Zeolite foam shows promise for use in better carbon-capture filters

In order to both reduce greenhouse gas emissions and harvest useful byproducts, scientists are increasingly investigating methods of capturing the carbon dioxide that's emitted by industrial smokestacks. A new filtration material may make doing so easier and more efficient than ever before.

Developed via a partnership between Sweden's Chalmers University of Technology and Stockholm University, the solid foam-style substance consists of tiny zeolite particles combined with gelatine and cellulose.

Zeolites are a type of aluminosilicate mineral, which are in turn silicates wherein aluminum replaces some of the silicon. Because zeolites are very porous, they're quite good at adsorbing carbon dioxide. That said, traditionally-produced and -implemented zeolite particles have reportedly proven difficult to work with, limiting their usability.

The new foam is claimed to get around this problem, first by utilizing particles that are much smaller than usual, thus increasing the total zeolite surface area. Secondly, because the particles are suspended three-dimensionally within a foam matrix, they're more accessible to CO2 that is passing through smokestack filters made out of that open, porous foam.

Up to 90 percent zeolites by weight, the material is not only said to be highly effective at adsorbing CO2, but it's also composed of what are described as environmentally-friendly materials. Additionally, it's reportedly lightweight, inexpensive, durable, and can be reused many times after the captured CO2 has been removed for conversion into products such as calcium carbonate.

"What surprised us most was that it was possible to fill the foam with such a high proportion of zeolites," says Chalmers PhD student Walter Rosas Arbelaez. "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."

A paper on the study, which was led by Chalmers' Prof. Anders Palmqvist, was recently published in the journal ACS Applied Materials & Interfaces.

Source: Chalmers University of Technology