Thermogravimetry Study of the Pyrolytic Characteristics and Kinetics of Fast-Growing Eucalyptus Residue

To utilize the fast-growing Eucalyptus residue (FGER) for energy application, the pyrolysis kinetics of FGER was studied by a new simple distributed activation energy model (DAEM) through thermogravimetry analysis at different heating rates of 10, 20, 30, 40, and 100 °C/min from room temperature to 1000 °C. The results showed that the DAEM could fit the experimental data well. The pyrolysis weight loss process of FGER could be divided into four stages. The first and second stages were attributed to hemicellulose decomposition located at α = 0–0.1 and α = 0.11–0.34 with activation energies of 117 and 155.8 kJ/mol, respectively. It was found that cellulose pyrolysis occurred in the third stage, which covers a conversion range of α = 0.35–0.74 with E = 182.9 kJ/mol. The fourth stage represented the tails of the differential thermogravimetry curve and occurred at high conversion with a high activation energy value. The DAEM fitted the experiments well in low conversion, α < 0.8. The weight fraction distribution in the fourth stage was complex, which indicated the heterogeneity of the reaction.