The highly active absorbent with oxidization based on fly ash, lime and additive was prepared. Experiments of simultaneous desulfurization and denitrification were carried out using fixture bed and duct injection. The...The highly active absorbent with oxidization based on fly ash, lime and additive was prepared. Experiments of simultaneous desulfurization and denitrification were carried out using fixture bed and duct injection. The influencial factors for the absorptive capacity of the absorbent were studied. The absorptive capacities of 120.7 mg for SO 2 and 43.7 mg for NOx were achieved at a Ca/(S+N) molar ratio 1.2, respectively, corresponding removal efficiencies of 87% and 76%, while spent absorbent appeared in the form of dry powder. The optimal temperature and humidity of flue gas treated with this process were shown to be approximately 50℃, and 5% respectively. The mechanism of removal for SO 2 and NOx was investigated. In comparison with traditional dry FGD, this process appears to have lower cost, less complicated configuration and simpler disposal of used absorbent. The valuable references can be provided for industrial application by this process. The foreground of application will be vast in China and in the world.展开更多
Fly ash,industry-grade lime and a few oxidizing manganese compound additive were used to prepare the“Oxygen-riched”highly reactive absorbent for simultaneous desulfurization and denitrification.Experiments of simult...Fly ash,industry-grade lime and a few oxidizing manganese compound additive were used to prepare the“Oxygen-riched”highly reactive absorbent for simultaneous desulfurization and denitrification.Experiments of simultaneous desulfurization and denitrification were carried out using the highly reactive absorbent in the flue gas circulating fluidized bed(CFB)system.Removal efficiencies of 94.5%for SO_(2)and 64.2%for NO were obtained respectively.The scanning electron microscope(SEM)and accessory X-ray energy spectrometer were used to observe micro-properties of the samples,including fly ash,common highly reactive absorbent,“Oxygen-riched”highly reactive absorbent and spent absorbent.The white flake layers were observed in the SEM images about surfaces of the common highly reactive absorbent and“Oxygen-riched”one,and the particle surfaces of the spent absorbent were porous.The content of calcium on surface was higher than that of the average in the highly reactive absorbent.The manganese compound additive dispersed uniformly on the surfaces of the“Oxygen-riched”highly reactive absorbent.There was a sulfur peak in the energy spectra pictures of the spent absorbent.The component of the spent absorbent was analyzed with chemical analysis methods,and the results indicated that more nitrogen species appeared in the absorbent except sulfur species,and SO_(2)and NO were removed by chemical absorption according to the experimental results of X-ray energy spectrometer and the chemical analysis.Sulfate being the main desulfurization products,nitrite was the main denitrification ones during the process,in which NO was oxidized rapidly to NO_(2)and absorbed by the chemical reaction.展开更多
An ＂Oxygen-enriched＂ highly reactive absor- bent was prepared by mixing fly ash, lime and a small quantity of KMnO4 for simultaneous desulfiarization and denitrification. Removal of SO2 and NO simultaneously was car...An ＂Oxygen-enriched＂ highly reactive absor- bent was prepared by mixing fly ash, lime and a small quantity of KMnO4 for simultaneous desulfiarization and denitrification. Removal of SO2 and NO simultaneously was carried out using this absorbent in a flue gas circulating fluidized bed （CFB）. The highest simultaneous removal efficiency, 94.5% of SO2 and 64.2% of NO, was achieved under the optimal experiment conditions. Scanning Electron Microscope （SEM） and Accessory X-ray Energy Spectrometer （EDX） were used to observe the surface characteristics of fly ash, lime, ＂Oxygen-enriched＂ highly reactive absorbent and the spent absorbent. An ion chromatograph （IC） and chemical analysis methods were used to determine the contents of sulfate, sulfite, nitrate and nitrite in the spent absorbents, the results showed that sulfate and nitrite were the main products for desulfurization and denitrification respectively. The mechanism of removing SO2 and NO simultaneously was proposed based on the analysis results of SEM, EDX, IC and the chemical analysis methods.展开更多
文摘The highly active absorbent with oxidization based on fly ash, lime and additive was prepared. Experiments of simultaneous desulfurization and denitrification were carried out using fixture bed and duct injection. The influencial factors for the absorptive capacity of the absorbent were studied. The absorptive capacities of 120.7 mg for SO 2 and 43.7 mg for NOx were achieved at a Ca/(S+N) molar ratio 1.2, respectively, corresponding removal efficiencies of 87% and 76%, while spent absorbent appeared in the form of dry powder. The optimal temperature and humidity of flue gas treated with this process were shown to be approximately 50℃, and 5% respectively. The mechanism of removal for SO 2 and NOx was investigated. In comparison with traditional dry FGD, this process appears to have lower cost, less complicated configuration and simpler disposal of used absorbent. The valuable references can be provided for industrial application by this process. The foreground of application will be vast in China and in the world.
基金This work was supported by the Significant Pre-research Foundat ion of the North China Electric Power University.
文摘Fly ash,industry-grade lime and a few oxidizing manganese compound additive were used to prepare the“Oxygen-riched”highly reactive absorbent for simultaneous desulfurization and denitrification.Experiments of simultaneous desulfurization and denitrification were carried out using the highly reactive absorbent in the flue gas circulating fluidized bed(CFB)system.Removal efficiencies of 94.5%for SO_(2)and 64.2%for NO were obtained respectively.The scanning electron microscope(SEM)and accessory X-ray energy spectrometer were used to observe micro-properties of the samples,including fly ash,common highly reactive absorbent,“Oxygen-riched”highly reactive absorbent and spent absorbent.The white flake layers were observed in the SEM images about surfaces of the common highly reactive absorbent and“Oxygen-riched”one,and the particle surfaces of the spent absorbent were porous.The content of calcium on surface was higher than that of the average in the highly reactive absorbent.The manganese compound additive dispersed uniformly on the surfaces of the“Oxygen-riched”highly reactive absorbent.There was a sulfur peak in the energy spectra pictures of the spent absorbent.The component of the spent absorbent was analyzed with chemical analysis methods,and the results indicated that more nitrogen species appeared in the absorbent except sulfur species,and SO_(2)and NO were removed by chemical absorption according to the experimental results of X-ray energy spectrometer and the chemical analysis.Sulfate being the main desulfurization products,nitrite was the main denitrification ones during the process,in which NO was oxidized rapidly to NO_(2)and absorbed by the chemical reaction.
文摘An ＂Oxygen-enriched＂ highly reactive absor- bent was prepared by mixing fly ash, lime and a small quantity of KMnO4 for simultaneous desulfiarization and denitrification. Removal of SO2 and NO simultaneously was carried out using this absorbent in a flue gas circulating fluidized bed （CFB）. The highest simultaneous removal efficiency, 94.5% of SO2 and 64.2% of NO, was achieved under the optimal experiment conditions. Scanning Electron Microscope （SEM） and Accessory X-ray Energy Spectrometer （EDX） were used to observe the surface characteristics of fly ash, lime, ＂Oxygen-enriched＂ highly reactive absorbent and the spent absorbent. An ion chromatograph （IC） and chemical analysis methods were used to determine the contents of sulfate, sulfite, nitrate and nitrite in the spent absorbents, the results showed that sulfate and nitrite were the main products for desulfurization and denitrification respectively. The mechanism of removing SO2 and NO simultaneously was proposed based on the analysis results of SEM, EDX, IC and the chemical analysis methods.
