Reactivity analysis of pulverised coal in O-2/N-2/CO2 environments was carried out using thermo-gravimetric method. At all temperature ranges, coal combustion in O-2/CO2 and O-2/N-2 environments using equivalent oxygen concentrations was almost similar. However, when oxygen concentration increased the coal burning rate also increased thus reducing the burnout time and net combustion gas volume. With increasing heating rate, coal particles burnt at shorter times and at higher temperatures. Mathematical models of Doyle, Coats-Redfern and Freeman-Carroll were applied to determine activation energy and pre-exponential factor of oxy-coal combustion at various heating rates. However, kinetic parameters decreased when heating rates increased from 10 to 50K/min.