Interrelation between the kinetic constant and the reaction order in pyrolysis

A numerical method for calculating the kinetic constants of the thermal decomposition of heterogeneous solids is proposed, considering the interdependence between the pre-exponential factor and the reaction order. This method is applied to the pyrolysis of poly-(ethylene terephtalate) with satisfactory results. The kinetic constants calculated with this method during the optimization goes preferably to parameters with correct physical meaning, and therefore, a lower number of iterations in the optimization calculation system is needed. The interdependence of the pre-exponential factor and the reaction order restricts the possible solutions of the calculations, and produces more valid solutions in the calculation procedure. (C) 2003 Elsevier Science B.V. All rights reserved.