CAJ | 학술논문

温度300~1100℃时,由程序控温电加热水平陶瓷管反应器在N2气氛和模拟气氛下,对乙烷在金属铁表面还原NO的特性进行了实验研究。结果表明,乙烷在金属铁表面能够高效地还原NO。在N2气氛中,温度高于900℃时,乙烷在金属铁表面的脱硝效率超过95%。在模拟烟气条件下,当温度超过900℃,且过量空气系数小于1.0时,乙烷在金属铁表面还原NO的效率能够达到90%以上。相同条件下,乙烷在金属铁表面脱硝效率高于甲烷的脱硝效率。 SO2对乙烷在金属铁表面还原NO的效率影响可以忽略。对反应后的铁样品的组分进行了XRD表征,在此基础上对反应机理进行了分析。结果表明,在模拟烟气条件下NO的还原通过乙烷的再燃脱硝和金属铁直接还原两个机理完成。金属铁直接还原NO时生成的氧化铁则被乙烷还原为金属铁,从而使得金属铁能够持续对NO进行直接还原。乙烷再燃还原NO的中间产物HCN被氧化铁氧化为N2,同时氧化铁也被HCN还原为金属铁。这一过程增强了NO的持续还原反应,同时避免了在燃尽时HCN二次氧化重新生成NO,从而保证了较高的NO还原效率。
온도300~1100℃시,유정서공온전가열수평도자관반응기재N2기분화모의기분하,대을완재금속철표면환원NO적특성진행료실험연구。결과표명,을완재금속철표면능구고효지환원NO。재N2기분중,온도고우900℃시,을완재금속철표면적탈초효솔초과95%。재모의연기조건하,당온도초과900℃,차과량공기계수소우1.0시,을완재금속철표면환원NO적효솔능구체도90%이상。상동조건하,을완재금속철표면탈초효솔고우갑완적탈초효솔。 SO2대을완재금속철표면환원NO적효솔영향가이홀략。대반응후적철양품적조분진행료XRD표정,재차기출상대반응궤리진행료분석。결과표명,재모의연기조건하NO적환원통과을완적재연탈초화금속철직접환원량개궤리완성。금속철직접환원NO시생성적양화철칙피을완환원위금속철,종이사득금속철능구지속대NO진행직접환원。을완재연환원NO적중간산물HCN피양화철양화위N2,동시양화철야피HCN환원위금속철。저일과정증강료NO적지속환원반응,동시피면료재연진시HCN이차양화중신생성NO,종이보증료교고적NO환원효솔。
NO reduction by ethane over iron was experimentally investigated in a one-dimensional temperature-programmed ceramic tubular reactor at 300~1 100℃ in nitrogen and simulated flue gas atmospheres. The results show that ethane can effectively reduce NO to N2 over the surface of metallic iron. In N2 atmosphere, more than 95% of NO is reduced by ethane over metallic iron when the temperature is higher than 900℃. In simulated flue gas atmosphere, more than 90% of NO is reduced by ethane over metallic iron above 900℃ when the excess air ratio is lower than 1. 0. Under the same conditions, NO reduction by ethane over iron is higher than that by methane. The effect of SO2 in simulated flue gas on NO reduction can be ignored. The iron samples were characterized with respect to their composition by XRD after reaction, and on this basis the reaction mechanism was further analyzed. There are two mechanisms for NO reduction, i. e. , the reburning of ethane and direct reduction by iron. The iron is oxidized to iron oxides after reducing NO and then ethane reduces the iron oxides to metallic iron, leading to the sustainable and durable reduction of NO by iron. Meanwhile, NO is reduced by ethane through reburning to from the intermediate HCN that could be oxidized to N2 by iron oxide, furthermore the iron oxides are reduced to iron simultaneously. This process enhances the NO reduction and prevents the additional NO formation due to the oxidization of HCN during burnout, leading to a high NO reduction efficiency.