Kinetic modelling for pyrolytic degradation of olive tree pruning residues with predictions under various heating configurations

Abstract

Herein, the aim was to develop an in-depth understanding of the kinetic behaviour of olive tree pruning residue (OTPR), an abundant agricultural waste, during pyrolysis. Thermal analysis at 1, 2, 4, 6 and 10 °C.min−1 was performed using TGA-thermogravimetric analysis, with the results subsequently used to determine the OTPR's kinetic thermal breakdown behaviour. Furthermore, advanced kinetics and technology solutions (AKTS) thermo-kinetic tool was applied to investigate the kinetic behaviour of OTPR and to generate kinetic predictions for various heating configurations. Friedman's method was the main approach used to evaluate the kinetic parameters. For comparison, other established kinetic modelling techniques, such as ASTM-E698 and Flynn-Wall-Ozawa (FWO) methods, were applied. The ASTM-E698 approach yielded an apparent activation energy (Ea) of 172.09 kJ.mol−1, whereas the FWO method yielded an Ea range from 38 to 172 kJ.mol−1. Finally, the differential iso-conversional approach yielded Ea values ranging between 85 and 191 kJ.mol−1. Kinetic predictions were then developed for isothermal, non-isothermal, and stepwise configurations using the kinetic parameters obtained via Friedman’s model. The forecasts shed light on optimising production throughput in a variety of reactor configurations.