The global construction industry is responsible for over 11 percent of global carbon emissions, with over 50 billion tons of rock crushed worldwide every year. The current crushing processes used in construction and mining do not capture CO2.
The University of Strathclyde study shows that carbon dioxide can be trapped in a stable, insoluble form in rocks composed of multiple minerals by grinding it into CO2 gas. The resulting rock powders can then be stored and used in the environment for construction and other purposes.
Previous research explored trapping carbon into single minerals by the same method. Still, the study found that this carbon was unstable and dissolved from the mineral when placed in water.
According to the study, if the technology were used everywhere, it could take in 0.5 percent of the world’s CO2 emissions, or 175 million tons of carbon dioxide per year. But Norway was used as an example for the calculation because the country publishes yearly data on how much hard rock aggregate is made for their construction industry.
Other countries, such as Australia and South Africa, will produce far more, as they have large mining industries and will look to crush and sell the waste rock, while others may make less.
The research team hopes that the sector could cut down on emissions by making changes to the way things are set up so that carbon from polluting gas streams, like those from making cement or gas-fired power plants, can be trapped. The technology could reduce the CO2 footprint associated with building houses and public infrastructure, such as roads, bridges, and coastal defenses.