Humanity has littered the sky with the refuse of fossil fuel use, releasing enough CO2 to change the planet’s climate. We are also chucking incredible sums of carbon in the form of plastics into landfills and into the environment around (and inside of) us. What if cleaning up one of these problems could also help clean up the other?
A new study led by Ruth Ebenbauer at Aarhus University experiments with this idea by upcycling discarded polystyrene into (part of) a material commonly used in carbon-capture systems.
Adding amines
This material is based on amines—a simple chemical group that conveniently acts like a sponge for CO2. An amine will grab CO2 molecules when exposed to them, but let go of the CO2 when heated or depressurized, leaving it ready to go again. The first “CO2 scrubbers” tried in smokestacks used amines dissolved in water to do this, but solid amines are used in all kinds of carbon-capture systems now because they require less energy. These solid materials—often made into granules similar to the activated carbon in a water filter—have high surface area and high porosity, so the amines can efficiently partner up with CO2 molecules.