Desulfurization and denitrification by using ozone has been widely used in recent years,but the technology for generating ozone at this stage has some shortcomings,which needs to be improved urgently.This paper advoca...Desulfurization and denitrification by using ozone has been widely used in recent years,but the technology for generating ozone at this stage has some shortcomings,which needs to be improved urgently.This paper advocates using mud-phosphorous slurry to produce ozone,which is environmentally friendly and economical.At the same time,SO_(2) and NO_(x) can be removed from mud-phosphorous slurry simultaneously.The amount of ozone generated during desulfurization and denitrification is particularly important,thus,this paper studies the effects of the temperature of reaction,oxygen content and solid-liquid ratio of mud-phosphorus slurry on the amount of ozone generated.The results showed that under the optimum conditions(the reaction temperature was 60℃,the solid-liquid ratio of mud-phosphorus slurry was 5.0 g/40 mL,the oxygen content was 30%),the amount of ozone was the largest,and the maximum generation amount was 573.8 mg/m^(3).Under these conditions,the removal rates of SO_(2) and NO_(x) can reach 99.5%and 99%respectively.This paper also analyzes the products of desulfurization and denitrification,and proposes the corresponding reaction mechanism.展开更多
Sm-doped Fe_(2)O_(3)catalysts,with a homogeneous distribution of Sm in Fe_(2)O_(3)nanoparticles,were synthesized using a citric acid-assisted sol-gel method.Kinetic studies show that the reaction rate for NO_(x)reduct...Sm-doped Fe_(2)O_(3)catalysts,with a homogeneous distribution of Sm in Fe_(2)O_(3)nanoparticles,were synthesized using a citric acid-assisted sol-gel method.Kinetic studies show that the reaction rate for NO_(x)reduction using the optimal catalyst(0.06 mol%doping of Sm in Fe_(2)O_(3))was nearly 11 times higher than that for pure Fe_(2)O_(3),when calculated based on specific surface area.Furthermore,the Fe_(0.94)Sm_(0.06)O_(x)catalyst maintains>83%NO_(x)conversion for 168 h at a high space velocity in the presence of SO_(2)and H_(2)O at 250℃.A substantial amount of surface-adsorbed oxygen was generated on the surface of Fe_(0.94)Sm_(0.06)O_(x),which promoted NO oxidation and the subsequent fast reaction between NO_(x)and NH_(3).The adsorption and activation of NH_(3)was also enhanced by Sm doping.In addition,Sm doping facilitated the decomposition of NH_(4)HSO_(4)on the surface of Fe_(0.94)Sm_(0.06)O_(x),resulting in its high activity and stability in the presence of SO_(2)+H_(2)O.展开更多
基金Projects(51968075,51568067)supported by the National Natural Science Foundation of ChinaProject(2018FD054)supported by the Applied Basic Research Surface Project of Yunnan Province,ChinaProject(2020Y0259)supported by the Scientific Research Fund Project of Yunnan Provincial Department of Education,China。
文摘Desulfurization and denitrification by using ozone has been widely used in recent years,but the technology for generating ozone at this stage has some shortcomings,which needs to be improved urgently.This paper advocates using mud-phosphorous slurry to produce ozone,which is environmentally friendly and economical.At the same time,SO_(2) and NO_(x) can be removed from mud-phosphorous slurry simultaneously.The amount of ozone generated during desulfurization and denitrification is particularly important,thus,this paper studies the effects of the temperature of reaction,oxygen content and solid-liquid ratio of mud-phosphorus slurry on the amount of ozone generated.The results showed that under the optimum conditions(the reaction temperature was 60℃,the solid-liquid ratio of mud-phosphorus slurry was 5.0 g/40 mL,the oxygen content was 30%),the amount of ozone was the largest,and the maximum generation amount was 573.8 mg/m^(3).Under these conditions,the removal rates of SO_(2) and NO_(x) can reach 99.5%and 99%respectively.This paper also analyzes the products of desulfurization and denitrification,and proposes the corresponding reaction mechanism.
文摘Sm-doped Fe_(2)O_(3)catalysts,with a homogeneous distribution of Sm in Fe_(2)O_(3)nanoparticles,were synthesized using a citric acid-assisted sol-gel method.Kinetic studies show that the reaction rate for NO_(x)reduction using the optimal catalyst(0.06 mol%doping of Sm in Fe_(2)O_(3))was nearly 11 times higher than that for pure Fe_(2)O_(3),when calculated based on specific surface area.Furthermore,the Fe_(0.94)Sm_(0.06)O_(x)catalyst maintains>83%NO_(x)conversion for 168 h at a high space velocity in the presence of SO_(2)and H_(2)O at 250℃.A substantial amount of surface-adsorbed oxygen was generated on the surface of Fe_(0.94)Sm_(0.06)O_(x),which promoted NO oxidation and the subsequent fast reaction between NO_(x)and NH_(3).The adsorption and activation of NH_(3)was also enhanced by Sm doping.In addition,Sm doping facilitated the decomposition of NH_(4)HSO_(4)on the surface of Fe_(0.94)Sm_(0.06)O_(x),resulting in its high activity and stability in the presence of SO_(2)+H_(2)O.
