Science

This foam can absorb CO2 from the atmosphere

Carbon Capture and Storage could have its breakthrough moment, thanks to zeolites.

by Thor Benson
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Carbon capture is a fascinating technology that the United Nations reports claim will be needed to avoid the possibly catastrophic effects of climate change. By removing CO2 from places where fossil fuels are being burned and from the atmosphere, Carbon Capture and Storage (CCS) can help not only stop greenhouse gas levels from increasing but could begin to reverse the buildup of greenhouse gases. Now, researchers in Sweden have developed a new foam that can help make this process more sustainable and cost-effective.

In a new study published in the journal ACS Applied Materials & Interfaces, researchers from Sweden’s Chalmers University of Technology and Stockholm University explain how a “bio-based hybrid foam” can be used to capture the CO2. This new material was made by combining gelatin and cellulose with zeolites, minerals known for their absorbent properties. The researchers claim this new material is cheap and absorbs CO2 extremely well.

Walter Rosas Arbelaez, a Ph.D. student at Chalmers’ Department of Chemistry and Chemical Engineering and one of the researchers behind the study, said in a statement that all of the compounds work really well together.

“Together, this makes a durable, lightweight, stable material with a high reusability,” Arbelaez said. “Our research has shown that the cellulose does not interfere with the zeolites’ ability to adsorb carbon dioxide. The cellulose and zeolites together therefore create an environmentally friendly, affordable material.”

As of now, carbon capture typically uses a solution that’s related to ammonia to absorb the CO2. The solution is heavy and not environmentally friendly. With this foam, the process could be sustainable and less difficult.

The foam they developed is so light it balances on a flower.

Luis Valencia

Professor Anders Palmqvist, research leader for the study at Chalmers, said in a statement that the fact it’s a solid substance helps simplify things.

“In addition to bio-based materials being more environmentally friendly, the material is a solid—once the carbon dioxide has been captured, it is therefore easier and more efficient to separate it than from the liquid amine solutions,” Palmqvist said.

However, some say it might not be quite as easy as these researchers claim. Howard Herzog, a senior research engineer at the MIT Energy Initiative, tells Inverse that it can be difficult to remove CO2 from zeolites.

“Big question to ask is how do they remove the CO2 from the zeolite,” Herzog says. “This issue of regeneration has been a major obstacle for using zeolites and other adsorbents in CO2 capture.”

Of course, you only need to remove the CO2 from the material if you’re intending to use it for fuel or something along those lines. If your goal is simply to capture the CO2 and store it somewhere, then there’s no need to remove the CO2 from the material.

See also: Carbon capture could become a big business, but should it?

The researchers claim in their study that their material is easier to work with than other materials that utilize zeolites because they prepared them as smaller particles in suspension in cellulose foam, rather than using larger zeolite particles as others have.

“What surprised us most was that it was possible to fill the foam with such a high proportion of zeolites. When we reached 90% by weight, we realized that we had achieved something exceptional,” Arbelaez said. “We see our results as a very interesting piece of the puzzle in the search for a solution to the complex challenge of being able to reduce the amount of carbon dioxide in the Earth’s atmosphere quickly enough to meet climate goals.”

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