Powered only by the sun – this device pulls water from dry air

engineering careers  Powered only by the sun – this device pulls water from dry air

Does a future where every home has a device which could pull all the water you need out of the air (even in dry or desert climates) using the sun sound good?

A new water ‘harvester’ has been constructed at the Massachusetts Institute of Technology works by using a special material – a metal-organic framework (MOF) – which was produced by material Engineers at the University of California, Berkeley.

The prototype device is able to pull 2.8l of water from air (with ~20-30 percent humidity) over a 12-hour period, using 1kg of MOF. The device was tested in real-world conditions (the rooftop at MIT).

This is a major breakthrough in the long-standing challenge of harvesting water from the air at low humidity […] There is no other way to do that right now, except by using extra energy. Your electric dehumidifier at home ‘produces’ very expensive water. Omar Yaghi, one of the authors of the paper

The device works on a daily cycle. A vent opens at night which allows cool night air in. The MOF then snags vapour by creating a small region of super humid air. During the day the devices vent closes, and a small greenhouse heats ups the remaining water vapour driving water onto the condensing pad – the water then drips into a holding chamber.

The schematic above shows the devices metal-organic framework. The lines in the models are organic linkers, and the intersections are multi-metallic units.

The next step for Omar and his team is to improve the prototype MOF and harvesting system so the device can produce more water.

Read the paper at “Water harvesting from the air with metal-organic frameworks powered by natural sunlight,” Science, science.

Read more at phys.org