富氧燃烧烟气低温锰氧化物SCR脱硝实验研究

Abstract

氮氧化物是燃煤电厂的主要污染排放源之一，而且烟气中的氮氧化物还会产生硝酸盐等颗粒物，从而进一步形成PM2.5，严重危害人类的身体健康。本论文通过实验研究锰氧化物对低温富氧燃烧烟气的脱硝作用，并且使用溶液燃烧合成以及共沉淀这两种不同的制备方法，得到了不同的结构形态和比表面积的SCR催化剂。在实验范围内，研究发现，在CO2气氛下，Mn3O4脱硝率随温度的上升先增大后减小，当温度为200℃时，Mn3O4脱硝率可达峰值90.2%；在N2气氛下，Mn3O4脱硝率随温度的上升先增大后减小，当温度为200℃时，Mn3O4脱硝率可达峰值93.6%。在CO2气氛下，Mn3O4/AC脱硝率随温度的上升而增大，当温度为300℃时，Mn3O4/AC脱硝率可达峰值75%；在N2气氛下，Mn3O4/AC脱硝率随温度的上升而增大，当温度为300℃时，Mn3O4/AC脱硝率可达峰值78%。在CO2或N2气氛下，Mn3O4/AC脱硝率随氧浓度的上升而增大，随二氧化硫浓度的上升而减小。 Nitrogen oxides are one of the major sources of pollution in coal-fired power plants, and they may produce nitrate particles further forming PM2.5, which causes serious damage to human health. In this paper, the denitrification effects of manganese oxides on low-temperature oxy-fuel combustion flue gas were studied based on the different SCR catalysts with different morphology and specific surface area obtained by two different preparation methods of solution combustion synthesis and coprecipitation. The results from experiments show that the denitrification rate of Mn3O4 increases first and then decreases with the increase of temperature under CO2 atmosphere, and it reaches the peak value of 90.2% at 200˚C; the denitrification rate of Mn3O4 increases first and then decreases with the increase of temperature under N2 atmosphere, and it reaches the peak value of 93.6% at 200˚C. As for Mn3O4/AC catalyst, under CO2 atmosphere, the denitrification rate increases with the increase of temperature and reaches 75% at 300˚C; under N2 atmosphere, it increases with the temperature increasing and reaches 78% at 300˚C. In CO2 or N2 atmosphere, Mn3O4/AC denitrification rate increases as the oxygen concentration increases and the rate decreases as the SO2 concentration increases.