模板法制备掺硫介孔碳固化脱除燃煤烟气汞的机理研究

The curing removal of mercury pollutant from coal-fired flue gas has become an important research topic for controlling mercury emission from coal-fired power plants and reducing mercury secondary release from spent sorbents. This project proposes using template method to prepare a sulfur-doped mesoporous carbon for mercury curing removal from coal-fired flue gas. The active sulfur groups with strong mercury affinity are incorporated into the precursor of mesoporous carbon and firmly fixed on the surface of mesoporous carbon through in situ doping. The effect of carbon, sulfur precursors and preparation process parameters on the morphological structure of sulfur-doped mesoporous carbon will be investigated, and the structure-activity relationship between morphological structure of mesoporous carbon and mercury removal efficiency will be thoroughly revealed. The effect of different flue gas component on mercury removal capability of sulfur-doped mesoporous carbon will be explored to reveal the competitive adsorption between mercury and other flue gas components, and the mechanism of mercury selective adsorption by sulfur-doped mesoporous carbon under mixed flue gas component will be clarified. The thermal and chemical stability of mercury removal product on spent sulfur-doped mesoporous carbon will be analyzed to reveal the mechanism of mercury curing removal by sulfur-doped mesoporous carbon, and a mass transfer-adsorption model for mercury curing removal by sulfur-doped mesoporous carbon will be built. Therefore, the research results of the project can provide ideas for the development of complete treatment technology for mercury pollutants from coal-fired flue gas, and have important scientific significance and potential industrial application prospects.

燃煤烟气汞污染物的固化脱除是当前燃煤电站控制汞排放与减少汞二次释放的重要研究课题。本项目提出采用模板法制备掺硫介孔碳，以前驱体掺杂的方式，将与汞极具亲和力的活性硫基团通过原位掺杂牢固地固定在介孔碳表面，实现燃煤烟气汞的固化脱除。项目将深入研究碳、硫前驱体与制备过程参数对掺硫介孔碳形貌结构的影响规律，揭示掺硫介孔碳的形貌结构与汞脱除效果间的构效关系；探究不同烟气组分对掺硫介孔碳脱汞性能的影响，揭示汞与其它烟气组分在掺硫介孔碳表面的竞争吸附机制，阐明混合烟气中掺硫介孔碳对汞的选择性吸附机制；分析掺硫介孔碳脱汞产物的热稳定性和化学稳定性，揭示掺硫介孔碳固化脱除燃煤烟气汞的机理，建立掺硫介孔碳固化脱汞的传质-吸附模型。本项目研究成果可为我国燃煤烟气汞污染物彻底治理技术的发展提供思路，具有重要的科学意义和潜在的工业应用前景。

燃煤烟气汞污染物的固化脱除是当前燃煤电站控制汞排放与减少汞二次释放的重要研究方向。项目采用模板法制备掺硫介孔炭，以前驱体掺杂的方式，将与汞极具亲和力的活性硫基团通过原位掺杂牢固地固定在介孔炭表面，实现燃煤烟气汞的固化脱除。项目主要工作和结论如下：.采用模板法制备了一系列掺硫介孔炭吸附剂，在固定床实验装置上研究了模板剂、前驱体、制备参数等对吸附剂脱汞性能的影响，揭示了掺硫介孔炭的形貌结构与汞脱除效果间的构效关系。结果表明：在前驱体（2-噻吩乙醇:百里香酚蓝）质量比为6:1，煅烧温度为900 ℃时制备获得的掺硫介孔炭有着最佳脱汞效率，高达97%。.在固定床实验装置上系统研究了烟气温度与烟气组分等因素对掺硫介孔炭脱汞性能的影响，结合物化特性表征，揭示了掺硫介孔炭的脱汞机理。同时对脱汞后吸附剂进行了热再生研究。结果表明：掺硫介孔炭表面的硫主要为噻吩态硫与氧化态硫，在脱汞过程起重要作用；掺硫介孔炭的脱汞产物主要为HgS；掺硫介孔炭具有高抗SO2性能与良好的再生性。.利用程序升温汞脱附实验（Hg-TPD）和毒性浸出实验（TCLP）分别研究了掺硫吸附剂脱汞产物的热稳定性与化学稳定性，并采用动力学模型分析了其汞吸附动力学与传质特性。结果表明：该掺硫介孔炭的脱汞产物具有较好的热稳定性与化学稳定性；汞在掺硫介孔炭表面的吸附首先为表面吸附，然后转为内扩散吸附。.本项目研究成果可为我国燃煤烟气汞污染物彻底治理技术的发展提供思路，具有潜在的工业应用前景。本项目发表学术论文6篇（其中SCI 4篇），申请发明专利3项（1项授权），作学术报告5次，培养硕士研究生4名。