The thermal behaviour of solid particles of plastic, tyre, coal and biomass as feedstock in pyrolysis processes was studied. The samples were pyrolyzed in a thermogravimetric analyzer in nitrogen atmosphere (surface flow rate 2.65.10(-3) m/s) at two different heating rates (5 and 10 degrees C/min) with temperatures ranging from 150 to 950 degrees C. This paper shows the successful application of the distributed energy model to study the effects of dynamic experiments on the solid pyrolysis, in particular, to ABS plastic and tyre rubber for the first time. In addition, the reaction model algorithm used was successfully implemented together with a heat transfer model to predict temperature profiles in the particle and to explore the effects of both solid characteristics and process conditions on the pyrolysis. Within the process conditions studied (particle size, inlet feedstock temperature, reactor temperature and global heat transfer coefficient) the particle size was the most influencing one. From the solid characteristics, the main influence in the particle behaviour was attributed to the characteristic devolatilisation obtained in thermobalance showing the physicochemical properties a weak influence on it. (c) 2011 Elsevier B.V. All rights reserved.