中国电机工程学报
中國電機工程學報
중국전궤공정학보
ZHONGGUO DIANJI GONGCHENG XUEBAO
2013年
20期
34-39
,共6页
唐志雄%曾环木%岑超平%陈志航%陈定盛%方平%陈雄波
唐誌雄%曾環木%岑超平%陳誌航%陳定盛%方平%陳雄波
당지웅%증배목%잠초평%진지항%진정성%방평%진웅파
选择性非催化还原%氮氧化物%氨%二氧化硫
選擇性非催化還原%氮氧化物%氨%二氧化硫
선택성비최화환원%담양화물%안%이양화류
selective non-catalytic reduction%nitrogen oxides%ammonia%sulfur dioxide
为考察部分烟气中高浓度SO2对选择性非催化还原法(electivity non-catalytic reduction，SNCR)脱硝的影响，采用固定床反应器开展了含硫条件下，温度775~975℃、氨氮摩尔比([NH3]/[NO])0.9~3.0、O2浓度5%~21%、SO2浓度0~0.022%和停留时间7.9~23.6 s对NH3选择性非催化还原NOx影响的实验研究。实验结果表明：对比无硫及含硫烟气，随着温度的上升，NOx转化率均逐步提高，特别是向烟气中添加 SO2后脱硝效率明显提升，且剩余的氨与 SO2发生反应形成硫酸铵盐，因此氨逃逸量极少；氨氮比小于1.6时，脱硝效率随氨氮比的增加而迅速上升，当氨氮比大于2.4时，氨逃逸浓度随着氨氮比的增长而迅速增加；随着O2浓度的增加，NOx的转化率逐渐降低，O2浓度超过10%后脱硝效率趋于平稳；900℃条件下 SO2的存在对 NH3选择性还原NOx有一定的促进作用；随着停留时间超过9.4 s，在富氧、高温环境下，SNCR 反应速率快且 NH3氧化反应更易发生使得脱硝效率有所降低。
為攷察部分煙氣中高濃度SO2對選擇性非催化還原法(electivity non-catalytic reduction，SNCR)脫硝的影響，採用固定床反應器開展瞭含硫條件下，溫度775~975℃、氨氮摩爾比([NH3]/[NO])0.9~3.0、O2濃度5%~21%、SO2濃度0~0.022%和停留時間7.9~23.6 s對NH3選擇性非催化還原NOx影響的實驗研究。實驗結果錶明：對比無硫及含硫煙氣，隨著溫度的上升，NOx轉化率均逐步提高，特彆是嚮煙氣中添加 SO2後脫硝效率明顯提升，且剩餘的氨與 SO2髮生反應形成硫痠銨鹽，因此氨逃逸量極少；氨氮比小于1.6時，脫硝效率隨氨氮比的增加而迅速上升，噹氨氮比大于2.4時，氨逃逸濃度隨著氨氮比的增長而迅速增加；隨著O2濃度的增加，NOx的轉化率逐漸降低，O2濃度超過10%後脫硝效率趨于平穩；900℃條件下 SO2的存在對 NH3選擇性還原NOx有一定的促進作用；隨著停留時間超過9.4 s，在富氧、高溫環境下，SNCR 反應速率快且 NH3氧化反應更易髮生使得脫硝效率有所降低。
위고찰부분연기중고농도SO2대선택성비최화환원법(electivity non-catalytic reduction，SNCR)탈초적영향，채용고정상반응기개전료함류조건하，온도775~975℃、안담마이비([NH3]/[NO])0.9~3.0、O2농도5%~21%、SO2농도0~0.022%화정류시간7.9~23.6 s대NH3선택성비최화환원NOx영향적실험연구。실험결과표명：대비무류급함류연기，수착온도적상승，NOx전화솔균축보제고，특별시향연기중첨가 SO2후탈초효솔명현제승，차잉여적안여 SO2발생반응형성류산안염，인차안도일량겁소；안담비소우1.6시，탈초효솔수안담비적증가이신속상승，당안담비대우2.4시，안도일농도수착안담비적증장이신속증가；수착O2농도적증가，NOx적전화솔축점강저，O2농도초과10%후탈초효솔추우평은；900℃조건하 SO2적존재대 NH3선택성환원NOx유일정적촉진작용；수착정류시간초과9.4 s，재부양、고온배경하，SNCR 반응속솔쾌차 NH3양화반응경역발생사득탈초효솔유소강저。
Selective non-catalytic reduction of NOx by NH3 in flue gas containing high concentration of SO2 was studied. Experiments in a fixed bed reactor showed the effects of temperature (775-975 ), molar ratio of NH℃ 3 to NOx (0.9-3.0), O2 concentration (5%-21%), SO2 concentration (0-0.022%), and residence time (7.9-23.6 s) on denitrification efficiency. The results show that the NOx conversion in flue gas with and without SO2 increases gradually with the rise of temperature. The denitrification efficiency improves significantly when SO2 is added to the flue gas, and the emission of NH3 is low because of the formation of ammonium sulfate by reaction between the remaining NH3 and SO2. The denitrification efficiency improves rapidly with the increase of the molar ratio of ammonia to nitrogen oxide ([NH3]/[NOx]) when [NH3]/[NOx] is below 1.6. The emission of NH3 increases rapidly with the increase of NH3/NOx when NH3/NOx exceeds 2.4. With the increase of the O2 concentration, the conversion of NOx is gradually reduced, and the efficiency of denitrification is stabilized when the O2 concentration exceeds 10%. The presence of SO2 promotes the reaction of NH3 selective reduction of NOx at 900℃. The denitrification efficiency decreases when the residence time of SO2 exceeds 9.4 s, this may be due to the faster SNCR reaction rate and the easier NH3 oxidation reaction under the conditions of high temperature and enriched oxygen.
