Abstract
A diesel particulate filter (DPF) system has been developed to reduce particulate matter, including soot, in diesel exhaust gas. The accumulation of particulate matter in a DPF can cause technical problems because of an associated increase in back pressure, which in turn can decrease fuel efficiency and engine output. Although the primary method of regenerating a DPF is to oxidize the PM by raising the temperature of the filter above 630 °C, the temperature of a DPF during the New European Driving Cycle (NEDC) representing urban driving is typically less than 300 °C. The use of an ozone-based system to oxidize particulate matter on the DPF is therefore helpful. Analysis of the temperature range over which ozone oxidation will proceed indicates that the NEDC provides the requisite temperature. With regard to commercial applications of this technology, two potential problems are apparent; ozone loss during transportation to the DPF must be decreased and the conversion efficiency of atmospheric oxygen to ozone must be improved.
