Do liquid metals have a part to play in keeping CO2 out of the atmosphere?

There is growing demand to develop methods for curbing the world's green house gas emissions. However, the capture, long term storage and utilisation of waste CO2 often pose significant technical challenges.

Whilst work in this area has typically been focused on capturing and compressing the gas for underground storage, we are now seeing the emergence of new technologies which may provide alternative options. Recent work by researchers at RMIT University, Melbourne provides a nice example of such an alternative technology. The method involves passing carbon dioxide through a liquid metal that converts the carbon dioxide directly into solid carbon.

The liquid metal used was a Eutectic Gallium Indium (EGaIn) alloy that undergoes a chemical reaction to produce gallium oxide along with the solid carbon. The reaction is reported to occur in a split second offering a very fast method for converting carbon dioxide into solid carbon. Such eutectic metal alloys are already well known, for example Galinstan (a eutectic alloy of gallium, indium and tin) is already used as a low-toxicity replacement for mercury in thermometers.

These new findings offer an interesting avenue for rapid carbon dioxide capture or storage. The solid carbon may also be used for future applications thus creating a circular economy. As with all new technologies, the real question will be in the long term commercial viability and the technology's tolerance to real life environments. These questions wait to be answered. In the meantime, we are pleased to see the researchers have protected their investment through the filing of a provisional patent application. We look forward to monitoring its progress over the next few years.