Formation and emission of nitric oxide in fluidized bed combustion

Abstract

Propane--air mixtures alone and with added nitric oxide, ammonia, or dimethylamine were burned in a fluidized bed. Bed temperature, flow rate, fuel--air ratio, particle size, bed depth, and the amount of fuel bound nitrogen were varied. Much less nitric oxide is formed from atmospheric nitrogen than is formed in conventional combustion processes. The amounts formed are higher than equilibrium amounts at each bed temperature with stoichiometric and rich mixtures and lower with lean mixtures. In lean flames, when nitrogen is chemically bound to fuel, virtually all of the fuel-bound nitrogen is converted to nitric oxide. Powdered nickel almost completely eliminated nitric oxide from the products of rich mixtures.