Valmet to Upgrade CFB Boiler at Stora Enso’s Ostrołęka Mill in Poland

Valmet has received an order from Stora Enso Narew Sp. z o.o. to modernize the circulating fluidized bed (CFB) boiler at Stora Enso’s Ostrołęka pulp and paper mill in Poland. The upgrade is aimed at improving boiler availability, reducing unplanned downtime and lowering operating costs as the mill increases its use of refuse-derived fuel (RDF) for energy production.

The project includes replacing the boiler bottom, upgrading the coarse material removal system and installing a new bottom ash sieving system. Valmet will also supply spare parts for two years to support commissioning and long-term operational performance.

The investment builds on the companies’ longstanding cooperation at the Ostrołęka mill. Valmet delivered the original CFB boiler in 2010 and has since supported the facility through lifecycle services and modernization projects.

According to Przemysław Niedźwiecki, Engineering and Investments Manager at Stora Enso Narew, increased RDF use has created new operational requirements in the boiler's bottom ash handling area. The modernization is expected to improve boiler availability, reduce maintenance shutdowns and lower operating costs through more efficient material handling and reduced sand consumption.

Jouni Koskinen, Senior Manager, Rebuild and Conversion Technologies, in Valmet’s Pulp, Energy and Circularity business area, said the project addresses operational challenges arising from changes in boiler operating conditions as the share of RDF has increased.

The order was recorded in Valmet’s orders received for the third quarter of 2026. The financial value of the contract has not been disclosed.

Installation of the upgraded equipment is scheduled to take place during the mill’s annual shutdown in June–July 2027.