Oregon BEST Research Helping Local Company Explore New Market for Straw

Oregon's grass-seed industry is world renowned and a vital part of the state’s economy. Each year, 1,500 growers produce some 800 million pounds of grass seed, bringing $500 million to Oregon and driving more than $1.35 billion in economic activity for the state.

Now a team of Oregon BEST researchers has teamed up with a large grass-seed services company in Oregon to look into ways to add value to the straw left behind after the seed is harvested. For years, the straw was considered a waste product and burned in the field. With strict burning bans now in place, however, Oregon BEST researchers Ganti Murthy, Christine Kelly, and Mike Penner, all OSU professors, are trying to determine the viability of grass straw as a feedstock for the production of biofuels.

“The big question we’re trying to answer is, ‘What are the environmental, economic and energy benefits of using grass straw as a feedstock for biofuels production in the Pacific Northwest?’” says Murthy, an assistant professor in the OSU Dept. of Biological and Ecological Engineering, and director of the Sustainable Technologies Lab.

Bioethanol is produced by fermenting sugars such as glucose, which can be obtained from starch or cellulose-rich feedstocks. Most of the ethanol in the U.S. is currently produced from corn, a first generation biofuel feedstock. However, rapid advances in cellulosic ethanol technologies are enabling a shift from first generation to second generation biofuel feedstocks, which include grass straw.

One of the challenges, Murthy says, is breaking down the complex carbohydrates into simpler sugars (hydrolysis) that can efficiently be fermented by yeast. Success of subsequent downstream processes is critically dependent on the pretreatment technology used; however, the choice of pretreatment technologies depends not only on the feedstock, but is also a function of energy use, capital costs, downstream processing, and environmental impacts.

So Murthy and his team are looking at the big picture: the environmental, economic, and energy benefits of using grass straw to make ethanol. They are modeling various pretreatment and production processes, performing lifecycle analyses, studying the economics, and assessing the environmental impacts of different approaches.

“To our knowledge, nobody has specifically looked at different pretreatment technologies and conducted a comprehensive life cycle analysis for Oregon grass straw,” Murthy says. Currently, much of Oregon’s grass-seed straw is baled and shipped to Korea and Taiwan where it is used as animal feed. “If grass straw can be used to sustainably produce ethanol right here in Oregon, it would help Oregon farmers, as well as the environment,” he says.

The research is supported by a $146,000 grant from Sun Grant, funding that was made possible in part using a 10 percent match from Oregon BEST.

“The matching funds from Oregon BEST were very important  to our receiving the Sun Grant funding,” says Murthy, whose research group also studies the bioprocessing of other feedstocks, including algae, and collaborates on research projects with other Oregon companies, including Pacific Power, Trillium Fiber Fuels, and Greenwood Resources.

On the grass straw project, Murthy is collaborating with, Ore.-based Rose Agri-Seed, a large grass-seed services company that is supplying Murthy’s team with grass straw and agricultural data used in the research.

Bill Rose, the company’s founder, contacted Murthy when he wanted to explore other markets for grass straw. Endophyte, a naturally occurring fungus in grass straw that makes the plant disease and insect resistant, also limits the amount of straw that can be included in cattle feed. The research by Murthy and colleagues will determine whether or not the fungus impacts the conversion process of the straw to ethanol.

“Dr. Murthy and his colleagues are outstanding, we have an excellent relationship with them, and already the work that’s been done has moved this project very far along,” Rose says. “If this works out, and it looks like it might be economically feasible, it will give the grass seed industry a new market for grass straw."

This summer, Murthy will mentor a high school student who will be working on the project in the lab as part of an IBM-sponsored Oregon BEST mentorship position through Saturday Academy.

If all goes well, and the right combination of pretreatment and processing methods are used, Murthy estimates it may be possible to produce ethanol from grass-seed straw that could sell for approximately $2.50 to $3.00 per gallon. At a production rate of 60 to 90 gallons per ton of straw, that’s adding great value to a product that currently sells for $30-$40 per ton and is often shipped across the Pacific.