Computational fluid dynamics of dual fluidized bed gasifiers for syngas production: Cold flow studies

Thermo-chemical conversion of biomass using Dual Fluidized Bed (DFB) gasifier is proven to be a promising way for the production of H-2 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. (c) 2020 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.