Outside of the debate over how big a role ethanol will have as a viable U.S. energy source has been the lingering problem of transporting the biofuel, which can eat away pipes used for traditional fuels.

Ethanol has not been shipped on a commercial scale in existing pipelines because its high oxygen content makes it too corrosive. It also absorbs water and impurities in pipelines.

Pipe companies that believe ethanol will be around for the foreseeable future have begun working to solve that problem.

Houston-based Kinder Morgan Energy Partners LP this month plans to run a test batch of ethanol through it's 105-mile long underground gasoline pipeline from Tampa to Orlando, Fla.

Currently, industry experts estimate a pipeline dedicated solely to ethanol would cost about $1 million per mile.

But demand has grown to the point where development of new transportation methods may finally pay off, said Jim Lelio, Kinder Morgan's director of business development.

About 8,000 barrels of straight ethanol will be run through the pipeline and, if successful, the pipeline could be transporting ethanol on a commercial scale by year's end, Lelio said.

The Association of Oil Pipe Lines, a Washington, D.C.-based trade group that represents about 50 pipeline companies, has been studying whether ethanol can be transported safely in existing pipelines.

"We're still primarily in the lab and we're still working on technical hurdles," said Raymond Paul, a spokesman for the Association of Oil Pipe Lines. "We're hoping we're close to a solution. And there may be more than one."

The federal Office of Pipeline Safety is studying technology in Brazil, where pipelines have been used successfully to transport sugar-based ethanol for decades, said spokeswoman Patricia Klinger.

While tests are being done to evaluate the impact of ethanol on pipelines, Houston-based oil and natural gas pipeline operator TEPPCO Partners LP conducted a study last year to see how existing pipelines affect the fuel.

TEPPCO moved 273,000 gallons, or about 6,500 barrels, of ethanol on a pipeline from Indianapolis to Ago, Ill., said Dan Ownby, director of business development.

The company found that colorless ethanol turned dark amber as it picked up three decades worth of impurities along the 150-mile line, Ownby said. The fuel had to be filtered before use.

The U.S. has 160 ethanol refineries and 51 more are being built, said Ron Lamberty, a vice president of the Sioux Falls, S.D.-based American Coalition for Ethanol.

Domestic ethanol production this year is pegged at 9.3 billion gallons, up from 6.5 billion gallons in 2007, Lamberty said.

Justin Kringstad, director of the newly formed North Dakota Pipeline Authority, said his agency will support pipeline companies that consider moving ethanol from factories in North Dakota.

"It's definitely something on our immediate radar," Kringstad said. "We want to make sure ethanol flows as freely in pipelines as natural gas or crude."

Klinger said technology must be developed to handle new flows of ethanol, because it will be part of the nation's energy mix.

"It's not a matter of if, but when," she said.