Removal of NO/sub x/ from diesel generator exhaust by pulsed electron beams

The objective of this paper is to determine the effects of electron beam pulse parameters on the utilization of the reactive free radicals for removal of NO/sub x/ from diesel generator exhaust. A dose per pulse less than 1 kGy has been determined to be optimum for effective radical utilization. During each post-pulse period, the radicals are utilized in the removal of NO/sub x/ in a timescale of around 100 microseconds; thus, with pulse frequencies of around 10 kHz or less, the radical concentrations remain sufficiently low to prevent any significant competition between radical-pollutant and radical-radical reactions. It is shown that a pulsed electron beam reactor, operating with a dose per pulse of less than 1 kGy/pulse and pulse repetition rate of less than 10 kHz, will have the same plasma chemistry efficiency (parts per million of removed NO/sub x/ per kGy of electron beam dose) as an electron beam reactor operating with a low dose rate of 50 kGy/s in continuous mode. Ozone accumulation is a limiting factor under high pulse frequency conditions. The total dose requirement determines the optimum combination of dose per pulse and pulse frequency for both radical utilization and prevention of ozone buildup.