SCR催化剂低负荷运行硫酸氢铵失活研究

针对国内燃煤机组低负荷运行SCR脱硝系统出现的催化剂因硫酸氢铵(ABS)失活问题,在实验室模拟烟气条件下,对催化剂ABS失活及活性恢复特性进行了研究。结果表明,毛细凝聚作用下的ABS液化-汽化是典型的物理可逆过程,且受到烟气中NH_3与SO_3体积分数的正相关影响。基于这一研究成果,提出了最低连续喷氨温度(MOT)的经验计算公式,该公式可用于评估实际运行烟气条件下的MOT。为指导SCR低负荷运行最佳方案的选择和ABS失活催化剂的活性恢复,在对SCR低负荷运行案例分析基础上,给出了MOT经验计算公式使用原则和方法。

Study on the Ammonium Bisulfate Deactivated SCR Catalyst at Low Load Operation

Aimed at the problem of ammonium bisulfate (ABS) deactivated SCR catalyst at low load operation, the characteristics of ABS deactivation and activity recovery are studied in the simulated flue gas environment in laboratory. It indicates that the ABS liquidation-vaporization under capillary condensation is a typical invertible process and the process is positively affected by the concentration of NH₃ and SO₃ in flue gas. In addition, the empirical formula used to evaluate the MOT under the actual operating condition is proposed. Based on the case analysis of the SCR operating at low load, the principle and method to use the experience formula MOT is given to guide the selection of the best plan for SCR operating at low load and the activity recovery of the ABS deactivated catalyst.