Waste Heat from Metsä Group’s Rauma Pulp Mill to be Utilised in Rauma District Heating Network
News
Metsä Fibre, part of Metsä Group, and Rauman Energia are progressing with their joint project to utilise waste heat from the Rauma pulp mill in district heat production in Rauma. The new district heating station required for the project has arrived at the mill site, and preparations for commissioning the system are under way. The aim is to start heat production in December 2026.
In the project, waste heat generated in the processes at the Rauma pulp mill will be recovered and transferred to Rauma’s district heating network. Following the arrival of the new district heating station at the mill site, the next steps are to connect the station to the mill’s systems, carry out testing and commission the system.
Preparations for the project at Metsä Fibre’s Rauma pulp mill have been under way since 2025. The necessary connection points were built into the mill’s steam and condensate systems during the 2025 annual maintenance shutdown. Construction of the district heating pipelines at the mill site began in January 2026, and the pipeline installations were completed during the spring.
Experts from Metsä Fibre and Rauman Energia have been involved in the planning and implementation of the project.
More Efficient Use of Waste Heat
The heat to be utilised in the district heating network originates from the Rauma mill’s recovery boiler, which is part of the pulp mill’s chemical recovery cycle. Black liquor is combusted in the recovery boiler, and the resulting heat is used to generate steam. The steam is primarily used to generate electricity in the turbine and generator and in the pulp mill’s processes.
The Rauma pulp mill generates more energy than is required for its own processes. Until now, some of the unutilised waste steam has had to be cooled in the condenser, with heat dissipated through cooling towers. The new district heating station will enable this waste heat to be utilised more efficiently and transferred to Rauma’s district heating network.
It is estimated that the heat utilised through the project could cover approximately 10–20 % of Rauman Energia’s total heat demand.
Read the full press release on this topic, published on November 11, 2026 metsagroup.com/fi/metsafibre.
