Effect of impurities on thermophysical properties and phase behaviour of a CCS stream

Abstract : CO 2 obtained by capture process is not 100% pure and may contain impurities such as O 2 , Ar, N 2 and water. The presence of such impurities in CO 2 stream can lead to challenging flow assurance and processing issues. The aim of this communication is to present experimental results on the phase behaviour and thermo-physical properties of carbon dioxide in the presence of O 2 , Ar, N 2 and water. The effect of these impurities on density and viscosity were experimentally and theoretically investigated over the range of temperature from 243.15 K to 423.15 K up to 150 MPa. A corresponding-state viscosity model was developed to predict the viscosity of the stream and a volume corrected equation of state approach was used to calculate densities. Saturation pressures and the hydrate stability (in water saturated and under-saturated conditions) of the CCS stream were also experimentally determined and modelled. It is demonstrated that the thermodynamic models and approaches were able to satisfactorily describe the thermophysical properties and phase behaviour of this CO 2-rich stream.