Simple approximate analytical solution for nonisothermal single-step transformations: Kinetic analysis

Abstract

We develop a method for obtaining the approximate solution for the evolution of single-step transformations under nonisothermal conditions. We have applied it to many reaction models and obtained very simple analytical expressions for the shape of the corresponding transformation rate peaks. These analytical solutions represent a significant simplification of the system's description allowing easy curve fitting to experiment. A remarkable property is that the evolutions of the transformed fraction obtained at different heating rates are identical when time is scaled by a time constant. The accuracy achieved with our method is checked against several reaction models and different temperature dependencies of the transformation rate constant. It is shown that its accuracy is closely related with that of the Kissinger method. © 2008 American Institute of Chemical Engineers.