Exploring Corymbia torelliana hydrochar combustion kinetics through thermogravimetric analysis, peak deconvolution and reaction profile modelling

This study aims to conduct an applied and innovative investigation to enhance the energy quality of wood residues through hydrothermal carbonization pretreatment. For this purpose, the treatment was carried out at three different temperatures: 180, 220, and 240 °C under autogenous pressure. The in natura material and the hydrochars were characterized, and thermogravimetric analyses were performed in an O₂ atmosphere with heating rates of 2.5, 5, 10, and 20 °C min⁻¹. The global activation energy for natura biomass combustion was determined to be 112.49 kJ.mol⁻¹. On the other hand, the hydrothermal carbonization process promoted a reduction in this value for the 94.85 kJ.mol⁻¹. The conversion function for the in natura biomass was characterized as \(\left(1-\alpha \right)\) $\left(1,-,\alpha \right)$ , order 1, while the hydrochars was 2(1−α) [−ln(1−α)] ^(1⁄2), Avrami-Erofe’ev I. Triple kinetic parameters were ascertained, and the conversion curves along with their respective derivatives were modeled, exhibiting minimal deviations between theoretical and experimental data. This facilitated the mathematical representation of the reaction processes and allowed for a comprehensive comparison of the results.