CO2 captured with DAC in concrete for the first time, claim companies

Three groundbreaking new companies have managed to capture carbon dioxide (CO2) via Direct Air Capture (DAC) and claimed to have permanently stored it in concrete. 

Heirloom, CarbonCure, and Central Concrete, the climate tech companies' combined efforts, resulted in this big development, according to a joint press release by the three firms published on Friday.

"Heirloom captured CO2 from the atmosphere using their DAC technology at their headquarters in Brisbane, California," said the press release.

"CarbonCure’s reclaimed water technology injected the captured CO2 into the process wastewater at a Central Concrete batch plant in San Jose, California,"

The joint press statement further noted that "Central Concrete used the CO2-treated wastewater to make fresh concrete, which was produced for a range of construction projects across the Bay Area.”

Three unique roles for one purpose

Each company has its own unique role in storing CO2, complementing the work of the other.

Heirloom runs America’s only operational DAC facility and uses limestone to pull CO2 from the air. The limestone is broken down into calcium oxide rock, and CO2 gas. The captured CO2 gas is then permanently stored safely underground or embedded in concrete.

CarbonCure’s reclaimed water technology is then used to store Heirloom’s CO2 at Central Concrete. The technology injects CO2 into reclaimed water (recycled water collected from washing out concrete trucks) at concrete plants.

When injected, the CO2 immediately reacts with cement in the water and mineralizes, permanently storing the CO2 and stabilizing the cement for reuse. The CO2-treated slurry is then used in new concrete mixes.

“This demonstration project is a global milestone for carbon removal technology that confirms concrete’s enormous potential as a climate solution that can permanently store carbon in our most essential infrastructure - from roads and runways to hospitals and housing,” said Robert Niven, Chair and CEO of CarbonCure Technologies. 

“We’re thrilled to be collaborating with Heirloom and Central Concrete on this groundbreaking world first.”

As the world moves toward zero-carbon energy generation, the companies’ DAC technologies will play a key role in decarbonizing industries as they develop and scale carbon-cutting solutions.

“The science is clear: In order to reach climate goals, we must remove billions of tons of already emitted CO2 from the atmosphere each year,” said Shashank Samala, CEO of Heirloom. 

“This is an important step toward that future and shows the promise of DAC technologies combined with smart, permanent methods of sequestration.”

As one of the world’s most-utilized building materials, concrete provides an important repository for permanent CO2 storage. Globally building stock is expected to double by 2060, giving concrete a key opportunity to store immense quantities of carbon dioxide in our built environment.