Publicação
Phase equilibria of d-glucose and sucrose in mixed solvents mixtures: comparison of UNIQUAC-based models
| Resumo: | Solid-liquid equilibrium measurements of ternary sucrose-mixed solvent mixtures at 25, 40, and 60 °C are carried out, using a simple and accurate analytical method. A search for a reliable activity coefficient model for sugar liquid mixtures is performed: three UNIQUAC based models are investigated - modified UNIQUAC, entropic free-volume and original Flory-Huggins. New UNIQUAC interaction parameters are estimated based on the aqueous and non-aqueous experimental data presented in this work together with those available in the literature. The solubility calculations were carried out using an equation based on fusion enthalpy data for the sugars. Although the UNIQUAC-based models investigated give in general a quite satisfactory representation of different thermodynamic properties of aqueous solutions containing D-glucose, D-fructose, and/or sucrose, it is shown that only the modified UNIQUAC model is able to accurately describe the ternary solubility data of D-glucose and sucrose in mixed solvent mixtures. |
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| Autores principais: | Peres, António M. |
| Outros Autores: | Macedo, Eugénia A. |
| Assunto: | Sugar solution equilibria Solid-liquid equilibria UNIQUAC Ternary solubility |
| Ano: | 1997 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Instituto Politécnico de Bragança |
| Idioma: | inglês |
| Origem: | Biblioteca Digital do IPB |
| Resumo: | Solid-liquid equilibrium measurements of ternary sucrose-mixed solvent mixtures at 25, 40, and 60 °C are carried out, using a simple and accurate analytical method. A search for a reliable activity coefficient model for sugar liquid mixtures is performed: three UNIQUAC based models are investigated - modified UNIQUAC, entropic free-volume and original Flory-Huggins. New UNIQUAC interaction parameters are estimated based on the aqueous and non-aqueous experimental data presented in this work together with those available in the literature. The solubility calculations were carried out using an equation based on fusion enthalpy data for the sugars. Although the UNIQUAC-based models investigated give in general a quite satisfactory representation of different thermodynamic properties of aqueous solutions containing D-glucose, D-fructose, and/or sucrose, it is shown that only the modified UNIQUAC model is able to accurately describe the ternary solubility data of D-glucose and sucrose in mixed solvent mixtures. |
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