Scientists have developed an efficient and inexpensive technology that uses solar energy to remove salt from seawater and produce drinking water. Although there is plenty of water on Earth, much of it is undrinkable seawater. Fresh water only makes up about 2.5% of the total, meaning much of the world is experiencing severe water shortages.
In "AIP Progress" published by AIP Press, Chinese scientists reported the development of an efficient seawater desalination device powered by solar energy. The device includes a titanium-containing layer, known as TiNO, or titanium nitride oxide, which absorbs solar energy. The titanium oxide is deposited on a special paper and foam that allows the solar absorber to float on sea water.
When sunlight hits the titanium layer, it heats up and quickly vaporizes the water.By placing the device in a transparent container with a sloping quartz roof, water vapor can be condensed and collected to produce large quantities of fresh water.
“In the field of solar energy, TiNO is a common commercial solar energy-absorbing coating that is widely used in solar water heating systems and photovoltaic devices,” said the author Zhang Chao. "It has a high solar absorption rate and a low thermal radiation rate, and can effectively convert solar energy into thermal energy."
Researchers developed a method to deposit a layer of TiNO using a technique called magnetron sputtering. They used a special type of highly porous paper called Airlaid paper as an absorbent material powered by a seawater tank, made from wood fibers and commonly used in disposable diapers.
The evaporate deviceion consists of three parts: the TiNO layer on top, the thermal insulator and the air cushion paper on the bottom. The insulation is polyethylene foam, which has numerous air-filled pores that trap heat, allowing the multi-layer unit to float above a seawater tank, minimizing heat loss in the environment. The porous air-cushioned paper used as a substrate for TiNO solar absorbers can be reused and recycled more than 30 times.
Salt precipitation on the TiNO surface could interfere with the effectiveness, but the researchers found that no salt layer formed on the surface, even after a long period of time. They believe that the porosity of the paper removes salt that might have formed on the surface and returns it to the seawater reservoir.
The salinity of ordinary seawater is above 75 000 milligrams of salt per liter. Water salinityOrdinary drinking water is about 200 milligrams per liter. Desalination equipment can reduce the salinity of seawater to less than 2 milligrams per liter.
The combination of low cost, high efficiency and no clogging of this desalination technology suggests that it has the potential to help solve fresh water shortages around the world .
Solar seawater desalination method
Solar desalination is a device that uses solar energy to provide a heat source to extract fresh water, sea water or brackish water. It uses solar air. to collect water. The heater and the plastic collector together provide the heat of the sea water. Source, heating and humidification method, the sea water is fully in contact with the high temperature air through a membrane of high efficiency humidification, humidification can reach more than 90%, and soft watere is obtained by condensation in the condenser. is safe and reliable and consumes little energy. For more details, you can pay attention to Huangming technology, there is a solar desalination process
Humanity used solar energy to desalinate sea water at the beginning, mainly Using solar energy for distillation, early solar desalination devices are generally called solar stills. Distillation Systems An example of a passive solar distillation system is the solar disk still, which has been in use for almost 150 years. Due to its simple structure and practical materials, it is still widely used. Research on solar disk stills mainly focuses on material selection, improvement of various thermal properties, and its use with various solar collectors. Compared to traditional energy sources and heat sources, energySolar has the advantages of safety and environmental protection. The combination of solar energy harvesting and desalination technology is a sustainable desalination technology. Solar desalination technology has gradually attracted people's attention due to its advantages of not consuming conventional energy, no pollution and high purity of the fresh water obtained.