Today, four out of every 10 people worldwide live in areas experiencing water scarcity. By 2025, as much as two thirds of the world’s population – an estimated 5.5 billion people - may be living in countries that face a water shortage. Lack of access to water – for drinking, hygiene and food security – inflicts enormous hardship on more than a billion members of the human family. Access to fresh, clean water has been a source of tensions and fierce competition between nations that could become even worse if present trends continue. The population of the world is increasing, and fresh water is the primary requirement for life in the universe. However, while water covers about three-quarters of the earth’s surface, only 3% is fresh water from various sources, and not all of this limited quantity is suitable for drinking.
Thus, water treatment is usually needed, and desalination is the most efficient method for providing fresh water from brackish and/or seawater. However, desalination is energy intensive, and because of scarce availability of wood and oil and high capital and operational cost, traditional mechanical methods make desalination very expensive. But solar desalination based on renewable, safe, free and clean solar energy is the promise for a cost-effective solution that Dove Biotech Company Limited offers to its client’s world wide with our “CSD” (Continuous Solar Distillation Technology)
Solar desalination and or distillation have been practiced for many generations. According to Malik et al., the earliest documented work is that of an Arab alchemist in the 5th century, as reported by Mouchot in 1869. Mouchot stated that an Arab alchemist had used polished Damascus mirrors for solar distillation. The great French chemist Lavoisier (1862) used large glass lenses mounted on collaborating supporting-structures to concentrate solar energy on the contents of distillation flasks.
Mouchot described the use of silver or aluminum-coated glass reflectors to concentrate solar energy for distillation. In the last century the use of solar concentrates in solar distillation was reported by Pasteur, who used a concentrator to focus solar rays onto copper boiler containing water. The steam generated from the boiler was piped to a conventional water-cooled condenser in which distilled water was accumulated
Renewal of interest in solar distillation occurred soon after the First World War. The principle of solar distillation is quite simple. When the air in the system is evacuated, the water boils at low temperature. Under conditions of higher temperatures of about 40°C and lower temperatures of about 5°C, solar radiation can be used many times for the distillation by re-use of the latent heat of condensation of steam for the next evaporation of steam at a few Kelvin degrees lower temperature. The smaller temperature difference being only a few Kelvin between an evaporator and a condenser makes it possible to get more fresh water. The “CSD” of Dove Biotech Company Limited is based upon the realization of an optimum heat and mass transfer process by considering the Second Law of Thermodynamics.