Gaithersburg, Maryland – Using existing gasoline pipelines to transport ethanol could result in degraded and cracked lines, according to new research by the U.S. National Institute of Standards and Technology (NIST).
The researchers caution that using pipelines instead of trucks or rail cars to transport ethanol could result in problems due to the ethanol and especially the bacteria that is sometimes found in it.
The NIST researchers have presented new experimental evidence that bacteria that feed on ethanol and produce acid boosted fatigue crack growth rates by at least 25 times the levels occurring in air alone. Ethanol and bacteria are known to cause corrosion, but this is the first study of their effects on fatigue cracking of pipeline steel.
“We have shown that ethanol fuel can increase the rate of fatigue crack growth in pipelines,” said researcher Jeffrey Sowards. “Substantial increases in crack growth rates were caused by the microbes. These are important data for pipeline engineers who want to safely and reliably transport ethanol fuel in repurposed oil and gas pipelines.”
Preliminary tests also suggested that glutaraldehyde, a biocide used in oil and gas operations, may help to control bacterial growth during ethanol transport. NIST staff expect to continue and possibly expand the research to other biofuels such as butanol and biodiesel.