Carbon Dioxide Pipelines

Carbon dioxide pipelines are similar to natural gas pipelines in many ways. Where they are similar, the pipeline industry has considerable experience and can rely on existing standards and regulations. But where they are different, the pipeline industry has less experience, and designers and operators must rely more heavily on basic engineering principles. This chapter focuses on the differences and the steps required to deal with the differences. In all cases, the differences are driven by the differences in properties between CO2 and natural gas. The differences include operating pressure ranges, running ductile fracture control, pressure fluctuations and fatigue, unique corrosion challenges, interaction with non-metallic components, blowdown stack design, and emergency response plans in the unlikely event of a line break. The intent is to provide the reader with a basic understanding of the design, operation, and maintenance of carbon dioxide pipelines where they are different from natural gas pipelines and where existing regulations, codes, and standards do not fully cover the special features of carbon dioxide pipelines. This basic understanding needs to be combined with sound engineering judgement to develop safe and reliable designs and procedures. In some cases where there is no consensus amongst experts in the field, the authors express their own opinions about how to proceed, but those opinions could change as more experience with carbon dioxide pipelines is obtained.