Thermogravimetric analysis and kinetics of the co-pyrolysis of coal blends with corn stalks

The coal, corn stalks (CS) and their blends with 25%, 50% and 75% CS mass ratio were studied through non isothermal thermogravimatric analysis (TGA) at five different heating rates comprising 10, 20, 30, 40 and 60 degrees C min(-1). The purpose of this study is to investigate the pyrolysis behaviors and to obtain kinetic parameters of thermal decomposition through the distributed activation energy model (DAEM). The results reveal that the thermochemical reactivity of CS is higher than that of coal. The devolatilization indexes for blends are lower than the values calculated from the additive model, indicating that the addition of CS may discourage the volatile release of the blends. The activation energies of coal, CS and their blends with 25%, 50% and 75% CS mass ratio were 63-273 kJ mol(-1) (x from 0.10 to 0.50), 35-142 kJ mol(-1) (x from 0.05 to 0.80), 21-238 kJ mol(-1) (x from 0.05 to 0.70), 29-219 kJ mol(-1) (x from 0.05 to 0.75) and 30-146 kJ mol(-1) (x from 0.05 to 0.75), respectively, and their corresponding frequency factors were e(6.1)-e(38.0) s(-1), e(3.6)-e(21.5) s(-1), e-(0.5)-C-32.8 s(-1), e(1.8)-e(18.8) s(-1) and e(2.3)-e(21.9) s(-1), respectively.