The Mo Loading Effect on SCR deNOx Performance for V-W-Mo/TiO2 Catalyst

The V(1)-W(4.5)-Mo(x)/TiO2 catalysts was prepared by the incipient dry impregnation method. The catalyst samples were ground and sieved for 0.3~0.6 mm. The NO catalytic efficiency, selectivity against N2O of the catalysts were investigated on a fixed bed reactor under simulated exhaust gas with a typical gas composition. The addition of Mo enhanced the catalytic efficiency of V(1)-W(4.5)-Mo(x)/TiO2 catalysts at low temperature region, while lessened that at high temperature, especially at the temperature above 400 °C. Increasing the loading of Mo from 1.5% w/w to 4.5% w/w advanced the maximum catalytic efficiency from 78% to 99% and enlarged the temperature window of the catalyst. The acceptable NO conversion (>60%) was attained at temperature as low as 240 °C for V(1)-W(4.5)-Mo(7.5)/TiO2 catalyst. The presence of Mo promoted the N2O generation. The V(1)-W(4.5)-Mo(0)/TiO2 catalyst showed higher catalytic selectivity for NO compared to the catalysts loading Mo.

Download Full-text

The W Loading Effect on SCR deNOx Performance for V-W-Mo/TiO2 Catalyst

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.774-776.743 ◽

2013 ◽

Vol 774-776 ◽

pp. 743-746 ◽

Cited By ~ 1

Author(s):

Ji Wei Peng ◽

Tao Luan ◽

Yan Gao

Keyword(s):

High Temperature ◽

Fixed Bed ◽

Catalytic Efficiency ◽

Fixed Bed Reactor ◽

Exhaust Gas ◽

Gas Composition ◽

High Temperature Region ◽

Loading Effect ◽

Scr Catalysts ◽

Temperature Window

The SCR catalysts were produced with V2O5, WO3, MoO3and anatase type TiO2. The catalyst samples were ground and sieved for 0.3~0.6mm.The NO catalytic efficiency, selectivity against N2O of the catalysts were investigated on a fixed bed reactor under simulated exhaust gas with a typical gas composition. The addition of W enhanced the catalytic efficiency of V(1)-W(x)-Mo (4.5)/TiO2catalysts at high temperature region, while lessened that at low temperature. Increasing the loading of W from 1.5% w/w to 4.5% w/w advanced the maximum catalytic efficiency from 88% to 99% and enlarged the temperature window of the catalyst. The presence of W promoted the N2O generation. The V(1)-W(4.5)-Mo (4.5)/TiO2catalyst showed higher catalytic selectivity for NO compared to the catalysts loading W.

Download Full-text

Structural/Texture Evolution During Facile Substitution of Ni into ZSM-5 Nanostructure vs. its Impregnation Dispersion Used in Selective Transformation of Methanol to Ethylene and Propylene

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207323666200825144543 ◽

2020 ◽

Vol 23 ◽

Cited By ~ 1

Author(s):

Parisa Sadeghpour ◽

Mohammad Haghighi ◽

Mehrdad Esmaeili

Keyword(s):

High Temperature ◽

Physicochemical Properties ◽

Active Sites ◽

Catalytic Performance ◽

Fixed Bed Reactor ◽

Light Olefins ◽

Isomorphous Substitution ◽

Impregnation Method ◽

Hydrothermal Temperature ◽

X Ray

Aim and Objective: Effect of two different modification methods for introducing Ni into ZSM-5 framework was investigated under high temperature synthesis conditions. The nickel successfully introduced into the MFI structures at different crystallization conditions to enhance the physicochemical properties and catalytic performance. Materials and Methods: A series of impregnated Ni/ZSM-5 and isomorphous substituted NiZSM-5 nanostructure catalysts were prepared hydrothermally at different high temperatures and within short times. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray (EDX), Brunner, Emmett and Teller-Barrett, Joyner and Halenda (BET-BJH), Fourier transform infrared (FTIR) and Temperature-programmed desorption of ammonia (TPDNH3) were applied to investigate the physicochemical properties. Results: Although all the catalysts showed pure silica MFI–type nanosheets and coffin-like morphology, using the isomorphous substitution for Ni incorporation into the ZSM-5 framework led to the formation of materials with lower crystallinity, higher pore volume and stronger acidity compared to using impregnation method. Moreover, it was found that raising the hydrothermal temperature increased the crystallinity and enhanced more uniform incorporation of Ni atoms in the crystalline structure of catalysts. TPD-NH3 analysis demonstrated that high crystallization temperature and short crystallization time of NiZSM-5(350-0.5) resulted in fewer weak acid sites and medium acid strength. The MTO catalytic performance was tested in a fixed bed reactor at 460ºC and GHSV=10500 cm3 /gcat.h. A slightly different reaction pathway was proposed for the production of light olefins over impregnated Ni/ZSM-5 catalysts based on the role of NiO species. The enhanced methanol conversion for isomorphous substituted NiZSM-5 catalysts could be related to the most accessible active sites located inside the pores. Conclusion: The impregnated Ni/ZSM-5 catalyst prepared at low hydrothermal temperature showed the best catalytic performance, while the isomorphous substituted NiZSM-5 prepared at high temperature was found to be the active molecular sieve regarding the stability performance.

Download Full-text

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

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2020-0163 ◽

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.

Download Full-text

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

Energies ◽

10.3390/en14113347 ◽

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.

Download Full-text

Tungsten Oxide-Modified SSZ-13 Zeolite as an Efficient Catalyst for Ethylene-To-Propylene Reaction

Catalysts ◽

10.3390/catal11050553 ◽

2021 ◽

Vol 11 (5) ◽

pp. 553

Author(s):

Mansurbek Urol ugli Abdullaev ◽

Sungjune Lee ◽

Tae-Wan Kim ◽

Chul-Ung Kim

Keyword(s):

Tungsten Oxide ◽

Fixed Bed ◽

Acid Sites ◽

Fixed Bed Reactor ◽

Incipient Wetness Impregnation ◽

Impregnation Method ◽

Efficient Catalyst ◽

X Ray ◽

Propylene Selectivity ◽

Temperature Programmed

Among the zeolitic catalysts for the ethylene-to-propylene (ETP) reaction, the SSZ-13 zeolite shows the highest catalytic activity based on both its suitable pore architecture and tunable acidity. In this study, in order to improve the propylene selectivity further, the surface of the SSZ-13 zeolite was modified with various amounts of tungsten oxide ranging from 1 wt% to 15 wt% via a simple incipient wetness impregnation method. The prepared catalysts were characterized with several analysis techniques, specifically, powder X-ray diffraction (PXRD), Raman spectroscopy, temperature-programmed reduction of hydrogen (H2-TPR), temperature-programmed desorption of ammonia (NH3-TPD), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and N2 sorption, and their catalytic activities were investigated in a fixed-bed reactor system. The tungsten oxide-modified SSZ-13 catalysts demonstrated significantly improved propylene selectivity and yield compared to the parent H-SSZ-13 catalyst. For the tungsten oxide loading, 10 wt% loading showed the highest propylene yield of 64.9 wt%, which was 6.5 wt% higher than the pristine H-SSZ-13 catalyst. This can be related to not only the milder and decreased strong acid sites but also the diffusion restriction of bulky byproducts, as supported by scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS) observation.

Download Full-text

99/03650 Simulation of high-temperature desulfurization in a fixed-bed reactor

Fuel and Energy Abstracts ◽

10.1016/s0140-6701(99)98856-2 ◽

1999 ◽

Vol 40 (6) ◽

pp. 386

Keyword(s):

High Temperature ◽

Fixed Bed ◽

Fixed Bed Reactor

Download Full-text

Effect of CO2 partial pressure on dry reforming of ethanol for hydrogen production

International Journal of Innovative Research and Scientific Studies ◽

10.53894/ijirss.v1i1.3 ◽

2018 ◽

Vol 1 (1) ◽

pp. 6-10

Author(s):

Fahim Fayaz ◽

Ahmad Ziad Sulaiman ◽

Sharanjit Singh ◽

Sweeta Akbari

Keyword(s):

Partial Pressure ◽

Fixed Bed ◽

Dry Reforming ◽

Fixed Bed Reactor ◽

Bet Surface Area ◽

Impregnation Method ◽

X Ray Diffraction ◽

Co2 Partial Pressure ◽

Temperature Programmed ◽

Al2o3 Catalyst

The effect of CO2 partial pressure on ethanol dry reforming was evaluated over 5%Ce-10%Co/Al2O3 catalyst at = PCO2 = 20-50 kPa, PC2H5OH = 20 kPa, reaction temperature of 973 K under atmospheric pressure. The catalyst was prepared by using impregnation method and tested in a fixed-bed reactor. X-ray diffraction measurements studied the formation of Co3O4, spinel CoAl2O4 and CeO2, phases on surface of 5%Ce-10%Co/Al2O3 catalyst. CeO2, CoO and Co3O4 oxides were obtained during temperature–programmed calcination. Ce-promoted 10%Co/Al2O3 catalyst possessed high BET surface area of 137.35 m2 g-1. C2H5OH and CO2 conversions was improved with increasing CO2 partial pressure from 20-50 kPa whilst the optimal selectivity of H2 and CO was achieved at 50 kPa.

Download Full-text

On efficiency of vanadium-oxide promoter in cobalt Fischer – Tropsch catalysts

Kataliz v promyshlennosti ◽

10.18412/1816-0387-2021-1-2-15 ◽

2021 ◽

Vol 1 (1-2) ◽

pp. 15

Author(s):

Elham Yaghoobpour ◽

Yahya Zamani ◽

Saeed Zarrinpashne ◽

Akbar Zamaniyan

Keyword(s):

Vanadium Oxide ◽

Active Sites ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Bet Surface Area ◽

Incipient Wetness Impregnation ◽

Impregnation Method ◽

Fischer Tropsch ◽

Co Conversion ◽

Loading Amount

Promoters and their loading amount have crucial roles in cobalt Fischer – Tropsch catalysts. In this regard, the effects of vanadium oxide (V2O5) as a proposed promoter for Co catalyst supported on TiO2 have been investigated. Three catalysts with 0, 1, and 3 wt.% of V2O5 promoter loading are prepared by the incipient wetness impregnation method, and characterized by the BET surface area analyzer, XRD, H2-TPR, and TEM techniques. The fixed-bed reactor was employed for their evaluations. It was found that the catalyst containing 1 wt.% V2O5 has the best performance among the evaluated catalysts, demonstrating remarkable selectivity: 92 % C5+ and 5.7 % CH4, together with preserving the amount of CO conversion compared to the unpromoted catalyst. Furthermore, it is reported that the excess addition of V2O5 promoter (> 1 wt.%) in the introduced catalyst leads to the detrimental effect on the CO conversion and C5+ selectivity, mainly owing to diminished active sites by V2O5 loading.

Download Full-text

Effects of Alkali and Alkaline Earth Metals on NOx Reduction in Coke Combustion

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.634-638.522 ◽

2013 ◽

Vol 634-638 ◽

pp. 522-525 ◽

Cited By ~ 1

Author(s):

Yan Guang Chen ◽

Hong Jing Han ◽

Jia Lu ◽

Dan Dan Li ◽

Jin Lian Li ◽

...

Keyword(s):

Alkaline Earth ◽

Nox Reduction ◽

Combustion Process ◽

Fixed Bed ◽

Alkaline Earth Metals ◽

Reduction Ratio ◽

Nox Emission ◽

Fixed Bed Reactor ◽

Impregnation Method ◽

Loading Amount

A series of coke samples with loading alkali and alkaline earth metals were prepared by the impregnation method, the NOx emission were investigated in a silica fixed bed reactor in the combustion process of raw coke and coke modified by Na, K, Ca and Mg. The results show that Na, K, Ca and Mg play in-situ catalytic effects on the NOx reduction reactions. When the loading amount of Na2CO3 is 2.0%, the NOx reduction ratio was around 17.4%, when the loading of K2CO3 is 2.0%, the amount of NOx emission is reduced by 26.5%. When the loading of CaCl2 is 2.0%, the amount of NOx emission is reduced by 22.3%. When the loading of MgCl2 is 2.0%, the NOx reduction ratio is about 10.9%.

Download Full-text