Selective Single‐step Co‐hydroprocessing of Light Cycle Oil and Waste Cooking Oil Mixtures for Diesel Fuel Production

Abstract

AbstractThis study investigates the co‐hydroprocessing of light cycle oil (LCO) with waste cooking oil (WCO) as a potential strategy to enhance LCO′s qualities and overall performance. The study involves the integration of LCO with WCO in three different ratios, facilitating a combined hydrotreatment process within a fixed bed continuous down‐flow reactor. The findings reveal that incorporating WCO into LCO hydrotreatment enhances LCO′s properties, albeit with a minor reduction in hydrodesulfurization efficacy. WCO demonstrates approximately 10.7 % density and 26 % cetane number improvements compared to the LCO/WCO (70/30) blend at 380 °C. The most significant reduction in di and poly‐aromatic compounds is observed at 340 °C for pure LCO, while WCO inclusion has minimal impact on poly‐aromatic saturation. The yield range for medium distillates across all products is between 87 % and 93 %. The time‐on‐stream study suggests excellent catalyst stability and activity up to 456 h, which is one of the highest lifetimes reported so far. TGA study of the spent catalyst indicates 22 wt % coke deposition complemented by TEM results. FTIR analysis revealed absorptions of alicyclic hydrocarbons‐type compounds deposited over the catalyst surface. This research contributes to the development of innovative catalysts for selectively converting LCO and WCO into diesel‐range hydrocarbons through single‐step process.