Tennessee revs up switchgrass study

Improved Switchgrass advances bioenergy with higher biomass yields for cellulosic ethanol under the RFS. Tennessee's UT, DOE, Ceres, and DDCE trial EG 1101/1102 across 1,000 acres to validate performance, sustainability, and supply chains.

Mid-summer is nearly here, and the University of Tennessee Biofuels Initiative UTBI is closely watching how more than 1,000 acres of newly planted, improved varieties of switchgrass are faring.

Only time will tell whether the improved plants will grow better, stronger or faster than the standard variety of switchgrass.

The massive planting is part of a U.S. DOE project designed to help make bioenergy production from renewable resources more efficient, cost-effective and sustainable, and aligns with federal moves like the biofuel loan aid supporting commercialization.

Sam Jackson and Nicole Labbe, UT biofuels researchers, are heading up the project team that also includes UT Extension biofuels specialists and partners at Ceres and Dupont Danisco Cellulosic Ethanol DDCE. Together with farmers from nine east Tennessee counties, the team has planted approximately 1,000 acres of improved varieties of switchgrass.

Throughout the year, the growth and yields from these fields will be compared to the growth and yields of a different 1,000 acres planted with the standard switchgrass variety "Alamo." These acres have been established on private farms as part of the UTBI farmer incentive program that, alongside TVA incentives that fuel homegrown power, now totals nearly 6,000 acres of switchgrass.

The idea is to improve switchgrass yields to help meet the 16 billion gallon level of production required by the national Renewable Fuels Standard RFS, reflecting debates over long-term solar subsidies and policy stability, for cellulosic biofuels by 2022.

The research and development being conducted in this project could have significant national impact on bioenergy production from cellulosic feedstocks, keeping Tennessee at the forefront of new power sources in the U.S. Improving per acre yields of biomass from dedicated energy crops like switchgrass will significantly reduce the land required to meet the RFS goals.

The improved switchgrass varieties were developed by the biotechnology company Ceres. They are sold under the company's Blade Energy Crops brand as EG 1101 an improved Alamo variety and EG 1102 an improved Kanlow variety. The Genera Energy/DDCE demonstration-scale biorefinery in Vonore, Tenn., will process the dedicated energy crop, akin to a biomass clean energy plant responding to market demand, into cellulosic ethanol.

Jackson says the project will have four phases: Comparing the large-scale production of the different varieties of the energy crop, analyzing the chemical and structural characteristics of the varieties, evaluating pre-processing techniques at Genera's Biomass Innovation Park in Vonore, and measuring the ethanol yield of the various varieties through the demonstration-scale biorefinery.

The scale of the acreage will also allow for assessment of the environmental and economic sustainability of the different varieties of switchgrass. Farmers and researchers should gain useful information on seed stock performance including disease and drought resistance, tolerance to humidity, and other agronomic variables, aligning with lessons from a Minnesota biomass farm that explored similar challenges.

"These are the largest acreages to be planted for growth comparisons on private farms in the nation," Jackson said. "The size of the project is necessary to adequately test and demonstrate the supply chain with local farm producers. We hope to prove the practicality of producing improved varieties of dedicated energy crops while providing a hands-on opportunity for farmers to be engaged in the development of a new biobased energy industry," he said.

Ceres sales director Frank Hardimon says growers have reported excellent success. "We are hearing reports of good establishment and healthy stands from the new seed varieties. This is a reflection of both improved genetics and high seed quality as well as excellent support from UT agronomists," said Hardimon.

He noted that the demonstration project will also help guide the development of the next generation of seed varieties and traits fine-tuned to the DDCE conversion processes. "We expect to make the same type of leaps in crop performance that seed companies have made in traditional crops. We're just scratching the surface of what's possible," Hardimon said.

Kyle Althoff, the director of feedstock development at DDCE noted this project provides a great opportunity for collaboration across the value chain for advanced biofuels, "By comparing the cellulosic ethanol conversion yields of these different varieties grown by local farmers, we will have a commercial demonstration of the economical, technological, and environmental impacts of each variety. It is integral for the biofuels industry to understand the effects that such variables have from the point the seed is planted through to the actual conversion into ethanol."

The state initially invested $70 million in 2007 to establish the UTBI for the construction of a demonstration-scale biorefinery, as well as for farmer incentives to grow the new energy crop and for research to help develop a new farm-based bioenergy industry for Tennessee, and to support initiatives such as the Tennessee solar research center that broaden the state's clean energy portfolio.

Kelly Tiller, program leader for external operations for the UT Center for Renewable Carbon and president and CEO of Genera Energy, says the $2.3 million investment in the variety comparison project brings the total return on the state's investment to more than 130 percent. "The state remains well positioned to be a national leader in biobased energy research and development. This planting is the next logical step in developing a complete farm to fuel model," she said.

The UTBI estimates that Tennessee farmers could sustainably produce enough switchgrass by 2025 to produce more than a billion gallons of ethanol annually on some 1 million acres without displacing the production of food and fiber crops.

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