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 ◽  
...  

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.

2018 ◽  
Vol 913 ◽  
pp. 900-906
Author(s):  
Dong Zhu Ma ◽  
Jian Li ◽  
Di Yin ◽  
Yuan Huang ◽  
Rui Min Wang ◽  
...  

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.


2011 ◽  
Vol 356-360 ◽  
pp. 1528-1534
Author(s):  
Wei Fang Dong

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.


2012 ◽  
Vol 524-527 ◽  
pp. 1140-1144
Author(s):  
Jie Mi ◽  
Meng Yu ◽  
Su Li Shang

In this study, the regeneration behavior of modified semi-coke supported (Fe, Zn, Ce) sorbents were investigated using a fixed bed reactor. The effects of the regeneration temperature, space velocity and oxygen concentration have been considered in order to obtain suitable regeneration conditions. The most suitable regeneration conditions were obtained including 650°C regeneration temperature, 4vol.% of oxygen content and 4000h-1 of space velocity. Typical properties of the sorbents before and after regeneration were characterized using XRD and BET methods. Then the sorbents were tested 3 cycle experiments of desulfurization and regeneration for the purpose of duration test. The breakthrough curves changed slightly and the sulfur capacity only decreased 14.2%, it proved that the sorbents had good regenerability, which implied that the sorbents could be used for hot gas desulfurization.


2013 ◽  
Vol 798-799 ◽  
pp. 231-234 ◽  
Author(s):  
Bing Nan Ren ◽  
Qiao Wen Yang

The metal oxide catalyst was prepared by loading MnxOyon carbon nanotubes (CNTs) with impregnation method. Then the catalyst was characterized by BET, TEM and XPS, and the catalytic activity of the catalyst for selective catalytic reduction (SCR) of NO at low-temperature was investigated. The results showed that the species of active components loaded on the catalyst were MnO2and Mn2O3. The NO conversion was improved with reduction temperature increase under 250°C, increased slowly over 250°C. The O2content had an outstanding effect on NO conversion of catalysts at a low concentration range. Once the oxygen content was enhanced over 5%, there was no significant increase in the NO conversion. With the increasing of space velocity, the NO conversion rate was decreased under the reaction conditions.


RSC Advances ◽  
2018 ◽  
Vol 8 (73) ◽  
pp. 42017-42024 ◽  
Author(s):  
Zhicheng Han ◽  
Qingbo Yu ◽  
Zhijia Xue ◽  
Kaijie Liu ◽  
Qin Qin

Trace amount of Sm-doped Mn-based Zr–Fe polymeric pillared interlayered montmorillonite promotes low temperature catalytic activity in excess oxygen.


Catalysts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 396 ◽  
Author(s):  
Laichao Li ◽  
Yusi Wang ◽  
Li Zhang ◽  
Yuxi Yu ◽  
Hanbing He

To improve NO conversion and sulfur resistance of low-temperature NO-CO selective catalytic reduction (SCR), it is urgent to seek new catalyst materials. Herein, using the pre-doping method, Cox-OMS-2 with different ratios of cobalt (Co) was obtained during hydrothermal synthesis of OMS-2 molecular sieves (where x represents the doping ratio of Co, i.e., x = 0.1, 0.2, 0.3, 0.4). Co was found to very efficiently intercalate into the crystal structure of OMS-2. Co and Mn work together to promote the selective reduction reaction of NOx;; the NO conversion of Co0.3-OMS-2 was the highest among all samples. Specifically, NO conversion at 50 °C increased from 72% for undoped OMS-2 to 90% for Co0.3-OMS-2. Moreover, due to the incorporation of Co, the latter also showed better sulfur resistance.


2011 ◽  
Vol 233-235 ◽  
pp. 1564-1567
Author(s):  
Zhi Hang Chen ◽  
Xue Hui Li ◽  
Chao Ping Cen ◽  
Xiang Gao ◽  
Le Fu Wang

The solid state reaction method, coprecipitation method and citric acid method were employed for the preparation of Cr-Mn mixed-oxide catalysts. Experimental results showed that this catalytic system has good selective catalytic reduction (SCR) properties of NOxby ammonia in the presence of excess oxygen at low temperature (80-220°C). 97.8% conversion of NOxwith 100% selectivity of N2had been achieved on Cr-MnOxmixed oxide prepared by the citric acid method at 120°C with the space velocity of 30,000 h-1. X-ray diffraction, BET were adopted for the characterization of the active phase. The characterization results showed that a new crystal phase CrMn1.5O4generated in mixed oxides which was the active center of the Cr-Mn catalysts.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1452
Author(s):  
Min Seong Lee ◽  
Sun-I Kim ◽  
Myeung-jin Lee ◽  
Bora Ye ◽  
Taehyo Kim ◽  
...  

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.


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