甲烷二氧化碳介质阻挡放电转化产物分布研究

针对介质阻挡放电甲烷二氧化碳转化实验,分析了反应的产物分布,探讨了进料组成和反应器结构对反应的影响.反应产物包括:高H2/CO摩尔比的合成气、气态烃、高辛烷值的汽油组分、醇和酸等含氧有机物.对所述电极结构,产物的选择性随碳数增加而降低;高的甲烷进料浓度有利于烃的生成,对醇和酸的最佳甲烷进料体积分数范围在67.4％～75.1％;放电间隙越小,原料转化率和烃、酸的选择性越大,大的放电间隙对醇的生成有利.

Product Distribution of Conversions of Methane and Carbon Dioxide Using Dielectric Barrier Discharge

Direct conversion of methane to more useful chemicals and fuels remains a challenge for the 21st century because of the high stability of methane molecule.In this work,direct conversion of methane and carb on dioxide using dielectric barrier di scharge plasma was investigated.The discharge gaps applied are 1.8mm an d 1.1mm,respectively.The product inclu des gaseous hydrocarbons(C 2 to C 5 ),syngas,liquid hydrocarbons(C 5 to C 11 )and oxygenates.The liquid hydrocarbons are highly branched which prese nts a high octane number as liquid fuel;and oxygenates mainly consist of alc ohols and acids.With the increasing of carbon atoms in the molecule,sele c-tivity of hydrocarbons and oxygenates decreases accordingly.A detaile d analysis of product distribution h as been conducted under variable feed condi tions with different discharge gaps.Higher CH 4 concentration in the feed is more favored for production of hydro carbons,while the highest selectiv ity of alcohols and acids is obtained at the methane feed concentration of 75.1%(volume fraction)and 67.4%(vulume fraction),respectively.To achieve a large conversion of CH 4 and CO 2 and a high yield of hydrocarbons and a cids,the narrower discharge gap(1.1mm)is preferred,while a wider discharg e gap(1.8mm)induces a more selectivity production of alcohols.