CO2 capture: why, how, with what constraints?

CO2 capture: why, how, with what constraints? Since 1900's, the fast-expanding industrialization has led to significant increase of CO2 emissions into atmosphere, which has contributed to global warming. In spite of alternative options development to reduce greenhouse effect (energy savings, green transport, and renewable energies), CO2 capture and storage is an interesting, perhaps inevitable climate change mitigation measure. In fact, one of the most significant sources of CO2 emissions worldwide is industrial fumes (flue gas stream, coal-fired power plants, refineries, cement, manufacturing plants). The process consists in recovering CO2 from flue gas streams, carrying by ships or pipelines and finally storing in depleted gas or oil fields or in deep saltwater aquifers. Among different considered solutions, post-combustion capture is now the most advanced technology because it can be applied to retrofit plants. Current applications are based on a reversible chemical reaction between CO2 and aqueous amine solution, which permits selective absorption. One of the main limits for this process is amine degradation, which leads to many by-products. These compounds generate many problems such as corrosion, fouling, solvent losses. As a consequence, the efficiency of capture units decreases and additional operating cost is a drawback. Thus, many investigations are still in course to improve this very promising concept.