Thermogravimetric Studies of Characteristics and Kinetics of Pyrolysis of Buton Oil Sand

Abstract

This work was aimed to study the pyrolysis behaviour and mechanisms of Buton oil sand via both experimentation and kinetic analysis. The non-isothermal pyrolysis experiments of the oil sand and its main organic component, bitumen, were carried out using a thermogravimetric analyser (TGA) operating at various heating rates of 2, 5, 10 and 20Kmin−1 from room temperature to 823K and in a nitrogen atmosphere. The activation energy of the oil sand pyrolysis was estimated using an integral model-free method based on the TGA experimental data. The results showed that the content of the bitumen in the oil sand was approximately 18% by weight and the pyrolysis process of the bitumen completed at 823K regardless of the heating rate. The calculated activation energy strongly depended on the degree of pyrolysis conversion (ranging from 100kJmol−1 to 250kJmol−1). Good agreement between the kinetic modelling and experimental data of dependence of conversion degree on temperature was obtained, suggesting that the integral model-free method can serve as an effective tool to predict the pyrolysis behaviour of the oil sand.