A survey of reported compositions along the saturation curve (sat.) and compositions of coexisting phases in equilibrium (eq.) for the system methanol-2,2,4-trimethylpentane-water is given in Table 15.

Saturation curve The system methanol-2,2,4-trimethylpentane-water forms a large miscibility gap of type 2 covering the majority of the concentration triangle. Two binary systems 2,2,4-trimethylpentane-water and 2,2,4-trimethylpentane-methanol are partially miscible. The data for these systems were compiled and critically evaluated in previously published SDS volumes, Refs. 3 and 4. The recommended values of mutual solubility of 2,2,4-trimethylpentane-water system, Ref. 3 and methanol-2,2,4-trimethylpentane system, Ref. 4 at 293 K are: x'₂=0.9995, x"₂=3·10^-7 and x'₂=0.890, x"₂=0.224, respectively. (The mutual solubilities of methanol-2,2,4-trimethylpentane system, reported in both papers^1,2 were also considered during evaluation of this binary system in Ref. 4) Compositions along the saturation curve at 291.2 K and 293.2 K by Buchowski and Teperek¹ were obtained by the titration method. They are consistent within each data set, as well as with one another. The paper of Budantseva et al.² contains information about phases in equilibrium at 293.2 K only. The hydrocarbon-poor phase shows smaller miscibility while the hydrocarbon-rich phase shows larger solubility² than data of Ref. 1 at the same temperature and than the “best” binary solubilities by Ref. 4. The data of Buchowski and Teperek,¹ were well documented (description of the method, description of pure substances properties and purity) while data of Ref. 2 were reported without any auxiliary information. Therefore data of Ref. 1 appear reliable, but all are considered as tentative.

Phases in equilibrium Compositions of coexisting phases in equilibrium for the ternary system methanol-2,2,4-trimethylpentane-water were reported in both references. Tie lines cover nearly the whole range of miscibility gap. In the paper of Buchowski and Teperek,¹ the reported hydrocarbon-rich phase did not contain detectable water (water concentration in the hydrocarbon-rich phase was neglected because solubility of water in 2,2,4-trimethylpentane is lower than 0.0005 mass fraction, Ref. 1). The data from Refs. 1 and 2 show slightly different directions of the tie lines. All of them are considered as tentative. To present system behavior, experimental data along the saturation curve and experimental compositions of coexisting phases in equilibrium at 293.2 K, are presented in Fig. 8 .