Acta Chimica Sinica ›› 2008, Vol. 66 ›› Issue (15): 1815-1826. Previous Articles     Next Articles

Original Articles

高溶解性盐水体系热力学模型预测能力的比较研究I: 二元体系

尹 霞 李琴香 万艳鹏 李碧海 曾德文*


  1. (湖南大学化学化工学院 长沙 410082)

  • 投稿日期:2007-10-15 修回日期:2008-03-20 发布日期:2008-08-14
  • 通讯作者: 曾德文

Comparison of Thermodynamic Models in High-Solubility Salt+H2O Systems I: Binary Systems

YIN, Xia LI, Qin-Xiang WAN, Yan-Peng LI, Bi-Hai ZENG, De-Wen*   

  1. (College of Chemistry and Chemical Engineering of Hunan University, Changsha 410082)
  • Received:2007-10-15 Revised:2008-03-20 Published:2008-08-14
  • Contact: ZENG, De-Wen

Five widely used typical thermodynamic models were selected to describe and predict the thermodynamic properties of the six binary salt-water systems, LiCl-H2O, LiBr-H2O, CaCl2-H2O, Mg(NO3)2-H2O, MnCl2-H2O and Mn(NO3)2-H2O. The predicted results were compared with reliable experimental results, showing that the primitive Pitzer model has poor prediction ability. The extended Pitzer model, although can reproduce the thermodynamic properties of a binary system to a quite high salt concentration, shows weak extrapolation prediction ability. The Pitzer-Simonson-Clegg model can reproduce and predict thermodynamic properties of some binary systems with satisfactory results. However, when the salt concentration range used for the parameterization of the thermodynamic models is far less than the solubility limit, the Pitzer-Simonson-Clegg model can not give accurate property prediction of the saturated solution. S-MSA model can not give accurate thermodynamic property prediction of the saturated solution. Furthermore, the requirement of solution density for this model limits its application. The BET model, showing strong extrapolation ability in all six binary system, is worthwhile to be recommended for the application in theoretical design of phase change materials.

Key words: phase change material, thermodynamic model, water activity, solubility, vapor pressure