Combustion behavior of corncob/bituminous coal and hardwood/bituminous coal

Abstract

The combustion performance of two typical herbaceous and woody samples (corncob and hardwood) and bituminous coal is evaluated using a thermal analysis technique. The biomasses show better ignition performance, volatile matter release performance and comprehensive combustion performance than those of the bituminous coal. With increasing the heating rates, the performances of corncob, hardwood and biomass/coal blends get obviously improved. The dominant mechanisms associated with combustion kinetics for corncob and most corncob/coal blends at pre-peak and post-peak are described by the Avrami–Erofeev equations (n = 3 or n = 4). The dominant mechanisms associated with combustion kinetics for hardwood and hardwood/coal blends at pre-peak are described by the Avrami–Erofeev equations (n = 3 or n = 4) or Z-L-T equation (n = 2). The dominant mechanisms associated with combustion kinetics for hardwood and hardwood/coal blends at post-peak are described by the Avrami–Erofeev equations (n = 3 or n = 4). The dominant mechanisms of combustion for bituminous coal during the pre-peak and post-peak period are determined to be the reaction order equations. Some significant synergistic interactions are detected between Chinese bituminous coal and corncob or hardwood, especially for all corncob/coal blends at heating rate of 90 °C/min and 80Cc20C blend at heating rate of 70 °C/min during the co-combustion.