Solubility of solids in near-critical fluids .5. CHI3 in ethane and in carbon dioxide

The solubilities of CHI3(s) in supercritical C2H6 and CO2 have been determined spectrophotometrically close to the solvents' critical points at temperatures of 312.90 K and 327.00 K in C2H6, and 312.73 K and 326.95 K in CO2, over a range of fluid densities. Isothermal solubilities show the sharp change with pressure characteristic of near-critical behaviour. Solubilities are almost twice as large in CO2 than in C2H6 over the whole reduced density range. Enhancement factors E were calculated and compared to those of CHI3(s) in C2H4, CHF3, and SF6. The differences observed in E correlate well with the charge distribution, and hence multi-pole moments, of the solvent molecules. (C) 1997 Academic Press Limited.