THERMAL DEGRADATION BEHAVIOR AND REACTION KINETICS OF WHEAT HUSK PYROLYSIS

Abstract

This study investigated the pyrolysis behavior and reaction kinetics of wheat husk (WH) using thermogravimetric analyzer (TGA) at heating rates of 10, 20, 30, 40, and 50 ºC/min from ambient temperature to 850 ºC. TGA profiles revealed that the most significant weight loss occurred within the major devolatilization region. A systematic increase in the peak temperature (T_max), the maximum devolatilization rate (W_max), and the final solid residue (SR) was observed with increasing higher heating rate. Kinetic analysis, performed using the Friedman and FWO methods., yielded activation energy (E_a) values that remained nearly constant until α=0.7, beyond which a pronounced increase was observed. The calculated E_a values ranged from 115.71 to 378.66 kJ/mol (Friedman), and 129.01 to 344.38 kJ/mol (FWO), with coefficient of determination (R² >0.96) for both methods validate the reliability of E_a calculations. The master plot technique identified the F3 reaction model as the most suitable mechanism for describing the pyrolysis process. Finally, the pre-exponential factor (A) values ranged from 2.44×10⁹ to 2.11×10²⁶ s^-1.