Reduction of nitric oxide by carbonaceous solids in an atmospheric pressure fluidized-bed reactor

The fluidized-bed combustion process, due to its ability to control pollutant emissions and its inherent capability to accommodate a wide variety of fuels, has been the subject of accelerating development for industrial and utility applications. However, fluidized-bed combustion boilers based on the current design and operation may not be able to meet the future stringent standards on nitrogen oxides emissions without additional provisions. In this paper, a preliminary study on the reduction reactions of nitric oxide with three different carbonaceous solids using a 9.6-centimeter diameter, electrically heated, batch fluidized-bed reactor operated at various design and operating conditions is discussed. Results of this investigation indicate that the NO reduction reaction appears to be dependent upon not only the operating variables such as bed temperature, carbonaceous solid loading in the bed, but also on the physical properties of the carbonaceous solids as well. Prediction of NO reduction by one of the carbonaceous solids using a two-phase bubble model shows good agreement with experimental data within the range of experimental conditions.