Fireside Corrosion during Oxyfuel Combustion Considering Various SO2 Contents

This work encompasses evaluation of deposit and material related limitations on boiler performance and lifetime of CO2-free, oxyfuel operated power plants. The aim of the study was to determine the reliability of advanced and conventional boiler materials. Six alloys, varying from state-of-the-art ferritic-martensitic and austenitic Fe-based steels to an advanced Ni-based superalloy, were selected for the corrosion tests. Impact of oxy-firing of two fuels is considered in the study: S-lean bituminous coal from Indonesia and S-rich bituminous coal from Venezuela. Fireside corrosion tests were performed by two laboratories using varying methodologies: exposures in a combustion test rig using cooled corrosion probes followed by laboratory exposures and isothermal laboratory exposures only. The tests result in a similar ranking of the alloys’ corrosion resistance, but also revealed some differences in the formed corrosion products.