Researchers from the North Carolina State University (NC) have demonstrated that carbon dioxide can be captured using 3D printed filters. The university says that the researchers created a hydrogel with carbonic anhydrase enzyme, which speeds up the reaction between carbon dioxide, water, and bicarbonate. The findings indicate that 3D-printing could be an easier, faster way to create filter designs.
“This manufacturing process, using 3D printing, makes everything faster and more precise,” said Jialong Shen, the study’s lead author and assistant research professor of textile engineering, chemistry, and science at NC State. “If you have access to a printer, and the raw materials, you can make this functional material.”
In the study, researchers in the NC State Wilson College of Textiles mixed a solution containing two different organic compounds – or the printing ‘ink’ – and an enzyme called carbonic anhydrase. Researchers then printed filaments like threads of hydrogel in a grid-like pattern, solidifying the solution as they printed it with UV light.
“We formulated the hydrogel in a way that would be mechanically strong enough to be 3D printed, and also extruded into a continuous filament,” said Shen. “The inspiration behind our design was our own cells, which have enzymes packed into compartmentalized spaces, filled with a fluid. That kind of environment is good for helping enzymes do their job.”
The researchers tested the properties of the material to understand how well it would bend and twist, and investigated the filter’s carbon capture performance. In a small experiment, the researchers found that the filter was able to capture 24% of carbon dioxide from a gas mixture. While the capture rate is lower than what they’ve achieved in previous designs, the filter was less than an inch (approximately 2cm) in diameter, and it could be made larger and in different modular shapes in order to stack them in a tall column – which would reportedly increase the capture efficiency.
“In order to get a higher capture rate, we would need to make the filter larger in diameter, or stack more filters on top of each other,” said Shen. “We don’t think that’s an issue; this was an initial test at a small scale for ease of testing.”
The researchers tested the durability of this material. They found that 52% of the initial carbon capture performance was retained after more than 1000 hours.
“This work is still early stage, but our findings suggest there are new ways to make materials for carbon capture devices,” said Sonja Salmon, the study’s co-corresponding author, and associate professor of textile engineering, chemistry, and science at NC State. “We’re offering hope for carbon capture.”
The study, “Carbonic Anhydrase Enhanced UV-Crosslinked PEG-DA/PEO Extruded Hydrogel Flexible Filaments and Durable Grids for CO₂ Capture,” was published online in Gels. Sen Zhang, Xiaomeng fang and others were also co-authors. Funding was provided by North Carolina State University, the Novo Nordisk Foundation, and the Alliance for Sustainable Energy, LLC – Managing and Operating Contractor for the National Renewable Energy Laboratory for the US Department of Energy.