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Compatibility Study for Plastic, Elastomeric, and Metallic Fueling Infrastructure Materials Exposed to Aggressive Formulations of Ethanol-Blended Gasoline

The Energy Independence and Security Act (EISA) of 2007 is an omnibus energy policy law designed to
move the United States toward greater energy security and independence. A key provision of EISA is the
Renewable Fuel Standard (RFS) which requires the nation to use 36 billion gallons per year (BGPY) of
renewable fuel in vehicles by 2022.1 Ethanol is the most widely used renewable fuel, and increasing the
allowable ethanol content from 10% to 15% is expected to push renewable fuel consumption to 21BGPY.
Therefore, a large portion of 36 billion gallon goal can be met by increasing the ethanol in gasoline to
15%. However, concerns were raised that this increase in ethanol may negatively impact the compatibility
of materials and components used in standard gasoline fueling hardware. In the summer of 2008, the U.S.
Department of Energy recognized the need to assess the impact of intermediate blends of ethanol on
the fueling infrastructure, specifically those systems located at the fueling station. A short time later
(March 2009), Growth Energy (a coalition of ethanol producers and supporters) requested a waiver from
the Environmental Protection Agency (EPA) to allow the use of 15% ethanol in gasoline.2
The first phase of this research focused on intermediate ethanol levels (10 to 25%), and the materials
evaluated at that time were limited to elastomers, metals and sealants. The results from the Phase 1effort
were published in March of 2011.3 At the conclusion of the Phase 1 activity, ORNL expanded the
material selection to include plastics, which included types typically found in fueling infrastructure
systems, including piping and underground storage tanks. Initially, the test fuels were those representing
gasoline containing 0 to 25% levels of ethanol, but later, test fuels representing the high ethanol blends,
E50 and E85, were added for completeness. Since elastomers and metals had not been evaluated in these
high ethanol blends, they were included along with the plastic materials.
The results contained within this report are divided into three sections according to material type. In the
first section, the compatibility results are presented for plastic materials exposed to gasoline test fuels
containing low and high levels of ethanol. The remaining two sections emphasize the compatibility of
elastomers and metals with gasoline test fuels containing high ethanol concentrations. Additional data
obtained from the earlier study on these materials are included for additional interpretation and summary.

Michael Kass
Contact Person
Tim Theiss
Contact Organization
Oak Ridge National Laboratory
Contact Email
Bioenergy Category
Publication Year
Funded from the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies Office.