Grass power

Williams, Minn. — Grass seed chaff could provide renewable energy to run a northern Minnesota seed-cleaning plant.

Northern Excellence Seed, LLC and AURI’s Center for Producer-Owned Energy will test the feasibility of generating power from gasified grass-seed screenings. The project could transform what is now agricultural waste into a renewable fuel — saving growers both disposal costs and energy expense.

Northern Excellence Seed, a group of 30 grass-seed producers in Roseau and Lake of the Woods counties, operates one of the state’s three main grass-seed processing plants. Minnesota is the nation’s number two producer of grass seeds, a crop that generates $120 million in economic activity for the state, according to a 2005 AURI estimate.

Northern Excellence Seed, which last year reported sales of $5 million, cleans and packages Kentucky bluegrass, ryegrass, timothy, reed canary and other grass seeds. The cleaning process separates the tiny seeds from the heads and straw, which are now hauled to a local landfill and burned.

Gasifying this waste material, instead, could potentially generate enough power to run the factory, says Michael Sparby, AURI project director. Gasification tests will be conducted this summer at the Energy Environment Research Center in Grand Forks, North Dakota. The research will look at how grass chaff and rye grass straw perform in a small, modular gasifier. Data will be collected on energy production, emissions and ash, as well as power-generation costs.

Gasification converts solid biomass into a synthetic fuel gas that can be burned like natural gas in a furnace, turbine or engine. Large-scale commercial biomass gasifiers, such as municipal solid waste incinerators, have been around for many decades, Sparby says. But small-scale biomass gasification technology is still developing.

However, small on-site crop-waste gasifiers hold great promise for generating renewable power for factories, schools and other buildings, Sparby says. The U.S. Department of Energy estimates that Minnesota has enough renewable biomass fuel to power three million homes.

Northern Excellence is the first in the nation to explore gasifying grass-seed processing waste, Sparby says. If it proves feasible, “this would definitely add value to a product grown in this region.”

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