CN-121988383-A - FCC catalyst for maximizing high-yield low-carbon olefin, and preparation method and application thereof

Abstract

The invention belongs to the technical field of catalysts, and discloses an FCC catalyst for maximizing the yield of low-carbon olefins, a preparation method and application thereof. The method successfully solves the core pain points of low-carbon olefin yield, poor selectivity, insufficient heavy oil conversion and over-strong hydrogen transfer of the prior FCC technology through the innovative combination of high P-ZSM-5 shape selective catalysis, moderate USY cracking activity, low rare earth hydrogen transfer inhibition and propylene auxiliary strengthening, realizes multiple targets of high light olefin yield, high selectivity, high-efficiency raw material utilization and stable and controllable reaction, and has remarkable technical advantages and extremely high industrialized popularization value in the field of producing low-carbon olefin by petrochemical catalytic cracking.

Inventors

• WANG YE
• SHI ZONGBO
• Qiu Henge
• ZHAO YULONG
• ZHANG QING
• ZHUO RUNSHENG

Assignees

• 润和催化剂股份有限公司

Dates

Publication Date

20260508

Application Date

20251224

Claims (10)

1. 1. A process for preparing an FCC catalyst for maximizing the production of lower olefins comprising the steps of: s1, preparing a silicon modified alumina matrix: adding pseudo-boehmite into a solvent, adding silica sol under stirring, continuously stirring, filtering, washing, and adding the solvent to obtain a silicon-modified alumina matrix; s2, preparing glue solution: Under the condition of room temperature, adding kaolin and aluminum sol into a solvent under high-speed stirring, adding the silicon-modified aluminum oxide matrix after uniform stirring, then adding mixed slurry consisting of a Y-type molecular sieve auxiliary agent, a lanthanum chloride solution and deionized water, continuously stirring for 0.5-0.8 h, then adding a shape-selective molecular sieve auxiliary agent, stirring for 1-1.5 h uniformly, and adding hydrochloric acid to form glue; S3, preparing a finished product: Treating the glue solution by a colloid mill until the glue solution is homogenized to obtain slurry, sending the slurry into a spray dryer, quickly drying the slurry into microsphere particles in hot air, and roasting, washing and drying to obtain a catalyst finished product; the Y-type molecular sieve auxiliary agent is a USY molecular sieve, the SiO 2 /Al 2 O 3 molar ratio is 5.1, and the solid content is 75-80%; the shape selective molecular sieve auxiliary agent is a P modified ZSM-5 molecular sieve.
2. 2. The method for preparing an FCC catalyst for maximizing the production of lower olefins according to claim 1, wherein in S1, pseudo-boehmite has a specific surface area of 237 m 2 /g, a pore volume of 0.97 cm 3 /g and a solid content of 61.5%; The solid content of the silica sol is 35-40%; The solvent is deionized water; The pseudo-boehmite is added into a solvent, and the amount of the solvent is 2 kg; the solvent was added in an amount of 1.5 kg.
3. 3. The method for preparing the FCC catalyst for maximizing the production of low-carbon olefins according to claim 2, wherein the mass ratio of the pseudo-boehmite to the silica sol is 0.610kg (0.075-0.638) kg.
4. 4. The method for preparing the FCC catalyst for maximizing the production of the low-carbon olefin according to claim 2, wherein the stirring temperature is 70-80 ℃ and the duration is 1-1.2 h.
5. 5. The method for preparing an FCC catalyst for maximizing the production of lower olefins according to claim 1, wherein in S2, the mass ratio of kaolin, alumina sol and solvent is (0.500-0.600) kg, 0.425kg, 6kg; The solvent is deionized water; the high-speed stirring speed is 600-800 rpm, and the duration is 0.5-1 h; the uniform stirring speed is 400-500 rpm, and the duration is 1.5-2 h.
6. 6. The method for preparing FCC catalyst for maximizing high yield of light olefins according to claim 5, wherein the mixing ratio of Y-type molecular sieve aid, lanthanum chloride solution and deionized water is (0.252-0.318) kg (0.02-0.027) kg/4 kg; The mass ratio of the shape selective molecular sieve auxiliary agent to the Y-type molecular sieve auxiliary agent is (0.341-0.372) kg (0.252-0.318); the mass concentration of the hydrochloric acid is 20%, and the ratio of acid to aluminum is 0.06-1.
7. 7. The method for preparing FCC catalyst for maximizing high yield of low carbon olefin as claimed in claim 1, wherein the operation condition of the spray dryer in S3 is that the inlet temperature is controlled to be 250-300 ℃ and the outlet temperature is controlled to be 100-120 ℃ so that the slurry is quickly dried into microsphere particles in hot air.
8. 8. The method for preparing an FCC catalyst for maximizing the production of lower olefins according to claim 7, wherein the calcination temperature is 450-550 ℃ and the duration is 1-2 hours.
9. 9. An FCC catalyst for maximizing the production of lower olefins, characterized in that it is obtained by the process according to any of claims 1 to 8.
10. 10. Use of the FCC catalyst of claim 9 in petrochemical catalytic cracking to produce lower olefins.

Description

FCC catalyst for maximizing high-yield low-carbon olefin, and preparation method and application thereof Technical Field The invention belongs to the technical field of catalysts, and particularly relates to an FCC catalyst for maximizing the yield of low-carbon olefins, a preparation method and application thereof. Background In the background of the development of petroleum refining and chemical engineering integration, fluid Catalytic Cracking (FCC) is used as a core process for lightening heavy oil, and product structure regulation and control of the FCC is increasingly attracting attention. The traditional FCC process mainly aims at maximally producing high-octane gasoline and diesel oil, and the active components mainly comprise Y-type molecular sieves, and are mainly focused on hydrogen transfer and aromatization reactions, but are unfavorable for the generation of low-carbon olefins. However, as the downstream demand for olefins increases rapidly, particularly, the importance of propylene and C4 olefins as raw materials of high-added-value chemical products such as polypropylene, propylene oxide, butyl rubber and the like is continuously improved, and the development of a novel FCC catalyst capable of efficiently and selectively producing low-carbon olefins is becoming a research hotspot. In order to improve the selectivity of the low-carbon olefin, various complex modification processes are often carried out on ZSM-5 molecular sieves in the prior art, such as the methods disclosed in patents of USP5236880, CN1143666A and the like, and the measures lead to high cost of the catalyst. For example, patent "an auxiliary agent for improving the octane number of propylene and gasoline, a preparation method and application thereof" (CN 119425780A) discloses a preparation method of the auxiliary agent for FCC process, aiming at simultaneously improving the propylene yield and the octane number of gasoline. The key of the method is to prepare a novel molecular sieve called 'regular ZSM-5'. The preparation process is unique, commercial ZSM-5 molecular sieve is first treated in alkali solution to dissociate its secondary structure unit, and then the alkali solution containing secondary structure is mixed with fresh silicon source and aluminum source and through hydrothermal crystallization, nanometer ZSM-5 molecular sieve with regular morphology, open pore canal and proper acidity is produced through the process of hydrothermal crystallization and the secondary structure as crystal nucleus. Finally, the regular ZSM-5 molecular sieve is mixed with phosphorus compound, clay, binder and the like to prepare the auxiliary agent. The innovation point of the method is that expensive organic template agent is not needed, and the molecular sieve prepared by the dissociation-recombination mechanism is high in crystallinity and excellent in acid property, so that low-octane components can be more effectively cracked in catalytic cracking reaction to generate more propylene and high-octane gasoline. However, the preparation process is complex and has large controllable challenges, and stability and reproducibility among batches are difficult to ensure in large-scale industrial production. And, catalyst life and activity stability under long-term operation may be inferior to those of the molecular sieves prepared by the conventional methods. In the patent 'a naphtha cracking catalyst and a preparation method thereof' (CN 119746918A), a gas-phase in-situ crystallization strategy is innovatively adopted. Specifically, ZSM-5 seed crystal, silica gel carrier and binder (such as alumina sol) are mixed, sprayed, granulated and roasted to obtain microballoons, and then the microballoons are subjected to high-temperature treatment in a closed reaction kettle in alkaline atmosphere provided by ammonia, urea and the like. Under the environment, the amorphous silica-alumina binder and the carrier in the microsphere are used as nutrition sources, and the seed crystal added in advance is used as a core to grow more MFI structure molecular sieves in situ. The method converts the inert binder into the active molecular sieve, thereby improving the density of the active sites of the catalyst, and the preparation process has no waste water, and is more environment-friendly. However, in the absence of a liquid phase environment, an organic templating agent and precise stoichiometry, the in situ grown molecular sieves may be inferior to the high quality ZSM-5 prepared by conventional methods in terms of their crystal structure integrity, acidity modulation accuracy and pore structure optimization, thereby affecting their final selective cracking performance. Moreover, the process requires a high-temperature high-pressure crystallization process for a long time (12-96 hours), has extremely high requirements on the tightness and safety of the reaction kettle, and can have extremely high energy consumption and equipment cost for large-scale indu