/ Concept /
/ Atmospheric water vapor: an unapped source of water /
The composition of the air is:
21% of oxygen
1% of other gases (argon, CO2, neon ...)
But this is dry air, and we often forget to mention water vapor, a gas that is essential to life. The quantity of water vapor contained in atmospheric air is very variable: close to zero in the polar regions and up to 4% in the equatorial zones. It is mostly contained in a thin atmospheric layer of a few kilometers close to the ground.
Overall, water vapor represents 0.25% of the weight of the atmosphere, which represents several times all rivers and streams.
In average conditions (30 ° C and 50% relative humidity) 1 km3 of air contains 6 Olympic swimming pools (15,000 m3).
In some industrial processes, water vapor in the air is harmful. Techniques have therefore been developed for a long time to capture this water vapor:
The air can contain an amount of water vapor which depends on its temperature. By lowering its temperature close to zero ° C using a refrigeration unit, part of the water vapor is condensed. This condensed water forms a mist and it is easy to separate water and air by filtration.
A specific adsorbent makes it possible to fix the water vapor contained in the air. A flow of air is directed through a bed of adsorbent which will be charged with water vapor, up to 40% of its weight. To extract the water vapor, simply heat the adsorbent. Water vapor is released at high temperature and then condensed at room temperature. No refrigeration unit but a heat source.
Solar energy, captured by photovoltaic or thermal technique, is particularly abundant in regions located between 40 ° north and south latitude.
In general, these regions unfortunately do not correspond to those where the energy need is the most important.
Agua de Sol uses solar energy for water production. In this case, there is a good match between the abundance of solar energy and the need for water.
Atmospheric water vapor