Co-pyrolysis of vineyards biomass waste and plastic waste: thermal behavior, pyrolytic characteristic, kinetics, and thermodynamics analysis

Biomass and waste plastic (WP) co-pyrolysis can reduce the oxygen content of pyrolysis oil and improve its quality. However, the current understanding of the interaction mechanisms during the co-pyrolysis process remains unclear and incomplete, hindering its further development. In this study, the thermal behaviors and pyrolytic characteristics of biomass co-pyrolysis with WP were investigated using TG-FTIR and Py-GC/MS, and kinetics and thermodynamics were further explored. The results indicated a significant interaction between biomass and WP during co-pyrolysis. The WP was softened by heat during the early stages of pyrolysis to envelop the biomass, thereby inhibiting the release of volatile components. In the later stage it showed a facilitating effect, where, free radicals generated from the biomass initiate the destruction of the WP polymer chains releasing hydrogen radicals. In turn, the hydrogen radicals act on the pyrolysis of the biomass to promote the production of aromatic hydrocarbons. The kinetics and thermodynamics analysis also revealed that co-pyrolysis reduces the activation energy and Gibbs free energy. This study promotes the synergistic disposal of two solid wastes and has the significance of realizing the green and efficient preparation of high-quality pyrolysis oil.