CN107971008B

CN107971008B - Catalytic cracking catalyst, preparation method thereof and petroleum hydrocarbon catalytic cracking method

Info

Publication number: CN107971008B
Application number: CN201610921278.1A
Authority: CN
Inventors: 王丽霞; 田辉平; 刘宇键; 周治; 袁帅; 孙敏; 欧阳颖; 庄立
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2016-10-21
Filing date: 2016-10-21
Publication date: 2020-02-28
Anticipated expiration: 2036-10-21
Also published as: CN107971008A

Abstract

The present disclosure relates to a catalytic cracking catalyst, a preparation method thereof and a petroleum hydrocarbon catalytic cracking method, wherein the catalyst comprises 24-75 wt% of BEA structure molecular sieve based on the dry weight of the catalyst, 5-65 wt% of natural clay based on the dry weight of the catalyst, 10-60 wt% of inorganic oxide binder based on the oxide, and P₂O₅0.1-15 wt% of phosphorus additive, and 0.1-15 wt% of metal additive calculated by metal oxide, and the proportion of mesoporous protonic acid in total acid of the catalyst is 20-70%. The catalytic cracking catalyst is used for catalytic cracking of petroleum hydrocarbon and has higher yield of low-carbon olefin and BTX.

Description

Catalytic cracking catalyst, preparation method thereof and petroleum hydrocarbon catalytic cracking method

Technical Field

The disclosure relates to a catalytic cracking catalyst, a preparation method thereof and a petroleum hydrocarbon catalytic cracking method.

Background

The low-carbon olefin such as ethylene, propylene, butylene and the like is an essential chemical raw material and can be used for synthesizing resin, fiber, rubber and the like. Among them, propylene is an important raw material for manufacturing petrochemicals next to ethylene, and is mainly used for producing chemical products such as polypropylene, acrylonitrile, propylene oxide, and the like. At present, the production of propylene at home and abroad mainly comes from byproducts generated in the production of ethylene by thermal cracking, and the second major source is an FCC device. The FCC unit provides about 30% of the propylene demand, and in the united states, the propylene produced by the FCC unit provides half of the propylene demand of petrochemicals.

In recent years, demand for propylene has increased rapidly, and it is predicted that global propylene consumption will increase more than ethylene by 2016 to about 5%. However, the ratio of propylene to ethylene in steam cracking cannot be flexibly adjusted, and the reaction temperature is up to 840-860 ℃, and the energy consumption accounts for about 40% of the energy consumption of petrochemical industry. Thus, the large production of propylene by FCC is an effective and efficient way to meet the increased demand for propylene.

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

Chinese patent CN103785460A discloses a catalyst for producing low-carbon olefins and a preparation method thereof, wherein a catalyst system compounded by an MFI structure molecular sieve and a phosphorus modified Beta molecular sieve is adopted for preparing propylene by catalytic cracking of naphtha, and the catalyst has higher yield of the low-carbon olefins.

Chinese patent CN103509588A discloses a cracking method for increasing the yield of low-carbon olefin and light aromatic hydrocarbon in raw oil containing more naphthenic rings, which adopts Beta molecular sieve and MFI structure molecular sieve to compound, and the weight ratio of the Beta molecular sieve to the MFI molecular sieve is not less than 1/3. The method has high yield of propylene and isobutene, and high BTX ratio in gasoline fraction aromatic hydrocarbon.

The Chinese patent CN102533315A adopts a modified Y molecular sieve and a modified Beta molecular sieve to prepare the catalyst, which is used for the hydrogenation and dearomatization of catalytic cracking diesel oil, the desulfurization rate and the denitrification rate both reach more than 97.5 percent, the dearomatization rate reaches more than 55 percent, and the yield of diesel oil fraction reaches more than 98 percent by weight.

Chinese patent CN102451753A utilizes Beta molecular sieve to increase gasoline octane number.

However, because the molecular sieve in the catalyst has a shape-selective effect, 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, and the reaction activity is influenced. Therefore, researchers directly synthesize the Beta molecular sieve material containing hierarchical pores or firstly enlarge pores of the molecular sieve and then prepare the molecular sieve material into the catalyst so as to improve the pore structure of the molecular sieve material. However, in the process of preparing the catalyst, the mesopores of the molecular sieve are blocked by the matrix, so that the efficiency of the mesopores of the molecular sieve is greatly reduced, and even the mesopores of the molecular sieve cannot play a role.

Disclosure of Invention

The present disclosure is directed to a catalytic cracking catalyst, a method for preparing the same, and a method for catalytically cracking petroleum hydrocarbons, wherein the catalytic cracking catalyst has high yields of lower olefins and BTX in the catalytic cracking of petroleum hydrocarbons.

To achieve the above object, a first aspect of the present disclosure: a catalytic cracking catalyst is provided, which comprises 24-75 wt% of BEA structure molecular sieve based on dry weight of the catalyst, 5-65 wt% of natural clay based on dry weight, 10-60 wt% of inorganic oxide binder based on oxide, and P₂O₅0.1-15% by weight of a phosphorus additive, and oxygen as metal0.1-15 wt% of metal additive calculated by compound, and the proportion of mesoporous protonic acid in the catalyst is 20-70% of total acid.

Preferably, with P₂O₅The phosphorus additive is present in an amount of from 0.5 to 6.5 wt.% based on the dry weight of the catalyst, and the metal additive is present in an amount of from 0.5 to 10 wt.% based on the dry weight of the catalyst and calculated as the metal oxide.

Preferably, the total specific surface area of the catalyst is 240-350m²The proportion of mesoporous protonic acid in the total acid is 25-50%.

Preferably, the mesoporous volume of the catalyst is 0.14-0.35ml/g, and the proportion of the mesoporous volume in the total pore volume is 35-60%.

Preferably, the natural clay is at least one selected from the group consisting of kaolin, halloysite, montmorillonite, diatomaceous earth, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite, and rectorite; the inorganic oxide binder is at least one selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, and amorphous silica-alumina.

Preferably, the metal is at least one selected from the group consisting of iron, cobalt, nickel, copper, manganese, zinc, tin, and titanium.

Preferably, the total specific surface area, mesoporous volume and total pore volume of the catalyst are measured using the nitrogen adsorption BET specific surface area method; the mesoporous protonic acid content is measured by adopting a 2, 6-di-tert-butylpyridine adsorption infrared acidity method, and the mesoporous protonic acid has a kinetic diameter of

The 2, 6-di-tert-butylpyridine molecule of (a) is capable of contacting with a protonic acid; the total acid content adopts NH₃The TPD method is used for the measurement.

In a second aspect of the present disclosure: there is provided a method for preparing a catalytic cracking catalyst, the method comprising the steps of: a. mixing BEA structure molecular sieve, natural clay, inorganic oxide binder precursor and water, pulping, and spray drying to obtain sprayDrying microspheres, wherein the spray dried microspheres comprise 25-75 wt% BEA structure molecular sieve based on dry weight, 5-65 wt% natural clay based on dry weight, and 10-60 wt% inorganic oxide binder precursor based on oxide, based on total dry weight of the spray dried microspheres; b. b, performing alkali treatment on the spray-dried microspheres obtained in the step a, and filtering and washing to obtain an alkali-treated material; c. b, performing composite acid treatment on the material subjected to the alkali treatment in a composite acid solution consisting of fluosilicic acid, organic acid and inorganic acid, and filtering and washing to obtain a material subjected to the composite acid treatment; d. c, carrying out phosphorus modification treatment, metal loading treatment and first roasting treatment on the material subjected to the composite acid treatment obtained in the step c to obtain a catalytic cracking catalyst, wherein P is used₂O₅The content of the phosphorus additive is 0.1-15 wt% calculated by the dry weight of the catalyst, and the content of the metal additive is 0.1-15 wt% calculated by the metal oxide and calculated by the dry weight of the catalyst; wherein the mesoporous protonic acid content of the catalyst accounts for 20-70% of the total acid content.

Preferably, the natural clay in step a is at least one selected from the group consisting of kaolin, halloysite, montmorillonite, diatomaceous earth, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite and rectorite; the inorganic oxide binder precursor is at least one selected from silica sol, aluminum sol, peptized pseudo-boehmite, silica-alumina sol and phosphorus-containing aluminum sol.

Preferably, the alkali treatment in step b comprises: mixing the spray-dried microspheres with an alkaline solution, wherein the alkaline solution is at least one selected from a sodium hydroxide solution, a potassium hydroxide solution, a lithium hydroxide solution, ammonia water and a high-alkali sodium metaaluminate solution.

Preferably, the mixing conditions include: the weight ratio of the spray dried microspheres to the base in the alkaline solution on a dry basis is 1: (0.01-0.35); 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 weight ratio of the spray dried microspheres to the base in the alkaline solution on a dry basis is 1: (0.05-0.25).

Preferably, the organic acid in step c 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 conditions of the complex acid treatment in step c are: the weight ratio of the material after alkali treatment, the fluosilicic acid, the inorganic acid and the organic acid is 1: (0.01-0.45): (0.01-0.45): (0.01-0.55).

Preferably, the conditions of the complex acid treatment in step c are: the weight ratio of the alkali-treated material, the fluosilicic acid, the inorganic acid and the organic acid is 1: (0.05-0.3): (0.1-0.3): (0.1-0.3).

Preferably, the method further comprises: and c, performing second roasting treatment on the material subjected to the composite acid treatment obtained in the step c to obtain a material subjected to second roasting treatment, performing ammonium exchange treatment on the material subjected to the second roasting treatment to obtain a material subjected to ammonium exchange treatment, and performing phosphorus modification treatment, load metal treatment and first roasting treatment.

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

Preferably, the ammonium exchange treatment is such that the catalytic cracking catalyst has a sodium content of less than 0.15 wt.%, calculated as sodium oxide and based on the total dry weight of the catalytic cracking catalyst; the ammonium exchange treatment comprises: and mixing the material after the second roasting treatment with ammonium salt, wherein the ammonium salt is at least one selected from ammonium chloride, ammonium sulfate, ammonium carbonate, ammonium bicarbonate, ammonium acetate and ammonium nitrate.

Preferably, the phosphorus modification treatment in step d comprises: and (2) impregnating and/or ion exchanging the molecular sieve with a phosphorus-containing compound, wherein the phosphorus-containing compound is at least one selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate.

Preferably, the supported metal treatment in step d comprises: the supported metal containing a compound of the supported metal, which is at least one selected from the group consisting of iron, cobalt, nickel, copper, manganese, zinc, tin and titanium, is supported on a catalyst by an impregnation method, and the compound of the supported metal is a water-soluble salt containing the supported metal.

Preferably, the metal-supporting compound is at least one selected from the group consisting of a sulfate, a nitrate and a chloride containing the supporting metal.

Preferably, the conditions of the first firing treatment in step d include: the atmosphere of the first roasting treatment is air atmosphere, nitrogen atmosphere or water vapor atmosphere; the roasting temperature is 400-800 ℃, and the roasting time is 0.5-8 hours.

A third aspect of the disclosure: there is provided a catalytic cracking catalyst prepared by the method provided in the second aspect of the present disclosure.

A fourth aspect of the present disclosure: there is provided a process for the catalytic cracking of petroleum hydrocarbons, the process comprising: under catalytic cracking conditions, petroleum hydrocarbons are subjected to a contact reaction with a catalytic cracking catalyst provided in the first or third aspect of the present disclosure.

Through the technical scheme, the catalytic cracking catalyst provided by the disclosure is used for catalytic cracking of petroleum hydrocarbon, and is beneficial to improving the yield of low-carbon olefin, especially propylene and BTX.

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

Detailed Description

The following describes in detail specific embodiments of the present disclosure. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

The first aspect of the disclosure: a catalytic cracking catalyst is provided, which comprises 24-75 wt% of BEA structure molecular sieve based on dry weight of the catalyst, 5-65 wt% of natural clay based on dry weight, 10-60 wt% of inorganic oxide binder based on oxide, and P₂O₅0.1-15 wt% of phosphorus additive, and 0.1-15 wt% of metal additive calculated by metal oxide, and the proportion of mesoporous protonic acid in total acid of the catalyst is 20-70%. Further, the catalyst comprises 29-55 wt% of BEA structure molecular sieve based on the dry weight of the catalyst, 8-50 wt% of natural clay based on the dry weight, 20-50 wt% of inorganic oxide binder based on the oxide, and P is used as P₂O₅0.5-6.5% by weight of a phosphorus additive, and 0.5-10% by weight of a metal additive, calculated as the oxide of the metal. Still further, the total specific surface area of the catalyst was 240-350m²The proportion of mesoporous protonic acid in the total acid is 25-50%. Further, the catalyst has a mesopore volume of0.14-0.35ml/g, and the proportion of the mesoporous volume in the total pore volume is 35-60%. The catalytic cracking catalyst provided by the first aspect of the disclosure has a rich mesoporous structure and excellent hydrothermal stability, is suitable for catalytic cracking reaction of petroleum hydrocarbon, and can improve the yield of low-carbon olefins, especially propylene and BTX. The catalytic cracking catalyst provided by the first aspect of the disclosure is particularly suitable for catalytic cracking reaction of naphtha, and can obviously improve the yield of BTX and propylene.

According to a first aspect of the present disclosure, the molecular sieve of BEA structure is well known to those skilled in the art and may be obtained without amine crystallization or after calcination of a molecular sieve prepared by a templating method, for example, a Beta molecular sieve.

According to the first aspect of the present disclosure, the natural clay may be conventionally used in the art, and is preferably at least one selected from the group consisting of kaolin, halloysite, montmorillonite, diatomaceous earth, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite, and rectorite. The inorganic oxide binder may be conventionally used in the art, and is preferably at least one selected from the group consisting of silica, alumina, zirconia, titania and amorphous silica-alumina.

According to the present disclosure, the metal of the metal additive refers to a metal loaded on the molecular sieve by a loading manner, and does not include aluminum and alkali metals such as sodium and potassium, and may include at least one selected from iron, cobalt, nickel, copper, manganese, zinc, tin and titanium, and may also include other metals, and the present invention is not limited thereto.

According to the disclosure, the total specific surface area, the mesoporous volume and the total pore volume of the catalyst are measured by a nitrogen adsorption BET specific surface area method, and are measured by an AS-3, AS-6 static nitrogen adsorption instrument manufactured by Quantachrome instruments company, and the specific method is 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 N₂An adsorption-desorption isothermal curve, then the total specific surface area is calculated by utilizing a BET formula with two parameters,proportional pressure P/P₀The adsorption capacity of 0.98 or less is the total pore volume of the sample, the pore size distribution of the mesoporous portion is calculated by the BJH formula, and the mesoporous volume is calculated by the integration method. The mesoporous protonic acid amount is measured by adopting a 2, 6-di-tert-butylpyridine adsorption infrared acidity method, for example, a Vertex70 model instrument produced by Bruker instruments company, and the specific method comprises the following steps: the catalyst was pressed to 10mg/cm²Into a band of CaF₂And (3) vacuumizing the infrared pool of the window at 400 ℃, then reducing the temperature to 150 ℃ to adsorb the 2, 6-di-tert-butylpyridine for 15 minutes, vacuumizing for 1 hour, reducing the temperature to room temperature to collect a spectrogram, and calculating the amount of the protonic acid. See Applied Catalysis A, General, 294, 2005: 92. the meaning of the mesoporous protonic acid is well known to those skilled in the art and refers to a kinetic diameter of

The 2, 6-di-tert-butylpyridine molecule can contact with protonic acid. The total acid content adopts NH₃The TPD method is used for measurement, for example, the TPD can be measured by an Autochem II 2920 temperature programmed desorption instrument of Michman, USA, and the method comprises the following steps: weighing 0.2g of sample to be detected, placing the sample into a sample tube, placing the sample tube in a thermal conductivity cell heating furnace, taking He gas as carrier gas (50mL/min), raising the temperature to 600 ℃ at the speed of 20 ℃/min, purging impurities adsorbed on the surface of the catalyst for 60min, then reducing the temperature 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 blow with He gas for 90min until the baseline is stable so as to desorb the physically adsorbed ammonia gas; heating to 600 ℃ at the heating rate of 10 ℃/min for desorption, keeping for 30min, and finishing desorption; and detecting the change of gas components by adopting a TCD detector, and automatically integrating by an instrument to obtain the total acid amount.

In a second aspect of the present disclosure: there is provided a method for preparing a catalytic cracking catalyst, the method comprising the steps of: a. mixing BEA structure molecular sieve, natural clay, inorganic oxide binder precursor and water, pulping, and spray drying the obtained slurry to obtain spray dried microspheres, such as BEA structure molecular sieve, natural clay, and oxygenInorganic oxide binder precursor (25-75): (5-65): (10-60) preferably (30-55): (8-50): (20-50) mixing the BEA structure molecular sieve, the natural clay, the inorganic oxide binder precursor and water according to the weight ratio, pulping, and performing spray drying to obtain spray-dried microspheres; wherein the spray dried microspheres comprise 25-75 wt% BEA structure molecular sieve based on dry weight, 5-65 wt% natural clay based on dry weight, and 10-60 wt% inorganic oxide binder precursor based on oxide, based on total dry weight of the spray dried microspheres; preferably, the spray dried microspheres comprise 30-55 wt% BEA structure molecular sieve based on dry weight, 8-50 wt% natural clay based on dry weight, and 20-50 wt% inorganic oxide binder precursor based on oxide, based on total dry weight of the spray dried microspheres; b. b, performing alkali treatment on the spray-dried microspheres obtained in the step a, and filtering and washing to obtain an alkali-treated material; b, performing composite acid treatment on the material subjected to the alkali treatment in a composite acid solution consisting of fluosilicic acid, organic acid and inorganic acid, and filtering and washing to obtain a material subjected to the composite acid treatment; d. c, carrying out phosphorus modification treatment, metal loading treatment and first roasting treatment on the material subjected to the composite acid treatment obtained in the step c to obtain a catalytic cracking catalyst, wherein P is used₂O₅The content of the phosphorus additive is 0.1-15 wt% calculated by the dry weight of the catalyst, and the content of the metal additive is 0.1-15 wt% calculated by the metal oxide and calculated by the dry weight of the catalyst; wherein the mesoporous protonic acid content of the catalyst accounts for 20-70% of the total acid content. Further, with P₂O₅The phosphorus additive is present in an amount of from 0.5 to 6.5 wt.% based on the dry weight of the catalyst, and the metal additive is present in an amount of from 0.5 to 10 wt.% based on the dry weight of the catalyst and calculated as the metal oxide. The total specific surface area of the catalyst is 240-350m²The proportion of mesoporous protonic acid in the total acid is 25-50%. Further, the catalyst has a mesopore volume of 0.14 to 035ml/g, the proportion of the mesoporous volume in the total pore volume is 35-60%.

The inventor of the present disclosure unexpectedly finds that, the conventional Beta molecular sieve is prepared into catalyst microspheres, and then the pore structure of the molecular sieve is modulated by an acid-base coupling treatment method, so that it can be ensured that newly generated mesopores are not blocked, such that the catalyst has a large specific surface area and a large mesopore volume, and the stability of the catalyst is improved, and the catalyst is used in the catalytic cracking of petroleum hydrocarbon, such that the catalyst is beneficial for improving the yield of low carbon olefins, especially propylene and BTX.

According to the second aspect of the present disclosure, the natural clay in step a may be conventionally used in the art, and is preferably at least one selected from the group consisting of kaolin, halloysite, montmorillonite, diatomaceous earth, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite, and rectorite; the inorganic oxide binder precursor may be conventionally used in the art, and is preferably at least one selected from the group consisting of silica sol, alumina sol, peptomite pseudo-boehmite, silica-alumina sol, and phosphorus-containing alumina sol.

According to the second aspect of the present disclosure, after obtaining the spray-dried microspheres in step a, a step of performing a third baking treatment on the spray-dried microspheres may be further included, where the conditions of the third baking treatment may include: the roasting atmosphere is air atmosphere or nitrogen 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.

According to a second aspect of the present disclosure, the alkali treatment in step b may comprise: mixing the spray-dried microspheres with an alkaline solution. The alkaline solution may be at least one selected from the group consisting of a sodium hydroxide solution, a potassium hydroxide solution, a lithium hydroxide solution, an ammonium hydroxide solution and an overbased sodium metaaluminate solution, and is preferably an overbased sodium metaaluminate solution. When the alkaline solution is a 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. The mixing conditions may include: the weight ratio of the spray-dried microspheres to the alkali in the alkaline solution on a dry basis is 1 (0.01-0.35), and further the weight ratio of the spray-dried microspheres to the alkali in the alkaline solution on a dry basis is 1 (0.05-0.25); 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 amount of water in the alkaline solution is not particularly limited, for example, the weight ratio of spray-dried microspheres to water in the alkaline solution on a dry basis may be 1: (5-15).

According to the second aspect of the present disclosure, the temperature of the alkali treatment may be 25 to 100 ℃, and the time of the alkali treatment may be 0.5 to 6 hours.

According to the second aspect of the present disclosure, the complex acid treatment in step c may be performed once or in multiple times, and the organic acid may be first mixed with the material after the alkali treatment, and then the fluosilicic acid and the inorganic acid are mixed with the material after the alkali treatment, that is, the organic acid is first added to the material after the alkali treatment, and then the fluosilicic acid and the inorganic acid are slowly added in parallel, or the fluosilicic acid is first added and then the inorganic acid is added, preferably the fluosilicic acid and the inorganic acid are slowly added in parallel. The organic acid in step c may be at least one selected from the group consisting of ethylenediaminetetraacetic acid, oxalic acid, citric acid and sulfosalicylic acid, and is preferably oxalic acid or citric acid, and is more preferably oxalic acid. The inorganic acid may be at least one selected from hydrochloric acid, sulfuric acid, and nitric acid, and is preferably hydrochloric acid or sulfuric acid, and is more preferably hydrochloric acid.

According to the second aspect of the present disclosure, the conditions of the complex acid treatment in step c may be: the weight ratio of the material after alkali treatment, the fluosilicic acid, the inorganic acid and the organic acid is 1 (0.01-0.45) to (0.01-0.55) on a dry basis, and the weight ratio of the material after alkali treatment, the fluosilicic acid, the inorganic acid and the organic acid is 1 (0.05-0.3) to (0.1-0.3) on a dry basis. The treatment temperature of the composite acid can be 25-100 ℃, and the treatment time can be 0.5-6 hours.

According to the second aspect of the present disclosure, in order to reduce the sodium content of the catalyst, the method may further comprise: and c, performing second roasting treatment on the material subjected to the composite acid treatment obtained in the step c to obtain a material subjected to second roasting treatment, performing ammonium exchange treatment on the material subjected to the second roasting treatment to obtain a material subjected to ammonium exchange treatment, and performing phosphorus modification treatment, load metal treatment and first roasting treatment. The second firing treatment is well known to those skilled in the art, and for example, the conditions of the second firing treatment may include: the atmosphere of the second roasting treatment is air atmosphere, nitrogen atmosphere or water vapor atmosphere, and the water vapor atmosphere is 1-100% of water vapor, preferably 100% of water vapor; the temperature of the roasting treatment is 400-800 ℃, preferably 500-600 ℃, and the time of the roasting treatment is at least 0.5 hour, preferably 0.5-8 hours.

According to a second aspect of the present disclosure, the ammonium exchange treatment is well known to those skilled in the art, for example, the ammonium exchange treatment may comprise: mixing the roasted material with an ammonium salt, wherein the roasted material may be: ammonium salt: h₂O is 1: (0.1-1): (5-10) the weight ratio is filtered after 0.5-2 hours of exchange at room temperature to 100 ℃, and this exchange process is repeated 1-4 times so that the catalytic cracking catalyst has a sodium content of less than 0.15% by weight, based on the total dry weight of the catalytic cracking catalyst, calculated as sodium oxide. The ammonium salt may be a commonly used inorganic ammonium salt, and for example, the ammonium salt may be at least one selected from the group consisting of ammonium chloride, ammonium sulfate, ammonium carbonate, ammonium bicarbonate, ammonium acetate, and ammonium nitrate.

According to a second aspect of the present disclosure, the phosphorus modification treatment in step d is well known to those skilled in the art, for example, the phosphorus modification treatment may comprise: the molecular sieve is impregnated and/or ion-exchanged with a phosphorus-containing compound, which may be at least one selected from the group consisting of phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate.

According to the second aspect of the present disclosure, the supported metal treatment in step d is well known to those skilled in the art, and means that the supported metal is supported on the catalyst by a supporting means, for example, a compound containing at least one supported metal selected from iron, cobalt, nickel, copper, manganese, zinc, tin and titanium may be supported on the catalyst by an impregnation method, the compound containing the supported metal may be a water-soluble salt of the supported metal, for example, at least one of a sulfate, a nitrate and a chloride, and the compound containing the supported metal is preferably iron sulfate, cobalt sulfate, nickel sulfate, copper sulfate, manganese sulfate, zinc sulfate, tin sulfate, titanium sulfate, iron nitrate, cobalt nitrate, nickel nitrate, copper nitrate, manganese nitrate, zinc nitrate, tin nitrate, titanium nitrate, iron chloride, cobalt chloride, nickel chloride, copper chloride, manganese chloride, tin nitrate, titanium chloride, iron chloride, cobalt chloride, nickel chloride, copper chloride, manganese chloride, zinc sulfate, tin nitrate, titanium nitrate, iron nitrate, At least one of zinc chloride, tin chloride and titanium chloride; the loading method may also include other common metal loading methods, and the present invention is not limited thereto.

According to a specific embodiment of the second aspect of the present disclosure, the phosphorus modification treatment and the metal-supporting treatment may be performed in three ways:

1. and c, pulping the material treated by the composite acid and the calculated amount of the aqueous solution of the phosphorus-containing compound at the temperature of between room temperature and 95 ℃, uniformly drying, roasting at the temperature of between 400 and 800 ℃, uniformly mixing with the calculated amount of the aqueous solution of the compound which contains at least one load metal of iron, cobalt, nickel, copper, manganese, zinc, tin and titanium at the temperature of between room temperature and 95 ℃, and drying.

2. And c, pulping the material treated by the composite acid and a calculated amount of phosphorus-containing compound aqueous solution at room temperature to 95 ℃, uniformly drying, and then uniformly mixing the material treated by the composite acid and the calculated amount of compound aqueous solution loaded with at least one metal of iron, cobalt, nickel, copper, manganese, zinc, tin and titanium at room temperature to 95 ℃, and drying, wherein the sequence of soaking the two solutions can also be reversed.

3. C, uniformly mixing the material treated by the composite acid obtained in the step c with a calculated amount of mixed aqueous solution of a phosphorus-containing compound and a metal-loaded compound containing at least one of iron, cobalt, nickel, copper, manganese, zinc, tin and titanium at room temperature to 95 ℃, and drying;

when the phosphorus modification treatment and the metal-loading treatment are carried out in an ion exchange manner, the material obtained in the step c after the composite acid treatment is pulped with calculated amount of aqueous solution of phosphorus-containing compound at room temperature to 95 ℃ and dried evenly, and then is roasted at 400-800 ℃, and then is mixed with calculated amount of aqueous solution of metal-loading compound containing at least one of iron, cobalt, nickel, copper, manganese, zinc, tin and titanium according to the following ratio of 1: and (5) uniformly mixing the solid-liquid ratio, stirring at 80-95 ℃ for 2-3 hours, filtering, repeatedly exchanging for multiple times, washing the sample obtained after exchanging for multiple times by using water, and drying.

According to a second aspect of the present disclosure, the first firing treatment in step d is well known to those skilled in the art, for example, the conditions of the first firing treatment may include: the atmosphere of the first roasting treatment is air atmosphere, nitrogen 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.

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 material may be rinsed with 5 to 10 times the weight of the material.

A fourth aspect of the present disclosure: there is provided a process for the catalytic cracking of petroleum hydrocarbons, the process comprising: under catalytic cracking conditions, petroleum hydrocarbons are subjected to a contact reaction with a catalytic cracking catalyst provided in the first or third aspect of the present disclosure. Preferably, the petroleum hydrocarbon comprises naphtha.

The catalytic cracking process described in the present disclosure is a conventional process in the petroleum processing field, and the operating conditions, raw materials, etc. are well known to those skilled in the art, and unless otherwise specified, the meaning of the process includes all petroleum hydrocarbon processing processes based on cracking reactions, including catalytic cracking processes aimed at the production of olefins. For example, the reaction conditions for the catalytic cracking may include: the reaction temperature can be 400-700 ℃, the pressure can be 0-0.2 MPa, the water-oil ratio can be 0.2-1, and the mass ratio of the catalyst to the petroleum hydrocarbon can be (4-15): 1.

the present disclosure is further illustrated by the following examples, which are not intended to be limiting and the instruments and reagents used in the examples of the present disclosure are those commonly used by those skilled in the art unless otherwise specified.

The influence of the catalytic cracking catalyst on the propylene yield and the BTX yield in the catalytic cracking of petroleum hydrocarbon is evaluated by using raw material oil ACE. The catalyst was aged at 800 ℃ under 100% water vapor for 14 hours, and evaluated on a fixed fluidized bed microreaction ACE device under conditions of a reaction temperature of 630 ℃ and a regeneration temperature of 670 ℃ with a catalyst-to-oil ratio of 10 (by weight ratio) as raw material oil (see Table 3 for composition and properties).

The total specific surface area, the mesoporous volume and the total pore volume of the catalyst are measured by a nitrogen adsorption BET specific surface area method, and are measured by AS-3 and AS-6 static nitrogen adsorbers produced by Quantachrome instruments, and the specific method comprises the following steps: 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 N₂An adsorption-desorption isothermal curve, then the total specific surface area is calculated by utilizing a BET formula with two parameters, and the specific pressure P/P is taken₀The adsorption capacity of 0.98 or less is the total pore volume of the sample, the pore size distribution of the mesoporous portion is calculated by the BJH formula, and the mesoporous volume is calculated by the integration method.

The mesoporous protonic acid amount is measured by adopting a 2, 6-di-tert-butylpyridine adsorption infrared acidity method, and is measured by adopting a Vertex70 instrument produced by Bruker instruments company, and the specific method comprises the following steps: the catalyst was pressed to 10mg/cm²Into a band of CaF₂In the infrared cell of the window, firstly, the vacuum is pumped at 400 ℃, and thenReducing the temperature to 150 ℃ to adsorb the 2, 6-di-tert-butylpyridine for 15 minutes, then vacuumizing for 1 hour, reducing the temperature to room temperature to collect a spectrogram, and calculating the amount of the protonic acid. See Applied Catalysis A, General, 294, 2005: 92.

total acid content adopts NH₃The TPD method is used for measurement, and an Autochem II 2920 programmed temperature desorption instrument of Michman, USA, and the method comprises the following steps: weighing 0.2g of sample to be detected, placing the sample into a sample tube, placing the sample tube in a thermal conductivity cell heating furnace, taking He gas as carrier gas (50mL/min), raising the temperature to 600 ℃ at the speed of 20 ℃/min, purging impurities adsorbed on the surface of the catalyst for 60min, then reducing the temperature 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 blow with He gas for 90min until the baseline is stable so as to desorb the physically adsorbed ammonia gas; heating to 600 ℃ at the heating rate of 10 ℃/min for desorption, keeping for 30min, and finishing desorption; and detecting the change of gas components by adopting a TCD detector, and automatically integrating by an instrument to obtain the total acid amount.

The sodium content, the phosphorus content and the content of the supported metal of the catalyst are determined by a GB/T30905-2014 standard method.

In each of the examples and comparative examples:

BTX yield (%) - (mass of BTX in product-mass of BTX in reaction)/mass of reaction × 100%

The propylene yield (%) -. mass of propylene in the product/mass of the reactant × 100%

The properties of the raw materials used in the examples and comparative examples are as follows: kaolin (purchased from china kaolin, su, with a solids content of 75 wt%), montmorillonite (purchased from red rock bentonite, koro, lou, inc., with a solids content of 75 wt%), alumina sol (purchased from zilu catalyst division, with an alumina content of 22.5 wt%), silica sol (purchased from Qingdao ocean chemical Limited, with a silica content of 25.5 wt%, pH 3.0), Beta molecular sieve (purchased from zilu catalyst division).

Example 1

470.6g of silica sol and 112g of kaolin are mixed, and are prepared into slurry with the solid content of 26.8 weight percent by using decationized water, 96g of beta molecular sieve is added after stirring for 2 hours to form slurry with the solid content of 35 weight percent, spray drying is carried out after continuous stirring, and then the slurry is roasted for 2 hours at 500 ℃ to prepare the spray-dried microsphere A1.

Taking 200g of the spray-dried microspheres A1 (dry basis weight) prepared above, adding water, pulping to obtain slurry with solid content of 10 wt%, adding 15.6g 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 a filter cake, pulping to obtain slurry with the solid content of 10 wt%, adding 6.2g of oxalic acid while stirring, then adding 54g of hydrochloric acid (the mass fraction is 10%) and 145g of fluosilicic acid (the concentration is 3%) in a concurrent flow manner, heating to 50 ℃, stirring at a constant temperature for 1h, filtering, washing and drying, roasting at 550 ℃ for 2 h, and then according to the weight of the roasted materials: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain slurry with the solid content of 40 weight percent, and adding 12.8gH₃PO₄(85% strength) and 17.6gFe (NO)₃)₃·9H₂Dissolving O in 90g of water, mixing and soaking the dissolved O with the slurry, drying the mixture, and roasting the mixture at 550 ℃ for 2 hours to obtain a catalyst sample A, wherein the phosphorus content of the catalyst sample A is 3.45 percent by weight, the iron content of the catalyst sample A is 3.48 percent by weight, and other physical and chemical properties are listed in Table 1; the ACE evaluation data of the raw oil after aging of the catalyst sample A at 800 ℃ and 100% steam for 14h is shown in Table 1.

Comparative example 1

200g of the spray-dried microspheres A1 (dry mass) prepared in example 1 were slurried with water to a solids content of 10% by weight, and 30.1g of an overbased sodium metaaluminate solution (Na) were 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, washing and drying are carried out, after the roasting treatment is carried out for 2 h at 550 ℃, according to the weight of the roasted material: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; filtering the filter cakeAdding water, pulping to obtain slurry with solid content of 40 wt%, adding 12.8g H₃PO₄(85% strength) and 17.6gFe (NO)₃)₃·9H₂Dissolving O in 90g of water, mixing and soaking the dissolved O with the slurry, drying the mixture, and roasting the mixture at 550 ℃ for 2 hours to obtain a catalyst sample A, wherein the phosphorus content of the catalyst sample A is 3.43 weight percent, the iron content of the catalyst sample A is 3.44 weight percent, and other physical and chemical properties are listed in Table 1; the ACE evaluation data of the feedstock oil after aging of the catalyst sample DB1 at 800 ℃ and 100% steam for 14h is shown in Table 1.

Comparative example 2

200g of spray-dried microspheres A1 (dry basis weight) prepared in example 1 was added with water to prepare a slurry with a solid content of 10 wt%, 6.0g of oxalic acid was added while stirring, 55g of hydrochloric acid (mass fraction: 10%) and 145g of fluorosilicic acid (concentration: 3%) were slowly added dropwise, the mixture was heated to 50 ℃ and stirred at a constant temperature for 1 hour, filtered, washed and dried, and after baking at 550 ℃ for 2 hours, the baked materials were: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain slurry with the solid content of 40 weight percent, and adding 12.8gH₃PO₄(85% strength) and 17.6gFe (NO)₃)₃·9H₂O was dissolved in 90g of water, mixed with the slurry, impregnated, dried, and calcined at 550 ℃ for 2 hours to obtain a catalyst sample A, the phosphorus content of which was 3.39% by weight and the iron content of which was 3.37% by weight, and other physicochemical properties are shown in Table 1, and the ACE evaluation data of the raw oil after aging of catalyst sample DB2 with 100% steam at 800 ℃ for 14 hours are shown in Table 1.

Comparative example 3

200g of spray-dried microspheres A1 (dry basis weight) prepared in example 1 were added with water to prepare a slurry with a solid content of 10 wt%, 18.7g of NaOH (purity 96%) was added, the mixture was heated to 50 ℃ and stirred at constant temperature for 0.5h, filtered and washed to neutrality; adding water into the filter cake, pulping to obtain slurry with the solid content of 10 wt%, adding 12.7g of oxalic acid while stirring, then adding 246g of hydrochloric acid (the mass fraction is 10%), heating to 50 ℃, stirring for 1h at constant temperature, filtering, washing and drying, roasting at 550 ℃ for 2 h, and finally obtaining the productThe roasted material is prepared by the following steps of (1) according to the weight of a dry basis: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain slurry with the solid content of 40 weight percent, and adding 12.8gH₃PO₄(85% strength) and 17.6gFe (NO)₃)₃·9H₂O was dissolved in 90g of water, mixed with the slurry, impregnated, dried, and calcined at 550 ℃ for 2 hours to obtain a catalyst sample A having a phosphorus content of 3.42% by weight and an iron content of 3.47% by weight, other physicochemical properties shown in Table 1, and raw oil ACE evaluation data shown in Table 1 after aging of catalyst sample DB3 at 800 ℃ for 14 hours with 100% steam.

Comparative example 4

200g of spray-dried microspheres A1 (dry basis weight) prepared in example 1 were added with water to prepare a slurry with a solid content of 10 wt%, 13.2g of NaOH (purity 96%) was added, the mixture was heated to 50 ℃ and stirred at constant temperature for 0.5h, filtered and washed to neutrality; adding water into the filter cake, pulping to obtain slurry with the solid content of 10 weight percent, adding 41.5g of oxalic acid while stirring, heating to 50 ℃, stirring for 1h at constant temperature, filtering, washing and drying, roasting at 550 ℃ for 2 h, and then, according to the weight of the roasted materials: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain slurry with the solid content of 40 weight percent, and adding 12.8gH₃PO₄(85% strength) and 17.6gFe (NO)₃)₃·9H₂O was dissolved in 90g of water, mixed with the slurry, impregnated, dried, and calcined at 550 ℃ for 2 hours to obtain a catalyst sample A having a phosphorus content of 3.44% by weight and an iron content of 3.40% by weight, other physicochemical properties shown in Table 1, and raw material ACE evaluation data shown in Table 1 after aging of catalyst sample DB4 at 800 ℃ for 14 hours with 100% steam.

Comparative example 5

200g of the spray-dried microspheres A1 (dry mass) prepared in example 1 were slurried with water to a solids content of 10% by weight, and 1 was added3.2g KOH (96 percent of purity), heating to 50 ℃, and stirring for 0.5h at constant temperature; adding water into the filter cake, pulping to obtain slurry with the solid content of 10 weight percent, adding 31.2g of oxalic acid while stirring, then slowly dropwise adding 112g of fluosilicic acid (the concentration is 3%), heating to 50 ℃, stirring for 1 hour at constant temperature, filtering, washing and drying, roasting at 550 ℃ for 2 hours, and then roasting according to the weight of the roasted materials: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain slurry with the solid content of 40 weight percent, and adding 12.8gH₃PO₄(85% strength) and 17.6gFe (NO)₃)₃·9H₂O was dissolved in 90g of water, mixed with the slurry, impregnated, dried, and calcined at 550 ℃ for 2 hours to obtain a catalyst sample A having a phosphorus content of 3.45% by weight and an iron content of 3.45% by weight, other physicochemical properties shown in Table 1, and raw oil ACE evaluation data shown in Table 1 after aging of catalyst sample DB5 at 800 ℃ for 14 hours with 100% steam.

Comparative example 6

200g of spray-dried microspheres A1 (dry basis weight) prepared in example 1 were added with water to prepare a slurry with a solid content of 10 wt%, 13.2LiOH (purity 96%) was added, and the mixture was heated to 50 ℃ and stirred at constant temperature for 0.5 h; adding water into the filter cake, pulping to obtain slurry with the solid content of 10 weight percent, adding 175g of hydrochloric acid (mass fraction of 10%) while stirring, slowly dropwise adding 112g of fluosilicic acid (concentration of 3%), heating to 50 ℃, stirring at constant temperature for 1h, filtering, washing and drying, roasting at 550 ℃ for 2 h, and then, according to the weight of the roasted materials: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain slurry with the solid content of 40 weight percent, and adding 12.8gH₃PO₄(85% strength) and 17.6gFe (NO)₃)₃·9H₂Dissolving O in 90g of water, mixing and soaking with the slurry, drying, and roasting at 550 ℃ for 2 hours to obtain a catalyst sample A, wherein the phosphorus content of the catalyst sample A is 3.42 weight percent, the iron content is 3.43 weight percent, and the physicochemical properties of the catalyst sample A are other than the phosphorus content and the iron content of the catalyst sample AThe qualities are shown in Table 1, and the ACE evaluation data of the raw oil after aging at 800 ℃ and 100% steam for 14h is shown in Table 1.

Comparative example 7

200g of spray-dried microspheres A1 (dry basis weight) prepared in example 1 were added with water to prepare a slurry with a solid content of 10 wt%, 13.2LiOH (purity 96%) was added, and the mixture was heated to 50 ℃ and stirred at constant temperature for 0.5 h; adding water into the filter cake, pulping to obtain slurry with the solid content of 10 weight percent, slowly dropwise adding 112g of fluosilicic acid (the concentration is 3%) while stirring, heating to 50 ℃, stirring for 1h at constant temperature, filtering, washing and drying, roasting at 550 ℃ for 2 h, and then, according to the weight of the roasted materials: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain slurry with the solid content of 40 weight percent, and adding 12.8gH₃PO₄(85% strength) and 17.6gFe (NO)₃)₃·9H₂O was dissolved in 90g of water, mixed with the slurry, impregnated, dried, and calcined at 550 ℃ for 2 hours to obtain a catalyst sample A having a phosphorus content of 3.38% by weight and an iron content of 3.47% by weight, other physicochemical properties shown in Table 1, and the ACE evaluation data of the feedstock oil after aging at 800 ℃ and 100% steam for 14 hours are shown in Table 1.

Comparative example 8

200g of spray-dried microspheres A1 (dry basis weight) prepared in example 1 were added with water to prepare a slurry with a solid content of 10 wt%, 13.2LiOH (purity 96%) was added, and the mixture was heated to 50 ℃ and stirred at constant temperature for 0.5 h; adding water into the filter cake, pulping to obtain slurry with the solid content of 10 wt%, adding 175g of hydrochloric acid (mass fraction of 10%) while stirring, heating to 50 ℃, stirring for 1h at constant temperature, filtering, washing and drying, roasting at 550 ℃ for 2 h, and then, according to the weight of the roasted materials: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain slurry with the solid content of 40 weight percent, and adding 12.8gH₃PO₄(85% strength) and 17.6gFe (NO)₃)₃·9H₂O solutionThe slurry was mixed and impregnated in 90g of water, and then dried, and calcined at 550 ℃ for 2 hours to obtain a catalyst sample A, the phosphorus content of which was 3.43% by weight and the iron content of which was 3.45% by weight, and other physicochemical properties are shown in Table 1, and the ACE evaluation data of the feedstock oil after aging with 100% steam at 800 ℃ for 14 hours are shown in Table 1.

Example 2

266.7g of alumina sol and 152g of montmorillonite are mixed and prepared into slurry with the solid content of 23.8 weight percent by using decationized water, 126g of beta molecular sieve is added after stirring for 1 hour to form slurry with the solid content of 35 weight percent, spray drying is carried out after continuous stirring, and then roasting is carried out for 2 hours at 350 ℃ to prepare the spray-dried microsphere B1.

Taking 200g of the spray-dried microspheres B1 (dry basis weight) prepared above, adding water to prepare slurry with the solid content of 10 weight percent, adding 20.5g of NaOH (with the purity of 96 percent), heating to 90 ℃, stirring at constant temperature for 0.5h, filtering and washing to be neutral; adding water into a filter cake, pulping to obtain slurry with the solid content of 10 wt%, adding 25.1g of oxalic acid while stirring, then adding 120g of sulfuric acid (the mass fraction is 10%) and 966.7g of fluosilicic acid (the concentration is 3%) in a concurrent flow manner, heating to 50 ℃, stirring at a constant temperature for 1h, filtering, washing and drying, roasting at 550 ℃ for 2 h, and then according to the weight of the roasted materials: ammonium salt: h₂O is 1: 0.5: 5 at room temperature for 0.5 hour, repeating the exchange process for 4 times, drying to obtain filter cake, adding water into the filter cake, pulping to obtain slurry with solid content of 40 wt%, and adding 9.3g (NH)₄)₂HPO₄And 29.1gZn (NO)₃)₂·6H₂O was dissolved in 90g of water, mixed with the slurry, impregnated, dried, and calcined at 550 ℃ for 2 hours to obtain a catalyst sample B having a phosphorus content of 4.58 wt% and a zinc content of 8.05 wt%, other physicochemical properties shown in Table 2, and the ACE evaluation data of the feedstock oil after aging at 800 ℃ for 14 hours with 100% steam are shown in Table 2.

Example 3

200g of the spray-dried microspheres B1 (dry mass) prepared in example 2 were slurried with water to a solids content of 10% by weight, and 33.1g KOH were added(purity 96%), heating to 50 ℃, stirring for 0.5h at constant temperature, filtering and washing to be neutral; adding water into a filter cake, pulping to obtain slurry with the solid content of 10 wt%, adding 34.2g of oxalic acid while stirring, then adding 235g of hydrochloric acid (the mass fraction is 10%) and 98g of fluosilicic acid (the concentration is 3%) in a concurrent flow manner, heating to 50 ℃, stirring at a constant temperature for 1h, filtering, washing and drying, roasting at 550 ℃ for 2 h, and then according to the weight of the roasted materials: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; adding water into the filter cake and pulping to obtain slurry with the solid content of 40 weight percent at 19.5gH₃PO₄(concentration 85%) adding 180g water, mixing with above slurry, soaking, oven drying, and baking at 550 deg.C for 2 hr; the phosphorus modified sample is mixed with Cu (NO) with the concentration of 6 percent according to the solid-liquid weight ratio of 5.2:1₃)₂The solution is exchanged for 2 hours at 80-90 ℃, filtered and exchanged for a plurality of times until the target amount is reached, and roasting treatment is carried out for 2 hours at 550 ℃ to obtain a catalyst sample C, wherein the phosphorus content of the catalyst sample C is 5.53 percent by weight, the copper content is 1.59 percent by weight, other physicochemical properties are shown in Table 2, and the ACE evaluation data of raw oil is shown in Table 2 after the catalyst sample C is aged for 14 hours at 800 ℃ and 100 percent of water vapor.

Example 4

200g of the spray-dried microspheres B1 (dry basis weight) prepared in example 2 were taken, water was added to prepare a slurry with a solid content of 10 wt%, 21.2g of NaOH (purity 96%) was added, the mixture was heated to 50 ℃ and stirred at constant temperature for 0.5h, filtered and washed to neutrality; adding water into a filter cake, pulping to obtain slurry with the solid content of 10 wt%, adding 5.6g of citric acid while stirring, then adding 247g of hydrochloric acid (the mass fraction is 10%) and 145g of fluosilicic acid (the concentration is 3%) in a concurrent flow manner, heating to 50 ℃, stirring at a constant temperature for 1h, filtering, washing and drying, roasting at 550 ℃ for 2 h, and then, according to the weight of the roasted materials: ammonium salt: h₂O is 1: 0.5: 5, performing ammonium exchange treatment at room temperature for 0.5 hour, filtering, repeating the exchange process for 4 times, and drying to obtain a filter cake; adding water into the filter cake, pulping to obtain slurry with solid content of 40 wt%, adding 1.95gH₃PO₄(concentrated)Degree 85%) and 35.4gCo (NO)₃)·6H₂O was dissolved in 90g of water, mixed with the slurry, impregnated, dried, and calcined at 550 ℃ for 2 hours to obtain a catalyst sample D, the phosphorus content of which was 0.52% by weight and the cobalt content of which was 9.10% by weight, and other physicochemical properties are shown in Table 2, and the ACE evaluation data of the feedstock oil after aging the catalyst sample D at 800 ℃ for 14 hours with 100% steam are shown in Table 2.

Comparative example 9

The basic procedure of this comparative example was as in example 1 except that the alkali treatment, complex acid treatment, phosphorus modification treatment and metal-supporting treatment were not conducted, and the obtained sample was comparative sample I whose physicochemical properties are shown in Table 2 and raw oil ACE evaluation data are shown in Table 2.

Comparative example 10

The basic procedure of this comparative example was as in example 1 except that phosphorus modification treatment and metal-loaded treatment were not conducted, and the obtained sample was comparative sample II whose physicochemical properties are shown in Table 2 and raw oil ACE evaluation data are shown in Table 2.

Comparative example 11

The basic procedure of this comparative example was as in example 1 except that no phosphorus modification treatment was carried out, and the sample obtained was comparative sample III, whose physicochemical properties are shown in Table 2 and raw oil ACE evaluation data are shown in Table 2.

Comparative example 12

The basic procedure of this comparative example was as in example 1 except that no metal-supporting treatment was carried out, and the obtained sample was comparative sample IV whose physicochemical properties are shown in Table 2 and raw oil ACE evaluation data are shown in Table 2.

As can be seen from the data in tables 1 and 2, the results were compared with the catalytic cracking results obtained by treating with alkali only (DB1), or with a complex acid consisting of fluosilicic acid, an organic acid and an inorganic acid only (DB2), or with organic acid oxalic acid alone (DB4), or with inorganic acid hydrochloric acid alone (DB8), or with fluosilicic acid alone for dealumination (DB7), or with both organic acid oxalic acid and inorganic acid hydrochloric acid (DB3), or with fluosilicic acid complex organic acid oxalic acid (DB5), or with fluosilicic acid complex inorganic acid hydrochloric acid (DB6)The catalyst adopts the method of preparing the conventional Beta molecular sieve into the catalyst and then carrying out acid-base coupling treatment to modulate the pore structure of the molecular sieve, so that the newly generated mesopores can be ensured not to be blocked, and the total specific surface area of the catalyst can be 240-350 m-²The proportion of the mesoporous protonic acid in the total acid is 20-70%, the mesoporous volume is 0.14-0.35ml/g, and the proportion of the mesoporous volume in the total pore volume is 35-60%. When the catalyst prepared by the method is used for naphtha catalytic cracking, the yield of BTX can be improved by 5-150%, the yield of propylene can be improved by 1-170%, and in addition, the selectivity of liquefied gas in products can be improved, and the selectivity of diesel oil and coke can be reduced.

TABLE 1

TABLE 2

TABLE 3

Claims

1. A catalytic cracking catalyst comprises 24-75 wt% of BEA structure molecular sieve based on dry weight of the catalyst, 5-65 wt% of natural clay based on dry weight, 10-60 wt% of inorganic oxide binder based on oxide, and P₂O₅0.1-15 wt% of phosphorus additive and 0.1-15 wt% of metal additive calculated by metal oxide, wherein the proportion of mesoporous protonic acid in the catalyst is 20-70% of total acid; the mesoporous protonic acid content is measured by adopting a 2, 6-di-tert-butylpyridine adsorption infrared acidity method, and the mesoporous protonic acid has a kinetic diameter of

The 2, 6-di-tert-butylpyridine molecule can contact with protonic acid.

2. The catalyst of claim 1, wherein P is₂O₅The phosphorus additive is present in an amount of from 0.5 to 6.5 wt.% based on the dry weight of the catalyst, and the metal additive is present in an amount of from 0.5 to 10 wt.% based on the dry weight of the catalyst and calculated as the metal oxide.

3. The catalyst as claimed in claim 1, wherein the total specific surface area of the catalyst is 240-350m²The proportion of mesoporous protonic acid in the total acid is 25-50%.

4. The catalyst according to claim 1, wherein the catalyst has a mesopore volume of 0.14-0.35ml/g, and the proportion of the mesopore volume to the total pore volume is 35-60%.

5. The catalyst according to claim 1, wherein the natural clay is at least one selected from the group consisting of kaolin, montmorillonite, diatomaceous earth, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite, and rectorite; the inorganic oxide binder is at least one selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, and amorphous silica-alumina.

6. The catalyst according to claim 1, wherein the metal is at least one selected from the group consisting of iron, cobalt, nickel, copper, manganese, zinc, tin, and titanium.

7. The catalyst according to any one of claims 1 to 4, wherein the total specific surface area, mesoporous volume and total pore volume of the catalyst are measured using a nitrogen adsorption BET specific surface area method; the total acid content adopts NH₃The TPD method is used for the measurement.

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

a. mixing and pulping BEA structure molecular sieve, natural clay, inorganic oxide binder precursor and water uniformly, and then spray-drying the obtained slurry to obtain spray-dried microspheres, wherein the spray-dried microspheres comprise 25-75 wt% of BEA structure molecular sieve based on the dry weight, 5-65 wt% of natural clay based on the dry weight, and 10-60 wt% of inorganic oxide binder precursor based on the oxide;

b. b, performing alkali treatment on the spray-dried microspheres obtained in the step a, and filtering and washing to obtain an alkali-treated material;

c. b, performing composite acid treatment on the material subjected to the alkali treatment in a composite acid solution consisting of fluosilicic acid, organic acid and inorganic acid, and filtering and washing to obtain a material subjected to the composite acid treatment;

d. c, carrying out phosphorus modification treatment, metal loading treatment and first roasting treatment on the material subjected to the composite acid treatment obtained in the step c to obtain a catalytic cracking catalyst, wherein P is used₂O₅The content of the phosphorus additive is 0.1-15 wt% calculated by the dry weight of the catalyst, and the content of the metal additive is 0.1-15 wt% calculated by the metal oxide and calculated by the dry weight of the catalyst;

wherein the mesoporous protonic acid content of the catalyst accounts for 20-70% of the total acid content; the mesoporous protonic acid content is measured by adopting a 2, 6-di-tert-butylpyridine adsorption infrared acidity method, and the mesoporous protonic acid has a kinetic diameter of

The 2, 6-di-tert-butylpyridine molecule can contact with protonic acid.

9. The method as claimed in claim 8, wherein the total specific surface area of the catalyst is 240-350m²(g) mesoporous protonsThe acid accounts for 25-50% of the total acid.

10. The method of claim 8, wherein the catalyst has a mesopore volume of 0.14-0.35ml/g, and the proportion of the mesopore volume to the total pore volume is 35-60%.

11. The method according to any one of claims 8 to 10, wherein the total specific surface area, mesoporous volume and total pore volume of the catalyst are measured using a nitrogen adsorption BET specific surface area method; the total acid content adopts NH₃The TPD method is used for the measurement.

12. The method according to claim 8, wherein the natural clay in step a is at least one selected from the group consisting of kaolin, montmorillonite, diatomaceous earth, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite and rectorite; the inorganic oxide binder precursor is at least one selected from silica sol, aluminum sol, peptized pseudo-boehmite, silica-alumina sol and phosphorus-containing aluminum sol.

13. The method of claim 8, wherein the alkali treatment in step b comprises: mixing the spray-dried microspheres with an alkaline solution, wherein the alkaline solution is at least one selected from a sodium hydroxide solution, a potassium hydroxide solution, a lithium hydroxide solution, ammonia water and a high-alkali sodium metaaluminate solution.

14. The method of claim 13, wherein the conditions of mixing comprise: the weight ratio of the spray dried microspheres to the base in the alkaline solution on a dry basis is 1: (0.01-0.35); 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.

15. The method of claim 14, wherein the weight ratio of the spray dried microspheres and the base in the alkaline solution on a dry basis is 1: (0.05-0.25).

16. The method according to claim 8, wherein the organic acid in step c 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.

17. The method of claim 8, wherein the conditions of the complex acid treatment in step c are: the weight ratio of the material after alkali treatment, the fluosilicic acid, the inorganic acid and the organic acid is 1: (0.01-0.45): (0.01-0.45): (0.01-0.55).

18. The method of claim 17, wherein the conditions of the complex acid treatment in step c are: the weight ratio of the alkali-treated material, the fluosilicic acid, the inorganic acid and the organic acid is 1: (0.05-0.3): (0.1-0.3): (0.1-0.3).

19. The method of claim 8, wherein the method further comprises: and c, performing second roasting treatment on the material subjected to the composite acid treatment obtained in the step c to obtain a material subjected to second roasting treatment, performing ammonium exchange treatment on the material subjected to the second roasting treatment to obtain a material subjected to ammonium exchange treatment, and performing phosphorus modification treatment, load metal treatment and first roasting treatment.

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

21. The process of claim 19, wherein the ammonium exchange treatment results in a sodium content of the catalytic cracking catalyst of less than 0.15 wt.%, based on sodium oxide and total dry basis weight of the catalytic cracking catalyst; the ammonium exchange treatment comprises: and mixing the material after the second roasting treatment with ammonium salt, wherein the ammonium salt is at least one selected from ammonium chloride, ammonium sulfate, ammonium carbonate, ammonium bicarbonate, ammonium acetate and ammonium nitrate.

22. The method of claim 8, wherein the phosphorus modification treatment in step d comprises: and (2) impregnating and/or ion exchanging the molecular sieve with a phosphorus-containing compound, wherein the phosphorus-containing compound is at least one selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate.

23. The method of claim 8, wherein the supported metal treatment in step d comprises: the supported metal containing a compound of the supported metal, which is at least one selected from the group consisting of iron, cobalt, nickel, copper, manganese, zinc, tin and titanium, is supported on a catalyst by an impregnation method, and the compound of the supported metal is a water-soluble salt containing the supported metal.

24. The method according to claim 23, wherein the metal-supporting compound is at least one selected from the group consisting of a sulfate, a nitrate and a chloride containing the supporting metal.

25. The method of claim 8, wherein the conditions of the first firing treatment in step d include: the atmosphere of the first roasting treatment is air atmosphere, nitrogen atmosphere or water vapor atmosphere; the roasting temperature is 400-800 ℃, and the roasting time is 0.5-8 hours.

26. A catalytic cracking catalyst, characterized in that it is prepared by the process according to any one of claims 8-25.

27. A process for the catalytic cracking of petroleum hydrocarbons, the process comprising: a petroleum hydrocarbon is subjected to a contact reaction with the catalytic cracking catalyst of any one of claims 1 to 7 and 26 under catalytic cracking conditions.