Corrosion Behaviour in CO2 Pipeline Transport: A Review of the Impact of Condensates and Impurities

The high emissions of carbon dioxide (CO2) into the atmosphere have driven the development of carbon capture, transport, and storage (CCTS) technologies. These focus on capturing CO2 from industrial exhaust gases and transporting it through existing pipeline networks. Although various capture techniques are available, they may introduce impurities such as O2, N2, Ar, H2O, NH3, and others into the CO2 stream. These contaminants can significantly alter the thermophysical behaviour of the fluid, making the phase behaviour predictions, reliable for pure CO2, much more complex. Pressure and temperature variations along pipelines can induce unexpected phase transitions, affecting fluid composition and potentially triggering corrosion. This review examines the formation of condensates within pipelines and their role in initiating corrosion phenomena, with a focus on top of the line corrosion (TLC) and conventional CO2-induced corrosion (sweet corrosion). The main literature findings highlight how phase changes and altered fluid composition due to corrosion processes can significantly intensify degradation mechanisms during CO2 transport.