Corrosion Mechanisms and Mitigation Strategies for CO

The presence of impurities such as H2O, H2S, SOx, NOx, and O2 within the CO2 stream can significantly increase the likelihood of internal corrosion, thereby posing a threat to the pipeline's structural integrity. This paper presents an updated review of corrosion mechanisms occurring in supercritical CO2 environments with varying impurity compositions, encompassing electrochemical processes, localized corrosion phenomena, and synergistic degradation effects. Particular attention is given to the influence of thermodynamic conditions, phase behavior, and the role of impurities in enhancing corrosivity. Furthermore, the discussion encompasses a range of mitigation strategies currently employed, including material selection, application of internal coatings, deployment of chemical inhibitors, and operational control to minimize impurity concentrations. Compared with prior studies, this work makes a novel contribution by providing a comprehensive, up-to-date review that integrates mechanistic insights into impurity-induced corrosion in CCS systems with practical engineering strategies for its mitigation.