Browsing by Author "Orge, Beatriz"
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- Group contribution modeling of activity coefficients in associating solutions containing water, alcohols and carboxylic acidsPublication . Ferreira, Olga; Orge, Beatriz; Foco, Gloria; Bottini, Susana B.A modified UNIFAC group contribution model for the prediction of activity coefficients in associating solutions (A-UNIFAC) is applied to calculate phase equilibria in binary and ternary mixtures of associating and non-associating species, including alcohols, water, carboxylic acids, esters, alkanes, aromatic hydrocarbons and alkyl chlorides. Self- and cross-association in these mixtures is adequately described by the definition of a single hydrogen-bonding group. The new model is able to give good predictions of vapor-liquid equilibria, liquid-liquid equilibria and infinite dilution activity coefficients, using a single set of group-interaction parameters.
- Liquid–liquid equilibria of mixtures containing methyl acetate + methanol + hexane or heptanePublication . Casás, Lídia M.; Orge, Beatriz; Ferreira, OlgaThis paper reports the results of a new experimental study of liquid–liquid equilibria for the mixtures methyl acetate + methanol + hexane or heptane at atmospheric pressure and at (268.15, 278.15, 288.15, and 298.15)K. The equilibrium compositions were measured by gas chromatography from samples split isothermally into a glass-stirred device, and phase diagrams are reported at each temperature. The experimentally determined liquid-liquid equilibria were satisfactorily correlated by the NRTL and UNIQUAC equations. A comparative analysis was performed by application of UNIFAC group contribution method and its modifications to predict experimental liquid–liquid equilibria (LLE) behavior of these ternary mixtures. A poor prediction was observed from these contribution methods.