AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
The Investigation of Water-Insoluble Particle Emissions of Butanol and Ethanol Gasoline Mixtures
DANIEL SHORT, Diep Vu, Maryam Hajbabaei, Georgios Karavalakis, Thomas D. Durbin, Akua Asa-Awuku, University of California, Riverside
Abstract Number: 223 Working Group: Combustion
Abstract Particle number and size information is important for anthropogenic combustion effects on air quality, climate, and health. The composition of particles from vehicular fuel combustion, may contain water insoluble black carbon (BC) and other insoluble material that modify particle nucleating properties. Conversely, the soluble fraction is important for particle water–uptake and wet deposition processes. Changes in fuel composition will modify the emissions of insoluble materials. Fuel mixtures of ethanol or butanol in gasoline are likely to decrease water-insoluble particle fractions. Compared to ethanol, butanol exhibits high energy content, better fuel economy, and more efficient combustion characteristics. The introduction of new engine technologies may also affect emissions and ultimately air quality. The penetration of gasoline direct injection (GDI) vehicles is expected to rapidly grow in the near future in both the US and European markets. However there are concerns that their elevated particulate emissions may adversely affect air quality, as they emit 3 to 4 times more particles than port fuel injection (PFI) counterparts.
In our study, ultrafine particle size and number concentrations are measured from a combination of conventional, flexible fuel, and GDI vehicles of leading automobile manufacturers. The particle emissions from different ethanol butanol blends in gasoline are compared. A water-based condensation particle counter (CPC) and a butanol-based CPC measure tail-pipe particle number concentrations from each fuel. Both instruments are coupled with a Scanning Mobility Particle Sizer (SMPS). Our measurement and analysis technique exploits the differences in particle distributions from the CPCs to infer insoluble particle mass fractions from real-time emissions. The data is correlated with BC measurements obtained with a Multi-Angle Absorption Photometer (MAAP). The contribution of insoluble mass from insoluble BC is determined. The results of this study will improve our understanding of alternative fuel mixture emissions for particle effects on air quality and climate.