Primena hemijsko kinetičkih modela kod numeričke simulacije procesa nekatalitičke redukcije NOX-a amonijakom u produktima sagorevanja biomase

Abstract

Research related to the development of secondary measures of denitrification of agrarian biomass combustion gases is becoming more and more actual due to the increasingly intensive application of this renewable fuel and the promotion of sustainable development, ie, the reduction of consumption of fossil fuels. Thereby, in spite of a number of advantages, agrarian biomass has an important disadvantage due to significant emissions of nitrogen oxides. The paper deals primarily with the chemical reactions of selective noncatalytic reduction of nitrogen monoxide using ammonia as a reagent. Two kinetic models, one rather simplistic, which takes into account only two net reactions and other, more complex with seven chemical reactions, are analyzed. The considered chemicalkinetic models are incorporated into a comprehensive CFD model of complex processes in an experimental denitrification chamber. The CFD model was included flow simulation, components mixing and monitoring of local chemical reactions. The results of presented numerical simulation were compared with literature experiments, as well as with the results of other authors' models. The same boundary conditions of the considered processes are provided, i.e. the input concentrations of the component are: 300 ppm NH3, 300 ppm NO, 4.0% O2, 4.5% H2O, and the residence time of the reactants in the chamber is 150 ms.