The reduction mechanism and kinetics of CoO-NiO/Al2O3 oxygen carrier using methane as the reduction gas were studied. Kinetics experiments were conducted in a novel fluidized bed CREC riser simulator under turbulent fluidized bed reaction conditions. A shrinking-core model was used for the kinetic modeling assuming spherical grains of the oxygen carrier particles. In the bimetallic carrier, Ni was present mainly as NiO. Therefore, in particle conversion calculations NiO was considered as the only reducible oxide phase, under the selected reaction conditions. The pore size of the carrier particle slightly increased after reduction, which is an indication of a possible shrinking core model since the molar volume of Ni (6.6 cc/mole) was lower than that of NiO (7.54 cc/mole). This is an abstract of a paper presented at the AIChE Annual Meeting (San Francisco, CA 11/12-17/2006).