Integrated conversion of marine polystyrene and Traditional Chinese Medicine through pressurized Co-Pyrolysis: Synergistic impact on product yields

Global energy demand is primarily met by fossil fuels, which significantly contribute to greenhouse gas emissions and climate change. To address these challenges, plastic waste can be converted into value-added products; however, pyrolysis of plastic alone typically yields low-quality oil. This study focuses on valorizing marine polystyrene (PS) and traditional Chinese medicine residue (TCMR) to provide an integrated solution for renewable energy production and waste management. Here, the pyrolysis of mixtures of polystyrene and lignocellulosic Chinese medicine waste was investigated at 500–800 °C and 0.1–2 MPa in a fixed-bed reactor using cobalt–molybdenum-loaded zeolite catalysts. The results show high oil quality and energy content at 600-700 °C under 1.0–1.5 MPa, with the 1:3 biomass-to-plastic ratio achieving the highest value of 43.84 MJ kg −1 and a corresponding BTEX yield of 45.3%. The synergistic effect of cobalt and molybdenum on the zeolite enhanced aromatization and hydrogen transfer reactions while simultaneously suppressing char formation. This work presents an integrated assessment of pressurized catalytic co-pyrolysis of marine PS and TCMR over Co-Mo/ZSM-5, demonstrating an efficient route for converting heterogeneous waste into value-added products.