Electron beam treatment of chloroethylenes/air mixture in a flow reactor

Abstract

Decomposition of chloroethylenes under electron beam irradiation in a flow reactor has been studied with different reaction environments, various initial concentrations and in the presence and absence of vaporized water. Three chlorinated ethylenes—dichloroethylene (DCE), trichloroethylene (TCE), perchloroethylene (PCE)—were used as model chlorocarbons. The degree of decomposition was 48% for DCE, 98% for TCE and 90% for PCE in air reaction environment at an initial concentration of 2000 ppm and a dose of 18–20 kGy irradiation. In the presence of water vapor (5600 ppm) decomposition of TCE was about 10% higher than in dry air. The main products were found to be CO, CO 2, HCl, dichloroacetic acid (DCAA), dichloroacetyl chloride (DCAC) and dichloroethyl ester acetic acid (DEAA). DCAA, DCAC and DEAA were identified as chloro-oxygenated hydrocarbons, which could be decomposed with CO and CO 2 production. Concentration profiles show that intermediate products and yields of CO and CO 2 decrease with decreasing number of chlorine substitutions in the initial hydrocarbons.