Thermodynamic Modeling of Carbon Dioxide Gas Solubility in Electrolyte Solution at High Pressure

The gas injection such as CO2 injection is widely used for enhanced oil recovery (EOR). Moreover,in underground besieging of CO2 to decrease greenhouse gases or in the injection of CO2 to theunderground brine, we face the solubility of this gas in the aqueous salt solutions, so studying thesolubility of CO2 in aqueous salt solutions in the wide range of concentrations, pressures, temperaturesand different electrolytes is very important.In this article, the electrolyte cubic square-well (ECSW) equation of state of Haghtalab and Mazloumi,Fluid Phase equilibrium, is used for investigating the solubility of CO2 in aqueous binary solutionsof the different salts such as NaCl, KCl, Na2SO4, MgSO4, MgCl2 and CaCl2. The results demonstratethat the ECSW equation is able to obtain the solubility data of ternary aqueous salt electrolyte systems especially NaCl in pressures up to 400 bar with very good accuracy.