At the sewage plant in Östersund, sewage sludge is fermented to biogas. The biogas is used for driving cars and garbage trucks as well as to power heat plants.
Sewage sludge turns into valuable and sustainable fuel
The facility has been in operation since 2007 and produces about 850 000 cubic meters of biogas annually.
The production of biogas uses sewage sludge and small amounts of by-products from the city’s dairy plant as raw material. It begins with fermentation in certain fermentation chambers, which results in methane, carbon dioxide and water. The mixture is then purified in an upgrading unit and turned into biogas. Most of the produced gas is used as vehicle fuel and the rest powers heat plants connected to the district heating system. The part that ends up as biogas for vehicles is constantly increasing.
Biogas has about 93 percent less environmental impact than conventional gasoline. The local production also eliminates the need for long transports of fuel, which is necessary with fossil alternatives. In addition, the raw material used for biogas production is a by-product that lacks alternative areas of usage, which stands in contrast to for instance ethanol production that often compete with food production.
Läs mer (öppnas i nytt fönster):