바이오매스 회분 촉매 열분해를 통한 폐 EPS(Expanded polystyrene)의 스티렌 모노머 전환 최적 조건 도출 연구

Study to identify optimal conditions for styrene monomer conversion from waste expanded polystyrene (EPS) via biomass ash catalytic pyrolysis

As plastic usage and production increase, the amount of waste plastic generated is increasing, which is causing soil and marine pollution and climate change problems. To reduce these problems, the importance of plastic recycling is emphasized, and among them, chemical recycling through pyrolysis is the most efficient in terms of high added value and waste reduction due to fuel and raw material conversion. Among various plastics, polystyrene is one of the promising alternatives as it has the highest oil and monomer yields during pyrolysis. In this study, the thermal decomposition of waste EPS, which accounts for a significant portion of polystyrene, was performed using a semi-batch reactor, and waste biomass ash was tested as a catalyst. Cashew nut shell (CNS) was selected as the biomass ash and compared with the most efficient BaO catalyst in previous studies. The effect of catalyst according to temperature condition variables was identified, and finally, pyrolysis oil and styrene monomer yields were compared. Pyrolysis experiments showed that the oil and SM masses produced was maximum (37.42 g oil, 30.18 g SM) when using CNS ash catalyst at 400 °C, which was selected as the optimal condition for waste EPS-based SM conversion.