You’ve probably never heard of magnesite, and why would you have? It’s a rather innocuous carbonate mineral, one in which magnesium is bound to carbon and three atoms of oxygen. According to a team led by Trent University, however, it could provide us with a way to combat climate change.
Its ability to store carbon dioxide is well-known, and through various geological processes, the formation of magnesite allows this to occur naturally. What if, though, we could manufacture it in greater quantities in a laboratory, trap carbon dioxide within it, and bury it deep underground?
Indeed, that lofty goal is precisely what the researchers have taken a step towards. Presenting their proof-of-concept work at the Goldschmidt conference in Boston this week, their abstract explains that experiments in the lab were designed to better explain how the mineral forms fairly speedily at Earth's surface under a range of conditions.
We now have a better understanding of nature’s ways, but those experiments clearly have profound implications. Independent carbon capture experts seem to agree.
Forbes’ Trevor Nace notes that the basics of magnesite production require first getting hydrogen carbonate by dissolving carbon dioxide into water. Then, you’d get magnesium to displace that hydrogen and voila, you have your magnesite.
This new work demonstrates that magnesite is able to form around very tiny spheres of polystyrene. This process is similar: the spheres are carboxylated, meaning they have an organic compound of carbon, oxygen, and hydrogen attached.
This allows for an efficient capture of magnesium, and permits a decent chunk of the mineral to form in just 72 days. Normally it takes centuries or even millennia to form magnesite minerals.
Prof. Ian Power, an environmental geochemist at Trent, led the work. He explained to IFLScience that magnesium ions are fairly small and dense with charge, which means they latch onto water molecules incredibly tightly. Removing the magnesium to form magnesite is therefore normally very difficult, but those microspheres act as effective thieves.
Previous work investigating this precise mechanism found that magnesite required fairly high temperatures to precipitate, which unfortunately requires additional energy input to achieve. This new process apparently takes place at room temperature.
There's plenty of potential here, sure. If you think that we're about to suddenly solve anthropogenic climate change, though, you've got another thing coming.