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Gasoline Composition in 2008
Citation:
WEAVER, J. W., L. R. EXUM, AND L. M. PRIETO. Gasoline Composition in 2008. Presented at 20th Annual Tanks Conference, Atlanta, GA, March 17 - 19, 2008.
Impact/Purpose:
This project seeks to develop a comprehensive approach to assessing releases of petroleum fuels that accounts for their multicomponent nature, specifically in the areas of multicomponent partitioning to air and ground water, and assessment of transport to receptors. The two major parts of this work are the generation of current multicomponent data on fuel composition and a transport modeling approach that can lead to a decision support system.
Description:
Gasoline composition in the U.S is determined by factors related to crude oil source, refinery capacity, geography and regulatory factors. Major regulation derived from the Clean Air Act and its amendments determines the benzene and former oxygenate requirements for reformulated gasoline. These were specified on a county, partial county, or city basis. Reformulated gasoline has historically accounted for 1/3 of the total gasoline used in the country, but is prevalent in the most highly populated regions of the country, especially the Northeast corridor and California. The remainder of the country uses conventional gasoline, where the benzene content is limited by 1990 producer baselines. This gasoline may have more benzene than reformulated gasoline as seen in EPA/ORD and many other data sets. The Mobile Source Air Toxics Rule of 2007 will limit benzene content across the U.S. by 2011. The passage of the Energy Policy Act of 2005 caused ethers to be removed from the U.S. gasoline supply. Data from the Department of Energy document an abrupt shift in reformulated gasoline to reformulated gasoline made with alcohol. Current data show that benzene levels continue to be responsive to Clean Air Act mandates and that ethanol content can vary from 6% to 12% in both reformulated and conventional gasoline.