Search Results

The modern Diesel engine is one of the most versatile power sources available for mobile applications. The high fuel economy and power of the Diesel engine has long made it the choice for heavy-duty applications worldwide. Over the coming years, global emissions legislation applied to heavy-duty Diesel (HDD) engines will become more and more stringent, necessitating the use of advanced emissions control technologies. In particular, the coming exhaust gas emissions legislation focuses on particulate matter (PM) emissions and emissions of nitrogen oxides (NOx). A filtration device can control PM emissions, and a possible technology for the abatement of NOx emissions involves NOx absorber catalysts. This paper describes investigations into the activity and system behaviour of a prototype HDD exhaust system based on NOx absorber technology. The system consists of a “single leg” containing NOx absorber catalyst that is bypassed during rich regeneration of the NOx absorbers.

The retrofitting of diesel engines with oxidation catalyst and particulate filter technology for the reduction of particulate matter (PM), hydrocarbons (HC) and carbon monoxide (CO) emissions has become an established practice. The design and performance of such systems have been commercially proven to the point that the application of these technologies is a cost effective means for states to effectively meet pollution reduction goals. One of the reasons that these technologies are so widely applied is because they can be sized and fitted based on easily measurable vehicle parameters and published engine emission information. These devices generally work passively with basic temperature and back pressure monitoring devices being used to alert the operator to upset conditions. The application of an effective NOx reduction technology in similar retrofit installation, is more complicated. There are no passive NOx reduction technologies that can be retrofit onto HDD vehicles.