Reactive species distribution characteristics and toluene destruction in the three-electrode DBD reactor energized by different pulsed modes
Reactive species distribution characteristics and toluene destruction in the three-electrode DBD reactor energized by different pulsed modes
复制标题
不同脉冲模式激励的三电极DBD反应器中反应物分布特征及甲苯破坏
DOI：
10.1016/j.cej.2018.05.154
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发表时间：
2018-10-15
影响因子：
15.1
通讯作者：
Wu, Yan
中科院分区：
文献类型：
--
作者：
Jiang, Nan;Guo, Lianjie;Wu, Yan
本文研究了滑动介质阻挡放电（DBD）反应器中甲苯的等离子体降解过程。本研究的总体目标是探索流光传播特性，反应物种的空间分布，以及在不同的脉冲放电条件下的滑动DBD等离子体的VOC降解性能。实验结果表明，当放电电极（电极#1）和对电极（电极#3）分别被+/-脉冲（或+脉冲）和-DC激励，而电极#2接地时，可以点燃滑动DBD等离子体。然而，滑动DBD现象时，两个暴露在空气中的电极分别由-脉冲和+ DC，这可以解释的基础上不同的演化机制的正，负流光不能观察到。光学分析结果表明，双极性脉冲有利于DBD等离子体的点燃，与单极性脉冲相比，双极性脉冲能产生更多的活性组分。在三电极DBD反应器中，-脉冲< +脉冲< +/-脉冲的顺序下，甲苯降解效率和能量产额增加。值得注意的是，当采用三电极DBD反应器而不是两电极DBD反应器时，可以观察到正脉冲放电在甲苯降解效率、能量产率和CO2选择性方面的显著改善，这可以归因于由于滑动DBD效应而在整个电极间距离内增加的反应物种的量。通过FT-IR分析监测放电后的气体，可以确定主要的分解产物包括CO，CO2，H2O，HCOOH和放电产物如O-3，N2 O，和HNO 3，无论使用的脉冲功率和放电反应器。
This work describes the plasma degradation process of toluene in the sliding dielectric barrier discharge (DBD) reactor based on three-electrode configuration energized by + pulse, -pulse, and +/- pulse, respectively. The overall aim of this investigation is to explore the streamer propagation characteristic, spatial distribution of reactive species, and VOC degradation performance of the sliding DBD plasma under different pulsed energization conditions. The experimental result shows that the sliding DBD plasma can be ignited when the discharge electrode (electrode #1) and counter electrode (electrode #3) are energized by +/- pulse (or + pulse) and -DC, respectively, while the electrode #2 is grounded. However, the sliding DBD phenomenon cannot be observed when the two air-exposed electrodes are driven by -pulse and + DC, respectively, which can be explained on the basis of different evolution mechanisms of positive and negative streamers. Optical analysis results indicate that bipolar pulse is beneficial to the ignition of DBD plasma, which can generate more reactive species compared with unipolar pulse. The toluene degradation efficiency and energy yield increase in the sequence -pulse < + pulse < +/- pulse in the three-electrode DBD reactor. It is worth noting that remarkable improvements in toluene degradation efficiency, energy yield, and CO2 selectivity can be observed for positive pulsed discharge when a three-electrode DBD reactor is employed instead of a two-electrode one, which can be attributed to the increased amount of reactive species within the entire inter-electrode distance due to sliding DBD effect. The postdischarge gas was monitored by FT-IR analysis, the main decomposition products including CO, CO2, H2O, HCOOH and discharge products such as O-3, N2O, and HNO3 can be identified regardless of the pulsed power and discharge reactor used.