Abstract: Separated-gasification chemical looping combustion (SGCLC) has high conversion efficiency for solid fuels. Fuel reactor (FR) in SGCLC is designed as a gasifier (GR) and a connected reduction reactor (RR) with gas, sand and oxygen carrier (OC) phases. In order to clearly know the multiphase flow characteristics, a FR prototype is designed and the gas-solid hydrodynamics in FR are investigated using computational fluid dynamic (CFD) method. The gas velocity and OC flowrate are changed in simulations to study their effects on flow behaviors. Bubble probability in GR increases from 0 at bottom to 0.64 at 0.33 m while the gas volume fraction reaches 0.80 herein under fundamental condition. Spatiotemporal statistical results of the characteristics of gas and solid phases demonstrate that increasing gas velocity can enhance the heterogeneity of pressure and gas velocity distributions in GR. The mean values of pressure and gas velocity standard deviations increase from 13.71 Pa to 18.66 Pa and from 2.08 m/s to 2.55 m/s at 0.33 m when gas velocity accelerates from 1.8 m/s to 2.2 m/s. On the contrary, it has opposite effect on heterogeneity of pressure distribution in RR. Increasing OC flowrate from 0.6 kg/s to 0.8 kg/s can enlarge OC inventory in RR and enhance the standard deviation of pressure distribution in RR. The mean value of pressure standard deviations in RR increase from 3.12 Pa to 4.82 Pa at 1.85 m. The gas-OC mixing and contact can be improved for sufficient combustion reaction.