摘要
近年来,臭氧多种污染物一体化脱除技术在大气环境治理方面得到了广泛应用。臭氧作为一种强氧化剂,除了可将烟气中的NO深度氧化外,还可实现对微量重金属元素Hg的氧化脱除。通过建立臭氧与多种烟气污染物的反应动力学机理,采用Chemkin Pro软件,对某垃圾焚烧烟气臭氧同时脱硝脱汞过程进行反应动力学模拟。通过对NO、Hg与O_(3)反应的敏感度系数分析,得到O_(3)对NO和Hg氧化的关键基元反应,从而提出O_(3)和Hg的氧化反应路径;并进一步改变原烟气的初始参数,探究烟气温度、摩尔比和反应时间对NO和Hg脱除过程的影响。模拟结果表明,随着O_(3)/NO摩尔比增大,NO和Hg的氧化脱除效率增大。温度对于O_(3)深度氧化NO过程和Hg氧化脱除过程均有显著影响,温度过低,反应速率较慢,氧化过程延长;温度过高,反应速率加快,但由于中间产物的氧化分解,导致总体氧化脱除效率降低;NO深度氧化为N_(2)O_(5)的反应时间远大于初级氧化为NO_(2)的反应时间,深度氧化时间为5~8 s,最佳反应温度为60~80℃;垃圾焚烧过程产生的HCl气体对Hg氧化具有促进作用,Hg氧化为Hg2+的反应时间在4~6 s,最佳反应温度在110℃左右,最终氧化产物为HgO和HgCl2。
In recent years,the integrated removal technology of multi-pollutants by ozone has been successfully applied in air pollution treatment.Ozone,as one of strong oxidant,can not only realize NO deep oxidation in flue gas,but also remove trace heavy metal Hg by oxidation.In this paper,the kinetics reaction mechanism of ozone and multi-pollutants was established and the simultaneous removal of NOx and Hg by ozone in waste incineration flue gas was investigated by using Chemkin Pro software.By analyzing the sensitivity coefficient of NO and Hg and O_(3) reaction,the key elementary reactions of NO and Hg oxidation by O_(3) were obtained,and the reaction pathways of NO and Hg oxidation were also proposed.Besides,the effect of reaction temperature,O_(3)/NO molar ratio and reaction time on NO_(x) and Hg removal were also studied by changing the initial parameters.The modeling results show that the NO and Hg oxidation efficiency increases with the increasing O_(3)/NO molar ratio.The reaction temperature plays an important role on the process of NO deep oxidation by O_(3) and the process of Hg oxidation removal.The low reaction rate at too low temperature leads to longer reaction time,while too high temperature resultes in the decomposition of intermediate species,thereby reducing the removal efficiency.The reaction time of NO deep oxidation to N_(2)O_(5) is much longer than that of primary oxidation to NO_(2).The reaction time for NO deep oxidation is about 5-8 s under the optimal reaction temperature 60-80℃.The presence of HCl in the waste incineration flue gas is beneficial for Hg oxidation.The Hg oxidation reaction time and optimal temperature is 4-6 s and 110-130℃,respectively,with HgO and HgCl_(2) as the finally products.
作者
邵嘉铭
王智化
林法伟
唐海荣
许岩韦
何勇
岑可法
SHAO Jiaming;WANG Zhihua;LIN Fawei;TANG Hairong;XU Yanwei;HE Yong;CEN Kefa(State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou 310027,China;School of Environmental Science and Engineerin,Tianjin University,Tianjin 300072,China;Everbright Environmental Technology Research Institute(Nanjing)Co.,Ltd.,Nanjing 211102,China)
出处
《洁净煤技术》
CAS
北大核心
2021年第3期211-216,共6页
Clean Coal Technology
基金
国家重点研发计划资助项目(2018YFB0605200)。
关键词
臭氧
脱硝脱汞
垃圾焚烧
Chemkin计算
反应动力学
ozone
simultaneous removal of NO and Hg
waste incineration
Chemkin calculation
reaction kinetics
