The objective of this study was to discuss the applicability of isoconversional models in estimating the activation energy and pre-exponential factor for biomass pyrolysis. Thermogravimetry and derivative thermogravimetry experiments of tucumã endocarp were performed at the heating rates of 5, 10,...

The objective of this study was to discuss the applicability of isoconversional models in estimating the activation energy and pre-exponential factor for biomass pyrolysis. Thermogravimetry and derivative thermogravimetry experiments of tucumã endocarp were performed at the heating rates of 5, 10, and 20 °C min−1 in an atmosphere of nitrogen. The isoconversional models of Ozawa–Flynn–Wall, modified Coats–Redfern, Friedman, and Vyazovkin were applied to the experimental data, considering first-order rate law, resulting in activation energies of 147.25, 144.64, 160.47, and 144.96 kJ mol−1, respectively. The pre-exponential factor varied from 9.75 to 11.95 log s−1. As isoconversional models consider the solid decomposition to be represented by a single reaction, described by only one peak in the derivative thermogravimetry data, only a satisfactory agreement between experimental and theoretical data was observed. The fit was verified by simulating curves of conversion as a function of temperature, in which the kinetic parameters obtained with Ozawa–Flynn–Wall and Vyazovkin models generated the lowest relative deviations (9.05 and 9.3 %, respectively). In consequence, the use of isoconversional models is attractive because this kind of model is easy to apply, generating satisfactory approximations for the actual kinetic parameters

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES

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