臭氧深度氧化烟气结合湿法喷淋脱除氮氧化物试验与机理研究
发布时间：2018-08-07 15:13
【摘要】：目前我国的能源结构仍离不开传统化石燃料为主体的情况,化石燃料带来的硫氧化物、氮氧化物、汞、VOCs、PM等污染物造成的污染物问题日趋严重,对生态环境、人类健康都造成了危害和隐患。目前在锅炉尾气污染物治理方面,从传统的针对单一污染物脱除向多种污染物协同脱除,并达到超低排放成为大势所趋。本文讨论了臭氧氧化烟气结合湿法脱除技术路线中的相关的问题,对主要影响因素进行了试验研究,主要有以下几点:1、在近尾部烟道温度(150℃)下,采用活性分子臭氧对含有NO的模拟烟气进行氧化,得到NO的氧化情况与O_3/NO摩尔比的关系。臭氧在低于150℃的烟气温度下可将烟气中的NO氧化为高价态的氮氧化物,在NO/O_3摩尔比1.2时,NO的主要氧化产物为NO_2,且烟气中SO_2的存在并不会显著影响NO的氧化情况。2、使用Na_2S_2O_3溶液对NO_2进行吸收脱除。分析了 Na_2S_3O_3溶液浓度、SO_2浓度和pH等因素对NO,的脱除效率的影响,并探究了氮元素迁移途径。在O_3/N0摩尔比为1.1～1.2时,使用浓度为2%的Na_2S_2O_3溶液作为喷淋液长时间持续运行时时,SO_2基本保持较高脱除效率,NOx脱除效率也基本维持在60%以上,Na_2S_2O_3与氧气反应缓慢,经喷淋吸收后,氮元素迁移的主要产物为NO_2~-,其次为NO_3~-。3、臭氧深度氧化后,使用Na_2CO_3溶液湿法对N2O5进行脱除。气相反应温度70℃,反应时间6 s,当O_3/NO摩尔比2.41时,NO_2被完全转化为N_2O_5。系统脱硝效率与液气比、Na_2CO_3溶液浓度、烟气塔内停留时间分别呈正相关关系。4、臭氧深度氧化后,使用Na_2CO_3溶液湿法对NO_2和N_2O_5进行脱除。当O_3/NO摩尔比1.2时,随着气相氧化反应时间的减少,反应室出口残留的NO_2越多,即臭氧非充分深度氧化。系统脱硝效率与喷淋液气比、Na_2CO_3溶液浓度、烟气塔内停留时间分别呈正相关关系,与烟气中SO_2浓度呈负相关关系。经湿法脱除后,烟气中NO_x主要以NO_3~-形式存在于喷淋浆液中。实际工程中已应用该技术。5、经过预处理后的717型树脂对模拟浆液中的NOO-进行脱除,反应在10min时基本平衡;SO_4~(2-)相较于CO_3~(2-)和HCO_3-,比NO_3~-有更强的树脂离子置换竞争性,对效率影响大;实际工程中喷淋液的pH值范围内,pH对树脂脱除硝酸根影响不大。
[Abstract]:At present, the energy structure of our country is still inseparable from the situation of traditional fossil fuels as the main body. The pollution problems caused by pollutants such as sulfur oxides, nitrogen oxides and mercury VOCsN PM brought by fossil fuels are becoming more and more serious, which is harmful to the ecological environment. Human health has caused hazards and hidden dangers. At present, in the treatment of boiler tail gas pollutants, it has become a general trend from the traditional removal of single pollutants to the coordinated removal of various pollutants, and to achieve ultra-low emissions. In this paper, the related problems in the technical route of flue gas removal by ozone oxidation combined with wet method are discussed, and the main influencing factors are studied experimentally. The main factors are as follows: 1, at the near tail flue temperature (150 鈩，
本文编号：2170431
[Abstract]:At present, the energy structure of our country is still inseparable from the situation of traditional fossil fuels as the main body. The pollution problems caused by pollutants such as sulfur oxides, nitrogen oxides and mercury VOCsN PM brought by fossil fuels are becoming more and more serious, which is harmful to the ecological environment. Human health has caused hazards and hidden dangers. At present, in the treatment of boiler tail gas pollutants, it has become a general trend from the traditional removal of single pollutants to the coordinated removal of various pollutants, and to achieve ultra-low emissions. In this paper, the related problems in the technical route of flue gas removal by ozone oxidation combined with wet method are discussed, and the main influencing factors are studied experimentally. The main factors are as follows: 1, at the near tail flue temperature (150 鈩，
本文编号：2170431
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