Experimental demonstration of NO reduction and ammonia slip  for diesel engine SCR system

2021 ◽  
Author(s):  
Guangzhao Yue ◽  
Tao Qiu ◽  
Yan Lei
Keyword(s):  
Conversion Efficiency ◽  
No Reduction ◽  
Control Method ◽  
Catalytic Reduction ◽  
Mean Value ◽  
No Conversion ◽  
Pulse Injection ◽  
Slip Pulse ◽  
Sample Test ◽  
Catalyst Temperature

Abstract This paper aims to investigate the characteristics of selective catalytic reduction(SCR) in a V2O5-WO3/TiO2 catalyst by studying the key parameter, and obtain the control method of NH3 injection under sample test bench. Four parameters are defined and adopted to represent the NO-NH3 reaction characteristics. The effect of NH3/NO ratio(NSR), catalyst temperature and NH3 injection period on NO conversion efficiency and NH3 slip was investigated. The correlation between NH3 slip and ammonia saturation storage level was studied. The experimental results show that the ammonia saturation storage level has great effects on NO reduction and NH3 slip. The NO conversion efficiency and NH3 slip strongly depends on the ammonia saturation storage level. Under such condition, the NO conversion efficiency is best when the ammonia saturation storage level is 68.2%~73%, until the value reach to 75% before the NH3 slip. Pulse injection can improve the NO conversion efficiency and NH3 slip. The period of pulse injection has few influence on the mean value of NO at the outlet, however, it affects the peak value of NO and NH3 slip. Using varied period pulse injection can further improve NO conversion efficiency and restrain NH3 slip. The outlet NO is able to be reduced by adopting suitable NH3 pulse injection interval.

Effect on Addictives Adding of Mn-Ce/TiO2 Selective Catalytic Reduction NO by NH3 at Low-Temperature

2014 ◽  
Vol 955-959 ◽  
pp. 25-29 ◽  
Author(s):  
Bin Wu
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Conversion Efficiency ◽  
Catalytic Properties ◽  
Catalytic Reduction ◽  
Catalytic Conversion ◽  
No Conversion ◽  
Performance Results

Additives addition into Mn-Ce/TiO2 which had good low-temperature catalytic properties was studied, so as to improve its low-temperature anti-poisoning performance. Results showed that catalytic activity of Mn-Ce/TiO2 added additives V, Fe and Cu (short for Mn-M-Ce/TiO2 ) was improved all, compared with 95% NO conversion efficiency of Mn-Ce/TiO2 at temperature of 120°C, the ratio of Mn-M-Ce/TiO2 reached nearly 100%. Mn-Fe-Ce/TiO2 had the best single anti-poisoning ability, under the existence of 7% vapor, its catalytic conversion efficiency could be always kept over 90% at 120°C.The anti-SO2 poisoning ability at low-temperature reduced after adding additives Fe and Cu. catalytic conversion efficiency of Mn-Fe-Ce/TiO2 and Mn-Cu-Ce/TiO2 could be close to 90% at temperature of 180°C when water and SO2 exist simultaneously.

Mechanistic insight into the influence of O2 on N2O formation in the selective catalytic reduction of NO with NH3 over Pd/CeO2 catalyst

2021 ◽  
Author(s):  
Liping Sheng ◽  
Songda Li ◽  
Zhaoxia Ma ◽  
Fei Wang ◽  
Hu He ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
No Reduction ◽  
Catalytic Reduction ◽  
Temperature Dependent ◽  
N2o Formation ◽  
Reduction Of No ◽  
Mechanistic Insight ◽  
Insight Into

O2 greatly affected the pathway for NO reduction over the Pd/CeO2 catalyst and resulted in a temperature-dependent NH3-SCR performance and formation of N2O.

scholarly journals Fe2O3 enhanced high-temperature arsenic resistance of CeO2–La2O3/TiO2 catalyst for selective catalytic reduction of NOx with NH3

RSC Advances ◽  
2021 ◽  
Vol 11 (16) ◽  
pp. 9395-9402
Author(s):  
Na Wang ◽  
Changfei Ye ◽  
Huidong Xie ◽  
Chang Yang ◽  
Jinhong Zhou ◽  
...  
Keyword(s):  
High Temperature ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Arsenic Resistance ◽  
No Conversion ◽  
Tio2 Catalyst ◽  
Reduction Of Nox ◽  
Better Than

The NO conversion of the CeLa0.5Fe0.2/Ti is obviously better than that of the commercial vanadium-based catalyst with regard to arsenic resistance and it has good N2 selectivity, and good SO2 resistance.

A Ce-Zr-Ti Oxide Catalyst for Selective Catalytic Reduction of NO with Ammonia

2014 ◽  
Vol 535 ◽  
pp. 709-712
Author(s):  
Ye Jiang ◽  
Yan Yan ◽  
Shan Bo Huang ◽  
Xiong Zhang ◽  
Xin Wei Wang ◽  
...  
Keyword(s):  
High Activity ◽  
Selective Catalytic Reduction ◽  
Oxide Catalyst ◽  
Catalytic Reduction ◽  
Space Velocity ◽  
Impregnation Method ◽  
Reduction Of No ◽  
No Conversion ◽  
Temperature Range ◽  
Ti Oxides

A Ce-Zr-Ti oxide catalyst was prepared by an impregnation method and tested for the selective catalytic reduction of NO with NH3. The Ce-Zr-Ti oxide catalyst exhibited high activity and more than 95% NO conversion was obtained within the temperature range 300-500 °C at the high gas hourly space velocity of 50,000 h-1. The addition of Zr improved the activity of Ce-Ti oxides especially at higher reaction temperatures and their resistance to SO2.

Sensorless Control of Switched Reluctance Motors Based on Pulse Injection, Position Sectors Divided and Variable Thresholds

2014 ◽  
Vol 989-994 ◽  
pp. 3252-3257
Author(s):  
Zi Fei Jia ◽  
De An Zhao ◽  
Yu Yan Zhao
Keyword(s):  
Control Method ◽  
Estimation Error ◽  
Position Estimation ◽  
Switched Reluctance Motors ◽  
Switched Reluctance ◽  
Variable Threshold ◽  
Pulse Injection ◽  
Angle Section ◽  
Two Phases ◽  
Rotor Position Estimation

To realize starting operation and reduce position estimation error of switched reluctance motor (SRM) without position sensor, a novel control method based on pulse injection, divided angle section and variable threshold is presented. The starting operation of SRM can be accomplished by injecting high frequency pulse and judging position sectors. Variable threshold is used to reduce position estimation error. The value of threshold is obtained by looking up table prestored in controller. The method avoids complicated mathematical model and is suitable for starting operation with two phases. Besides, rotor position estimation error of this method is analyzed and the method which can decreased the error is proposed. At last, the experiment has been done to verify the performance of the control method.

scholarly journals Kinetics of Selective Catalytic Reduction of Nitric Oxide over Pt-Cu-Zsm5 Catalyst

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Ismail Mohd Saaid ◽  
Abdul Rahman Mohamed and Subhash Bhatia
Keyword(s):  
Nitric Oxide ◽  
Selective Catalytic Reduction ◽  
Active Sites ◽  
No Reduction ◽  
Bimetallic Catalyst ◽  
Catalytic Reduction ◽  
Covalent Bond ◽  
Reaction Parameters ◽  
Heterogeneous Model ◽  
Kinetics Of

Kinetics for the selective catalytic reduction (SCR) of nitric oxide (NO) using i-C4H10 as the reducing agent over Pt-Cu-ZSM5 has been investigated in the temperature range of 200 ?C – 450 oC. Langmuir-Hinshelwood-Hougen-Watson model was proposed for kinetics of the reaction and reaction parameters were evaluated.  The heat of adsorption of NO was found to be considerably high, attributed to strong covalent bond between NO gas molecules and metal active sites.  Using reaction parameters obtained from the experiment, the heterogeneous model could form a good correlation between experimental and simulated values of NO reduction. Key Words: Reaction kinetics, Selective catalytic reduction, NO reduction, Bimetallic catalyst, H-ZSM-5 zeolite.

Efficiency of Phosphotungstic Acid Modified Mn-Based Catalysts to Promote Activity and N2 Formation for Selective Catalytic Reduction of NO with Ammonia

2019 ◽  
Vol 17 (7) ◽  
Author(s):  
Yongqiang Huang ◽  
Peixin Li ◽  
Runduo Zhang ◽  
Ying Wei
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Acid Sites ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brønsted Acid Sites ◽  
No Conversion ◽  
Brönsted Acid ◽  
Brönsted Acid Sites ◽  
Nitrate Species

Abstract In this work, the modified Mn-based NH3-SCR (NH3 low-temperature selective catalytic reduction) catalysts with excellent NO conversion and N2 selectivity be designed. N2 yield was hardly more than 75 % over MnOx/TiO2 for NH3-SCR reaction, whereas the NH3-SCR performance has been significantly improved by using 50 wt.% HPW (H3PW12O40)-MnOx/TiO2. 100 % NO conversion and more than 95 % N2 yield was obtained in wide operating temperature window (150–400°C), suggesting that the addition of HPW could effectively improve the NO reduction conversion. After that, the catalysts were further characterized by XRD, H2-TPR, XPS and in situ DRIFT. DRIFT analysis implied that the introduction of HPW significantly improve the capacity of NH4 + species adsorbed on Brønsted acid sites accompanied with inhibiting the formation and consumption of nitrite species. It proved that the non-selective catalytic reduction reaction over HPW-MnOx/TiO2 catalysts are restrained. HPW could accelerate the formation and consumption of NH4 + species adsorbed on Brønsted acid sites with deactivation of nitrate species. In addition, NH3(ad) could be hardly oxidized to NH species and then reacted with nitrate species (L-H mechanism) and gaseous NO (E-R mechanism). More importantly, the oxidation of NH3 was also suppressed, which plays a dominate role to form N2O above 300°C. Besides, the deactivation of potassium poisoning on the SCR activity significantly weakened for modified samples compared to parent catalyst.

Observer-Based Power Management for Multi-Source Electric Vehicles Using Optimized Splitting Ratios

2018 ◽  
Author(s):  
Ahmed M. Ali ◽  
Dirk Söffker
Keyword(s):  
Power Conversion Efficiency ◽  
Real Time ◽  
Power Management ◽  
Conversion Efficiency ◽  
Electric Vehicles ◽  
Control Method ◽  
Power Conversion ◽  
Observer Design ◽  
Power Handling ◽  
Optimal Power

Optimal power management in real-time is a core technology of hybrid electric vehicles (HEVs). The online application of optimized power split ratios based on driver demand is a promising approach allowing near optimal power handling decisions in real-time. However, the fulfillment of exact power delivery (driveability) is an open challenge of this approach due to interpolation of driver’s demand to the optimized discrete solutions. Finding balanced power management that handles unscheduled loads and sustains required power conversion efficiency may significantly improve the experimental application of this approach. This work proposes an observer-based control method integrated to the power management system that ensures better driveability with minimal effect on power handling optimality. Modeling of traction system for observer design is based on a simplified brushless DC motor model. Identification of system parameters is achieved by a newly introduced error minimization algorithm using NSGA-II to obtain the same dynamic response as the original system. Results analysis shows 7% reduction of power consumption and 98% improvement of driveability at minimal mitigation of power conversion efficiency.

scholarly journals Insights into the promotion role of phosphorus doping on carbon as a metal-free catalyst for low-temperature selective catalytic reduction of NO with NH3

RSC Advances ◽  
2020 ◽  
Vol 10 (22) ◽  
pp. 12908-12919
Author(s):  
Weifeng Li ◽  
Shuangling Jin ◽  
Rui Zhang ◽  
Yabin Wei ◽  
Jiangcan Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
No Reduction ◽  
Catalytic Reduction ◽  
Carbon Aerogels ◽  
Phosphorus Doping ◽  
Reduction Of No ◽  
Metal Free

P species can effectively enhance the catalytic activity of carbon aerogels for NO reduction at low temperature.

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