【摘要】 控制燃煤锅炉中Hg的排放已经越来越被电力行业所关注。已有数据表明气相排放的和残留在飞灰中的Hg的变化范围很大。引起这种变化的原因还不清楚。在尾部烟道附近,Hg以元素态和HgCl2蒸汽形式存在,已知其中HgCl2更容易从烟气中脱除。为了更好地控制Hg的排放,必须了解燃烧过程中Hg的反应产物以及各浓度与时间的关系,即Hg的反应动力学机理。文中首先采用化学热平衡分析的方法研究了烟气中痕量元素汞的形态和分布,继而提出了Hg/O/H/Cl系统的氧化动力学模型。后者与前者进行了对比,并与Mamani-Paco等人的实验结果进行了比较,取得了令人满意的结果。更多还原

【Abstract】 The potential for regulation of mercury emi-ssions from coal-fired boilers is a concern for the electric utility industry. Field data show a wide variation in the fraction of mercury that is emitted as a vapor vs. that retained in the solid products. The reason for this variation is not well understood. Near the end of the flue gas path, mercury exists as a combina-tion of elemental vapor and HgCl2 vapor. The data show that HgCl2 is more likely to be removed from the flue gas. Mercury chemical kinetic mechanisms are needed to describe accurately mercury reaction products and their concentrations-time correlation. It is necessary to develop mercury chemical kineti-cs for application to real combustion system. This paper uses firstly chemical equilibrium analysis to study the speciation of mercury in flue gases during coal combustion and gasification. A simple chemical kinetic model of mercury oxidation in Hg/O/H/Cl system is then developed. The results from the model calculation are in reasonable agreement with Mamani-Paco抯 experimental data.更多还原