Fully polymeric distillation unit based on polypropylene hollow fiber membranes: Thermal performance analysis

Abstract

: Water scarcity is one of the current threats for many people around the globe. Desalination processes are a crucial solution for areas with access to sea water on the one hand and with the inadequacy of fresh water on the other. Used technology, membrane distillation, is a thermally driven separation process using a porous membrane to set liquid and gas phases apart. Water evaporates and its vapour crosses the membrane’s pores. Polypropylene membrane modules and chaotic hollow fiber condenser were used to construct a (fully polymeric) sweep gas membrane distillation unit. Data of four membrane modules were measured to evaluate the unit thermal performance. Limitations lay in 1) the fiber (geometrical) separation of membrane modules, 2) proper utilization of the sweep gas velocity, and 3) improving condensation system. Still, the device shows a significant thermal efficiency ( > 60 %) even at low operating temperatures. Moreover, further improvements are concrete and reachable.