A review on oxidation of elemental mercury from coal-fired flue gas with selective catalytic reduction catalysts

2015 ◽  
Vol 5 (7) ◽  
pp. 3459-3472 ◽  
Author(s):  
Lingkui Zhao ◽  
Caiting Li ◽  
Xunan Zhang ◽  
Guangming Zeng ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Flue Gas ◽  
Catalytic Reduction ◽  
Elemental Mercury ◽  
P Transformation ◽  
Scr Catalysts ◽  
Mechanism And Kinetics ◽  
Reduction Catalysts

Transformation and speciation of Hg in coal-fired flue gas, mechanism and kinetics for oxidizing Hg0 with SCR catalysts were discussed.

Deactivation Mechanism of Multipoisons in Cement Furnace Flue Gas on Selective Catalytic Reduction Catalysts

2019 ◽  
Vol 53 (12) ◽  
pp. 6937-6944 ◽  
Author(s):  
Dong Wang ◽  
Jinming Luo ◽  
Qilei Yang ◽  
Junchen Yan ◽  
Kaihang Zhang ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Flue Gas ◽  
Catalytic Reduction ◽  
Cement Furnace ◽  
Reduction Catalysts ◽  
Deactivation Mechanism

The DeNOx Characteristics of V/Ti Plate SCR Catalysts

2011 ◽  
Vol 356-360 ◽  
pp. 1712-1715
Author(s):  
Qiang Lu ◽  
Shu Hua Su ◽  
Shi Ye Fen ◽  
Wei Liang Cheng ◽  
Chang Qing Dong
Keyword(s):  
Nitric Oxide ◽  
Catalytic Activity ◽  
Selective Catalytic Reduction ◽  
Flue Gas ◽  
Catalytic Reduction ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Negative Effects ◽  
V2o5 Content ◽  
Scr Catalysts

A series of V2O5/WO3/TiO2plate catalysts were prepared via the incipient wetness impregnation method, with the V2O5content of 0.68 wt%, 1.01 wt%, 1.19 wt%, 1.5 wt% and the WO3loading of 4.8 wt%, 6.2 wt%, 7.9 wt%, 9.2 wt%, respectively. Selective catalytic reduction of nitric oxide by ammonia (NH3-SCR) experiments were performed to investigate the effects of the several factors on the performance of the catalysts, including the V2O5, WO3and MoO3content in the catalysts and the O2concentration in the flue gas. The results indicated that as the rising of the V2O5 content, the SCR activity of the V2O5/WO3/TiO2catalysts was firstly increased and then slightly decreased, with the best activity obtained at the V2O5content of 1.19 wt%. As the increasing of the WO3content, the activity was firstly increased slightly and then almost kept constant. Furthermore, the loading of the MoO3on the V2O5/WO3/TiO2plate catalysts would bring negative effects to the catalytic activity. In addition, the capability of the catalysts would slightly increase as the O2concentration rising up to 7%, and then became stable at higher O2concentrations.

scholarly journals Recovery of vanadium and tungsten from waste selective catalytic reduction catalysts by K2CO3 roasting and water leaching followed by CaCl2 precipitation

2020 ◽  
Author(s):  
Xianghui Liu ◽  
Qiaowen Yang
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Environmental Hazards ◽  
Leaching Rate ◽  
Water Leaching ◽  
Scr Catalysts ◽  
Amorphous Si ◽  
Reduction Catalysts ◽  
And Tungsten

Abstract Waste selective catalytic reduction (SCR) catalysts are potential environmental hazards. In this study, the recovery of vanadium and tungsten from waste SCR catalysts by K2CO3 roasting and water leaching was investigated. The roasting and leaching conditions were optimized: the leaching efficiencies of vanadium and tungsten were 91.19% and 85.36%, respectively, when 18 equivalents of K2CO3 were added to perform the roasting at 900 °C for 2 h, followed by leaching at 90 °C for 1 h. Notably, in the described conditions, the leaching rate of silicon was only 28.55%. Titanates, including K2Ti6O13 and KTi8O17, were also produced. Si removal was achieved in 85% efficiency adjusting the pH to 9.5, and the Si impurity thus isolated was composed of amorphous Si. Tungsten and vanadium were precipitated using CaCl2. At pH 10 and following the addition of 0.10 mol of H2O2 and 16 equivalents of CaCl2, the precipitating efficiencies of tungsten and vanadium were 96.89% and 99.65%, respectively. The overall yield of tungsten and vanadium was 82.71% and 90.87%, respectively. Graphic abstract

Experimental and kinetic analysis of hydrothermal aging effects on ammonia adsorption capacity over a commercial Cu-zeolite selective catalytic reduction catalyst

2018 ◽  
Vol 233 (12) ◽  
pp. 3030-3042
Author(s):  
Tae Joong Wang ◽  
In Hyuk Im
Keyword(s):  
Adsorption Capacity ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Adsorption Site ◽  
Selective Catalytic Reduction Catalyst ◽  
Aging Effects ◽  
Hydrothermal Aging ◽  
Ammonia Adsorption ◽  
Fresh Catalyst ◽  
Reduction Catalysts

Ammonia/urea selective catalytic reduction is an efficient technology to control NOx emission from diesel engines. One of its critical challenges is the performance degradation of selective catalytic reduction catalysts due to the hydrothermal aging experienced in real-world operations during the lifetime. In this study, hydrothermal aging effects on the reduction of ammonia adsorption capacity over a commercial Cu-zeolite selective catalytic reduction catalyst were investigated under actual engine exhaust conditions. Ammonia adsorption site densities of the selective catalytic reduction catalysts aged at two different temperatures of 750°C and 850°C for 25 h with 10% H2O were experimentally measured and compared to that of fresh catalyst on a dynamometer test bench with a heavy-duty diesel engine. The test results revealed that hydrothermal aging significantly decreased the ammonia adsorption capacity of the current commercial Cu-zeolite selective catalytic reduction catalyst. Hydrothermal treatment at 750°C reduced the ammonia adsorption site to 62.5% level of that of fresh catalyst, while hydrothermal treatment at 850°C lowered the adsorption site to 37.0% level of that of fresh catalyst. Also, in this study, numerical simulation and kinetic analysis were carried out to quantify the impact of hydrothermal aging on the reduction of ammonia adsorption capacity by introducing an aging coefficient. The kinetic parameter calibrations based on actual diesel engine tests with a commercial monolith Cu-zeolite selective catalytic reduction catalyst provided a highly realistic kinetic parameter set of ammonia adsorption/desorption and enabled a mathematical description of hydrothermal aging effect.

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