Carbon Dioxide Pipeline Transportation & Network

Effective transportation of carbon dioxide has been identified as a significant challenge for a large-scale deployment of the Carbon Capture and Sequestration (CCS). Pipelines are considered the most cost-effective and safest option to transport large amounts of CO2 over long distances. The development of integrated pipeline networks may enable a faster large-scale development of the CCS exploiting the economies of scale. The aim of this study was to evaluate pressure and temperature profiles in carbon dioxide pipelines and identify key parameters affecting transport. A one-dimensional, steady state, non-isothermal, multi-component model for natural gas network was adapted for carbon dioxide. The model is composed of two loop cycles, the fluid-dynamic (flow equation) and the energy problem (energy equation). The physical properties of pure CO2 have been calculated for dense (T<304,25 K and p>73 bar) and supercritical phase (T>304,25 K and p>73 bar). The pipeline outlet pressure and temperature were calculated for an Australian network connecting single sources to single storage sites. The outlet temperature was found to reach the soil value for onshore pipes and sea water value for offshore pipes in almost all cases apart from those which are very short (less than 100 km). The outlet pressure was showed to be strictly related to the ambient and inlet temperature, flow-rate, length and diameter of each pipeline. The pressure drop was showed to increase as the inlet temperature increases due to higher level of turbulence during the transport. The temperature profile along the pipeline for the Latrobe Valley to Gippsland was also assessed. It was found that the pipeline inlet temperature affects the profile due to the heat transfer between the trunk and the environment. The pressure profile along the pipeline was found to be linear and was higher in the onshore trunk where temperature differences between the fluid and the environment are high. An assessment of pipeline networks was also undertaken providing a booster station at the Junction (Latrobe Valley and South New South Wales to the Gippsland Basin; South-Eastern Queensland). The results show that the pumping duty (kW) is approximately 37% higher when booster stations are not used. An analysis to understand the effect on the inlet pressure with variable flowrates was carried out using two sources from the South-Eastern Queensland Hub Network (Tarong North and Millmerran). The inlet pressure for Tarong North was shown to be usually higher than for Millmerran due to the longer pipeline length and smaller diameter.