The heart of the kraft pulping process is the digester, a pressure vessel that is over 60 metres tall that breaks down wood chips into pulp. However, digesters are at risk of a dangerous and often misunderstood damage mechanism—stress corrosion cracking (SCC). If left undetected, these cracks can propagate and lead to catastrophic failures such as the 2020 explosion at a mill in Jay, Maine. The failure at Jay resulted in permanently shutting down operations and devastated the local economy. The incident highlights the urgent need for better inspection techniques, awareness, and solutions to prevent similar disasters.
This issue is more significant than just one company—it’s an industry-wide problem. Many pulp mills across North America rely on continuous digesters, and their safety is critical. FPInnovations is leading a major research initiative to understand the causes of SCC better, identify high-risk environments and conditions, and develop more effective detection and prevention strategies. By analyzing digester process chemistries, testing steel samples, and evaluating inspection techniques, this research aims to establish industry-wide best practices.
Education and awareness are crucial for the success of this project. Without proper knowledge and tools, the risk of another catastrophe remains high. FPInnovations is uniquely positioned to bridge this knowledge gap, bringing together experts, mills, and industry stakeholders to develop science-based solutions.
This problem has persisted for over 40 years with no definitive solution. Now is the time to act. By working together, the industry can prevent another disaster, protect workers and communities, and secure the future of pulp mills. The safety of these facilities must be a top priority, and through research, collaboration, and innovation, we can ensure a safer and more sustainable future for the industry.
FPInnovations is organizing an industry research group intending to support this work, ensure this research leads to real-world improvements, and work with mills to address concerns about their specific liquor chemistries.
Contact Matthew Tunnicliffe (matthew.tunnicliffe@fpinnovations.ca) or Victor Padilla (victor.padilla@fpinnovations.ca) for more information.
