Thermal degradation kinetic analysis and conversion of Aesculus indica to porous carbon

Abstract

Thermal degradation and kinetic analysis are the key elements for the conversion of biomass into bioenergy for sustainable pyrolysis. To determine the thermal degradation behavior of Himalayan horse chestnuts (HHCN), pyrolysis was performed at different heating rates (5, 10, 20 and 40 K/min) under inert environment. Three isoconversional methods (Kissinger-Akahira-Sunose (KAS), Friedman-Reich-Levi (FRL), and Flynn-Wall-Ozawa (FWO)) were applied to evaluate the kinetic parameters. The activation energies were found to be 119.45, 140.11, and 145.76 kJ/mol for KAS, FWO, and FRL methods, respectively. The variance in activation energies revealed that pyrolysis process of HHCN proceeds through multiple step kinetics. Master plot and Coats-Redfern methods were applied to determine the probable reaction mechanism. Thermodynamic parameters were evaluated from the activation energies, while the Gibb’s free energy (211.80–217.26 kJ/mol) and high heating value (15.97 MJ/kg) have shown bioenergy potential of HHCN. After pyrolysis, the porous structure of residual carbon was characterized by SEM-EDX, XRD, and Raman spectroscopy. The results revealed that it has potential to be used as adsorbent and active electrode material in energy storage devices.