摘要
我国是燃煤大国,元素汞是燃煤烟气排放过程的主要有害痕量元素之一,毒性很强,给人类健康和生态环境带来了极大的影响。燃煤过程中汞的排放,特别是大型燃煤电厂的汞排放,在全球汞循环中具有相当大的危害性,所以煤炭开采与利用过程引起的汞污染问题应当引起广泛重视,如不采取一定措施加以控制,将会造成难以弥补的危害。燃煤电厂所引起的环境污染非常严重,控制汞的排放已成为急需解决的环境问题。元素汞脱除的关键在于元素汞的价态转化,采用NH4Cl为氧化剂进行了模拟烟气中元素汞的氧化脱除实验,并考察了氧化剂浓度、反应温度、烟气滞留时间对元素汞氧化脱除的影响。结果表明,氧化剂浓度达到120 ppm,反应温度超过1 200 K,烟气滞留时间达到2 S时,燃煤烟气中的元素汞转化率可达到90%以上。
Elemental mercury emitted from coal-fired flue gas is one of the main harmful trace elements, and is highly toxic, giving human health and the environment posed a great impact. Mercury emissions from coal-burning process, especially large coal-fired power plant has considerable harm in the global mercury cycle, so mercury pollution problems of coal mining and utilization process caused by widespread attention, if not taken certain measures to control, will cause irreparable harm. Hg pollution from its combustion is a severe environmental issue so that the control on Hg emission from the combustion has been concerned widely. The key to elemental mercury removal is the valence transformation. We produced an oxidation removal experiments of elemental mercury in the simulated flue gas using NH4C1 as the oxidant, and studied oxidant concentration, reaction temperature, and gas residence time influence on the oxidation removal of elemental mercury. The results show that when the oxidant concentration is 120 ppm, the reaction temperature exceeds 1 200 K, and the flue gas residence time to 2 s, elemental mercury of the coal-fired flue gas conversion rate can reach 90%.
出处
《沈阳师范大学学报（自然科学版）》
CAS
2012年第1期77-80,共4页
Journal of Shenyang Normal University:Natural Science Edition
基金
国家863计划专题课题(2009AA05Z317)
辽宁省教育厅重点实验室基金资助项目(LS2010156)
关键词
燃煤烟气
元素汞
化学氧化法
coal-fired flue gas
elemental mercury
chemical oxidation
