AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Secondary Organic Aerosol Formation from Photo-oxidation of Evaporated Fuel: Experimental Results and Implications for Aerosol Formation from Combustion Emissions
SHANTANU JATHAR, Marissa Miracolo, Daniel S. Tkacik, Neil Donahue, Peter Adams, Allen Robinson, UC Davis
Abstract Number: 518 Working Group: Aerosol Chemistry
Abstract We conducted photo-oxidation experiments on evaporated fuels to investigate the role of fuel composition on secondary organic aerosol (SOA) formation from evaporated fuel and determine its implications on the atmospheric formation and composition of SOA from combustion emissions. We used a smog chamber to perform hydroxyl radical-initiated, high NOx experiments at typical atmospheric organic aerosol concentrations on gasoline, three types of jet fuel and six different diesel fuels. For a unit mass of fuel reacted, evaporated diesel formed the most SOA followed by Jet Propellent-8, Fischer-Tropsch (natural gas), gasoline and Fischer-Tropsch (coal). Qualitatively, these trends are consistent with the differences in fuel volatility and molecular structure. Aerosol mass spectrometer data indicate that the SOA is moderately oxygenated (O:C~0.2-0.4), which is similar to the semi-volatile oxygenated organic aerosol (SV-OOA) factor derived from ambient data. The estimated SOA mass yields for the evaporated jet and diesel fuel (SOA/Fuel reacted) are within a factor of two of SOA mass yields of dilute emissions from combustion sources operated on those fuels. This suggests that fuels are able to explain the variability in SOA formation observed with combustion emissions. However, for gasoline vehicle emissions, the vehicle emissions certification standard appears to play an important role in SOA formation potential, suggesting that other variables in a combustion system also influence SOA formation.