Metsä Tissue is dedicated to improving its energy efficiency by 10 per cent by 2020 from the 2009 level
At Metsä Tissue’s Mänttä mill, the operators monitor energy consumption in real-time. The consumption of steam and electricity has been reduced by eight per cent per produced paper tonne compared to previous years. Moreover, the specific consumption of water has also been reduced over the past couple of years by as much as 14 per cent.
“We have been able to reach these savings by reviewing all our processes and improving how we measure energy consumption,” says Jyrki Leppäaho, Development and Energy Engineer, Mänttä Mill.
“We defined optimal consumption values for each subject, and built, together with an IT vendor, a new system to monitor energy usage. Now, the operators actively follow up the use of steam, gas, electricity and water. We also study the reports for each part of the process on a monthly basis while changes are monitored daily.
“We need to track the potential deviations as quickly as possible. The collected information also helps operative work and maintenance - a sudden increase in water consumption, for instance, may indicate a leaking valve.”
Infrastructure Specialist Risto Savonmäki has worked in the energy efficiency projects at Mänttä Mill:
“The potential energy loss is most often connected to the warm water and drying. Jyrki has done a fantastic job in closing the water circulations.
“If, for instance, we have a malfunction with the paper machine fibre reclaiming filter, and more water than normal is discarded, the result is that energy consumption increases. Warm water is too valuable a resource to be wasted!”
Mänttä Mill gets the steam and part of the electricity it needs from its neighbour, Mänttä Energia’s power plant, jointly owned by Metsä Tissue and Mäntän Kaukolämpö. The plant produces energy from woodchips, peat as well as from by-products from Metsä Group’s mills.
The operator can adjust the energy consumption to achieve the best possible production efficiency without risking product quality and work safety. Any malfunctions in the process or discarded products weaken the operating efficiency of the machine. One of the adjustment possibilities is connected with steam usage.
“We can save on energy costs, for instance by ensuring that the maximum amount of steam used on the yankee cylinder is produced at our own power plant. The more I can increase the steam pressure, the less gas we consume. This is important as liquid gas needs to be imported and it costs more,” explains Operator Markku Saarinen.
Markku operates paper machine 10 that mainly produces Serla and Lambi toilet and household tissues.
Energy efficiency high on the agenda in Metsä Group
Energy costs matter as they are the second largest expenditure at Mänttä Mill after raw materials! The efficiency improvement measures carried out at the mill are part of Metsä Tissue’s extensive energy programme. Last year, Metsä Tissue was one of the finalists in an international energy efficiency competition organized by Deutsche Energie-Agentur (DENA). The company received an honorary award for the work it carried out at its Stotzheim Mill in Germany.
Metsä Tissue, like the entire Metsä Group, is dedicated to improving its energy efficiency by 10 per cent by 2020 from the 2009 level. Energy efficiency is an important sustainability theme in Metsä Group.
From left: Risto Savonmäki, Jyrki Leppäaho and Markku Saarinen