Fill’er Up with Grassoline
By Jay Mayfield
Tennessee business people, farmers, scientists, and
political leaders have begun to rally around a shared
vision of a statewide economy powered by ethanol, but this
fuel has a distinctly Tennessee twist. What sets Tennessee’s
vision apart from other states with an eye toward biofuels
is the commitment to make that ethanol from sources other
than corn—mostly from a hardy plant called switchgrass.
And what will they call the fuel? Grassoline, of course.
The effort, known as the Tennessee Biofuels Initiative,
took a major step forward recently with the announcement of
a site for a demonstration plant that will produce the first
batches of Tennessee-grown grassoline within just a few
years. Converting switchgrass into ethanol is a complex
process—more difficult than converting corn. A major part of
the Biofuels Initiative’s work is to make that process less
expensive and more efficient, and the heart of that effort
is the creation of this new facility to convert switchgrass
to ethanol on a large scale.
The plant, to be built in partnership with national
biofuels leader Mascoma Inc., will operate on about
one-tenth the scale of a full commercial production
facility. UT announced in August that the plant would be in
Monroe County at the Niles Ferry Industrial Park.
“The site sits in the heart of a productive farm region
where the agricultural community has shown interest in the
biofuels effort,” said Dr. Kelly Tiller, director of
external operations for the UT Office of Bioenergy Programs.
An agricultural economist, Tiller is also one of the authors
of the business model for the Biofuels Initiative.
“The site has all needed infrastructure to support the
facility and is close enough to Knoxville to allow easy
movement by researchers and students to and from the site,”
Construction on the demonstration plant, expected to cost
roughly $40 million, is expected to begin by the start of
2008, with a goal of reaching its full production level of 5
million gallons of grassoline each year by the middle of
Just as the sugars extracted from grapes become the
ethanol in wine, the sugars—mostly in cellulose—inside
switchgrass are what become ethanol for fuel. Researchers at
UT have been working on methods to more easily convert,
extract, and separate those sugars for conversion into
The challenge is that, unlike the sugars stored around a
plant’s seeds in a fruit like grapes or a vegetable like
corn, the sugars in switchgrass are contained within the
plant’s tough cell walls. Scientists can approach that
challenge in a couple of ways.
One approach is to alter the plant itself, finding ways
to make genetic changes that allow the cells to be broken
down more easily. UT is part of a recently announced
$125-million joint Bioenergy Research Center led by Oak
Ridge National Laboratory that will focus on these issues.
The center will be housed in the UT–ORNL Joint Institute for
The other approach is to find ways to improve upon the
chemical and biological processes that are currently used to
free and convert the sugar found in switchgrass and other
forms of biomass, like wood chips.
The second approach will be the work of the demonstration
facility. UT and Mascoma scientists will use the plant to
fine-tune and refine both the conversion process and the
logistics of moving the switchgrass from the field to the
plant. By creating a working model, they hope to show
farmers and private industry that the model can be recreated
across the state in full-scale facilities.
The plant will also serve as a massive research site for
UT, creating a one-of-a-kind laboratory for students and
faculty researchers to better understand and work with the
methods used to convert biomass into ethanol. Part of the
Biofuels Initiative plan is to create more college graduates
who are prepared to work in the emerging biofuels industry.
Some have likened the challenges of creating such an
industry from scratch to another well-known causality
conundrum—the chicken or the egg. To sustain a facility like
the one to be built, there must be enough switchgrass grown
in the surrounding area to keep the plant in production. But
to convince farmers to commit their land to switchgrass,
they have to know that they’ll have a place to sell it once
To jump-start the process, farmers will receive
incentives to plant switchgrass, which takes 3 years to
mature for harvesting. Tiller and others involved with UT’s
biofuels work have made regular visits to farmers around the
state to help inform and educate them about the goals of the
Biofuels Initiative, as well as about the basics of
They point to a study by UT agricultural economist Dr.
Daniel de la Torre Ugarte showing that Tennessee has more
potential in terms of climate and soil conditions to support
a major switchgrass crop than nearly any other location in
The demonstration plant is likely to produce its first
fuel from wood chips and other biomass as the first
plantings of switchgrass in and around the Monroe County
site grow to maturity. The process relies on production
facilities and switchgrass crops being located near each
other to reduce the cost of transporting the crop to the
According to Tiller and other UT researchers, this
facility is a vitally important first step in a process they
believe has the potential to change the fundamental economy
of the state for decades to come. Their optimism is shared
by Governor Phil Bredesen.
“We are a biomass state,” said Bredesen when he announced
the funding for the demonstration plant in early 2007. “We
have the right conditions, climate, and resources to grow
virtually unlimited quantities of biomass. We also have the
scientific and research communities in our universities and
laboratories required to help us realize this potential in a
way that can be truly transformational for our state and our