Influence of novel cycle concepts on the high‐temperature corrosion of power plants

The aim to reduce CO₂ emissions has triggered the evaluation of new cycle concepts for power plants. CO₂‐capture concepts are also evaluated to add on new and existing power plants. For combined cycle power plants (CCPP), different cycles are investigated such as integrated gasification (IGCC) or oxy‐fuel firing. Besides the difference in combustion compared to a conventional CCPP, the environmental boundary conditions are changed and will affect the oxidation and corrosion life of the materials in the hot‐gas path of the gas turbine and the heat‐recovery steam generator. For the circulating fluidised bed power plants, the biomass co‐firing and the oxy‐fuel firing are also foreseen for CO₂‐emission reduction. The fireside corrosion of the water walls will be influenced by these concepts and the changed fuel. The corrosion risk has been evaluated for two new power plant concepts: combined cycle with exhaust gas recirculation and pulverised coal‐fired boiler with oxy‐fuel firing. Based on this evaluation, the consequences for the testing conditions and the material selection have been discussed in detail.