CN107971000B

CN107971000B - Catalytic cracking auxiliary agent containing phosphorus-containing Beta molecular sieve and preparation method thereof

Info

Publication number: CN107971000B
Application number: CN201610921220.7A
Authority: CN
Inventors: 陈振宇; 朱玉霞; 周灵萍; 张蔚琳; 田辉平; 庄立; 罗一斌
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: CN107971000A

Abstract

The invention discloses a catalytic cracking assistant containing a phosphorus-containing Beta molecular sieve and a preparation method thereof, wherein the assistant contains 10-75 wt% of the phosphorus-containing Beta molecular sieve, 0-60 wt% of clay, 15-60 wt% of inorganic oxide binder and P₂O₅0-25 wt.% of a phosphorus additive and 0-15 wt.% of a group VIII metal additive, calculated as oxides, wherein the molecular sieve has an Al distribution parameter D satisfying: d is more than or equal to 0.4 and less than or equal to 0.8; the specific surface area of the micropores of the molecular sieve is 420-520 m²The proportion of the mesoporous volume of the molecular sieve in the total pore volume is 30-70% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 20-60%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100; the molecular sieve has a phosphorus content of 0.3-10 wt%. The auxiliary agent of the invention is applied to catalytic cracking, and can improve the yield of isobutene and propylene and improve the octane number of gasoline.

Description

Catalytic cracking auxiliary agent containing phosphorus-containing Beta molecular sieve and preparation method thereof

Technical Field

The invention relates to a catalytic cracking assistant containing a phosphorus-containing Beta molecular sieve and a preparation method thereof.

Background

The low-carbon olefin is an important organic chemical raw material, and the worldwide demand for the low-carbon olefin is increasing year by year. Fluidized catalytic cracking is one of the important processes for producing low-carbon olefins, and for most catalytic cracking units, addition of an auxiliary agent is an effective technical way for increasing the yield of the low-carbon olefins. But the prior art has no obvious effect on improving the concentration of isobutene in liquefied gas. Beta molecular sieve (also called beta zeolite, beta molecular sieve) is an effective active component from the viewpoint of isobutylene generation and reaction chemistry in the FCC process. The main problems of the beta molecular sieve in use are that the structure of the beta molecular sieve is easily damaged in the process of removing the template agent, and the activity stability is poor due to easy dealumination in the reaction process.

Early patents disclose cracking catalysts or promoters containing beta zeolite to increase gasoline octane and to increase the production of lower olefins and liquefied gases, such as U.S. Pat. Nos. 4,4740292, 4898846, 4911823 and WO 95026533. Some of the beta zeolites used in these patents are characterized as low sodium hydrogen zeolites and some are characterized as high silica to alumina zeolites. Beta with high silicon-aluminum ratio can be directly synthesized or obtained by hydrothermal treatment or acid treatment.

US4837396 discloses a catalyst comprising a beta zeolite and a Y zeolite, and containing a metal ionic compound as a stabilizer to improve the hydrothermal stability and mechanical strength of the catalyst. The stabilizer may be [ Al ]₂(OH)₅Cl]_xOr is Al₃Zr(OH)₉Cl₄. The stabilizer may be directly reacted with the beta zeolite or added during the preparation of the catalyst.

US6355591 discloses a catalytic cracking aid comprising 4-20% aluminum phosphate, 1-40% ZSM-5, beta and mixtures thereof, 40-90% clay for improved LPG production. The preparation method of the aluminum phosphate comprises the following steps: adding concentrated phosphoric acid into deionized water for dilution, adding aluminum powder for dissolution, wherein Al and PO are₄At a molar ratio of 1:3 and a pH of less than 2.0. And uniformly mixing the prepared aluminum phosphate and kaolin, mixing the mixture with molecular sieve slurry, and finally spraying and forming. The patent claims show that the auxiliary agent does not contain other binders besides aluminum phosphate and does not contain other bindersAn organic oxide. In addition, the preparation method and performance of the beta zeolite-containing adjuvant are not given in the examples of the patent.

Chinese patent CN 1043450a proposes a method for modifying a beta molecular sieve, which comprises roasting a Na beta molecular sieve, removing part of framework aluminum with acid, performing potassium exchange to make the potassium content of the zeolite 0.5-2.5 wt%, drying, roasting, soaking in a near-neutral phosphate buffer solution containing potassium hydrogen phosphate-potassium dihydrogen phosphate, hypophosphorous acid-potassium hypophosphite, and phosphorous acid-potassium phosphite at room temperature for 4-10 hours, washing or not to wash as appropriate to make the phosphorus content on the zeolite 0.01-0.5 wt%, drying, and roasting; the beta molecular sieve modified by the method is suitable for serving as a hydrocarbon processing catalyst related to hydroisomerization reaction.

Chinese patent CN 1179994A proposes a modification method of a beta molecular sieve, which uses ammonium ions to exchange Na on zeolite for Na beta molecular sieve₂The O content is less than 0.1 weight percent; then, treating the ammonium exchanged beta molecular sieve with acid to remove part of framework aluminum, so that the silicon-aluminum ratio of the beta molecular sieve is more than 50; mixing the dealuminized beta molecular sieve with phosphoric acid or phosphate uniformly, and drying to obtain zeolite P₂O₅In an amount of 2-5% by weight; finally, the mixture is hydrothermally roasted for 0.5 to 4 hours at the temperature of 450-650 ℃ in the steam atmosphere. The beta molecular sieve modified by the method can obtain higher olefin yield, especially isoolefin yield and lower coke yield when being used for cracking reaction of hydrocarbons.

Chinese patent CN1205249A discloses a method for modifying beta zeolite, which comprises the steps of mixing the synthesized beta zeolite raw powder with Al₂O₃Source, P₂O₅Source, SiO₂Source, H₂O₂And water in a mixture according to zeolite beta Al₂O₃:P₂O₅:SiO₂:H₂O₂:H₂Mixing O1 (0.001-0.02): (0.01-0.30): (0-0.05): (0-0.10): 1.0-3.0) uniformly, drying, heating to 400-650 deg.C, calcining for 1-5 hr, and exchanging with ammonium ion to Na₂O content of less than 0.1 wt.%, and the method canThe activity stability of beta zeolite is obviously improved, and the crystal retention degree of beta zeolite is also improved.

Chinese patent CN1616351 discloses a method for preparing phosphorus-containing beta zeolite, which comprises preparing a working solution from an aluminum source, an alkali source and a tetraethylammonium cation solution in water, mixing silica gel with a particle size of 20-300 meshes as a silicon source with the silica gel and the working solution to wet the surface of the silica gel particles with the working solution, and keeping the mixture at 80-140 ℃ for 20-80 hours to obtain a crystal seed gel; adding aluminum phosphate 5-30 wt% of the seed crystal gel material into the prepared seed crystal gel, uniformly mixing, crystallizing at 140-170 deg.C for 50-100 hr, separating out solid product, washing to Na₂The content of O is less than 0.1 weight percent, and the product is obtained after drying. The method can prepare beta zeolite with the phosphorus content of up to 5 weight percent, and has higher catalytic selectivity when being used in alkylation reaction.

Chinese patent CN1872685A discloses a modified beta molecular sieve, which is characterized in that the anhydrous chemical expression of the beta molecular sieve is (0-0.3) Na in terms of the mass of an oxide₂O·(0.5-10)Al₂O₃·(1.3-10)P₂O₅·(0.7-15)M_xO_y·(70-97)SiO₂Wherein M is selected from one of Fe, Co, Ni, Cu, Mn, Zn and Sn. The zeolite can be used as an active component of a catalyst or an auxiliary agent in catalytic cracking.

Chinese patent CN101434401A discloses a phosphorus-containing beta molecular sieve, which is characterized in that the phosphorus content of the beta molecular sieve is P₂O₅The weight loss is 0.01-10 wt%, and a weight loss peak appears at 220 +/-25 ℃ in a thermogravimetric characterization map. The molecular sieve is obtained by roasting a beta molecular sieve in an air atmosphere to remove an organic template agent, and then treating with a phosphorus compound aqueous solution at the temperature of 100-250 ℃.

Chinese patent CN101450318A discloses a method for modifying a beta molecular sieve, which is characterized in that a sodium type beta molecular sieve is prepared according to the following steps of preparing the molecular sieve from ammonium salt and H₂Exchanging the mixture of (0.1-1) and (5-10) at room temperature to 100 deg.C for 0.3-1 hr, filtering, and adding solution containing phosphorus compound and metal compound to the molecular sieveAnd (3) carrying out impregnation modification, wherein the pH value of the impregnation liquid is adjusted to 6-8, and then drying and roasting.

Chinese patents CN102971065A and CN105312081A disclose a method for NO_xReduced novel metal-containing zeolite beta. The preparation process does not need an organic Structure Directing Agent (SDA). The metal may include Fe or Cu in an amount of 1 to 10 wt%. Also disclosed is a method for selective catalytic reduction of nitrogen oxides in exhaust gas using the disclosed zeolite.

Chinese patent CN103447068A discloses a catalytic cracking catalyst promoter containing beta zeolite and application thereof, relating to a beta zeolite catalyst promoter which is suitable for catalytic cracking reaction and can increase liquid yield, reduce coke and increase propylene yield. The catalyst auxiliary agent is prepared by modifying, demoulding and aging kaolin microsphere in-situ crystallized beta zeolite and is applied to catalytic cracking reaction. Compared with the beta zeolite catalyst promoter prepared by a binder method, the in-situ crystallization beta zeolite promoter has stronger capacities of increasing the yield of propylene, resisting coking and increasing liquid yield by replacing 2-50 wt% of a base catalyst with the in-situ crystallization microspheric beta zeolite catalyst promoter.

Chinese patent CN103771437A discloses a modified beta molecular sieve containing phosphorus, which is characterized in that P is used as a P-containing compound₂O₅The content of phosphorus is 3-10 wt%, and the molecular sieve is prepared by²⁷In the Al MAS NMR, the ratio of the area of the resonance signal peak at a chemical shift of 40. + -.3 ppm to the area of the resonance signal peak at a chemical shift of 54 ppm. + -.3 ppm is 1 or more. The molecular sieve has the advantages that the coordination of phosphorus and framework aluminum is sufficient, the framework aluminum is sufficiently protected, and the molecular sieve has excellent hydrothermal stability and better product selectivity.

Chinese patent CN103785455A discloses a cracking assistant for increasing the concentration of catalytically cracked low-carbon olefins, which comprises 10-75 wt% of phosphorus and transition metal modified beta molecular sieve, 0-60 wt% of clay, 15-60 wt% of inorganic oxide binder, 0.5-15 wt% of VIII family metal additive and 2-25 wt% of phosphorus additive; the transition metal is selected from one or more of Fe, Co, Ni, Cu, Mn, Zn, Sn and Bi; the beta molecular sieve containing phosphorus and transition metal is P₂O₅The phosphorus content is 1-10 wt%(ii) 0.5 to 10% by weight of metal, calculated as metal oxide, of the molecular sieve²⁷In the Al MAS NMR, the ratio of the area of the resonance signal peak with a chemical shift of 40. + -.3 ppm to the area of the resonance signal peak with a chemical shift of 54. + -.3 ppm is more than 1, and the percentage of the sum of the areas of the resonance signal peaks with a chemical shift of 0. + -.3 ppm and a chemical shift of-12. + -.3 ppm in the total peak area is less than 10%. The cracking catalyst composition is applied to the catalytic cracking of petroleum hydrocarbon, can increase the yield of catalytic cracking liquefied gas, improve the concentration of low-carbon olefin in the liquefied gas, particularly the concentration of isobutene, and simultaneously improve the ratio of ethylene to dry gas and the octane number of gasoline.

Chinese patent CN103785456A discloses a cracking assistant for increasing the concentration of low-carbon olefin, which contains a modified beta molecular sieve, a phosphorus-aluminum inorganic binder containing first clay, other inorganic binders and a VIII-group metal additive, and optionally contains second clay; the phosphorus-aluminum inorganic binder containing the first clay comprises an aluminum component, a phosphorus component and the first clay; the phosphorus and transition metal modified beta molecular sieve is P₂O₅The phosphorus content is 1-10 wt%, the metal content is 0.5-10 wt%, calculated by metal oxide, the molecular sieve is prepared by²⁷In the Al MAS NMR, the ratio of the area of a resonance signal peak having a chemical shift of 40. + -.3 ppm to the area of a resonance signal peak having a chemical shift of 54. + -.3 ppm is 1 or more, and the percentage of the total area of the areas of resonance signal peaks having a chemical shift of 0. + -.3 ppm and a chemical shift of-12. + -.3 ppm is 10% or less. The cracking catalyst composition is applied to the catalytic cracking of petroleum hydrocarbon, can increase the yield of catalytic cracking liquefied gas, improve the concentration of low-carbon olefin in the liquefied gas, especially the concentration of isobutene, simultaneously improve the ratio of ethylene to dry gas, improve the octane number of gasoline, and does not influence the heavy oil conversion capability of a main catalyst when being mixed with an auxiliary agent in a large proportion.

Chinese patent CN103785457A discloses a cracking assistant for increasing the concentration of low-carbon olefin, which comprises 10-75 wt% of beta molecular sieve containing phosphorus and transition metal, 0-60 wt% of clay, and 15-60 wt% of inorganic oxide binder, wherein P is used as P in the beta molecular sieve containing phosphorus and transition metal₂O₅The phosphorus content is 1-10 wt% calculated as metal oxideThe metal content is 0.5-10 wt%; of said phosphorus and transition metal containing beta molecular sieves²⁷In the Al MAS NMR, the ratio of the area of the resonance signal peak with a chemical shift of 40. + -.3 ppm to the area of the resonance signal peak with a chemical shift of 54. + -.3 ppm is more than 1, and the percentage of the sum of the areas of the resonance signal peaks with a chemical shift of 0. + -.3 ppm and a chemical shift of-12. + -.3 ppm in the total peak area is less than 10%. The assistant is applied to catalytic cracking, and can improve the concentration of ethylene in catalytic cracking dry gas and the concentration of propylene and isobutene in liquefied gas.

Chinese patent CN103785458A discloses a cracking assistant for increasing the concentration of low-carbon olefin, which contains a phosphorus-aluminum inorganic binder containing phosphorus and transition metal and containing first clay, other inorganic binders and second clay; wherein the first clay-containing phosphorus-aluminum inorganic binder comprises Al₂O₃15 to 40 wt.% of an aluminum component in terms of P₂O₅45-80 wt% of a phosphorus component and 1-40 wt% of a first clay on a dry basis, wherein the P/Al weight ratio is 1-6; the beta molecular sieve containing phosphorus and transition metal is P₂O₅The content of phosphorus is 1-10 wt%, the content of metal is 0.5-10 wt%, and the molecular sieve is prepared from phosphorus, metal oxide and inorganic salt²⁷In the Al MAS NMR, the ratio of the area of the resonance signal peak with a chemical shift of 40. + -.3 ppm to the area of the resonance signal peak with a chemical shift of 54. + -.3 ppm is more than 1, and the percentage of the sum of the areas of the resonance signal peaks with a chemical shift of 0. + -.3 ppm and a chemical shift of-12. + -.3 ppm in the total peak area is less than 10%. The auxiliary agent is applied to catalytic cracking, and can improve the ethylene concentration in catalytic cracking dry gas and the propylene and isobutene concentrations in liquefied gas.

Chinese patent CN103787357A discloses a modified beta molecular sieve, P₂O₅The phosphorus content is 1-10 wt.%, the metal content is 0.5-10 wt.% in terms of metal oxide, characterized in that the molecular sieve has²⁷In the Al MAS NMR, the ratio of the area of a resonance signal peak having a chemical shift of 40. + -.3 ppm to the area of a resonance signal peak having a chemical shift of 54. + -.3 ppm is 1 or more, and the percentage of the total area of the areas of resonance signal peaks having a chemical shift of 0. + -.3 ppm and a chemical shift of-12. + -.3 ppm is 10% or less. The molecular sieve deviceHas excellent hydrothermal stability and has better product selectivity when being used as an active component of a catalyst or an auxiliary agent in a catalytic cracking or catalytic cracking process.

Chinese patent CN103787358A discloses a beta molecular sieve containing phosphorus and metal, which is characterized in that P is used as the beta molecular sieve₂O₅The phosphorus content is 1-10 wt%, the metal content is 0.5-10 wt%, calculated by metal oxide, the molecular sieve is prepared by²⁷In the Al MAS NMR, the ratio of the area of the resonance signal peak at a chemical shift of 40. + -.3 ppm to the area of the resonance signal peak at a chemical shift of 54 ppm. + -.3 ppm is 1 or more.

Chinese patent CN103787359A discloses a phosphorus-containing silicon-rich beta molecular sieve, which is characterized in that P is used as a P-containing silicon-rich beta molecular sieve₂O₅The phosphorus content is 1-10 wt%, and the molecular sieve has²⁷In the Al MAS NMR, the ratio of the area of the resonance signal peak with a chemical shift of 40. + -.3 ppm to the area of the resonance signal peak with a chemical shift of 54. + -.3 ppm is 1 or more, and the percentage of the total peak area occupied by the sum of the areas of the resonance signal peaks with a chemical shift of 0. + -.3 ppm and a chemical shift of-12 ppm. + -.3 ppm is 10% or less. The patent also provides a preparation method of the phosphorus-containing silicon-rich beta molecular sieve, which is characterized in that the beta molecular sieve raw powder is subjected to temperature programming roasting to remove a template agent, then aluminum is extracted, and then phosphorus modification is carried out.

Due to the unique pore channel 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. However, due to the shape-selective action of the molecular sieve, when the kinetic size of reactant molecules exceeds the pore diameter of the microporous molecular sieve, the reactant molecules cannot diffuse into the molecular sieve; due to the existence of the acidity of the outer surface, the reaction product generates nonselective reaction on the surface of the molecular sieve, and the distribution of the product is influenced. In order to overcome the defects that the pore diameter of the microporous material is small and the surface of the microporous material has more acidity, catalytic materials with silicon-rich surfaces and rich mesopores are increasingly paid attention by people.

Chinese patent CN1769169A discloses a method for preparing a beta molecular sieve with a hierarchical pore structure, which mainly comprises the following steps: the method comprises the steps of directly treating the molecular sieve with crystal form ammonium salt through low-temperature nucleation and high-temperature crystallization, filtering and drying the crystal form, performing three-section temperature-controlled roasting and demolding, performing acid treatment under a mild condition, and performing pressurized hydrothermal treatment, wherein the obtained beta molecular sieve has the silicon-aluminum ratio of 80-120 and has the distribution of three pore diameters of 0.1-1.7 nm, 1.7-6.0 nm and 10-90.0 nm, so that the surface utilization rate of the beta molecular sieve is improved.

Chinese patent CN101003378 discloses a preparation method of beta zeolite with multilevel pore channels, which comprises the steps of dipping a silica gel monolithic column with a sucrose solution, drying, polymerizing, carbonizing to obtain a carbon-silicon compound, wetting the carbon-silicon compound with a mixed solution composed of an aluminum source, an inorganic base, organic amine and water, crystallizing and recovering a product. The carbon material effectively protects the pore structure of the silica gel monolithic column during crystallization, and the carbon material is not damaged during crystallization. The beta zeolite material prepared by the method has micron-sized macropores, mesopores, micropores and other multi-level pore channels, and overcomes the limitation of zeolite molecular sieve micropores on the catalytic performance of the beta zeolite material, wherein the existence of the permeable macropores can shorten the diffusion distance of reaction molecules, reduce the pressure drop of the device and further improve the unit processing capacity of the device, ensure that the selectivity of the product is easy to adjust and control, and the mesopores can provide rich internal specific surface area, thereby having very important significance for the catalytic reaction of macromolecules.

Chinese patent CN101538049 discloses a preparation method of beta zeolite with multilevel pore channels, belonging to the technical field of preparation and application of zeolite. The method is characterized in that carbon particles generated under the constraint of ordered mesoporous channels are used as a hard template, a small molecular organic ammonium soft template is added to convert mesoporous silicon-aluminum wrapped with the carbon particles into microporous beta zeolite in situ, and the beta zeolite containing the hierarchical channels can be obtained after the soft and hard templates are removed by roasting. Compared with the method of directly using mesoporous carbon as a template, the method for preparing the beta zeolite with the multilevel pore channels, which is synthesized by the method provided by the patent, does not need to remove mesoporous silicon-aluminum firstly and then introduce silicon-aluminum species for synthesizing the zeolite again, thereby reducing complex working procedures and saving raw materials. Can greatly reduce diffusion resistance and secondary reaction, has better catalytic performance, and has great potential application value in the fields of petrochemical industry, fine chemical industry and the like.

Chinese patent CN102050463A discloses a mesoporous-containing beta molecular sieve and a silicification preparation method thereof, wherein the preparation method comprises: dealuminizing the roasted H beta molecular sieve in an acid solution; mixing the dealuminized sample with a template agent-silicon source solution, and crystallizing; filtering, drying and roasting to obtain the product.

Chinese patent CN102826564A discloses a method for preparing a beta molecular sieve with a hierarchical pore structure, which uses tetraethoxysilane as a silicon source, sodium metaaluminate as an aluminum source, and hexaammonium cationic quaternary ammonium salt surfactant as a template agent to prepare a hierarchical pore molecular sieve containing mesopores and beta micropores by a hydrothermal synthesis method under an alkaline condition.

Chinese patent CN102826565A discloses a preparation method of a hierarchical pore Beta molecular sieve, under the condition of no second template agent, a quasi-solid-phase aluminosilicate is used for synthesizing the hierarchical pore Beta molecular sieve in one step, the hierarchical pore Beta molecular sieve comprises a cellular structure or large particles with the particle size of 5-60 microns, the cellular structure or the large particles are polymerized by nano-scale molecular sieve small crystal grains, the size of the nano-scale molecular sieve small crystal grains is 10-100 nanometers, the mesoporous aperture polymerized by the nano-scale molecular sieve small crystal grains is 3-45 nanometers, and the micropore aperture is 0.6-0.8 nanometers.

Chinese patent CN103318911A discloses a preparation method of beta zeolite with multilevel pore channels: uniformly mixing a silicon source, a tetraethylammonium hydroxide solution, sodium hydroxide and a completely dissolved aluminum source, and stirring at a constant temperature until a dry gel is formed; carrying out first hydrothermal treatment on the obtained xerogel at 120-180 ℃, cooling and grinding the xerogel, and adding a proper amount of silane coupling agent; carrying out second hydrothermal treatment at 120-180 ℃, cooling, filtering and roasting to obtain beta zeolite with multilevel pore channels; the preparation method and the post-treatment method are simple, the yield is high, and the industrial scale-up production is easy to realize.

Chinese patent CN103964458A discloses a beta molecular sieve with high silica-alumina ratio and multilevel pore canals and a preparation method thereof. The pore channels of the molecular sieve are distributed with pore diameters below 2nm, 5-11 nm and above 50nm, wherein the volume of micropores is 0.19cm³More than one gram, and the total volume of the mesopores and the macropores is 0.35cm³More than g, the silicon-aluminum ratio is more than 90, and the specific surface area is 400m²More than g. The preparation method comprises the following steps: carrying out primary acid treatment on raw material beta zeolite; roasting the beta zeolite subjected to the first acid treatment for the first time; and carrying out second acid treatment on the beta zeolite subjected to the first roasting to obtain the beta zeolite with the high silica-alumina ratio and the hierarchical pore canal.

Chinese patent CN104261423A discloses a preparation method of a monocrystalline hierarchical pore beta molecular sieve. Firstly, adding an inorganic alkali source and an aluminum source into a water solution of a micropore template agent (TEA +), then adding a proper amount of N-methyl-2-pyrrolidone (NMP) and a silicon source, uniformly stirring, and synthesizing the single-crystal hierarchical pore Beta molecular sieve by a simple hydrothermal method.

Chinese patent CN104321280A discloses a beta-type zeolite and its manufacturing method. The method is characterized in that: (i) SiO 2₂/Al₂O₃A ratio of 8 to 30, and SiO₂The ratio of ZnO to ZnO is 8-1000; (ii) the surface area of the micropores was 300m²/g～800m²(ii)/g; (iii) micropore volume of 0.1cm³/g～0.3cm³(ii)/g; (iv) has a diameter of 2 to 6nm and a volume of 0.001cm in the state of being kept as it is after synthesis³/g～0.3cm³(ii) mesopores per g. The zeolite beta may suitably be produced by: the zinc silicate salt beta-type zeolite is added as a seed crystal to a reaction mixture containing a silica source, an alumina source, an alkali source and water, and a reaction is carried out.

Chinese patent CN104353484A discloses a preparation method of cheap strong-acid hierarchical pore Beta zeolite. The method comprises the following steps: firstly, calcining Beta zeolite to obtain microporous hydrogen type Beta zeolite; adding the microporous hydrogen type Beta zeolite into an alkaline solution, stirring, washing and drying to obtain sodium type desiliconized hierarchical porous Beta zeolite; adding the sodium desiliconized hierarchical pore Beta zeolite into an ammonium nitrate aqueous solution for exchange, and calcining to obtain hydrogen desiliconized hierarchical pore Beta zeolite; fourthly, adding the hydrogen-type desiliconized hierarchical pore Beta zeolite into an acid solution, stirring, washing, drying, and then repeating the third step to obtain the strong acid hierarchical pore Beta zeolite.

Chinese patent CN104402020A discloses a medium-micro double-hole beta molecular sieve and a preparation method and application thereof. The method takes sodium metaaluminate as an optimal aluminum source, tetraethoxysilane as an optimal silicon source, eight-head Bola type quaternary ammonium salt surfactants with different carbon chain lengths as template agents, and prepares the beta multi-stage pore zeolite molecular sieve with mesoporous and microporous structures by a hydrothermal method under an alkaline condition.

Chinese patents CN104418345A, CN104418346A, CN104418347A, CN104418348A, CN104418349A, CN104418350A, CN104418351A, CN104418352A and CN104418353A disclose a group of beta molecular sieves with a multi-stage pore channel structure and a preparation method thereof, wherein high molecular polymers such as polyquaternium-6, polyquaternium-7, polyquaternium-10, polyquaternium-11, polyquaternium-22, polyquaternium-32, polyquaternium-37, polyquaternium-39, polyquaternium-44 and the like are adopted as guiding agents of micropores and mesopores in the synthesis process, and the synthesized beta molecular sieves have mesopores of 8-20 nm and macropores of 50-200 nm at the same time.

Chinese patent CN105692644A discloses a method for preparing hierarchical pore zeolite, which is to use various alkali vapors as zeolitization mineralizers and amorphous mesoporous/macroporous materials as precursors, and prepare hierarchical pore zeolite materials by alkali vapor heat treatment. The amorphous mesoporous/macroporous material suitable for the patent is an amorphous porous inorganic precursor of various mesoporous or macroporous molecular sieves, and the suitable multi-stage pore zeolite relates to MFI zeolite, beta zeolite, Y zeolite and silicalite-1 zeolite. This is the first example of an alkali metal steam thermal process for preparing a multigrade pore zeolite, with comparable or higher HF and broader zeolite preparation applicability than the prior art.

The methods for preparing the hierarchical pore beta all have the problems that organic ammonium salt sewage is not easy to treat, the preparation process is long, the molecular sieve pore structure is damaged, the surface aluminum distribution is not modulated, and the like.

Disclosure of Invention

The invention aims to provide a catalytic cracking auxiliary agent containing a phosphorus-containing Beta molecular sieve and a preparation method thereof.

In order to achieve the above object, the present inventionThe catalytic cracking assistant contains phosphorus Beta molecular sieve in 10-75 wt% dry basis, clay in 0-60 wt% dry basis, inorganic oxide as binder in 15-60 wt% dry basis, and P₂O₅0-25 wt.% of a phosphorus additive and 0-15 wt.% of a group VIII metal additive, calculated as oxides, wherein the molecular sieve has an Al distribution parameter D satisfying: d is more than or equal to 0.4 and less than or equal to 0.8, wherein D is Al (S)/Al (C), Al (S) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the inward H distance of the crystal face edge of the molecular sieve crystal grain measured by a TEM-EDS method, Al (C) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the outward H distance of the geometric center of the crystal face of the molecular sieve crystal grain measured by the TEM-EDS method, wherein H is 10 percent of the distance from a certain point of the crystal face edge to the geometric center of the crystal face; the specific surface area of the micropores of the molecular sieve is 420-520 m²The proportion of the mesoporous volume of the molecular sieve in the total pore volume is 30-70% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 20-60%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100; with P₂O₅The molecular sieve has a phosphorus content of 0.3 to 10 wt.% based on the dry weight of the molecular sieve.

Preferably, the molecular sieve has an Al distribution parameter D that satisfies: d is more than or equal to 0.55 and less than or equal to 0.75; the specific surface area of the micropores of the molecular sieve is 450-500 m²Per gram, the proportion of the mesoporous volume of the molecular sieve in the total pore volume is 35-60 percent by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 25-55%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 35-75; with P₂O₅The molecular sieve has a phosphorus content of 1-8 wt.% based on the dry weight of the molecular sieve.

Preferably, the adjuvant comprises 20-60 wt% phosphorus-containing Beta molecular sieve, 10-45 wt% clay, 25-50 wt% inorganic oxide binder, P₂O₅5-15% by weight of a phosphorus additive and oxygen1-10 wt.% of a group VIII metal additive, calculated as compound.

Preferably, the clay includes at least one selected from the group consisting of kaolin, metakaolin, sepiolite, attapulgite, montmorillonite, rectorite, diatomaceous earth, halloysite, saponite, bentonite and hydrotalcite, and the inorganic oxide binder includes at least one selected from the group consisting of pseudo-boehmite, alumina sol, silica alumina sol and water glass.

Preferably, the phosphorus additive is introduced to the adjuvant in the form of a phosphorus-containing compound comprising at least one selected from the group consisting of oxides, phosphates, phosphites, basic phosphates and acid phosphates of phosphorus; the group VIII metal comprises at least one selected from Fe, Co and Ni, and the group VIII metal additive is introduced to the promoter in the form of a metal-containing compound comprising at least one selected from the group consisting of oxides, hydroxides, chlorides, nitrates, sulfates, phosphates and organic compounds.

The invention also provides a preparation method of the catalytic cracking assistant, which comprises the following steps: mixing a phosphorus-containing Beta molecular sieve, an inorganic oxide binder and water, adding or not adding clay, pulping, and spray-drying; wherein, a phosphorus additive is introduced or not introduced, and a group VIII metal additive is introduced or not introduced; the preparation raw materials of the auxiliary agent comprise 10-75 wt% of phosphorus-containing Beta molecular sieve, 0-60 wt% of clay, 15-60 wt% of inorganic oxide binder and P₂O₅0-25% by weight of a phosphorus additive and 0-15% by weight of a group VIII metal additive calculated as the oxide; the Al distribution parameter D of the molecular sieve meets the following requirements: d is more than or equal to 0.4 and less than or equal to 0.8, wherein D is Al (S)/Al (C), Al (S) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance H from the edge of the crystal face of the molecular sieve crystal grain to the inside measured by a TEM-EDS method, Al (C) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance H from the geometric center of the crystal face of the molecular sieve crystal grain to the outside measured by the TEM-EDS method, wherein H is the aluminum content from a certain point of the edge of the crystal face to the geometric center of the crystal face10% of the center distance; the specific surface area of the micropores of the molecular sieve is 420-520 m²The proportion of the mesoporous volume of the molecular sieve in the total pore volume is 30-70% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 20-60%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100; with P₂O₅The molecular sieve has a phosphorus content of 0.3 to 10 wt.% based on the dry weight of the molecular sieve.

Preferably, the preparation step of the phosphorus-containing Beta molecular sieve comprises the following steps: a. carrying out alkali treatment on the sodium type Beta molecular sieve in an alkaline solution, and filtering and washing to obtain an alkali-treated molecular sieve; b. b, dealuminizing the alkali-treated molecular sieve obtained in the step a in a composite acid dealuminizing agent solution consisting of fluosilicic acid, organic acid and inorganic acid, and filtering and washing to obtain a dealuminized molecular sieve; c. and c, carrying out phosphorus modification treatment and roasting treatment on the dealuminized molecular sieve obtained in the step b to obtain the phosphorus-containing Beta molecular sieve.

Preferably, 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, ammonia water and an overbased sodium metaaluminate solution; the sodium content of the high-alkali sodium metaaluminate solution is 270-310 g/L, the aluminum content is 30-50 g/L and the density of the high-alkali sodium metaaluminate solution is 1.25-1.45 g/mL.

Preferably, the conditions of the alkali treatment in step a include: the weight ratio of the molecular sieve to the alkali in the alkaline solution on a dry basis is 1: (0.02-0.3); wherein the weight of the alkali in the sodium hydroxide solution is based on the weight of sodium hydroxide, the weight of the alkali in the potassium hydroxide solution is based on the weight of potassium hydroxide, the weight of the alkali in the lithium hydroxide solution is based on the weight of lithium hydroxide, the weight of the alkali in the ammonia water is based on the weight of ammonia monohydrate, and the weight of the alkali in the high-alkali sodium metaaluminate solution is based on the weight of sodium oxide.

Preferably, the conditions of the alkali treatment in step a include: the temperature of alkali treatment is 25-100 ℃, and the time of alkali treatment is 0.5-6 hours.

Preferably, the organic acid in step b is at least one selected from the group consisting of ethylenediaminetetraacetic acid, oxalic acid, citric acid and sulfosalicylic acid, and the inorganic acid is at least one selected from the group consisting of hydrochloric acid, sulfuric acid and nitric acid.

Preferably, the dealumination treatment conditions in step b include: the weight ratio of the molecular sieve, the fluosilicic acid, the organic acid and the inorganic acid is 1: (0.03-0.5): (0.05-0.4): 0.05-0.5); the treatment temperature is 25-100 ℃, and the treatment time is 0.5-6 hours.

Preferably, the dealumination treatment conditions in step b include: the weight ratio of the molecular sieve, the fluosilicic acid, the organic acid and the inorganic acid is 1: (0.05-0.3):(0.1-0.3):(0.1-0.3).

Preferably, the phosphorus modification treatment comprises: at least one phosphorus-containing compound selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate is used to impregnate and/or ion-exchange the molecular sieve.

Preferably, the conditions of the calcination treatment include: the atmosphere of the roasting treatment is air atmosphere or water vapor atmosphere; the roasting temperature is 400-800 ℃, and the roasting time is 0.5-8 hours.

The cracking assistant provided by the invention adopts the phosphorus-containing Beta molecular sieve as an active component, and can also introduce a proper amount of phosphorus additive and VIII metal additive, thereby improving the yield and selectivity of isobutene, propylene and ethylene, improving the octane number of catalytic cracking gasoline, and increasing the liquid yield of catalytic cracking reaction.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Detailed Description

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 invention provides a catalytic cracking auxiliary agent containing a phosphorus-containing Beta molecular sieve, which comprises 10-75 wt% of the phosphorus-containing Beta molecular sieve, 0-60 wt% of clay, 15-60 wt% of inorganic oxide binder and P, wherein the weight of the phosphorus-containing Beta molecular sieve is calculated on a dry basis, and the weight of the auxiliary agent is calculated on a dry basis₂O₅0-25 wt.% of a phosphorus additive and 0-15 wt.% of a group VIII metal additive, calculated as oxides, wherein the molecular sieve has an Al distribution parameter D satisfying: d is more than or equal to 0.4 and less than or equal to 0.8, wherein D is Al (S)/Al (C), Al (S) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the inward H distance of the crystal face edge of the molecular sieve crystal grain measured by a TEM-EDS method, Al (C) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the outward H distance of the geometric center of the crystal face of the molecular sieve crystal grain measured by the TEM-EDS method, wherein H is 10 percent of the distance from a certain point of the crystal face edge to the geometric center of the crystal face; the specific surface area of the micropores of the molecular sieve is 420-520 m²The proportion of the mesoporous volume of the molecular sieve in the total pore volume is 30-70% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 20-60%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100; with P₂O₅The molecular sieve has a phosphorus content of 0.3 to 10 wt.% based on the dry weight of the molecular sieve. Preferably, the molecular sieve has an Al distribution parameter D that satisfies: d is more than or equal to 0.55 and less than or equal to 0.75; the specific surface area of the micropores of the molecular sieve is 450-500 m²Per gram, the mesopore volume of the molecular sieve accounts for the total poresThe volume proportion is 35-60% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 25-55%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 35-75; with P₂O₅The molecular sieve has a phosphorus content of 1-8 wt.% based on the dry weight of the molecular sieve.

According to the present invention, it is well known to those skilled in the art to determine the aluminum content of the molecular sieve by using the TEM-EDS method, wherein the geometric center is also well known to those skilled in the art, and can be calculated according to a formula, which is not repeated in the present invention, and the geometric center of the general symmetric figure is the intersection point of the connection lines of the relative vertexes, for example, the geometric center of the square crystal face of the conventional cubic Beta molecular sieve is at the intersection point of the connection lines of the relative vertexes. The crystal plane is a plane of regular crystal grains, and the inward and outward directions are both inward and outward directions on the crystal plane.

According to the invention, the proportion of the micropore specific surface area and the mesopore volume of the molecular sieve in the total pore volume is measured by a nitrogen adsorption BET specific surface area method, wherein the mesopore volume refers to the pore volume with the pore diameter of more than 2 nanometers and less than 100 nanometers; the strong acid amount of the molecular sieve is NH in proportion to the total acid amount₃The TPD method, the acid centre of which is NH₃Desorbing the corresponding acid center at the temperature of more than 300 ℃; and the ratio of the acid amount of the B acid to the acid amount of the L acid is measured by adopting a pyridine adsorption infrared acidity method.

According to the present invention, the clay and the inorganic oxide binder are well known to those skilled in the art, for example, the clay may include at least one selected from the group consisting of kaolin, metakaolin, sepiolite, attapulgite, montmorillonite, rectorite, diatomaceous earth, halloysite, saponite, bentonite and hydrotalcite, and preferably include at least one selected from the group consisting of kaolin, metakaolin, diatomaceous earth, sepiolite, attapulgite, montmorillonite and rectorite; the inorganic oxide binder may include at least one selected from the group consisting of pseudoboehmite, alumina sol, silica alumina sol, and water glass, and preferably includes pseudoboehmite and/or alumina sol.

According to the invention, the phosphorus additive can be introduced into the auxiliary agent in the form of a phosphorus-containing compound, wherein the phosphorus-containing compound comprises one or more of inorganic compounds and organic compounds of phosphorus, can be easily soluble in water, and can also be difficultly soluble in water or insoluble in water, and for example, at least one of phosphorus oxide, phosphate, phosphite, basic phosphate and acid phosphate is selected; the preferable phosphorus compound is one or more of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, aluminum phosphate and phosphorus alumina sol. The phosphorus additive may be present in any location where an adjunct may be present, such as may be present inside the pores of the zeolite, on the surface of the zeolite, in the matrix material, or both. The phosphorus additive is present in the form of a phosphorus compound (e.g., an oxide, phosphate, phosphite, basic phosphate, acid phosphate of phosphorus).

According to the invention, the group VIII metal may comprise at least one selected from the group consisting of Fe, Co and Ni, more preferably Fe, and the group VIII metal additive may be introduced to the promoter in the form of a metal-containing compound which may comprise at least one selected from the group consisting of an oxide, a phosphate, a phosphite, a basic phosphate and an acid phosphate. The metal additive may be present in any location where an adjuvant may be present, such as inside the pores of the zeolite, on the surface of the zeolite, in the matrix material, or both, preferably in the matrix material. The group VIII metal additive may be present in any possible form in the adjuvant, for example it may be one or more of an oxide, phosphate, phosphite, basic phosphate or acid phosphate of the metal.

The invention also provides a preparation method of the catalytic cracking assistant, which comprises the following steps: mixing a phosphorus-containing Beta molecular sieve, an inorganic oxide binder and water, adding or not adding clay, pulping, and spray-drying; wherein, a phosphorus additive is introduced or not introduced, and a group VIII metal additive is introduced or not introduced; dry raw material by weight and prepared by the aid of the auxiliary agentBased on the weight of the base, the preparation raw materials of the auxiliary agent comprise 10-75 wt% of phosphorus-containing Beta molecular sieve based on dry base, 0-60 wt% of clay based on dry base, 15-60 wt% of inorganic oxide binder based on dry base, and P₂O₅0-25% by weight of a phosphorus additive and 0-15% by weight of a group VIII metal additive calculated as the oxide; the Al distribution parameter D of the molecular sieve meets the following requirements: d is more than or equal to 0.4 and less than or equal to 0.8, wherein D is Al (S)/Al (C), Al (S) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the inward H distance of the crystal face edge of the molecular sieve crystal grain measured by a TEM-EDS method, Al (C) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the outward H distance of the geometric center of the crystal face of the molecular sieve crystal grain measured by the TEM-EDS method, wherein H is 10 percent of the distance from a certain point of the crystal face edge to the geometric center of the crystal face; the specific surface area of the micropores of the molecular sieve is 420-520 m²The proportion of the mesoporous volume of the molecular sieve in the total pore volume is 30-70% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 20-60%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100; with P₂O₅The molecular sieve has a phosphorus content of 0.3 to 10 wt.% based on the dry weight of the molecular sieve.

According to the present invention, the preparation step of the phosphorus-containing Beta molecular sieve may comprise: a. carrying out alkali treatment on the sodium type Beta molecular sieve in an alkaline solution, and filtering and washing to obtain an alkali-treated molecular sieve; b. b, dealuminizing the alkali-treated molecular sieve obtained in the step a in a composite acid dealuminizing agent solution consisting of fluosilicic acid, organic acid and inorganic acid, and filtering and washing to obtain a dealuminized molecular sieve; c. and c, carrying out phosphorus modification treatment and roasting treatment on the dealuminized molecular sieve obtained in the step b to obtain the phosphorus-containing Beta molecular sieve.

According to the present invention, the sodium type Beta molecular sieve is well known to those skilled in the art, and can be obtained by amine-free crystallization or calcination of a molecular sieve prepared by a template method, specifically, see U.S. Pat. No. 3,308,069 and chinese patent CN 00107486.5, and the sodium content in the sodium type Beta molecular sieve can be 4-6 wt% calculated as sodium oxide.

According to the invention, the alkali treatment is used for removing part of framework silicon atoms of the molecular sieve to generate more secondary pores, and the alkaline solution can be at least one selected from sodium hydroxide solution, potassium hydroxide solution, lithium hydroxide solution, ammonia water and high-alkali sodium metaaluminate solution, and is preferably high-alkali sodium metaaluminate solution; the sodium content of the high-alkali sodium metaaluminate solution can be 270-310 g/L, the aluminum content can be 30-50 g/L and the density of the high-alkali sodium metaaluminate solution can be 1.25-1.45 g/mL calculated by oxide; the conditions of the alkali treatment in step a may include: the weight ratio of the molecular sieve to the base in the alkaline solution on a dry weight basis may be 1: (0.02-0.3), preferably 1: (0.03-0.25); wherein the weight of the alkali in the sodium hydroxide solution is based on the weight of sodium hydroxide, the weight of the alkali in the potassium hydroxide solution is based on the weight of potassium hydroxide, the weight of the alkali in the lithium hydroxide solution is based on the weight of lithium hydroxide, the weight of the alkali in the ammonia water is based on the weight of ammonia monohydrate, and the weight of the alkali in the high-alkali sodium metaaluminate solution is based on the weight of sodium oxide; the temperature of the alkali treatment can be 25-100 ℃, and the time of the alkali treatment can be 0.5-6 hours.

The dealumination treatment according to the present invention is well known to those skilled in the art, but the use of an inorganic acid, an organic acid and a fluosilicic acid together for the dealumination treatment has not been reported. The dealumination treatment can be carried out once or for multiple times, organic acid can be firstly mixed with the alkali treatment molecular sieve, and then fluosilicic acid and inorganic acid are mixed with the alkali treatment molecular sieve, namely, the organic acid is firstly added into the alkali treatment molecular sieve, and then the fluosilicic acid and the inorganic acid are slowly and concurrently added, or the fluosilicic acid is firstly added and then the inorganic acid is added, preferably the fluosilicic acid and the inorganic acid are slowly and concurrently added. The organic acid in step b may be at least one selected from ethylenediaminetetraacetic acid, oxalic acid, citric acid and sulfosalicylic acid, preferably oxalic acid or citric acid, and more preferably oxalic acid; the inorganic acid is at least one selected from hydrochloric acid, sulfuric acid and nitric acid, preferably hydrochloric acid or sulfuric acid, and more preferably hydrochloric acid; the dealumination treatment conditions in step b may include: the weight ratio of the molecular sieve, the fluosilicic acid, the organic acid and the inorganic acid on a dry basis weight basis may be 1: (0.03-0.5): (0.05-0.4): 0.05-0.5), preferably 1: (0.05-0.3): (0.1-0.3): 0.1-0.3); the treatment temperature may be 25-100 deg.C and the treatment time may be 0.5-6 hr.

According to the present invention, phosphorus modification treatments are well known to those skilled in the art, and include, for example: at least one phosphorus-containing compound selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate is used to impregnate and/or ion-exchange the molecular sieve.

The calcination treatment according to the present invention is well known to those skilled in the art, and for example, the conditions of the calcination treatment may include: the atmosphere of the roasting treatment is air atmosphere or water vapor atmosphere, and the water vapor atmosphere is 1-100% of water vapor, preferably 100% of water vapor; the roasting temperature is 400-800 ℃, preferably 500-600 ℃, and the roasting time is at least 0.5 hour, preferably 0.5-8 hours.

The washing according to the invention is well known to the person skilled in the art and is generally referred to as water washing, for example, the molecular sieve may be rinsed with 5 to 10 times the weight of the molecular sieve.

When the catalytic cracking assistant provided by the invention contains a phosphorus additive, the phosphorus additive can be introduced by one of the following methods or a combination of several methods, but is not limited to the methods for introducing the phosphorus additive into the assistant:

1. adding a phosphorus compound to the slurry before the spray drying and forming of the auxiliary agent;

2. after the spray drying and forming of the auxiliary agent, the phosphorus compound is impregnated or chemically adsorbed, and the phosphorus compound is introduced through solid-liquid separation (if needed), drying and roasting processes, wherein the drying temperature can be between room temperature and 400 ℃, preferably 100-300 ℃, the roasting temperature can be between 400-700 ℃, preferably 450-650 ℃, and the roasting time can be between 0.5 and 100 hours, preferably between 0.5 and 10 hours. The phosphorus compound may be selected from one or more of various inorganic and organic compounds of phosphorus. The phosphorus compound may be either readily water-soluble or poorly water-soluble or water-insoluble. Examples of the phosphorus compound include oxides of phosphorus, phosphoric acid, orthophosphates, phosphites, hypophosphites, phosphorus-containing organic compounds, and the like. Preferred phosphorus compounds are selected from one or more of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, aluminum phosphate and the like.

Thus, the phosphorus additive may be present in any location where an adjunct may be present, such as may be present inside the pores of the zeolite, on the surface of the zeolite, in the matrix material, or both. The phosphorus additive is present in the form of a phosphorus compound (e.g., an oxide of phosphorus, an orthophosphate, a phosphite, a basic phosphate, an acid phosphate).

According to the present invention, the metal additive may be introduced in the form of a metal compound, and the metal additive may be introduced by adding the metal compound to the slurry at any step prior to spray-drying molding in the preparation process of the assistant; or can be introduced by impregnating or chemisorbing the metal compound and then calcining after the spray drying and forming of the auxiliary agent, which comprises the steps of impregnating or chemisorbing the auxiliary agent with the aqueous solution of the metal-containing compound, and then carrying out solid-liquid separation (if needed), drying and calcining, wherein the drying temperature is between room temperature and 400 ℃, preferably 100-300 ℃, the calcining temperature is 400-700 ℃, preferably 450-650 ℃, and the calcining time is 0.5-100 hours, preferably 0.5-10 hours. The metal compound is selected from one or more of inorganic compounds and organic compounds thereof, and can be easily soluble in water, or insoluble in water. Examples of the metal compound include oxides, hydroxides, chlorides, nitrates, sulfates, phosphates, organic compounds of metals, and the like of the metal compound. Preferred metal compounds are selected from one or more of their chlorides, nitrates, sulfates and phosphates.

The catalytic cracking assistant provided by the invention is suitable for catalytic cracking of various hydrocarbon oils. When the catalyst is used in the catalytic cracking process, the catalyst can be added into a catalytic cracking reactor independently or can be mixed with a catalytic cracking catalyst for use. In general, the promoter provided by the present invention is not more than 30 wt%, preferably 1 to 25 wt%, and more preferably 3 to 15 wt% of the total amount of the FCC catalyst and the promoter mixture provided by the present invention, and the hydrocarbon oil is selected from one or more of various petroleum fractions, such as crude oil, atmospheric residue, vacuum residue, atmospheric wax oil, vacuum wax oil, straight-run wax oil, propane light/heavy deoiling, coker wax oil, and coal liquefaction product. The hydrocarbon oil may contain heavy metal impurities such as nickel and vanadium, and sulfur and nitrogen impurities, for example, the content of sulfur may be as high as 3.0 wt%, the content of nitrogen may be as high as 2.0 wt%, and the content of metal impurities such as vanadium and nickel may be as high as 3000 ppm.

The catalytic cracking assistant provided by the invention is used in the catalytic cracking process, and the catalytic cracking condition of the hydrocarbon oil can be conventional catalytic cracking condition. Generally, the hydrocarbon oil catalytic cracking conditions include a reaction temperature of 400-600 ℃, preferably 450-550 ℃, and a weight hourly space velocity of 8-120 hours^-1Preferably 8 to 80 hours^-1The ratio of the solvent to the oil (weight ratio) is 1-20, preferably 3-15. The catalytic cracking auxiliary agent provided by the invention can be used for various existing catalytic cracking reactors, such as a fixed bed reactor, a fluidized bed reactor, a riser reactor, a multi-reaction-zone reactor and the like.

The present invention will be further illustrated by the following examples, but the present invention is not limited thereto, and 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 properties of some of the raw materials used in the examples and comparative examples of the present invention are as follows: the pseudoboehmite is an industrial product produced by Shandong aluminum industry company, and has the solid content of 61 percent by weight; the aluminum sol is an industrial product, Al, produced by the Qilu division of the medium petrochemical catalyst₂O₃The content was 21.5 wt%; the water glass is an industrial product, SiO, produced by the middle petrochemical catalyst Qilu division₂Content 28.9 wt.%, Na₂The O content was 8.9% by weight; the kaolin is kaolin specially used for a cracking catalyst produced by Suzhou kaolin company, and has the solid content of 78 weight percent.

SiO in the invention₂、Al₂O₃、Na₂O、P₂O₅The content of the active component is carried out by adopting a GB/T30905-2014 standard methodAnd (4) measuring.

The TEM-EDS determination method of the invention is described in the research methods of solid catalysts, petrochemical industry, 29(3), 2000: 227.

the determination method of the specific surface area, the pore volume and the total pore volume of the micropores of the invention is as follows:

the measurement was carried out by using AS-3, AS-6 static nitrogen adsorption apparatus manufactured by Quantachrome instruments.

The instrument parameters are as follows: the sample was placed in a sample handling system and evacuated to 1.33X 10 at 300 deg.C^-2Pa, keeping the temperature and the pressure for 4h, and purifying the sample. Testing the purified samples at different specific pressures P/P at a liquid nitrogen temperature of-196 DEG C₀The adsorption quantity and the desorption quantity of the nitrogen under the condition are obtained to obtain N₂Adsorption-desorption isotherm curve. Then, the total specific surface area, the micropore specific surface area and the mesopore specific surface area are calculated by utilizing a two-parameter BET formula, and the specific pressure P/P is taken₀The adsorption capacity below 0.98 is the total pore volume of the sample, the pore size distribution of the mesoporous part is calculated by using BJH formula, and the mesoporous pore volume (2-100 nm) and the mesoporous pore volume of 2-20 nm are calculated by adopting an integration method.

The method for measuring the acid content of B acid and the acid content of L acid in the invention is as follows:

an FTS3000 Fourier Infrared spectrometer manufactured by BIO-RAD of America was used.

And (3) testing conditions are as follows: pressing the sample into tablet, sealing in an in-situ cell of an infrared spectrometer, and vacuumizing to 10 deg.C at 350 deg.C^-3Pa, keeping for 1h to enable gas molecules on the surface of the sample to be desorbed completely, and cooling to room temperature. Introducing pyridine vapor with pressure of 2.67Pa into the in-situ tank, balancing for 30min, heating to 200 deg.C, and vacuumizing to 10 deg.C^-3Pa, keeping for 30min, cooling to room temperature at 1400-1700cm^-1Scanning in wave number range, and recording infrared spectrogram of pyridine adsorption at 200 ℃. Then the sample in the infrared absorption cell is moved to a heat treatment area, the temperature is raised to 350 ℃, and the vacuum is pumped to 10 DEG^-3Pa, keeping for 30min, cooling to room temperature, and recording the infrared spectrogram of pyridine adsorption at 350 ℃. And automatically integrating by an instrument to obtain the acid content of the B acid and the acid content of the L acid.

The method for measuring the total acid amount and the strong acid amount is as follows:

an Autochem II 2920 programmed temperature desorption instrument of Michman, USA, is adopted.

And (3) testing conditions are as follows: weighing 0.2g of a sample to be detected, putting the sample into a sample tube, putting the sample tube into a thermal conductivity cell heating furnace, taking He gas as carrier gas (50mL/min), heating the sample tube to 600 ℃ at the speed of 20 ℃/min, and purging the sample tube for 60min to remove impurities adsorbed on the surface of the catalyst. Then cooling to 100 ℃, keeping the temperature for 30min, and switching to NH₃-He mixed gas (10.02% NH)₃+ 89.98% He) for 30min, and then continuing to purge with He gas for 90min until the baseline is stable, so as to desorb the physically adsorbed ammonia gas. And (4) heating to 600 ℃ at the heating rate of 10 ℃/min for desorption, keeping for 30min, and finishing desorption. Detecting gas component change by TCD detector, automatically integrating by instrument to obtain total acid amount and strong acid amount, wherein acid center of strong acid is NH₃The desorption temperature is higher than 300 ℃ of the corresponding acid center.

The D value is calculated as follows: selecting a crystal grain and a certain crystal face of the crystal grain in a transmission electron mirror to form a polygon, wherein the polygon has a geometric center, an edge and a 10% distance H (different edge points and different H values) from the geometric center to a certain point of the edge, any one of regions in the inward H distance of the edge of the crystal face which is larger than 100 square nanometers and any one of regions in the outward H distance of the geometric center of the crystal face which is larger than 100 square nanometers are respectively selected, measuring the aluminum content, namely Al (S1) and Al (C1), calculating D1 to Al (S1)/Al (C1), respectively selecting different crystal grains to measure for 5 times, and calculating the average value to be D.

Examples 1-6 molecular sieves provided by the present invention were prepared; comparative examples 1-9 comparative molecular sieves were prepared.

Example 1

100g of beta molecular sieve (SiO, produced by catalyst Qilu division)₂/Al₂O₃25, sodium oxide content 4.5 wt%, the same applies below; dry basis weight) was added with water and slurried to obtain a molecular sieve slurry having a solid content of 10% by weight, and 11.1g of a high-alkali sodium metaaluminate solution (Na) was added₂O is 290g/L, Al₂O₃40g/L, the solution density is 1.353g/mL), the temperature is increased to 50 ℃, the constant temperature is kept, the stirring is carried out for 0.5h, and the solution is filtered and washed to be neutral; adding water into the filter cake and pulping to obtain the molecular sieve with the solid content of 20 weight percentAdding 5.3g of oxalic acid into the slurry while stirring, slowly adding 51g of hydrochloric acid (10 mass percent) and 17g of fluosilicic acid (20 concentration) dropwise at the same time, heating to 50 ℃, stirring for 1h at constant temperature, filtering, washing and drying to obtain a filter cake; adding water into the filter cake and pulping to obtain molecular sieve slurry with the solid content of 40 weight percent, and adding 6.8gH₃PO₄(the concentration is 85%) is dissolved in 30g of water, and the solution is mixed with molecular sieve slurry, soaked and dried; and roasting the obtained sample at 550 ℃ for 2 hours to obtain the modified Beta molecular sieve A.

Elemental analytical chemical composition was 0.1Na₂O·3.0Al₂O₃·4.0P₂O₅·93.0SiO₂Other physicochemical properties are shown in Table 1.

Comparative example 1

Adding water into 100g of beta molecular sieve (dry mass basis) and pulping to obtain molecular sieve pulp with the solid content of 10 weight percent, and adding 22.4g of high-alkali sodium metaaluminate solution (Na)₂O is 290g/L, Al₂O₃40g/L, the solution density is 1.353g/mL), the temperature is increased to 50 ℃, the constant temperature is kept, the stirring is carried out for 0.5h, and the solution is filtered and washed to be neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with the solid content of 20 wt%, slowly dropwise adding 240g of fluosilicic acid (the concentration is 20%), heating to 50 ℃, stirring for 1h at constant temperature, filtering, washing and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 7.8g of H₃PO₄(the concentration is 85%) is dissolved in 30g of water, and the solution is mixed with molecular sieve slurry, soaked and dried; the obtained sample was calcined at 550 ℃ for 2 hours to obtain molecular sieve sample DB1, and the physicochemical properties of molecular sieve sample DB1 are shown in Table 2.

Comparative example 2

100g of beta molecular sieve (dry basis mass) was added with water to prepare a molecular sieve slurry having a solid content of 10% by weight, and 25g of a high-alkali sodium metaaluminate solution (Na) was added₂O is 280g/L, Al₂O₃40g/L, the solution density is 1.25g/mL), the temperature is raised to 50 ℃, the constant temperature is kept, the stirring is carried out for 0.5h, the filtration and the washing are carried out until the solution is neutral, and the filter cake is obtained after the drying; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 7.8g of H₃PO₄(the concentration is 85%) is dissolved in 30g of water, and the solution is mixed with molecular sieve slurry, soaked and dried; the obtained sample is roasted at 550 ℃ for 2 hours to obtain a molecular sieve sample DB2 which is divided intoThe physicochemical properties of the sub-sieve sample DB2 are listed in Table 2.

Comparative example 3

Adding water into 100g of beta molecular sieve (dry basis mass) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 5.3g of oxalic acid while stirring, slowly dropwise adding 51g of hydrochloric acid (mass fraction of 10%) and 17g of fluosilicic acid (concentration of 20%), heating to 50 ℃, stirring for 1h at constant temperature, filtering, washing and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 7.8g of H₃PO₄(the concentration is 85%) is dissolved in 30g of water, and the solution is mixed with molecular sieve slurry, soaked and dried; the obtained sample was calcined at 550 ℃ for 2 hours to obtain molecular sieve sample DB3, and the physicochemical properties of molecular sieve sample DB3 are shown in Table 2.

Comparative example 4

Adding water into 100g of beta molecular sieve (dry basis mass) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 16.42g of NaOH (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 molecular sieve slurry with the solid content of 20 wt%, adding 12g of oxalic acid while stirring, adding 280g of hydrochloric acid (the mass fraction is 10%), heating to 50 ℃, stirring for 1h at constant temperature, filtering, washing and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 7.8g of H₃PO₄(the concentration is 85%) is dissolved in 30g of water, and the solution is mixed with molecular sieve slurry, soaked and dried; the obtained sample was calcined at 550 ℃ for 2 hours to obtain molecular sieve sample DB4, and the physicochemical properties of molecular sieve sample DB4 are shown in Table 2.

Comparative example 5

Adding water into 100g of beta molecular sieve (dry basis mass) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 10.42g of NaOH (with the purity of 96 percent), heating to 50 ℃, stirring for 0.5h at constant temperature, filtering and washing to be neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with the solid content of 20 weight percent, adding 40g of oxalic acid while stirring, heating to 50 ℃, stirring for 1h at constant temperature, filtering, washing and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 7.8g of H₃PO₄(the concentration is 85%) is dissolved in 30g of water, and the solution is mixed with molecular sieve slurry, soaked and dried; roasting the obtained sample at 550 ℃ for 2 hours to obtain the molecular sieveThe physicochemical properties of sample DB5, molecular sieve sample DB5 are listed in Table 2.

Comparative example 6

Adding water into 100g of beta molecular sieve (dry basis mass) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 10.42g of NaOH (with the purity of 96 percent), heating to 50 ℃, and stirring at constant temperature for 0.5 h; adding water into the filter cake, pulping to obtain molecular sieve slurry with the solid content of 20 wt%, adding 300g of hydrochloric acid (mass fraction of 10%) while stirring, heating to 50 ℃, stirring at constant temperature for 1h, filtering, washing and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 7.8g of H₃PO₄(the concentration is 85%) is dissolved in 30g of water, and the solution is mixed with molecular sieve slurry, soaked and dried; the obtained sample was calcined at 550 ℃ for 2 hours to obtain molecular sieve sample DB6, and the physicochemical properties of molecular sieve sample DB6 are shown in Table 2.

Comparative example 7

Adding water into 100g of beta molecular sieve (dry basis mass) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 10.42g of LiOH (the purity is 96 percent), heating to 50 ℃, and stirring at constant temperature for 0.5 h; adding water into the filter cake, pulping to obtain molecular sieve slurry with the solid content of 20 wt%, adding 30g of oxalic acid while stirring, slowly dropwise adding 100g of fluosilicic acid (the concentration is 20%), heating to 50 ℃, stirring for 1h at constant temperature, filtering, washing and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 7.8g of H₃PO₄(the concentration is 85%) is dissolved in 30g of water, and the solution is mixed with molecular sieve slurry, soaked and dried; the obtained sample was calcined at 550 ℃ for 2 hours to obtain molecular sieve sample DB7, and the physicochemical properties of molecular sieve sample DB7 are shown in Table 2.

Comparative example 8

Adding water into 100g of beta molecular sieve (dry basis mass) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 10.42g of NaOH (with the purity of 96 percent), heating to 50 ℃, and stirring at constant temperature for 0.5 h; adding water into the filter cake, pulping to obtain molecular sieve slurry with the solid content of 20 wt%, adding 180g of hydrochloric acid (mass fraction of 10%) while stirring, slowly dropwise adding 100g of fluosilicic acid (concentration of 20%), heating to 50 ℃, stirring at constant temperature for 1h, filtering, washing and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 7.8g of H₃PO₄(85% strength) inMixing 30g of water with the molecular sieve slurry, soaking and drying; the obtained sample was calcined at 550 ℃ for 2 hours to obtain molecular sieve sample DB8, and the physicochemical properties of molecular sieve sample DB8 are shown in Table 2.

Example 2

Adding water into 100g of beta molecular sieve (dry basis mass) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 17g of NaOH (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 molecular sieve slurry with the solid content of 20 wt%, adding 16g of oxalic acid while stirring, slowly dropwise adding 108g of hydrochloric acid (the mass fraction is 10%) and 26g of fluosilicic acid (the concentration is 20%), heating to 50 ℃, stirring at constant temperature for 1h, filtering, washing and drying to obtain a filter cake; adding water into the filter cake and pulping to obtain molecular sieve slurry with the solid content of 40 weight percent, and adding 11.8gH₃PO₄(the concentration is 85%) is dissolved in 90g of water, and the mixture is mixed with filter cakes, soaked and dried; and roasting the obtained sample at 550 ℃ for 2 hours to obtain the modified Beta molecular sieve B.

Elemental analytical chemical composition was 0.1Na₂O·1.9Al₂O₃·7.0P₂O₅·91.0SiO₂Other physicochemical properties are shown in Table 1.

Example 3

Adding water into 100g of beta molecular sieve (dry basis weight) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 19g of KOH, 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 molecular sieve slurry with the solid content of 20 wt%, adding 26g of oxalic acid while stirring, slowly dropwise adding 250g of hydrochloric acid (the mass fraction is 10%) and 95g of fluosilicic acid (the concentration is 20%), heating to 50 ℃, stirring at constant temperature for 1h, filtering, washing and drying to obtain a filter cake; adding water into the filter cake and pulping to obtain molecular sieve slurry with the solid content of 40 weight percent; 4.2gNH₄H₂PO₄Dissolving in 60g of water, mixing with a filter cake, soaking, drying, and roasting at 550 ℃ for 2 hours to obtain the modified Beta molecular sieve C.

Elemental analytical chemical composition was 0.3Na₂O·1.7Al₂O₃·2.5P₂O₅·95.5SiO₂Other physicochemical properties are shown in Table 1.

Example 4

Adding water into 100g of beta molecular sieve (dry basis mass) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 29g of NaOH (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 molecular sieve slurry with the solid content of 20 wt%, adding 33g of oxalic acid while stirring, slowly dropwise adding 240g of hydrochloric acid (the mass fraction is 10%) and 95g of fluosilicic acid (the concentration is 20%), heating to 50 ℃, stirring at constant temperature for 1h, filtering, washing and drying to obtain a filter cake; adding water into the filter cake and pulping to obtain molecular sieve slurry with the solid content of 40 weight percent; mixing 6.9gH₃PO₄(the concentration is 85%) is dissolved in 90g of water, and the mixture is mixed with filter cakes, soaked and dried; and roasting the obtained sample at 550 ℃ for 2 hours to obtain the modified Beta molecular sieve D.

Elemental analytical chemical composition was 0.1Na₂O·2.8Al₂O₃·4.1P₂O₅·93.0SiO₂Other physicochemical properties are shown in Table 1.

Example 5

Adding water into 100g of beta molecular sieve (dry basis mass) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 21g of NaOH (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 molecular sieve slurry with the solid content of 20 wt%, adding 5g of oxalic acid while stirring, slowly dropwise adding 250g of nitric acid (with the mass fraction of 10%) and 130g of fluosilicic acid (with the concentration of 20%), heating to 50 ℃, stirring at constant temperature for 1h, filtering, washing and drying to obtain a filter cake; adding water into the filter cake and pulping to obtain molecular sieve slurry with the solid content of 40 weight percent; 9.3gH₃PO₄(the concentration is 85%) is dissolved in 90g of water, and the mixture is mixed with filter cakes, soaked and dried; the obtained sample is roasted for 2 hours at 550 ℃ in the atmosphere of 100% water vapor, and the modified Beta molecular sieve E is obtained.

Elemental analytical chemical composition was 0.1Na₂O·2.4Al₂O₃·5.4P₂O₅·92.1SiO₂Other physicochemical properties are shown in Table 1.

Example 6

Adding water into 100g of beta molecular sieve (dry basis mass) to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 25g of NaOH (the purity is 96 percent), heating to 50 ℃, stirring at constant temperature for 0.5h, and filteringWashing to be neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with the solid content of 20 wt%, adding 35g of oxalic acid while stirring, slowly dropwise adding 190g of nitric acid (the mass fraction is 10%) and 90g of fluosilicic acid (the concentration is 20%), heating to 50 ℃, stirring at constant temperature for 1h, filtering, washing and drying to obtain a filter cake; adding water into the filter cake and pulping to obtain molecular sieve slurry with the solid content of 40 weight percent; 2.1gH₃PO₄(the concentration is 85%) is dissolved in 90g of water, and the mixture is mixed with filter cakes, soaked and dried; and roasting the obtained sample at 550 ℃ for 2 hours to obtain the modified Beta molecular sieve F.

Elemental analytical chemical composition was 0.15Na₂O·1.2Al₂O₃·1.5P₂O₅·97.15SiO₂Other physicochemical properties are shown in Table 1.

Comparative example 9

100g (dry basis) of zeolite Beta are treated with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; 6.9gH were added₃PO₄(the concentration is 85%) is dissolved in 90g of water, and the mixture is mixed with filter cakes, soaked and dried; the obtained sample was subjected to baking treatment at 550 ℃ for 2 hours to obtain a comparative sample DB 9.

Elemental analytical chemical composition 0.1Na₂O·6.0Al₂O₃·4.1P₂O₅·89.8SiO₂Other physicochemical properties are shown in Table 1.

As can be seen from the data in tables 1 and 2, the conventional alkali treatment can make the Beta molecular sieve surface rich in aluminum (DB2), dealuminate by using a single organic acid oxalic acid (DB5), or dealuminate by using a single inorganic acid hydrochloric acid (DB6) and compound by using two acids of organic acid oxalic acid and inorganic acid hydrochloric acid (DB4), so that Al in the molecular sieve can not be effectively removed, the molecular sieve still has the surface rich in aluminum, and a good dealumination effect can be obtained only after the fluosilicic acid is used, and the aluminum distribution of the molecular sieve is improved. When the fluosilicic acid is used alone for dealumination (DB1), the aluminum distribution of the molecular sieve can be improved, but the mesopores are relatively less, the proportion of strong acid in the total acid is lower, and the proportion of B acid/L acid is lower. The fluosilicic acid and organic acid composite oxalic acid dealumination (DB7) can not obtain higher mesoporous proportion and better acidity distribution. The composite inorganic acid fluosilicate dealumination (DB8) has increased mesoporous volume, but the proportion of strong acid in total acid and the proportion of B acid/L acid are not as high as those of the molecular sieve provided by the invention. The method only adopts composite acid for treatment (DB3), and the mesoporous pore volume cannot be increased, and the method adopts a composite acid system to perform dealumination treatment under the synergistic action of three acids after the molecular sieve is subjected to desiliconization treatment, so that the aluminum distribution and the acid distribution can be improved on the premise of ensuring the integrity of a molecular sieve crystal structure and a mesoporous pore channel structure.

Examples 7-15 preparation of cracking aids provided by the present invention; comparative examples 10-18 comparative adjuvants were prepared.

Example 7

Preparing phosphor aluminum glue: pulping 1.05 kg of pseudo-boehmite (dry basis) and 3.35 kg of deionized water for 30 minutes, adding 4.9 kg of concentrated phosphoric acid (chemical purity, 85 wt% of phosphoric acid) into the slurry while stirring, heating to 70 ℃, and reacting at the temperature for 45 minutes to prepare colorless and transparent aluminum phosphate gel (aluminum phosphate sol). In which it contains P₂O₅30.6 wt.% of Al₂O₃The content was 10.5% by weight, and the pH was 1.7.

Taking molecular sieve A, pseudo-boehmite and kaolin, adding decationized water and aluminum sol, pulping for 120 minutes, adding FeCl under stirring₃·6H₂Aqueous solution of O (FeCl)₃Concentration 30% by weight FeCl used in the examples below₃·6H₂Concentration of O in aqueous solution, FeCl₃Concentration of 30 wt%), controlling the solid content of colloid to be 34 wt%, adjusting pH value of the slurry to 3.0 by hydrochloric acid, then pulping for 45 minutes, adding aluminum phosphate gel, stirring for 30 minutes, and then spray-drying the obtained slurry to obtain the microsphere. And (3) roasting the microspheres at 500 ℃ for 1 hour to obtain the auxiliary C1. The adjuvant formulation is shown in table 3.

Comparative examples 10 to 18

Comparative examples 9 to 16 were prepared according to the same procedure as in example 7 except that molecular sieves DB1-DB9 were used instead of A to prepare comparative aids D1-D9. The comparative adjuvant formulation is shown in table 3.

Example 8

And adding decationized water and alumina sol into the molecular sieve B and kaolin, pulping for 120 minutes to obtain slurry with the solid content of 40 weight percent, and spray-drying the obtained slurry to obtain the microspheres. And (3) roasting the microspheres at 500 ℃ for 1 hour to obtain the auxiliary C2 provided by the invention. The adjuvant formulation is shown in Table 4.

Example 9

Taking molecular sieve C, kaolin and pseudo-boehmite, adding decationized water and alumina sol, pulping for 120 minutes to obtain slurry with the solid content of 30 weight percent, adding hydrochloric acid with the concentration of 36 weight percent while stirring, wherein the use amount of the hydrochloric acid enables the pH value of the slurry to be 3.0, pulping for 45 minutes, then adding phosphor-aluminum glue (prepared according to the method of example 7) into the mixed slurry, stirring for 30 minutes, and performing spray drying on the obtained slurry to obtain the microspheres. And (3) roasting the microspheres at 500 ℃ for 1 hour to obtain the auxiliary C3. The adjuvant formulation is shown in Table 4.

Example 10

Taking molecular sieve C, kaolin and pseudo-boehmite, adding decationized water and aluminum sol, pulping for 120 minutes, adding FeCl under stirring₃·6H₂And O to obtain slurry with the solid content of 30 weight percent, adding hydrochloric acid with the concentration of 36 weight percent, wherein the hydrochloric acid is used for ensuring the pH value of the slurry to be 3.0, pulping for 45 minutes, and spray drying the obtained slurry to obtain the microspheres. And (3) roasting the microspheres at 500 ℃ for 1 hour to obtain the auxiliary C4. The adjuvant formulation is shown in Table 4.

Example 11

Mixing decationized water and aluminum sol, adding molecular sieve B, diatomite and pseudoboehmite, pulping for 120 min, adding FeCl under stirring₃·6H₂And (3) obtaining serous fluid with the solid content of 35 weight percent by using an O aqueous solution, adding hydrochloric acid to adjust the pH value of the serous fluid to be 2.8, pulping for 30 minutes, adding diammonium hydrogen phosphate solid, pulping for 30 minutes, then carrying out spray drying on the obtained serous fluid to obtain microspheres, and roasting the microspheres at 500 ℃ for 1 hour to obtain the auxiliary agent C5. The adjuvant formulation is shown in Table 4.

Example 12

Adding decationized water and aluminum sol into molecular sieve A and kaolin, pulping for 120 min, adding Co (NO) under stirring₃)₂·6H₂Aqueous solution of O (Co (NO)₃)₂Concentration 20% by weight) to give a solid content of 38 wt% slurry, adjusting the pH of the slurry to 3.3 with hydrochloric acid, then beating for 30 minutes, then adding phosphor-alumina gel (prepared according to the method of example 7) to the mixed slurry, stirring for 30 minutes, and spray-drying the obtained slurry to obtain microspheres. And (3) roasting the microspheres at 500 ℃ for 1 hour to obtain the auxiliary C6. The adjuvant formulation is shown in Table 4.

Example 13

Adding decationized water and aluminum sol into molecular sieve D and pseudoboehmite, pulping for 120 min, adding Ni (NO) under stirring₃)₂·6H₂Aqueous solution of O (Ni (NO)₃)₂Concentration 20 wt%), to obtain a slurry having a solid content of 30 wt%, adding hydrochloric acid to make the pH of the slurry 3.0, then beating for 45 minutes, and spray-drying the obtained slurry to obtain microspheres.

And roasting the obtained microspheres at 500 ℃ for 1 hour, adding diammonium hydrogen phosphate aqueous solution, heating to 60 ℃ under stirring, reacting at the temperature for 20 minutes, carrying out vacuum filtration and drying on the slurry, and roasting at 500 ℃ for 1 hour to obtain the auxiliary C7. The adjuvant formulation is shown in Table 4.

Example 14

Taking molecular sieve E, kaolin and water glass, adding decationized water, pulping for 120 minutes, adding FeCl under stirring₃·6H₂O in water to obtain a slurry with a solid content of 33 wt%, adjusting the pH of the slurry to 3.0 by hydrochloric acid, then beating for 45 minutes, then adding phosphor-alumina gel (prepared according to the method of example 7) to the slurry, stirring for 30 minutes, and spray-drying the obtained slurry to obtain microspheres. And (3) roasting the microspheres at 400 ℃ for 1 hour to obtain the auxiliary C8. The adjuvant formulation is shown in Table 4.

Example 15

Taking molecular sieve F, kaolin and pseudo-boehmite, adding decationized water and alumina sol, pulping for 120 minutes to obtain slurry with the solid content of 30 weight percent, adding hydrochloric acid to enable the pH value of the slurry to be 3.0, pulping for 45 minutes, then adding phosphor-alumina sol (prepared according to the method of example 7) into the slurry, stirring for 30 minutes, and carrying out spray drying on the obtained slurry to obtain the microspheres.

Calcining the obtained microspheres at 500 ℃ for 1 hour, andaqueous diammonium hydrogen phosphate solution (P)₂O₅8 wt%) according to the weight ratio of 1:1, drying at 120 deg.C, roasting at 500 deg.C for 1 hr, and mixing with FeCl₃·6H₂Aqueous solution of O (FeCl)₃Concentration 4 wt%) according to a weight ratio of 1:1, drying at 120 ℃, and then roasting at 500 ℃ for 1 hour to obtain the assistant C9. The adjuvant formulation is shown in Table 4.

Examples 16 to 24

The following examples illustrate the cracking reaction effect of the cracking aid provided by the present invention in terms of a fixed fluidized bed reactor.

30g of auxiliaries C1-C9 were respectively aged at 800 ℃ for 12 hours in an atmosphere of 100% water vapor. The aging-treated assistants C1-C9 of different weights were mixed with industrial FCC equilibrium catalysts (the industrial FCC equilibrium catalyst with the trade name DVR-3, the main properties are shown in Table 5) of different weights. The catalyst mixture was charged into a reactor of a small-sized fixed fluidized bed reactor, and the raw oil shown in Table 6 was subjected to catalytic cracking. The composition by weight of the catalyst mixture used, the reaction conditions and the reaction results are given in tables 7 and 8.

Comparative examples 19 to 28

The following comparative examples illustrate the use of the comparative additive in a fixed fluidized bed reactor.

The same feed oil was catalytically cracked by the method of example 16, except that the catalysts used were 100% commercial FCC equilibrium catalyst, comparative promoters D1-D9 aged by the method of example 16, and a mixture of commercial FCC equilibrium catalyst, respectively. The composition of the catalyst mixture used, the reaction conditions and the reaction results are given in Table 7.

It can be seen from tables 7 and 8 that, compared with the contrast agent, the catalytic assistant provided by the present invention can effectively increase the yield of catalytic cracking liquefied gas, especially the yield of isobutene and propylene, significantly increase the concentration of propylene and isobutene in the catalytic cracking liquefied gas, increase the ethylene concentration in the dry gas, and simultaneously increase the octane number of gasoline, increase the yield of catalytic cracking liquid and the conversion rate, and improve the coke selectivity.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

Item	Industrial equilibrium catalyst DVR-3
		Metal content, ppm
Ni/V	8762/1387
		Fe/Sb	5214/2512
Ca	1516
		Micro activity index	60

TABLE 6

Raw oil name	Residual oil mixed with wax oil for pipeline transportation
		Density (20 deg.C), g/cm³	0.9070
Viscosity (100 ℃ C.), mm²Second/second	10.41
		Freezing point, DEG C	40
Carbon residue, by weight%	3.1
		The element composition by weight percent
C/H	86.39/12.53
		S/N	0.8/0.29
Four components, by weight%
		Saturated hydrocarbons	56.8
Aromatic hydrocarbons	24.2
		Glue	18.2
Asphaltenes	0.8
		Metal content, ppm
V/Ni	0.8/7.0
		Fe/Cu	7.8/0.1
Na	2.6
		Distillation range, deg.C
Initial boiling point/5%	241/309
		10％/20％	343/387
30％/40％	413/432
		50％/60％	450/466
70％/80％	493/535

TABLE 7

TABLE 8

Claims

1. A catalytic cracking aid containing phosphorus-containing Beta molecular sieve, wherein the aid contains 10-75 wt% of phosphorus-containing Beta molecular sieve, 0-60 wt% of clay, 15-60 wt% of inorganic oxide binder and P₂O₅0-25 wt.% of a phosphorus additive and 0-15 wt.% of a group VIII metal additive, calculated as oxides, wherein the molecular sieve has an Al distribution parameter D satisfying: d is more than or equal to 0.4 and less than or equal to 0.8, wherein D = Al (S)/Al (C), Al (S) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance H from the edge of the crystal face of the molecular sieve crystal grain to the inside measured by a TEM-EDS method, Al (C) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance H from the geometric center of the crystal face of the molecular sieve crystal grain to the outside measured by a TEM-EDS method, wherein H is 10% of the distance from a certain point of the edge of the crystal face to the geometric center of the crystal face; the specific surface area of the micropores of the molecular sieve is 420-520 m²Per gram, the proportion of the mesoporous volume of the molecular sieve in the total pore volume is 30-70%; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 20-60%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100; with P₂O₅Based on the dry weight of the molecular sieveThe phosphorus content is 0.3-10 wt%.

2. The adjuvant according to claim 1, wherein the molecular sieve has an Al distribution parameter D satisfying: d is more than or equal to 0.55 and less than or equal to 0.75; the specific surface area of the micropores of the molecular sieve is 450-500 m²Per gram, the proportion of the mesoporous volume of the molecular sieve in the total pore volume is 35-60%; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 25-55%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 35-75; with P₂O₅The molecular sieve has a phosphorus content of 1-8 wt.% based on the dry weight of the molecular sieve.

3. The adjuvant of claim 1, wherein the adjuvant comprises, by weight and based on the dry weight of the adjuvant, 20-60% by weight on a dry basis of the phosphorus-containing Beta molecular sieve, 10-45% by weight on a dry basis of the clay, 25-50% by weight on a dry basis of the inorganic oxide binder, and P₂O₅5-15% by weight of a phosphorus additive and 1-10% by weight of a group VIII metal additive, calculated as the oxide.

4. The adjuvant according to claim 1, wherein the clay comprises at least one selected from the group consisting of kaolin, metakaolin, sepiolite, attapulgite, montmorillonite, rectorite, diatomaceous earth, halloysite, saponite, bentonite, and hydrotalcite, and the inorganic oxide binder comprises at least one selected from the group consisting of pseudo-boehmite, alumina sol, silica alumina sol, and water glass.

5. The adjuvant of claim 1, wherein the phosphorus additive is introduced to the adjuvant in the form of a phosphorus-containing compound comprising at least one selected from the group consisting of oxides, phosphates, phosphites, basic phosphates, and acid phosphates of phosphorus;

the group VIII metal comprises at least one selected from Fe, Co and Ni, and the group VIII metal additive is introduced to the promoter in the form of a metal-containing compound comprising at least one selected from the group consisting of oxides, hydroxides, chlorides, nitrates, sulfates, phosphates and organic compounds.

6. A preparation method of a catalytic cracking assistant comprises the following steps:

mixing a phosphorus-containing Beta molecular sieve, an inorganic oxide binder and water, adding or not adding clay, pulping, and spray-drying; wherein, a phosphorus additive is introduced or not introduced, and a group VIII metal additive is introduced or not introduced;

the preparation raw materials of the auxiliary agent comprise 10-75 wt% of phosphorus-containing Beta molecular sieve, 0-60 wt% of clay, 15-60 wt% of inorganic oxide binder and P₂O₅0-25% by weight of a phosphorus additive and 0-15% by weight of a group VIII metal additive calculated as the oxide;

the Al distribution parameter D of the molecular sieve meets the following requirements: d is more than or equal to 0.4 and less than or equal to 0.8, wherein D = Al (S)/Al (C), Al (S) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance H from the edge of the crystal face of the molecular sieve crystal grain to the inside measured by a TEM-EDS method, Al (C) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance H from the geometric center of the crystal face of the molecular sieve crystal grain to the outside measured by a TEM-EDS method, wherein H is 10% of the distance from a certain point of the edge of the crystal face to the geometric center of the crystal face; the specific surface area of the micropores of the molecular sieve is 420-520 m²Per gram, the proportion of the mesoporous volume of the molecular sieve in the total pore volume is 30-70%; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 20-60%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100; with P₂O₅The molecular sieve has a phosphorus content of 0.3 to 10 wt.% based on the dry weight of the molecular sieve.

7. The method of claim 6, wherein the step of preparing the phosphorus-containing Beta molecular sieve comprises:

a. carrying out alkali treatment on the sodium type Beta molecular sieve in an alkaline solution, and filtering and washing to obtain an alkali-treated molecular sieve;

b. b, dealuminizing the alkali-treated molecular sieve obtained in the step a in a composite acid dealuminizing agent solution consisting of fluosilicic acid, organic acid and inorganic acid, and filtering and washing to obtain a dealuminized molecular sieve; the organic acid is at least one selected from ethylenediamine tetraacetic acid, oxalic acid, citric acid and sulfosalicylic acid, and the inorganic acid is at least one selected from hydrochloric acid, sulfuric acid and nitric acid;

c. and c, carrying out phosphorus modification treatment and roasting treatment on the dealuminized molecular sieve obtained in the step b to obtain the phosphorus-containing Beta molecular sieve.

8. The production method according to claim 7, 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, aqueous ammonia and an overbased sodium metaaluminate solution; the sodium content of the high-alkali sodium metaaluminate solution is 270-310 g/L, the aluminum content is 30-50 g/L and the density of the high-alkali sodium metaaluminate solution is 1.25-1.45 g/mL.

9. The preparation method according to claim 8, wherein the conditions of the alkali treatment in step a include: the weight ratio of the molecular sieve to the alkali in the alkaline solution on a dry basis is 1: (0.02-0.3); wherein the weight of the alkali in the sodium hydroxide solution is based on the weight of sodium hydroxide, the weight of the alkali in the potassium hydroxide solution is based on the weight of potassium hydroxide, the weight of the alkali in the lithium hydroxide solution is based on the weight of lithium hydroxide, the weight of the alkali in the ammonia water is based on the weight of ammonia monohydrate, and the weight of the alkali in the high-alkali sodium metaaluminate solution is based on the weight of sodium oxide.

10. The production method according to claim 7, wherein the conditions of the alkali treatment in step a include: the temperature of alkali treatment is 25-100 ℃, and the time of alkali treatment is 0.5-6 hours.

11. The production method according to claim 7, wherein the conditions of the dealumination treatment in step b include: the weight ratio of the molecular sieve, the fluosilicic acid, the organic acid and the inorganic acid is 1: (0.03-0.5): (0.05-0.4): 0.05-0.5); the treatment temperature is 25-100 ℃, and the treatment time is 0.5-6 hours.

12. The production method according to claim 7, wherein the conditions of the dealumination treatment in step b include: the weight ratio of the molecular sieve, the fluosilicic acid, the organic acid and the inorganic acid is 1: (0.05-0.3):(0.1-0.3):(0.1-0.3).

13. The production method according to claim 7, wherein the phosphorus modification treatment includes: at least one phosphorus-containing compound selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate is used to impregnate and/or ion-exchange the molecular sieve.

14. The production method according to claim 7, wherein the conditions of the baking treatment include: the atmosphere of the roasting treatment is air atmosphere or water vapor atmosphere; the roasting temperature is 400-800 ℃, and the roasting time is 0.5-8 hours.

15. The production method according to claim 6, wherein the clay comprises at least one selected from the group consisting of kaolin, metakaolin, sepiolite, attapulgite, montmorillonite, rectorite, diatomaceous earth, halloysite, saponite, bentonite and hydrotalcite, and the inorganic oxide binder comprises at least one selected from the group consisting of pseudo-boehmite, alumina sol, silica alumina sol and water glass.

16. The production method according to claim 6, wherein the phosphorus additive is introduced into the auxiliary in the form of a phosphorus-containing compound including at least one selected from an oxide of phosphorus, a phosphate, a phosphite, a basic phosphate, and an acid phosphate;