Amazing breakthrough ‘rewinds emissions clock’ by turning CO2 into coal

27 Feb 2019

Image: © fotosr52/

Australian scientists are celebrating the discovery of a method that allows them to turn CO2 into coal, but this doesn’t mean it will be used for fuel.

While there are many efforts underway to significantly cut the amount of CO2 the world will produce in the future, many scientists are attempting to remove much of the gas we have already released into our atmosphere. Over the years a number of different carbon capture methods have been proposed, but a new one announced in Australia is being heralded as something altogether different.

Publishing their findings in Nature Communications, researchers from RMIT University in Melbourne revealed they have found a way to efficiently convert CO2 from a gas into solid particles of carbon. Essentially, this means that CO2 in our atmosphere can be turned back into coal and reburied underground.

Existing carbon-capture technologies and storage focus on compressing CO2 into a liquid form, which is then transported to a location and injected back into the ground. However, this is not only an expensive task, but could potentially result in an ecological disaster if this liquid leaks from storage sites.

“While we can’t literally turn back time, turning CO2 back into coal and burying it back in the ground is a bit like rewinding the emissions clock,” said Dr Torben Daeneke of the research team.

“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.”

How it works

The technique used to convert the CO2 is electrochemical in nature, with the researchers having designed a liquid metal catalyst with surface properties that made it extremely efficient at conducting electricity while chemically activating the surface.

During the process, the CO2 is dissolved in a beaker with an electrolyte liquid and a small amount of the liquid metal, all of which is charged with an electric current. This converts the CO2 into solid carbon flakes that are naturally detached from the liquid metal surface.

According to the study’s lead author, Dr Dorna Esrafilzadeh, this carbon could also have uses 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,” Esrafilzadeh said.

“The process also produces synthetic fuel as a by-product, which could also have industrial applications.”

In the meantime, all we can hope is that our distant ancestors don’t decide to use this coal as fuel.

Colm Gorey was a senior journalist with Silicon Republic