2. Distillation

2.1 Single-action distillation

This process has long been used on ships, where diesel engines emit a significant amount of recoverable heat. The principle is simple: it reproduces the natural water cycle. In a closed enclosure, a heating coil brings seawater to the boil (figure 1 ). The steam produced condenses on contact with a second coil fed with cold seawater. An ejector (or pump) evacuates non-condensable gases. An electric pump draws off the distillate (condensed water); a second draws off the concentrated seawater or brine.

To establish the heat balance, the flow of...