微纳米气液分散体系催化氧化并吸收复杂烟气中NO机理研究

Some of flue gas contains more water vapor and high concentration of NO with other complicated components and all kinds pollutant at the same time. It’s temperature is low. These factors seriously affect the NOx reduction efficiency of Selective Catalytic Reduction (SCR). So, some of scientists pay attention to catalytic oxidation and wet absorption technology under consideration of simultaneous removal of multi—pollutions from the flue gas. The proposers have found that the micro/nanometer gas-liquid dispersion system（pneumatic nebulization, micro/nano bubbles ） can capture and oxidize NO into NOx through inducing oxygen into oxygen radical because of special properties of the micro/nanometer gas bubble, which has long residence time( the ascending velocity of 10µm micro /nano meter gas bubble is 3mm/min ), high mass transfer efficiency( highest mass transfer efficiency to several times comparing with that of large gas bubble ), high surface potential (highest surface to thousands of times and release oxygen free radicals in absorbing medium. In the same time, the high denitration rate can be gained by use of this gas-liquid dispertion system and electrostatic mist eliminator. It will be further investigated that coupling NO of micro-nano bubble capture and oxygen transfer catalyst catalytic oxidation to gain high absorption rate of NOx in flue gas by the micro/nanometer gas-liquid dispersion system. BY use of the instruments(such as Micro-nano Bubble Tester,X-ray Microscopic CT , Isotope Spectrometer, High-speed Camera) with fluent sofware modeling and the double-film theory model, this research project focuses on the denitration process and mechanism of micro-nano bubble capture NO, oxygen transfer catalyst oxidation NO and absorption NOx; The denitration process and mechanism of micro-nano bubble capture NO and oxygen transfer catalyst catalytic oxidation NO; the effect of more pollutants in flue gas on The denitration process and mechanism of NO capture, catalytic oxidation and NOx of the absorption process； kinetics of Catalytic oxidation chemical reaction of NO and NOx absorption kinetics of micro/nano gas-liquid dispersion system . This study aims to analyze the major drawback of micro/nano gas-liquid dispersion capture system coupled with catalytic oxidation for effective denitration of NO as key steps To explore the low cost and highy efficient oxidation system for flue gas in a efficient way by integration to remove more pollutants at the same time. As well to provide denitration technology on theoretical basis.

烟气中NO浓度高，组分复杂，含有各类污染物，与吸收液接触时间短，降低了湿法催化氧化并吸收含复杂污染物烟气脱硝效率。本项目基于申请人实验发现气动雾化、微纳米气泡等气液分散体系可以捕获并诱导氧气氧化NO，再利用此气液系统和电除雾器高效脱硝的结果，进一步研究微纳米气液分散体系捕获耦合催化氧化NO并吸收NOx的机理。本项目依托电子自旋共振波谱仪等手段重点研究微纳米气泡捕获NO并诱导氧气氧化NO、原位吸收脱硝过程和机理、微纳米气泡捕获NO耦合氧转移催化剂（OTC）催化氧化NO反应过程和机理、复杂组分对微纳米分散体系脱硝反应及过程干扰与促进作用、OTC催化氧化NO耦合微纳米气液分散体系吸收化学反应动力学等。为剖析制约微纳米气液分散体系捕获耦合催化氧化NO高效脱硝的关键步骤，探索适应烟气复杂组成的低成本高能氧氧化NO高效途径，为实现烟气一体化多污染物同时脱除技术提供理论基础。

本项目针对烟气中NO浓度高，组分多且复杂，与吸收液接触时间短，降低了湿法催化氧化的效果，影响脱硝效率，现有污染控制技术工艺复杂、设备多套、工艺适应性有待加强的特点，在前期研究发现基础上提出微纳米气液分离体系催化氧化并吸收复杂烟气中NO的研究思路，为实现适应烟气复杂组成的低成本、高能氧化NO，实现烟气脱硝具有重要的意义。主要研究成果如下：本项目在3年时间内建立和完善微纳米气泡气液分散体系，并将该体系用于NO的氧化吸收；研究微纳米气泡催化氧化NO的反应过程，讨论pH、过渡金属离子、氯化钠以及表面活性剂对NO去除率的影响，通过对微纳米气泡气液分散体系的动力学分析，讨论其机理；研究复杂组分（SO2等）存在条件下对微纳米气泡捕获NO的脱除率变化，研究了微纳米气液分散体系耦合过硫酸盐、双氧水、OTC催化剂（硫化铁、四氧化三铁、氧化锰铁等）催化氧化并吸收NO的反应过程并进行反应机理分析等。研究结果表明各类氧化剂、空气、O3、过渡金属离子、pH、NaCl、十二烷基磺酸钠（SDS）、尿素、和Mn2+/Fe2+等因素对NOx吸收效率有影响,MP存在对NOx脱除率影响各不相同。酸性物质污染物有促进作用，PM2.5以上的颗粒需要提前脱除。在最佳条件下，5000ppmNO和5000ppmSO2几乎完全脱除，PM2.5、盐酸和Hg脱除率99%，PM2.5可以降到4ppm。微气泡产生的活性氧将NO氧化为高价态可吸收的NOx，进而促进NOx吸收完全。另外活性氧的利用率有待提高，多污染物是否相互影响脱除率及其可能产生二次污染需要进一步研究。.本课题在国家自然科学基金的支持下，共发表SCI、EI论文14篇（其中含已接收SCI论文2篇）中文核心5篇，获得专利1项，申请专利5项。培养研究生11名，其中包括毕业研究生5名，毕业博士生3名，基本完成研究目标。