Effect of Electrode Configuration on Microdischarge Characteristics in Porous Ceramics and Benzene Degradation
Shang Kefeng1,2, Cao Wudi2, Fu Mengji1
1. School of Electrical Engineering Dalian University of Technology Dalian 116024 China; 2. Key Laboratory of Industrial Ecology and Environmental Engineering Dalian University of Technology Dalian 116024 China
Abstract:Dielectric barrier discharge (DBD), which is characterized by numerous microdischarge channels in narrow gas gap, can stably produce discharge plasma at atmospheric pressure and room temperature. DBD process is simple and easy to operate, leading to a wide range of applications such as waste gas/water treatment, material surface modification, biomedicine and so on. Especially DBD has been hotly studied for volatile organic compounds (VOCs) treatment because of its low breakdown voltage, high electron density and reactive species. Previous studies have found that the electrode configuration of DBD device would change the plasma distribution and the generation characteristics of reactive species. However, few studies have focused on how to enhance the microdischarge in DBD reactor for promoting the degradation of VOCs. In this paper a coaxial tri-electrode DBD device filled with a porous ceramic tube with micron pore size is proposed for benzene degradation. The coaxial DBD reactor has a three electrode configuration which was named surface-volume hybrid DBD. The mesh or spring type high-voltage electrode was tightly pasted at the inside wall of a quartz tube tightly and then a porous ceramic tube with 60 μm pore size was put in the quartz tube (QTⅠ) and acted as a barrier dielectric. The high voltage electrode was powered by an AC (0~60 kV, 50 Hz) power supply. A rod-like electrode wrapped in a quartz tube (QTⅡ) was put in the middle of ceramic tube to act as one of ground electrode as well as an aluminum foil sheet was wrapped on the outside of QTⅠ to act as another ground electrode. Firstly, the effect of electrode configuration and electrode geometry on the microdischarge characteristics including voltage and current waveforms, microdischarge channel distribution, Lissajous figures was measured. The three-electrode configuration presented stronger microdischarge which was characterized by more current pulses on the current waveforms, more and brighter microdischarge channels on the discharge images and larger Lissajous figure area, and mesh electrode also presented stronger microdischarge than spring electrode, but a decrease in the spring gap of spring electrode can effectively enhance the microdischarge intensity. The dielectric equivalent capacitance and charge characteristics calculated from Lissajous figures showed that the dielectric equivalent capacitance, the peak-peak charge and discharge charge of the three-electrode configuration was 3.5 times, 3.2 and 4.4 times that of the two-electrode configuration. In addition, mesh high-voltage electrode configuration can further improve the effective discharge area compared to spring electrode configuration. Moreover, the discharge power was increased from 0.8 W (two-electrode configuration) to 8.6 W (three-electrode configuration) and the benzene degradation efficiency was correspondingly increased by 35.1%. Compared to spring electrode, the mesh high-voltage electrode can enlarge the discharge area and intensity, and enhance the electric discharge power by 4 W, leading to higher benzene degradation efficiency and comparable energy efficiency to spring electrodes, moreover, the energy efficiency of spring electrode with smaller spring gap (4 mm gap) was slightly higher than that of 9mm gap. The study is helpful for understanding how to strengthen the generation of microdischarges and then promotes the application of microdischarges in gaseous pollutant treatment and ozone generation.
商克峰, 曹无敌, 符梦辑. 电极结构对多孔陶瓷孔内微放电特性及苯降解的影响[J]. 电工技术学报, 2023, 38(6): 1687-1694.
Shang Kefeng, Cao Wudi, Fu Mengji. Effect of Electrode Configuration on Microdischarge Characteristics in Porous Ceramics and Benzene Degradation. Transactions of China Electrotechnical Society, 2023, 38(6): 1687-1694.
[1] 王新新. 介质阻挡放电及其应用[J]. 高电压技术, 2009, 34(1): 1-11. Wang Xinxin.Dielectric barrier discharge and its applications[J]. High Voltage Engineering, 2009, 34(1): 1-11. [2] 王燕, 赵艳辉, 白希尧, 等. DBD等离子体及其应用技术的发展[J]. 自然杂志, 2002, 24(5): 277-282. Wang Yan, Zhao Yanhui, Bai Xiyao, et al.DBD plasma and the development of its application[J]. Nature Magazine, 2002, 24(5): 277-282. [3] 夏文杰, 刘定新. Ar等离子体射流处理乙醇水溶液的放电特性及灭菌效应[J]. 电工技术学报, 2021, 36(4): 765-776. Xia Wenjie, Liu Dingxin.Discharge characteristics and bactericidal effect of Ar plasma jet treating ethanol aqueous solution[J]. Transactions of China Electrotechnical Society, 2021, 36(4): 765-776. [4] 魏俊, 钱树楼, 王城, 等. 填充床介质阻挡放电臭氧发生器的实验研究[J]. 高电压技术, 2017, 43(8): 2696-2701. Wei Jun, Qian Shulou, Wang Cheng, et al.Experimental study of packed-bed dielectric barrier discharge applied on ozone reactor[J]. High Voltage Engineering, 2017, 43(8): 2696-2701. [5] Yao Shuiliang, Wu Zuliang, Han Jingyi, et al.Study of ozone generation in an atmospheric dielectric barrier discharge reactor[J]. Journal of Electrostatics, 2015, 75: 35-42. [6] Zeng Xin, Zhang Yafang, Guo Liangyin, et al.Ozone generation enhanced by silica catalyst in packed-bed DBD reactor[J]. Plasma Science and Technology, 2021, 23(8): 085501. [7] 米彦, 苟家喜, 刘露露, 等. 脉冲介质阻挡放电等离子体改性对BN/EP复合材料击穿强度和热导率的影响[J]. 电工技术学报, 2020, 35(18): 3949-3959. Mi Yan, Gou Jiaxi, Liu Lulu, et al.Effect of pulse dielectric barrier discharge plasma modification on breakdown strength and thermal conductivity of BN/EP composites[J]. Transactions of China Electrotechnical Society, 2020, 35(18): 3949-3959. [8] 詹振宇, 阮浩鸥, 律方成, 等. 等离子体氟化改性环氧树脂及其在C4F7N/CO2混合气体中电气性能研究[J]. 电工技术学报, 2020, 35(8): 1787-1798. Zhan Zhenyu, Ruan Haoou, Lü Fangcheng, et al.Plasma fluorinated epoxy resin and its insulation properties in C4F7N/CO2 mixed gas[J]. Transactions of China Electrotechnical Society, 2020, 35(8): 1787-1798. [9] 吴阳阳, 贾敏, 王蔚龙, 等. 新型介质阻挡放电等离子体激励器的放电与诱导流动特性实验[J]. 电工技术学报, 2016, 31(24): 45-53. Wu Yangyang, Jia Min, Wang Weilong, et al.Experimental research on the discharge and induced flow characteristics of a new dielectric barrier discharge plasma actuator[J]. Transactions of China Electrotechnical Society, 2016, 31(24): 45-53. [10] 张明, 李丁晨, 李传, 等. 离子风的应用研究进展[J]. 电工技术学报, 2021, 36(13): 2749-2766. Zhang Ming, Li Dingchen, Li Chuan, et al.Research progress in the application of ion wind[J]. Transactions of China Electrotechnical Society, 2021, 36(13): 2749-2766. [11] Shang Kefeng, Ren Jingyu, Zhang Qi, et al.Successive treatment of benzene and derived byproducts by a novel plasma catalysis-adsorption process[J]. Journal of Environmental Chemical Engineering, 2021, 9(4): 105767. [12] Shang Kefeng, Li Jie, Morent R.Hybrid electric discharge plasma technologies for water decontamination: a short review[J]. Plasma Science and Technology, 2019, 21(4): 043001. [13] Shang Kefeng, Wang Meiwei, Peng Bangfa, et al.Characterization of a novel volume-surface DBD reactor: discharge characteristics, ozone production and benzene degradation[J]. Journal of Physics D: Applied Physics, 2020, 53(6): 065201. [14] Shang Kefeng, Morent R, Wang Ning, et al.Degradation of sulfamethoxazole (SMX) by water falling film DBD Plasma/Persulfate: reactive species identification and their role in SMX degradation[J]. Chemical Engineering Journal, 2022, 431: 133916. [15] 张晓星, 王宇非, 崔兆仑, 等. 不同填充材料对介质阻挡放电降解SF6的实验研究[J]. 电工技术学报, 2021, 36(2): 397-406. Zhang Xiaoxing, Wang Yufei, Cui Zhaolun, et al.Experimental study on the degradation of SF6 by dielectric barrier discharge with different packing materials[J]. Transactions of China Electrotechnical Society, 2021, 36(2): 397-406. [16] Penache C, Miclea M, Bräuning-Demian A, et al.Characterization of a high-pressure microdischarge using diode laser atomic absorption spectroscopy[J]. Plasma Sources Science and Technology, 2002, 11(4): 476-483. [17] Hensel K, Matsui Y, Katsura S, et al.Generation of microdischarges in porous materials[J]. Czechoslovak Journal of Physics, 2004, 54(3): C683. [18] Hensel K, Katsura S, Mizuno A.DC microdischarges inside porous ceramics[J]. IEEE Transactions on Plasma Science, 2005, 33(2): 574-575. [19] Nguyen D B, Shirjana S, Hossain M M, et al.Effective generation of atmospheric pressure plasma in a sandwich-type honeycomb monolith reactor by humidity control[J]. Chemical Engineering Journal, 2020, 401: 125970. [20] Takaki K, Hatanaka Y, Arima K, et al.Influence of electrode configuration on ozone synthesis and microdischarge property in dielectric barrier discharge reactor[J]. Vacuum, 2008, 83(1): 128-132. [21] 周波, 王晓静, 孙才新. 电极结构对介质阻挡放电参数的影响研究[J]. 高压电器, 2010, 46(4): 31-34, 39. Zhou Bo, Wang Xiaojing, Sun Caixin.Effect of electrode structure on the parameters of dielectric barrier discharge[J]. High Voltage Apparatus, 2010, 46(4): 31-34, 39. [22] 李清泉, 马磊. 影响介质阻挡放电的因素[J]. 高电压技术, 2007, 33(9): 10-12, 16. Li Qingquan, Ma Lei.Experimental study of factors affecting dielectric-barrier discharge[J]. High Voltage Engineering, 2007, 33(9): 10-12, 16. [23] 商克峰, 曹晓萌, 王肖静, 等. 高压电极构型对DBD装置放电特性及臭氧生成的影响[J]. 高电压技术, 2016, 42(5): 1394-1400. Shang Kefeng, Cao Xiaomeng, Wang Xiaojing, et al.Effect of high voltage electrode geometry on the discharge characteristics and the ozone generation of a DBD device[J]. High Voltage Engineering, 2016, 42(5): 1394-1400. [24] Mei Danhua, Zhu Xinbo, He Yaling, et al.Plasma-assisted conversion of CO2 in a dielectric barrier discharge reactor: understanding the effect of packing materials[J]. Plasma Sources Science and Technology, 2014, 24(1): 015011. [25] Tu Xin, Gallon H J, Twigg M V, et al.Dry reforming of methane over a Ni/Al2O3 catalyst in a coaxial dielectric barrier discharge reactor[J]. Journal of Physics D: Applied Physics, 2011, 44(27): 274007. [26] 巩银苗, 鲁西坤, 景旭, 等. 基于Lissajous图形的同轴结构电极介质阻挡放电特性研究[J]. 电气技术, 2018, 19(9): 41-45. Gong Yinmiao, Lu Xikun, Jing Xu, et al.Research on discharge characteristics of dielectric barrier discharge on coaxial structure electrode base on Lissajous graphics[J]. Electrical Engineering, 2018, 19(9): 41-45. [27] 冉冬立, 蔡忆昔, 王军, 等. 基于Q-V Lissajous图形法的介质阻挡放电试验研究[J]. 绝缘材料, 2009, 42(4): 72-76. Ran Dongli, Cai Yixi, Wang Jun, et al.Experimental study on dielectric barrier discharge based on the Q-V Lissajous figure method[J]. Insulating Materials, 2009, 42(4): 72-76.