VAN DER WAALS MIXING RULES FOR THE REDLICH-KWONG EQUATION OF STATE APPLICATION FOR SUPERCRITICAL SOLUBILITY MODELING
Abstract: A
solid-supercritical fluid system is highly asymmetric in terms of the size and
energy differences of the components. The key point in extending a cubic
equation of state to such system is on the choice of proper mixing rules. New
mixing rules for the Redlich-Kwong equation of state are developed. The developement
is based on the statistical-mechanical theory of the van der Waals mixing
rules. The Redlich Kwong equation of state with the proposed mixing rules along
with the original ones is used to predict solubilities of solids in
supercritical fluid. The prediction is done with k ij equal zero, as well as
with optimized k ij . The results show superiority of the proposed mixing rules
over the original ones. For most of the systems considered, the proposed mixing
rules with the k ij equal zero are closer to the experimental data than the
original ones do. For 28 systems with 521 data points taken from various
sources, the original and the proposed mixing rules give the overall AAD of
13.4%, while the original mixing rules give 45.9%.
Author: Ratnawati
Journal Code: jpkimiagg060010
