Efficient Conversion of Light Cycle Oil into High-Octane-Number Gasoline and Light Olefins over a Mesoporous ZSM‑5 Catalyst

Abstract

Producing high-octane-number (ON) gasoline and light olefins is a promising route to valorize light cycle oil (LCO). In this work, the LCO was mildly hydrogenated and then catalytically cracked to produce high-ON gasoline and light olefins. Mesoporous ZSM-5 zeolite (meso-ZSM-5) was prepared and, for the first time, was applied in this process to crack the hydrogenated LCO (hydro-LCO). The catalytic performance of meso-ZSM-5 was evaluated in detail under different reaction temperatures and weight hourly space velocities (WHSVs). The results showed that, in comparison to less than 64 wt % hydro-LCO conversion over the conventional ZSM-5 catalyst, the novel catalyst exhibited excellent performance in cracking hydro-LCO with quite a high conversion of 84.8 wt %, affording a gasoline yield of 56.4 wt % and light olefin yield of 19.3 wt % at 560 °C and 10 h^–1. In addition, the conversion behaviors of hydro-LCO components were analyzed over both the conventional ZSM-5 and meso-ZSM-5 catalysts. Finally, on the basis of the study of the acid and pore properties of both catalysts, a detailed intrinsic reason for enhanced performance was elucidated. It demonstrated that the remarkable catalytic performance of the meso-ZSM-5 catalyst was closely related to the high diffusion of reactants and the accessibility of acid sites