Kinetic analysis of reversible solid-gas reactions in films: application to the decomposition of CaCO₃ and BaCO₃ carbonates

To determine the decomposition conditions of carbonates in the form of films, we investigated the dependence of the kinetics on carbon dioxide partial pressure, temperature and film thickness. Three different analyses allow us to determine the functional dependence of the decomposition onset temperature on the CO ₂ 2 partial pressure, of the reaction rate on the temperature and of the kinetics on the film thickness. The latter analysis also reveals geometrical aspects of the reaction mechanism. Experiments have been carried out with CaCO ₃ 3 and BaCO ₃ 3 films. The simple geometry of the films and their relatively fast heat and gas transport allow the reaction kinetics to be easily explored.