7.3 Design considerations for CO2 pipelines

Pipeline engineering is a mature profession. However, for the specific field of CO2 transportation, there are a number of issues that need to be taken into account. With more projects completing their FEED studies, further insights are being created among the key design considerations of CO2 infrastructure – see for example the FEED study of the CO2 transport pipeline for the Jänschwalde project in Germany (Vattenfall 2012), the American Electric Power Mountaineer Project FEED (AEP 2012), and the FEED close-out studies created by the Scottish. Power CCS Consortium that focuses on CO2 pipelines (Scottish. Power CCS Consortium 2011). In addition, a series of interviews with CCS project engineers and CO2 pipeline operators has been undertaken by the Global CCS Institute to discuss the main design considerations for CO2 transportation infrastructure. For pipeline transportation system design the following data is generally required:

  1. pipeline route, profile, and depth of cover;
  2. maximum and minimum inlet, operating, and delivery temperatures/pressures;
  3. ground/environment temperature;
  4. pipe material/grade, diameter, wall thickness, and roughness;
  5. piping pressure loss through compression, pumping, and measurement stations;
  6. CO2 mixture properties (level of impurities) and density/pressure changes;
  7. pipeline flow and flow build-up;
  8. cost data of materials and labour; and
  9. applicable codes, standards, and regulations.

Items 6–9 are considered to be of special importance when designing CO2 pipelines (compared to standard practices around the transportation of hydrocarbons) and are discussed in more detail below.