Upcycling Post-Consumer Polystyrene Waste into Liquid Organic Hydrogen Carriers

Abstract

To address the challenges of plastic waste and sustainable hydrogen storage, we propose an innovative strategy to upcycle post-consumer polystyrene (PS) waste into liquid organic hydrogen carriers (LOHCs). The process involves pyrolyzing PS into aromatic monomers, which are subsequently hydrogenated into cyclic hydrocarbons. Dehydrogenation of hydrogen-rich LOHCs releases high-purity hydrogen, with catalytic performance influenced by the properties of supported Pt catalysts. However, polycyclic compounds in the PS-derived LOHCs led to catalyst deactivation via coke formation, necessitating a distillation step to remove these precursors. Life cycle assessment and techno-economic analysis confirmed that upcycling PS waste into LOHCs offers both environmental benefits and economic viability. This work contributes to advancing circular carbon strategies and the hydrogen economy.