Anaerobic digestion in Denmark: Past, present and future

Centralized biogas plants (CBP) in Denmark codigest mainly manure, together with other organic waste such as industrial organic waste, source sorted household waste and sewage sludge. Today 22 large scale CBP's are in operation in Denmark and in 2001 they treated approx. 1.2 mio tonnes of manure as well as approx. 300,000 tonnes organic industrial waste.

Besides the CBPs there is a large number of smaller farm scale plants. The long term energy plan objective is a 10-fold increase of 1998 level biogas production by the year 2020. This will help to achieve a target of 12-14% of the national energy consumption being provided by renewable energy by the year 2005 and 33% by the year 2030.

A major part of this increase is expected to come from new centralized biogas plant. The annual potential for biogas production from biomass resources available in Denmark is estimated to be approx. to 30 PJ. Manure comprises about 80% of this potential. Special emphasis has been paid to establish good sanitation and pathogen reduction of the digested material, to avoid risk of spreading pathogens when applying the digested manure as fertilizer to agricultural soils.