Holier-than-thou: Highly porous powder captures double the carbon
As CO2 emissions continue to rise and the world continues to warm, we're seeing more possibilities emerge around the idea of capturing carbon before it makes its way into the atmosphere. A promising new technology developed at Canada's University of Waterloo hinges on a special kind of powder that could be applied as a filter at power plants to gather CO2 molecules at the source, and is claimed to offer double the efficiency of the materials that are currently available.
A number of interesting technologies have popped up in recent years that could open up new pathways around carbon capture. A recent example from engineers at MIT borrows tiny snippets of plant cells and embeds them in hydrogel to pluck carbon out of the air. Another, less recent, example relies on highly porous metal organic frameworks activated by another natural element, sunlight.
The new technology developed by a team led by University of Waterloo chemical engineer Zhongwei Chen touches on both these themes, and makes use of the natural abilities of carbon to snap up CO2 molecules. These molecules will adhere to the surface of carbon when they come into contact with it, and Chen and his team have supercharged these abilities by tweaking the composition of the material.
Just like the engineers at MIT, the scientists extracted a carbon material from plant matter, in this case, in black powder form using heat and salt. This powder was made up of tiny carbon spheres already featuring tons of tiny microscopic pores, a very useful attribute for carbon capture. But the team was able to give this a huge boost via an ionic activation technique that allowed them to ramp up the porosity.
"The porosity of this material is extremely high," said Chen. "And because of their size, these pores can capture CO2 very efficiently. The performance is almost doubled."
The team imagines putting their highly porous powder to work at fossil fuel power plants, where it would become saturated with carbon dioxide and then stored in underground geological formations. That is an area where some particularly exciting progress is being made, with scientists in Iceland recently turning captured carbon into solid minerals within just two years.
"This will be more and more important in the future," Chen says. "We have to find ways to deal with all the CO2 produced by burning fossil fuels."
The research is to be published in the journal Carbon.
Source: University of Waterloo