Quantcast
Popular
This device can pull liters of water from arid air. Photo credit: MIT photo from laboratory of Evelyn Wang

Solar-Powered Device Can Pull Water Out of Thin Air, Even in Deserts

As a worldwide water crisis looms, engineers have invented a solar-powered harvester that can pull water out of thin air—even in dry, desert environments.


A team from the Massachusetts Institute of Technology and the University of California, Berkeley have created a device using a specially designed metal-organic framework (MOF) capable of pulling liters of water in conditions where humidity is as low as 20 percent, a level common in arid areas. Impressively, it only needs the power of the sun to operate.

This breakthrough was published in a paper Thursday in the journal Science.

There are already dehumidifiers and other products out there that can collect water from humid air. The process, however, can be energy-intensive and essentially leave you with "very expensive water," as senior author Omar Yaghi of Lawrence Berkeley National Laboratory put it in a statement.

The new device, however, "is capable of harvesting 2.8 liters of water per kilogram of MOF daily at relative humidity levels as low as 20 percent, and requires no additional input of energy," the authors state in their paper. That's about 2.8 liters of water in 12 hours.

"We wanted to demonstrate that if you are cut off somewhere in the desert, you could survive because of this device," Yaghi said. "A person needs about a Coke can of water per day. That is something one could collect in less than an hour with this system."

The Berkeley professor invented metal-organic frameworks more than 20 years ago. MOFs combine metals such as magnesium or aluminum with organic molecules to form rigid, porous structures that can store gases and liquids. More than 20,000 different MOFs have been created by researchers worldwide.

According to a news release, here's how this new solar-powered, water-collecting MOF works:

In 2014, Yaghi and his UC Berkeley team synthesized a MOF—a combination of zirconium metal and adipic acid—that binds water vapor, and he suggested to Evelyn Wang, a mechanical engineer at MIT, that they join forces to turn the MOF into a water-collecting system.

The system Wang and her students designed consisted of more than two pounds of dust-sized MOF crystals compressed between a solar absorber and a condenser plate, placed inside a chamber open to the air. As ambient air diffuses through the porous MOF, water molecules preferentially attach to the interior surfaces. X-ray diffraction studies have shown that the water vapor molecules often gather in groups of eight to form cubes.

Sunlight entering through a window heats up the MOF and drives the bound water toward the condenser, which is at the temperature of the outside air. The vapor condenses as liquid water and drips into a collector.

When two-thirds of the world's population is experiencing water shortages, the water vapor and droplets in the atmosphere—estimated to be around 13,000 trillion liters—is a natural resource that could address the global water problem, the authors explained in Science.

The team noted that their harvester is proof of concept and has room for improvement. The current device can absorb only 20 percent of its weight in water. They hope to double that amount or tweak the invention so that it can be more effective at higher or lower humidity levels.

Still, as Yaghi pointed out, "this is a major breakthrough." This invention could enable people to have an off-grid water supply."

"One vision for the future is to have water off-grid, where you have a device at home running on ambient solar for delivering water that satisfies the needs of a household," Yaghi said. "To me, that will be made possible because of this experiment. I call it personalized water."

Show Comments ()
Sponsored
Shutterstock

September 2017: Earth's 4th Warmest September on Record

By Dr. Jeff Masters

September 2017 was the planet's fourth warmest September since record keeping began in 1880, said the National Oceanic and Atmospheric Administration's (NOAA) National Centers for Environmental Information (NCEI) and NASA this week. The only warmer Septembers came during 2015, 2016 and 2014. Minor differences can occur between the NASA and NOAA rankings because of their different techniques for analyzing data-sparse regions such as the Arctic.

Keep reading... Show less

Shocking Photo of Dehorned Black Rhino Wins Top Award

Africa loses an average of three rhinos a day to the ongoing poaching crisis and the illegal rhino horn trade. In 2016 alone, 1,054 rhinos were reported killed in South Africa, representing a loss in rhinos of approximately six percent. That's close to the birth rate, meaning the population remains perilously close to the tipping point.

This year, the Natural History Museum in London awarded photographer Brent Stirton the 2017 Wildlife Photographer of the Year grand title for his grisly image of a black rhino with its two horns hacked off in South Africa's Hluhluwe-Imfolozi Park.

Keep reading... Show less
Popular
Smallholder agriculture in southern Ethiopia. Smallholder farmers are particularly vulnerable to food insecurity. Leah Samberg

How Climate Change and Wars Are Increasing World Hunger

By Leah Samberg

Around the globe, about 815 million people—11 percent of the world's population—went hungry in 2016, according to the latest data from the United Nations. This was the first increase in more than 15 years.

Between 1990 and 2015, due largely to a set of sweeping initiatives by the global community, the proportion of undernourished people in the world was cut in half. In 2015, UN member countries adopted the Sustainable Development Goals, which doubled down on this success by setting out to end hunger entirely by 2030. But a recent UN report shows that, after years of decline, hunger is on the rise again.

Keep reading... Show less
Pixabay

Two Graphs Explain Why California’s Wildfires Will Only Get Worse

By Molly Taft

The deadly wildfires ripping through Northern California are just the latest in a season of record-defying natural disasters in the U.S. As the death toll passes 40, reports of Californians hiding in pools as their houses burn and scenes of devastated homes and vineyards add to 2017's apocalyptic picture of how climate change is impacting America today.

As the Trump administration guts environmental protections and undermines science, California is one of the states leading the way on climate action. Ironically, experts agree the state can expect devastating fires like the ones in Napa to become the new normal. Drier and drier conditions and creeping temperatures in the American Southwest, definitively linked to climate change, serve to create tinderbox conditions for massive, catastrophic fires to explode.

Keep reading... Show less
Sponsored
Leonardo DiCaprio / Facebook

Leonardo DiCaprio Invests in Plant-Based Food Company

Animal agriculture is responsible for more greenhouse gas emissions than the entire transportation sector, but eating a burger doesn't have to come with a side of guilt.

Actor and environmentalist Leonardo DiCaprio has invested in Beyond Meat, the makers of the world's first vegan burger that's famously known to look, smell and even taste a lot like the real deal.

Keep reading... Show less
www.facebook.com

Guard Dog Wouldn’t Leave Goat Flock During California Fires—And Lived to Tell the Story

By Andrew Amelinckx

The fire the Hendels barely escaped was part of the Northern California firestorm that has so far claimed 40 lives—including one of their neighbors, Lynne Powell—destroyed countless homes, and caused billions of dollars in damage.

"Later that morning when we had outrun the fires I cried, sure that I had sentenced Odie to death, along with our precious family of bottle-raised goats," Roland Hendel wrote in a recent Facebook post.

Keep reading... Show less
Sponsored
Climate activists Emily Johnston and Annette Klapstein shut down Enbridge's tar sands pipelines 4 and 67 in Minnesota on Oct. 11, 2016. Shutitdown.today

Judge Allows Vital 'Necessity Defense' for Climate Activists

By Jessica Corbett

In a decision that is being called "groundbreaking" and "precedent-setting," a district court judge in Minnesota has ruled that he will allow oil pipeline protesters to present a "necessity defense" for charges related to a multi-state action by climate activists last October.

In his decision last week, Judge Robert Tiffany ruled that four activists who participated in the #ShutItDown action—in which pipelines across five states were temporarily disabled, halting the flow of tar sands oil from Canada into the U.S.—may present scientists and other expert witnesses to explain the immediate threat of climate change to justify their action.

Keep reading... Show less
www.youtube.com

Why Are Incarcerated Women Battling California Wildfires for as Little as $1 a Day?

As raging wildfires in California scorch more than 200,000 acres—roughly the size of New York City—more than 11,000 firefighters are battling the blazes, and a number of them are prisoners, including many women inmates.

Keep reading... Show less
Sponsored

mail-copy

Get EcoWatch in your inbox