Revolutionary Powder Sucks Up CO2 Like a Tree

To limit global warming to 2 degrees Celsius above preindustrial levels, we need to limit carbon dioxide in the atmosphere to below 450 parts per million, per the Los Angeles Times. Given there are around 423 ppm in the atmosphere and more being added all the time, this will mean pulling CO2 out. But how? At the University of California, Berkeley, a plan is taking shape owing to "a fluffy yellow powder" capable of sucking up as much CO2 as a large tree does in a year, reports the Times. It does this "at least 10 times faster" than other materials used for direct air capture, says Zihui Zhou, a materials chemist and UC Berkeley PhD student, who is credited as an inventor of the powder dubbed COF-999.

A porous polymer known as a covalent organic framework, COF-999 doesn't get rid of CO2, it just traps it through compounds called amines. Less than half a pound of COF-999 can trap about 88 pounds of CO2, or as much as a large tree absorbs in a year. By applying heat, the CO2 molecules can be loosened, then stored—ideally deep underground, Zhou tells the Times. Each time CO2 is grabbed and released counts as one cycle. A study published Wednesday in Nature shows COF-999 remains effective after 100 cycles. But a newer version has been shown to work for 300 cycles and "we think it will go to thousands of cycles," UC Berkeley reticular chemist Omar Yaghi, a fellow COF-999 inventor and study co-author alongside Zhou, tells the Times.

In campus tests, air entering one end of a tube containing COF-999 had CO2 concentrations of between 410 ppm to 517 ppm. When it went out the other end, there was no CO2 at all. Researchers say they're constantly making improvements to the powder, which is relatively cheap to make, more durable than comparable materials, and gives up its CO2 hold around 140 degrees Fahrenheit, rather than 250 degrees. This "could mean big energy savings on an industrial scale," per ZME Science. The chemists envision using COF-999 in direct air capture plants, where air would flow through a large metal box containing the powder. According to Zhou, such a scenario may only be a couple of years away. (More carbon dioxide stories.)