水汽相变协同控制Hg和PM2.5的机理研究

项目名称： 水汽相变协同控制Hg和PM2.5的机理研究

项目编号： No.51506099

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 能源与动力工程

项目作者： 鲍静静

作者单位： 四川大学

项目金额： 21万元

中文摘要： 汞和细颗粒物（PM2.5）污染问题日益受到重视，控制燃煤电厂烟气中汞和PM2.5排放是亟待解决的关键问题。鉴于现有湿法烟气脱硫（WFGD）装置不能有效脱除汞和PM2.5，本项目在湿法烟气脱硫系统中应用水汽相变技术，一方面水汽相变过程中通过热泳、扩散泳作用拖曳气态汞在PM2.5表面富集，另一方面促使富集汞的细颗粒凝结长大脱除，实现燃煤烟气中汞和PM2.5的协同高效脱除。湿法脱硫及水汽相变环境下烟气中气态汞在细颗粒物表面的吸附凝结特性和富集规律是本技术的关键；为此，针对湿法脱硫烟气降温过程中气态汞形态变化特性、水汽相变对气态汞的凝结脱除特性及其在PM2.5表面的富集规律的影响机制以及水汽相变促进WFGD系统协同脱除汞和PM2.5的性能进行试验和理论研究，以期揭示WFGD系统中应用水汽相变协同脱除汞和PM2.5的技术基础，从而为实现燃煤烟气中汞和PM2.5协同高效脱除提供试验和理论依据。

中文关键词： 水汽相变；Hg；PM2.5；湿法烟气脱硫；脱除

英文摘要： Emission of mercury and particulate matters with an aerodynamic diameter less than 2.5μm has attracted more and more attentions. Coal-fired power plants are the main pollution source. Hence, control of mercury and PM2.5 emitted from coal-fired power plants is the key problem urgently to be solved. Since mercury and PM2.5 can not be removed efficiently in the existing wet flue gas desulfurization (WFGD) process, simultaneous removal of mercury and PM2.5 by combination of vapor heterogeneous condensation and WFGD system is proposed in this project. As vapor condenses, gaseous mercury can be dragged on to the surface of PM2.5 by thermophoresis and diffusiophoresis. Meanwhile, PM2.5 with mercury on it’s surface can enlarged and then removed efficiently. Condensation characteristic and accumulation regulation of gaseous mercury on the surface of PM2.5 in the stream phase transition room is the key point of this technique. Therefore, chemical speciation change of mercury, their accumulation regulation on the surface of PM2.5, influence of vapor heterogeneous condensation on the condensation and removal characteristic of gaseous mercury, and the simultaneous removal effect of mercury and PM2.5 in the stream phase transition room will be investigated in this project. The aims are to seek the technical basis of the simultaneous removal of mercury and PM2.5 by vapor heterogeneous condensation in the WFGD system. The research results will contribute to fundamentals for the simultaneous removal of mercury and PM2.5 from coal-fired flue gas with high efficiency.

英文关键词： vapor heterogeneous condensation;Hg;PM2.5;wet flue gas desulfurization;removal