Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Solubility of cholesterol in supercritical ethane and binary gas mixtures containing ethane

Journal Article · · Industrial and Engineering Chemistry Research; (United States)
DOI:https://doi.org/10.1021/ie00023a055· OSTI ID:5641052

The solubility of cholesterol in supercritical ethane at 313.1, 323.1, and 333.1 K and 70--190 bar is presented as well as the solubility in ethane with 3.5 and 14 mol% propane and ethane with 3.5, 14, 50, and 96.5 mol% carbon dioxide at temperatures from 308.1 to 338.1 K and 85--220 bar. The results are compared with previous measurements in pure carbon dioxide and are discussed in terms of the effect of mixture density and properties of the solute. Cholesterol appears to behave as a predominantly hydrocarbon molecule despite the presence of an OH group and a dipole moment of 1.9 D. The cosolvent effects observed with propane and with CO[sub 2] can be explained by the density behavior of the solvent mixtures. The data are correlated with the Peng-Robinson and Patel-Teja equations of state. It is shown that estimated critical properties for cholesterol are unsatisfactory for phase equilibrium calculations, and a modified Peng-Robinson equation is introduced in which the solute parameters a[sub 2] and b[sub 2] are made adjustable. The resulting equation of state has three adjustable parameters for an entire binary solid-supercritical fluid data set instead of one parameter per isotherm. With the modified Peng-Robinson equation, the solubility of cholesterol in the ethane-CO[sub 2] mixtures was predicted with an average absolute relative deviation of 21% using only parameters from the binary systems.

OSTI ID:
5641052
Journal Information:
Industrial and Engineering Chemistry Research; (United States), Journal Name: Industrial and Engineering Chemistry Research; (United States) Vol. 32:11; ISSN IECRED; ISSN 0888-5885
Country of Publication:
United States
Language:
English