Chapter 16 - Future Directions in Membrane Distillation

Abstract

The membrane distillation (MD) researchers discuss the high-energy consumption of MD units, the difficulties with long-term operation with the simultaneous risk of membrane wetting and fouling, the lack of MD membranes and MD modules, and the uncertain energetic and economic costs. Therefore, MD technology takes more academic role than commercial, although it has some significant advantages over other processes, such as low sensitivity to feed concentration, operating at low temperatures, high resistance to fouling compared with other membrane separation processes, very high rejection factors of nonvolatile solutes present in water, high system compactness, and use of energy sources such as waste or solar heat. Commercial membranes are often used although these membranes can also be fabricated for other purposes. Moreover, for the same membrane different operational parameters are reported and the permeate fluxes obtained by different groups, which seem to disagree sometimes by an order of magnitude. In general, there are a plenty of opportunities for the MD separation process in all-modern industrial sectors. Taking the advantages of the MD technology over the other water treatment processes into consideration, the perspectives for the future of MD are very promising especially in desalination and environmental applications.