“We are committed to improving energy efficiency at all our mills. In this respect, the biggest contribution comes from our bioproduct mills. Our new production plants are designed to be extremely energy efficient,” says Pirita Mikkanen, VP, Energy from Metsä Group.
The real-time control of electricity use and smooth production at mills are part of daily work at Metsä Group.
“Metsä Group is a significant player in the Finnish electricity market. Operating efficiently helps us reduce emissions and gives us an edge in costs. Meanwhile, each energy efficiency measure reduces our use of electricity from the grid,” says Mikkanen.
Examples of our energy efficiency measures:
The pulp mill's surplus electricity production is fed into the national grid
A considerable share of Finland’s renewable energy is generated in connection with pulp production. Heat is used to produce electricity for the mill’s own needs, and the surplus is fed into the national grid.
Metsä Fibre’s sawmill, completed next to the Rauma pulp mill in 2022, procures all its heat energy from the pulp mill.
“Thanks to the sawmill, we can use the heat generated in pulp production more efficiently and prevent energy being wasted,” says Jaakko Rautala, Development Engineer.
As a result of the company’s investment in energy efficiency, the volume of electricity fed into the national grid has increased.
“Most recently, the improvements made to the operations of the Rauma sawmill’s recovery boiler had a direct impact on our electricity production,” says Rautala.
The electricity that the Rauma pulp mill produces daily for the national grid is equivalent to the electricity consumption of around 30 electrically heated single-family homes (~20,000 kWh/a).
The renewal of pneumatic equipment led to big savings
Notable energy savings were achieved by renewing the old pneumatic system at Metsä Board’s Kaskinen mill. Compressed air plays an important role in the reliable operations of our mills: valves, for example, do not operate without it.
“The new equipment, designed especially for our needs, is extremely energy-efficient and requires less maintenance. Cooperation with the equipment supplier’s maintenance service is one of the factors guaranteeing the mill’s smooth operation,” says Jari Pitkäkoski, Operating Engineer.
The new equipment also enables energy to be recovered from the compressor’s cooling water.
Top-rate energy efficiency at the bioproduct mill
Energy efficiency has been fine-tuned to perfection at Metsä Fibre’s Äänekoski bioproduct mill. The mill does not use any fossil fuels. Instead, all the energy is obtained from the production side streams.
“The bioproduct mill is a large mill, where a small change can result in substantial annual savings. The good availability of the mill and its turbine is without doubt the most important factor affecting energy efficiency,” says Hannu Loiri, Development Engineer.
In addition to the pulp mill and recovery, this year’s energy efficiency survey of the mill focused on the pulp drying machinery, which shows a potential for energy savings. Savings can also be obtained by focusing on electricity consumption and production in real time.
“We keep close tabs on electricity prices, as the market changes rapidly. Indeed, we recently organised training for our staff concerning developments in the electricity market, as well as forecasting electricity production and consumption,” says Loiri.
Energy efficiency renovation at the Vilppula power plant
Rami Annala, Maintenance Planner at Metsä Fibre’s Vilppula sawmill, tackled the power plant’s energy use in 2019. Over two years, the power plant focused on automation and equipment repairs.
“The investment in improvements to the power plant was recovered in savings in two years. For example, electricity production increased by nearly 45. Cooperation between our own staff and other experts was key. After all, it’s impossible to achieve success like this alone,” says Annala.