|Project Type||Farm Scale|
|Population Feeding Digester||1,200|
|Baseline System||Storage Lagoon|
|Digester Type||Mixed Plug Flow|
|System Designer||DVO, Inc. (formerly GHD, Inc.)|
|Generating Capacity||450 kW|
|Receiving Utility||WE Energies, Inc.|
Farm Bill Funded Project
Quantum Dairy produces approximately 55,000 gallons of manure and liquids for treatment each day. Manure is scraped into a reception pit three times daily and then pumped into a mixed plug flow digester.
The mixed plug flow digester is below ground with a fixed concrete cover. The digester uses biogas induced mixing and return of activated sludge to stimulate microbial growth. The system maintains an operating temperature around 100°F and has a hydraulic retention time of approximately 22 days.
Moisture is removed from the biogas which is then sent to a 300 kW Caterpillar turbo-charged engine generator set. Electricity is sold to We Energies under a sell-all contract, and recovered heat is used to heat the farm house, shop, milking parlors, and the engine generator set building.
Solids are separated from digester effluent using a screw press solids separator. The dairy produces about 133 tons of digested solids per week and use about 100 tons on the farm. Excess solids are sold to other dairies for bedding and to area gardening businesses. The owners of Quantum dairy plan to expand their operation to approximately 2,100 cows and increase their generating capacity.
Quantum Dairy's digester project includes the following benefits:
- Electricity and heat production
- Savings on bedding costs
- Revenue from the sale of excess solids to other dairies or gardening businesses