Abstract
•Karanj fruit hulls (KFH) hydrochar combustion profiles were developed.•Two isoconversional methods were applied for kinetic data evaluation.•The KFH hydrochar combustion follows multi-steps kinetics.•Diffusion mechanisms controlled the combustion reactions.
This study examined the combustion profile and kinetics of hydrochar produced from hydrothermal carbonisation (HTC) of Karanj fruit hulls (KFH). The HTC-KFH hydrochar combustion kinetics was investigated at 5, 10, and 20°C/min by thermogravimetric analysis. The kinetics model, Kissinger–Akahira–Sunose revealed the combustion kinetics parameters for the extent of conversion from 0.1 to 0.8; the activation energy varies from 114 to 67kJ/mol respectively. The hydrochar combustion followed multi-steps kinetics; the Coats–Redfern models predicted the activation energies and pre-exponential constants for the hydrochar combustion zones. The diffusion models are the effective mechanism in the second and third zone.