Treatment of automotive exhaust gases by high-speed electrons

At present, most treatment techniques of automotive exhaust both inside and outside of engine only influence CO and HC, but not NOx. This is true for both diesel and non-diesel engines. However, NOx gas is the main constituent in the formation of photochemical smog and acid rain. Using a new technique involving a strong electric field discharge, the electric field intensity can reach 200 kV/cm in narrow discharge gap. Electrons accelerated by this field can gain 16 eV average energy, which is higher than the chemical bonding energy of CO, NOx and HC molecules. Thus, NOx, CO, HC gases can be dissociated and ionized to form molecules of N2, O2, H2O, CO2 and particle C. From experimental results, the dissociation efficiency of NOx gas is 72.5–73.7%, CO, 61.7–73.7%, HC, 86.0–88.0%, and the removal efficiency of fly ash is over 80%. This method can be used for both diesel and non-diesel car exhaust.