Reviews of materials of construction (MOC) to adequately solve and control complex corrosion problems in flue gas desulfurization systems (FGD) of coal fired power plants have been fairly well documented. The utilities, which were forced to abide by the revised clean air act of 1970, suddenly found themselves in the position of being “chemical plant operators”, a role for which they were ill prepared. Their expertise in mechanical engineering, electrical engineering, water chemistry and coal management was of little or no use, thus leading to an onslaught of monumental corrosion problems, unscheduled shut downs, soaring maintenance costs, lost revenues and the penalties imposed from buying power from the grid, while quick fixes were being developed. This paper describes the chronology of legislative regulations over the past 30 years, the various evolutionary material solutions, both via metallic and non-metallic MOC, the changes in the design philosophy occurring over the past 25 years, and future trends and challenges facing this industry.
Kevwords: Flue gas desulfurization, FGD, nickel alloys, Ni-Cr-Mo alloys, 6M0 alloys, wall-papering, alloy 59, UNS N06059, alloy C-276, UNS N 10276, localized corrosion, acid dew point corrosion, scrubbers.