Kinetic modelling for pyrolytic conversion of dedicated short rotation woody crop with predictions for isothermal, non-isothermal and stepwise heating regimes

Sesbania sesban, a promising short rotation woody crop, was first evaluated in order to assess its physicochemical attributes as a feedstock material in biochar manufacturing. Additionally, thermogravimetric analysis (TGA), performed at 0.5, 1, 4 and 8 °C.min⁻¹, was utilised to conduct thermal analysis, with the results being used to analyse the feedstock's kinetic behaviour during thermal degradation in an inert environment. For the first time, advanced kinetics and technology solutions (AKTS) software was used to analyse the kinetic parameters of sesbania pyrolysis and make kinetic predictions under various thermal conditions. The apparent activation energy (E_a) was determined using Friedman's differential iso-conversional model, which is the primary kinetic modelling method utilised. Other traditional models, such as the integral Flynn-Wall-Ozawa (FWO) and ASTM-E698 methods, were employed for comparison purposes. The activation energy of 124.53 kJ.mol⁻¹ was obtained using the ASTM-E698 technique, while the E_a value for the FWO method ranged from 50 to 200 kJ.mol⁻¹. As it accurately reflects the dynamic nature of lignocellulosic biomass degradation, the differential iso-conversional technique is the most reliable and precise approach, with E_a values ranging from 20 to 205 kJ.mol⁻¹. Predictions under isothermal, step-based and non-isothermal conditions were then constructed using the results computed through the differential iso-conversional model. This information can be used to improve production throughput in a variety of reactors. Additionally, the derived kinetic parameters can be used for process modelling.