Advancing Waste Plastic Valorization: Catalytic Production of Aviation Fuel over Zeolite and Ru/CNT-Based Catalysts

This work investigates the hydroprocessing of polyolefins using both model and waste plastics. A catalyst screening using low-density polyethylene (LDPE) identified Ru/CNTox + HY (Si/Al = 24) and Ru/CNTox + CNTox + HY as the most effective systems for producing hydrocarbons in the aviation fuel range (C8–C16). Under optimized conditions (i.e., 325 °C, 30 bar H2, 3 h), the Ru/CNTox + HY catalytic system produced up to 80% liquids in the C8–C16 range with significant isomerization (iso/n = 4). When applied to real plastic residues, such as used pipet tips and a plastic bag, C8–C16 selectivities of 80–90% in the liquid phase were achieved, with iso/n ratios of up to 9. These results highlight the potential of combining carbon-supported metal catalysts with zeolites as a robust bifunctional catalytic system for the valorization of plastic waste into high-quality aviation fuel, contributing to sustainable solutions for plastic management and energy production.