Corrosion of pipelines used for CO₂ transport in CCS: Is it a real problem?

The transport of carbon dioxide (CO₂) from capture to storage is a vital aspect of any CO₂ capture and storage (CCS) process - and it is essential that it is effective, safe and economical. Transport by pipelines is one of the preferred options and thus, for safe operations, such pipelines should not be subject to internal corrosion. Present CO₂ pipelines used for enhanced oil recovery (EOR) have suffered only minimal corrosion over the last 20 years, however, such pipelines operate under stringent regulations with regard to water and contaminant levels in the CO₂ stream. This paper reviews the literature on the range of potential compositions in CCS CO₂ streams and the likely phases that will be in such streams, the relevant history of CO₂ pipelines, and laboratory studies of CO₂ corrosion, with a view to understanding the corrosion threat to pipelines where CO₂ is the primary fluid.