A Simplified Mathematical Model for Biomass Combustion in a Fluidized Bed Combustor

Abstract

The combustion of biomass fuels like rice husk, sawdust, groundnut shells etc. in a grate type furnace is slow and inefficient yielding low combustion efficiency. Fluidized bed combustion of these biomass fuels was shown feasible for efficient combustion along with high combustion intensity. A mathematical model has been developed for the exit-gas composition and combustion efficiency for a laboratory scale fluidized bed biomass fuel combustor. The model allows for bubble-size variation with height and predicts the consumption of oxygen and its variation along the height, outlet-gas composition, oxygen concentration in different phases i.e., bubble, cloud-wake and emulsion phases, average O2 concentration along the bed height and combustion efficiency. Model predictions are compared with the literature data and reasonable agreement has been obtained.