Heterogeneous agglomeration (HA) is a very potential technology for coal-fired flue gas treatment.In this paper,the distribution and migration mechanisms of trace elements (TEs such as Se,As and Pb in CFPPs were studi...Heterogeneous agglomeration (HA) is a very potential technology for coal-fired flue gas treatment.In this paper,the distribution and migration mechanisms of trace elements (TEs such as Se,As and Pb in CFPPs were studied on a 30,000 m^(3)/hr pilot-scale experimental plat form.The influences of HA on the removal efficiency of gaseous and particulate TEs were well analyzed.The results showed that Se,As and Pb were enriched in fly ash,and their sen sitivity to particle size is quite different.The content of Se was the highest in PM1,reaching193.04 mg/kg at the electrostatic precipitator (ESP) outlet.The average particle size of the total dust before ESP increased significantly from 21.686 to 62.612μm after injecting the heterogeneous agglomeration adsorbent,conducive to its further removal by ESP.In addi tion,the concentrations of gaseous Se,As and Pb in the flue gas decreased after adsorben spray,and accordingly,their contents in the hierarchical particles increased,indicating tha the adsorbent could effectively promote the adsorption of gaseous trace elements in fly ash and reduce the possibility of their escape to the atmosphere.Total concentrations of Se,As and Pb emitted by wet flue gas desulfurization (WFGD) are 0.223,0.668 and 0.076μg/m^(3)which decreased by 59.98%,47.69%and 90.71%,respectively.Finally,a possible HA mecha nism model was proposed,where chemical adsorption,physical condensation and collision agglomeration of gaseous TEs and fine particles with adsorbent droplets occurred to form larger agglomerates.展开更多
基金supported by the National Key Research and Development Program (No. 2018YFB0605104)the National Natural Science Foundation of China (No. 42030807)+1 种基金the Program for HUST Academic Frontier Youth Team (No. 2018QYTD05)the Hubei Provincial Key Research and Development Program (No. 2020BCA076)。
文摘Heterogeneous agglomeration (HA) is a very potential technology for coal-fired flue gas treatment.In this paper,the distribution and migration mechanisms of trace elements (TEs such as Se,As and Pb in CFPPs were studied on a 30,000 m^(3)/hr pilot-scale experimental plat form.The influences of HA on the removal efficiency of gaseous and particulate TEs were well analyzed.The results showed that Se,As and Pb were enriched in fly ash,and their sen sitivity to particle size is quite different.The content of Se was the highest in PM1,reaching193.04 mg/kg at the electrostatic precipitator (ESP) outlet.The average particle size of the total dust before ESP increased significantly from 21.686 to 62.612μm after injecting the heterogeneous agglomeration adsorbent,conducive to its further removal by ESP.In addi tion,the concentrations of gaseous Se,As and Pb in the flue gas decreased after adsorben spray,and accordingly,their contents in the hierarchical particles increased,indicating tha the adsorbent could effectively promote the adsorption of gaseous trace elements in fly ash and reduce the possibility of their escape to the atmosphere.Total concentrations of Se,As and Pb emitted by wet flue gas desulfurization (WFGD) are 0.223,0.668 and 0.076μg/m^(3)which decreased by 59.98%,47.69%and 90.71%,respectively.Finally,a possible HA mecha nism model was proposed,where chemical adsorption,physical condensation and collision agglomeration of gaseous TEs and fine particles with adsorbent droplets occurred to form larger agglomerates.
