An innovative evaluation method for kinetic parameters in distributed activation energy model and its application in thermochemical process of solid fuels

Abstract

The interaction among kinetic parameters in the distributed activation energy model was investigated. The surface and contour plots of prediction error were depicted to explain non-uniqueness of the kinetic parameters. The kinetic compensation effect between mean activation energy and pre-exponential factor was confirmed based on the isokinetic point. An innovative estimation method for kinetic parameters was proposed, which not only eliminated the non-uniqueness of kinetic parameters but also ensured that the model owns a robust predicting ability. The Maximum Likelihood Estimation was used to estimate the mean activation energy. A combination of Gauss-Hermite Quadrature numerical algorithm and pattern search method was applied to determine the pre-exponential factor and standard deviation. In addition, the developed method was successfully employed to estimate the pyrolysis kinetics of sewage sludge. The new method will promote the application of the distributed activation energy model in the thermochemical utilization of solid fuels.