Theoretical Determination of a Thermogravimetric Model of Oak Cork (Quercus variabilis) Using Málek Kinetic Analysis

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Abstract The purpose of this study was to determine the expression of a kinetic model and the determination of kinetic parameters for cork. Thermal analysis kinetics of cork and impurities (sclereids and lenticels) were studied by thermogravimetric (TG) curves. The Málek method was used to obtain kinetic parameters in this experiment. Reconstruction models of y(α) and z(α) were compared with standard curves to determine appropriate kinetic models. The results showed that the RO(n) model was suitable to describe the dynamic process of cork, sclereids, and lenticels. The expressions of kinetic models were f(α) = (1 − α)4.89 for cork, f(α) = (1 − α)5.82 for sclereids, and f(α) = (1 − α)5.00 for lenticels. The natural log values ln A were 19.56, 28.90, and 28.88 ln s−1 for cork, sclereids, and lenticels, respectively. Fitting errors of parameters for cork, sclereids, and lenticels were less than 5 percent. The fitted conversion rate and curves of mass fraction were in good agreement with experimental data. Obtaining the kinetic model and parameters provides a basis for prediction of thermal properties of cork.