Finding efficient techniques to separate and remove greenhouse gases from the atmosphere is key to decelerating climate change. In a recent study published online in Chemical Engineering Journal on August 9, 2021 (to be published in Volume 427 of the journal on January 1, 2022) , a team of scientists, including Dr. Sol Geo Lim from National Korea Maritime & Ocean University, investigated the potential of a class of compounds called organic hydroquinone (HQ) clathrates to capture two key greenhouse gases, carbon dioxide (CO 2 ) and nitrous oxide (N 2 O). “In our previous work, we demonstrated the effectiveness of these clathrates for the recovery of CO 2 and N 2 O individually. But capturing them simultaneously could be even more environmentally effective,” says Dr. Lim.
Organic clathrates, such as HQ clathrates, are substances with a grid-like structure that enable it to trap other molecules (usually gases). The grid structure is termed the ‘host’ and the gases are ‘guests.’ But HQ clathrates selectively prefer different guests based on the composition of the gas mixtures they interact with. This makes it important to understand the different guest behaviors in HQ clathrates.
In their work, the research team exposed HQ clathrates to gas mixtures that had varying compositions of CO 2 and N 2 O. They then performed experiments to investigate the interactions in the clathrate. They found that, unlike in experiments with other gas mixtures, the final composition of CO 2 and N 2 O in the β-HQ was the same as that of the initial gas mixture, i.e., the HQ did not prefer either gas. When two components exist in the same composition in two different phases (here, solid and vapor), the mixture is called an azeotrope. This is the first ever report of an azeotropic HQ clathrate.
The research team further saw that CO 2 , N 2 O and CO 2 –N 2 O all had very similar clathrate formation kinetics. “The azeotrope formation can be attributed to the compelling similarity of CO 2 and N 2 O guests in HQ clathrates. This valuable knowledge on host – host and guest – guest interactions in clathrates will help us develop new gas capture technologies,” says Dr. Lim.
With studies like this to steer the research, perhaps it won’t be long before we usher in a new era of climate protection.
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Reference
DOI: https://doi.org/10.1016/j.cej.2021.131560
Authors: Sol Geo Lim 1 , Jiyeong Jang 1 , Jong Won Lee 2 , Minjun Cha 3 , Jeasung Park 4 , Michihiro Muraoka 5 , Yoshitaka Yamamoto 5 , Dohyun Moon 6 , Ji-HoYoon 1,7
Affiliations:
About National Korea Maritime & Ocean University
South Korea’s most prestigious university for maritime studies, transportation science and engineering, the National Korea Maritime & Ocean University is located on an island in Busan. The university was established in 1945 and since then has merged with other universities to currently being the only post-secondary institution that specializes in maritime sciences and engineering. It has four colleges that offer both undergraduate and graduate courses.
Website: http://www.kmou.ac.kr/english/main.do
About the author
Sol Geo Lim is an M.S. candidate at the Department of Convergence Study on Ocean Science and Technology, Ocean Science and Technology (OST) School, Korea Maritime and Ocean University (KMOU). He obtained his B.S. from the Energy and Resources Engineering department of KMOU, in 2020.
Chemical Engineering Journal
Experimental study
Not applicable
Azeotropic clathrate: Compelling similarity of CO2 and N2O uptake in an organic crystalline host
1-Jan-2022
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.