Food waste beads could boost direct air capture by 10% to 50%

Still life featuring protein beads loaded with potassium hydroxide. The porous act as a sponge for CO2. Credit: Mezzenga Lab / ETH Zurich

In order to stabilize global warming at less than 1.5°C in the long term, there is a need not only for a drastic reduction in greenhouse gas emissions but also for technologies to remove and store hundreds of billions of tons of carbon dioxide (CO2) from the atmosphere. This is also the underlying basis of the scenarios set out in the latest Assessment Report from the Intergovernmental Panel on Climate Change (IPCC).

For years, research groups and startups have therefore been working on ways to remove CO2 directly from the air—a process known as "direct air capture." The company Climeworks, which was founded as an ETH spin-off in 2009, is one of the world's first commercial providers of DAC. To this day, however, the direct removal of CO2 from the air remains an energy-intensive and expensive process.

Porous protein beads bind carbon dioxide

In a study published in the journal PNAS, researchers present a promising new approach to DAC. A group led by materials scientist Raffaele Mezzenga, a professor at the Department of Health Sciences and Technology at ETH Zurich, uses whey and byproducts from tofu production for CO2 absorption.