Growing Green in More Ways Than One

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When Kelly Tiller was a young girl growing up in nearby Greenback, she spent weekends and long summer afternoons at the family farm. There, she forged her strong connection to farming and agriculture. In keeping with her family’s farming legacy, she participated in 4-H throughout middle and high school.

Kelly TillerAlong the way, Tiller also discovered a natural talent for math. Accounting came easy to her in college. While she was earning her bachelor’s degree from UT Chattanooga, she learned to love the nuances of economics and soon connected the ideas to her passion for farming.

"I feel fortunate, math and economics just clicked with me," she recalls. "I had some excellent professors, such as Ziad Keilany in Chattanooga and Bill Park in Knoxville. Tiller received her master’s and doctorate in agricultural economics from UT Knoxville, where she focused on environmental and natural resources policy.

After her postdoctoral work, she stayed with UT’s Department of Agricultural Economics, working for the Agricultural Policy Analysis Center on tobacco pol-icy and general farm commodity policy. When she finished her work related to federal tobacco programs in 2004, Tiller turned her attention to energy policy.

When UT became a Southeastern Regional Sun Grant Center and began gearing up for bioenergy research in the region, her involvement and interest escalated.

From Switchgrass to Fuel – How It Works

The process for converting the switchgrass grown in a farmer’s field to the ethanol that can be used to power your automobile is, at its core, about taking the sugar stored in every switchgrass cell and releasing it, allowing it to be fermented into ethanol.

Harvested switchgrass will arrive at the facility in bales. The first step will be breaking up the bales and shredding the switchgrass, separating the long stalks into much smaller pieces for processing. Once the material is shredded, it will be heated to very high temperatures with steam, then treated with an acid designed to break switchgrass down into its chemical building blocks.

This breakdown releases three substances: cellulose, hemicellulose and lignin. The cellulose and hemicellulose are the ingredients used to create ethanol, while the lignin can be used in other products. One of the keys to the facility’s long-term success will be the ability to put the leftover components from the ethanol conversion process to good use.

Cellulose and hemicellulose are long chains of simple sugars; and for them to be converted into ethanol, the chains need to be broken down to provide access to the individual sugar molecules. Specially created enzymes are used to pull the sugar molecules apart.

The actual process of converting the sugar into ethanol is a familiar one – it’s nearly the same as the one used to create the alcohol in beer, wine and whiskey. Yeast is combined with the sugars, and the action of the yeast converts the sugar to ethanol, which is a type of alcohol. The ethanol is distilled to remove water and make it more potent and useful as a fuel.

From there, the ethanol will be shipped to fuel companies where it will be blended with regular gasoline for use by consumers.

In 2006, the UT Institute of Agriculture put a high priority on leadership in biomass energy and biomass economics, Tiller recounted. She and Tim Rials, director of research and development for the UT Office of Bioenergy Programs, led a group of faculty who prepared a comprehensive business model that won quick support from the university, the governor, state agricultural industry leaders, and ultimately from the state legislature.

The model, called the Tennessee Biofuels Initiative, proposes a totally new industry for the state. Tennesseans in all walks of life stand to benefit from the pro-duction of a new commodity – switchgrass – and the manufacture, distribution and retail sale of cellulosic ethanol as a renewable, sustainable transportation fuel.

"The effort gained traction, and we were able to move forward quickly. We received full funding in June 2007," Tiller says. The state legislature allotted some $70 million, which includes $40.7 million in capital funds for the biorefinery, $8.25 million for the initial farmer incentive program as well as additional re-search and commodity development funding for four years.

"Our vision is to establish switchgrass as a dedicated energy crop in Tennessee," Tiller explains. "It’s a good fit for our farmers and an excellent income-producing op-tion for the region."

When operating at full capacity, the new biorefinery will require 170 tons per day of switchgrass and other agricultural and forest biomass. The incentive pro-gram will encourage farmers to begin growing the crop before commercial markets have been developed.

She notes that the Biofuels Initiative has two main focuses: developing a complete supply chain for this dedicated energy crop and demonstrating the technology for converting those biomass crops to biofuels. The bottom line is creating a cash crop for farmers and keeping them solvent and financially stable. Anticipating its suc-cess, UT officials are pursuing a trademark for the term "Grassoline."

"I think this presents a tremendous opportunity to revitalize some rural farm communities," Tiller says. "Especially for those who are not full-time farmers, it is a great low-maintenance fit. The pure economics are huge!"

For example, a typical hayfield can yield average harvests between one and two tons per acre, but switchgrass can average between six to eight tons per acre when mature. One of the dominant species of the American prairie, switchgrass is considered a good candidate for biofuel production due to its hardiness in poor soil and tough climate conditions as well as its rapid growth and low requirements for fertilization and herbicide.

UT has entered into a partnership with Mascoma Corporation to construct and operate the five-million-gallon-per-year biorefinery. The principal product of the facility will be cellulosic ethanol.

The Biofuels Initiative outlines how the biorefinery will demonstrate and refine biofuels production technology and work out issues related to production, transportation and distribution.

With continued improvements in technology and economics, it is expected that government and private partners will invest in multiple commercial-scale bio-refineries across the state.

Potential benefits of implementing the Biofuels Initiative business model include the following:
• 4,000 new jobs in rural Tennessee counties
• $400 million in new state and local tax collections annually
• Satellite plants with 3,000 jobs and $1 billion in annual revenue from products useful in other manufacturing processes
• $100 million annually in new farm revenue to about 20,000 of the state’s producers

The plant will be about one-tenth the size of a commercial production facility, allowing researchers to fine-tune operations before the system is expanded across the state in coming years.

SwitchgrassThe demonstration-scale facility will complement research efforts at the Oak Ridge National Laboratory, another key partner in the state’s biofuels strategy. In June 2007, ORNL was awarded $125 million from the U.S. Department of Energy to fund the Bioenergy Science Center. This collaboration will address fun-damental science and technology challenges related to commercial cellulosic ethanol production.

"We view the biorefinery as a laboratory for large-scale chemistry experiments in cellulosic conversion to ethanol," says David Millhorn, UT’s executive vice president.

"Tennessee’s Biofuels Initiative has the potential to establish Tennessee as a national leader in ethanol production from cellulosic biomass," Millhorn contin-ues. "This, in turn, should lead to new business and economic development opportunities for our farmers throughout the state."

"To generate income from something produced in the state is very exciting," Tiller says.

Tiller lists numerous advantages to the project. First, it can revitalize rural farm communities while helping meet the demand for transportation fuels. Millions if not billions of dollars currently leaving the state — and often the country – will circulate through local economies because of switchgrass production, trans-portation of commodities, wholesale and retail sales, and the local tax revenues generated by the commerce.

"It’s complicated," Tiller says of the effort ahead. "There are a lot of issues to address, for example, choosing the variety of switchgrass, refining harvesting methods, and planning for transportation and storage," she continues, noting that the farmers incentive program will roll out later this fall within a 50-mile ra-dius of the plant.

The Office of Bioenergy Programs also oversees BIOSUCCEED, a joint initiative with North Carolina State University and North Carolina A&T to develop a new academic curriculum for educating a workforce in the skills that will support biomass utilization. See http://www.utbioenergy.org/Biosucceed/.

More information on the Office of Bioenergy Programs, the Biofuels Initiative, or the Southeastern Regional Sun Grant Center can be found online at www.utbioenergy.org. A video story about the biorefinery is available online at http://www.agriculture.utk.edu/news/VideoReleases/

 

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