(348c) Ultra-Low Temperature Microwave-Assisted Catalytic Upcycling of Polyolefin Waste into Light Olefins

The escalating accumulation of plastic waste, particularly polyolefins such as polyethylene (PE) and polypropylene (PP), poses significant challenges to environmental sustainability and resource recovery. Conventional recycling methods typically rely on high-temperature thermal cracking (>500 °C), which suffers from high energy consumption, as well as poor product selectivity, and limited compatibility with complex and additive-laden plastic mixtures—hindering practical implementation. To address these challenges, this study introduces a low-temperature (200 °C) microwave-assisted catalytic upcycling (MACU) strategy. The system is specifically designed to achieve efficient depolymerization under mild conditions over a developed Ru–Fe₂O₃–ZSM-5 composite catalyst.

Under optimized microwave conditions at 200 °C, the catalyst achieves >85% gas production in plastic depolymerization and >75% selectivity toward light olefins, primarily ethylene and propylene. This represents one of the lowest reported operating temperatures for effective polyolefins upcycling and highlights the potential of this approach as a breakthrough in the field.

The catalyst demonstrates excellent thermal stability, recyclability, and resistance to contaminant deactivation across multiple cycles. Compared to conventional high-temperature processes, the proposed MACU strategy offers a highly energy-efficient, scalable, and industrially viable pathway for converting polyolefins waste into valuable chemical feedstocks— advancing sustainable materials management and promoting a circular plastic economy.