Membranes could theoretically separate the carbon dioxide from other gases with less energy input. But no existing membrane materials can do the job while being robust enough to operate in the hostile flue-gas environment and inexpensive enough for the large areas needed.
"The volume is truly incredible any way you look at it how much coal is burned or how much gas is produced per second," said Sholl, who is a Georgia Research Alliance eminent scholar in energy sustainability. "With a really good membrane, we would need something like a million square meters of area per power plant. That amount sounds impossible, but it's something already being done in water desalination facilities."
Hollow fibers no thicker than a hair are the key to providing sufficient membrane surface area, said William Koros, who is working on both projects as a professor in the School of Chemical and Biomolecular Engineering.
"Depending on the details of the design, the contact area that can be packaged into a cubic meter of membrane or sorbent volume can be hundreds or thousands of times higher than could be achieved through competitive approaches," said Koros, who is a Georgia Research Alliance eminent scholar in membrane science and technology. "This would allow us to fit the new carbon capture materials into already-cramped power plants."
Sholl and his colleagues are using computational techniques to screen the nearly 5,000 compounds that could be used in the metal-organic framework materials, which are sub-micron-scale crystals that will be added to the fibers to separate the carbon dioxide from other gases. Using the computational techniques, they hope to cut the number of candidate materials to as few as 50 that would be synthesized and tested.
"We are trying to connect the computational screening and prediction to a ma
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Georgia Institute of Technology Research News