Low Temperature Dehydration of Glycerol to Acrolein in Vapor Phase with Hydrogen as Dilution: From Catalyst Screening via TPSR to Real-Time Reaction in a Fixed-Bed

Temperature programmed surface reaction (TPSR) was developed as a method for rapid screening of catalysts. In this study, a series of acid catalysts was screened for the low-temperature dehydration of glycerol to acrolein via TPSR. Results suggested that most catalysts show activity of glycerol conversion to acrolein at a greatly different temperature range. HY, SiO2 supported H4SiW12O40 (STA/SiO2), SO42−/ZrO2, and SO42−/TiO2 were observed to be efficient for the conversion of glycerol into acrolein at 210 °C, which was significantly lower than that generally reported (250–340 °C). Moreover, high selectivity of acrolein was gained at 85% and 86% over SiW/SiO2 and SO42−/TiO2, respectively. A new style catalyst, ZnCl2/SiO2, was also found to be highly selective to acrolein and evaluated in a conventional fixed-bed reactor. Especially, stability tests showed that the catalyst life was up to 300 h with no clear deactivation on ZnCl2/SiO2 with hydrogen as dilution.

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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.

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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.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.356-360.1528 ◽

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.

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Modified Cuo/ZnO/Al2O3 Catalysts for Methanol Synthesis from Co and CO2 Co-Hydrogenation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.1529 ◽

2013 ◽

Vol 690-693 ◽

pp. 1529-1534

Author(s):

Wen Gui Gao ◽

Hua Wang ◽

Wen Yan Liu ◽

Feng Jie Zhang

Keyword(s):

Methanol Synthesis ◽

Active Sites ◽

Co Hydrogenation ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Total Carbon ◽

X Ray Diffraction ◽

Wet Impregnation ◽

Temperature Programmed ◽

Co Precipitation

A series of CuO-ZnO-Al2O3catalysts modified by different promoter were prepared by co-precipitation or incipient wet impregnation and characterized by X-ray diffraction (XRD), N2physisorption, hydrogen temperature-programmed reduction (H2-TPR) and carbon dioxide temperature-programmed desorption (CO2-TPD). The modified catalysts were tested for methanol synthesis from CO/CO2co-hydrogenation in a fixed bed reactor with feed containing CO, CO2and H2(CO:CO2:H2=1.0:1.08:6.24, volume radio). It is revealed that the catalysts modified by Zr, Mg, Ca has higher activity of methanol synthesis by CO and CO2co-hydrogenation. Especially, the addition of Zr enhances the conversion of total carbon and the selectivity of methanol, which is due to the improved surface area, much more active sites, and the synergistically interaction between CuO and ZnO caused by the addition of Zr promoter.

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High Active Co/Mg1-xCex3+O Catalyst: Effects of Metal-Support Promoter Interactions on CO2 Reforming of CH4 Reaction

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.16.1.9969.97-110 ◽

2021 ◽

Vol 16 (1) ◽

pp. 97-110

Author(s):

Faris A. Jassim Al-Doghachi ◽

Diyar M. A. Murad ◽

Huda S. Al-Niaeem ◽

Salam H. H. Al-Jaberi ◽

Surahim Mohamad ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Dry Reforming Of Methane ◽

Precipitation Method ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Co2 Reforming Of Ch4 ◽

Temperature Programmed

Co/Mg1−XCe3+XO (x = 0, 0.03, 0.07, 0.15; 1 wt% cobalt each) catalysts for the dry reforming of methane (DRM) reaction were prepared using the co-precipitation method with K2CO3 as precipitant. Characterization of the catalysts was achieved by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (H2-TPR), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). The role of several reactant and catalyst concentrations, and reaction temperatures (700–900 °C) on the catalytic performance of the DRM reaction was measured in a tubular fixed-bed reactor under atmospheric pressure at various CH4/CO2 concentration ratios (1:1 to 2:1). Using X-ray diffraction, a surface area of 19.2 m2.g−1 was exhibited by the Co/Mg0.85Ce3+0.15O catalyst and MgO phase (average crystallite size of 61.4 nm) was detected on the surface of the catalyst. H2 temperature programmed reaction revealed a reduction of CoO particles to metallic Co0 phase. The catalytic stability of the Co/Mg0.85Ce3+0.15O catalyst was achieved for 200 h on-stream at 900 °C for the 1:1 CH4:CO2 ratio with an H2/CO ratio of 1.0 and a CH4, CO2 conversions of 75% and 86%, respectively. In the present study, the conversion of CH4 was improved (75%–84%) when conducting the experiment at a lower flow of oxygen (1.25%). Finally, the deposition of carbon on the spent catalysts was analyzed using TEM and Temperature programmed oxidation-mass spectroscopy (TPO-MS) following 200 h under an oxygen stream. Better anti-coking activity of the reduced catalyst was observed by both, TEM, and TPO-MS analysis. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.913.900 ◽

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.

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Kinetic Study Based on the Carbide Mechanism of a Co-Pt/γ-Al2O3 Fischer–Tropsch Catalyst Tested in a Laboratory-Scale Tubular Reactor

Catalysts ◽

10.3390/catal9090717 ◽

2019 ◽

Vol 9 (9) ◽

pp. 717 ◽

Cited By ~ 1

Author(s):

Marco Marchese ◽

Niko Heikkinen ◽

Emanuele Giglio ◽

Andrea Lanzini ◽

Juha Lehtonen ◽

...

Keyword(s):

Carbon Number ◽

Fixed Bed ◽

Tubular Reactor ◽

Fixed Bed Reactor ◽

Molar Ratio ◽

Fischer Tropsch ◽

Mechanism Model ◽

Conversion Level ◽

Temperature Programmed ◽

Xrd Techniques

A Co-Pt/γ-Al2O3 catalyst was manufactured and tested for Fischer–Tropsch applications. Catalyst kinetic experiments were performed using a tubular fixed-bed reactor system. The operative conditions were varied between 478 and 503 K, 15 and 30 bar, H2/CO molar ratio 1.06 and 2.11 at a carbon monoxide conversion level of about 10%. Several kinetic models were derived, and a carbide mechanism model was chosen, taking into account an increasing value of termination energy for α-olefins with increasing carbon numbers. In order to assess catalyst suitability for the determination of reaction kinetics and comparability to similar Fischer–Tropsch Synthesis (FTS) applications, the catalyst was characterized with gas sorption analysis, temperature-programmed reduction (TPR), and X-ray diffraction (XRD) techniques. The kinetic model developed is capable of describing the intrinsic behavior of the catalyst correctly. It accounts for the main deviations from the typical Anderson-Schulz-Flory distribution for Fischer–Tropsch products, with calculated activation energies and adsorption enthalpies in line with values available from the literature. The model suitably predicts the formation rates of methane and ethylene, as well as of the other α-olefins. Furthermore, it properly estimates high molecular weight n-paraffin formation up to carbon number C80.

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Comparative study of catalytic conversion of glycerol, a by-product of transesterification, to cyclic hydrocarbons using MCM-22, ZSM-5 and alumina

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2021-0102 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Sandeep Kumar ◽

Dinesh Kumar ◽

Neeru Anand ◽

Vinay Shah

Keyword(s):

Rate Constant ◽

Reaction Rate ◽

Fixed Bed ◽

Liquid Product ◽

Value Added ◽

Fixed Bed Reactor ◽

High Yield ◽

Esterification Reaction ◽

Glycerol Conversion ◽

Ms Analysis

Abstract Recently chemical consumption has increased due to the growth of human population and industrialization. Depleting fuel reserves and increase in chemicals rise has led and researcher to focus on alternative bio based chemicals. Glycerol which is produced as a major byproduct from the trans-esterification reaction of fatty acids for producing biodiesel has been used in this work for conversion to value added products. Conversion of glycerol in presence of alumina, MCM-22 (pure silica based mesoporous catalyst) and ZSM-5 (Si-Al based catalyst) is investigated at different temperature and catalyst weight in a fixed bed reactor. The conversion of glycerol was found to be maximum in presence of alumina whereas maximum liquid products were obtained with ZSM-5. GC/MS analysis confirmed the production of Furan compounds in higher fraction with both alumina as well as ZSM-5 showing the importance of acid sites for the glycerol conversion to higher hydrocarbons. The GC/MS analysis of liquid product obtained in presence of catalyst was also observed with high area% of unconverted glycerol. The order is as follow 54% (MCM-22) > 44% (ZSM-5) > 42.2% (Alumina). For the investigation of the conversion for varying catalyst weight (0–3 g with 0.5 g weight difference), reaction temperature were varied between 450 and 550 °C. Different values of n = 0, 1, 2 etc. were used for the fitting of the respective plot. A change in reaction rate and the rate constant indicated that with the change of temperature, reaction rate was increased. The rate constant value obtained between 0.09 and 0.12 h−1. In all cases 450 °C and catalyst weight of 2.5 g was obtained as optimum for higher liquid yield. TGA analysis of spent catalyst also showed that alumina give high yield (∼50% by weight) of coke as compared to ZSM-5 and MCM-22.

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Effect of Steam Treatment on Catalytic Performance of La2O3-HZSM-5 for Methylation of Toluene with Methanol

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.629.381 ◽

2012 ◽

Vol 629 ◽

pp. 381-385 ◽

Cited By ~ 2

Author(s):

Jun Hui Li ◽

Zhong Hua Hu ◽

Ya Nan Wang ◽

Hao Xiang ◽

Zhi Rong Zhu

Keyword(s):

High Selectivity ◽

Fixed Bed ◽

Shape Selectivity ◽

Catalytic Performance ◽

Acid Sites ◽

Fixed Bed Reactor ◽

Steam Treatment ◽

By Products ◽

Poor Stability ◽

Excellent Catalytic Performance

Methylation of toluene with methanol to synthesize p-Xylene was performed in a fixed-bed reactor. HZSM-5 zeolite as a catalyst was prepared by modification with La2O3. In addition, effect of steam treatment for La2O3-modified HZSM-5 on its catalytic performance was investigated as well. The properties of as-prepared catalysts were characterized by XRD, BET and NH3-TPD. The results indicate that modification with La2O3can narrow the size of HZSM-5 channel effectively. And more than 90% selectivity of p-Xylene is obtained over HZSM-5 with loading of 24% and 30% La2O3. However, above La2O3-modified HZSM-5 with high-selectivity exhibit a poor stability for time on-stream of the methylation reaction. Steam treatment of La2O3-modified HZSM-5 can improve its stability and shape selectivity, decreasing by-products. These effects can be attributed to distortion & narrowing of HZSM-5 channel and reduction of HZSM-5 strong Bronsted acid sites during steam treatment. As a result, the excellent catalytic performance is obtained over 24.0% La2O3-modified HZSM-5 by steam treatment at 773 K for 1.0 h, being 23% conversion of toluene, 93% selectivity of p-Xylene during time on-stream.

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