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的非热等离子体-化学混合工艺。采用FTIR和离子色谱仪进行了NO_x和SO_x的同时脱除效果评价，并对N_2O、CO、HNO_2、HNO_3NO_3和SO_4等反应副产物进行了定量分析。在不降低NO_x浓度的情况下，由NO氧化为NO_2。（反应副产物最少）和功率消耗最少是优化反应器运行条件的关键。采用阻挡式填料床和脉冲电晕等离子体反应器，再采用化学反应器，将生产的NO_2用Na_2SO_3和Na_2SO_4完全转化为N_2和Na_2SO_4。该混合工艺在20℃条件下的总运行成本为1,156 ~ 1,1726美元/吨，在130℃条件下的总运行成本为1,173 ~ 1,753美元/吨，在N_2O和CO含量低于5 ppm的情况下实现100%的NO_x脱除，比传统的选择性催化还原（SCR）工艺经济性低10倍。利用焚烧厂的滑水流对该混合系统进行了研究。在正常条件下（低于水分含量的15%），NO_x去除率达到95%以上。当含水率为30% ~ 40%时，NO_x去除率降至80%。然而，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.