DECOMPOSITION OF DILUTE CONCENTRATIONS OF CARBON-TETRACHLORIDE IN AIR BY AN ELECTRON-BEAM GENERATED PLASMA

A laboratory-scale 100 keV electron-beam reactor has been used to selectively decompose dilute concentrations of carbon tetrachloride in atmospheric pressure air streams. CCl4 intake mole concentrations in the 10-700 ppm range and flow rates of 0.003-0.7 ft3/min were studied. The fractional removal of CCl4 was determined as a function of the electron-beam power deposited in the gas. Adiabatic temperature increases for 90% removal of CCl4 in dry air were approximately 15 to 160 K, depending upon intake concentration, substantially less than the temperatures required for thermal decomposition. The results are approximately consistent with dissociative electron attachment as the major decomposition mechanism. Fractional removal as high as 99.8% was measured (current limit of gas analysis). The energy requirements for humid air were generally on the order of two times larger than those for dry air. The decomposition products were dissolved in aqueous solutions.