Experimental investigations on solar driven stand-alone membrane distillation systems for remote areas

In many places world wide drinkable water is already a scarce good and its lack will rise dramatically in the future. Missing energy sources and no grid connections complicates the use of standard desalination techniques in these places. Fraunhofer ISE develops solar thermally driven compact desalination systems based on membrane distillation (MD) for capacity range between 100 and 500 L/day and larger systems for the capacity range up to 10 m3/day. All systems can be operated energy self sufficient and almost maintenance free. Membrane distillation is a technique which is operated with thermal energy but also uses a membrane for the separation of pure water from the concentrated solution. With regard to the implementation in solar driven standalone desalination systems it holds important advantages. Altogether eight pilot plants were installed in five different countries.

Six compact systems with daily capacities between 60 and 150 L were installed in different countries. Long term performance tests in different countries demonstrate that a durable operation is possible even with very low maintenance. One compact unit in Gran Canaria is running since January 2005. The redesign of MD modules increases the distillate production rate Acknowledgments The authors want to thank all partners from the MEMDIS and SMADES Project for operating and monitoring the demonstration units. Special thanks to ITC Gran Canaria, Alexandria, University Egypts, JUST University and Marine Science Station Jordan.