Comparison of Isothermal Predictions Based on Model-Free and Model-Based Kinetic Methods

摘要

Isothermal predictions based on dynamic measurements do not work correctly for all reactions. This work considers isothermal predictions for model-free and model-based methods for simple reactions and two-step reactions. It is shown that for complex reactions, the model-free analysis based on dynamic measurements always depends on the heating rates of measurements. For this reason, predicted times to a specified degree of conversion are often much longer than true times. Kinetic data from model-free analyses can provide correct isothermal predictions only in cases where the activation energy is either constant or increasing with respect to conversion. If the activation energy decreases with increasing conversion in a model-free analysis, additional isothermal measurements and a correct kinetic model derived from the isothermal measurements are necessary to make correct predictions.