NOx emitted from combustion devices pose significant risks to both the environment and human health. Among post-combustion denitrification methods, selective catalytic reduction (SCR) technology is the most widely adopted, owing to its high efficiency, technological maturity, and lack of harmful byproducts. However, alkali metals such as K, Na, Ca, and Mg present in flue gas can poison SCR catalysts, leading to deactivation and reduced performance of the SCR system. Therefore, studying the alkali metal poisoning mechanism and anti-poisoning measures of the SCR catalyst is crucial for increasing the service life of a catalyst and reducing the operation cost of a SCR denitration system. This review provided a systematic examination of recent research on the poisoning mechanisms of alkali metals in SCR catalysts, with a focus on vanadium-based, manganese-based, copper-based, cerium-based, and iron-based catalysts. This review also summarized various strategies to counter alkali metal poisoning and some regeneration measures for alkali metal poisoning SCR catalysts. The results demonstrate that the deposits of alkali metals on SCR catalysts can reduce the specific surface area and pore volume of the catalyst and also destroy the active sites on the catalyst surface, which eventually lead to poisoning of the catalyst. The doping of the catalyst with other elements, rational design of catalyst structures, and effective use of catalyst supports can effectively improve the anti-poisoning ability of the SCR catalyst. Water washing, acid washing, and electrophoresis treatment are some common methods for the regeneration of alkali-poisoned catalysts.
Audience Take Away Notes:
The audience can understand the poisoning mechanisms of alkali metals for SCR catalysts.
The audience can understand various anti-alkali metal poisoning measures and mechanisms for SCR catalysts.
The audience can learn about some regeneration measures for alkali metal poisoning SCR catalysts.
The audience can obtain the challenges and future research suggestions of alkali metal poisoning SCR catalysts.
Biography:
Mr. Wu is a PHD student majoring in thermal engineering at the School of Energy and Power Engineering, Jiangsu University, China. He is mainly engaged in the research of flue gas mercury removal using biochar adsorption.
