Ammonia Storage and Slip in a Urea Selective Catalytic Reduction Catalyst under Steady and Transient Conditions

2011 ◽  
Vol 50 (21) ◽  
pp. 11863-11871 ◽  
Author(s):  
Yanguang Zhao ◽  
Jing Hu ◽  
Lun Hua ◽  
Shijin Shuai ◽  
Jianxin Wang
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Selective Catalytic Reduction Catalyst ◽  
Transient Conditions ◽  
Ammonia Storage

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.

Effect of manganese and/or ceria loading on V2O5–MoO3/TiO2 NH3 selective catalytic reduction catalyst

2020 ◽  
Vol 38 (7) ◽  
pp. 725-734 ◽  
Author(s):  
Daojun Zhang ◽  
Ziran Ma ◽  
Baodong Wang ◽  
Tao Zhu ◽  
Duan Weng ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Selective Catalytic Reduction Catalyst

scholarly journals Simultaneous soot combustion and NO x reduction over a vanadia-based selective catalytic reduction catalyst

2018 ◽  
Vol 21 (3-4) ◽  
pp. 221-231 ◽  
Author(s):  
Julie Schobing ◽  
Valérie Tschamber ◽  
Jean-François Brilhac ◽  
Aglaé Auclaire ◽  
Yves Hohl
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Selective Catalytic Reduction Catalyst ◽  
Soot Combustion
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