Comprehensive Investigation of the Thermal Degradation Characteristics of Biodiesel and Its Feedstock Oil through TGA-FTIR

With the rapid growth of biodiesel production in recent years, it is essential to evaluate the thermal degradation characteristics of biodiesel and its feedstock oil, for they are concerned with plenty of scientific applications. This study investigates thermal degradation of biodiesel and its feedstock oil through thermogravimetric analysis in conjunction with Fourier transform infrared spectroscopy (TGA-FTIR). The experiments are conducted under inert conditions from 298 to 873 K, and are operated at temperature heating rates of 5, 10, 15, and 20 K min(-1). Based on TGA results, the activation energy and enthalpy are calculated via the model free approach and the reaction order is determined by the Avrami theory. Besides the pre-exponential factor, the Gibbs free energy and entropy are calculated at the initial weight loss and the maximum weight loss temperature. Finally, the evolved products during the thermal degradation of biodiesel and its feedstock oil are detected by FTIR in real time.