Solar water desalination
Solar Seawater Desalination is the process of cleaning seawater from salts, minerals, impurities, and sediments by evaporation, then condensation using solar thermal energy, with the aim of obtaining clean water that is usable, whether for drinking or for agriculture.
The history of solar water desalination
is considered by Arab chemists as the first to use solar energy to desalinate sea water in the sixteenth century, while the first solar distillation project was established in 1872 AD in Chile, specifically in the city of Las Salinas specialized in mining. About 4.700 square meters, and the project was able to produce about 22.700 liters of pure water on a daily basis for forty years. It is reported that Aristotle was the first to imagine a way to desalinate sea water using solar energy in the fourth century BC.
Solar seawater desalination device
The device used for desalination is known as the solar distillation device, and it is a closed space in the form of a greenhouse, covered from the bottom in black color, while the roofs are covered with transparent glass panels placed in a hierarchical slanting shape, and inside the greenhouse and on both sides there are two channels for the purpose of collecting Water vapor, which will condense on the roof of the greenhouse, and collect in the form of freshwater.
Solar seawater desalination mechanism:
The salty sea water is placed at the bottom of the black greenhouse, then the greenhouse is exposed to the sunlight that will penetrate through the glass surfaces, which leads to the water absorbing the sun’s heat, increasing its temperature, energizing it, and converting it from a liquid state to a vapor. When the steam hits the greenhouse wall, the steam will condense and collect in the form of fresh water droplets that will later collect in the side channels and be used for drinking, cooking or agriculture.
CAUTION: In this case, the water does not reach the boiling point, it is only heated, and therefore it evaporates at a slow or rapid rate depending on the strength of the sun rays falling on the basin.
The benefits of solar seawater desalination
- are inexpensive, and it produces about five liters of pure water per day per square meter of area, thus providing fresh water to a large number of residents, especially with the exacerbation of the problem of the shortage of consumable water around the world.
- Suitable for use in desert areas with less freshwater, and suitable for miners.
- It is used to obtain table salt in many countries around the world.
- The method is also used to desalinate groundwater.
- Environmentally friendly, as floating desalination plants can be set up at long distances in the sea, thus reducing noise, and saving the land of economic importance.