NO_x Removal in N₂ by Pulse Intense Electron Beam Irradiation

Abstract

As an application of pulse intense electron beam for pollution control, removal of nitrogen oxides (NO x ) in atmospheric pressure N 2 was demonstrated. The pulse electron beam (energy; ∼200 keV, current; ∼140 A, current density; ∼2.2 A/cm 2 and pulse width; ∼500 ns) was injected into a gas cell filled by 1 atmospheric pressure N 2 with an initial concentration of 200 ppm of NO and at a temperature of 26°C. The typical removal ratio was 17% for the first shot and reached to 93% after 8 successive shots. This removal ratio corresponds to 2740 nmol of removed NO x and to a 192 nmol/J removal efficiency. Many nitrogen radicals produced by the electron beam interaction with N 2 play an important role in the reduction of NO. The removal ratio was increased to 33% for the first shot when the initial concentration of NO was decreased to 64 ppm. However, the amount of removed NO x was smaller at low initial concentrations. When the filling pressure was decreased to 260 Torr, the amount of removed NO x decreased almost proportional to the pressure.