The current demand for energy tends to rise. The resources used to produce energy or fuels are not sufficient to meet this demand. The awareness of the limited availability of fuels leads to increasing of attention to use biomass as an alternative fuel. Direct combustion of biomass gives a low efficiency. Therefore the converting of biomass to useful product is necessary. Gasification is one of the important technologies for converting biomass to gaseous product which gives high conversion and overall energy efficiency. The gasification of biomass in a fluidized bed offer advantages but the calorific value of gaseous product is relative low because of the dilution by amount of nitrogen from air used in a combustor. Dual-bed gasifier has been developed to overcome this weak point by separating the combustion and gasification zones. In oder to develop and improve the process, the understanding of the hydrodynamics inside dual-bed gasifier is required. In this study, computational fluid dynamics have been performed, Eulerian approach coupled with the kinetic theory of granular flow and chemicals reaction was applied. Commercial computational fluid dynamics software ANSYS FLUENT version 12.1 has been employed to simulate the hydrodynamic and chemicals reaction in dual-bed gasifier.
