Advances in Potassium Catalyzed NOx Reduction by Carbon Materials: An Overview

The research work conducted in our group concerning the study of the potassium-catalyzed NO x reduction by carbon materials is presented. The importance of the different variables affecting the NO x −carbon reactions is discussed, e.g. carbon porosity, coal rank, potassium loading, influence of the binder used, and effect of the gas composition. The catalyst loading is the main feature affecting the selectivity for NO x reduction against O 2 combustion. The NO x reduction without important combustion in O 2 occurs between 350 and 475 °C in the presence of the catalyst. The presence of H 2 O in the gas mixture enhances NO x reduction at low carbon conversions, but as the reaction proceeds, it decreases as the selectivity does. The presence of CO 2 diminishes the activity and selectivity of the catalyst. SO 2 completely inhibits the catalytic activity of potassium due to sulfate formation.