(152m) Novel Synthesis of Polyethylene Terephthalate (PET) Wastes-Derived Activated Carbon for CO2 Adsorption

Plastic waste has become a significant environmental concern worldwide, as it harms wildlife, pollutes the environment, and risks human health. Developing activated carbon for CO₂ adsorption from plastic waste has been suggested as a promising solution for addressing the issues of plastic pollution and greenhouse effects. A novel synthesis method, autogenic pressure pyrolysis and activation, was studied to develop PET waste-derived activated carbon in this work. Autogenic pressure pyrolysis is a simple and catalyst-free method that can efficiently convert carbon precursors into activated carbon. In this method, the decomposition products of carbon precursor are confined in a closed reactor and go through a series of secondary reactions without being swept out by the carrier gas. The pyrolysis process was carried out in a closed stainless-steel reactor, followed by KOH activation of the resulting pyrolytic PET. Two different methods were employed to mix the pyrolytic PET with an activated agent (KOH here): dry mixing (DM) and solution mixing (SM). The optimal sample CPET6-K8-DM obtained from the study showed a specific surface area of 1931 m²/g. Its CO₂ adsorption uptake was measured to be 4.87 mmol/g at 1 bar and 25 ^oC, and the CO₂/N₂ selectivity was 7.99. In conclusion, converting PET waste into activated carbon using autogenic pressure pyrolysis is a promising approach to tackle the plastics pollution and greenhouse effect problems simultaneously. The resulting material has excellent adsorption properties and has application potential in CO₂ adsorption capture.