These crystals can help to sequester carbon dioxide. Photo courtesy of Oak Ridge National Laboratory.
While working a system to remove contaminants from water, scientists at the Oak Ridge National Laboratory stumbled on a system to remove carbon dioxide from air, by storing it in crystals. The crystals are formed when a synthetic guanidine in water is exposed to air.
“When we left an aqueous solution of the guanidine open to air, beautiful prism-like crystals started to form,” said researcher Radu Custelcean. “After analyzing their structure by X-ray diffraction, we were surprised to find the crystals contained carbonate which forms when carbon dioxide from air reacts with water.”
The system makes it possible to remove carbon dioxide directly from the air, which could be a huge help in combating global climate change.
This isn’t the first such system, though it could end up being the most efficient. While we already have systems to remove CO2 from the atmosphere, we have to then separate it from whatever it’s bonded with, and then pump it deep underground for storage. Breaking that bond can be difficult, with traditional methods requiring compounds to be heated to 900 degrees Celsius to do so, which can itself create even more carbon dioxide. But the crystals release their carbon at a mere 80 to 120 degrees Celsius, which a regular home oven can handle.
Because this system is so very new, it’s going to take a lot of effort to make it efficient and scalable, so it’s not going to save the planet tomorrow. But it is promising, so more research is going to happen. Removing carbon dioxide from the atmosphere is one way to help slow global warming, though not letting it get there in the first place is obviously a better choice. The system discovered by the researchers could potentially be implemented earlier in the pollution process, as a part of the industrial processes that create carbon dioxide in the first place, in order to reduce output.
The real coup would come in being able to use these crystals for something, instead of using more energy to separate and sequester carbon dioxide. In this way we could not only reduce CO2 in the air but gain a new and potentially valuable resource from that process.