Comparison of combustion behaviors and pollutant emissions using bituminous coal and corncob in a fluidized bed combustor

Abstract

ABSTRACTThe combustion behaviors and pollutant emissions of corncob and bituminous coal in a pilot scale vortexing fluidized bed combustor was compared. The flue gas recirculation combustion mode was used in this study. The effects of operating parameters, such as stoichiometric oxygen ratio, and bed temperature on the pollutant emissions were investigated. The results show that the combustion fractions vary with different kinds of fuels, resulting in different CO and NOx emission characteristics. Corncob combusts primarily in the freeboard zone, whereas bituminous coal combusts primarily in the bed zone. Therefore, the CO emission decreases with the increasing bed temperature in bituminous coal combustion, whereas the effect of bed temperature on CO emission is not obvious in corncob combustion. The CO emission of corncob combustion decreases with the stoichiometric oxygen ratio, whereas the CO emission of bituminous coal combustion has the inverse trend. For both fuels, the NOx emissions increase with the bed temperature but decrease with the stoichiometric oxygen ratio. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.