Influences of H2 and O2 and in situ Ca(OH)2 absorption on nonthermal plasma decomposition of trichloroethylene in N2

The decomposition of trichloroethylene (TCE) with a wire-in-tube pulsed corona reactor was experimentally investigated. It was found that the decomposition of TCE was higher in N2 gas, compared to the decomposition in the gas stream containing H2 or O2 gas. The main gaseous products were HCl and Cl2 for TCE decomposition in N2 gas. With the existence of 2% H2 in gas stream, the yield of HCl was three times higher than that in N2 gas. When O2 gas was added into N2 gas stream, the main decomposition products were COCl2, CO2 and DCAC. In order to prevent the production of unwanted byproducts from TCE decomposition, a combination of plasma decomposition and in situ absorption was proposed by coating a layer of Ca(OH)2 on the surface of the grounding electrode. It was demonstrated that the Ca(OH)2 sorbent in the plasma reactor played an effective role as a scavenger participating in the TCE decomposition by in situ capturing of the unwanted products like HCl, therefore resulting in the increase of TCE decomposition.