A California startup using rocks to absorb carbon dioxide from the air has teamed up with a Canadian company to mineralize the gas in concrete, a first-of-its-kind technology tie-up they say could be a model for combating climate change worldwide.
Reuters he says:
Heirloom Carbon Technologies handed over about 30 kilograms of CO2 it managed to collect from the air around its headquarters in the San Francisco Bay Area to neighboring Central Concrete, a subsidiary of Vulcan Materials ( VMC.N ). Central Concrete announced Wednesday that it has incorporated the gas into concrete.
This amount of carbon dioxide (CO2) is equivalent to the exhaust emissions of driving approximately 120 km in a car.
The joint effort succeeded for the first time in absorbing carbon dioxide from the atmosphere using Direct Air Capture (DAC) technology. It was then secured in concrete, where the CO2 will remain for centuries, several scientists said.
Heirloom Carbon Technologies heats crushed limestone to release naturally absorbed CO2. He then places the CO2-absorbing limestone in columns, which act like sponges, soaking up the gas for three days.
The crushed limestone is then heated to release the carbon dioxide it has collected from the environment and the cycle repeats.
Canada CarbonCure, a concrete technology company, mixes CO2 with concrete ingredients, turning it into a concrete-strengthening mineral, reducing the need for cement – the part of concrete with the largest carbon footprint.