Catalytic valorization of post-consumer plastic waste into high-octane gasoline: Integrated upgrading and engine-scale validation

The rapid accumulation of plastic waste and the continued reliance on fossil-derived gasoline necessitate sustainable and scalable waste-to-energy solutions. An integrated catalytic process is demonstrated that converts post-consumer polyethylene and polypropylene waste into super pyrolysis gasoline (SPG), a high-octane fuel. Pyrolysis at 450°C yields 70–75 wt% oil, from which the C 5 –C 12 fraction is distilled and upgraded by hydrodesulfurization (350°C, 50 bar H 2 , Ni-Mo/Al 2 O 3 ) and reforming/isomerization (500°C, Ni–ZSM-5). X-ray diffraction, X-ray photoelectron spectroscopy (XPS), and ammonia temperature-programmed desorption (NH 3 -TPD) confirm robust Ni dispersion and retained Brønsted acidity; operando DRIFTS/Raman reveals minimal coke deposition (D/G ≈ 0.45). DFT calculations indicate Ni sites lower C–C scission barriers by ∼0.3 eV, favouring branched and aromatic species. SPG achieves research octane number (RON) of 103, motor octane number (MON) of 91,