The effect of particle polydispersion in a gasifier bed dynamics using Eulerian-Eulerian models

Abstract The influence of the coal particle size distribution on the performance of a fluidized bed gasifier is investigated by means of a multiphase Eulerian-Eulerian model embodied in the OpenFOAM CFD code. To distinguish the effects of combustion from those of particle segregation we compare the solutions obtained by modeling of solids as, alternatively, monodispersed or polydispersed particles; and as reactive or inert ones. Results reveal that the preferential motion of the smaller particles towards the bed top significantly delays char consumption at the bottom layers, favors volatile oxidation, and results in a more uneven lateral distribution of the off-gas.