THE SYSTEM CARBON DIOXIDE-WATER AND THE KRICHEVSKY-KASARNOVSKY EQUATION

The system carbon dioxide-water has been studied often. However, there is some controversy about the thermodynamic description of the behavior of this system. Some researchers indicate that the system CO2-H2O is accurately modeled by the Krichevsky-Kasarnovsky equation. Others say that it is not. This paper investigates this controversy. As a part of this study an overview of Henry's law and a discussion of the limitations of the Krichevsky-Kasarnovsky equation are preserved. From the analysis presented in this paper, it must be concluded that for temperatures lower than about 100-degrees-C, the system CO2-H2O is accurately modeled by the Krichevsky-Kasarnovsky equation. On the other hand, at 100-degrees-C and higher, it is not. In order to arrive at this conclusion, four models of the solubility were investigated. Using these models, it is clearly demonstrated that the activity coefficients are not negligible and hence the Krichevsky-Kasarnovsky equation is not applicable at high temperatures.