Shakopee mdewakanton sioux community

The burning of byproducts from malting and food processing along with raw materials like wood chips, biosolids, and dry grasses is used to generate electricity and thermal energy at Koda Energy. The specific fuel mix burned in Koda is a blend of materials to maintain a consistent heat output and limit emissions.

General Mills provides about nine, 20-ton truckloads a day of oat hulls from the processing of cereals like Cheerios from their Fridley and St. Paul plants. Wood Chip of Princeton, an affiliate of Sylva Corporation, provides about eight, 20-ton loads a day, six days a week, of wood chips.

Rahr Malting blows about 95 tons of barley dust and other byproducts including malt sprouts and over and under sized seeds per day from the malting process to the fuel storage site.

Other products burned, deemed “Opportunistic Fuels” include ground up pallets, sawdust, sunflower hulls, and other agricultural seed products.

From the fuel storage site, fuel is moved using a drag conveyor to four hammer mills that reduce the particle size to a fine dust, approximately the size of talcum power. The dust-sized fuel particles are then blown into the boiler where they instantly ignite to optimize heat production while limiting emissions in a process designed to capture heat that otherwise would be wasted. Heat from the boiler generates steam that powers a Siemens steam turbine to generate electricity. A glycol loop carries the captured heat to Rahr Malting to meet their needs.

There is very little remaining solid waste in the form of non-toxic ash to fill landfills or use in agricultural processes or products. The biomass to energy process produces about 40,000 pounds of dry ash per day which is useful as a soil amendment for cropland, for composting. The ash could potentially be used in concrete for road projects. Air emissions are low and closely monitored at all times.

The SMSC is exploring options for burning native prairie plants in the Koda Energy facility. Koda Energy has the potential to be an important regional source driving a conversion of marginal cropland to perennial grassland cover/energy crop. This could reduce agricultural run-off, create wildlife habitat, and be an important biofuel source. The SMSC is currently conducting agronomical research on energy crops. (See Prairie Restoration) This research is the first of its kind at a functional scale to determine optimal plant mixtures and actual output of native prairie plants (tons/acre).

The Shakopee Mdewakanton Sioux Community sees Koda and the associated energy crop research as a very important tool for future self-sufficiency and sustainability. The SMSC is at the forefront of this technology in hopes that this work will benefit other tribes in years to come, especially those with a large land base. Producing energy from crops will create jobs, fuel self-sufficiency, and support sovereignty.

Biomass fuels are one of the largest sources of renewable energy. Purpose grown energy crops can sequester carbon in their root system thus lowering overall atmospheric carbon. There is no net gain of carbon dioxide (the major greenhouse gas) to the environment. Unlike coal burning generators, no mercury is released into the environment. The $60+ million construction project has created 15 new jobs with an annual payroll of $750,000 per year. Each year $6 million will be spent in the local area for biomass purchases. Another benefit is reduced soil erosion and carbon sequestration by dedicated energy crops.

• Six storage silos hold four days worth of product to burn. Currently, two silos each are dedicated to oat hulls, barley waste, and dry wood.
• All product burned in Koda Energy comes from within a 60 mile radius of the plant.
• Two-thirds of raw materials for burning arrive by truck. The remaining one-third is blown over from Rahr Malting.
• Product coming in must be no larger than the size of a jelly bean and must be 15% moisture or less.
• Four hammer mills, also called grinders, grind 21 tons of product per hour to 7/64 of an inch in size, like talcum powder.
• Up to 7 tons of dry wood can be burned per hour.
• 170,000 tons a year of biomass is required to fuel Koda Energy.
• Sylva Corporation’s affiliate, Wood Chip of Princeton, provides about eight, 20-ton loads a day, six days a week, of wood chips. Other products burned, deemed “Opportunistic Fuels” include ground up pallets, sawdust, sunflower hulls, and other agricultural see products.
• Every day General Mills provides nine trucks with each containing 20 tons of oat hulls which are waste products from its Cheerios and other cereals from their Fridley and St. Paul plants as a fuel for Koda Energy.

• Boiler system is 17 stories tall.
• Boiler expands an additional 16 inches when it gets hot through expansion joints.
• 25 gallons of water per minute are processed through the Reverse Osmosis system before it flows into the boiler.
• The boiler was built specifically for the type of product it burns. Burning
• Koda recovers more than 70% of energy in the products burned.
• There are three levels of burners for a total of six burners.
• The firebox heats up to 1,600-1,700 degrees Fahrenheit.
• Up to 900 pounds per square inch pressure in the boiler.
• 220,000 pounds of steam produced per hour.

Electric power generated averages 12.5 megawatts, with net power generated at approximately 24.1 megawatts. Amounts fluctuate based on largely on Rahr’s demand for heat. Rahr Malting uses the waste heat from the generation of electricity in their malting process. The balance is used for powering Koda and Rahr Malting with excess sold to Xcel Energy.

• Byproduct is fly ash which is used in the concrete industry or to produce asphalt shingles.
• Smokestack is 228 feet tall.
• Two, 35-foot cooling towers help precipitate the steam vapor.
• Dust is controlled at various steps along the process.
• As a final step an electrostatic precipitator charges dust particles which are attracted to plates with a negative charge of 50,000 volts which cause the dust particles to be filtered out by removing the fine particulate matter.
• Emissions meet all Environmental Protection Agency and Minnesota Pollution Control Agency Standards.

• Rahr uses heat to replace natural gas for their malting process which can last from 156-180 hours (6.5 – 7.5 days) for the three stages: steeping, germination, and kilning/drying.
• Control room operators have a minimum of eight years experience and are state-certified.
• Cost of project in excess of $60 million.
• Koda Energy operates 51 weeks a year with one week for repair and maintenance.
• 2 ½ acre site
• 15 good paying jobs with benefits were created by Koda Energy.
• The plant is designed to have a 60-70 year operational life.
• The Siemens turbine is approximately 18 feet by 20 feet wide by 38 feet long.