Experimental Study on the Solubility of Carbon Dioxide in Systems Containing Ethane-1,2-diol + Water + Salt (Sodium Chloride or Calcium Carbonate)

The influence of salt concentration on the solubility of gases in aqueous solutions is of interest in many processes of the oil and gas processing industry. Here, we show the influence of the presence of different concentrations of sodium chloride or calcium carbonate on the solubility of carbon dioxide (CO2) in mixtures of monoethylene glycol (MEG) and water by using a gas expansion method. From the experimental data, the solubility and Henry’s constant were measured as a function of pressure (from 0.1 to 0.5 MPa) and temperature (from 298 to 333 K), in pure water, pure MEG and in its equimolar mixture, using concentrations of salt up to saturation for all the studied solvents. The experimental data indicate that the increase in temperature decreases the CO2 solubility in the liquid mixture, whereas pressure shows a positive linear influence on the dissolution of gas. The addition of salt reduced the CO2 solubility in all mixtures due to the salting-out effect.