Kinetic analysis and pyrolysis behavior of low-value waste lignocellulosic biomass for its bioenergy potential using thermogravimetric analyzer

A substantial amount of renewable feedstocks study has been dedicated to bio-fuel and biochemical generation, preferably thermochemical conversion processes such as pyrolysis. In this work, the physicochemical study, pyrolysis behaviouer and kinetic parameters of Cascabela thevetia (SK) Delonix regia (SG) and Manilkara zapota (CK) seeds were tested in the thermogravimetric analysis (TGA) at three rates of heating (10–50 °C min⁻¹) to estimate its bioenergy potential. Further, the kinetic constraints were investigated by using model-free approaches, namely Kissinger-Akahira Sunose (KAS), Friedman model (FM), Cots-Redfern model (CR), Distributed Activation Energy Model (DAEM), Ozawa-Flynn-Wall (OFW), and Vyazovkin method (VZ). Characterization study of applied biomass showed an attendance of extensive amount of volatile matter (73.15–75.24%), carbon content (50.12–55.02%), heating value (20.52–25.12 MJ kg⁻¹), and lower ash content (2.20–3.15%) and nitrogen content (3.01–5.10%). Further, DSC inspection of applied biomass recognized that biomass decayed under the endothermic process during the heating process. The average activation energy for CK, SG, and SK was originated to be 157.81, 150.90, 166.28 kJ mol⁻¹ for KAS, 164.55, 166.59, 177.05 kJ mol⁻¹ for OFW, 168.47, 166.05, 185.22 kJ mol⁻¹ for FM, 194.87, 157.87, 199.74 kJ mol⁻¹ for DEAM and 168.75, 158.86, 102.28 kJ mol⁻¹ for VZ respectively. Additionally, CR model yields 49.99, 35, 38.71 kJ mol⁻¹ at n = 1 and 34.79, 29.18, 27.7 kJ mol⁻¹ at n ≠ 1 for CK, SG, and SK, respectively. Finally, the variation between activation energy and enthalpy of reaction showed promising product formation. In contrast, Gibbs free energy and higher heating value (HHV) of biomass exhibited its potential for energy and fuel production.