To verify the optimal models for a two-dimensional (2D) full loop simulation of a circulating fluidized bed (CFB), different turbulent models and drag models are studied according to relevant pressure profile, voidage distribution and particle collision energy. With regard to a laminar model and turbulent models including Standard k-epsilon, RNG k-epsilon and Realizable k-epsilon, the experimental data reveals that the RNG k-epsilon model is the best at predicting pressure, voidage, axial solid velocity and granular temperature. Besides, through the comparison of four drag models, it is found that the Gidaspow model can achieve a higher accuracy of prediction. Therefore, it can be concluded that the combination of the RNG and Gidaspaw models is suitable for the 2D full loop simulation of a CFB, and therefore potential models for the prediction of flow characteristics. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.