Relative Ozone Forming Potential of Methanol-Fueled Vehicle Emissions andGasoline-Fueled Vehicle Emisons in Outdoor Smog Chambers

摘要

This experimental program compares the relative NO oxidation and O3 formingcapabilities of surrogate VOC mixtures that are representative of urban air, emissions from vehicles using methanol fuels, and emission from vehicles using industry-average gasoline and Fuel F, one of the reformulated fuels used in the Auto/Oil test program. The urban VOC mixture was based upon ambient air analyses conducted by EPA for 6-9 AM in 41 cities over the period 1984-1988. The automotive VOC mixtures were based upon exhaust, evaporative, and running loss measurements made in the Auto/Oil Air Quality Improvement Research Program and upon the application of EPA's MOBILE4 emissions model applied in an Urban Airshed scenario in Dallas/Fort Worth in the year 2005. In addition to testing the relative reactivity of each VOC mixture against the other mixtures, the majority of the experiments used mixtures in which 50% of the carbon was from urban mix and 50% of the carbon was from industry-average gasoline vehicle emissions or 50% of the carbon was from the methanol-fueled vehicle emissions. Some experiments were also conducted with higher fractions of formaldehyde (HCHO) in either the urban mix or in the methanol mix. Another set of experiments compared just the alkane and alkene fractions while in another set, just the aromatic species reactivities were compared.