电极结构及填充介质对二氧化碳重整甲烷制合成气的影响

Effects of Electrode Structure and Packing Materials on Conversion of Methane and Carbon Dioxide into Synthesis Gas

为了考察电极结构及填充介质对放电及二氧化碳重整效果的影响,对线管式介质阻挡放电（DBD）反应装置3种不同电极结构及下的电信号进行了测量,并分析了不同电极结构及不同形貌填充介质下的重整效果。结果表明：反应气体为CH_4和CO_2,DBD反应装置的内电极分别为光滑电极、螺纹电极、线圈电极时,反应装置放电起始电压依次减小。相同电压下,线圈电极下放电功率大于其他2个电极,CH_4和CO_2的转化率也高于其他2个电极所在的反应器,但是CO的选择性明显低于其他2个电极。在放电间隙填充介质后,介质表面形成极化电场,放电区域局部场强增大,促进CH_4和CO_2的分解,活性三氧化二铝小球对CO_2有一定的吸附性,填充三氧化二铝小球下CO_2的转化率高于玻璃珠填充;与球状填充介质相比,填充不规则块状活性三氧化二铝时,放电区域产生的局部电场放电强度增大,CH_4的转化率有明显的提升,但是与无填充相比其对CO_2转化影响很小。

In order to investigate the effects of electrode structure and packing materials on plasma discharge and carbon dioxide reforming effect,we measured the electrical signals of the linear tube DBD reaction device with three different electrode structures. At the same time, we analyzed the effects of different electrode structures and different packing materials media on reforming effect. The results show that when the internal electrode of the DBD reaction device is smooth electrode, bolt electrode, and coil electrode, the initial voltage decreases in turn. Under the same discharge voltage, the discharge power and the CO_2 as well as CH_4 conversion rates with coil electrode are all higher than those of other two electrodes. However, the selectivity of CO with coil electrode is much lower than that with other two electrodes. Packing dielectric materials into discharge gap of DBD reactor enables the production of partial discharges at the contact points and forms a polarized electric field on the surface of materials, which can accelerate the conversion of CH_4 and CO_2. Compared to packing glass beads, the alumina balls have better performances for the adsorption of CO_2. When packing alumina bulks, the reactor shows significant increases in the conversion of CH_4 because of the increasing part field strength generated at the edge of alumina bulks, but no obvious effect on the conversion of CO_2 is observed when packing alumina bulks compared with no packing.