ETH Zurich turns dairy and tofu waste into beads that capture CO2 from air, outperforming conventional DAC

Researchers at ETH Zurich have developed a new direct air capture material made from protein-rich waste from the dairy and tofu industries. They extracted proteins from the waste, formed them into porous beads, and loaded them with potassium hydroxide. In lab tests, one gram of the material captured 97 milligrams of CO2, which is 10 to 50 percent better than conventional DAC technologies. The findings were published in PNAS in June 2026. The approach tackles two problems at once: it finds a use for a large industrial waste stream and improves the efficiency of carbon removal. The researchers say the protein beads outperform existing solid sorbents used in direct air capture. However, the technology is still at the lab stage and would need to scale significantly to make a dent in the billions of tonnes of CO2 that need to be removed from the atmosphere each year.