Vapor-Liquid Equilibrium of Trioxane-Formaldehyde-Water Mixtures: New Division of Components in UNIFAC Groups

摘要

A thermodynamic model of trioxane-formaldehyde-water mixtures was revised to describe vapor-liquid and chemical equilibrium. In the model, division of components into UNIFAC groups wasdeveloped, according to different hygroscopicity of the CH_2O-groups with different positions in the poly(oxymethylene) glycol molecule. These new group-interaction parameters were calculated usingexperimental data in literatures. This leads to a distinctly improved agreement of model predictions withexperimental results while largely keeping the simplicity of the functional group approach.