Fe^(2+)EDTA溶液络合-铁还原脱除烟气中NO

Removing NO from flue gas by chelate of Fe^(2+)EDTA solutions and reduction of iron powder

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体积分数对NO络合量的影响,以及铁粉用量、铁粉粒径、搅拌速度对NO脱除效率的影响,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O2的体积分数从0%增加到4.2%,NO络合量下降90.2%;NO脱除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;过程的最佳工艺参数为,铁粉用量0.8g,铁粉粒径≤0.077mm,搅拌速度900r·min-1,在此条件下,对O2体积分数为5%的模拟烟气在搅拌反应器中可取得90%以上的NO脱除效率;用铁粉在1台搅拌反应器中取得的NO脱除效率和用铁屑在2个鼓泡反应器串联时所取得的效率相当。

The article proposes a novel recovery process for removal NO from flue gas by the absorption of acid followlng the complex of ferrous chelate in aquoous solution with reduction of iron powder. 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, are investigated in detail. The optimal NO removal conditions for denitrificaiton process with iron powder are established. And the effects of removal NO with iron filings and iron powder are compared. The results show that capacity for NO decreases by 90.2% when the O2 content in the simulated flue gas increases fi＇om 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 8%, the size of iron powder particulate below 0.077 mm, and the rotating speed of the reactor 900 r·min^-1, NO removal efficiency for flue gas containing 02 5% exceeds 90% in the stirred reactor. Denitrification efficiency with iron powder in a stirred reactor can be compared with iron filings in two series bubble column.