Heating element of an air preheater in a utility boiler as an SCR reactor removing NO by NH3

Abstract

A heating element coated with V2O5-WO3/TiO2 catalyst has been prepared by a two-roll forward method as a parallel passage type reactor (PPR) for simultaneously exchanging heat and removing NO in the air preheater of a utility boiler. The performance of the heating element coated with the catalyst has been examined as a carrier for heat transfer and a catalytic reactor reducing NO in utility boilers. No alteration of the overall heat transfer coefficient of the heating element, PPR, due to the coating of the catalyst on the surface of the element has been observed. A reactor model has been developed for the design of a heating element as a PPR removing NO by NH3. The kinetic parameters obtained over the catalyst powder of V2O5-WO3/TiO2 are directly employed for estimating the performance of a heating element as a PPR. The model predicts NO conversion as well as NH3 slip quite well, regardless of the reactor operating conditions, including reactor space velocity, NH3/NO feed ratio, the length of the heating element, and reaction temperatures.