of the first composition are mixed with an alkali metal oxide (ammonium hydroxide as NH) based on the weight of the alkali metal oxide₃In terms of the weight ratio of the basic compound is 1 (0.01-0.35). Preferably, the microspheres of the first composition are mixed with the alkali metal oxide (ammonium hydroxide as NH) on a dry weight basis₃In terms of the weight ratio of the basic compounds) is 1: (0.05-0.25) or 1: (0.01-0.15).

The preparation method of the catalytic cracking catalyst provided by the invention comprises the following steps: the weight ratio of the microspheres of the first composition to water on a dry basis is 1: (5-20).

The preparation method of the catalytic cracking catalyst provided by the invention comprises the following steps: the temperature of the treatment is 25 ℃ to 100 ℃, preferably 40 ℃ to 75 ℃ or 45 ℃ to 65 ℃, and the treatment time is 10 minutes or more, for example, 0.2 to 6 hours, or 0.2 to 4 hours, or 0.3 to 3 hours.

In the preparation method of the catalytic cracking catalyst, in the step b, the alkali-treated first composition microspheres obtained in the step a are treated in a solution of composite acid consisting of fluosilicic acid, organic acid and inorganic acid, wherein the treatment is to contact the alkali-treated first composition microspheres with a composite acid aqueous solution consisting of fluosilicic acid, organic acid and inorganic acid for more than 10 minutes, such as 0.2-10 hours or 0.5-6 hours, filter and optionally wash. The filter cake obtained by filtration or the filter cake after washing can also be contacted with an ammonium salt solution to carry out an ammonium exchange sodium washing treatment so that the sodium oxide in the obtained catalyst is not more than 0.2 wt%, preferably not more than 0.15 wt%. The ammonium salt may be a commonly used ammonium salt, for example, at least one selected from the group consisting of ammonium chloride, ammonium sulfate, ammonium carbonate, ammonium bicarbonate, ammonium acetate, and ammonium nitrate.

In the step b, the treatment temperature is 25-100 ℃, for example, 30-75 ℃ or 45-65 ℃.

According to the preparation method of the catalytic cracking catalyst, at least one of the organic acid selected from ethylenediamine tetraacetic acid, oxalic acid, acetic acid, citric acid and sulfosalicylic acid in the step b is preferably oxalic acid, and at least one of the inorganic acid selected from hydrochloric acid, sulfuric acid and nitric acid is preferably hydrochloric acid. Preferably, the organic acid in step b is oxalic acid, and the inorganic acid is hydrochloric acid.

In the preparation method of the catalytic cracking catalyst provided by the invention, the treatment conditions in the step b are as follows: the weight ratio of the first composition microspheres, the fluosilicic acid, the inorganic acid and the organic acid is 1 (0.003-0.3) to 0.01-0.45 to 0.01-0.55 on a dry basis.

Preferably, in the preparation method of the catalytic cracking catalyst provided by the invention, the treatment conditions in the step b are as follows: the weight ratio of the first composition microspheres, the fluosilicic acid, the organic acid and the inorganic acid is 1 (0.005-0.3): (0.02-0.3): or 1 (0.005-0.17): 0.015-0.15): 0.02-0.15): or 1 (0.005-0.1): 0.02-0.2): 0.02-0.15. . The weight ratio of the fluosilicic acid to the first composition microspheres is preferably (0.005-0.3): 1 or (0.005-02): 1 or (0.005-0.17): 1 or (0.005-0.1): 1; the weight ratio of the organic acid to the first composition microspheres is preferably (0.02-0.3): 1 or (0.015 to 0.15): 1 or (0.02-0.2): 1; the weight ratio of the inorganic acid to the first composition microspheres is preferably (0.01-0.2): 1 (or 0.02-0.3): 1, or (0.02-0.15): 1 or (0.02-0.15): 1.

in the preparation method of the catalytic cracking catalyst provided by the invention, in the step b, the weight ratio of water to the first composition microspheres calculated on a dry basis is 3-20: 1 is, for example, 4 to 15:1 or 5-10: 1.

in the preparation method of the catalytic cracking catalyst according to the present invention, the ammonium exchange sodium-washing exchange process in step b contacts the composition obtained by the complex acid treatment with an ammonium salt solution, wherein the ammonium salt may be a commonly used ammonium salt, for example, at least one selected from the group consisting of ammonium chloride, ammonium sulfate, ammonium carbonate, ammonium bicarbonate, sodium acetate and ammonium nitrate. Ammonium salt exchange sodium wash treatment followed by filtration, optionally washing, to wash out exchanged sodium and non-exchanged ammonium salts from the catalyst. For example, in ammonium exchange sodium washing, the weight ratio of an ammonium salt solution to the composition obtained by the complex acid treatment is 5-20: 1, the concentration of the ammonium salt solution is 1-10 wt%, the contact temperature is 30-80 ℃, and the contact time is 0.5-2 hours.

In the preparation method of the catalytic cracking catalyst provided by the invention, the washing in the step b is a conventional method, for example, according to a weight ratio of the first composition microspheres to water of 1: and leaching with water in a weight ratio of 5-10. In the washing, the washing liquid after washing is generally neutral, for example, the pH value is 6 to 8.

According to the preparation method of the catalytic cracking catalyst, the roasting treatment conditions in the step c comprise the following steps: the atmosphere of the roasting treatment is air atmosphere, nitrogen atmosphere or water vapor atmosphere or the mixture atmosphere of the above atmospheres; the roasting temperature is 400-800 ℃, and the roasting time is 0.5-8 hours. Preferably, the roasting treatment is carried out at 500-600 ℃ for 0.5-8 hours.

According to the method of the present invention, the baking process in step c may be wet baking, and the wet baking is performed in an atmosphere of 1 to 100 vol% of water vapor (i.e., the atmosphere contains 1 to 100 vol% of water vapor), more preferably 100 vol% of water vapor.

The catalytic cracking catalyst provided by the invention can be used for producing low-carbon olefin by catalytic cracking of hydrocarbon oil, and the method for producing low-carbon olefin by catalytic cracking of hydrocarbon oil comprises the step of contacting hydrocarbon oil with the catalytic cracking catalyst provided by the invention. The reaction conditions can refer to the existing conditions for producing the low-carbon olefin by catalytic cracking. The hydrocarbon oil is petroleum hydrocarbon, can be partial fraction petroleum hydrocarbon or full fraction petroleum hydrocarbon, and is particularly suitable for producing low-carbon olefin by cracking heavy oil. Such as one or more of vacuum residue, atmospheric residue, catalytic cracking light cycle oil, catalytic cracking heavy cycle oil, solvent deasphalted oil, lubricating oil refined oil and hydrotreated oil obtained by hydrotreating the above-mentioned oil products.

The catalytic cracking catalyst provided by the invention has rich mesoporous structures, proper mesoporous acidity and higher hydrothermal stability, is used for heavy oil catalytic cracking reaction, and has the advantages of higher conversion rate, low heavy oil yield, high liquefied gas yield, low coke yield, high propylene yield, high BTX yield and particularly good propylene selectivity. Compared with the existing method, the method for producing the low-carbon olefin by catalytic cracking has higher hydrocarbon oil cracking activity, higher conversion rate and higher propylene yield and BTX yield. The preparation method of the catalytic cracking catalyst provided by the invention adopts a Y-type molecular sieve and the aperture is smaller thanThe molecular sieve or more than two molecular sieves with the pore diameter smaller than 6.9 angstroms is prepared into a catalyst, and then the pore structure of the molecular sieve is further modulated by an alkali and acid coupling treatment method, so that the stability of the catalyst and the selectivity of low-carbon olefin and BTX are improved.

Detailed Description

The catalytic cracking catalyst provided by the invention contains natural minerals, wherein the natural minerals comprise one or more of kaolin, halloysite, montmorillonite, diatomite, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite, rectorite and the like. The content of the natural mineral in the catalyst provided by the invention is 5-65 wt%, preferably 8-60 wt%, for example 15-60 wt%, or 8-45 wt%, or 20-55 wt%, calculated by weight percentage based on the total amount of the catalyst, on a dry basis.

The catalytic cracking catalyst provided by the invention contains an oxide binder component, wherein the oxide is one or a mixture of more than two of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, amorphous silica-alumina and aluminum phosphate material, and the oxide binder is derived from a corresponding oxide precursor thereof, such as a sol-state substance of the oxide, such as one or more of silica sol, alumina sol, pepto-pseudo-boehmite, silicon-alumina sol and phosphorus-containing alumina sol. The content of the oxide binder is 10 to 60 wt%, preferably 15 to 55 wt%, for example 10 to 30 wt%, or 20 to 50 wt%, or 25 to 50 wt%, or 12 to 28 wt%, in terms of the weight percentage of the oxide based on the total amount of the catalyst.

The catalytic cracking catalyst provided by the invention contains a first molecular sieve, wherein the first molecular sieve is a Y-type molecular sieve and has a pore diameter smaller than that of the first molecular sieveThe Y-type molecular sieve is a molecular sieve used for a catalytic cracking catalyst, and the Y-type molecular sieve is at least one of a DASY molecular sieve, a rare earth-containing DASY molecular sieve, a USY molecular sieve, a rare earth-containing USY molecular sieve, a REY molecular sieve, a REHY molecular sieve, and an HY molecular sieve. Preferably, the Y-type molecular sieve has a pore size smaller than that of the zeoliteThe weight ratio of the molecular sieve (b) is 1: 8-4: 0.1 or 0.3: 1-20: 1 or 0.15: 1-1: 1 or 1: 4-4: 0.1 or 1: 3-15: 1. the content of the first molecular sieve is preferably 25 to 65 wt%, for example 30 to 55 wt% or 30 to 65 wt% or 30 to 55 wt% or 35 to 50 wt%.

The aperture is smaller thanThe molecular sieve is at least one of MFI structure molecular sieve, IMF structure molecular sieve, BEA structure molecular sieve and ferrierite. The above-mentionedThe MFI structure molecular sieve of (b) may be a sodium MFI structure molecular sieve, or may be an MFI structure molecular sieve obtained by subjecting a sodium MFI structure molecular sieve to various modification methods, for example, an ammonium MFI structure molecular sieve obtained by ammonium exchange, a hydrogen MFI structure molecular sieve, or a modified MFI structure molecular sieve containing one or more of phosphorus and/or a transition metal. The MFI structure molecular sieve is one or more of ZSM-5, ZRP and ZSP molecular sieves, and the ZSM-5 molecular sieve can be NaZSM-5 or a molecular sieve obtained by modifying NaZSM-5 molecular sieve, such as HZSM-5, ZSM-5 containing phosphorus and transition metal, wherein the transition metal is one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga. The molecular sieve with the IMF structure can be a sodium-type IMF structure molecular sieve, or a modified IMF structure molecular sieve obtained by modifying the IMF structure molecular sieve by various modification methods, such as an ammonium-type IMF structure molecular sieve, a hydrogen-type IMF structure molecular sieve, and one or more IMF structure molecular sieves containing phosphorus and/or transition metals, wherein the transition metals are one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga. The molecular sieve with IMF structure, such as IM-5, can be Na-type IM-5, and can also be a modified IM-5 molecular sieve obtained by modifying NaIM-5, such as hydrogen-type IM-5. The molecular sieve with the BEA structure is, for example, a beta molecular sieve, can be a sodium type beta molecular sieve, and can also be a modified beta molecular sieve obtained by modifying the sodium type beta molecular sieve, such as H beta. The ferrierite such as Fer molecular sieve can be sodium type Fer molecular sieve, also can be modified Fer molecular sieve obtained by modifying sodium type Fer molecular sieve, such as HFer, NH₄A Fer molecular sieve modified with one or more of a Fer molecular sieve, phosphorus and/or a transition metal, such as one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga. The aperture is smaller thanThe molecular sieve is preferably in the sodium, hydrogen or ammonium form and has a pore diameter smaller than that of the molecular sieveThe molecular sieve of (1).

The sodium-type IMF structure molecular sieve is well known to those skilled in the art and is commercially available and can be prepared by itself, for example, the sodium-type IMF structure molecular sieve is prepared by the steps comprising: filtering and washing the slurry of the IMF structure molecular sieve obtained by amine crystallization to obtain a washed molecular sieve; wherein the washed molecular sieve has a sodium content of less than 3.0 wt.% as sodium oxide based on the total dry basis weight of the washed molecular sieve; and drying and air roasting the washed molecular sieve to obtain the sodium type IMF structure molecular sieve. The molecular sieve with the IMF structure is preferably a molecular sieve obtained by amine crystallization, wherein the amine crystallization refers to the preparation of the molecular sieve by adopting a template agent to carry out hydrothermal crystallization, and specific documents refer to Chinese patents CN102452667A, CN103708491A, CN102452666A and CN103723740A by taking the preparation of the IMF molecular sieve as an example. The air roasting is used for removing the template agent in the washed molecular sieve, and the temperature of the air roasting can be 400-700 ℃, and the time can be 0.5-10 hours.

The cracking catalyst provided by the invention can also contain an auxiliary component. The content of the auxiliary components is not more than 30% by weight, for example 0 to 30% by weight or 0.5 to 25% by weight, based on dry basis. The additive component is at least one of a desulfurization additive component, a denitration additive component and a combustion improver component.

The cracking catalyst provided by the invention also can contain a second molecular sieve, wherein the second molecular sieve is other molecular sieves except the first molecular sieve, and the molecular sieves are often combined with an active component of a catalytic cracking catalyst. The content of the second molecular sieve is 0-20 wt%. Such as SAPO molecular sieves, MCM molecular sieves.

In the preparation method of the catalytic cracking catalyst provided by the invention, the catalyst is prepared by a Y-type molecular sieve with the aperture smaller than that of the catalystA microspherical composition of molecular sieve (also called molecular sieve with pore diameter less than 0.69 nm), natural mineral, oxide binder, and then modified. The preparation comprises Y-type molecular sieve and pore diameterIs less thanThe microspheroidal composition of molecular sieve, natural mineral, oxide binder of (a) may be prepared by: the diameter of the Y-shaped molecular sieve is smaller than that of the poreThe microsphere composition is prepared by the method of pulping, spray drying and optionally roasting the molecular sieve, the natural mineral, the precursor of the oxide binder component, the optional second molecular sieve, the optional auxiliary component and water, and the microsphere composition is called as the microsphere of the first composition. The spray drying and roasting are the prior art, and the invention has no special requirements. For example, the temperature of the calcination may be 300 to 650 ℃ or 350 to 500 ℃, and the calcination time may be 0.5 to 10 hours. The firing may be carried out in an air atmosphere, a nitrogen atmosphere, or an atmosphere containing water vapor.

The preparation method of the catalytic cracking catalyst provided by the invention comprises the steps of mixing and pulping the natural minerals, the first molecular sieve, the oxide binder such as oxide sol and/or oxide gel and water. The components are used in such amounts that the final catalyst contains, based on the total weight of the catalyst, 5 to 65 wt% of the natural mineral, 10 to 60 wt% of the oxide, and 24 to 75 wt% of the first molecular sieve. More preferably, the components are used in amounts such that the composition of the final catalyst comprises: the natural mineral content is 5 to 50 wt% on a dry basis, for example 8 to 45 wt%, the first molecular sieve content is 30 to 65 wt% on a dry basis, for example 30 to 55 wt%, and the oxide binder content is 15 to 55 wt% on an oxide basis, for example 25 to 50 wt% or 15 to 45 wt% or 20 to 35 wt% or 12 to 28 wt%.

According to the preparation method of the catalytic cracking catalyst provided by the invention, the natural mineral substances comprise one or more of kaolin, halloysite, montmorillonite, diatomite, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite, rectorite and the like. The amount of the natural minerals is such that the content of the natural minerals in the obtained catalytic cracking catalyst is 15-65 wt%, preferably 20-55 wt%, based on the total amount of the catalyst.

The preparation method of the catalytic cracking catalyst provided by the invention is characterized in that the oxide binder precursor is one or more of silica sol, alumina, zirconia, titania, amorphous silica-alumina and aluminum phosphate material sol or gel, such as one or more of silica sol, alumina sol, peptized pseudo-boehmite, silica-alumina sol and phosphorus-containing alumina sol. The amount of the oxide binder precursor is such that the oxide binder content in the resulting catalytic cracking catalyst is 10 to 60 wt.%, for example 10 to 30 wt.%, or 15 to 35 wt.%, preferably 12 to 28 wt.%, in terms of oxide weight percentage based on the total amount of the catalyst.

The preparation method of the catalytic cracking catalyst provided by the invention has the advantages that the dosage of the first molecular sieve (namely the Y-type molecular sieve and the pore diameter smaller thanThe dosage of the molecular sieve or more than two pore diameters are less thanThe amount of the molecular sieve) is such that the content of the first molecular sieve in the obtained catalytic cracking catalyst is 24 to 75 wt%, preferably 30 to 70 wt% or 25 to 65 wt%, for example 30 to 55 wt%, on a dry basis. Wherein the aperture of the Y-shaped molecular sieve is less thanThe weight ratio of the molecular sieve (b) is 1: 8-4: 0.1 or 0.3: 1-20: 1 or 0.15: 1-1: 1 or 1: 4-4: 0.1 or 1: 3-15: 1. the Y-type molecular sieve is one or more of DASY molecular sieve, DASY molecular sieve containing rare earth, USY molecular sieve containing rare earth, REY molecular sieve, REHY molecular sieve and HY molecular sieve.

The preparation method of the catalytic cracking catalyst provided by the invention has the pore diameter smaller thanThe molecular sieve is at least one of MFI structure molecular sieve, IMF structure molecular sieve, BEA structure molecular sieve and ferrierite. The MFI structure molecular sieve is one or more of ZSM-5, ZRP and ZSP molecular sieves, and the ZSM-5 molecular sieve can be NaZSM-5 or a molecular sieve obtained by modifying NaZSM-5 molecular sieve, such as HZSM-5, ZSM-5 containing phosphorus and/or transition metal, wherein the transition metal is one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga. The molecular sieve with the IMF structure can be a sodium-type IMF structure molecular sieve, or a modified IMF structure molecular sieve obtained by modifying the IMF structure molecular sieve by various modification methods, such as an ammonium-type IMF structure molecular sieve, a hydrogen-type IMF structure molecular sieve, and one or more IMF structure molecular sieves containing phosphorus and/or transition metals, wherein the transition metals are one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga. For example, IM-5 can be Na type IM-5, and also can be modified IM-5 molecular sieve obtained by modifying NaIM-5, such as IM-5 in hydrogen type, IM-5 in ammonium type, and IM-5 molecular sieve modified by one or more of phosphorus and/or transition metals, such as one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi and Ga. . The molecular sieve with the BEA structure is, for example, a beta molecular sieve, can be a sodium type beta molecular sieve, and can also be a modified beta molecular sieve obtained by modifying the sodium type beta molecular sieve, such as H beta and NH₄Beta molecular sieve, phosphorus, and/or one or more transition metals such as one or more of RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi, and Ga. The ferrierite such as Fer molecular sieve can be sodium type Fer molecular sieve, or modified Fer molecular sieve obtained by modifying sodium type Fer molecular sieve such as HFer, NH₄Fer molecular sieves modified with one or more of phosphorus and/or transition metals such as RE, Fe, Ni, Co, Cu, Mn, Zn, Sn, Bi, andone or more of Ga. The aperture is smaller thanThe molecular sieve is preferably in the sodium, hydrogen or ammonium form and has a pore diameter smaller than that of the molecular sieveThe molecular sieve of (1).

In the preparation method of the catalyst provided by the present invention, preferably, based on the weight of the first composition microspheres, the weight ratio of the natural mineral substance in dry basis, the first molecular sieve in dry basis and the oxide binder in oxide basis in the first composition microspheres (also referred to as the first microsphere composition) is 5 to 65: 24-75: 10-60, preferably 8-55: 30-65: 15-55, more preferably 8-45: 30-55: 20 to 50. Preferably, the first composition microspheres contain 5% to 65% of natural mineral substance on a dry basis, 10% to 60% of oxide binder on an oxide basis, and 24% to 75% of first molecular sieve on a dry basis, and preferably, the first microsphere composition contains 8% to 55% of natural mineral substance on a dry basis, 15% to 55% of oxide binder on an oxide basis, and 25% to 55% of first molecular sieve on a dry basis, based on the weight of the first composition microspheres. More preferably, the first composition microspheres contain 8 to 45 wt%, such as 20 to 45 wt%, on a dry basis, of the natural mineral, 20 to 50 wt%, such as 10 to 30 wt%, on an oxide basis, of the oxide binder, and 30 to 55 wt%, such as 35 to 50 wt%, on a dry basis, of the first molecular sieve.

The preparation method of the catalyst provided by the invention comprises the following steps of mixing a precursor of an inorganic oxide binder, such as pseudo-boehmite, alumina sol, silica-alumina gel or a mixture of two or more of the pseudo-boehmite, the alumina sol, the silica-alumina sol and the silica-alumina gel, with a natural mineral substance, such as kaolin and water (such as decationized water and/or deionized water), preparing a slurry with the solid content of 10-50 wt%, uniformly stirring, optionally adjusting the pH of the slurry to 1-4, such as 2-3, by using an inorganic acid, such as hydrochloric acid, nitric acid, phosphoric acid or sulfuric acid, uniformly stirring, and optionally adjusting the pH to 20 DEGStanding for 0-2 hours at 80 ℃, for example, 0.3-2 hours, and then adding a first molecular sieve, wherein the pore diameter of the first molecular sieve is smaller than that of the first molecular sieveThe molecular sieve and the Y-type molecular sieve have a pore diameter smaller thanThe slurry of the first composition, which has a solid content of, for example, 20 to 45% by weight, is spray-dried to prepare a microspherical composition. And then roasting the microspherical composition for 0.5 to 6 hours at 300 to 650, preferably 350 to 550 ℃, for example, to obtain the first composition microsphere. If the catalytic cracking catalyst includes a promoter component and/or a second molecular sieve, the first composition slurry also contains the promoter component and the second molecular sieve, which are introduced into the first composition slurry at any step prior to spray drying.

The washing according to the present invention is well known to those skilled in the art and, without particular reference thereto, generally refers to water washing, for example, a molecular sieve may be rinsed with 5 to 10 times the weight of the molecular sieve.

The catalytic cracking catalyst prepared by the preparation method provided by the invention has more mesoporous protonic acid, and the proportion of the mesoporous protonic acid in the total acid amount is 20-70%, such as 25-65%, preferably, such as 25-50% or 30-55%.

The total specific surface area of the catalytic cracking catalyst prepared by the method is more than 240m²A total specific surface area (also referred to as specific surface area) of 240 to 350m²A/g, for example, of 250 to 320m²/g。

According to the preparation method of the catalytic cracking catalyst provided by the invention, the proportion of the mesoporous volume of the prepared catalytic cracking catalyst in the total pore volume is 35-60%, such as 40-60%, 45-58% or 35-45%. The mesoporous volume of the catalytic cracking catalyst is 0.14-0.35ml/g, such as 0.15-0.30 ml/g or 0.16-0.32 ml/g.

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation. The instruments and reagents used in the examples of the present invention are those commonly used by those skilled in the art unless otherwise specified.

The influence of the catalytic cracking catalyst on the propylene yield and the BTX yield in the catalytic cracking of petroleum hydrocarbon is evaluated by using raw material oil ACE. The method comprises the following steps: the catalyst was aged at 800 ℃ for 15 hours with 100% water vapor, and evaluated on stationary fluidized bed micro-reaction ACE under conditions of reaction temperature 530 ℃ and regeneration temperature 620 ℃ with a catalyst-to-oil ratio of 5 (weight ratio) with the raw oil being hydrotreated oil (see Table 3 for composition and properties).

The specific surface area of the present invention was measured by the standard method of GBT 5816-1995.

The pore volume of the present invention was determined using standard methods of GB/T5816-1995.

The total acid content of the invention adopts NH₃TPD method see research methods for solid catalysts, petrochemical, 30(12), 2001: 952.

the mesoporous protonic acid of the method is determined by adopting a 2, 6-di-tert-butylpyridine adsorption infrared acidity method. The specific method comprises the following steps: the catalyst was pressed to 10mg/cm²Into a band of CaF₂In the infrared bath of the window. Vacuumizing at 400 ℃, then reducing the temperature to 150 ℃, adsorbing the 2, 6-di-tert-butylpyridine for 15 minutes, and then vacuumizing for 1 hour. And cooling to room temperature to collect a spectrogram, and calculating the amount of the protonic acid. See Applied Catalysis A, General, 294, 2005: 92.

na of the invention₂The content of O is measured by adopting a GB/T30905-2014 standard method.

The RIPP standard method can be found in petrochemical analysis, Yangcui and other editions, 1990 edition.

The following examples illustrate the catalysts and the process for their preparation according to the invention, in which the raw materials used have the following properties: kaolin (Chinese character of 'Kaolin')Examples of the inorganic silica sol include, but are not limited to, clay (suzhou china kaolin, 75 wt% in solid content), halloysite (guizhou zuiyan sanhe white ore, 75 wt% in solid content), rectorite (hubei zhongxiang rectorite, 75 wt% in solid content), montmorillonite (75 wt% in solid content, hou yangtao bentonite, korshin-yang, hou), pseudoboehmite (65 wt% in solid content, from shandong aluminum corporation, when used, peptized with 31 wt% hydrochloric acid, the molar ratio of the hydrochloric acid to the pseudoboehmite in terms of alumina being 0.20), alumina sol (zilu catalyst division, 22.5 wt% in alumina content), silica sol (Qingdao ocean chemical corporation, 25.5 wt% in silica content, pH 3.0), phosphoalumina sol (16 wt% in P content, 8 wt% in Al content, pH 2.0), IM-5 molecular sieves (produced by long-green division, china petrochemical catalyst, synthesized by amine method, sodium type, silicon to aluminum ratio (SiO)₂/Al₂O₃A molar ratio, the same below) of 30), a ZSM-5 molecular sieve (NaZSM-5, a silica-alumina ratio of 44, manufactured by china petrochemical catalyst co., ltd.), a beta molecular sieve (H β, a silica-alumina ratio of 30, manufactured by china petrochemical catalyst co., ltd.), a REY molecular sieve (rare earth content of 10 mass%, manufactured by china petrochemical catalyst co., ltd.), a DASY molecular sieve (ltd. ), a rare earth content (in RE), a DASY molecular sieve (ltd., lt₂O₃Calculated) was 1.5 wt%). USY molecular sieves (Qilu division, China petrochemical catalyst, Inc.), rare earth content (in RE)₂O₃Calculated) is 1.5 weight percent, and the silicon-aluminum ratio is SiO₂/Al₂O₃The molar ratio was 5.8). ZRP-1 molecular sieves, products of the Qilu division of China petrochemical catalyst Ltd., silicon to aluminum ratio (SiO)₂/Al₂O₃Molar ratio) was 40.

The solid content is the weight ratio of the solid product obtained by roasting the material at 800 ℃ for 1 hour to the material.

Example 1

267g of alumina sol and 168g of kaolin are mixed, and prepared into slurry with the solid content of 31 weight percent by using decationized water, after stirring for 0.5 hour, molecular sieve slurry containing 24g of USY, 45g of beta molecular sieve and 45g of ferrierite is added to form composition slurry (the solid content is 35 weight percent), the mixture is uniformly stirred and spray-dried to prepare composition microspheres, and then the composition microspheres are roasted for 1 hour at 500 ℃ to prepare first composition microspheres A1.

200g of the first composition microspheres A1 (dry basis weight, the same applies hereinafter) prepared above were taken, water was added and slurried to obtain a slurry having a solid content of 10% by weight, and 11.4g of a high-alkali sodium metaaluminate solution (Na) was added₂O is 290g/L, Al₂O₃40g/L, the solution density is 1.353g/mL), heating to 50 ℃, stirring at constant temperature for 0.5h, filtering, and washing to neutrality (the washing to neutrality means that the washing liquid after washing is neutral, and the pH is 6-8); adding water into the filter cake, pulping to obtain slurry with the solid content of 10 weight percent, adding 5.3g of oxalic acid while stirring, then adding 51g of hydrochloric acid (the mass fraction of HCl is 10 percent) and 33.4g of fluorosilicic acid solution (the concentration of fluosilicic acid is 3 weight percent), heating to 50 ℃, stirring for 1 hour at constant temperature, filtering, washing and drying to obtain the catalytic cracking catalyst A provided by the invention. The physicochemical properties of catalyst sample A are shown in Table 1, and the results of ACE evaluation of the feedstock after 100% steam aging at 800 ℃ for 17 hours are shown in Table 2, and the properties of the feedstock for evaluation are shown in Table 3.

Example 2

Mixing 411.8g of silica sol and 80g of montmorillonite, preparing slurry with the solid content of 30 weight percent by using decationized water, stirring for 2 hours, adding slurry formed by 75g of a polyethylene Y molecular sieve, 60g of a ZSM-5 molecular sieve and water, uniformly stirring to form first composition slurry (with the solid content of 35 weight percent), spray-drying to prepare composition microspheres, and roasting the composition microspheres at 350 ℃ for 2 hours to obtain the first composition microspheres B1.

Taking 200g of the prepared first composition microspheres B1 (dry basis weight), adding water to prepare first composition microsphere slurry with the solid content of 10 weight percent, adding 16g of NaOH (with the purity of 96 percent), heating to 70 ℃, stirring at constant temperature for 0.3h, filtering, and washing to be neutral; adding water into the filter cake, pulping to obtain slurry with the solid content of 10 wt%, adding 16g of oxalic acid while stirring, then adding 38g of hydrochloric acid (HCl with the mass fraction of 10%) and 35g of fluorosilicic acid solution (with the concentration of 3 wt%), heating to 80 ℃, stirring at constant temperature for 0.8h, filtering, washing and drying to obtain the catalytic cracking catalyst B provided by the invention. The physicochemical properties of catalyst sample B are shown in Table 1, and after aging at 800 ℃ for 17 hours with 100% steam, the raw oil ACE evaluation was performed using the raw oil shown in Table 3, and the results are shown in Table 2.

Example 3

Mixing 400g of alumina sol and 80g of montmorillonite, preparing slurry with the solid content of 30 weight percent by using decationized water, stirring for 1 hour, adding slurry comprising 30g of ZRP-1 type molecular sieve, 60 gIM-5 molecular sieve and 60g of beta molecular sieve, stirring to form slurry of a first composition (the solid content is 35 weight percent), and carrying out spray drying to prepare the microsphere composition. The microsphere composition was then calcined at 350 ℃ for 2 hours to provide first composition microspheres C1.

Taking 200g of the prepared first composition microspheres C1 (dry basis weight), adding water to prepare first composition microsphere slurry with the solid content of 10 weight percent, adding 19g of KOH (purity of 96 percent), heating to 60 ℃, stirring for 1 hour at constant temperature, filtering, and washing to be neutral; adding water into the filter cake, pulping to obtain slurry with solid content of 10 wt%, adding 26g oxalic acid while stirring, and adding 250g sulfuric acid solution (H) at 30-80ml/min₂SO₄10 percent of mass fraction) and 95g of fluorosilicic acid solution (the concentration of fluorosilicic acid is 3 percent by weight), heating to 70 ℃, stirring for 2 hours at constant temperature, filtering, washing and drying to obtain the catalyst C provided by the invention. Physicochemical properties of catalyst sample C; after aging at 800 ℃ for 17 hours with 100% steam, stock oil ACE evaluation was performed using the stock oils shown in Table 3, and the results of evaluation of conversion, gas yield, coke amount, etc. are shown in Table 2.

Example 4

Taking 200g of the prepared catalyst C1 (dry basis weight), adding water to prepare slurry with the solid content of 10 weight percent, adding 30g of NaOH (with the purity of 96 percent), heating to 90 ℃, stirring for 2 hours at constant temperature, filtering and washing to be neutral; adding water into the filter cake, pulping to obtain slurry with the solid content of 10 weight percent, adding 33g of oxalic acid while stirring, then adding 70g of hydrochloric acid (the mass fraction of HCl is 10 weight percent) and 667g of fluorosilicic acid solution (the concentration is 3 weight percent), heating to 30 ℃, stirring at constant temperature for 5.5h, filtering, washing and drying the catalytic cracking catalyst D provided by the invention. Physicochemical properties of catalyst sample D; after aging at 800 ℃ and 100% steam for 17 hours, the raw oil was evaluated by ACE, and the results of evaluation of conversion, gas yield, coke amount and the like are shown in Table 2.

Example 5

353g of silica sol and 80g of montmorillonite are mixed, and prepared into slurry with the solid content of 10-50 wt% by using decationized water, the slurry is uniformly stirred, the mixture is kept stand for 1 hour, 45g of DASY type molecular sieve, 60g of ferrierite and 45 gIM-5 in terms of dry basis are added, the mixture is uniformly stirred to form composition slurry (the solid content is 35 wt%), the composition slurry is prepared into a microspherical composition through spray drying, and the microspherical composition is roasted for 2 hours at 350 ℃ to obtain the first composition microsphere D1.

Taking 200g of the prepared first composition microspheres D1 (dry basis weight), adding water to prepare first composition microsphere slurry with the solid content of 10 weight percent, adding 22g of NaOH (with the purity of 96 percent), heating to 30 ℃, stirring for 3 hours at constant temperature, filtering, and washing to be neutral; adding water into the filter cake, pulping to obtain alkali treatment composition slurry with the solid content of 10 wt%, adding 5g of citric acid while stirring, then adding 120g of hydrochloric acid (the mass fraction of HCl is 10 wt%) and 55g of fluorosilicic acid solution (the concentration of fluosilicic acid is 3 wt%), heating to 60 ℃, stirring at constant temperature for 2.5h, filtering, washing and drying to obtain the catalytic cracking catalyst E provided by the invention. The physicochemical properties of catalyst sample E are shown in Table 1, and the results of evaluation of raw oil ACE after 100% steam aging at 800 ℃ for 17 hours, such as conversion, gas yield, coke amount, etc., are shown in Table 2.

Example 6

Taking 200g of the first composition D1 (dry basis weight) prepared above, adding water to prepare slurry with the solid content of 10 weight percent, adding 25g of KOH (with the purity of 96 percent), heating to 50 ℃, stirring at constant temperature for 0.5h, filtering and washing to be neutral; adding water into the filter cake, pulping to obtain slurry with the solid content of 10 wt%, adding 35g of oxalic acid while stirring, slowly adding 50g of nitric acid solution (the mass fraction of the nitric acid is 10%) and 90g of fluorosilicic acid solution (the concentration is 3 wt%), heating to 50 ℃, stirring at constant temperature for 1h, filtering, washing and drying to obtain a catalyst sample F, wherein the physicochemical property of the catalyst sample F is evaluated by raw oil ACE after 100% steam aging at 800 ℃, 17h and the results are listed in Table 2.

Comparative example 1

The basic procedure in this comparative example is as in example 1, except that the modification treatment is carried out without alkali and acid treatment, sodium is washed by exchange with a solution of ammonium sulfate, and the sample obtained is comparative sample I. The physicochemical properties and the ACE evaluation results of the raw oil are shown in Table 2 (the evaluation method is the same as that of example 1, and the evaluation method of the following comparative example is the same).

Comparative example 2

A catalyst was prepared by following the procedure of example 1 except that, in the acid treatment, only an organic acid and an inorganic acid were used without conducting the alkali treatment, and the fluorosilicic acid was replaced with an equimolar amount of hydrochloric acid.

Comparative example 3

The basic procedure in this comparative example follows the procedure of example 1 except that no complex acid treatment is performed and an exchange wash with ammonium nitrate solution is used to reduce the sodium content, and the resulting sample is comparative sample III. The physicochemical properties and the ACE evaluation results of the raw oil are shown in Table 2.

Comparative example 4

A catalytic cracking catalyst was prepared by following the procedure of example 1, except that the treatment with the complex acid was not conducted, but the treatment with the fluorosilicic acid and oxalic acid, in which hydrochloric acid was replaced with an equimolar amount of oxalic acid, to obtain catalyst sample IV. The physicochemical properties are shown in Table 1, and the results of ACE evaluation of the raw oil by the method of example 1 are shown in Table 2.

Comparative example 5

A catalytic cracking catalyst was prepared by following the procedure of example 1 except that the treatment with the complex acid was not conducted and the treatment with hydrochloric acid was conducted. The resulting sample was comparative sample V. The physicochemical properties and the ACE evaluation results of the raw oil are shown in Table 2.

TABLE 1

V_{Mesoporous structure}/V_{General hole}Is the ratio of the mesopore volume to the total pore volume

TABLE 2

TABLE 3

Item	Raw oil
		Density (20 ℃ C.), g/cm³	0.9334
Dioptric light (70 degree)	1.5061
		Four components, m%
Saturated hydrocarbons	55.6
		Aromatic hydrocarbons	30
Glue	14.4
		Asphaltenes	<0.1
Freezing point, DEG C	34
		Metal content, ppm
Ca	3.9
		Fe	1.1
Mg	<0.1
		Na	0.9
Ni	3.1
		Pb	<0.1
V	0.5
		C m％	86.88
H m％	11.94
		S m％	0.7
M% of carbon residue	1.77

As can be seen from Table 2, compared with the contrast agent, the catalyst provided by the invention has high hydrocarbon oil cracking conversion rate, higher propylene and BTX (benzene, toluene and xylene) yield, higher liquefied gas selectivity and obviously lower slurry oil selectivity.

Claims

1. A catalytic cracking catalyst comprising the following components in weight percent:

A) 5-65% of natural mineral substances on a dry basis;

B) oxide binder accounting for 10-60 percent of the oxide;

C) 24-75% of a first molecular sieve based on a dry basis, wherein the first molecular sieve is a Y-type molecular sieve and has a pore diameter smaller than that of the first molecular sieveThe molecular sieve of (2), or the first molecular sieve is a molecular sieve with a pore diameter smaller than that ofTwo or more of the molecular sieves of (1);

the proportion of the mesoporous protonic acid amount of the catalytic cracking catalyst in the total acid amount is 20-70%.

2. The catalytic cracking catalyst according to claim 1, wherein the total specific surface area of the catalyst is 240 to 350m²The proportion of mesoporous protonic acid in the total acid is 25-50%.

3. The catalytic cracking catalyst according to claim 1, wherein the catalyst has a mesoporous volume of 0.14 to 0.35ml/g, and the ratio of the mesoporous volume to the total pore volume is 35 to 60%.

4. The catalytic cracking catalyst according to claim 1, wherein the catalyst has a mesopore volume of 0.15 to 0.30 ml/g.

5. The catalyst of claim 1, wherein the natural minerals comprise one or more of kaolin, halloysite, montmorillonite, diatomaceous earth, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite, and rectorite; the oxide is silicon oxide, aluminum oxide and oxygenOne or more of zirconium oxide, titanium oxide and amorphous silica-alumina; the Y-type molecular sieve is at least one of DASY molecular sieve, rare earth-containing DASY molecular sieve, USY molecular sieve, rare earth-containing USY molecular sieve, REY molecular sieve, REHY molecular sieve and HY molecular sieve, and the pore diameter is smaller thanThe molecular sieve is at least one of MFI structure molecular sieve, IMF structure molecular sieve, BEA structure molecular sieve and ferrierite.

6. The catalyst of claim 1, wherein the first molecular sieve is a Y-type molecular sieve and has a pore size of less thanThe molecular sieve of (1), the Y-type molecular sieve and the pore diameter of the molecular sieve are less thanThe weight ratio of the molecular sieve (B) is 1: 8-4: 0.1.

7. The catalyst of claim 1 wherein the Y-type molecular sieve has a pore size less thanThe weight ratio of the molecular sieve (b) is 0.3: 1-20: 1 or 0.15: 1-1: 1.

8. A method of preparing a catalytic cracking catalyst, comprising:

forming first composition microspheres comprising the first molecular sieve, natural minerals and oxide binders, and modifying the first composition microspheres; the first molecular sieve is a Y-type molecular sieve and has a pore diameter smaller than that of the first molecular sieveThe molecular sieve or the first molecular sieve is pore diameterIs less thanThe modification treatment of the microspheres of the first composition comprises the following steps:

b. b, treating the alkali-treated first composition microspheres obtained in the step a in a composite acid solution consisting of fluosilicic acid, organic acid and inorganic acid, filtering and washing to obtain composition microspheres rich in mesopores; or treating the alkali-treated first composition microspheres obtained in the step a in a composite acid solution consisting of fluosilicic acid, organic acid and inorganic acid, filtering, optionally washing, performing ammonium exchange sodium washing treatment, filtering and optionally washing to obtain composition microspheres rich in mesopores;

c. roasting at 400-800 deg.c for at least 0.5 hr.

9. The method of claim 8, wherein the catalytic cracking catalyst optionally comprises a second molecular sieve, optionally comprises a promoter component, and the step of forming microspheres of the first composition comprising the first molecular sieve, the natural mineral, and the oxide binder comprises:

mixing the first molecular sieve, the natural mineral substance, the precursor sol of the oxide, the optional second molecular sieve, the optional auxiliary agent component and water, pulping, spray drying and optional roasting.

10. The method according to claim 8, wherein the alkaline solution in step a comprises alkaline compounds, and the alkaline compounds are one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonium hydroxide and high-alkali sodium metaaluminate.

11. The method according to claim 8, wherein the treating in step a is: bag (bag)Comprises contacting the first composition microspheres with an alkaline solution, wherein the alkaline solution comprises an alkaline compound, the weight ratio of the first composition microspheres to the alkaline compound is 1 (0.01-0.35) calculated by the weight of the first composition microspheres and the alkaline compound on a dry basis, the alkali metal alkaline compound is calculated by alkali metal oxide, and ammonium hydroxide is calculated by NH₃And (6) counting.

12. The method according to claim 8, wherein in the treatment in step a: the weight ratio of the microspheres of the first composition to water on a dry basis is 1: (5-20), wherein the treatment temperature is between room temperature and 100 ℃, and the treatment time is 0.2-4 hours.

13. The method according to claim 8, wherein the conditions of said treatment in step a are: the weight ratio of the first composition microspheres to the basic compound on a dry basis is 1: (0.05-0.25) or 1: (0.01-0.15) wherein the alkali metal compound is calculated as alkali metal oxide, and the ammonium hydroxide is calculated as NH₃And (6) counting.

14. The method of claim 8, wherein the organic acid in step b is at least one of ethylenediaminetetraacetic acid, oxalic acid, acetic acid, citric acid, and sulfosalicylic acid, and the inorganic acid is at least one of hydrochloric acid, sulfuric acid, and nitric acid.

15. The method according to claim 8, characterized in that the conditions of the treatment in step b are: the weight ratio of the first composition microspheres, the fluosilicic acid, the organic acid and the inorganic acid is 1 (0.003-0.3) to 0.01-0.55 to 0.01-0.45.

16. The method according to claim 8, characterized in that the conditions of the treatment in step b are: the weight ratio of the first composition microspheres, the fluosilicic acid, the organic acid and the inorganic acid is 1 (0.005-0.3) to (0.02-0.3).

17. The process according to claim 8, characterized in that the temperature of the treatment in step b is between 25 and 100 ℃ and the time is between 0.5 and 6 hours.

18. The method of claim 8, wherein the ammonium exchange sodium wash treatment process of step b comprises the step of contacting an ammonium salt solution with the acid-treated microspheres of the first composition, wherein the ammonium salt is an ammonium salt commonly used in the preparation of exchange washes of catalytic cracking catalysts, and is selected from at least one of ammonium chloride, ammonium sulfate, ammonium carbonate, ammonium bicarbonate, ammonium acetate and ammonium nitrate; the ammonium exchange sodium wash treatment preferably results in a catalytic cracking catalyst having a sodium oxide content of no more than 0.2 wt.%.

19. The method of claim 8, wherein the conditions of the firing treatment of step c include: the atmosphere of the roasting treatment is air atmosphere, nitrogen atmosphere or water vapor atmosphere or the mixture atmosphere of the above atmospheres; the roasting temperature is 400-800 ℃, and the roasting time is 0.5-8 hours.

20. The method for preparing a catalytic cracking catalyst according to claim 8, wherein the oxide binder precursor sol is one or more of silica sol, alumina sol, peptized pseudo-boehmite, silica-alumina sol, and phosphorus-containing alumina sol.

21. The method for preparing a catalytic cracking catalyst according to claim 6, wherein the microspheres of the first composition comprise, based on the weight of the microspheres of the first composition: 14 to 65 percent of natural mineral substance by dry basis, 10 to 60 percent of oxide binder by oxide and 24 to 75 percent of first molecular sieve by dry basis.

22. The catalytic cracking catalyst preparation method of claim 8, wherein the alkaline solution is at least one selected from the group consisting of a sodium hydroxide solution, a potassium hydroxide solution, a lithium hydroxide solution, an ammonium hydroxide solution, and a high alkali sodium metaaluminate solution.

23. The method of claim 16, wherein the weight ratio of the first composition microspheres, the fluosilicic acid, the organic acid and the inorganic acid is 1 (0.005-0.17): (0.015-0.15): 0.02-0.15).

24. The method of claim 16, wherein the weight ratio of the first composition microspheres, the fluosilicic acid, the organic acid and the inorganic acid is 1 (0.005-0.1): 0.02-0.2): 0.02-0.15.

25. A method for producing low-carbon olefins by catalytic cracking of hydrocarbons, comprising the step of contacting hydrocarbon oil with the cracking catalyst of any one of claims 1 to 7 for reaction.