IDENTIFICATION OF MECHANISMS FOR DECOMPOSITION OF AIR-POLLUTANTS BY NONTHERMAL PLASMA PROCESSING

Non-thermal plasma processing methods have been shown to be effective for treating dilute concentrations of pollutants in large-volume atmos pheric-pressure air streams. This paper presents results from basic ex perimental and theoretical studies aimed at identifying the main react ions responsible for the decomposition of four representative compound s: carbon tetrachloride, methylene chloride, trichloroethylene and met hanol. Each of these compounds is shown to be decomposed by a differen t plasma species: electrons, nitrogen atoms, oxygen radicals and posit ive ions, respectively. By understanding what plasma species is respon sible for the decomposition of a pollutant molecule, it is possible to establish the electrical power requirements of the plasma reactor and help identify the initial reactions that lead to the subsequent proce ss chemistry. These studies are essential for predicting the scaling o f the process to commercial size units.