Thermal Analysis Kinetics Study of Pulverized Coal Combustion under Oxygen-Rich Atmosphere

The thermal analysis kinetic behavior of pulverized coal combustion in different oxygen-rich atmospheres is studied with a thermogravimetric (TG) analyzer. The effects of heating rate on combustion characteristic are considered. The results showed that the combustion rate of pulverized coal increased and the burnout time decreased under the conditions of an oxygen-enriched atmosphere and high heating rate. As the heating rate increases, the TG and derivative TG curves of the coal samples generally move toward the high-temperature region, and the thermal hysteresis phenomenon occurs. The changes in oxygen concentration and heating rate mainly affect the combustion stage of coal samples. The decrease in heating rate or the increase in oxygen concentration will cause a decrease in ignition point temperature and burnout temperature. Under the condition of 40% O-2, the oxygen concentration and heating rate have the greatest influence on the combustion characteristic parameters. In addition, the combustion reaction of pulverized coal in the warming process was analyzed by FWO and KAS methods, respectively. The results showed that the changes in oxygen concentration and heating rate affected the activation energy, and the activation energy of coal samples increased with the increase in oxygen concentration.