Chinese scientists set record in water desalination with solar power

Chinese scientists have set a record in desalinating water through solar steam evaporation – a method they say is “green and efficient” and capable of filtering more water per day than similar methods.
Through their method, the team was able to purify around 22 litres of water per square metre (0.54 per square foot) a day – about enough for 10 adults and “significantly higher” than other solar steam desalination methods, the scientists wrote in a paper published in the peer-reviewed journal Nature on September 13.
The scientists used a new metallic titanium powder with a high solar absorption capacity and mixed it with other materials to create cylindrical evaporators. The cup-shaped evaporators were designed to minimise energy loss compared to flat evaporators, and they were able to achieve an evaporation rate of 6.09kg (13.4lbs) per hour, according to the paper.

‘Asian water tower’ is facing a worsening supply imbalance, study finds

Yang Bo, the first author and an associate professor at Northeastern University in Liaoning province, told the Science Times on Monday that their method “set a world record” in evaporation rate.

Traditional desalination uses reverse osmosis to separate salt from seawater. To do this, water is passed through small membranes under pressure, which separate it from the other components. This is an energy-intensive process. According to the US Department of Energy, about 25 to 40 per cent of the cost of desalinated water comes from the power required to run pumps to create the osmotic pressure.

In the solar steam method, the evaporators absorb heat, turning the water into vapour and leaving behind the salt. The vapour moves to a collection space that is cooler, causing it to condense into purified water.

The scientists say their cup-shaped evaporator is able to minimise energy loss and prevent salt blockages compared to other devices used in solar steam desalination. Photo: Nature

Yang told Science Times the vapour method was “green and efficient” and did not produce any carbon emissions as it relied on sunlight rather than pressure to desalinate.

Yang said the research provided “a new direction” for desalinating seawater that could effectively deal with water shortages while saving energy through its design, according to Science Times.

Thanks to its enlarged surface area, the team’s cylindrical evaporator is able to prevent salt blockages, which is essential to improving the performance of solar steam systems, according to the paper.

The scientists added that the process not only provides a more sustainable way to desalinate seawater but could also be extended to fuel production, steam sterilisation and electricity generation.

Source link

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button