burns oat hulls Construction is under way this spring on a biomass steam boiler at the Golden Valley-based company's milling plant in Fridley, where it produces oat flour for Cheerios, Lucky Charms and other cereals. The boiler, scheduled to go online early next year, will burn oat hulls left over from the milling process. It replaces natural-gas boilers, making the mill partially self-sustaining, said John Hellwig, the project's manager. General Mills produces 90,000 tons of oat hulls a year from its two mills in Fridley and northeast Minneapolis, and it will use about 10 percent of that to power its Fridley plant. The company also sells its oat hulls to the Koda Energy plant in Shakopee, a joint venture between Rahr Malting Co. and the Shakopee Mdewakanton Sioux Community. The plant is 100 percent biomass-powered and produces malt for brewing