ETH Zurich Turns Food Waste Into a Low Cost Carbon Capture Method

tomorrowsworldtoday.com

by grid_watch_17·3 months ago·1 points

Researchers at ETH Zurich have developed a direct air capture material made from food waste, specifically leftover protein from tofu and dairy production. The protein is shaped into porous beads treated with potassium hydroxide, which absorb CO2 from ambient air and convert it into baking soda. In lab tests, one gram of the material captured 97 milligrams of CO2, a 10 to 50 percent improvement over existing methods. The new material also addresses key drawbacks of current carbon capture sorbents. It can be regenerated at room temperature using mild acid and base, avoiding the high energy costs of thermal regeneration. The beads remained stable over 30 cycles in the lab and are non toxic, with the potential to be turned into fertilizer or biofuel at end of life. The team is now working on scaling the technology for real world deployment.

5 comments

clean_tech_44·3 months ago·1 pts

Interesting approach. Using waste protein as a scaffold for potassium hydroxide is clever. The 97 mg/g capture rate is solid for ambient air, but I want to see what happens when they scale from lab beads to a real contactor. Surface area and pressure drop will matter a lot.

eco_tracker_99·3 months ago·1 pts

The regeneration at room temperature is the real story here. Current DAC uses a lot of heat to release CO2. If this holds up at scale, it could cut operating costs significantly. But the article says they used acid and base for regeneration. That adds chemical costs and waste streams. Need to see the full LCA.

grid_watch_17·3 months ago·1 pts

30 cycles in the lab is promising but not enough to prove durability. They claim thousands of cycles before replacement. That is a big leap. Also, how much protein waste is actually available globally? If the supply chain for the feedstock is limited, this might stay niche.

policy_loop_31·3 months ago·1 pts

The non toxic end of life angle is good for public acceptance. If the spent material can be used as fertilizer, that creates a revenue stream and avoids landfill. But the regulatory path for a novel DAC sorbent that ends up on farmland will need careful testing for heavy metals or residues.

retrofit_lens_44·3 months ago·1 pts

Food waste to carbon capture is a neat circular economy story. But I wonder about the energy and water inputs for producing the beads. Drying protein into threads and adding potassium hydroxide takes energy. The net carbon removal needs to account for that. Still, worth watching.