Comparative analysis of kinetic model-fitting methods and selection priority for horse manure pyrolysis

The diverse origins of biomass wastes provide a constraint on the practical application of pyrolysis, as it leads to uncertain chemical reactions, feedstock conversion, and energy consumption. Various model-fit methods are available to identify the decomposition kinetics, however, limited studies have compared the reliability and accuracy of those kinetic models. This work compared five different kinetic models, two based on model-fit methods (Coats–Redfern (CR), Kennedy-Clark (KC) and three based on the application forms of Criado Master Plots (CMP I, CMP II and CMP III). The mass loss data from the pyrolysis of horse manure (HM) through a thermogravimetric analyser was used as a biomass sample for evaluation. Results demonstrated that all five model-fit methods report different kinetics data. Although the model-fit methods (CR and KC) allow a direct determination of kinetic triplets, the accuracy of data is lower. The CMP-II and CMP-III methods (incorporating model-free data in the model-fit methods) showcase multi-step chemical kinetics and better describe the decomposition behavior of HM due to its multi-compositional properties. To obtain kinetic triplets with enhanced accuracy, it is recommended to incorporate model-free data into the model-fit method. Improved precision of the kinetics data is essential for developing experimental parameters and optimizing the process. Future research should include the selection criteria of model-fit methods shown in this study to improve the accuracy of kinetic data.