Membrane distillation - a theoretical study of evaporation through microporous membranes

✍ Scribed by A.-S. Jönsson; R. Wimmerstedt; A.-C. Harrysson

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 342 KB
• Volume: 56
• Category: Article
• ISSN: 0011-9164
• DOI: 10.1016/0011-9164(85)85028-1

✦ Synopsis

Membrane distillation is a process in which, for example, water in a heated salt solution, evaporates through a porous membrane. The vapour condenses on a coolant surface on the other side of the membrane. The two liquid streams, the salt solution and the condensate, are separated by a highly porous hydrophobic membrane. Surface tension forces withhold liquids from the pores and prevent contact between the two liquids.

The temperature difference, causing a corresponding vapour pressure difference across the membrane, provides the driving force of the membrane distillation process. Evaporation will occur at the solution surface if the vapour pressure on the solution side is greater than the vapour pressure at the condensate surface. Vapours then diffuse through the pores to the cooler surface, where they condense.

The dependence of mass and heat transport upon different process and membrane parameters involved in membrane distillation has been investigated theoretically.