Selective Non-catalytic Reduction Technology Research Articles

REDUCTION OF NOX CONCENTRATIONS IN BOILER FLUE GAS BY INJECTING SELECTIVE REAGENTS

Present EU regulations promote search for efficient means of reducing environmental pollution caused by fuel‐burning equipment. Primary means of NOx reduction are of a limited efficiency. The aim of this study is investigation and development of Selective Non‐Catalytic Reduction (SNCR) for NOx Control. This method can be applied in the existing boilers that have no external flue gas cleaning equipment, and that is the main advantage of the method. Experimental investigation of the influence of various reagent solutions on NOx concentration was carried out in a stand simulating a boiler furnace. Reagents and their operation conditions were selected, desirable efficiency of SNCR method was determined. The experimental results indicated positive application perspectives of this method. Reduction of NOx concentration by 40 % was reached. It was determined that improperly selected SNCR technology can even increase NOx concentration.

MILD COMBUSTION FOR FUEL-NOx REDUCTION

One source of pollution in the combustion of fossil fuels is the formation of nitrogen oxides. Their production is strictly bound to the presence of molecular nitrogen in the combustion air and to the so-called fuel nitrogen, that is, the N chemically bound to the fuel. Thermal NOx formation, which is the most important source of nitrogen oxides in high-temperature combustion processes, can be limited and controlled by the relatively new “mild” technology, also called “flameless” combustion. However, if a fuel containing some nitrogen is used, other ways of NOx production become important. The aim of this study was to investigate the possibility of reducing fuel-NOx emissions using a laboratory-scale burner for mild combustion. Two selective noncatalytic reduction technologies, namely a reburning-like and thermal DeNOx-like have been coupled with mild combustion to further reduce NOx formation and the experimental results have been discussed using detailed kinetic calculations.