3D Numerical Simulation of Gas Flow and Selective Catalytic Reduction (SCR) of NO in the Honeycomb Reactor

Abstract

Selective catalytic reaction(SCR) of NOx by ammonia is a very efficient method to reduce the NOx emission from coal-fired power plants and large boilers. The ammonia is injected into the exhaust gas stream and is mixed NOx. The mixture passes through the honeycomb-type catalyst bed, where NOx reacts on the catalyst surface with adsorbed ammonia in the presence of excess oxygen, decomposing into diatomic nitrogen and water molecules, thereby reducing the NOx level in the exhaust gas. The present study discusses theNOx reduction mechanism in the honeycomb channel. In this work, 3-dimensional computational fluid dynamics (CFD) simulations are carried out to investigate the effects of the various state parameters on the De-NOx reaction at the catalyst. Research results showed that the gas temperature, flow velocity and concentration ratio all are important parameters of theNOx reduction with ammonia in the honeycomb catalyst.