非平衡等离子体技术处理甲苯的实验研究

Experimental Research on Removal of Toluene with Non-equilibrium Plasma Technology

为了进行平衡等离子技术处理挥发性有机物(VOCs)的实验研究,采用电晕放电与介质阻挡放电相结合的放电形式处理甲苯(C7H8)废气,以此探讨电压、内电极直径及不同电介质条件对C7H8去除效率η的影响,并对放电过程的放电参量进行了测量。结果表明,电压的提高有利于C7H8的去除,电压较低时细电极反应器对C7H8的η要比粗电极高,但随着电压的上升,粗电极效率比细电极要高;陶瓷反应器对C7H8的去除效果要优于有机玻璃反应器;在反应器内填充电介质有利于C7H8的去除,填有陶瓷拉西环填料的反应器对C7H8的去除效果要优于无电介质的空管反应器;利用电压—电荷利萨如图形法测得的反应过程放电功率表明:等离子法处理VOCs能耗低,放电功率的提高对C7H8的去除有利。

An experimental study on VOCs removal with non-equilibrium plasma generated by the combination of corona discharge and dielectric barrier discharge was carried out. Toluene was chosen as the target contamination in the experiment. In order to optimize the geometry of the non-thermal plasma reactor, the removal efficiency of toluene was compared for various inner electrode diameters （ 1.20 mm, 1.65 mm, 2.0 m respectively）, different reactor materials （ceramic and PMMA）, the presence and absence of ceramic raschig-ring packing. In addition, electricity parameters during the discharge process were measured under the experimental condition. Experimental results showed that toluene removal ratio increased significantly with increasing the voltage. With respect to toluene conversion, the smaller size electrode was slightly superior to the bigger size electrode when the voltage was low. However, the reverse was the case with further increase in voltage. Under the same experimental conditions, the removal efficiency of toluene with ceramic reactor was higher than that with PMMA reactor. Obviously, the removal of toluene was enhanced by filling some dielectric in the reactor. In the presence of ceramic raschig-ring packing, the convection was remarkably improved against in absence of padding. The discharge power during plasma processing to decompose toluene was measured using the U-Q Lissajous diagram. It was proved that the degradation of toluene with non-equilibrium plasma consumed less energy compared with other methods, and increasing discharge power was beneficial to toluene removal.