Membrane distillation utilizes vacuum chambers and temperature differentials to promote concentration of product through evaporation and condensation. It can achieve two goals: extraction of water for reuse and product concentration.
Increases Water Supply
Several Pilot Studies
How Does It Work
Water containing solute is heated to 50-80 C and then sent to a container that has a hydrophobic microporous membrane separating it from a vacuum. This membrane allows water vapor to pass through but blocks the movement of liquid water and/or solute.
At the opposite end of a vacuum chamber, a thin foil lies between the steam and the next chamber of cooler water. The water on the other side of the foil is slightly cooler, which causes the purified steam to condense and drip to a collection pipe at the bottom of the chamber.
The condensation energy released at the foil causes the water in the second stage to heat up, resulting in evaporation and repeating the earlier process. The concentrated solution is collected and disposed of or further processed to recover valuable products such as whey protein.