Abstract
Diesel engines have low fuel consumption and enough torque compared with equivalent gasoline engines. Diesel engines emitted less CO2 which is known well as the greenhouse gas, and a percentage of new diesel passenger car registrations is increasing in EU year by year. However, NOx and soot (particulate matter, PM) emitted by diesel engines are a source of pollution with impact on the environment and human health. Since the automobile regulations have been stricter, new technologies for diesel emissions abatement have been proposed, including the addition of fuel additives for diesel smoke reduction. A diesel particulate filter (DPF) is one of the most important technologies for the above 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 loss increases by the formation of a thick soot cake as the PM is accumulated, the DPF needs to be periodically regenerated by burning off the accumulated soot. In our previous works we showed that the simultaneous use of a microwave (MW) applicator and a specifically 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 modify the active species formulation in order to simultaneously further reduce the PM oxidation temperature and keep low the pressure drop.
