Those properties include permeance the ability to allow carbon dioxide through and selectivity, which will allow it to exclude other gases. That screening should cut the number of candidates to a handful that would actually be used to make membranes for more detailed testing, Sholl said.
At the end of the two-year grant period, the researchers expect to have produced and tested hollow-fiber membranes at the laboratory scale. They would then partner with a manufacturer to produce bundles of the fibers for a pilot-scale test.
Power plant flue gases contain nitrogen oxide and sulfur oxides, as well as moisture, which can combine to cause corrosion. Moisture alone can also cause problems for some membranes. In addition, flue gases contain trace amounts of compounds such as chlorine and mercury that could also harm the membranes.
"We won't really know what the contaminants will do until we put the membrane into the flue-gas stream," Sholl said. "A key issue will be to show that these materials will work today and tomorrow, and for a long time afterward. The robustness of the materials in a real environment is something that we have to understand."
A carbon capture system based on the hollow-fiber membranes could potentially remove as much as 90 percent of the carbon dioxide from plant emissions. But that would come at a cost: even in the best-case calculations, removal would require at least 10 percent of the plant's energy.
"The reality is that all countries around the world are going to burn coal for the foreseeable future," Sholl added. "We really don't have a choice because we don't have other good sources of baseline load at the level we get from coal. Any technol
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Georgia Institute of Technology Research News