MEASUREMENTS OF BINARY DIFFUSION-COEFFICIENTS OF C-16-C-24 UNSATURATED FATTY-ACID METHYL-ESTERS IN SUPERCRITICAL CARBON-DIOXIDE

Binary diffusion coefficients were measured for C16-C24 unsaturated fatty acid methyl esters in supercritical carbon dioxide (at 313 K and 16.0 MPa) and linoleic acid methyl ester in supercritical carbon dioxide (at 308-328 K and 14.0-33.6 MPa). We propose an empirical equation that correlates the diffusion coefficients in terms of Schmidt numbers, (Sc - Sc*)/Sc*, with molar volumes, (upsilon-2 - (upsilon-2)0)/upsilon-2)0, where Sc and Sc* are Schmidt numbers at the prescribed pressure and at atmospheric pressure, respectively, and where upsilon-2 and (upsilon-2)0 are molar volumes at the prescribed pressure and at which viscous flow ceases, respectively. Also, it was found that CO2 self-diffusion coefficient values recommended by Chen (1983) were well correlated by this equation.