Synergistic interactions and co-pyrolysis characteristics of lignocellulosic biomass components and plastic using a fast heating concentrating photothermal TGA system

Co-pyrolysis of lignocellulosic biomass (LCB) with plastic has gained significant attention recently. Studying the pyrolysis kinetic behavior of LCB and plastic is beneficial for developing a framework for designing and improving biofuel production. The co-pyrolysis behavior, synergistic interactions and kinetic triplet parameters of the three main LCB components, i.e., cellulose, hemicellulose and lignin, and two plastics (polyethylene terephthalate [PET] and polyvinyl chloride [PVC]) were evaluated using a fast heating concentrating photothermal TGA system. The maximum decrease in mass loss rate with increasing heating rates was observed for cellulose with PET (1.23–0.94%/°C) and with PVC (1.05–0.62%/°C). The mechanism of synergistic interaction between hemicellulose and PET proceeded with polymer degradation and conversions of monomer units into excess volatiles in the higher heating rate regime. Distributed Activation Energy Model [DAEM] and Coats-Redfern [CR]) were used to calculate the kinetic parameters. DAEM results confirmed that mixed samples required lower activation energy to start the reaction. Using the CR method, the first degradation phase showed the best synergistic effect for lowering the PET and PVC activation energy, particularly with hemicellulose and lignin.