Exhaust-Gas Recirculation - A Measure to Reduce Exhaust Emissions of DI Diesel Engines

Effect of Oxygenated Hydrocarbon Additives on Exhaust Emission of a Diesel Engine

“…The influence of EGR on HC emission is shown in Figure 9. It is clear from the figure that EGR decreases HC emissions as illustrated by Dürnholz et al (1992), but a slight increase was observed at maximum loading conditions due to the reduction in the availability of oxygen. Nitrogen oxides emissions are predominately temperature phenomena, the presence of oxygen increases the heat release rate for the oxygenated fuel and hence the NOx emission will be high.…”

“…Dederichs et al (2002) outlined the main technical issues of EGR technology for thermal barrier coated HD engines with EGR up to 30% and more of the exhaust gases and found the same results. Dürnholz et al (1992) reported in particular that so called 'hot EGR', which keeps the temperature of the re circulated exhaust gases at a very high level, not only helps reduce NOx but also contributes distinctly to achieving lower hydrocarbon (HC) and PM emissions. In addition, there is no adverse affect of EGR on the fuel economy.…”

Control of NOx from A DI Diesel Engine With Hot EGR And Ethanol Fumigation: An Experimental Investigation

“…Firstly, as given amount of fuel will have to diffuse over a wider region to find sufficient O 2 , some of EGR constituents like CO 2 and water vapor are also included in the mixture [6][7][8]. These high specific heat EGR contents absorb heat energy released by combustion [9][10]. The second factor is due to reduced availability of oxygen.…”

Membrane-based air composition control for light-duty diesel vehicles : a benefit and cost assessment.

“…One such technique is exhaust-gas recirculation (EGR), in which part of the exhaust gas is mixed with the ambient intake air. This method, the most costeffective way of reducing NO x emissions from spark-ignition (SI) engines, is being considered by many investigators for use with compression-ignition (CI) engines (Dürnholz et al 1992;Ladommatos et al 1996;Psaras et al 1997). However, its applicability for diesel engines is uncertain because of such drawbacks as increases in both particulates and smoke at higher engine loads, reduced engine durability (Nagai et al 1983), and possible oil contamination caused by sulfur dioxide (SO 2 ) and soot particles in recirculated exhaust gas (Nagaki and Korematsu 1995).…”