Thursday, 27 January 2011 18:21 Last Updated on Thursday, 27 January 2011 18:37
NEW Organic anaerobic bio-digester proves its' worth
NEW Organic’s anaerobic bio-digester is producing results far beyond expectations, according to Rob Larsen, part owner of the 1.8 million gallon waste processing plant. The prototype, a joint venture between Larsen’s Northern Concrete and American Foods Group, is producing three to four hundred percent of the output they hoped for in the planning stage.
The anaerobic bio-digester, or tank, as Larsen affectionately refers to it, takes paunch, or the waste product from cows’ stomachs at slaughter, combines it with a proprietary mix of bacteria and various other non-chemical ingredients, and effectively digests it. Three different products come out the other end; starchy fibrous material that can be used for bedding or even pellet burning furnaces, organic liquid fertilizer, and methane.
The steady hum of two room sized methane powered generators is music to Larsen’s ears. The generators use the methane produced in the tank for fuel, in turn attached to electric generators. NEW Organic sells that electricity to Wisconsin Public Service (WPS) in Green Bay under a special agreement called Advanced Renewables Tariff (ART). Under this newest agreement, WPS has offered to purchase a small amount of steady electricity from biogas producers.
Larsen says he had hoped to begin breaking ground on a second digester, but they have hit a snag. The agreement between NEW Organic and WPS will only allow him to sell about 3200 kilowatts (kW) of electricity into the grid at the higher price associated with the ART. Another digester similar to the first could produce as much as 2400 kW by itself, according to Larsen.