Potential economies of scale in CO2 transport through use of a trunk pipeline

A number of existing models for the transport of CO2 in carbon capture and storage assume the CO2 will be carried through isolated pipelines that connect each source to the nearest storage site. However storage costs will vary geographically, and it may be more economical to transport the CO2 farther away to a lower cost storage site if the pipelines can be linked to the site via a primary trunkline. We evaluate this alternative by developing an engineering-economic model that computes the levelized cost of transporting captured CO2 through pipes of different diameters and over varying distances. The model also computes the additional energy use and resulting CO2 emissions involved in the transport and is used to arrive at a generalized correlation for estimating the cost of CO2 transport ($/tonne/km) for different mass flow rates. Model results indicate that the cost for transporting CO2 could be significantly reduced using a large-diameter trunkline networked to pipelines from individual CO2 sources. This suggests that the design of CO2 transport systems could be an important influence on the selection of storage sites, particularly where there is a tradeoff between nearby but high-cost sites and distant, low-cost sites.