大強度パルス相対論的電子ビームによるNO<SUB>x</SUB>処理

Abstract

Removal of NOx has been successfully demonstrated using an intense, pulsed relativistic electron beam (IREB). The elongate gas chamber (1.8 m long) is filled up with dry-N2-balanced or dry-N2/O2-balanced NO gas mixture with the pressure of 120 kPa, and is irradiated by the IREB. The kinetic energy, current and pulse width of the IREB are ∼2 MeV, ∼2.2 kA and ∼90 ns (full width at half maximum), respectively. With the initial NO concentration of 100 ppm in N2-balanced NO gas mixture, ∼96 % of NOx is removed by firing 10 shots of the IREB. We have obtained the energy efficiency of NOx removal of ∼220 nmol/J in N2-balanced NO gas mixture with the initial NO concentration of 880 ppm. The energy efficiency of NOx removal increases with increasing the initial NO concentration. In N2/O2-balanced NO gas mixture, NOx is removed if the initial NO concentration is less than 200 ppm. However, the NO2 is also generated by the irradiation of the IREB. The theoretical calculation on the half-life time of NO shows that the NO2 is generated by the oxidation of NO by O or O3.