Deactivation Characteristics of SCR Catalyst at Different Stages in Coal-Fired Flue Gas

Through analyzing the impact of the factors of catalyst deactivation, different factors are classified according to timeliness characteristics. In this research, experiments were made under the condition of coal combustion flue gas on a coal-fired boiler to study the characteristics of the early deactivation of the SCR catalyst. Analysis shows that the main cause of early deactivation of catalyst is chemical poisoning (mainly alkali metal) and pores clogging on the surface of the catalyst. While the main cause of long-term deactivation is deeper chemical poisoning, pores clogging and the chemical form changes of elements on the surface of the catalyst. Through analyzing the influence of the factors of catalyst deactivation, separate factors are classified according to timeliness characteristics. This research provides a strong fundamental support to clear the deactivation mechanism of the SCR catalyst.