铁络合物混合吸收体系脱除氮氧化物的研究

Study on Removal of Nitrogen Oxides by Iron Complex Mixed Absorption System

络合吸收是常温液体脱销的有效方法之一,不同金属离子和配体对NO的络合吸收能力各有不同,其中,由于铁络合物的脱硝效果比较突出,受到了广泛关注。铁络合物常用的配体是EDTA二钠,本文主要以喷淋塔为主要反应装置,以EDTA二钠和柠檬酸钠为配体的铁络合物对模拟烟气中氮氧化物的脱除进行了研究。对硫酸亚铁铵,EDTA二钠和柠檬酸钠按照一定比例配合后对NO的吸收性能进行了分析,考察了络合物,温度,pH,液气比对脱硝效率的影响。得到最佳的络合吸收条件:混合络合物浓度为0.05mol/L,温度为45℃,液气比为10,pH值为6,在此条件下氮氧化物脱除率高达85%。

Complex absorption is one of the effective methods for liquid off-gas at room temperature.Different metal ions and ligands have different complexing absorbability to NO,among which,iron complexes have attracted wide attention because of their outstanding denitrification effect.The common ligand of iron complex is EDTA disodium.In this paper,the spray tower is used as the main reaction device,and the iron complexes with EDTA disodium and sodium citrate as ligands are used to simulate the removal of nitrogen oxides from flue gas.The absorption properties of NO were studied after ammonium ferrous sulfate,EDTA disodium and sodium citrate were combined according to a certain ratio.The effects of complex concentration,temperature,pH and liquid-gas ratio on denitrification efficiency were investigated.The optimum complex absorption conditions were obtained:the concentration of mixed complex was 0.05 mol/L,the temperature was 45℃,the liquid-gas ratio was 10,and the pH was 6.Under these conditions,the removal rate of nitrogen oxides was as high as 85%.