Control of byproduct distributions in plasma chemical processing of hazardous air pollutants

Plasma chemical behavior of hazardous air pollutants (HAPs) (Cl ₂C=CCl₂, Cl₂C=CHCl, Cl₃C-CH ₃, Cl₂CH-CH₂Cl, CH₃Cl, and CH₃Br), their molecular probes (CH₄, CH₃-CH₃, and CH₂=CH₂), and the carbon oxides was investigated with a ferroelectric packed-bed plasma reactor to obtain information on the formation of carbon oxides and N₂O. If has been shown that the oxidation of CO to CO₂ is a slow reaction in plasma, and that CO and CO₂ mainly result from different precursors. The control of CO_x selectivities is rather difficult at this stage. The process of N ₂O formation is affected by HAP structures and oxygen concentration. In the decomposition of olefinic HAPs such as Cl₂ C=CCl₂ and Cl₂C=CHCl, residence time reduction is effective in suppressing N₂O formation. In the cases of CH₃Cl and CH₃Br, low specific energy density operations could be necessary to reduce N₂O concentrations. The yields and selectivities of CO, CO₂, and N₂O change drastically by adding only 2% of oxygen to N₂ and oxygen concentration is not a good factor to control these inorganic oxides