DAC Concrete for the US

​​Could this innovation provide a concrete solution to the climate crisis?

Two firms have joined forces to permanently store carbon dioxide (CO2) in concrete using pioneering innovation to help fight climate change.

The ground-breaking partnership between Californian-based Heirloom and CarbonCure Technologies in Canada has seen CO2 captured in a series of tests via direct air capture (DAC) technology.

The milestone demonstration project has been underway at Heirloom’s headquarters in Brisbane, California, where the company runs America’s only operational DAC facility. The Microsoft-backed start-up uses limestone to extract CO2 from the air as it is inexpensive and easy to obtain.

The process to remediate climate damage

The limestone is broken down into calcium oxide rock and CO2 gas, during the cyclic process, using a renewable energy-powered electric kiln to provide the heat.

The calcium oxide, once spread onto virtual trays, acts like a sponge to absorb CO2 from the air before it is returned to the kiln for a repeat procedure and the captured gas can then be stored safely underground or embedded in concrete.

Using its reclaimed water technology, CarbonCure Technologies injected the captured CO2 into the wastewater (collected from washing out concrete trucks) at a Central Concrete batch plant in San Jose, California. The CO2 then immediately reacts with cement in the water and mineralizes, permanently storing the CO2 and creating greener cement for reuse at various construction projects across the Bay Area.

The CO2 will not be returned to the atmosphere, even if the concrete is demolished, as it is sequestered as calcium carbonate.

The power of CO2 storage

The global building stock is expected to double by 2060 - equivalent to building another New York City every month - therefore concrete’s ability to store immense quantities of carbon dioxide in our built environment has opened new opportunities.

With a global transition towards generating zero-carbon energy, DAC technologies will be vital to mitigate previous carbon emissions and help decarbonize industries as they scale solutions to reduce carbon.

DAC technologies have recently received financial backing from the U.S. government through the Department of Energy’s $3.5bn DAC hub program and the Inflation Reduction Act (IRA).

Concrete is the world’s most used building material due to its durability, providing excellent permanent storage for CO2, at a crucial time when the world must eliminate all CO2 emissions by 2040, to meet the 1.5-degree climate target.

The built environment generates 40 percent of annual global CO2 emissions, comprising 27 percent from building operations and 13 percent from building, infrastructure materials and construction (otherwise known as embodied carbon).

A future with less CO2

Heirloom builds inexpensive DAC technology that permanently removes CO2 from the atmosphere, with a real path towards removing one billion tons of CO2 by 2035.
CarbonCure Technologies is a global leader in permanent carbon storage in concrete, licensing a series of carbon mineralization solutions for global concrete plants.

Central Concrete, a subsidiary of Vulcan Materials Company, was the first concrete supplier in the Bay Area to use CarbonCure’s technologies for ready-mixed concrete, and continually offers innovative solutions for building and infrastructure projects. The technical team focuses on sustainability and cutting-edge research to provide robust solutions for the built environment.

Robert Niven, Chair and CEO of CarbonCure Technologies, said: “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.”

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

Shashank Samala, CEO of Heirloom, said: “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.

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

Shaun Andah, Consultant – Sustainable Energy at Acre USA, said: “Heirloom and CarbonCure Technologies’ collaboration to permanently store CO2 in the concrete is a prime example of a new wave of carbon storage and removal technologies that are seamlessly incorporated into the production process.

“It is not enough for companies to design processes to remove and store carbon; there also needs to be a push to incorporate these technologies into production processes that would put carbon into the atmosphere in the first place. Companies like CarbonCure are changing the way we build out cities and helping to create a more sustainable and net zero future.”