Some methodological problems concerning nonisothermal kinetic analysis of heterogeneous solid-gas reactions

Isoconversional methods, those using only one curve alpha = alpha (T) (alpha is the conversion degree and T is the temperature), and invariant kinetic parameter method were applied to estimate the kinetic parameters from the following nonisothermal data (1) simulatedTG curves for a single reaction; (2) TG curves for thermal degradation of PVC; and (3) TG curves for the dehydration of CaC2O4.H2O. The results obtained by applying various methods for the same system are compared and discussed. Finally, a procedure of kinetic analysis is suggested its application could lead to kinetic parameter values that can be used to predict either alpha = alpha (t) curves for other heating rates or alpha = alpha (T) curves for isothermal conditions. (C) 2001 John Wiley & Sons, Inc.