An FCC Catalyst for Maximizing Gasoline Yield

A Y zeolite-containing wide-pore composite was synthesized by in situ technique using polyvinyl alcohol and silica sol material. A fluid catalytic cracking (FCC) catalyst for maximizing gasoline yield was successfully developed with the modified composition. The as-made zeolite Y in its sodium form had a relative crystallinity of 52.9 % with a high silica/alumina amount of substance ratio of 5.7. The FTIR analysis showed that the acid distribution of the catalyst modified with rare earth, phosphorus and steaming stabilization process was more concentrated on the range of intermediate and strong acidity. This kind of modification can direct more hydrocarbons to enter into the pores to be converted, as well as remarkably increases the possibility of gasoline formation through a cracking reaction. The nitrogen adsorption–desorption analysis showed that the catalyst had more meso- and macro-pores distribution, which can effectively reduce the mass-transfer resistance in the reaction process and accelerate the diffusion of the product molecules. The evaluated results indicated that the prepared catalyst could decrease the excessive cracking of middle distillate and improve the gasoline yield effectively. The gasoline yield by mass had increased by 2.69 %, while the coke yield and dry gas yield had decreased by 0.91 % and 0.19 %, respectively, and then the olefin content by volume in the cracked gasoline reduced by 4.6 %, the research octane number (RON) and motor octane number (MON) increased by 0.6 and 0.5, respectively. The good product selectivity and higher gasoline yields of the prepared catalyst were obviously related to its wide pore structure and its optimized acidity distribution. This work is licensed under a Creative Commons Attribution 4.0 International License.
Zeolit Y velikih pora sintetiziran je in situ upotrebom polivinilnog alkohola i sola silicijeva dioksida. Za krekiranje u fluidiziranom sloju (FCC) razvijen je katalizator promijenjena sastava. Zeolit Y u natrijskom obliku imao je relativnu kristalnost 52,9 % i visoki množinski omjer SiO2/Al2O3 5,7. Katalizator s elementima rijetkih zemalja, fosforom i stabiliziran izlaganjem pari, prema analizi FTIR-om, imao je više aktivnih mjesta srednje i jake kiselosti. S takvim preinačavanjem katalizatora više ugljikovodika ulazi u pore i povećava se proizvodnja benzina krekiranjem. Analiza adsorpcijom i desorpcijom dušika pokazuje da katalizator ima više mezo- i makropora što može olakšati prijenos materijala i ubrzati difuziju molekula produkata. Rezultati pokazuju da bi pripravljeni katalizator mogao smanjiti pretjerano krekiranje srednjeg destilata i povećati iskorištenje s obzirom na benzin. Iskorištenje benzina po masi povećalo se za 2,69 %, a iskorištenje koksa i suhog plina smanjilo za 0,91 i 0,19 %. Obujamski udjel olefina u benzinu smanjio se za 4,6 % dok su istraživački oktanski broj (RON) i motorni oktanski broj porasli za 0,6 i 0,5. Dobra selektivnost s obzirom na produkte i visoka iskorištenja benzina u katalizi s pripravljenim katalizatorom očito su povezana sa širokoporoznom strukturom i optimiranom distribucijom kiselosti. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.