AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
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Organic Emission Profiles for Gasoline, Gas-turbine and Diesel Engines Using the Volatility Basis Set
QUANYANG LU, Yunliang Zhao, Albert Presto, Tim Gordon, Andrew May, Allen Robinson, Carnegie Mellon University
Abstract Number: 667 Working Group: Regional and Global Air Quality and Climate Modeling
Abstract Organic emissions from motor sector are important contributors of both primary organic aerosol (POA) and secondary organic aerosol (SOA) precursors in urban environment. Recently, extensive researches have been conducted on intermediate volatile organic compound (IVOC) and semi-volatile organic compounds (SVOC) emissions, and measurements have been performed on different engines using gasoline, jet and diesel fuel. Based on the results of recent studies, complete emission profiles for on- and off-road gasoline, gas-turbine and diesel engines were integrated and evaluated across the entire volatility range. Sources using same type of fuel shares similar ranges of IVOC content, 3-10% of IVOC is identified for on- and off-road gasoline engines while 20-40% of IVOC is observed for jet engine, and more than half of IVOC fraction in total emission for on- and off-road diesel vehicles. Comparison between EPA profiles, fuel composition and exhaust measurements indicated close relationship between unburnt fuel and exhaust, while EPA profiles fall short in IVOC and SVOC collection and speciation. SOA potential based on measurements showed consistency with EPA profiles for VOC forming SOA, but gain 0.5, 13 and 24 times increase on total SOA yield due to updated IVOC and SVOC contents in terms of gasoline, jet and diesel engine exhaust. Combing EPA profiles with IVOC composition in liquid fuel using SOA-weighted enrichment factors provide us with close approximation of SOA forming potential from IVOCs. Box model calculation of total OA production based 2014 National Emission Inventory using new profiles indicate 40% increase by off-road gasoline engines, 1.2 times for on- and off-road diesel engines and 3 times for aircrafts. Model-ready profiles based on exhaust measurements are also proposed.