NaClO_(3)电解液对工业废气中NO_(x)的去除

Removal of NO_(x) from industrial flue gas by NaClO_(3) electrolyte

为研究NaClO_(3)电解液用于工业废气脱硝的可行性,采用实验室自制的小型喷淋反应器,对NaClO_(3)电解液的脱硝性能进行了探究,考察了有效氯浓度、pH、温度及NO体积分数对脱硝性能的影响,并探讨了在不同运行条件下,NaClO_(3)电解液的脱硝性能及NaClO_(3)和有效氯的浓度变化。结果表明:提高电解液中有效氯浓度、降低pH及NO体积分数均可有效提高NO_(x)去除率,但温度超过45℃时不利于去除NO_(x);电解液在有效氯浓度2000 mg·L^(-1)条件下(pH 3.1,25℃),NO_(x)去除率可达89.9%。循环喷淋实验结果显示,NaClO_(3)电解液能在420 min内保持较高的脱硝效率,NO和NO_(x)去除率分别保持在62.5%与58.9%以上。脱硝主要消耗电解液中有效氯,NaClO_(3)浓度的积累对NO_(x),因此,NaClO_(3)电解液应用于工业废气脱硝是可行的。以上研究结果可为非电工业炉窑烟气湿法脱硝提供参考。

The feasibility of the principle that controls industrial flue gas NO_(x) emissions through NaClO_(3) electrolyte scrubbing is evaluated with a lab-scale scrubber.The effects of concentration of available chlorine concentration,pH,temperature as well as NO volume fraction on NO_(x) removal efficiency was investigated.The NO_(x) removal performance of NaClO_(3) electrolyte and the concentration changes of NaClO_(3) and available chlorine under different operating conditions were discussed.The results showed that NO_(x) removal efficiency was improved by increasing the available chlorine,reducing the pH and the NO volume fraction,while solution temperature higher than 45℃was not beneficial for NO_(x) removal.When the available chlorine concentration was 2000 mg·L^(-1)(pH 3.1,25℃),the NO_(x) removal efficiency reached 89.9%.In recirculating scrubbing mode,the NaClO_(3) electrolyte could maintain high denitrification efficiency within 420 min,and the removal efficiencies of NO and NO_(x) maintained above 62.5%and 58.9%,respectively.Denitrification mainly consumed available chlorine in the electrolyte,and the accumulation of NaClO_(3) concentration had an insignificant effect on the NO_(x) removal efficiency.Further analysis showed that the application of NaClO_(3) electrolyte on denitrification from industrial flue gas was feasible.The above results can provide a reference for the wet DeNO_(x) from flue gas of non-electric industrial furnaces.