甲烷介质阻挡放电等离子体转化的研究

Conversion of Methane Through Dielectric-Barrier Discharge Plasma

运用4个介质阻挡放电反应器,考察了甲烷介质阻挡放电等离子体转化过程中,高压电极位置、放电间隙、内电极形式、氢气与甲烷的体积比、空气冷却方式等因素对甲烷转化率和产物分布的影响。实验结果表明,高压加于外电极时甲烷的转化率明显低于加于内电极时甲烷的转化率;对外电极进行空气冷却后,反应温度升高速率变缓,可将反应温度控制在理想范围(60～150℃)内,同时可获得较高的甲烷转化率,且操作安全。反应器参数对甲烷转化率有明显的影响,而对产物分布影响不显著,主要产物为乙烷、乙烯和丙烷。在反应系统中加入氢气,在氢气与甲烷的体积比为1.50时,C2烃选择性为74.50%。

Methane coupling to produce C2 hydrocarbons through dielectric -barrier discharge （DBD） plasma reaction was studied in four DBD reactors. Effects of high voltage electrode position, different discharge space, types of inner electrode, volume ratio of hydrogen to methane and air cooling method on conversion of methane and distribution of products were investigated. Conversion of methane is obviously lower when high voltage electrode acts as outer electrode than when high voltage electrode acts as inner electrode. Lifting of reaction temperature becomes slow due to cooling of outer electrode, and the temperature can be controlled in expected range of 60 - 150 ℃ for ensuring better methane conversion and safe operation. Parameters of reactors have obvious effects on methane conversion, but it affects only slightly on distribution of products. The main product are ethylene, ethane and propane. The selectivity to C2 hydrocarbons can reach 74.50% when volume ratio of hydrogen to methane is 1.50.