Prediction of supercritical CO2 solubility using the Krichevsky-Ilinskaya equation with (upsilon)over-bar(2)(infinity) as an adjustable parameter

A predictive model based on the Krichevsky-Ilinskaya equation (KIE) combine d with Peng Robinson EOS and the modified Huron-Vidal mixing rules has been proposed to estimate hydrocarbon solubility in both the vapour and liquid phases. For solubility in the liquid phase, the proposed model estimates th e partial molar volume from an equation of state with Huron-Vidal mixing ru les whereby a modified UNIFAC model is used to predict the asymmetric activ ity coefficient. The hydrocarbon data considered for modeling were non-pola r liquid hydrocarbons such as n-alkanes and aromatic benzene compounds. For the hydrocarbons studied, the proposed model satisfactorily predicted the supercritical carbon dioxide solubility in the vapour phase. It was compara ble to that correlated using equations of state with fitted interaction par ameter applied to both phases. However, the liquid phase were less satisfac torily predicted with an AAD ranging from 5 to 24%. Partial molar volume at infinite dilution was found to be a critical input parameter as changing t his parameter improved the error deviation between 4.1 and 10%. (C) 2001 El sevier Science B.V. All rights reserved.