操作条件对V2O5/TiO2催化剂选择性催化还原烟气脱硝性能的影响

操作条件对V₂O₅/TiO₂催化剂选择性催化还原烟气脱硝性能的影响

摘要: 采用浸渍法制备了V2O5/TiO2催化剂,考察了操作条件对该催化剂选择性催化还原(SCR)烟气脱硝性能的影响。结果表明:在典型的SCR反应温度范围(300～400℃)内,催化剂具有较高的脱硝率(92.7%～98.8%);当反应温度超过400℃时,N2O开始生成,催化剂的选择性下降。空速对催化剂脱硝率的影响与反应温度有关。n(NH3)/n(NO)与催化剂的脱硝率和氨逃逸密切相关。催化剂表现出较广的NO浓度适应性。当O2体积分数超过2%时,可以消除其对催化剂脱硝率的影响;O2是SCR反应过程中被还原活性位再氧化的主要氧源。

Abstract: V2O5/TiO2 catalysts were prepared by impregnation method.Effects of operation conditions on their performance for selective catalytic reduction of NO in flue gas were determined.The results show that the NO removal efficiency is high and the NO conversion reaches from 92.7 percent to 98.8 percent at the typical SCR reaction temperature（300 ℃ to 400 ℃）.When the reaction temperature exceed 400 ℃,N2O appear,thereby decreasing the catalysts selectivity.The effect of space velocity on NO removal efficiency is related to reaction temperature.The molar ratio of NH3/NO plays an important part in NO removal and NH3 slip.The adaptability of catalysts to NO concentration is wide.O2 is the main oxygen source for active sites and has no influence on NO removal efficiency when its volume fraction exceed 2 percent.