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 proce ss performance in breaking azeotropic mixtures such as formic acid/ water s ystem 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 predi ct the process behavior under other experimentally unstudied process parame ters. (C) 1999 Elsevier Science Ltd.