The Importance of the Heterogeneous Reactions in the Formation and Destruction of NOx from Char Combustion

Abstract

AbstractThis paper presents a theoretical study of the NOx behavior in a char‐NO‐N2‐O2 system in order to assess the importance of the gas‐solid reactions on NOx emission using a model described by Feng et al. (1997). The results show that gas‐solid reactions can be important in the NO destruction in the cases of both fuel‐lean and fuel‐rich conditions, depending on the heterogeneous reaction rates. The reaction of NO with char does not appear to be important if Levy's rate is applied. However, the reaction becomes important if Chan 's reaction rate is applied. Levy's rate has been used frequently in CFD codes and the heterogeneous reactions have been thought to be unimportant when using Levy's rate. This study shows that the heterogeneous reactions may be important if the reaction rate of NO with char increases.