Mathematical Simulation of SO2 Emissions from a Fluidized Bed

In this paper a mathematical model and experimental techniques to describe the combustion behavior of coal and biomass in a fluidized bed is presented. This study sis of practical interest due to its significant involvement in heating systems and power plant operations. One dimensional Mathematical model is being developed to predict the SO2 emissions under different operating conditions like bed temperature, Ca/S molar ratio, solids circulation rate, excess air ratio and secondary to primary air ratio from a burning coal and biomass. For the fast section of the bed, momentum and energy balance equations are used to predict temperature and velocity profiles for gas and particles. The model performs mass balances for the chemical gas species (O2, H2O, CO2, CO and SO2) with consideration on the last being given for retention by limestone particles. A bubbling bed model is considered to simulate the bottom of the fluidized bed. These parameters are varied to validate the model and encouraging correlation is found between the experimental values and model predictions. The model is applied to typical conditions of a boiler and the results show the expected trends