Olefin production from catalytic cracking of light fuel oil over different additives

The catalytic cracking of a fuel oil over fluid catalytic cracking (FCC) catalyst has been investigated applying different additives. Catalyst mixtures consisting of a equilibrium FCC catalyst (E-Cat) blended with ZSM-5, MCM-41 and Mordenite additives were examined at the additive levels of 25 wt.%. The catalytic performance of the matrix was studied in a fixed bed micro-activity test unit (MAT) at 600 ˚C and catalyst/oil ratio of 3.6. Two types of ZSM-5 with different Si/Al ratios were utilized. Results indicate that the yield of light olefins significantly increased by operating hybrid catalysts in comparison with the base E-Cat. The highest olefin yield of 61.46 wt.% in the gas phase products was achieved over E-Cat/ZSM-5 of low Si/Al ratio. The maximum propylene production was observed over MCM-41, besides applying mordenite as additive showed more propylene to ethylene ratio in products. Butenes were also increased by use of all additives, whereas iso-butene shows the maximum yield over all E-Cat/additives.