Use of exhaust gas recirculation (EGR) and cyclonic separator for simultaneous NOx and PM reduction in DI diesel engines

This study presents the results of exhaust gas recirculation (EGR) and cyclonic separator for simultaneous oxides of nitrogen (NOx) and particulate matter (PM) reduction in a direct injection (DI) diesel engine under different engine loads and speeds. There is a significant NOx reduction by EGR, but PM is hugely increased, especially at high EGR rate-high load conditions. A significant reduction in PM is achieved by the use of cyclonic separator without deteriorating other emissions. At high speed-high load conditions, the cyclonic separator has a greater efficiency. Both NOx and PM reduce simultaneously when EGR and cyclonic separator are used together. Using cyclonic separator with high EGR rates, a remarkable NOx reduction is possible keeping the PM level significantly lower than non-EGR level.