Kinetics and thermodynamics profiling of CO2-driven coconut husk gasification via thermal analysis

This study explores the thermal degradation and gasification behavior of coconut husk as a potential feedstock for syngas production. Comprehensive biomass characterization including proximate, ultimate and biochemical analyses as well as estimating higher heating value (HHV) was conducted to assess its suitability. Thermo-gravimetric analysis (TGA) was conducted under a CO₂ environment (flow rate: 100 mL/min) across a temperature range ofroom temperature to 1000 °C, with heating rates of 10, 20, and 30 °C/min. The TGA results indicated that the primary mass loss occurred in temperature range 200 to 550 °C. Kinetic and thermodynamic parameters were evaluated by applying iso-conversional models like Kissinger-Akahira-Sunose (KAS), Tang, Flynn-Wall-Ozawa (FWO) and Starink. The mean activation energy values calculated were 57.066 kJ/mol (FWO), 52.235 kJ/mol (KAS), 52.600 kJ/mol (Starink), and 52.184 kJ/mol (Tang), all of which are lower than those reported for other biomass materials commonly used in gasification and pyrolysis. The calculated energy gap of 4.68 kJ/mol within the activation energy and the enthalpy suggesting conducive thermodynamics to form product. The reaction mechanisms and order were further elucidated using the Criado master plot and Coats-Redfern method, providing deeper insights into the gasification behavior of coconut husk under CO₂ atmospheres. These results highlight the viability of coconut husk as an economical and efficient feedstock for syngas production, thereby supporting the advancement of sustainable energy technologies.