摘 要：活性焦烟气脱硫是一种先进的干法脱硫技术，该技术脱硫效率高且脱硫过程不消耗水，没有废水、废渣排放，脱硫后解吸产物为高浓度SO2气体，可用来生产硫酸、硫磺、液体SO2、化肥等产品。活性焦用于除汞同样能达到很高的脱除效果。
活性焦干法联合烟气净化技术是燃煤烟气多污染物控制的重要手段，本文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℃范围内，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%。
在固定床反应器上，模拟真实烟气条件进行了联合脱硫脱汞及N2气氛下热再生实验，考察活性焦原焦及再生活性焦对SO2和Hg的吸附性能。实验结果表明：在4000h-1空速下，活性焦具有良好的再生脱硫脱汞活性，可以重复用于烟气脱硫脱汞；活性焦对SO2、Hg吸附过程同时存在着二者的解吸。活性焦热再生过程中，SO2、Hg的解吸附主要发生在200℃~400℃温度区间，活性焦对SO2、Hg的吸附量及热再生后的解吸量相当，热再生时吸附的SO2及Hg均以气态SO2及单质汞形态释放。
关键词：活性焦；脱硫；脱汞；工艺参数；联合净化；热再生
Abstract：The activated coke desulphurization process is an advanced dry desulphurization technology. This process has several excellent features, including high desulphurization efficiency, no water consumption, no waste water, no waste residue, and obtaining high consumption SO2 from desorption, which could be used to produce sulfuric acid, sulfur,iquid SO2, chemical fertilizer and so on. Activated coke used in the removal of mercury can also achieve high removal efficiency.
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 indicated that the adsorption performance of SO2 and Hg0 with activated coke was influenced by temperature obviously and the lower temperature was in favor of the removal process with activated coke in the range of 130 to 190℃. With the increasing of the concentration of SO2, the adsorptive capacity had a tendency of increasing. Compared with the baseline condition, the average adsorptive capacity of Hg0 decreased about 33% under the conditions of Baseline(BL)+1500ml/m3 SO2. There was competitive adsoption between SO2 and Hg0 on the surface of activated coke and the appearance of SO2 suppressed 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 400ml/m3 NO additive in baseline condition. In the BL+SO2+NO gas condition, the adsorptive capacity of Hg0 decreased 3.8% compared with baseline condition. The competition between SO2 and NO caused a little decrease in Hg0 capture capacity of the sorbent.
Experiment of desulfuration and de-mercury was conducted at a space velocity of 4000h-1 in the simulated flue gas with a fixed bed reactor. Then thermal regeneration was conducted with saturated activated coke and the removal capacities of sulfur-dioxide and mercury by regenerative activatd coke was investgated. Results indicated that regenerated activated coke had excellent SO2 and mercury removal performance. The desorption of SO2 and Hg which also existed in the removal process.occurred mainly between 200℃ and 400℃. The adsorption and desorption amount of SO2 and mercury maintained roughly the same. Gaseous SO2 and mercury released during the regenerated process.
Keyword：activated coke; desulfurization; de-mercury; operation parameters；combined purification ；thermal regeneraton
