等离子体作用下甲烷和氮氧化物活化转化研究

比较了不同的放电方式,即单纯脉冲火花放电、脉冲流光放电(针-板式、线-筒式)、介质阻挡放电(正脉冲、交流)对NO和CH4的活化转化能力。其中脉冲火花放电和针-板式脉冲流光放电对CH4的活化能力较强,CH4的最大转化率分别为100%和36%,但是在N2+O2体系中NOx的合成加剧。如在针-板式脉冲流光放电中,在O2体积分数为9.8%时,NO的体积分数为449μL/L。线-筒式脉冲流光放电中,即使在输入功率为14.4W时,CH4的最大转化率小于3%,而NO的最大转化率为25%。正脉冲介质阻挡放电中,在21.6kV、输入功率6.4W时,NO和CH4的转化率分别为31%和4.4%,在交流介质阻挡放电中,在低温下有利于NO的转化,在100℃、输入功率为6W时,NO转化率为34.5%,但是对CH4的活化能力较弱。

Activation and Reduction of CH4 and NOx in Different Discharge Plasmas

Pure pulsed spark discharge,pulsed streamer discharge(needle to plane,wire to cylinder),and dielectric barrier discharge (DBD,positive pulsed,alternative current)have been investigated in application to CH4 activation and reduction of NOx. Results show that CH4 can be effectively activated in pulsed spark discharge and needle to plane streamer discharge,the maximum value is 100% and 36%,respectively. But large amounts of NOx are generated in the mixtures of N2 and O2 atmosphere,such as NO output is 449 μL/L,when 9.8% O2 added to needle to plane pulsed streamer discharge. In wire to cylinder pulsed streamer discharge,CH4 conversion efficiency is smaller than 3% and the maximum removal efficiency of NO is only 25%. In positive pulsed DBD plasmas,NO and CH4 conversion are 31% and 4.4% at input voltage of 21.6 kV and input power of 6.4 W. In alternative current DBD plasmas,low temperature is beneficial to NO conversion,34.5% of NO is eliminated at 100 ℃ and input power of 6 W. While CH4 conversion is quite lower.