Oxy-coal combustion: stability of coaxial pulverized coal flames in O2/CO2 environments

Oxy-coal combustion, in which air is replaced by an O2/ CO2 mixture, is one of the few technologies that may allow CO2 capture and sequestration technologies to be applied to existing coal-fired boilers. One issue of interest is to understand and predict the effects of near-burner-zone environment, now consisting of O2 and CO2 instead of O2 and N2, on flame stability. This dissertation is directed towards understanding how the composition of the coal transport medium (primary CO2 and O2) affects the ignition standoff distance in 40kW coaxial turbulent diffusion, oxy-coal flames, supported in a specially designed combustion test rig, rated at 100kW. The focus is on mechanisms of interaction between turbulent mixing in coaxial jets and coal particle ignition, rather than on each physical or chemical process taken individually.