Researchers develop better systems for filtering CO2 in space; step toward O2 conversion?
CLEVELAND–If humans are going to someday successfully rocket their way to Mars, we're going to have to figure out how to haul enough oxygen along–or better, find a way to make some on the way.
But before that, scientists first have to improve how carbon dioxide (CO2) is filtered in our spacecraft. Burcu Gurkan, an assistant professor of chemical engineering at Case Western Reserve University and expert in CO2 capture and storage, is working on that initial step.
Technology that now captures CO2 in space vehicles creates dust that causes problems in the mechanisms of other equipment. Further, the captured CO2 is then wasted, she said.
"Right now, we're inefficiently capturing–and then disposing into space–the C02 that humans breathe out," said Gurkan, who is also affiliated with Case Western Reserve's Great Lakes Energy Institute. "So, we're working on a better system to not only capture the waste CO2, but potentially turn it into a viable resource to help make long-distance space travel possible."
That system would use ionic liquids (salt in liquid state) to capture the metabolically generated excess CO2 and then electrochemically convert the CO2 to other resources, such as oxygen to allow the astronauts to breathe on long space trips.
Ionic liquids aren't flammable and won't generate dust that can damage other equipment, she said.
Gurkan's proposal to develop an ionic-liquid carbon-capture system has been selected by NASA to receive $600,000 over the next three years as one of 11 "university-led proposals for the study of innovative, early-stage technologies that address high-priority needs of America's space program," according to an agency news release.
NASA announced the grants in early August. Other awardees will be researching additional aspects of CO2 capture or removal, while some will test battery performance at extremely cold temperatures or work to improve landing and guiding vehicles on other planets.
For the next three years, Gurkan and collaborators at the Marshall Space Center in Alabama hope to develop the actual carbon-capture equipment for future space flights.
"We are already synthesizing ionic liquids for this purpose and designing the architecture to hold them in place in microgravity," she said. "This grant will accelerate our work."
And while using that filtered CO2 to create breathable oxygenhas not yet been accomplished fully–it remains the ultimate goal.
"It's really just impractical to try to bring enough oxygen along because you would need such a large and heavy amount," Gurkan said. "Being able to filter the CO2 and then convert it to oxygen–that would be the big breakthrough."