Critical study of Li-Tang isoconversional method: Application on simulated chemical processes and lignocellulosic biomass thermal decomposition processes

Although the Li-Tang isoconversional method has been commonly used to evaluate the activation energies of complex reactions, its applicability remains questionable. In this study, the applicability of the Li-Tang isoconversional method is critically studied for its effectiveness in analyzing three simulated chemical processes and the thermal decomposition processes of two lignocellulosic biomasses. This method can accurately determine activation energies for chemical processes with constant kinetic parameters; however, it produced significant inaccuracies when applied to chemical processes with varying kinetic parameters, distributed activation energy model (DAEM) processes, corn stover pyrolysis, and tobacco stem combustion. These inaccuracies arise from the inherent assumption of constant activation energy in the Li-Tang isoconversional method's derivation, so caution is advised when applying it to complex reactions. Based on the Friedman isoconversional method (an accurate isoconversional method for calculating activation energies), the actual activation energies for corn stover pyrolysis range from 182 to 280 kJ mol−1, while those for tobacco stem combustion vary between 101 and 207 kJ mol−1 in the conversion range of 0.05–0.95, highlighting their complex reactivities in lignocellulosic biomass thermal decomposition.