Iron oxides as efficient sorbents for CO2 capture

Abstract Carbon dioxide capture/release reactions using magnetite, Fe 3 O 4 , and hematite, Fe 2 O 3 , as sorbents were studied. Kinetics of mechanically activated chemical reactions between iron oxides and CO 2 was investigated as a function of CO 2 pressure and planetary ball mill process parameters. It was found that complete carbonation of iron oxides can be accomplished at room temperature and elevated CO 2 pressure (10–30 bar). Siderite calcination was studied in vacuum and argon atmospheres. FeCO 3 can be decomposed at 367 °C yielding magnetite, carbon and/or iron. This mixture can reversibly re-absorb carbon dioxide in multiple carbonation–calcination cycles. These results suggest that siderite or iron oxides are prospective and efficient reversible sorbents for CO 2 capture.