A simplified kinetic model based on a universal description for solid fuels pyrolysis: Theoretical derivation, experimental validation, and application demonstration

A kinetic model for the prediction of the conversion rate is crucial for research and development of biomass pyrolysis. The complexity of the existing kinetic studies and the diversity in pyrolysis kinetic data largely compromise the application of kinetic models. For the purpose of developing a generalized kinetic model, in this paper, we derive a universal description for all the common reaction mechanisms of solid fuels pyrolysis, among which the first-order reactions can be described as standardized general extreme value distribution. Based on the universal description, a simplified kinetic model with only one kinetic parameter is proposed. Then, we perform an experimental study of cellulose and poplar wood pyrolysis in order to validate the new model and to demonstrate its usefulness. The prediction results of the new model are very consistent with those from the conventional Arrhenius model and also agree well with the experimental data. Afterwards, the new model is applied to evaluate the kinetics for poplar wood pyrolysis, and comparisons between our model results and the commonly used Friedman method in terms of accuracy and applicability are shown. The new model also illustrates that the activation energies vary remarkably with the conversion degree and heating rate.