Abstract: Recovery boilers are used in the biomass industry, in part, to recycle pulping chemicals for future reuse. Within the upper boiler region, superheater tubes attempt to salvage lost thermal energy by heating steam within inside them that is subsequently sent to power steam turbines. Operating temperatures of recovery boilers are generally near 500°C, however increasing their operating temperature is limited due to the failure of its superheater tubes. These superheater tubes are exposed to multiple sulfur, water vapor, and oxygen containing gaseous environments, in addition to molten salt deposits (sulfates, carbonates, and chlorides, etc.) whose compositions can be wide-ranging. Our work aims to assess the performance of select iron and nickel candidate alloys by studying each corrosive component individually through the use of exposure testing and post-exposure characterization. This study’s purpose is to understand what corrosive products are formed and what kind of corrosion mechanisms are present in these environments.
Authors: Kasey Hanson and Preet Singh
Keywords: Corrosion, Biomass, Oxidation