In this seminar, we will review some prior and recent work on the understanding of how oxygenated fuels affect the sooting tendency of fuel mixtures and how oxygenated fuels affect the nanostructure and oxidative reactivity of soot. The desire to reduce the soot emitted by combustion sources derives from concerns over health effects and environmental impacts of fine particulate emissions.  Oxygenated fuels have been considered for several decades as a means of preventing engine soot emissions by preventing soot formation.  For many years, the mechanism by which soot emissions were inhibited by oxygenated fuels was not well understood, nor was there a good understanding of why some oxygenates exhibited greater impacts on sooting tendency that other oxygenates. 

In addition, it was first observed by our research group that combustion of biodiesel fuels (typically derived from soybean oils in the United States) led to emissions of soot with greater oxidative reactivity.  While we are still working out a good explanation of the “why” in this case, we have new results that demonstrate that there is a very specific effect that derives from the methyl ester chemical structure of which biodiesel is comprised.