Numerical modelling of different solid fuel combustion and gasification in fluidized bed under air and oxy-fuel conditions

This thesis presents an extensive numerical study of combustion and gasification of different solid fuels in fluidized bed combustors using Computational Fluid Dynamics (CFD) modelling techniques. The combustion and gasification models are developed and coupled with the Eulerian-Eulerian gas-solid flow model in the commercial CFD software AVL Fire. The model is capable of solving solid hydrodynamics and complex thermal conversion of different fuels and applied to simulate thermal conversion of various solid fuels, such as coal, biomass and sewage sludge, using air and oxygen enriched recycled flue gas in bubbling fluidized bed combustors of different scale sizes.