Authors:P.M. Ghogomu, Elise Provost, M. Bouroukba, M. Dirand, and M. Hoch
The solubility of two n-alkanes in commercial organic liquids, such as diesel fuel and jet fuel represent a problem to industry,
because they precipitate in an unpredictable fashion. First we calculated the metastable enthalpy and entropy of fusion of
the low temperature forms of the n-alkanes. We analyzed the solubility of alkanes n-C22H46, n-C23H48, n-C24H50 and n-C28H58
in ethylbenzene, m-xylene, n-heptane and gas oil. All systems seem to be close ideal, possibly with a slight positive deviation.
We analyzed the solubility at constant temperature of the ternary system solvent C22H46-C24H50, C23H48-C24H50, C13H28-C16H34,
C20H42-C22H46, C20H42-C24H50 and C20H42-C28H58, and looked at cloud points in various ternary systems. When the difference
in the number of carbon atoms in the two alkanes is small, four or less, a metastable solid solution precipitates from the
solvent. If the difference in the number of carbon atoms is six or more, the ‘equilibrium’ phases, or at least phases with
low solubility precipitate.