摘要
针对当前Fenton氧化法脱除燃煤烟气中NO的过程中H_(2)O_(2)大量无效分解生成氧气的缺点,本文采用二乙烯三胺五亚甲基膦酸(DTPMPA)/Fenton系统进行氧化脱除NO的实验研究。结果表明:该系统在NO脱除效率为95.1%的情况下,H_(2)O_(2)无效分解占比降低至15.5%。DTPMPA浓度的增加抑制了H_(2)O_(2)无效分解,其浓度较低时促进NO脱除而浓度较高时抑制NO脱除;H_(2)O_(2)及Fe^(2+)浓度的增加均对NO脱除及H_(2)O_(2)无效分解有一定的促进作用,但二者浓度过高时亦均对脱除NO有一定抑制作用;降低反应温度对NO脱除影响较小,但会削弱H_(2)O_(2)无效分解;SO_(2)^(-)对NO的脱除及H_(2)O_(2)无效分解影响甚小。电子自旋共振技术和淬灭剂添加实验结果表明:DTPMPA的添加提高了Fenton系统中·OH自由基和·O_(2)^(-)自由基的含量,且·O_(2)^(-)自由基为脱除NO的主要活性物质,·O_(2)^(-)+HO·→O_(2)^(-)+HO-为氧气生成的主要途径。反应产物离子色谱表明:NO在反应过程中被氧化为NO_(2)^(-)和NO-3。
In view of the current Fenton oxidation method to remove NO in coal-fired flue gas,a large amount of H_(2)O_(2)ineffectively decomposes to generate oxygen,the DTPMPA(diethylenetriamine pentamethylphosphonic acid)/Fenton system was used to oxidize and remove NO.The results showed that when NO removal efficiency of the system was 95.1%,the proportion of H_(2)O_(2)ineffective decomposition decreased to 15.5%.The increase of DTPMPA concentration inhibited H_(2)O_(2)ineffective decomposition,and it promoted NO removal when the concentration was low but inhibited NO removal when the concentration was high.The increase of H_(2)O_(2)and Fe^(2+)concentrations had a certain promoting effect on NO removal and H_(2)O_(2)ineffective decomposition,but when the concentration of both was too high,it also had a certain inhibitory effect on NO removal.Lower reaction temperature had little effect on NO removal,but weakened H_(2)O_(2)ineffective decomposition.SO_(2)^(-)had little effect on NO removal and H_(2)O_(2)ineffective decomposition.Electron spin resonance technology and quenching addition experiments showed that the addition of DTPMPA increased the content of·OH radicals and·O_(2)^(-)-radicals in the Fenton system,·O_(2)^(-)radicals were the main active species for NO removal,and the main pathway of oxygen generation was·O_(2)^(-)+HO·→O_(2)^(-)+HO-.Ion chromatography of the reaction products showed that NO was oxidized to NO_(2)^(-)and NO-3 during the reaction.
作者
白志华
张军
BAI Zhihua;ZHANG Jun(College of Energy and Environment,Southeast University,Nanjing 210096,Jiangsu,China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2023年第9期4967-4973,共7页
Chemical Industry and Engineering Progress
关键词
芬顿法
二乙烯三胺五亚甲基膦酸
自由基
脱硝
无效分解
Fenton
diethylenetriamine pentamethylphosphonic acid
radical
denitration
ineffective decomposition
