Sensitivity study of fluid dynamic effects on nitric oxide formation in CFB combustion of wood

The paper presents results from simulations by a 1.5D numerical model developed to study the formation of the NO and N2O emissions in a circulating fluidized bed combustor (CFBC) under different operating conditions and burning different fuels. A comprehensive kinetic scheme for the homogeneous chemistry and a single particle model for char combustion are used. Fluiddynamic factors, including gas mixing and release of volatiles, are investigated in the case of wood combustion under normal air staging conditions. The pattern of release of volatiles, the mixing of secondary air, and the lateral mixing of gas are observed to play significant roles in the formation of the relatively high NO emissions from combustion of wood. Comparisons are made with measurement data and also with coal combustion