光/热协同活化过硫酸铵一体化脱硫脱硝脱汞的基础研究

Emissions of SO2, NOx and Hg from coal-fired flue gas result in a great harm for human health and ecosystem. Simultaneous removal of SO2, NOx and Hg in a device, which is also called integrated desulfurization, denitration and demercuration, may effectively reduce the equipment space and system complexity, and save the investment and operating costs. Therefore, in recent years, studying new technologies and theories about integrated desulfurization, denitration and demercuration has become one of the hot issues in the field. In this project, based on impinging stream theory, a novel approach on integrated desulfurization, denitration and demercuration using light/heat-activated ammonium persulfate was proposed. Basing on the combination method of model and experiment, several important basic problems, mainly including the main influencing factors, reaction mechanism, mass transfer-reaction kinetics and kinetic model, of integrated desulfurization, denitration and demercuration using light/heat-activated ammonium persulfate were first studied in a novel photochemical impinging stream reactor. The main influencing factors and optimum operating parameters of integrated desulfurization, denitration and demercuration were obtained. The reaction mechanism was revealed. The mass transfer-reaction kinetic law and kinetic model were also obtained. The realization of this project will provide some preliminary theoretical foundation and key data for the follow-up development and industrial applications of this technology.

燃煤烟气中SO2﹑NOx和Hg的排放对人体健康和生态环境具有极大的危害。在一个装置中现实对SO2﹑NOx和Hg的同时脱除，即一体化脱硫脱硝脱汞，有望减少系统的复杂性和占地面积﹑降低投资和运行费用，近年来已成为该领域的研究热点和前沿问题之一。本项目创新性提出了基于撞击流理论的光/热协同活化过硫酸铵一体化脱硫脱硝脱汞的新方法。采用模型和实验相结合的手段，率先在新型光化学撞击流反应器上对光/热协同活化过硫酸铵一体化脱硫脱硝脱汞的关键影响因素﹑反应机理﹑传质-反应动力学规律和动力学模型等重要基础问题展开研究。预期目标是获得影响脱除过程的关键因素和优化操作参数，揭示反应机理，掌握气液传质-反应动力学规律和动力学模型。本项目的实现可为该技术的后续发展和工业应用提供理论基础和关键数据。

燃煤烟气中SO2﹑NOx和汞的排放对人体健康和生态环境造成了很大的危害。本项目创新性提出了基于多种新型反应器的活化自由基脱硫脱硝脱汞新方法。采用模型和实验相结合的手段，对相关脱除过程的基础问题展开了系统深入的研究。取得的代表性成果如下：（1）在光化学喷淋塔上，研究了真空紫外光诱导双氧水﹑水﹑氧气产生活性物种氧化脱除烟气中SO2和NO的基础问题。结果表明：臭氧﹑氧原子和羟基诱导的氧化反应是NO脱除的主导路径，而紫外光分解和双氧水氧化是NO脱除的次要路径。（2）在光化学撞击流反应器上，对紫外光辐射过硫酸铵诱导自由基脱除NO的机理和动力开展了研究。研发发现：硫酸根自由基和羟基在NO的氧化脱除中发挥了主导作用，NO脱除满足拟一级快速反应。（3）在撞击流反应器上对过渡金属离子协同高温活化Oxone同时脱硫脱硝的机制和动力学开展了研究。结果表明：硫酸根自由基和羟基是NO脱除的主导路径，且过渡金属离子和高温协同活化是自由基的主要来源。NO脱除满足拟一级快速反应。基于双膜理论，建立了NO脱除的动力学模型。（4）在紫外光喷淋塔上，开展了紫外光分解氯化物诱导自由基脱除NO的基础问题。结果表明，紫外光和次氯酸盐之间展现了显著的协同效应，且羟基是实现NO脱除的主要氧化剂。NO脱除满足拟一级快速反应，即传质是NO脱除的控制环节。（5）在开发的超声反应器上，研究了超声﹑过渡金属离子和过氧化物协同诱导自由基脱除NO的基础问题。结果发现，超声和过渡金属离子可协同活化过氧化物产生更多的自由基氧化脱除NO。超声可从强化传质和化学反应速率两个角度同时促进NO的脱除，但强化传质是主要作用。在超声和过渡金属离子共同诱导的活化系统中，羟基和硫酸根自由基是实现NO有效脱除的主要介质。（6）此外，申请人还在生物炭吸附脱除烟气单质汞等领域开展了研究，取得了创新性成果。以上成果可为相关技术的工业应用提供关键的理论指导。