Combustion reactivity estimation parameters of biomass compared with lignite based on thermogravimetric analysis

Combustion reactivity of biomass (Robinia Pseudoacacia) was compared with lignite’s reactivity using various parameters (group A) based on thermal analysis data including ignition temperature (T_i), burning rate (dw/dt), burnout temperature (T_b), heat-flow (H), weights/temperatures/times, etc., and some calculated parameters (Group B) such as conversions or indices of reactivity/combustion performance [mean combustion reactivity (R_m), time-based reactivity (R_t), reactivity normalized to initial sample weight (R_w), ignition index (D_i), comprehensive combustion index (S), burnout performance index (D_b), combustion index (H_f), and combustion stability indices (D_cs, D_w)]. Although the conversion yields as well as R_t or R_w pointed out that biomass was more reactive than lignite, some reactivity parameters such as the T_i, temperature/time at 5% conversion, the temperature of maximum heat flow implied that lignite’s reactivity was higher probably due to catalytic effects of minerals. Therefore, a comparison of reactivity considering only the Group A parameters especially for low temperatures can lead to misconception.