Abstract
Diesel Particulate Filter (DPF) is the most applied device to control the Particulate Matter (PM) from diesel engine exhaust: it consists of alternately plugged parallel square channels (wall-flow monolith) so that the exhaust gases flow through the porous inner walls and the particles are collected on the surface and in the porosity of the channel walls, progressively blocking the pores, causing a growing pressure drop. The accumulated PM is removed by periodic combustion, triggered by an increase in the exhaust temperature, i.e. by injection of fuel into the exhaust gases. The exothermic PM combustion leads in some cases to excessive temperature rise, resulting in filter damage. The development of a cost effective, fast and safe regeneration procedure is the major remaining technological challenge in the use of this device. In our previous works we showed that the simultaneous use of a Microwave (MW) applicator and a specifically catalysed DPF, with 15%wt of CuFe2O4, allows to reduce the temperature, the energy and the time required for the DPF regeneration. Starting by these very promising results, we continued to study in order to further improve the performances of the catalyzed DPF in terms of catalytic activity, to reduce the temperature and the MW energy required for the regeneration. The objectives of this work are to optimize both the preparation procedure of the catalytic DPF and the load of active species, and to verify the feasibility of the MW technology by assessing the energy balance of the regeneration phase, comparing it to the actually employed regeneration technologies. In the future we want to evaluate the activity towards the other pollutants present in the diesel exhausts (such as NOx).
