Even though the earth is ~71% water only 3 percent of that is freshwater with a minuscule .3 percent of the water is accessible for us to use. This is the cause of major concern as the population increases and more water is being consumed by data-centers powering AI & Bitcoins there is a major water shortage worldwide. As of now over 1.1 billion people worldwide lack access to water and it is expected that two-thirds of the world’s population may face water shortages in the next few years. (source). Which makes this a very important and urgent problem for us to solve. One of the ways to address this is to desalinate sea water and there are various systems that use desalination techniques to convert sea-water into freshwater but most of them require a lot of energy making them costly and hard to scale.
Which is why this new research by Xi Shen of the Hong Kong Polytechnic University is so important. They have created an aerogel that is far more efficient at turning over fresh water than previous methods of desalination. Aerogels are ultralight materials made of carbon nanotubes which are quite cheap to manufacture and when added to water and exposed to sunlight the aerogel works as a evaporator that creates water-vapor that can be condensed and drunk. The research was published in the ACS Energy Letters.
The spongy aerogel, 3D-printed in layers from a paste that contained carbon nanotubes and cellulose nanofibers, had thin boundaries in between its long, evenly distributed microscopic pores. This was intended to increase vapor output. Each layer was also frozen right after it was printed, so it would be solid when the next layer was printed on top.
The research team tested out the aerogel by submerging it in a cup of seawater with a curved cover made of transparent plastic. When sunlight shone through the plastic, it heated the aerogel in the cup, and water vapor evaporated and condensed on the lid, flowing into a funnel that took it to a separate container. Their system had an output of about 3 tablespoons of drinkable water, but because this aerogel is both durable and allows for scaling up without compromising efficiency, it has the potential to go much further.
“We have tested the performance for up to a week and saw no performance degradation,” Shen told Ars Technica. “While I cannot give you a definitive answer on how regularly the aerogel will need to be replaced, because this work is still in the early stages, we are now planning to do real-world tests to see its long-term performance.”
The research is still in early phases but looks promising based on the existing results. I am looking forward to reading more about this as the technology matures.
Source: ArsTechnica.com: This aerogel and some sun could make saltwater drinkable
– Suramya