Researchers from the Massachusetts Institute of Technology (MIT) in the US have developed a new technology to capture carbon dioxide from a stream of air, virtually at any concentration level, an advance that may pave the way for new strategies to reduce atmospheric greenhouse gas levels. Researchers said that while most methods of removing carbon dioxide from a stream of gas required higher concentrations such as those found in the flue emissions from fossil fuel-based power plants, the new method could take out the gas even when it was present in very low concentrations.
In a study, published in the journal Energy and Environmental Science, the researchers described the device as a large, specialized battery with a stack of electrodes that absorbs carbon dioxide from the air passing over its surface as it was being charged up, and then released the gas as it was being discharged. The study noted that a chemical reaction takes place at the surface of each of a stack of electrodes as the battery charges.
The researchers said that the electrodes are coated with a compound called polyanthraquinone compounded with carbon nanotubes. The study noted that the electrodes have a natural affinity for carbon dioxide and readily reacted with its molecules in the airstream or feed gas. The device operates at room temperature and normal air pressure.
The study co-author Sahag Voskian said that the greatest advantage of this technology over most other carbon capture or carbon absorbing technologies is the binary nature of the adsorbent’s affinity to carbon dioxide. Voskian said that the new system is energy efficient compared to existing methods — consistently using about one gigajoule of energy per ton of carbon dioxide captured.