Vapor-Liquid Equilibrium Modeling of Associated Systems using a Linear Solvatochromic Approach


Abstract: A modified linear solvation energy relation (LSER) has been proposed to estimate the properties and vapor-liquid equilibria (VLE) of associated systems. The model combines the solvatochromic parameters of solvation energy of solution with the thermodynamic factors derived from a group contribution method, i.e., the UNIFAC-original activity coefficient model. The reliability of the model has been analyzed against the VLE data of three alcohol-containing binary systems given in the literature, namely, methyl propanoate + 1-butanol (I), 1-butanol + 2-methyl-1-butanol (II) and cumene + benzyl alcohol (III), where system III exhibits extremely nonideal behaviors. The proposed log-basis equation (METLER) is expected to be an improvement in data fit clarifying the simultaneous impact of hydrogen bonding, solubility and thermodynamic factors of components on vapor-liquid equilibria. The model matches the experimental data reasonably over the entire composition range, yielding a mean relative error of 9.6 % for all the systems considered.

Keywords: Vapor-liquid equilibria; Associated system; Modified LSER model

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