II.19 - Thermodynamic prediction of the risk of hot corrosion in gas turbines

Abstract

Publisher Summary This chapter discusses the thermodynamic prediction of the risk of hot corrosion in gas turbines. Thermodynamic modeling was used in the chapter to estimate the risk of hot corrosion in gas turbines, driven by cleaned coal-based flue gases. The effectiveness of the hot-gas clean-up concerning alkali removal was evaluated. The limitation of fossil fuel resources and the necessity of reducing CO2 emission require an increase in the efficiency of power plants by using combined cycle power systems. The direct use of hot flue gases originating from coal combustion or gasification for driving a gas turbine requires a hot-gas clean-up to prevent the corrosion of the turbine blading. One of the main problems is the alkali release during the coal conversion process. The alkali metals are mainly bound in the mineral matter of the coal as salts and silicates. The alkali release leads to an alkali concentration in the flue gas significantly higher than the specifications of the gas turbine manufacturers. The use of computational thermochemistry is a means to generate the results within a short time and at low cost.