Effects of ethanol and aromatic contents of fuel on the non-regulated exhaust emissions and their ozone forming potential of E10-fueled China-6 compliant vehicles

Traffic-related volatile organic compounds (VOCs) emissions are regarded as the primary anthropogenic source of ambient VOCs in urban areas and precursors to ozone formation. Given the extensive use of gasoline-ethanol mixtures on light-duty vehicles, it is essential to discuss its effects on the atmospheric environment, especially the VOCs emissions and ozone forming potential (OFP) values of one typical formulation called the “match-blend.” In this paper, VOCs emission factors, VOCs distributions, specific reactivity (SR) values, and OFP values of a China-6 commercial gasoline and four E10 match-blend fuels used on seven China-6 vehicles were studied. Thirteen carbonyls detected by high-performance liquid chromatography along with seven VOCs detected by gas chromatography-mass spectrometry were considered in the calculation of OFP and SR. Besides, the effects of test temperatures are discussed. Results show that ethanol increases VOCs emissions, OFP, and SR values at cold-start/room temperature, but behaves oppositely at cold-start/low temperature. Increases in heavy aromatics always lead to higher VOCs emissions and OFP values.