Efficient solution exploits waste
Biovakka's customer, Turun seudun puhdistamo Oy, is a wastewater treatment service provider jointly owned by ten municipalities. Earlier, the excess sludge from Turku's old wastewater treatment plant was composted and not utilised in any way. The Biovakka solution now uses the anaerobic digestion process to produce biogas and recycled nutrients from that sludge.
Recycled nutrients are used in agriculture, and are a safe way of returning nutrients to the soil. The energy contained in biogas is utilised in the Turku Energia district heating network or turned into electricity for the electric grid. At this time, 96,000 kilowatt hours of energy is produced from the sludge each day. For example, the energy consumption for an average house is approximately 16,000 kilowatt hours per year. The Biovakka solution can produce enough energy to meet the annual energy requirements of a house in just four hours.
The first Biovakka plant was built in Vehmaa, and the Turku plant was completed at the beginning of 2009. At this time, they are the only plants of this size in Finland that can simultaneously process many different kinds of materials. However, there is no barrier to implementing the solution at other wastewater treatment plants. In the future, Biovakka also plans to build a plant in Nastola. That site will provide the opportunity to utilise biogas as a transport fuel. Biogas can be fed into the natural gas network, after which Gasum would handle further distribution. The method used by Biovakka could also be exploited elsewhere in the world, and some similar plants already exist in Europe.
For more information about Biovakka's solutions: www.biovakka.fi
