State scientists hope to grow fuel by North Carolina's roadsides

Seed-oil crops planted along highways could someday provide biofuel for state vehicles

CorrespondentAugust 9, 2010 

  • What is biodiesel? In the United States, it's typically a blended fuel using petroleum products plus processed seed crops such as soybeans and canola.

    How is it produced? A chemical process called transesterification separates out glycerin for use in soaps and other products and leaves behind methyl esters that are the fuel.

    Is biodiesel catching on? U.S. production grew from 28 million gallons in 2004 to 91 million gallons in 2005. That is still only 0.15 percent of the U.S. diesel market, but production in 2006 was estimated at 245 billion gallons.

    Can it damage engines? Yes and no. Biodiesel typically has a higher cetane rating than petroleum diesel. The cetane rating is a measure of diesel's combustion quality - similar to an octane rating for gasoline.

    Biodiesel also has better lubricity - a measure of lubricating properties - than current low-sulfur petroleum diesel, making it attractive for blending. Lubricity is important for fuel injectors and some types of fuel pumps.

    But at low temperatures, diesel fuel can clog fuel lines and filters. At even lower temperatures, diesel fuel becomes a gel that cannot be pumped. Biodiesel performance in cold conditions is worse than that of petroleum diesel. Additives can ease the problems.

    Is it cost efficient? Biodiesel from soybeans costs an estimated $2 to $2.50 per gallon to produce. Biodiesel from yellow grease is about $1 a gallon cheaper, but the available supply in the U.S. is much smaller.

    SOURCE: Energy Future Coalition of the United Nations Foundation



A story about biofuels in the Science & Technology section on Aug. 9 referred to nuclear energy as renewable. While nuclear energy provides an alternative to fossil fuels, nuclear fission materials such as uranium are not renewable.

****** As alternative energy continues to gain momentum, renewable sources such as nuclear, solar and wind power are the usual options for replacing fossil fuels.

In North Carolina, however, another solution is sprouting on the side of the road.

In conjunction with a national program known as "FreeWays to Fuel" (, researchers at N.C. State University are working to grow canola and sunflower crops along the wasted edges of highways and other marginal areas.

The national program, which began in Utah and has spread across the United States, originally used municipal zones to plant crops for biofuels. Utah's first harvests are now being used to power Department of Transportation vehicles in Salt Lake County.

In North Carolina, Matt Veal, an assistant professor in the Biological and Agricultural Engineering Department at NCSU, has focused his research on sowing sunflower and canola crops. These powerhouse plants, whose seeds contain 50 percent oil, are excellent for biodiesel production. Once harvested, cleaned and crushed, they are put through a chemical process known as "transesterification" to obtain the fuel.

Already, researchers have grown successful harvests in experimental plots. In some cases, they have been able to produce 550 pounds of sunflower seeds and 40 gallons of biodiesel per acre. Ultimately, Veal hopes enough fuel can be made to power N.C. Department of Transportation vehicles.

"Our focus is biodiesel, and the Department of Transportation is a large consumer of biodiesel fuel," Veal said.

The department's equipment currently runs on "B20," a mixture of 20 percent biodiesel and 80 percent petroleum-based diesel fuel, which releases 20 percent less particulate matter into the air. Unmodified diesel engines can run safely on B20 without risking maintenance or performance issues, making it one of the more versatile blends.

A bonus for N.C. farmers

If FreeWays to Fuel were scaled up in North Carolina, Veal and others think local farmers could benefit from producing the biodiesel crops.

"The way I see it, contracting with farmers to grow these crops will give them additional income, so they can maintain their own farmland," Veal said.

Ted Sherrod, an environmental field operations engineer with N.C. DOT, agrees.

"If bioenergy crops can be cultivated on the roadside, farmers will have more success as they expand their growing operations," he said.

Larger plots will be key,Sherrod added, as the department searches for suitable roadside shoulders and other unused spaces.

DOT crews already are hard at work identifying areas where biofuels crops could be grown. Selecting large plots would make startup operations economically worthwhile. "Our perspective is that sizeable acreages will beideal," Sherrod said.

According to Veal, there are additional economic incentives for growing the biofuels crops. The state DOT has already demonstrated the potential cost savings of the program. By growing sunflowers on a 10-acre plot, the department saved tax dollars that would have been spent on routine mowing and maintenance.

Saving taxpayer money

Facing an expected $4.4 million cut in road maintenance spending next year, the department is eager to find ways to trim its budget.

"We spend close to $18 million a year on maintaining the grass shoulders of North Carolina highway rights-of-way, and those are costs to taxpayers we would like to reduce or offset," Sherrod said.

From a land-use perspective, FreeWays to Fuel makes sense, Veal said. Growing oilseed crops along roadsides and marginal lands is more compatible with traditional agriculture, returning prime acreage to food crops rather than tying it up in ethanol production.

"With FreeWays to Fuel, we are avoiding the fuel versus food debate," Veal said.

He added that processing oilseeds, compared with processing corn for ethanol production, is also simpler and easier to manage.

"With sunflower and canola, we use a chemical process, transesterification. This is much easier to control than a biological process using microorganisms, such as fermentation in the production of ethanol," Veal said.

Arguments against it

Biofuels have their detractors. Extraction processes for oil crops are energy intensive, and environmentalists question whether using fossil fuel energy to produce "green" energy is worthwhile.

Additionally, with advances in technology, there may be less need for liquid fuels in general.

"New generation vehicles, like plug-in hybrids, will certainly reduce the demand for liquid fuels, including biodiesel," said David McNelis, director of the Center for Sustainable Energy, Environment, and Economic Development at UNC-Chapel Hill.

Generating funding for future projects may be another struggle for the biodiesel industry and FreeWays to Fuel.

The federal biodiesel tax credit, which expired in 2009, had been crucial for expanding the biofuels industry. Over the past five years, it helped create more than 53,000 green jobs, supported development of 150 biodiesel plants and led to the commercialization of the first advanced biofuels in the United States, according to Joe Jobe, CEO of the National Biodiesel Board.

As industry officials lobby for extension of the tax credits, FreeWays to Fuel is cited as a model program. Additional research and development could lead to large-scale, economically viable harvests, proponents said, blossoming into alternative sources of fuel, tax savings and support for the agricultural industry.

And with such scenic science on the side of the road, taking the highway could make for a pleasing commute.

Sam Harris:

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