Task 2.2: CO2 mixture properties – CO2Mix
Overall objective: To acquire accurate data for thermophysical properties of CO2-rich mixtures at conditions relevant for CCS.
Contribution to one or more of the overall goals/objectives of BIGCCS
CO2 captured in a CCS process will never be absolutely pure. Even small quantities of impurities can significantly affect the thermophysical properties of CO2. Therefore, to be able to design capture processes, transport systems and injection schemes, we need high-quality data for the various impurities in the relevant range of concentrations, pressure and temperature. Presently, there are several white areas on the map, and we aim to fill some of them.
Task 2.2 achievements thus far
- Accurate experimental setups have been constructed to measure the following properties of CO2-rich mixtures
- Vapour-liquid equilibrium
- Density of gas and super-critical phases
- Speed-of-sound of gas and super-critical phases
- All setups are currently conducting measurement campaigns
- Two PhD candidates are being educated
- Three conference articles have been published, and several presentations at scientific conferences held
Phase Equilibrium Cell for CO2 Mixtures (SINTEF ER)
The phase equilibrium setup is using an analytical technique and allows for very precise control of pressure and temperature. The film clip above shows the magic moment of phase separation as the pressure of a CO2-N2 mixture is reduced from supercritical to subcritical.
Density and Speed of Sound Measurements (Ruhr-Universität Bochum)
The speed of sound meter measures the echo time of short acoustic pulses. The density is found by measuring the buoyancy of a single sinker using a magnetic coupling technique developed at RUB. The two apparatuses are connected by the same manifold such that the two properties easily can be measured for the same mixtures.