Determination of the apparent activation energy surface from isothermal data of char combustion and gasification

In this paper, the apparent activation energy (AAE) surface was determined by using isothermal data of char combustion and gasification and the apparent Arrhenius equations where the activation parameters depended on temperature and conversion. The dependence of the logarithm of the reaction rate on temperature and conversion was described by the empirical polynomial to increase the accuracy of fitting and the AAE was calculated by the isoconversional method and the fitting of reaction rate and conversion. The AAE surfaces determined for the four examples of char combustion and gasification varied considerably and differently from each other with temperature and conversion. This provides new information for a better understanding of these processes and their kinetic models.