SCR催化剂碱(土)金属中毒及其改性再生研究进展

摘要

选择性催化还原(SCR)技术因其脱硝效率高、运行成本低、不产生二次污染等优点而被广泛应用于燃煤电厂等企业的烟气脱硝.催化剂是SCR技术的核心,SCR催化剂的中毒失活导致废SCR催化剂的产生量越发增多,而碱(土)金属是引起SCR催化剂中毒失活的主要因素.详细总结了碱金属(K、Na)和碱土金属(Ca、Mg)导致SCR催化剂中毒的机理及其各相应化合物对催化剂性能的影响,初步探讨了提高新鲜催化剂抗碱(土)金属中毒的措施和碱金属中毒催化剂的改性再生,为延长SCR催化剂的使用寿命进而减少废SCR催化剂的产生量提供参考.%Selective catalytic reduction (SCR) technology is widely used in flue gas denitrification of coal-fired power plants because of its high efficiency of denitrification,low running cost and no secondary pollution.The catalyst was the core of SCR technology,and the poisoning inactivation of SCR catalyst leaded to an increase amount of SCR catalyst spent,while alkali (earth) metal was the main factor causing SCR catalyst poisoning inactivation.The poisoning mechanism of SCR catalyst by alkali metal (K,Na) and alkaline earth metals (Ca,Mg) and the effect of the performance of the corresponding compounds on the catalyst in detail were summarized.At the same time,the effects of improving the anti-alkali (earth) metal poisoning of fresh catalyst and the modified regeneration of alkali metal poisoning catalyst were discussed,which could provide reference for prolonging the service life of SCR catalyst in order to reduce the generation of spent SCR catalyst.