O_(3)-NH_(3)协同活性焦脱硫脱硝的均相预反应特性研究  

Characteristics of simultaneous removal of NO_(x) and SO_(2)by O_(3)-NH_(3) synergy

作　　者：卞若愚 安忠义 李启超 朱纯 孙镇坤 段伦博 BIAN Ruo-yu;AN Zhone-yi;LI Qi-chao;ZHU Chun;SUN Zhen-kun;DUAN Lun-bo(Key Laboratory of Energy Thermal Conversion and Control,Ministry of Education,Southeast University,Nanjing 210096,China;China Metallurgical Group Corporation Huatian Nanjing Engineering Technology,Nanjing 210019,China)

机构地区：[1]东南大学能源与环境学院能源热转换及其过程测控教育部重点实验室,江苏南京210096 [2]中冶华天南京工程技术有限公司,江苏南京210019

出　　处：《中国环境科学》2021年第10期4476-4483,共8页China Environmental Science

基　　金：国家重点研发计划(2019YFE0100100-08)。

摘　　要：为进一步提高活性焦脱硫脱硝性能,提出臭氧(O_(3))预氧化协同喷氨(NH_(3))的工艺优化思路.通过在固定床上开展相关均相反应实验,研究外部引入的O_(3)、NH_(3)对NO_(x)、SO_(2)的反应特性.结果表明,O_(3)对NO的氧化反应为逐级过程,随着O_(3)/NO物质的量比增大,O_(3)将NO依次氧化为NO_(2)和N2O5.O_(3)对SO_(2)的均相氧化作用十分有限,O_(3)/SO_(2)=1时SO_(2)氧化率低于5.0%.在O_(3)预氧化条件下喷入NH_(3)后,O_(3)/NH_(3)=1时约有6.7%的O_(3)消耗量;当O_(3)/NO=1时,预氧化产物NO_(2)含量显著下降,同时NO排放浓度小幅上升;当O_(3)/NO=1.5时,NO_(x)排放水平与未喷入NH_(3)条件时相当.在O_(3)和NH_(3)协同作用下,SO_(2)的氧化率显著提高,推测此时脱硫反应产物为更加稳定的NH4HSO4或(NH4)2SO4.O_(3)-NH_(3)协同脱硫脱硝反应中,O_(3)/NO不超过1时,NH_(3)-NO_(2)和NH_(3)-SO_(2)反应同时发生,提高NH_(3)引入量能够同时提高脱硫率和脱硝率.O_(3)/NO>1时,NH_(3)-N2O5反应优先级最高,N2O5对NH_(3)的消耗抑制了NH_(3)-SO_(2)脱硫反应发生.仅运用O_(3)预氧化和NH_(3)协同作用方式的脱硫脱硝效率较为有限,但对烧结烟气中氮、硫污染物的形态的改变产生重要影响.A technology of O_(3)pre-oxidation combined with NH_(3)injection had been proposed to improve the performance of desulfurization and denitrification for sintering flue gas.The characteristics of the homogeneous reaction among the introduced O_(3)and NH_(3),and the NO_(x) and SO_(2)from the sintering flue gas had been studied in a fixed-bed reactor.Results show that the oxidation of NO by O_(3)proceeds in a step-by-step manner.With the increase of the mole ratio of O_(3)/NO in the gas mixture with only O_(3)and NO,O_(3)had firstly oxidized NO into NO_(2),while subsequently to N2O5.However,the oxidation of SO_(2)by O_(3)in the gas mixture with only SO_(2)and O_(3)was very limited.When O_(3)/SO_(2)=1in the gas mixture of O_(3)and NO,the oxidation efficiency of SO_(2)was less than 5.0%.After NH_(3)had been introduced into the pre-reacted gas mixture of O_(3)and NO,about 6.7%of O_(3)was consumed.In this gas mixture,when O_(3)/NO=1,the pre-oxidation product NO_(2)decreased significantly from 278×10-6to 144×10-6,while the NO concentration at reactor outlet increased slightly from 16×10-6 to 35×10-6.When O_(3)/NO=1.5,the NO_(x) concentration at reactor outlet was equal to that without NH_(3)introduction.With the simultaneous introduction of O_(3)and NH_(3),the oxidation rate of SO_(2)increased significantly from 24.0%to 41.1%.It had been speculated that the desulfurization products was the compound of NH4HSO4 or(NH4)2SO4,which was stable in the reaction condition.During the reaction among SO_(2),NO_(x) and the simultaneously introduced O_(3)and NH_(3),the reactions of NH_(3)-NO_(2)and NH_(3)-SO_(2)took place at the same time when the ratio of O_(3)/NO<1.Therefore,the increasing amount of NH_(3)could improve both the desulfurization and denitrification efficiencies.When O_(3)/NO>1,the reaction between NH_(3)and N2O5 showed the highest priority,and the consumption of NH_(3)by N2O5 inhibited the desulfurization reaction of between NH_(3)and SO_(2).The simultaneous introduction of O_(3)and NH_(3)had limited impact on des

关 键 词：活性焦 吸附 O_(3)预氧化 脱硫脱硝 

分 类 号：X701[环境科学与工程—环境工程]