As use of ethanol grows as an affordable, domestically produced fuel option, researchers are evaluating whether existing infrastructure can safely store and dispense higher ethanol-gasoline blends. More than a decade ago, the Department of Energy’s Oak Ridge National Laboratory conducted foundational research that continues to inform industry decisions today.
Working with Underwriters Laboratories (UL), ORNL evaluated how metals, plastics and elastomers respond to ethanol exposure. The results helped guide standards for the safe use of ethanol in existing fuel infrastructure and provided data that industry still relies on.
Why it matters
Most gasoline sold in the United States today contains 10 percent ethanol, known as E10. The use of 15 percent ethanol blends (E15) continues to grow. As the nation expands the use of domestically produced fuels, ensuring compatibility with existing storage and dispensing infrastructure is essential.
ORNL’s research provided critical data on whether commonly used materials, including steel tanks, piping and dispensing equipment, can safely store and deliver ethanol-blended fuels.
Real-world impact
Findings from ORNL’s 2012 study continue to support documentation showing that UL-listed steel fuel tanks are compatible with ethanol and ethanol-gasoline blends. The collaboration between ORNL and UL also contributed to certification standards that allow fuel dispensers to support ethanol blends up to 25 percent ethanol.
This work helped expand fuel options while supporting the continued use of existing infrastructure, reducing costs and enabling broader deployment of domestically produced fuels.
Key findings include:
- Common metals used in fuel systems, including mild steel and stainless steel, showed very low corrosion rates when exposed to ethanol blends.
- Even for more reactive materials, measured degradation was minimal and did not indicate significant incompatibility.
- Researchers evaluated materials across a range of vehicles, including flexible-fuel vehicles that use a high-ethanol blend, known as “E85.”
The benefits:
- Supports safe use of existing infrastructure for ethanol-blended fuels.
- Reduces the need for costly replacement of compatible tanks and fuel-system components.
- Provides a technical basis for manufacturer documentation and industry standards.
- Helped inform certification standards for fuel dispensers compatible with ethanol blends up to 25 percent ethanol.
The innovation
ORNL combined controlled materials testing with real-world fuel conditions to directly measure how infrastructure materials respond to ethanol exposure. The research bridged laboratory testing, standards development and practical deployment, helping industry make informed decisions about fuel infrastructure compatibility.
Backed by science
The research is documented in ORNL technical reports on ethanol compatibility of fueling infrastructure materials, developed in collaboration with UL and industry stakeholders. The reports continue to serve as a reference for industry and standards organizations.
Deep dive
Read the full report: Compatibility Study for Plastic, Elastomeric, and Metallic Fueling Infrastructure Materials (ORNL/TM-2012/88). This research is supported by the U.S. Department of Energy’s Transportation Technology Office.
The big picture
ORNL’s ethanol compatibility research demonstrates how materials science can support the deployment of secure, affordable and domestically produced fuel options. By generating trusted data that industry continues to use years later, ORNL helps ensure new energy solutions can be implemented safely, cost-effectively and with existing infrastructure.
