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  • 1 University of Yaounde I Department of Inorganic Chemistry, Faculty of Science P.O. Box 812 Yaounde Cameroon P.O. Box 812 Yaounde Cameroon
  • 2 École Nationale Supérieure des Industries Chimiques, 1 Laboratoire de Thermodynamique des Séparations rue Grandville BP 451 54001 Nancy Cédex- France rue Grandville BP 451 54001 Nancy Cédex- France
  • 3 University of Cincinnati Department of Materials Science and Engineering Cincinnati Ohio 45221-0012 USA Cincinnati Ohio 45221-0012 USA
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Abstract  

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.