Thermal decomposition kinetics modeling of energy cane Saccharum robustum

Three thermal decomposition stages were identified: dehydration, pyrolysis and carbonization. The activation energies were determined through three model-free methods (Friedman, Flynn-Wall-Ozawa, and Vyazovkin) varying between 107.5 and 204 kJ/mol. The master plots showed different representations of conversion functions (reaction orders from 2 to 7). The linear model fitting method validated the activation energy (177.1 kJ/mol) obtained by single-step reaction. Moreover, a multi-step method was proposed considering four independent parallel reactions (extractives, hemicellulose, cellulose, and lignin) obtaining activation energies from 60 to 181 kJ/mol, pre-exponential factor from 1.1 ∙ 102 to 5.8 ∙ 1012 1/s, 1st and 3rd reaction orders, and compositions from 0.12 to 0.43 with high quality of fit.