燃煤电厂汞排放控制技术研究

摘要

Recently, mercury emission from coal fired power plants has rosen up as important air pol ution like SO2 , NOx , and soot.Since the legislation of control ing mercury emission from coal fired power plants in China, research on the control technique becomes urgent.Based on their different physical and chemical characters, element state mercy ( Hg0 ) is more difficult for removing from the smoke, compared with oxidation state mercy ( Hg2+) and particulate mercy ( Hgp ) .Therefore, the precondition of removing mercy is to improve the oxida-tion percentage of Hg0 .Several control techniques of mercury emission are investigated, including,pre-boiler control, in-boiler control, and after-boiler control.Also, the prospect for control technique of mercury emis-sion from coal fired power plants is suggested.%近年来，燃煤电厂烟气中的汞成为继SO2、NOx和烟尘之后又一公认的大气环境污染物，我国已正式立法控制燃煤电厂汞排放，这使得燃煤电厂汞排放技术的研究迫在眉睫。不同形态汞的理化性质不同，元素态汞（ Hg0）较之氧化态汞（Hg2＋）和颗粒态汞（Hgp）更难去除，因此，脱汞的前提是提高Hg0的氧化率。介绍并简单分析了目前国内外已有的汞排放控制技术：燃烧前控制（清洁燃煤发电技术）、燃烧中控制（煤基添加剂技术和炉膛喷射技术），和燃烧后控制（利用现有的烟气控制设备协同控制），并对我国脱汞技术发展方向提出了展望。