活性焦改性同时脱除烟气中的单质汞和VOCs的理论与方法

The coal-fired flue gas has become the largest emission source of mercury and volatile organic compounds (VOCs) in the atmosphere with the ever-growing of coal consumption. The key to control mercury and VOCs emissions is to promote the oxidation of elemental mercury and VOCs in the flue gas. Therefore, this project is expected to adsorb and oxidize elemental mercury and VOCs in the flue gas by modified activated coke. The effects of the impact factors, such as the modification of activated coke, chemical composition of active agent (additive agent) and flue gas components, on adsorption, oxidation and removal of elemental mercury and VOCs will be investigated. The physical and chemical process of elemental mercury and VOCs over the surface and in the micropore of the (modified) activated coke will also be studied. Besides, the interaction between mercury and VOCs removal behavior over the (modified) activated coke will be researched as well. Moreover, on the basis of the research on the chemical thermodynamics and chemical dynamics of the adsorption and oxidation of elemental mercury and VOCs, the simultaneous removal of mercury and VOCs will be modeled by numerical simulation. Furthermore, the mechanism of adsorption and oxidation of elemental mercury and VOCs with modified activated coke will be clarified. Meanwhile, new theories and methods for simultaneous removal of mercury and VOCs will be built. Through this project, the new theories, methods and approaches will be provided for mercury and VOCs pollution control from the coal-fired flue gas, which make it possible to efficiently remove mercury and VOCs in the existing desulfuration and denitration system with activated coke adsorbents. Additionally, theoretical guidance and practical basis will be provided to control air pollution in the atmosphere economically and efficiently.

日益增长的煤炭消费导致燃煤烟气是大气中汞和挥发性有机物（VOCs）的最大排放源。控制汞和VOCs排放的关键是促进烟气中的单质汞和VOCs的氧化。本项目期望对活性焦进行改性，吸附和氧化烟气中的单质汞和VOCs。 研究活性焦的改性、活性剂（添加剂）的化学组成、烟气成分等对单质汞和VOCs的吸附、氧化和去除的影响；研究单质汞和VOCs在（改性）活性焦表面及微孔中的物理化学过程；研究活性焦改性同时脱汞脱VOCs时的相互影响；在研究单质汞和VOCs吸附氧化的化学热力学和动力学基础上，进行脱汞脱VOCs的数值模拟研究；阐明改性活性焦吸附氧化单质汞和VOCs的机制，建立燃煤烟气同时脱汞脱VOCs的新理论新方法。本项目的实施，为控制燃煤烟气汞污染和VOCs污染提供新理论、新方法和新途径，将使目前已有应用的活性焦脱硫脱硝系统实现脱汞脱VOCs成为可能，为经济、高效地控制空气污染提供重要的理论指导和实践基础。

继SO2和NOx之后，人为排放的汞（Hg）和挥发性有机物(VOCs)造成的区域大气污染问题日益受到重视。如何有效控制VOCs和Hg的排放，已经成为研究者广泛关注的课题，其关键是促进烟气中单质汞及VOCs的氧化。本项目研究了对活性焦进行改性，吸附和氧化烟气中的单质汞和VOCs。采用不同改性方法及不同活性组分，制备高效改性活性焦；在模拟实验台上研究改性方法、活性组分及其含量、反应温度、烟气条件对改性活性焦上Hg0及VOCs去除效率的影响；对反应前后的（改性）活性焦进行表征分析，研究其表面形态、空间结构及化学组分的变化，据此分析单质汞及VOCs在（改性）活性焦表面的物理化学行为，揭示（改性）活性焦对Hg0及VOCs去除的作用机制；研究单质汞和VOCs在（改性）活性焦表面的物理化学过程，解释脱汞和脱VOCs之间的相互作用机制，并提出（改性）活性焦协同脱汞脱VOCs的作用机理，实现改性活性焦在促进Hg0去除的同时，提高VOCs的氧化作用；基于Fluent软件，对活性焦联合脱除反应塔进行模拟和优化设计。研究开发了3种以上的改性活性焦，实验室脱汞脱VOCs效率均达到90%以上。发表相关论文24篇，其中SCI论文22篇、中文核心期刊论文2篇；获得授权发明专利1项、实用新型专利1项；申请发明专利3项、实用新型专利1项；培养出站博士后1人、毕业博士生1人、毕业硕士生15人。本项目的研究，为控制烟气汞污染和VOCs污染提供新方法和新途径，使目前已有应用的脱硫脱硝系统实现脱汞脱VOCs成为可能，为经济、高效地控制空气污染提供重要的理论指导和实践基础。