(2020) Journal of Hazardous Materials_Catalytic Pyrolysis of Polystyrene over Steel Slag under CO₂ Environment

Lee T., Jung S., Park Y.-K., Kim T., Wang H., Moon D.H., Kwon E.E.

(Elsevier B.V.) Journal of Hazardous Materials ISSN: 3043894 Vol.395 Issue. Article No.122576 DOI: 10.1016/j.jhazmat.2020.122576

As the consumption of plastic materials has been dramatically increased, the abundant presence of their debris has become a significant problem worldwide. Thus, this study proposes a sustainable plastic conversion platform for energy recovery. In detail, polystyrene pyrolysis was examined as a case study under CO₂ atmosphere in reference to N₂ condition. The major gaseous and liquid products from polystyrene pyrolysis include permanent gases (syngas and C_1-2 hydrocarbons) and condensable aromatic compounds. Under CO₂ environment, the reduction of polycyclic aromatic hydrocarbons (PAHs) was achieved during polystyrene pyrolysis, in comparison with N2 condition. Since its slow reaction kinetics, conversion of condensable hydrocarbons into permanent gases was not fully activated. Therefore, a cheap industrial waste, steel slag (SS), was employed as a catalyst to increase reaction kinetics. The synergistic effects of SS and CO₂ contributed to doubling H₂ production, while CO formation increased more than 300 times, in reference to non-catalytic pyrolysis. Because CO₂ acted as an oxidant for CO production, control of H₂/CO ratio was achieved in different conditions. Thus, the utilization of CO₂ would suggest a promising way to reduce the formation of PAHs, adopting the reliable platform to produce syngas from plastic waste. © 2020 Elsevier B.V.

This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korea government (MSIT) ( NRF-2019R1A4A1027795 and NRF-2019H1A2A1076293 ).