(2022) Journal of Hazardous Materials_Functional use of CO₂ to mitigate the formation of bisphenol A in catalytic pyrolysis of polycarbonate

Lee T., Jung S., Baek K., Tsang Y.F., Lin K.-Y.A., Jeon Y.J., Kwon E.E.

(Elsevier B.V.) Journal of Hazardous Materials ISSN: 3043894 Vol.423 Issue. Article No.126992 DOI: 10.1016/j.jhazmat.2021.126992

The growing consumption of plastic materials has increased hazardous threats to all environmental media, since current plastic waste management methods release microplastics and toxic chemicals. As such, massive generation of plastic derived pollutants leads to significant public health and environmental problems. In this work, an environmentally sound method for valorization of plastic waste is suggested. In detail, pyrolysis of polycarbonate-containing plastic waste such as automotive headlight housing (AHH) was carried out using CO₂ as a co-reactant. AHH was chosen as it discharges bisphenol A (BPA) and aromatic compounds. Under CO₂ condition, emissions of BPA and its derivatives were suppressed by 14.5% due to gas phase reactions (GPRs) with CO₂. Nevertheless, reaction kinetics for GPRs was not significant. To impart the GPRs, catalytic pyrolysis was done using Ni and Co-based catalysts. During catalytic pyrolysis, syngas production was more than tenfold up comparing to pyrolysis without catalyst. The expedited GPRs over catalysts resulted in the enhanced syngas formation. Total concentration of the toxic chemicals from CO₂-assisted catalytic pyrolysis of AHH decreased by 86.1% and 66.7% over Ni and Co catalysts, comparing to those from N2 environment. © 2021 Elsevier B.V.

This work was supported by NRF (National Research Foundation of Korea) grants funded by the Korean Government ( NRF-2019R1A4A1027795 and NRF-2019H1A2A1076293-Global Ph.D. Fellowship Program).