This New, Yellow Powder Quickly Pulls Carbon Dioxide From the Air, and Researchers Say ‘There’s Nothing Like It’

Increasing concentrations of carbon dioxide in the atmosphere have caused intense hurricanes, wildfires, extreme heat, floods, droughts and more in recent years. Alongside efforts to reduce emissions of the gas from burning fossil fuels, some scientists are also looking for processes that could remove some of the carbon dioxide that’s already up there.

“You have to take CO2 from the air—there’s no way around it,” Omar Yaghi, a chemist at UC Berkeley tells the Los Angeles Times’ Karen Kaplan. “Even if we stop emitting CO2, we still need to take it out of the air. We don’t have any other options.”

Now, Yaghi and his team have developed a new material that they say could be a game changer for this task and potentially be used in industrial facilities within the next few years. To the naked eye, it looks like a yellow powder. Under a microscope, it looks like tiny basketballs with billions of miniscule holes, per the L.A. Times. The powder has a hexagonal structure made of carbon and nitrogen, held together by covalent bonds—some of the strongest bonds in chemistry.

The porous material, known as a covalent organic framework, is called COF-999. Within the framework are compounds called amines, which have a basic pH. When air flows through the material, most components pass freely through, but the amines snatch up acidic molecules of carbon dioxide.

The team’s research into covalent organic frameworks has been ongoing for about 20 years. In results recently reported in the journal Nature, Yaghi and his team found that COF-999 performs remarkably well at absorbing carbon dioxide.

In one experiment, they put a tube filled with the material outside and measured the carbon dioxide concentrations after air passed through. The exiting air was totally free of the greenhouse gas.

“We were scrubbing the CO2 out of the air entirely,” Yaghi tells Scientific American’s Alec Luhn.

Study lead author Zihui Zhou, a materials chemist at UC Berkeley, says in a statement that a mere 200 grams of COF-999, or just under half a pound of material, can absorb up to 44 pounds of carbon dioxide in one year—the same as a large tree.

“There’s nothing like it out there in terms of performance,” Yaghi adds in the statement. “It breaks new ground in our efforts to address the climate problem.”

Especially promising is how COF-999 releases carbon dioxide after absorbing the molecules. Typically, after carbon capture technologies remove the gas from the atmosphere, engineers have to heat the material to get it to release the absorbed carbon dioxide. Then, the gas is often used in industrial applications or sequestered in geologic reservoirs deep in bedrock.

This heating process is expensive and energy-intensive, since traditional carbon capture materials must be heated to high temperatures. But COF-999 releases its stores at just 140 degrees Fahrenheit—more than 100 degrees cooler than the materials currently in use, reports the L.A. Times. What’s more, it can go through more than 100 cycles of absorbing and releasing carbon dioxide without losing any effectiveness.

Some experts caution that it’s too soon to regard COF-999 as a miracle savior for the planet, as it hasn’t yet been tested in real-life situations. Jennifer Wilcox, a chemical engineer at the University of Pennsylvania not involved with the work, tells Scientific American that many questions remain, like whether COF-999 might restrict airflow when applied to a filter and whether that would increase energy consumption, in turn. The answers, says Wilcox, “will ultimately dictate costs”—and determine the material’s usefulness.

Regardless, chemists will continue to work on new carbon capture technologies. As Yaghi tells Chemical & Engineering News’ Brianna Barbu, “carbon capture is the problem of our society today … it’s also a fantastic chemistry problem.”

Rudy Molinek | READ MORE

Rudy Molinek is Smithsonian magazine's 2024 AAAS Mass Media Fellow.