Simultaneous So_x and No_x Removal Using Plasma-Chemical Hybrid Process from Power Plant

本研究的目的是开发一种经济有效的同时去除NO_x和SO_x的低温等离子体-化学复合工艺。通过一系列的实验研究，评价了该工艺同时脱除NO_x和SO_x的效果，并利用红外光谱仪和离子色谱仪对反应副产物N_2O、CO、HNO_2、HNO_3NO_3和SO_4进行了定量分析。在不降低NO_x浓度的情况下，最少的反应副产物）和最少的功率消耗是最佳反应器操作条件的关键。采用阻挡型填充床、脉冲电晕等离子体反应器和化学反应器，分别用Na_2SO_3和NaOH将产生的NO_2完全转化为N_2和Na_2SO_4。在20℃和130 ℃时，复合工艺的总运行成本分别为1,156 × 1726美元/t和1,173 × 1,753美元/t，实现了100%NO_x的去除，且N_2O和CO的排放量小于5 ppm，经济性不到传统选择性催化还原（SCR）工艺的10倍。这种混合系统也进行了研究，使用滑流从焚烧厂。在正常工况下（含水率小于15%），NO_x的去除率可达95%以上。当含水率在30 ~ 40%时，NO_x的去除率降低到80%左右。但运行成本仅为SCR工艺的1/7。

The objective of this study was to develop a cost effective simultaneous removal of NO_x and SO_x using the nonthermal plasma-chemical hybrid process. A series of experiments were performed to evaluate the simultaneous NO_x and SO_x removal efficiency and to quantify all the reaction byproducts such as N_2O, CO, HNO_2 HNO_3NO_3 and SO_4 using FTIR and ion chromatograph which was purchased for this project. The oxidation from NO to NO_2 without decreasing NO_x concentration(i.e., minimum reaction byproducts)and with least power consumption is the key for the optimum reactor operating condition. The produced NO_2 was totally converted to N_2 and Na_2SO_4 with Na_2SO_3 with and without NaOH using the barrier-type packed-bed and the pulsed corona plasma reactor followed by the chemical reactor. The total operating cost of the hybrid process becomes $1,156〜1,1726/ton of NO at 20℃ and $1,173〜1,753/ton at 130 ℃ to achieve 100% NO_x removal with less than 5 ppm of N_2O and CO, which is less than 10 times economical than the conventional selective catalytic reduction(SCR) process. This hybrid system was also investigated using the slip stream from the incineration plant. More than 95% of NO_x removal was achieved under normal conditions(less than 15% of moisture content). When the moisture content was in the range of 30 and 40%, NO_x removal efficiency was reduced to 80%. However, the operating cost was only 1/7 of the SCR process.