Siderite decomposition at room temperature conditions for CO2 capture applications

The decomposition of synthetic siderite (FeCO3) in air atmosphere at room temperature conditions was studied. Siderite was formed by mechanochemical reaction of Fe3O4 and graphite at high CO2 pressure in the presence of water. Kinetics of decomposition reaction was studied over period up to 9 days and it is shown that decomposition reaction obeys geometrical contraction solid-state reaction mechanism model. It was found that the water influences not only the kinetics of siderite formation but also its stability. Siderite completely decomposes at ambient conditions yielding magnetite (Fe3O4) and hematite (Fe2O3) which can reversibly re-absorb carbon dioxide.