A multi-week test has demonstrated that carbon dioxide (CO2) from flue gas streams of natural gas- and coal-fired generating units can successfully be injected into concrete blocks to reduce carbon emissions.

Carried out by CarbonBuilt and the US Department of Energy’s National Energy Technology Laboratory’s (NETL) National Carbon Centre, the trial saw CO2 injected into more than 5,000 blocks where it is now stored for good.

Proved a success, it is believed that the technology used within the test, developed at the UCLA Samueli School of Engineering, could reduce concrete’s carbon emissions by more than 50%.

Called CarbonBuilt’s Reversa™ process, the technology utilises innovations to both the concrete mix design and the curing process. The Reversa formulation significantly reduces consumption of cement while enabling the increased and more flexible use of waste materials like fly ash or slag.

During the curing process, dilute CO2 from flue gas streams is directly injected into and permanently sequestered within the concrete, with no requirement for carbon capture or purification.

Commenting on the technology and the tests, Rahul Shendure, CEO of CarbonBuilt, said, “Our approach offers utilities and other industrial plants a pathway for beneficial reuse of CO2 emissions. At the same time, we offer concrete producers a way to increase operating margins significantly while reducing overall carbon emissions from production by more than 50%.”

“This winning combination could unlock gigaton-level emissions reductions in the coming years.”

Teams from CarbonBuilt, the National Carbon Capture Centre – which is managed and operated by Southern Company and sponsored by DOE’s NETL – UCLA and Blair Block worked to test CarbonBuilt’s Reversa technology under a range of conditions.

Post-production analysis of the blocks verified both the CO2 uptake from the flue gas streams and performance relative to industry standards. The testing was successful across all metrics.

John Northington, National Carbon Capture Centre Director and Director of Net-Zero Technologies for Southern Company, added, “Helping advance technologies toward commercialisation is the core of our mission.” 

“It is exciting to work with CarbonBuilt and UCLA to test and evaluate their concrete production technology. Utilising carbon dioxide to produce essential products like concrete will be an important solution as the world moves to reduce overall carbon emissions.”