氨-Fe(Ⅱ)EDTA法同步脱硫脱硝中试研究

Pilot-scale experimental study on simultaneous removal of SO_2 and NO by ammonia-Fe(Ⅱ) EDTA absorption

在中试吸收塔反应器中,以氨基湿法烟气脱硫为基础,结合Fe(Ⅱ)EDTA络合吸收NO技术,实现同步脱硫脱硝;采用单一变量法研究了塔型、填料几何特性、填料层高度、液气比和Fe(Ⅱ)EDTA浓度等因素对同步脱硫脱硝的影响。结果表明,在相同的条件下,填料塔比空喷塔和鼓泡塔有利于同步脱硫脱硝;空隙率高、填料因子小的填料能明显提高脱硫脱硝效率,填料层高度从0 mm增加到900 mm,脱硫脱硝效率分别增大了4.49%和19.55%;液气比和Fe(Ⅱ)EDTA浓度越大,脱硝效率越高,但对SO_2的吸收没有影响。最佳工艺条件为:ф25 mm鲍尔环作填料且填料层高度为900 mm的填料塔、液气比为12 L/m^3、Fe(Ⅱ)EDTA浓度为0.05 mol/L,在此条件下,脱硫脱硝效率分别达到100%和51.55%。

In this study,based on the ammonia-based wet flue gas desulfurization（ WFGD）,simultaneous removal of SO2 and NO was achieved in a pilot-scale absorption reactor with an aqueous solution of Fe（ Ⅱ） EDTA for NO removal. The factors affecting the efficiency of simultaneous removal of SO2 and NO were researched including the tower types,geometric properties of packing,packing height,liquid-gas ratio and concentrations of Fe（ Ⅱ） EDTA by using simple variable method. The results show that the packed tower was more conducive to simultaneous removal of SO2 and NO under the same conditions. The packing with a higher porosity and a smaller packing factor could improve the efficiency of NO removal significantly,the SO2 and NO removal efficiency increased by 4. 49% and 19. 55%,respectively when the packing height from 0 mm to 900 mm. With the liquidgas ratio and concentration of Fe（ Ⅱ） EDTA increasing,NO removal efficiency gradually increased,but it did not work on the absorption of SO2. Under the optimal conditions of the packing ф25 mm Bauer ring,the packing height 900 mm,the liquid-gas ratio 12 L/m^3,and the concentration of Fe（ Ⅱ） EDTA 0. 05 mol/L,SO2 and NO removal efficiency could reach to 100% and 51. 55%,respectively.