Optimizing the capture of a notorious greenhouse gas
Optimizing the capture of a notorious greenhouse gas lead image
Capturing and sequestering carbon dioxide (CO2), a harmful greenhouse gas, is a costly and inefficient process. The current method used to capture exhaust gas from power plants, chemical adsorption, involves an enormous amount of energy to separate the gas molecules from the chemical solvents to make them reuseable.
Sandip Thakur and Ashutosh Giri computationally studied CO2 gas infiltration on the thermal transport properties of a prototype metal organic framework, MOF-5.
MOFs are crystalline, microporous materials that have emerged as possible options for trapping large amounts of gases because of their immense porosities and large surface areas.
“One gram of an MOF can have the same surface area as a football field, allowing for considerably larger amounts of gases to be adsorbed inside the nanoporous framework,” said author Ashutosh Giri.
However, a major challenge in using MOFs for gas storage and separation lies in the excessive amount of heat generated when the gas enters and interacts with the nanoporous surfaces. The researchers used atomistic simulations to investigate these interactions. They found that CO2 modifies the thermal conductivity of the MOF. At low temperatures gas adsorption decreases the thermal conductivity of the system. However, at high temperatures and high gas loadings the opposite behavior is found due to the different behavior of CO2 diffusivities at both temperatures.
Understanding these heat transfer mechanisms allows tailoring of the thermal properties of the MOFs for better CO2 capture.
“Our work allowed us to study how the interactions of a large number of gas molecules within the vast porous network of MOFs can influence the heat transfer mechanisms in these solid/gas systems,” said Giri. “It offers much-needed strategies to systematically control heat conduction in MOF/gas systems.”
This paper is part of the 2024 JCP Emerging Investigators Special Collection, learn more here.
Source: “Impact of carbon dioxide loading on the thermal conductivity of metal organic frameworks,” by Sandip Thakur and Ashutosh Giri, Journal of Chemical Physics (2025). This article can be accessed at https://doi.org/10.1063/5.0252904 .
