Carbon dioxide solubility in aqueous solutions of NaCl: Measurements and modeling with electrolyte equations of state

A new high pressure cell was developed to measure the high pressure phase behavior of gas + aqueous salt solutions and validated through the measurement, and comparison against literature data, of two systems, the H2O + CO2 and H2O + CO2 + NaCl, at temperatures up to 363 K and pressures up to 13 MPa. As previously reported by others, a salting out effect on the carbon dioxide solubility in water by NaCl is observed, decreasing its solubility as the salt concentration increases. Electrolyte versions of the cubic-plus-association and the RKSA-Infochem equations of state were used to estimate the H2O + CO2 and H2O + CO2 + NaCl phase behavior, with both EoS providing a good representation of the experimental data.