操作参数对生物质再燃脱硝特性的影响

Influence of Operation Parameters on NO Reduction Through Biomass Reburning

以稻壳（RH）、木屑（SD）和生物质炭（BC）3种生物质为对象,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）、停留时间（τ）、NO初始浓度（CNO,in）、水蒸气含量、生物质种类及添加剂等对生物质再燃脱硝效果的影响.结果表明：在T2=850℃-1150℃范围内,随着T2升高,再燃脱硝效率呈现逐渐上升的趋势.在SR2=0.5-1.0范围内,生物质再燃脱硝效率随着SR2降低而逐渐上升.在τ=0.5-1.3 s范围内,生物质再燃脱硝效率随着τ增加呈现先上升后趋于稳定的趋势.在CNO,in=300-600μL/L范围内,生物质再燃脱硝效率随着CNO,in增加逐渐增加,但当CNO,in〉400μL/L时,脱硝效率增加不明显.随着烟气中水蒸气含量增加,生物质再燃脱硝效率呈现先增加后降低并逐渐趋于平稳的趋势,模拟烟气中含有4%水蒸气时的脱硝效率最大.不同生物质的再燃脱硝效率显著不同,RH和SD的脱硝效率明显高于BC.添加剂对脱硝效果有一定的促进作用,其中, NaCl促进作用最为显著.添加剂（Fe2O3）浓度（50-150μmol/mol）对生物质再燃脱硝效率的影响不大.

NO reduction through reburning with biomass named rice husk（RH）,saw dust（SD）,biomass char（BC）are carried out in an entrained flow reactor （ EFR ） . The effects of reaction temperature in the reburning-zone （ T2 ） , stoichiometric ratio in the reburning-zone（SR2）,residence time（τ）,the initial NO concentration（CNO,in）,water vapor content,biomass species and additives, et al. are analyzed. The results indicate that：NO removal efficiency of biomass reburning increases with the increase of the reaction temperature in the reburning-zone at T2=850 ℃ -1 150 ℃. NO removal efficiency increases with the decrease of SR2 at SR2=0. 5 -1. 0. NO removal efficiency shows a tendency of increasing at first,and becoming stable gradually with increasing residence time whileτ=0. 5 ~1. 3 s. NO removal efficiency increases with the increase of the initial NO concentration in the range of 300 ~600 μL/L. NO removal efficiency shows a tendency of increasing at first, decreasing later and becoming stable with increasing water vapor content,and the best NO removal efficiency is obtained at 4% water vapor content in the simulated flue gas. Different bi-omasses have different performances on NO reduction. The NO removal efficiency of RH and SD is more than BC. Additives have certain promoting effects on NO reduction and the improvement of NaCl on NO reduction is more effective than other additives. The concentration of additives（ Fe2 O3 ） has no significant effect on NO reduction in the range of 50~150 μmol/mol.