NaClO_2/尿素复合吸收剂湿法脱除烟气中的SO_2和NO

Removal of SO_2 and NO from flue gas by wet process of NaClO_2/urea composite absorbent

在自行设计的喷淋塔中对Na ClO_2/尿素复合吸收剂脱除烟气中的SO_2和NO进行了实验研究,实验分析了NaClO_2/尿素复合吸收剂脱除SO_2和NO机理。结果表明:SO_2被吸收液吸收的过程分为2个部分,一部分SO_2溶于水被NaClO_2氧化为SO_2-4,另一部分SO_2溶于水与尿素和氧气反应生成(NH4)2SO_4;难溶于水的NO被Na ClO_2主要氧化为NO-3,进而被尿素吸收,NO被还原为环境友好气体N2。此外,实验主要探索了Na ClO_2浓度、尿素浓度、NO进口浓度、SO_2进口浓度、初始pH值、温度对脱除NO的影响,优化选择最佳工艺条件,Na ClO_2浓度为4 mmol·L^(-1),尿素浓度为0.5 mol·L^(-1),吸收液初始pH值为7.0,温度为50℃时,平均SO_2和NO脱除率分别为100%和95.2%。

The experiment was performed to study the removal of SO2 and NO from the flue by NaClO2/urea composite absorbent in the spray tower designed by ourselves,the mechanism of removal of SO2 and NO from the flue gas by NaClO2/urea composite absorbent was analyzed. The results indicated that SO2 was absorbed liquid absorption process was divided into two parts,a part of SO2 dissolved in water was oxidized to SO2-4by NaClO2,another part of the SO2 dissolved in water and reacted with urea and oxygen to generate（NH4）2SO4. NO which was insoluble in water was oxidized into NO-3by NaClO2 and then absorbed by urea,NO was reduced to environmentally friendly gas N2. Furthermore,the experiments mainly explored the effect of NaClO2 concentration,urea concentration,SO2 inlet concentration,NO inlet concentration,initial pH value and temperature on the removal efficiency of NO,optimize the process conditions,the average removal rate of SO2 and NO were 100% and 95. 2%,respectively when the absorption liquid NaClO2 concentration was 4 mmol·L^-1,urea concentration was 0. 5 mol·L^-1,the initial pH was 7,the temperature was 50 ℃.