液相络合-铁粉还原-酸吸收回收法脱除烟气中NO

提出了Fe2+螯合剂络合-铁粉还原-酸吸收回收法脱除烟气中NO的新工艺,重点研究了模拟烟气中O₂含量对NO络合量的影响,以及铁粉用量、铁粉粒径和搅拌速度对脱氮效率的影响,确定了最佳的铁粉脱氮工艺条件,并对铁粉和铁屑的脱氮效果进行了比较.结果表明:烟气中φ(O₂)从0增加到4.2%,NO络合量下降90.2%;脱氮效率随铁粉用量和反应器搅拌速度的增加而增加,随铁粉粒径的增加而降低;最佳工艺参数为,铁粉用量0.8 g,铁粉粒径≥200目(≤0.077 mm),搅拌速度900 r/min,在该条件下,对φ(O₂)为5%的模拟烟气在搅拌反应器中可取得90%以上的脱氮效率;用铁粉在1台搅拌反应器中取得的脱氮效率和用铁屑在2个鼓泡反应器串联时所取得的效率相当. 

Removal of NO from Flue Gas with the Recovery Process of Absorption with Acid Following Complexation in Aqueous Solution and Reduction with Iron Powder

A novel recovery process for removing NO from flue gas with the recovery process of absorption with acid following complexation with ferrous chelate in aqueous solution and reduction with iron powder was proposed. The effect of O₂ content in stimulated flue gas on the NO complexing capacity of denitrification liquor and the parameters influencing the NO removal efficiency, including the amount of iron powder, the size of iron powder particulate, and the rotating speed of reactor, were investigated in detail. The optimal NO removal conditions for denitrificaiton process with iron powder were established. The difference for removing NO with iron filings and iron powder was compared. The results show that capacity for NO decreases by 90.2% when the O₂ content in the simulated flue gas increases from 0 to 4.2%. Denitrification efficiency increases with the increasing of the amount of iron powder and rotating speed of the reactor, and decreases with the increasing of the size of iron powder particulate. Under the optimal conditions of the amount of iron powder 0.8 g, the size of iron powder particulate over 200 mesh（≤0.077 mm）, and the rotating speed of the reactor 900 r/min, NO removal efficiency for flue gas containing O₂ content of 5% exceeds 90% in the stirred reactor. Denitrification efficiency with iron powder in a stirred reactor can be comparison with iron filings in two series bubble column.