Fe-ZSM-5催化S2O82-脱除烟气中Hg0的研究
Research on Fe-ZSM-5 catalyzed S2O82-removal of Hg0 from flue gas
王泉海 1刘柱 1卢啸风 1刘志村1
作者信息
- 1. 重庆大学低品位能源利用技术及系统教育部重点实验室,重庆 400044
- 折叠
摘要
烟气中的零价汞Hg0难以被脱除,是燃煤电厂汞排放的主要形式.过硫酸根可以有效地氧化脱除Hg0,但其本身反应效率不佳限制了其在燃煤电厂中氧化脱除Hg0的工业应用.为此,从催化S2O82-与Hg0的氧化反应入手,以商用H-ZSM-5为原料,通过浸渍法成功制备了不同Fe含量的Fe-ZSM-5催化剂.结合ESEM-EDS、XRD、BET和XPS等分析方法对制备的催化剂进行了表征,发现随着Fe负载量的增大,分子筛表面的分散度越大且Fe均匀分布在表面上,有助于催化反应的进行,同时浸渍的Fe主要以Fe2+和 Fe3+形式存在于ZSM-5,Fe负载量的增大也会导致Fe2+占比增大,而Fe2+对氧化反应有极大的促进作用,Fe主要以Fe-Si-O形式存在,ZSM-5被铁改性后仍保持其完整的骨架结构和孔隙形状.实验结果表明,3.0Fe-ZSM-5作催化剂时效果最佳,氧化脱除Hg0效率最高能达到88.31％.
Abstract
Mercury is one of the main pollutants in coal-fired power plants.Hg0,whose removal from the flue gas is difficult,thus is the main form of mercury emissions from coal-fired power plants.Persulfate can effectively oxidize and remove Hg0,but its poor reaction efficiency limits its industrial application in coal-fired power plants.This paper first conducts the catalytic oxidation reaction between S2O82-and Hg0,and successfully prepares Fe-ZSM-5 catalysts with different Fe contents using commercial H-ZSM-5 as raw material through impregnation method.The prepared catalyst is characterized by the analysis methods such as ESEM-EDS,XRD,BET,and XPS.We find that with the rise of Fe loading,the dispersion of the molecular sieve surface increases and Fe is uniformly distributed on the surface,which is conducive to the catalytic reaction.Meanwhile,the impregnated Fe mainly exists in the form of Fe2+and Fe3+in ZSM-5.The rise of Fe loading also cause an increase in the proportion of Fe2+,which greatly promotes the oxidation reaction.Fe mainly exists in the form of Fe-Si-O,and ZSM-5 maintains its intact skeleton structure and pore shape after being modified by iron.Our experimental results show the best effect is achieved when 3.0Fe-ZSM-5 is used as a catalyst,and the highest efficiency of Hg0 oxidation removal reaches 88.31％.
关键词
过硫酸根/零价汞/Fe-ZSM-5/催化氧化Key words
potassium persulfate/zero valent mercury/Fe-ZSM-5/catalytic oxidation引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据