BIODIESEL COMBUSTION AND EMISSIONS

André Boehman Professor of Fuel ScienceDepartment of Energy and Geo-Environmental EngineeringPennsylvania State UniversityAbstractIn this work, we consider the behavior of biodiesel fuels during diesel combustion, including the injection process, pollutant formation and the characteristics of the pollutants. Topics covered include the unique features of the ignition process for biodiesel fuels, the anomalous "NOx Effect" that is observed in diesel engines running on biodiesel and impacts of biodiesel on the characteristics of diesel soot. Past and ongoing work seeks to relate the nanostructure and oxidative reactivity of soot. This work shows that the initial structure alone does not dictate the reactivity of diesel soot and rather the initial oxygen groups have a strong influence on the oxidation rate. A comparison of the complete oxidation behavior and burning mode was made to address the mechanism by which biodiesel soot enhances oxidation. Diesel soot derived from neat biodiesel (B100) is far more reactive during oxidation than soot from neat Fischer-Tropsch diesel fuel (FT100). B100 soot undergoes a unique oxidation process leading to capsule-type oxidation and eventual formation of graphene ribbon structures. Incorporation of greater surface oxygen functionality in the B100 soot provides the means for more rapid oxidation and drastic structural transformation during the oxidation process. These characteristics of diesel soot have implications for the operation and regeneration of diesel particulate filters and, as a consequence of the coupling that can arise between particulate and NOx controls, for the operation of urea-selective catalytic reduction of NOx.

Location: Seaver Science Library, Rm 150

Audiences: Everyone Is Invited

Contact: April Mundy