Experimental study of the memsys vacuum-multi-effect-membrane-distillation (V-MEMD) module

Abstract

The memsys has successfully commercialized the vacuum-multi-effect-membrane-distillation (V-MEMD) module. This compact memsys module employs hydrophobic membranes as a separating medium and makes use of vacuum to enhance membrane distillation process. This novel V-MEMD module enables highly efficient heat recovery. Compared with conventional thermal desalination processes, the memsys module shows advantages in lower investment and operational cost, and higher energy efficiency. In this paper, solar and diesel heater were used as heating sources to drive the memsys V-MEMD module. The solar driven memsys system illustrates good operating performance with a flux at approximately 7 LMH on a sunny day using seawater as feed. The diesel heater driven memsys system was used to investigate the effects of heating, cooling and feed conditions on the module performance using tap water as feed at a relatively low operating temperature (45~60°C). The results show that heating and cooling temperature are the main factors affecting flux and energy efficiency. The optimization of number of module stage and size of each stage were also studied. The experimental results show that the memsys module has great potential in increasing the Gain Output Ratio (GOR), which is one of the most important criteria for industrialization of MD technology.