Ignition and Combustion Characteristics of Different Rank Coals in O2/CO2 Environments

Previous works on flame stability and stand-off distance under oxy-coal combustion conditions has been conducted with a co-axial turbulent diffusion burner for different rank coals in a 100kW pulverized coal test rig at the University of Utah. The pilot-scale results indicate that oxygen partial pressure and coal compositions have a significant effect on the ignition and flame stability of coal particles in the oxy-coal combustion. The aim of the present paper is to investigate the ignition and combustion characteristics of three different rank coals at variable oxygen partial pressures in O-2/N-2 and O-2/CO2 environments by Thermo-gravimetric Analyzer (TGA). The experimental results reveal the significant difference of the devolatilization, ignition and combustion properties between three rank coals in O-2/CO2 environments. It could provide fundamental understanding on pulverized coal combustion in O-2/CO2 environments and elucidate the effect of coal compositions on the ignition and flame stability in pilot-scale oxy-coal combustion.