An international team of researchers led by the University of Newcastle has developed a membrane that can separate carbon dioxide from air and release it without having to resort to external energy inputs, such as heat and pressure. The process only utilizes the electric potential differences of moisture present in the atmosphere
The study on the innovative membrane to capture CO2 from the air is published in Nature Energy
Direct Air Capture (DAC) technology is one of the areas on which climate solutions research focuses most. The latest IPCC report estimates that DAC and other similar technologies are needed to some extent to keep global warming below or close to the 1.5 degree threshold. Only a transition path of seven of those outlined in the report does not require it, but presupposes halving global energy consumption in 30 years. The DAC, however, has objective limitations that make it expensive: CO2 is poorly concentrated and the capture and release process requires large amounts of energy. What if, instead, it was possible to capture CO2 from the air using only the energy in the environment?
The humidity to capture CO2 from the air
The solution was developed by an international team of researchers led by the University of Newcastle. A study published in Nature Energy presents a membrane capable of capturing CO2 from the air by exclusively exploiting the electrical potential of moisture present in the atmosphere. This avoids resorting to other energy inputs, such as heat and pressure, commonly used in carbon dioxide capture and release processes.
How does it work? Researchers use natural humidity differences to separate CO2 from air, thereby reducing energy requirements. At the same time, water accelerates the transport of CO2 through the membrane, increasing the process’s capture capacity.
The researchers tested “a new carbon dioxide permeable membrane with a variety of moisture differences applied to it,” explains Evangelos Papaioannou of the University of Newcastle and co-author of the research. “When the humidity was higher on the output side of the membrane, the membranes spontaneously pumped carbon dioxide into that outflow.”
The qualifying part of the work consists of the molecular-scale modeling of the processes that occur inside the membrane. This is an essential step in determining which configuration and potential differences allow maximizing the efficiency of the CO2 capture process from the air by exploiting its moisture.
