Magnesite, which the chemical formula is MgCO3, has the ability to absorb CO2 from the atmosphere in a sustainable manner. It consists of magnesium, carbon and oxygen. One tonne of magnesite is capable of capturing about 500 kg of carbon dioxide. This faculty is called mineral carbonation, it results from a reaction between magnesium (or calcium) and CO2 that causes the formation of so-called stable inorganic carbonates. These have no impact on the environment.
This rock is very rare on the planet. It takes hundreds of thousands of years for it to be formed. Currently, there is only one deposit still active on Earth, it is located in Australia. But researchers at Trent University in Ontario, Canada with the cooperation of the Canadian Ian Power were able to make it in less than 72 days at room temperature. It was already possible to manufacture it easily at temperatures between 60 and 90 ° C but at this level it was necessary to make energy expenditure and thus produce CO2.
The researchers used polystyrene microbeads to act as a catalyst, promoting and accelerating the chemical reaction that allows the formation of the mineral. It remains to be seen whether the experiment can be replicated on an industrial scale.
Calcite, which is very abundant on Earth, can also capture CO2 in large quantities. However, it is very sensitive to bad weather, rain, acidity. It dissolves quickly and unfortunately releases its carbon reserves. While magnesite is stable and carbon dioxide is captured permanently for millions of years.
There is currently 3200 gigatonnes of CO2 in the atmosphere, or 3200 billion tons of carbon dioxide! And every year it is 40 billion tons that are produced by mankind and are added to this gargantuan mass.