scholarly journals Dictating Selectivity in the Catalytic Vapor-Phase Conversion of Glycerol

2021 ◽  
Vol 7 (1) ◽  
pp. 1-10
Author(s):  
Della Pina Cristina ◽  
Falletta Ermelinda ◽  
Rossi Michele
Keyword(s):  
Vapor Phase ◽  
Energy Savings ◽  
Ambient Pressure ◽  
Fixed Bed ◽  
Value Added ◽  
Catalyst Stability ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Phase Conversion ◽  
Experimental Conditions

A viable route for the vapor-phase conversion of glycerol into value-added chemicals is herein presented. This procedure allows to dictate selectivity towards hydroxyacetone (acetol) or methylglyoxal (pyruvaldehyde) by simply tuning the experimental conditions while retaining the same catalytic system. A series of gold- and copper-based catalysts supported on gamma-alumina, including bimetallic formulations, were prepared by incipient wetness impregnation method and tested in a continuous-flow fixed-bed vertical glass reactor at ambient pressure and T = 250-300°C. The best performance was achieved with 1%wt Au/Al2O3. Accordingly, the selectivity could be directed to acetol (sel. 72%) at 87% conversion when performing the reaction at 300°C and adding H2 to the carrier N2, or towards pyruvaldehyde (sel. 79%) at 92% conversion when adding O2 to N2 at 250°C. These relatively mild conditions not only allow for energy savings with respect to the common procedures so far reported, but also for catalyst stability that can be easily regenerated after use. Furthermore, the low metal loading in the catalyst (1% wt) and its small amount requested for each test (0.1 g catalyst) make this procedure economically sustainable.

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.

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

Catalysts ◽  
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.

Vapor-phase Oxidation of Cyclohexane over Supported Fe-Mn Catalysts: In-Situ DRIFTS studies

2021 ◽  
Author(s):  
Vijendra Kumar Yadav ◽  
Taraknath Das
Keyword(s):  
Surface Area ◽  
Raman Spectra ◽  
Vapor Phase ◽  
Oxide Catalysts ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
In Situ Drifts ◽  
Mn Oxide ◽  
Phase Oxidation

Alumina-supported Fe-Mn oxide catalysts were synthesized by the incipient wetness impregnation method. The catalysts were characterized by using various characterization techniques such as surface area, XRD, H2-TPR, and Raman spectra...

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

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.

What is the Effect of Promoter Loading on Alkalized Bimetallic Co-Mo Catalyst for Higher Alcohols Synthesis from Syngas?

2019 ◽  
Vol 19 (2) ◽  
pp. 86-94
Author(s):  
R. G. Moqadam ◽  
A. Tavasoli ◽  
M. Salimi
Keyword(s):  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Incipient Wetness Impregnation ◽  
Operating Pressure ◽  
Impregnation Method ◽  
Higher Alcohol Synthesis ◽  
Higher Alcohol ◽  
Alcohol Synthesis ◽  
Higher Alcohols Synthesis ◽  
Methanol Formation

Manganese and nickel co-modified K/Co/MoS2 catalysts supported on graphene were prepared by incipient wetness impregnation method for application in higher alcohol synthesis (HAS). All catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorptiondesorption, temperature-programmed reduction (TPR) and transmission electron microscopy (TEM). The effect of promoters, as well as supports on higher alcohol synthesis production from syngas, was investigated in a fixed bed reactor. The process was performed with an molar ratio H2 : CO = 1 : 1, operating pressure and temperature of 4 MPa and 330 °C, respectively, and gas hourly space velocity (GHSV) 3.84 m3 (STP)/(kgcat.·h) as reaction conditions (STP – standard temperature and pressure). Results originated from practical works showed that the addition of Ni to the graphene-based catalyst increased HAS production and decreased methanol formation. The total alcohols space-time yield (STY) and alcohol selectivity on Ni/Mn/Co/Mo/K/graphene catalyst reached a maximum at 0.41 galc./(gcat.·h) and 63.51 %, respectively, which is higher than the same composition over alumina supported catalyst.

Catalytic Wet Oxidation of Acrylic Acid: Studies with Manganese-based Oxides

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Adrián M.T. Silva ◽  
Rita R.N. Marques ◽  
Rosa M. Quinta-Ferreira
Keyword(s):  
Liquid Phase ◽  
Acrylic Acid ◽  
Industrial Effluents ◽  
Operating Conditions ◽  
Catalyst Stability ◽  
Acid Oxidation ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Catalytic Wet Oxidation ◽  
Catalytic Systems

Development of active, stable and economical catalysts for oxidation of acrylic acid contained in industrial effluents is nowadays of great importance. Several manganese-based solids catalysts supported in Ce, Zr, Ti and Al oxides were prepared in our laboratory by incipient wetness impregnation for oxidation of acrylic acid in a batch high-pressure reactor at slurry conditions under 200°C and 15 bar of oxygen partial pressure. The Mn-Ce-O catalyst was the most active leading to high conversions (92.3%) in terms of total organic carbon (TOC) and total degradation of acrylic acid in the first 30 min of reaction. The TOC reductions were lower with Mn-Zr-O (45.6%), Mn-Ti-O (43.6%) and Mn-Al-O (28.2%) as well as acrylic acid was not completely degraded even after 180 min of reaction. The impregnation method used for catalyst preparation was compared with the co-precipitation procedure, being the last one less effective for TOC reduction (87.0%) although the same activity to oxidation of acrylic acid was observed. Acetic and formic acids were found as reaction intermediates being refractory compounds for the catalysts supported in Zr, Ti and Al. Catalyst stability was also evaluated and Mn-Ce-O prepared by impregnation showed low leaching of Mn to the liquid phase as well as carbon adsorption was not found strengthening the catalyst potentialities in the treatment of wastewaters containing acrylic acid. Since under non-catalytic conditions acrylic acid is refractory up to high temperatures (260°C), this work offers a step forward in the design of an economical catalyst able to promote acrylic acid oxidation in the liquid-phase at lower operating conditions than those used in non-catalytic systems.

scholarly journals Supported Bimetallic Catalysts for the Solvent-Free Hydrogenation of Levulinic Acid to γ-Valerolactone: Effect of Metal Combination (Ni-Cu, Ni-Co, Cu-Co)

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1354
Author(s):  
Mahlet N. Gebresillase ◽  
Reibelle Q. Raguindin ◽  
Hern Kim ◽  
Jeong Gil Seo
Keyword(s):  
Bimetallic Catalysts ◽  
Levulinic Acid ◽  
Value Added ◽  
Single Step ◽  
Solvent Free ◽  
Catalyst Loading ◽  
Fuel Additive ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Highly Active

γ-valerolactone (GVL) is an important value-added chemical with potential applications as a fuel additive, a precursor for valuable chemicals, and polymer synthesis. Herein, different monometallic and bimetallic catalysts supported on γ-Al2O3 nanofibers (Ni, Cu, Co, Ni-Cu, Ni-Co, Cu-Co) were prepared by the incipient wetness impregnation method and employed in the solvent-free hydrogenation of levulinic acid (LA) to GVL. The influence of metal loading, metal combination, and ratio on the activity and selectivity of the catalysts was investigated. XRD, SEM-EDS, TEM, H2-TPR, XPS, NH3-TPD, and N2 adsorption were used to examine the structure and properties of the catalysts. In this study, GVL synthesis involves the single-step dehydration of LA to an intermediate, followed by hydrogenation of the intermediate to GVL. Ni-based catalysts were found to be highly active for the reaction. [2:1] Ni-Cu/Al2O3 catalyst showed 100.0% conversion of LA with >99.0% selectivity to GVL, whereas [2:1] Ni-Co/Al2O3 yielded 100.0% conversion of LA with 83.0% selectivity to GVL. Moreover, reaction parameters such as temperature, H2 pressure, time, and catalyst loading were optimized to obtain the maximum GVL yield. The solvent-free hydrogenation process described in this study propels the future industrial production of GVL from LA.

scholarly journals Study on Low-Temperature Catalytic Dehydrogenation Reaction of Tail Chlorine by Pd/Al2O3

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Hanhan Wang ◽  
Tingting Lu ◽  
Yuna Li ◽  
Bo Wu ◽  
Jianwei Xue ◽  
...  
Keyword(s):  
Low Temperature ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Incipient Wetness Impregnation ◽  
Catalytic Dehydrogenation ◽  
Impregnation Method ◽  
Pd Catalysts ◽  
Dehydrogenation Reaction ◽  
Loading Amount ◽  
Oxygen Reaction

The catalytic dehydrogenation reaction of tail chlorine by Pd was studied using a fixed-bed reactor at low temperature from 30 to 100°C. Different catalyst supports such as SiO2 and Al2O3 were applied to prepare Pd catalysts by the incipient-wetness impregnation method. And the catalysts were characterized by XRD, FTIR, XPS, SEM, and N2 adsorption-desorption. The catalyst Pd loading on both SiO2 and Al2O3 had a catalytic effect on the dehydrogenation reaction, but the carrier Al2O3 was more superior. The hydrogen conversion and selectivity of hydrogen-oxygen reaction increased first and then decreased with Pd loading amount and temperature by using Pd/Al2O3 as catalysts, but the influence of temperature was limited when it was higher than 60°C. The hydrogen conversion was 97.38% and selectivity of hydrogen-oxygen reaction was 79% when the reaction temperature was at 60°C with 1 wt.% Pd/Al2O3.

scholarly journals Ca-Modified Co/SBA-15 Catalysts for Hydrogen Production through Ethanol Steam Reforming

2013 ◽  
Vol 24 ◽  
pp. 1-16 ◽  
Author(s):  
Chen-Bin Wang ◽  
Siao Wun Liu ◽  
Kuan Fu Ho ◽  
Hsin Hua Huang ◽  
Chih Wei Tang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Coke Deposition ◽  
Incipient Wetness Impregnation ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
Steam Reforming Of Ethanol ◽  
Incipient Wetness

Hydrogen production through steam reforming of ethanol (SRE) over the Ca-modified Co/SBA-15 catalysts was studied herein to evaluate the catalytic activity, stability and the behavior of coke deposition. The Ca-modified SBA-15 supports were prepared from the Ca(NO3)2·4H2O (10 wt%) which was incorporated to SBA-15 by incipient wetness impregnation (assigned as Ca/SBA-15) and direct hydrothermal (assigned as Ca-SBA-15) method. The active cobalt species from the Co(NO3)2·6H2O (10 wt%) was loaded to SiO2, SBA-15 and modified-SBA-15 supports with incipient wetness impregnation method to obtain the cobalt catalysts (named as Co/SiO2, Co/SBA-15, Co-Ca/SBA-15 and Co/Ca-SBA-15, respectively). The prepared catalysts were characterized by using X-ray diffraction (XRD), temperature programmed reduction (TPR), transmission electron microscopy (TEM) and BET. The catalytic performance of the SRE reaction was evaluated in a fixed-bed reactor. The results indicated that the Co/Ca-SBA-15 catalyst was preferential among these catalysts and the ethanol can be converted completely at 375 °C. The hydrogen yield (YH2) approached 4.76 at 500 °C and less coke deposited. Further, the long-term stability test of this catalyst approached 100 h at 500 °C and did not deactivate.

scholarly journals Aromatization of Heavy Naphtha using Modified Zeolite Supported Catalyst

2019 ◽  
Vol 7 (4.14) ◽  
pp. 142
Author(s):  
A Fakruldin ◽  
A Ramli ◽  
M I. Abdul Mutalib
Keyword(s):  
Fixed Bed ◽  
Supported Catalyst ◽  
Value Added ◽  
Continuous Reactor ◽  
Impregnation Method ◽  
Slight Improvement ◽  
Wet Impregnation ◽  
Modified Zeolite ◽  
Alternative Sources ◽  
Wet Impregnation Method

Growing population has increased the dependency toward sustainable energy sources. Research industries have groomed their facilities to find alternative sources of energy. Heavy naphtha can be converted to value added fuel such as gasoline via catalytic conversion. Modified zeolite supported catalyst was employed for aromatization of heavy naphtha to gasoline like liquid. The catalyst was impregnated with 3 wt.% Fe via wet impregnation method. The catalysts prepared were send for characterization using BET, FESEM-EDX and TPD. Catalytic activity was performed at 430-480 °C, LHSV 1 hr-1 and 14 bar in a fixed-bed continuous reactor. The result revealed that the by adding Fe onto the zeolite supported catalyst provides slight improvement of yield. 

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