The unsteady characteristics of bubble dynamics inside the air reactor within the first 0–40 s of reforming has always been studied for defining the design criteria of the reactor. In the study, a temporal aspect of the hydrodynamics and chemical kinetics in the reactor of a chemical looping reforming system in form of volume fraction contours of solid species and molar fraction of H₂O has been numerically simulated by considering manganese (Mn) and iron (Fe) based metal oxides as oxygen carriers. The Finite Volume Method based approach has been employed to simulate the steam reactor model by encompassing it as a fluidized bed reactor. The granular flow under kinetic theory has been employed using a multiphase Eulerian-based approach for both gas and solid phases in the form of a shrinking core model. An influence of various operating parameters such as particle size of the oxygen carriers, steam inlet velocity, and temperature of the steam reactor on an overall conversion rate of iron-based oxide (FeO) and manganese-based oxide (MnO). The maximum steam conversion rate for FeO and MnO was observed at 32% and 34% at 0.6 m/s steam velocity, 48% and 60% at a maximum temperature of 1273 K, and 47% and 64% at a particle size of 100 µm, respectively.