Emissions during active regeneration of a diesel particulate filter on a heavy duty diesel engine: Stationary tests

Abstract We studied the influence of active regeneration of a diesel particle filter (DPF) on the particle emission. A 10.5 l heavy duty (HD) diesel engine was equipped with a hydrocarbon injection (HCI) system, diesel oxidation catalyst (DOC) and DPF. Besides the gaseous emissions, particle number (PN), soot mass and particle size distributions were measured. Additionally, thermogravimetric measurements (TGA) were performed, investigating soot from HCI mode and standard operating mode. Regeneration of the empty and soot loaded filter was performed at stationary points. In contrast to some other researchers we did not find a significant increase in the total number of emitted particles during active regeneration. The filtration efficiency at 1800 rpm 25% load by particle number slightly decreases during active regeneration, from 99.9% to 99.6%. For the Filter Smoke Number (FSN) there is a decrease to 98.7%. The soot filtration efficiency measured with the microsoot sensor (MSS) decreases to 96.6%. The results clearly show that it is possible to apply an active regeneration while retaining high filtration efficiencies when the appropriate setup (HCI strategy, DPF material) is chosen.