Engineers at the University of Delaware (UD) have demonstrated a way to effectively capture 99% of carbon dioxide from the air using a novel electrochemical system powered by hydrogen. This is a significant advance for carbon dioxide capture and could bring more environmentally friendly fuel cells closer to the market.
Fuel cells work by converting fuel chemical energy directly into electricity. They can be used to transport things like a hybrid or zero-emissions vehicles. Henri Bellin du Pont Chair of Chemical, Biomolecular Engineering at UD, and Yan has been working for some time to improve hydroxide exchange membrane (HEM) fuel cells, which are an economical alternative to the traditional acid-based fuel cells used today.
But HEM fuel cells have one drawback that has kept them off the road – they are extremely sensitive to carbon dioxide in the air. Essentially, the carbon dioxide makes it difficult for the HEM fuel cell to breathe. This defect reduces the performance and efficiency of the fuel cell by up to 20%, making the fuel cell no better than a gasoline engine. Yan’s research group has been searching for a solution to this carbon dioxide puzzle for more than 15 years.
Now, the research team had an electrochemical device that looked like a typical filtration membrane designed to separate gases, but the ability to continuously pick up minute amounts of carbon dioxide from the air like a more complex electrochemical system.
The research team’s results showed that an electrochemical cell measuring 2 inches by 2 inches could continuously remove about 99% of the carbon dioxide found in the air flowing at a rate of about two liters per minute. An early prototype spiral device, about the size of a 12-ounce soda can, is capable of filtering 10 liters of air per minute and expelling 98% carbon dioxide, the researchers said.
According to Shi, since the electrochemical system is powered by hydrogen, as the hydrogen economy develops, this electrochemical device could also be used in airplanes and buildings, where air could be used as an energy-saving measure. Later this month, after defending his dissertation, Xi will join Versogen, a UD spinoff company founded by Yan, to advance research toward sustainable green hydrogen.
Co-authors on the Yan lab’s paper include Yun Zhao, co-first author, and research associate, who performed the experimental work required to test the device; Stephanie Matz, a doctoral student who contributed to the design and fabrication of the spiral module, and Samson Gottsfeld, an assistant professor of chemical and biomolecular engineering at UD. Gottsfeld was the principal investigator on the 2019 project, funded by the Advanced Research Projects Agency-Energy (ARPA-E), which led to this conclusion.
Source: University of Delaware