The development of new energy technologies to harness renewable energies, such as diluted and intermittent solar and wind power, requires the development of energy storage processes. One way of storing these energies is to transform them into chemical energy. The most classic example is the electrolysis of water into hydrogen, which can then be used as a fuel, notably in fuel cells. What we're dealing with here is the storage of renewable energies by converting carbon dioxide into carbon molecules, through the formation of energy-rich carbon-hydrogen and carbon-carbon bonds. In a way, it's a case of going backwards. The increase inCO2 in the atmosphere comes from human activities, through the combustion of oil, gas and coal. With this strategy, the dream is to recover thisCO2 and transform it into fuels, thus closing the virtuous cycle.CO2 then becomes a molecule worthy of interest, a rich source of carbon for human uses, and no longer the molecule accused of all the evils (global warming).
Unfortunately, the challenge is enormous, given the stability of theCO2 molecule and the difficulty of activating it to transform it. The constraints are not only thermodynamic, but also kinetic. This calls for the development of high-performance processes, including efficient catalysts for the reactions under study. The lecture discusses current research into the various chemical, photochemical, electrochemical, enzymatic and biotechnological processes for recoveringCO2.