Kinetic Study on Pyrolysis of Tung Seed Shells and In Situ Characterization by Using TG–FTIR Analysis

This study investigates the pyrolysis behavior of tung seed shells (TSSs), an underutilized lignocellulosic residue from Vernicia fordii, using thermogravimetric analysis (TGA) and in situ TG–FTIR spectroscopy. The thermal decomposition process was found to occur in multiple stages, corresponding to the sequential degradation of hemicellulose, cellulose, and lignin. Particle size and heating rate strongly influenced the decomposition profile, with finer particles exhibiting enhanced devolatilization due to improved heat and mass transfer. Kinetic analysis using the Coats–Redfern, Doyle, and Kissinger methods revealed apparent activation energies ranging from 30 to 122 kJ/mol, consistent with typical values for lignocellulosic biomass. The evolution of gaseous species, including CO, CO2, and CH4, throughout all pyrolysis stages confirms the potential of TSSs for bio-syngas and biochar production. These findings provide new insights into the kinetic and mechanistic characteristics of tung seed shell pyrolysis and support its application as a renewable feedstock for sustainable bioenergy generation.