New system removes carbon dioxide from the air

Scientists at the Massachusetts Institute of Technology (MIT) have presented a method by which you can filter harmful substances or remove carbon dioxide from the atmosphere. The device requires virtually no energy to function.

The new system, developed by chemical engineers at the Massachusetts Institute of Technology (MIT), could provide a way to continuously remove carbon dioxide from a stream of gases or air. The key component is an electrochemically supported membrane, the filtration function can be turned on or off without the use of moving parts and with relatively little energy.

The membranes themselves, made of anodized aluminum oxide, have a honeycomb structure consisting of hexagonal holes. However, the passage of gas can be blocked by electrically covering the pores of the membrane with a thin layer of metal. This work is described in more detail in the journal Science Advances.

This “gas seal” can be used to continuously remove carbon dioxide from industrial exhaust gases and air, the paper says. Scientists have presented a concept for a device to show this process in action.

The device uses a carbon-absorbing redox material that is embedded between two switchable gas seal membranes. The sorbent and the gate membranes are in close contact with each other and are immersed in an organic electrolyte.

The two gate membranes can be opened or closed by switching the voltage polarity between them, causing zinc ions to move from one side to the other. Ions simultaneously block harmful substances, forming a metal film over it.

When the sorbent layer is opened to the side, the material easily absorbs carbon dioxide until it reaches its capacity. The voltage can then be turned off to shut off the supply side and open the other side, where a concentrated stream of almost pure carbon dioxide is released.

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