(487c) Particulate Formation From Pulverized Coal Under Oxy-Fuel Combustion Conditions

Oxy-fuel coal combustion has been recognized as a promising technology for pulverized coal-fired power plants. This research is investigating particulate formation and morphology of ash particulate produced from oxy-fuel coal combustion in a high-temperature drop tube furnace. In this study, ash particulate has been studied as function of temperature, coal type and gas-phase conditions, namely carbon dioxide versus nitrogen. The ash particle size distributions were obtained by a Scanning Mobility Particle Sizer (SMPS) and Aerodynamic Particle Sizer (APS), which allows for measurement of particles in size ranges between 14.3 nm to 20 microns. A Berner Low Pressure Impactor (BLPI) was also used to collect particles on eleven stages to perform morphology and element analysis by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). A tri-model particle size distribution including an ultrafine mode, a submicron mode and a supermicron mode was found. Furthermore, the results showed that in the presence of carbon dioxide, less ultrafine particles were formed, as compared to nitrogen. These results support the hypothesis that the refractory oxides are governed by the equation: MO(s) + CO(g) ↔ CO2(g) + M(g).