The hydrodynamics in a gas-solid airlift loop reactor were simulated by using two-fluid model and granular kinetics theory in this paper.The gas-solid inter-phase drag force function included in the two-fluid model was modified accounting for the interparticles clustering.The simulated time averaged values of solid fraction and particle velocity agree well with the experimental data

verifying the feasibility of the numerical simulation method.The simulated results demonstrate that the profiles of transient solid fraction present the similar heterogeneous feature of aggregative fluidization usually occurred in normal fluidized beds.The axial profiles of bed pressure fluctuation qualitatively reflect the information about the bubble movement in a certain extent.The time series of particle velocity and their probability density functions display that both the particle upward and downward movement appears at each local bed position.The microcosmic internally circulating flow pattern of particles exists simultaneously when the mainstream of particles move upward in the bed.The particle transient velocity profiles offer a microcosmic interpretation for the macroscopical lateral nonuniform distribution of time averaged particle velocity.