Metsä Group’s next-generation bioproduct mill in Äänekoski came into operation as planned last August. Pulp deliveries from the new mill to customers began in early September 2017. The construction project was carried out as planned, in accordance with its schedule and its EUR 1.2 billion budget.
Before the bioproduct mill started up, the old pulp mill in Äänekoski was shut down and its dismantling is currently in progress. The bioproduct mill will achieve its nominal capacity approximately a year after start-up. The mill will produce 1.3 million tonnes of pulp per year, along with other bioproducts such as tall oil and turpentine. New bioproducts that already complement the product concept include product gas from bark, sulphuric acid from the mill’s odorous gases, and biogas and biofuel pellets from sludge.
With this new bioproduct mill Äänekoski’s industrial ecosystem is developing and growing, and the mill will be a platform for production of new bioproducts. Several processes and product paths are being actively studied. The most important new bioproduct development projects are lignin products, textile fibres, and biocomposites.
The core of Metsä Group’s bioproduct mill lies in the world’s most efficient pulp mill, with an annual capacity of 1.3 million tonnes. Expanding this core with the production of numerous new bioproducts is a leading principle behind Metsä Group’s bioproduct concept.
“Our action plan aims at incorporating new bioproducts and partnerships into our developing and competitive pulp business in phases,” said Ilkka Hämälä, CEO of Metsä Fibre, a part of Metsä Group.
The first step in implementing the bioproduct concept was taken in April 2015, when Metsä Group made the investment decision concerning the bark gasification plant. The bark-derived product gas is produced for the bioproduct mill’s own use, whereby the mill becomes fully free of any fossil fuels. The renewable product gas will replace some 45,000 cubic metres of heavy fuel oil a year. The gasification plant began production at the same time as the bioproduct mill. The bioproduct concept is complemented by the agreements made in February 2016 with biogas manufacturer EcoEnergy SF Oy and biocomposite producer Aqvacomp Oy.
The biogas plant that EcoEnergy SF Oy has built at Metsä Group’s bioproduct mill in Äänekoski is the first in the world to make use of the sludge generated in pulp production. The plant produces approximately 20 gigawatt hours of biogas a year, which is equal to the annual fuel consumption of roughly 1,800 passenger cars. The possible uses of the biogas include transport fuels. The Ministry of Employment and the Economy has granted EcoEnergy SF an investment aid from the government’s spearhead programme funds for carbon-free, clean, renewable energy. Furthermore, a letter of intent on making use of the biogas produced by the plant has been signed with Gasum Oy.
The bioproduct concept is further developed along several avenues. Metsä Group is, for instance, developing a concept, in which the odorous gases of the bioproduct mill are converted into sulphuric acid, to be used as a raw material by the mill instead of sulphuric acid bought from the market. A sulphuric acid plant connected to the pulp production process would represent a significant step towards more closed chemical cycles.
Textile fibres made from softwood pulp is another central development project in the context of new bioproducts. The new, environmentally-friendly production process for producing textile fibre from wood is based on ionic liquid technology developed in the research programmes of FIBIC Oy. Metsä Group has continued the development in cooperation with the Japanese Itochu Corporation. The first garments produced on a laboratory-scale, utilising this new production process, are now ready, and will function as a basis for considering a shift to pilot-plant scale.