Effect of the particle size on combustion characteristics of pulverized coal in an O2/CO2 atmosphere

The effects of the particle size on combustion characteristics of pulverized coals under O2/N2 and O2/CO2 atmospheres were compared using thermo-gravimetric analysis method. The results show the effect is greater in O2/CO2 atmosphere. It presents obvious fluctuation, which becomes greater as the volatile matter content of coal increases. The effects of O2 concentrations were also compared. The results show a noticeable discrepancy between O2/N2 and O2/CO2 atmospheres at a low O2 concentration and indiscernible at a high O2 concentration. Meanwhile, the fluctuation effect is different under the different O2 concentrations, which can be related to the reaction rate. In conclusion, under the O2/CO2 atmosphere, the effect of the particle size on pulverized coal combustion is completely different from that under O2/N2 condition.