Enhanced hydrogen production through temperature-optimized pyrolysis of mixed plastic waste for sustainable energy recovery
Daegi Kim, Seunghyun Lee, Sun-Young Woo, Ki Young Park
Abstract
This study examines the pyrolysis of mixed plastic waste (PW) for hydrogen (H 2 ) and other gas production under controlled temperatures. It analyzes the effects of individual plastics like PET, HDPE, LDPE, PP, and PS on gas composition and yields. Findings reveal those higher temperatures (900–1000 ℃) significantly boost H 2 production, particularly from PET and PS, due to their distinct molecular structures. PET's oxygen-rich composition aids CO and CO 2 generation, whereas PS supports secondary reactions that enhance H 2 output. The diverse makeup of PW leads to balanced gas production, suggesting that pyrolysis is a versatile and sustainable method for managing plastic waste and recovering valuable gases, thus supporting circular economy objectives. The study also highlights the need for optimal pyrolysis conditions that balance efficiency with economic viability, considering the energy costs associated with higher temperatures. Further, the unique properties of plastics in PW, such as PET’s ability to generate CO and CO 2 and the contribution of hydrocarbon-rich plastics like PP and PE to CH 4 and H 2 production, are detailed. PS is noted for producing the highest H 2 yields due to its aromatic structure, which promotes efficient secondary reactions. Future research should focus on catalytic enhancements and scalability for industrial application.