Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (11): 2567-2573.doi: 10.3866/PKU.WHXB201208211

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Equilibrium Solubility Modeling of CO2 in Na2Cr2O7 Solutions

ZHOU En-Nian1,2,3, YU Zhi-Hui1,2, QU Jing-Kui1,2, Qi Tao1,2, Han Xiao-Ying1,2,3, ZHANG Guo-Qing4   

  1. 1 National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China;
    2 Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China;
    3 Graduate University of Chinese Academy of Sciences, Beijing 100049, P. R. China;
    4 Sichuan AnxianYinHe Construction & Chemical Group Co. Ltd., Anxian622656, SichuanProvince, P. R. China
  • Received:2012-04-11 Revised:2012-08-20 Published:2012-10-17
  • Supported by:

    The project was supported by the National Outstanding Youth Scientists Foundation of China (51125018), National Natural Science Foundation of China (21006119), and High-Tech Research and Development Program of China (863) (2009AA035000, 2011AA060700).

Abstract:

The solubility of CO2 in aqueous Na2Cr2O7 solutions of different concentrations (0, 0.361, 0.650, and 0.901 mol·kg-1) was measured in a stirred vapor-liquid high-pressure equilibrium cell using the static method at temperatures and pressures in the ranges of 313.2 to 333.2 K and 0.1 to 1.9 MPa, respectively. The results indicated that the phenomenon of CO2 dissolved in aqueous Na2Cr2O7 could be interpreted according to a “salting-out effect”. Furthermore, our solubility data for CO2 in aqueous Na2Cr2O7 was in agreement with Henry's law, and the Henry constant appeared to be a function of temperature, pressure, and the concentration of Na2Cr2O7. Two thermodynamic models were applied to correlate the experimental data, including the modified Setschenow and Peng-Robinson-Pitzer equations, and the averaged relative deviations were found to be 4.24% and 3.32%, respectively.

Key words: CO2 solubility, Na2Cr2O7 solution, Thermodynamic model, Setschenow equation, Peng-Robinson-Pitzer equation, Henry constant