活性焦脱硫脱硝的机理研究

Mechanism of Removal of SO_2 and NO on Activated Coke

采用质谱仪在线检测的方法,研究了不同组成的模拟烟气在活性焦上的吸附行为;并应用SEM、FT-IR、XPS、BET等手段表征了活性焦的结构性质。结果表明,活性焦脱硫脱硝性能与活性焦的孔隙结构和表面化学特性密切相关,孔容是决定污染物初期脱除率的主要因素;表面官能团则在污染物的化学吸附上发挥着重要作用,是吸附、催化的活化中心;二氧化硫较一氧化氮优先吸附在活性焦上;烟气中氧气或水蒸汽的单独存在对脱硫脱硝均不会有明显的影响,当烟气中同时存在氧气和水蒸汽时,活性焦的脱硫脱硝效果可明显改善;氨的存在既可将一氧化氮还原为氮气,又能增强活性焦脱除二氧化硫的效果。

In order to clarify the mechanism of desulphurization and denitrification from flue gas on activated coke,the adsorption behaviors of SO2 and NO on activated coke in various simulating flue gas were studied in the experiment,and the pore structures and surface properties were analyzed using SEM,FT-IR,XPS and BET respectively.The experimental results show that the performance of desulphurization and denitrification were related to the pore structures and the surface chemistry of activated coke,and the pore volume was the key factor,and the surface functions was the important factor which was the activating centre for adsorption and catalysis of SO2 and NO.Besides,SO2 took priority of NO on activated coke;and single O2 or H2O had no distinct effect on desulphurization and denitrification from flue gas,but the effect of desulphurization and denitrification were distinct while O2 and H2O existed in flue gas at one time.Moreover,NH3,which reduced NO to N2,could enhance the capacity of de-SO2 of activated coke.