Shakopee mdewakanton sioux community

 

 

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Koda Energy

Stewards of the Earth

Koda Energy Photo Gallery

Koda Energy is an environmentally friendly energy production facility in Shakopee, Minnesota, which is a joint venture between the Shakopee Mdewakanton Sioux Community and the 166-year old company, Rahr Malting. Considerably cleaner than a coal plant and considered CO2 neutral, this combined heat and power plant is the only facility in the United States which burns exclusively natural, non-manmade materials. Using a suspension boiler for maximum efficiency to burn only renewable products, its heat conversion rate is much higher than coal. Products burned in Koda Energy are agricultural and plant byproducts, so they do not deter land from use as row crops. This biomass energy generation project is able to provide energy for Koda Energy and Rahr Malting, with excess sold to the grid.

Electric power generated averages 19.7 megawatts, with net power generated at approximately 16.8 megawatts. Amounts fluctuate based on largely on Rahr’s demand for waste heat from the generation of electricity which is used in the malting process.

Construction on Koda Energy began shortly after the September 13, 2007, groundbreaking. The facility began generating electricity in March 2009 and became fully operational in late May 2009.

Koda Energy: The Process

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 ten, 20-ton truckloads a day of oat hulls from the processing of cereals like Cheerios from their Fridley and St. Paul plants. Various other suppliers bring in another ten truckloads of clean, dry, and chipped wood waste from cabinet shops and pallet manufacturing facilities. Rahr Malting blows barley dust and other byproducts including malt sprouts and over and under sized seeds from the malting process to the fuel storage site. Other products burned, deemed “Opportunistic Fuels” include 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 biomass flour. 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 damp ash which is useful as a soil amendment for cropland, for composting. Air emissions are low and closely monitored at all times.

Native Prairie Plants as Potential Fuel

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. 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 Energy 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. Another benefit is reduced soil erosion and carbon sequestration by dedicated energy crops.

The $60+ million construction project has created 18 new jobs with an annual payroll of $1,000,000 per year. Each year about $8.4 million is spent in the local area for biomass purchases.

By the Numbers:
  • All product burned in Koda Energy comes from within a 60 mile radius of the plant.
  • Three quarters of raw materials for burning arrive by truck. The remaining quarter 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 coarse ground flour.
  • Up to 13 tons of dry wood can be burned per hour.
  • 170,000 tons a year of biomass is required to fuel Koda Energy.
  • Every day General Mills provides ten 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.
  • Various other suppliers bring in another ten truckloads of clean, dry, and chipped wood waste from cabinet shops and pallet manufacturing facilities.
  • Koda and the SMSC have constructed a facility to chip and dry clean urban forest trimmings from the city of Minneapolis to use as fuel in the Koda boiler.
  • Boiler system is 17 stories tall; boiler expands an additional 9.5 inches when it gets hot through thermal expansion.
  • Koda recovers more than 70% of energy in the products burned.
  • The firebox heats up to 2,000-2,300 degrees Fahrenheit.
  •  Electric power generated averages 19.7 megawatts, with net power generated at approximately 16.8 megawatts.
  • Emissions meet all Environmental Protection Agency and Minnesota Pollution Control Agency Standards.
  • Rahr uses the heat to replace approximately 75,000,000 cubic feet of natural gas/month 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-licensed.
  •  The plant is designed to have a 60-70 year operational life.
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