ClO_2溶液去除烟气中NO的效果及工程应用

采用实验室规模喷淋脱硝装置对ClO_2溶液去除NO的效果及影响因素进行探讨,通过脱硝产物的测定对ClO_2溶液去除NO的能力及机理进行分析;在此基础上考察ClO_2溶液对供热厂燃煤锅炉烟气的实际脱硝效果。实验结果表明:在液气比为20L/m~3、反应温度为20℃,反应pH为4.0、进气NO质量浓度为250 mg/m~3,ClO_2质量浓度为200 mg/L的条件下,NO去除率达97%以上;ClO_2溶液可将NO氧化吸收为NO_3~-,氧化后产生的NO_x也可被NaOH溶液吸收转化为NO_2~-和NO_3~-;在ClO_2质量浓度为200~500 mg/L,反应pH为5.5~7.0的条件下处理初始NO质量浓度为212~230 mg/m~3的燃煤锅炉烟气,NO去除率为85.7%~94.6%,NO_x去除率为80.4%~88.8%,出口NO_x质量浓度低于46 mg/m~3,远低于GB 13271—2014规定的排放限值。

Effect and engineering application of clO2 solution on removal of NO from flue gas

The effect of ClO2 solution on NO removal and the influence factors were studied using a lab-scale spray denitrification device. The NO removal capability and mechanism of ClO2 solution were analyzed through the denitrification products. Based on these results,the actual denitrification effect of ClO2 solution to flue gas from a coal-fired boiler in heating plant was investigated. The experimental results show that:Under the conditions of liquid-gas ratio 20 L/m3,reaction temperature 20℃,reaction pH 4.0,inlet NO mass concentration 250 mg/m3 and ClO2 mass concentration 200 mg/L,the NO removal rate is over 97%;NO can be absorbed by ClO2 solution and oxidized to NO3-,and the oxidation product NOx can also be absorbed by NaOH solution and converted into NO2-and NO3-;When the flue gas from coal-fired boiler was treated under the conditions of ClO2 mass concentration 200-500 mg/L,reaction pH 5.5-7.0 and initial NO mass concentration 212-230 mg/m3,the NO removal rate is 85.7%-94.6%,the NOx removal rate is 84.4%-88.8%,and the outlet NOx mass concentration is below 46 mg/m3,which is far lower than the national emission standard of GB 13271-2014.