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Practical Magic

Carbon-sucking concrete is capturing attention and funding

CarbonCure technology image

CarbonCure's technology can be installed at a concrete plant in one day.

CarbonCure

Carbon-sequestering concrete is having a moment.

In mid-April, two climate-tech startups focused on decarbonizing the world’s most widely used construction material, CarbonCure Technologies and UCLA CarbonBuilt, split the top prize in the $20 million NRG COSIA Carbon XPRIZE competition. Each will receive $7.5 million to further the development and commercialization of their approaches.

Both startups address CO2 at the manufacturing site. The UCLA CarbonBuilt approach captures CO2 generated during production and then infuses it into the concrete, using hydrated lime. The process uses 60 to 90 percent less ordinary portland cement (aka calcium silicate cement), and it doesn’t require as much heat, which has an energy efficiency benefit. CarbonCure also fixes CO2 into concrete. Its equipment (roughly the size of a microwave) is installed for free, but the company using it needs to purchase CO2 elsewhere. Right now, that CO2 is food-grade, but the idea is that it eventually could be collected anywhere. 

Jennifer Wagner, president of CarbonCure, said her company’s technology is installed in about 300 plants — it added 50 units in the first quarter of this year. (For perspective, there are about 100,000 concrete factories globally.) CarbonCure’s technology is finding proponents among manufacturers setting carbon-reduction goals as well as with companies looking to invest in projects that sequester CO2 permanently, including Shopify and Stripe. Amazon and Microsoft are also among its backers. CarbonCure’s ambition is to help sequester 500 million metric tons of CO2 annually by 2030. 

"What makes us unique is how scalable our solution is, and how it integrates with the existing supply chain," Wagner told me.

Two other teams focused on turning captured carbon dioxide into material for revenue-generating products also received recognition. They are Carbon Upcycling and Newlight Technologies, which collaborated to test nanoparticles that could have an application in construction; and Carbon Corp., which is turning CO2 into nanotubes that could be used in building products or, ultimately, for industrial catalysis, batteries or nanoelectronics.

What makes us unique is how scalable our solution is, and how it integrates with the existing supply chain.

When I spoke with him about the results, Marcius Extavour, vice president of climate and energy at XPRIZE, told me that while the focus of the competition wasn’t explicitly concrete, he wasn’t surprised by the outcome. "There is a huge opportunity; these aren’t niche solutions," Extavour noted, particularly in developing economies.

The traditional process of making concrete accounts for nearly 10 percent of all global carbon dioxide emissions, while the U.S., China and India accounting for the largest portion of that footprint, according to a report about potential decarbonization solutions for the sector published by ClimateWorks Foundation. The focus on concrete is particularly timely, given the trillions of dollars that could be spent on infrastructure projects during the COVID-19 recovery. "One clear conclusion we arrived at in the course of our research is that there is no single solution, but rather a range of small and large changes that will be necessary to achieve net-zero emissions targets," wrote one of the report authors.

The Portland Cement Association (PCA), which represents producers of cement, a core component of concrete, last November published its "ambition" to make the cement and concrete industries carbon neutral by 2050. It’s focusing, among other things, not just on the production process, but also on addressing policies and building codes that make the transition tougher, said Rick Bohan, vice president of sustainability at PCA. "There is a huge desire to make this happen … With the right incentives in place, we could do that."

Oodles of startups also are focused on making the process of concrete production less carbon-intensive.

Keep your eyes on Solidia Technologies, which last week disclosed a $78 million funding round (including new backing from previous investors John Doerr and Bill Joy) and named a new CEO with long-time connections in the industry. Solidia binds CO2 into its materials and uses a less energy-intensive production process. 

Another one I’m watching is Nexii Building Solutions, which is producing lightweight panels that can be bolted together on construction sites. The company touts its ability to dramatically cut construction waste, and its material has been used in about a dozen buildings, including a Starbucks cafe built in just six days, reducing the embodied carbon associated with the project by an estimated 30 percent. Nexii has some pretty intriguing backers and advisers, including actor Michael Keaton (who is helping the company build a factory in Pittsburgh) and Ronald Sugar, chairman of Uber and an Apple board member. 

By the way, XPRIZE is seeking entries for a new $100 million competition intended to catalyze carbon removal approaches, funded by Elon Musk’s foundation. The focus is on technologies or nature-based solutions that pull CO2 directly from the air or oceans. Take heed: "Fully operational solutions are required to win." 

This story was updated May 7 to clarify the impact of Nexii's material.

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