Thermogravimetric pyrolysis kinetics of bamboo waste via Asymmetric Double Sigmoidal (Asym2sig) function deconvolution

Thermogravimetric kinetic of bamboo waste (BW) pyrolysis has been studied using Asymmetric Double Sigmoidal (Asym2sig) function deconvolution. Through deconvolution, BW pyrolytic profiles could be separated into three reactions well, each of which corresponded to pseudo hemicelluloses (P-HC), pseudo cellulose (P-CL), and pseudo lignin (P-LG) decomposition. Based on Friedman method, apparent activation energy of P-HC, P-CL, P-LG was found to be 175.6 kJ/mol, 199.7 kJ/mol, and 158.4 kJ/mol, respectively. Energy compensation effects (ln k0,z vs. Ez) of pseudo components were in well linearity, from which pre-exponential factors (k0) were determined as 6.22E+11 s−1 (P-HC), 4.50E+14 s−1 (P-CL) and 1.3E+10 s−1 (P-LG). Integral master-plots results showed pyrolytic mechanism of P-HC, P-CL, and P-LG was reaction order of f(α) = (1 − α)2, f(α) = 1 − α and f(α) = (1 − α)n(n = 6-8), respectively. Mechanism of P-HC and P-CL could be further reconstructed to n-th order Avrami-Erofeyev model of f(α) = 0.62(1 − α)[−ln(1 − α)]−0.61(n = 0.62) and f(α) = 1.08(1 − α)[−ln(1 − α)]0.074 (n = 1.08). Two-steps reaction was more suitable for P-LG pyrolysis.