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Melissa L. Holtmeyer
Department of Energy, Environmental and Chemical Engineering
Washington University in St. Louis
Advisor: Richard L. Axelbaum
Abstract
Gaseous flame studies of non-premixed diffusion flames in one-g and micro-g conditions provide insight and motivation for application of oxy-fuel combustion to coal and biomass combustion. Under one-g conditions, flames were designed to decrease soot formation by redirecting some or all of the nitrogen from the oxidizer into the fuel, which also made stronger flames more resistant to extinction. Oxy-fuel combustion is applied to both coal combustion (oxy-coal combustion) and biomass co-firing combustion (oxy-co-firing combustion) to study the potential for pollutant formation reductions, namely NOx. Air-fired cases were compared to 30 vol.% O2/70 vol.% CO2 oxy-combustion cases experimentally to determine the effects on NO emissions. A 20% reduction in NO emissions was seen and compares well with available literature. The effects of co-firing and biomass particle size on NO formation are studied numerically using Computational Fluid Dynamics (CFD). The nature of NO formation differs between coal only and co-fired cases. The numerical model shows that large biomass particles have a delayed volatile release, which affects the overall flame structure and local temperature and species concentrations resulting in higher nitrogen conversion to NO during co-firing.
Melissa Holtmeyer is from Washington, MO, and is pursuing a Ph.D. in Energy, Environmental & Chemical Engineering at Washington University in St. Louis under the direction of Dr. Richard Axelbaum. She completed her Master of Science with a specialization in Fluid Thermal Science and Bachelor of Science, both in Mechanical Engineering, also at Washington University in St. Louis. Her current research interests include computational fluid dynamic (CFD) modeling of coal systems, including oxy-coal and biomass co-firing scenarios. As well as studying abroad in China, to research renewable energy distributed power generation. She has been honored at the 2008 Central States Combustion Institute Meeting as the Outstanding Student Presenter. She aspires to do energy-related research at either a national lab or in academia.
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