co2

Earlier this year, a Swiss startup began removing CO2 from the atmosphere using a large vacuum-like machine.

Their ultimate goal is to start reversing the damaging effects of climate change by reducing CO2 — a major component of atmospheric pollution — on a global scale.

While the machine's development is a huge step forward, one little problem remains — where does all that collected CO2 go?

Gaurav Sant, a professor of civil and environmental engineering at UCLA, has one solution: turn it into cement.

(And we're not just talking about any old cement.)

Gaurav Sant. Photo via UCLA.

Sant has figured out how to make a stronger, more lightweight, more structurally sound cement out of — wait for it — CO2.

Believe it or not, the regular construction of cement is responsible for 9% of the world's CO2 emissions. And it is widely accepted that CO2 emissions play a huge role in global warming and, by effect, climate change.

Sant, along with his team at UCLA, decided to try to turn two negatives into a positive. They found a way to integrate CO2 into the production of cement, thereby keeping it out of the atmosphere and upcycling it into something useful and even profitable.  

It all started from tiny cement cylinders created by Sant's 3D printer.

Sant with his 3D printer. Photo via UCLA.

Well, that and a pretty important discovery of how CO2 can help accelerate the cement-making process.

In simplest terms, Sant's team discovered that the CO2 in flue gas streams from coal and natural gas power plants accelerates the mineral-making processes that can be used to create cementing agents. They decided to use CO2 to produce a new type of concrete that they've named CO₂NCRETE^TM.

Curious how they did that? Here's the breakdown.

When a mineral called portlandite absorbs CO2, it turns into limestone, which is a cementing agent. While this process normally takes years to happen naturally, Sant's team figured out how to make it happen quickly — 450 pounds of CO2 into several tons of CO₂NCRETE^TM quickly — and efficiently using their 3D printer.

Unlike traditional cement-making on a construction site, 3D technologies allow them to create basic construction pieces out of their new CO2-based concrete that fit together perfectly.

This means they can make cement pieces that are stronger, more lightweight, and more structurally sound.

Sant with a fellow researcher creating cones of CO₂NCRETE^TM. Photo via UCLA.

"As a child that played with Legos, I have long recognized that the idea of constructing buildings and infrastructure like a large Lego set is (a) fast, (b) intuitive, and, (c) offers improved quality control since 'factory made' pieces are simply assembled on site," Sant explains in an email.  

What sort of impact could this have on reducing global CO2 emissions? Turns out, a pretty big one.

[rebelmouse-image 19475646 dam="1" original_size="600x338" caption="Traditional concrete being poured. Photo by Circe Denyer/PublicDomainPictures.net." expand=1]Traditional concrete being poured. Photo by Circe Denyer/PublicDomainPictures.net.

According to Sant and his team, if CO₂NCRETE^TM were to be mass-produced globally, it could reduce CO2 emissions from traditionally made cement by 50%. And since those emissions currently make up 9% of all CO2 emissions on the planet, that's no small amount.

What's more, since there's been little change made in the construction industry over the last two centuries, it's primed for an efficiency makeover.

"CO₂NCRETE^TM has the potential to serve as an example of how CO2 emissions — even those associated with dilute CO2 streams — can be repurposed to create value and minimize environmental impact," writes Sant.

[rebelmouse-image 19475647 dam="1" original_size="1280x854" caption="Photo by Robert Jones/Pixabay." expand=1]Photo by Robert Jones/Pixabay.

And it's not like this goal is a faraway dream. They've made incredible progress on this new cement and are starting to shop it around.

They've figured out how to streamline the cement-making process so it takes much less time and energy than it did initially. They've also done an analysis of the construction market and see huge potential for such a sustainable product.

"This is especially significant as jurisdictions, globally, including states and nations, seek to limit CO2 emissions and impose CO2 penalties on industrial processes," writes Sant.

And in terms of progress with CO2 capture, Sant's work could offer an economically viable alternative to storing the CO2 underground, which can get pretty expensive.

If the world recognizes the economic value of upcycled cement along with the environmental impact, this discovery could revolutionize the future of construction.

[rebelmouse-image 19475648 dam="1" original_size="1280x720" caption="Photo by Pexels/Pixabay." expand=1]Photo by Pexels/Pixabay.

Engineering solutions like this can offer a way to mitigate climate change and be profitable at the same time. Now it's just about keeping an open mind and seeing the enormous potential in a small, concrete cylinder.

As for Sant and his associates, they're just thrilled to be on the precipice of real, necessary change.

"As humans, we all want to make positive impact," says Sant. "To be a part of the solution is a very empowering accomplishment that we wish to socialize."