The first breakthrough, published in Nature Communications, introduces a membraneless electrochemical process that slashes energy requirements for amine-based carbon dioxide capture. The second breakthrough, featured on the cover of ES&T Engineering, demonstrates a vanadium redox flow system capable of both capturing carbon and storing renewable energy.
“Climate change mitigation was basically the reason we pursued this research,” Rahimi said. “We need solutions, and we wanted to be part of the solution. The biggest suspect out there is CO2 emissions, so the low-hanging fruit would be to eliminate those emissions.”
Originally published in a research paper titled “A Membraneless Electrochemically Mediated Amine Regeneration for Carbon Capture,” the team first focused on replacing the conventional ion-exchange membrane in the electrochemically mediated amine regeneration process with gas diffusion electrodes.
That proved to be a game-changer. Not only were the membranes the most expensive part of the system, but they were also a primary reason for performance issues and maintenance cost.
By engineering the gas diffusion electrodes, the team was able to achieve more than 90% CO2 removal, nearly 50% more than traditional EMAR approaches. That’s a capture cost of approximately $70 per metric ton of CO2, which makes it competitive with state-of-the-art amine scrubbing methods, according to Ph.D. student Ahmad Hassan.
“By removing the membrane and the associated hardware, we’ve streamlined the EMAR workflow and dramatically cut energy use,” said Hassan, who was leading author of the paper. “This opens the door to retrofitting existing industrial exhaust systems with a compact, low-cost carbon capture module.”
Fellow Ph.D. student Mohsen Afshari built on those advances, publishing his findings in “A Vanadium Redox Flow Process for Carbon Capture and Energy Storage.” That paper presented a reversible flow battery architecture that absorbs CO2 during charging and releases it upon discharge.
Using the vanadium’s chemistry, the process displayed strong cycle stability and a high capture capacity, suggesting the technology could provide carbon removal and grid balancing when paired with intermittent renewables.
“Integrating carbon capture directly into a redox flow battery lets us tackle two challenges in one device,” Afshari said. “Our front-cover feature highlights its potential to smooth out renewable generation while sequestering CO2.”
These discoveries could reduce the costs for carbon capture technology and the energy industry going forward.
“These publications reflect our group’s commitment to fundamental electrochemical innovation and real-world applicability,” Rahimi said. “From membraneless systems to scalable flow systems, we’re charting pathways to decarbonize hard-to-abate sectors and support the transition to a low-carbon economy.”