1. Department of Thermal Engineering,Tsinghua University,Beijing　 100084,China;2. Key Laboratory for Thermal Science and Power Engineering of Minis-try of Education,Tsinghua University,Beijing　 100084,China

循环流化床锅炉内以CO为主的还原性气体,在大量灰的催化下对NO具有显著的还原作用。针对NO-CO反应动力学进行实验研究,重点考察了灰的存在及其成分对该反应速率的影响。实验中选取5个典型煤种制取灰样,通过X射线荧光光谱技术分析灰成分,并利用小型固定床实验测量不同温度、不同反应物浓度下的NO还原比例,进而拟合反应动力学参数。结果表明,灰中各主要成分对NO-CO反应的催化活性排序为Fe2O3>CaO/MgO>Al2O3>SiO2,且Fe2O3的作用显著偏高,而SiO2和Al2O3可以视作惰性成分。利用最小二乘法计算灰中各主要成分影响权重,引入基于灰成分质量份额加权和的指数γash,以修正Arrhenius形式的NO-CO反应动力学公式。该公式的计算结果较好地预测了人为配制灰催化条件下的NO-CO反应动力学参数。

The gas reduction in the circulating fluidized bed (CFB) boiler,mainly CO,plays an important role on the reduction of NO catalyzed by the massive ash in the furnace and cyclones. The kinetic study of NO-CO reaction was conducted experimentally and the influences of ash existence and composition on the reactions were highlighted. Five typical coals were selected and the corresponding ash was prepared on the specific conditions,and the compositions were measured by X-Ray Fluorescence (XRF) method. A small-scale fixed bed test rig was set up and the ratios of NO reduction through the bed were obtained in different temperatures and reactant concentrations. The kinetic parame- ters were fitted by the experimental results subsequently. Ordered by the catalytic activity on NO-CO reaction,the rank of main metallic components in the ash is Fe2 O3 >CaO / MgO>Al2 O3 >SiO2 . Among them,the effect of Fe2 O3 is signifi- cantly higher,and SiO2 / Al2 O3 can be treated as inert components. By using the least square method (LSM) in the da- ta processing,an index was introduced as γash based on the weighted sum of mass fractions of ash components,to make the correction of NO-CO kinetic formula in the Arrhenius form. The formula was validated by the experimental results of NO-CO reaction catalyzed by the ash prepared artificially.

国家重点基础研究发展计划(973)资助项目(2012CB214900)；

Li Jingji,Zhang Yi,Yang Hairui,et al. Study of the effect of ash composition in coal on the kinetic parameters of NO reduction reaction by CO[J]. Journal of China Coal Society,2016,41(10):2448-2453.