摘要
臭氧氧化污染物协同脱除技术利用臭氧的强氧化性,将烟气中溶解度较低的NO_(x)、Hg、VOCs等多种污染物氧化为高价态或易溶解的形式,并结合尾部湿法喷淋系统实现污染物的同时脱除。由于其具有温度窗口低、脱硝效率高、反应速率快及改造难度小等优点,在工业锅炉、窑炉及非电行业得到广泛应用。但是在此过程中的污染物实际转化路径,尤其是氮氧化物的输入/输出平衡,目前还未有详细的验证试验支撑。因此本文针对典型臭氧氧化脱硝过程,对污染物脱除过程中的氮氧化物输入/输出平衡及氮元素流向进行了分析试验。试验结果表明,气相输入的NO经过臭氧氧化耦合湿法喷淋后逐渐转化为液相中硝酸根和亚硝酸根离子。在不同O_(3)/NO摩尔比下,气相氮元素的减少量均以液相中硝酸根及亚硝酸根的增加量存在,不存在其他含氮形式。同时,吸收浆液中硝酸盐及亚硝酸盐的转化率也与烟气中NO_(x)脱除率相匹配。在NO/SO_(2)同时氧化条件下,调节O_(3)/NO摩尔比,结合湿法喷淋系统可以实现NO_(x)/SO_(2)的协同高效脱除,同时系统满足氮元素输入/输出平衡,为臭氧氧化污染物协同脱除技术的工程应用推广提供了依据。
The synergistic removal technology of ozone oxidation pollutants utilizes the strong oxidizing property of ozone to oxidize various pollutants such as NO_(x),Hg,VOCs and other pollutants with low solubility in flue gas into high valence or easily soluble forms,and combined with the tail wet spray system to achieve simultaneous removal of pollutants.Due to its advantages of low temperature window,high denitration efficiency,fast reaction rate and less difficulty in transformation,it is widely used in industrial boilers,kilns and non-electric industries.However,the actual transformation path of pollutants in this process,especially the input/output balance of NO_(x),has not been verified in detail by experiments.Therefore,for the typical ozone oxidation denitrification process,this paper analyzes NO_(x) input/output balance and nitrogen flow direction in the process of pollutant removal.The experimental results show that the NO input in the gas phase is gradually converted into nitrate and nitrite in the liquid phase after ozone oxidation coupled with wet spraying.Under different O_(3)/NO molar ratios,the reduction of nitrogen in the gas phase is converted into the increase of nitrate and nitrite in the liquid phase,and there is no other nitrogen containing form.At the same time,the conversion rate of nitrate and nitrite in the absorption slurry is also matched with the NOx removal rate in the flue gas.Under the condition of simultaneous oxidation of NO/SO_(2),adjusting the O_(3)/NO molar ratio,combined with the wet absorption system,it can achieve simultaneous and high-efficiency removal of NOx/SO_(2),and the system can satisfy the nitrogen input/output balance.It can provide a basis for the engineering application and popularization of ozone oxidation pollutant synergistic removal technology.
作者
张逸伟
唐海荣
何勇
朱燕群
王智化
ZHANG Yiwei;TANG Hairong;HE Yong;ZHU Yanqun;WANG Zhihua(State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou 310027,Zhejiang,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2022年第4期1732-1742,共11页
CIESC Journal
基金
国家自然科学基金杰出青年基金项目(52125605)。
关键词
臭氧氧化
氮平衡
污染
喷淋吸收
氮氧化物
反应
ozone oxidation
nitrogen balance
pollution
spray absorption
NOx
reaction
