Thermal degradation behaviour and chemical kinetic characteristics of biomass pyrolysis using TG/DTG/DTA techniques

Abstract

AbstractThe goal of the current study is to investigate the thermal degradation of palm fronds (PF), olive leaves (OL), and wheat straw (WS) through pyrolysis and calculate their kinetic data using TG-DTG and DTA approaches. The kinetic parameters were assessed using isoconversional techniques like the Ozawa-Flynn-Wall (OFW) and Kissinger–Akahira–Sunose (KAS) methods, as well as model-fitting techniques like the integral method, which employs various diffusion and reaction order models. Using kinetics data models, typical parameters for pyrolysis and thermodynamics were estimated. For PF, OL, and WS, the values of activation energy (E) from the integral method ranged between 8.82 and 167.13, 23.06 and 149.20, and 11.01 and 156.27, respectively, for diffusion models. On the other hand, the values of (E) ranged between 22.3 and 117.49, 51.69 and 92.88, and 23.48 and 125.97, respectively, for reaction-order models. The average activation energies (E) calculated by using PF, OL, and WS samples are 91.9, 69.1, and 65.2, respectively, for the OFW method and 87.5, 101.8, and 63.4, respectively, for the KAS method. The results demonstrated that the integral method provided values of (E) that were almost identical to those produced by the KAS and OFW methods. In the same range of (α), results showed that reaction order models yielded greater frequency factor values than diffusion models, demonstrating how simpler and quicker pyrolysis is. The values of ($${\Delta \mathrm{G}}_{av}$$ Δ G av ) demonstrated the acceptability of these materials for pyrolysis, and for the OFW and KAS techniques, the sequence of the degradation process was OL > WS > PF. The calculated ($${\Delta \mathrm{G}}_{av}$$ Δ G av ) showed that more heat energies are required for OL, PF, and WS to dissociate the reagent bonds, which agrees with the (E) values derived from the OFW model. Graphical Abstract