Abstract
In the automotive market, the diesel engines are attractive for their higher fuel efficiency, reliability, and high torque, but they are one of the major sources of Particulate Matter (PM) and Nitrous Oxides (NOx) in the urban area, pollutants associated to environmental and health issues. Thanks to the continuous fundamental and applied research on diesel engine improvement, good results in terms of PM reductions were achieved by combustion system re-design, engine layout modification and the use of more efficient after treatment devices. The Diesel Particulate Filter (DPF) is one of the most important technology to fulfill the strict PM regulations, consisting in alternately plugged parallel square channels, so that the exhaust gases are forced to flow through the porous inner walls: in this way the particles are collected on the surface and in the porosity of the channel walls, progressively blocking the pores. Since the pressure drop increases by the formation of a soot cake as the PM is accumulated, the DPF needs to be periodically regenerated by burning off the accumulated soot. Therefore, DPF is mainly demanded three performances: filtration, pressure drop, and regeneration. In our previous works we showed that the simultaneous use of a MW applicator and a specifically 15 %wt of CuFe2O4 catalysed DPF, allows to reduce the temperature, the energy and the time required for the filter regeneration. Starting by these very promising results, the objectives of this work are to optimize the catalyst load on the DPF, in order to simultaneously further reduce the PM oxidation temperature and keep low the pressure drop and verify the feasibility of the MW heating technology by comparing the energy balance of the entire process to the actually employed regeneration technologies.
