Calculation of liquid-liquid equilibrium of aqueous two-phase systems using a chemical-theory-based excess Gibbs energy model

Brazilian Journal of Chemical Engineering

P. A. Pessôa Filho¹  R. S. Mohamed¹ 

[1] ,Universidade Estadual de Campinas Faculdade de Engenharia Química Campinas SP ,Brazil

关键词: Aqueous two-phase systems;    thermodynamic modeling;    Gibbs energy;    liquid-liquid equilibrium;   

DOI  :  10.1590/S0104-66322004000300011

来源: SciELO

【 摘 要 】

Mixtures containing compounds that undergo hydrogen bonding show large deviations from ideal behavior. These deviations can be accounted for through chemical theory, according to which the formation of a hydrogen bond can be treated as a chemical reaction. This chemical equilibrium needs to be taken into account when applying stability criteria and carrying out phase equilibrium calculations. In this work, we illustrate the application of the stability criteria to establish the conditions under which a liquid-phase split may occur and the subsequent calculation of liquid-liquid equilibrium using a chemical-theory-modified Flory-Huggins equation to describe the non ideality of aqueous two-phase systems composed of poly(ethylene glycol) and dextran. The model was found to be able to correlate ternary liquid-liquid diagrams reasonably well by simple adjustment of the polymer-polymer binary interaction parameter.

【 授权许可】

CC BY   
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