S. Futamura et al., Mechanisms for formation of inorganic byproducts in plasma chemical processing of hazardous air pollutants, IEEE IND AP, 35(4), 1999, pp. 760-766
Plasma chemical behavior of hazardous air pollutants (HAP's) (Cl2C=CCl2, Cl
2C=CHCl, Cl3C-CH3, Cl2CH-CH2Cl, CH3Cl, CH3Br, and benzene), their molecular
probes (CH4 CH3-CH3, and CH2=CH2), and carbon oxides (COx) was investigate
d with a ferroelectric packed-bed plasma reactor to obtain information on t
he formation of COx and N2O. It has been shown that the oxidation of CO to
CO2 is a slow reaction in plasma, and that CO and CO2 mainly result from di
fferent precursors. Simultaneous achievement of complete oxidative decompos
ition of HAP's in plasma and recovery of CO as a chemical feedstock could b
e favorable. The process of N2O formation is affected by HAP structures and
oxygen concentration. In the decomposition of olefinic HAP's, such as Cl2C
=CCl2 and Cl2C=CHCl, high-power short-residence-time operations are effecti
ve in suppressing N2O formation. In the cases of CH3Cl and CH3Br, low speci
fic energy density operations could be necessary to reduce NaO concentratio
ns. The yields and selectivities of CO, CO2, and N2O change drastically by
adding only 2% of oxygen to N-2, and oxygen concentration is not a good fac
tor to control these inorganic oxides.