title: Methane production and energy evaluation of a farm scaled biogas plant in cold climate area.
abstract: The aim of this study was to investigate the specific methane production and the energy balance at a small farm scaled mesophilic biogas plant in a cold climate area. The main substrate was dairy cow slurry. Fish silage was used as co-substrate for two of the three test periods. Energy production, substrate volumes and thermal and electric energy consumption was monitored. Methane production depended mainly on type and amount of substrates, while energy consumption depended mainly on the ambient temperature. During summer the main thermal energy consumption was caused by heating of new substrates, while covering for thermal energy losses from digester and pipes required most thermal energy during winter. Fish silage gave a total energy production of 1623 k Wh/m(3), while the dairy cow slurry produced 79 k Wh/m(3) slurry. Total energy demand at the plant varied between 26.9% and 88.2% of the energy produced.
authors.affiliation: Department of Mathematical Sciences and Technology, Faculty of Environmental Sciences and Technology, Norwegian University of Life Sciences, P. O. Box 5003, 1432 Aas, Norway. Electronic address: krfj@hials.no.
authors.forename: Kristian
authors.initials: K
authors.lastname: Fjørtoft
authors.affiliation: Department of Mathematical Sciences and Technology, Faculty of Environmental Sciences and Technology, Norwegian University of Life Sciences, P. O. Box 5003, 1432 Aas, Norway.
authors.forename: John
authors.initials: J
authors.lastname: Morken
authors.affiliation: Department of Chemistry, Biotechnology and Food Science, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P. O. Box 5003, 1432 Aas, Norway.
authors.forename: Jon Fredrik
authors.initials: JF
authors.lastname: Hanssen
authors.affiliation: Bioforsk Soil and Environment, Frederik A. Dahls vei 20, 1432 Aas, Norway.
authors.forename: Tormod
authors.initials: T
authors.lastname: Briseid
mesh_terms: D000383:Agriculture; D000641:Ammonia / Q000032:analysis; D000818:Animals; D056804:Biofuels; D019149:Bioreactors; D002417:Cattle; D003081:Cold Climate; D005399:Fishes; D006863:Hydrogen-Ion Concentration; D008697:Methane / Q000096:biosynthesis*; D009664:Norway; D012820:Silage; D013696:Temperature; D013997:Time Factors; D014835:Volatilization
chemical_list: D056804:Biofuels; D000641:Ammonia; D008697:Methane
keywords: Biogas; Dairy cow slurry; Energy balance; Fish silage