Removal of Vapor-Phase Elemental Mercury over a CuO/AC Catalyst

2012 ◽  
Vol 610-613 ◽  
pp. 64-67
Author(s):  
Jun Wei Wang ◽  
Xue Jun Kong ◽  
Rong Bin Du ◽  
Yanjie Dong

Removal of vapor-phase elemental mercury (Hg0) over an activated coke (AC) and activated coke supported CuO catalyst (CuO/AC) were studied under N2+HCl atmosphere. This paper describes the influences of CuO loading, reaction temperature, Hg0 concentration and space velocity on Hg0 removal over CuO/AC. It was found that CuO/AC had a higher Hg0 removal capability than that of AC, which can be attributed to the oxidation activity of CuO. The capability of CuO/AC for Hg0 removal increased with an increase of CuO loading (1-20 wt.%). The Hg0 removal capability was the highest at around 180 °C in the temperature range of 120-200 °C, which can be due to the co-effect of adsorption and oxidation. As Hg0 concentration and space velocity decreased, the Hg0 removal efficiency increased.

2012 ◽  
Vol 518-523 ◽  
pp. 210-213
Author(s):  
Jun Wei Wang ◽  
Rui Qing Liu ◽  
Xue Jun Kong

Gas-phase elemental mercury (Hg0) removal by an activated coke (AC) supported Fe2O3 catalyst (Fe2O3/AC) was studied under N2+HCl atmosphere and compared with that by AC. The influences of Fe2O3 loading, temperature and inlet Hg0 concentration on Hg0 removal were investigated. The results indicate that the Hg0 removal capability of Fe2O3/AC was much higher than that of AC, indicating the important role of Fe2O3 oxidation activity. The capability of Fe2O3/AC increased with an increase of Fe2O3 loading (1-10 wt.%) and temperature (120-200 °C). Scanning electron microscope-energy dispersive X-ray (SEM-EDX) analysis confirmed the correlation between Fe2O3 and Hg adsorbed over Fe2O3/AC.


2019 ◽  
Vol 20 (4) ◽  
pp. 61-66
Author(s):  
Halah M. Hussain ◽  
Abdulhaleem A.K. Mohammed

Hydroisomerization of Iraqi light naphtha was studied on prepared Ni-Pt/H-mordenite catalyst at a temperature range of 220-300°C, hydrogen to hydrocarbon molar ratio of 3.7, liquid hourly space velocity (LHSV) 1 hr-1 and at atmospheric pressure. The result shows that the hydrisomerization of light naphtha increases with the increase in reaction temperature at constant LHSV. However, above 270 0C the isomers formation decreases and the reaction is shifted towards the hydrocracking reaction, a higher octane number of naphtha was formed at 270 °C.


Author(s):  
Buyan-Ulzii Battulga ◽  
Tungalagtamir Bold ◽  
Enkhsaruul Byambajav

AbstractNi based catalysts supported on γ-Al2O3 that was unpromoted (Ni/γAl2O3) or promoted (Ni–Fe/γAl2O3, Ni–Co/γAl2O3, and Ni–Fe–Co/γAl2O3) were prepared using by the impregnation – co-precipitation method. Their catalytic performances for CO methanation were studied at 3 atm with a weight hourly space velocity (WHSV) of 3000 ml/g/h of syngas with a molar ratio of H2/CO = 3 and in the temperature range between 130 and 350 °C. All promoters could improve nickel distribution, and decreased its particle sizes. It was found that the Ni–Co/γAl2O3 catalyst showed the highest catalytic performance for CO methanation in a low temperature range (<250 °C). The temperatures for the 20% CO conversion over Ni–Co/γAl2O3, Ni–Fe/γAl2O3, Ni–Fe–Co/γAl2O3 and Ni/γAl2O3 catalysts were 205, 253, 263 and 270 °C, respectively. The improved catalyst distribution by the addition of cobalt promoter caused the formation of β type nickel species which had an appropriate interacting strength with alumina support in the Ni–Co/γAl2O3. Though an addition of iron promoter improved catalyst distribution, the methane selectivity was lowered due to acceleration of both CO methanation and WGS reaction with the Ni–Fe/γAl2O3. Moreover, it was found that there was no synergetic effect from the binary Fe–Co promotors in the Ni–Fe–Co/γAl2O3 on catalytic activity for CO methanation.


2014 ◽  
Vol 535 ◽  
pp. 709-712
Author(s):  
Ye Jiang ◽  
Yan Yan ◽  
Shan Bo Huang ◽  
Xiong Zhang ◽  
Xin Wei Wang ◽  
...  

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.


Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 93 ◽  
Author(s):  
Jing Wu ◽  
Hong-Juan Liu ◽  
Xiang Yan ◽  
Yu-Jie Zhou ◽  
Zhang-Nan Lin ◽  
...  

It is important to develop full-performance bio-jet fuel based on alternative feedstocks. The compound 1-butanol can be transformed into jet fuel through dehydration, oligomerization, and hydrogenation. In this study, a new catalyst consisting of Zn-Mn-Co modified γ-Al2O3 was used for the dehydration of high-concentration 1-butanol to butenes. The interactive effects of reaction temperature and butanol weight-hourly space velocity (WHSV) on butene yield were investigated with response surface methodology (RSM). Butene yield was enhanced when the temperature increased from 350 °C to 450 °C but it was reduced as WHSV increased from 1 h−1 to 4 h−1. Under the optimized conditions of 1.67 h−1 WHSV and 375 °C reaction temperature, the selectivity of butenes achieved 90%, and the conversion rate of 1-butanol reached 100%, which were 10% and 6% higher, respectively, than when using unmodified γ-Al2O3. The Zn-Mn-Co modified γ-Al2O3 exhibited high stability and a long lifetime of 180 h, while the unmodified γ-Al2O3 began to deactivate after 60 h. Characterization with X-ray diffraction (XRD), nitrogen adsorption-desorption, pyridine temperature-programmed desorption (Py-TPD), pyridine adsorption IR spectra, and inductively coupled plasma atomic emission spectrometry (ICP-AES), showed that the crystallinity and acid content of γ-Al2O3 were obviously enhanced by the modification with Zn-Mn-Co, and the loading amounts of zinc, manganese, and cobalt were 0.54%, 0.44%, and 0.23%, respectively. This study provides a new catalyst, and the results will be helpful for the further optimization of bio-jet fuel production with a high concentration of 1-butanol.


2013 ◽  
Vol 634-638 ◽  
pp. 526-530
Author(s):  
Chun Xiang Geng ◽  
Qian Qian Chai ◽  
Wei Yao ◽  
Chen Long Wang

Selective Catalytic Reduction (SCR) processes have been one of the most widely used denitration methods at present and the property of low tempreture catalyst becomes a hot research. The Mn-Ce/TiO2 catalyst was prepared by incipient impregnation method. The influence of load capacity, reaction temperature, O2 content, etc. on denitration were studied by a fixed bed catalyst reactor with ammonia gas. Results showed that catalyst with load capacity 18% performed high NO removal rate of 90% at conditions of reaction temperature 160°C, low space velocity, NH3/NO molar ratio 1: 1, O2 concentration 6%.


2020 ◽  
Vol 20 (9) ◽  
pp. 5725-5729
Author(s):  
Sharon Jo ◽  
Byung Chol Ma ◽  
Young Chul Kim

The objective of this study was to investigate the effect of feed composition, space velocity, and reaction temperature on methane/carbon dioxide conversion and H2/CO ratio. Independent variables were feed ratio, flow rate, and reaction temperature while CH4 conversion, CO2 conversion, and H2/CO ratio were set as dependent variables in the complex reaction of methane. As a result of mixed reforming reaction of methane through RSM modeling method, the reaction temperature was found to have the greatest influence. This is because the reaction temperature has the greatest influence on the reaction rate and equilibrium state as a factor directly affecting the thermodynamic value of the catalyst.


Author(s):  
Tsuyoshi Maeda ◽  
Toshio Shinoki ◽  
Jiro Funaki ◽  
Katsuya Hirata

The authors reveal the dominant chemical reactions and the optimum conditions, supposing the design of ethanol steam-reforming reactors. Specifically speaking, experiments are conducted for Cu/ZnO/Al2O3 catalyst, together with those for Ru/Al2O3 catalyst for reference. Using a household-use-scale reactor with well-controlled temperature distributions, the authors compare experimental results with chemical-equilibrium theories. It has revealed by Shinoki et al. (2011) that the Cu/ZnO/Al2O3 catalyst shows rather high performance with high hydrogen concentration CH2 at low values of reaction temperature TR. Because, the Cu/ZnO/Al2O3 catalyst promotes the ethanol-steam-reforming and water-gas-shift reactions, but does not promote the methanation reaction. So, in the present study, the authors reveal that the Ru/Al2O3 catalyst needs high TR > 770 K for better performance than the Cu/ZnO/Al2O3 catalyst, and that the Ru/Al2O3 catalyst shows lower performance at TR < 770 K. Then, the Ru/Al2O3 catalyst is considered to activate all the three reactions even at low TR. Furthermore, concerning the Cu/ZnO/Al2O3 catalyst, the authors reveal the influences of liquid-hourly space velocity LHSV upon concentrations such as CH2, CCO2, CCO and CCH4 and the influence of LHSV upon the ethanol conversion XC2H5OH, in a range of LHSV from 0.05 h−1 to 0.8 h−1, at S/C = 3.0 and TR = 520 K. And, the authors reveal the influences of the thermal profile upon CH2, CCO2, CCO, CCH4 and XC2H5OH, for several LHSV’s. To conclude, with well-controlled temperatures, the reformed gas can be close to the theory. In addition, the authors investigate the influences of S/C.


2011 ◽  
Vol 393-395 ◽  
pp. 1212-1216 ◽  
Author(s):  
Huan Wang ◽  
Yong Fa Diao

As to figure out the effect that modified fly ash, which is prepared by fly ash –CaO, and modified fly ash dust layer attached on the surface of the filter material adsorbed elemental mercury, experimental studies are administrated in a laboratory-scale fixed bed reactor system with gaseous elemental mercury produced by a mercury vapor generator and simulated flue gas composition. The experimental results indicated that the adsorption performance of fly ash and CaO relatively poor. The proportion of CaO in the modified fly ash will affected the mercury removal efficiency of the absorbent which prepared by fly ash and CaO. It will be an optimal effect when the blend ratio of the flying ash and CaO is 2 to 1, and the maximum removal efficiency is up to 34%.As the adsorption temperature increases the removal efficiency of the modified fly ash deteriorates. The efficiency of dust layer attaching on the surface of the filter material is getting higher with the larger porosity of dust layer and smaller particle material size.


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