For the first time ever, scientists have successfully turned carbon dioxide back into coal, a breakthrough that can ultimately lead to cleaner air.

Researchers from RMIT have developed a technique that can efficiently convert carbon dioxide from a gas state into solid particles of carbon. They believe this technique offers an ‘alternative pathway’ for safely and permanently removing greenhouse gases from the atmosphere.

Researcher Torben Daeneke said that converting the gas into a solid state could prove to be a more sustainable approach. He said, “While we can’t literally turn back time, turning carbon dioxide back into coal and burying it back in the ground is a bit like rewinding the emissions clock.”

New artificial leaf design can absorb way more carbon dioxide than natural ones

Daily Mail explained, the team developed the electro-chemical technique to capture and convert the atmospheric carbon dioxide to storable coal. To convert it, they designed a liquid metal catalyst with specific surface properties that made it really efficient at conducting electricity while chemically activate the surface.

“To date, CO2 has only been converted into a solid at extremely high temperatures, making it industrially unviable. By using liquid metals as a catalyst, we’ve shown it’s possible to turn the gas back into carbon at room temperature, in a process that’s efficient and scalable,” said Daeneke.

The gas is dissolved in a beaker filled with an electrolyte liquid and a small amount of the liquid metal, which is then charged with an electric current. The CO2 slowly converts into solid flakes of coal, which are then naturally detached from the liquid metal surface, letting the continuous production of carbon.

Lead researcher Dorna Esrafilzadeh said that the solid carbon produced can also be used as an electrode. “A side benefit of the process is that the carbon can hold electrical charge, becoming a supercapacitor, so it could potentially be used as a component in future vehicles. The process also produces synthetic fuel as a by-product, which could also have industrial applications.”

Researchers acknowledged that though more research still needs to be done, it is a vital step to ‘delivering solid storage or carbon’, reported Independent.