伊敏煤焦恒温燃烧氮转化特性

The Characteristic of Nitrogen Conversion during Yimin Coal Char Combustion at Constant Temperature

选用伊敏褐煤焦作为试验焦样,在水平管式炉中进行燃烧试验,研究了温度、氧浓度、粒径、水等因素对煤焦燃烧过程中焦炭氮向NO转化的影响规律。结果表明,焦炭氮向NO的转化率随温度的升高而降低,这是因为随着温度的升高,NO异相还原反应速率的增速高于NO异相生成反应速率的增速,燃烧过程中生成的NO在焦炭表面被大量还原。当氧含量为3%时,焦炭氮向NO的转化率最低。受限于固定床条件,试验未发现粒径对焦炭氮向NO转化率有明显的影响。水的添加使得NO生成总量及焦炭氮向NO的转化率略有上升,水的添加还会加快焦炭的燃尽。

The burning behaviors of Yimin lignite coal char were investigated in a horizontal tube furnace. The effects of temperature, oxygen concentration, particle size and water on the conversion of char nitrogen to NO during char combustion were mainly studied. The results show that the conversion rate of char nitrogen to NO decreases with temperature increasing. As the temperature increases, the growth rate of reaction rate of NO heterogeneous reduction is higher than that of NO heterogeneous formation. NO generated during combustion is significantly reduced on the surface of char. The conversion of char nitrogen to NO is the lowest at 3% oxygen concentration. Limited by the fixed bed conditions, it has not found that the particle size of char has a significant effect on the on the conversion rate of char nitrogen to NO. The addition of water will increase the total amount of NO emission and the conversion rate of char nitrogen to NO;and it will also accelerate the burnout of coal char. Experimental methods and results have guiding significance for related teaching experiments and industrial production.