The world’s first next-generation bioproduct mill concept allows for the integrated manufacture of new bioproducts, the resource-efficient use of side streams from the industrial process, and the creation of a new type of bioeconomy ecosystem. The Äänekoski bioproduct mill represents the highest levels of energy, material and environmental efficiency in the world.

Even though its production capacity is nearly three times higher than that of the previous pulp mill
of Äänekoski, the bioproduct mill operates within the same emission limits and wastewater conditions of the previous mill´s environmental permit.

The environmental impact assessment (EIA) process has been used to assess and minimise the environmental effects of the project. The Regional State Administrative Agency for Western and Inland Finland has granted an environmental permit and a water intake permit for the bioproduct mill. These permits made it possible for the mill to begin operations.

Wood supply

We use pine, spruce and birch pulpwood from sustainably managed forests, as well as sawmill chips as raw materials. The wood we use is obtained mainly from Finland, mainly 100 - 150 kilometers from the mill. Over 90% of wood comes from certified forests. Our wood raw material is always fully traceable.

Effects on water

We monitor and measure actively load of the water, such as chemical and biological oxygen demand, and phosphorus and nitrogen load. Our mill uses an efficient, multiphase biological wastewater treatment plant that purifies the wastewater produced by the mill. The sludges from the wastewater treatment plant are directed to the mill’s biogas plant, where they are refined into biopellets and, in the future, also biogas.

The Central Finland and North Savo ELY Centre approved the impact monitoring plan for the natural waterway downstream of the bioproduct mill and fish stock. The related sampling programme is implemented on a yearly basis. The monitoring programme enables close monitoring of the waterways’ status.

We conduct long-term work to decrease the use of process water, and we have mapped new sites to increase the efficiency of water use in our process. With these measures, we will implement Metsä Group's sustainable development goal to reduce the use of process water by 25 percent per product tonne in 2018–2030. We can thus also minimise the nutrient load on waterways.

Air quality and noise

We participate in joint monitoring of air quality in our area. The results are monitored by local environmental authorities. The city of Äänekoski is responsible for carrying out the monitoring.

The bioproduct mill uses a powerful collection and processing system for odorous gases, which collects odorous gases. Odour nuisance occurs in conjunction with process malfunction, as well as shutdown and ramp-up situations at the mill.

Some of the odorous gases are utilized on production of sulfuric acid, which is used in the mill's process to replace the sulfuric acid supplied to the mill as a purchasing chemical.

Noise caused by the mill's operations is managed in day-to-day operations by taking care of the maintenance of equipment and machinery, and by taking noise into account when planning investments and purchasing new equipment. The mill’s noise emission level is checked regularly with measurements and model calculations.

The noise caused by the equipment was especially considered already when planning the Äänekoski bioproduct mill and selecting devices. Limit values were set for noise when acquiring equipment for the mill. Equipment that causes noise was placed in such a way that its environmental impact is minimised.

Local traffic

Raw wood is transported from the forest to the mill by lorries and trains. A total of 240 raw wood lorries and 70 flat wagons arrive at the mill each day, and 44 wagons of pulp is transported to the Vuosaari Harbour.

For our part, we want to ensure that movement in the Ääneseutu area is as safe as possible. Metsä Fibre cooperates with the road authorities and the local authorities to improve road safety. To increase the fluidity and safety of traffic, wood trucks have a route different from chemical and product transports. In addition, Metsä Group organises a road safety tour for primary school children each autumn in the Äänekoski area. At the events organised under the road safety tour, schoolchildren get to see a timber truck and receive practical advice on road safety.


The sidestreams from the Äänekoski bioproduct mill are utilised efficiently as different bioproducts and bioenergy. Bark is used to produce fossil free product gas for the mill’s own use, and odorous gases are used to produce sulphuric acid for use as a process chemical. The lime and ash from bark gasification are also utilised for a useful purpose. In addition, a business ecosystem functions around the mill. It utilises pulp and production side streams to produce and develop different bioproducts.

Metsä Group’s goal is to utilise production side streams fully by 2030 and to achieve a state in which our production will not generate landfill waste. At the moment, green liquor dregs generated in the pulp process is the only fraction that is landfilled. Other end uses for it are being actively sought.


Read more about the bioproduct mill