O_2/CO_2气氛下煤燃烧SO_2/NO析出特性

SO_2/NO emission characteristics during O_2/CO_2 coal combustion process

在水平管式炉上研究了O2浓度、CO2浓度、温度及石灰石添加等各参数对O2/CO2气氛下徐州烟煤和龙岩无烟煤燃烧过程中SO2/NO排放特性的影响。结果发现,O2/CO2气氛下,烟煤和无烟煤燃烧SO2/NO的析出规律与空气气氛下不同,同等O2浓度下析出量比空气气氛下小。O2/CO2气氛下,随着O2浓度的提高,烟煤和无烟煤SO2/NO排放量均增大;随着CO2浓度的升高,SO2/NO排放量均减小。O2/CO2气氛下,石灰石添加对SO2排放的抑制作用低于空气气氛下;石灰石添加对NO的排放有一定减排作用。对煤灰的元素分析显示O2/CO2燃烧对SO2的抑制主要是由于煤灰的自固硫能力增强,而对NO的减排作用则是促进燃料N向其他含N气体的转换。

The effects of O2 concentration, CO2 concentration, temperature and limestone addition on SO2/ NO emission characteristics from Xuzhou bituminous coal and Longyan anthracite coal combustion in O2/ CO2 atmosphere were studied in a horizontal tube furnace. The results showed that the release characteristics of SO2/NO were different between O2/CO2 combustion and air combustion, and with the same O2 concentration, SO2 and NO emissions were lower in O2/CO2 combustion than those in air combustion. As O2 concentration increased, SO2/NO emission during O2/CO2 combustion increased and with increasing CO2 concentration, SO2/NO emission decreased. In O2/CO2 atmosphere, the sulfur retention ability of limestone addition was lower than that in air atmosphere, while limestone addition could reduce the NO emission. The element composition of coal ash indicated that the reduction of SO2 during O2/CO2 coal combustion was due to improved sulfur retention ability of coal ash, and the reduction of NO was due to intensified transformation of fuel-N to other N-containing gaseous species.