Internal Corrosion of Supercritical CO2 Pipelines: Integrated Influencing Factors, Mitigation Strategies, and Future Perspectives

Carbon capture and storage (CCS) is widely recognized as a key technology for reducing carbon dioxide (CO2) emissions from large industrial sources. Among the stages of the CCS chain, CO2 transportation plays a decisive role in determining overall system safety, reliability, and economic viability. CO2 transportation through pipelines is generally preferred for large-scale, long-distance applications and is commonly operated under dense or supercritical conditions to maximize efficiency. However, internal corrosion of pipeline steels remains a major integrity concern, with corrosion accounting for approximately 45% of reported CO2 pipeline failures. This review provides a comprehensive assessment of internal uniform and localized corrosion phenomena in CO2 pipelines operating under supercritical CO2 environments. The influence of key CO2 stream impurities, including H2O, O2, H2S, SOx, and NO2, is examined, considering their individual and synergistic effects on corrosion mechanisms, corrosion morphology, corrosion products, and severity ranking. In addition, an in-depth analysis of operating parameters such as temperature, pressure, flow conditions, and exposure time is presented alongside material-related factors, including steel grade, internal surface roughness, and welded regions. Corrosion mitigation approaches are also reviewed, with particular emphasis on organic, inorganic, and composite corrosion inhibitors. The review concludes by identifying key knowledge gaps and outlining future perspectives for improving corrosion control in CO2 transport systems supporting large-scale CCS deployment.