Modern climate change is caused by greenhouse gases like carbon dioxide (CO2), power plants being one of the largest emitters. Many people have been developing technologies that can capture CO2 from such places as it’s being emitted. In some systems, captured CO2 is pumped into the ground. The problem with this is that the technology – called a carbon capture system (CCS) – is costly, “No one wants to pay the price for it,” says Julien Leclaire, a researcher at the University of Lyon, France.
To make CCS more attractive to big businesses, Leclaire and colleagues found a way to use the gas so it would be worth money to capture it. They discovered that CO2 could be used to extract valuable metals from recycled technology – such as batteries from smartphones – which is much better than just burying it underground. The technique gives value to capturing a greenhouse gas, making it economical to stop it from entering the atmosphere.
Leclaire explained:
By simultaneously extracting metals by injecting CO2, you add value to a process that is known to be cost-intensive.
How does it work? First, carbon dioxide is collected, the research team collected it from a car exhaust for this study. Then, the gas is cooled and pumped into a mix of chemicals called polyamines. When the carbon dioxide combines with the polyamines it turns into a variety of molecules of different sizes and shapes.
The team performed a series of experiments and found that the process sorts out mixtures of metals just by the way different metals react differently to the liquid. Some metals would form a solid in the liquid while others would dissolve. The researchers eventually got the solution just right where it successfully separated cobalt, lanthanum, and nickel – all of which are used in smartphones, batteries, magnets, and computers. The study has been published in the journal Nature Chemistry.
The method could potentially be a more environmentally friendly way to recycle batteries or any other electrical equipment that’s made with these metals. All the researchers have to do now is figure out how to scale the process up.
Usually, the method of recycling these materials is done using highly reactive chemicals – such as acids – which can be polluting and bad for the environment. If those toxic substances can be replaced with captured CO2, it would result in a much lower environmental footprint.
Other companies and researchers have been working on developing ways of converting captured carbon dioxide into useful materials – such as plastic – which is generally produced from petroleum. However, this process is chemically complicated. Leclaire’s approach, on the other hand, is more in line with how CO2 behaves naturally.
“Instead of mimicking what we know how to do better and cheaper with oil, let’s find things you can only do with CO2,” he says.
As long as CO2 is serving us in some way other than causing global warming, it’s a win!
