Ambient-pressure conversion of plastic waste to jet fuel cycloalkanes by tandem hydropyrolysis and vapour-phase hydrogenation

Abstract

Converting plastic waste into jet fuel could support the decarbonization of the aviation industry, yet current upcycling routes rely on high pressures (~3 MPa) and prolonged reaction times (up to 144 h). Here we report a tandem hydropyrolysis and vapour-phase hydrogenation strategy enabled by a single-atom Ru catalyst on Co-Al oxides (RuSA@CoAlOx). The catalyst achieves a turnover frequency of 144 s−1 for benzene hydrogenation at atmospheric pressure, exceeding that of commercial Ru/C by over 100-fold. In a tandem fixed-bed reactor with hydropyrolysis at 460 °C and downstream vapour-phase hydrogenation at 160 °C, polystyrene is converted to 94.8 wt% cycloalkanes at 0.15 MPa and to 59 wt% cycloalkanes at atmospheric pressure. The approach extends to mixed plastics, achieving jet-fuel-range hydrocarbon yields above 82 wt%. The catalyst remains stable for over 110 h during continuous vapour-phase hydrogenation. Life-cycle analysis indicates a 73% reduction in well-to-pump CO2 emissions relative to petroleum-based jet fuel, and techno-economic analysis suggests a competitive minimum selling price of US$1.0–1.8 per kg.