煤燃烧过程中汞形态转化机理及其治理新方法研究

Mercury in the environment is a serious issue and mercury emissions from coal-fired power plants are a major source. The study of the mercury transformation mechanism during coal combustion were performed. The experimental data and the modeling analysis demonstrate that the gaseous mercury concentrations in the flue gas are between 10 and 15 ?g/Nm3 , the content of mercury in ash is below 20%, which suggests that the majority of mercury go into flue gas with gaseous state. The mechanisms and rate of elemental mercury (Hg0) capture by activated carbons and oter sorbents have been studied using a bench-scale fixed-bed apparatus. Results show that the sorption mechanism is a combination of physisorption and chemisorption. The presence of SO2，HCl and other flue gases have effects on the adsorption of mercury. Sorbents were impregnated with compound such as chloride, which resulted an increase of mercury removal capacity. The mercury control technology on the basis of semi-dry method was brought forward and will be carried out in several processing approaches, the final technology can be applied in the coal-fired boilers.

本项目围绕当前容易被忽视又极具潜在危害性的大型燃煤锅炉汞污染问题开展研究。研究在煤燃烧过程中汞的挥发、迁移、形态转化机理，建立汞形态转化反应热力学模型，并提出汞形态转换和综合治理的制汞新方法。通过本项目的研究对于了解和改善我国燃煤汞污染危害具有极其重要的现实和未来意义，并具有广泛的工程应用前景。