A new experimental system was designed to measure the solubility of CO2at pressures and temperatures (150bar, 323.15-423.15K) relevant to geologic CO2sequestration. At 150bar, new CO2solubility data in the aqueous phase were obtained at 323.15, 373.15, and 423.15K from 0 to 6molkg-1NaCl(aq) for the CO2-NaCl-H2O system. A γ-ϕ (activity coefficient-fugacity coefficient) type thermodynamic model is presented for the calculation of both the solubility of CO2in the aqueous phase and the solubility of H2O in the CO2-rich phase for the CO2-NaCl-H2O system. Validation of the model calculations against literature data and other models (MZLL2013, AD2010, SP2010, DS2006, and OLI) show that the proposed model is capable of predicting the solubility of CO2in the aqueous phase for the CO2-H2O and CO2-NaCl-H2O systems with a high degree of accuracy (AAD <3.9%) at temperatures from 273.15 to 573.15K and pressures up to 2000bar. A comparison of modeling results with experimental values revealed a pressure-bounded "transition zone" in which the CO2solubility decreases to a minimum then increases as the temperature increases. CO2solubility is not a monotonic function of temperature in the transition zone but outside of that transition zone, the CO2solubility is decrease or increase monotonically in response to increased temperature. A link of web-based CO2solubility computational tool can be provided by sending a message to Haining Zhao at firstname.lastname@example.org.
All Science Journal Classification (ASJC) codes
- Geochemistry and Petrology