Measurement and modeling of extraction of chlorinated hydrocarbons from water with supercritical carbon dioxide

• Published in: The Journal of supercritical fluids Vol. 7; no. 3; pp. 201 - 209
• Main Authors: Sengupta, Satyajit, Gupta, Sumnesh, Dooley, Kerry M., Knopf, F.Carl
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.1994
• Subjects: 2-dichloroethane; 2-tetrachloroethane; 2-trichloroethane; hardsphere equation of state; supercritical-fluid extraction; water; 1; 2; supercritical-fluid extraction; hardsphere equation of state; 2-tetrachloroethane; 2-trichloroethane; 2-dichloroethane; water
• ISSN: 0896-8446; 1872-8162
• DOI: 10.1016/0896-8446(94)90027-2

Supercritical-fluid extraction (SCFE) for the removal of toxic chlorinated organics from water has been studied using a continuous-flow view-cell system. The solubilities of pure 1,2-dichloroethane, 1,1,2-trichloroethane, and 1,1,2,2,-tetrachloroethane in subcritical and supercritical C0 2 have been obtained at 313.2 and 323.2 K and over a pressure range of 6.2–8.27 MPa. All the compounds studied were completely miscible in C02 at the temperatures studied and at pressure > 9 MPa. Equilibrium data for the removal of these compounds from water using supercritical C02 were obtained at two temperatures (313.2 and 323.2 K) and over a pressure range 9.65-16.54 MPa. The distribution coefficients (K-values) of these three compounds between supercritical C0 2 and an aqueous phases were in the range of 20 to 200. These high distribution coefficients verify that extraction with supercritical C0 2 is an effective method to remove chlorinated hydrocarbons from water. The results have been modeled using a hardsphere, perturbation-theory-based Camahan-Starling-DeSantis-Redlich-Kwong equation of state and simple mixture rules.