Safe and quick carbon sequestration

Geological sequestration of carbon dioxyde is considered as an important tool to fight global warming but long term safety is an essential issue due to the risk of accidental leakages. The CarbFix experimentation has shown the possibility to turn hundreds tons of CO₂ into inert carbonated rocks in less than 2 years. This CO₂ injection took place in basaltic rocks. Basaltic rocks allows an adequate diffusion of the gas because of its porosity and favors the acido-base chemical reaction that turns CO₂ into inert and stable carbonates. This experiment was performed with CO₂ dissolved in water in order to limit leaks, basaltic layers being naturally cracked, and to accelerate the formation of carbonates by dissolving the metal ions coming from the rocks. The important quantity of water required for this technique, limits its use to coastal sites. (A.C.)