September 20, 2006 | General

Ethanol, Biomass Plants Planned For Minnesota

BioCycle September 2006, Vol. 47, No. 9, p. 54
Proposed facilities prepare to turn organic residuals into electricity, methane and synthesis gas “with minimal emissions and more profit.”

AN ETHANOL plant in Little Falls, Minnesota is building an on-site gasifier that will convert wood waste and distiller’s grains to gas for generating electricity and heat to serve the needs of the Central Minnesota Ethanol Cooperative. At the same time, the University of Minnesota, Morris campus, is building a corn stover gasification unit which will generate synthesis gas to run the college’s steam plant.
As reported in the latest issue of the Agricultural Utilization Research Institute’s (AURI) Ag Innovation News, other state groups are looking seriously at gasification as a renewable energy solution. A grass seed cooperative in Williams is testing a unit for seed chaff to produce electricity for the seed cleaning plant. The sugar beet industry is evaluating gasifying beet pulp, while soybean crushers are cofiring hulls for gasification. A local community is looking into gasifying corn stover to make methane for an industrial park.
Reasons for this increased activity is world demand for natural gas and high prices, explains Cecil Massie, a renewable energy systems expert at Sebesta Blomberg, an engineering firm specializing in energy utilities. Average annual price of natural gas rose 42 percent between 2000 and 2004, according to the Energy Information Administration (EIA). Last year prices soared, reaching an average of $14.61 per thousand cubic feet in October – up 60 percent from October 2004. EIA forecasts that the prices for 2006 would range from $11.56 to $13.31 per thousand cu. ft. At these prices, making synthesis gas from renewable biomass is cheaper than burning natural gas, says Massie.
Last year, AURI and Sebesta Blomberg helped the city of Morris calculate costs for a municipal utility that would produce methane from corn stover gasification. The proposal called for the city to invest $9 million to generate 500 million cu. ft. of pipeline-quality gas for use by the local ethanol plant. The study estimated that the city could make methane for $10.44 per million BTU – nearly 30 percent less than the average 2006 contracted prices.
According to experts like Massie, biomass gasification is best suited for relatively small power systems – between 5 kilowatts and 5 megawatts. That’s because biomass is a widely-dispersed, bulky, low energy fuel feedstock. “It’s not economical to haul biomass more than about 20 miles,” sums up Massie. “Biomass gasification has great potential for every agricultural processing plant. All of them produce coproducts that earn very little money.” Materials such as barley, oat and soybean hulls, beet pulp, distiller’s grains, vegetable processing residues and mill waste often sell for “far less money than the value of the energy they could produce for the plant,” he adds. Within 10 years, experts predict many biomass gasification plants will be in place.
A proposed plant in International Falls, Minnesota would convert municipal solid waste into energy and slag with “minimal emissions and more profit.” The $30 million Renewable Energy Clean Air Project (RECAP) has unified “a handful of private interests with county, state and federal agencies,” notes Ag Innovation News. John Howard and Stephen Korstad, principals of Coronal, the project’s architects, are confident that the plant would generate solid returns for its owner, Koochiching County. Four key revenue sources are: Tipping fees; Sale of biofuels (as pure hydrogen, biodiesel, E-85 alcohol and industrial gas similar to propane); Sale of steam and electricity; and Sale of tile, rock wool, etc.
“We’ve got enough sources of revenue that the feasibility study will show that this will fly,” says Steve Kluess, coordinator of the USDA’s Laurentian Resource and Conservation Development Council based in Duluth. “People are starting to see that MSW has value.” Both Minnesota Power and Boise Cascade have expressed interest in buying the by-product electricity. The proposed plant would handle 36,000 tons/year of MSW. Verbal commitments from a 14-county region of Northeastern Minnesota add up to more than 90,000 tons annually. – J.G.
Dan Lemke of Agricultural Utilization Research Institute, Cecil Massie of Sebesta Blomberg, and Steve Kluess of the Laurentian Resource and Conservation Development Council will all be presenting papers at BioCycle’s Renewable Energy From Organics Recycling Conference, October 30-31, November 1, 2006 in Minneapolis. (See pages 15-17 for the full conference agenda.)

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