Development of a self-sustained model to predict the performance of direct contact membrane distillation

Abstract

In this paper, comprehensive experimental and theoretical studies on the performance of direct contact membrane distillation (DCMD) are presented. Although extensive research has been carried out on the modeling of the DCMD process, they mostly relied on some experimentally-determined parameters. In this study, inspired by the ∈-NTU method, a new approach of theoretical model was developed based on heat and mass transfer analyses of the DCMD process. The results from our model, which is independent of the experimentally measured values, were in good agreement with experimental results, with only a 10% deviation. The results showed that feed temperature and membrane porosity, pore size, and thickness were the most effective parameters on the permeate flux and energy efficiency on the DCMD system. A 60% increase in the temperature of the feed solution increased the permeate flux and energy efficiency by 181% and 20%, respectively. Also, by almost a 20% increase in membrane porosity, the permeate flux, and energy efficiency increased about 30% and 21%, respectively. The developed model was also used to minimize the undesirable temperature and concentration polarization phenomena and allowed for the proposal of optimum conditions for achieving higher performance in terms of energy efficiency and permeate flux.