Microwave-assisted catalytic technology for sustainable production of valuable chemicals from plastic waste with enhanced catalyst reusability

Abstract

High energy consumption and catalyst deactivation hinder thermal plastic waste decomposition for chemical production. This study employs a microwave-assisted catalytic process with Ru/ZSM-5 as the catalyst for polyethylene waste. At 300 °C under the first cycle of microwave heating, gas yield reaches 90 wt%, with 23 wt% aromatics selectivity and 30 wt% light olefins selectivity. In the first cycle of thermal heating, gas yield is 72 wt%, with 67 wt% alkanes and 32 wt% light olefins selectivity. In microwave cycle reactions, gas yield remains around 88 wt% through seven cycles over the spent catalyst (without regeneration), shifting product composition to 80 wt% light olefins in the 7th cycle. In contrast, in thermal cycle reactions, catalyst activity is lost after one cycle, and gas yield drops from 72 wt% to 45 wt%. Microwave-assisted catalytic technology shows potential for economically producing valuable chemicals from plastic waste, as lower reaction temperature and high catalyst reusability.