Biogas production in common biogas plants
Denmark has a unique position in having dense animal husbandry production and high level of farmers organisation embedded in a tradition for co-operation on any aspects of farming. This also applies for farm-owned common biogas plants for animal manure and slurry treatment and a growing interest for establishment of biogas plants for organic farmers including biomass supply from energy crops (grass, sugar beet, maize) and harvested biomass from semi-natural areas, such as meadows. By including biomass harvested in meadows you can re-introduce some of the nutrients lost during decades to meadows from agricultural fields and include them as digested biomass for crop fertilizer. At present we have some 20 farmer-owned common Biogas plants (7 in Central Denmark Region) and several under planning. Some of the farms have investing in slurry separation equipment to reduce transportation costs. In some cases, the slurry is/will be pumped in new pipelines to the biogas plant and back to the farmers. In most cases the farmers pay to have their slurry/manure/fibers treated and the biogas plants are seen as energy producer and as nutrient distribution centres in dense animal husbandry areas. The positive implications for the implementation of the Waterframe and Nitrate Directives are obvious. The produced biogas is mostly used for Combined Heat and Power for district heating, but the possibility for uploading biogas to the natural gas infrastructure is being investigated.
Photo 1. Lemvig Biogas is a large Biogas plant for Combined Heat and Power for district heating
