화학공학소재연구정보센터
Chemical Engineering & Technology, Vol.32, No.9, 1384-1391, 2009
Multicomponent Mass Transfer Model for Supercritical Extraction: Application to Isopropyl Alcohol Production
A multicomponent mass transfer model based on the generalized Maxwell-Stefan equations (GMS) for an extraction process with supercritical fluids is presented. The solution is obtained from the differential film model equations rather than from an explicit expression for the fluxes. The approach presented here also provides concentration profiles along the diffusion path length, which allow rigorous consideration of the dependence of mass transfer coefficients and thermodynamic factors on concentration, if desired. The volume translated Peng-Robinson equation of state is used along with a g(E) mixing rule (g(E) - molar excess Gibbs free energy) in order to account for strongly nonideal thermodynamics that necessarily arise in unstable liquid mixtures. The results show strong diffusional coupling effects for the system under consideration, propene (1)-isopropyl alcohol (2)-water (3). Finally, we demonstrate how diffusional coupling may provide options for process intensification.