Heavy oil catalytic cracking catalyst with high light oil yield and preparation method thereof

Abstract

The invention relates to a heavy oil catalytic cracking catalyst with high light oil yield and a preparation method thereof. The catalyst contains 2-50 wt% of a magnesium modified ultrastable rare earth Y-type molecular sieve, 0.5-30 wt% of one or several other molecular sieves, 0.5-70 wt% of clay, 1-65 wt% of a refractory inorganic oxide and 0.01-12.5 wt% of rare earth oxide. The magnesium modified ultrastable rare earth Y-type molecular sieve is prepared from a raw material NaY molecular sieve through rare earth exchange, dispersing pre-exchange, magnesium salt exchange modification, ammonium exchange for reducing sodium, and ''two exchanges and two roasting''. The catalyst provided by the invention has characteristics of strong heavy oil conversion ability and high light oil yield.

Description

technical field [0001] The invention relates to a high-light-yield heavy oil catalytic cracking catalyst with high heavy oil conversion capability and a preparation method thereof, more specifically, a high-light-yield catalytic cracking catalyst suitable for blending residual oil and a preparation method thereof. Background technique [0002] Catalytic cracking unit is an important secondary processing method for crude oil. Its comprehensive product distribution, especially the yield of high value-added light oil products, determines the economic benefits of the refinery. In recent years, with the trend of heavy oil feedstock, FCC catalysts are required It has stronger heavy oil conversion ability and higher light oil yield. As a key active component that determines the reaction selectivity of heavy oil cracking catalysts, Y-type molecular sieves with high target product selectivity and high activity stability have always been the core technical subject of research in the f...

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Problems solved by technology

In the modification method involved in this patent, a solution containing ammonium ions needs to be added, the purpose of which is to reduce the sodium oxide content in the molecular sieve or reduce the damage to the molecular sieve structure by acid gas during the roasting process, but this technology has the following technical defects: 1) preparation A large amount of ammonium ions are added during the process, and ammonium ions eventually enter the atmosphere or sewage, increasing ammonia nitrogen pollution and pollution control costs; 2) This patented method cannot effectively solve the problem of molecular sieve particle agglomeration, which reduces the specific surface and pore volume of molecular sieves , increasing the pore resistance of the molecular sieve exchange process, making it difficult to accurately locate and quantify the modified elements in the molecular sieve cage; Rare earth ions are introduced by means of ion exchange. During the exchange process, there is a competitive reaction between ammonium ions and rare earth ions. Ammonium ions will preferentially occupy the positions of rare earth ions, which increases the resistance of rare earth ions to enter the molecular sieve cage and reduces the resistance of rare earth ions. Utilization

In this technology, the rare earth modification uses the "cross-baking" product as the raw material for the second exchange modification. After the molecular sieve undergoes "cross-baking", the unit cell shrinks, and the aluminum fragments inside the channels block the channels, increasing the rare earth ions. Exchange resistance, making it difficult for rare earth ions to locate accurately in the sodalite cage

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