Study on the Treatment of Exhaust Gases at Diesel Engines with the Purpose of Reducing the Emissions of Nitrogen Oxides

The paper presents the possibility of chemically treating the gases resulted from the burning process at Diesel engines. The importance of this issue resides in the fact that the pollution norms are very restrictive especially in the case of nitrogen oxides. The aspects highlighted by the authors achieve a connection between the chemical processes taking part after the combustion and the beneficial effects as regards the environment. The tests performed comparatively on engines equipping high-capacity motor vehicles endowed or not with the technology of chemical treatment with the purpose of reducing the nitrogen compounds validate the imposed desiderata. The mechanism of nitrogen oxides formation is influenced by the high temperature necessary to a complete combustion and the excess of air in the combustion chamber. The emissions were established according to the ESC testing norms for high-capacity engines. At present the chemical treatment of exhaust gases with urea solution and water represents the most viable solution both from the viewpoint of the technology applied and of the afferent costs.