Possibilities of NOx Reduction in the Emissions of Compression Ignition Engines through Ceramic Oxygen Conductors and Thermoelectric Materials

One of the main issues in the development of diesel engines is the NO_x emission while the chief cause for such emission is high nitrogen content in the air and high temperature of combustion. There is a variety of methods to reduce this particular emission. One of the most widespread is exhaust gas recirculation and one of the most recent is the application of Adblue additive into the exhaust gases as a reducing agent. There are also catalytic converters capable of reducing the said emission but their efficiency is as yet insufficient. One of the more daring related concepts is the elimination of nitrogen from the air supplied to the combustion chamber through the application of ceramic ionic conductors. The technology applied in the last method is a dynamically advancing trend in material engineering. The development in this field indicates that, soon, an oxygen generator useful in the automotive engineering will become a reality. The authors of the paper present the influence of nitrogen elimination on the toxic emissions and the thermal parameters of the combustion process. The paper presents the results and the analysis of an indication of an engine supplied with air and subsequently pure oxygen. The results of the investigation show an improved combustion process when supplied with pure oxygen. The results of the emission (NO_x mainly) and opacity tests are promising as well. Additional information regarding the combustion process was obtained based on the endoscopic video analysis.