The present Computational Fluid Dynamics (CFD) work deals with the modeling of complete coal direct chemical looping sub-pilot unit which use coal as fuel and ferric oxide supported on alumina as an oxygen carrier. The 2D CFD model of the complete arrangement incorporating both fuel and air reactors and their inter-connecting parts was solved using FLUENT. The CFD model was run with two different sets of reactions - the first set with eleven and second set with eighteen reactions. Computed results for second set of reactions were found to be in good agreement with the published pilot plant data. The CFD model with second set of reactions predicted fuel conversion for Sub-Bituminous Coal (SBC) and Metallurgical Coke (MC) were 95.39% and 87.07% respectively while, the published results were 97-99% and 70-99% respectively. Further, the purity of CO2 in fuel reactor exhaust were 92.34% and 90.19%, while, the published were 99.8% and 99.6% for SBC & MC respectively.