水蒸气与添加剂对生物质再燃/高级再燃脱硝特性的影响

Influences of Water Vapor and Additives on NO Reduction Through Biomass Reburning/Advanced Reburning

以稻壳和氨气还原剂为对象，利用携带流脱硝试验装置，研究了再燃区反应温度（T2）、再燃区化学计量比（SR2）、水蒸气含量、添加剂种类与浓度等对生物质再燃／高级再燃脱硝效果的影响。结果表明：随着疋升高，生物质再燃与高级再燃的脱硝效率呈现不同的趋势，高级再燃下脱硝效率呈现先上升后下降再趋于稳定的趋势，其相应的脱硝窗口温度为950～1100℃。随着舔2降低，稻壳再燃脱硝效率逐渐升高，而高级再燃脱硝效率先增加后降低，最佳舔：在0．7～0．9之间。随着水蒸气含量增加，生物质再燃／高级再燃脱硝效率均呈现先增加后降低的趋势，水蒸气量为4％左右时脱硝效率最佳。添加剂对生物质再燃／高级再燃脱硝均有一定的促进作用，其中Fe2O3促进作用最为显著，NaOH和Na2CO3次之，KCl和Ca（OH）2的促进作用较差。添加剂浓度（50～150μmol／mol）对脱硝效率的影响不显著，水蒸气与添加剂耦合可显著增加生物质再燃／高级再燃脱硝效率；与无水蒸气和无添加剂相比，4％水蒸气含量与100pmol／molNa2CO3耦合作用的再燃／高级再燃脱硝效率分别提高13．5％与11．4％。

NO reduction through reburning （BR）/advanced rebuming （AR） with biomass （rice husk, RH） and reducing agent （ammonia） were carried out in an entrained flow reactor （EFR）. The effects of reaction temperature in the reburningzone （T2）, stoichiometric ratio in the reburning-zone （SR2）, water vapor, and additives, et al. on NO reduction through BR and AR with biomass were analyzed. The results indicate that NO removal efficiencies ofbiomass BR and AR show different trends with the increase of T2. NO removal efficiency of biomass AR shows a tendency of increasing first, decreasing later and reaching a certain value with the increase of T2, and the temperature window of NO reduction is 950-1 100℃. With the increase of SR2, NO removal efficiency of biomass BR increases gradually, while that of biomass AR shows the pattern of increasing first and decreasing later and the optimal SR2 of AR is in the range of 0.7-0.9. NO removal efficiency of biomass BR and AR shows a tendency of increasing first and decreasing later with the increase of water vapor content, and the best NO removal efficiency is obtained while water vapor is about 4%. Additives have certain promoting effects on NO reduction, in which, the promoting effect of Fe2O3 on NO reduction is the most obvious, followed by NaOH and Na2CO3, and KCl and Ca（OH）2 are the worst. The additive concentration （50-150μmol/mol） has little significant effect on NO reduction NO reduction through biomass BR and AR can be promoted by the coupling effect of water vapor and additive. Compared with the condition without water vapor and additives, NO removal efficiencies through biomass BR and AR at 4% water vapor and 100 μmol/mol NazCO3 increase 13.5% and 11.4%, respectively.