UT researcher says cars may soon run on $1.50-per-gallon 'grassoline'

Rick Wagner • May 2, 2008 at 12:00 AM

By 2025, Tennessee-produced “grassoline” made from switchgrass and other biomass could supply about 25 percent of the transportation fuel needs for the Volunteer State.

And those 1 billion annual gallons of ethanol could be produced for less than $1.50 a gallon.

Those are among the goals and predictions of the University of Tennessee Biofuels Initiative.

“We can’t do that today,” Kelly Tiller told Kiwanis Club of Kingsport members at a luncheon meeting Friday. But the goal is to have viable commercial plants in operation by 2012 competing with petroleum fuel.

Tiller is director of external operations for the University of Tennessee’s Office of Bioenergy Programs and holds a faculty appointment in the Agricultural Policy Analysis Center at UT.

She said the state is spending $70 million over five years on the ethanol initiative, which also has drawn a U.S. Department of Energy grant of $26 million to assist in building a demonstration plant near Knoxville.

“I heard recently that the Southeast will eventually be known as the Saudi Arabia of cellulose,” Tiller said of the region’s ease in growing native switchgrass and other potential supplies of biomass that could be used for cellulosic alcohol production.

In 20 years of research, UT has found that switchgrass — a biennial crop that takes two or three years to reach maximum potential with minimal fertilizer even on marginal soils — in one year can produce six to 10 tons an acre compared to hay, which produces one or two tons an acre and requires substantially more fertilizer.

New research may bring that to 12 to 15 tons an acre in the next few years, Tiller said. Research also is looking at ways to more densely pack switchgrass in bales, convert it to pellets, or even alter it genetically to start breaking down soon after harvest.

Still, Tiller said a 50-mile radius is the most efficient area from which to draw switchgrass.

Richard Venable, chairman of NETWORKS – Sullivan Partnership, said he is working with UT and area economic developers with the idea of ultimately bringing an ethanol plant based on switchgrass production to Northeast Tennessee.

Most U.S. ethanol is produced from corn, but federal legislation is capping corn ethanol production at 15 billion gallons a year, compared to 9 billion gallons a year now. The cap is to keep ethanol from taking too much corn from human food consumption.

Total U.S. gas usage, however, is 400 million gallons a day.

“It (current corn-based production) still would only supply our gasoline usage for a couple of weeks,” Tiller said.

She said the goal is that by 2022, U.S.-produced cellulosic ethanol and other biofuels would reach 16 billion gallons.

Another issue with corn ethanol is the efficiency of production. Taking a comprehensive look — including the fuel used by farm equipment and energy to make and transport fertilizer — Tiller said that for every unit of fossil fuel energy used, corn ethanol produces 1.4 units in energy.

In contrast, she said cellulosic ethanol, pending further research, can provide five to 10 units of energy for every 1 unit of fossil fuel used in production.

UT scientists already are making ethanol from switchgrass, wood byproducts and forest products in a laboratory setting and plan in early 2010 to have a demonstration plant operating in Vonore, Tenn., southwest of Knoxville.

The Biofuels Initiative is paying farmers to grow 720 acres of switchgrass this year, which will grow to 3,000 acres in 2009 and to 4,000 acres in 2010.

Tiller explained that the process under study uses a “steam explosion” — forcing heat and steam into the biomass and then drastically relieving the pressure — to coax the sugars out of switchgrass and other biomass, making the biomass “explode like popcorn.”

A lignin byproduct can be used to make biodiesel, other oils, carbon fibers and plastics, depending on the most efficient use and market demand.

And the cellulose and hemicellulose — aside from going to the fermentation and distillation process to make ethanol — also can be used to make biodiesel and other products, depending on economics and demands.

Tiller said ethanol, biodiesel and other alternative fuels are needed to balance the U.S. energy situation since this country has 2 percent of the world’s proven oil reserves but uses 25 percent of the world’s oil.

For more information, visit www.utbioenergy.org.

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