Turning carbon dioxide back into coal

Researchers from RMIT University in Australia used liquid metals to turn carbon dioxide back into coal-like solid particles.

Current technologies for carbon capture focus and storage focus on turning CO2 into a liquid form and injecting it underground. While it was already possible to turn carbon dioxide into a solid material, earlier attempts needed extremely high temperatures, making it industrially unviable.

By using liquid metals as a catalyst, the researchers showed that it was possible to turn the gas into solid carbon at room temperature. The process is efficient and scalable according to the team.

To convert CO2, the researchers designed a liquid metal catalyst with specific surface properties that made it extremely efficient at conducting electricity while chemically activating the surface.

The carbon dioxide is dissolved with an electrolyte liquid and a bit of liquid metal, and tehn charged with an electrical current. The CO2 slowly converts into solid flakes of carbon, which are naturally detached from the liquid metal surface.

“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,” Dr Torben Daeneke, one of the researchers, says.

In addition to solid carbon, the process also produces synthetic fuel as a byproduct, which could have industrial applications.