Transport of CO2: Presentation of New Thermophysical Property Measurements and Phase Diagrams

CO2 transportation is an integral part of the CCS chain. After capture, CO2 needs to be transported to locations whereby it is stored or alternatively used in various processes. CO2 can be transported via ship or pipeline. In both cases, the required compression pressure can be 100–300 bar, depending on the distance and intended disposal or use of CO2. The CO2 rich stream can contain a lot of impurities which can modify the phase diagram and change the thermophysical properties of the stream in comparison with the ones of pure CO2. Indeed, along with carbon dioxide, a great number of compounds such as water, O2, N2, Ar, SOx, NOx, H2 and CO can be present at different levels of concentration. During transportation by pipeline, if the pipe suffers a major fracture due to an accidental release or a failure, CO2 can rapidly expand and cool: vapour cloud followed by solid formation of CO2 may appear. The impurities could change the characteristics of the leak and change the conditions and compositions of CO2 clouds and solid. The presence of water can also be a source of gas hydrate formation, ice or corrosion. In this communication we will present new experimental data and their modelling concerning the phase diagrams of systems rich in CO2 and their thermophysical properties. Comparisons of the results obtained using different equations of state are also reported.