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Cold temperature effects on speciated MSAT emissions from light duty vehicles operating on gasoline and ethanol blends
Citation:
George, I., M. Hays, R. Snow, J. Faircloth, T. Long, AND R. Baldauf. Cold temperature effects on speciated MSAT emissions from light duty vehicles operating on gasoline and ethanol blends. Presented at 2015 CRC Mobile Source Air Toxics Workshop, Sacramento, CA, February 17 - 19, 2015.
Impact/Purpose:
This poster highlights APPCD research activities on air toxics emissions characterization from mobile sources from the EPAct dynamometer study. Speciated emissions from light-duty vehicles running on gasoline and ethanol blends at cold temperature from chassis dynamometer measurements at RTP are presented. The poster will be presented to academics, industry representatives and environmental regulators at the CRC Mobile Source Air Toxics Workshop.
Description:
Emissions of speciated volatile organic compounds (VOCs), including mobile source air toxics (MSATs), were measured in vehicle exhaust from three light-duty gasoline vehicles. Vehicle testing was conducted using a three phase LA92 driving cycle on a temperature controlled chassis dynamometer at two ambient temperatures (-7 °C and 24 °C). Vehicles were operated on gasoline (E0) and ethanol blended (E10 and E85) fuels during testing. The most abundant MSAT emissions sampled from the vehicle exhaust overall were acetaldehyde and monoaromatic compounds, i.e. benzene, toluene, ethylbenzene and xylenes (BTEX). The first cold start phase and cold temperature dramatically increased MSAT emissions by up to several orders of magnitude compared to emissions during other phases and warm ambient temperature testing, respectively. The use of ethanol blends at 24 °C led to reductions in BTEX and increases in formaldehyde and acrolein, where changes were greater in magnitude with E85 fuel compared to E10. Although aromatics were also reduced for the -7 °C tests, benzene increased with use of E85. MSAT emissions from vehicles operating on the ethanol blends greatly increased during cold temperature tests compared to E0, which were dominated by a rise in acetaldehyde emissions. MSAT emission profiles from this study will be compared to SPECIATE emission profiles for light duty gasoline vehicles operating on gasoline and ethanol blends.