A heavy oil catalytic cracking catalyst and a preparation method thereof

Abstract

The present application provides a heavy oil catalytic cracking catalyst, comprising 5-20 mass% of Y type molecular sieve based on dry basis, 10-40 mass% of ZSM-5 type molecular sieve modified by phosphorus and metal oxide composite based on dry basis, 20-40 mass% of inorganic oxide binder based on oxide, 10-45 mass% of clay based on dry basis and 0.5-6 mass% of silicon-based nanometer rare earth composite material based on dry basis, based on total mass of the catalyst; the preparation method of the silicon-based nanometer rare earth composite material is as follows: mixing water-soluble rare earth compound, silicon-based mesoporous molecular sieve, deionized water and organic alcohol, stirring, drying and roasting to obtain rare earth silicon-based mesoporous molecular sieve, mixing the rare earth silicon-based mesoporous molecular sieve with alkaline substance solution, water glass and surfactant, uniformly mixing, then performing temperature increasing recrystallization reaction, filtering, washing and drying the reaction product to obtain the silicon-based nanometer rare earth composite material.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of catalytic cracking catalysts, and particularly relates to a heavy oil catalytic cracking catalyst and a preparation method. BACKGROUND

[0002] After 70 years of development, catalytic cracking process is not only mature, but also continuously improved, with flexible operation, relatively mild conditions, low pressure grade, and the ability to produce high-octane gasoline components and low-carbon olefins. In particular, based on catalytic cracking, a catalytic cracking process technology with higher reaction severity is developed to produce propylene, butene and other light olefins while co-producing ethylene. These low-carbon olefins become an important source of low-cost basic chemical raw materials and an important way for refineries to improve efficiency.

[0003] As the core technology of catalytic cracking, catalysts, whether used alone or in conjunction with special processes, fully demonstrate the outstanding advantages of low cost, good effect, and flexible use. Compared with the catalytic cracking reaction temperature of about 520℃, the catalytic cracking reaction temperature can be between 550-680℃ according to needs, and the catalyst has the greatest impact on the reaction product distribution. It can be said that the catalyst is the key to the progress of catalytic cracking technology. With the increase of reaction severity and the requirement of increasing the yield of low-carbon olefins, the carrier, shape-selective molecular sieve, and Y molecular sieve need to have stronger hydrothermal stability, more developed pore structure, higher reaction selectivity, lower coke yield, and stronger feedstock adaptability. These all urgently need to further improve the performance of catalytic materials to meet the demand for efficient catalytic reaction.

[0004] The special catalyst for catalytic cracking process is a microspherical catalyst with shape-selective molecular sieve as the active component, which is an attractive new technology for producing propylene from heavy oil feedstock. Since there are many similarities between the design of catalytic cracking propylene-rich catalysts and catalytic cracking catalysts, the focus of research and development of catalytic cracking catalysts can also be seen from catalytic cracking propylene-rich catalysts.

[0005] CN107974281B discloses a catalytic cracking method for producing low-carbon olefins and light aromatics, which reacts heavy feedstock and light feedstock with catalytic cracking catalysts in multiple reaction zones, and combines process and catalyst to improve the yield of low-carbon olefins and light aromatics.

[0006] CN113070095A discloses a light hydrocarbon catalytic cracking catalyst for producing low-carbon olefins and a preparation method thereof. The catalyst uses MFI structure molecular sieve as the active component, and introduces P2O5, a small amount of alkaline earth metal, iron, manganese and rare earth elements. The invented catalyst has the advantages of high di-olefin yield, low methane yield, and high C4 component secondary cracking rate.

[0007] CN108097303B discloses a preparation method of a catalyst for catalytic cracking of diesel to produce low-carbon olefins. The catalyst is prepared by introducing phosphoric acid into the substrate, using iron and zinc modified ZSM-5 molecular sieve, and introducing modified Y-type molecular sieve, and then spray granulation, water washing and drying. The modified molecular sieve improves the selectivity of low-carbon olefins and improves the wear index.

[0008] CN112642470A discloses a catalyst for catalytic cracking and a preparation method thereof. The active component is HZSM-5 molecular sieve doped with tungsten element and transition metal elements Mn, Cr and Ti. The transition metal doped HZSM-5 zeolite molecular sieve has the characteristics of high temperature resistance, high activity and large specific surface area. The multi-level pore structure is beneficial to reduce the diffusion resistance of reactant molecules in the pore, improve the contact probability of reactant molecules with active sites of the catalyst, and thus improve the yield of olefin, aromatic hydrocarbon and other products.

[0009] CN112642475A discloses a catalytic cracking catalyst for producing low-carbon olefins from hydrocarbon oil. The catalyst comprises BEA structure molecular sieve, MFI structure molecular sieve, optional FAU structure molecular sieve, natural mineral and binder. By using improved aluminum sol binder, the pore structure of the catalyst is strengthened. The catalytic cracking catalyst has good strength and high activity, and is used for catalytic cracking of hydrocarbon oil to produce high yield of low-carbon olefins and high yield of liquefied gas.

[0010] CN112473731A and CN112473732A disclose two kinds of catalytic cracking catalysts and preparation methods thereof by using zirconium-aluminum composite sol and containing BEA structure molecular sieve and MFI structure molecular sieve, respectively. The catalysts have good strength, high activity, high raw material conversion rate and low-carbon olefin yield.

[0011] CN112138710A and CN112138712A disclose two kinds of catalytic cracking catalysts, preparation methods and application methods thereof. The catalytic cracking catalysts contain Y-type molecular sieve, MFI structure molecular sieve containing mesopore, inorganic binder and optional second clay. The catalytic cracking catalysts have high ethylene selectivity in petroleum hydrocarbon catalytic cracking reaction, and can also produce propylene and BTX.

[0012] CN102019200A discloses a highly active catalytic pyrolysis catalyst and its preparation method. This catalytic pyrolysis catalyst is a solid composition with a multi-pore size distribution and different types of catalytic active centers, composed of highly active phosphorus-modified ZSM-5 zeolite, highly active rare-earth-modified Y zeolite, an alumina-based binder, tetracarbonyl nickel vapor deposition-modified porous silicide, and clay as filler. Another important feature is that the pore capacity provided by the mesoporous ZSM-5 zeolite in this catalytic pyrolysis catalyst should be approximately equal to the pore capacity provided by the macroporous Y zeolite. The solid composition slurry is spray-dried to form microspheres of the catalytic pyrolysis catalyst, which exhibits particularly high activity and selectivity when used in a catalytic pyrolysis unit, effectively converting heavy feedstocks and increasing the yield of low-carbon olefins such as ethylene and propylene.

[0013] In summary, catalysts are a crucial factor influencing the product distribution of heavy oil catalytic cracking. Cracking catalysts must possess not only high activity and selectivity but also high stability. Currently, catalysts used in heavy oil catalytic cracking reactions are mainly divided into two types: metal oxides and zeolite molecular sieves. Most domestic catalytic cracking catalysts are based on modifications of ZSM series shape-selective molecular sieves. Although some progress has been made in improving catalyst activity, breakthroughs in the systematic research of high-performance key new materials are needed to simultaneously meet higher demands for activity, selectivity, and hydrothermal stability.

[0014] Catalytic cracking reactions occur at high temperatures. If heavy oil contains high levels of sodium and vanadium, these elements will gradually deposit on the catalyst surface during the reaction. Due to the synergistic effect of vanadium and sodium, the co-existence of sodium and vanadium facilitates the formation of NaOH and H3VO4. Under harsh catalytic cracking conditions, even small amounts of sodium and vanadium can damage the active sites of the catalyst. This necessitates heavy oil catalytic cracking catalysts with high thermal and hydrothermal stability. Furthermore, in the presence of vanadium, the catalyst must possess strong resistance to heavy metal contamination. However, the resistance of rare earth elements to vanadium is closely related to their chemical environment. In conventional preparation methods, rare earth elements are introduced into the preparation system in ionic form. During catalyst preparation and calcination, these rare earth ions migrate to the molecular sieve framework. The interaction between vanadium and the framework rare earth elements disrupts the [RE–OH–RE] structure of the molecular sieve. 5+ The RE–O bond simultaneously abstracts oxygen from the molecular sieve framework, generating stable REVO4, thereby exacerbating the collapse of the framework structure. Summary of the Invention

[0015] The purpose of this invention is to solve the above-mentioned problems by proposing a heavy oil catalytic cracking catalyst. The catalytic cracking catalyst of this invention has excellent resistance to vanadium pollution, good coke selectivity, strong heavy oil conversion ability, and high activity retention rate, and significantly improves the catalyst's resistance to vanadium pollution in application.

[0016] Another objective of this invention is to provide a method for preparing a heavy oil catalytic cracking catalyst.

[0017] To achieve the above objectives, the present invention provides a heavy oil catalytic cracking catalyst, comprising, by total mass of the catalyst, 5-20% by mass (dry basis) of Y-type molecular sieve, 10-40% by mass (dry basis) of ZSM-5 molecular sieve modified with phosphorus and metal oxides, 20-40% by mass (oxide basis) of inorganic oxide binder, 10-45% by mass (dry basis) of clay, and 0.5-6% by mass (dry basis) of silicon-based nano-rare earth composite material.

[0018] The preparation method of the silicon-based rare earth nanocomposite material is as follows: water-soluble rare earth compound, silicon-based mesoporous molecular sieve, deionized water and organic alcohol are mixed, stirred, dried and calcined to obtain rare earth silicon-based mesoporous molecular sieve. The rare earth silicon-based mesoporous molecular sieve is mixed with alkaline substance solution, water glass and surfactant. After mixing evenly, a recrystallization reaction is carried out by heating. The reaction product is filtered, washed and dried to obtain silicon-based rare earth nanocomposite material.

[0019] The heavy oil catalytic cracking catalyst of the present invention comprises a water-soluble rare earth compound, calculated as rare earth oxide, and the mass ratio of the water-soluble rare earth compound, the silica-based mesoporous molecular sieve, the deionized water, and the organic alcohol is 0.1-1:1:1-10:0.1-5.

[0020] The heavy oil catalytic cracking catalyst of the present invention comprises a water glass (calculated as silica), and a rare earth silicon-based mesoporous molecular sieve, an alkaline substance, water glass, and a surfactant in a mass ratio of 1:0.05-0.3:0.01-0.3:0.001-0.05.

[0021] The heavy oil catalytic cracking catalyst of the present invention comprises one or more of the water-soluble rare earth compounds selected from the chloride or nitrate salts of lanthanum, cerium, pyroxene, neodymium, and yttrium.

[0022] The heavy oil catalytic cracking catalyst of the present invention comprises one or more of the following: M41S, SBA, HMS, MSU, and ZSM-5 molecular sieve with a silicon-to-aluminum ratio ≥300 and an average pore size ≥3.0 nm.

[0023] The heavy oil catalytic cracking catalyst of the present invention comprises one or more of ethanol, propanol, ethylene glycol and glycerol.

[0024] The heavy oil catalytic cracking catalyst of the present invention comprises a surfactant that is hexadecyltrimethylammonium bromide and / or hexadecyltrimethylammonium chloride, and an alkaline substance that is sodium hydroxide and / or potassium hydroxide.

[0025] The heavy oil catalytic cracking catalyst of the present invention comprises one or more of HY, USY, REUSY and REY molecular sieves.

[0026] The heavy oil catalytic cracking catalyst of the present invention comprises a phosphorus- and metal oxide-modified ZSM-5 molecular sieve prepared by the following method: a water-soluble phosphorus-containing compound, a ZSM-5 molecular sieve, and deionized water are mixed, stirred, and then dried to obtain a phosphorus-modified ZSM-5 molecular sieve, denoted as P-ZSM-5; a water-soluble metal compound, P-ZSM-5, and deionized water are mixed, stirred, and then dried to obtain a phosphorus- and metal oxide-modified ZSM-5 molecular sieve.

[0027] The heavy oil catalytic cracking catalyst of the present invention has a water-soluble phosphorus compound, calculated as elemental phosphorus, with a mass ratio of water-soluble phosphorus compound, ZSM-5 molecular sieve and deionized water of 0.01-0.08:1:2-10; and a water-soluble metal compound, calculated as elemental metal, with a mass ratio of water-soluble metal compound, P-ZSM-5 and deionized water of 0.005-0.05:1:2-10.

[0028] The heavy oil catalytic cracking catalyst of the present invention comprises water-soluble phosphorus-containing compound, ZSM-5 molecular sieve and deionized water, which are continuously stirred at 60-90°C for 1-3 hours and then flash-dried; and water-soluble metal compound, P-ZSM-5 and deionized water, which are continuously stirred at 60-90°C for 0.5-2 hours and then flash-dried.

[0029] The heavy oil catalytic cracking catalyst of the present invention has a silicon-to-aluminum ratio of 20-100 for ZSM-5 molecular sieves modified with phosphorus and metal oxides.

[0030] The heavy oil catalytic cracking catalyst of the present invention comprises a water-soluble phosphorus-containing compound being one or more of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate, and phosphoric acid; and a water-soluble metal compound being one or more of iron, zinc, nickel, cobalt chloride or nitrate.

[0031] The heavy oil catalytic cracking catalyst of the present invention comprises an inorganic oxide binder that is boehmite or a mixture of boehmite and one or more of aluminum sol, silica sol and silica-alumina sol; and a clay that is one or more of kaolinite, halloysite, montmorillonite, sepiolite, hydrotalcite and rettoite.

[0032] To achieve the above objectives, the present invention also provides a method for preparing the above-mentioned heavy oil catalytic cracking catalyst, comprising the following steps:

[0033] (1) Mix deionized water, clay and inorganic oxide binder to prepare a colloid, and then add acidic substances for gelation treatment;

[0034] (2) Continue to add Y-type molecular sieve, phosphorus and metal oxide composite ZSM-5 molecular sieve and silicon-based nano rare earth composite material, mix and stir to make slurry;

[0035] (3) The slurry is spray-molded, calcined and cured, and washed with water to obtain the catalyst.

[0036] The method for preparing the heavy oil catalytic cracking catalyst of the present invention, wherein the acidic substance is one or more of hydrochloric acid, nitric acid, phosphoric acid, formic acid and acetic acid.

[0037] The method for preparing the heavy oil catalytic cracking catalyst of the present invention includes boehmite as an inorganic oxide binder. The mass ratio of acidic substances to boehmite in the inorganic oxide binder is 0.10 to 0.25 based on alumina, and the gelation treatment temperature is 60 to 80°C.

[0038] In the preparation method of the heavy oil catalytic cracking catalyst of the present invention, the washing water in the water washing step (3) is an aqueous solution of ammonium chloride or ammonium sulfate with a pH value of 3.0 to 6.0, and the washing temperature is 30 to 90°C.

[0039] Beneficial effects of this invention:

[0040] This invention introduces a silicon-based nano-rare earth composite material into the catalyst slurry during catalyst preparation. This material is prepared by recrystallization of a rare earth ion-efficiently exchanged silicon-based mesoporous molecular sieve. The rare earth components are encapsulated within the silicon-based material, allowing for stable dispersion in an acidic colloidal system during catalyst preparation. During high-caustic catalytic cracking of high-vanadium feedstock oil, it prevents the migration of rare earth components into the molecular sieve crystal phase, maintaining the cleanliness of the Y-type molecular sieve's supercage structure and maximizing the anti-vanadium contamination effect of rare earth elements. Furthermore, introducing this material during catalyst preparation enriches the catalyst's pore structure, further improving the diffusion performance of oil and gas molecules during the catalytic reaction. Additionally, this invention employs a phosphorus- and metal oxide-modified ZSM-5 molecular sieve. Modifying the ZSM-5 molecular sieve with phosphorus effectively improves its acidity and hydrothermal stability, thereby reducing catalyst deactivation. Modifying the ZSM-5 molecular sieve with iron, zinc, nickel, and other metal elements effectively improves its selectivity for low-carbon olefins.

[0041] The combined use of this vanadium-resistant technology and composite-modified ZSM-5 molecular sieve can significantly improve the vanadium-resistant performance of catalytic cracking catalysts without significantly altering their selectivity. It features good coke selectivity, strong heavy oil conversion capacity, strong cracking performance, high yield of olefins and other products, good hydrothermal stability, and high activity retention. Detailed Implementation

[0042] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0043] Origin and specifications of raw materials used in the embodiments of this invention:

[0044] REUSY, REY, low-silica ZSM-5, high-silica mesoporous ZSM-5, water glass (silica content 28%), alumina sol (alumina content 21%), pseudoboehmite (alumina content 62%), kaolin, halloysite: industrial products, supplied by Lanzhou Petrochemical Catalyst Plant.

[0045] Lanthanum chloride, lanthanum nitrate, cerium nitrate, yttrium nitrate, praseodymium nitrate, ethanol, propanol, sodium hydroxide, diammonium hydrogen phosphate, ammonium phosphate, phosphoric acid, ferric chloride, zinc chloride, nickel nitrate, cobalt nitrate, and cetyltrimethylammonium bromide (CTAB) are commercially available reagents of analytical grade.

[0046] Example 1

[0047] (1) Preparation of silicon-based lanthanum oxide nanocomposite material: Take 25 g of MCM-41 molecular sieve, add 150 g of deionized water and 11 g of lanthanum nitrate, mix and slurry, then add 6 g of anhydrous ethanol, stir continuously at room temperature for 2 hours, dry, and calcine at 300℃ for 6 hours to obtain rare earth silicon-based mesoporous molecular sieve. Take 30 g of the rare earth silicon-based mesoporous molecular sieve, add 30 g of deionized water, 2 g of sodium hydroxide, 3 g of water glass, and 0.5 g of hexadecyltrimethylammonium bromide (CTAB), mix evenly, heat to 80℃ and continue to react for 5 hours, filter, wash and dry the reaction product to obtain silicon-based lanthanum oxide nanocomposite material.

[0048] (2) Preparation of phosphorus-iron modified ZSM-5 molecular sieve: Take 300 g of ZSM-5 molecular sieve (silicon-to-aluminum ratio 25), add 600 g of deionized water and 22.3 g of diammonium hydrogen phosphate, mix and slurry, stir continuously at room temperature of 60℃ for 3 h, and flash dry to obtain phosphorus-modified molecular sieve P-ZSM-5. Take 250 g of the above P-ZSM-5 molecular sieve, add 500 g of deionized water and 18.1 g of ferric chloride, mix and slurry, stir continuously at room temperature of 60℃ for 3 h, and flash dry to obtain phosphorus-iron modified ZSM-5 molecular sieve.

[0049] (3) Preparation of catalytic cracking catalyst: Deionized water, halloysite, boehmite, and alumina sol were mixed at room temperature to prepare a colloid. Then, hydrochloric acid with a concentration of 36% to 38% was added for sol-gel treatment at a temperature of 60°C. REUSY zeolite molecular sieve, phosphorus-iron modified ZSM-5 molecular sieve, and silicon-based nano-lanthanum oxide composite material were added and stirred to form a slurry. The mass ratio of REUSY zeolite molecular sieve, phosphorus-iron modified ZSM-5 molecular sieve, boehmite, alumina sol, halloysite, and silicon-based nano-lanthanum oxide composite material in the slurry was 5:40:20:14:15:6. The solid content of the slurry was 30%, and the amount of hydrochloric acid added was 15 wt% of the amount of boehmite added. The slurry was spray-formed, and the catalyst obtained by spraying was cured and calcined at 550°C for 1 h. Then, it was washed with ammonium chloride solution at 30°C and pH 3, filtered, and dried to obtain the catalyst provided by this invention.

[0050] The sample is designated S1. The physicochemical properties of the sample are shown in Table 1, and the reactivity is shown in Table 2.

[0051] Example 2

[0052] (1) Preparation of silicon-based nano-cerium oxide composite material: Take 25 g of high-silica mesoporous ZSM-5 molecular sieve (silicon-to-aluminum ratio 300, average pore size 3.0 nm), add 220 g of deionized water and 16 g of cerium nitrate, mix and slurry, then add 30 g of anhydrous ethanol, stir continuously at room temperature for 1 hour, dry, and calcine at 300℃ for 3 hours to obtain rare earth mesoporous molecular sieve. Take 25 g of this rare earth mesoporous molecular sieve, add 50 g of deionized water, 3.6 g of potassium hydroxide, 3.5 g of water glass and 1.2 g of CTAB, mix evenly, heat to 80℃ and continue to react for 5 hours, filter, wash and dry the reaction product to obtain silicon-based nano-cerium oxide composite material.

[0053] (2) Preparation of phosphorus-zinc modified ZSM-5 molecular sieve: Take 300 g of ZSM-5 molecular sieve (silicon-to-aluminum ratio 30), add 600 g of deionized water and 19.5 g of phosphoric acid, mix and slurry, stir continuously at room temperature of 80℃ for 2 h, and flash dry to obtain phosphorus-modified molecular sieve. Take 250 g of the above P-ZSM-5 molecular sieve, add 750 g of deionized water and 18.2 g of zinc chloride, mix and slurry, stir continuously at room temperature of 80℃ for 2 h, and flash dry to obtain phosphorus-zinc modified ZSM-5 molecular sieve.

[0054] (3) Preparation of catalytic cracking catalyst: Ionized water, kaolin, boehmite, and alumina sol were mixed at room temperature to prepare a colloid. Then, hydrochloric acid with a concentration of 36% to 38% was added for sol-gel treatment at a temperature of 65°C. HY zeolite molecular sieve, zinc-phosphorus modified ZSM-5 molecular sieve, and silicon-based nano-cerium oxide composite material were added and stirred to form a slurry. The mass ratio of HY zeolite molecular sieve, zinc-phosphorus modified ZSM-5 molecular sieve, boehmite, alumina sol, kaolin, and silicon-based nano-cerium oxide composite material in the slurry was 20:10:10:10:45:5. The solid content of the slurry was 30%, and the amount of hydrochloric acid added was 15 wt% of the amount of boehmite added. The slurry was spray-formed, and the catalyst obtained by spraying was cured and calcined at 550°C for 1 h. Then, it was washed with ammonium chloride solution at 60°C and pH 4, filtered, and dried to obtain the catalyst provided by this invention.

[0055] The sample is designated as S2. The physicochemical properties of the sample are shown in Table 1, and the reactivity is shown in Table 2.

[0056] Example 3

[0057] (1) Preparation of silicon-based nano-yttrium oxide composite material: Take 25 g of high-silica mesoporous ZSM-5 molecular sieve (silicon-to-aluminum ratio 500, average pore size 3.5 nm), add 500 g of deionized water and 36 g of yttrium nitrate, mix and slurry, then add 100 g of anhydrous ethanol, stir continuously at room temperature for 1 hour, dry, and calcine at 500℃ for 1 hour to obtain rare earth mesoporous molecular sieve. Take 25 g of this rare earth mesoporous molecular sieve, add 70 g of deionized water, 4.2 g of sodium hydroxide, 3.3 g of water glass and 1.4 g of CTAB, mix evenly, heat to 80℃ and continue to react for 5 hours, filter, wash and dry the reaction product to obtain silicon-based nano-yttrium oxide composite material.

[0058] (2) Preparation of phosphorus-nickel modified ZSM-5 molecular sieve: Take 300 g of ZSM-5 molecular sieve (silicon-to-aluminum ratio 50), add 600 g of deionized water and 21 g of phosphoric acid, mix and slurry, stir continuously at room temperature of 80℃ for 2 h, and flash dry to obtain phosphorus-modified molecular sieve. Take 250 g of the above P-ZSM-5 molecular sieve, add 750 g of deionized water and 25 g of nickel nitrate, mix and slurry, stir continuously at room temperature of 80℃ for 2 h, and flash dry to obtain phosphorus-nickel modified ZSM-5 molecular sieve.

[0059] (3) Preparation of catalytic cracking catalyst: Ionized water, kaolin, boehmite, and alumina sol were mixed at room temperature to prepare a colloid. Then, hydrochloric acid with a concentration of 36% to 38% was added for sol-gel treatment at a temperature of 70°C. USY zeolite molecular sieve, phosphorus-nickel modified ZSM-5 molecular sieve, and silicon-based nano-yttrium oxide composite material were added and stirred to form a slurry. The mass ratio of USY zeolite molecular sieve, phosphorus-nickel modified ZSM-5 molecular sieve, boehmite, alumina sol, kaolin, and silicon-based nano-yttrium oxide composite material in the slurry was 14.5:35:25:15:10:0.5. The solid content of the slurry was 30%, and the amount of hydrochloric acid added was 15 wt% of the amount of boehmite added. The slurry was spray-formed, and the catalyst obtained by spraying was cured and calcined at 550°C for 1 h. Then, it was washed with ammonium chloride solution at 90°C and pH 5, filtered, and dried to obtain the catalyst provided by this invention.

[0060] The sample is designated as S3. The physicochemical properties of the sample are shown in Table 1, and the reactivity is shown in Table 2.

[0061] Example 4

[0062] (1) Preparation of silicon-based nano-praseodymium oxide composite material: Take 25 g of SBA-15 molecular sieve, add 250 g of deionized water and 36 g of praseodymium nitrate, mix and slurry, then add 250 g of anhydrous ethanol, stir continuously at room temperature for 0.5 hours, dry, and calcine at 500℃ for 1 hour to obtain rare earth mesoporous molecular sieve. Take 45 g of the rare earth mesoporous molecular sieve, add 70 g of deionized water, 3.2 g of sodium hydroxide, 3.1 g of water glass and 1.5 g of CTAB, mix evenly, heat to 70℃ and continue to react for 5 hours, filter, wash and dry the reaction product to obtain silicon-based nano-praseodymium oxide composite material.

[0063] (2) Preparation of phosphorus-cobalt modified ZSM-5 molecular sieve: Take 300 g of ZSM-5 molecular sieve (silicon-to-aluminum ratio 80), add 1500 g of deionized water and 35 g of ammonium phosphate, mix and slurry, stir continuously at room temperature of 60℃ for 3 h, and flash dry to obtain phosphorus-modified molecular sieve. Take 300 g of the above P-ZSM-5 molecular sieve, add 1000 g of deionized water and 25.1 g of cobalt nitrate, mix and slurry, stir continuously at room temperature of 80℃ for 2 h, and flash dry to obtain phosphorus-cobalt modified ZSM-5 molecular sieve.

[0064] (3) Preparation of catalytic cracking catalyst: Ionized water, kaolin, boehmite, and alumina sol were mixed at room temperature to prepare a colloid. Then, hydrochloric acid with a concentration of 36% to 38% was added for sol-solution treatment at a temperature of 80°C. REY zeolite molecular sieve, phosphorus-cobalt modified ZSM-5 molecular sieve, and silicon-based nano-praseodymium oxide composite material were added and stirred to form a slurry. The mass ratio of REY zeolite molecular sieve, phosphorus-cobalt modified ZSM-5 molecular sieve, boehmite, alumina sol, kaolin, and silicon-based nano-praseodymium oxide composite material in the slurry was 5:30:18:8:38:1. The solid content of the slurry was 30%, and the amount of hydrochloric acid added was 20 wt% of the amount of boehmite added. The slurry was spray-formed, and the catalyst obtained by spraying was cured and calcined at 550°C for 1 h. Then, it was washed with ammonium chloride solution at a temperature of 60°C and a pH of 6, filtered, and dried to obtain the catalyst provided by this invention.

[0065] The sample is designated S4. The physicochemical properties of the sample are shown in Table 1, and the reactivity is shown in Table 2.

[0066] Example 5

[0067] (1) Preparation of silicon-based yttrium oxide nanocomposite material: Take 25 g of HMS molecular sieve, add 100 g of deionized water and 42 g of yttrium nitrate, mix and slurry, then add 75 g of propanol, stir continuously at room temperature for 0.1 hours, dry, and calcine at 500℃ for 1 hour to obtain rare earth mesoporous molecular sieve. Take 30 g of the rare earth mesoporous molecular sieve, add 80 g of deionized water, 4.2 g of sodium hydroxide, 2.5 g of water glass and 1.4 g of CTAB, mix evenly, heat to 80℃ and continue to react for 5 hours, filter, wash and dry the reaction product to obtain silicon-based yttrium oxide nanocomposite material.

[0068] (2) Preparation of phosphorus-nickel modified ZSM-5 molecular sieve: Take 300 g of ZSM-5 molecular sieve (silicon-to-aluminum ratio 30), add 600 g of deionized water and 24.5 g of phosphoric acid, mix and slurry, stir continuously at room temperature of 60°C for 2 h, and flash dry to obtain phosphorus-modified molecular sieve. Take 250 g of the above P-ZSM-5 molecular sieve, add 500 g of deionized water and 20 g of nickel nitrate, mix and slurry, stir continuously at room temperature of 80°C for 2 h, and flash dry to obtain phosphorus-nickel modified ZSM-5 molecular sieve.

[0069] (3) Preparation of catalytic cracking catalyst: Ionized water, halloysite, boehmite, and alumina sol were mixed at room temperature to prepare a colloid. Then, hydrochloric acid with a concentration of 36% to 38% was added for sol-solution treatment at a temperature of 60°C. REUSY zeolite molecular sieve, phosphorus-nickel modified ZSM-5 molecular sieve, and silicon-based nano-yttrium oxide composite material were added and stirred to form a slurry. The mass ratio of REUSY zeolite molecular sieve, phosphorus-nickel modified ZSM-5 molecular sieve, boehmite, alumina sol, halloysite, and silicon-based nano-yttrium oxide composite material in the slurry was 13:27:20:12:24:4. The solid content of the slurry was 30%, and the amount of hydrochloric acid added was 25 wt% of the amount of boehmite added. The slurry was spray-formed, and the catalyst obtained by spraying was cured and calcined at 550°C for 1 h. Then, it was washed with ammonium chloride solution at a temperature of 60°C and a pH of 3.5, filtered, and dried to obtain the catalyst provided by this invention.

[0070] The sample is designated as S5. The physicochemical properties of the sample are shown in Table 1, and the reactivity is shown in Table 2.

[0071] Example 6

[0072] (1) Preparation of silicon-based lanthanum oxide nanocomposite material: Take 25 g of MSU molecular sieve, add 100 g of deionized water and 36 g of lanthanum nitrate, mix and slurry, then add 50 g of anhydrous ethanol, stir continuously at room temperature for 0.1 hours, dry, and calcine at 500℃ for 1 hour to obtain rare earth mesoporous molecular sieve. Take 30 g of the rare earth mesoporous molecular sieve, add 35 g of deionized water, 2.3 g of sodium hydroxide, 2.1 g of water glass, and 0.8 g of hexadecyltrimethylammonium chloride (CTAC), mix evenly, heat to 80℃ and continue to react for 5 hours, filter, wash and dry the reaction product to obtain silicon-based lanthanum oxide nanocomposite material.

[0073] (2) Preparation of phosphorus-iron modified ZSM-5 molecular sieve: Take 300 g of ZSM-5 molecular sieve (silicon-to-aluminum ratio 30), add 650 g of deionized water and 23 g of phosphoric acid, mix and slurry, stir continuously at room temperature of 80℃ for 2 h, and flash dry to obtain phosphorus-modified molecular sieve. Take 250 g of the above P-ZSM-5 molecular sieve, add 750 g of deionized water and 15.3 g of ferric chloride, mix and slurry, stir continuously at room temperature of 60℃ for 2 h, and flash dry to obtain phosphorus-iron modified ZSM-5 molecular sieve.

[0074] (3) Preparation of catalytic cracking catalyst: Ionized water, kaolin, boehmite, and alumina sol were mixed at room temperature to prepare a colloid. Then, hydrochloric acid with a concentration of 36% to 38% was added for sol-solution treatment at a temperature of 60°C. REUSY zeolite molecular sieve, phosphorus-iron modified ZSM-5 molecular sieve, and silicon-based nano-lanthanum oxide composite material were added and stirred to form a slurry. The mass ratio of REUSY zeolite molecular sieve, phosphorus-iron modified ZSM-5 molecular sieve, boehmite, alumina sol, kaolin, and silicon-based nano-lanthanum oxide composite material in the slurry was 6:35:20:10:27:2. The solid content of the slurry was 30%, and the amount of hydrochloric acid added was 15 wt% of the amount of boehmite added. The slurry was spray-formed, and the catalyst obtained by spraying was cured and calcined at 550°C for 1 hour. Then, it was washed with ammonium chloride solution at a temperature of 60°C and a pH of 4, filtered, and dried to obtain the catalyst provided by this invention.

[0075] The sample is designated as S6. The physicochemical properties of the sample are shown in Table 1, and the reactivity is shown in Table 2.

[0076] Example 7

[0077] (1) Preparation of silicon-based nano-lanthanum oxide composite material: Take 25 g of high-silica mesoporous ZSM-5 molecular sieve (silicon-to-aluminum ratio 500, average pore size 3.5 nm), add 20 g of deionized water and 3.6 g of lanthanum nitrate, mix and slurry, then add 10 g of anhydrous ethanol, stir continuously at room temperature for 1 hour, dry, and calcine at 500℃ for 1 hour to obtain rare earth mesoporous molecular sieve. Take 30 g of the rare earth mesoporous molecular sieve, add 70 g of deionized water, 4.2 g of sodium hydroxide, 3.3 g of water glass and 1.4 g of CTAB, mix evenly, heat to 80℃ and continue to react for 5 hours, filter, wash and dry the reaction product to obtain silicon-based nano-lanthanum oxide composite material.

[0078] (2) Preparation of phosphorus-iron modified ZSM-5 molecular sieve: Take 300 g of ZSM-5 molecular sieve (silicon-to-aluminum ratio 30), add 600 g of deionized water and 18.9 g of phosphoric acid, mix and slurry, stir continuously at room temperature of 70℃ for 2 h, and flash dry to obtain phosphorus-modified molecular sieve. Take 250 g of the above P-ZSM-5 molecular sieve, add 750 g of deionized water and 16 g of ferric chloride, mix and slurry, stir continuously at room temperature of 70℃ for 1 h, and flash dry to obtain phosphorus-iron modified ZSM-5 molecular sieve.

[0079] (3) Preparation of catalytic cracking catalyst: Ionized water, kaolin, boehmite, and alumina sol were mixed at room temperature to prepare a colloid. Then, hydrochloric acid with a concentration of 36% to 38% was added for sol-solution treatment at a temperature of 60°C. REY zeolite molecular sieve, phosphorus-iron modified ZSM-5 molecular sieve, and silicon-based nano-lanthanum oxide composite material were added and stirred to form a slurry. The mass ratio of REY zeolite molecular sieve, phosphorus-iron modified ZSM-5 molecular sieve, boehmite, alumina sol, kaolin, and silicon-based nano-lanthanum oxide composite material in the slurry was 12:25:15:12:33:3. The solid content of the slurry was 30%, and the amount of hydrochloric acid added was 20 wt% of the amount of boehmite added. The catalyst obtained by spraying was cured and calcined at 550°C for 1 h. Then, it was washed with ammonium sulfate solution at a temperature of 60°C and a pH of 4, filtered, and dried to obtain the catalyst provided by this invention.

[0080] The sample is designated as S7. The physicochemical properties of the sample are shown in Table 1, and the reactivity is shown in Table 2.

[0081] Comparative Example 1

[0082] Preparation of catalytic cracking catalyst: Deionized water, kaolin, boehmite, and alumina sol were mixed at room temperature to prepare a colloid. Then, hydrochloric acid with a concentration of 36%–38% was added for sol-gel treatment at a temperature of 70°C. REUSY zeolite molecular sieve, phosphorus-iron modified ZSM-5 molecular sieve (same as in Example 7), and lanthanum nitrate were added and stirred to form a slurry. The mass ratio of REUSY zeolite molecular sieve, phosphorus-iron modified ZSM-5 molecular sieve, kaolin, boehmite, lanthanum nitrate (calculated as lanthanum oxide), and alumina sol in the slurry was 8:35:28:15:3:11. The solid content of the slurry was 30%, and the amount of hydrochloric acid added was 15 wt% of the amount of boehmite added. The slurry was spray-dried, and the catalyst obtained by spraying was cured and calcined at 550°C for 1 hour. Then, it was washed with ammonium chloride solution at 60°C and pH 4, filtered, and dried to obtain the catalyst.

[0083] The sample is designated as D1. The physicochemical properties of the sample are shown in Table 1, and the reactivity is shown in Table 2.

[0084] Comparative Example 2

[0085] (1) Preparation of silicon-based nano-lanthanum oxide composite material: Take 25 g of high-silica mesoporous ZSM-5 molecular sieve (silicon-to-aluminum ratio 500, average pore size 3.5 nm), add 500 g of deionized water and 36 g of lanthanum nitrate, mix and slurry, stir continuously at room temperature for 2 hours, dry, and calcine at 500℃ for 1 hour to obtain rare earth mesoporous molecular sieve. Take 20 g of the rare earth mesoporous molecular sieve, add 70 g of deionized water, 4.2 g of sodium hydroxide, 3.3 g of water glass and 1.4 g of CTAB, mix evenly, heat to 80℃ and continue to react for 5 hours, filter, wash and dry the reaction product to obtain silicon-based nano-lanthanum oxide composite material.

[0086] (2) Preparation of phosphorus-iron modified ZSM-5 molecular sieve: Take 300 g of ZSM-5 molecular sieve, add 600 g of deionized water and 19 g of phosphoric acid, mix and slurry, stir continuously at room temperature of 70℃ for 2 h, and flash dry to obtain phosphorus-modified molecular sieve. Take 250 g of the above P-ZSM-5 molecular sieve, add 750 g of deionized water and 16 g of ferric chloride, mix and slurry, stir continuously at room temperature of 70℃ for 1 h, and flash dry to obtain phosphorus-iron modified ZSM-5 molecular sieve.

[0087] (3) Preparation of catalytic cracking catalyst: Ionized water, kaolin, boehmite, and alumina sol were mixed at room temperature to prepare a colloid. Then, hydrochloric acid with a concentration of 36% to 38% was added for sol-gel treatment at a temperature of 65°C. REUSY zeolite molecular sieve, phosphorus-iron modified ZSM-5 molecular sieve, and silicon-based nano-lanthanum oxide composite material were added and stirred to form a slurry. The mass ratio of REUSY zeolite molecular sieve, phosphorus-iron modified ZSM-5 molecular sieve, kaolin, boehmite, silicon-based nano-lanthanum oxide composite material, and alumina sol in the slurry was 9:32:23:20:5:11. The solid content of the slurry was 30%, and the amount of hydrochloric acid added was 20 wt% of the amount of boehmite added. The slurry was spray-formed, and the catalyst obtained by spraying was cured and calcined at 550°C for 1 h. Then, it was washed with ammonium chloride solution at 60°C and pH 4, filtered, and dried to obtain the catalyst.

[0088] The sample is designated as D2. The physicochemical properties of the sample are shown in Table 1, and the reactivity is shown in Table 2.

[0089] Catalyst evaluation:

[0090] The elemental content in the catalyst was determined by X-ray fluorescence analysis.

[0091] Preparation of vanadium contamination solution: Take 18.36g of ammonium metavanadate, add 800mL of deionized water, heat and dissolve in a 90℃ water bath, transfer to a 1000mL volumetric flask and make up to volume to obtain an 8g / L vanadium solution for later use.

[0092] The method for vanadium contamination of catalyst is as follows: the catalyst to be contaminated is dried in an oven at 120°C for 4 hours, 100g of the dried catalyst is taken and added to 100mL of the above vanadium contamination solution for impregnation in an equal volume, allowed to stand, dried in an oven, and then calcined in a muffle furnace at 500°C for 2 hours.

[0093] The ACE assay was used to evaluate the reaction performance of the catalytic cracking catalyst. The catalyst sample was placed in the reactor used in the ACE experiment. The reaction temperature was 560℃, the regeneration temperature was 685℃, the feed rate was 1.80 g, the cold trap temperature was -13.5℃, and the catalyst-to-oil ratio was 9.0. The product distribution and conversion rate after the reaction were analyzed and calculated.

[0094] Table 1 Elemental analysis after catalyst contamination

[0095] Catalyst S1 S2 S3 S4 S5 S6 S7 D1 D2 V, wt% 0.82 0.82 0.81 0.82 0.83 0.82 0.83 0.81 0.82

[0096] Table 2. Catalyst ACE Evaluation Results (8000ppm V)

[0097]

[0098] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A heavy oil catalytic cracking catalyst, characterized in that, Based on the total mass of the catalyst, it includes 5-20% by mass of Y-type molecular sieve on a dry basis, 10-40% by mass of ZSM-5 molecular sieve modified with phosphorus and metal oxides on a dry basis, 20-40% by mass of inorganic oxide binder on an oxide basis, 10-45% by mass of clay on a dry basis, and 0.5-6% by mass of silicon-based nano-rare earth composite material on a dry basis. The preparation method of the silicon-based rare earth nanocomposite material is as follows: water-soluble rare earth compound, silicon-based mesoporous molecular sieve, deionized water and organic alcohol are mixed, stirred, dried and calcined to obtain rare earth silicon-based mesoporous molecular sieve; the rare earth silicon-based mesoporous molecular sieve is mixed with alkaline substance solution, water glass and surfactant; after mixing evenly, a recrystallization reaction is carried out by heating; the reaction product is filtered, washed and dried to obtain silicon-based rare earth nanocomposite material. The metal in the metal oxide is one or more of iron, zinc, nickel, and cobalt; The water-soluble rare earth compound, calculated as rare earth oxide, has a mass ratio of 0.1~1:1:1~10:0.1~5 for the water-soluble rare earth compound, silica-based mesoporous molecular sieve, deionized water, and organic alcohol. The water glass, calculated as silicon dioxide, has a mass ratio of rare earth silicon-based mesoporous molecular sieve, alkaline substance, water glass, and surfactant of 1:0.05~0.3:0.01~0.3:0.001~0.

05.

2. The heavy oil catalytic cracking catalyst according to claim 1, characterized in that, The water-soluble rare earth compound is one or more of the chloride or nitrate salts of lanthanum, cerium, praseodymium, neodymium, and yttrium.

3. The heavy oil catalytic cracking catalyst according to claim 1, characterized in that, The silicon-based mesoporous molecular sieve is one or more of M41S, SBA, HMS, MSU, and ZSM-5 molecular sieve with a silicon-to-aluminum ratio ≥300 and an average pore size ≥3.0 nm.

4. The heavy oil catalytic cracking catalyst according to claim 1, characterized in that, The organic alcohols are one or more of ethanol, propanol, ethylene glycol, and glycerol.

5. The heavy oil catalytic cracking catalyst according to claim 1, characterized in that, The surfactant is hexadecyltrimethylammonium bromide and / or hexadecyltrimethylammonium chloride, and the alkaline substance is sodium hydroxide and / or potassium hydroxide.

6. The heavy oil catalytic cracking catalyst according to claim 1, characterized in that, The Y-type molecular sieve is one or more of HY, USY, REUSY, and REY.

7. The heavy oil catalytic cracking catalyst according to claim 1, characterized in that, The phosphorus and metal oxide composite modified ZSM-5 molecular sieve is prepared by the following method: a water-soluble phosphorus-containing compound, ZSM-5 molecular sieve and deionized water are mixed, stirred and dried to obtain a phosphorus-modified ZSM-5 molecular sieve, denoted as P-ZSM-5; a water-soluble metal compound, P-ZSM-5 and deionized water are mixed, stirred and dried to obtain a phosphorus and metal oxide composite ZSM-5 molecular sieve.

8. The heavy oil catalytic cracking catalyst according to claim 7, characterized in that, The mass ratio of water-soluble phosphorus compounds, ZSM-5 molecular sieve, and deionized water is 0.01~0.08:1:2~10, calculated as elemental phosphorus; the mass ratio of water-soluble metal compounds, P-ZSM-5, and deionized water is 0.005~0.05:1:2~10, calculated as elemental metal.

9. The heavy oil catalytic cracking catalyst according to claim 7, characterized in that, Water-soluble phosphorus compounds, ZSM-5 molecular sieves, and deionized water are stirred continuously at 60-90℃ for 1-3 hours, and then flash-dried; water-soluble metal compounds, P-ZSM-5, and deionized water are stirred continuously at 60-90℃ for 0.5-2 hours, and then flash-dried.

10. The heavy oil catalytic cracking catalyst according to claim 7, characterized in that, The silica-alumina ratio of ZSM-5 molecular sieves used for composite modification with phosphorus and metal oxides is 20-100.

11. The heavy oil catalytic cracking catalyst according to claim 7, characterized in that, The water-soluble phosphorus-containing compound is one or more of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate, and phosphoric acid; the water-soluble metal compound is one or more of iron, zinc, nickel, cobalt chloride or nitrate.

12. The heavy oil catalytic cracking catalyst according to claim 1, characterized in that, The inorganic oxide binder is boehmite or a mixture of boehmite and one or more of aluminum sol, silica sol, and silica-alumina sol; the clay is one or more of kaolinite, halloysite, montmorillonite, sepiolite, hydrotalcite, and rettoite.

13. The method for preparing the heavy oil catalytic cracking catalyst according to any one of claims 1 to 12, characterized in that, Includes the following steps: (1) Mix deionized water, clay and inorganic oxide binder to prepare a colloid, and then add acidic substances for gelation treatment; (2) Continue to add Y-type molecular sieve, phosphorus and metal oxide composite ZSM-5 molecular sieve and silicon-based nano rare earth composite material, mix and stir to make slurry; (3) The slurry is spray-molded, calcined and cured, and washed with water to obtain the catalyst.

14. The method for preparing the heavy oil catalytic cracking catalyst according to claim 13, characterized in that, The acidic substance is one or more of hydrochloric acid, nitric acid, phosphoric acid, formic acid, and acetic acid.

15. The method for preparing the heavy oil catalytic cracking catalyst according to claim 13, characterized in that, The inorganic oxide binder includes boehmite. The mass ratio of acidic substances to boehmite in the inorganic oxide binder is 0.10~0.25, calculated as alumina, and the sol-gel treatment temperature is 60~80℃.

16. The method for preparing the heavy oil catalytic cracking catalyst according to claim 13, characterized in that, In step (3), the washing water is an aqueous solution of ammonium chloride or ammonium sulfate with a pH value of 3.0 to 6.0, and the washing temperature is 30 to 90°C.

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