Perspective on SCR NOx control for diesel vehicles

2019 ◽  
Vol 4 (6) ◽  
pp. 969-974 ◽  
Author(s):  
Christine K. Lambert
Keyword(s):  
Steady State ◽  
Selective Catalytic Reduction ◽  
Research Design ◽  
Catalytic Reduction ◽  
System Research ◽  
Reduction Of No ◽  
Diesel Vehicles ◽  
Aqueous Urea ◽  
Nox Control ◽  
Scr System

The selective catalytic reduction of NOx with aqueous urea (“urea SCR”) is originally a steady-state technology that has been successfully applied to diesel vehicles worldwide. This Perspective summarizes 20+ years of SCR system research, design, and future improvements.

A Computational Investigation of Industrial Selective Catalytic Reduction Systems for NOx Control

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Oghare Victor Ogidiama ◽  
Tariq Shamim
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Inlet Temperature ◽  
Complex Processes ◽  
Fast Scr ◽  
Conversion Performance ◽  
Nox Control ◽  
No2 Reduction ◽  
Scr System ◽  
Reaction Processes

The selective catalytic reduction (SCR) is a promising NOx (a mixture of NO and NO2) reduction technology for various applications. The SCR process entails the conversion of NOx by the use of a reducing agent such as ammonia and a suitable catalyst. Due to increasingly stricter NOx emission regulations, the SCR technology for NOx control needs continuous improvement. The improvement requires better understanding of complex processes occurring in the SCR system. The current study employs a mathematical model to elucidate the effect of key operating and geometric parameters on the performance of SCR systems. The model considers both standard and fast SCR reaction processes. The model was used to investigate the effects of NH3/NOx and NO2/NOx ratios in the exhaust on the SCR performance and the effect of using a dual layer SCR system. Furthermore, the effect of different operating parameters and the interdependence of parameters is analyzed by using a factorial approach. The results show that the SCR performance is very sensitive to NH3/NOx ratio. The SCR performance is also affected by the NO2/NOx ratio particularly at low temperatures. The optimal NOx conversion performance requires a combination of NH3/NOx ratio of 1.0, NO2/NOx ratio of 0.5, low space velocities, and high inlet temperature. The results depict that adding a second catalyzed layer results in increased reaction activity especially when the concentration is still high after the first layer.

Selective catalytic reduction of NO with NH3 on iron zeolite monolithic catalysts: Steady-state and transient kinetics

2011 ◽  
Vol 104 (1-2) ◽  
pp. 110-126 ◽  
Author(s):  
Pranit S. Metkar ◽  
Nelson Salazar ◽  
Rachel Muncrief ◽  
Vemuri Balakotaiah ◽  
Michael P. Harold
Keyword(s):  
Steady State ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Transient Kinetics ◽  
Reduction Of No ◽  
Monolithic Catalysts

Effect of Fe on the Selective Catalytic Reduction of NO by NH3 at Low Temperature over Mn/CeO2-TiO2 Catalyst

2012 ◽  
Vol 27 (5) ◽  
pp. 495-500 ◽  
Author(s):  
Da-Wang WU ◽  
Qiu-Lin ZHANG ◽  
Tao LIN ◽  
Mao-Chu GONG ◽  
Yao-Qiang CHEN
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Reduction Of No

The synergistic effects between Ce and Cu in CuyCe1−yW5Ox catalysts for enhanced NH3-SCR of NOx and SO2 tolerance

2019 ◽  
Vol 9 (3) ◽  
pp. 718-730 ◽  
Author(s):  
Jian-Wen Shi ◽  
Yao Wang ◽  
Ruibin Duan ◽  
Chen Gao ◽  
Baorui Wang ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Selective Catalytic Reduction ◽  
Low Temperatures ◽  
Catalytic Reduction ◽  
Synergistic Effects ◽  
Reduction Of No ◽  
Nh3 Scr ◽  
So2 Tolerance ◽  
Scr Of Nox

Non-manganese-based metal oxides are promising catalysts for the NH3-SCR (selective catalytic reduction) of NOx at low temperatures.

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