Distillation - How does it work?
Distillation is a water purification process
that uses a heat source to vaporize water and separate it from
contaminants and other undesirable elements commonly found in
ground and surface water. Distillation heats raw (untreated)
water until the water reaches its boiling point and begins to
vaporize. The heat is then kept at a constant temperature to
maintain water vaporization while prohibiting other undesirable
elements from vaporizing. Water has a lower boiling point than
salt and other mineral sediments. This process also separates
the water molecules from microscopic, disease-causing organisms.
Once all of the water has vaporized, the vapor is led into a
condenser, where, upon cooling, the water reverts to the liquid
form and runs into a receiving container. The remaining elements,
whose boiling point was too high to permit vaporization, remain
in the original container and constitute the sediment (Holland,
Siqueiros, Santoyo, Heard, & Santoyo, 1999). Because the distillation
process can never ensure a complete separation between water
and other materials, it is often repeated one or more times
with the treated water. Many alcoholic beverages, like brandy,
gin, and whiskey, are distilled, using an apparatus similar
in constitution to the water distillation apparatus.
Throughout history, people have experiment with the use of solar power in distillation (Holland et al, 1999). Because of the cost of a heating source to initiate the distillation process, solar power seems an efficient and environmentally friendly alternative to traditional power. Though solar power can be effective for distillation purposes, it works only with relatively small amounts of liquid. Also, the time required for multiple distillations is much greater when relying on solar power than when using traditional power sources.