Flue gas treatment of nitrogen oxides by pulsed relativistic electron beam

Removal of NOx has been studied experimentally by intense, pulsed, relativistic electron beam (IREB) using an induction linac, "ETIGO-III". The IREB has the following parameters: 2-8 MeV, 5 kA, 60-80 ns (FWHM). As the preliminary stage of the experiment, the interaction chamber was first designed to be 20 cm long, which is much shorter than the range of IREB, for example, 9 in and 31 m for 2-MeV and 8-MeV energy of IREB, respectively. At 100 ppm of NO filled as the initial state, 5 ppm NO has been removed per shot at ambient gas pressure of 120 kPa. After firing 10 shots, the initial NO was reduced to the half. The remove ability was evaluated to be 3 mumol/shot. At the second stage, we have studied the similar experiments by the extension of the interaction chamber to be 1.8 m long. From the preliminary experiments, significant improvement of NO treatment with an order of magnitude (40 ppm/shot) has been observed with the new configuration. Further studies are being carried out by the extension of the chamber up to 6 m long because from a viewpoint of industrial applications the high energy IREB is suitable for a long tunnel or chimney.