Kinetic study on pyrolysis of mustard stalk using thermogravimetric analysis

Abstract

Mustard stalk (MS) was investigated for its thermal degradation and kinetics using thermogravimetric analysis (TGA) at 30 to 900 °C at four different heating rates (10, 20, 30, and 40 °C.min−1). Kinetic and thermodynamic parameters were determined within the active pyrolysis zone using three non-isothermal models viz. Flynn-Wall-Ozawa; Kissinger-Akahira-Sunose; and Starink method. The results indicate that MS undergoes thermal degradation experiencing different stages of mass loss like dehydration, active pyrolysis, and passive pyrolysis as main stages. The active pyrolysis stage resulted in maximum mass loss. The average activation energy (Eα) was 173.83; 173.18 and 172.94 kJ.mol−1 determined using FWO, KAS, and Starink model, whereas the average pre-exponential factor (A) was 2.22 × 1017, 3.21 × 1017, and 2.92 × 1017 respectively. Change in enthalpy (ΔH*), Gibbs free energy (ΔG*), and entropy (ΔS*) determined were in good agreement for all three methods.