Theoretical investigation of membrane distillation role in breaking the formic acid-water azeotropic point: Comparison between Fickian and Stefan-Maxwell-based models

A comparison between the Stefan-Maxwell and the Fickian mass transfer-based mathematical models for predicting the air-gap membrane distillation process performance in breaking azeotropic mixtures such as formic acid/ water system is carried out in this paper. The predictions of Stefan-Maxwell model which incorporated temperature and concentration polarization effects were closer to the reported literature experimental data than the Fickian-based model that was developed by Udriot et al. The model was also used to predict the process behavior under other experimentally unstudied process parameters. (C) 1999 Elsevier Science Ltd.