Revolutionary Method for Removing Carbon Dioxide from Air Developed

There's a new way of removing carbon dioxide from the air and it could prove a game-changer. This is because the new system can work on the gas at virtually any concentration level.

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And unlike other variations that do work with lower concentrations, the new method is by far less energy-intensive and expensive. The system has been developed by MIT postdoc Sahag Voskian and T. Alan Hatton, the Ralph Landau Professor of Chemical Engineering.

A binary nature

“The greatest advantage of this technology over most other carbon capture or carbon absorbing technologies is the binary nature of the adsorbent’s affinity to carbon dioxide,” explained Voskian. “This binary affinity allows capture of carbon dioxide from any concentration, including 400 parts per million, and allows its release into any carrier stream, including 100 percent CO₂."

The device is essentially a large battery that absorbs carbon dioxide from the air passing over its electrodes as it is being charged up. Then, as it is being discharged, it releases the gas.

The end-product is pure carbon dioxide that can be used in a variety of applications such as in soft-drink bottling plants or in the feeding of plants in greenhouses. The new system could eliminate the need for fossil fuels in these cases while actually removing the greenhouse gas right out of the air. 

The pure carbon dioxide stream released could also be compressed and injected underground for long-term disposal. The process this system uses for capturing and releasing carbon dioxide “is revolutionary” said Voskian.

A revolutionary process

“All of this is at ambient conditions — there’s no need for thermal, pressure, or chemical input. It’s just these very thin sheets, with both surfaces active, that can be stacked in a box and connected to a source of electricity," explained Voskian.

“In my laboratories, we have been striving to develop new technologies to tackle a range of environmental issues that avoid the need for thermal energy sources, changes in system pressure, or addition of chemicals to complete the separation and release cycles,” Hatton added. “This carbon dioxide capture technology is a clear demonstration of the power of electrochemical approaches that require only small swings in voltage to drive the separations.”​

Best of all, the system uses only about one gigajoule of energy per ton of carbon dioxide captured. The researchers are now working to commercialize the process and hope to develop a pilot-scale plant within the next few years.

The study is described in a new paper in the journal Energy and Environmental Science.