Phase behavior of binary mixtures of water,carbon dioxide and decane predicted with a lattice-gas model

The Kleintjens—Koningsveld lattice-gas model is used to predict the phase behavior of pure CO₂, water and decane, and of binary mixtures of CO₂ with water and decane. The model, with parameters fitted to experimental data, predicts very accurate vapor pressures and liquid—vapor coexistence densities for the pure fluids. For the binary mixtures, the model correctly predicts the qualitative patterns of phase behavior using two temperature-dependent mixture parameters fitted to simple polynomials over a small range of temperature. For quantitative predictions over wide temperature ranges, however, the temperature dependence of the mixture parameters must be fitted carefully over the same ranges of temperatures. The performance of the Kleintjens—Koningsveld model is compared to that of the Peng—Robinson model.