The calcium looping technology using entrained flow reactors seems particularly suited for integration in cement plants due to the fine particle diameters and high gas velocities that are characteristic of these plants. However, there is little experimental information available in the literature on the carbonation performance of fine CaO-based particles with a few seconds of gas/solid contact times. In this work, the carbonation of calcium oxide has been experimentally investigated in a 6 m long and 0.1 m internal diameter drop tube reactor. Carbonation tests between 600 and 700 °C using sorbents with different CO2 sorption capacities have been carried out.The effect of the carbon dioxide and steam on the extent of the carbonation reaction has been evaluated.