Upcycling of polyethylene terephthalate waste into porous carbon as potential CO2 adsorbents through autogenic pressure carbonization

초록

Plastic waste is a significant environmental concern worldwide because it harms wildlife pollutes the environment and poses a risk to human health. Upcycling plastic waste into porous carbon for CO2 capture is regarded as a promising solution to address plastic pollution and global warming. In this study a novel synthesis method involving autogenic pressure carbonization and KOH activation was developed to prepare polyethylene terephthalate (PET) waste-derived porous carbon. Autogenic pressure carbonization is a simple process that can efficiently convert carbon precursors into pyrolytic carbon in which the decomposition products of carbon precursors are confined in a closed reactor and undergo a series of secondary reactions without being removed. In this study two distinct methods dry mixing and solution mixing were employed to mix pyrolytic carbon with the activation agent KOH and their effects were compared. The optimal porous carbon CPET6-K8-DM obtained through autogenic pressure carbonization at 600 °C KOH activation at 800 °C and dry mixing showed a relatively large specific surface area of 1931 m2/g and decent CO2 adsorption performance (CO2 adsorption uptake of 4.44 mol/kg at 101.3 kPa and 25 °C and CO2/N2 selectivity of 7.99). In addition standard life cycle assessments were used to evaluate the environmental impact of the prepared porous carbon. A comparative analysis revealed that autogenic pressure carbonization has more environmentally friendly characteristics than conventional carbonization conducted under atmospheric pressure conditions for PET waste upcycling. © 2024 Elsevier B.V.

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