Hydrodynamic Modelling of Coal-Biomass Mixture in a Bubbling Fluidized Bed Reactor

Biomass is a renewable and sustainable energy source. Co-firing of biomass with coal will increase the renewable energy share by decreasing the coal consumption. In the present paper, hydrodynamic behaviour of coal and biomass mixture is investigated in a fluidized bed reactor. A Computational Fluid Dynamic (CFD) model is developed and the hydrodynamic behaviour of gas and solid is investigated in detail. The CFD model is based on Eulerian-Eulerian multiphase modelling approach where the solid phase properties are obtained by applying the Kinetic Theory of Granular Flow (KTGF). Six different weight percentages of coal and biomass (۱۰۰:۰, ۹۵:۵, ۹۰:۱۰, ۸۰:۲۰, ۷۰:۳۰ and ۵۰:۵۰) are used for the present study. The hydrodynamic behaviour is analyzed in terms of the important hydrodynamic parameters like bed pressure drop, bed expansion ratio, particle volume fraction distribution and velocity distribution. The numerical model is also validated by comparing some of the numerical results with our own experimental data generated in a laboratory scale bubbling fluidized bed reactor.

Keywords:

Hydrodynamics , CFD modelling , Fluidized bed , Biomass , Coal