碳氧官能团对煤焦低温还原NO的影响

Role of carbon-oxygen complexes on low temperature reduction of NO by coal char

在450℃对神木煤制半焦还原NO进行研究,采用Raman、FT-IR、XPS等分析方法探究了半焦脱硝影响因素与其表面碳氧官能团的关系。结果表明:热解制焦温度、烟气中氧气浓度以及负载金属对脱硝效果的影响都与半焦表面碳氧官能团有关,降低热解温度、增大氧气浓度、负载金属均有利于增加C—O官能团。采用XPS表征对金属负载半焦表面的碳氧官能团进行分析,发现热力学相对稳定的C—O官能团含量与脱硝指标之间存在明显的线性关系(R^(2)>0.96)。研究进一步揭示了热力学稳定的C—O官能团在半焦脱硝过程的重要地位。

The reduction of NO by Shenmu coal char was studied at 450℃,and the relationship between the influencing factors of coal char denitrification and its surface carbon-oxygen functional groups was explored by Raman,FT-IR,XPS and other analytical methods.Combining the results of isothermal experiments and characterizations,close connection between influencing factors and carbon-oxygen complexes was revealed.The effect of coal char preparation temperature,oxygen concentration in flue gas as well as influence of metallic elements could be in connection with carbon-oxygen complexes on coal char surface.More specifically,lowering pyrolysis temperature,increasing oxygen concentration,and loading metals were all conducive to the retention and formation of thermally stable C—O species on coal char surface.Strong linear relationship was discovered via XPS method between thermally stable C—O species and experimental evaluation indexes(R^(2)>0.96).Carbon-oxygen complexes,especially thermally stable C—O compounds,played a key character in NO reduction by coal char.