Reaction Kinetics, Mechanisms and Catalysis, 2026 (SCI-Expanded, Scopus)
This study investigated the physicochemical properties and combustion behavior of hydrochar obtained through the hydrothermal carbonization (HTC) of banana peel waste. Banana peel hydrochars produced at different temperatures (HTC-250, HTC-300, HTC-350) exhibited improved properties compared to the raw sample; specifically, carbon content and fixed carbon increased, and higher calorific values were achieved. As the process temperature increased, the hydrochars evolved from the lignite region toward the sub-bituminous coal region, exhibiting lower oxygen content and higher energy density. Combustion behavior and kinetic analyses were examined using the thermogravimetric method at heating rates of 10, 20, and 30 °C/min, and it was observed that the maximum combustion rate shifted toward higher temperatures with increasing heating rates. Kinetic analyses were conducted using a comparative application of the Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), Starink, and Vyazovkin methods. The results demonstrated that increasing HTC temperature facilitated the combustion kinetics of the hydrochar by reducing the activation energy (Ea) from approximately 160 to 58 kJ/mol. These findings provide useful insights for evaluating the solid fuel potential of banana peel waste and for guiding advanced applications.