Measurement and Correlation of Solubility Data for CO2 in NaHCO3 Aqueous Solution

To investigate the influence of NaHCO3 on the CO2, absorption in aqueous solution, the solubility of CO2 in NaHCO3 aqueous solutions [(0, 0.05, 0.1, 0.5, and 1.0) mol.kg(-1)] was measured in the temperature range from (313 to 333) K with pressure range from (0.3 to 2.0) MPa by employing a new designed batch apparatus. The results showed that the solubility data for CO2 in NaHCO3 aqueous solutions agreed well with Henry's law, and the Henry constant appeared to be a function of temperature and the concentration of NaHCO3. Two thermodynamic models were proposed for correlating the experimental data, that is, the modified Setschenow and Peng-Robinson (PR)-Duan equations. It was proved that the models fitted well in with the experimental data, and the average relative deviations were (4.06 and 3.90) %, respectively. In addition, the Henry constant in pure water can be basically predicted at a certain temperature range. The influence of NaHCO3 on the solubility of CO2 is interpreted by "salting-out effect" which is usual for the salt-containing solutions.