Northwestern University researchers have been developing a new approach to capture carbon from ambient environmental conditions using moisture swing absorption.
The researchers performing the experiment have achieved multiple breakthroughs including expanding and optimising the number of ions used to make the reaction possible and developing the technology used for carbon capture to improve the process. The focus has been using the process of moisture-swing for carbon capture because there has recently been a large focus developing around it as it has multiple benefits.
Dravid is the Abraham Harris Professor of Materials Science and Engineering at Northwestern’s McCormick School of Engineering and director of global initiatives at the International Institute for Nanotechnology. Ph.D. It was Dravid’s research team who conducted the experiments around moisture-swing carbon capture and students, John Hegarty and Benjamin Shindel, were the co-first authors of the paper which was written from this experiment.
Dravid commented, “We are not only expanding and optimizing the choice of ions for carbon capture, but also helping unravel the fundamental underpinnings of complex fluid-surface interactions. This work advances our collective understanding of DAC, and our data and analyses provide a strong impetus to the community, for theorists and experimentalists alike, to further improve carbon capture under practical conditions.”
Shindel, one of the authors of the paper, said, they wanted to use ambient environmental conditions to facilitate the reaction, “we liked moisture-swing carbon capture because it doesn’t have a defined energy cost. Even though there’s some amount of energy required to humidify a volume of air, ideally you could get humidity ‘for free,’ energetically, by relying on an environment that has natural dry and wet reservoirs of air close together.”
John Hegarty, another author of the paper said, “Not only have we doubled the number of ions that exhibit the desired humidity-dependent carbon capture, we have also discovered the highest-performing systems yet. Traditional carbon capture holds onto CO2 tightly, which means it takes significant energy to release it and reuse it.”
The downside of the project, Shindel added, is that moisture swing absorption methods won’t work everywhere, for example, concrete and steel manufacturers, are large contributors to emissions but take up large footprints, so it isn’t possible to capture carbon emissions at one source.
The researchers plan to continue their work and aim to have future experiments which once coupled with computational modelling, will reveal why certain ions are more effective than others. Their other aim is to integrate such CO2 capturing materials with their previously developed porous sponge platform, which was developed to remove environmental toxins such as oil, phosphates and microplastics.