Application of the SCE optimization algorithm in determining thermal decomposition kinetics of Pinus radiata needles and Eucalyptus globulus leaves

The goal of this work was to study the thermal decomposition kinetics of two exotic Chilean wildland fuels, namely, Pinus Radiata (PR) needles and Eucalyptus Globulus (EG) leaves, by using thermogravimetric analysis (TGA) experiments, and the shuffled complex evolution (SCE) technique to estimate kinetic parameters through an inverse optimization process, and 0D simulations to validate a kinetic model against experimental mass loss rates (MLR). TGA experiments were monitored under inert (N₂) and oxidative (air) atmospheres at a temperature range from 200 to 600 °C. Analyses were performed at four heating rates of 5, 10, 15, and 20 °C min⁻¹. We demonstrated the effectiveness of the SCE algorithm in determining solid-phase kinetics parameters by correlating several reaction mechanisms of inert and oxidative decomposition with experimental TGA data. Optimized parameters were used in the Gpyro simulation suite to predict MLR. Results show that, under inert conditions, the conversion from dry fuel to char can be modeled with a three-step mechanism for both species. Under oxidative conditions, the analysis showed that MLR could be predicted with a good fit using a five-step reaction kinetic mechanism for EG leaves, and four reactions for PR needles. Finally, a set of kinetic parameters is proposed for thermal decomposition models.