Multicomponent diffusivities in supercritical and liquid ternary systems

Abstract

A database of tracer multicomponent diffusivities (Dm,i) in sub/supercritical and liquid ternary systems was compiled, comprised of 1530 points and 153 systems. Two Dm,i hybrid free-volume equations were developed, the predictive Multicomponent Tracer Liu-Silva-Macedo (Multi-TLSM) and the 1-parameter Multi-TLSMAD correlation. Furthermore, six literature models were tested: the Wilke-Chang equation, the 2-parameters Dymond–Hildebrand–Batschinski (DHB) correlation, and four 2-parameters correlations of Magalhães et al. Their performance was assessed calculating the average absolute relative deviation (AARD) and average relative deviation (ARD), leading to the following conclusions: (i) the Multi-TLSM model is recommended for Dm,i estimation, (AARD = 10.38 % and ARD = −0.20 %), even for many polar and hydrogen-bonding systems; (ii) the Wilke-Chang equation (AARD = 12.46 % and ARD = 4.37 %) is also recommended because of its simplicity; (iii) The Multi-TLSMAD (AARD = 4.32 % and ARD = −0.29 %) and three correlations of Magalhães et al. (AARD = 2.94–3.03 % and ARD = 0.14–0.40 %) can be chosen if their parameters are known or if some data points are available for their preliminary estimation.