多尖端旋转电极辉光放电甲烷偶联研究

石油资源的日趋短缺使人们对世界大储量能源天然气的开发利用越来越重视.甲烷(CH4)是天然气的主要成份.由于CH4分子具有很高的稳定性,用CH4直接偶联制C2烃(乙烷、乙烯、乙炔)在热力学上十分不利,采用常规催化手段一直未取得突破性进展[1],而辉光放电等冷等离子体对于CH4偶联是一种非常有效的方法,近年来已成为物理化学跨学科前沿研究热点.在本研究领域中,利用脉冲电晕等离子体结合催化剂进行甲烷转化[2],其等离子体在空间分布上是非连续的,活性较低,反应区较小,甲烷的转化率及C2烃收率必然是有限的;利用微波诱导甲烷在催化剂上转化制C2烃[3],由于温度很高,能量密度太大,很容易使甲烷完全裂解,生成大量积碳,C2烃的收率也较低;利用介质阻挡放电使CH4偶联[4],能耗太大,能量利用率很低.因此,冷等离子体CH4偶联实现工业化的课题就是要在提高CH4转化率及C2烃收率的同时降低能耗,以提高能量利用率.

Study on Coupling of Methane in Glow-discharge Reactor with Rotating poly-tip Electrodes

Coupling of methane in the present of hydrogen to C2hydrocarbons operated at atmospheric pressure in order to evaluate a newly-developed plasma reactor with rotating poly-tip electrodes, in which circular glow discharge plasma zone between a stator and a rotor with polytip electrodes is vertical to the way of the stream of flowing reactants. No substantial amount of carbon formation was observed on the surface of the electrodes after a long period of the reaction(>1 h) when the molar ratio of feed flow of CH4∶H2is 1∶1 and the A.C. glow discharge at 20kHz, input power of 856 V(rms). C2hydrocarbons single pass yield is 42.6%, in which C2H2 38.9% and C2H43.5% respectively, with 62.3% methane conversion but with carbon formation when input power is 1010 V(rms)