Alloys for corrosion resistance in FGD system
Nickel based alloys and stainless steel grades are recommended construction materials for preventing corrosion in the flue gas desulfurization (FGD) systems.
FGD systems are significant in treating the severely contaminated gases before they are released into air. The system’s chief components include inlet duct, by-pass duct, fan, damper, absorber inlet, absorber tower, spray headers, mist eliminators, outlet duct and stack. Traditionally, steels such as carbon steel and clad steel types were used but they couldn’t provide the required service. With the passage of time, advanced alloys were developed such as high performance nickel alloys that have become a recommended material for use in manufacturing FGD’s components, the most suitable materials are Inconel 718, Hastelloy C-276 and Hastelloy C-22 that are extremely resistant to the chemical corrosive conditions that occur in this system.