Application of pulse high-energy electron beams for decomposition of chlorofluorocarbon in atmospheric-pressure air

It is experimentally shown that a pollutant (Freon) in atmospheric-pressure air can be decomposed by irradiation of pulse high-energy electron beams. Pulse electron beams having 100-220 kV energy with about 500 ns pulse width and a current density of about 3 A/cm2 were injected into air contaminated with Freon-12 of 300-4800 ppm. Freon-12 in the gas cell was reduced by about 5% per pulse. Freon might be decomposed to CO2, hydrides of Cl or F and intermediate large molecules through the chemical reaction between Freon, air and the mixed hydrogen or residual water vapor. The decomposition rate was almost constant even though the density of Freon was changed from 300 to 4800 ppm. The decomposition rate and the decomposed amount greatly increased upon increasing the beam energy (150 to 220 keV) and current (310 to 780 A). The efficiency of decomposition for beam power increased to 100 nmol/J upon increasing beam energy to 82 J per pulse. (author)