Materials for flue gas desulfurization systems operating in Korea and their failures

Abstract

Most flue gas desulfurization (FGD) systems operating in Korea are wet systems which are exposed to aggressive chemical and mechanical environments. Many kinds of materials such as stainless steels, nickel-based alloys, fiberglass reinforced plastic (FRP), C276 or Ti clad steels, and non-metallic coatings/linings over carbon steel have been used for the FGD systems, with their ductwork and chimney exposed in the severe environments. The materials are required to survive during their design life, but some materials are not sufficiently resistant to the corrosive environments in the FGD systems, resulting in the failures of materials and hence increased maintenance costs. Especially, the non-metallic materials and stainless steels have been used extensively in early installations in order to reduce the initial material costs, but they frequently failed early in the severe corrosive environments. This paper presents some representative examples of failures that occurred at the wet FGD systems operating in Korea and their counter measures.