Energy and Waste Water
Heating and electricity from renewable energy
The heart of our energy production on site is the so-called recovery boiler with 90 megawatts of thermal output and steam back pressure turbine. The Brown liquor resulting from the cooking process contains resins, hemicellulose and lignin with a high calorific value. First, the brown liquor is concentrated in an evaporation system until it has a dry content of up to 60 percent and then it is burned. During the burning process, steam is produced for the production and green energy which we use ourselves. At the same time, the chemicals in the brown liquor are largely recovered.
In 2005, the site invested around 36 million euros in building a biomass thermal power station (BHCP). Each hour, 30 megawatts of thermal output demands 15 tons of fuel. A large proportion of the fuel requirement is served using internal residual materials from the factory, for example bark and fines from the Wood yard, rejects from the pulp production and sludge from the waste water treatment. In addition, wood logs and forest wood chips from the region are used.
Green power and district heating for Salzburg
Today, the plant provides the operations with steam, supplies green power and district heating to the public grid. And the BHCP makes an essential contribution to achieving climate targets in Austria. Fossil fuels such as natural gas is only used for auxiliary firing when starting up after downtime. The proportion of biogenic fuels in the overall use at the site is around 99.6 percent today. Using an innovative fermentation procedure, we generate biogas from filtrates produced by the pulp factory and since 2016 have also been processing this in a thermal power station into green power and district heating. This means that the plant is one of the largest bioenergy producers in Austria and supplies up to 27,000 households in the region with green power and 14,000 households with district heating.
Waste water treatment for a green Salzach
After the anaerobic biogas system, the procedure leads to a biological treatment plant. In aeration tanks (activated sludge), aerobic microorganisms (biofilm on carriers) break down the biological impurities in the water under constant air supply. In a secondary clarification basin, the sludge is separated from the water through sedimentation, dewatered in a sludge press and burned in the biomass thermal power plant. A two-kilometre-long sewer conveys the treated waste water south of Hallein into the Salzach.
solid cubic metres of energy wood
households supplied with green energy
households supplied with district heating