Valmet to supply ash crystallization plant to Mercer Stendal mill in Germany
Valmet will deliver a new ash crystallization plant to Mercer Stendal’s pulp mill in Arneburg, Germany, supporting the mill’s long-term strategy to reduce emissions and improve operational performance. The investment is intended to strengthen chemical circulation within the mill while helping to extend recovery boiler maintenance intervals beyond 24 months.
According to Mercer Stendal, the new ash crystallization system forms part of the company’s broader sustainability and operational improvement programme. “Since the mill started up in 2004, we have systematically invested in improving its performance and sustainability,” said Dr. Martin Zenker, Mill Manager at Mercer Stendal. “Our sustainability efforts are guided by the Mercer vision and values and our long-standing philosophy of responsible business practices that encompass sustainability, safety, financial responsibility, and strong leadership. The new ash crystallization plant will help us to further improve both operational and environmental performance. We chose Valmet to deliver this project based on both their technical expertise and our previous joint projects.”
Reducing non-process elements and emissions
The Valmet Ash Crystallizer plant will recover sodium salts while removing non-process elements, mainly chloride and potassium, from the mill’s liquor cycle. By reducing the accumulation of these elements, the system helps decrease plugging and corrosion inside the recovery boiler, allowing longer operating campaigns between shutdowns and improving long-term boiler availability.
Valmet stated that the technology also eliminates the need for ash dumping, reducing wastewater generation and lowering make-up chemical consumption. The solution provides both operational and environmental benefits by improving resource efficiency and reducing associated emissions.
Large-scale ash processing capacity
The new ash crystallization plant will have a processing capacity of 140 tonnes of ash per day. Valmet’s delivery scope includes the complete plant, electrical and instrumentation systems, steel structures, erection works and an expansion of the existing Valmet DNA automation system. The new system will be integrated mainly with the mill’s evaporation plant and broader production operations. Start-up of the new plant is scheduled for the fourth quarter of 2027.
About Mercer Stendal
Mercer Stendal, part of Mercer International Group, operates one of Europe’s most modern pulp mills. The Arneburg facility started operations in 2004 and currently has an annual production capacity of 740,000 tonnes of bleached softwood kraft pulp. The site also operates one of Germany’s largest biomass power plants, with a generation capacity of 148 MW, producing renewable energy for both internal use and the national grid. In addition to pulp production, the mill operates as a biorefinery producing bioenergy and biochemicals including tall oil, methanol and turpentine.
