CATALYST EFFECT ON PROPYLENE TO ETHYLENE RATIO IN THE CATALYTIC CRACKING OF FUEL OIL

Catalytic cracking of fuel oil to light olefins especially propylene and ethylene was carried out in a fixed-bed micro-activity test (MAT) unit. Light and heavy fuel oils of Tehran refinery wereapplied as feedstock. Catalyst mixtures consisting of a equilibrium catalyst (E-Cat) as base catalyst blended with ZSM-5, MCM-41 and Mordenite additives were examined at the additive levels of 25 wt.%.Two kind of ZSM-5 with different SiO2/Al2O3 ratio were investigated. The experimental results indicated that the porous structure of the catalyst and also the SiO2/Al2O3 ratio play an important rolein the catalyst performance. The influence of catalyst bed in propylene to ethylene (P/E) production ratio was investigated. The results showed that MCM-41 and mordenite are more selective to propylene and resulted in higher P/E ratio of 2.28 and 2.35, respectively. ZSM-5 zeolite with lower SiO2/Al2O3 ratio exhibit more ethylene production relative to propylene.

Keywords:

Fuel oil , Cracking , Catalyst , Zeolite , Propylene , Ethylene