Three-dimensional full-loop simulation of a dual fluidized-bed biomass gasifier

A three-dimensional CFD model was developed to simulate the full-loop of a dual fluidized-bed biomass gasification system consisting of a gasifier, a combustor, a cyclone separator, and a loop-seal. This full-loop simulation includes the chemical kinetic modeling of biomass drying and pyrolysis, heterogeneous char reactions, and homogeneous gas-phase reactions. In the model, the gas phase is described using Large Eddy Simulation (LES) and the particle phase is described with the Multiphase Particle-In-Cell (MP-PIC) method. The simulation was performed using the GPU-accelerated computing and the simulation results were compared with the gas composition and temperature measurements from a pilot-scale biomass gasification power plant (1 MWth, 6 tons biomass/day). The independence of the accuracy of the model on mesh resolution and computational particle number was determined. The impacts of the particle size distributions (PSD) and drag models on the reactive flows were also investigated.