Removing carbon dioxide from the atmosphere may become an important tool for slowing climate change. Climate models from the Intergovernmental Panel on Climate Change show that limiting global warming to 1.5 degrees Celsius will require not only cutting emissions, but also removing hundreds of billions of tons of carbon dioxide already in the atmosphere.
One promising approach is direct air capture, a technology that uses specialized materials to pull carbon dioxide from the air. But most systems are both expensive and energy intensive.
In a study recently published in the Proceedings of the National Academy of Sciences, researchers at ETH Zurich in Switzerland have unveiled a new carbon capture material made from a surprising source: food waste.
The research team used proteins from whey, along with byproducts from tofu production, to create porous beads containing potassium hydroxide.
The material acts like a sponge, absorbing CO2 from the air. In lab tests, one gram of the protein beads captured 97 milligrams of CO2, a rate that researchers say is 10 to 50% higher than conventional direct air capture materials.
This new approach also requires less energy. Instead of using heat and pressure to release captured carbon dioxide, the researchers sprayed the beads with a mild acid and base treatment at room temperature, which breaks the chemical bonds and allows the CO2 to be isolated.
The technology is still being tested, but researchers say turning food waste into a carbon capture system could offer a more sustainable path for removing carbon dioxide from the atmosphere.
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Turning food waste into carbon captors
