Valmet bioenergy technology has ‘key’ role at Metsä bioproducts mill
Valmet has delivered a range of technology to Metsä Group’s newly started bioproducts mill in the Finnish town of Äänekoski. According to a statement from Valmet, the company’s technology will maximise the use of bioenergy and make the pulp mill totally fossil fuel-free.
The technology supplied to the mill includes a recovery boiler, pulp drying line, gasification plant, lime kiln, sulphuric acid plant, and mill-wide Valmet DNA automation system. Valmet claims that the recovery boiler, pulp drying line and lime kiln are the largest in Europe.
Construction on the bioproducts mill was started in 2015. At €1.2 billion, it is the largest investment into Finland’s forestry industry yet.
"This project has been important for us both from the technology and employment perspective. Majority of the technology provided by Valmet was engineered and manufactured in Tampere, Jyväskylä, Ulvila and Raisio,” says Bertel Karlstedt, Pulp and Energy Business Line President from Valmet.
“It is our pleasure to rise to the challenge, when a customer like Metsä Group is taking the industry forward with investments of this magnitude. Success in a project like this is made possible by close cooperation between the two parties. Our cooperation has been open and constructive, and we have worked together to find the right solutions,"
"We have a long experience of co-operating with Valmet in our pulp mills in Finland. Throughout the project Valmet has been a good and innovative partner when building the world-class bioproduct mill in Äänekoski," said Timo Merikallio, Project Director, Metsä Group.
Bioenergy and biofuels help achieve self-sufficiency
The Valmet supplied biomass gasification plant will dry plant bark using double-layer drying process with material recirculation. Dried bark is gasified to make product gas, which is then used as fuel for the lime kiln.
In the lime kiln, active lime is regenerated using biofuels, with a stationary product cooler setting new standards for recovering process heat.
The largest piece of equipment provided by Valmet is the recovery boiler. The boiler is designed for a capacity of 7,200 tds/d (tonnes dry solids a day). The Äänekoski recovery boiler has multiple high-power features, including patented heat recovery from flue gas to combustion air, enabling the mill to produce 260 MW of electricity and sell 1.4 times more electricity to the grid than it needs for its own operation.
The produced pulp is dried in the pulp drying line, where the pulp web is formed, pressed and dried before being cut into bales. Individual 250 kg bales are wrapped and consolidated into 2,000 kg units for transportation.