Corrosion and polarization behavior of carbon steel in MEA-based CO2 capture process

This work reveals levels of corrosion rate and polarization behavior of carbon steel immersed in aqueous solutions of monoethanolamine (MEA) used in the absorption-based carbon dioxide (CO2) capture process for greenhouse gas reduction from industrial flue gas streams. Such information was obtained from electrochemical-based corrosion experiments under a wide range of the CO2 capture process conditions. The corrosion of carbon steel was evaluated in respect to process parameters including partial pressure of oxygen (O2), CO2 loading in solution, solution velocity, solution temperature, MEA concentration and metal surface condition. Results show that the aqueous MEA solution containing CO2 provides a favorable condition for the corrosion of carbon steel to proceed. Corrosion rate is increased by all tested process parameters. These parametric effects were explained by the electrochemical kinetic data obtained from polarization curves and by the thermodynamic data obtained from Pourbaix diagram.