Nonrandom Factor Model for the Excess Gibbs Free Energy of Sugar Solutions

One of the popular methods for the representation of the thermodynamic properties is the application of local composition concept for modeling the solutions systems. Cruz and Renon, Chen and Evans, and Haghtalab and Vera applied the local composition ex pression of NRTL for prediction of binary electrolyte systems.The NRTL-NRF model of Haghtalab and Vera is useful for strong binary and multicomponent electrolyte systems. The model of Haghtalab and Nosrati which is a modified NRTL–NRF model was developed only for phosphoric acid solution as a weak and complex electrolyte.In this work, a new version of NRTL-NRF model has been proposed for modeling of some sugar solutions i.e. sucrose, glucose, fructose, and maltose. The model contains two adjustable parameters which were determined using water activity experimental data. Comparison of extended model with other models results is presented.

Keywords:

Excess Gibbs free energy , Sugar , Water activity