ACTIVATION-ENERGY FOR THE OXIDATION OF MALAYSIAN COAL CHARS

The oxidation of two Malaysian coal chars has been studied by means of a thermal gravimetric analyser (TGA). The weight-loss data were analy sed by the Temperature Program Reaction (TPR) technique, which employe d the random pore model of Bhatia & Perlmutter(1). All experiments wer e conducted within a temperature range of 698-773 K (isothermal condit ion) and heating rates of 2-10 K min(-1) (dynamic condition) with char samples in the size range 53-75 mu m. It was found that the random po re model can accurately describe the oxidation of char to yield activa tion energy that is similar to that obtained from model free kinetics, provided the structural parameter psi, which is an input to the model , is taken as an adjustable parameter.