摘要
通过模拟选择性催化还原(SCR)系统,研究烟气组分中HCl、SO2、NO以及O2对于烟气中零价汞(Hg0)氧化效率的影响。实验结果表明:HCl会明显促进Hg0的氧化效率,随着HCl浓度的增大,Hg0的氧化效率呈大幅度上升的趋势,但会逐渐趋于一个常量;SO2的存在会明显抑制Hg0的氧化,当SO2的浓度由105.0 mg/m3升高到525.0 mg/m3时,Hg0的氧化率由93.3%下降到86.7%;NO对于Hg0的氧化有一定的促进作用,当NO浓度由149.2 mg/m3升高到298.4 mg/m3时,Hg0的氧化率由86.7%升高到93.3%;O2是提高Hg0氧化率必不可少的条件,O2含量的增加可以明显促进Hg0的氧化。正交实验表明:4种主要烟气成分对Hg0氧化效率的影响作用排序为:HCl>O2>SO2>NO,获得汞的最大氧化效率实验方案为:HCl、O2、SO2、NO的浓度分别为4.8 mg/m3、5%、105.0 mg/m3和186.5 mg/m3。
The simulated SCR device was employed for the study of the oxidation effect of elemental mercury by HCl, SO2,NO and O2 in flue gas. The experimental results indicated that HCl had an obviously promoting effect on the Hg0 oxidation.Hg0showed a trend of substantial increase of oxidation efficiency with the increasing of HCl concentration, but eventually tended to be a constant. SO2 had a restraining effect on the oxidation of Hg0, the oxidation rate of Hg0 decreased from 93.3%to 86.7% when the concentration of SO2 increased from 105.0 mg/m3 to 525.0 mg/m3. NO also promoted Hg0 oxidation in a certain degree, when NO concentration increased from 149.2 mg/m3 to 298.4 mg/m3, Hg0 oxidation rate rose from 86.7% to93.3%. As an essential condition of improving Hg0 oxidation rate, the increase of O2 would significantly promote Hg0 oxidation. Orthogonal experiment showed that the rank of main simulated flue gas efficiency on the Hg0 oxidation in order of HCl O2SO2NO. The experiment scheme of HCl, O2, SO2 and NO as 4.8 mg/m3, 5%, 105.0 mg/m3 and 186.5 mg/m3 respectively would obtain the highest oxidation efficiency of mercury.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2014年第11期37-41,52,共6页
Environmental Science & Technology
基金
宁波市科技创新团队项目(2011B82003)
福建省自然科学基金面上项目(2011J01060)
