Skip to comments.NIST finds that ethanol-loving bacteria accelerate cracking of pipeline steels
Posted on 08/03/2011 8:17:14 AM PDT by decimon
U.S. production of ethanol for fuel has been rising quickly, topping 13 billion gallons in 2010. With the usual rail, truck and barge transport methods under potential strain, existing gas pipelines might be an efficient alternative for moving this renewable fuel around the country. But researchers at the National Institute of Standards and Technology (NIST) caution that ethanol, and especially the bacteria sometimes found in it, can dramatically degrade pipelines.
At a conference this week,* NIST researchers 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 occuring in air alone.
The NIST team used a new biofuels test facility to evaluate fatigue-related cracking in two common pipeline steels immersed in ethanol mixtures, including simulated fuel-grade ethanol and an ethanol-water solution containing common bacteria, Acetobacter aceti. Ethanol and bacteria are known to cause corrosion, but this is the first study of their effects on fatigue cracking of pipeline steels.
"We have shown that ethanol fuel can increase the rate of fatigue crack growth in pipelines," NIST postdoctoral researcher Jeffrey Sowards says. "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."
Ethanol, an alcohol that can be made from corn, is widely used as a gasoline additive due to its oxygen content and octane rating. Ethanol also can be used as fuel by itself in modified engines. The NIST tests focused on fuel-grade ethanol.
The tests were performed on X52 and X70 pipeline steels, which are alloys of more than a dozen metals. Simulated fuel-grade ethanol significantly increased crack growth at stress intensity levels found in typical pipeline operating conditions, but not at low stress levels. The cracking is related to corrosion. The X70 steel, which is finer-grained than X52, had lower rates of crack growth at all stress levels. This was expected because larger grain size generally reduces resistance to fatigue. In the bacteria-laden solutions, acid promoted crack growth at stress intensity levels found in typical pipeline operating conditions.
Preliminary tests also suggested that glutaraldehyde, a biocide used in oil and gas operations, may help control bacterial growth during ethanol transport.
The findings are the first from NIST's biofuels test facility, where material samples are installed in hydraulic test frames and subjected to load cycles while immersed in fuel inside a transparent polymer tank. Fatigue crack growth and other properties are observed over a period of up to 10 days. NIST staff expect to continue and possibly expand the research to other potential biofuels such as butanol or biodiesel.
Collaborators at the Colorado School of Mines provided the bacteria, which were isolated from industrial ethanol storage tanks. The research was supported by the U.S. Department of Transportation.
* J.W. Sowards, T.D. Weeks, J.D. McColskey, C. Williamson, L. Jain and J.R. Fekete. Effect of ethanol fuel and microbiologically influenced corrosion on the fatigue crack growth behavior of pipeline steels. Presented at DOD Corrosion Conference 2011, La Quinta, Calif., August 1, 2011.
It will doom us to higher food prices and evidence like this keeps mounting against the wisdom of using it. Republicans will keep voting for it. This hurts.
Ethanol bad, Butanol good
Thus vehicle engines are not safe either.
Ethanol DESTROYS engines!
My landscaper (a nice conservative small businessman) has called Congress to complain about ethanol subsidies. Last time he was at my house, he told me how the ethanol destroys his landscaping equipment, corroding the engine. I said wtf would be the effect on car engines!?? He said, “What do you think?”
This stuff is poison, and to hear “conservatives” like Rick Santorum speak to Iowa farmers about how great it is & how we need to increase subsidies just makes me sick. Is there anyone left who’s not part of the problem???
Think of all the union jobs that will be created replacing pipelines and vehicles destroyed by ethanol.
We're all going to be RICH!
One of the reasons that petro fuels and products have become so widespread, efficient and economical is the long useful lifespan they give to ALL the equipment that they come in contact with.
Big oil is not at all evil when compared to big environment.
I haven’t yet had a problem with the 10% ethanol blend. Maybe I eventually will but I haven’t.
It lists alcohol free gasoline suppliers for PA (and everyplace else).
He may be able to fuel his small engines for longer life.
Good for boats, too.
MTBE (methyl tertiary butyl ether) was touted as the ideal substitute for lead in gasoline engines to reduce knock and to meet stricter clean air laws. It may have accomplished that but is preferentially soluble in water. So when a leak from an underground or above ground storage tank occurs, it will contaminate a considerable amount of groundwater.
Ethanol was then touted as a replacement for MTBE and now, though more environmentally friendly, it causes damage to engines and pipelines and may damage hoses as well. That is why you see trainloads of tank cars with ethanol and why pipeline companies will not move it from manufacturing plants to terminals for mixing with gasoline.
Beware of unintended consequences.
Check out this site. Quite informative. It talks about storing and using E10 in different uses and testing the actual ethanol level. Very important for some users (farmers, businesses that have fleets and marine uses) and just the average users.
Leftist answer: Good, ride a bicycle.
Absolutely poison to fuel-system components! A monumental lobbying oversight by the Outdoor Powered Equipment Institute. No way to tell how much I have spent in the last twelve months repairing household landscaping equipment. Enough to make me want to return to electric and just rent anything gas I need. Either that, or travel 50 miles outside metro Atlanta to buy non-ethanol fuel.
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