5 Jun 2024

Charged carbon sorbent captures CO2 from simulated air and regenerates at 90 to 100 °C

Climate and environment
AI illustration · Illustrative scene, not a photograph of the specific device or experiment.

What was demonstrated

Activated carbon loaded with hydroxide ions by electrochemical charging (charged-sorbent) captured CO2 from simulated dry air containing 400 ppm CO2 at 30 °C. In a sealed box at 37% relative humidity, CO2 fell from about 500 ppm to about 25 ppm in 25 minutes. The abstract reports regeneration at about 90 to 100 °C. Direct Joule heating at 7 to 8 V raised a 2 × 1 cm piece to about 90 °C within about one minute. The paper reports four proof-of-concept direct air capture cycles using Joule-heating regeneration, although one extended data figure lists five. Dry-air capture tests at 400 ppm ran for ten adsorption-desorption cycles, and a separate test ran 150 cycles at 30% CO2 in nitrogen. All measurements were on small laboratory samples.

Why it matters

The result shows that a conductive, electrically charged sorbent can bind CO2 from air at a low concentration and release it at 90 to 100 °C, as reported in the abstract. If the approach holds at larger scale, it could reduce the heat needed to regenerate direct air capture sorbents.

Caveats

  • All results come from laboratory samples of activated carbon. Uniform charging and performance across larger sheets or packed beds were not shown.
  • Only four proof-of-concept direct air capture cycles used Joule-heating regeneration in ambient air, and the paper's own figure lists five. The 150-cycle test used 30% CO2 in nitrogen, not air, so it does not show durability in ambient air.
  • The paper gives an estimated minimum heating energy of 6.5 GJ per tonne of CO2 at 11% relative humidity and 11.4 GJ per tonne at 38% relative humidity. It does not report cost, and capacity fell as humidity rose. The authors note that capacity must improve for the process to be more energy-efficient. Behaviour in outdoor air with varying humidity and contaminants was not tested.

Technology profiles

Sources

  1. peer reviewed paper
    Capturing carbon dioxide from air with charged-sorbents
    Huaiguang Li, Mary E. Zick, Teedhat Trisukhon et al.. Nature, 5 Jun 2024. DOI: 10.1038/s41586-024-07449-2.

Last reviewed 21 Oct 2026.