Dew-point Measurements For Water In Compressed Carbon Dioxide
Christopher W. Meyer, Allan H. Harvey
When transporting CO2 for sequestration, it is important to know the water dew point in order to avoid condensation that can lead to corrosion. We have constructed a flow apparatus to measure the water content at saturation in a compressed gas. A saturator humidifies the flowing gas by equilibrating it with liquid water. Then, a gravimetric hygrometer measures the water mole fraction of the humid gas. We report dew-point data on six isotherms between 10 °C and 80 °C at pressures from 0.5 MPa to 5 MPa. Our uncertainties in water content at the dew point (expanded uncertainty with coverage factor k=2) are on average 0.3%, significantly smaller than in any previous work. The data have been analyzed to extract the interaction second virial coefficient; our values are consistent with the theoretical estimates of Wheatley and Harvey but have a much smaller uncertainty.