The FGD Corrosion Challenge
Flue gas desulfurization systems remove sulfur dioxide from power plant exhaust by scrubbing flue gases with alkaline slurries. This creates an exceptionally corrosive environment combining hot acidic condensates (sulfuric and hydrochloric acids), chloride-rich slurries from absorbed HCl, abrasive limestone particles, temperatures cycling between ambient and 350°F, and alternating wet-dry conditions that concentrate corrosive species. Conventional stainless steels and even high-molybdenum grades like 316L and alloy 20 suffer unacceptable corrosion rates in the most aggressive zones of FGD systems.
Inconel 625 in FGD Systems
Inconel 625 is the premium material choice for the most corrosion-critical components in FGD systems. Its resistance to both reducing (HCl, H2SO4) and oxidizing conditions, combined with chloride pitting resistance, provides reliable service in zones where lesser alloys fail within months. CastAlloy produces Inconel 625 FGD components including scrubber vessel internals, spray headers, and nozzle assemblies, outlet ductwork operating in the acid dew point zone, damper blades and frames, reheat heat exchanger tubes and tube sheets, and pump components handling abrasive-corrosive slurries.
Cost-Effective Solutions
CastAlloy helps FGD operators optimize material costs by using Inconel 625 selectively in the most aggressive corrosion zones while specifying less expensive alloys where conditions permit. Our engineering team can review your FGD system design and recommend the optimal material for each component based on the specific temperature, chemistry, and flow conditions at each location. Contact us for a FGD component consultation and quotation.