Corrosion and Scale Problems in Recovery and Power Boilers in Pulp and Paper Operations

January 18, 2021

Author: John A. Kelly, Ted (Edward S.) Beardwood, October 2018, TAPPI 2018 PEERS Conference, https://www.tappi.org

ABSTRACT: Corrosion and corrosion product deposition are major concerns in utility and recovery boiler operations in pulp and paper mills. They can ultimately lead to a loss in efficiency, serious under-deposit corrosion as in caustic attack, short and long term overheating, circulation problems and tube failures. Feedwater upsets from condenser tube leaks and corrosion product release throughout the system cause boiler tube deposits. Condensate system passivation using blended amines plus a volatile reducing agent reduces the impact of acid upsets temporarily on the total system. This enhances better operational performance. Plant profitability and production losses generally cannot be recovered when tube failures occur. Production losses resulting from reduced steam capacity or downtime in the recovery boiler are potentially far greater than the actual repair and maintenance costs incurred during the shutdown. Corrosion problems and metallographic indicators will also be discussed.