Engineers from the University of Delaware developed a method for effectively capturing 99 percent of carbon dioxide from the air using an electrochemical system powered by hydrogen, a press statement reveals.
Aside from boosting the overall performance of carbon capture technology, the new method could also enable the commercial production of more sustainable fuel cells.
Capturing 99% of CO2 from the air
The new system, outlined in a new paper in the journal Nature Energy, was actually born out of a setback in another research project. The team behind the new technology was originally working on hydroxide exchange membrane (HEM) fuel cells, a more affordable and environmentally friendly alternative to traditional acid-based fuel cells. While working on that technology, the team was faced with a serious obstacle. HEM fuel cells, they found, are very sensitive to carbon dioxide in the air, making it hard for the batteries to function properly.
Fast forward a few years later, and the researchers that once tried to combat the effects of carbon dioxide on HEM fuel cells are now using it to our advantage. "Once we dug into the mechanism, we realized the fuel cells were capturing just about every bit of carbon dioxide that came into them, and they were really good at separating it to the other side," said Brian Setzler, a co-author on the paper.
The team leveraged the built-in "self-purging" process seen in HEM fuel cells to create a carbon dioxide separator that could be placed upstream from their fuel cell stacks. "It turns out our approach is very effective. We can capture 99 percent of the carbon dioxide out of the air in one pass if we have the right design and right configuration," said study lead and UD Professor Yushan Yan.
Carbon capture: silver bullet or dangerous distraction?
Today, the team has a more compact system that is capable of filtering greater quantities of air. According to the researchers, their soda can-sized early prototype device is capable of filtering roughly 10 liters of air per minute and of removing about 98 percent of CO2. What's more, they found that a smaller electrochemical cell measuring 2 inches by 2 inches could be used to continuously remove roughly 99 percent of CO2 found in the air flowing at a rate of approximately two liters per minute.
The team's prototype is designed to scrub CO2 out of a vehicle's exhaust, though it could also be used for a number of other applications, including aircraft, spacecraft, and submarines.
While the new system has great potential for improving carbon capture as a whole, some scientists have cautioned that carbon capture will not be enough to avert the climate crisis. In fact, in July last year, scientists from the U.S. Center for International Environmental Law went as far as writing that carbon capture was a "dangerous distraction" that could be used as an excuse to slow the transition away from fossil fuel consumption. Nevertheless, several large carbon capture projects are currently in the works, including a new carbon capture facility in Scotland that will remove up to 1 million tons of CO2 from the atmosphere per year.