Experimental and Modeling Investigations of Some Thermophysical Properties of CO2 Rich Mixtures

Abstract

In CCS operations, the CO2 stream captured from industrial installations using oxycombustion process is not a pure CO2: it contains some associated compounds. This mixture of gases may have significantly different thermo-physical properties as compared to pure CO2. For a global account of these impacts and for a precise specification of maximal amounts of associated compounds that can be tolerated in CO2 flues, further investigations are strongly required. Obtaining accurate knowledge of the thermodynamic behaviour of CO2-associated gases mixtures is part of the studies that are necessary to develop optimized CCS processes. In the present study, the thermodynamic behaviour and transport properties of some CO2 rich mixtures have been investigated using different complementary approaches: experimental measurements, molecular simulation and equation of state modelling. We have first investigated some simple binary mixtures, and then focused on the study of the CO2 flue injected in the Rousse CO2 storage pilot conducted by TOTAL SA. In this pilot, CO2 is produced by oxycombustion from natural gas transformed into fuel gas at the Lacq plant, and transported in a pipeline 30 km away to the depleted gas reservoir of Rousse. This CO2 stream is a quaternary mixture composed of CO2, O2, N2 and Ar.