The removal of dichloromethane from atmospheric pressure nitrogen gas streams using plasma-assisted catalysis

A non-thermal, atmospheric pressure plasma utilising a dielectric packed bed was used to study the destruction of dichloromethane, CH2Cl2, (DCM) in gas streams of nitrogen with the presence of catalysts. The effect of plasma-assisted catalysis was investigated in two configurations; one where the catalyst was incorporated into the packed bed itself and the other where the catalyst was downstream of the plasma. The combination of plasma and a catalyst allowed improved destruction of DCM. γ-Al2O3 in a one-stage reactor configuration was the most successful in terms of the total destruction of DCM as well as providing the best result in the two-stage reactor configuration compared with the eight catalysts chosen which included alumina, TiO2 and various zeolites. Products as detected by FTIR were CO, CO2, HCN, HCl and H2O with the by-product of N2O. The nature of the catalyst plays a vital role with respect to the effectiveness of DCM destruction and the selectivity of the end-products.