Gasification groundwork  Pilot biomass gasifers going up around the state

By E. M. Morrison

Minnesota's got gas!

The state is becoming a leader in the development of small-scale biomass gasification systems, which produce synthetic natural gas. “There’s a considerable amount of buzz about biomass gasification in Minnesota,” says AURI project manager Michael Sparby.
 

Several gasifiers are now being built around the state and more are in the works. The facilities will convert ag products, such as corn stover, grass-seed chaff and sawdust, into energy for use on-site. AURI has provided technical assistance to most of them.
 

These pilot projects will show that small-scale biomass gasification can work, laying the groundwork for commercialization, Sparby says. Although wood and coal gasification has been around for more than a century, small-scale biomass gasification technology is still in the development stage. “Once the demonstration plants are up and running, people can see how it works and go in and kick the tires.”
 

Pilot gasifiers will also allow engineers to fine-tune the technology and learn more about operation and maintenance in real-life commercial settings, says Darren Schmidt, research manager at the University of North Dakota Energy & Environmental Research Center in Grand Forks. EERC recently installed a pilot gasifier at Grand Forks Truss Company. The 100-kilowatt unit converts the plant’s scrap wood to electricity.
 

These new gasifiers will be platforms for basic research, too. A corn-stover gasification plant at the University of Minnesota, Morris, which broke ground July 27, will do more than heat and cool the college campus. It will also assess gasification economics, experiment with a wide variety of feedstocks, and develop new ways to collect and handle local biomass crops.
 

These early gasifiers will also set the stage for converting synthetic natural gas to liquid fuels, such as ethanol, Schmidt says.

“We’re seeing an immense amount of interest in this new technology,” says Schmidt, adding that the EERC could keep a staff member busy doing nothing but fielding inquiries about biomass gasification.

Here’s a quick look at Minnesota’s small biomass gasifiers:

First in the nation
Central Minnesota Ethanol Cooperative in Little Falls, Minn., was the first American ethanol plant to install biomass gasification. Late last year, the 20-million-gallon corn dry mill began converting about 280 tons of wood per day into synthesis gas. The biogas runs CMEC’s ethanol and distiller’s grains
drying operations and also powers a 1.1 megawatt steam turbine, which generates a portion of the plant’s electricity.

Campus greenery
UMM broke ground in July on a $9 million biomass gasifier that will fuel the campus steam plant. The facility is expected to begin operating next spring. The gasifier will consume about 72 tons of corn stover a day, producing 18 million Btus per hour of green power. It’s expected to furnish about 80 percent of UMM’s heating and cooling needs. The U of M’s West Central Research and Outreach Center and the USDA North Central Soil Conservation Research Lab will also use the gasifier for research.

New energy for ethanol
Chippewa Valley Ethanol Company, a 45- million-gallon corn dry mill in Benson, Minn., will gasify wood chips and corn stover to power its manufacturing operations. In July, the ethanol company began construction of a biomass gasifier that will burn about 75 tons of biomass per day — enough to furnish one-quarter of the plant’s natural gas needs. The facility is expected to begin producing synthesis gas in December. Eventually, CVEC plans to gasify about 300 tons of biomass a day, replacing 90 percent of its natural gas consumption.

Grassroots power
Northern Excellence Seed in Williams, Minn., plans to gasify grass-seed screenings and straw to power its seed cleaning plant. In July, the farmer-owned company received a $230,000 USDA-NRCS grant to build a gasifier that will run a 100-kilowatt generator. The gasifier will burn about two million pounds of grass-seed waste a year, providing all the plant’s electricity.

Charging up communities

AURI is helping several rural Minnesota towns look into community gasification projects. Roseau, in northwestern Minnesota, hopes to build a 400-kilowatt gasifier that would burn grass-seed screenings and straw produced in the area. Stevens County, in west central Minnesota, is organizing a $55,000 study to explore corn stover gasification at the Morris Industrial Park. Little Falls, in central Minnesota, is exploring local markets for synthesis gas. In southern Minnesota, a Redwood Falls company is interested in small-scale gasification of garbage.■