Benzene conversion by manganese dioxide assisted silent discharge plasma

Non-thermal plasma technologies have shown their promising potential specially for the low concentration of volatile organic compound control in indoor air in recent years. But it is also high energy consuming. So, to improve the energy efficiency, adding catalysts which enhance the plasma chemical reactions to plasma reactors may be a good selection. Therefore, in this study the manganese dioxide assisted silent discharge plasma was developed for benzene conversion at a relatively high energy efficiency. The results show that MnO2 could promote complete oxidation of benzene with O2 and O3 produced in the plasma discharge zone. The energy efficiency of benzene conversion with MnO2 was two folds as much as that without catalysts. It was also found that the site of MnO2 in the reactor and the energy density had effects on benzene conversion. While the energy density was lower than 48 J/L, benzene conversion decreased with the increase in the distance between MnO2 bed and the plasma discharge zone. Whereas when the energy density was higher than 104 J/L, benzene conversion had an optimal value that was governed by the distance between MnO2 bed and the plasma discharge zone. The mechanism of benzene oxidation in plasma discharges and over MnO2 is discussed in detail. © 2007 Higher Education Press and Springer-Verlag.