(2024) Chemosphere_Sustainable management of medical plastic waste through carbon dioxide-assisted pyrolysis

Kim J.Y.; Park J.; Lee D.-J.; Choi Y.-B.; Kwon E.E.

(Elsevier Ltd) Chemosphere  ISSN:456535 Vol.364 Issue. Article No.143266 DOI: 10.1016/j.chemosphere.2024.143266

To address the challenges associated with medical plastic waste and to characterize its heterogeneity, non-recyclability, and potential biohazard risks, this study explored a carbon dioxide (CO₂)-assisted pyrolysis process as a sustainable disposal method. Medical plastic waste typically includes polypropylene, polystyrene, and polyvinyl chloride. To experimentally evaluate the functional reactivity of CO₂, we employed three pyrolysis setups (one-stage, two-stage, and catalytic processes). The technical advantages of using CO₂ over inert gases such as nitrogen (N₂) were demonstrated through pyrolysis tests. The results showed that energy production was enhanced under CO₂ conditions, with catalytic pyrolysis generating 146% more flammable gases compared to pyrolysis in an N2 environment. The use of CO₂ also led to a reduction in the formation of toxic chemicals due to improved thermal cracking. The CO₂-assisted pyrolysis process exhibited net negative CO₂ emissions when a catalyst was present, as a substantial amount of CO₂ was consumed during the process. In conclusion, CO₂-assisted pyrolysis of medical plastic waste offers a sustainable management solution that maximizes the utilization of carbon resources. © 2024 Elsevier Ltd

This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. RS-2023-00219667).