US team advances atmospheric carbon capture

The team from the US Department of Energy’s Oak Ridge National Laboratory (ORNL) was initially studying methods to remove environmental contaminants such as sulphate, chromate or phosphate from water. To remove those negatively charged ions, the researchers synthesised a compound - guanidine - to bind strongly to the contaminants and form insoluble crystals that are easily separated from water.

In the process, they are said to have discovered a method to capture and release carbon dioxide that requires minimal energy and chemical input. Their results are published in Angewandte Chemie International Edition.

“When we left an aqueous solution of the guanidine open to air, beautiful prism-like crystals started to form,” ORNL’s Radu Custelcean said in a statement. “After analysing their structure by X-ray diffraction, we were surprised to find the crystals contained carbonate, which forms when carbon dioxide from air reacts with water.”

Decades of research has led to the development of carbon capture and long-term storage strategies to lessen the output or remove power plants’ emissions of carbon dioxide. Carbon capture and storage strategies comprise an integrated system of technologies that collect carbon dioxide from the point of release or directly from the air, then transport and store it at designated locations.