Non-isothermal kinetics of biomass-pyrolysis-derived-tar (BPDT) thermal decomposition via thermogravimetric analysis

Thermal decomposition kinetics of biomass-pyrolysis-derived-tar (BPDT) was studied via non-isothermal thermogravimetric analysis. Single-step kinetics results from iso-conversional procedure showed the kinetic of BPDT thermal decomposition had apparent activation energy of E-0 = 79.6 kJ/mol, pre-exponential factor of A(0)= 2.42E7 s(-1), and reaction order of n = 4.6. Single-step reaction was not suitable for BPDT thermal decomposition, since the apparent activation energy varied largely with the conversion. The first step was controlled by diffusion with activation energy of E-1= 36.6 kJ/mol. The second step which was main contributed step (fraction of c(2) = 0.93) followed a reaction order mechanism of f(alpha)= (1 - alpha)(2.26) with activation energy of E-2 = 44.6 kJ/mol. Distributed activation energy model (DAEM) was also investigated using Gaussian, Gamma, Weibull, Logistic, Rayleigh and Log-normal distributions. According to calculated results different DAEMs, energy compensation effect was found to be reasonable. Although the fitting goodness of different DAEMs were very well, Akaike Information Criteria (AIC) test showed that the Rayleigh DAEM was the most suitable kinetic model for BPDT thermal decomposition. (C) 2017 Elsevier Ltd. All rights reserved.