Preparation and Performance of Several Non-Precious Metal Oxides Catalysts for the Low Temperature SCR of NOx with NH3

2011 ◽  
Vol 356-360 ◽  
pp. 1528-1534
Author(s):  
Wei Fang Dong
Keyword(s):  
Low Temperature ◽  
Metal Oxides ◽  
Flue Gas ◽  
Precious Metal ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Low Temperature Scr ◽  
Scr Of Nox

A series of non-precious metal oxides catalysts were prepared for low-temperature selective catalytic reduction (SCR) of NOx with NH3 in a fixed bed reactor. The catalytic performance was evaluated by the removal efficiency of NOx and N2selectivity which were respectively detected by flue gas analyzer and flue gas chromatograph. Furthermore, the components of gas products from the above experiments were analysed with 2010 GC-MS. The results illustrated that the MnO2exhibited the highest NOx conversion to 95.46% and the highest selectivity of N2to 100% at temperature of 393K, then followed ZrO2, Al2O3and Fe2O3.

Denitrification Activities of Mo-V-Ti Catalysts Prepared by Dipping Method at Low Temperature

2018 ◽  
Vol 913 ◽  
pp. 900-906
Author(s):  
Dong Zhu Ma ◽  
Jian Li ◽  
Di Yin ◽  
Yuan Huang ◽  
Rui Min Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Conversion Efficiency ◽  
Flue Gas ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Optimum Ratio ◽  
Denitrification Activity ◽  
Gas Space

Mo-V-Ti catalysts of low temperature denitrification were prepared by dipping method. In order to study the activity of selective catalytic reduction, the catalyst was placed in a fixed bed reactor. Industrial flue gas was simulated with cylinder gas. The experimental condition is NO: 500ppm, NH3:500ppm, O2:8%, SO2:100ppm, N2: equilibrium gas, space velocity: 36000h-1. Results indicate that the catalyst prepared by dipping method had good denitrification activity and sulfur resistance at low temperature. The optimum ratio of catalyst was 3V2O5-6MoO3-91TiO2 (wt %). The conversion efficiency of NO was 80~93%, and the conversion efficiency of SO2 was less than 1% at 180~260 °C.

Denitrification Activities of Mg-Mo-V-Ti Catalysts Prepared by Dipping Method at Low Temperature

2018 ◽  
Vol 913 ◽  
pp. 893-899
Author(s):  
Dong Zhu Ma ◽  
Jian Li ◽  
Ling Zhang ◽  
Peng Guo ◽  
Zi Qiang Wen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Oxygen Content ◽  
Oxygen Concentration ◽  
Flue Gas ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Sulfur Resistance

Mg-Mo-V-Ti catalysts of low temperature denitrification were prepared by dipping method. In order to study the activity of selective catalytic reduction, the catalyst was placed in a fixed bed reactor. Industrial flue gas was simulated with cylinder gas. Results indicate that the 0.1wt% content of MgO catalyst has good performance on denitration activity and sulfur resistance. The effects of oxygen content, space velocity and reaction temperature on the activity of the 0.1MgO-6MoO3-3V2O5-TiO2 wt% catalyst were investigated. With the increase of oxygen concentration, the denitrification efficiency increases when the oxygen concentration is less than 8%. When the oxygen content is greater than 8%, the denitrification efficiency is almost the same. The denitrification efficiency decreases with the increase of space velocity. The removal efficiency of NO 0.1MgO-6MoO3-3V2O5-TiO2 wt% catalyst over increases first and then becomes stable with the increase of temperature, and the conversion efficiency of SO2 is less than or equal to 2.2% at 120~240 °C.

scholarly journals Effect of Catalyst Crystallinity on V-Based Selective Catalytic Reduction with Ammonia

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1452
Author(s):  
Min Seong Lee ◽  
Sun-I Kim ◽  
Myeung-jin Lee ◽  
Bora Ye ◽  
Taehyo Kim ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Fixed Bed Reactor ◽  
Scr Catalysts ◽  
Catalyst Systems ◽  
The One ◽  
No2 Formation

In this study, we synthesized V2O5-WO3/TiO2 catalysts with different crystallinities via one-sided and isotropic heating methods. We then investigated the effects of the catalysts’ crystallinity on their acidity, surface species, and catalytic performance through various analysis techniques and a fixed-bed reactor experiment. The isotropic heating method produced crystalline V2O5 and WO3, increasing the availability of both Brønsted and Lewis acid sites, while the one-sided method produced amorphous V2O5 and WO3. The crystalline structure of the two species significantly enhanced NO2 formation, causing more rapid selective catalytic reduction (SCR) reactions and greater catalyst reducibility for NOX decomposition. This improved NOX removal efficiency and N2 selectivity for a wider temperature range of 200 °C–450 °C. Additionally, the synthesized, crystalline catalysts exhibited good resistance to SO2, which is common in industrial flue gases. Through the results reported herein, this study may contribute to future studies on SCR catalysts and other catalyst systems.

Fabrication of Mn-FeOx/CNTs Catalysts for Low-Temperature NO Reduction with NH3

NANO ◽  
2015 ◽  
Vol 10 (04) ◽  
pp. 1550050 ◽  
Author(s):  
Yanbing Zhang ◽  
Zhe Xu ◽  
Xie Wang ◽  
Xiulian Lu ◽  
Yuying Zheng
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Metal Oxides ◽  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
Amorphous Structure ◽  
X Ray ◽  
Temperature Programmed ◽  
Xrd Patterns ◽  
Low Temperature Scr

Mn - FeO x/carbon nanotubes (CNTs) catalysts were firstly prepared via simple incipient wetness method and used for low-temperature selective catalytic reduction (SCR) of NO with NH 3. The structure and surface properties of the catalysts were characterized by N 2 sorption, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction by hydrogen ( H 2-TPR). It was found that Mn - FeO x/CNTs catalyst exhibited excellent low-temperature SCR activity and SO 2 resistance. XRD patterns revealed that metal oxides catalysts were possessed of amorphous structure. FESEM and TEM images showed that metal oxides catalysts were successfully supported on CNTs. The XPS results indicated that the obtained catalyst presented high Mn 4+/ Mn 3+ and OS/(OS + OL) ratios. The H 2-TPR profiles showed that Mn - FeO x/CNTs catalyst possessed better low-temperature reducibility. Besides, the obtained catalyst exhibited better SO 2 resistance.

Experimental Research on Catalysts of V2O5/AC and V2O5/CNTs for Low Temperature SCR Denitrification

2014 ◽  
Vol 694 ◽  
pp. 478-483 ◽  
Author(s):  
Jing Liu ◽  
Kai Zhang ◽  
Meng Si ◽  
Jing Hong Lian ◽  
Lian Sheng Liu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Experimental Research ◽  
Reaction Temperature ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
No Conversion ◽  
Temperature Range ◽  
Effects Of Temperature ◽  
Low Temperature Scr

Two catalysts (V2O5/AC and V2O5/CNTs) with different loadings, prepared by impregnation method, were used to research the DeNOx activity under N2and CO2atmospheres respecitively at the temperature range from 100°C to 300°C using a fixed bed reactor. Effects of temperature, loading and support on the DeNOx activity were studied. The results show that the NO conversion of the both catalysts increases with the reaction temperature. The loading and support have significant effects on the activities. 9%V2O5/AC and 9%V2O5/CNTs yielded 80% and 66.6% NO conversion at 250°C respectively under N2atmosphere, however, they yielded 78.1% and 75.1% respectively under CO2atmosphere.

scholarly journals Studies on H2-Assisted Liquefied Petroleum Gas Reduction of NO over Ag/Al2O3 Catalyst

2018 ◽  
Vol 13 (2) ◽  
pp. 227 ◽  
Author(s):  
Pratichi Singh ◽  
Deepak Yadav ◽  
Pooja Thakur ◽  
Jitendra Pandey ◽  
Ram Prasad
Keyword(s):  
Low Temperature ◽  
No Reduction ◽  
Flow Reactor ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Liquefied Petroleum Gas ◽  
Lean Burn ◽  
Reduction Of No ◽  
Al2o3 Catalyst ◽  
Scr Of Nox

Hydrocarbon-Selective catalytic reduction (HC-SCR) is one of the potential methods to remove NOx emissions from diesel engine, lean burn petrol engines and natural gas engines exhaust. Ag/Al2O3 is a good catalyst for HC-SCR of NOx under lean-burn conditions. Further, addition of small amount of H2 is effective for enhancing HC-SCR activity. This effect is unique to silver and to specific Ag/support combinations, namely, Ag/γ-Al2O3. Various HC reductants, such as: octane, decane, dodecane and propane, have been reported in the literatures. Only a single study on LPG as a reductant over Cu-ZSM catalyst was reported. There was no work reported on H2 assisted LPG over Ag/Al2O3 catalyst. Thus, this gap in the literature is filled with the present investigation of NO reduction over 2 wt.% Ag/Al2O3 catalyst using LPG reductant. The fresh and used catalyst was characterized by various techniques like low temperature N2-adsorption, XRD, XPS and SEM. There was practically no change in the characteristics of the fresh and used catalyst. Two different reductants of CO and LPG were compared for SCR of NO over the catalyst without and with H2-assisted. The experiments were performed in a fixed bed tubular flow reactor under the following conditions: 100mg catalyst; 0.13% NO, 2.5% LPG/CO, 1% H2, 10% O2, rest Ar; total flow rate 60 mL/min; temperature ambient 400 oC and pressure 1 atm. Around 100% conversion of NO was achieved using LPG reductant. Light off temperature of NO reduction significantly reduced by H2assisted LPG reductant. The maximum conversion of NO with CO was limited to 35.15% at temperature of 224 oC and above. Whereas, 97.79 % NO conversion was achieved at 365 oC with LPG reductant. While, the maximum conversions with H2-LPG and H2-CO reductants were 100 and 99.46% at 117 and 220 oC, respectively. Therefore, H2-LPG-SCR of NOx over 2 wt.% Ag/Al2O3 catalyst system can be used to get 100% reduction at low temperature. Copyright © 2018 BCREC Group. All rights reservedReceived: 24th June 2017; Revised: 6th October 2017; Accepted: 10th November 2017; Available online: 11st June 2018; Published regularly: 1st August 2018How to Cite: Singh, P., Yadav, D., Thakur, P., Pandey, J., Prasad, R. (2018). Studies on H2-Assisted Liquefied Petroleum Gas Reduction of NO over Ag/Al2O3 Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (2): 227-235 (doi:10.9767/bcrec.13.2.1307.227-235) 

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.

CO2 valorization into synthetic natural gas (SNG) using a Co–Ni bimetallic Y2O3 based catalysts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Radwa A. El-Salamony ◽  
Sara A. El-Sharaky ◽  
Seham A. Al-Temtamy ◽  
Ahmed M. Al-Sabagh ◽  
Hamada M. Killa
Keyword(s):  
Reaction Mechanism ◽  
Natural Gas ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Synthetic Natural Gas ◽  
Methanation Reaction ◽  
Co2 Valorization

Abstract Recently, because of the increasing demand for natural gas and the reduction of greenhouse gases, interests have focused on producing synthetic natural gas (SNG), which is suggested as an important future energy carrier. Hydrogenation of CO2, the so-called methanation reaction, is a suitable technique for the fixation of CO2. Nickel supported on yttrium oxide and promoted with cobalt were prepared by the wet-impregnation method respectively and characterized using SBET, XRD, FTIR, XPS, TPR, and HRTEM/EDX. CO2 hydrogenation over the Ni/Y2O3 catalyst was examined and compared with Co–Ni/Y2O3 catalysts, Co% = 10 and 15 wt/wt. The catalytic test was conducted with the use of a fixed-bed reactor under atmospheric pressure. The catalytic performance temperature was 350 °C with a supply of H2:CO2 molar ratio of 4 and a total flow rate of 200 mL/min. The CH4 yield was reached 67%, and CO2 conversion extended 48.5% with CO traces over 10Co–Ni/Y2O3 catalyst. This encourages the direct methanation reaction mechanism. However, the reaction mechanism over Ni/Y2O3 catalyst shows different behaviors rather than that over bi-metal catalysts, whereas the steam reforming of methane reaction was arisen associated with methane consumption besides increase in H2 and CO formation; at the same temperature reaction.

scholarly journals Performance Analysis of TiO2-Modified Co/MgAl2O4 Catalyst for Dry Reforming of Methane in a Fixed Bed Reactor for Syngas (H2, CO) Production

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3347
Author(s):  
Arslan Mazhar ◽  
Asif Hussain Khoja ◽  
Abul Kalam Azad ◽  
Faisal Mushtaq ◽  
Salman Raza Naqvi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Dry Reforming ◽  
Fixed Bed Reactor ◽  
Dry Reforming Of Methane ◽  
Catalyst Stability ◽  
Feed Ratio ◽  
Catalyst Loading ◽  
Impregnation Method

Co/TiO2–MgAl2O4 was investigated in a fixed bed reactor for the dry reforming of methane (DRM) process. Co/TiO2–MgAl2O4 was prepared by modified co-precipitation, followed by the hydrothermal method. The active metal Co was loaded via the wetness impregnation method. The prepared catalyst was characterized by XRD, SEM, TGA, and FTIR. The performance of Co/TiO2–MgAl2O4 for the DRM process was investigated in a reactor with a temperature of 750 °C, a feed ratio (CO2/CH4) of 1, a catalyst loading of 0.5 g, and a feed flow rate of 20 mL min−1. The effect of support interaction with metal and the composite were studied for catalytic activity, the composite showing significantly improved results. Moreover, among the tested Co loadings, 5 wt% Co over the TiO2–MgAl2O4 composite shows the best catalytic performance. The 5%Co/TiO2–MgAl2O4 improved the CH4 and CO2 conversion by up to 70% and 80%, respectively, while the selectivity of H2 and CO improved to 43% and 46.5%, respectively. The achieved H2/CO ratio of 0.9 was due to the excess amount of CO produced because of the higher conversion rate of CO2 and the surface carbon reaction with oxygen species. Furthermore, in a time on stream (TOS) test, the catalyst exhibited 75 h of stability with significant catalytic activity. Catalyst potential lies in catalyst stability and performance results, thus encouraging the further investigation and use of the catalyst for the long-run DRM process.

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