Decomposition of Carbon Tetrachloride by a Pulsed Corona Reactor Incorporated with In Situ Absorption

Abstract

The decomposition of carbon tetrachloride by a wire-in-tube pulsed corona reactor was tested to investigate the influence of the reaction agents H 2 and O 2 on the plasma decomposition of carbon tetrachloride, as well as on the control of unwanted products. It was found that the decomposition of carbon tetrachloride was higher with 2% H 2 in N 2 gas and lower with 2% O 2 in N 2 gas, compared to the decomposition in N 2 atmosphere. Cl 2 and ClCN were regarded as the major products from CCl 4 decomposition in N 2 atmosphere. HCl was the major FTIR-detected product from CCl 4 decomposition in a 2% H 2 /N 2 gas mixture, whereas the products CO 2 , CO, and COCl 2 were detected when carbon tetrachloride was decomposed in a 2% O 2 /N 2 gas mixture. To prevent the production of unwanted byproducts such as ClCN and COCl 2 from CCl 4 decomposition, a combination of nonthermal plasma and in situ absorption by coating a layer of Ca(OH) 2 on the surface of the grounding electrode was proposed. It was demonstrated that the Ca(OH) 2 sorbent in the plasma reactor played an effective role as a scavenger participating in the CCl 4 decomposition reaction by in situ capturing of the unwanted intermediates.