Abstract
Keywords - Lean NOx Reduction, Emission, Catalyst, Automotive, European Project
Abstract - Decreased fuel consumption for vehicles occurs when operating with a large excess of oxygen, i.e. under lean-burn conditions. One drawback of operating under such conditions is the formation of nitrogen oxides, NOx. The emission of NOx from vehicles is regulated according to strict maximum levels as it has negative impacts on the human health and the environment. To reduce the amount of NOx, several measures can be taken. One of these measures is the catalytic conversion of NOx into nitrogen, which was the focus of the present project. In a consortium of European industrial partners and research institutes, a combination of industrial development and scientific research was organized. The project lasted for three years. The main objectives were: To show the potential for a, under lean conditions, continuously NOx reducing catalytic system fitted on a diesel car to comply with the EU standard of Year 2005 for emissions, simultaneously addressing the CO2 emission issue. Achieving a level of 60% average NOx conversion between 200 and 550 °C for continuous catalytic NOx reduction systems. To reach these goals we believe that an understanding of the underlying fundamental steps through basic research is essential. Thus research activities were conducted in the areas ranging from basic research based on a theoretical approach to full-scale emission system development. The catalytic systems developed through basic research that was conducted for this project showed large potential and were transferred to full-scale monoliths. The project resulted in the assembly of a diesel automobile demonstrator that uses the active catalytic NOx reduction system developed. The vehicle showed 60%-70% NOx conversion at high loads. It was also shown that high NOx conversion, i.e. 90% and better, was possible at low loads and at temperatures well below 300
°C. Under such conditions, hydrocarbons and a small amount of hydrogen were added simultaneously. It was possible to reach about 50% NOx conversion in a hot started European emission test cycle utilizing the remarkable hydrogen effect at low loads. The project has been sponsored by EU under the Fifth RTD Framework Program, Competitive and Sustainable Growth.