Thermo-chemical conversion of biomass using Dual Fluidized Bed (DFB) gasifier is proven to be a promising way for the production of H2 rich syngas. In the present work, the hydrodynamics in the DFB gasifier is investigated experimentally and with Computation Fluid Dynamics (CFD) at cold flow conditions. Three-dimensional Eulerian-Eulerian multi-phase model combined with the kinetic theory for the granular phase has been applied to investigate unsteady-state behaviours of a DFB gasifier. The developed CFD model is validated with experimentally obtained pressure distributions across the riser. The model prediction shows deviation from experimental results (10-14%), which are mainly due to the Gidaspow drag model over predicting drag force. Simulation results are presented in terms of the pressure profile, solids hold-up and solid circulation rate.
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