ABSTRACT The results of kinetic studies of the reduction of nitric oxide (NO) by simple hydrocarbons and real fuels (methane-ethane mixture, ethane, ethylene, acetylene, natural gas and liquefied petrol gas) in simulated conditions of the reburning zone, undertaken in a fused silica jet-stirred reactor operating at 1 atm, at temperatures ranging from 900 to 1500 K, are reviewed. In these experiments, the initial mole fraction of NO and fuel were varied. The equivalence ratio was varied from 0.75 to 2. It was demonstrated that the reduction of NO is favored when the temperature is increased and that for a given temperature, a maximum reduction of NO occurs slightly above stoichiometric conditions. Thus, operating in optimal NO-reburning conditions is possible for particular combinations of equivalence ratio and temperature. These results generally follow those obtained in previous studies involving simple hydrocarbons or natural gas as reburn fuel. A detailed chemical kinetic modeling of these experiments was used to delineate the major routes involved in NO reduction. The similitudes and differences observed when the fuel is changed are discussed from a chemical kinetic point of view. The kinetic modeling indicates that the reduction of NO mostly proceeds by reaction with HCCO in the conditions reviewed here. Then the ability of the reburn fuel to produce HCCO determines the reburn fuel potential for NO reduction.
Buy this Article
|