氧化球团烟气中SO2和H2O(g)对SCR脱硝的影响

选择性催化还原(SCR)具有效率高、技术成熟的优势,但处理球团烟气需要加热才能达到SCR脱硝的反应温度,导致能耗和运行成本高.氧化球团预热Ⅱ段(PH段)烟气温度在300℃以上,满足SCR反应所需温度,但是烟气中含有的SO2和H2O(g),会对催化剂的脱硝性能产生影响.研究了 PH段烟气中SO2和H2O(g)对V/Ti催...

Effect of SO2 and H2O(g)in flue gas of pellet on SCR catalytic denitrification

Selective catalytic reduction (SCR) has the advantages of high efficiency and mature technology, but the flue gas of the pellets needs to be heated to reach the reaction temperature of SCR denitrification, resulting in high energy consumption and operating costs. The flue gas temperature of oxidized pellet preheating section II (PH section) is above 300℃, which meets the temperature required for the SCR reaction, but the SO2 and H2O (g) contained in the flue gas will affect the denitrification performance of the catalyst. The effect of SO2 and H2O(g) in the flue gas in the PH section on the denitrification performance of the V/Ti catalyst and its mechanism were studied. The results show that both SO2 and H2O(g) will reduce the denitrification performance of the catalyst to a certain extent. The effect of denitrification is smaller and reversible than that of SO2. The presence of SO2 and H2O(g) has the worst impact on the denitrification performance of the catalyst and is irreversible. The denitrification rate of the catalyst decreases from 96.1% to 77.2% after reacting for 5 hours at a concentration of 10%H2O(g)+1100mg/m3SO2. The ammonium sulfate formed by the reaction of SO2 and H2O(g) in the flue gas with NH3 is deposited and adsorbed on the surface of the catalyst, which reduces the specific surface area and dispersion of the reacted catalyst, which is not conducive to the adsorption of NO and NH3, thereby reducing the denitrification performance of the catalyst. Therefore, the control of the content of SO2 and H2O(g) in the flue gas and the optimization of the denitrification conditions are very important for the SCR denitrification in the PH section.