Fire-damaged Minnesota biomass plant reopens after redesign
14 February 2014
Koda Energy of Shakopee, Minnesota, has reopened its biomass facility with a new design to enhance safety and reduce emissions. The original facility was demolished after a silo fire last April. After recommissioning, it remains one of the only heat and power plants in the US to burn exclusively natural materials.
Koda, a partnership between Rahr Corporation and the Shakopee Mdewakanton Sioux Community, provides environmentally-friendly biomass energy for Xcel Energy as well as Rahr Corporation, which uses the residual heat from electricity generation in its malting process.
After the fire, the company began working with Minneapolis-based Barr Engineering on a facility safety assessment. That assessment presented multiple choices for reopening: rebuild using the same vertical silo storage system, modify that system, or completely redesign the facility.
Koda opted for a new horizontal system inside a two-story unloading and storage building connected to the existing fuel processing facility costing $7 million. The company says the lower-profile design will bring many benefits, including improved safety, reduced particulate emissions by 20%, increased reliability and more efficient fuel unloading.
The facility will continue to provide environmentally friendly biomass energy by burning a blend of agricultural and plant seed byproducts, such as wood chips, oat hulls, malt byproducts, sawdust, and ground-up wood pallets.
Koda officials said the fire was most likely caused by an ember from a piece of equipment igniting dust particles or wood chips, which ignited material in two of Koda Energy’s silos. This suspected cause helped in the planning process for the facility’s new design and operations.
The company said that the fire that occurred in the previous facility could not occur now, based on the fact that the new facility does not include silos, containment, or explosive concentrations of airborne dust. The new facility also has infrared detectors that would help identify potential ignition sources.