Solvent effects on the supercritical gas extraction of coal The role of mixed solvents

Supercritical gas extraction of the same coal was carried out using various commercially available mixed hydrocarbon solvents. A correlation between the conversion and the calculated critical temperatures of the solvent mixtures was found and this correlation was in good agreement with that previously reported for single solvents. A good empirical correlation was found between coversion and the boiling point multiplied by the density (at 20°C) for sixteen pure solvents and nine solvent mixtures.