Study On The Decomposition Of Mixed VOCs With Dielectric Barrier Discharge Plasma

The control of volatile organic compounds (VOCs) is receiving more and more attention. Recently, non-thermal plasma technology is regarded as a promising new technology in VOCs control all over the world. In normal temperature and pressure, VOCs can be decomposed by this technology in a short time. It's a significant way to reduce the energy cost and improve the decomposition rate.In this study, the improvement of removing mixed VOCs in air is investigated. On elementary theory of non-thermal plasma, a set of equipment for experiment has been set up. On this equipment, the experiment is carried out to study the effect of the destruction of Tetrachloroethylene and 1, 3-Xylene Mixture.The influences of the removal efficiency of single and multi component Tetrachloroethylene and 1, 3-Xylene by the parameters of power supplies (AC high voltage or bipolar pulse high voltage and engineering mainly are researched. Furthermore, the influence of energy efficiency by bipolar pulse-power, and the mechanisms of different plasma promoted processes were discussed.The results indicated:(1)The decomposition of mixed VOCs by the silent system is in evidence, and the characteristic of decomposition matters with gas component. The decomposition of tetrachloroethylene in mixture changes more compared with the single-composition that the highest decomposition rate of tetrachloroethylene changes from 76% to 27% and the rate of 1, 3-xylene is maintaining about 90% in the processing of mixture.(2) To adjust electrode gap can change the injected power density of discharge area. When the high voltage electrode structure is the same, the bigger of the power density, the better of the VOCs decomposition is. In this experiment, it's 5 mm of the electrode gap that reached the best power density. Three electrode gaps of the reactor show different decomposition ability as: 5mm>7.5mm>10mm.(3)In the condition of the same electrode diameter, Better results are attained with stainless steel stick as the high voltage electrodes than screw thread steel stick, because of its proportional discharge. In hence, it's important of the high voltage electrode structure to the state of plasma. (4) The silent discharge reactor induced bipolar pulse power-supply has advantages over AC power because it can combine advantages of short pulse corona discharge and dielectric barrier discharge as well. The highest decomposition rates of Tetrachloroethylene and 1, 3-Xylene mixture are 54% and 97% with energy efficiency 14.7g/(kWh) at the condition that the applied voltage is 18.8kV and the flow rate is 0.5L/min.