Impact of Impurities on the Corrosion of CO₂ Dense Phase Transmission Pipelines

With the growth of CO₂ utilization for enhanced oil recovery (EOR) and the expansion of carbon capture and sequestration projects, there is a greater need for reliable and safe CO₂ transportation infrastructure. Impurities present in the dense phase CO₂ stream can have a detrimental effect on the corrosion mechanism of the pipeline, leading to catastrophic failure and increased maintenance costs. The current research focused on understanding and quantifying the impact of impurities on the corrosion severity of CO₂ dense phase transmission pipelines. This paper shares a review of the impact of different impurities on the corrosion severity in dense phase CO₂ environment. The various mechanisms by which impurities can promote corrosion are discussed, including chemical and electrochemical reactions. Furthermore, this work will present future research in this area aimed at improving the understanding and impact of impurities in industrial applications.

A dense phase or supercritical CO₂ pipeline is a crucial state in the oil and gas sector, particularly when it comes to enhanced oil recovery (EOR) and carbon capture and storage (CCS)¹. The process of CCS involves three stages: capture from sources (e.g., cement factories and power plants), transportation process, and storage. Generally, these pipelines carry CO₂ from different industrial facilities to geological formations ^2–4. The process of EOR involves injecting large amounts of CO₂ into underground oil reservoirs. However, there are multiple key issues in the CO₂ transmission pipelines regarding the physical and chemical properties of CO₂³, composition of the CO₂ stream, which includes the presence of various impurities and maintaining the CO₂ properties at the required level throughout the pipeline network while avoiding exceeding safe limits ⁵. Figure 1 shows a schematic flowchart of the CO₂ gathering and sequestration process. The process starts using different technologies to capture the CO₂ gas produced by natural resources or energy-related and industrial sources, then removing the impurities in conditioning stage, followed by CO₂ compression to be transported via pipeline and finally injecting for EOR¹. The transportation of CO₂ from the source to the storage sites is carried out through long pipelines and due to their low environmental impact and safe operation, carbon steels have been considered as the ideal materials for pipeline construction.