工艺参数对活性焦烟气中联合脱硫脱汞性能的交互影响

Interactive effect of operation parameters on the combined removal of SO_2 and mercury in flue gas using activated coke

在固定床吸附反应器上,考察了温度、SO2浓度、NO浓度、O2浓度等工艺参数对活性焦联合脱硫脱汞性能的影响。结果表明:温度在130～190℃内,温度降低有利于活性焦联合脱硫脱汞;随着SO2浓度提高,活性焦对SO2吸附量呈增大趋势;基准工况(BL)+1500mL/m3SO2体系下,活性焦对单质汞(Hg0)单位吸附量比在BL中下降33%,SO2与单质汞在活性焦表面存在竞争吸附,SO2对活性焦对单质汞吸附能力有明显的抑制作用;NO与O2生成具有氧化性的NO2和O原子,增强了单质汞的氧化,BL+400mL/m3NO体系中活性焦的单质汞单位吸附量比在BL中升高24%;BL+SO2+NO体系中,活性焦的单质汞吸附能力比在BL中下降3.8%。

A series of studies on the characteristic of the combined removal of SO2 and mercury in simulated flue gas were conducted with a laboratory-scale fixed-bed reactor and the interactive effect of operation parameters,such as temperature,the concentration of SO2,NO and O2 on the removal capacities of SO2 and Hg0 using activated coke was investigated.The experiment results indicate that the adsorption performance of SO2 and Hg0 with activated coke is influenced by temperature obviously and the lower temperature is in favor of the removal process with activated coke in the range of 130 ～ 190 ℃.With the increasing of the concentration of SO2,the adsorptive capacity has a tendency of increasing.Compared with the baseline condition,the average adsorptive capacity of Hg0 decreases about 33% under the conditions of Baseline（BL） ＋ 1 500 mL/m3 SO2.There is competitive adsoption between SO2and Hg0 on the surface of activated coke and the appearance of SO2 suppresses the Hg0 removal.The NO will react with O2 and generate NO2,O atom with oxidizability which result in about 24% increasing of average adsorptive capacity of Hg0 with 400 mL/m3 NO additive in baseline condition.In the BL ＋ SO2 ＋ NO gas condition,the adsorptive capacity of Hg0 decreases 3.8% compared with baseline condition.The competition between SO2 and NO causes a little decrease in Hg0 capture capacity of the sorbent.