Valmet improves boiler reliability and reduces downtime with CFB boiler upgrade at Stora Enso Ostrołęka mill in Poland

Valmet Oyj’s trade press release on November 10, 2026 at 9:30 a.m. EET

Valmet has received an order from Stora Enso Narew Sp. z o.o. to modernize the circulating fluidized bed (CFB) boiler at the Ostrołęka pulp and paper mill in Poland. The upgrade will improve boiler availability, reduce unplanned downtime, and lower operating costs.

The order reflects the long-standing cooperation between Valmet and Stora Enso at the Ostrołęka mill. Since delivering the original CFB boiler in 2010, Valmet has supported the mill through lifecycle services and modernization projects that help maintain reliable and cost-effective operation. This latest investment supports the mill's continued efforts to increase the use of refuse-derived fuel (RDF) while improving boiler availability and operational performance.

Upgrade supports reliable operation with higher RDF use

Valmet’s delivery will include the replacement of the boiler bottom, an upgraded coarse material removal system, and a new bottom ash sieving system. The delivery also includes spare parts for two years to support a smooth start-up and long-term operational performance.

“Circularity and resource efficiency are central to Stora Enso and the Ostrołęka mill. As the boiler’s use of refuse-derived fuel has increased, new operational needs have emerged in the bottom ash area. This upgrade is expected to improve boiler availability, reduce maintenance shutdowns, and lower operating costs through more efficient material handling and reduced sand consumption,” says Przemysław Niedźwiecki, Engineering and Investments Manager, Stora Enso Narew Sp. z o.o.

The modernized CFB boiler will enable Stora Enso Ostrołęka mill to increase the use of RDF for energy production. Picture: Stora Enso

"As the share of refuse-derived fuel has increased at the Ostrołęka mill over the years, the operating conditions of the boiler have also changed. This upgrade addresses a specific operational challenge by improving coarse material removal and supporting more stable boiler operation. The project is a good example of how targeted lifecycle services and modernization investments can help customers improve availability, reduce maintenance-related shutdowns, and maximize the long-term value of existing boiler assets," says Jouni Koskinen, Senior Manager, Rebuild and Conversion Technologies, Pulp, Energy and Circularity business area, Valmet.

The order was included in Valmet's orders received for the third quarter of 2026. The value of the order will not be disclosed. The upgraded equipment is scheduled to be installed during the mill's annual shutdown in June–July 2027.

About the customer

Stora Enso's Ostrołęka mill in Poland is part of the company's Packaging Materials business. The integrated site produces recycled containerboard and kraft paper and includes energy production facilities that support efficient and reliable mill operations.

VALMET

Corporate Communications

Further information:

Jouni Koskinen, Senior Manager, Rebuild and Conversion Technologies, Energy and Circularity, Pulp, Energy and Circularity business area, Valmet, tel. +358 40 545 8704

Niina Ollikka, Vice President, Boilers and Gasifier solutions, Energy and Circularity, Pulp, Energy and Circularity business area, Valmet, tel. +358 40 551 5616

Valmet is a global technology leader in serving process industries. We work with our customers throughout the lifecycle, delivering cutting-edge technologies and services, as well as mission-critical automation and flow control solutions. Backed by more than 225 years of industrial experience and a global team of 19,400 professionals close to customers, we are uniquely positioned to transform industries toward a regenerative tomorrow.

In 2025, Valmet’s net sales totaled approximately EUR 5.2 billion. Our head office is in Espoo, Finland, and we have experts in approximately 40 countries around the world. Valmet’s shares are listed on Nasdaq Helsinki.

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