摘要
零价汞的高效去除是燃煤烟气汞污染控制过程中的关键环节。为了促进烟气中的零价汞转化为易于去除的氧化态汞,分别考察了在有HCl存在时,几种过渡金属氧化物(Cu、Fe、Mn、Co和Zr)对零价汞氧化的催化作用,以筛选出性能较好的催化组分;为提高催化剂的抗SO2性能,分别尝试了利用几种金属元素(Sr、Ce、W和Mo)对催化剂进行掺杂改性的方法。结果表明,锰氧化物的催化作用最好,其最佳使用温度在573 K左右;SO2对零价汞的催化氧化有明显抑制作用,在无SO2及1 400 mg/m3SO2时锰催化剂对零价汞催化氧化效率分别为93%和78%。而Mo改性的锰氧化物催化剂的抗硫性能大幅提高,在1 400 mg/m3SO2存在的情况下其对零价汞的催化氧化效率可达到90%以上,较其他改性元素高。
How to make elemental mercury removed efficiently is the key point for the control of mercury emission from the coal-fired flue gas.To obtain a high conversion from elemental mercury to its oxidation state,which can be easily captured by flue gas desulfurization systems,some catalysts were employed to assist with the oxidation of elemental mercury in the presence of hydrogen chloride,and four metals（strontium,cerium,tungsten,molybdenum） were used tentatively to modify the Mn-catalyst to improve their tolerance capacity to sulfur dioxide（SO2）.The results showed that the manganese oxide displayed the highest catalytic oxidative efficiency at 573 K,and the removal efficiency of mercury by manganese can reach 93% and 78% without SO2 and with 1 400 mg/m3 SO2,respectively.Once modified with molybdenum,the removal efficiency of manganese oxides was above 90% with 1 400 mg/m3 SO2,which was significantly higher than the catalysts modified with the other elements.
出处
《环境工程学报》
CAS
CSCD
北大核心
2010年第5期1143-1146,共4页
Chinese Journal of Environmental Engineering
基金
国家"863"高技术研究发展计划项目(2007AA06Z340)
关键词
燃煤烟气
零价汞
催化氧化
掺杂改性
coal-fired gas
elemental mercury
catalytic oxidation
catalyst modification
