Significant differences were not observed at high ionic strength due to the presence of large concentrations of competing cations (Na, Ca, Mg). EDTA increased dissolution of dolomite at low ionic strength due to its strong complexation affinity for Ca/Mg with slightly greater removal of Ca than Mg. These linear correlation equations predicted CO 2 solubility within 1% of the Bravo Dome brine and within 10% of two mixed moreВ В» brines from literature (a 10 wt % NaCl + KCl + CaCl 2 brine and a natural Na +, Ca 2+, Cl - type brine with minor amounts of Mg 2+, K +, Sr 2+ and Br -). Strong correlations were also identified between CO 2 solubility and hydration enthalpy and hydration entropy. Dissolved CO 2 was strongly correlated (R 2 = 0.96) to electrostricted water concentration. A new equation was developed to use ion hydration number to calculate the concentration of electrostricted water molecules in solution. Increasing ionic strength decreased CO 2 solubility for all solutions when the salt type remained unchanged, but ionic strength was a poor predictor of CO 2 solubility in solutions with different salts.

Here in this study, CO 2 solubility was experimentally determined in water, NaCl, CaCl 2, Na 2SO 4, and NaHCO 3 solutions and a mixed brine similar to the Bravo Dome natural CO 2 reservoir ionic strengths ranged up to 3.4 molal, temperatures to 140 вЊ, and CO 2 pressures to 35.5 MPa. Ions in solution partially control the amount of CO 2 that dissolves, but the mechanisms of the ion's influence are not clearly understood and thus CO 2 solubility is difficult to predict. Dissolution of CO 2 into deep subsurface brines for carbon sequestration is regarded as one of the few viable means of reducing the amount of CO 2 entering the atmosphere.

Solubility of co2 in water winprop