(100b) Membrane Distillation: Challenges and Outlook

Membrane distillation is a thermal process using vapor pressure difference as the driving force for water transport.  It has tremendous potential for eliminating corrosion problems associated with conventional thermal desalination processes and allowing process intensification by significantly reducing the plant volume per unit distillate produced.   While it and the related process of osmotic distillation have been intensively studied for the past three decades for applications in treatment of industrial and food streams, it is only within the last ten years that significant progress has been made in engineering modules and materials that allow commercial application of this technology in desalination.  This is partly driven by the desire to harness renewable energy for desalination in remote locations with relatively simple and robust technologies.

This lecture will overview technical challenges involved in implementing membrane distillation (temperature and concentration polarization, efficient heat recovery, improving membrane mass transfer coefficients, scaling and fouling, membrane packing).  In addition we will highlight selected strategies in terms of membrane materials and module design for coping with these challenges.