A first for Finland - power from municipal waste1 February 2007
Finnish waste management specialist Ekokem is currently building the country’s first waste incineration plant able to generate heat and power from municipal waste on its Riihimäki waste disposal site. When the plant begins operation in 2007, it will combust municipal household, industrial and commercial waste – making it the first power plant in Finland to be fuelled by municipal household waste.
The plant will generate district heat for the nearby cities of Hyvinkää and Riihimäki, and heat and electricity for Ekokem’s own processes. In total, the plant will burn approximately 150 000 tons of waste per year, and help to generate energy from waste flows that would otherwise need to be landfilled, a practice which runs counter to EU recommendations.
Ekokem, which is owned in roughly one-third shares by business, the state, and various municipalities, specialises in waste treatment and management. It’s main operation is at Riihimäki, a 20 hectare site that includes landfill areas and treatment plant, chemical and incineration, for all kinds of municipal and industrial waste, including hazardous waste. Nonetheless its emission figures are among the lowest in the world and exceed by a worthwhile margin the legislated standard that forms the basis of its licence.
There are three incineration lines at the site. Two of them, rotary kilns 12 m long by 5m in diameter, operate at 1350°C with excess O2 to ensure complete incineration. The third operates at 800°C, a temperature high enough to vaporise organics but low enough to allow metals to be recovered.
CHP is not new to the site. It is already supplying 80% of the municipality’s entire heat demand for district heating, and is self sufficient in electricity.
Flue gases from the existing incineration plants on site are subjected to an intense clean up process, as demanded by Finnish law, going throughelectrostatic and fabric filter stages followed by scrubber stages, and where needed, chemical injection to remove unusual flue content.
Metso Automation will supply automatic controls for the new plant. The contract includes a metsoDNA automation system and an HIMA integrated safety system for the plant’s combustion line, which will be burning mainly municipal household waste.
Metso. which has automated other waste incineration plants, in the UK and in Austria, first delivered basic automation to Ekokem’s waste treatment plants around twenty years ago. It’s energy automation applications have been widely installed in a number of combined cycle plants, combined heat and power plants and facilities generating energy from biofuels or waste.