助剂(C_2H_4、NH_3)添加对AC/DC流光放电等离子体脱硝效果的影响

Effect of additive(C_2H_4,NH_3) addition on denitrification effect of AC/DC streamer discharge plasma

等离子体法脱硝被认为是一种非常环保有效的脱硝技术,为了探究等离子体对NO_x的作用过程,选用AC/DC流光放电等离子体及模拟烟气,考察了烟气流量和NO初始浓度、添加剂的种类与含量以及SO_2对等离子体脱硝的影响。结果表明:NO的脱除过程由氧化过程和还原过程同时作用,在同一功率下,NO_x脱除率随流量的增加而降低,NO初始浓度对NO_x脱除率无直接影响。氨的添加可以促进NO_x的还原脱除,乙烯的添加可以促进NO氧化转化为NO_2。烟气中SO_2存在会导致NO_x脱除效率降低,此时氨助剂的加入可以显著提高NO_x脱除率。当NH3∶SO_2=2∶1时,在15 W下SO_2脱除率可达100%,NO_x脱除率60%。

The plasma method is considered an effective and environmentally friendly denitration technique. To explore the effect of plasma on NO_x,AC /DC streamer discharge plasma and simulated flue gas were used,and several influencing factors were investigated,such as the flue gas flow rate,initial NO concentration,type and content of chemical additives,and the presence of SO_2. The removal of NO was found to occur by oxidation and reduction simultaneously. Under the same discharge power,the De-NO_xrate decreased with increasing flow rate.Meanwhile,the initial NO concentration had no direct effect on the De-NO_xrate. The addition of ammonia could promote the reduction of NO_x,while the addition of ethylene could promote the oxidation of NO to NO_2. In the presence of sulfur dioxide,the removal efficiency of NO_xdecreased,but when ammonia was used as an additive,the removal rate of NO_xwas significantly improved. At NH_3∶ SO_2= 2 ∶ 1,the removal rate of SO_2 reached 100%,and the removal rate of NO_xwas 60%.