Mercury emission and adsorption characteristics of fly ash in PC and CFB boilers

作     者：Li JIA Baoguo FAN Xianrong ZHENG Xiaolei QIAO Yuxing YAO Rui ZHAO Jinrong GUO Yan JIN Li JIA;Baoguo FAN;Xianrong ZHENG;Xiaolei QIAO;Yuxing YAO;Rui ZHAO;Jinrong GUO;Yan JIN

作者机构：College of Electrical and Power EngineeringTaiyuan University of TechnologyTaiyuan 030024China 

出 版 物：《Frontiers in Energy》 (能源前沿（英文版）)

年 卷 期：2021年第15卷第1期

页      面：112-123页

核心收录：

学科分类：080703[工学-动力机械及工程] 08[工学] 0807[工学-动力工程及工程热物理] 

基　　金：This work was financially supported by the National Natural Science Foundation of China(Grant Nos.U1510135 U1810126 and U1910214) 

主　　题：mercury combustion modes coal property fly ash particle size 

摘      要：The mercury emission was obtained by measuring the mercury contents in flue gas and solid samples in pulverized coal (PC) and circulating fluidized bed (CFB) utility boilers. The relationship was obtained between the mercury emission and adsorption characteristics of fly ash. The parameters included unburned carbon content, particle size, and pore structure of fly ash. The results showed that the majority of mercury released to the atmosphere with the flue gas in PC boiler, while the mercury was enriched in fly ash and captured by the precipitator in CFB boiler. The coal factor was proposed to characterize the impact of coal property on mercury emissions in this paper. As the coal factor increased, the mercury emission to the atmosphere decreased. It was also found that the mercury content of fly ash in the CFB boiler was ten times higher than that in the PC boiler. As the unburned carbon content increased, the mercury adsorbed increased. The capacity of adsorbing mercury by fly ash was directly related to the particle size. The particle size corresponding to the highest content of mercury, which was about 560 ng/g, appeared in the range from 77.5 to 106 µm. The content of mesoporous (4–6 nm) of the fly ash in the particle size of 77.5–106 µm was the highest, which was beneficial to adsorbing the mercury. The specific surface area played a more significant role than specific pore volume in the mercury adsorption process.