AN IMPROVED MODEL CALCULATING CO2 SOLUBILITY IN PURE WATER AND AQUEOUS NACL SOLUTIONS FROM 273 TO 533 K AND FROM 0 TO 2000 BAR

Abstract

A thermodynamic model for the solubility of carbon dioxide (CO2) in pure water and in aqueous NaCl solutions for temperatures from 273 to 533 K, for pressures from 0 to 2000 bar, and for ionic strength from 0 to 4.3 m is presented. The model is based on a specific particle interaction theory for the liquid phase and a highly accurate equation of state for the vapor phase. With this specific interaction approach, this model is able to predict CO2 solubility in other systems, such as CO2-H2O-CaCl2 and CO2-seawater, without fitting experimental data from these systems. Comparison of the model predictions with experimental data indicates that the model is within or close to experimental uncertainty, which is about 7% in CO2 solubility.