Waste to watts

Northern Minnesota company to gasify grass-seed chaff

By E. M. Morrison
 

Williams, Minn. –A grassroots power movement is taking hold in northwest Minnesota.

Northern Excellence Seed, LLC, plans to gasify grass-seed chaff and straw to make electricity. The Lake of the Woods County business is one of the first companies in Minnesota to generate on-site power from biomass. And it may be the only factory in the country to gasify grass-seed waste.
 

Converting waste into watts will furnish energy to run the seed-cleaning plant, and will save the company at least $60,000 a year in electricity and waste disposal costs, says Brent Benike, general manager of Northern Excellence Seed.
 

Just as important, the 100-kilowatt gasifier will be a model for other rural Minnesota communities that want to make renewable power from local biomass, says AURI project manager Michael Sparby, who has worked with Northern Excellence since 2002. “If it works in Williams, we can apply what’s
learned all over the state.”
 

Beyond that, the pilot project “signals a commitment by our country to use more renewable fuels, to reduce our oil consumption, and to mitigate global climate change,” says Steve Helmstetter, a Roosevelt,
Minn., farmer and chair of Northern Excellence Seed.
 

The Williams gasifier is funded by a $230,000 Conservation Innovation Grant from the USDA Natural Resource Conservation Service. The University of North Dakota Energy & Environmental Research Center (EERC) in Grand Forks will design and build the gasification system. Benike expects facility
permitting to take about nine months. The company hopes to break ground next spring and begin generating power in the fall of 2008.      

Excellent way to use waste
Northern Excellence Seed cleans and bags about eight million pounds of grass seed a year, mainly Kentucky bluegrass and perennial ryegrass. Two million pounds of dry seed coverings, or chaff, are left over after processing.

In the past, the company has hauled this material to a landfill and burned it, spending $10,000 to $15,000 a year for disposal. “Currently, it’s a waste product with no value whatsoever,” Benike says. Yet, this “waste” has an energy content greater than wood.                                                                                       Brent Benike, GM of Northern Excellence Seed

Sparby thought the small-scale biomass gasifiers being developed at the University of North Dakota “might be a good fit for us,” says Helmstetter, the board chairman. Gasification converts solid organic material, such as plant residue, into a low-Btu gas that can be burned like natural gas in a furnace, turbine or engine.
 

Gasification is especially well-suited for ag processors that generate biomass waste onsite and need energy, says Darren Schmidt, EERC research manager. It’s too expensive for small factories to install steam power systems to burn their residues, he says. “It wouldn’t make economic sense. What would
make sense is an engine and generator. But an engine can’t burn biomass. So what we do with gasification is turn the residue into a gas, which an engine can consume. We can do this at low pressure and in a cost-effective way that produces a return on capital investment.”
 

“We saw the potential right away,” Helmstetter says. “We’re big biomass producers here, and we’re looking for some way to make use of it.”

Getting started
In late 2005, AURI’s Center for Producer- Owned Energy sponsored a five-day gasification trial at the EERC’s Grand Forks pilot plant. “We got very good quality gas from grass-seed residue,” Schmidt says. Screenings yielded 140- to 150-Btu gas per cubic foot — about 15 percent better than the yield from wood gasification.
 

Those successful tests led to plans for what may be the nation’s first commercial grass-chaff gasifier, Benike says. “AURI has been a tremendous help in getting this off the ground.”
 

Grass-seed screenings will be combusted at low oxygen levels in a proprietary EERC reactor. The cylinder shaped gasification chamber will be about 10 feet tall and specially designed to handle light, fluffy chaff without expensive pelletizing. The resulting biogas will be filtered, then used to fuel an
engine and generator, which will produce 100 kilowatts of electricity. That’s a typical power
load for a small manufacturing business, Schmidt says. The whole installation will be small enough to fit into a two-car garage.
 

In addition to grass-seed screenings, the gasifier will also burn perennial-grass straw from two northwest Minnesota grass farms. Other readily available biomass, such as wood chips, could also be used, Schmidt says.

Northern Minnesota biofuels future

Minnesota’s grass-seed industry is concentrated in Roseau and Lake of the Woods counties. The climate, influenced by the vast Lake of the Woods, is wet and cool — ideal for growing grass. The industry took off in 1953, when the University of Minnesota released Park Kentucky bluegrass, a variety bred for northern Minnesota.
 

In 2002, the state produced about 40,000 acres of grass seed, according to the most recent Census of Agriculture. Today, Helmstetter estimates that northern Minnesota grass-seed acreage has swollen to
about 60,000 acres, making the state a leading producer, along with Washington and Oregon.
 

Supplying biomass for energy is an obvious match for northern Minnesota’s grass-based agriculture, Helmstetter says. A typical rotation for the area includes ryegrass planted into wheat stubble in the fall, followed by no-till soybeans or canola, followed by wheat. The region’s largest grass crop, bluegrass, remains productive for 20 years without replanting or tillage. In this

                  Steve Helmstetter                   production system, “it’s an advantage to remove the straw” from

                                                      wheat, ryegrass and bluegrass fields, Helmstetter says. “So we already have a lot of acres of biomass available.”
 

New strains of high-yielding native prairie grasses, which are now being developed at the U of M, also hold great promise as northern Minnesota energy crops, Helmstetter says. He notes that the region’s lower land values would give biomass crops a competitive edge there. In addition, northern farmers already have a lot of experience raising perennial grass crops. Plus, “we have a lot of underused forest products.”

For all these reasons, “we’re excited about the future potential of gasification in our area,” Helmstetter says.
 

Once the bugs are worked out, small-scale gasification systems “will be fairly easy to mass produce, and the price will come down,” Helmstetter predicts. Adds Benike: “Every area has some kind of biomass that could be converted to electricity. Towns up and down the road could have a gasifier to power their main industry, or a school or hospital.” ■

Producing excellent seed  Start-up company serves Northern Minnesota grass-seed growers

Northern Excellence Seed, LLC, was founded in 2002 by 29 northern Minnesota grass-seed growers. The processing and marketing company is based in Williams, Minn., a town of 200 located 20 miles east of Warroad in Lake of the Woods County.
 

Williams-area growers teamed up with the local elevator, Northern Farmers Co-op, to build a $2 million grass-seed cleaning plant — Minnesota’s third. The co-op, in business since 1936, owns 40 percent of the seed company. Grower-shareholders raise Kentucky bluegrass, ryegrass, timothy and other specialty grass seeds.
 

The first year, Northern Excellence Seed produced 3 million pounds of grass seed. Today the plant contracts for 18,000 acres of grass and cleans and bags about 8 million pounds of seed, posting annual sales of about $5 million. Marketing through LaCrosse Forage and Turf of LaCrosse, Wisc., Northern
Excellence ships its products around the globe. ■