复杂工况烟气氮氧化物催化净化

Catalytic purification of nitrogen oxides for complex industrial flue gas

氮氧化物作为主要的大气污染物之一,对人类健康和大气环境造成严重危害。近年来,我国电力行业持续减少烟气中的氮氧化物排放,非电行业和新兴发电行业如垃圾焚烧/生物质燃烧发电等领域的烟气氮氧化物污染控制成为固定源烟气减排的重点。目前,氨法选择性催化还原是应用最广泛且最有效的烟气氮氧化物净化技术。然而,非电行业和新兴发电行业烟气氮氧化物净化工况条件十分复杂,烟气中通常存在大量酸性气体(SO_(2)、HCl)、碱/碱土金属(Na、K、Ca)、重金属(Pb、Cd、As)和磷化合物等毒物,极易导致催化剂中毒失活。为了解决在复杂工况烟气中氮氧化物净化催化剂失活的问题,研究人员对催化剂的抑制中毒作用进行了广泛且系统的研究,包括提高催化剂对SO_(2)的耐受性、改善对碱金属和碱土金属的抗性,以及提升复杂工况烟气条件下的复合中毒抗性。综述了复杂工况烟气氮氧化物催化净化技术的研究进展,总结了催化剂抑制SO_(2)中毒、抑制碱/碱土金属中毒以及抑制复合中毒的有效策略,为开发高效、稳定且抑制中毒的烟气氮氧化物净化催化剂提供了参考和思路,同时也为推进氮氧化物净化催化剂在非电行业和新兴发电行业的复杂工况烟气净化中的实际应用提供了理论指导。

Nitrogen oxides,as one of the main atmospheric pollutants,cause potential risks to human health and the atmospheric environment.In recent years,nitrogen oxide emissions from power plants have been reduced,and controlling nitrogen oxide pollution in non-electric industries and emerging power generation sectors,such as waste incineration power generation and biomass combustion power generation,has become the focus of flue gas emission control from stationary sources.Currently,the most widely used and effective technology for nitrogen oxide purification is Selective Catalytic Reduction(SCR)using ammonia.The complex working conditions of flue gas purification technology for non-electric industries and emerging power generation sectors often result in the presence of large amounts of H_(2)O,acidic gases(SO_(2),HCl),alkali/alkali earth metals(Na,K,Ca),heavy metals(Pb,Cd,As),and phosphorus compounds in the flue gas.These components can lead to catalyst poisoning and severe deactivation.To address the deactivation issues of nitrogen oxide purification catalysts during practical application,researchers have conducted extensive studies on improving SO_(2)tolerance,alkali metal and alkali earth metal resistance,and resistance to multiple poisons under complex flue gas conditions.This paper reviews recent research on nitrogen oxide catalytic purification technology for flue gas under complex conditions and summarizes strategies to improve resistance to SO_(2)poisoning,alkali metal poisoning,and multiple poisoning.This review provides guidance and strategies for the development of efficient,stable and anti-poisoning nitrogen oxide purification catalysts.At the same time,it offers a theoretical foundation for promoting the practical application of nitrogen oxide purification catalysts in the complex flue gas purification from non-electric industries and emerging power generation sectors.