Environment

"Electro-swing" battery captures CO2 from power plants or ambient air

"Electro-swing" battery captur...
A diagram detailing the new device from MIT. Air or flue gas can be pumped into the device (bottom), which captures carbon dioxide (red) from it, leaving only fresh air (blue) to come out. When the device is full, it can be flushed out and captured as pure CO2 for industrial use
A diagram detailing the new device from MIT. Air or flue gas can be pumped into the device (bottom), which captures carbon dioxide (red) from it, leaving only fresh air (blue) to come out. When the device is full, it can be flushed out and captured as pure CO2 for industrial use
View 2 Images
A render of the system as it may appear in a power plant setting. Incoming flue gas can be sent into one of the two large chambers to capture CO2 from it, while the other is discharging its own captured CO2 into a separate collection chamber (right)
1/2
A render of the system as it may appear in a power plant setting. Incoming flue gas can be sent into one of the two large chambers to capture CO2 from it, while the other is discharging its own captured CO2 into a separate collection chamber (right)
A diagram detailing the new device from MIT. Air or flue gas can be pumped into the device (bottom), which captures carbon dioxide (red) from it, leaving only fresh air (blue) to come out. When the device is full, it can be flushed out and captured as pure CO2 for industrial use
2/2
A diagram detailing the new device from MIT. Air or flue gas can be pumped into the device (bottom), which captures carbon dioxide (red) from it, leaving only fresh air (blue) to come out. When the device is full, it can be flushed out and captured as pure CO2 for industrial use

Researchers at MIT have developed a new method for pulling carbon dioxide out of any passing gas stream – whether that’s a chimney flue at a power plant or even just ambient air. The new device is basically a specialized battery that can absorb carbon dioxide while it’s charging, then release it as a pure, steady stream for industrial use when discharging.

The new device is made up of chambers that hold an array of battery electrodes, arranged in stacks with small gaps between them that allow gas to flow through. These electrodes are coated in a compound called polyanthraquinone, which is made up of carbon nanotubes.

When the battery is charging, an electrochemical reaction takes place at the surface of each electrode stack. Because the electrodes have a natural affinity for carbon dioxide, molecules of it floating past will be attracted to them, sticking to the walls of the electrode.

When those electrodes are too full of CO2 to hold any more, the system can then be run in reverse to clear it out. Discharging the battery will detach the molecules from the walls, where they can then be blown out into a separate chamber as pure CO2, which itself is a useful industrial product.

The team says that the most useful aspect of the device’s design is that the electrodes’ affinity for carbon dioxide is essentially all or nothing – when it’s charging, it has a high affinity for the molecule, but while discharging it drops to basically zero, efficiently clearing out the captured carbon.

“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,” says Sahag Voskian, co-lead author of the study. “This binary affinity allows capture of carbon dioxide from any concentration, including 400 parts per million (the levels in the atmosphere), and allows its release into any carrier stream, including 100 percent CO2.”

A render of the system as it may appear in a power plant setting. Incoming flue gas can be sent into one of the two large chambers to capture CO2 from it, while the other is discharging its own captured CO2 into a separate collection chamber (right)
A render of the system as it may appear in a power plant setting. Incoming flue gas can be sent into one of the two large chambers to capture CO2 from it, while the other is discharging its own captured CO2 into a separate collection chamber (right)

The researchers say that the system could be scaled up relatively easily, and outlined how it might be put to work in, for example, a power plant setting. Two sets of these electrode stacks could be placed in a flue, with one charging and one discharging at any given time. Exhaust gas is directed into the charging electrode stacks to capture CO2, while the others are discharging and releasing the captured carbon into a separate chamber. When the charging stacks are full, the process is reversed, letting them empty their CO2 cache while the gas is diverted to the freshly-discharged stacks.

That process would not only drastically reduce the CO2 pumped into the atmosphere, but it would produce a steady stream of pure CO2 gas. This can then be used in applications such as carbonating drinks or feeding plants in greenhouses, which normally have to make it from scratch, often by burning fossil fuels. Otherwise the gas could be sequestered straight underground, or processed into other fuels.

The team says that the device is relatively energy efficient, using up about one gigajoule of energy per ton of carbon dioxide captured. Others, they say, can consume between one and 10 gigajoules per ton. Better yet, other similar systems usually require more energy like heat, or chemical processing to release the captured carbon.

In lab tests, the researchers showed that it could endure 7,000 charging and discharging cycles, with a 30 percent reduction in efficiency. In the future the team believes that it can be bumped up to 20,000 to 50,000 cycles.

The research was published in the journal Energy and Environmental Science. The device is demonstrated in detail in the video below.

Electro-swing adsorption for high efficiency carbon capture

Source: MIT

5 comments
paul314
If you sourced that gigajoule from combustion-based sources, it would release about 200-250 kg of CO2, so at least the net would still be going in the right direction. Better to use something renewable and non-combustion though.
DaveWesely
Pulling CO2 from the atmosphere is better than sourcing it from oil. But in the grand scheme of things, it doesn't solve our Global Warming problem. All of these industrial uses of CO2 just release it back into the atmosphere. Whereas plants pull CO2 out of the atmosphere and turn the carbon into a solid compound. As long as you don't burn or decompose it back into CO2, it can be easily sequestered. Of course subsidizing that process benefits farmers, not oil companies.
Brian M
@DaveWesely Article does say it could be sequestered straight underground so removing it from the atmosphere or used to make fuel, so recycling the CO2. So if it works seems to be a good additional breakthrough in science's arsenal to help us combat climate change.
meofbillions
It's a shame the writer of the article doesn't understand the device. In the video, what is the "electrochemical" activation and deactivation of the electrodes? The key to operation relies on that, and it isn't mentioned in the text.
WagTheSchmoo
Depressing to think how many supposedly educated folks believe in "climate change"/"global warming" ... most notably, "New Atlas" itself, which is obviously an outlet for the movement. The ONLY differences in our climate from the climates of billions of years on our planet are coming from "climate weaponry," mostly caused by orbiting satellite weapons and ground weapons, and mostly American, though there is a good probability that numerous other nations have joined forces with us to create the strange weather patterns and fires we've been seeing for several years. But anyone who denies the polluting of our air with heavy metals by the numerous large planes spewing "chemtrail" for the last 30 plus years all around the world is blind or lying or just plain dumb. The WHOLE raison d'être for this con is to MAKE MONEY ... LOTS OF MONEY for the WORLD COMMUNITY aka the UN, the EU, and numerous lesser agencies throughout the world. After Religion it is, in my opinion, the biggest con ever conjured by man. We rational, intelligent, honest, and patriotic humans must fight this con with everything we can. The alternative is an eventual One World Government with a small cabal of Gods at the top and millions of servants (slaves) beneath them. We cannot let this happen!