Carbon dioxide solubility in aqueous solutions of sodium chloride at geological conditions: Experimental results at 323.15, 373.15, and 423.15 K and 150 bar and modeling up to 573.15 K and 2000 bar. (15th January 2015)

• Record Type: Journal Article
• Authors: Zhao, Haining; Fedkin, Mark V.; Dilmore, Robert M.; Lvov, Serguei N.
• Is Part Of: Geochimica et cosmochimica acta. Volume 149(2015:Jan. 15)
• Page Start: 165
• Page End: 189
• Publication Date: 2015-01-15
• Subjects: Geochemistry -- Periodicals; Meteorites -- Periodicals; Géochimie -- Périodiques; Météorites -- Périodiques; Geochemie; Astrochemie; Electronic journals; 551.905
• DOI: 10.1016/j.gca.2014.11.004
• Languages: English
• ISSNs: 0016-7037

Abstract

Abstract: A new experimental system was designed to measure the solubility of CO2 at pressures and temperatures (150 bar, 323.15–423.15 K) relevant to geologic CO2 sequestration. At 150 bar, new CO2 solubility data in the aqueous phase were obtained at 323.15, 373.15, and 423.15 K from 0 to 6 mol kg −1 NaCl(aq) for the CO2 –NaCl–H2 O system. A γ − φ (activity coefficient − fugacity coefficient) type thermodynamic model is presented for the calculation of both the solubility of CO2 in the aqueous phase and the solubility of H2 O in the CO2 -rich phase for the CO2 –NaCl–H2 O 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 CO2 in the aqueous phase for the CO2 –H2 O and CO2 –NaCl–H2 O systems with a high degree of accuracy (AAD <3.9%) at temperatures from 273.15 to 573.15 K and pressures up to 2000 bar. A comparison of modeling results with experimental values revealed a pressure-bounded "transition zone" in which the CO2 solubility decreases to a minimum then increases as the temperature increases. CO2 solubility is not a monotonic function of temperature in the transition zone but outside of that transition zone, the CO2 solubility is decrease or increase monotonically in response to increased temperature. A link of web-based CO2 solubility computational tool can be provided by sending a message to Haining Zhao [e-mail] .